bluuebunny/crossref_metadata_2025 huggingface dataset:
A robust control strategy for a class of distributed network with transmission delays
Authors: Naghavi S. Vahid , Safavi A.A. , Khooban Mohammad Hassan , Pourdehi S. , Ghaffari Valiollah
Published: September 2016

Purpose

The purpose of this paper is to concern the design of a robust model predictive controller for distributed networked systems with transmission delays.

Design/methodology/approach

The overall system is composed of a number of interconnected nonlinear subsystems with time-varying transmission delays. A distributed networked system with transmission delays is modeled as a nonlinear system with a time-varying delay. Time delays appear in distributed systems due to the information transmission in the communication network or transport of material between the sub-plants. In real applications, the states may not be available directly and it could be a challenge to address the control problem in interconnected systems using a centralized architecture because of the constraints on the computational capabilities and the communication bandwidth. The controller design is characterized as an optimization problem of a “worst-case” objective function over an infinite moving horizon.

Findings

The aim is to propose control synthesis approach that depends on nonlinearity and time varying delay characteristics. The MPC problem is represented in a time varying delayed state feedback structure. Then the synthesis sufficient condition is provided in the form of a linear matrix inequality (LMI) optimization and is solved online at each time instant. In the rest, an LMI-based decentralized observer-based robust model predictive control strategy is proposed.

Originality/value

The authors develop RMPC strategies for a class of distributed networked systems with transmission delays using LMI-Based technique. To evaluate the applicability of the developed approach, the control design of a networked chemical reactor plant with two sub-plants is studied. The simulation results show the effectiveness of the proposed method.
Intelligent energy management for hybrid fuel cell/battery system
Authors: Boukhnifer Moussa , Ouddah Nadir , Azib Toufik , Chaibet Ahmed
Published: September 2016

Purpose

The purpose of this paper is to propose two energy management strategies (EMS) for hybrid electric vehicle, the power system is an hybrid architecture (fuel cell (FC)/battery) with two-converters parallel configuration.

Design/methodology/approach

First, the authors present the EMS uses a power frequency splitting to allow a natural frequency decomposition of the power loads and second the EMS uses the optimal control theory, based on the Pontryagin’s minimum principle.

Findings

Thanks to the optimal approach, the control objectives will be easily achieved: hydrogen consumption is minimized and FC health is protected.

Originality/value

The simulation results show the effectiveness of the control strategy using optimal control theory in term of improvement of the fuel consumption based on a comparison analysis between the two strategies.
Investigation of rotor thermal stress in squirrel cage induction motor with broken bar faults
Authors: Xie Ying , Wang Ze , Shan Xueting , Li Yangyang
Published: September 2016

Purpose

Thermal stress of the rotor in a squirrel cage induction motor is generated due to the temperature rise, and the structure of the rotor will be destroyed if the stress acted on the rotor exceeds its limits, so the thermal stress is also one of the main causes led to broken bar fault. The purpose of this paper is to report the thermal stress coupled analysis for the induction motor with healthy and faulty rotor, and to find the variation tendency of the temperature and thermal stress due to broken bars, and the part most likely to break in the rotor as a result of the thermal stress load are identified.

Design/methodology/approach

The steady temperature and thermal stress of the rotor in the case of the healthy and faulty conditions are calculated by finite element method, and the 3D model of the motor used in the experiments is established and the experimental results are presented for both healthy and faulty machines.

Findings

The influence of the broken bars fault on the motor thermal profile and thermal stress can be found, and it explains why the breaking point always appears in the joint of the bars and end rings.

Originality/value

The paper presents the 3D thermal stress coupled model and performance characteristics of induction motor with broken bars. The reasonable constraint is established according to the contact of components each other, and more reasonable fracture location is selected. The results obtained by the simulation model are in a good agreement with practical situation, because the effect of skewed rotor were taken into consideration in the process of simulation.
Erroneous branch parameters detection and correction in real time simulation of power systems
Authors: Helmzadeh Amin , Kouhsari Shahram M.
Published: September 2016

Purpose

The purpose of this paper is to propose an efficient method for detection and modification of erroneous branch parameters in real time power system simulators. The aim of the proposed method is to minimize the sum of squared errors (SSE) due to mismatches between simulation results and corresponding field measurements. Assuming that the network configuration is known, a limited number of erroneous branch parameters will be detected and corrected in an optimization procedure.

Design/methodology/approach

Proposing a novel formulation that utilizes network voltages and last modified admittance matrix of the simulation model, suspected branch parameters are identified. These parameters are more likely to be responsible for large values of SSE. Utilizing a Gauss-Newton (GN) optimization method, detected parameters will be modified in order to minimize the value of SSE. Required sensitivities in optimization procedure will be calculated numerically by the real time simulator. In addition, by implementing an efficient orthogonalization method, the more effective parameter will be selected among a set of correlated parameters to avoid singularity problems.

