Search results for: the urban improvement
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7884

Search results for: the urban improvement

5004 A Simulated Evaluation of Model Predictive Control

Authors: Ahmed AlNouss, Salim Ahmed

Abstract:

Process control refers to the techniques to control the variables in a process in order to maintain them at their desired values. Advanced process control (APC) is a broad term within the domain of control where it refers to different kinds of process control and control related tools, for example, model predictive control (MPC), statistical process control (SPC), fault detection and classification (FDC) and performance assessment. APC is often used for solving multivariable control problems and model predictive control (MPC) is one of only a few advanced control methods used successfully in industrial control applications. Advanced control is expected to bring many benefits to the plant operation; however, the extent of the benefits is plant specific and the application needs a large investment. This requires an analysis of the expected benefits before the implementation of the control. In a real plant simulation studies are carried out along with some experimentation to determine the improvement in the performance of the plant due to advanced control. In this research, such an exercise is undertaken to realize the needs of APC application. The main objectives of the paper are as follows: (1) To apply MPC to a number of simulations set up to realize the need of MPC by comparing its performance with that of proportional integral derivatives (PID) controllers. (2) To study the effect of controller parameters on control performance. (3) To develop appropriate performance index (PI) to compare the performance of different controller and develop novel idea to present tuning map of a controller. These objectives were achieved by applying PID controller and a special type of MPC which is dynamic matrix control (DMC) on the multi-tanks process simulated in loop-pro. Then the controller performance has been evaluated by changing the controller parameters. This performance was based on special indices related to the difference between set point and process variable in order to compare the both controllers. The same principle was applied for continuous stirred tank heater (CSTH) and continuous stirred tank reactor (CSTR) processes simulated in Matlab. However, in these processes some developed programs were written to evaluate the performance of the PID and MPC controllers. Finally these performance indices along with their controller parameters were plotted using special program called Sigmaplot. As a result, the improvement in the performance of the control loops was quantified using relevant indices to justify the need and importance of advanced process control. Also, it has been approved that, by using appropriate indices, predictive controller can improve the performance of the control loop significantly.

Keywords: advanced process control (APC), control loop, model predictive control (MPC), proportional integral derivatives (PID), performance indices (PI)

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5003 Efficiency of Secondary Schools by ICT Intervention in Sylhet Division of Bangladesh

Authors: Azizul Baten, Kamrul Hossain, Abdullah-Al-Zabir

Abstract:

The objective of this study is to develop an appropriate stochastic frontier secondary schools efficiency model by ICT Intervention and to examine the impact of ICT challenges on secondary schools efficiency in the Sylhet division in Bangladesh using stochastic frontier analysis. The Translog stochastic frontier model was found an appropriate than the Cobb-Douglas model in secondary schools efficiency by ICT Intervention. Based on the results of the Cobb-Douglas model, it is found that the coefficient of the number of teachers, the number of students, and teaching ability had a positive effect on increasing the level of efficiency. It indicated that these are related to technical efficiency. In the case of inefficiency effects for both Cobb-Douglas and Translog models, the coefficient of the ICT lab decreased secondary school inefficiency, but the online class in school was found to increase the level of inefficiency. The coefficients of teacher’s preference for ICT tools like multimedia projectors played a contributor role in decreasing the secondary school inefficiency in the Sylhet division of Bangladesh. The interaction effects of the number of teachers and the classrooms, and the number of students and the number of classrooms, the number of students and teaching ability, and the classrooms and teaching ability of the teachers were recorded with the positive values and these have a positive impact on increasing the secondary school efficiency. The overall mean efficiency of urban secondary schools was found at 84.66% for the Translog model, while it was 83.63% for the Cobb-Douglas model. The overall mean efficiency of rural secondary schools was found at 80.98% for the Translog model, while it was 81.24% for the Cobb-Douglas model. So, the urban secondary schools performed better than the rural secondary schools in the Sylhet division. It is observed from the results of the Tobit model that the teacher-student ratio had a positive influence on secondary school efficiency. The teaching experiences of those who have 1 to 5 years and 10 years above, MPO type school, conventional teaching method have had a negative and significant influence on secondary school efficiency. The estimated value of σ-square (0.0625) was different from Zero, indicating a good fit. The value of γ (0.9872) was recorded as positive and it can be interpreted as follows: 98.72 percent of random variation around in secondary school outcomes due to inefficiency.

Keywords: efficiency, secondary schools, ICT, stochastic frontier analysis

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5002 Understanding Awareness, Agency and Autonomy of Mothers and Potential of Digital Technology in Expanding Maternal Health Information Access: A Survey of Mothers in Urban India

Authors: Sumiti Saharan, Pallav Patankar, Lily W. Lee

Abstract:

Understanding the health-seeking behaviors and attitudes of women towards maternal health in the context of gender roles and family dynamics is tremendously crucial for designing effective and impactful interventions aimed at improving maternal and child health outcomes. Further, as the digital world becomes more accessible and affordable, it is imperative to scope the potential of digital technology in enabling access to maternal health information in different socio-economic groups (SEGs). In the summer of 2017, we conducted a study with 500 women across different SEGs in urban India who were pregnant or had had a delivery in the last year. The study was undertaken to assess their maternal health information seeking behavior with a particular focus on probing their use of digital technology for health-related information. The study also measured women's decision-making autonomy in the context of maternal health, awareness of their rights to quality and respectful maternal healthcare, and agency to voice their rights. We probed the impact of key variables including education, age, and socioeconomic status on all outcome variables. In terms of health-seeking behaviors, we found that women heavily relied on medical professionals and/or their mothers and mothers-in-law for all maternal health advice. Digital adoption was found to be high across all SEGs, with around 70% of women from all populations using the internet several times a week. On the other hand, use of the internet for both accessing maternal health information and choosing maternity hospitals were both significantly dependent on SEG. The key reasons reported for not using the internet for health purposes were lack of awareness and lack of trust on content accuracy. Decisions around health practices and type of delivery were found to be jointly made by women and other family members. Almost all women reported their husbands to play a key role in all maternal health decisions and for decisions with a clear financial implication like choice of hospital for delivery, husbands were reported to be the sole decision maker by a majority of women. The agency of women was also found to be low in interactions with maternal healthcare providers with a third of respondents not comfortable with voicing their opinions and preferences to their doctors. Interestingly, we find that this relatively low agency was prominent in both lower middle class and middle-class SEGs. Recognition of the sociocultural determinants of behavior is the first step in developing actionable strategies for improving maternal health outcomes. Our study quantifies the agency and autonomy of women in urban India and the variables that impact them. Our findings emphasize the value of gender normative approaches that factor in the key role husbands play in guiding maternal health decisions. They also highlight the power of digital approaches for catalyzing access to maternal health information. These insights into the attitude and behaviors of mothers in context of their sociocultural environments—and their relationship with digital technology—can help pave the way towards designing effective, scalable maternal and child health programs in developing nations like India.

