bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent developments toward understanding magnetization processes in Nd‐Fe‐B permanent magnet materials
Authors: Hirosawa S. , Fukagawa T. , Maki T. 
Published: December 2007

AbstractThe quick rise of an enormous market of high‐coercivity grades of Nd‐Fe‐B sintered magnets for hybrid electric vehicles (HEV) has created a new concern about resources of certain elements such as Tb and Dy which is used in order to guarantee stability of magnetic flux at operating temperatures. Accordingly, improvements of coercivity in the Nd‐Fe‐B magnets at elevated temperatures without heavily using these scarece elements are required. For this goal, deeper understanding of the coercivity mechanism is neccesarry. In order to clearly study the relationship beween local microstructure and coercivity related to that microstructure, an approach using a model magnet composed of a thin sintered magnet and an Nd layer doposited on its surface is reported. Besides this micropscopic apporach, macroscopic approaches are also indespensable. Also described in this paper is investigation of successive recoil curves and their relation with magnetic domain structures in a system composed of submicron size grains of Nd2Fe14B that can be prepared by means of hydrogenation‐disproportionation‐dehydrogenation‐decomposition process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of interface intermixing on the magnetoresistive and the exchange coupling in bottom‐ and top‐spin valves
Authors: Kim Jong Soo , Park Dae‐Won , Lee Seong‐Rae 
Published: December 2007

AbstractWe investigated the interfacial mixing phenomena associated with magnetoresistance and exchange coupling in a top spin valve (T‐SV) and bottom spin valve (B‐SV) at IrMn/CoFe and CoFe/IrMn interfaces. The difference in the surface free energies of IrMn and CoFe is the major factor determining the degree to which interfacial mixing occurs, but it depends on the deposition sequence. A B‐SV featuring a gradational IrMn/CoFe interface had a small Hex in the as‐deposited state, but showed improved exchange coupling on annealing as a result of limited interdiffusion. By contrast, a T‐SV featuring a sharp CoFe/IrMn interface had a high Hex in the as‐deposited state, but suffered a reduction in exchange coupling on annealing, due to a moderate level of interdiffusion. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annealing temperature dependence of microwave permeability in CoFe/MnIr bilayers
Authors: Kim Dong Young , Parvatheeswara Rao B. , Kim Chong‐Oh , Tsunoda Masakiyo , Takahashi Migaku 
Published: December 2007

AbstractWe measured microwave permeability in thermal annealed CoFe/MnIr bilayers. The ferromagnetic resonance frequency (fFMR) and Gilbert damping constant (αG) are analyzed using the Landau‐Lifshitz‐Gilbert equation. The fFMR increases with the exchange bias field, and it can be easily tuned over 10 GHz either by controlling the CoFe thickness or through modifications of unidirectional anisotropy by thermal annealing. The extracted αG is inversely proportional to the exchange bias field, and this behavior is caused by the suppression of the anisotropy field distribution due to an increase in the exchange bias field. Thus, low loss performance in microwave frequency range can be achieved in exchange biased CoFe/MnIr bilayers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exchange bias effect in Fe films deposited on Si(100) substrates
Authors: Wang Wenhong , Takano Fumiyoshi , Takenaka Masato , Ofuchi Hironori , Akinaga Hiro 
Published: December 2007

AbstractThe crystal structure and exchange bias effect in Fe films deposited on Si(100) substrates have been investigated. X‐ray diffraction and fluorescence‐extended X‐ray absorption fine structure measurements reveal that the as‐deoposited Fe films are polycrystalline with a preferred (110) texture. In addition, we observe a shift in the magnetic hysteresis loop of Fe films deposited on Si (100) where there is existance of a thin oxidized layer. By comparison, for Fe film deposited on Si(100) lacking the oxidized layer, it does not exhibit any features of shift in the magnetic hysteresis loop. We postulate the effect results from a coupling between the ferromagnetic Fe film and the antiferromagnetic Fe oxide that forms spontaneously in the interface. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design and construction of a claw‐pole PM dynamo
Authors: Hwang C. C. , Li P. L. , Lai Y. C. , Liang C. H. 
Published: December 2007

