Search results for: Active Contour Model (ACM)

Authors: Neslihan Şahin Çelik, Ali Eraslan

Abstract:

In recent years, mathematics educators have frequently stressed the necessity of instructing students about models and modeling approaches that encompass cognitive and metacognitive thought processes, starting from the first years of school and continuing on through the years of higher education. The purpose of this study is to examine the thought processes of 4th-grade primary school students in their modeling activities and to explore the difficulties encountered in these processes, if any. The study, of qualitative design, was conducted in the 2015-2016 academic year at a public state-school located in a central city in the Black Sea Region of Turkey. A preliminary study was first implemented with designated 4th grade students, after which the criterion sampling method was used to select three students that would be recruited into the focus group. The focus group that was thus formed was asked to work on the model eliciting activity of the Paper Airplane Problem and the entire process was recorded on video. The Paper Airplane Problem required the students to determine the winner with respect to: (a) the plane that stays in the air for the longest time; (b) the plane that travels the greatest distance in a straight-line path; and (c) the overall winner for the contest. A written transcript was made of the video recording, after which the recording and the students' worksheets were analyzed using the Blum and Ferri modeling cycle. The results of the study revealed that the students tested the hypotheses related to daily life that they had set up, generated ideas of their own, verified their models by making connections with real life, and tried to make their models generalizable. On the other hand, the students had some difficulties in terms of their interpretation of the table of data and their ways of operating on the data during the modeling processes.

Keywords: primary school students, model eliciting activity, mathematical modeling, modeling process, paper airplane problem

Procedia PDF Downloads 358

Authors: Francois Defay, Martim Calao, Jean Francois Dassieu, Laurent Salvetat

Abstract:

Electrical vehicles are a solution for reducing the pollution using green energy. The shell Eco-Marathon provides rules in order to minimize the battery use for the race. The use of solar panel combined with efficient motor control and race strategy allow driving a 60kg vehicle with one pilot using only the solar energy in the best case. This paper presents a complete modelization of a solar vehicle used for the shell eco-marathon. This project called Helios is cooperation between non-graduated students, academic institutes, and industrials. The prototype is an ultra-energy-efficient vehicle based on one-meter square solar panel and an own-made brushless controller to optimize the electrical part. The vehicle is equipped with sensors and embedded system to provide all the data in real time in order to evaluate the best strategy for the course. A complete modelization with Matlab/Simulink is used to test the optimal strategy to increase the global endurance. Experimental results are presented to validate the different parts of the model: mechanical, aerodynamics, electrical, solar panel. The major finding of this study is to provide solutions to identify the model parameters (Rolling Resistance Coefficient, drag coefficient, motor torque coefficient, etc.) by means of experimental results combined with identification techniques. One time the coefficients are validated, the strategy to optimize the consumption and the average speed can be tested first in simulation before to be implanted for the race. The paper describes all the simulation and experimental parts and provides results in order to optimize the global efficiency of the vehicle. This works have been started four years ago and evolved many students for the experimental and theoretical parts and allow to increase the knowledge on electrical self-efficient vehicle.

Keywords: electrical vehicle, endurance, optimization, shell eco-marathon

Procedia PDF Downloads 266

Authors: Dawei Shen, Ming Xu, Pengfei Liu

Abstract:

The joints between simply supported bridge decks and abutments need to be regularly repaired, which would greatly increase the cost during the service life of the bridge. Simply supported girder bridges suffered the most severe damage during earthquakes. Another type of bridge, the integral bridge, of which the superstructure and abutment are rigidly connected, was also used in some European countries. Because no bearings or joints exit in the integral bridge, this type of bridge could significantly reduce maintenance requirements and costs. However, conventional integral bridge usually result in high earth pressure on the abutment and surface settlement in the backfill. To solve these problems, a new type of integral bridge, geosynthetic-reinforced soil (GRS) integral bridge, was come up in recent years. This newly invented bridge has not been used in engineering practices. There was a lack of research on the seismic behavior of the conventional and new type of integral abutments. In addition, no common design code could be found for the calculation of seismic pressure of soil behind the abutment. This paper developed a dynamic constitutive model, which can consider the soil behaviors under cyclic loading. Numerical analyses of the seismic response of a full height integral bridge and GRS integral bridge were carried out using the two-dimensional numerical code, FLAC. A parametric study was also performed to investigate the soil-structure interaction. The results are presented below. The seismic responses of GRS integral bridge together with conventional simply supported bridge, GRS conventional bridge and conventional integral bridge were investigated. The results show that the GRS integral bridge holds the highest seismic stability, followed by conventional integral bridge, GRS simply supported bridge and conventional simply supported bridge. Compared with the integral bridge with 1 m thick abutments, the GRS integral bridge with 0.4 m thick abutments is subjected to a smaller bending moment, and the natural frequency and horizontal displacement remains almost the same. Geosynthetic-reinforcement will be more effective when the abutment becomes thinner or the abutment is higher.

Keywords: geosynthetic-reinforced soil integral bridge, nonlinear hysteretic model, numerical analysis, seismic response

Procedia PDF Downloads 463

Authors: Atara Shriki, Ilana Lavy

Abstract:

In a rapidly changing technological society, creativity is considered as an engine of economic and social progress. No doubt the education system has a central role in nurturing all students’ creativity, however, it is normally not encouraged at school. The causes of this reality are related to a variety of circumstances, among them: external pressures to cover the curriculum and succeed in standardized tests that mostly require algorithmic thinking and implementation of rules; teachers’ tendency to teach similarly to the way they themselves were taught as school students; relating creativity to giftedness, and therefore avoid nurturing all students' creativity; lack of adequate learning materials and accessible tools for following and evaluating the development of students’ creativity; and more. Since success in academic studies requires, among other things, creativity, lecturers in higher education institutions should consider appropriate ways to nurture students’ creative thinking and assess its development. Obviously, creativity has a multifaceted nature, numerous definitions, various perspectives for studying its essence (e.g., process, personality, environment, and product), and several approaches aimed at evaluating and assessing creative expressions (e.g., cognitive, social-personal, and psychometric). In this framework, we suggest nurturing students’ creativity through engaging them in problem posing activities that are part of inquiry assignments. In order to assess the development of their creativity, we propose to employ a model that was designed for this purpose, based on the psychometric approach, viewing the posed problems as the “creative product”. The model considers four measurable aspects- fluency, flexibility, originality, and organization, as well as a total score of creativity that reflects the relative weights of each aspect. The scores given to learners are of two types: (1) Total scores- the absolute number of posed problems with respect to each of the four aspects, and a final score of creativity; (2) Relative scores- each absolute number is transformed into a number that relates to the relative infrequency of the posed problems in student’s reference group. Through converting the scores received over time into a graphical display, students can assess their progress both with respect to themselves and relative to their reference group. Course lecturers can get a picture of the strengths and weaknesses of each student as well as the class as a whole, and to track changes that occur over time in response to the learning environment they had generated. Such tracking may assist lecturers in making pedagogical decisions about emphases that should be put on one or more aspects of creativity, and about the students that should be given a special attention. Our experience indicates that schoolteachers and lecturers in higher education institutes find the combination of engaging learners in problem posing along with self-assessment of their progress through utilizing the graphical display of accumulating total and relative scores has the potential to realize most learners’ creative potential.