Keywords: access to healthcare information, behavior, digital health, maternal health

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5001 Merchants’ Attitudes towards Tourism Development in Mahane Yehuda Market: A Case Study

Authors: Rotem Mashkov, Noam Shoval

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In an age when a tourist’s gaze is more focused on the daily lives of locals, it is evident that local food markets are being rediscovered. Traditional urban markets succeed in reinventing themselves as a space for consumption, recreation, and culture, enabling authentic experiences and interpersonal interactions with the local culture. Alongside this, the pressure of tourism development may result in commercialization and retail gentrification to the point of losing the sense of local identity. The issue of finding a balance between tourism development and the preservation of unique local features is at the heart of this study and is being tested using the case of the Mahane Yehuda market in Jerusalem. The research question—how merchants respond to tourism development in the Mahane Yehuda food market— focuses on local traders, a group of players who are usually absent from the research arenas, although they influence tourism development as well as influenced by it. Three main research methods were integrated into this study. The first two methods, a survey of articles survey and comparative mapping of the business mix, were used to characterize the changes in the Mahane Yehuda market both consciously and physically. The third research method, involving in-depth interviews with merchants, was used to examine the traders' attitudes and responses to tourism development. The findings indicate that there has been a turnaround in the market image over the past decade and a half. Additionally, there has been a significant physical change in the business mix, reflected by a decline of 15% in the number of stalls selling food products and delicacies. The data from the interviews on the traders’ attitudes towards tourism development were inconclusive; there were disagreements among the traders about the economic contribution of tourism development in relation to their dependence on the tourism industry. However, there was a consensus on the need for authentic elements in the marketplace. The findings of the study also indicate a strong link between the merchants’ response to tourism development and their stall ownership status as the merchant could exercise their position in various ways depending on the possession type.

Keywords: business mix, Jerusalem, local food markets, Mahane Yehuda market, merchants’ attitude, ownership status, retail gentrification, tourism development, traditional urban markets

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5000 Effect of the Community Chair-Based Exercise Programme on the Balance of the Elderly in Hong Kong

Authors: Wai Sang Wu, Florence Pik Sze Mok

Abstract:

Introduction: Ageing population is one of the hot topics nowadays in the world and this phenomenon is believed to exacerbate continuously in the future. According to the latest information from World Health Organization (WHO) in 2016, the proportion of people aged more than 60 years is projected to be doubled from 12% in 2015 to 22% in 2050 of the world's population. Similarly, according to figures released by the Census and Statistic Department of Hong Kong in 2015, the contribution of elderly aged more than 65 years olds is projected to increase from 15% in 2014 to 34% in 2064 in local community. On the other hand, falls in elderly is a common problem, and it can bring along many negative consequences among elders, such as reducing their mobility level as well as their quality of life. In addition, it can also increase the caring stress of their family caregivers and as well increase the reliance and burden on the medical care system of Hong Kong. Therefore, appropriate measures should be implemented in order to minimize the risk of fall among elders. The objective of this study is to evaluate the effectiveness of the chair-based exercise programme in affecting the balance of the elderly in Hong Kong. Methods: Thirteen healthy subjects (males = 2; females = 11; mean age: 76.2 ± 7.8 years old) were recruited from an elderly social centre in the community to participate in a structural chair-based exercise programme for 6 weeks (1 session per week; 60-minutes per session). Subjects were being assessed on their balance ability using three commonly used clinical assessments, namely, 1) single leg stance (SLS) test, 2) functional reach test, and 3) 360-degree turn test, before and after their participation in the chair-based exercise programme. Pre and post within-subject comparison was adopted to assess the effectiveness of the programme. Results: There was significant improvement (p < 0.05) in all balance parameters of the subjects after their participation in the exercise programme. Elderly demonstrated significant improvement in SLS (p < 0.012), functional reach (p < 0.030) and 360 degree turn (p < 0.043). Conclusions: This study showed that a community chair-based exercise programme is effective in improving the balance ability of the elders. It seems to be another exercise regime that should be promoted among the elders in order to minimize their risk of falls and its negative consequence.

Keywords: balance, chair-based exercise programme, community, elderly

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4999 Using Technology to Enhance the Student Assessment Experience

Authors: Asim Qayyum, David Smith

Abstract:

The use of information tools is a common activity for students of any educational stage when they encounter online learning activities. Finding the relevant information for particular learning tasks is the topic of this paper as it investigates the use of information tools for a group of student participants. The paper describes and discusses the results with particular implications for use in higher education, and the findings suggest that improvement in assessment design and subsequent student learning may be achieved by structuring the purposefulness of information tools usage and online reading behaviors of university students.

Keywords: information tools, assessment, online learning, student assessment experience

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4998 Numerical Study for Spatial Optimization of DVG for Fin and Tube Heat Exchangers

Authors: Amit Arora, P. M. V. Subbarao, R. S. Agarwal

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This study attempts to find promising locations of upwash delta winglets for an inline finned tube heat exchanger. Later, location of winglets that delivers highest improvement in thermal performance is identified. Numerical results clearly showed that optimally located upwash delta winglets not only improved the thermal performance of fin area in tube wake and tubes, but also improved overall thermal performance of heat exchanger.

Keywords: apparent friction factor, delta winglet, fin and tube heat exchanger, longitudinal vortices

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4997 Wideband Performance Analysis of C-FDTD Based Algorithms in the Discretization Impoverishment of a Curved Surface