AbstractThis paper aims to develop a claw‐pole permanent magnet (PM) dynamo for the generation of electric power for bicycles. The design of the machine is done with the aid of electromagnetic field analysis based on the finite element method (FEM). The prototype dynamo has been simulated and tested under no‐load and load conditions. The comparison of terminal voltages between the predicted and measured is seen to be excellent. The generation of terminal voltage of the dynamo meets the voltage requirement for bicycles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A superconductor material model for hysteresis losses computation
Authors: Satiramatekul Thitipong , Bouillault Frédéric 
Published: December 2007

AbstractThe aim of this work was to calculate the hysteresis losses in the superconductor materials. For that, we used one macroscopic model which obtained by altering Bean's model. We propose the finite element method for the numerical modeling. Our problem consists of an infinitely long superconducting line plunged in a uniform field varying periodically in time. In this paper, we present the influence of the shape and the amplitude of the applied magnetic field to the instantaneous losses. We also present two various methods for calculating the average losses. Moreover, we could in particular obtain the quantities such as the current density or the magnetization in order to know the phenomenon of superconductivity in superconductor materials. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annealing effect on an exchange‐biasing Co/IrMn system
Authors: Chen Yuan‐Tsung , Jen S. U. , Yao Y. D. , Liao J. H. , Wu T. B. 
Published: December 2007

AbstractThe top‐configuration Co(y)/IrMn(90 Å) exchange‐biasing phenomenon has been studied by sputtering method with two conditions: (a) the substrate temperature (Ts) was kept at room temperature (RT) only, and (b) Ts = RT with an in‐plane field (h) = 500 Oe deposition and postdeposition annealing in the field at TA = 250 °C for 1 h, with the samples field cooled to RT. High resolution electron cross‐sectional transmission electron microscopy (HR X‐TEM) reveals that the IrMn (111) texturing plays a main role to exchange‐biasing field (Hex) and interfacial energy (Jk). The Hex versus y result shows that Hex increases when y decreases in case (b). Since Jk = HexMsy, where Ms is Co magnetization, it is easy to derive Hex = Jk/(Msy). Therefore, if Hex is inversely proportional to y, with Jk/Ms constant, we find Hexy = constant. In case (a), Hex is very small in general, while in case (b), Hex is of the order of 60‐180 Oe. Moreover, the y dependence of Jk is similar to that of Ms for each curve. Finally, the Hc is inversely proportional to y because of the surface pinning effects from the Ta/Co and Co/IrMn interfaces. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bayesian monitoring to detect a shift in process mean
Authors: Marcellus Richard L. 
Published: December 2007

AbstractA Bayesian analogue of the Shewhart X‐bar chart is defined and compared with cumulative sum charts. The comparison identifies types of production process where the Bayesian chart has better expected performance than the cumulative sum chart. Implementing the Bayesian chart requires more detailed knowledge of the process structure than is required by the best‐known types of charts, but acquiring this information can yield tangible benefits. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of linear predictors obtained by data transformation, generalized linear models (GLM) and response modeling methodology (RMM)
Authors: Shore Haim 
Published: December 2007

AbstractThe data‐transformation approach and generalized linear modeling both require specification of a transformation prior to deriving the linear predictor (LP). By contrast, response modeling methodology (RMM) requires no such specifications. Furthermore, RMM effectively decouples modeling of the LP from modeling its relationship to the response. It may therefore be of interest to compare LPs obtained by the three approaches. Based on numerical quality problems that have appeared in the literature, these approaches are compared in terms of both the derived structure of the LPs and goodness‐of‐fit statistics. The relative advantages of RMM are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
A comparison of two methods of analysing staircase fatigue test data
Authors: Grove Daniel , Campean Felician 
Published: December 2007

