ARROW@DIT

The Analysis of Rush Orders Risk in Supply Chain: a Simulation Approach

Amr Arisha et al. — Wed, 16 May 2012 07:51:19 PDT

Satisfying customers by delivering demands at agreed time, with competitive prices, and in satisfactory quality level are crucial requirements for supply chain survival. Incident of risks in supply chain often causes sudden disruptions in the processes and consequently leads to customers losing their trust in a company’s competence. Rush orders are considered to be one of the main types of supply chain risks due to their negative impact on the overall performance. Using integrated definition modeling approaches (i.e. IDEF0 & IDEF3) and simulation modeling technique , a comprehensive integrated model has been developed to assess rush order risks and examine two risk mitigation strategies. Detailed functions sequence and objects flow were conceptually modeled to reflect on macro and micro levels of the studied supply chain. Discrete event simulation models were then developed to assess and investigate the mitigation strategies of rush order risks, the objective of this is to minimize order cycle time and cost.

Job Shop Scheduling Problem: an Overview

Amr Arisha et al. — Wed, 16 May 2012 07:51:17 PDT

The Job-shop scheduling is one of the most important industrial activities, especially in manufacturing planning. The problem complexity has increased along with the increase in the complexity of operations and product-mix. To solve this problem, numerous approaches have been developed incorporating discrete event simulation methodology. The scope and the purpose of this paper is to present a survey which covers most of the solving techniques of Job Shop Scheduling (JSS) problem. A classification of these techniques has been proposed: Traditional Techniques and Advanced Techniques. The traditional techniques to solve JSS could not fully satisfy the global competition and rapidly changing in customer requirements. Simulation and Artificial Intelligence (AI) have proven to be excellent strategic tool for scheduling problems in general and JSS in particular. The paper defined some AI techniques used by manufacturing systems. Finally, the future trends are proposed briefly.

Flow Shop Scheduling Problem: a Computational Study

Amr Arisha et al. — Wed, 16 May 2012 07:51:15 PDT

A computational study has been developed to obtain optimal / near optimal solution for the flow shop scheduling problem with make-span minimization as the primary criterion and the minimization of either the mean completion time, total waiting time or total idle time as the secondary criterion. The objective is to determine a sequence of operations in which to process ‘n’ jobs on ‘m’ machines in same order (flow shop environment) where skipping is allowed. The Simulation approach for deterministic and stochastic flow shop scheduling has been developed. It reads and manipulates data for 500 jobs on 500 machines. Different factorial experiments present a comparative study on the performance of different dispatching rules, such as FCFS, SPT, LPT, SRPT and LRPT with respect to the objectives of minimizing makespan, mean flow time, waiting time of jobs, and idle time of machines.

The proposed model is evaluated and found to be relatively more effective in finding optimal/ near optimal solutions in many cases. The influence of the problem size in computational time for this model is discussed and recommendations for further research are presented.

On the Selection of Simulation Software for Manufacturing Application

Amr Arisha et al. — Wed, 16 May 2012 07:51:13 PDT

The growing complexity of manufacturing along with the need for higher efficiency, greater flexibility, better product quality and lower cost urged the use of simulation in manufacturing systems. The number and variety of simulation software packages on the market increased as well. Consequently, the varieties of these packages led to some bewilderment on the part of potential users when faced the selection process. The present article addresses an overview of material addressed in journals, conferences, and textbooks on the selection of appropriate simulation software. It also suggests a classification of main criteria to be considered in evaluating simulation software packages. Moreover, a checklist of simulation software features with five levels of indication will be included. A proposed methodology has been employed in interpreting the checklist. Finally, future trends towards the provision of more effective selection tools will be discussed.

Evaluation of Scheduling Strategies on the Performance of a Flexible Manufacturing Cell:a Simulation Study

Amr Arisha et al. — Wed, 16 May 2012 07:51:11 PDT

The current trend in semiconductor manufacturing is characterized by expanding product variety, decreasing lead times from order to delivery, exacting standards of quality, and competitive prices. One possible means of achieving this is in the form of increased flexibility. Providing flexibility is typically an expensive proposition so, industrial engineers aim to provide more economic approaches to enable flexible manufacturing cells and related equipment to operate appropriately in an efficient manner. It is essential to characterize these tools in detail before the production plans are finalized. Using state-of-the-art computer simulation, a generic model of photolithography tools has been developed. The model examines the impact of changing product volumes, buffer size, product sequence and product-mix on performance criteria, e.g. throughput time. The high investment cost of flexible manufacturing cells justifies the use of computer simulation support to maintain high system performance and reduce risk by predicting the system behavior under any feasible production schedule. Simulation results presented in a Taguchi experimental design framework offer a robust methodology to gain quick insights into the behavior of selected parameters within flexible manufacturing system environments. The developed model has been evaluated and found to be relatively more effective than simplified deterministic approaches when measured against actual production.