Authors: Lucas L. L. Fortes, Sandro T. M. Gonçalves

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In this work, it is analyzed the wideband performance with the mesh discretization impoverishment of the Conformal Finite Difference Time-Domain (C-FDTD) approaches developed by Raj Mittra, Supriyo Dey and Wenhua Yu for the Finite Difference Time-Domain (FDTD) method. These approaches are a simple and efficient way to optimize the scattering simulation of curved surfaces for Dielectric and Perfect Electric Conducting (PEC) structures in the FDTD method, since curved surfaces require dense meshes to reduce the error introduced due to the surface staircasing. Defined, on this work, as D-FDTD-Diel and D-FDTD-PEC, these approaches are well-known in the literature, but the improvement upon their application is not quantified broadly regarding wide frequency bands and poorly discretized meshes. Both approaches bring improvement of the accuracy of the simulation without requiring dense meshes, also making it possible to explore poorly discretized meshes which bring a reduction in simulation time and the computational expense while retaining a desired accuracy. However, their applications present limitations regarding the mesh impoverishment and the frequency range desired. Therefore, the goal of this work is to explore the approaches regarding both the wideband and mesh impoverishment performance to bring a wider insight over these aspects in FDTD applications. The D-FDTD-Diel approach consists in modifying the electric field update in the cells intersected by the dielectric surface, taking into account the amount of dielectric material within the mesh cells edges. By taking into account the intersections, the D-FDTD-Diel provides accuracy improvement at the cost of computational preprocessing, which is a fair trade-off, since the update modification is quite simple. Likewise, the D-FDTD-PEC approach consists in modifying the magnetic field update, taking into account the PEC curved surface intersections within the mesh cells and, considering a PEC structure in vacuum, the air portion that fills the intersected cells when updating the magnetic fields values. Also likewise to D-FDTD-Diel, the D-FDTD-PEC provides a better accuracy at the cost of computational preprocessing, although with a drawback of having to meet stability criterion requirements. The algorithms are formulated and applied to a PEC and a dielectric spherical scattering surface with meshes presenting different levels of discretization, with Polytetrafluoroethylene (PTFE) as the dielectric, being a very common material in coaxial cables and connectors for radiofrequency (RF) and wideband application. The accuracy of the algorithms is quantified, showing the approaches wideband performance drop along with the mesh impoverishment. The benefits in computational efficiency, simulation time and accuracy are also shown and discussed, according to the frequency range desired, showing that poorly discretized mesh FDTD simulations can be exploited more efficiently, retaining the desired accuracy. The results obtained provided a broader insight over the limitations in the application of the C-FDTD approaches in poorly discretized and wide frequency band simulations for Dielectric and PEC curved surfaces, which are not clearly defined or detailed in the literature and are, therefore, a novelty. These approaches are also expected to be applied in the modeling of curved RF components for wideband and high-speed communication devices in future works.

Keywords: accuracy, computational efficiency, finite difference time-domain, mesh impoverishment

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4996 Characters of Developing Commercial Employment Sub-Centres and Employment Density in Ahmedabad City

Authors: Bhaumik Patel, Amit Gotecha

Abstract:

Commercial centres of different hierarchy and sizes play a vital role in the growth and development of the city. Economic uncertainty and demand for space leads to more urban sprawl and emerging more commercial spaces. The study was focused on the understanding of various indicators affecting the commercial development that can help to solve many issues related to commercial urban development and can guide for future employment growth centre development, Accessibility, Infrastructure, Planning and development regulations and Market forces. The aim of the study was to review characteristics and identifying employment density of Commercial Employment Sub-centres by achieving objectives Understanding various employment sub-centres, Identifying characteristics and deriving behaviour of employment densities and Evaluating and comparing employment sub-centres for the Ahmedabad city. Commercial employment sub-centres one in old city (Kalupur), second in highly developed commercial (C.G.road-Ashram road) and third in the latest developing commercial area (Prahladnagar) were identified by distance from city centre, Land use diversity, Access to Major roads and Public transport, Population density in proximity, Complimentary land uses in proximity and Land price. Commercial activities were categorised into retail, wholesale and service sector and sub categorised into various activities. From the study, Time period of establishment of the unit is a critical parameter for commercial activity, building height, and land-use diversity. Employment diversity is also one parameter for the commercial centre. The old city has retail, wholesale and trading and higher commercial density concerning units and employment both. Prahladnagar area functioned as commercial due to market pressure and developed as more units rather than a requirement. Employment density is higher in the centre of the city, as far as distance increases from city centre employment density and unit density decreases. Characters of influencing employment density and unit density are distance from city centre, development type, establishment time period, building density, unit density, public transport accessibility and road connectivity.

Keywords: commercial employment sub-centres, employment density, employment diversity, unit density

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4995 Adaptation Nature-Based Solutions: CBA of Woodlands for Flood Risk Management in the Aire Catchment, UK

Authors: Olivia R. Rendon

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More than half of the world population lives in cities, in the UK, for example, 82% of the population was urban by 2013. Cities concentrate valuable and numerous infrastructure and sectors of the national economies. Cities are particularly vulnerable to climate change which will lead to higher damage costs in the future. There is thus a need to develop and invest in adaptation measures for cities to reduce the impact of flooding and other extreme weather events. Recent flood episodes present a significant and growing challenge to the UK and the estimated cost of urban flood damage is 270 million a year for England and Wales. This study aims to carry out cost-benefit analysis (CBA) of a nature-based approach for flood risk management in cities, focusing on the city of Leeds and the wider Aire catchment as a case study. Leeds was chosen as a case study due to its being one of the most flood vulnerable cities in the UK. In Leeds, over 4,500 properties are currently vulnerable to flooding and approximately £450 million of direct damage is estimated for a potential major flood from the River Aire. Leeds is also the second largest Metropolitan District in England with a projected population of 770,000 for 2014. So far the city council has mainly focused its flood risk management efforts on hard infrastructure solutions for the city centre. However, the wider Leeds district is at significant flood risk which could benefit from greener adaptation measures. This study presents estimates of a nature-based adaptation approach for flood risk management in Leeds. This land use management estimate is based on generating costings utilising primary and secondary data. This research contributes findings on the costs of different adaptation measures to flood risk management in a UK city, including the trade-offs and challenges of utilising nature-based solutions. Results also explore the potential implementation of the adaptation measures in the case study and the challenges of data collection and analysis for adaptation in flood risk management.

Keywords: green infrastructure, ecosystem services, woodland, adaptation, flood risk

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4994 Examining the Changes in Complexity, Accuracy, and Fluency in Japanese L2 Writing Over an Academic Semester

