bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional diversification of a basic helix–loop–helix protein due to alternative transcription during generation of amphidiploidy in tobacco plants
Authors: Kodama Yutaka , Sano Hiroshi 
Published: April 2007

A plastid-resident basic helix–loop–helix protein, previously identified in Nicotiana tabacum and designated as NtWIN4 (N. tabacum wound-induced clone 4), has been converted from a nuclear transcription repressor into a plastid-resident regulatory factor through replacement of the DNA-binding domain with a plastid transit sequence during evolution. N. tabacum is a natural amphidiploid plant derived from Nicotiana tomentosiformis and Nicotiana sylvestris and immunoblot staining using anti-NtWIN4 antibodies identified two protein species, a 26 kDa form and a 17 kDa form, in N. sylvestris, whereas only the 17 kDa form was found in N. tabacum. The 26 kDa protein is produced when translation starts from the first AUG codon of the mRNA and is predominantly localized in the cytoplasm and nucleus, whereas the 17 kDa protein is derived from a 24 kDa precursor protein, synthesized from the second AUG codon, and localizes only to plastids. Subsequent analyses revealed that the lengths of the mRNAs vary in the two plant species. One major form lacks the first AUG, while minor populations possess variable 5′-untranslated regions prior to the first AUG codon. Translation of the two types produces the 24 kDa and 26 kDa proteins respectively. In vitro translation assays indicated that initiation frequency from the first AUG codon is higher in mRNAs from N. sylvestris than from N. tabacum. In contrast, initiation from the second AUG codon was found to be equally efficient in mRNAs from both species. These results suggest that both mRNA populations and translation efficiency changed during the amphidiploidization responsible for generation of N. tabacum. This scheme could reflect a molecular mechanism of protein evolution in plants.
Evaluation of web sites for B2C e‐commerce
Authors: Oppenheim Charles , Ward Louise 
Published: April 2007

PurposeThe purpose of this research is to report the results of research that was carried out to evaluate the effectiveness of a number of web sites selling chocolate.Design/methodology/approachThe research was founded on a series of criteria for evaluating such web sites, based upon a review of the literature. A series of criteria were developed and a scoring system associated with them was generated. Following a pilot test, a panel of eight volunteers evaluated ten chocolate‐related web sites which were carefully chosen for their range of characteristics.FindingsAspects evaluated included presentation, content, accessibility, language, navigation and structure, transaction page, security, privacy and authority, and marketing factors. The resulting scores were then analysed. Using two different methods of analysis, it was found that the best web site was www.danschocolates.com, but that there was significant inter‐scorer discrepancy in some of the scores assigned.Research limitations/implicationsOnly a small number of sites were evaluated, using a relatively small number of evaluators.Practical implicationsConclusions are drawn regarding the most important factors that web designers should take into account when developing a site for selling chocolate or similar products. Comments are also made on the need to involve real users when developing criteria for the evaluation of web sites.Originality/valueThe paper provides a possible general methodology for evaluating web sites.
A genre analysis of scientific abstracts
Authors: Cross Cate , Oppenheim Charles 
Published: April 2007

PurposeThe purpose of the paper is to analyse the structure of a small number of abstracts that have appeared in the CABI database over a number of years, during which time the authorship of the abstracts changed from CABI editorial staff to journal article authors themselves. This paper reports a study of the semantic organisation and thematic structure of 12 abstracts from the field of protozoology in an effort to discover whether these abstracts followed generally agreed abstracting guidelines.Design/methodology/approachThe method adopted was a move analysis of the text of the abstracts. This move analysis revealed a five‐move pattern: move 1 situates the research within the scientific community; move 2 introduces the research by either describing the main features of the research or presenting its purpose; move 3 describes the methodology; move 4 states the results; and move 5 draws conclusions or suggests practical applications.FindingsThematic analysis shows that scientific abstract authors thematise their subject by referring to the discourse domain or the “real” world. Not all of the abstracts succeeded in following the guideline advice. However, there was general consistency regarding semantic organisation and thematic structure.Research limitations/implicationsThe research limitations were the small number of abstracts examined, from just one subject domain.Practical limitationsThe practical implications are the need for abstracting services to be clearer and more prescriptive regarding how they want abstracts to be structured as the lack of formal training in abstract writing increases the risk of subjectivity and verbosity and reduces clarity in scientific abstracts. Another implication of the research are that abstracting and indexing services must ensure that they maintain abstract quality if they introduce policies of accepting author abstracts. This is important as there is probably little formal training in abstract writing for science students at present. Recommendations for further research are made.Originality/valueThis paper reports a study of the semantic organisation and thematic structure of 12 abstracts from the field of protozoology.
The ARTstor Digital Library: a case study in collection building
Authors: Marmor Max 
Published: April 2007

