Search results for: Extreme values theory
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3963

Search results for: Extreme values theory

2163 Knowledge Sharing Behaviour among Academic Staff at a Public Higher Education Institution in Malaysia

Authors: Noor Asilah Nordin, Normala Daud, Wan Ummi Kalsom Meor Osman

Abstract:

This study applied Theory of Planned Behaviour (TPB) to explain the knowledge sharing behaviour among academic staff at a Public Higher Education Institution (HEI) in Malaysia. The main objectives of this study are; to identify the components that influence knowledge sharing behaviour and to determine the levels of knowledge sharing behaviour among academic staff. A total of 200 respondents were participated in answering questionnaires. The findings of this study revealed that level of perceiving and implementing knowledge sharing behaviour among academic staff at a Public HEI in Malaysia exist but not openly or strongly practiced. The findings were discussed and recommendations for the future research were also addressed.

Keywords: Attitude, Knowledge Sharing Behaviour, Perceived Behavioural Control, Subjective Norm.

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2162 An Approach to Control Design for Nonlinear Systems via Two-stage Formal Linearization and Two-type LQ Controls

Authors: Kazuo Komatsu, Hitoshi Takata

Abstract:

In this paper we consider a nonlinear control design for nonlinear systems by using two-stage formal linearization and twotype LQ controls. The ordinary LQ control is designed on almost linear region around the steady state point. On the other region, another control is derived as follows. This derivation is based on coordinate transformation twice with respect to linearization functions which are defined by polynomials. The linearized systems can be made up by using Taylor expansion considered up to the higher order. To the resulting formal linear system, the LQ control theory is applied to obtain another LQ control. Finally these two-type LQ controls are smoothly united to form a single nonlinear control. Numerical experiments indicate that this control show remarkable performances for a nonlinear system.

Keywords: Formal Linearization, LQ Control, Nonlinear Control, Taylor Expansion, Zero Function.

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2161 Temperature Field Study of Brake Disc in a Belt Conveyor Brake

Authors: Hou Youfu, Wang Daoming, Meng Qingrui

Abstract:

To reveal the temperature field distribution of disc brake in downward belt conveyor, mathematical models of heat transfer for disc brake were established combined with heat transfer theory. Then, the simulation process was stated in detail and the temperature field of disc brake under conditions of dynamic speed and dynamic braking torque was numerically simulated by using ANSYS software. Finally the distribution and variation laws of temperature field in the braking process were analyzed. Results indicate that the maximum surface temperature occurs at a time before the brake end and there exist large temperature gradients in both radial and axial directions, while it is relatively small in the circumferential direction.

Keywords: Downward belt conveyor, Disc brake, Temperature field, Numerical simulation.

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2160 Optimization of Hydraulic Fluid Parameters in Automotive Torque Converters

Authors: S. Venkateswaran, C. Mallika Parveen

Abstract:

The fluid flow and the properties of the hydraulic fluid inside a torque converter are the main topics of interest in this research. The primary goal is to investigate the applicability of various viscous fluids inside the torque converter. The Taguchi optimization method is adopted to analyse the fluid flow in a torque converter from a design perspective. Calculations are conducted in maximizing the pressure since greater the pressure, greater the torque developed. Using the values of the S/N ratios obtained, graphs are plotted. Computational Fluid Dynamics (CFD) analysis is also conducted.

Keywords: Hydraulic fluid, Taguchi's method, optimization, pressure, torque.

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2159 Surface Topography Measurement by Confocal Spectral Interferometry

Authors: A. Manallah, C. Meier

Abstract:

Confocal spectral interferometry (CSI) is an innovative optical method for determining microtopography of surfaces and thickness of transparent layers, based on the combination of two optical principles: confocal imaging, and spectral interferometry. Confocal optical system images at each instant a single point of the sample. The whole surface is reconstructed by plan scanning. The interference signal generated by mixing two white-light beams is analyzed using a spectrometer. In this work, five ‘rugotests’ of known standard roughnesses are investigated. The topography is then measured and illustrated, and the equivalent roughness is determined and compared with the standard values.

Keywords: Confocal spectral interferometry, Nondestructive testing, Optical metrology, Surface topography, Roughness.