Authors: Robert Long

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The results of a one-year study on the evolution of complexity, accuracy, and fluency (CAF) in the compositions of Japanese L2 university students throughout a semester are presented in this study. One goal was to determine if any improvement in writing abilities over this academic term had occurred, while another was to examine methods of editing. Participants had 30 minutes to write each essay with an additional 10 minutes allotted for editing. As for editing, participants were divided into two groups, one of which utilized an online grammar checker, while the other half self-edited their initial manuscripts. From the three different institutions, there was a total of 159 students. Research questions focused on determining if the CAF had evolved over the previous year, identifying potential variations in editing techniques, and describing the connections between the CAF dimensions. According to the findings, there was some improvement in accuracy (fewer errors) in all three of the measures), whereas there was a marked decline in complexity and fluency. As for the second research aim relating to the interaction among the three dimensions (CAF) and of possible increases in fluency being offset by decreases in grammatical accuracy, results showed (there is a logical high correlation with clauses and word counts, and mean length of T-unit (MLT) and (coordinate phrase of T-unit (CP/T) as well as MLT and clause per T-unit (C/T); furthermore, word counts and error/100 ratio correlated highly with error-free clause totals (EFCT). Issues of syntactical complexity had a negative correlation with EFCT, indicating that more syntactical complexity relates to decreased accuracy. Concerning a difference in error correction between those who self-edited and those who used an online grammar correction tool, results indicated that the variable of errors-free clause ratios (EFCR) had the greatest difference regarding accuracy, with fewer errors noted with writers using an online grammar checker. As for possible differences between the first and second (edited) drafts regarding CAF, results indicated there were positive changes in accuracy, the most significant change seen in complexity (CP/T and MLT), while there were relatively insignificant changes in fluency. Results also indicated significant differences among the three institutions, with Fujian University of Technology having the most fluency and accuracy. These findings suggest that to raise students' awareness of their overall writing development, teachers should support them in developing more complex syntactic structures, improving their fluency, and making more effective use of online grammar checkers.

Keywords: complexity, accuracy, fluency, writing

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4993 Pinch Analysis of Triple Pressure Reheat Supercritical Combined Cycle Power Plant

Authors: Sui Yan Wong, Keat Ping Yeoh, Chi Wai Hui

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In this study, supercritical steam is introduced to Combined Cycle Power Plant (CCPP) in an attempt to further optimize energy recovery. Subcritical steam is commonly used in the CCPP, operating at maximum pressures around 150-160 bar. Supercritical steam is an alternative to increase heat recovery during vaporization period of water. The idea of improvement using supercritical steam is further examined with the use of exergy, pinch analysis and Aspen Plus simulation.

Keywords: exergy, pinch, combined cycle power plant, supercritical steam

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4992 AI-based Digital Healthcare Application to Assess and Reduce Fall Risks in Residents of Nursing Homes in Germany

Authors: Knol Hester, Müller Swantje, Danchenko Natalya

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Objective: Falls in older people cause an autonomy loss and result in an economic burden. LCare is an AI-based application to manage fall risks. The study's aim was to assess the effect of LCare use on patient outcomes in nursing homes in Germany. Methods: LCare identifies and monitors fall risks through a 3D-gait analysis and a digital questionnaire, resulting in tailored recommendations on fall prevention. A study was conducted with AOK Baden-Württemberg (01.09.2019- 31.05.2021) in 16 care facilities. Assessments at baseline and follow-up included: a fall risk score; falls (baseline: fall history in the past 12 months; follow-up: a fall record since the last analysis); fall-related injuries and hospitalizations; gait speed; fear of falling; psychological stress; nurses experience on app use. Results: 94 seniors were aged 65-99 years at the initial analysis (average 84±7 years); 566 mobility analyses were carried out in total. On average, the fall risk was reduced by 17.8 % as compared to the baseline (p<0.05). The risk of falling decreased across all subgroups, including a trend in dementia patients (p=0.06), constituting 43% of analyzed patients, and patients with walking aids (p<0.05), constituting 76% of analyzed patients. There was a trend (p<0.1) towards fewer falls and fall-related injuries and hospitalizations (baseline: 23 seniors who fell, 13 injury consequences, 9 hospitalizations; follow-up: 14 seniors who fell, 2 injury consequences, 0 hospitalizations). There was a 16% improvement in gait speed (p<0.05). Residents reported less fear of falling and psychological stress by 38% in both outcomes (p<0.05). 81% of nurses found LCare effective. Conclusions: In the presented study, the use of LCare app was associated with a reduction of fall risk among nursing home residents, improvement of health-related outcomes, and a trend toward reduction in injuries and hospitalizations. LCare may help to improve senior resident care and save healthcare costs.

Keywords: falls, digital healthcare, falls prevention, nursing homes, seniors, AI, digital assessment

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4991 The Spatial Pattern of Economic Rents of an Airport Development Area: Lessons Learned from the Suvarnabhumi International Airport, Thailand

Authors: C. Bejrananda, Y. Lee, T. Khamkaew

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With the rise of the importance of air transportation in the 21st century, the role of economics in airport planning and decision-making has become more important to the urban structure and land value around it. Therefore, this research aims to examine the relationship between an airport and its impacts on the distribution of urban land uses and land values by applying the Alonso’s bid rent model. The New Bangkok International Airport (Suvarnabhumi International Airport) was taken as a case study. The analysis was made over three different time periods of airport development (after the airport site was proposed, during airport construction, and after the opening of the airport). The statistical results confirm that Alonso’s model can be used to explain the impacts of the new airport only for the northeast quadrant of the airport, while proximity to the airport showed the inverse relationship with the land value of all six types of land use activities through three periods of time. It indicates that the land value for commercial land use is the most sensitive to the location of the airport or has the strongest requirement for accessibility to the airport compared to the residential and manufacturing land use. Also, the bid-rent gradients of the six types of land use activities have declined dramatically through the three time periods because of the Asian Financial Crisis in 1997. Therefore, the lesson learned from this research concerns about the reliability of the data used. The major concern involves the use of different areal units for assessing land value for different time periods between zone block (1995) and grid block (2002, 2009). As a result, this affect the investigation of the overall trends of land value assessment, which are not readily apparent. In addition, the next concern is the availability of the historical data. With the lack of collecting historical data for land value assessment by the government, some of data of land values and aerial photos are not available to cover the entire study area. Finally, the different formats of using aerial photos between hard-copy (1995) and digital photo (2002, 2009) made difficult for measuring distances. Therefore, these problems also affect the accuracy of the results of the statistical analyses.