AbstractWhen the fatigue strength of components or material is tested by the staircase or up‐and‐down method, the data can be analysed in either the fatigue strength domain, which is the most popular approach, or the life domain, based on life regression models. In this paper we exploit a simple relationship between families of models in the two domains to obtain an estimate of the distribution of fatigue strength directly from a fitted life regression model. We use simulation to compare the two approaches, concluding that for estimating important features of the fatigue strength distribution the method of maximum likelihood is more effective if it is applied in the life domain. In particular, it is more robust to the choice of xh, the step height of the staircase, provided xh is in the range σX–2σX, where σX is the standard deviation of the log‐strengths. Most of our results are insensitive to the value of the initial stress amplitude. Copyright © 2007 John Wiley & Sons, Ltd.
Prediction of the Watson Characterization Factor of Hydrocarbon Components from Molecular Properties
Authors: Gharagheizi Farhad , Fazeli Ali 
Published: December 2007

AbstractIn the present work, a Quantitative Structure–Property Relationship (QSPR) study was performed to predict the Watson characterization factor of hydrocarbon components. A Genetic Algorithm‐based Multivariate Linear Regression (GA‐MLR) was applied to select the most statistically effective molecular descriptors of the Watson characterization factor. Then, based on the selected molecular descriptors by GA‐MLR, a three‐layer Feed Forward Neural Network (FFNN) was constructed to predict the Watson characterization factor. The obtained results showed that the constructed FFNN can accurately predict the Watson characterization factor of hydrocarbon components.
Prediction of Flash Point Temperature of Pure Components Using a Quantitative Structure–Property Relationship Model
Authors: Gharagheizi Farhad , Alamdari Reza Fareghi 
Published: December 2007

AbstractIn this work, a general Quantitative Structure–Property Relationship (QSPR) model ($\rm{ R^2 = 0.9669}$, $\rm{ Q_{{\rm{LOO}}}^{\rm{2}} = 0.9663}$, and $\rm{ s = 12.691}$) for the prediction of flash points of 1030 pure compounds is developed. Genetic Algorithm‐based Multivariate Linear Regression (GA‐MLR) technique is used to select four chemical structure‐based molecular descriptors from a pool containing 1664 molecular descriptors.
Maintaining network connectivity and performance in robot teams
Authors: Hsieh M. Ani , Cowley Anthony , Kumar Vijay , Taylor Camillo J. 
Published: December 2007

AbstractIn this paper, we present an experimental study of strategies for maintaining end‐to‐end communication links for tasks such as surveillance, reconnaissance, and target search and identification, where team connectivity is required for situational awareness. Our main contributions are threefold: (a) We present the construction of a radio signal strength map that can be used to plan multi‐robot tasks, and also serve as useful perceptual information. We show how a nominal model of an urban environment obtained by aerial surveillance, is used to generate strategies for exploration. (b) We present reactive controllers for communication link maintenance; and (c) we consider the differences between monitoring signal strength versus data throughput. Experimental results, obtained using our multi‐robot testbed in three representative urban environments are presented with each of our main contributions. © 2008 Wiley Periodicals, Inc.
Supporting wilderness search and rescue using a camera‐equipped mini UAV
Authors: Goodrich Michael A. , Morse Bryan S. , Gerhardt Damon , Cooper Joseph L. , Quigley Morgan , Adams Julie A. , Humphrey Curtis 
Published: December 2007