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2158 The Relationship between Internal Corporate Social Responsibility and Organizational Commitment within the Banking Sector in Jordan

Authors: Al-bdour, A. Ali., Ellisha Nasruddin., Soh Keng Lin

Abstract:

This study attempts to investigate the relationship between internal CSR practices and organizational commitment based on the social exchange theory (SET). Specifically, we examine the impact of five dimensions of internal CSR practices on organizational commitment: health and safety, human rights, training and education, work life balance and workplace diversity. The proposed model was tested on a sample of 336 frontline employees within the banking sector in Jordan. Results showed that all internal CSR dimensions are significantly and positively related to affective and normative commitment. In addition, the findings of this study indicate that all internal CSR dimensions did not have a significant relationship with continuance commitment. Limitations of the study, directions for future research, and implications of the findings are discussed.

Keywords: Internal CSR, organizational commitment, Jordan, banking sector.

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2157 A Multi-Attribute Utility Model for Performance Evaluation of Sustainable Banking

Authors: Sonia Rebai, Mohamed Naceur Azaiez, Dhafer Saidane

Abstract:

In this study, we develop a performance evaluation model based on a multi-attribute utility approach aiming at reaching the sustainable banking (SB) status. This model is built accounting for various banks’ stakeholders in a win-win paradigm. In addition, it offers the opportunity for adopting a global measure of performance as an indication of a bank’s sustainability degree. This measure is referred to as banking sustainability performance index (BSPI). This index may constitute a basis for ranking banks. Moreover, it may constitute a bridge between the assessment types of financial and extra-financial rating agencies. A real application is performed on three French banks.

Keywords: Multi-attribute utility theory, Performance, Sustainable banking.

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2156 Solving Partially Monotone Problems with Neural Networks

Authors: Marina Velikova, Hennie Daniels, Ad Feelders

Abstract:

In many applications, it is a priori known that the target function should satisfy certain constraints imposed by, for example, economic theory or a human-decision maker. Here we consider partially monotone problems, where the target variable depends monotonically on some of the predictor variables but not all. We propose an approach to build partially monotone models based on the convolution of monotone neural networks and kernel functions. The results from simulations and a real case study on house pricing show that our approach has significantly better performance than partially monotone linear models. Furthermore, the incorporation of partial monotonicity constraints not only leads to models that are in accordance with the decision maker's expertise, but also reduces considerably the model variance in comparison to standard neural networks with weight decay.

Keywords: Mixture models, monotone neural networks, partially monotone models, partially monotone problems.

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2155 Tissue Composition and Muscularity of Lamb Legs Fed with Sunflower Seeds and Vitamin E

Authors: A. G. Silva Sobrinho, G. M. Manzi, N. L. L. Lima, F. A. Almeida, V. Endo, N. M. B. L. Zeola

Abstract:

The purpose of this study was to evaluate the tissue composition and carcass muscularity of 32 legs of Ile de France lambs fed with diets containing sunflower seeds and vitamin E, with mean body weight of 15 kg, lodged in individual pens at 15 kg and slaughtered at 32 kg of body weight. The treatments influenced (P<0,05) leg weight, femur length and muscle:bone ratio, being the highest values (2,13 kg, 16,19 cm and 7,38, respectively) in lambs that received diet without sunflower seeds and vitamin E. The other variables were not affected (P>0,05) by the treatments. The interaction of the sunflower and vitamin E was positive for bone total weights and intermuscular fat.

Keywords: sheep, conformation, feedlot, nutrition, sugar-cane

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2154 Organization as System, Psychic Dynamism as Equilibration: A Conceptualization

Authors: Abbas Moshref Razavi, Rodina Ahmad

Abstract:

Organizations are supposed to be systems and consequently require defining the notion of equilibrium within. However, organizations comprise people and unavoidably entail their irrational aspects. Then, the question is what is the organizational equilibrium and equilibrating mechanisms considering these aspects. Hence, some arguments are provided here to conceptualize human unconsciousness, irrationalities and consequent uncertainties within organizations in the form of a system of psychic dynamism. The assumption is this dynamism maintains the psychic balance of the organization through a psychodynamic point of view. The resultant conceptualization expected to promote the understanding of such aspects in different organizational settings by hypothesizing organizational equilibration from this perspective. As a result, the main expectation is, if it is known that how the organization equilibrates in this sense, we can explain and deal with such irrationalities and unconsciousness by rational and, of course conscious, planning and accomplishing.

Keywords: Equilibration, General System Theory, Organization, Psychodynamic.