Keywords: airport development area, economic rents, spatial pattern, suvarnabhumi international airport

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4990 Magnetoelastically Induced Perpendicular Magnetic Anisotropy and Perpendicular Exchange Bias of CoO/CoPt Multilayer Films

Authors: Guo Lei, Wang Yue, Nakamura Yoshio, Shi Ji

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Recently, perpendicular exchange bias (PEB) is introduced as an active topic attracting continuous efforts. Since its discovery, extrinsic control of PEB has been proposed, due to its scientific significance in spintronic devices and potential application in high density magnetic random access memory with perpendicular magnetic tunneling junction (p-MTJ). To our knowledge, the researches aiming to controlling PEB so far are focused mainly on enhancing the interfacial exchange coupling by adjusting the FM/AFM interface roughness, or optimizing the crystalline structures of FM or AFM layer by employing different seed layers. In present work, the effects of magnetoelastically induced PMA on PEB have been explored in [CoO5nm/CoPt5nm]5 multilayer films. We find the PMA strength of FM layer also plays an important role on PEB at the FM/AFM interface and it is effective to control PEB of [CoO5nm/CoPt5nm]5 multilayer films by changing the magnetoelastically induced PMA of CoPt layer. [CoO5nm/CoPt5nm]5 multilayer films were deposited by magnetron sputtering on fused quartz substrate at room temperature, then annealed at 100°C, 250°C, 300°C and 375°C for 3h, respectively. XRD results reveal that all the samples are well crystallized with preferred fcc CoPt (111) orientation. The continuous multilayer structure with sharp component transition at the CoO5nm/CoPt5nm interface are identified clearly by transmission electron microscopy (TEM), x-ray reflectivity (XRR) and atomic force microscope (AFM). CoPt layer in-plane tensile stress is calculated by sin2φ method, and we find it increases gradually upon annealing from 0.99 GPa (as-deposited) up to 3.02 GPa (300oC-annealed). As to the magnetic property, significant enhancement of PMA is achieved in [CoO5nm/CoPt5nm]5 multilayer films after annealing due to the increase of CoPt layer in-plane tensile stress. With the enhancement of magnetoelastically induced PMA, great improvement of PEB is also achieved in [CoO5nm/CoPt5nm]5 multilayer films, which increases from 130 Oe (as-deposited) up to 1060 Oe (300oC-annealed), showing the same change tendency as PMA and the strong correlation with CoPt layer in-plane tensile stress. We consider it is the increase of CoPt layer in-plane tensile stress that leads to the enhancement of PMA, and thus the enhancement of magnetoelastically induced PMA results in the improvement of PEB in [CoO5nm/CoPt5nm]5 multilayer films.

Keywords: perpendicular exchange bias, magnetoelastically induced perpendicular magnetic anisotropy, CoO5nm/CoPt5nm]5 multilayer film with in-plane stress, perpendicular magnetic tunneling junction

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4989 Recommendations for Environmental Impact Assessment of Geothermal Projects on Mature Oil Fields

Authors: Daria Karasalihovic Sedlar, Lucija Jukic, Ivan Smajla, Marija Macenic

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This paper analyses possible geothermal energy production from a mature oil reservoir based on exploitation of underlying aquifer thermal energy for the purpose of heating public buildings. Research was conducted based on the case study of the City of Ivanic-Grad public buildings energy demand and Ivanic oil filed that is situated in the same area. Since the City of Ivanic is one of the few cities in the EU where hydrocarbon exploitation has been taking place for decades almost entirely in urban area, decommissioning of oil wells is inevitable; therefore, the research goal was to investigate how to extend the life-time of the reservoir by exploiting geothermal brine beneath the oil reservoir in an environmental friendly manner. This kind of a project is extremely complex in all segments, from documentation preparation, implementation of technological solutions, and providing ecological measures for environmentally acceptable geothermal energy production and utilization. New mining activities that will be needed for the development of geothermal project at the observed Hydrocarbon Exploitation Field Ivanic will be carried out in order to prepare wells for increasing geothermal brine production. These operations involve the conversion of existing wells (well completion for conversion of the observation wells to production ones) along with workover activities, installation of new heat exchangers, and pipelines. Since the wells are in the urban area of the City of Ivanic-Grad in high density populated area, the inhabitants will be exposed to the different environmental impacts during preparation phase of the project. For the purpose of performing workovers, it will be necessary to secure access to wellheads of existing wells. This paper gives guidelines for describing potential impacts on environment components that could occur during geothermal production preparation on existing mature oil filed, recommends possible protection measures to mitigate these impacts, and gives recommendations for environmental monitoring.

Keywords: geothermal energy production, mature oil filed, environmental impact assessment, underlying aquifer thermal energy

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4988 Epileptic Seizure Prediction by Exploiting Signal Transitions Phenomena

Authors: Mohammad Zavid Parvez, Manoranjan Paul

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A seizure prediction method is proposed by extracting global features using phase correlation between adjacent epochs for detecting relative changes and local features using fluctuation/deviation within an epoch for determining fine changes of different EEG signals. A classifier and a regularization technique are applied for the reduction of false alarms and improvement of the overall prediction accuracy. The experiments show that the proposed method outperforms the state-of-the-art methods and provides high prediction accuracy (i.e., 97.70%) with low false alarm using EEG signals in different brain locations from a benchmark data set.

Keywords: Epilepsy, seizure, phase correlation, fluctuation, deviation.

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4987 Simulating the Surface Runoff for the Urbanized Watershed of Mula-Mutha River from Western Maharashtra, India

Authors: Anargha A. Dhorde, Deshpande Gauri, Amit G. Dhorde

Abstract:

Mula-Mutha basin is one of the speedily urbanizing watersheds, wherein two major urban centers, Pune and Pimpri-Chinchwad, have developed at a shocking rate in the last two decades. Such changing land use/land cover (LULC) is prone to hydrological problems and flash floods are a frequent, eventuality in the lower reaches of the basin. The present research brings out the impact of varying LULC, impervious surfaces on urban surface hydrology and generates storm-runoff scenarios for the hydrological units. The two multi-temporal satellite images were processed and supervised classification is performed with > 75% accuracy. The built-up has increased from 14.4% to 34.37% in the 28 years span, which is concentrated in and around the Pune-PCMC region. Impervious surfaces that were obtained by population calibrated multiple regression models. Almost 50% area of the watershed is impervious, which attribute to increase surface runoff and flash floods. The SCS-CN method was employed to calculate surface runoff of the watershed. The comparison between calculated and measured values of runoff was performed in a statistically precise way which shows no significant difference. Increasing built-up areas, as well as impervious surface areas due to rapid urbanization and industrialization, may lead to generating high runoff volumes in the basin especially in the urbanized areas of the watershed and along the major transportation arteries. Simulations generated with 50 mm and 100 mm rainstorm depth conspicuously noted that most of the changes in terms of increased runoff are constricted to the highly urbanized areas. Considering whole watershed area, the runoff values 39 m³ generated with 1'' rainfall whereas only urbanized areas of the basin (Pune and Pimpari-Chinchwad) were generated 11154 m³ runoff. Such analysis is crucial in providing information regarding their intensity and location, which proves instrumental in their analysis in order to formulate proper mitigation measures and rehabilitation strategies.

