bluuebunny/crossref_metadata_2025 huggingface dataset:
Organisational, work group related and personal causes of mobbing/bullying at work
Authors: Zapf Dieter
Published: July 2002

This article investigates the causes of mobbing (bullying) at work. Mobbing is defined as a severe form of social stressors at work. Unlike “normal” social stressors, mobbing is a long lasting, escalated conflict with frequent harassing actions systematically aimed at a target person. It is argued that the organisation, the social system, a certain perpetrator and the victim have to be considered as potential causes of mobbing. Results of two samples of mobbing victims and a control group support this view. It is concluded that one‐sided explanations on the causes of mobbing are likely to be inappropriate and that many cases are characterised by multi‐causality – a common finding in conflict research.
Leadership amid the constraints of trust
Authors: Fairholm Matthew R. , Fairholm Gil
Published: July 2002

The leader’s role is a two‐fold cultural and teaching enterprise: institutionalizing cultural principles in their organizations and then teaching followers to internalize these cultural principles in their actions. The specific features of an organization’s culture condition what leaders do and how they do it. However, leaders also condition the culture by their actions and beliefs. Seen this way, a leader’s primary activity is to create a culture supportive of desired values. As followers internalize these cultural values, they develop a devotion to the institution that cannot come in any other way. This both requires trust and encourages trust. The task is not simple; it is fraught with difficulty, pitfalls, and barriers. This article explains some constraints that hinder the development of a culture based on trust specifically and the enterprise of leadership in general.
An empirical examination of the effects of information systems integration on business process improvement
Authors: Bhatt Ganesh D.
Published: July 2002

Since the mid‐1980s, the subject of information systems (IS) integration and its role in business process improvement (BPI) has been of considerable interest to business managers and researchers. The present study examines the effects of IS integration on BPI. The moderating effects of industry type, information intensity of the industry, and time since the initiation of the existing program in the firm have also been analyzed. The data for the study were gathered through a survey of Fortune 500 US firms at divisional levels. The results of the study support the hypotheses that data integration and communication networks integration affect the dimensions of BPI. However, none of the moderators, except industry type, was found significantly affecting the relationships between networks integration and process improvement effect and customer focus.
Human resource development in Ireland: organizational level evidence
Authors: Heraty Noreen , Morley Michael J.
Published: July 2002

The ability of the Irish economy to continue growing depends not only on demand, but also on supply conditions. While these have remained favourable up to now, there are signs of increasing skill shortages and ongoing pressure on economic infrastructure. It has been established that human resources development (HRD) is vital to maintaining Ireland’s competitiveness internationally. This paper seeks to document the nature of HRD at organizational level in Ireland. Following a brief sketch of the Irish context, we draw on a nationally representative survey of HRD practices and present data on where responsibilities for HRD policy decisions lie, the extent of and the approaches to the identification of HRD needs, HRD coverage and delivery, and the nature of longer‐term developmental activities. Variations between firms of different size, between sectors, between firms of different origin, and between unionized and non‐union environments are, where appropriate, highlighted.
The Concept of the Learning Organization
Authors: West Penny
Published: July 2002

Starts from the premiss that, although initiatives such as Investors in
People and total quality management link with the concept of the
learning organization and attempt to inspire change to structural,
cultural and ethical aspects of work organization, our understanding of
organizations must aspire to a higher level of intellectual analysis if
they are to be recognized as complex learning organisms within a
turbulent environment. Beginning with a systems approach, explores ways
in which organizations may learn and positively influence their
environments. Suggests further insight, using biological, cybernetic,
dialectical and chaos analyses to connect with the concept of the
learning organization. Discusses implications for the position and
perception of organizations in society if learning organizations are to
evolve, and concludes that, while the concept presents a viable and,
indeed, essential ideology to match current and future uncertainty,
managers may find the transition problematic, with little guidance to
effect such ground‐breaking change.
Line managers and human resource development
Authors: Heraty Noreen , Morley Michael
Published: July 2002

Focuses on the line manager as a key stakeholder in the human
resource development process. Considers the general trend towards
devolvement of human resource activities to line specialists. Examines
issues involved in devolving training and development to the line, with
specific emphasis on the potential difficulties. Recent empirical
evidence is represented. Concludes that the shape of things to come, at
least for the foreseeable future, will be a sharing of responsibilities
between the specialist and the line.
Crew resource management for teams in the offshore oil industry
Authors: Flin Rhona H.
Published: July 2002

The international aviation industry uses a special form of human
factors training with their flight deck crews and other teams, called
crew resource management (CRM). CRM is designed by psychologists and
pilots to reduce errors and accidents and to improve emergency response
capability by improving teamwork skills. Key topics include
communication, decision making, assertiveness and stress management. CRM
courses are now being used in shipping, medicine and the nuclear power
industry. Follows an outline of CRM and describes an application in the
offshore oil industry with control room operators and emergency command
teams.
Entrepreneurship education and training ‐ introducing entrepreneurship into non‐business disciplines
Authors: Hynes Briga
Published: July 2002