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2153 A System of Automatic Speech Recognition based on the Technique of Temporal Retiming

Authors: Samir Abdelhamid, Noureddine Bouguechal

Abstract:

We report in this paper the procedure of a system of automatic speech recognition based on techniques of the dynamic programming. The technique of temporal retiming is a technique used to synchronize between two forms to compare. We will see how this technique is adapted to the field of the automatic speech recognition. We will expose, in a first place, the theory of the function of retiming which is used to compare and to adjust an unknown form with a whole of forms of reference constituting the vocabulary of the application. Then we will give, in the second place, the various algorithms necessary to their implementation on machine. The algorithms which we will present were tested on part of the corpus of words in Arab language Arabdic-10 [4] and gave whole satisfaction. These algorithms are effective insofar as we apply them to the small ones or average vocabularies.

Keywords: Continuous speech recognition, temporal retiming, phonetic decoding, algorithms, vocal signal, dynamic programming.

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2152 Influence of Transverse Steel and Casting Direction on Shear Response and Ductility of Reinforced Ultra-High Performance Concrete Beams

Authors: Timothy E. Frank, Peter J. Amaddio, Elizabeth D. Decko, Alexis M. Tri, Darcy A. Farrell, Cole M. Landes

Abstract:

Ultra-high performance concrete (UHPC) is a class of cementitious composites with a relatively large percentage of cement generating high compressive strength. Additionally, UHPC contains disbursed fibers, which control crack width, carry the tensile load across narrow cracks, and limit spalling. These characteristics lend themselves to a wide range of structural applications when UHPC members are reinforced with longitudinal steel. Efficient use of fibers and longitudinal steel is required to keep lifecycle cost competitive in reinforced UHPC members; this requires full utilization of both the compressive and tensile qualities of the reinforced cementitious composite. The objective of this study is to investigate the shear response of steel-reinforced UHPC beams to guide design decisions that keep initial costs reasonable, limit serviceability crack widths, and ensure a ductile structural response and failure path. Five small-scale, reinforced UHPC beams were experimentally tested. Longitudinal steel, transverse steel, and casting direction were varied. Results indicate that an increase in transverse steel in short-spanned reinforced UHPC beams provided additional shear capacity and increased the peak load achieved. Beams with very large longitudinal steel reinforcement ratios did not achieve yield and fully utilized the tension properties of the longitudinal steel. Casting the UHPC beams from the end or from the middle affected load-carrying capacity and ductility, but image analysis determined that the fiber orientation was not significantly different. It is believed that the presence of transverse and longitudinal steel reinforcement minimized the effect of different UHPC casting directions. Results support recent recommendations in the literature suggesting that a 1% fiber volume fraction is sufficient within UHPC to prevent spalling and provide compressive fracture toughness under extreme loading conditions.

Keywords: Fiber orientation, reinforced ultra-high performance concrete beams, shear, transverse steel.

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2151 Application of 1-MCP on ‘Centro’ Melon at Different Days after Harvest

Authors: L. P. L. Nguyen, G. Hitka, T. Zsom, Z. Kókai

Abstract:

This study is aimed to investigate the influence of postharvest delays of 1-Methylcyclopropene (1-MCP) treatment on prolonging the storage potential of melon. Melons were treated with 625-650 ppb 1-MCP at 10 °C for 24 hours on the 1st, 3rd and 5th day after harvest. Decreased ethylene production and retarded softening of melon fruits after 7 days of storage at 10 °C plus 3 days of shelflife were obtained by 1-MCP applications. 1-MCP strongly affected the chlorophyll fluorescence characteristics and hue angle values of melon. After shelf-life, the peel color of treated melon was slow in turning to yellow compared to the control. Additionally, firmness of melons treated on the first day after harvest was 38% higher than that of the control fruit. Results showed that fruits treated on the 1st and the 3rd day after harvest could maintain the quality of melon.

Keywords: 1-MCP, delay, muskmelon, storage.

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2150 Constructing a Fuzzy Net Present Value Method to Evaluating the BOT Sport Facilities

Authors: Huei-Fu Lu

Abstract:

This paper is to develop a fuzzy net present value (FNPV) method by taking vague cash flow and imprecise required rate of return into account for evaluating the value of the Build-Operate-Transfer (BOT) sport facilities. In order to clearly manifest a more realistic capital budgeting model based on the classical net present value (NPV) method, some uncertain financial elements in NPV formula will be fuzzified as triangular fuzzy numbers. Through the conscientious manipulation of fuzzy set theory, we will find that the proposed FNPV model is a more explicit extension of classical (crisp) model and could be more practicable for the financial managers to capture the essence of capital budgeting of sport facilities than non-fuzzy model.