Keywords: land use/land cover, LULC, impervious surfaces, surface hydrology, storm-runoff scenarios

Procedia PDF Downloads 218
4986 Improving the Design of Blood Pressure and Blood Saturation Monitors

Authors: L. Parisi

Abstract:

A blood pressure monitor or sphygmomanometer can be either manual or automatic, employing respectively either the auscultatory method or the oscillometric method. The manual version of the sphygmomanometer involves an inflatable cuff with a stethoscope adopted to detect the sounds generated by the arterial walls to measure blood pressure in an artery. An automatic sphygmomanometer can be effectively used to monitor blood pressure through a pressure sensor, which detects vibrations provoked by oscillations of the arterial walls. The pressure sensor implemented in this device improves the accuracy of the measurements taken.

Keywords: blood pressure, blood saturation, sensors, actuators, design improvement

Procedia PDF Downloads 456
4985 Creating Smart and Healthy Cities by Exploring the Potentials of Emerging Technologies and Social Innovation for Urban Efficiency: Lessons from the Innovative City of Boston

Authors: Mohammed Agbali, Claudia Trillo, Yusuf Arayici, Terrence Fernando

Abstract:

The wide-spread adoption of the Smart City concept has introduced a new era of computing paradigm with opportunities for city administrators and stakeholders in various sectors to re-think the concept of urbanization and development of healthy cities. With the world population rapidly becoming urban-centric especially amongst the emerging economies, social innovation will assist greatly in deploying emerging technologies to address the development challenges in core sectors of the future cities. In this context, sustainable health-care delivery and improved quality of life of the people is considered at the heart of the healthy city agenda. This paper examines the Boston innovation landscape from the perspective of smart services and innovation ecosystem for sustainable development, especially in transportation and healthcare. It investigates the policy implementation process of the Healthy City agenda and eHealth economy innovation based on the experience of Massachusetts’s City of Boston initiatives. For this purpose, three emerging areas are emphasized, namely the eHealth concept, the innovation hubs, and the emerging technologies that drive innovation. This was carried out through empirical analysis on results of public sector and industry-wide interviews/survey about Boston’s current initiatives and the enabling environment. The paper highlights few potential research directions for service integration and social innovation for deploying emerging technologies in the healthy city agenda. The study therefore suggests the need to prioritize social innovation as an overarching strategy to build sustainable Smart Cities in order to avoid technology lock-in. Finally, it concludes that the Boston example of innovation economy is unique in view of the existing platforms for innovation and proper understanding of its dynamics, which is imperative in building smart and healthy cities where quality of life of the citizenry can be improved.

Keywords: computing paradigm, emerging technologies, equitable healthcare, healthy cities, open data, smart city, social innovation

Procedia PDF Downloads 336
4984 A Study on Neighborhood of Dwelling with Historical-Islamic Architectural Elements

Authors: M.J. Seddighi, Moradchelleh, M. Keyvan

Abstract:

The ultimate goal in building a city is to provide pleasant, comfortable and nurturing environment as a context of public life. City environment establishes strong connection with people and their surrounding habitant, acting as relevance in social interactions between citizens itself. Urban environment and appropriate municipal facilities are the only way for proper communication between city and citizens and also citizens themselves.There is a need for complement elements between buildings and constructions to settling city life through which the move, comfort, reactions and anxiety will adjust and reflect the spirit to the city. In the surging development of society, urban’ spaces are encountered evolution, sometimes causing the symbols to fade and waste, and as a result, leading to destroy belongs among humans and their physical liquidate. Houses and living spaces exhibit materialistic reflection of life style. In the other words, way of life makes the symbolic essence of living spaces. In addition, it is of sociocultural factor of lifestyle, consisting the concepts and culture, morality, worldview, and national character. Culture is responsible for some crucial meaningful needs which can be wide because they depend on various causes such as perception and interpretation of believes, philosophy of life, interaction with neighbors and protection against climate and enemies. The bi-lateral relationship between human and nature is the main factor that needs to be properly addressed. It is because of the fact that the approach which is taken against landscape and nature has a pertinent influence on creation and shaping the structure of a house. The first response of human in tackling the environment is to build a “shelter” and place as dwelling. This has been a crucial factor in all time periods. In the proposed study, dwelling in Khorasgan’ Stream, as an area located in one of the important historical city of Iran, has been studied. Khorasgan’ Stream is the basic constituent elements of the present architectural form of Isfahan. The influence of Islamic spiritual culture and neighborhood with the historical elements on the dwelling of the selected location, subsequently on other regions of the town are presented.

Keywords: dwelling, neighborhood, historical, Islamic, architectural elements

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4983 Designing Self-Healing Lubricant-Impregnated Surfaces for Corrosion Protection

Authors: Sami Khan, Kripa Varanasi

Abstract:

Corrosion is a widespread problem in several industries and developing surfaces that resist corrosion has been an area of interest since the last several decades. Superhydrophobic surfaces that combine hydrophobic coatings along with surface texture have been shown to improve corrosion resistance by creating voids filled with air that minimize the contact area between the corrosive liquid and the solid surface. However, these air voids can incorporate corrosive liquids over time, and any mechanical faults such as cracks can compromise the coating and provide pathways for corrosion. As such, there is a need for self-healing corrosion-resistance surfaces. In this work, the anti-corrosion properties of textured surfaces impregnated with a lubricant have been systematically studied. Since corrosion resistance depends on the area and physico-chemical properties of the material exposed to the corrosive medium, lubricant-impregnated surfaces (LIS) have been designed based on the surface tension, viscosity and chemistry of the lubricant and its spreading coefficient on the solid. All corrosion experiments were performed in a standard three-electrode cell using iron, which readily corrodes in a 3.5% sodium chloride solution. In order to obtain textured iron surfaces, thin films (~500 nm) of iron were sputter-coated on silicon wafers textured using photolithography, and subsequently impregnated with lubricants. Results show that the corrosion rate on LIS is greatly reduced, and offers an over hundred-fold improvement in corrosion protection. Furthermore, it is found that the spreading characteristics of the lubricant are significant in ensuring corrosion protection: a spreading lubricant (e.g., Krytox 1506) that covers both inside the texture, as well as the top of the texture, provides a two-fold improvement in corrosion protection as compared to a non-spreading lubricant (e.g., Silicone oil) that does not cover texture tops. To enhance corrosion protection of surfaces coated with a non-spreading lubricant, pyramid-shaped textures have been developed that minimize exposure to the corrosive solution, and a consequent twenty-fold increased in corrosion protection is observed. An increase in viscosity of the lubricant scales with greater corrosion protection. Finally, an equivalent cell-circuit model is developed for the lubricant-impregnated systems using electrochemical impedance spectroscopy. Lubricant-impregnated surfaces find attractive applications in harsh corrosive environments, especially where the ability to self-heal is advantageous.