Keywords: creativity, problem posing, psychometric model, self-assessment

Procedia PDF Downloads 321

Authors: Glenda Wrenn, Juliet Muzere, Meldra Hall, Allyson Belton, Kisha Holden, Chanita Hughes-Halbert, Martha Kent, Bekh Bradley

Abstract:

Understanding the help seeking decision making process and experiences of health disparity populations with posttraumatic stress disorder (PTSD) is central to development of trauma-informed, culturally centered, and patient focused services. Yet, little is known about the decision making process among adult Black women who are non-treatment seekers as they are, by definition, not engaged in services. Methods: Audiotaped interviews were conducted with 30 African American adult women with clinically significant PTSD symptoms who were engaged in primary care, but not in treatment for PTSD despite symptom burden. A qualitative interview guide was used to elucidate key themes. Independent coding of themes mapped to theory and identification of emergent themes were conducted using qualitative methods. An existing quantitative dataset was analyzed to contextualize responses and provide a descriptive summary of the sample. Results: Emergent themes revealed that active mental avoidance, the intermittent nature of distress, ambivalence, and self-identified resilience as undermining to help seeking decisions. Participants were stuck within the help-seeking phase of ‘recognition’ of illness and retained a sense of “it is my decision” despite endorsing significant social and environmental negative influencers. Participants distinguished ‘help acceptance’ from ‘help seeking’ with greater willingness to accept help and importance placed on being of help to others. Conclusions: Elucidation of the decision-making process from the perspective of non-treatment seekers has implications for outreach and treatment within models of integrated and specialty systems care. The salience of responses to trauma symptoms and stagnation in the help seeking recognition phase are findings relevant to integrated care service design and community engagement.

Keywords: culture, help-seeking, integrated care, PTSD

Procedia PDF Downloads 235

Authors: Jean-michel Sahut, Lubica Hikkerova, Wissal Ben Arfi

Abstract:

The Internet of Things (IoT) emerged over the last few decades in many fields. Healthcare can significantly benefit from IoT. This study aims to examine factors influencing the adoption of IoT in eHealth. To do so, an innovative framework has been developed which applies both the Technology Acceptance Model (TAM) and the United Theory of Acceptance and Use of Technology (UTAUT) model and builds on them by analyzing trust and perceived-risk dimensions to predict intention to use IoT in eHealth. In terms of methodology, a Partial Least Approach Structural Equation Modelling was carried out on a sample of 267 French users. The findings of this research support the significant positive effect of constructs set out in the TAM (perceived ease of use) on predicting behavioral intention by adding the effects identified for UTAUT variables. This research also demonstrates how perceived risk and trust are significant factors for models examining behavioral intentions to use IoT. Perceived risk enhanced by the trust has a significant effect on patients’ behavioral intentions. Moreover, the results highlight the key role of prescription as a moderator of IoT adoption in eHealth. Depending on whether an individual has a prescription to use connected devices or not, ease of use has a stronger impact on adoption, while trust has a negative impact on adoption for users without a prescription. In accordance with the empirical results, several practical implications can be proposed. All connected devices applied in a medical context should be divided into groups according to their functionality: whether they are essential for the patient’s health and whether they require a prescription or not. Devices used with a prescription are easily accepted because the intention to use them is moderated by the medical trust (discussed above). For users without a prescription, ease of use is a more significant factor than for users who have a prescription. This suggests that currently, connected e-Health devices and online healthcare systems have to take this factor into account to better meet the needs and expectations of end-users.

Keywords: internet of things, Healthcare, trust, consumer acceptance

Procedia PDF Downloads 144

Authors: Kanupreiya, Rajani Sharma

Abstract:

Construction of a single underground structure is itself a challenging task, and it becomes more critical in tectonically active young mountains such as the Himalayas which are highly anisotropic. The Himalayan geology mostly comprises of incompetent and sheared rock mass in addition to fold/faults, rock burst, and water ingress. Underground tunnels form the most essential and important structure in run-of-river hydroelectric projects. Punatsangchhu I hydroelectric project (PHEP-I), Bhutan (1200 MW) is a run-of-river scheme which has four parallel underground desilting chambers. The Punatsangchhu River carries a large quantity of silt load during monsoon season. Desilting chambers were provided to remove the silt particles of size greater than and equal to 0.2 mm with 90% efficiency, thereby minimizing the rate of damage to turbines. These chambers are 330 m long, 18 m wide at the center and 23.87 m high, with a 5.87 m hopper portion. The geology of desilting chambers was known from an exploratory drift which exposed low dipping foliation joint and six joint sets. The RMR and Q value in this reach varied from 40 to 60 and 1 to 6 respectively. This paper describes different rock engineering principles undertaken for safe excavation and rock support of the moderately jointed, blocky and thinly foliated biotite gneiss. For the design of rock support system of desilting chambers, empirical and numerical analysis was adopted. Finite element analysis was carried out for cavern design and finalization of pillar width using Phase2. Phase2 is a powerful tool for simulation of stage-wise excavation with simultaneous provision of support system. As the geology of the region had 7 sets of joints, in addition to FEM based approach, safety factors for potentially unstable wedges were checked using UnWedge. The final support recommendations were based on continuous face mapping, numerical modelling, empirical calculations, and practical experiences.

Keywords: dam siltation, Himalayan geology, hydropower, rock support, numerical modelling

Procedia PDF Downloads 92

Authors: P. T. Ngan

Abstract:

Purpose: The study aims to answer the question what are motivational conditions that have great influences on employees’ innovative work behaviors by investigating the case of SATAMANKULMA/ Anya Productions Ky in Kuopio, Finland. Design/methodology: The main methodology utilized was the qualitative single case study research, analysis was conducted with an adapted thematic content analysis procedure, created from empirical material that was collected through interviews, observation and document review. Findings: The paper highlights the significance of combining relevant synergistic extrinsic and intrinsic motivations into the organizational motivation system. The findings show that intrinsic drives are essential for the initiation phases while extrinsic drives are more important for the implementation phases of innovative work behaviors. The study also offers the IDEA motivation model-interpersonal relationships & networks, development opportunities, economic constituent and application supports as an ideal tool to optimize business performance. Practical limitations/ implications: The research was only conducted from the perspective of SATAMANKULMA/Anya Productions Ky, with five interviews, a few observations and with several reviewed documents. However, further research is required to include other stakeholders, such as the customers, partner companies etc. Also the study does not offer statistical validity of the findings; an extensive case study or a qualitative multiple case study is suggested to compare the findings and provide information as to whether IDEA model relevant in other types of firms. Originality/value: Neither the innovation nor the human resource management field provides a detailed overview of specific motivational conditions might use to stimulate innovative work behaviors of individual employees. This paper fills that void.

