bluuebunny/crossref_metadata_2025 huggingface dataset:
The export competitiveness of dynamic Asian economies 1983‐1995
Authors: Wilson Peter
Published: July 2002

Compares changes in the competitive position of six Dynamic Asian Economies (DAEs) – Singapore, Thailand, Malaysia, Korea, Taiwan and Hong Kong – exporting to the USA, Japan and the European Union (EU) between 1983 and 1995. Dynamic shift‐share methods are applied to two digit data for the top five manufactured exports to the USA and the EU, and the top four in the case of Japan. Findings emphasise the magnitude of the structural transformation which occurred over this period as the emerging DAEs such as Malaysia and Thailand became more competitive across a broad range of manufactured goods relative to the older DAEs, while the latter endeavoured to switch into higher value‐added manufacturing and services or new markets, or to establish manufacturing facilities overseas as a substitute for exports.
A complete algorithm for designing passive fences to orient parts
Authors: Wiegley Jeff , Goldberg Ken , Peshkin Mike , Brokowski Mike
Published: July 2002

Reviews Peshkin and Sanderson (1988) who showed that parts can be aligned as they move on a conveyor belt against a passive sequence of fences. Describes the first complete algorithm to design such sequences for a given convex polygonal part. The algorithm is complete in the sense that it is guaranteed to find a design if one exists and to terminate with a negative report otherwise. Based on an exact breadth‐first search of the design space, the algorithm is also guaranteed to find the design requiring the fewest fences. Describes the algorithm and compares results with those previously reported. Conjectures that a fence design exists to orient any convex polygonal part defined by a sequence of rational vertices.
Integrated microsystem for blue/ultraviolet detection
Authors: Pauchard A. , Furrer B. , Randjelovic Z. , Rochas A. , Manic D. , Popovic R.S.
Published: July 2002

A fully integrated sensor microsystem for blue/ultraviolet radiation detection is presented. The photosensitive part combines a blue/UV selective stripe‐shaped photodiode with a small compensation infrared photodiode. A transimpedance amplifier with 1 GΩ feedback resistor is integrated on the same silicon chip. The main features of the op amp are a low offset (<0.5mV) and fail‐safe operation. This sensor has a maximal responsivity of 150 mV/nW at λ = 420 nm, corresponding to 43 percent quantum efficiency. A ratio of the responsivities at 420 nm and 1 μm as large as 560 is achieved. The system has a noise equivalent power of 5 10‐13W. The 2.2 mm2microsystem is realized in a standard CMOS 0.5 μm process.
Micro sensor developments in Japan
Authors: Tsuruta Kazuhiro , Mikuriya Yoshikazu , Ishikawa Yuichi
Published: July 2002

This paper describes some aspects of micro sensors developed as part of the micromachine project in Japan. This national R&D project, industrial science and technology frontier program “Micromachine technology”, was inaugurated in 1991 as a ten‐year project. The R&D goal is to establish technologies to realize micromachines for the following practical applications; maintenance and repair of power plant facilities; miniaturization of manufacturing facilities; medical diagnosis and treatment. As a result, various types of micro sensors have been successfully developed.
The teaching of leadership on UK MBA programmes
Authors: Mellahi Kamel
Published: July 2002

This study investigates the compatibility of leadership values taught on MBA programmes in the United Kingdom (UK) and the expected, accepted and effective leadership values in three non‐western cultures. The study was conducted on 272 full‐time MBA graduates from Asian, Arab and African countries soon after obtaining an MBA from UK business schools. The analysis reveals that leadership curricula on MBA programmes is broadly conceived in the US corpus and assumes universality. The ethnocentric approach to the teaching of leadership is due to a large extent to the unavailability of alternative theories and published empirical evidence outside the USA and the low level of faculty expertise and interest in international dimensions of effective leadership styles. The research argues that there is a need for western management schools to adopt a more eclectic view of leadership teaching and to cast their perspective beyond western idiosyncrasies and include non‐western business perspectives.
Dealing with rights of light
Authors: Francis Andrew
Published: July 2002

The law relating to light is complex. This paper explains the law of light, how rights to light may be acquired, and how they may be defended. The particular positions of landlords, tenants, the Crown and the City of London are explained in the context of the law of light. In addition, the relevance of claims for injunctions and damages is also explained in this context.
Integrating human behavior and response issues into fire safety management of facilities
Authors: Meacham Brian J.
Published: July 2002