Keywords: Fuzzy sets; Capital budgeting, Sport facility, Net present value (NPV), Build-Operate-Transfer (BOT) scheme

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2149 An Efficient Feature Extraction Algorithm for the Recognition of Handwritten Arabic Digits

Authors: Ahmad T. Al-Taani

Abstract:

In this paper, an efficient structural approach for recognizing on-line handwritten digits is proposed. After reading the digit from the user, the slope is estimated and normalized for adjacent nodes. Based on the changing of signs of the slope values, the primitives are identified and extracted. The names of these primitives are represented by strings, and then a finite state machine, which contains the grammars of the digits, is traced to identify the digit. Finally, if there is any ambiguity, it will be resolved. Experiments showed that this technique is flexible and can achieve high recognition accuracy for the shapes of the digits represented in this work.

Keywords: Digits Recognition, Pattern Recognition, FeatureExtraction, Structural Primitives, Document Processing, Handwritten Recognition, Primitives Selection.

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2148 Knowledge Creation and Innovation in Classroom

Authors: Salina Daud, Rabiah Eladwiah Abdul Rahim, Rusnita Alimun

Abstract:

The concepts of knowledge creation and innovation have a strong relationship but this relationship has not been examined systematically. This study examines the utilization of knowledge creation processes of the Theory of Knowledge Creation in Higher Education Institutions. These processes consist of socialization, externalization, combination and internalization. This study suggests that the utilization of these processes will give impacts on innovation in academic performance. A cross-sectional study was conducted using survey questionnaires to collect data of the utilization of knowledge creation processes and classroom-s innovation. The samples are Business Management students of a Malaysian Higher Education Institution. The results of this study could help Higher Education Institutions to enrich the learning process of students through knowledge creation and innovation.

Keywords: Knowledge creation, innovation, business schools.

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2147 Properties and Approximation Distribution Reductions in Multigranulation Rough Set Model

Authors: Properties, Approximation Distribution Reductions in Multigranulation Rough Set Model

Abstract:

Some properties of approximation sets are studied in multi-granulation optimist model in rough set theory using maximal compatible classes. The relationships between or among lower and upper approximations in single and multiple granulation are compared and discussed. Through designing Boolean functions and discernibility matrices in incomplete information systems, the lower and upper approximation sets and reduction in multi-granulation environments can be found. By using examples, the correctness of computation approach is consolidated. The related conclusions obtained are suitable for further investigating in multiple granulation RSM.

Keywords: Incomplete information system, maximal compatible class, multi-granulation rough set model, reduction.

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2146 Modeling and Analysis of Twelve-phase (Multi- Phase) DSTATCOM for Multi-Phase Load Circuits

Authors: Zakir Husain

Abstract:

This paper presents modeling and analysis of 12-phase distribution static compensator (DSTATCOM), which is capable of balancing the source currents in spite of unbalanced loading and phase outages. In addition to balance the supply current, the power factor can be set to a desired value. The theory of instantaneous symmetrical components is used to generate the twelve-phase reference currents. These reference currents are then tracked using current controlled voltage source inverter, operated in a hysteresis band control scheme. An ideal compensator in place of physical realization of the compensator is used. The performance of the proposed DTATCOM is validated through MATLAB simulation and detailed simulation results are given.

Keywords: DSTATCOM, Modeling, Load balancing, Multiphase, Power factor correction.

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2145 Wet Strength Improvement of Pineapple Leaf Paper for Evaporative Cooling Pad

Authors: T. Khampan, N. Thavarungkul, J. Tiansuwan, S. Kamthai

Abstract:

This research aimed to modify pineapple leaf paper (PALP) for using as wet media in the evaporation cooling system by improving wet mechanical property (tensile strength) without compromising water absorption property. Polyamideamineepichorohydrin resin (PAE) and carboxymethylcellulose (CMC) were used to strengthen the paper, and the PAE and CMC ratio of 80:20 showed the optimum wet and dry tensile index values, which were higher than those of the commercial cooling pad (CCP). Compared with CCP, PALP itself and all the PAE/CMC modified PALP possessed better water absorption. The PAE/CMC modified PALP had potential to become a new type of wet media.