Keywords: employee innovative work behaviors, extrinsic motivation, intrinsic motivation, organizational innovativeness

Procedia PDF Downloads 267

Authors: Joseph Falzon, Margaret Nelson

Abstract:

Background: Policy makers at European Union (EU) and national levels address the re-use of historic buildings calling for sustainable practices and approaches. Implementation stages of policy are crucial so that EU and national strategic objectives for historic building sustainability are achieved. Governance remains one of the key objectives to ensure resource sustainability. Objective: The aim of the research was to critically examine policies for the regeneration and adaptive re-use of historic buildings in the EU and national level, and to analyse gaps between EU and national legislation and policies, taking Malta as a case study. The impact of policies on regeneration and re-use of historic buildings was also studied. Research Design: Six semi-structured interviews with stakeholders including architects, investors and community representatives informed the research. All interviews were audio recorded and transcribed in the English language. Thematic analysis utilising Atlas.ti was conducted for the semi-structured interviews. All phases of the study were governed by research ethics. Findings: Findings were grouped in main themes: resources, experiences and governance. Other key issues included identification of gaps in policies, key lessons and quality of regeneration. Abandonment of heritage buildings was discussed, for which main reasons had been attributed to governance related issues both from the policy making perspective as well as the attitudes of certain officials representing the authorities. The role of authorities, co-ordination between government entities, fairness in decision making, enforcement and management brought high criticism from stakeholders along with time factors due to the lengthy procedures taken by authorities. Policies presented an array from different perspectives of same stakeholder groups. Rather than policy, it is the interpretation of policy that presented certain gaps. Interpretations depend highly on the stakeholders putting forward certain arguments. All stakeholders acknowledged the value of heritage in regeneration. Conclusion: Active stakeholder involvement is essential in policy framework development. Research informed policies and streamlining of policies are necessary. National authorities need to shift from a segmented approach to a holistic approach.

Keywords: adaptive re-use, historic buildings, policy, sustainable

Procedia PDF Downloads 393

Authors: Haritha Saranga

Abstract:

Service quality has become an important driver of competition in manufacturing industries of late, as many products are being sold in conjunction with service offerings. With increase in computational power and data capture capabilities, it has become possible to analyze and estimate various aspects of service quality at the granular level and determine their impact on business performance. In the current study context, dealer level, model-wise warranty data from one of the top two-wheeler manufacturers in India is used to estimate service quality of individual dealers and its impact on warranty related costs and sales performance. We collected primary data on warranty costs, number of complaints, monthly sales, type of quality upgrades, etc. from the two-wheeler automaker. In addition, we gathered secondary data on various regions in India, such as petrol and diesel prices, geographic and climatic conditions of various regions where the dealers are located, to control for customer usage patterns. We analyze this primary and secondary data with the help of a variety of analytics tools such as Auto-Regressive Integrated Moving Average (ARIMA), Seasonal ARIMA and ARIMAX. Study results, after controlling for a variety of factors, such as size, age, region of the dealership, and customer usage pattern, show that service quality does influence sales of the products in a significant manner. A more nuanced analysis reveals the dynamics between product quality and service quality, and how their interaction affects sales performance in the Indian two-wheeler industry context. We also provide various managerial insights using descriptive analytics and build a model that can provide sales projections using a variety of forecasting techniques.

Keywords: service quality, product quality, automobile industry, business analytics, auto-regressive integrated moving average

Procedia PDF Downloads 120

Authors: Geum Yeon Sim, Tyler Pigott, Julio Vasquez

Abstract:

A 38-year-old obese female with no apparent past medical history presented with left knee pain. Six months ago, she sustained a left knee dislocation in a motor vehicle accident that was managed with a skin graft over the left lower extremity without any reconstructive surgery. She developed persistent pain and stiffness in her left knee that worsened with walking and stair climbing. Examination revealed healed extensive skin graft over the left lower extremity, including the left knee. Palpation showed moderate tenderness along the superior border of the patella, exquisite tenderness over MCL, and mild tenderness on the tibial tuberosity. There was normal sensation, reflexes, and strength in her lower extremities. There was limited active and passive range of motion of her left knee during flexion. There was instability noted upon the valgus stress test of the left knee. Left knee magnetic resonance imaging showed high-grade (grade 2-3) injury of the proximal superficial fibers of the MCL and diffuse thickening and signal abnormality of the cruciate ligaments, as well as edema-like subchondral marrow signal change in the anterolateral aspect of the lateral femoral condyle weight-bearing surface. There was also notable extensive scarring and edema of the skin, subcutaneous soft tissues, and musculature surrounding the knee. The patient was managed with left knee immobilization for five months, which was complicated by limited knee flexion. Physical therapy consisting of quadriceps, hamstrings, gastrocnemius stretching and strengthening, range of motion exercises, scar/soft tissue mobilization, and gait training was given with marked improvement in pain and range of motion. The patient experienced a further reduction in pain as well as an improvement in function with home exercises consisting of continued strengthening and stretching.

Keywords: ligamentous injury, trauma, rehabilitation, knee pain

Procedia PDF Downloads 109

Authors: David Maina Muthegethi

Abstract:

For decades, archaeological work of Swahili Civilization has mainly concentrated on exploration of economic and political dynamics of City states. This paper moves further and explore how gender roles were formed, maintained, negotiated and re-negotiated through time and space in Gede City. Unlike other Swahili city states, Gede was located around two miles away from the shores of Indian Ocean. Nonetheless, the city was characterized by security walls, stone houses, mosques and tombs typical of Swahili City states such as Kilwa. The study employed several methods of data collection namely: archival research, survey, re-examination of collected materials and excavation of Gede archaeological site. Since, the study aimed to examine gender roles across different social class, a total of three houses were excavated based on their social hierarchy. Thus, the houses were roughly categorized as belonging to elites, middle class and lower class. The house were located in the inner wall, second inner wall and the outer wall of Gede City respectively. Key findings shows that gender roles differed considerably along classes in Gede archaeological site. For instance, the women of the elite and middle class were active participants in Gede international trade through production and consumption of imported goods. This participation corresponded with commercialization of Gede households especially in elite’ areas where they hosted international traders. On the other hand, the middle class houses, women concentrated on running of light industries aimed at supplying goods for the urban community. Thus, they were able to afford exotic goods as their elites counterparts. Lastly, the gender roles of lower class entailed subsistence gender roles with little participation in Gede formal commerce. Interestingly, gender roles in Gede were dynamic in nature and response to cultural diffusion, spread of Islam, intensification of trade, diversification of subsistence patterns and urbanization. Therefore, this findings, demonstrate centrality of gender in reconstruction of social lives of Swahili Civilization.