Thin-Film Simulation Model for Comparing Production Schedules in a Semiconductor Fabrication Facility

Amr Arisha et al. — Wed, 16 May 2012 07:51:09 PDT

Analysis of advanced manufacturing systems in any manufacturing industry requires certain level of knowledge about the system. Flexible manufacturing cells, in particular, are commonly used in most wafer fabrication to provide the ability to change product without requiring the construction of new manufacturing plant. This level of flexibility comes at a significant capital cost and, in order to achieve the maximum potential of each cell, it is essential to characterize and establish the performance of these cells in detail before a new production plan is implemented. Using state-of-the-art computer simulation and a structured modelling methodology a generic model of flexible manufacturing cells has been developed and used to examine the impact of changing product volumes (ramps), product priority, and maintenance schedules on the toolset performance. The model has been developed and validated using actual production data and found to effectively duplicate the behaviour of the manufacturing installation. Various criteria, e.g. tool utilization & product cycle time, are used to evaluate the response of the cell to the demands made on it by different manufacturing plans. In this way, a plan that maximizes system performance and reduces risk may be achieved.

A Simulation Model to Characterize Photolithography Process of a Semiconductor Wafer Fabrication

Amr Arisha et al. — Wed, 16 May 2012 07:19:00 PDT

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex devices are increasing requiring ever higher efficiency from the manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterising and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the most complex processes in a semiconductor manufacturing environment. Using state-of-the-art computer simulation and a structured modelling methodology a generic model of photolithography flexible manufacturing cells has been developed and used to mimic actual performance of the tools. Comparison of the output from the model with data from the plant showed the quality of the model. This paper discusses the technique used to develop the simulation model to characterize the photolithography process tools. Details on the structured modelling approach taken to develop reusable simulation models have also been presented. Conclusions and recommendations to maximize the process performance and reduce risk have been included.

Applications of Simulation in Semiconductor Manufacturing Facilities

Amr Arisha et al. — Wed, 16 May 2012 07:18:59 PDT

Semiconductor fabrication facilities face many challenges through the many phases of their life cycle including design, build, various production ramps, and many levels of production. Confronted with global competition and rapidly changing technology and customer requirements, there is an increasing demand for rapid solution techniques to improve efficiency in manufacturing. The complexities and forces of both market and the process combine to make the use of simulation crucial at many different planning and control levels. While not a panacea for sustainable performance, simulation provides an effective vehicle for defining the path from competitive concepts to real world solutions and gives an opportunity to experiment with, and assess the impact of, production plans, aiding the management and production teams’ decisions. Integrating simulation with common approaches; Operations Research (OR) and Artificial Intelligence (AI) to solve manufacturing problems is a new trend towards higher quality solutions. This paper presents an overview of how simulation can be employed to improve manufacturing performance and reduce costs

Simulation in Semiconductor Manufacturing Facilities

Amr Arisha et al. — Wed, 16 May 2012 07:18:58 PDT

Semiconductor manufacturing is one of the most complex industries in terms of technology and manufacturing procedure. The life cycle of a semiconductor facility (FAB) has many phases, in their life cycle including capacity planning, new products introduction, variation of products/technologies, and decline phase. The complexity of the manufacturing and the external forces from markets and technology growth make predicting the effects of changes in the manufacturing system problematic. Simulation, if used correctly, is a powerful hands-on tool which may be used to give a better insight of the effect of engineering/management decisions on the performance of the manufacturing system. While not a panacea for sustainable performance, simulation provides an effective vehicle for defining the path from competitive concepts to real world solutions and gives an opportunity to experiment with, and assess the impact of, production plans, aiding the management and production teams’ decisions.

This paper presents some examples of simulation applied to semiconductor manufacturing for performance improvement and costs reduction. Integrating Simulation with Operations Research (OR) and Artificial Intelligence (AI), promises to significantly improve the ability to address complex problems for highly complex manufacturing facilities.

Evaluating the Impact of Production Scheduling on Tool Performance

Amr Arisha et al. — Wed, 16 May 2012 07:18:56 PDT

Scheduling of a semiconductor manufacturing facility is one of the most complex tasks encountered. Confronted with a high technology product market, semiconductor manufacturing is increasingly more dynamic and competitive in the introduction of new products in shorter time intervals. Simulation provides an effective decision support tool in scheduling of semiconductor manufacturing. Simulation model was developed as a risk assessment tool for one of the implant process area. The model examines the impact of production schedule on tool performance by testing different production scenarios. Production ramping, local buffer capacity, product sequence and product mix seem to be influential factors of the toolset performances.

