bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear Fermion Systems, Molecular Field Models, and the KMS Condition
Authors: van Hemmen Leo 
Published: July 2007

AbstractWe take advantage of the simplifications made possible by assuming the system to be infinite from the beginning, to study some exactly solvable models in statistical mechanics. (1) For fermi lattice systems with quadratic hamiltonians the unifying concept of our treatment is a precise formulation of the idea of a linear system. This concept makes it possible to define a dynamical matrix which incorporates all the information one needs for equilibrium and non‐equilibrium problems. As an example, we consider the alternating X Y chain. Furthermore we pay some attention to ergodicity, pointing out the similarity to the infinite harmonic crystal. (2) For molecular field models, including the BCS model, the method is to consider an arbitrary extremal homogeneous state, to construct the dynamics in the representation determined by that state, and then to use the KMS condition to single out the equilibrium state of the infinite system. A synthesis of these methods – (1) and (2) – enables us to give a new simple treatment of the BCS model and a direct analysis of its mathematical structure. In addition we show the equivalence of Kac and van der Waals (spin) systems in the so‐called van der Waals limit. Finally we indicate briefly how to deal with molecular field models with polynomial and more general interactions.
Quantenfeldtheorie wechselwirkender Vielteilchensysteme zur semiklassischen Beschreibung von kollektiver Bewegung mit großen Amplituden
Authors: Reinhardt H. 
Published: July 2007

AbstractUnter Benutzung von Funktionalintegralmethoden wird eine kollektive Quantenfeldtheorie wechselwirkender Vielteilchensysteme abgeleitet, deren klassischer Grenzfall durch die zeitabhängige Mean‐Field‐Approximation gegeben ist. Auf diese Weise wird die Mean‐Field‐Approximation in die volle Quantenmechanik eingebettet und die Quantenkorrekturen zur „klassischen”︁ Mean‐Field‐Approximation können systematisch berechnet werden. Unter Einschluß der dominierenden Quantenkorrekturen zur Mean‐Field‐Approximation wird eine semiklassische Theorie der kollektiven Bewegungen großer Amplituden in Vielteilchensystemen, die eine stark nichtlineare Dynamik besitzen und den konventionellen störungstheoretischen Methoden nicht zugängig sind, entwickelt. Die semiklassische Theorie wird explizit für gebundene Zustände und Zerfallsprozesse ausgearbeitet. Für gebundene Zustände führt dies zur Quantisierung der nichtlinearen zeitabhängigen Hartree‐Fock‐Theorie, die am Beispiel einer gleichförmigen Kernrotation illustriert wird.
Mean time to system recovery
Authors: Guess Frank M. , Kitchin John F. 
Published: July 2007

AbstractWe establish a linkage between mean time to system recovery (MTTSR) in fault‐tolerant repairable systems and the mean residual life (MRL) concept. Specifically we show that the MTTSR is equal to the MRL of time to repair when the time to failure of the redundant component is fixed. Several examples are provided to illustrate the two concepts.
The use of a generalized signal‐to‐noise ratio to identify adjustment and dispersion factors in taguchi experiments
Authors: Winterbottom Alan 
Published: July 2007

AbstractA signal‐to‐noise ratio proposed by Taguchi for ‘nominal the best’ can be made more flexible and used additionally for the cases ‘smaller the better’ and ‘larger the better’. The main feature which distinguishes this generalized ratio from Taguchi's signal‐to‐noise ratios is that its precise form is determined by the experimental data. Taken together with a transformation of the mean response it effectively identifies adjustment (signal) factors and dispersion factors. Examples are given to illustrate the routine operational procedure and also to demonstrate that Taguchi's signal‐to‐noise ratios can lead to inefficient, and sometimes incorrect, identification of design factors. Two important considerations are to preserve the evident appeal of the Taguchi method to engineers and also to provide a theoretical justification which is acceptable to statisticians.The principal objective of the joint transformation is to achieve approximate functional independence between the mean and variance in the new metric. This, in turn, leads to efficient identification of adjustment and dispersion factors. A comparison is made with a similar approach using Box and Cox transformations.
Statistical analysis of an age model for imperfectly repaired systems
Authors: Guo R. , Love C. E. 
Published: July 2007

