Search results for: multi-objective combinatorial optimization problem

Authors: K. C. Ching

Abstract:

There is growing public concern over the increasing prevalence of student suicide in Hong Kong. Some identify the problem with insufficient social support, while some attribute it to the vast fluctuations in emotional experience and the hindrances to emotion-regulation, both typical of adolescence and emerging adulthood. This study is thus designed to explore the respective effect of perceived social support and emotion self-confidence, on positive emotions and negative emotions. Fifty-seven Hong Kong higher-education students (17 males, 40 females) aged between 18 and 25 (M = 21.78) responded to an online questionnaire consisted of self-reported measures of perceived social support, emotional self-confidence, positive emotions, and negative emotions. Hierarchical regression analysis revealed that emotional self-confidence positively associated with positive emotions and negatively with negative emotions, while perceived social support positively associated with positive emotions but was not related to negative emotions. Perceived social support and emotional self-confidence both predicted positive emotions, but did not interact to predict any emotional outcome. It is concluded that students’ positive and negative emotional experiences are closely related to their emotion-regulation process. But for social support, its effect is merely protective, meaning that although perceived social support generally promotes positive emotions, it alone does not suffice to alleviate students’ negative emotions. These conclusions carry profound implications to suicide prevention practices, including that most existing suicide prevention campaigns should advance from merely fostering mutual support to directly promoting adaptive coping of emotional negativity.

Keywords: emerging adulthood, emotional self-confidence, hong kong, perceived social support, suicide prevention

Procedia PDF Downloads 142

Authors: Rama Bhargava, Surabhi Nishad

Abstract:

The infusion of nanofluids has dramatically enhanced the heat-carrying capacity of the fluids, applicable to many engineering and medical process where the temperature below freezing is required. Cryosurgery is an efficient therapy for the treatment of cancer, but sometimes the excessive cooling may harm the nearby healthy cells. Efforts are therefore done to develop a model which can cause to generate the low temperature as required. In the present study, a mathematical model is developed based on the bioheat transfer equation to simulate the heat transfer from the probe on a tumor (with irregular domain) using the hybrid technique consisting of element free Galerkin method with αα-family of approximation. The probe is loaded will nano-particles. The effects of different nanoparticles, namely Al₂O₃, Fe₃O₄, Au on the heat-producing rate, is obtained. It is observed that the temperature can be brought to (60°C)-(-30°C) at a faster freezing rate on the infusion of different nanoparticles. Besides increasing the freezing rate, the volume of the nanoparticle can also control the size and growth of ice crystals formed during the freezing process. The study is also made to find the time required to achieve the desired temperature. The problem is further extended for multi tumors of different shapes and sizes. The irregular shape of the frozen domain and the direction of ice growth are very sensitive issues, posing a challenge for simulation. The Meshfree method has been one of the accurate methods in such problems as a domain is naturally irregular. The discretization is done using the nodes only. MLS approximation is taken in order to generate the shape functions. Sufficiently accurate results are obtained.

Keywords: cryosurgery, EFGM, hybrid, nanoparticles

Procedia PDF Downloads 123

Authors: Daniel Angwenyi

Abstract:

Relationships between protected area managers and adjacent communities, as well as communities' attitudes, views and perceptions of these areas, are critical for the success of conservation efforts. It is, therefore, of utmost importance for protected area managers and administrators understand how local communities view these areas and their management, so that they can build sustainable working relationships. This paper is based on a survey of 375 semi-structured questionnaires administered to household heads, living at distances ranging from the edge of the reserves to 50 km away from the reserve boundary across Great Fish River, Mkambati, Hluleka, and Tsolwana in the Eastern Cape Province, South Africa. The paper provides a longitudinal assessment of households’ knowledge on the role of reserves and how the reserves. In addition to households’ knowledge, the paper also provides an assessment of their attitudes towards the location and management, as well as views on the best way to manage the reserves. For 79% of community members reserves are important as they were seen to conserve biodiversity and valuable ecological systems necessary for sustaining life. Most (75%) respondents indicated that closely located reserves gave them opportunities to learn about nature conservation and to subsidize their incomes through tourism ventures. However, 58% had a problem with reserves’ staff, due to restrictions on resource use, which negatively impacted their livelihoods. Over half (51%) of the households were of the view that sustainable conservation can only be achieved through an integrated approach, where local communities’ and conservation needs are given equal weighting. Thus, it is concluded that reserve management should look at communities as active partners in the running of protected areas if sustainable conservation objectives are to be realised.

Keywords: nature conservation, conservation knowledge, local communities, views, protected areas

Procedia PDF Downloads 146

Authors: Pongsakorn Komutpol, Pravej Serichetaphongse, Soontra Panmekiate, Atiphan Pimkhaokham

Abstract:

Statement of Problem: The important parameter of esthetic assessment in anterior maxillary implant include pink esthetic of gingiva and white esthetic of restoration. While the 3 dimensional (3D) implant position are recently concerned as a key for succeeding in implant treatment. However, to our knowledge, the authors did not come across any publication that demonstrated the relations of esthetic outcome and 3D implant position. Objectives: To investigate the correlation between positional accuracy of single-tooth implant restoration (STIR) in all 3 dimensions and their esthetic outcomes. Materials and Methods: 17 patients’ data who had a STIR at central incisor with pristine contralateral tooth were included in this study. Intraoral photographs, dental models, and cone beam computed tomography (CBCT) images were retrieved. The esthetic outcome was assessed in accordance with pink esthetic score and white esthetic score (PES/WES). While the number of correct position in each dimension (mesiodistal, labiolingual, apicocoronal) of the implant were evaluated and defined as 'right' or 'wrong' according to ITI consensus conference by one investigator using CBCT data. The different mean score between right and wrong position in all dimensions was analyzed by Mann-Whitney U test with 0.05 was the significant level of the study. Results: The average score of PES/WES was 15.88 ± 1.65 which was considered as clinically acceptable. The average PES/WES score in 1, 2 and 3 right dimension of the implant position were 16.71, 15.75 and 15.17 respectively. None of the implants placed wrongly in all three dimensions. Statistically significant difference of the PES/WES score was found between the implants that placed right in 3 dimensions and 1 dimension (p = 0.041). Conclusion: This study supported the principle of 3D position of implant. The more properly implant was placed, the higher esthetic outcome was found.

