• 제목/요약/키워드: combining function

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Performance Enhancement of CDMA Cellular System Using Genetic Algorithm (유전 알고리즘을 이용한 CDMA 셀룰러 시스템의 성능 개선)

  • Lee, Young-Dae;Kang, Jeong-Jin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.5
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    • pp.197-203
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    • 2008
  • In this work, we present a novel genetic approach to solve the problem of combining power control and data rate transmission adjustment for the performance enhancement of the next generation CDMA system. We obtained the optimal solution of multi rate and power control problem by compromising slightly on SIR limit values. The proposed algorithm was able to handle many more users with comparable or faster convergent service. While this paper considered two kinds of fitness function such as maximizing the total transmission data rate and maximizing the acceptable mobiles of CDMA cellular network, the evaluation function combining these two cases or others can be also easily implemented. The simulation results showed the effectiveness and validity of our approach.

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Bit Error Probability of Noncoherent M-ary Orthogonal Modulation over Generalized Fading Channels

  • Simon, Marvin K.;Alouini, Mohamed-Slim
    • Journal of Communications and Networks
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    • v.1 no.2
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    • pp.111-117
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    • 1999
  • Using a method recently reported in the literature for analyzing the bit error probability (BEP) performance of noncoherent Mary orthogonal signals with square-law combining in the presence of independent and identically distributed Nakagami-m faded paths, we are able to reformulate this method so as to apply to a generalized fading channel in which the fading in each path need not be identically distributed nor even distributed ac-cording to the same family of distribution. The method leads to exact expressions for the BEP in the form of a finite-range integral whose integrand involves the moment generating function of the combined signal-to-noise ratio and which can therefore be readily evaluated numerically. The mathematical formalism is illustrated by applying the method to some selected numerical examples of interest showing the impact of the multipath intensity profile (MIP) as well as the fading correlation profile (FCP) on the BEP performance of M-ary orthogonal signal over Nakagami-m fading channels. Thses numerical results show that both MIP and FCP induce a non-negligible degradition in the BEP and have therefore to be taken into account for the accurate prediction of the performance of such systems.

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Translation-invariant Wavelet Denoising Method Based on a New Thresholding Function for Underwater Acoustic Measurement (수중 음향 측정을 위한 새로운 임계치 함수에 의한 TI 웨이블렛 잡음제거 기법)

  • Choi, Jae-Yong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.11 s.116
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    • pp.1149-1157
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    • 2006
  • Donoho et al. suggested a wavelet thresholding denoising method based on discrete wavelet transform. This paper proposes an improved denoising method using a new thresholding function based on translation-invariant wavelet for underwater acoustic measurement. The conventional wavelet thresholding denoising method causes Pseudo-Gibbs phenomena near singularities due to the lack of translation-invariant of the wavelet basis. To suppress Pseudo-Gibbs phenomena, a denoising method combining a new thresholding function based on the translation-invariant wavelet transform is proposed in this paper. The new thresholding function is a modified hard-thresholding to each node according to the discriminated threshold so as to reject unknown external noise and white gaussian noise. The experimental results show that the proposed method can effectively eliminate noise, extract characteristic information of radiated noise signals.

Multiclass LS-SVM ensemble for large data

  • Hwang, Hyungtae
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.6
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    • pp.1557-1563
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    • 2015
  • Multiclass classification is typically performed using the voting scheme method based on combining binary classifications. In this paper we propose multiclass classification method for large data, which can be regarded as the revised one-vs-all method. The multiclass classification is performed by using the hat matrix of least squares support vector machine (LS-SVM) ensemble, which is obtained by aggregating individual LS-SVM trained on each subset of whole large data. The cross validation function is defined to select the optimal values of hyperparameters which affect the performance of multiclass LS-SVM proposed. We obtain the generalized cross validation function to reduce computational burden of cross validation function. Experimental results are then presented which indicate the performance of the proposed method.

ID-Based Optimistic Fair Exchange Scheme Based on RSA

  • Youn, Taek-Young;Chang, Ku-Young
    • ETRI Journal
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    • v.36 no.4
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    • pp.673-681
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    • 2014
  • Fairness of exchange is a significant property for secure online transactions, and a fair exchange scheme is a useful tool for ensuring the fairness of exchanges conducted over networks. In this paper, we propose an ID-based optimistic fair exchange scheme based on the RSA function, one which is designed by combining a well-known RSA-based signature scheme and the (naive) RSA function. Note that the main contribution of this paper is to give the first provably secure ID-based fair exchange scheme based on the RSA function, whose security can be proved under fully formalized security models. Our scheme has the following additional strongpoints. The scheme is setup-free; hence, there is no registration step between a user and an arbitrator. Moreover, the proposed scheme is designed in an ID-based setting; thus, it is possible to eliminate the need for certificates and avoid some related problems.