Keywords: wet strength, evaporative cooling, pineapple leaves, polyamideamine-epichorohydrin, carboxymethylcellulose.

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2144 Percolation Transition with Hidden Variables in Complex Networks

Authors: Zhanli Zhang, Wei Chen, Xin Jiang, Lili Ma, Shaoting Tang, Zhiming Zheng

Abstract:

A new class of percolation model in complex networks, in which nodes are characterized by hidden variables reflecting the properties of nodes and the occupied probability of each link is determined by the hidden variables of the end nodes, is studied in this paper. By the mean field theory, the analytical expressions for the phase of percolation transition is deduced. It is determined by the distribution of the hidden variables for the nodes and the occupied probability between pairs of them. Moreover, the analytical expressions obtained are checked by means of numerical simulations on a particular model. Besides, the general model can be applied to describe and control practical diffusion models, such as disease diffusion model, scientists cooperation networks, and so on.

Keywords: complex networks, percolation transition, hidden variable, occupied probability.

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2143 Quintic Spline Solution of Fourth-Order Parabolic Equations Arising in Beam Theory

Authors: Reza Mohammadi, Mahdieh Sahebi

Abstract:

We develop a method based on polynomial quintic spline for numerical solution of fourth-order non-homogeneous parabolic partial differential equation with variable coefficient. By using polynomial quintic spline in off-step points in space and finite difference in time directions, we obtained two three level implicit methods. Stability analysis of the presented method has been carried out. We solve four test problems numerically to validate the derived method. Numerical comparison with other methods shows the superiority of presented scheme.

Keywords: Fourth-order parabolic equation, variable coefficient, polynomial quintic spline, off-step points, stability analysis.

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2142 Thyroids Dose Evaluation and Calculation of Backscatter Factors for Co-60 Irradiations

Authors: D. Kısınma, A. B. Tugrul

Abstract:

The aim of the study is evaluation of absorbed doses for thyroids by using neck phantoms. For this purpose, it was arranged the irradiation set with different phantoms. Three different materials were used for phantom materials as, water, parafine and wood. The phantoms were three different dimensions for simulation of different ages and human race for each material. Co-60 gammao source was used for irradiation and the experimental procedure applied rigorously with narrow beam geometry.  As the results of the experiments the relative radiation doses are evaluated for therapic applications for thyroids and backscattering factors were calculated and shown that water, parafine and wood can appropriate for phantom material with the converge values of backscattering factors.

Keywords: Co-60, Dosimetry, phantom, thyroids.

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2141 Sensitivity Analysis during the Optimization Process Using Genetic Algorithms

Authors: M. A. Rubio, A. Urquia

Abstract:

Genetic algorithms (GA) are applied to the solution of high-dimensional optimization problems. Additionally, sensitivity analysis (SA) is usually carried out to determine the effect on optimal solutions of changes in parameter values of the objective function. These two analyses (i.e., optimization and sensitivity analysis) are computationally intensive when applied to high-dimensional functions. The approach presented in this paper consists in performing the SA during the GA execution, by statistically analyzing the data obtained of running the GA. The advantage is that in this case SA does not involve making additional evaluations of the objective function and, consequently, this proposed approach requires less computational effort than conducting optimization and SA in two consecutive steps.

Keywords: Optimization, sensitivity, genetic algorithms, model calibration.

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2140 Parallel Joint Channel Coding and Cryptography

Authors: Nataša Živić, Christoph Ruland

Abstract:

Method of Parallel Joint Channel Coding and Cryptography has been analyzed and simulated in this paper. The method is an extension of Soft Input Decryption with feedback, which is used for improvement of channel decoding of secured messages. Parallel Joint Channel Coding and Cryptography results in improved coding gain of channel decoding, which achieves more than 2 dB. Such results are an implication of a combination of receiver components and their interoperability.

Keywords: Block length, Coding gain, Feedback, L-values, Parallel Joint Channel Coding and Cryptography, Soft Input Decryption.

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2139 Sun, Salon, and Cosmetic Tanning: Predictors and Motives

Authors: Andrew Reilly, Nancy A. Rudd

Abstract:

The appearance management behavior of tanning by gay men is examined through the lens of Impression Formation. The study proposes that body image, self-esteem, and internalized homophobia are connected and affect the motives for engaging in sun, salon, and cosmetic tanning. Motives examined were: to look masculine, to look attractive to (potential) partners, to look attractive in general, to socialize, to meet a peer standard, and for personal satisfaction. Using regression analysis to examine data of 103 gay men who engage in at least one method of tanning, results reveal that components of body image and internalized homophobia–but not self-esteem–are linked to various motives and methods of tanning. These findings support and extend the literature of Impression Formation Theory and provide practitioners in the health and healthrelated fields new avenues to pursue when dealing with diseases related to tanning.