Entrepreneurs or the move towards self‐employment is, and will continue to become, an increasingly important element of economic growth and development. It is now recognized that small firms in Ireland are “net creators of jobs while the large firm sector is a net shedder of jobs”. To ensure that a sustained increase in self‐employment continues, it is critical that the correct infrastructure is in place to facilitate this development. One critical aspect of this infrastructure is the creation of an enterprise culture which will encourage and entice individuals to take the risk of starting a business. Examines one of the core components of an enterprise culture, which is education, and how the various educational programmes can incorporate entrepreneurship as a subject area which will foster the interest in enterprise. Focuses on how a process model for enterprise education can be used to target various student groups in an interdisciplinary manner, and emphasizes the need to teach entrepreneurship to non‐business students, who in many instances are the originators of ideas, but unfortunately do not have the business knowledge to develop the idea further.
Time harmonic eddy currents in non‐linear media
Authors: Paoli Gerhard , Bíró Oszkár
Published: July 2002

One way to deal with non‐linearity in the case of time harmonic excitation of the electric and magnetic fields in ferromagnetic media is to introduce an effective material to model the ferromagnetic region. This fictitious material is constant throughout a period but inhomogeneous and it takes into account the non‐linear relationship between the field quantities. Several methods to create an effective magnetization curve are presented and different finite element formulations are applied to these. Some of these methods are known from the literature for 1D and 2D problems but not for 3D ones and they have only be used for a magnetic vector potential formulation so far. In the present paper they are extended for general vector and scalar potential formulations. Further possible ways to introduce such an effective material to take into account saturation effects are shown. All these different methods are investigated on a non‐linear 3D time harmonic eddy current problem using complex formalism.
The biocybernetics of BSE and Prion disease
Authors: James Brennig
Published: July 2002

Comments on the current BSE epidemic taking a biocybernetical view. Produces a possible scenario which could explain how protein might replicate, albeit indirectly, using DNA as its agent.
Aspects of identity, cohesion, citizenship and performance in recursive organisations
Authors: Espejo Raul
Published: July 2002

Develops the idea of complexity and its implications for our understanding of organisations and society. One such implication is the constitution of autonomous units within autonomous units. This notion is at the core of recursive organisations. Each of these autonomous units requires strengthening in its identity, cohesion and citizenship in order to perform well in its medium. However, in contemporary societies the rule is fragmented institutions rather than whole organisations. Further research is necessary in order to understand how to make more likely the emergence in society of recursive organisations.
New developments in polyurethane and PU/acrylic dispersions
Authors: Manock H.L.
Published: July 2002

Waterborne polyurethane dispersions (PUDs) continue to show growth in commercial usage due to the ever increasing environmental legislation to reduce VOC in coating and adhesive materials. The transition from solvent‐based to waterborne has also been facilitated by advances in both the chemistry and technology employed and the formulation expertise required. This has resulted in coating performance that cannot only match but in some cases surpass their solvent‐based counterparts. This paper gives an overview of PUDs and introduces urethane/acrylic hybrids, giving an insight into the chemistry and technology. Particular emphasis is given to new developments and the application areas where they are finding increasing use. Some formulating techniques are also illustrated.
Leadership and the development of quality culture in schools
Authors: Berry Geoff
Published: July 2002

There is emerging evidence that leadership is an indispensable element in the process of initiating and sustaining the development of a quality culture in organizations. Such leadership is of particular importance to schools, where cultural, political and organizational factors make the management of quality problematic. For leaders to make decisions about the development of quality culture within their schools they require a thorough understanding of the theoretical basis of current approaches to quality management in education. In an effort to contribute to this theoretical understanding, considers the paradigm of total quality management (TQM) as a broad philosophy for the development of quality culture in schools. Describes how TQM is being identified increasingly as a viable paradigm for the development of a quality culture in school education and has been the focus for improvement efforts in individual schools internationally and in school districts, particularly in the USA.
The dynamics of accounting change Inter‐play between new practices, routines, institutions, power and politics
Authors: Burns John
Published: July 2002

This paper explores accounting change in the product development department of a small UK chemicals manufacturer. An institutional framework of accounting and a framework of power mobilisation help tease out the dynamics of the processes of change. The case highlights power over resources, decision making and meanings as being key facilitators to the implementation of accounting change. It also demonstrates barriers to change and conflict which emerge as new accounting routines fail to impinge on existing laboratory ways of thinking. Focusing on the processes of accounting change within a specific organisational setting illuminates aspects of the change process which more conventional “static” approaches would likely ignore.
Algebraic modelling of pattern design: the abelian pattern semi‐group
Authors: Ng Roger , Chan C.K. , Pong T.Y. , Au Raymond
Published: July 2002

