• Title/Summary/Keyword: coding method

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A Study of Web Application Attack Detection extended ESM Agent (통합보안관리 에이전트를 확장한 웹 어플리케이션 공격 탐지 연구)

  • Kim, Sung-Rak
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.161-168
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    • 2007
  • Web attack uses structural, logical and coding error or web application rather than vulnerability to Web server itself. According to the Open Web Application Security Project (OWASP) published about ten types of the web application vulnerability to show the causes of hacking, the risk of hacking and the severity of damage are well known. The detection ability and response is important to deal with web hacking. Filtering methods like pattern matching and code modification are used for defense but these methods can not detect new types of attacks. Also though the security unit product like IDS or web application firewall can be used, these require a lot of money and efforts to operate and maintain, and security unit product is likely to generate false positive detection. In this research profiling method that attracts the structure of web application and the attributes of input parameters such as types and length is used, and by installing structural database of web application in advance it is possible that the lack of the validation of user input value check and the verification and attack detection is solved through using profiling identifier of database against illegal request. Integral security management system has been used in most institutes. Therefore even if additional unit security product is not applied, attacks against the web application will be able to be detected by showing the model, which the security monitoring log gathering agent of the integral security management system and the function of the detection of web application attack are combined.

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Manipulation of the Compressed Video for Multimedia Networking : A Bit rate Shaping of the Compressed Video (멀티미디어 네트워킹을 위한 압축 신호상에서 동영상 처리 : 압축 동영상 비트율 변환)

  • 황대환;조규섭;황수용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.11A
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    • pp.1908-1924
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    • 2001
  • Interoperability and inter-working in the various network and media environment with different technology background is very important to enlarge the opportunity of service access and to increase the competitive power of service. The ITU-T and advanced counties are planning ahead for provision of GII enabling user to access advanced global communication services supporting multimedia communication applications, embracing all modes of information. In this paper, we especially forced the heterogeneity of end user applications for multimedia networking. The heterogeneity has several technical aspects, like different medium access methods, heterogeneous coding algorithms for audio-visual data and so on. Among these elements, we have been itemized bit rate shaping algorithm on the compressed moving video. Previous manipulations of video has been done on the uncompressed signal domain. That is, compressed video should be converted to linear PCM signal. To do such a procedures, we should decode, manipulate and then encode the video to compressed signal once again. The traditional approach for processing the video signa1 has several critical weak points, requiring complexity to implement, degradation of image quality and large processing delay. The bit rate shaping algorithm proposed in this paper process the manipulation of moving video on the completely compressed domain to cope with above deficit. With this algorithms. we could realized efficient video bit rate shaping and the result of software simulation shows that this method has significant advantage than that of pixel oriented algorithms.

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Experimental Performance Analysis of BCJR-Based Turbo Equalizer in Underwater Acoustic Communication (수중음향통신에서 BCJR 기반의 터보 등화기 실험 성능 분석)

  • Ahn, Tae-Seok;Jung, Ji-Won
    • Journal of Navigation and Port Research
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    • v.39 no.4
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    • pp.293-297
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    • 2015
  • Underwater acoustic communications has been limited use for military purposes in the past. However, the fields of underwater applications expend to detection, submarine and communication in recent. The excessive multipath encountered in underwater acoustic communication channel is creating inter symbol interference, which is limiting factor to achieve a high data rate and bit error rate performance. To improve the performance of a received signal in underwater communication, many researchers have been studied for channel coding scheme with excellent performance at low SNR. In this paper, we applied BCJR decoder based ( 2,1,7 ) convolution codes and to compensate for the distorted data induced by the multipath, we applying the turbo equalization method. Through the underwater experiment on the Gyeungcheun lake located in Mungyeng city, we confirmed that turbo equalization structure of BCJR has better performance than hard decision and soft decision of Viterbi decoding. We also confirmed that the error rate of decoder input is less than error rate of $10^{-1}$, all the data is decoded. We achieved sucess rate of 83% through the experiment.

A Blind Watermarking Algorithm using CABAC for H.264/AVC Main Profile (H.264/AVC Main Profile을 위한 CABAC-기반의 블라인드 워터마킹 알고리즘)

  • Seo, Young-Ho;Choi, Hyun-Jun;Lee, Chang-Yeul;Kim, Dong-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.2C
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    • pp.181-188
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    • 2007
  • This paper proposed a watermark embedding/extracting method using CABAC(Context-based Adaptive Binary Arithmetic Coding) which is the entropy encoder for the main profile of MPEG-4 Part 10 H.264/AVC. This algorithm selects the blocks and the coefficients in a block on the bases of the contexts extracted from the relationship to the adjacent blocks and coefficients. A watermark bit is embedded without any modification of coefficient or with replacing the LSB(Least Significant Bit) of the coefficient with a watermark bit by considering both the absolute value of the selected coefficient and the watermark bit. Therefore, it makes it hard for an attacker to find out the watermarked locations. By selecting a few coefficients near the DC coefficient according to the contexts, this algorithm satisfies the robustness requirement. From the results from experiments with various kinds and various strengths of attacks the maximum error ratio of the extracted watermark was 5.02% in maximum, which makes certain that the proposed algorithm has very high level of robustness. Because it embeds the watermark during the context modeling and binarization process of CABAC, the additional amount of calculation for locating and selecting the coefficients to embed watermark is very small. Consequently, it is highly expected that it is very useful in the application area that the video must be compressed right after acquisition.