Keywords: gender roles, Islam, Swahili civilization, urbanization

Procedia PDF Downloads 94

Authors: Benjamin Castillo, Luis Pastenes, Fernando Cordova

Abstract:

The pathogen growth in animal source foods is a common problem in the food industry, causing monetary losses due to the spoiling of products or food intoxication outbreaks in the community. In this sense, the quality of the product is reflected by the population of deteriorating agents present in it, which are mainly bacteria. The factors which are likely associated with freshness in animal source foods are temperature and processing, storage, and transport times. However, the level of deterioration of products depends, in turn, on the characteristics of the bacterial population, causing the decomposition or spoiling, such as pH level and toxins. Knowing the growth dynamics of the agents that are involved in product contamination allows the monitoring for more efficient processing. This means better quality and reasonable costs, along with a better estimation of necessary time and temperature intervals for transport and storage in order to preserve product quality. The objective of this project is to design a secondary model that allows measuring the impact on temperature bacterial growth and the competition for pH adequacy and release of bacteriocins in order to describe such phenomenon and, thus, estimate food product half-life with the least possible risk of deterioration or spoiling. In order to achieve this objective, the authors propose an analysis of a three-dimensional ordinary differential which includes; logistic bacterial growth extended by the inhibitory action of bacteriocins including the effect of the medium pH; change in the medium pH levels through an adaptation of the Luedeking-Piret kinetic model; Bacteriocin concentration modeled similarly to pH levels. These three dimensions are being influenced by the temperature at all times. Then, this differential system is expanded, taking into consideration the variable temperature and the concentration of pulsed bacteriocins, which represent characteristics inherent of the modeling, such as transport and storage, as well as the incorporation of substances that inhibit bacterial growth. The main results lead to the fact that temperature changes in an early stage of transport increased the bacterial population significantly more than if it had increased during the final stage. On the other hand, the incorporation of bacteriocins, as in other investigations, proved to be efficient in the short and medium-term since, although the population of bacteria decreased, once the bacteriocins were depleted or degraded over time, the bacteria eventually returned to their regular growth rate. The efficacy of the bacteriocins at low temperatures decreased slightly, which equates with the fact that their natural degradation rate also decreased. In summary, the implementation of the mathematical model allowed the simulation of a set of possible bacteria present in animal based products, along with their properties, in various transport and storage situations, which led us to state that for inhibiting bacterial growth, the optimum is complementary low constant temperatures and the initial use of bacteriocins.

Keywords: bacterial growth, bacteriocins, mathematical modelling, temperature

Procedia PDF Downloads 135

Authors: Mostafa Shahriari, Sergio Rojas, David Pardo, Angel Rodriguez- Rozas, Shaaban A. Bakr, Victor M. Calo, Ignacio Muga

Abstract:

Logging-While Drilling (LWD) is a technique to record down-hole logging measurements while drilling the well. Nowadays, LWD devices (e.g., nuclear, sonic, resistivity) are mostly used commercially for geo-steering applications. Modern borehole resistivity tools are able to measure all components of the magnetic field by incorporating tilted coils. The depth of investigation of LWD tools is limited compared to the thickness of the geological layers. Thus, it is a common practice to approximate the Earth’s subsurface with a sequence of 1D models. For a 1D model, we can reduce the dimensionality of the problem using a Hankel transform. We can solve the resulting system of ordinary differential equations (ODEs) either (a) analytically, which results in a so-called semi-analytic method after performing a numerical inverse Hankel transform, or (b) numerically. Semi-analytic methods are used by the industry due to their high performance. However, they have major limitations, namely: -The analytical solution of the aforementioned system of ODEs exists only for piecewise constant resistivity distributions. For arbitrary resistivity distributions, the solution of the system of ODEs is unknown by today’s knowledge. -In geo-steering, we need to solve inverse problems with respect to the inversion variables (e.g., the constant resistivity value of each layer and bed boundary positions) using a gradient-based inversion method. Thus, we need to compute the corresponding derivatives. However, the analytical derivatives of cross-bedded formation and the analytical derivatives with respect to the bed boundary positions have not been published to the best of our knowledge. The main contribution of this work is to overcome the aforementioned limitations of semi-analytic methods by solving each 1D model (associated with each Hankel mode) using an efficient multi-scale finite element method. The main idea is to divide our computations into two parts: (a) offline computations, which are independent of the tool positions and we precompute only once and use them for all logging positions, and (b) online computations, which depend upon the logging position. With the above method, (a) we can consider arbitrary resistivity distributions along the 1D model, and (b) we can easily and rapidly compute the derivatives with respect to any inversion variable at a negligible additional cost by using an adjoint state formulation. Although the proposed method is slower than semi-analytic methods, its computational efficiency is still high. In the presentation, we shall derive the mathematical variational formulation, describe the proposed multi-scale finite element method, and verify the accuracy and efficiency of our method by performing a wide range of numerical experiments and comparing the numerical solutions to semi-analytic ones when the latest are available.

Keywords: logging-While-Drilling, resistivity measurements, multi-scale finite elements, Hankel transform

Procedia PDF Downloads 386

Authors: Mustafa Gulsen, Nihan Pekyavas, Emine Atıcı

Abstract:

Purpose: The aim of this study is to investigate the effects of Kinesio taping on postural stability and in young soccer players. Subjects and Methods: 62 volunteered soccer players from Cayyolu Sports Club were included in our study. Permissions were also taken from the club directors about the inclusion of their players to our study. Soccer players between the age of 12 and 16 were included in our study. Players that had previous injury on lower extremities were excluded from the study. Players were randomly divided into two groups: Kinesio taping (KT) (n=31), and control group (n = 31). KT application including gastrocnemius and quadriceps femoris muscle facilitation techniques were applied to the first group. A rest time for 45 minutes was given in order to see the best effectiveness of the tape. The second group was set as the control group and no application was made. All participants were assessed before the application and 45 minutes later. In order to provide the double-blind design of the study, an experienced physiotherapist has done the assessments and another experienced physiotherapist has done the taping. The patients were randomly assigned to one of the two groups using an online random allocation software program. Postural stability was assessed by using Tetrax Interactive Balance System. Thermographic assessment was done by using FLIR E5 (FLIR Systems AB, Sweden) thermal camera in order to see which muscles have the most thermal activity while maintaining postural stability. Results: Statistically significant differences were found in all assessment parameters in both Kinesio Taping and control groups (all p<0.05) except thermal imaging of dominant gastrocnemius muscle results (p=0.668) (Table 1). In comparison of the two groups, statistically significant differences were found in all parameters (all p<0.05). Conclusion: In this study, we investigated the effects of Kinesio taping on postural stability in young soccer players and found that KT application on Quadriceps and Gastrocnemius muscles may have decreased the risk of falling more than the control group. According to thermal imaging assessments, both Quadriceps and Gastrocnemius muscles may be active in maintaining postural stability but in KT group, the temperature of these muscles are higher which leads us to think that they are more activated.