Pattern design is a transformation process from the design sketch to the final production pattern. In order to computerize such a process, a mathematical model is indispensable. When a garment is decomposed into components of pattern pieces, this decomposition process can be modelled by using semi‐group. Presents the construction of this semi‐group structure, which is called the abelian pattern semi‐group, and the associated lattice structure with proofs and examples. Illustrates the interpretation and application of this algebraic model with the optimal control problem of the production line.
Modelling the dynamic drape of garments on synthetic humans in a virtual fashion show
Authors: Stylios George K. , Wan T.R. , Powell N.J.
Published: July 2002

Reports the dynamic modelling of garments on synthetic humans. Develops the model based on a physical analogue to a deep shell system for describing and predicting the real 3‐D shape of clothes. Determines the garment motion by fabric deformation energy, gravity and external constraints of the garment, such as collision forces, using the deformable node bar concept. Justifies the model by agreement between real fabric prediction of static and dynamic drapes using our newly developed drape metre. Demonstrates the garment simulation using garments from two different fabrics in a virtual fashion show. Also describes the work on modelling and animating a synthetic female. The advantages of this model are that engineering parameters can be used as model parameters directly and that the model is configured based on the surface co‐ordinate system, which are important for the next generation of fashion CAD systems incorporating virtual fashion shows. This consideration is fundamental in the context of global retailing and becomes an integral part of intelligent textile and garment manufacture. Proposes the consequences of this work in cinema, TV, advertising and in graphics and animation are also important, but does not examine these.
Investigation of fabric deformations under different loading conditions
Authors: Nikolic Milanka D. , Mihailovic Tatjana V.
Published: July 2002

The phenomenon of fabric deformation can be observed not only keeping in mind the type of material, the raw material, geometric and constructive parameters, but also the conditions which which material is exposed under action of tensile force (the size of force, time, velocity of acting and so on). Investigates the influence of the tensile force size on total deformation as well as the deformation components: elastic, viscoelastic and plastic. Reports an experiment conducted on clothing wool fabrics (18 different samples) which were exposed to various tensile forces (5, 10, 15, 20, 25, 30 and 35 per cent of breaking force) during 15 minutes. After this time limit had expired, their relaxation in a period of 24 hours was examined. From the diagrams of fabric relaxation (126 diagrams), determines deformation components and presents a summary using diagrams. On the basis of imposed analysis claims it can be stated that elastic deformation component predominates while no plastic deformation exists at lower values of tensile force.
A guide line for manufacturing “ideal fabrics”
Authors: Kawabata Sueo , Niwa Masako , Yamashita Yoshihiro
Published: July 2002

This paper reports the recent progress in the ideal fabrics project that started in 1996. The aim of this project is to initiate the engineered manufacturing of “ideal fabric”. Ideal fabric is the fabric which satisfies the three conditions, good hand, good appearance of suit, and mechanical comfort for wear. The objective evaluation method of these three properties has been developed, and these objective method and fabric mechanics theories are fully applied to this project. Some ideal fabrics have been manufactured as the guideline for manufacturing ideal fabrics in the future. These trial fabrics are now being commercialized to assess the response of consumers.
The objective evaluation of blanket hand and durability
Authors: Niwa Masako , Inoue Mari , Kawabata Sueo
Published: July 2002

The purpose of this study is to investigate an objective method of evaluating the tactile comfort of blankets by a method of connecting the mechanical parameters of blankets to subjective evaluation. The two methods are preliminarily investigated as follows: (1) Transformation equations for the fabric hand of suiting, KN‐101‐W for primary hand values and KN‐301‐W for THV, are applied, with the mean and standard deviation applied to these equations replaced with new values for the blanket population. (2) A new prediction equation is constructed for deriving THV directly from the mechanical parameters and thermal properties. The prediction accuracy of method (2) is a little higher than that of (1). The durability of blankets during repeated use and repeated dry cleaning determined by the initial performance of blankets is also investigated.
Towards the objective evaluation of garment appearance
Authors: Fan J. , Hui C.L.P. , Lu D. , MacAlpine J.M.K.
Published: July 2002

As a first step towards objective evaluation of garment appearance, the present work considered seams on three‐dimensional surfaces which simulate actual garment surfaces. The geometric profiles of the 3‐D seams were scanned using a laser scanner. 1‐D and 2‐D digital filters were applied to obtain pucker signals from the geometric profiles by removing “high frequency” components due to fabric surface texture and “low frequency” components due to garment silhouette and drape. The advantages and disadvantages of the 1‐D and 2‐D digital filters are compared. Four physical parameters are examined to see their relevance to the subjective pucker grade. It was found that log(σ2), i.e. the logarithm of the variance of the heights of pucker signals, is the best set of physical parameters for the objective evaluation of seam pucker. In addition, latest attempts at capturing and analyzing 3D garment image using a Cyberware laser scanner and Surfacer software are reported.
Trust in schools: a conceptual and empirical analysis
Authors: Tschannen‐Moran Megan , Hoy Wayne
Published: July 2002