Although there is a growing international movement toward the use of engineered or performance‐based fire safety design, current practice is dominated by prescriptive‐based design. In prescriptive‐based fire safety design, only those requirements prescribed by appropriate building regulations, installation standards, or approved documents tend to be applied. Because these requirements typically include fire protection measures, such as fire detection and signaling systems, automatic sprinkler systems, fire compartmentation, and emergency egress systems, there is often an assumption that occupants, employees, and users of a facility will be safe should a fire occur. However, there are a variety of factors that could affect the actual fire safety of a facility that comply with the appropriate regulations. Fuel type, loading, configuration, and location can change, leading to an increase in fire risk. Occupants may not see, hear or understand fire alarm signals as fire alarm signals. Fire detection and signaling systems, fire suppression systems, or smoke management systems may not be 100 percent functional at all times. Fortunately, many of these factors can be controlled for, if they are understood and addressed, within a fire safety management plan. To assist with such planning, this paper discusses various human behavior and response issues that may affect life safety during a fire or emergency, and provides suggestions for integrating these issues into a fire safety management plan.
Fire safety management and risk assessment
Authors: Ramachandran G.
Published: July 2002

The paper discusses the problems encountered in the management and quantitative evaluation of fire risk and safety in a building. Rational methods for obtaining solutions to these problems are provided by non‐deterministic mathematical models rather than deterministic models. This is due to the fact that the occurrence and spread of an accidental (not arson) fire are random phenomena affected by uncertainties caused by several factors. Non‐deterministic models discussed briefly in the paper include simple statistical and probabilistic models, regression methods, probability distributions, fault and event trees and stochastic models. The paper only provides a framework for applying these models to any type of facility. For any type, it may be necessary to modify these techniques, collect all the relevant data and perform the analyses to derive results and conclusions applicable to that type.
Problems surrounding the retail property market in a complex conurbation: the case of Stoke‐on‐Trent, UK
Authors: Hallsworth Alan , Jayne Michael
Published: July 2002

This paper examines the nature of property advice in fragmented local property investment markets using, as an exemplar, the retail sector in The Potteries conurbation. The views of major actors within the process, obtained from in‐depth interviews, are discussed and placed in context alongside the unique fragmentation to be found in The Potteries conurbation. The approaches to market analysis and understanding of locational decision making by local and national property agents are compared and contrasted. Evidence is found for the use of objective and detailed data gathering and modelling as well as the more traditional market empathy or “feel”. The potential role of a GIS for handling the information is also covered. The conclusion is that, while a GIS would improve awareness, knowledge and understanding of the retail locations vary and that this only strengthens the need for local experts.
Current trends in interlending and document delivery in the UK
Authors: Prowse Stephen William
Published: July 2002

Examines the current state of interlending and document delivery from a UK perspective. In particular, focuses on four trends that have recently gained momentum and come to the fore – international interlending, resource discovery, online access to full text and the problem of monographs, and unmediated requesting. Reports on developments in these areas and the way one area will influence another. Document delivery is widening in scope and meshing with serials and acquisitions in an electronic environment, while traditional ILL is focusing on more problematical areas. Also looks at how the activities of the British Library are shaping events.
Finite element linear and nonlinear, static and dynamic analysis of structural elements – an addendum – A bibliography (1996‐1999)
Authors: Mackerle Jaroslav
Published: July 2002

A bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view is given. The bibliography at the end of the paper contains 1,726 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1996‐1999.
A new element bisection algorithm for unstructured adaptive tetrahedral mesh generation
Authors: Wilson J.K. , Topping B.H.V.
Published: July 2002

A newh‐refinement adaptive tetrahedral mesh generation algorithm is presented. Three‐dimensional domains, to be analysed by the finite element method, are initially modelled by a coarse background mesh of tetrahedral elements. This mesh forms the input for finite element analysis and error estimation by the Zienkiewicz‐Zhu simple error estimator. Adaptive mesh refinement proceeds by selecting an element for remeshing whose longest edge is shared by elements that also require refinement. This group of elements is refined by inserting a new node at the mid‐point of the shared edge thereby bisecting all elements within the group. Adaptive parameters are calculated for the new node and elements. Refinement then proceeds until no further group of elements can be found for refinement or no elements within the current mesh require further refinement. The shape quality of the current mesh is then enhanced by the iterative application of nodal relaxation plus three topological transformations. The entire refinement process is repeated iteratively until the required degree of mesh refinement is reached. Ten‐noded linear strain tetrahedral finite element meshes have been used for the finite element and error estimation analyses. Four examples of adaptive tetrahedral mesh generation for linear elastic stress/displacement analysis are presented which show that this algorithm is robust and efficient in terms of reduction of the domain error with a minimum number of degrees of freedom being generated, number of iterations, and therefore finite element analyses, required and computational time for refinement when compared to the advancing front method and Delaunay triangulation.
From public baths to public library – or “how to save a historic building”
Authors: Astill Mag
Published: July 2002

