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

{"title":"Algorithms for the minimum partitioning problems in graphs","authors":"H. Nagamochi","doi":"10.1002/ECJC.20341","DOIUrl":"https://doi.org/10.1002/ECJC.20341","url":null,"abstract":"In this paper, the author explains the recent evolution of algorithms for minimum partitioning problems in graphs. When the set of vertices of a graph having non-negative weights for edges is divided into k subsets, the set of edges for which both endpoints are contained in different subsets is called a k-way cut or k-cut. The problem of obtaining the k-way cut that minimizes the sum of the weights is an important research topic that appears in many practical applications such as VLSI design. In this paper, the author introduces recent results including cases in which sets of terminals or sets of terminal pairs that are to be separated are further specified in this problem and cases in which the objects to be partitioned are extended from graphs to hypergraphs or submodular set functions. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(10): 63– 78, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20341","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"758 1","pages":"63-78"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77520119","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, T. Umezaki, N. Matsumoto, K. 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":"33 1","pages":"40-53"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89154456","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, T. Umezaki, Yukio Sato","doi":"10.1002/ECJC.20346","DOIUrl":"https://doi.org/10.1002/ECJC.20346","url":null,"abstract":"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","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"84 1","pages":"54-62"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83556227","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":"S. Narieda, K. Yamashita","doi":"10.1002/ECJC.20304","DOIUrl":"https://doi.org/10.1002/ECJC.20304","url":null,"abstract":"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","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"25 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86643471","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":"The construction of periodically time‐variant convolutional codes using binary linear block codes","authors":"Naonori Ogasahara, Manabu Kobayashi, S. Hirasawa","doi":"10.1002/ECJC.20271","DOIUrl":"https://doi.org/10.1002/ECJC.20271","url":null,"abstract":"In 1996 Rosenthal and York proposed (time-invariant) BCH convolutional codes [4] in which the parity check matrix of a BCH code is used in the construction of the convolutional code. The lower bound on the minimum free distance of a BCH convolutional code is guaranteed by the BCH limit. In this paper we propose a periodically time-variant convolutional code that can be constructed not only using the BCH parity check matrix but using the check matrix of any binary linear block code and show that the lower bound on the minimum free distance is guaranteed by the minimum free distance of the binary linear block code. In addition, taking 12 binary linear block codes as examples, we perform comparisons of the proposed codes with BCH convolutional codes using three evaluation criteria (minimum free distance, number of delay elements, coding rate) and show that there exist proposed codes that are superior to existing ones. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 31– 40, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20271","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"49 3 1","pages":"31-40"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76334589","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":"Overfitting of boosting and regularized Boosting algorithms","authors":"T. Onoda","doi":"10.1002/ECJC.20344","DOIUrl":"https://doi.org/10.1002/ECJC.20344","url":null,"abstract":"The impressive generalization capacity of AdaBoost has been explained using the concept of a margin introduced in the context of support vector machines. However, this ability to generalize is limited to cases where the data does not include misclassification errors or significant amounts of noise. In addition, the research of Schapire and colleagues has served to provide theoretical support for these results from the perspective of improving margins. In this paper we propose a set of new algorithms, AdaBoostReg,ν-Arc, and ν-Boost, that attempt to avoid the overfitting that can occur with AdaBoost by introducing a normalization term into the objective function minimized by AdaBoost. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 69– 78, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20344","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"19 1","pages":"69-78"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85930379","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":"Fast aperiodic correlation algorithm for real-valued shift-orthogonal finite-length sequence of length 2ν+1","authors":"Y. Tanada, Takahiro Matsumoto","doi":"10.1002/ECJC.20301","DOIUrl":"https://doi.org/10.1002/ECJC.20301","url":null,"abstract":"Real-valued shift-orthogonal finite-length sequences are sequences in which the side lobes of the aperiodic autocorrelation function become 0, except for the endpoints of the shift to both sides, and can be applied in pulse compression radar and spread spectrum communications. In this paper, a fast correlation algorithm for efficiently calculating the periodic correlation function is discussed for real-valued shift-orthogonal finite-length sequences with length M=2ν+1. For input data, including a real-valued shift-orthogonal finite-length sequence over a certain range, the value of the aperiodic correlation function is found in a certain shift range. Based on the synthesis of this sequence by the convolution of ν+1 partial sequences, the correlation processing is broken down into correlation processing of the ν+1 stages of partial sequences. As a result, the number of multiplications and the number of additions can be suppressed on the order Mlog2M. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 18– 30, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20301","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"38 1","pages":"18-30"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81507795","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, Y. Itoh, J. Okello","doi":"10.1002/ECJC.20305","DOIUrl":"https://doi.org/10.1002/ECJC.20305","url":null,"abstract":"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","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"104 1","pages":"10-17"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80818026","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 a system for running two coexisting Linux systems","authors":"Tabuchi Masaki, Ken Ichi Itoh, Y. Nomura, H. Taniguchi","doi":"10.1002/ECJC.20343","DOIUrl":"https://doi.org/10.1002/ECJC.20343","url":null,"abstract":"A method to independently run two coexisting Linux systems on one computer is proposed. Up to the present time a virtual computer method has been used as a method to run multiple operating systems on one computer. This method has a problem, however, in which the guest operating system depends on the running state of the host operating system making it impossible to efficiently utilize the processing performance of each operating system. In contrast to this, because each operating system runs independently in the proposed method by time sharing the processes and exclusively dividing the other hardware resources, one of the operating systems and applications running on the operating systems are not influenced by the other operating system and the applications running on the operating system. This paper presents the proposed method and reports the results of performance evaluations when actually implemented in Linux. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 56– 68, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20343","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"50 1","pages":"56-68"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75819960","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":"Fast rate‐distortion optimized coding mode decision for H.264","authors":"A. Tanizawa, Shin-ichiro Koto, Takeshi Chujoh","doi":"10.1002/ECJC.20342","DOIUrl":"https://doi.org/10.1002/ECJC.20342","url":null,"abstract":"In H.264/MPEG-4 AVC a wide range of different prediction block forms and prediction signal generation methods are available. By selecting an optimal combination of coding modes from the multiple possible combinations of such modes, improvements in coding efficiency can be achieved. However, when using the rate-distortion optimized coding mode decision method based on the Lagrange multipliers, at the same time as seeing a significant improvement in coding efficiency, we are faced with the problem that the mode decision procedure becomes extremely demanding computationally. The H.264/MPEG-4 AVC high profile introduces adaptive block size transformations thereby making the number of combinations of coding mode that can be selected even larger than under the main profile. In this paper we investigate a method for hierarchically and adaptively reducing the number of mode combinations. Specifically we propose a method for quickly deciding the coding mode while limiting the reductions in coding efficiency by the correlation information between two mode decision cost functions in accordance with a quantization parameter. The results of experiments confirm that by using the proposed method, the encoding time excluding the motion search can be reduced by up to 4 times for the main profile and by up to 7 times for the high profile as compared to rate-distortion optimized coding mode decision. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(9): 41– 55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20342","PeriodicalId":100407,"journal":{"name":"Electronics and Communications in Japan (Part III: Fundamental Electronic Science)","volume":"26 1","pages":"41-55"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79376705","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}