Enabling RFID Technology in Irish Hospitals

Khaled Ismail et al. — Wed, 16 May 2012 07:18:55 PDT

Hospitals represent a significant part of healthcare systems and account for no less than 60% of the entire healthcare service in most of developed countries. Therefore, improving service in hospitals is an important element to the process of healthcare reform. Better use of resources, more consistent quality, and a higher service level are the keys to rationalise the huge expenditure in healthcare systems due to higher growth in demand. Even though massive spending has been directed towards hospital improvement in Ireland, services provided in Irish hospitals are ranked relatively low comparing to the other European countries. Growth of population, aging, European Union regulations, and demanding patients place more pressure on healthcare researchers to provide innovation solutions for Irish hospitals. In the last two decades, the use of technology had a significant impact on hospital performance in terms of responsiveness, quality, and management practices. Radio Frequency Identification (RFID) technology has been successfully implemented in a number of hospital systems in many developed countries. It is an emerging technology for applications such as managing and tracking patients, equipment, and drugs. Integrating RFID technology into hospital systems allows a dramatic enhancement in hospital efficiency and effectiveness measures to happen. This paper gives a comprehensive review on the up-to-date applications of RFID technology in hospital systems. It includes a classification of RFID applications at different areas of hospitals. Inclusive analysis of the impact of RFID implementation on the overall performance of the hospitals is presented. As new technology, this paper looks into the challenges and problems facing the management in employing the technology. Recommendations on potential impact of using RFID in Irish hospitals are discussed.

Risk Assessment Model for Emergency Departments in Dublin Hospitals

Michael Thorwarth et al. — Wed, 16 May 2012 07:18:54 PDT

The internal dynamics of emergency departments (ED) in Irish hospitals represent complex non-linear stochastic systems with an environment of uncertainty, variability and limited resources. Planning and managing such systems pose overwhelming demands. To improve operations, patient service, resource planning, and real-time reaction to unexpected events, sophisticated tools to efficiently achieve these goals must be applied.

Advanced solution techniques (e.g. simulation and optimisation) have been successfully applied in manufacturing operations to improve the delivery, cost-effectiveness and service quality. Yet, random arrival of patients, limited resources and multitasking are challenges in EDs that add more complexity to this critical area. This study delivers a contribution to both theory and practice. By the elaboration of patient risks types, simulation is investigated for its compliance with risk management approaches that hence delivered modifications to the simulation modelling approach. This investigation and the modifications allows the conclusion that simulation is suited for risk management and that simulation models are applicable as risk assessment models for healthcare once the modifications are considered by the modeller.

Effect of N-Doping on the Photocatalytic Activity of Sol–Gel TiO2

Nicholas Nolan et al. — Wed, 16 May 2012 06:50:14 PDT

In order to study the visible light photocatalytic activity of nitrogen doped titanium dioxide, the interaction between nitrogen dopant sources and titania precursors during sol–gel synthesis is investigated. N–TiO2 was synthesised using the sol–gel method using 1,3-diaminopropane as a nitrogen source. Samples were annealed several temperatures and the percentage of rutile present determined by X-ray diffraction to be 0% (500 ◦C), 46% (600 ◦C), and 94% (700 ◦C). The reducing amounts of anatase at higher temperatures are studied using FTIR, which suggests the absence of any polymeric chains formed by the chelating agents, which would normally extend anatase-to-rutile transformation temperatures. Differential scanning calorimetry shows that crystalliation occurs before 500 ◦C, providing the crystalline form determined by XRD at 500 ◦C. Increased temperature also resulted in diminished visible light absorption capability, with only the 500 ◦C sample showing significant absorption in the visible region. XPS studies revealed that nitrogen remained within the TiO2 lattice at higher temperatures. Consequent with the reduced visible light absorption capacity, photocatalytic activity also reduced with increased annealing temperature. Degradation kinetics of methylene blue, irradiated with a 60 W house-bulb, resulted in first order degradation rates constants of 0.40 × 10⁻², 0.19 × 10⁻², and 0.22 × 10⁻² min−1 for 500, 600, and 700 ◦C respectively. Degradation of Degussa P25 was minimal under the same conditions, and that of undoped TiO2 was 0.02 × 10⁻² min⁻¹. Similarly, using 4-chlorophenol under solar irradiation conditions, the N-doped sample at 500 ◦C substantially out-performed the undoped sample. These results are discussed in the context of the effect of increasing temperature on the nature of the band gap.