Warwickshire County Council’s Libraries and Heritage Department has opened two new libraries in the past year – one of them in a former public swimming pool in the centre of Royal Leamington Spa. The £7 million redevelopment of the town’s Royal Pump Room complex presented an unexpected and irresistible opportunity which, you might say, plunged Libraries and Heritage “in at the deep end”. Almost 12 months on, members of the project team reflect on the process and problems of adapting a derelict listed building for a new purpose – and then moving an entire library across town. They review reactions to the new library and its extended services, both initially and once things settled down. Outstanding issues and ongoing concerns are covered, as well as the new library’s successes.
The essence of HRD orientation: evidence from the Finnish metals industry
Authors: Luoma Mikko
Published: July 2002

This article introduces the term human resource development (HRD) orientation as the key factor affecting the use of training and development activities in companies. In the study, several strategic approaches to HRD are identified and treated as components of HRD orientation. The usability of the concept is tested with data from Finnish metals industry companies. The results show that the differences in the way companies perceive the role of HRD in business are related to the differences in HRD orientation. In addition, the most common forms of HRD orientation are studied. The usability of the concept is tested with data from Finnish metals industry companies. The results show that the differences in the way companies perceive the role of HRD in business are related to the differences in HRD orientation. In addition, the most common forms of HRD orientation are studied. It is suggested that companies tend to choose between emphasizing either training needs or strategic capabilities in their HRD.
Feedforward indirect vector control of a matrix converter‐fed induction motor drive
Authors: Sünter Sedat , Clare Jon C.
Published: July 2002

This paper describes the development of closed loop control techniques for matrix converter fed induction motor drives. A prototype drive rated at 2.5kW is used to demonstrate closed loop speed control using vector control technique. Solutions to the special problems associated with the power circuit and implementation of closed loop control in the matrix converter drive are given. Experimental results demonstrating the control techniques are presented for both motoring and generating operations of the matrix converter drive in transient and steady‐state.
Virtual communities in cyberspace
Authors: Geyer Felix
Published: July 2002

Reintroduces alienation theory and research. Considers alienation in a cybernetic sense as a generic term for different types of information processing problems in individuals. Considers these, more often than not, to be ultimately caused by developments in their social environment and reflecting back on that environment. Discusses the emergence of virtual communities, giving as an example the Thematic Group on Sociocybernetics and Social Systems. Describes its function and composition in a virtual community context. Considers whether Norbert Wiener foresaw the emergence of virtual communities and examines the link with the society envisaged by Niklas Luhmann.
13. Applications of the theory of blown‐ups to weather forecasting
Authors: Peng Chunhua , Li Wujie
Published: July 2002

The nonhomogeneous information is applied to the study of sudden and severe weather processes in this paper, based on the theory of blown‐ups (OuYang, 1994). Severe weather processes, such as torrential rain and severe convection, are clarified first by using the nonhomogeneous parameters in the spring in Hubei Province, and second by combining with the severe convection forecasting criteria. We can distinguish the severe convective weather processes and forecast the short‐range severe convective weather by using this theory in the spring in Hubei province. After practical applications from March 15 to May 15 in 1995, it showed that the forecast accuracy was satisfactory.
The use of differential geometry in array signal processing
Authors: Manikas A. , Dowlut N.H.
Published: July 2002

This paper reports some investigative results obtained through the application of differential geometry to the array manifold of a direction finding (DF) sensor array. It emphasises the crucial but so far disregarded role of the array manifold in the performance of subspace‐based direction finding (DF) algorithms and then proceeds to a compact mathematical analysis of the array manifold using the tools of differential geometry. The results thus obtained are used to quantify the effects of the array manifold properties on the performance of a DF system and to design superresolution sensor arrays.
Colloidal and film properties of carboxylated acrylic latices ‐ effect of surfactant concentration
Authors: Amalvy J.I.
Published: July 2002

The effects of amount of conventional surfactant sodium dodecyl sulfate in the synthesis of carboxylated acrylic latices prepared by semicontinuous emulsion polymerization method were investigated. The properties considered were particle size and colloidal stability by addition of sodium chloride solution, on the latex system and water sorption, tensile strength at break and elongation, on latex films. It was found that the surfactant concentration had an important effect on the above mentioned properties. The particle size decreases with increasing surfactant concentration and the colloidal stability has a maximum value. The critical coagulation concentration value found in this work, seems to indicate an additional stabilisation of latex particles, due to a steric factor. The water uptake and the mechanical behaviour of latex films are affected considerably when SDS concentration rises. In conclusion, depending on the final use of latex, there is an optimal surfactant concentration for which the properties are appropriate.
Developing constructive tension between teaching and research
Authors: Rowley Jennifer
Published: July 2002