Keywords: accuracy, dental implant, esthetic, 3D implant position

Procedia PDF Downloads 179

Authors: Alice Morenike Olagunju, Olufemi A. Fakolade, Abiodun Ezekiel Adesina, Olufemi Akinloye Bolaji, Oriyomi Rabiu

Abstract:

The use of computer-assisted instruction(CAI) has been suggested as a way out of the problem of Colleges of Education (CoE) in Southwest, Nigeria persistent high failure rate in and negative attitude towards Agricultural Economics (AE).The impacts of this are yet unascertained on high-flyers. This study, therefore, determined the impacts of CAI onhigh-flyers pre-service teachers’ attitude towards AE concepts in Southwest, Nigeria. The study adopted pretest-posttest, control group, quasi-experimental design. Six CoE with e-library facilities were purposively selected. Fourty-nine 200 level Agricultural education students offering introduction to AE course across the six CoE were participants. The participants were assigned to two groups (CAI, 22 and control, 27). Treatment lasted eight weeks. The AE Attitude Scale(r=0.80), Instructional guides and Teacher Performance Assessment Sheets were used for data collection. Data were analysed using t-test. The participants were 62.8% male with mean age of 22 years. Treatment had significant effects on high-flyers pre-service teachers’ attitude (t = 17.44; df = 47, p < .5). Participants in CAI ( =71.03) had higher post attitude mean score compared to those in control ( = 64.92) groups. Gender had no significant effect on attitude (t= 3.06; df= 47, p > .5). The computer assisted instructional mode enhanced students’ attitude towards Agricultural Economics concepts. Therefore, CAI should be adopted for improved attitude towards agricultural economics concepts among high-flyers pre-service teachers.

Keywords: attitude towards agricultural economics concepts, colleges of education in southwest Nigeria, computer-assisted instruction, high-flyers pre-service teachers

Procedia PDF Downloads 249

Authors: Christine Pichler

Abstract:

The German word Bildung in a comprehensive understanding can be defined as the development of the personality and as a process, which lasts from birth, or even before birth, until death. Gaining experience, acquiring abilities and knowledge as a lifelong learning process is what Bildung means. The development of the personality is intransitive because of the personality’s development itself, and transitive because of influences on the formation of a person by individuals and institutions. In public and political discussions, the term Bildung is understood with a constricted usage as education at schools. This leads to the research question, which consequences this limited comprehension of the term Bildung implies and how a comprehensive term of Bildung has to be defined. In discussions, Bildung is limited to its formal part. The limited understanding prevents from accurate analyses and discussions as well as adequate actions. This hypothesis and the research issue will be processed by theoretical analyses of the factors of Bildung, guideline-controlled expert interviews and a qualitative content analysis. The limited understanding on the term Bildung is a methodological problem. This results in inaccuracies in the analysis of the processes of Bildung and their effects on the development of personality structures. On the one hand, an individual is influenced by formal structures in the system of Bildung (e.g. schools) and on the other hand an individual is influenced by gained individual and informal personality and character attributes. In general, too little attention is given to these attributes and individual qualifications. The aim of this work is to demonstrate informative terms so the educational process with all its facets could be considered and applicable analyses can be made. If the informative terms can be defined, it´s also possible to identify and discuss the components of a comprehensive term Bildung to enable correct action.

Keywords: Bildung, development of personality, education, formative process, organized and non-organized Bildung

Procedia PDF Downloads 121

Authors: A. Kaeotawee, N. Bunmas, W. Chomthong

Abstract:

Background: The cancellation of elective surgery is a major indicator of poor operating room efficiency. Furthermore, it is recognized as a major cause of emotional trauma to patients as well as their families. This study was carried out to assess the incidence and causes of elective surgery cancellation in our setting and to find the appropriate solutions for better quality management. Objective: To determine the incidence and causes of elective surgery cancellations in Songklanagarind Hospital. Material and Method: A prospective survey was conducted from September to November 2012. All patients who had their scheduled elective operations cancelled were assessed. Data was collected on the following 2 components: (1) patient demographics;(2) main reasons for cancellations, which were grouped into patient-related factors and organizational-related factors. Data are reported as a percentage of patients whose operations were cancelled. The association between cancellation status and patient demographics was assessed using univariate logistic regression. Results: 2,395 patients were scheduled for elective surgery and of these 343 (14.3%) had their operations cancelled. Cardiothoracic surgery had the highest rate of cancellations (28.7%) while the least number of cancellations occurred in ophthalmology (10.1%). The main reasons for cancellations were related to the unit's organization (53.6%), due to the surgeon (48.4%). Patient related causes (46.4%), due to non medical reasons (32.1%). The most common cause of cancellation by the surgeon was lack of theater time (21.3%), by patients due to the patient’s nonappearance (25.1%). Cancellation was significantly associated with type of patient, health insurance, type of anesthesia and specialties (p<0.05). Conclusion: Surgery cancellations by surgeons relating to a lack of theater time was a significant problem in our setting. Appropriate solutions for better quality improvement are needed.

Keywords: elective cases, surgery cancellation, quality management, appropriate solutions

Procedia PDF Downloads 260

Authors: S. Raja Mohamed, M. H Shwehdi, D. Devaraj

Abstract:

This paper is to present and discuss the new planned 380 kV transmission line performance under steady and transient states. Dynamic modeling and analysis of such inter-tie, which is, proposed to transfer energy from west to south and vice versa will be demonstrated and discussed. The west-central-south inter-tie links Al-Aula-Zaba-Tabuk-Tubajal-Jawf-Hail. It is essential to investigate the transient over-voltage to assure steady and stable transmission over such inter-tie. Saudi Electricity Company (SEC) has been improving its grid to make the whole country as an interconnected system. Already east, central and west were interconnected, yet mostly each is fed with its local generation. The SEC is planning to establish many inter-ties to strengthen the transient stability of its grid. The paper studies one of the important links of 380 kV, 220 km between Tabouk and Tubarjal, which is a step towards connecting the West with the South region. Modeling and analysis using some softwares will be utilized under different scenarios. Adoption of methods to stabilize and increase its power transmission are also discussed. Improvement of power system transients has been controlled by FACTS elements such the Static Var Compensators (SVC) receiving a wide interest since many technical studies have proven their effects on damping system oscillations and stability enhancement. Illustrations of the transient at each main generating or load bus will be checked in all inter-tie links. A brief review of possible means to solve the transient over-voltage problem using different FACTS element modeling will be discussed.