The conceptual foundations of trust as a multi‐dimensional construct are reviewed, and relevant related issues are discussed with a focus on trust in schools. An empirical analysis of faculty trust in colleagues and trust in the principal demonstrates that faculty trust is an important aspect of the openness and health of school climate. It is related to the authenticity of both the principal’s and the teachers’ behavior; however, elements of climate and behavior that predict trust in the principal are different from those that predict trust in colleagues. Finally, a research agenda for the study of trust in schools is sketched.
Does national culture influence consumers’ evaluation of travel services? A test of Hofstede’s model of cross‐cultural differences
Authors: Crotts John C. , Erdmann Ron
Published: July 2002

The influence of national culture on consumer evaluations of travel services was the focus of this study. Drawing from a representative sample of overseas visitors to the USA, and controlling for socio‐economic and trip characteristics, results provide a limited indication that national culture influences how customers evaluate travel services and their willingness to repeat purchase and recommend a service to others. The implications for researchers are that national cultural differences are one of many forces influencing consumer decision making. It is a measurable construct, like gender and socio‐economic class, that conditions how consumers interact with others and should be taken into account in our attempts to better understand consumers needs and expectations.
The impact of affirmative action legislation on women working in higher education in Australia: progress or procrastination?
Authors: Noble Carolyn , Mears Jane
Published: July 2002

This article focuses on the impact of the Australian Affirmative Action (Equal Employment Opportunity) legislation (1986), on women’s employment in the higher education sector. This Act aimed to address the disadvantage faced by women in the workplace. In the academy, this meant that some of the difficulties encountered by women who aspired to careers and senior positions were to be documented and addressed. Fourteen years after its implementation, while there has been a general growth in women’s employment in the sector, there still exists a glass ceiling preventing women in both academic and administrative positions moving into management structures. This article examines some of the issues that have emerged in attempting to create a “level playing field” for women in the academy with regard to supporting promotional opportunities and encouraging a positive and supportive workplace. Strategies for overcoming existing barriers and the importance of future research are emphasised.
Student perceptions of service quality in a UK university business and management faculty
Authors: Oldfield Brenda M. , Baron Steve
Published: July 2002

Student perceptions of service quality in higher education, particularly of the elements not directly involved with content and delivery of course units, are researched using a performance‐only adaptation of the SERVQUAL research instrument. A principal components factor analysis performed on data collected from a sample of 333 undergraduate business and management students suggests that students’ perceived service quality has three dimensions: “requisite elements”, which are essential to enable students to fulfil their study obligations; “acceptable elements”, which are desirable but not essential to students; and “functional elements”, which are of a practical or utilitarian nature. A comparison of perceptions of service quality between first and final year students suggests that perceptions of service quality elements change over a period of study, with “acceptable elements” having increasing importance. Implications for course management teams are discussed, and suggestions for further research are made.
Managing and controlling computer misuse
Authors: Dhillon Gurpreet
Published: July 2002

This paper argues that many of the losses owing to computer‐related fraud could be avoided if organizations adopt a more pragmatic approach in dealing with such incidents. The paper suggests that in implementing controls, both within organizations and computer systems, a balanced approach be adopted. Such an approach should place equal emphasis on technical, formal and informal interventions. The argument is conducted by reviewing the nature of security breaches that have taken place in different parts of the world.
An empirical study of Internet usage and difficulties among medical practice management in the UK
Authors: Howcroft Debra , Mitev Nathalie
Published: July 2002

Considers the use of information technology in the UK National Health Service (NHS) as the government pledges to connect every doctor or general practitioner (GP) to the NHS’s information superhighway by the year 2002. This paper uses a case study of a particular UK health authority as a vehicle to illustrate the complexity of the social and technical considerations surrounding this issue. At a grass roots level, the adoption and diffusion of information technology within general practices (surgeries or groups of GPs) is highly varied and there are huge contrasts in the levels of commitment to information management. Within the case study this is evident on an individual level, in that some GPs enthuse about technology, while others are positively “technophobic”. On the general practice level, there are other elements to consider, especially in relation to the levels of financial support available. Non‐fund holding general practices in socially deprived areas are far less willing to embrace information management and technology. One explanation suggested for this is based on priorities: when faced with the option of “cruising” the information superhighway, as opposed to treating seriously ill patients living in socially deprived areas, the former may simply be relegated as less important.
Specifying non‐uniform cusp heights as a potential aid for adaptive slicing
Authors: Cormier Denis , Unnanon Kittinan , Sanii Ezat
Published: July 2002