AbstractAn age model is proposed for modelling imperfect repairable systems operating under a non‐homogeneous Poisson framework. The imperfect repair model investigated here effectively includes good‐as‐new, imperfect repair and bad‐as‐old regimes that have appeared separately in reliability engineering literature. To incorporate the impact of the equipment's operating environment, proportional intensities assumptions are integrated into the age model. Maximum likeihood estimates are derived for the parameters of interest.
An extension of the rapid wafer‐level wijet method and its comparison with conventional electromigration testing
Authors: Jeuland F. , Normandon Ph. , Lormand G. , Boudou A. 
Published: July 2007

AbstractWith an evaluation of the current density acceleration factorNand an improved temperature control, the rapid wafer‐level WIJET electromigration test is extended to the ‘XWIJET’ method. Results for passivated AlSi1%1·2 m̈m wide lines are presented and compared with others obtained by conventional electromigration testing. An excellent agreement of the two methods is found for the values of the current density acceleration coefficientNand of the activation energy Q0. A difference between the values of the standard deviation of time‐to‐failure distributions obtained with both methods is explained by the competition between two failure modes.
Reliability and performance analysis of time – space – time switching networks with multiple separated space switches
Authors: Sung Dan K. , Kang Sang H. 
Published: July 2007

AbstractSince electronic switching systems usually require very strict reliability requirements as well as good performance objectives, we need to jointly analyse the performance and reliability of switching systems. In this paper, we compare conventional time–space–time switches with single space switches with those with multiple separated space switches, from the viewpoints of reliability and performance. We consider time–space–time switching networks which consist ofNincoming time switches, i.e. oneNxNspace switch, two (N/2)x(N/2) space switches, and four (N/4)x(N/4) space switches. We introduce a Markov reliability model to study the effect of failures and analyse the reliability and performance of three different types of switching networks in terms of average blocking probability and the mean time to unreliable operation, as we vary the offered traffic. As a result, T–S–T switching networks with multiple separated space switches exhibit better performance and reliability than those with single space switches.
Comparative study of quantitative models for hardware, software and human reliability assessment
Authors: Bodsberg Lars 
Published: July 2007

AbstractVarious models which may be used for quantitative assessment of hardware, software and human reliability are compared in this paper. Important comparison criteria are the system life cycle phase in which the model is intended to be used, the failure category and reliability means considered in the model, model purpose, and model characteristic such as model construction approach, model output and model input. The main objective is to present limitations in the use of current models for reliability assessment of computer‐based safety shutdown systems in the process industry and to provide recommendations on further model development. Main attention is given to presenting the overall concept of various models from a user's point of view rather than technical details of specific models. A new failure classification scheme is proposed which shows how hardware and software failures may be modelled in a common framework.
‘On‐line’G‐control chart for attribute data
Authors: Glushkovsky Eli A. 
Published: July 2007

AbstractOn the basis of thetheory of random processesthe concept of aG‐chart is elaborated. In this case the observed variableGis a number of conforming units between two consecutive appearances of non‐conforming ones. If the process is a Poisson one thenG‐variables are geometrically distributed (theG‐chart is called after the distribution type). Application of a new SPC concept for attribute data makes it possible to improve SPC employment for:high quality processeswith ṗ < 10−4(100 ppm);low volume manufacturing, short runsand‘stepped’ processes.In the paperindividual G, G‐barandstabilized G/Ḡcharts are presented. The sensitivities of aG‐chart and a classicalp‐chart for the detection of process changes are compared by constructing operating characteristic curves and ARL curves. Depending on the required degree of the detection process changes, an optimal size of subgroup is found. For this size of subgroup the average number of non‐conforming units and the average number of observed units between the process change and this change detection are minimal. Compared with the classicalp‐chart of the same sensitivity, theG‐chart requires on the average fewer observed units for process change detection and also on the average fewer non‐conforming units are produced.
Proportional hazards modelling of repairable systems
Authors: Kumar Dhananjay 
Published: July 2007