Keywords: transient stability, static var compensator, central-west interconnected system, damping controller, Saudi Electricity Company

Procedia PDF Downloads 609

Authors: Maria Lita Sudo

Abstract:

The debate is an effective tool in cultivating critical thinking skills in English classes. It involves writing evidence-based arguments about a resolution in a form of constructive speech and oral discussion using constructive speech, which will then be attacked and defended. In the process of writing, EFL learners may experience anxiety, an emotional problem that affects writing achievement and cognitive processing. Thus, this study explored the sources and effect of English writing anxiety in the context of debate writing with a view to providing EFL teachers pedagogical suggestions in alleviating English writing anxiety in debate writing. The participants of this study are 95 Japanese senior high school EFL learners and 3 Japanese senior high school English teachers. In selecting the participants, opportunity sampling was employed and consent from Japanese English teachers was sought. Data were collected thru (1) observation (2) open-ended questionnaire and (3) semi-structured interview. This study revealed that not all teachers of English in the context of this study recognize the existence of English writing anxiety among their students and that the very nature of the debate, in general, may also be a source of English writing anxiety in the context of debate writing. The interview revealed that English writing anxiety affects students’ ability to retrieve L2 vocabulary. Further, this study revealed different sources of writing anxiety in debate writing, which can be categorized into four main categories: (1) L2 linguistic ability-related factors (2) instructional –related factors, (3) interpersonal-related factors, and (4) debate- related factors. Based on the findings, recommendations for EFL teachers and EFL learners in managing writing anxiety in debate writing are provided.

Keywords: debate, EFL learners, English writing anxiety, sources

Procedia PDF Downloads 137

Authors: Tzu-Yang Lin, Chuan-Ching Sue

Abstract:

Sleep mechanisms are commonly used to ensure the energy efficiency of each optical network unit (ONU) that concerns a single class delay constraint in the Ethernet Passive Optical Network (EPON). How long the ONUs can sleep without violating the delay constraint has become a research problem. Particularly, we can derive an analytical model to determine the optimal sleep time of ONUs in every cycle without violating the maximum class delay constraint. The bandwidth allocation considering such optimal sleep time is called Green Bandwidth Allocation (GBA). Although the GBA mechanism guarantees that the different class delay constraints do not violate the maximum class delay constraint, packets with a more relaxed delay constraint will be treated as those with the most stringent delay constraint and may be sent early. This means that the ONU will waste energy in active mode to send packets in advance which did not need to be sent at the current time. Accordingly, we proposed a QoS-aware GBA using a novel intra-ONU scheduling to control the packets to be sent according to their respective delay constraints, thereby enhancing energy efficiency without deteriorating delay performance. If packets are not explicitly classified but with different packet delay constraints, we can modify the intra-ONU scheduling to classify packets according to their packet delay constraints rather than their classes. Moreover, we propose the switchable ONU architecture in which the ONU can switch the architecture according to the sleep time length, thus improving energy efficiency in the QoS-aware GBA. The simulation results show that the QoS-aware GBA ensures that packets in different classes or with different delay constraints do not violate their respective delay constraints and consume less power than the original GBA.

Keywords: Passive Optical Networks, PONs, Optical Network Unit, ONU, energy efficiency, delay constraint

Procedia PDF Downloads 284

Authors: Xiaogang Li, Jieqiong Miao

Abstract:

As for the problem of the grey forecasting model prediction accuracy is low, an improved grey prediction model is put forward. Firstly, use trigonometric function transform the original data sequence in order to improve the smoothness of data , this model called SGM( smoothness of grey prediction model), then combine the improved grey model with support vector machine , and put forward the grey support vector machine model (SGM - SVM).Before the establishment of the model, we use trigonometric functions and accumulation generation operation preprocessing data in order to enhance the smoothness of the data and weaken the randomness of the data, then use support vector machine (SVM) to establish a prediction model for pre-processed data and select model parameters using genetic algorithms to obtain the optimum value of the global search. Finally, restore data through the "regressive generate" operation to get forecasting data. In order to prove that the SGM-SVM model is superior to other models, we select the battery life data from calce. The presented model is used to predict life of battery and the predicted result was compared with that of grey model and support vector machines．For a more intuitive comparison of the three models, this paper presents root mean square error of this three different models .The results show that the effect of grey support vector machine (SGM-SVM) to predict life is optimal, and the root mean square error is only 3.18%. Keywords: grey forecasting model, trigonometric function, support vector machine, genetic algorithms, root mean square error

Keywords: Grey prediction model, trigonometric functions, support vector machines, genetic algorithms, root mean square error

Procedia PDF Downloads 461

Authors: Ahmad Fauzi Makarim, Okkie Puspitorini, Hani'ah Mahmudah, Nur Adi Siswandari, Ari Wijayanti

Abstract:

As a maritime country, Indonesia needs a solution in maritime connectivity which can assist the maritime communication system which including communication from harbor to the ship or ship to ship. The needs of many application services for maritime communication, whether for safety reasons until voyage service to help the process of voyage activity needs connection with a high bandwith. To support the government efforts in handling that kind of problem, a research is conducted in maritime communication issue by applying the new developed technology in Indonesia, namely IEEE 802.11. In this research, 3 outdoor WiFi devices are used in which have a frequency of 5.8 GHz. Maritime of Tanjung Perak harbor in Surabaya until Karang Jamuang Island are used as the location of the research with defining permission of ship node spreading by Navigation District Class 1. That maritime area formed by state 1 and state 2 areas which are the narrow area with average wave height of 0.7 meter based on the data from BMKG S urabaya. After that, wave height used as one of the parameters which are used in analyzing characteristic of signal propagation at sea surface, so it can be determined on the coverage area of transmitter system. In this research has been used three samples of outdoor wifi, there is the coverage of device A can be determined about 2256 meter, device B 4000 meter, and device C 1174 meter. Then to analyze of network connectivity for the ship to ship is used AODV routing algorithm system based on the value of the power transmit was smallest of all nodes within the transmitter coverage.