Findings

Unlike state estimation-based methods, the proposed method does not need the mathematical functions of measurements to simulation model parameters. The method can enhance other parameter estimation methods that are based on state estimation. Simulation results demonstrate the high efficiency of the proposed optimization method.

Originality/value

Incorrect branch parameter detection and correction procedures are investigated in real time simulators.
Modelling of TCSC for voltage regulation in power systems
Authors: Yalçın Faruk
Published: September 2016

Purpose

The purpose of this paper is to propose a voltage regulation solution in power systems through adjusting the power flow of the system via thyristor controlled series compensator (TCSC). For this aim, a new power flow model has been proposed based on TCSC.

Design/methodology/approach

TCSC’s admittance effect has been included as state variable into the Jacobian matrix to avoid divergence problem. TCSC’s admittance is ignored in the bus admittance matrix to prevent rebuilding requirement of the bus admittance matrix in each power flow iteration. So, faster convergence for power flow calculation has been provided. For this aim, new power equations have been obtained. Also, the proposed approach has not required to handle each terminal of TCSC as an individual bus in the power flow calculation. So, increasing of the Jacobian and bus admittance matrixes caused by the total bus number has been prevented.

Findings

The proposed approach has been tested on IEEE 57-bus test system. The obtained results have proved that the proposed approach has provided efficient, reliable and fast convergence.

Originality/value

This study is the first one that uses TCSC for voltage regulation in the literature. On the other hand, the results have shown that the approach of considering the TCSC admittance values as state variables provides robust convergence, according to the approaches that consider TCSC firing angles as state variables.
An efficient code compression for MIPS32 processor using dictionary and bit-mask based static and dynamic frequency algorithm
Authors: Ramani G. , Geetha K.
Published: September 2016

Purpose

Memory plays a vital role in designing embedded systems. A larger memory can accommodate more and larger applications but increases cost area, as well as energy requirements. Hence, the purpose of this paper is to propose code compression techniques to solve this issue by minimizing the code size of the application program by compressing the instructions with higher static frequency.

Design/methodology/approach

The idea is based on the static and dynamic frequency-based algorithm combined with bit mask and dictionary-based algorithm for MIPS32 processor, in order to minimize the code size and improves compression ratio.

Findings

The experimental result shows that the proposed system achieves up to 67 percent compression efficiency.

Originality/value

The paper presents enhanced versions of the code compression technique.
Boundary layer flow and heat transfer of a non-Newtonian nanofluid over a non-linearly stretching sheet
Authors: Madhu Macha , Kishan Naikoti , Chamkha A.
Published: September 2016

Purpose

The purpose of this paper is to study the boundary layer flow and heat transfer of a power-law non-Newtonian nanofluid over a non-linearly stretching sheet.

Design/methodology/approach

The governing equations describing the problem are transformed into a nonlinear ordinary differential equations by suitable similarity transformations. The resulting equations for this investigation are solved numerically by using the variational finite element method.

Findings

It was found that the local Nusselt number increases by increasing the Prandtl number, stretching sheet parameter and decreases by increasing the power-law index, thermophoresis parameter and Lewis number. Increases in the stretching sheet parameter, Prandtl number and thermophoresis parameter decrease the local Sherwood number values. The effects of Brownian motion and Lewis number lead to increases in the local Sherwood number values.

Originality/value

The work is relatively original as very little work has been reported on non-Newtonian nanofluids.
Additional results for the problem of MHD boundary-layer flow past a stretching/shrinking surface
Authors: Pop Ioan , Roşca Natalia C. , Roşca Alin V.
Published: September 2016

Purpose

The purpose of this paper is to reinvestigate the problem of multiple similarity solutions of the two-dimensional magnetohydrodynamic boundary-layer flow of an incompressible, viscous and electrically conducting fluid past a stretching/shrinking permeable surface studied by Aly et al. (2007).

Design/methodology/approach

The transformed ordinary (similarity) differential equation was solved numerically using the function bvp4c from MATLAB. The relative tolerance was set to 10^(−10).

Findings

Dual solutions were found and a stability analysis was performed to show which solutions are stable and which are not stable. On the other hand, Aly et al. (2007) have shown that for each value of the power index and magnetic parameter in the range and for any specific values of the stretching/shrinking parameter and suction parameter the problem has only a solution.