Keywords: lubricant-impregnated surfaces, self-healing surfaces, wettability, nano-engineered surfaces

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4982 A Secure Digital Signature Scheme with Fault Tolerance Based on the Improved RSA System

Authors: H. El-Kamchouchi, Heba Gaber, Fatma Ahmed, Dalia H. El-Kamchouchi

Abstract:

Fault tolerance and data security are two important issues in modern communication systems. In this paper, we propose a secure and efficient digital signature scheme with fault tolerance based on the improved RSA system. The proposed scheme for the RSA cryptosystem contains three prime numbers and overcome several attacks possible on RSA. By using the Chinese Reminder Theorem (CRT) the proposed scheme has a speed improvement on the RSA decryption side and it provides high security also.

Keywords: digital signature, fault tolerance, RSA, security analysis

Procedia PDF Downloads 476
4981 Influence of Nanomaterials on the Properties of Shape Memory Polymeric Materials

Authors: Katielly Vianna Polkowski, Rodrigo Denizarte de Oliveira Polkowski, Cristiano Grings Herbert

Abstract:

The use of nanomaterials in the formulation of polymeric materials modifies their molecular structure, offering an infinite range of possibilities for the development of smart products, being of great importance for science and contemporary industry. Shape memory polymers are generally lightweight, have high shape recovery capabilities, they are easy to process and have properties that can be adapted for a variety of applications. Shape memory materials are active materials that have attracted attention due to their superior damping properties when compared to conventional structural materials. The development of methodologies capable of preparing new materials, which use graphene in their structure, represents technological innovation that transforms low-cost products into advanced materials with high added value. To obtain an improvement in the shape memory effect (SME) of polymeric materials, it is possible to use graphene in its composition containing low concentration by mass of graphene nanoplatelets (GNP), graphene oxide (GO) or other functionalized graphene, via different mixture process. As a result, there was an improvement in the SME, regarding the increase in the values of maximum strain. In addition, the use of graphene contributes to obtaining nanocomposites with superior electrical properties, greater crystallinity, as well as resistance to material degradation. The methodology used in the research is Systematic Review, scientific investigation, gathering relevant studies on influence of nanomaterials on the properties of shape memory polymeric, using the literature database as a source and study methods. In the present study, a systematic reviewwas performed of all papers published from 2014 to 2022 regarding graphene and shape memory polymeric througha search of three databases. This study allows for easy identification of themost relevant fields of study with respect to graphene and shape memory polymeric, as well as the main gaps to beexplored in the literature. The addition of graphene showed improvements in obtaining higher values of maximum deformation of the material, attributed to a possible slip between stacked or agglomerated nanostructures, as well as an increase in stiffness due to the increase in the degree of phase separation that results in a greater amount physical cross-links, referring to the formation of shortrange rigid domains.

Keywords: graphene, shape memory, smart materials, polymers, nanomaterials

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4980 Genetic Improvement Potential for Wood Production in Melaleuca cajuputi

Authors: Hong Nguyen Thi Hai, Ryota Konda, Dat Kieu Tuan, Cao Tran Thanh, Khang Phung Van, Hau Tran Tin, Harry Wu

Abstract:

Melaleuca cajuputi is a moderately fast-growing species and considered as a multi-purpose tree as it provides fuelwood, piles and frame poles in construction, leaf essential oil and honey. It occurs in Australia, Papua New Guinea, and South-East Asia. M. cajuputi plantation can be harvested on 6-7 year rotations for wood products. Its timber can also be used for pulp and paper, fiber and particle board, producing quality charcoal and potentially sawn timber. However, most reported M. cajuputi breeding programs have been focused on oil production rather than wood production. In this study, breeding program of M. cajuputi aimed to improve wood production was examined by estimating genetic parameters for growth (tree height, diameter at breast height (DBH), and volume), stem form, stiffness (modulus of elasticity (MOE)), bark thickness and bark ratio in a half-sib family progeny trial including 80 families in the Mekong Delta of Vietnam. MOE is one of the key wood properties of interest to the wood industry. Non-destructive wood stiffness was measured indirectly by acoustic velocity using FAKOPP Microsecond Timer and especially unaffected by bark mass. Narrow-sense heritability for the seven traits ranged from 0.13 to 0.27 at age 7 years. MOE and stem form had positive genetic correlations with growth while the negative correlation between bark ratio and growth was also favorable. Breeding for simultaneous improvement of multiple traits, faster growth with higher MOE and reduction of bark ratio should be possible in M. cajuputi. Index selection based on volume and MOE showed genetic gains of 31 % in volume, 6 % in MOE and 13 % in stem form. In addition, heritability and age-age genetic correlations for growth traits increased with time and optimal early selection age for growth of M. cajuputi based on DBH alone was 4 years. Selected thinning resulted in an increase of heritability due to considerable reduction of phenotypic variation but little effect on genetic variation.

Keywords: acoustic velocity, age-age correlation, bark thickness, heritability, Melaleuca cajuputi, stiffness, thinning effect

Procedia PDF Downloads 182
4979 The Use of Remotely Sensed Data to Model Habitat Selections of Pileated Woodpeckers (Dryocopus pileatus) in Fragmented Landscapes

Authors: Ruijia Hu, Susanna T.Y. Tong

Abstract:

Light detection and ranging (LiDAR) and four-channel red, green, blue, and near-infrared (RGBI) remote sensed imageries allow an accurate quantification and contiguous measurement of vegetation characteristics and forest structures. This information facilitates the generation of habitat structure variables for forest species distribution modelling. However, applications of remote sensing data, especially the combination of structural and spectral information, to support evidence-based decisions in forest managements and conservation practices at local scale are not widely adopted. In this study, we examined the habitat requirements of pileated woodpecker (Dryocopus pileatus) (PW) in Hamilton County, Ohio, using ecologically relevant forest structural and vegetation characteristics derived from LiDAR and RGBI data. We hypothesized that the habitat of PW is shaped by vegetation characteristics that are directly associated with the availability of food, hiding and nesting resources, the spatial arrangement of habitat patches within home range, as well as proximity to water sources. We used 186 PW presence or absence locations to model their presence and absence in generalized additive model (GAM) at two scales, representing foraging and home range size, respectively. The results confirm PW’s preference for tall and large mature stands with structural complexity, typical of late-successional or old-growth forests. Besides, the crown size of dead trees shows a positive relationship with PW occurrence, therefore indicating the importance of declining living trees or early-stage dead trees within PW home range. These locations are preferred by PW for nest cavity excavation as it attempts to balance the ease of excavation and tree security. In addition, we found that PW can adjust its travel distance to the nearest water resource, suggesting that habitat fragmentation can have certain impacts on PW. Based on our findings, we recommend that forest managers should use different priorities to manage nesting, roosting, and feeding habitats. Particularly, when devising forest management and hazard tree removal plans, one needs to consider retaining enough cavity trees within high-quality PW habitat. By mapping PW habitat suitability for the study area, we highlight the importance of riparian corridor in facilitating PW to adjust to the fragmented urban landscape. Indeed, habitat improvement for PW in the study area could be achieved by conserving riparian corridors and promoting riparian forest succession along major rivers in Hamilton County.