Keywords: maritime of Indonesia, maritime communications, outdoor wifi, coverage, AODV

Procedia PDF Downloads 351

Authors: Amna bibi, Hina Rana

Abstract:

In the social, behavioral, and medical sciences, and particularly in Pakistani popular culture and political discourse, transgender issues are a relatively recent subject of research. The present study aimed to explore the lived experiences related to psycho-social issues faced by transgenders in Pakistani society. In this qualitative study, phenomenology research design was used. The purposive and snowball sampling techniques were used for data collection and in-depth interviews were conducted with N= 8 transgenders belonging to Lahore city, Pakistan. All interviews were audio recorded and transcribed properly. Interpretative phenomenological analysis was used to generate results in terms of themes. The results of the current study revealed different major themes such as psychological, social, and financial problems. Several emergent and sub-themes were also generated such as insomnia, suicidal ideation, stress, physical abuse, social rejection, discrimination at work workplace, less job opportunities, and harassment. Current study indicate that transgender suffer from different problems and struggle hard for their daily living. It was concluded that there should be a step taken at government level for the betterment of this community. The findings of the present study can help out transgender communities and activist to uncover their problem and empowering transgender individuals through education, skill development, and opportunities for growth. Their abilities can be utilized by providing education, polishing their skills, and employment opportunities. The data provides the knowledge that there should be strategies at family, society and government level for the betterment of transgenders.

Keywords: psychological issues, social issues, financial issues, transgender, Pakistani society

Procedia PDF Downloads 24

Authors: Amna Bibi, Hina Rana

Abstract:

In the social, behavioral, and medical sciences, and particularly in Pakistani popular culture and political discourse, transgender issues are a relatively recent subject of research. The present study aimed to explore the lived experiences related to psycho-social issues faced by transgenders in Pakistani society. In this qualitative study, phenomenology research design was used. The purposive and snowball sampling techniques were used for data collection and in-depth interviews were conducted with N= 8 transgenders belonging to Lahore city, Pakistan. All interviews were audio recorded and transcribed properly. Interpretative phenomenological analysis was used to generate results in terms of themes. The results of the current study revealed different major themes such as psychological, social, and financial problems. Several emergent and sub-themes were also generated such as insomnia, suicidal ideation, stress, physical abuse, social rejection, discrimination at work workplace, less job opportunities, and harassment. Current study indicate that transgender suffer from different problems and struggle hard for their daily living. It was concluded that there should be a step taken at government level for the betterment of this community. The findings of the present study can help out transgender communities and activist to uncover their problem and empowering transgender individuals through education, skill development, and opportunities for growth. Their abilities can be utilized by providing education, polishing their skills, and employment opportunities. The data provides the knowledge that there should be strategies at family, society and government level for the betterment of transgenders.

Keywords: psychological issues, social issues, financial issues, transgender, Pakistani society

Procedia PDF Downloads 31

Authors: Vaishali Chaurasia

Abstract:

Ageing is the universal phenomenon that is associated with deteriorating health status. As the human becomes old, certain changes take place in an organism leading to morbidities, disabilities, and event death. Furthermore, older people are more vulnerable for the various kinds of diseases and health problem. Due to the some unhealthy conventions like smoking, drinking and unhealthy foods is the genesis of the lifestyle diseases. These diseases associated with the way a person or group of people lives. The main purpose of the study is to determine the prevalence of lifestyle diseases and its association with physical activity as well as the risk factors associated with it among the adult population in India. Longitudinal Aging Study in India and Study on Global Aging and Adult Health in India were used in the study. We will take population aged 50 and older, began in 1935, and regularly refreshed at younger ages with new birth cohorts. Life style diseases are more prominent in 65+ age group. The study finds an association between prevalence of life style diseases and life style risk factors. The lifestyle disease prevalence is more among higher age group people, female, richest quintile, and doing lesser physical activity. A higher prevalence of lifestyle diseases associated with the multiple risk factors. The occurrence of three and four risk factors was more prevalent in India. The frequency of different type of life style disease is higher among those who hardly or never do any physical activity as compare to those who do physical activity every day. The pattern remains the same in Moderate as well as vigorous physical activity. Those who are regularly doing physical activities have lesser percentage of having any disease and those who hardly ever or never do any physical activities and equally involve with some risk factors have higher percentage of having all type of diseases.

Keywords: lifestyle disease, morbidity, disability, physical activity

Procedia PDF Downloads 345

Authors: Adonis Menezes, J. C. Passos

Abstract:

The current panorama of technology in heat transfer and the scarcity of information about the convective boiling of CO₂ and hydrocarbon in small diameter channels motivated the development of this work. Among non-halogenated refrigerants, CO₂/ R744 has distinct thermodynamic properties compared to other fluids. The R744 presents significant differences in operating pressures and temperatures, operating at higher values compared to other refrigerants, and this represents a challenge for the design of new evaporators, as the original systems must normally be resized to meet the specific characteristics of the R744, which creates the need for a new design and optimization criteria. To carry out the convective boiling tests of CO₂, an experimental apparatus capable of storing (m= 10kg) of saturated CO₂ at (T = -30 ° C) in an accumulator tank was used, later this fluid was pumped using a positive displacement pump with three pistons, and the outlet pressure was controlled and could reach up to (P = 110bar). This high-pressure saturated fluid passed through a Coriolis type flow meter, and the mass velocities varied between (G = 20 kg/m².s) up to (G = 1000 kg/m².s). After that, the fluid was sent to the first test section of circular cross-section in diameter (D = 4.57mm), where the inlet and outlet temperatures and pressures, were controlled and the heating was promoted by the Joule effect using a source of direct current with a maximum heat flow of (q = 100 kW/m²). The second test section used a cross-section with multi-channels (seven parallel channels) with a square cross-section of (D = 2mm) each; this second test section has also control of temperature and pressure at the inlet and outlet as well as for heating a direct current source was used, with a maximum heat flow of (q = 20 kW/m²). The fluid in a biphasic situation was directed to a parallel plate heat exchanger so that it returns to the liquid state, thus being able to return to the accumulator tank, continuing the cycle. The multi-channel test section has a viewing section; a high-speed CMOS camera was used for image acquisition, where it was possible to view the flow patterns. The experiments carried out and presented in this report were conducted in a rigorous manner, enabling the development of a database on the convective boiling of the R744 in macro and micro channels. The analysis prioritized the processes from the beginning of the convective boiling until the drying of the wall in a subcritical regime. The R744 resurfaces as an excellent alternative to chlorofluorocarbon refrigerants due to its negligible ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) rates, among other advantages. The results found in the experimental tests were very promising for the use of CO₂ in micro-channels in convective boiling and served as a basis for determining the flow pattern map and correlation for determining the heat transfer coefficient in the convective boiling of CO₂.