A Study on the Derivation and Sensitivity Analysis of the Adjustment Factor in the Software Cost Estimation Guidelines (소프트웨어 사업대가기준 보정계수의 유도 및 민감도 분석)

  • Byun, Boon-Hee;Kwon, Ki-Tae
    • The KIPS Transactions:PartD
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    • v.15D no.1
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    • pp.61-72
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    • 2008
  • One of the most significant tasks of software development project is to know how much it will be the software development cost in the early stage of software development cycle. The software development environment and technology are changing very rapidly. For accuracy, we should apply those to the software cost estimation. And it is important that we select the suitable adjustment factor and the value of a suitable adjustment factor. For that, this paper have applied the method of AHP. And we have also analyzed the sensitivity of the adjustment factor which is influenced by decision metrics. In conclusion, the value of the application type adjustment factor is responded more sensitively to the data complexity and the control complexity than processing complexity. And the value of the language adjustment factor is responded more sensitively to the supplying manpower and the time of the coding than the time of the debugging. In the future, we will research the selection of an additional adjustment factor and a suitable value of the adjustment factor which are influenced by the environment and the technology of the domestic software development. And then, in the language adjustment factor, we will try to calculate the value about the individual programming language.

The Fast Search Algorithm for Raman Spectrum (라만 스펙트럼 고속 검색 알고리즘)

  • Ko, Dae-Young;Baek, Sung-June;Park, Jun-Kyu;Seo, Yu-Gyeong;Seo, Sung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3378-3384
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    • 2015
  • The problem of fast search for raman spectrum has attracted much attention recently. By far the most simple and widely used method is to calculate and compare the Euclidean distance between the given spectrum and the spectra in a database. But it is non-trivial problem because of the inherent high dimensionality of the data. One of the most serious problems is the high computational complexity of searching for the closet codeword. To overcome this problem, The fast codeword search algorithm based on the mean pyramids of codewords is currently used in image coding applications. In this paper, we present three new methods for the fast algorithm to search for the closet codeword. the proposed algorithm uses two significant features of a vector, mean values and variance, to reject many unlikely codewords and save a great deal of computation time. The Experiment results show about 42.8-55.2% performance improvement for the 1DMPS+PDS. The results obtained confirm the effectiveness of the proposed algorithm.

Study on Relationship Between Consumption Values of Masstige and Consumer Happiness (매스티지 브랜드의 소비가치와 소비자 행복과의 관계에 관한 연구)

  • Kim, Yu-Kyung
    • Journal of Distribution Science
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    • v.13 no.1
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    • pp.105-118
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    • 2015
  • Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

A Study on Difference between Korea and China Consumers in importance of Attributes, Shopping Value and Loyalty in Social Commerce (한국과 중국소비자의 소셜커머스 속성의 중요도, 쇼핑가치 및 충성도 차이에 관한 연구)

  • Kim, Moon-Jung
    • Journal of Distribution Science
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    • v.13 no.1
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    • pp.47-55
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    • 2015
  • Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusion - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

Systematic Review of Short Stature and Growth Related Qualitative Researches (저신장 및 성장과 관련된 질적연구에 대한 체계적 문헌 고찰)

  • Kim, Hye Jin;Jeon, Chae Heun;Roh, Min Yeong;Han, Ye Ji;Kim, Hyun Ho;Cheong, Moon Joo;Leem, Jung Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.33 no.4
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    • pp.74-88
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    • 2019
  • Objectives The aim of this study is systematic evaluation of the quality of qualitative studies related to short stature. It will be utilized as fundamental data for future qualitative research about Korean Medicine Pediatrics treatment for short stature. Methods We searched qualitative studies related to short stature in the Pubmed. Two researchers independently assessed the quality of the qualitative researches by using Consolidated criteria for reporting qualitative research (COREQ) and Critical Appraisal Skills Program (CASP). We also qualitatively synthesized theme of each included studies. We presented integrated theme and categories with in vivo coding about qualitative research about short stature. Results A total of 47 papers were screened and 7 papers were finally selected. In the quality assessment using COREQ, detalied information about the researchers, methods of approach, reasons for non-participation, presence of non-participants, participant's review of the transcript, and participant's review of the findings were insufficient. In the quality evaluation using CASP, there were lack of justifications for the research methods, description method of research, and bias in process of data analysis. The findings were synthesized into three themes: fixed idea about height, discomfort caused by small stature and personal coping strategy with stress caused by short stature. Conclusions In further qualitative research, it is necessary to report the research according to COREQ and CASP checklist. It is also necessary to understand the stress and coping strategies to short stature of patients, We need to develop a social management strategy for short stature.