• Title/Summary/Keyword: 부호책

Search Result 36, Processing Time 0.026 seconds

A Fast Encoding Algorithm for Image Vector Quantization Based on Prior Test of Multiple Features (복수 특징의 사전 검사에 의한 영상 벡터양자화의 고속 부호화 기법)

  • Ryu Chul-hyung;Ra Sung-woong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.30 no.12C
    • /
    • pp.1231-1238
    • /
    • 2005
  • This paper presents a new fast encoding algorithm for image vector quantization that incorporates the partial distances of multiple features with a multidimensional look-up table (LUT). Although the methods which were proposed earlier use the multiple features, they handles the multiple features step by step in terms of searching order and calculating process. On the other hand, the proposed algorithm utilizes these features simultaneously with the LUT. This paper completely describes how to build the LUT with considering the boundary effect for feasible memory cost and how to terminate the current search by utilizing partial distances of the LUT Simulation results confirm the effectiveness of the proposed algorithm. When the codebook size is 256, the computational complexity of the proposed algorithm can be reduced by up to the $70\%$ of the operations required by the recently proposed alternatives such as the ordered Hadamard transform partial distance search (OHTPDS), the modified $L_2-norm$ pyramid ($M-L_2NP$), etc. With feasible preprocessing time and memory cost, the proposed algorithm reduces the computational complexity to below the $2.2\%$ of those required for the exhaustive full search (EFS) algorithm while preserving the same encoding quality as that of the EFS algorithm.

On the Performance of Sample-Adaptive Product Quantizer for Noisy Channels (표본적응 프러덕트 양자기의 전송로 잡음에서의 성능 분석에 관한 연구)

  • Kim Dong Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.42 no.3 s.303
    • /
    • pp.81-90
    • /
    • 2005
  • When we transmit signals, which are quantized by the vector quantizer (VQ), through noisy channels, the overall performance of the coding system is very dependent on the employed quantization scheme and the channel error effect. In order to design an optimal coding system, the source and channel coding scheme should be jointly optimized as in the channel-optimized VQ. As a suboptimal approach, we may consider the robust VQ (RVQ). In RVQ, we consider developing an index assignment function for mapping the output of quantizers to channel symbols so that the effect of the channel errors is minimized. Recently, a VQ, which can reduce the encoding complexity and is called the sample-adaptive product quantizer (SAPQ), has been proposed. SAPQ has very similar quantizer structure as to the product quantizer (PQ). However, the quantization performance can be better than PQ. Further, the encoding complexity and the memory requirement for the codebooks are lower than the regular full-search VQ case. In this paper, SAPQ is employed in order to design an RVQ to channel errors by reducing the vector dimension. Discussions on the codebook structure of SAPQ and experiments are introduced in an aspect of robustness to noisy channels.

A Study on Effects of Corporate Governance Information on Credit Financial Ratings (기업지배구조정보가 신용재무평점에 미치는 영향)

  • Kim, Dong-Young;Kim, Dong-Il;Seo, Byoung-Woo
    • Journal of Digital Convergence
    • /
    • v.13 no.2
    • /
    • pp.105-113
    • /
    • 2015
  • If the watchdog role of good corporate governance, corporate executives and reduce agency costs and information asymmetries. Corporate governance score higher because enterprise internal control systems and financial reporting system is well equipped with the company management is enabled and corporate performance is higher because the high financial credit rating. Under these assumptions and hypotheses set up this study corporate governance (CGI) has been studied demonstrated how the financial impact on the credit rating (CFR). Findings,

    relevant corporate governance (CGI) and financial credit rating was found to significantly affect the positive (+), Regression coefficient code is expected code of positive (+), the value

    indicated by the value of all positive. The results of corporate governance (CGI) has showed excellent results, such as the more predictable will increase the credit score financial rating. The results of this study will have more CGI-credit financial rating the greater good. This study might be expected to provide a useful guide that corporate social responsibility, the company with a good governance and oversight systems enable to to get a higher credit rating in practice and research.