Keywords: Body image, gay men, tanning.

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2138 Periodic Solutions in a Delayed Competitive System with the Effect of Toxic Substances on Time Scales

Authors: Changjin Xu, Qianhong Zhang

Abstract:

In this paper, the existence of periodic solutions of a delayed competitive system with the effect of toxic substances is investigated by using the Gaines and Mawhin,s continuation theorem of coincidence degree theory on time scales. New sufficient conditions are obtained for the existence of periodic solutions. The approach is unified to provide the existence of the desired solutions for the continuous differential equations and discrete difference equations. Moreover, The approach has been widely applied to study existence of periodic solutions in differential equations and difference equations.

Keywords: Time scales, competitive system, periodic solution, coincidence degree, topological degree.

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2137 Toward a Model for Knowledge Development in Virtual Environments: Strategies for Student Ownership

Authors: N.B. Adams

Abstract:

This article discusses the concept of student ownership of knowledge and seeks to determine how to move students from knowledge acquisition to knowledge application and ultimately to knowledge generation in a virtual setting. Instructional strategies for fostering student engagement in a virtual environment are critical to the learner-s strategic ownership of the knowledge. A number of relevant theories that focus on learning, affect, needs and adult concerns are presented to provide a basis for exploring the transfer of knowledge from teacher to learner. A model under development is presented that combines the dimensions of knowledge approach, the teacher-student relationship with regards to knowledge authority and teaching approach to demonstrate the recursive and scaffolded design for creation of virtual learning environments.

Keywords: Virtual learning environments, learning theory, teaching model, online learning.

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2136 Thermal Performance of Hybrid PVT Collector with Natural Circulation

Authors: K. Touafek, A. Khelifa, I. Tabet, H. Haloui, H. Bencheikh El Houcine, M. Adouane

Abstract:

Hybrid photovoltaic thermal (PVT) collectors allow simultaneous production of electrical energy thus heat energy. There are several configurations of hybrid collectors (to produce water or air). For hybrids water collectors, there are several configurations that differ by the nature of the absorber (serpentine, tubes...). In this paper, an absorber tank is studied. The circulation of the coolant is natural (we do not use the pump). We present the obtained results in our experimental study and we analyzed the data, and then we compare the results with the theory practices. The electrical performances of the hybrid collector are compared with those of conventional photovoltaic module mounted on the same structure and measured under the same conditions.

We conducted experiments with natural circulation of the coolant (Thermosyphon), for a flow rate of 0.025kg/m².

Keywords: Experimental, Photovoltaic, Solar, Temperature, Tank.

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2135 Adolescents’ Role in Family Buying Decision Making

Authors: Harleen Kaur, Deepika Jindal Singla

Abstract:

Buying decision making is a complicated process, in which consumer’s decision is under the impact of others. The buying decision making is directed in a way that they have to act as customers in the society. Media and family are key socialising agents for adolescents’. Moreover, changes in the socio-cultural environment in India necessitate that adolescents’ influence in family’s buying decision-making should be investigated. In comparison to Western society, Indian is quite different, when compared in terms of family composition and structure, behaviour, values and norms which effect adolescents’ buying decision-making.

Keywords: Adolescents’, buying behaviour, Indian urban families, consumer socialization.

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2134 Nonlinear Stability of Convection in a Thermally Modulated Anisotropic Porous Medium

Authors: M. Meenasaranya, S. Saravanan

Abstract:

Conditions corresponding to the unconditional stability of convection in a mechanically anisotropic fluid saturated porous medium of infinite horizontal extent are determined. The medium is heated from below and its bounding surfaces are subjected to temperature modulation which consists of a steady part and a time periodic oscillating part. The Brinkman model is employed in the momentum equation with the Bousinessq approximation. The stability region is found for arbitrary values of modulational frequency and amplitude using the energy method. Higher order numerical computations are carried out to find critical boundaries and subcritical instability regions more accurately.

Keywords: Convection, porous medium, anisotropy, temperature modulation, nonlinear stability.

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