Keywords: convective boiling, CO₂/R744, macro-channels, micro-channels

Procedia PDF Downloads 143

Authors: M. Venegas, M. De Vega, N. García-Hernando

Abstract:

Absorption cooling chillers have received growing attention over the past few decades as they allow the use of low-grade heat to produce the cooling effect. The combination of this technology with solar thermal energy in the summer period can reduce the electricity consumption peak due to air-conditioning. One of the main components, the absorber, is designed for simultaneous heat and mass transfer. Usually, shell and tubes heat exchangers are used, which are large and heavy. Cooling water from a cooling tower is conventionally used to extract the heat released during the absorption and condensation processes. These are clear inconvenient for the generalization of the absorption technology use, limiting its benefits in the contribution to the reduction in CO2 emissions, particularly for the H2O-LiBr solution which can work with low heat temperature sources as provided by solar panels. In the present work a promising new technology is under study, consisting in the use of membrane contactors in adiabatic microchannel mass exchangers. The configuration here proposed consists in one or several modules (depending on the cooling capacity of the chiller) that contain two vapour channels, separated from the solution by adjacent microporous membranes. The solution is confined in rectangular microchannels. A plastic or synthetic wall separates the solution channels between them. The solution entering the absorber is previously subcooled using ambient air. In this way, the need for a cooling tower is avoided. A model of the configuration proposed is developed based on mass and energy balances and some correlations were selected to predict the heat and mass transfer coefficients. The concentration and temperatures along the channels cannot be explicitly determined from the set of equations obtained. For this reason, the equations were implemented in a computer code using Engineering Equation Solver software, EES™. With the aim of minimizing the absorber volume to reduce the size of absorption cooling chillers, the ratio between the cooling power of the chiller and the absorber volume (R) is calculated. Its variation is shown along the solution channels, allowing its optimization for selected operating conditions. For the case considered the solution channel length is recommended to be lower than 3 cm. Maximum values of R obtained in this work are higher than the ones found in optimized horizontal falling film absorbers using the same solution. Results obtained also show the variation of R and the chiller efficiency (COP) for different ambient temperatures and desorption temperatures typically obtained using flat plate solar collectors. The configuration proposed of adiabatic membrane-based absorber using ambient air to subcool the solution is a good technology to reduce the size of the absorption chillers, allowing the use of low temperature solar heat and avoiding the need for cooling towers.

Keywords: adiabatic absorption, air-cooled, membrane, solar thermal energy

Procedia PDF Downloads 285

Authors: Mrunalini Sonne

Abstract:

Aquaculture uses a variety of broad spectrum antibiotics to manage and prevent a variety of diseases without understanding their mechanisms of action. This has led to water pollution in the modern world. The necessity for alternate control measures against bacterial illnesses in the aquaculture sector is highlighted by issues brought on by antibiotic-resistant bacteria and the dearth of effective control strategies. Bacteriophages (phages) have shown promise as therapeutic agents for the efficient management of bacterial infections in aquaculture. In the current study, a variety of investigations were conducted to determine if utilizing lytic phages to reduce Aeromonas spp. infection in fish aquaculture was appropriate. Motile Aeromonas septicaemia is a fish disease that has caused financial harm to the aquaculture sector. Currently, the production of aquaculture depends significantly on antibiotics, which adds to the worldwide problem of the rise of bacteria that are resistant to medicines and resistance genes. To decrease the usage of antibiotics in aquaculture systems, it is crucial to create efficient antibiotic substitutes. Bacteriophages are capable of acting as a natural antagonist, mostly because of their great specificity, capacity for self-replication, and ability to quickly eradicate dangerous bacteria. There is a need for research that goes beyond just isolating and characterising lytic bacteriophages to examine their morphology, stability, and efficacy in various environmental conditions. Bacteriophage (or phage) therapy is a promising technique to control dangerous microbes in farmed fish. More phage therapy research in aquaculture is required in order to effectively employ phage treatment to lessen infection in fish brought on by Aeromonas.

Keywords: aquaculture, bacteriophages, fish, freshwater

Procedia PDF Downloads 104

Authors: Imen Amari, Kaouther Gasmi, Asma Rebaya, Salem Hasnaoui

Abstract:

The problem of scheduling and mapping data flow applications on multi-core architectures is notoriously difficult. This difficulty is related to the rapid evaluation of Telecommunication and multimedia systems accompanied by a rapid increase of user requirements in terms of latency, execution time, consumption, energy, etc. Having an optimal scheduling on multi-cores DSP (Digital signal Processors) platforms is a challenging task. In this context, we present a novel technic and algorithm in order to find a valid schedule that optimizes the key performance metrics particularly the Latency. Our contribution is based on Satisfiability Modulo Theories (SMT) solving technologies which is strongly driven by the industrial applications and needs. This paper, describe a scheduling module integrated in our proposed Workflow which is advised to be a successful approach for programming the applications based on NoC-DSP platforms. This workflow transform automatically a Simulink model to a synchronous dataflow (SDF) model. The automatic transformation followed by SMT solver scheduling aim to minimize the final latency and other software/hardware metrics in terms of an optimal schedule. Also, finding the optimal numbers of cores to be used. In fact, our proposed workflow taking as entry point a Simulink file (.mdl or .slx) derived from embedded Matlab functions. We use an approach which is based on the synchronous and hierarchical behavior of both Simulink and SDF. Whence, results of running the scheduler which exist in the Workflow mentioned above using our proposed SMT solver algorithm refinements produce the best possible scheduling in terms of latency and numbers of cores.