Most adaptive slicing implementations assume a maximum allowable cusp height which applies to the entire part. Practically speaking, however, most parts do not have uniform cusp height requirements. Some faces are required to be smooth while other faces are relatively unimportant. With a uniform cusp height implementation, users must specify the most stringent cusp height which applies to the entire part. However, with non‐uniform cusp height specifications, it is possible that further gains in adaptive slicing efficiency can be achieved. This paper presents an approach to specifying non‐uniform cusp height requirements. First, a procedure is developed which uses an edge finding algorithm to identify faces on the part. The faces are then rendered using the OpenGL graphics libraries, and the user is prompted to enter the maximum allowable cusp height for each highlighted face. Implementation details and test results are presented.
Managing service quality for competitive advantage in small engineering firms
Authors: Maclaran Pauline , McGowan Pauric
Published: July 2002

Examines how small firms can maximise service quality to determine a competitive marketing advantage for their enterprise. Demonstrates how there is little in the conventional service quality literature to guide the small firm and that current models of service quality are most relevant to larger organisations. From the results of a two‐stage empirical study which focused on small engineering firms, a model of service quality is put forward which more truly reflects the circumstances of the smaller enterprise. Finally, the paper outlines the main considerations for the enterprise owner in developing a competitive advantage through service quality management.
Key challenges in the search for the effective management of knowledge in management consulting firms
Authors: Dunford Richard
Published: July 2002

Consulting firms cite knowledge management as a core capability for achieving competitive advantage. Consistent with this claim has been their increasing investment in systems that seek to formalize knowledge management and allow firms to leverage the knowledge held within the firm. However, despite some successes, knowledge management remains a major challenge. Investigates this situation, using a framework that distinguishes between input and output challenges. Input challenges relate to the production of a knowledge base that is able to be shared within the firm. Output challenges relate to the capacity for effective utilization of any such knowledge base. Concludes with a discussion of the way in which changes in the pattern of consulting services has implications for the sort of knowledge that various consulting firms wish to codify, the dangers associated with codification and the means by which these can be managed.
Style analysis and property fund performance
Authors: Lee Stephen
Published: July 2002

There are three basic approaches to style analysis: (i) an examination of the portfolio and security selection procedures used by the fund managers, (ii) a factor model approach, and (iii) return‐based approaches, all with their own strengths and weaknesses. Of the return‐based methods the effective asset mix approach, as devised and popularised by Sharpe, offers the investor the simplest route to style analysis. This study applies this approach to a sample of 37 property funds in the UK and shows that style analysis can make an important contribution to the analysis of portfolio performance. Results that should prove of considerable interest to fund managers and property professionals alike.
Distinct sensitizing effects of the cAMP‐PKA second messenger cascade on rat dural mechanonociceptors
Authors: Levy D. , Strassman A. M.
Published: July 2002

Activation of the cAMP/protein kinase A (PKA) second messenger cascade has been implicated in the induction of mechanical hyperalgesia by inflammatory mediators. We examined the role of this cascade in mechanical sensitization of nociceptive neurons that innervate the meninges, a process thought to be involved in the pathophysiology of headache syndromes such as migraine. Single unit activity was recorded in the trigeminal ganglion from 40 mechanosensitive dural afferents (conduction velocitity: 0.3–6.6 m s−1) and nine mechanically insensitive dural afferents (MIAs) (conduction velocitity: 0.3–2.8 m s−1) while stimulating the dura with a servo force‐controlled stimulator or von Frey monofilaments, respectively. Local application to the dura of dibutyryl adenosine 3′,5′‐cyclic monophosphate (dbcAMP, 100 μm), a stable membrane‐permeant cAMP analogue, produced mechanical sensitization in the majority of mechanosensitive units (19/29, 66 %). Two distinct patterns of mechanical sensitization were observed. Thirty‐eight per cent of the units exhibited only a decrease in threshold (TH group), while 28 % showed only an increase in suprathreshold responses (STH group). dbcAMP also induced mechanosensitivity in the majority of MIA units (6/9, 67 %). dbcAMP‐induced sensitization was blocked by the PKA inhibitors, Rp‐cAMP (1 mm) and H‐89 (100 μm). A mixture of inflammatory mediators induced both components of sensitization in the majority of mechanosensitive units tested. However, in each unit, PKA inhibitors blocked only one of the two effects (either TH or STH). Units that were classified as TH or STH also differed in their baseline stimulus‐response slopes, thresholds and conduction velocities. These findings implicate the cAMP‐PKA cascade in sensitization of dural mechanonociceptors and suggest that this cascade may produce sensitization through at least two different mechanisms operating in separate neuronal populations.
Hard Turning: Chip Formation Mechanisms and Metallurgical Aspects
Authors: Poulachon Ge´rard , Moisan Alphonse L.
Published: July 2002