Analysis on Sentence Error Types of Mathematical Problem Posing of Pre-Service Elementary Teachers (초등학교 예비교사들의 수학적 '문제 만들기'에 나타나는 문장의 오류 유형 분석)

  • Huh, Nan;Shin, Hocheol
    • Journal of the Korean School Mathematics Society
    • /
    • v.16 no.4
    • /
    • pp.797-820
    • /
    • 2013
  • This study intended on analyzing the error patterns of mathematic problem posing sentences by the 100 elementary pre-teachers and discussing about the solutions. The results showed that the problem posing sentences have five error patterns: phonological error patterns, word error patterns, sentence error patterns, meaning error patterns, and notation error patterns. Divided into fourteen specific error patterns, they are as in the following. 1) Phonological error patterns are consisted of the 'ㄹ' addition error pattern and the abbreviated word error pattern. 2) Words error patterns are divided with the inappropriate usage of word error pattern and the inadequate abbreviation error pattern, which are formulized four subgroups such as the case maker, ending of the word, inappropriate usage of word, and inadequate abbreviation of article or word error pattern in detail. 3) Sentence error patterns are assumed four kinds of forms: the reference, ellipsis of sentence component, word order, and incomplete sentence error pattern. 4) Meaning error patterns are composed the logical contradiction and the ambiguous meaning. 5) Notation error patterns are formed four patterns as the spacing, punctuation, orthography of Hangul, and spelling rules of foreign words in Korean. Furthermore, the solutions for these error patterns were discussed: First, it has to be perceived the differences between spoken and written language. Second, it has to be rejected the spoken expressions in written contexts. Third, it should be focused on the learning of the basic sentence patterns during the class. Forth, it is suggested that the word meaning should have the logical development perception based on what it means. Finally, it is proposed that the system of spelling of Korean has to be learned. In addition to these suggestions, a new understanding is necessary regarding writing education for college students.

  • PDF

A Study Research on the Corporate Social Responsibilities (IV) : Emphasizing the Attitudes of Religious Groups on Social Expenditures (기업의 사회적 책임에 관한 실증적 연구(IV) - 사회적 지출에 대한 종교집단의 태도를 중심으로 -)

  • Han, Kee-Soo
    • Korean Business Review
    • /
    • v.6
    • /
    • pp.201-228
    • /
    • 1993
  • The objective of this research is to investigate the attetudes of religious groups(christian, buddhist, atheist) towards corporate social expenditures. Methodology was a questionnair survey. The data analysis was done by the Kruscal Wallis test and Wilcoxon signed ranks test. The results of this rssearch is that the difference of attitudes between christian group and other groups and between religious groups and atheist group on the social expenditures did not turn out to be statistically significant. The implication of this results is that the variables of religious groups can be ignored when we are going to study on the attitudes of values for the Korean people.

  • PDF

3-Factor Authentication Using HMAC-based One-Time Password (HMAC 기반의 일회용 패스워드를 이용한 3-Factor 인증)

  • Kim, Ji-Hong;Oh, Sei-Woong
    • Journal of the Korea Society of Computer and Information
    • /
    • v.14 no.6
    • /
    • pp.27-32
    • /
    • 2009
  • Recently, most of information services are provided by the computer network, since the technology of computer communication is developing rapidly, and the worth of information over the network is also increasing with expensive cost. But various attacks to quietly intercept the informations is invoked with the technology of communication developed, and then most of the financial agency currently have used OTP, which is generated by a token at a number whenever a user authenticates to a server, rather than general static password for some services. A 2-Factor OTP generating method using the OTP token is mostly used by the financial agency. However, the method is vulnerable to real attacks and therefore the OTP token could be robbed and disappeared. In this paper, we propose a 3-Factor OTP way using HMAC to conquer the problems and analyze the security of the proposed scheme.