Keywords: multi-cores DSP, scheduling, SMT solver, workflow

Procedia PDF Downloads 286

Authors: Sih-Li Chen, Chih-Hao Chen, Chi-Tong Chan

Abstract:

Poor ventilation and high carbon dioxide (CO2) concentrations lead to the formation of sick buildings. This problem cannot simply be resolved by introducing fresh air from outdoor environments because this creates extra loads on indoor air-conditioning systems. Desiccants are widely used in air conditioning systems in tropical and subtropical regions with high humidity to reduce the latent heat load from fresh air. Desiccants are usually used as a packed-bed type, which is low cost, to combine with air-conditioning systems. Nevertheless, the pressure drop of a packed bed is too high, and the heat of adsorption caused by the adsorption process lets the temperature of the outlet air increase, bringing about an extra heat load, so the high pressure drop and the increased temperature of the outlet air are energy consumption sources needing to be resolved. For this reason, the gas-solid fluidised beds that have high heat and mass transfer rates, uniform properties and low pressure drops are very suitable for use in air-conditioning systems.This study experimentally investigates the performance of silica gel fluidized bed device which applying to an air conditioning system. In the experiments, commercial silica gel particles were filled in the two beds and to form a fixed packed bed and a fluidized bed. The results indicated that compared to the fixed packed bed device, the total adsorption and desorption by amounts of fluidized bed for 40 minutes increased 20.6% and 19.9% respectively when the bed height was 10 cm and superficial velocity was set to 2 m/s. In addition, under this condition, the pressure drop and outlet air temperature raise were reduced by 36.0% and 30.0%. Given the above results, application of the silica gel fluidized bed to air conditioning systems has great energy-saving potential.

Keywords: fluidized bed, packed bed, silica gel, adsorption, desorption, pressure drop

Procedia PDF Downloads 536

Authors: Revoti Prasad Bora, Saurabh Yadav, Nikita Katyal

Abstract:

In the context of educational data mining, the use case of extracting information from images containing both text and diagrams is of high importance. Hence, document analysis requires the extraction of diagrams from such images and processes the text and diagrams separately. To the author’s best knowledge, none among plenty of approaches for extracting tables, figures, etc., suffice the need for real-time processing with high accuracy as needed in multiple applications. In the education domain, diagrams can be of varied characteristics viz. line-based i.e. geometric diagrams, chemical bonds, mathematical formulas, etc. There are two broad categories of approaches that try to solve similar problems viz. traditional computer vision based approaches and deep learning approaches. The traditional computer vision based approaches mainly leverage connected components and distance transform based processing and hence perform well in very limited scenarios. The existing deep learning approaches either leverage YOLO or faster-RCNN architectures. These approaches suffer from a performance-accuracy tradeoff. This paper proposes a U-Net based architecture that formulates the diagram extraction as a segmentation problem. The proposed method provides similar accuracy with a much faster extraction time as compared to the mentioned state-of-the-art approaches. Further, the segmentation mask in this approach allows the extraction of diagrams of irregular shapes.

Keywords: computer vision, deep-learning, educational data mining, faster-RCNN, figure extraction, image segmentation, real-time document analysis, text extraction, U-Net, YOLO

Procedia PDF Downloads 137

Authors: Zaralyn Bernardo, Dante Boac, Annabelle Del Rosario

Abstract:

Professional individuals who are in a primary role to impart learning with the new generation are alarmingly tend to have a vast decrease in their workforce due to stress at work. Thus, the study used mixed method research design to explore the ideal and actual coping patterns of college school teachers, both private and public, using Coping Response Inventory-Adult (CRI-Adult). It was suggested that in order for coping to be effective there must be a congruence or good match between coping efforts and preferred coping style. Results basically provided the same information on sources of teacher stress. However, workload and low salary were more likely heightened, for public and private school, respectively. There is also a significant difference between the ideal and actual coping style of college school teachers. Though the public school teachers leaned towards problem-focused as their ideal way of coping, both public and private teachers are somewhat inclined to use emotion-focused coping in actual situation. Results of FGD identified the factors that contribute to the incongruence or mismatch in their preferred style of coping and actual efforts to cope. Identified factors based on thematic analysis (TA) are clustered into themes such as affectivity and rehearsal of the preferred coping responses, sensitivity to pressure impairs coping efficacy, seeking for social acceptance and approval, indefinite appraisal of perceived stress, emotional dysregulation, and impulsivity, immediate desire to terminate negative emotion and adversity. Most of the factors somewhat provide partial elucidation on the engagement of the respondents on emotion-focused coping.

Keywords: coping responses subtypes, appraisal, teacher stress, ideal and actual coping

Procedia PDF Downloads 165

Authors: Tahnee West

Abstract:

Drama education is increasingly understood as a useful tool in promoting positive social change and cultural awareness. The effects of both positive and negative peer relationships are also a researched facet of education systems. Despite this, very little research has been conducted in the intersection of these two areas, even given current, significant public interest surrounding multicultural relationships. This research addresses a problem faced by educators and students: facilitating meaningful multicultural relationships. The research explores the following question in an Australian context: in what ways does Drama education affect peer relationships between culturally diverse students? In doing so, the study explores the various challenges and experiences of a multicultural group of adolescents, in terms of forming and maintaining effective intercultural friendships, while participating in a series of drama workshops. The project presents a starting point for providing educators with strategies for inclusivity and relationship development amongst diverse student populations. Findings show that Drama education can positively affect culturally diverse young people’s peer relationships; interactions between participants and data collected in focus groups throughout the eight-week Drama program show a steady improvement in sense of trust, support, tolerance, empathy, familiarity with other participants, and enjoyment. Data also points to a positive correlation between the Drama activities and improved conflict resolution and communication skills, as well as an improved understanding of the other participants’ cultures. Diversities and commonalities within the group were explored, with similarities encouraging social cohesion, and decreasing cultural ‘cliques’.