A 100Cr6 (AISI E52100) steel in the hardness range of 180 to 750 HV10 was machined. Quick stop tests were carried out at various hardness values to observe the different chip formation mechanisms. A limit was found between the shearing and cracking chip formation. Experiments on the selected steel at 750 HV10 were carried out at various cutting speeds and feed rates. The “saw tooth chips” obtained were examined geometrically and metallurgically on longitudinal midsections. A relationship has been established between the chip geometry and the cutting conditions. A theoretical study of the chip shape was made, in particular its thickness. The friction stick slip velocities, and the segment apparition frequency were calculated. Each stage of the chip formation could be observed on each micrograph of Q.S.T, especially the crack initiation. A discussion on the apparition of the thin white layers is also proposed. [S1087-1357(00)01502-1]
Theoretical and Statistical Analysis of Ship Grounding Accidents
Authors: Simonsen Bo Cerup , Hansen Peter Friis
Published: July 2002

Today, the ship kinetic energy and structural crushing resistance is not taken into account in any regulation concerned with the damaged state of a conventional ship (damage stability, oil outflow, etc.). However, the past few years of experience with high-speed craft (HSC) have clearly demonstrated that impact damage is indeed related to the kinetic energy and the strength of the ship. The present paper discusses various aspects related to rational design against grounding accidents. A relatively simple theory is reviewed for comparing the expected grounding damage of different ships, taking into account the structure, the displacement and the sailing velocity. It is shown that based on simple requirements of similitude, it is possible to scale certain types of grounding bottom damage. Then 130 grounding accidents are investigated. Attempts are first made at identifying the governing grounding scenarios and deriving a formula for the relation between the volume of deformed structure and the energy absorption (like the Minorsky formula). Moreover, the damage statistics is used to illustrate that the damage length divided by ship length is a function of the ship size. This observation is not in agreement with current regulations where bottom damage is proportional to ship length. The scaling theory is then used to explain that large ships experience longer relative damages than small ships. Major conclusions of the study are that the quality of future damage records should be improved, that various requirements and rules involving bottom damage may need to be revised, and that a method has been proposed for ranking ships according to their crashworthiness in grounding accidents. [S0892-7219(00)00103-5]
A Damage Evolution Model for Thermal Fatigue Analysis of Solder Joints
Authors: Zhang Xiaowu , Lee S-W. Ricky , Pao Yi-Hsin
Published: July 2002

Thermal fatigue of solder joints is critical to the performance and reliability of electronic components. It is well known that the fatigue life of solder joints is rather difficult to be estimated because of the complicated material behaviors and solder joint geometry. Conventional life prediction methods such as Coffin-Manson equation or its modifications usually over-estimate the thermal fatigue life. The main reason for this phenomenon is that the material properties are assumed constant during thermal cycling. In this paper, a damage evolution model is introduced for predicting the thermal fatigue life of solder joints. This method not only considers the degradation of material properties in the solder, but also saves substantial computational effort. In the present study, a damage function is determined by the hysteresis loops of creep shear stress-strain of solder joints in a double-beam specimen. The proposed model is then applied to investigate the solder joint reliability of a 272 PBGA package and a bottom-leaded plastic (BLP) package for model verification. The results from the present analysis seem to be encouraging. [S1043-7398(00)01003-3]
Dynamic Coefficients of Stepped Labyrinth Gas Seals
Authors: Kwanka Klaus
Published: July 2002

Rotor-fluid interactions can cause self-excited shaft vibrations of high density turbomachinery. Often the amplitude of the vibrations reaches unacceptably high amplitudes and the scheduled power or running speed cannot be achieved. One of the most important sources of excitation is the flow through labyrinth seals. For a reliable design it is necessary to predict these forces exactly, including not only stiffness but also damping coefficients. As the forces in labyrinth gas seals are rather small only minimal experimental data is available for the comparison and validation of calculations. Meanwhile a new and easy-to-handle identification procedure enables the investigation of numerous seal geometrys. The paper presents dynamic coefficients obtained with a stepped labyrinth and the comparison with other seal concepts. [S0742-4795(00)00903-0]
The Mechanics of Heterotypic Cell Aggregates: Insights From Computer Simulations
Authors: Brodland G. Wayne , Chen Helen H.
Published: July 2002