Multiple Solutions of the Quasi Relativistic Choquard Equation

Michael Melgaard et al. — Wed, 16 May 2012 06:35:48 PDT

We prove existence of multiple solutions to the quasi relativistic Choquard equations with a scalar potential.

Existence of a Minimizer for the Quasi-Relativistic Kohn-Sham Model

Carlos Argaez et al. — Wed, 16 May 2012 06:35:46 PDT

We study the standard and extended Kohn-Sham models for quasi-relativistic N-electron Coulomb systems; that is, systems where the kinetic energy of the electrons is given by the quasi-relativistic operator (see article) . For spin-unpolarized systems in the local density approximation, we prove existence of a ground state (or minimizer) provided that the total charge Z of K nuclei is greater than N-1 and that Z is smaller than a critical charge (see article).

Stiefel and Grassmann Manifolds in Quantum Chemistry

Eduardo Chiumiento et al. — Wed, 16 May 2012 06:35:45 PDT

We establish geometric properties of Stiefel and Grassmann manifolds which arise in relation to Slatertype variational spaces in many-particle Hartree-Fock theory and beyond. In particular, we prove thatthey are analytic homogeneous spaces and submanifolds of the space of bounded operators on the single-particle Hilbert space. As a by-product we obtain that they are complete Finsler manifolds. These geometric properties underpin state-of-the-art results on existence of solutions to Hartree-Fock type equations.

The Experiences and Views of Lesbian Parents and Adult Children of Lesbian Parents in Ireland: an Exploratory Study

Aoife Quille — Tue, 15 May 2012 03:23:37 PDT

This research focused on the experiences and views of lesbian parents and adult children of lesbian parents. The experiences of the members of lesbian-parented families determined the main areas that were explored. The lack of international and Irish research on the lived experiences of lesbian parents and their children prompted this investigation. The study was conducted using qualitative, semi-structured interviews. The sample consisted of three lesbian parents and two adult children of lesbian parents from two parent lesbian families. The findings highlighted the experiences of the parents and adult children from lesbian-parented families in reference to: the Irish legal context; dealing with disclosure of their family type to others for lesbian parents and their children; sources of support for lesbian parents and their children; lesbian parents and their children in the education system; homophobic bullying of children with lesbian parents and the division of labour and the difference in parenting roles between the biological and non-biological mother. Recommendations made in this study included addressing the rights of same-sex families in Irish law, additional support groups for same-sex parents and their children and that further research undertaken with a wider sample including an exploration of the experiences of male gay parents and their children.

An Evaluation of the Succession Law Changes Introduced by the Civil Partnership and Certain Rights and Obligations of Cohabitants Act 2010

Niamh Dennehy — Tue, 15 May 2012 03:23:37 PDT

The Succession Act 1965 introduced a curb on a person‘s freedom of testation and gave protection to spouses and children on the death of a husband/wife, mother or father. As a result, certain relationships took precedence over others in the distribution of an estate, e.g. a surviving spouse‘s legal right share to a deceased spouse‘s estate is absolute. Since that legislation was enacted Irish society has changed greatly with a new variety and complexity of family structures. The provisions introduced by the Civil Partnership and Certain Rights and Obligations of Cohabitants Act 2010 are an attempt to keep pace with the changes which have taken place in modern society. As a result of the succession law provisions in the Act of 2010 certain relationships take priority over other competing interests in an estate. Thus, a new hierarchy of claimants to an estate is created. For example, a biological child can make an application which can have the effect of eroding the legal right share of a surviving civil partner but not that of a surviving spouse, their step-parent.

I plan to review the succession law provisions contained in the Act of 1965 and the amendments made to the 1965 Act by the Act of 2010 and analyse and examine which competing interests in an estate will take precedence, the varying degrees of protection afforded to individuals in the newly recognised family structures, the rationale behind these variations and the possible ramifications in the future.

Early School Leaving : an Exploration of the Factors Contributing to School Non-Completion

Jennifer McGarr — Tue, 15 May 2012 03:23:36 PDT

This study is of an explorative nature, investigating early school leaving in Ireland today. Despite a range of interventions to address school non-completion, approximately 14% of students (as of 2007) continue to leave school without completing their education every year (Byrne & Smyth, 2010). A disproportionate amount of these young people come from disadvantaged backgrounds (Barnardos, 2006). Education is a powerful predicator of life chances and opportunities. Those who leave school with little or no formal education have less opportunities in later life, are more likely to be unemployed, have lower levels of general health and are at a greater risk of becoming involved in crime (Barnardos, 2009).