Originality/value

The paper describes how multiple (dual) solutions for the flow reversals were obtained. The stability analysis has shown that the lower solution branches are unstable, while the upper solution branches are stable.
The effect of weather on the European stock market
Authors: Sariannidis Nikolaos , Giannarakis Grigoris , Partalidou Xanthi
Published: September 2016

Purpose

The purpose of this paper is to ascertain whether weather variables can explain the stock return reaction on the Dow Jones Sustainability Europe Index by employing a number of macroeconomic indicators as control variables.

Design/methodology/approach

The authors incorporate the generalized autogressive conditional heteroskeasticity model in methodology for the period August 26, 2009 to May 30, 2014 using daily data.

Findings

The empirical results indicate that not only do changes in humidity and wind levels seem to affect positively the European stock market but changes in returns oil and gold prices as well. However, the results show that the volatility of the US dollar/Yen exchange rate and ten-year bond value exerts significant negative impact on companies’ stock returns.

Originality/value

This study adds to the international literature by documenting the impact of weather variables on socially responsible companies.
Rental index rate as an alternative to interest rate in Musharakah Mutanaqisah home financing
Authors: Yusof Rosylin Bt Mohd , Mahfudz Akhmad Affandi , Che Mohamed Arif Ahmad Suki , Ahmad Nor Hayati
Published: September 2016

Purpose

This paper aims to propose a new pricing alternative called Rental Rate Index (RR-I) that captures the true value of property to be used by Islamic banks in Musharakah Mutanaqisah (MM) contract for home financing.

Design/methodology/approach

By formulating a profit rate based on Rental Index (RI) and House Price Index (HPI), the proposed rate eliminates conventional profit rate benchmarking, and, at the same time, suggests a fair, equitable and sustainable financing. This new RR-I (measured by RPI/HPI) enables computerization of the MM system in home financing to be easily implemented. A financial simulation is developed to demonstrate the feasibility of this newly proposed rate.

Findings

This newly proposed RR-I is found to be more stable, having less fluctuations, resilient to macroeconomic conditions and yet comparable to the conventional interest rates, without depending on them. It can also be regarded as a rate that is fair and sustainable to both the customer and the bank, as it measures the actual rate of return to both parties in MM contract.

Research limitations/implications

The paper confines one contract, namely, MM, as it is claimed to be more Shariah-compliant than others.

Practical implications

The finding also sheds some light on the recommendation by Bank Negara Malaysia, which is to consider RR that is more indicative of the actual rental price while taking into account the competitiveness of the product. (BNM, 2007).

Social implications

This paper wreaks customer patronage in selecting the contract of home financing.

Originality/value

This paper attempts to resolve the issue of benchmarking RR to the conventional interest rate in the MM contract. Studies conducted on this issue via simulation approach are meager.
Disclosure practices and governance quality: evidence from micro finance institutions
Authors: Ahmed Kamran , Khan Rakib
Published: September 2016

Purpose

The purpose of this paper is to assess the role of governance structure and composition and other institution-specific attributes in disclosure practices of microfinance institutions (MFIs) in an emerging market contest. Bangladesh is a country which is considered to be a pioneer in providing micro-finance to the underprivileged people to improve their entrepreneurial capacity.

Design/methodology/approach

The paper utilises a survey of three groups of users to elicit their opinions and the recommendation of the donor and regulatory agencies to construct a disclosure index. Further ordinary least squares regressions, both parametric and non-parametric, are used to analyse the association between disclosure levels and governance mechanisms and other MFI characteristics.

Findings

Using a large sample of 564 MFI firm-year reports in Bangladesh, the results show that the overall disclosure levels were around 70 per cent in 2010 and have not improved since 2004. The results also show that the frequency of board meetings, qualifications of MFIs’ board members and MFI size are positively associated with MFIs disclosures. However, board size, board independence, audit firm and other control variables have no such effect on disclosure. This implies that MFIs should focus in board effectiveness rather than its composition.

Research limitations/implications

Using a general purpose financial reporting framework, the paper examines how effective boards can improve financial reporting standards of MFIs for better monitoring by international donor agencies, regulatory bodies and depositors.

Originality/value

This is the first substantive study, to the best of the authors’ knowledge, that uses data based on a questionnaire survey and the annual financial statements of a large sample of MFIs from Bangladesh that has been at the forefront of microfinance in emerging countries. Prior studies only used Web-based information, namely, Mix-Market, which ranks country on the basis of its disclosure criteria supplied voluntarily by MFIs, and thus suffer from selection bias. In this study, an attempt has been made to develop an empirical model to explain the role of governance quality in disclosure practices of MFIs.
The valuation of fixed assets in Norwegian health care: an account of change agent struggle
Authors: Kaarbøe Katarina , Robbestad Anne
Published: September 2016

Purpose

This paper aims to explore how accrual accounting is translated into new accounting norms and what role change agents have had in that process. The main research question is: How were private sector accounting norms translated within the Norwegian public health sector?