AbstractWilderness Search and Rescue (WiSAR) entails searching over large regions in often rugged remote areas. Because of the large regions and potentially limited mobility of ground searchers, WiSAR is an ideal application for using small (human‐packable) unmanned aerial vehicles (UAVs) to provide aerial imagery of the search region. This paper presents a brief analysis of the WiSAR problem with emphasis on practical aspects of visual‐based aerial search. As part of this analysis, we present and analyze a generalized contour search algorithm, and relate this search to existing coverage searches. Extending beyond laboratory analysis, lessons from field trials with search and rescue personnel indicated the immediate need to improve two aspects of UAV‐enabled search: How video information is presented to searchers and how UAV technology is integrated into existing WiSAR teams. In response to the first need, three computer vision algorithms for improving video display presentation are compared; results indicate that constructing temporally localized image mosaics is more useful than stabilizing video imagery. In response to the second need, a goal‐directed task analysis of the WiSAR domain was conducted and combined with field observations to identify operational paradigms and field tactics for coordinating the UAV operator, the payload operator, the mission manager, and ground searchers. © 2008 Wiley Periodicals, Inc.
Hough based terrain classification for realtime detection of drivable ground
Authors: Poppinga Jann , Birk Andreas , Pathak Kaustubh 
Published: December 2007

AbstractThe usability of mobile robots for surveillance and search and rescue missions can be significantly improved by adding intelligent functionalities that decrease the cognitive load on the operator or that even allow autonomous behavior of the robots, e.g., when communication fails. Mobility in this regard is not only the mechatronic endeavor of developing suited locomotion apparatuses, but also a perception, modeling, and planning challenge. Here, the perception issue of detecting drivable ground is addressed, a particularly important issue for safety, security, and rescue robots, which have to operate in a vast range of unstructured, challenging environments. The simple yet efficient approach is based on the Hough transform of planes. The idea is to design the parameter space such that drivable surfaces can be easily detected by the number of hits in the bins corresponding to drivability. A decision tree on the bin properties increases robustness as it allows the robot to handle uncertainties, especially sensor noise. In addition to the binary distinction of drivable/nondrivable ground, a classification of terrain types is possible. The algorithm is applied to 3D data obtained from two different sensors, namely, a near‐infrared time of flight camera and a stereo camera. Experimental results are presented for typical indoor as well as outdoor terrains, demonstrating robust realtime detection of drivable ground. Seven datasets recorded indoors and outdoors under very varying conditions are used for this purpose. About 6800 snapshots of range data are processed in total. It is shown that drivability can be robustly detected with success rates ranging between 83% and 100%. Computation is extremely fast in the order of 5 to 50 ms. © 2008 Wiley Periodicals, Inc.
Change in teachers' knowledge of subject matter: A 17‐year longitudinal study
Authors: Arzi Hanna J. , White Richard T. 
Published: December 2007

AbstractThis longitudinal study explored change in teachers' knowledge of subjects they teach from preservice training through 17 years of professional experience. It followed secondary school science teachers in Australia, through sequences of individual interviews in which change in content knowledge (mainly energy‐related) was probed primarily via concept profiles—a word‐association method. Change was found to be multifaceted, with details of unused content fading from memory, alongside growth that results from improved understanding and reorganization of structure more than from accretion of new material. Across personal and professional life tracks that produce variation between individuals, development is facilitated by “critical mass” of teachers' knowledge and interest in their chosen disciplines of study and certification, whereas deficiencies tend to persist in the other subjects they are asked to teach. The required curriculum is the single most powerful determinant of teacher knowledge, serving as both its organizer and source. Based on the study, a three‐phase model of teacher content‐knowledge development is proposed, and the discussion highlights the need for career‐long support for growth, even in teachers' major subjects where expertise is taken for granted. © 2007 Wiley Periodicals, Inc. Sci Ed 92:221–251, 2008
Examining the cognitive processes used by adolescent girls and women scientists in identifying science role models: A feminist approach
Authors: Buck Gayle A. , Clark Vicki L. Plano , Leslie‐Pelecky Diandra , Lu Yun , Cerda‐Lizarraga Particia 
Published: December 2007