Keywords: Kinesio taping, fall risk, muscle temperature, postural stability

Procedia PDF Downloads 241

Authors: Jhe-Hao Huang, Kun-Da Wu, Wei-Cheng Shih, Jui-Pin Hung

Abstract:

This study presented the investigation on the dynamic characteristics of a spindle tool system by experimental and finite element modeling approaches. As well known facts, the machining stability is greatly determined by the dynamic characteristics of the spindle tool system. Therefore, understanding the factors affecting dynamic behavior of a spindle tooling system is a prerequisite in dominating the final machining performance of machine tool system. To this purpose, a physical spindle unit was employed to assess the dynamic characteristics by vibration tests. Then, a three-dimensional finite element model of a high-speed spindle system integrated with tool holder was created to simulate the dynamic behaviors. For modeling the angular contact bearings, a series of spring elements were introduced between the inner and outer rings. The spring constant can be represented by the contact stiffness of the rolling bearing based on Hertz theory. The interface characteristic between spindle nose and tool holder taper can be quantified from the comparison of the measurements and predictions. According to the results obtained from experiments and finite element predictions, the vibration behavior of the spindle is dominated by the bending deformation of the spindle shaft in different modes, which is further determined by the stiffness of the bearings in spindle housing. Also, the spindle unit with tool holder shows a different dynamic behavior from that of spindle without tool holder. This indicates the interface property between tool holder and spindle nose plays an dominance on the dynamic characteristics the spindle tool system. Overall, the dynamic behaviors the spindle with and without tool holder can be successfully investigated through the finite element model proposed in this study. The prediction accuracy is determined by the modeling of the rolling interface of ball bearings in spindles and the interface characteristics between tool holder and spindle nose. Besides, identifications of the interface characteristics of a ball bearing and spindle tool holder are important for the refinement of the spindle tooling system to achieve the optimum machining performance.

Keywords: contact stiffness, dynamic characteristics, spindle, tool holder interface

Procedia PDF Downloads 298

Authors: Tanka Nath Dahal

Abstract:

Community-based forestry is seen as a promising instrument for sustainable forest management (SFM) through the purposeful involvement of local communities. Globally, forest area managed by local communities is on the rise. However, transferring management responsibilities to forest users alone cannot guarantee the sustainability of forest management. A monitoring tool, that allows the local communities to track the progress of forest management towards the goal of sustainability, is essential. A case study, including six forest user groups (FUGs), two from each three community-based forestry models—community forestry (CF), buffer zone community forestry (BZCF), and collaborative forest management (CFM) representing three different physiographic regions, was conducted in Nepal. The study explores which community-based forest management model (CF, BZCF or CFM) is doing well in terms of sustainable forest management. The study assesses the overall performance of the three models towards SFM using locally developed criteria (four), indicators (26) and verifiers (60). This paper attempts to quantify the sustainability of the models using sustainability index for individual criteria (SIIC), and overall sustainability index (OSI). In addition, rating to the criteria and scoring of the verifiers by the FUGs were done. Among the four criteria, the FUGs ascribed the highest weightage to institutional framework and governance criterion; followed by economic and social benefits, forest management practices, and extent of forest resources. Similarly, the SIIC was found to be the highest for the institutional framework and governance criterion. The average values of OSI for CFM, CF, and BZCF were 0.48, 0.51 and 0.60 respectively; suggesting that buffer zone community forestry is the more sustainable model among the three. The study also suggested that the SIIC and OSI help local communities to quantify the overall progress of their forestry practices towards sustainability. The indices provided a clear picture of forest management practices to indicate the direction where they are heading in terms of sustainability; and informed the users on issues to pay attention to enhancing the sustainability of their forests.

Keywords: community forestry, collaborative management, overall sustainability, sustainability index for individual criteria

Procedia PDF Downloads 248

Authors: T. Abdelkrim, K. Ben Seddik, B. Bezza, K. Benamrane, Aeh. Benkhelifa

Abstract:

This paper proposes an implementation of boost converter for a resistive load using photovoltaic energy as a source. The model of photovoltaic cell and operating principle of boost converter are presented. A PIC micro controller is used in the close loop control to generate pulses for controlling the converter circuit. To performance evaluation of boost converter, a variation of output voltage of PV panel is done by shading one and two cells.

Keywords: boost converter, microcontroller, photovoltaic power generation, shading cells

Procedia PDF Downloads 878

Authors: Mafawez Alharbi, Mahdi Jemmali

Abstract:

E-learning is a developing area especially in education. E-learning can provide several benefits to learners. An intelligent system to collect all components satisfying user preferences is so important. This research presents an approach that it capable to personalize e-information and give the user their needs following their preferences. This proposal can make some knowledge after more evaluations made by the user. In addition, it can learn from the habit from the user. Finally, we show a walk-through to prove how intelligent process work.

Keywords: artificial intelligence, architecture, e-learning, software engineering, processing

Procedia PDF Downloads 191

Authors: Tebeu Pierre Marie

Abstract:

Introduction: WHO defines community participation as a process in which the local population, take responsibility in planning for their health, participates in the strategy’s development for implementation and accessibility to physical, moral and social well-being. For the purpose of dealing with health, the community participation is made through the organization called health Centre committee leader (HCCL/COSA) for Integrated health Center and District hospital committee leaser (HDCL/COGES) for District Hospital. Little is known about the effective participation of the community in health related activities in Ignié-Ngabé-Mayama health district. Objective: This study aimed at assessing the involvement of community in the health system running at the Ignié-Ngabé-Mayama health district. Methods: This was a qualitative cross-sectional study conducted in the Ignié-Ngabé-Mayama health district from 15 December 2020 to 30 April 2021. The study population consisted of 10 HCCL and one District hospital committee leaser (DHCL). Data were collected using a pretested questionnaire and validated by the investigating team. The variables of interest were; effective existence of HCCL/DHCL, their involvement HCCL/DHCL in health related activities, their financing management, planning of activities and leadership. Results: A total of 11 participants were interviewed, including 10 HCCL and 1 DHCL. The Sex-Ratio was 9/11; with primary level 6/11 and were mostly farmers 6/11. Analyzing the involvement of the HDCL/DHCL in health promotion and preventive activities; this was effective only for two of them (2/11). Analyzing the barriers for their involvement, the leaders reported the lack of financial support by the state, lack NGO support. Additionally, they reported to have been very active when there was Performance Based Founding Project in the District. Conclusion: Only two of the (HDCL/HCCL) out of 11 were really functioning. Reported barriers to their running were: lack of state/NGOs support and ending of PBF Project. There is a need to organize a tripartite forum including stats, NGOs and Community for boosting the community participation in health related activities in Ignié-Ngabé-Mayama health district.