Keywords: deadwood detection, generalized additive model, individual tree crown delineation, LiDAR, pileated woodpecker, RGBI aerial imagery, species distribution models

Procedia PDF Downloads 53
4978 Improved Wi-Fi Backscatter System for Multi-to-Multi Communication

Authors: Chang-Bin Ha, Yong-Jun Kim, Dong-Hyun Ha, Hyoung-Kyu Song

Abstract:

The conventional Wi-Fi back scatter system can only process one-to-one communication between the Wi-Fi reader and the Wi-Fi tag. For improvement of throughput of the conventional system, this paper proposes the multi-to-multi communication system. In the proposed system, the interference by the multi-to-multi communication is effectively cancelled by the orthogonal multiple access based on the identification code of the tag. Although the overhead is generated by the procedure for the multi-to-multi communication, because the procedure is processed by the Wi-Fi protocol, the overhead is insignificant for the entire communication procedure. From the numerical results, it is confirmed that the proposed system has nearly proportional increased throughput in according to the number of the tag that simultaneously participates in communication.

Keywords: backscatter, multi-to-multi communication, orthogonality, Wi-Fi

Procedia PDF Downloads 510
4977 Identifying the Challenges and Opportunities of Using Lesson Study in English Language Teaching Through the Lenses of In-Service Ecuadorian EFL Teachers

Authors: Cherres Sara, Cajas Diego

Abstract:

This paper explores how EFL teachers understand the process of Lesson Study in Ecuadorian schools and the challenges and opportunities that it brings to the improvement of their teaching practice. Using a narrative research methodology, this study presents the results of the application of the four steps of Lesson Study carried out by seven teachers in four different schools located in the Southern part of Ecuador during four months. Before starting the implementation of the lesson study, 30 teachers were trained on this model. This training was opened to EFL teachers working in public and private schools without any charge. The criteria to select these teachers were first, to be minimum a one-year in-service teacher, second, to have a b2 level of English, and third, to be able to commit to follow the course guidelines. After the course, seven teachers decided to continue with the implementation of the Lesson Study in their respective institutions. During the implementation of the Lesson Study, data was collected through observations, in-depth interviews and teachers’ planning meetings; and analyzed using a thematic analysis. The results of this study are presented using the lenses of seven EFL teachers that explained the challenges and opportunities that the implementation of Lesson Study conveyed. The challenges identified were the limited capacity of reflection and recognition of the activities that required improvement after the class, limited capacity to provide truthful peer feedback, teachers wrong notions about their performance in their classes, difficulties to follow a collaborative lesson plan; and, the disconnection between class activities and the class content. The opportunities identified were teachers’ predisposition to collaborate, teachers’ disposition to attend professional development courses, their commitment to work extra hours in planning meetings, their openness and their desired to be observed in their classes; and, their willingness to share class materials and knowledge. On the other hand, the results show that there is a disconnection between teachers’ knowledge of ELT and its proper application in class (from theory to practice). There are also, rigid institutional conceptions of teaching that do not allow teaching innovations. The authors concluded that there is a disconnection between teachers’ knowledge of ELT and its proper application in class (from theory to practice). There are also, rigid institutional conceptions of teaching that do not allow teaching innovations for example: excessive institutional paperwork and activities that are not connected to the development of students’ competences.

Keywords: ELT, lesson study, teachers’ professional development, teachers’ collaboration

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4976 Optimal Number and Placement of Vertical Links in 3D Network-On-Chip

Authors: Nesrine Toubaline, Djamel Bennouar, Ali Mahdoum

Abstract:

3D technology can lead to a significant reduction in power and average hop-count in Networks on Chip (NoCs). It offers short and fast vertical links which copes with the long wire problem in 2D NoCs. This work proposes heuristic-based method to optimize number and placement of vertical links to achieve specified performance goals. Experiments show that significant improvement can be achieved by using a specific number of vertical interconnect.

Keywords: interconnect optimization, monolithic inter-tier vias, network on chip, system on chip, through silicon vias, three dimensional integration circuits

Procedia PDF Downloads 303
4975 Energy Efficient Refrigerator

Authors: Jagannath Koravadi, Archith Gupta

Abstract:

In a world with constantly growing energy prices, and growing concerns about the global climate changes caused by increased energy consumption, it is becoming more and more essential to save energy wherever possible. Refrigeration systems are one of the major and bulk energy consuming systems now-a-days in industrial sectors, residential sectors and household environment. Refrigeration systems with considerable cooling requirements consume a large amount of electricity and thereby contribute greatly to the running costs. Therefore, a great deal of attention is being paid towards improvement of the performance of the refrigeration systems in this regard throughout the world. The Coefficient of Performance (COP) of a refrigeration system is used for determining the system's overall efficiency. The operating cost to the consumer and the overall environmental impact of a refrigeration system in turn depends on the COP or efficiency of the system. The COP of a refrigeration system should therefore be as high as possible. Slight modifications in the technical elements of the modern refrigeration systems have the potential to reduce the energy consumption, and improvements in simple operational practices with minimal expenses can have beneficial impact on COP of the system. Thus, the challenge is to determine the changes that can be made in a refrigeration system in order to improve its performance, reduce operating costs and power requirement, improve environmental outcomes, and achieve a higher COP. The opportunity here, and a better solution to this challenge, will be to incorporate modifications in conventional refrigeration systems for saving energy. Energy efficiency, in addition to improvement of COP, can deliver a range of savings such as reduced operation and maintenance costs, improved system reliability, improved safety, increased productivity, better matching of refrigeration load and equipment capacity, reduced resource consumption and greenhouse gas emissions, better working environment, and reduced energy costs. The present work aims at fabricating a working model of a refrigerator that will provide for effective heat recovery from superheated refrigerant with the help of an efficient de-superheater. The temperature of the refrigerant and water in the de-super heater at different intervals of time are measured to determine the quantity of waste heat recovered. It is found that the COP of the system improves by about 6% with the de-superheater and the power input to the compressor decreases by 4 % and also the refrigeration capacity increases by 4%.

Keywords: coefficiency of performance, de-superheater, refrigerant, refrigeration capacity, heat recovery

Procedia PDF Downloads 320