AbstractWomen remain underrepresented in science professions. Studies have shown that students are more likely to select careers when they can identify a role model in that career path. Further research has shown that the success of this strategy is enhanced by the use of gender‐matched role models. While prior work provides insights into the value of using role models, it does not explain the cognitive process involved in girls identifying role models from nontraditional careers for women. This feminist study addresses this gap by examining the cognitive process eighth‐grade girls use in identifying a person as a science role model and comparing it to the process used by women scientists seeking to serve as possible science role models. Data revealed that the girls' process in identifying a role model involved personal connections and their initial image of a scientist led them to believe they could not have such a connection with a scientist. The initial views expressed by the women suggested they felt pressure to portray “perfect“ scientists in order to be a role model. A common understanding of a science role model was realized only after changes occurred in the girls' image of scientists and the scientists' image of a role model. The catalysts for these changes were the relationships that developed between girls and women scientists. © 2007 Wiley Periodicals, Inc. Sci Ed 92:688–707, 2008
Using data mining to predict K–12 students' performance on large‐scale assessment items related to energy
Authors: Liu Xiufeng , Ruiz Miguel E. 
Published: December 2007

AbstractThis article reports a study on using data mining to predict K–12 students' competence levels on test items related to energy. Data sources are the 1995 Third International Mathematics and Science Study (TIMSS), 1999 TIMSS‐Repeat, 2003 Trend in International Mathematics and Science Study (TIMSS), and the National Assessment of Educational Progress (NAEP). Student population performances, that is, percentages correct, are the object of prediction. Two data mining algorithms, C4.5 and M5, are used to construct a decision tree and a linear function to predict students' performance levels. A combination of factors related to content, context, and cognitive demand of items and to students' grade levels are found to predict student population performances on test items. Cognitive demands have the most significant contribution to the prediction. The decision tree and linear function agree with each other on predictions. We end the article by discussing implications of findings for future science content standard development and energy concept teaching. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 554–573, 2008
Parastomal Hernia‐Repair Using Mesh and an Open Technique
Authors: Guzmán‐Valdivia Gilberto , Guerrero Teresa Soto , Laurrabaquio Hilda Varela 
Published: December 2007

AbstractIntroductionParastomal hernia occurs in 35%‐50% of patients who have had a stoma formed, whether for the digestive tract or the urinary tract. There are many repair techniques including primary repair and repair using different types of mesh prosthesis, and the surgical approach may be open or laparoscopic. However, all techniques suffer the disadvantage of a high index of hernia recurrence.Patients and methodsThis study included 125 patients from the stoma clinic at our hospital. Hernia repair was performed on 25 of these patients who had a terminal colostomy because of either cancer or inflammatory disease. Preoperative colon preparation involved a cathartic, an evacuating enema, and antibiotic therapy in the preoperative period. The repair was conducted via an anterior approach, dissecting the skin around the stoma in the way a plastic surgeon handles an umbilical scar during abdominoplasty, in order to enter the hernia site. The hernial sac was left intact to form a bed on which to lay a lightweight polypropylene mesh, and this was then fixed to the deep face of the aponeurosis all around the stoma, with sutures placed in a U‐shape with 1/0 or 2/0 non‐absorbent material. The mesh was also fixed to the external surface of the colon with simple sutures of 3/0 polyglycocolic acid. A closed supra‐aponeurotic drain was left in situ, and the skin was closed with 3/0 nylon.ResultsOf the corpus, 50 patients presented with parastomal hernia (40%), and 25 of them underwent surgery. These patients were followed for a period of 12 months, on average (range: 8–24 months). After operation, 2 patients (8%) experienced hernia recurrence and underwent further surgery to reinforce the abdominal wall with a new insertion of mesh prosthesis; 2 patients (8%) suffered surgical wound infection; and 2 patients (8%) developed a seroma. There was no rejection of the mesh, erosion of the colon, or fistula formation.ConclusionsInserting a mesh prosthesis by this technique is a safe effective treatment for parastomal hernia, adding another option to the available repair solutions. Prospective and comparative studies are required to reinforce this study, and they should ideally include a greater number of patients in the study corpus.