AbstractThe purpose of this paper is to illustrate some situations under which the proportional hazards model (PHM) and its extensions can be used for identification of the most important covariates influencing a repairable system. First of all an overview of the application of the PHM in engineering is presented. Then the concepts of the PHM and its extensions, such as stratified PHM, PHM in the case of non‐homogeneous Poisson processes and PHM in the case of jumps in the hazard rate or different intensity function at failures of a large number of copies of a repairable system, are presented. Selection of a suitable extension of the PHM for given data on the basis of residual plots is also discussed. Finally applications of the PHM and its extensions are illustrated with a suitable example. Only the semi‐parametric method has been considered. The assumptions made in the PHM for the analysis of repairable systems have been explained graphically as far as possible. Perfect, minimal or imperfect repairs carried out on repairable systems can be taken into consideration for the reliability analysis using the PHM.
Time and communication complexity in parallel computations
Authors: Ishioka Hiroshi , Maruoka Akira , Kimura Masayuki 
Published: July 2007

AbstractIn this paper we model the computational problem to be solved as ad‐dimensional grid withndmodes corresponding to computed values, andd(n ‐ 1)nd‐1 edges denoting dependencies. A nontrivial tradeoff between timeTand communicationCto compute the values corresponding to the nodes is shown:TCd‐1= (nd2‐n+1). Furthermore, we can meet this lower bound, to within a constant factor, by some schedules assigning a fixed number of processors to the nodes. As an example of the algorithm whose data dependency is given by ad‐dimensional grid, the algorithm for the subsequence ofdsymbol sequences is shown.
A public‐key cryptosystem based on the difficulty of solving a system of nonlinear equations
Authors: Tsujii Shigeo , Itoh Toshiya , Fujioka Atsushi , Kurosawa Kaoru , Matsumoto Tsutomu 
Published: July 2007

AbstractThis paper proposes a new public‐key cryptosystem based on the difficulty of solving a system of nonlinear equations. The proposed cryptosystem has the following features:
The public‐key is a nonlinear transform from a plaintext to a ciphertext in the form of rational functions.
The complexity of both encryption and decryption is O(m2), where m is the plaintext length.
Digital signature is possible.
The two previously proposed systems based on the matrix decomposition and the squared matrix are special cases of the proposed system. The reliability of the cryptosystem when nonlinearity is limited to the polynomial form is discussed. Next, a publickey cryptosystem based on the difficulty of solving a system of nonlinear equations with rational functions is proposed, its decryption algorithm is studied, and the conditions for this cryptosystem to ensure reliability are derived. Finally, the computational complexity of encryption and decryption, the description volume of public and secret keys, and the possibility of digital signature are studied.
Nmr image reconstruction method using complex kalman filter
Authors: Nishiyama Kiyoshi , Mita Tutomu 
Published: July 2007

AbstractAs in the case of NMR‐CT, it is sometimes required that an image with a high resolution is obtained from the limited number of data because of the long data acquisition time due to the spin‐lattice relaxation time. This paper attempts to cope with such a requirement, and proposes a reconstruction method for NMR image with improved resolution from a limited number of data. The proposed image reconstruction method first models the observed signal sequence by a multidimensional complex stochastic system with a matrix state probability variable. Then the state probability variable is estimated using a complex Kalman filter. To demonstrate the usefulness of the proposed method, an image is reconstructed from 128 × 128 data acquired from the cross section of the human head using NMR‐CT of 0.1 [T]. The result is compared with the NMR image reconstructed by the traditional two‐dimensional discrete‐Fourier transform. It is shown as a result that the proposed method not only improves the image resolution but also emphasizes the edge of the image and realizes an enlargement of the image. Furthermore, it is shown that an image emphasizing the contrast due to the spin‐spin relaxation time can be obtained.
Phoneme recognition expert system using spectrogram reading knowledge and neural networks
Authors: Komori Yasuhiro , Kawabata Takeshi , Hatazaki Kaichiro , Shikano Kiyohiro 
Published: July 2007