This study investigates the reasons why young people are opting out of school, the contributing factors to their leaving school and the barriers that prevent them from achieving their educational potential. Using a mixed methods approach, data was collected from early school leavers, teachers and stakeholders within the school system. Both qualitative and quantitative methods were adopted to provide for a thorough examination of this educational problem. Findings highlight the complex and multifaceted nature of early school leaving. Disengagement from education is essentially a process which does not have one sole cause and for many, starts as far back as primary school. A variety of factors and influences impact on a young person’s educational career, with a greater incidence of early school leaving occuring where a number of risk factors co-exist. This study offers a number of recommendations for increasing student retention, with a particular emphasis on improving school relationships and revising the curriculum and modes of assessment.

An Exploration into the Nature and Extent of Violence Experienced by Secondary School Teachers

Ciana Lernihan — Tue, 15 May 2012 03:23:35 PDT

The purpose of the present study was to explore the nature and extent of violence experienced by secondary school teachers. A combination of quantitative and qualitative research methods were used in order to gain the greatest insight into teachers experiences of violence and intimidation in schools. The research instrument used in order to gather data was a questionnaire. One hundred and ten questionnaires were gathered from teachers in a number of different schools. The study investigates teachers own experiences of violence and intimidation, the reporting of violence, the effects of violence on teachers health, moral and personal and professional lives. Adequate levels of teacher training and in-services on dealing with violence are also investigated. Finally, support services available for teachers who are experiencing difficulties and an awareness of such support services amongst teachers are also investigated. The findings highlighted that teacher’s experience violence in a number of different forms ranging from verbal abuse, physical abuse, threats and intimidations. A number of different perpetrators were found to abuse teachers including students, parents and other staff members. A number of effects were also found to have affected teachers who experienced violence and intimidation. Stress, anxiety, taking leave from working, visiting a GP and low morale are a number of the key issues found to have affected teachers. A lack of awareness amongst teachers of support services available to them was also found in this study. The importance of teacher training is presented and the demand for an increase in such training has been supported by this study. School policies on violence have been found to be very important for schools in dealing with incidences of violence and the incorporation of teachers within is vital. In accordance with the findings the present research recommends that all schools have a clear policy on violence in place that incorporates teachers. Also compulsory and increased training on preventing and dealing with incidences of violence be given to teachers. Finally a greater awareness amongst teachers of support network in place for them be created so as teachers can avail of them if they so require.

Mothers Who Use Illicit Drugs:an Exploration of Professional Workers’ Perceptions Towards Mothers Who Use Illicit Drugs

Julieann Lane — Tue, 15 May 2012 03:23:34 PDT

Although much has been written in recent times about women’s drug use, there has been a scarcity of research into motherhood and drug use in Ireland as it remains both a complex and sensitive issue. Since the 1980’s Ireland has seen a dramatic and unprecedented increase in the availability of illicit drugs. This increased availability reflects rising consumption of illicit drugs amongst women. The aim of this study was to explore the perceptions that a sample of professional workers hold of mothers who use illicit drugs in Ireland. The study reviews the literature applicable to the area of drug use and motherhood with, looking at both Irish research and international research in gaining an accurate picture of drug use and motherhood. The study examines the issues that mothers are faced with and examines factors such as Parenting and Childcare. It also examines in thorough detail the stigmatisation which is prevalent in Irish society and amongst professionals who come into contact with mothers who use drugs. A qualitative approach was adopted in order to gain insights into the professional’s views towards this marginal group. The qualitative techniques used were semi structured interviews with a variety of disciplines and participant observations in a family support organisation that worked with many service users, some of which were mothers who used drugs. The data was obtained and analysed using five dominant themes throughout the findings. Both primary and secondary data was analysed and reviewed accordingly. The findings from the research highlight many important factors in relation to the care that mothers who use drugs access. Many Professionals held ambivalent attitudes towards mothers and there was a general consensus that drug use and motherhood is mutually exclusive. It emerged that varying groups of professions perceive mothers in very different ways and many appear to approach it from a deficits perspective.

Emerging Adulthood in Ireland: Is the Quarter-Life Crisis a Common Experience?

Mairead Murphy — Tue, 15 May 2012 03:23:33 PDT

The purpose of this study was to explore the experiences of young people between the ages of eighteen and twenty-eight in Ireland to establish the prevalence of what has become known in popular culture as the quarter-life crisis. This transitional period in a young person’s life is academically referred to as emerging adulthood and is a time of great change and personal growth. The study utilised a qualitative approach; individual interviews and focus groups were carried out with the identified research group. The findings of the study indicated that indeed, emerging adulthood is a challenging time, and for some, it is a time in crisis. A variety of stressors commonly arise in the lives of emerging adults, relating mainly to personal relationships, living arrangements, financial issues and identity development. Emotional responses to these were varied, including both positive and negative emotions as participants reflected on their current life and future. In many instances, it became apparent that the crisis experienced during emerging adulthood served a purpose, as a stimulus for change and development. The significance of this study rested in its attempt to expand literature on this life period within an Irish context and to determine ways in which emerging adults might be supported during this challenging period of developmental transition.