Keywords: health district committee, health Centre committee, community participation, Brazzaville, Congo

Procedia PDF Downloads 170

Authors: Serge Provost, Abdous Saboor

Abstract:

A q-analogue of the generalized extreme value distribution which includes the Gumbel distribution is introduced. The additional parameter q allows for increased modeling flexibility. The resulting distribution can have a finite, semi-infinite or infinite support. It can also produce several types of hazard rate functions. The model parameters are determined by making use of the method of maximum likelihood. It will be shown that it compares favourably to three related distributions in connection with the modeling of a certain hydrological data set.

Keywords: extreme value theory, generalized extreme value distribution, goodness-of-fit statistics, Gumbel distribution

Procedia PDF Downloads 349

Authors: Tianyue Wan

Abstract:

Lost space is the space that has not been used for a long time and is in decline, proposed by Roger Trancik. And in his book Finding Lost Space: Theories of Urban Design, the concept of lost space is defined as those anti-traditional spaces that are unpleasant, need to be redesigned, and have no benefit to the environment and users. They have no defined boundaries and do not connect the various landscape elements in a coherent way. With the rapid development of urbanization in China, the blind areas of urban renewal have become a chaotic lost space that is incompatible with the rapid development of urbanization. Therefore, lost space needs to be reconstructed urgently under the background of infill development and reduction planning in China. The formation of lost space is also an invisible division of social hierarchy. This paper tries to break down the social class division and the estrangement between people through the regeneration of lost space. Ultimately, it will enhance vitality, rebuild a sense of belonging, and create a continuous open public space for local people. Based on the concept of lost space and energy field, this paper clarifies the significance of the energy field in the lost space renovation. Then it introduces the energy field into lost space by using the magnetic field in physics as a prototype. The construction of the energy field is support by space theory, spatial morphology analysis theory, public communication theory, urban diversity theory and city image theory. Taking Wuhan’s Lingjiao Park of China as an example, this paper chooses the lost space on the west side of the park as the research object. According to the current situation of this site, the energy intervention strategies are proposed from four aspects: natural ecology, space rights, intangible cultural heritage and infrastructure configuration. And six specific lost space renewal methods are used in this work, including “riveting”, “breakthrough”, “radiation”, “inheritance”, “connection” and “intersection”. After the renovation, space will be re-introduced into the active crow. The integration of activities and space creates a sense of place, improve the walking experience, restores the vitality of the space, and provides a reference for the reconstruction of lost space in the city.

Keywords: dynamic vitality intervention, lost space, space vitality, sense of place

Procedia PDF Downloads 112

Authors: Ren-Jy Ben, Jo-Chi Jao, Chiu-Ya Liao, Ya-Ru Tsai, Lain-Chyr Hwang, Po-Chou Chen

Abstract:

Cancer is still one of the serious diseases threatening the lives of human beings. How to have an early diagnosis and effective treatment for tumors is a very important issue. The animal carcinoma model can provide a simulation tool for the study of pathogenesis, biological characteristics and therapeutic effects. Recently, drug delivery systems have been rapidly developed to effectively improve the therapeutic effects. Liposome plays an increasingly important role in clinical diagnosis and therapy for delivering a pharmaceutic or contrast agent to the targeted sites. Liposome can be absorbed and excreted by the human body, and is well known that no harm to the human body. This study aimed to compare the therapeutic effects between encapsulated (doxorubicin liposomal, LipoDox) and un-encapsulated (doxorubicin, Dox) anti-tumor drugs using Magnetic Resonance Imaging (MRI). Twenty-four New Zealand rabbits implanted with VX2 carcinoma at left thigh were classified into three groups: control group (untreated), Dox-treated group and LipoDox-treated group, 8 rabbits for each group. MRI scans were performed three days after tumor implantation. A 1.5T GE Signa HDxt whole body MRI scanner with a high resolution knee coil was used in this study. After a 3-plane localizer scan was performed, Three-Dimensional (3D) Fast Spin Echo (FSE) T2-Weighted Images (T2WI) was used for tumor volumetric quantification. And Two-Dimensional (2D) spoiled gradient recalled echo (SPGR) dynamic Contrast-enhanced (DCE) MRI was used for tumor perfusion evaluation. DCE-MRI was designed to acquire four baseline images, followed by contrast agent Gd-DOTA injection through the ear vein of rabbits. Afterwards, a series of 32 images were acquired to observe the signals change over time in the tumor and muscle. The MRI scanning was scheduled on a weekly basis for a period of four weeks to observe the tumor progression longitudinally. The Dox and LipoDox treatments were prescribed 3 times in the first week immediately after VX2 tumor implantation. ImageJ was used to quantitate tumor volume and time course signal enhancement on DCE images. The changes of tumor size showed that the growth of VX2 tumors was effectively inhibited for both LipoDox-treated and Dox-treated groups. Furthermore, the tumor volume of LipoDox-treated group was significantly lower than that of Dox-treated group, which implies that LipoDox has better therapeutic effect than Dox. The signal intensity of LipoDox-treated group is significantly lower than that of the other two groups, which implies that targeted therapeutic drug remained in the tumor tissue. This study provides a radiation-free and non-invasive MRI method for therapeutic monitoring of targeted liposome on an animal tumor model.