AbstractA human expert spectrogram reader is able to recognize phonemes in high‐accuracy performing phoneme segmentation and phoneme identification simultaneously using one's spectrogram reading knowledge. Spectrogram reading knowledge consists mainly of two parts: a strategic part for phoneme segmentation and identification and a pattern‐matching part. There are several knowledge‐based approaches in which all knowledge is implemented as rules. However, it is especially difficult to describe the pattern matching part of the knowledge as rules and to extract acoustic features automatically for phoneme identification. Here, we construct a phoneme recognition expert system which consists of two parts: (1) rule‐based phoneme segmentation, and (2) neural network‐based phoneme identification for knowledge such as pattern matching. This paper presents the architecture of the phoneme recognition expert system with its experimental result tested on Japanese consonants. The experimental result shows that 90.8 percent of the phonemes were segmented correctly and 92.4 percent of the phonemes were identified correctly within the correct segments, which means 83.9 percent of the phonemes were correctly recognized both in segmentation and identification.
A method for threshold selection in binary images using mean adjacent‐pixel number
Authors: Sasakawa Koichi , Kuroda Shin‐ichi , Ikebata Shigeki 
Published: July 2007

AbstractThis paper proposes a method of selecting an appropriate adaptive threshold in binarization (0 or 1) of a gray‐level image. A measure representing compactness of a connected component in an image, “the mean adjacent‐pixel number,” is introduced. The best threshold is determined by taking the maximal of this measure. The method is applied successfully to actual gray‐level images. The results show that appropriate thresholds can be obtained even for difficult images (e.g., a small object in a noisy and low‐contrast image) which are less successful in conventional adaptive methods (e.g., the gray‐level histogram method). Conventional methods using an adaptive threshold generally have a shortcoming in that the amount of computation is proportional to the number of thresholds. This paper also proposes a method to calculate the mean adjacent‐pixel number at a high speed by combining the rank filters and histograms so that the amount of computation becomes independent of the number of thresholds.
A matching algorithm of deformed planar curves using multiscale convex/concave structures
Authors: Ueda Naonori , Suzuki Satoshi 
Published: July 2007

AbstractThis paper proposes a new multiscale segment matching method which is applicable to heavily deformed planar shapes. First, multiscale representations are obtained using curvature scale space filtering. Then inflection point correspondence is developed between consecutive smoothed shapes. The representation in this paper, unlike the well‐known curvature scale space image description, ensures that it always satisfies the consistency of hierarchical segment replacement. Moreover, it requires less processing time and memory allocation. Finally, optimum scale segments are matched by a new multiscale segment matching method proposed herein. In this method, the matching problem is formulated as a minimization problem of the total amount of segment dissimilarity. The minimization problem is solved effectively using dynamic programming. The proposed matching method makes it possible to obtain intuitively relevant correspondences even if the shapes have some local heavy deformation.
Speaker adaptation method for fenonic markov model‐based speech recognition
Authors: Nishimura Masafumi 
Published: July 2007

AbstractThis paper proposes a speaker adaptation method for speech recognition based on the discrete hidden Markov models (HMM), especially the fenonic Markov model, which is a framewise model. The method consists largely of two parts—the adaptation of the vector quantization codebook and the adaptation of Markov models. The former employs a method which is based on the difference between the feature parameter distributions of the training speech and the word baseform as the basis for the adaptation, where the two are divided into N segments on the time axis. The latter employs a method based on a linear mapping, which is estimated from the matching between the quantized training speech and the word baseform.In this study, a recognition experiment was executed using 150 words with high similarities. Using the speech in which all object words are uttered ten times by a male, the codebook and the Markov models are estimated as the basis for the adaptation. Then the adaptation training is executed for seven males and four females by uttering once 25 words in the object vocabulary. The average error rate, i.e., 25.0 and 45.2 percent, respectively, for the males and females, is improved to 4.1 and 7.8 percent. Thus, the usefulness of the proposed method is demonstrated.
Face of the Seven Spheres: The Urban Morphology and Architecture of Nineteenth-Century Isfahan (Part Two)
Authors: Walcher Heidi 
Published: July 2007

