Electronics and Communications in Japan (Part III: Fundamental Electronic Science)最新文献

{"title":"Representation method for cracks on drying 3D solid by physical model","authors":"Kimiya Aoki, Ngo Hai Dong, T. Kaneko","doi":"10.1002/ECJC.20317","DOIUrl":"https://doi.org/10.1002/ECJC.20317","url":null,"abstract":"Constructing a method for representing natural objects and natural phenomena is one of the important topics of research in the field of computer graphics. In the current research, the authors propose a method of realistically representing cracks that occur in 3D objects in computer graphics. Cracking is a familiar natural phenomenon that is seen on mud walls, the surface of rice fields, ceramics, and the bark of trees. The objective of the current research is to reproduce the cracking that occurs when an object that consists of mud or clay shrinks when it dries out. To represent cracking in computer graphics, rules based on observation or approaches based on simple physical models have been considered. However, the current research uses a method based on a physical model since changes in the material properties, environment, or external forces can easily be represented. Specifically, by introducing a spring network model to represent the shrinking, elasticity, and pliability of the clay and a moisture content model to represent the moisture movement within the object due to drying and integrating these two models, the authors simulate a mechanism for generating cracks due to drying. They also investigate a method of measuring the physical parameters that are used based on the moisture content. Finally, they performed experiments for 3D objects having various shapes to verify the effectiveness of the proposed method. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(5): 50– 59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20317","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84342802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of degradation by heat and heat‐resistance property in electret condenser microphone","authors":"Y. Yasuno, Y. Riko","doi":"10.1002/ECJC.20283","DOIUrl":"https://doi.org/10.1002/ECJC.20283","url":null,"abstract":"This paper describes improvement of the heat resistance of a fixed electrode electret microphone for mobile equipment. First, hypotheses are presented on the cause of the thermal degradation and the corresponding charge behavior in the fixed electrode electret microphone and a model of the internal electric field is formed. The validity of the model is investigated by the thermal stimulated current (TSC) method. Next, the lifetime of the microphone is estimated by reference to the isothermal charge decay test (ICD method) in addition to the hypotheses. As a model, the charges are assumed to be shifted in the direction of greater depth with reduction of the surface potential. This phenomenon is accelerated by heat. The magnitude of the degradation depends on the process used for fabrication of the electret forming film. However, there is sufficient lifetime margin at room temperature. By applying this margin, the environmental characteristic may be improved if the charges are shifted to the interior or injected deeply to avoid the causes of degradation. As an example, for a general-purpose FEP film with a thickness of 12.5 µm, it is estimated that a lifetime of 1000 hours at 100 °C can be guaranteed by deep injection at depths up to about 8 µm from the electret surface. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(5): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20283","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80535671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new error backpropagation learning algorithm for a layered neural network with nondifferentiable units","authors":"Hidenori Naganuma, T. Oohori, Kazuhisa Watanabe","doi":"10.1002/ECJC.20318","DOIUrl":"https://doi.org/10.1002/ECJC.20318","url":null,"abstract":"This paper proposes a new error backpropagation method (DBP) for a three-layered neural network containing a nondifferentiable binary output unit. In contrast to the conventional simple perceptron, in which the teacher signal is given only to the output layer, in the DBP method the teacher signal is also given to the middle layer so that the output error is decreased. Consequently, it is possible in the DBP method to correct the coupling weights in both the lower layer and the upper layer. This makes it easy to construct a network composed only of binary output units, which results in high-speed operation and is suitable for hardware implementation. When the DBP method is applied to linearly inseparable tasks such as XORing, the learning performance is greatly improved compared to learning by the simple perceptron, and almost the same learning performance as the conventional BP is obtained. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(5): 40– 49, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20318","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84681339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and evaluation of UDLR satellite network model","authors":"Hidetaka Izumiyama, Haruhito Watanabe, J. Murai","doi":"10.1002/ECJC.20319","DOIUrl":"https://doi.org/10.1002/ECJC.20319","url":null,"abstract":"For satellite communication links to be used comprehensively and in a manner consistent with their features as a basis for Internet communications, it has become necessary to add a framework based on the features of satellite communications to the protocol architecture of the Internet. For this purpose, the authors' group has been engaged in the development of the new UDLR (unidirectional link routing) protocol mechanism. This paper discusses UDLR from the following viewpoints. (1) The method of actual network construction should be established effectively so as to make use of the features and advantages of satellite communications. (2) Conditions other than protocol definitions should be stated clearly for the purpose. (3) A feasibility network should be constructed to explore the optimal application area. The principles in their current form are summarized for each of the above points. UDLR has been implemented on the feasibility testbed over the whole Asian area. The transparent coexistence of a multicast video distribution system utilizing the concurrency feature of satellite communications and other Internet application systems has been achieved. It is demonstrated that UDLR functions effectively in the use of satellite communications in the Internet. The possibility of using satellite communications to support new modes of Internet application, such as broadcast stream distribution, is shown. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(5): 60– 69, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20319","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77313437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A realization method of cyclic filter banks","authors":"F. Itami, E. Watanabe, A. Nishihara","doi":"10.1002/ECJC.20070","DOIUrl":"https://doi.org/10.1002/ECJC.20070","url":null,"abstract":"In recent years theories on filter banks (cyclic filter banks) in cyclic LTI systems have been proposed. Not only are cyclic filter banks that use cyclic convolution suitable for processes such as picture signals (finite signals), the design of cyclic filter banks is also limited to specific discrete frequency points. Consequently, there are advantages such as greater freedom of design compared to filter banks (noncyclic filter banks) in noncyclic LTI systems which use conventional linear convolution. Definite design methods have been given which realize a two-partition construction as a cyclic filter bank with linear phase characteristics and orthogonality at the same time not possible in conventional noncyclic filter banks up to the present. Other than this, there have been no discussions on multipartition construction utilizing, for example, a modulated structure, methods that utilize various other advantages which can obtain a cyclic LTI system, or discussions on problems which can be solved by these. Based on this, we propose one method to achieve a cyclic filter bank in this paper. We propose a configuration that uses DFT modulation. To start with, we lead with polyphase expressions of cyclic filter banks that use DFT modulation and then present complete reconstruction conditions. We subsequently mention that the complete reconstruction conditions are given as a linear equation whose synthesized coefficients are unknown parameters by means of using a resolution given beforehand. Next, we examine the essential properties of a cyclic LTI system and then describe the advantages of this configuration method obtained by means of using these properties. Finally, we provide a design example of the proposed cyclic filter bank and show that a cyclic filter bank can be configured with DFT modulation. In addition, we mention the combined effects when dividing and synthesizing image signals based on applying this method to image compression applications. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(5): 9– 18, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20070","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76025570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of fingerprint identification technology to systems against inside information leaks and a proposal for its development form","authors":"Mitsuharu Kodama,&nbsp;Taizo Umezaki,&nbsp;Yukio Sato","doi":"10.1002/ecjc.20346","DOIUrl":"https://doi.org/10.1002/ecjc.20346","url":null,"abstract":"<p>Changes are occurring in the environment surrounding business organizations, such as the development of open networks and flexible migration of employees. In the context of such changes, it has recently been considered more important to prepare measures against information leaks from inside the organization. Among these, an urgent issue in ordinary organizations is to reinforce the existing business system so as to realize highly cost-effective security functions. This paper considers an actual case of information leakage as a model and systematically summarizes the conditions regarding security functions, based on the views of legal specialists. An actually introduced security system based on fingerprint identification is investigated, and it is shown that practical security measures can be established. A development configuration is then proposed in which part of the security system is placed in a data center and shared by multiple organizations. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(10): 54– 62, 2007; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/ecjc.20346</p>","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20346","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71981560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A proposal and evaluation of a coordinated checkpointing technique using incremental snapshots","authors":"Mamoru Ohara, M. Arai, S. Fukumoto, K. Iwasaki","doi":"10.1002/ECJC.20296","DOIUrl":"https://doi.org/10.1002/ECJC.20296","url":null,"abstract":"Coordinated checkpointing techniques ensure that a consistent global state is maintained by means of coordination between processes. The approach requires that application messages temporarily cease to be exchanged but the rollback procedure when recovering from a fault is consequently simplified and the recovery costs are small. With current reductions in communications costs, the importance of coordinated techniques may be seen to be growing. However, in large-scale systems there is a possibility that performance will be seriously impaired due to the frequent halting of the exchange of messages. In this paper we propose a method whereby coordination is performed at only a subset of the checkpoint generation points that are periodically visited while at the remaining points each process independently generates an incremental snapshot. This method aims to both alleviate the performance degradation incurred from coordination and to realize relatively high-speed recovery. In evaluating the effectiveness of this method we estimate the checkpointing overheads and recovery costs using a probabilistic model and simulations and compare it with existing coordination methods. The results show that the proposed method is more effective than existing coordination methods from the perspective of both performance and reliability in environments with a relatively low frequency of messages. In addition, we perform comparisons of two different delta schemes for representing the incremental snapshots and discuss which environments they are each respectively suited to. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(8): 39– 53, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20296","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91183021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of low-quality images and imaging enhancement methods for fingerprint verification","authors":"Hideyo Takeuchi,&nbsp;Taizo Umezaki,&nbsp;Noriyuki Matsumoto,&nbsp;Katsumi Hirabayashi","doi":"10.1002/ecjc.20345","DOIUrl":"https://doi.org/10.1002/ecjc.20345","url":null,"abstract":"A serious problem of fingerprint verification devices which are easily available on the market is how to handle ‘‘dry fingers,’’ which make the reading of fingerprints difficult and often result in incorrect verification. Dry fingers are frequently observed in the elderly and in housewives who are frequently engaged in wet work. In these cases, the observed fingerprint tends to become an eroded fingerprint image, with disconnected ridges. This paper proposes a method of handling eroded fingerprint images in which such images that will result in incorrect verification are automatically identified and the ridges are recovered rapidly. First, a method for image quality evaluation that consists of evaluating the noise in the fingerprint image is discussed and the effectiveness of the method is demonstrated. Then, simple ridge recovery is performed by using edge emphasis for images which are automatically judged to be eroded fingerprints. In the experiment, a fingerprint database was acquired in winter, when dry fingers are common. The acceptance rate for the right person (recognition rate) is found to be 94.8% when the rejection rate for other persons is set as 99.99%. When the ridges are recovered in fingerprint images whose quality is judged to be low by the image evaluation measure proposed in this paper, the recognition rate is improved to 96.2%. Furthermore, when tolerance to dry fingers is considered and verification is not performed for low-quality image judged to be difficult to recover, the recognition rate is improved to 97.2%. In environments in which few users have dry fingers, the recognition rate will be improved to 98.8% when the rejection rate for other persons is set as 99.99%. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(10): 40– 53, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20345","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20345","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71976117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study on an estimation system of inverse transfer function using adaptive filter estimating minimum-phase and allpass transfer function","authors":"Masaki Kobayashi,&nbsp;Yoshio Itoh,&nbsp;James Okello","doi":"10.1002/ecjc.20305","DOIUrl":"https://doi.org/10.1002/ecjc.20305","url":null,"abstract":"<p>A structure is proposed for an adaptive system with an adaptive filter located before the unknown system (pre-inverse adaptive system) for estimation of the inverse of the transfer function (inverse transfer function) of the unknown system. In general, when an adaptive transversal filter is used as an adaptive filter, the delay signal of the output of the unknown system is needed in the adaptive algorithm for the weights. Since an adaptive filter is inserted in the front stage, this signal cannot be observed, so that a replica of the unknown system is needed. In this paper, an adaptive system that does not require this replica is discussed. Estimation of the inverse transfer function of the minimum phase of the unknown system is performed by an adaptive exponential filter and an inverse copy of the weights of the exponential filter placed in front of the unknown system. The signal within the adaptive algorithm consists of the observable input signal to the adaptive exponential filter and the estimation error. Estimation of the inverse transfer function for the allpass transfer function of the unknown system is performed by the adaptive transversal filter and the reversing copy of the weight to the transversal filter located before the unknown system. The signal in the adaptive system consists of the observable input signal to the exponential filter and the estimation error. Convergence of the weight is studied from the point of view of monotonic increase of the gradient. The unique feature of the approach is that the algorithm of the two adaptive filters consists of a gradient algorithm with guaranteed convergence for the weights and of copies of the weights after updating. Finally, a performance evaluation of the adaptive system and a comparison with conventional systems are performed by numerical simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 10– 17, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20305</p>","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20305","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71976124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maximum likelihood criterion based space-time linear precoding method for eigenmode SNR increasing","authors":"Shusuke Narieda,&nbsp;Katsumi Yamashita","doi":"10.1002/ecjc.20304","DOIUrl":"https://doi.org/10.1002/ecjc.20304","url":null,"abstract":"<p>This paper discusses a method for increasing the eigenmode SNR by using a space-time linear precoder designed on a maximum likelihood (ML) basis (henceforth called the space-time linear ML precoder). First, the effect of the length of the precoded signal generated in the ML precoder on the eigenmode SNR is studied. It is shown that the eigenmode SNR can be increased by varying the precoded signal length depending on the condition of the channel. Next, a transceiver configuration for increasing the eigenmode SNR by the space-time linear ML precoder is presented. In the proposed method, error propagation may be generated due to the transceiver configuration and the BER characteristics may be degraded, even if the eigenmode SNR is increased. In this paper, in order to reduce the effect of the error propagation on the BER characteristics, the relationship between the average length of the error propagation and the precoded signal length in the proposed configuration is presented. It is demonstrated that the effect of error propagation can be minimized by limiting the region of search for the precoded signal length. Finally, the effectiveness of the proposed method is verified by numerical simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(10): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20304</p>","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ecjc.20304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71976120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}