Design/methodology/approach

This study uses framing theory to understand how the different actors involved in the translation frame their arguments. The field study considers the specific case of public health care. The main data sources are archival data combined with semi-structured interviews.

Findings

The empirical study uses framing theory to show how the Big Four consultants worked as change agents to impose a valuation based on a full accrual accounting logic. The first finding shows that there are two framing processes to valuate fixed assets. The central government has a pragmatic framing trying to get the budget in balance, while the Big Four consultants together with private sector accounting experts have an accrual accounting ideology framing. The second finding shows how the Big Four consultants become a change agent by forming alliances with accounting experts, health enterprises and politicians. These findings point to the need to focus explicitly on the role of change agents as drivers of public sector organizational change and the important role accounting as a tool can have.

Practical implications

The paper is likely to be useful for governments, practitioners and researchers to gain knowledge about the implementation of accrual accounting.

Originality/value

This paper contributes to our understanding of change agent's role in successfully introducing a new accounting logic in the public sector, especially within an inter-organizational setting.
Management controls for minimising risk in public-private partnerships in a developing country
Authors: Appuhami Ranjith , Perera Sujatha
Published: September 2016

Purpose

The purpose of the study is to examine the use of management controls by a public partner to minimise risks associated with a public-private partnership (PPP) in a developing country.

Design/methodology/approach

Using case study method, management controls used in a power project formed as a PPP are examined based on data gathered from semi-structured interviews and documentary analysis.

Findings

The study reveals that the public partner of the PPP used multiple controls depending on the nature of risks in different phases of the project. While bureaucratic control was the predominantly used control pattern throughout the three phases (namely, selecting, building and operating) of the PPP, trust-based controls also played an important role. Market controls on the other hand played, somewhat, a nominal role, particularly in the selecting phase of the project. The study also highlights the problematic nature of forming PPPs in developing countries despite the various benefits associated with such organisational arrangements. Additionally, the study provides insights into how certain contextual features of developing countries affect the way in which controls are applied.

Practical implications

The insights provided in this paper would be beneficial to policy makers, in developing countries in particular, when making decisions in relation to implementation, management and risk control of PPPs.

Originality/value

This study makes an original contribution to the existing literature on PPPs by examining the way in which management controls are used to minimise risk in a PPP in a developing country.
Autism, sexual offending, and the criminal justice system
Authors: Mogavero Melanie Clark
Published: September 2016

Purpose

There has been growing concern among stakeholders about individuals with autism spectrum disorders (ASD) and sex offending as research supports an indirect association. The purpose of this paper is threefold: first, bring more awareness of the sexuality and deviant/criminal sexual behavior among those with ASD to stakeholders in the criminal justice system (CJS); second, demonstrate that much of the deviant or sexual offending behavior exhibited among those with ASD is often a manifestation of their ASD symptoms and not malice; and third, demonstrate the necessity to address specific needs of individuals with ASD who enter the CJS due to criminal sexual behavior.

Design/methodology/approach

This paper provides an overview of the ASD symptomology, including the diagnostic changes, a review of the literature on ASD and sexuality, which includes deviant sexual behavior and sexual offending.

Findings

The author linked examples of deviant or sexual behavior in the research literature to the ASD symptomology and described how the symptomology explains such behavior.

Originality/value

Sexual offending among those with ASD has received little research outside the mental health field. This review is of particular importance to those in the CJS unfamiliar with ASD, as they should handle them differently with regard to formal interviewing, measures of competency, capacity, and sentencing.
Developing involvement during a programme of recovery research
Authors: Slade Mike , Trivedi Premila , Chandler Ruth , Leamy Mary
Published: September 2016

Purpose

The purpose of this paper is to consider the process of working with a Lived Experience Advisory Group (LEAP) and its outcomes in REFOCUS, a large five-year programme of recovery research.

Design/methodology/approach

Narrative reflections on the experience of working with LEAP were collected from five members and the chair of LEAP, two REFOCUS researchers and the principal investigator. These were synthesised to show both the process and outcomes of LEAP involvement in REFOCUS, and how involvement evolved organically over time.

Findings

Individual reflective accounts showed how working with LEAP impacted (to a greater or lesser extent) on each individual involved in the process, providing new insights and influencing, to varying degrees, the way in which they then worked with LEAP. Synthesis of the reflections showed how these changes impacted organically on LEAP’s process of involvement, with a shift in LEAP’s role from being purely consultative/advisory towards one which was much more about co-production, with LEAP pro-actively contributing to some aspects of REFOCUS in the later stages of the study.