Indicates that many universities are revisiting the issue of the development of an integrated teaching and research environment. Explores strategies which can be adopted to support the development of a research ethos in a teaching institution. These include: writing textbooks, publishable action learning materials and other publishable learning material; generating projects based on students’ work; encouraging research students to publish; experimenting with and evaluating different teaching and learning approaches; and integrating data collection into student learning or assessment activities.
Nurturing innovation: how much does collaborative management help?
Authors: Cooperman Dan
Published: July 2002

Collaborative decision making and site‐based management have been proposed as essential foundations for reform of classroom instruction. Using data from the nationally‐compiled PROSPECTS Data Survey, this study analyzes the data for key variables pertaining to school organization, teacher characteristics, and classroom instruction. The purpose is to determine the degree to which innovative practice relates to collaborative decision‐making process, individual teacher background characteristics, or another combination of factors. The results surprisingly downplay the impact of collaborative management on instructional practice, identifying instead sustained inservice programs and teacher belief in student ability to learn as potentially more promising directions for future research and practice aimed at the question of instructional reform.
TMA, DMA, DSC and TGA of lead free solders
Authors: Lau John H. , Chang Chris
Published: July 2002

Most of the electronics packaging materials, especially solders, are temperature dependent. Their temperature‐dependent material properties can be obtained by TMA (thermal mechanical analysis), DMA (dynamic mechanical analysis), DSC (differential scanning calorimetry), and TGA (thermogravimetric analysis). In this study, the thermal coefficient of expansion (TCE), storage modulus, moisture uptake, and melting point of two lead free solders, 96.5wt%Sn‐3.5wt%Ag and 42wt%Sn‐58wt%Bi provided from two different vendors, are measured by, respectively, TMA, DMA, TGA, and DSC. For comparison purpose, the 63wt%Sn‐37wt%Pb solder is also considered.
The economic emergence of Turkey
Authors: Etkin Lawrence P. , Helms Marilyn M. , Turkkan Umit , Morris Daniel J.
Published: July 2002

For centuries, Turkey has been the nexus of trade and enterprise in Southeastern Europe. Located between the continents of Europe and Asia, Turkey remains the historical portal of the Eastern and Western worlds. Although rooted in an entrepreneurial spirit, the antiquated trade laws in Turkey hindered the sprawling nation’s ability to trade with others. In the late 1980s however, Turkey liberalized its economic legislation, thus enabling the private sector to take the lead in generating growth and employment. This paper examines the evolving Turkish economy through the vehicles of history, the banking system, foreign investments, government apparatuses, and domestic markets and trade policy. Moreover, this paper identifies strategies and market sectors for potential investors. Finally, this paper offers a counterpoint which notes several possible and current economic pitfalls which have and may continue to handicap Turkey in the global marketplace.
Mentoring for educational leaders: a practitioner’s perspective
Authors: Playko Marsha A.
Published: July 2002

Reflects on the practice of mentoring from a practitioner′s
perspective. Explores the strengths of mentoring programmes and notes
these far outweigh some of the limitations which might exist. Draws
attention to some important issues such as planning, training, and
appropriate matching of mentors and protégés which must be
considered by schools and districts with an interest in mentoring if
these programmes are to achieve success.
Educational restructuring gone astray in paradise? The Papua New Guinea experience
Authors: O′Donoghue Thomas A.
Published: July 2002

Argues that the proposals for primary education in the latestEducation Sector Reviewin Papua New Guinea are seriously misguided. Recommends a major overhaul of the system in order to facilitate greater pupil access to primary school yet such an aim can be achieved by taking the much less radical step of increasing the average primary school class size. The structural proposals are also made in order to facilitate the introduction of a primary school programme based on a child‐centred notion of curriculum. The review would have done better to have recommended that the present primary school educational structures be maintained, that the present subject‐based curriculum be implemented properly, that steps be taken to improve the quality of the formal style of teaching with which the majority of teachers feel most comfortable and that everything possible be done to ensure that the quality of students entering the teachers′ colleges be of the highest intellectual calibre.
Peer‐assisted leadership: reducing educational managers’ professional isolation
Authors: Dussault Marc , Barnett Bruce G.
Published: July 2002

Presents a study that verified the effects of the peer‐assisted leadership programme (PAL) on communication networks and professional isolation of educational managers. The study used a one‐group pre‐test post‐test design to test its hypotheses. The subjects were 41 educational managers from two school districts of the province of Québec, Canada. A first PAL group, from a suburban school district (n= 16), followed the programme in 1993‐1994. A second group (n= 25), from a rural school district of the northern part of Québec, participated in PAL in 1994‐1995. The study used the ÉSUL a validated French version of the University of California at Los Angeles loneliness scale, to assess isolation. A sociometric questionnaire inspired by the ones used by previous researchers was used to assess subjects’ informal networks. The results indicate that PAL significantly reduces professional isolation without greatly enhancing the extent of communication networks of participants.
The leadership requirements of secondary school principals in Kuwait
Authors: Al‐Jaber Zeinab
Published: July 2002