Keywords: cultural diversity, drama education, friendship, multicultural, peer relationships

Procedia PDF Downloads 143

Authors: Marie Komorna, Katerina Hadkova

Abstract:

One reason why hearing disabilities as compared to other disabilities are considered to be less serious, is the belief that deaf and hard of hearing persons can read and write without problems and can therefore fairly easily compensate for problems related to their limited ability to hear sound. However in reality this is not the case, especially as regards written Czech, deaf persons are often not able to communicate their message clearly to its recipients. Their inability to communicate fully in written language is one of the most severe problems facing a number of deaf persons, a problem which they face and which makes it difficult for them to function in a sound-based environment. Despite this fact, this issue is one which has been given only a minimum of attention in the Czech Republic. That is why we decided to focus our research on this issue, specifically targeting written communication of deaf pupils in primary and secondary schools. The paper summarizes the background and objectives of this research. The written work of deaf respondents was obtained in response to a narrative based on a series of images which depicted a continuous storyline. Based on an analysis of the obtained written work we tried to describe the specifics of the narrative abilities of the deaf authors of these texts. We also analyzed other aspects and specific traits of text written by deaf authors at a phonetic-phonological, lexical-semantic, morphological and syntactic, respectively pragmatic level. Based on the results of the project it will be possible to increase knowledge of the communication abilities of deaf persons in written Czech. The obtained data may be used during future research and for teaching purposes and/or education concepts for teaching Czech to deaf pupils.

Keywords: communication competence, deaf, narrative, written texts

Procedia PDF Downloads 338

Authors: Yeimis Milton, Palomino Pichihua

Abstract:

The city, like living organisms, originates from codes, structured information in the form of rules that condition the physical form and performance of urban space. Usually, the so-called urban codes clash with the spontaneous nature of the city, with the urban Kháos that contextualizes the free creation (poiesis) of human collectives. This contradiction is especially evident in Latin America, which, like other developing regions, lacks adequate instruments to guide urban growth. Thus constructing a hybrid between the formal and informal city, categories that are difficult to separate one from the other. This is a comparative study focusing on the urban codes created to address the pandemic. The objective is to build an overview of these innovations in the region. The sample is made up of official norms published in pandemic, directly linked to urban planning and building control (urban form). The countries analyzed are Brazil, Mexico, Argentina, Peru, Colombia, and Chile. The study uncovers a shared interest in facing future urban problems, in contrast to the inconsistency of proposed legal instruments. Factors such as the lack of articulation, validity time, and ambiguity, among others, accentuate this problem. Likewise, it evidences that the political situation of each country has a significant influence on the development of these norms and the possibility of their long-term impact. In summary, the global emergency has produced opportunities to transform urban systems from their internal rules; however, there are very few successful examples in this field. Therefore, Latin American cities have the task of learning from this defeat in order to lay the foundations for a more resilient and sustainable urban future.

Keywords: pandemic, regulation, urban planning, latin America

Procedia PDF Downloads 100

Authors: Macky Kato, Takeshi Sato, Mizuki Nakajima

Abstract:

One major problem related to the use of smartphones is texting while simultaneously engaging in other things, resulting in serious road accidents. Apart from texting while driving being one of the most dangerous behaviors, texting while walking is also dangerous because it narrows the pedestrians’ field of vision. However, many of pedestrian text while walking very habitually. Smartphone users often overlook the potential harm associated with this behavior even while crossing roads. The successful texting while walking make them think that they are safe. The purpose of this study is to reveal of the influence of peripheral vision to the stability of walking trajectory with texting while walking. In total, 9 healthy male university students participated in the experiment. Their mean age was 21.4 years, and standard deviation was 0.7 years. They attempted to walk 10 m in three conditions. First one is the control (CTR) condition, with no phone and no restriction. The second one is the texting while walking (TWG) with no restrictions. The third one is restriction condition (PRS), with phone restricted by experimental peripheral goggles. The horizontal distances (HDS) and directions are measured as the scale of horizontal stability. The longitudinal distances (LDS) between the footprints were measured as the scale of the walking rhythm. The results showed that the HDS of the footprints from the straight line increased as the participants walked in the TWG and PRS conditions. In the PRS condition, this tendency was particularly remarkable. In addition, the LDS between the footprints decreased in the order of the CTR, TWG, and PRS conditions. The ANOVA results showed significant differences in the three conditions with respect to HDS. The differences among these conditions showed that the narrowing of the Pedestrian's vision because of smartphone use influences the walking trajectory and rhythm. It can be said that the pedestrians seem to use their peripheral vision marginally on texting while walking. Therefore, we concluded that the texting while walking narrows the peripheral vision so danger to increase the risk of the accidents.

Keywords: peripheral vision, stability, texting while walking, walking trajectory

Procedia PDF Downloads 257

Authors: Eny Syatriana, Ardiansyah

Abstract:

The purpose of recent study was to develop a learning model on writing, based on the reading texts which will be read by the students using reflection strategy. The strategy would allow the students to read the text and then they would write back the main idea and to develop the text by using their own sentences. So, the writing practice was begun by reading an interesting text, then the students would develop the text which has been read into their writing. The problem questions are (1) what kind of learning model that can develop the students writing ability? (2) what is the achievement of the students of STKIP YPUP through reflection strategy? (3) is the using of the strategy effective to develop students competence In writing? (4) in what level are the students interest toward the using of a strategy In writing subject? This development research consisted of some steps, they are (1) need analysis (2) model design (3) implementation (4) model evaluation. The need analysis was applied through discussion among the writing lecturers to create a learning model for writing subject. To see the effectiveness of the model, an experiment would be delivered for one class. The instrument and learning material would be validated by the experts. In every steps of material development, there was a learning process, where would be validated by an expert. The research used development design. These Principles and procedures or research design and development .This study, researcher would do need analysis, creating prototype, content validation, and limited empiric experiment to the sample. In each steps, there should be an assessment and revision to the drafts before continue to the next steps. The second year, the prototype would be tested empirically to four classes in STKIP YPUP for English department. Implementing the test greatly was done through the action research and followed by evaluation and validation from the experts.