Practical implications

The authors stress the importance of considering process as well as outcomes in patient and public involvement, and make practical recommendations for improving both in future programmes of research.

Originality/value

This is the first empirical evaluation of user and carer involvement and its development during a large recovery research programme.
Aims for service user involvement in mental health training: staying human
Authors: Lea Laura , Holttum Sue , Cooke Anne , Riley Linda
Published: September 2016

Purpose

The purpose of this paper is to examine the impact of service user involvement in mental health training but little is known about what staff, trainees and service users themselves want to achieve.

Design/methodology/approach

Three separate focus groups were held with service users, training staff and trainees associated with a clinical psychology training programme. Thematic analysis was used to identify aims for involvement.

Findings

All groups wanted to ensure that future professionals “remained human” in the way they relate to people who use services. Service user and carer involvement was seen as a way of achieving this and mitigating the problem of “them and us thinking”. The authors found that groups had some aims in common and others that were unique. Service users highlighted the aim of achieving equality with mental health professionals as an outcome of their involvement in teaching.

Research limitations/implications

The samples were small and from one programme.

Practical implications

Common aims can be highlighted to foster collaborative working. However, the findings suggest that service users and carers, staff and trainees may also have different priorities for learning. These need to be recognised and addressed by mental health educators.

Originality/value

This was the first study to explore in depth the differing aims of different stakeholder groups for service user involvement. Clarification of aims is a vital first step in developing any future measure of the impact of service user involvement on mental health practice.
Learning from stories of mental distress in occupational therapy education
Authors: Walsh Susan
Published: September 2016

Purpose

The purpose of this paper is to describe processes of learning from personal experiences of mental distress when mental health service users participate in occupational therapy education with tutors and students who have also had experiences of mental distress.

Design/methodology/approach

A post-structural theoretical perspective was applied to stories which emerged from the research process. Semi-structured group and individual interviews were used with three service users, three students and three tutors (including the author) who had all had, at some time in their lives, experiences of mental distress.

Findings

Stories based on previously hidden personal experiences of mental distress began to shift dominant understandings. Further, as educators, service users challenged whose authority it is to speak about mental distress and permitted different narrative positions for students and tutors. However, technologies of power and technologies of self of powerful discourses in professional education continued to disqualify and exclude personal knowledges. Learning from stories requires a critical approach to storytelling to expose how hidden power relations maintain some knowledges as dominant. Further, learning requires narrative work, which was often hidden and unaccounted for, to navigate complex and contradictory positions in learning.

Social implications

Although storytelling based on personal experience can help develop a skilled and healthy mental health workforce, its impact will be limited without changes in classrooms, courses and higher education which support learning at the margins of personal/professional and personal/political learning.

Originality/value

Learning from stories of mental distress requires conditions which take account of the hidden practices which operate in mental health professional education.
Why do firms adopt enterprise risk management (ERM)? Empirical evidence from France
Authors: Khan Majid Jamal , Hussain Dildar , Mehmood Waqar
Published: September 2016

Purpose

Enterprise risk management (ERM) is a risk management approach that calls for integrating all the organization-wide risks and takes a portfolio view point of managing organizational risks. The purpose of this paper is to investigate the factor that influence a firm’s decision to adopt ERM.

Design/methodology/approach

The authors employ a particular technique of survival data analysis, the Cox proportional hazards model, to investigate the factors that lead towards the decision of initiating an ERM programme. The authors constructed a unique sample of French firms derived from the information in 315 corporate news announcements for the hiring of a chief risk officer and information retrieved from publicly available annual reports to identify firms that initiated an ERM programme, over the period from year 1999 to 2008.

Findings

The results suggest that besides the growing international and local regulatory pressure, factors that are internal to the organizations like the expected probability of financial distress and its explicit and implicit costs, poor earnings performance and the existence of growth opportunities play vital role in motivating firms to adopt ERM. It was also found that corporate governance practices such as the independence of the board may also lead towards an initiation of the ERM.

Originality/value

This study makes theoretical and methodological contribution the ERM literature by employing a novel methodology and presenting empirical evidence based on data form French firms.
Effects of trust and distrust on effort and budgetary slack: an experiment
Authors: Gago-Rodríguez Susana , Naranjo-Gil David
Published: September 2016

Purpose

The purpose of this paper is to evaluate whether trust and distrust in upper-level managers exert different influences on the budgetary proposals of middle managers. Such proposals involve different levels of managerial effort that impact overall budgetary slack.

Design/methodology/approach

This paper is based on a laboratory experiment with 160 business managers.

Findings

The results show that the more (less) middle managers trust (distrust) their upper-level managers, the more (the less) effort they commit to budgetary proposals. The authors also find that middle managers with low trust are prone to invest more effort and thus create less budgetary slack than managers with high distrust. The results also show that the introduction of suspicion does not vary this initial choice of effort and budgetary slack.