Keywords: doxorubicin, dynamic contrast-enhanced MRI, lipodox, magnetic resonance imaging, VX2 tumor model

Procedia PDF Downloads 457

Authors: Elena Kokkoni, Prasanna Kannappan, Ashkan Zehfroosh, Effrosyni Mavroudi, Kristina Strother-Garcia, James C. Galloway, Jeffrey Heinz, Rene Vidal, Herbert G. Tanner

Abstract:

Early immobility affects the motor, cognitive, and social development. Current pediatric rehabilitation lacks the technology that will provide the dosage needed to promote mobility for young children at risk. The addition of socially assistive robots in early interventions may help increase the mobility dosage. The aim of this study is to examine the feasibility of an early intervention paradigm where non-walking infants experience independent mobility while socially interacting with robots. A dynamic environment is developed where both the child and the robot interact and learn from each other. The environment involves: 1) a range of physical activities that are goal-oriented, age-appropriate, and ability-matched for the child to perform, 2) the automatic functions that perceive the child’s actions through novel activity recognition algorithms, and decide appropriate actions for the robot, and 3) a networked visual data acquisition system that enables real-time assessment and provides the means to connect child behavior with robot decision-making in real-time. The environment was tested by bringing a two-year old boy with Down syndrome for eight sessions. The child presented delays throughout his motor development with the current being on the acquisition of walking. During the sessions, the child performed physical activities that required complex motor actions (e.g. climbing an inclined platform and/or staircase). During these activities, a (wheeled or humanoid) robot was either performing the action or was at its end point 'signaling' for interaction. From these sessions, information was gathered to develop algorithms to automate the perception of activities which the robot bases its actions on. A Markov Decision Process (MDP) is used to model the intentions of the child. A 'smoothing' technique is used to help identify the model’s parameters which are a critical step when dealing with small data sets such in this paradigm. The child engaged in all activities and socially interacted with the robot across sessions. With time, the child’s mobility was increased, and the frequency and duration of complex and independent motor actions were also increased (e.g. taking independent steps). Simulation results on the combination of the MDP and smoothing support the use of this model in human-robot interaction. Smoothing facilitates learning MDP parameters from small data sets. This paradigm is feasible and provides an insight on how social interaction may elicit mobility actions suggesting a new early intervention paradigm for very young children with motor disabilities. Acknowledgment: This work has been supported by NIH under grant #5R01HD87133.

Keywords: activity recognition, human-robot interaction, machine learning, pediatric rehabilitation

Procedia PDF Downloads 292

Authors: Hong Li, Haiyang Yu, Shiqing Cheng, Nai Cao, Zhiliang Shi

Abstract:

Unconventional resources have gradually become the main direction for oil and gas exploration and development. However, the productivity of gas wells, the level of water production, and the seepage law in tight fractured gas reservoirs are very different. These are the reasons why production prediction is so difficult. Firstly, a three-dimensional multi-scale fracture and multiphase mathematical model based on an embedded discrete fracture model (EDFM) is established. And the material balance method is used to calculate the water body multiple according to the production performance characteristics of water-producing gas well. This will help construct a 'virtual water body'. Based on these, this paper presents a numerical simulation process that can adapt to different production modes of gas wells. The research results show that fractures have a double-sided effect. The positive side is that it can increase the initial production capacity, but the negative side is that it can connect to the water body, which will lead to the gas production drop and the water production rise both rapidly, showing a 'scissor-like' characteristic. It is worth noting that fractures with different angles have different abilities to connect with the water body. The higher the angle of gas well development, the earlier the water maybe break through. When the reservoir is a single layer, there may be a stable production period without water before the fractures connect with the water body. Once connected, a 'scissors shape' will appear. If the reservoir has multiple layers, the gas and water will produce at the same time. The above gas-water relationship can be matched with the gas well production date of the Xujiahe gas reservoir in the Sichuan Basin. This method is used to predict the productivity of a well with hydraulic fractures in this gas reservoir, and the prediction results are in agreement with on-site production data by more than 90%. It shows that this research idea has great potential in the productivity prediction of water-producing gas wells. Early prediction results are of great significance to guide the design of development plans.

Keywords: EDFM, multiphase, multilayer, water body

Procedia PDF Downloads 194

Authors: Chloé Kernaléguen, Laura Kundun, Tessie Lery, Ryan Laleg, Zhangyun Tan

Abstract:

This study explores global disparities in respiratory syncytial virus (RSV) bronchiolitis incidence among children aged 0-2 years, focusing on the human development index (HDI) as a key determinant. RSV bronchiolitis poses a significant health risk to young children, influenced by factors, including socio-economic conditions captured by the HDI. Through a comprehensive systematic review and dataset selection (Switzerland, Brazil, United States of America), we formulated an HDI-SEIRS numerical model within the SEIRS framework. Results show variations in RSV bronchiolitis dynamics across countries, emphasizing the influence of HDI. Modelling reveals a correlation between higher HDI and increased bronchiolitis spread, notably in the USA and Switzerland. The ratios HDIcountry over HDImax strengthen this association, while climate disparities contribute to variations, especially in colder climates like the USA and Switzerland. The study raises the hypothesis of an indirect link between higher HDI and more frequent bronchiolitis, underlining the need for nuanced understanding. Factors like improved healthcare access, population density, mobility, and social behaviors in higher HDI countries might contribute to unexpected trends. Limitations include dataset quality and restricted RSV bronchiolitis data. Future research should encompass diverse HDI datasets to refine HDI's role in bronchiolitis dynamics. In conclusion, HDI-SEIRS models offer insights into factors influencing RSV bronchiolitis spread. While HDI is a significant indicator, its impact is indirect, necessitating a holistic approach to effective public health policies. This analysis sets the stage for further investigations into multifaceted interactions shaping bronchiolitis dynamics in diverse socio-economic contexts.

Keywords: bronchiolitis propagation, HDI influence, respiratory syncytial virus, SEIRS model

Procedia PDF Downloads 67

Authors: David Ugalde, Arturo Castillo, Leopoldo Breschi

Abstract:

The Tuned Mass Dampers (TMDs) are an effective system for mitigating vibrations in building structures. These dampers have traditionally focused on the protection of high-rise buildings against earthquakes and wind loads. The Camara Chilena de la Construction (CChC) building, built in 2018 in Santiago, Chile, is a 21-story RC wall building equipped with a 150-ton TMD and instrumented with six permanent accelerometers, offering an opportunity to monitor the dynamic response of this damped structure. This paper presents the system identification of the CChC building using power spectral density plots of ambient vibration and two seismic events (5.5 Mw and 6.7 Mw). Linear models of the building with and without the TMD are used to compute the theoretical natural periods through modal analysis and simulate the response of the building through response history analysis. Results show that natural periods obtained from both ambient vibrations and earthquake records are quite similar to the theoretical periods given by the modal analysis of the building model. Some of the experimental periods are noticeable by simple inspection of the earthquake records. The accelerometers in the first story better captured the modes related to the building podium while the upper accelerometers clearly captured the modes related to the tower. The earthquake simulation showed smaller accelerations in the model with TMD that are similar to that measured by the accelerometers. It is concluded that the system identification through power spectral density shows consistency with the expected dynamic properties. The structural health monitoring of the CChC building confirms the advantages of seismic protection technologies such as TMDs in seismic prone areas.