PurposeThe purpose of this paper is to outline the approach to collection development that has characterized the building of the ARTstor Digital Library.Design/methodology/approachThe approach adopted is a brief history, overview, and analysis of the development of the ARTstor collections.FindingsThe paper finds that ARTstor has sought to pursue a strategic approach to collection development, taking as its point of departure the needs of potential users.Originality/valueThe paper offers an inside view of the development of a new non‐profit digital library.
Using document delivery data for selecting medical titles in a large STM library: the experience of CISTI
Authors: Ireland Michael , Brown Beverly 
Published: April 2007

PurposeThe Canada Institute for Scientific and Technical Information (CISTI) undertook an in‐depth analysis of its current serial subscriptions to determine whether they were meeting the needs of internal clients at the National Research Council of Canada (NRC) and document delivery clients. The assumptions were that extended gaps existed in business literature needed by NRC clients and medical literature needed by document delivery clients. Seeks to address this issue.Design/methodology/approachThe analysis was done from two perspectives: review and analysis of usage of the print serials subscriptions; and analysis of unfilled document delivery orders. The project team matched current serial titles with document delivery usage and then classified the titles by subject. Second, the team used data from unfilled orders to create a ranked list of titles not held at CISTI but for which clients were requesting articles. The ranked titles were validated by data from the National Library of Medicine (NLM) on titles requested by Canadian libraries and not widely available in Canada.FindingsNRC users showed a need for more business titles and all client groups showed a marked need for medical titles. While 36 percent of titles in the collection were medical, they accounted for 57.2 percent of document delivery activity and for 64.6 percent of unfilled orders. As a result, CISTI purchased 135 new medical serial subscriptions and will update its collection development policy to allow for a broader collection in medicine and business.Originality/valueThe study shows that document delivery usage data can play a key role in supporting strategic collection decisions.
Integrated waveguides for optical interconnects
Authors: Sweatman Denis , Powell Olly , Francis Shinoj 
Published: April 2007

PurposeTo detail results of research into optical waveguides fabricated from silicon on insulator (SOI) for on‐chip high speed applications and from polymer for more general applications.Design/methodology/approachThis paper shows the processes for wet etch fabrication of SOI single mode rib waveguides including compact crystal plane turning mirrors. Losses for the mirror facets are determined by difference measurements. Multimode polymer strip waveguides are fabricated on glass substrates by conventional photolithography using SU8 polymer and tested for attenuation.FindingsFabrication of compact turning mirrors for silicon waveguides requires precise alignment of masks and controlled etching of the corner facets in order to obtain correct alignment of the mirror face with the incoming and outgoing waveguides. Measurements of losses per mirror facet show typical losses of 1‐2 dB/facet. Suggestions for improvements are made. Preliminary results for polymer waveguides show the necessity for high quality lithography.Originality/valueOptical interconnects for high speed communication on board and on chip are part of the ITRS Road Map for advanced interconnects. Design of optical elements to enable this, including reduction of on‐chip area by turning mirrors, is necessary for on‐chip optical technology to be successful. Compact etched mirrors described here extend previous designs and enable fabrication at any position on‐chip. New etch mask techniques for silicon waveguide fabrication are also described.
Pricing multicallable range accruals with the Libor Market Model
Authors: Chalamandaris George 
Published: April 2007

PurposeThe paper aims to propose a consistent and robust pricing/hedging methodology for callable fixed income structures with embedded caplet‐linked options.Design/methodology/approachA range of recently published (1997‐2003) works about the Libor Market Model (LMM) tackle the problems of modelling the forward curve with more than two factors and calibrating it to caps either/or to swaps. Other articles involve the pricing of Bermudan options using Monte Carlo simulation. In the form of case study, the very popular structure of multicallable range accrual bonds is used. A complete calibration methodology is described in detail, which links the structure's price to the market caps and swaptions prices as well as to the historical correlations between forward rates. We present the direct implementation of the Monte Carlo technique for this particular problem. Furthermore, we explore the application of the Longstaff–Schwartz least squares algorithm and its variations for the estimation of the expected value of continuation.FindingsThis paper suceeds in producing a consistent and robust pricing/hedging methodology for callable fixed income structures with embedded caplet‐linked options.Practical implicationsThe increased complexity of similar fixed income structures makes traditional approaches like Black–Derman–Toy or Hull‐White trees inadequate for the task of consistent pricing and hedging. Therefore, care must be taken to ensure consisted hedging across the different volatility markets.Originality/valueThis article explores variations and settings of the popular LMM and the Longstaff‐Scwartz algorithm that can be relatively consistent with both the cap and swaption volatility market. The framework is built using as a benchmark the most liquid fixed income structure so that it can be tested for robustness.
Interval approach to robust design
Authors: Lamberti Patrizia , Tucci Vincenzo 
Published: April 2007