Aims to identify the leadership requirements of secondary school principals in Kuwait after the Iraqi invasion and subsequent liberation. Twenty‐nine administrative superintendents, 59 secondary school principals and 719 teachers, were given a questionnaire consisting of 30 items dealing with principals’ duties. One‐way analysis of variance was computed to test differences of the sample means in the five dimensions of the questionnaire. Results showed that teachers see higher demands for principals in educational goals than do principals themselves; and supervisors see higher demands for principals in the school climate, faculty development, students’ problems, curriculum and supervision than do teachers and principals themselves.
Preliminary explorations of indigenous perspectives of educational management
Authors: Bajunid Ibrahim Ahmad
Published: July 2002

Attempts to clarify and articulate the need to understand and search for indigenous perspectives of educational management. Notes that any understanding of an indigenous perspective requires a real understanding of the theoretical bases of the subject, and an understanding of the particular indigenous environment or setting. Argues that, in order to differentiate culture free and culture bound content in educational management, the core corpus of educational management theories, concepts and terminology have to be identified; the culture specific ways of knowing must be examined; and unique categories made identifiable. Uses the Malaysian experience as an example of the quest for an indigenous perspective of educational management.
A continuing professional development model for quality assurance in higher education
Authors: Farrugia Charles
Published: July 2002

Proposes a model which lecturers in higher education can adopt to evaluate their current state of professional standing and stimulate their developmental growth. Currently, there is greater awareness in many professional groups, especially those in higher education, of the need to engage in critical self‐reflection, quality assurance and the enhancement of educational services. Many are concerned about the threat of deprofessionalization. Introduces the continuous professional development model and describes the significant contributions it can make to staff development programmes, as well as in sensitizing and educating an educational institute’s clients to appreciate fully the services they receive.
Factors in the selection of a risk assessment method
Authors: Lichtenstein Sharman
Published: July 2002

A risk assessment method is used to carry out a risk assessment for an organization’s information security. Currently, there are many risk assessment methods from which to choose, each exhibiting a variety of problems. For example, methods may take a long time to perform, may rely on subjective estimates for the security input data, may rely heavily on quantification of financial loss due to vulnerability, or may be costly to purchase and use. Discusses requirements for an ideal risk assessment method, and develops and evaluates factors to be considered in the selection method. Empirical research was carried out at two large, Australian organizations, in order to determine and validate factors. These factors should be of use to organizations in the evaluation, selection or development of a risk assessment method. Interesting conclusions are drawn about decision making in organizational information security.
Practical management of programme risk: the case of the National Strategy for Police Information Systems for England and Wales
Authors: Frosdick Steve
Published: July 2002

Presents a case study of managing risk in an IS/IT programme. Introduces the National Strategy for Police Information Systems for England and Wales. Outlines a framework for managing risk. Discusses the nature of risk and risk perception from a behavioural science perspective and introduces the theory of cultural complexity. Describes the management of risk processes adopted for the programme and the products to which these gave rise. Details the key areas of risk identified . Discusses the implications for the programme’s projects. Concludes the process has been worthwhile and that the case may interest other programme and project managers.
Consumer perceptions of generic products: a Mexican study
Authors: Yelkur Rama
Published: July 2002

Previous research studies on generic products focus mainly on mature markets such as the USA. These studies measure consumer perceptions of all generic products as a whole, with respect to price and quality. With the passing of the NAFTA, retailers’ interest in the relatively young Mexican market has increased. The purpose of this study is to determine Mexican consumers’ overall perceptions of generic grocery products, to examine if there are any differences in perception across demographic groups and to determine if there are differences in the perception of generic products across product categories. Two variables were examined: risk perception of generic products and satisfaction with generic products.
Changing forms of workplace representation: the United States Steel Corporation, 1933‐1937
Authors: Hogler Raymond L.
Published: July 2002

Since the National Labor Relations (Wagner) Act of 1935, American labor law has prohibited certain forms of workplace organization in nonunion firms. Congress routinely considers legislation to overturn that prohibition and allow employers more flexibility in creating workplace teams. Systems of employee representation were a prominent feature in American firms after World War I, and in the early 1930s, employers used them extensively as a union substitution technique. At United States Steel, ironically, employee representation provided the means for unionization of the firm. The company’s experience offers insight in the contemporary debate.
Rapid prototyping in Singapore: 1988 to 1997
Authors: Chee Kai Chua , Kah Fai Leong
Published: July 2002