A Study on Economic Power dispatch Using Evolutionary Algorithm (진화 알고리즘을 이용한 전력경제급전에 관한 연구)

  • Yang, S.O.;Mun, K.J.;Hwang, G.H.;Lee, H.S.;Park, J.H.
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.12-14
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    • 1994
  • Traditionally one convex cost function for each generation is assumed in economic power dispatch. However, it is more realistic to represent the cost function as a piecewise quadratic function rather than one convex function. This paper presents evolutionary algorithm approaches to solve the problems of economic power dispatch with quadratic cost functions and piecewise quadratic cost functions. To improve GA, EP and ES characteristics. optimization methods combining GA with ES and EP with ES are proposed. The results for the proposed algorithms are compared with those of numerical method and show the better solutions in the ELD problem.

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The Research on Herb and Its Allocation Form in Landscape

  • Zhang, Li-Qin;Piao, Yong-Ji;Shen, Ning;Cho, Tae-Dong
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.131-138
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    • 2013
  • In order to provide a scientific foundation for herb application in landscape, the photographs were taken from the herb landscape in urban green space and sightseeing garden. The questionnaire-based survey was also applied to analyze the cognitive situation of herb. Most investigators love herb, but have a low level of herb; Interviewees' consideration of herb function lie in ornamental, healthcare and medical treatment; The bulk of the visitors think herb landscape is insufficient; Investigators' preferences for herb application forms are landscape edging and combining with stone. We also probe into the optimum allocation form combining herb with landscape elements. When we combine herb with landscape water or landscape architecture, artistic conception and reasonable plant allocation should be considered; When we combine herb with landscape path or garden ornament, reasonable plant disposition and appearance and practical collocation should be thought over; When we combine herb with flower-border, richly colored landscape and reasonable plant allocation should be deliberated on.

A Study on Development of Lighting Design Utilizing Traditional Materials and Natural Objects (전통소재와 자연물을 활용한 조명디자인 개발 연구)

  • Yoon, Yeoh-Hang;Kim, Ji-Soo
    • Journal of the Korea Furniture Society
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    • v.28 no.1
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    • pp.80-87
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    • 2017
  • As modern society attaches important to a value in mental aspect and characteristics of consumers who become diverse and individualistic, lighting design also changes closely with everyday life. This study suggests a new concept of indoor lighting design, combining natural objects with lattice and Korean paper, one of our representative traditional materials in lighting design used in everyday life. In particular, it was designed with aesthetic sense of traditional culture and Korean sentiment besides external effect and function by combining Korean paper with natural objects such as insect and plant, material that could be easily obtain around us. As a result, it is intended to enhance quality of life and pursue happiness by suggesting a new concept of lighting design which is modern, harmonizes with everyday life of modern humans who become individualistic, and can arouse sensibility, overcoming the limitations of traditional lighting in indoor lighting.

CT Image Analysis of Hepatic Lesions Using CAD ; Fractal Texture Analysis

  • Hwang, Kyung-Hoon;Cheong, Ji-Wook;Lee, Jung-Chul;Lee, Hyung-Ji;Choi, Duck-Joo;Choe, Won-Sick
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.05a
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    • pp.326-327
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    • 2007
  • We investigated whether the CT images of hepatic lesions could be analyzed by computer-aided diagnosis (CAD) tool. We retrospectively reanalyzed 14 liver CT images (10 hepatocellular cancers and 4 benign liver lesions; patients who presented with hepatic masses). The hepatic lesions on CT were segmented by rectangular ROI technique and the morphologic features were extracted and quantitated using fractal texture analysis. The contrast enhancement of hepatic lesions was also quantified and added to the differential diagnosis. The best discriminating function combining the textural features and the values of contrast enhancement of the lesions was created using linear discriminant analysis. Textural feature analysis showed moderate accuracy in the differential diagnosis of hepatic lesions, but statistically insignificant. Combining textural analysis and contrast enhancement value resulted in improved diagnostic accuracy, but further studies are needed.

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Performance Evaluation of Access Channel Slot Acquisition in Cellular DS/CDMA Reverse Link

  • Kang, Bub-Joo;Han, Young-Nam
    • ETRI Journal
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    • v.20 no.1
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    • pp.16-27
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    • 1998
  • In this paper, we consider the acquisition performance of an IS-95 reverse link access channel slot as a function of system design parameters such as postdetection integration length and the number of access channel message block repetitons. The uncertainty region of the reverse link spreading codes compared to that of forward link is very small, since the uncertainty region of the reverse link is determined by a cell radius. Thus, the parallel acquisiton technique in the reverse link is more efficient than a serial acquisition technique in terms of implementation and of acquisition time. The parallel acquisition is achieved by a bank of N parallel I/Q noncoherent correlator are analyzed for band-limited noise and the Rayleigh fast fading channel. The detection probability is derived for multiple correct code-phase offsets and multipath fading. The probability of no message error is derived when rake combining, access channel message block combining, and Viterbi decoding are applied. Numerical results provide the acquisition performance for system design parameters such as postdetection integration length and number of access channel message block repetitions in case of a random access on a mobile station.

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