Adolescents Who Sexually Abuse: Exploring the Impact on the Family

Tracey Carroll — Tue, 15 May 2012 03:23:32 PDT

This research project considers a frequently ignored dimension of adolescent sexual abuse, the parents and families of the adolescent perpetrator. This study focuses on eliciting professionals‟ views of the impact on the family when an adolescent member has sexually abused. The context for the study is outlined with an account of the prevalence of and explanations for adolescent sexual abuse. The study proceeds to look at legislation and the impact on labelling. Areas relating to the family on the impact of disclosure, parental reactions and the process of engagement are explored.

Semi-structured interviews were conducted with five professionals working within the child welfare and criminal justice system who worked with young people who had sexually abused and their families. The purpose of the study was to explore with professionals their perceived perception of the impact having an adolescent sexual abusing member has on families, from their contact with family members.

The findings and analysis suggest, from the professionals‟ perspective, that families are faced with many issues when confronted with the discovery that their child has sexually abused. These include emotional upheaval, risk management and issues regarding engaging with services. If the aim of therapeutic intervention with sexually abusing youth is to reduce the risk of further abuse and to help the young person develop a healthy lifestyle, this study contends from the professionals‟ perspective, that family involvement in this process is essential. The researcher concludes this study by making recommendations.

Nonthermal Plasma Inactivation of Food-Borne Pathogens

N. N. Misra et al. — Tue, 15 May 2012 03:10:39 PDT

Non-thermal plasma (NTP) is electrically energized matter, composed of highly reactive species including gas molecules, charged particles in the form of positive ions, negative ions, free radicals, electrons and quanta of electromagnetic radiation (photons) at near-room temperature. NTP is an emerging nonthermal technology with potential applications for decontamination in the food industries. An upsurge in the research activities for plasma based inactivation of food borne pathogens is evident in the recent years. These studies have shown that NTP can be used for the surface decontamination of raw produce, dried nuts and the packaging materials etc. This paper reviews the action of plasma agents on the microbial classes and describes proven and potential applications in food processing. Novel developments in the technology and a future outlook for the application to foods are discussed.

Formative Assessment Practices in Built Environment Higher Education Programmes and the Enhancement of the Student Learning Experience

Lloyd Scott et al. — Fri, 11 May 2012 08:07:09 PDT

It is widely accepted across Higher Education (HE) that assessment has a strong link with learning and a key factor in this link is formative assessment. Formative assessment is generally defined as an activity taking place during a programme or unit of learning with the express purpose of improving and enhancing student learning. However, there is still considerable disagreement over the roles of lecturers and students in this process. It is therefore very important to understand how lecturers in built environment (BE) undergraduate education perceive their own roles and the role of their students in using assessment strategy to deliver deep learning. An investigation into lecturers' perceptions of their roles and their conceptions related to the assessment process of students in BE programmes is reported. An on-line survey was conducted with over 130 Irish BE academics involved with the delivery of undergraduate programmes in the areas of Architecture, Architectural Technology, Quantity Surveying and Construction Management. Additional data were also obtained and analysed from their associated programme documentation. Discussion is focused on a critical evaluation of the findings of the study with the current literature on the roles of BE academics in the formative assessment process. As a result recommendations are made on how lecturers may better formulate appropriate assessments for their students that will encourage deep learning and thus create enhanced HE learning experiences.

Practical Simulation Application: Evaluation of Process Control Parameters in Twisted-Pair Cables Manufacturing System

Amr Mahfouz et al. — Fri, 11 May 2012 06:59:22 PDT

Intensive competition and rapid technology development of Twisted-Pair Cables (TPC) industry have left no room for competing manufacturers to harbour system inefﬁciencies. TPC are used in various communication and networks hardware applications; their manufacturing facilities face many challenges including various product conﬁgurations with different equipment settings, different product ﬂows and Work in Process (WIP) space limitations. The quest for internal efﬁciency and external effectiveness forces companies to align their internal settings and resources with external requirements/orders, or in different words, signiﬁcant factors must be set appropriately and identiﬁed prior to manufacturing processes. Integrated deﬁnition models (IDEF0, IDEF3) in conjunction with a simulation model and a design of experiments (DOE) have been developed to characterize the TPC production system, identify the signiﬁcant process parameters and examine various production setting scenarios aiming to get the best product ﬂow time.