Finite element–based computer simulations are used to investigate a number of phenomena, including tissue engulfment, cell sorting, and checkerboard-pattern formation, exhibited by heterotypic cell aggregates. The simulations show that these phenomena can be driven by a single equivalent force, namely a surface (or interfacial) tension, that results from cytoskeletal components and cell–cell adhesions. They also reveal that tissue engulfment, cell sorting, and checkerboard-pattern formation involve several discernible mechanical features or stages. With the aid of analytical arguments, we identify the conditions necessary for each of these phenomena. These findings are consistent with previous experimental investigations and computer simulations, but pose significant challenges to current theories of cell sorting and tissue engulfment. [S0148-0731(00)01304-2]
Tribological Properties and Gear Performance of Polyoxymethylene Composites
Authors: Kurokawa Masaya , Uchiyama Yoshitaka , Nagai Susumu
Published: July 2002

Tribological properties of polyoxymethylene (POM) composites containing a trace amount of silicon carbide (SiC) and/or calcium salt of octacosanoic acid (Ca-OCA) as well as containing polytetrafluoroethylene (PTFE) were investigated by means of a pin-on-disk type wear apparatus. The spherulite size of POM composites was measured using a polarizing microscope. Mechanical properties and gear performance of the composites were also evaluated. It was found that the coefficient of friction was drastically lowered due to the lubricant effect of Ca-OCA added to POM/SiC composites. Further, the wear rate was also decreased by the nucleating effect of SiC and Ca-OCA. Especially, POM/SiC(0.1)/Ca-OCA(1) composite containing SiC 0.1 wt.% and Ca-OCA 1 wt.% showed the coefficient of friction as low as that of POM/PTFE(24) composite containing PTFE 24 wt.%, keeping higher wear resistance. Also, its mechanical properties were found to be the same level as those of unfilled POM, except that its izod impact strength became higher than that of unfilled POM. Furthermore, its gear performance was confirmed to be satisfactory without generating noise under the dry running condition, when the same gears were combined below 13 MPa of bending stress. [S0742-4787(00)00304-0]
Machining Performance of PM Material Containing MnX Additives1
Authors: Barnes Stuart , Nash Michael J. , Lim Moh. H.
Published: July 2002

A new free-machining additive, MnX, has been reported to improve the machining performance of ferrous powder metallurgy (PM) materials. This work investigated this claim by comparing the performance of three otherwise identical PM materials containing: no additive, conventional manganese sulphide (MnS) additions and the new MnX additive. A turning operation and cutting speeds of 100–250 m/min were used during which cutting forces, tool wear and surface finish were measured. The MnX material was found to exhibit superior performance. However, this was most noticeable at higher cutting speeds and at the lower cutting speeds, differences in performance were substantially reduced. [S0094-4289(00)02004-1]
Review of Power Cylinder Friction for Diesel Engines
Authors: Richardson D. E.
Published: July 2002

Power cylinder friction is a major contributor to overall engine friction. For engines of the future to become more fuel efficient it will be necessary to reduce power cylinder friction. To be able to reduce the friction it is important to fully understand it. This paper is a review of power cylinder friction with a specific emphasis on diesel engines. This paper first describes how significant the contribution of power cylinder friction is compared to all the other losses of the engine. It compares the mechanical friction of the engine to the total energy produced by the engine. Then a comparison is made of the power cylinder friction to overall mechanical friction. A comparison of different methods of friction measurement is be made. The advantages and disadvantages are given for each method. There is also a comparison of motoring versus firing friction tests. An equation is given to estimate the effect of bore and stroke on power cylinder friction. Other equations for estimating power cylinder friction are also shown. More sophisticated cylinder kit models are reviewed. Finally a review is made of methods for reducing friction. These are based on a broad review from various companies. [S0742-4795(00)01604-5]
A Generalized Traction Curve for EHL Contacts
Authors: Jacod B. , Venner C. H. , Lugt P. M.
Published: July 2002

In this paper the subject of friction prediction is revisited, with the aim of obtaining a general formula predicting the coefficient of friction over a wide range of operating conditions. By means of full numerical simulations of the smooth isothermal elliptic contact, and assuming an Eyring non-Newtonian behavior, the coefficient of friction is computed for a wide range of operating conditions. It is shown that with respect to sliding friction, all results can be presented on a single generalized friction curve relating a reduced coefficient of friction to a characteristic nondimensional shear stress. Finally, it is shown that some measured data presented in the literature when presented in terms of the derived parameters closely follow the derived behavior, which provides a validation of the theoretical results.
An Investigation of Screw Systems in the Finite Displacements of Bennett-Based 6R Linkages
Authors: Huang Chintien , Sun Chi-Chih
Published: July 2002

This paper investigates, via numerical simulations, the finite displacements of all the known Bennett-based 6R overconstrained linkages: Goldberg’s 6R, variant Goldberg 6R, Waldron’s hybrid 6R, and Wohlhart’s hybrid 6R linkages. An investigation of the finite displacements of nine distinct linkages reveals that every Bennett-based 6R linkage, except for the isomerization of Wohlhart’s hybrid linkage, inherits the linear properties of the Bennett mechanism. The relative finite displacement screws of some non-adjacent links of these linkages form screw systems of the second order. Thirty-one screw systems are reported in this paper. [S1050-0472(00)02204-2]
The Influence of Transient Inlet Distortions on the Instability Inception of a Low-Pressure Compressor in a Turbofan Engine
Authors: Leinhos Dirk C. , Schmid Norbert R. , Fottner Leonhard
Published: July 2002