Research limitations/implications

This paper shows the importance of trust and distrust as informal control systems in organizations. The findings support the importance of extrinsic motivation for enhancing effort and reducing budgetary slack. There are a wide range of exogenous variables that have an effect on the development of trust and distrust.

Practical implications

Practitioners may improve their management control by facilitating trust and preventing distrust in interpersonal relationships because both are informal controls that can reduce and increase, respectively, dysfunctional behaviors in organizations, such as budgetary slack.

Originality/value

This paper is among the first to show the distinct effects of trust and distrust (high and low) in the efforts of middle managers. This study provides a dynamic viewpoint of trust through the introduction of suspicion in a budget negotiation.
A holistic fuzzy approach to create competitive advantage via quality management in services industry (case study: life-insurance services)
Authors: Vaziri Jalil , Beheshtinia Mohammad Ali
Published: September 2016

Purpose

In today’s highly competitive business environment, the main approach of all businesses is to optimally provide customers’ requirements and gain their satisfaction and trust. The process of value creation for customers consists of value chain activities which are concentrated on providing maximum level of customers’ needs. The purpose of this paper is to propose a holistic model by which the quality, the transferred value to customers and the firm’s competitive advantage would be improved simultaneously under budget constraint.

Design/methodology/approach

This study uses a combination of several quality management (QM) tools including SERVQUAL, Kano’s model, quality function deployment and knapsack problem. Moreover, the triangular fuzzy logic is used throughout the model to address data uncertainty and increase the model flexibility. The proposed model includes five steps which are implemented in the case study of life-insurance services.

Findings

The lack of coordination and cooperation between the people working in the inherently related sections leads to incorrect decisions and also the failure in implementation of adopted decisions. Hence, the interface between quality and strategic management should be well considered in organizations. The model generates an integrated vision to the process of decision making in this interface. The framework has several significant outcomes which would be used by both researchers and practitioners.

Research limitations/implications

The study shows that the individual elements of decision-making process in the interface between quality and strategic management are related to each other, recommending the need to coordinated and consistent effort between different parts of a firm. The results are limited by the sample size and geography of the survey.

Originality/value

This paper is among the few in the literature that have presented a holistic and step-by-step approach to the decisions on the intersection between two areas of quality and strategic management, recommending the managers to not have insular look to the issues and try to make a sufficient and efficient relationship between the different sections. This study is an important step in reflecting these relations and the need to create an integrated decision model.
Simulating surface tension of Sn-based lead free solder using an artificial neural network
Authors: Wu Min , Su Xiangyu
Published: September 2016

Purpose

Because of the complexity of relationship between surface tension and its decisive factors, such as temperature, concentration, electronic density, molar atomic volume and electro-negativity, a reasonable predicting model of surface tension of Sn-based solder alloys has not been developed yet. The paper aims to address the surface tension issue that has to be considered if the new lead free solder will be applied for electronics.

Design/methodology/approach

Using an artificial neural network (ANN) model with back-propagation (BP) algorithm, the surface tension for Sn-based binary solder alloys was simulated, and the comparison between the simulating results and data from experiments and literatures was analyzed as well. In addition, the relationship between surface tension and its decisive factors would be discussed based on the ANN and orthogonal design methods.

Findings

It is shown that the predicting model of surface tension of Sn-based solder alloys is constructed according to the BP–ANN theory, and the predicted value from the BP–ANN is in excellent agreement with the experimental results. The surface tension of Sn-based solders is determined by five factors, i.e. temperature, concentration, electronic density, molar atomic volume and electro-negativity. Among of the factors, molar atomic volume is major factor, and the order of degree of influence on surface tension is molar atomic volume > electro-negativity > electronic > density > concentration > temperature. Moreover, a simply reasonable equation is proposed to estimate the surface tension for Sn-based solders.

Originality/value

The five decisive factors of surface tension for Sn-based binary solder alloys have been analyzed theoretically, and a reasonable model of surface tension for Sn-based binary solder alloys is proposed as well. It is shown that ANN theory will be applied well to simulate the surface tension of Sn-based lead free solder.
Effect of P and Ge doping on microstructure of Sn-0.3Ag-0.7Cu/Ni-P solder joints
Authors: Yan Xingchen , Xu Kexin , Wang Junjie , Wei Xicheng , Wang Wurong
Published: September 2016

Purpose

The purpose of this paper is to comparatively investigate the microstructure and interfacial intermetallic compound (IMC) layer of Cu/SACPG/Ni and Cu/SAC0307/Ni solder joints after thermal aging.