Keywords: system identification, tuned mass damper, wall buildings, seismic protection

Procedia PDF Downloads 126

Authors: A. S. Ibrahim Mamane, S. Giljean, M.-J. Pac, G. L’Hostis

Abstract:

Fiber reinforced composite laminates are particularly subject to residual stresses due to their heterogeneity and the complex chemical, mechanical and thermal mechanisms that occur during their processing. Residual stresses are now well known to cause damage accumulation, shape instability, and behavior disturbance in composite parts. Many works exist in the literature on techniques for minimizing residual stresses in thermosetting and thermoplastic composites mainly. To study in-depth the influence of processing mechanisms on the formation of residual stresses and to minimize them by establishing a reliable correlation, it is essential to be able to measure very precisely the profile of residual stresses in the composite. Residual stresses are important data to consider when sizing composite parts and predicting their behavior. The incremental hole drilling is very effective in measuring the gradient of residual stresses in composite laminates. This method is semi-destructive and consists of drilling incrementally a hole through the thickness of the material and measuring relaxation strains around the hole for each increment using three strain gauges. These strains are then converted into residual stresses using a matrix of coefficients. These coefficients, called calibration coefficients, depending on the diameter of the hole and the dimensions of the gauges used. The reliability of the incremental hole drilling depends on the accuracy with which the calibration coefficients are determined. These coefficients are calculated using a finite element model. The samples’ features and the experimental conditions must be considered in the simulation. Any mismatch can lead to inadequate calibration coefficients, thus introducing errors on residual stresses. Several calibration coefficient correction methods exist for isotropic material, but there is a lack of information on this subject concerning composite laminates. In this work, a Python program was developed to automatically generate the adequate finite element model. This model allowed us to perform a parametric study to assess the influence of experimental errors on the calibration coefficients. The results highlighted the sensitivity of the calibration coefficients to the considered errors and gave an order of magnitude of the precisions required on the experimental device to have reliable measurements. On the basis of these results, improvements were proposed on the experimental device. Furthermore, a numerical method was proposed to correct the calibration coefficients for different types of materials, including thick composite parts for which the analytical approach is too complex. This method consists of taking into account the experimental errors in the simulation. Accurate measurement of the experimental errors (such as eccentricity of the hole, angular deviation of the gauges from their theoretical position, or errors on increment depth) is therefore necessary. The aim is to determine more precisely the residual stresses and to expand the validity domain of the incremental hole drilling technique.

Keywords: fiber reinforced composites, finite element simulation, incremental hole drilling method, numerical correction of the calibration coefficients, residual stresses

Procedia PDF Downloads 132

Authors: Yanto Santosa, Dede Aulia Rahman, Cory Wulan, Abdul Haris Mustari

Abstract:

The global demand for long-tailed macaques for medical experimentation has continued to increase. Fulfillment of Indonesian export demands has been mostly from natural habitats, based on a harvesting quota. This quota has been determined according to the total catch for a given year, and not based on consideration of any demographic parameters or physical environmental factors with regard to the animal; hence threatening the sustainability of the various populations. It is therefore necessary to formulate a method for calculating a sustainable harvesting quota, based on population parameters in natural habitats. Considering the possibility of variations in habitat characteristics and population parameters, a time series observation of demographic and physical/biotic parameters, in various habitats, was performed on 13 groups of long-tailed macaques, distributed throughout the West Java, Lampung and Yogyakarta areas of Indonesia. These provinces were selected for comparison of the influence of human/tourism activities. Data on population parameters that was collected included data on life expectancy according to age class, numbers of individuals by sex and age class, and ‘ratio of infants to reproductive females’. The estimation of population growth was based on a population dynamic growth model: the Leslie matrix. The harvesting quota was calculated as being the difference between the actual population size and the MVP (minimum viable population) for each sex and age class. Observation indicated that there were variations within group size (24 – 106 individuals), gender (sex) ratio (1:1 to 1:1.3), life expectancy value (0.30 to 0.93), and ‘ratio of infants to reproductive females’ (0.23 to 1.56). Results of subsequent calculations showed that sustainable harvesting quotas for each studied group of long-tailed macaques, ranged from 29 to 110 individuals. An estimation model of the MVP for each age class was formulated as Log Y = 0.315 + 0.884 Log Ni (number of individual on ith age class). This study also found that life expectancy for the juvenile age class was affected by the humidity under tree stands, and dietary plants’ density at sapling, pole and tree stages (equation: Y= 2.296 – 1.535 RH + 0.002 Kpcg – 0.002 Ktg – 0.001 Kphn, R2 = 89.6% with a significance value of 0.001). By contrast, for the sub-adult-adult age class, life expectancy was significantly affected by slope (equation: Y=0.377 = 0.012 Kml, R2 = 50.4%, with significance level of 0.007). The infant to reproductive female ratio was affected by humidity under tree stands, and dietary plant density at sapling and pole stages (equation: Y = -1.432 + 2.172 RH – 0.004 Kpcg + 0.003 Ktg, R2 = 82.0% with significance level of 0.001). This research confirmed the importance of population parameters in determining the minimum viable population, and that MVP varied according to habitat characteristics (especially food availability). It would be difficult therefore, to formulate a general mathematical equation model for determining a harvesting quota for the species as a whole.

Keywords: harvesting, long-tailed macaque, population, quota

Procedia PDF Downloads 424

Authors: Zilungile Sosibo

Abstract:

Constructivism in teacher education is growing tremendously in both the developed and developing world. Proponents of constructivism emphasize active engagement of students in the teaching and learning process. In an effort to keep students engaged while they learn to learn, teachers use a variety of methods to incorporate constructivism in the teaching-learning situations. One area that has a potential for realizing constructivism in the classroom is self-assessment. Sadly, students are rarely involved in the assessment of their work. Instead, the most knowing teacher dominates this process. Student involvement in self-assessments has a potential to teach student teachers to become objective assessors of their students’ work by the time they become credentialed. This is important, as objectivity in assessments is a much-needed skill in the classroom contexts within which teachers deal with students from diverse backgrounds and in which biased assessments should be avoided at all cost. The purpose of the study presented in this paper was to investigate whether student teachers acquired the skills of administering self-assessments objectively after they had been immersed in a formal training program and participated in four sets of self-assessments. The objectives were to determine the extent to which they had mastered the skills of objective self-assessments, their growth and development in this area, and the challenges they encountered in administering self-assessments objectively. The research question was: To what extent did student teachers acquire objectivity in self-assessments after their theoretical and practical engagement in this activity? Data were collected from student teachers through participant observation and semi-structured interviews. The design was a qualitative case study. The sample consisted of 39 final-year student teachers enrolled in a Bachelor of Education teacher education program at a university in South Africa. Results revealed that the formal training program and participation in self-assessments had a minimal effect on students’ acquisition of objectivity in self-assessments, due to the factors associated with self-aggrandizement and hegemony, the latter resulting from gender, religious and racial differences. These results have serious implications for the need to incorporate self-assessments in the teacher-education curriculum, as well as for extended formal training programs for student teachers on assessment in general.

Keywords: objectivity, self-assessment, student teachers, teacher education curriculum

Procedia PDF Downloads 273