PurposeAims to present a novel approach for the worst‐case, robust design (RD) of an electromagnetic system able to overcome some discretionary aspects of the available methods.Design/methodology/approachThe proposed methodology is based on a suitable application of the interval arithmetic and considers the width of the interval Taylor extension (WITE) of the performance function (PF) as a valuable robustness index (RI). In particular, the most robust stationary point is obtained by looking for the minimum of a continuous, non‐differentiable function thanks to the properties of WITE.FindingsThe method furnishes a reliable classification of the robust solutions with PFs expressed by either mono or multi‐dimensional polynomial forms and provides the over‐bounding of the PF without additional computational efforts.Research limitations/implicationsLimitations concern the necessity of an analytic formulation of the system performance. The IA approach may lead to lose some robust solution.Practical implicationsA RI can be assigned in analytic form and it can be suitably used as a figure of merit in a multi‐objective optimisation problem.Originality/valueThe use of the interval analysis for the worst‐case, RD of an electromagnetic system is original. The system designer may find the most robust stationary solution by means of a continuous, non‐differentiable function.
Krylov subspaces from bilinear representations of nonlinear systems
Authors: Condon Marissa , Ivanov Rossen 
Published: April 2007

PurposeThe paper is aimed at the development of novel model reduction techniques for nonlinear systems.Design/methodology/approachThe analysis is based on the bilinear and polynomial representation of nonlinear systems and the exact solution of the bilinear system in terms of Volterra series. Two sets of Krylov subspaces are identified which capture the most essential part of the input‐output behaviour of the system.FindingsThe paper proposes two novel model‐reduction strategies for nonlinear systems. The first involves the development, in a novel manner compared with previous approaches, of a reduced‐order model from a bilinear representation of the system, while the second involves reducing a polynomial approximation using Krylov subspaces derived from a related bilinear representation. Both techniques are shown to be effective through the evidence of a standard test example.Research limitations/implicationsThe proposed methodology is applicable to so‐called weakly nonlinear systems, where both the bilinear and polynomial representations are valid.Practical implicationsThe suggested methods lead to an improvement in the accuracy of nonlinear model reduction, which is of paramount importance for the efficient simulation of state‐of‐the‐art dynamical systems arising in all aspects of engineering.Originality/valueThe proposed novel approaches for model reduction are particularly beneficial for the design of controllers for nonlinear systems and for the design and analysis of radio‐frequency integrated circuits.
Comparison ofhp‐adaptive methods in finite element electromagnetic wave propagation
Authors: Schober Marc , Kasper Manfred 
Published: April 2007

PurposeThis paper aims to show that simple geometry‐basedhp‐algorithms using an explicita posteriorierror estimator are efficient in wave propagation computation of complex structures containing geometric singularities.Design/methodology/approachFour differenthp‐algorithms are compared with commonh‐ andp‐adaptation in electrostatic and time‐harmonic problems regarding efficiency in number of degrees of freedom and runtime. An explicita posteriorierror estimator in energy norm is used for adaptive algorithms.FindingsResidual‐based error estimation is sufficient to control the adaptation process. A geometry‐basedhp‐algorithm produces the smallest number of degrees of freedom and results in shortest runtime. Predicted error algorithms may choose inappropriate kind of refinement method depending onp‐enrichment threshold value. Achieving exponential error convergence is sensitive to the element‐wise decision onh‐refinement orp‐enrichment.Research limitations/implicationsInitial mesh size must be sufficiently small to confine influence of phase lag error.Practical implicationsInformation on implementation ofhp‐algorithm and use of explicit error estimator in electromagnetic wave propagation is provided.Originality/valueThe paper is a resource for developing efficient finite element software for high‐frequency electromagnetic field computation providing guaranteed error bound.
Inductor design using signomial programming
Authors: Jabr R.A. 
Published: April 2007

PurposeThis paper seeks to consider the design of small, naturally cooled, and high‐frequency (in excess of 10 kHz) inductors. Its purpose is to show that the design of such inductors can be obtained from the solution of a signomial program. In its most general form, the signomial program calls for minimising the total mass (or cost) of the inductor whilst ensuring the satisfaction of the inductance value together with constraints imposed by the copper fill‐factor, the allowed temperature rise, Kirchhoff's mmf law, and the core flux density.Design/methodology/approachThe signomial program is solved using a sequential geometric programming (SGP) approach specifically tailored to the inductor design problem. In essence, SGP seeks a constrained minimum mass (or cost) solution by optimally setting the inductor geometry parameters, the air‐gap length, and the relevant electrical and magnetic quantities.FindingsDesign results reveal that including the inductor geometry parameters in the set of problem variables leads to significant savings in the inductor mass (or cost).Practical implicationsIn cases where there are restrictions on the inductor weight, the optimal solution of the signomial program can be used for manufacturing inductors having cores with non‐standard sizes. In other applications where core dimensions are chosen from the manufacturer's database, the SGP approach can be used to complete the design by either maximising the inductance value or minimising the total loss whilst enforcing a given inductance value.Originality/valueThis work presents a first attempt to optimise an inductor design via signomial programming. The proposed solution methodology is based on SGP, but specifically adapted to the inductor design problem.
Ant colony based hybrid optimization for data clustering
Authors: Nath Sinha Amarendra , Das Nibedita , Sahoo Gadadhar 
Published: April 2007