Design/methodology/approach

The specimens were thermally aged at 150°C for 0, 24, 168 and 500 h. The microstructure and morphology of the interface IMC layer were observed by means of scanning electron microscope. The IMCs and the solder bump surface were analyzed by EDS. Moreover, the thickness of IMC layer was measured by using the image analysis software.

Findings

The morphology of IMC of Cu/SAC0307/Ni solder joint was consistent with that of the Cu/SACPG/Ni joint, which indicates that the addition of P and Ge had little effect on the IMC formation. The needle-like (Cu,Ni)6Sn5 was formed at the interface of solder/Ni solder joints. Meanwhile, the tiny particles inferred as Ag3Sn phase attached to the surface of (Cu,Ni)6Sn5. The growth rate of IMC layer of the Cu/SACPG/Ni joint was smaller than that of Cu/SAC0307/Ni joint with aging time increasing, which means the addition of trace P and Ge can slightly suppress the diffusion rate of the interfacial IMC.

Originality/value

There are no previous studies on the formation mechanism of the IMC layer of SAC0307 solder alloys with P and Ge addition.
Analytical and finite element methodology modeling of the thermal management of 3D IC with through silicon via
Authors: Wu Mei-Ling , Lan Jia-Shen
Published: September 2016

Purpose

This paper aims to develop the thermal resistance network model based on the heat dissipation paths from the multi-die stack to the ambient and takes into account the composite effects of the thermal spreading resistance and one-dimensional (1D) thermal resistance. The thermal spreading resistance comprises majority of the thermal resistance when heat flows in the horizontal direction of a large plate. The present study investigates the role of determining the temperature increase compared to the thermal resistances intrinsic to the 3D technology, including the thermal resistances of bonding layers and through silicon vias (TSVs).

Design/methodology/approach

This paper presents an effective method that can be applied to predict the thermal failure of the heat source of silicon chips. An analytical model of the 3D integrated circuit (IC) package, including the full structure, is developed to estimate the temperature of stacked chips. Two fundamental theories are used in this paper – Laplace’s equation and the thermal resistance network – to calculate 1D thermal resistance and thermal spreading resistance on the 3D IC package.

Findings

This paper provides a comprehensive model of the 3D IC package, thus improving the existing analytical approach for predicting the temperature of the heat source on the chip for the 3D IC package.

Research limitations/implications

Based on the aforementioned shortcomings, the present study aims to determine if the use of an analytical resistance model would improve the handling of a temperature increase on the silicon chips in a 3D IC package. To achieve this aim, a simple rectangular plate is utilized to analyze the temperature of the heat source when applying the heat flux on the area of the heat source. Next, the analytical model of a pure plate is applied to the 3D IC package, and the temperature increase is analyzed and discussed.

Practical implications

The main contribution of this paper is the use of a simple concept and a theoretical resistance network model to improve the current understanding of thermal failure by redesigning the parameters or materials of a printed circuit board.

Social implications

In this paper, an analytical model of a 3D IC package was proposed based on the calculation of the thermal resistance and the analysis of the network model.

Originality/value

The aim of this work was to estimate the mean temperature of the silicon chips and understand the heat convection paths in the 3D IC package. The results reveal these phenomena of the complete structure, including TSV and bump, and highlight the different thermal conductivities of the materials used in creating the 3D IC packages.
The role of weather and density dependence on population dynamics of Alpine‐dwelling red deer
Authors: BONARDI Anna , CORLATTI Luca , BRAGALANTI Natalia , PEDROTTI Luca
Published: September 2016

The dynamics of red deer Cervus elaphus populations has been investigated across different environmental conditions, with the notable exception of the European Alps. Although the population dynamics of mountain‐dwelling ungulates is typically influenced by the interaction between winter severity and density, the increase of temperatures and the reduction of snowpack occurring on the Alps since the 1980s may be expected to alter this pattern, especially in populations dwelling at medium ‐ low elevations. Taking advantage of a 29‐year time series of spring count data, we explored the role of weather stochasticity and density dependence on growth rate and vital rates (mortality and weaning success), and the density‐dependent variation in body mass in a red deer population of the Italian Alps. The interaction between increasing values of density and snow depth exerted negative and positive effects on growth and mortality rates, respectively, while weaning success was negatively affected by increasing values of density, female‐biased sex ratio and snow depth. Body mass of males and females of different age classes declined as population size increased. Our data support the role of winter severity and density dependence as key components of red deer population dynamics, and provide insight into the species' ecology on the European Alps. Despite the recent decline of snowpack on the Alpine Region, the negative impacts of winter severity and population abundance on growth rrate (possibly mediated by the density‐dependent decline in body mass) confirms the importance of overwinter mortality in affecting the population dynamics of Alpine‐dwelling red deer.
Addressing Inconsistencies in the Social Norms Drinking Literature: Development of the Injunctive Norms Drinking and Abstaining Behaviors Questionnaire
Authors: Meisel Samuel N. , Colder Craig R. , Read Jennifer P.
Published: September 2016