While studies on compressor flow instabilities under the presence of inlet distortions have been carried out with steady distortions in the past, the investigation presented here focuses on the influence of transient inlet distortions as generated by variable geometry engine intakes of super- and hypersonic aircraft on the characteristic and the nature of the instability inception of a LPC. The flow patterns (total pressure distortion with a superimposed co- or counterrotating swirl) of the distortions are adopted from a hypersonic concept aircraft. A LARZAC 04 twin-spool turbofan was operated with transient inlet distortions, generated by a moving delta wing, and steady total pressure distortions starting close to the LPC’s stability limit until it stalled. High-frequency pressure signals are recorded at different engine power settings. Instabilities are investigated with regard to the inception process and the early detection of stall precursors for providing data for a future stability control device. It turned out that the transient distortion does not have an influence on the surge margin of the LPC compared to the steady distortion, but that it changes the nature of stall inception. The pressure traces are analyzed in the time and frequency domain and also with tools like Spatial FFT, Power Spectral Density, and Traveling Wave Energy. A Wavelet Transformation algorithm is applied as well. While in the case of clean inlet flow, the compressor exhibits different types of stall inception depending on the engine speed, stall is always initiated by spike-type disturbances under the presence of steady or transient distortions. Modal disturbances are present in the mid-speed range that do not grow into stall, but rather interact with the inlet flow and produce short length scale disturbances. The obtained early warning times prior to stall are adversely affected by transient distortions in some cases. The problem of appropriate thresholding becomes evident. The best warning times have been acquired using a statistical evaluation of the Wavelet coefficients, which might be promising to apply in a staged active control system. This system could include different phases of detection and actuation depending on the current precursor.
Compressor Stability Enhancement Using Discrete Tip Injection
Authors: Suder Kenneth L. , Hathaway Michael D. , Thorp Scott A. , Strazisar Anthony J. , Bright Michelle B.
Published: July 2002

Mass injection upstream of the tip of a high-speed axial compressor rotor is a stability enhancement approach known to be effective in suppressing stall in tip-critical rotors. This process is examined in a transonic axial compressor rotor through experiments and time-averaged Navier-Stokes CFD simulations. Measurements and simulations for discrete injection are presented for a range of injection rates and distributions of injectors around the annulus. The simulations indicate that tip injection increases stability by unloading the rotor tip and that increasing injection velocity improves the effectiveness of tip injection. For the tested rotor, experimental results demonstrate that at 70 percent speed the stalling flow coefficient can be reduced by 30 percent using an injected massflow equivalent to 1 percent of the annulus flow. At design speed, the stalling flow coefficient was reduced by 6 percent using an injected massflow equivalent to 2 percent of the annulus flow. The experiments show that stability enhancement is related to the mass-averaged axial velocity at the tip. For a given injected massflow, the mass-averaged axial velocity at the tip is increased by injecting flow over discrete portions of the circumference as opposed to full-annular injection. The implications of these results on the design of recirculating casing treatments and other methods to enhance stability will be discussed.
Total Knee Replacement Polyethylene Stresses During Loading in a Knee Simulator
Authors: Giddings Virginia L. , Kurtz Steven M. , Edidin Avram A.
Published: July 2002

We investigated the stresses and kinematics of a total knee replacement during the duty cycle of a knee simulator. Finite element models were constructed of the tibial and the femoral component of a commercially available cruciate retaining total knee replacement. Time dependent flexion/extension, axial loading, and anterior/posterior loading were applied to the components of the arthroplasty to match those generated by the knee simulator. We evaluated the effect of varying the stiffness of a spring-loaded bumper system for anterior-posterior constraint on the joint kinematics as well as on the stresses within the polyethylene tibial component. Both the joint kinematics and the stresses and strains subjected to the polyethylene tibial component, were found to be comparatively insensitive to the stiffness of the spring bumper system for this design. When the stiffness of the bumper system was increased by two orders of magnitude, the maximum contact stresses, von Mises stresses, and von Mises strains in the polyethylene tibial component varied by only 15 to 59 percent. In general, increasing the stiffness of the bumper system decreased the displacements of the base plate, but the relationships were nonlinear, possibly due to the added constraints imposed by the tibiofemoral contact interaction. The long-term goal of this research is to develop a validated structural model to predict the stresses, kinematics, and ultimately, the wear, of total joint replacement components in a contemporary knee joint simulator.