PurposeA new algorithm based on ant colony optimization (ACO) for data clustering has been developed.Design/methodology/approachACO technique along with simulated annealing, tournament selection (GA), Tabu search and density distribution are used to solve unsupervised clustering problem for making similar groups from arbitrarily entered large data.FindingsDistinctive clusters of similar data are formed metaheuritically from arbitrarily entered mixed data based on similar attributes of data.Research limitations/implicationsThe authors have run a computer program for a number of cases related to data clustering. So far, there are no problems in convergence of results for formation of distinctive similar groups with given data set quickly and accurately.Practical implicationsACO‐based method developed here can be applied to practical industrial problems for mobile robotic navigation other than data clustering and travelling salesman.Originality/valueThis paper will enable the solving of problems related to mixed data, which requires the formation of a number of groups of similar data without having a prior knowledge of divisions, which lead to unbiased clustering. The computer code developed in this work is based on a metaheuristic algorithm and presented here to solve a number of cases.
Effects of thermal history on the intermetallic growth and mechanical strength of Pb‐free and Sn‐Pb BGA solder balls
Authors: Liang J. , Dariavach N. , Callahan P. , Shangguan D. 
Published: April 2007

PurposeTo investigate effects of the thermal history on intermetallic thickness and morphology and on the resulting shear strength of the ball attachment for a variety of BGA components.Design/methodology/approachIn this study, a variety of BGA components with balls made of Pb‐free Sn‐Ag‐Cu (SAC) 305, Sn‐Pb eutectic and high‐temperature 90Pb‐10Sn alloys, were subjected to different thermal histories, including up to ten reflow cycles, and aged at 125°C from 24 to 336 h. The intermetallic thickness and morphology after these thermal events were then examined under optical and scanning electronic microscopes. Ball shearing tests were conducted to investigate effects of the thermal history and intermetallic thickness and morphology on shearing strength of these solder balls.FindingsThe results show that effects directly from intermetallic layers may or may not be detectable; and the shear strength of solder balls is largely dependent on the solder alloy and its microstructure. Shear strength increases are observed after multiple reflow cycles and ageing at elevated temperature for the two Pb‐bearing alloys, while the SAC305 lead‐free alloy shows slight reductions in both strength and ductility after thermal exposure.Practical implicationsPresented results can be used for estimation of reliability for electronic assemblies subjected to multiple rework and repair operations, which expose sensitive components, such as BGAs, to elevated temperatures.Originality/valueIt is believed that a sound understanding of the effects of intermetallic morphology and thickness on reliability of BGA solder balls can lead to more intelligent choice of soldering processes, as well as to rework/repair process optimisation and to establishing their operational limits.
Optimization of lead free solder 01005 component assembly
Authors: Liu Yueli , Wayne Johnson R. 
Published: April 2007

PurposeTo optimize the printed circuit board design and assembly processes to minimize defects in the assembly of 01005 size chip resistors.Design/methodology/approachA test board was designed with a range of pad sizes, pad shapes, pad spacings and pad orientations. This test board was used in a series of designed experiments to optimize the printing, placement and reflow processes. Assembly defects were analyzed as a function of board design and assembly processes.FindingsAn electroformed, 76 μm stencil yielded a robust paste printing process and higher process capability indices (Cp) compared to a 102 μm stencil. Nitrogen reflow was required to achieve good solder wetting due to the high surface‐to‐volume ratio of the solder deposits. With regard to bridging defects, no defects were observed if the pad‐to‐pad spacing for parallel resistors was 150 μm or larger. Rectangular pads with no vias‐in‐pad and designed at 90 percent of nominal pad size (pad size type 2) with the ramp profile, independent of 0° or 90° resistor orientation yielded the lowest number of defects. Given the undersized pads on the actual board, the 90 percent pad average width was 170 μm (versus a design value of 183 μm) and the measured width of the 01005 chip resistor was 180 μm. Thermal cycle reliability testing of the solder joints with this pad size showed no failures after 1,000 thermal cycles.Originality/valueThe results of this work provide a set of design and assembly processes recommendations for those who must implement 01005 size component assembly in production.