Keywords: learning model, reflection, strategy, reading, writing, development

Procedia PDF Downloads 365

Authors: E. Asadollahi-Yazdi, J. Gardan, P. Lafon

Abstract:

Nowadays, manufactures are encountered with production of different version of products due to quality, cost and time constraints. On the other hand, Additive Manufacturing (AM) as a production method based on CAD model disrupts the design and manufacturing cycle with new parameters. To consider these issues, the researchers utilized Design For Manufacturing (DFM) approach for AM but until now there is no integrated approach for design and manufacturing of product through the AM. So, this paper aims to provide a general methodology for managing the different production issues, as well as, support the interoperability with AM process and different Product Life Cycle Management tools. The problem is that the models of System Engineering which is used for managing complex systems cannot support the product evolution and its impact on the product life cycle. Therefore, it seems necessary to provide a general methodology for managing the product’s diversities which is created by using AM. This methodology must consider manufacture and assembly during product design as early as possible in the design stage. The latest approach of DFM, as a methodology to analyze the system comprehensively, integrates manufacturing constraints in the numerical model in upstream. So, DFM for AM is used to import the characteristics of AM into the design and manufacturing process of a hybrid product to manage the criteria coming from AM. Also, the research presents an integrated design method in order to take into account the knowledge of layers manufacturing technologies. For this purpose, the interface model based on the skin and skeleton concepts is provided, the usage and manufacturing skins are used to show the functional surface of the product. Also, the material flow and link between the skins are demonstrated by usage and manufacturing skeletons. Therefore, this integrated approach is a helpful methodology for designer and manufacturer in different decisions like material and process selection as well as, evaluation of product manufacturability.

Keywords: additive manufacturing, 3D printing, design for manufacturing, integrated design, interoperability

Procedia PDF Downloads 316

Authors: Bekim Berisha, Sebastian Hirsiger, Pavel Hora

Abstract:

Advanced material models involving several sets of model parameters require a big experimental effort. As models are getting more and more complex like e.g. the so called “Homogeneous Anisotropic Hardening - HAH” model for description of the yielding behavior in the 2D/3D stress space, the number and complexity of the required experiments are also increasing continuously. In the context of sheet metal forming, these requirements are even more pronounced, because of the anisotropic behavior or sheet materials. In addition, some of the experiments are very difficult to perform e.g. the plane stress biaxial compression test. Accordingly, tensile tests in at least three directions, biaxial tests and tension-compression or shear-reverse shear experiments are performed to determine the parameters of the macroscopic models. Therefore, determination of the macroscopic model parameters based on virtual experiments is a very promising strategy to overcome these difficulties. For this purpose, in the framework of multiscale material modeling, a dislocation density based crystal plasticity model in combination with a FFT-based spectral solver is applied to perform virtual experiments. Modeling of the plastic behavior of metals based on crystal plasticity theory is a well-established methodology. However, in general, the computation time is very high and therefore, the computations are restricted to simplified microstructures as well as simple polycrystal models. In this study, a dislocation density based crystal plasticity model – including an implementation of the backstress – is used in a spectral solver framework to generate virtual experiments for three deep drawing materials, DC05-steel, AA6111-T4 and AA4045 aluminum alloys. For this purpose, uniaxial as well as multiaxial loading cases, including various pre-strain histories, has been computed and validated with real experiments. These investigations showed that crystal plasticity modeling in the framework of Representative Volume Elements (RVEs) can be used to replace most of the expensive real experiments. Further, model parameters of advanced macroscopic models like the HAH model can be determined from virtual experiments, even for multiaxial deformation histories. It was also found that crystal plasticity modeling can be used to model anisotropic hardening more accurately by considering the backstress, similar to well-established macroscopic kinematic hardening models. It can be concluded that an efficient coupling of crystal plasticity models and the spectral solver leads to a significant reduction of the amount of real experiments needed to calibrate macroscopic models. This advantage leads also to a significant reduction of computational effort needed for the optimization of metal forming process. Further, due to the time efficient spectral solver used in the computation of the RVE models, detailed modeling of the microstructure are possible.

Keywords: anisotropic hardening, crystal plasticity, micro structure, spectral solver

Procedia PDF Downloads 315

Authors: Intissar Farid

Abstract:

Groundwater quality assessment is crucial for sustainable water use, especially in semi-arid regions like the Jeloula basin in Tunisia, where groundwater is essential for domestic and agricultural needs. The present research aims to characterize the suitability of groundwater for irrigational purposes by considering various parameters: total salt concentration as measured by Electrical Conductivity EC, relative proportions of Na⁺ as expressed by %Na and SAR, Kelly’s ratio, Permeability Index, Magnesium hazard and Residual Sodium chloride. Chemical data indicate that the percent sodium (%Na) in the study area ranged from 26.3 to 45.3%. According to the Wilcox diagram, the quality classification of irrigation water suggests that analyzed groundwaters are suitable for irrigation purposes. The SAR values vary between 2.1 and 5. Most of the groundwater samples plot in the Richards’C3S1 water class and indicate little danger from sodium content to soil and plant growth. The Kelly’s ratio of the analyzed samples ranged from 0.3 to 0.8. These values indicate that the waters are fit for agricultural purposes. Magnesium hazard (MH) values range from 27.5 to 52.6, with an average of 38.9 in the analyzed waters. Hence, the Mg²⁺ content of the groundwater from the shallow aquifer cannot cause any problem to the soil permeability. Permeability index (PI) values computed for the area ranged from 33.6 to 52.7%. The above result, therefore, suggests that most of the water samples fall within class I of the Doneen chart and can be categorized as good irrigation water. The groundwaters collected from the Jeloula shallow aquifer were found to be within the safe limits and thus suitable for irrigation purposes.

Keywords: Kelly's ratio, magnesium hazard, permeability index, residual sodium chloride

Procedia PDF Downloads 26