Rapid prototyping (RP) is fast becoming a “strategic” technology, one that cannot be simply overlooked. This is because the production of a physical prototype from the computer model can be achieved in a very short turnaround time and without the fuss required by NC programming systems. In Singapore, like many countries around the world, there is great interest in this emerging technology. Discusses the evolution of the RP scene in Singapore from 1988 to 1997.
Abrasive flow finishing of stereolithography prototypes
Authors: Williams Robert E. , Melton Vicki L.
Published: July 2002

This research investigated the use of two relatively new technologies, abrasive flow machining (AFM) and stereolithography (SL), to minimize the time to develop a finished prototype. Statistical analysis was used to determine effects of media grit size, media pressure, build style, build orientation and resin type on flatness, material removal rate and surface roughness. Results indicated that media pressure, grit size, and build orientation were significant in at least one of the experiments performed. Scanning electron microscope (SEM) images showed the stair‐stepping effect of the SL process before AFM and the removal of the stair‐stepping after AFM. The SEM images showed a lack of typical AFM flowlines on the surface and suggested that the workpiece material is removed by brittle fracture. Data dependent systems analysis techniques were also used to study the surface roughness profiles.
Effectiveness of conformal coatings on a PBGA subjected to unbiased high humidity, high temperature tests
Authors: Zhang Kang , Pecht Michael
Published: July 2002

Plastic ball grid array (PBGA) packages are non‐hermetic surface mount packages, designed in response to market demands for cost‐effective, high I/O count, small footprint, and low profile components. Because of the materials and construction, PBGA packages can be vulnerable to failure mechanisms associated with exposure to temperature and humidity. In some applications, conformal coating has been used as a potential means to mitigate these problems by enhancing moisture ingress resistance. This study focused on the ability of two popular kinds of conformal coatings to protect PBGA packages from moisture‐induced failures. As part of the study, PBGA packages with and without conformal coatings were subjected to moisture ingress, moisture desorption and unbiased high temperature high humidity tests. The principal failure mechanisms observed were delamination and cracking in the packages. Although it was observed that parylene coating did slow down the moisture ingress, the high temperature high humidity tests did not demonstrate that two tested conformal coatings had significant protection against moisture‐induced failures for PBGA packages.
Towards a better understanding of underfill encapsulation for flip chip technology: proposed developments for the future
Authors: Gilleo Ken , Witt Matthew , Blumel David , Ongley Peter
Published: July 2002

Most flip chip assemblies require underfill to bestow reliability that would otherwise be ravished by stress due to thermomechanical mismatch between die and substrate. While underfill can be viewed as “polymer magic” and the key to modern flip chip success, many see it as the process “bottleneck” that must be eliminated in the future. Both views are accurate. A substantial amount of R&D is being focused on making underfill more user‐friendly. Electronic materials suppliers, various consortia, government labs and university researchers are working diligently to shatter the bottleneck and fully enable flip chip ‐ the final destination for micropackaging. This paper will describe these efforts and provide a status report on state‐of‐the‐art underfill technologies. We will also examine new processing strategies.
Interconnect solutions for advanced area array packaging
Authors: Hendriksen M.W. , Frimpong F.K. , Ekere N.N.
Published: July 2002

CSP (chip scale packaging) and flip chip area array technologies are emerging within the electronics packaging industry to provide solutions capable of fulfilling the technological demands of computer, telecom and consumer electronic products. However, the full potential of area array attach can only be realised if the next level of interconnect is capable of supporting the fine pitch and high I/O characteristics of emerging CSP and flip chip technology. Celestica has addressed this issue by investigating next generation printed circuit board (PCB) technology, to assess the capability of organic based laminate as a high density interconnect. This paper describes the manufacturing experiments performed to produce a laser microvia interconnect solution. The mechanical performance of the interconnect is also presented to confirm its compatibility with area array assembly.
A new approach to flip chip on board technology using SMT compatible processes
Authors: Zhang S. , De Baets J. , Van Calster A.
Published: July 2002

A flip chip on board technology fully compatible with current PCB facilities is reported. It used reflow soldering for chip attachment. It required electroless nickel/immersion gold finishing on the board pads as well as on the chip pads. A no‐clean solder paste was printed on the boards before chip placement. Thus, there was no requirement for solder deposition on the chip side. Assembly tests with various chip formats proved the feasibility of this technology. X‐ray inspection and cross‐sectioning revealed the good shape and alignment of the reflowed solder joints. The reliability of underfilled assemblies was studied by ‐40 to 125°C thermal cycling. This approach is especially suitable for prototype or low volume productions as it eliminates the solder bumping process on the chip side, which is usually performed on the wafer level.
Disulfide structure of alfimeprase: A recombinant analog of fibrolase
Authors: Jones Geoff , Ronk Michael , Mori Faith , Zhang Zhongqi
Published: July 2002