Three Key Challenges Facing Higher Education and Policymakers

Ellen Hazelkorn — Thu, 10 May 2012 09:13:03 PDT

Our preoccupation with the relative standing of universities and national education systems—illustrated by the growing popularity and obsession with university rankings—reflects the consensus that higher education is essential for economic growth, global competitiveness and a civil society. Universities and nations are being measured according to indicators of global capacity and potential in which comparative and competitive advantages come into play. The more globalization drives a single market in education, as it does in most goods and services, the more higher education is a beacon for investment and talent—the more this kind of barometer is inevitable.

Can the Use of Clickers or Continous Assessment Motivate Critical Thinking?: a Case Study Based on Corporate Finance Students

Lucia Morales — Thu, 10 May 2012 09:00:44 PDT

This study explores the use of clickers as a tool to support, encourage and motivate critical thinking in higher education students. A case study was carried out with a cohort of undergraduate students undertaking the BSc. in Accounting and Finance during the academic year 2009/10, were corporate finance was a major component. Since the students in this sample had previously demonstrated passivity during their corporate finance classes, it was proposed that clickers would help motivate them to participate during face to face sessions. Previous research on the use of clickers shows evidence that this tool has a positive effect on student participation and interaction in the classroom. The results of this study suggest that clickers can positively affect classroom dynamics; they help activate the learning experience and provide a more relaxed atmosphere, where students can interact with their teacher. However, little evidence was found to indicate that clickers are a good device to enhance critical thinking skills. In this context, strategies based on a problem-centered approach to learning appear to provide a better outcome.

Interactivie Web-Based Simulation for Supply Chain Education

John Crowe et al. — Thu, 10 May 2012 08:41:08 PDT

Knowledge economies are based on the concept of knowledge transfer between education institutes and stakeholders. In response, the significant move away from traditional teaching methods to the emerging paradigm of eLearning has become increasingly in evidence across many academic disciplines. To assist in the transition from traditional learning to eLearning, more interactive and virtually orientated teaching aids are needed. This chapter introduces a simulation-based learning framework that integrates web-based simulation and a web content management hierarchy model. Using the complex subject of supply chain management as a case study, the new framework allows users to examine various real-life strategic management scenarios, encourages group work and has remote access capabilities for distance learning. Interactive learning is facilitated using the web-based simulation portal, enabling instructors to demonstrate the complexity of decisions in multiple criteria environment and also show the users the impact of strategies on performance. Supply chain simulation creates an animated experience and better understanding of system dynamics including risk. The framework assists in the knowledge and skills transfer between third-level education institutes and their stakeholders, primarily industry partners and the wider community

Virtual ED:Utilisation of a Discrete Event Simulation-Based Framework in Identifying ‘real-time’ Strategies to Improve Patient Experience Times in an Emergency Department

Waleed Abo-Hamad et al. — Thu, 10 May 2012 08:14:21 PDT

Objectives and Backgrounds Emergency Department (ED) overcrowding and associated excessive Patient Experience Times (PETs) have proven deleterious impacts on patient mortality, morbidity and overall length of hospital stay. Health systems constantly seek cost-effective organisational strategies to reduce ED crowding and improve patient outcomes, but complex change implementation is constrained by the necessity of maintaining concurrent safe patient-care. Computer modelling in a “virtual reality” has been successfully utilised in industries outside medicine, in providing innovative “real-time” solutions to outdated practices. Therefore a bespoke “Virtual ED” computer model, based on a Discrete Event Simulation (DES) -Based Framework was constructed to determine the best simulation scenarios needed for effective “real-time” strategies to improve PETs in a Dublin teaching hospital ED. The three simulation scenarios tested were: (1) Increasing medical staffing. (2) Increasing assessment space. (3) Enforcing the national 6-h boarding limit.

Methods A collaborative interactive decision support model was constructed to analyse patient flow through the ED, considering the variability in patients' arrival rate, the complexity levels of patients' acuity, and the dynamic interactions between key resources (eg, clinical staffing, physical capacity, and spatial relationships). ED Process Mapping utilised IDEF0, for modelling complex systems in a hierarchical form and Extend Suite V.7 software was used to develop the DES—based framework model. Historical, anonymised ED patient data of 59 986 patient episodes (tracking times, indirect acuity and clinical resource utilisation) was analysed from the “real-time” ED Information System. Baseline ED Key Performance Indicators (KPIs), PETS and resource utilisation was determined for comparison with the DES model. Distinct study scenario variables (Abstract 007 table 1) were added to the DES model and run for 3 month continuous blocks to eliminate confounders. Continuous verification and validation of the ED simulation model was ensured by using Kolmogorov–Smirnov goodness of fit test with a 5% significance level. The ultimate results of the simulation model were validated using three techniques; face validation, comparison testing, and hypothesis testing, with the deviation between actual and simulated results ranging from 1% to 9% with an average of only 5% deviation.