Background

Informed by inconsistent findings regarding the association between injunctive norms (IN) and drinking behaviors, the current study developed a new measure of IN, the Injunctive Norms Drinking and Abstaining Behaviors Questionnaire (IN‐DABQ). This measure addressed several psychometric weaknesses of prior assessment of this construct, specifically, reliance on single‐item measures, and assessment of a limited range of drinking behaviors. The new measure also assessed norms for reasons for abstaining from drinking as college students often have simultaneous motives to use and inhibit their drug use. A parallel measure of descriptive norms (DN), the Descriptive Norms Drinking and Abstaining Behaviors Questionnaire (DN‐DABQ), was created to allow for a comparison of the relative predictive effects of descriptive and IN in relation to different drinking outcomes.

Methods

A college sample (N = 254, female = 50.42%) was recruited using Amazon's Mechanical Turk. Participants completed an online survey assessing demographic characteristics, social norms for 3 referents, weekly alcohol use, and alcohol‐related consequences.

Results

Exploratory factor analyses indicated 2 factors for the DN‐DABQ and 3 factors for the IN‐DABQ. The IN Drinking Behaviors factor consistently predicted weekly consumption and alcohol‐related consequences across 3 reference groups (typical college student at your school, friends, and closest friends).

Conclusions

These findings suggest that prior inconsistencies in the relationship between IN and drinking behaviors are likely a function of poor measurement of this construct. Implications for normative feedback interventions are discussed.
Market Return, Liquidity, and Trading Activity of Various Trader Types in the Emerging Market: A Study of the TAIFEX
Authors: Hao Ying , Chou Robin K. , Ho Keng‐Yu , Weng Pei‐Shih
Published: September 2016

Using a large data set with detailed classifications of different trader types, this study sheds further light on the trading activity of various trader types on the Taiwan futures exchange (TAIFEX). Compared with domestic traders on the TAIFEX, we find that foreign institutional traders act as contrarians. In addition, when the market becomes illiquid, foreign institutional traders are net buyers and individual traders are net sellers. The result implies that both foreign institutional traders and individual traders may contribute to the recovery of liquidity dry‐ups together. Among all traders, only the order imbalance of foreign institutional investors presents return predictability when the market is illiquid, which suggests they have an information advantage in such a market.
Liquidity Commonality in Individuals’ Order Flows: New Evidence from the Taiwanese Stock Market
Authors: Hsieh Wen‐liang Gideon , Lin Yuan‐yi
Published: September 2016

By using data that distinguish order flow among types of trader, we provide new evidence that retail investors’ trading leads to strong liquidity commonality in the Taiwanese stock market. The liquidity provision of retail traders is cross‐sectionally correlated with each other and comoves closely with the market‐wide liquidity. Order flows of foreign and domestic institutional traders, despite co‐moving within their order flows, contribute substantially less to the market‐wide commonality. Commonality is stronger for large and index‐included stocks. The size effect and index inclusion effect are found for retailers’ order flows but not with institutional liquidity provision. Our results suggest that herd trading among retail investors can drive liquidity commonality in markets with active individual participants.
Effects of fatty acid transport protein 1 on proliferation and differentiation of porcine intramuscular preadipocytes
Authors: Chen Xiaoling , Luo Yanliu , Wang Ruisheng , Zhou Bo , Huang Zhiqing , Jia Gang , Zhao Hua , Liu Guangmang
Published: September 2016

Fatty acid transport protein 1 (FATP1) plays an important role in the fatty acid transmembrane transport and fat deposition. However, its role in porcine intramuscular preadipocytes proliferation and differentiation remain poorly understood. Here, we examined the effects of pFATP1 on porcine intramuscular preadipocytes proliferation and differentiation. Overexpression of pFATP1 in porcine intramuscular preadipocytes significantly promoted the proliferation of porcine intramuscular preadipocytes, and also significantly upregulated the expressions of peroxisome proliferator‐activated receptor γ, CCAAT enhancer binding protein α, lipoprotein lipase, fatty acid synthetase and perilipin 1. Moreover, overexpression of pFATP1 in porcine intramuscular preadipocytes significantly increased fat accumulation and downregulated β‐catenin protein expression. Overall, our results indicated that pFATP1 played an important role in porcine intramuscular preadipocytes proliferation and differentiation, and it might promote adipogenesis in porcine intramuscular preadipocytes by repressing Wnt/β‐catenin signaling pathway.