The disulfide structure of alfimeprase, a recombinant analog of fibrolase, was experimentally determined by a combination of peptide mapping, Edman degradation, and mass spectrometry. The three disulfide bonds were determined to be Cys‐116/196, Cys‐156 /180, and Cys‐158/163 with the residue number system of alfimeprase.
Solution nuclear magnetic resonance structure of a protein disulfide oxidoreductase from Methanococcus jannaschii
Authors: Cave John W. , Cho Ho S. , Batchelder Abigail M. , Yokota Hisao , Kim Rosalind , Wemmer David E.
Published: July 2002

The solution structure of the protein disulfide oxidoreductase Mj0307 in the reduced form has been solved by nuclear magnetic resonance. The secondary and tertiary structure of this protein from the archaebacterium Methanococcus jannaschii is similar to the structures that have been solved for the glutaredoxin proteins from Escherichia coli, although Mj0307 also shows features that are characteristic of thioredoxin proteins. Some aspects of Mj0307's unique behavior can be explained by comparing structure‐based sequence alignments with mesophilic bacterial and eukaryotic glutaredoxin and thioredoxin proteins. It is proposed that Mj0307, and similar archaebacterial proteins, may be most closely related to the mesophilic bacterial NrdH proteins. Together these proteins may form a unique subgroup within the family of protein disulfide oxidoreductases.
Ligand‐modulation of the stability of the glucose transporter GLUT 1
Authors: Epand Raquel F. , Epand Richard M. , Jung Chan Y.
Published: July 2002

The glucose transporter GLUT 1 was isolated from human erythrocytes and reconstituted into endogenous membrane lipids. Results from thermal denaturation studies, using differential scanning calorimetry, indicate that the thermal denaturation temperature of GLUT 1 is significantly lower in the presence of ATP. The lowering of this transition temperature is very dependent on pH. At more acidic pH, ATP has a greater effect of lowering the thermal denaturation temperature of the protein. For example, with 4.8 mM ATP, the denaturation endotherm is lowered by over 10 degrees at pH 4.3, whereas at pH 7.4, ATP does not alter this transition temperature. However, a change in pH alone, in the absence of ATP, has very little effect on the denaturation temperature. Both glucose and salt partially reverse the lowering of the temperature of thermal denaturation caused by ATP. Studies of acrylamide quenching of the Trp residues of GLUT 1 indicate that at neutral pH, ATP increases the Stern‐Volmer quenching constant, while glucose lowers it. The results indicate that ATP binds to GLUT 1 and destabilizes the native structure, leading to a lowering of the thermal denaturation temperature and an increase in acrylamide quenching. The effects of ATP are reversed in part by glucose and are also partly electrostatic in nature.
Closed-Loop Input Shaping for Flexible Structures Using Time-Delay Control1
Authors: Kapila Vikram , Tzes Anthony , Yan Qiguo
Published: July 2002

Input shaping techniques reduce the residual vibration in flexible structures by convolving the command input with a sequence of impulses. The exact cancellation of the residual structural vibration via input shaping is dependent on the amplitudes and instances of impulse application. A majority of the current input shaping schemes are inherently open-loop where impulse application at inaccurate instances can lead to system performance degradation. In this paper, we develop a closed-loop control design framework for input shaped systems. This framework is based on the realization that the dynamics of input shaped systems give rise to time delays in the input. Thus, we exploit the feedback control theory of time delay systems for the closed-loop control of input shaped flexible structures. A Riccati equation-based and a linear matrix inequality-based frameworks are developed for the stabilization of systems with uncertain, multiple input delays. Next, the aforementioned framework is applied to two input shaped flexible structure systems. This framework guarantees closed-loop system stability and performance when the impulse train is applied at inaccurate instances. Two illustrative numerical examples demonstrate the efficacy of the proposed closed-loop input shaping controller. [S0022-0434(00)00103-9]
Toward Safe and Human Friendly Hydraulics: The Passive Valve
Authors: Li Perry Y.
Published: July 2002

Hydraulic systems, as power sources and transmissions, offer many advantages over electromechanical or purely mechanical counterparts in terms of power density, flexibility, and portability. Many hydraulic systems require touching and contacting the physical environments; and many of these systems are directly controlled by humans. If hydraulic systems are passive, they would be both safer to interact with, and easier for humans to control. In this paper, it is shown that a critical hydraulic component, the directional control valve, is not passive. However, the directional valve, as a one-port or a two-port device can become passive if appropriate spool valve dynamics are imposed. Methods to passify the valve for both first-order and second-order spool dynamics are considered. In the case of second-order spool dynamics, a passive method that relies on hardware modification, and an active feedback method, are proposed. [S0022-0434(00)01803-7]
Computation of QFT Bounds for Robust Sensitivity and Gain-Phase Margin Specifications
Authors: Nataraj P. S. V. , Sardar Gautam
Published: July 2002