Supply Chain Simulation: Experimentation without Pain

Amr Arisha et al. — Thu, 10 May 2012 08:00:26 PDT

Bridging the gap between theory and practice has always been a key issue for students and graduates. The magnitude and scope of subject areas that students at third level institutions have to learn in theory means that visualising them without any practical experience can be very difficult. Understanding the complexity of supply chain networks and how to manage them create a considerable level of difficulty for students and professionals. Theories and applications included in supply chain management subjects are the key to empathise the real challenges. Nevertheless, teaching these theories needs substantial efforts and new innovative approaches to deliver the concepts and assure successful transfer of the learning outcomes.

To complicate things more, the levels of uncertainty and risk within an entire supply chain are still not fully recognised or understood even by industry professionals. Research studies showed the need for more transparency and collaborative approaches to take place among supply chain partners in order to achieve more sustainable operations. Making sure students comprehend the scale of activities and stochastic nature of a supply chain before they carry on their industrial careers is therefore crucial.

Using computer simulation integrated with structured modelling techniques, a detailed, animated and generic supply chain simulation-based learning framework can be developed to incorporate many areas of learning undertaken by students in relation to the supply chain management. Experimenting on the simulation models allow the students to examine quantitatively the impact of changing critical factors (e.g. inventory level, demand, suppliers’ lead time) on the performance of supply chain. This paper demonstrates the impact of using interactive simulation technologies in teaching third level education with special reference to supply chain management and discusses the benefits of learning through such a level of immersion.

Distributed Supply Chain Simulation Portal: Design and Implementation

Amr Arisha et al. — Thu, 10 May 2012 07:56:16 PDT

The emerging paradigm of eLearning is becoming increasingly in evidence across many academic disciplines acknowledging the concept that learning processes no longer support traditional teaching methods alone. It can be argued that today’s third level education students are part of a new virtual era where the blackboard has been replaced with an interactive whiteboard. To assist in the transition from traditional learning to eLearning, more interactive and virtually orientated teaching aids are needed. A simulation-based learning framework that integrates web-based simulation and a web content management hierarchy model is the key objective of this paper. Using the highly complex subject of supply chain management as a case study, the new framework allows users to examine various management strategies of real-life scenarios, encourages group work and has remote access capabilities for distance learning. Interactive learning is facilitated using the web-based simulation portal, enabling instructors to demonstrate the complexity of decisions in multiple criteria environment and also show the users the impact of strategies on performance. Supply chain simulation creates an animated experience and better understanding of the system dynamics including risks. The portal interface is friendly and hence there is a potential to be applied in other subject areas.

Web-Based Supply Chain Simulation: an Integrated Approach

Amr Arisha et al. — Thu, 10 May 2012 07:49:51 PDT

This is an era marked by rapid technology development in all different educational arenas. Alongside this growing demand of technology, learning process is getting new forms and hence traditional teaching approaches tend to struggle and lack the requisite qualities to meet new generation expectations. In third level education, this problem is increasing in magnitude and new dimensions, especially when it comes to teaching difficult subjects such as supply chain management. Understanding the complexity of supply chain networks and how to manage them create a considerable level of difficulty for students and professionals. Collaboration between supply chain members is now recognised as an important strategic factor in creating a solution to the complexity of the supply chain system. New technologies are beginning to bring a huge transformation into teaching delivery methods. This paper presents an integrated web-based simulation framework that supports learning supply chain concepts and challenges. Simulation-based learning environment allow participants to examine various management strategies without real disruptions to the current system. Using supply chain simulation creates a vibrant experience and a better understanding to the impact of uncertainty and risks within supply chains. Integrating web technologies to simulation has added an edge to the learning environment with the friendly graphical user interface.

Reducing Whole Body Vibration Levels in Off-road, Heavy-duty Vehicles: A Case Study with Computer Modelling

Shaun McFadden et al. — Wed, 09 May 2012 01:22:45 PDT

This paper describes a case study involving the dynamic ride performance of a 30-ton, articulated dumper vehicle. The vehicle in question was originally fitted with a front-end, solid axle with leading arm mechanism. After an engineering design program, the vehicle was custom-fitted with a Timoney Independent suspension system. Extensive testing and modelling activities using LMS Virtual.lab Motion® were undertaken to determine the productivity levels of each vehicle. It was demonstrated that the vehicle fitted with a Timoney suspension could achieve a productivity increase of up to 50%. A health analysis is also presented which shows the Timoney Independent suspension system reduces the potential health risk.