“Have you seen Isfahan, that city like Paradise, that holy cypress, that soul nourishing Eden, that palace of the nation and that throne of government, that face of the seven spheres, that eye of the seven lands,” Jamal al-Din al-IsfahaniOne essential aspect in the discussion of nineteenth-century Qajar approaches to the Safavid city and Qajar architecture is the fact that Isfahan was no longer the capital, with the inevitable consequences that many Safavid palaces, no longer used by the city's ruling elite, had lost their administrative purpose. Architecture was created and used in a socio-political context, which determined the scope of new construction, function, style, and form. Natural deterioration and socio-economic change also required new constructions for changed purposes.Construction activity and architectural aspirations in nineteenth-century Isfahan were inseparably tied to the state of the city's overall prosperity, the affluence and beneficence of the city's leading patricians, the relationship of the Tehran court to the city, and, to some extent, the self-image and prestige in which the city perceived itself at various times during Qajar rule.
Communication and Revolution in Iran: The Passing of a Paradigm
Authors: Tehranian Majid 
Published: July 2007

“I am glad that the good God has created us all ignorant; I am glad that if we change his plans, we do it at our own risk.”— Mark Twain“We are struggling against autocracy, for democracy, by means of xerocracy.”— A Tehran University Professor, October 1978The purpose of this essay is twofold; to present an argument on the role of communication in the processes of modernization that goes substantially against the dominant views of the last two decades, and to illustrate that point of view by the example of Iran. The article was written at a moment of enthusiasm, in January-February of 1979, when the Iranian revolution looked like one of the most unanimous, nonviolent and liberating social revolts of modern history, enjoying widespread domestic and international support. Alas, that rare historical opportunity was spoiled by division and rancor in the revolutionary leadership.
Love and Sexuality in the Poetry of Forugh Farrokhzad: A Reconsideration
Authors: Milani Farzaneh 
Published: July 2007

No documents chart more accurately the difficult road to liberation and the arduous journey of the Iranian woman than her poetry. It is a rich, virtually unexplored record of the development of her consciousness and identity, experienced within, but not limited by, traditional Iranian culture. Furthermore, an evaluation of the Iranian woman's poetry is indispensable to an understanding of her life and the cultural pressures she experiences.I am talking about the poetry of, among others, Tahereh, better known as Qorratol'ayn (1819-1852), ᶜAlam Taj Zhaleh Qa'em Maqami (1884-1946), Parvin E'tesami (1907-1941), Parvin Dowlatabadi (b. 1922), Simin Behbahani (b. 1927), Lo'bat Vala Shaybani (b. 1930), Mahin Sekandari (b. 1940), Forugh Farrokhzad (1935-1967), and Tahereh Saffarzadeh (b. 1936).Unfortunately, most criticism of Iranian woman's poetry is rife with misconceptions, sexually biased assumptions, and tenacious refusals to confront this poetry on its own terms.
The Council for the Investigation of Grievances: A Case Study of Nineteenth Century Iranian Social History
Authors: Nezam‐Mafi Mansoureh Ettehadieh 
Published: July 2007

Among the demands formulated by the ˓ulamā and the tujjār (merchants) who took bast in the shrine of Shah ˓Abd al Azim in December of 1905 was the establishment of an ‘Edālat Khāneh (House of Justice).The significance of the House of Justice was that it proved to be the prototype for what later became the Majles-e Shūrā-ye Mellī (National Assembly). Paradoxically, this also proved to be obstructive to its becoming a focus for scholarly attention, in the sense that it was soon superseded by the Majles itself, which began to function in the summer of 1906. The role of addressing public grievances was in fact the basic function of the Edalat Khaneh. However, the basic engraving on the society that the Majles was a substitute for the Edalat Khaneh is well illustrated by the fact that during the early period of the Majles over 1000 petitions and complaints were addressed to it.