Algorithms are presented for generation of QFT controller bounds to achieve robust sensitivity reduction and gain-phase margin specifications. The proposed algorithms use quadratic constraints and interval plant templates to derive the bounds, and present several improvements over existing QFT bound generation algorithms: (1) The bounds can be generated over interval controller phases, as opposed to discrete controller phases in existing QFT algorithms. This feature essentially solves the safety problems associated with phase discretization process in QFT bound generation; (2) The generated bounds are guaranteed to be safe and reliable, even for very coarse interval templates (of poor accuracy), and despite all kinds of computational errors; (3) Inner as well as outer enclosures of the exact bound values can be obtained using the proposed algorithms. Such enclosures directly provide upper bounds on the error in the generated results for any given interval template; (4) A very significant reduction in computational effort—typically, reduction in flops by 2–3 orders of magnitude is achieved; (5) The vertical line (or rectangle) nature of plant templates exhibited in the low and high frequency ranges can be readily exploited to obtain bounds with very little effort; (6) The number of flops required to generate the bounds for any given template can be estimated closely a priori; (7) The (entire) algorithms can be programmed using vectorized operations, resulting in small execution times. [S0022-0434(00)02403-5]
DSMC Analysis of Rarefied Gas Flow Over a Rectangular Cylinder at All Knudsen Numbers
Authors: Cheng Chin-Hsiang , Liao Feng-Liang
Published: July 2002

The present study is concerned with the flow behavior of the rarefied gas over a rectangular square cylinder. Attention has been focused on the transition regime between the continuous flow (at low Knudsen number) and the molecular flow (at high Knudsen number). The direct simulation Monte Carlo method (DSMC) is employed for predicting the distributions of density, velocity, and temperature for the external cross-flow. Meanwhile the pressure, skin friction, and net heat transfer coefficients on the surfaces of the cylinder are also evaluated. The length (l) and width (h) of the cross-section of the cylinder are both fixed at 0.06 m. The Mach number (Ma) ranges from 0.85 to 8, and the Knudsen number (Kn) is in the range 0.01⩽Kn⩽1.0. Results for various parameter combinations are presented. For some special cases, the numerical predictions are compared with existing information, and close agreement has been found. [S0098-2202(00)01404-8]
On Shaping With Motion
Authors: Ilies¸ Horea T. , Shapiro Vadim
Published: July 2002

Mechanical parts are modeled as (predominantly rigid) solid shapes that may move in space in order to function, be manufactured (for example, machine or be machined), and be assembled or disassembled. While it is clear that such mechanical shapes are greatly influenced by collision, interference, containment, and contact constraints through prescribed motions, the motion itself is usually not part of these shape models. This in turn leads to proliferation of computational methods for modeling and analysis of various motion-related constraints. We show that all motion-related constraints can be formulated and applied within the same computational framework that treats motion as an integral part of the model. Our approach relies on two computational utilities. The first one is the unsweep operation which, given an arbitrary n-dimensional subset of Euclidean space E and a general motion M, returns the largest subset of E that remains inside E under M. The second modeling utility is a disjoint decomposition of space induced by the operations of unsweep and the standard set operations. The proposed approach subsumes and unifies the traditional sweep-based modeling of moving parts, and provides improved computational support for mechanical shape design. [S1050-0472(00)02404-1]
A Differential-Geometric Analysis of Singularities of Point Trajectories of Serial and Parallel Manipulators
Authors: Ghosal Ashitava , Ravani Bahram
Published: July 2002

In this paper, we present a differential-geometric approach to analyze the singularities of task space point trajectories of two and three-degree-of-freedom serial and parallel manipulators. At non-singular configurations, the first-order, local properties are characterized by metric coefficients, and, geometrically, by the shape and size of a velocity ellipse or an ellipsoid. At singular configurations, the determinant of the matrix of metric coefficients is zero and the velocity ellipsoid degenerates to an ellipse, a line or a point, and the area or the volume of the velocity ellipse or ellipsoid becomes zero. The degeneracies of the velocity ellipsoid or ellipse gives a simple geometric picture of the possible task space velocities at a singular configuration. To study the second-order properties at a singularity, we use the derivatives of the metric coefficients and the rate of change of area or volume. The derivatives are shown to be related to the possible task space accelerations at a singular configuration. In the case of parallel manipulators, singularities may lead to either loss or gain of one or more degrees-of-freedom. For loss of one or more degrees-of-freedom, the possible velocities and accelerations are again obtained from a modified metric and derivatives of the metric coefficients. In the case of a gain of one or more degrees-of-freedom, the possible task space velocities can be pictured as growth to lines, ellipses, and ellipsoids. The theoretical results are illustrated with the help of a general spatial 2R manipulator and a three-degree-of-freedom RPSSPR-SPR parallel manipulator.