• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.79-86
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• 2009

In this paper, it has the performance metrics and the utility evaluation of the collusion codes about multimedia fingerprinting code based on BIBD and then the tracing algorithm of all colluders is proposed. Among the collusion codes, the bit stream of "all 0" or "all 1" are generated, also same collusion code and bit reversed code with user's fingerprinting code are generated. Thus there was occurred some problems, in which a colluder is deciding to anti-colluder or anti-colluder is deciding to colluder. In this paper, for the performance metrics and the utility evaluation of the collude codes, the experiment onto the total solution is processed by the logical collusion operation added with a partially processed averaging attack in the past papers. The proposed performance metrics and the utility evaluation about the collusion code generated from multimedia fingerprinting code based on BIBD is operated. Through the experiment, it confirmed that the ratio of colluder tracing is 100%.

• The Korean Journal of Financial Studies
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• v.4 no.1
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• pp.177-203
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• 1998

기존의 최초공모주 발행제도하에서는 일반투자자의 공모주식수요에 대한 의사가 공모가 결정과정에 반영될 수 있는 기회가 없음으로 인해 최초공모주의 심각한 저가발행 현상이 나타나고 있다. 이에 대한 문제점을 보완 개선하기 위하여 본 연구는 기업공개시 주식매각의 한 방안으로 경쟁입찰방식을 제시하였으며, 우리 나라 실정에 맞는 입찰모형의 설정을 위한 제반요인들을 조사 분석하였다. 또한, 경쟁입찰방식을 통한 최초공모주 발행의 장점과 경쟁입찰방식과 관련하여 예상되는 경제적 제 문제들을 공개입찰을 통한 장외등록기업 사레와 공기업민영화 사례를 통해 간접적으로 유추 검토하였다. 경쟁입찰방식하에서는 발행기업의 진실된 가치와 시장투자자들의 최초공모주에 대한 수요의사가 입찰과정을 통해 최적공모가격 결정에 적절히 반영되어 기존의 발행방식과 비교해 저평가율도 낮아질 것으로 기대되며, 심각한 문제가 없을 것이라는 판단하에 본 논문은 경쟁입찰방식을 통한 최초공모주발행이 기존의 발행방식에 대한 하나의 경제적 대안으로 선호될 수 있음을 보여 주었다.

• The Journal of Small Business Innovation
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• v.19 no.4
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• pp.41-52
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• 2016

This paper examines the effect of unique underwriter lockup on the initial returns of an initial public offering (IPO) in the Korean Securities Dealers Automated Quotation (KOSDAQ). Underwriter lockup induces underwriters to underprice IPOs and stabilize aftermarket prices. The inducement is explored with respects to the mixtures of distributions of the initial returns consistent with underpricing and stabilization. Whether the inducement is meaningful when other factors are controlled is also explored. These explorations provide evidence that underwriter lockup leads to more positive average initial returns in the three aftermarket months.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.713-720
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• 2008

Fingerprinting scheme uses digital watermarks to trace originator of unauthorized or pirated copies, however, multiple users may collude and escape identification by creating an average or median of their individually watermarked copies. Previous research works are based on ACC (anti-collusion code) for identifying each user, however, ACC are shown to be resilient to average and median attacks, but not to LCCA and cannot support large number of users. In this paper, we propose a practical SACC (scalable anti-collusion code) scheme and its angular decoding strategy to support a large number of users from basic ACC (anti-collusion code) with LCCA (linear combination collusion attack) robustness. To make a scalable ACC, we designed a scalable extension of ACC codebook using a Gaussian distributed random variable, and embedded the resulting fingerprint using human visual system based watermarking scheme. We experimented with standard test images for colluder identification performance, and our scheme shows good performance over average and median attacks. Our angular decoding strategy shows performance gain over previous decoding scheme on LCCA colluder set identification among large population.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.1-8
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• 2011

In multimedia fingerprinting field, it is many used a code based on BIBD, which has a strong resiliency of anti-collusion. When a collusion-attack code is generated with a logical XOR operation using the code based on BIBD, then some cases are occurred that a colluded code could be generated to the same fingerprint of non-colluder on the other hand, the colluder is decided to the non-colluder so that he would be excepted in the colluder tracing. For solving the serious problem of the wrong decision of the colluder tracing in this paper, XOR-ACC is implemented using multi-layer perceptron neural network among (AND, OR, XOR and Averaging)-ACC by the measured correlation coefficient. Through the experiment, it confirms that XOR-ACC efficiency of multimedia fingerprinting code{7,3,1} based on BIBD is improved to 88.24% from the conventional 41.18%, so that a ratio of the colluder tracing is also improved to 100% from the conventional 53%. As a result, it could be traced and decided completely a sectional colluder and non-colluder about the collusion attacks.

• Korean Educational Research Journal
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• v.38 no.1
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• pp.41-59
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• 2017

The quality of education is determined by the quality of teachers, and in particular the competence of principals is important for the desirable flow of schooling. The Principal employment system was adopted as one of the educational reforms introduced by the government. However, even though it has been 10 years since the enactment of PES, the perception of that has been low. To solve this, first, government should be more active in promoting publicity for the principal. Second, the elected principal should not be concentrated only in small areas, but should spread to urban areas. Finally, principals must increase the rate at which practitioners are able to contribute substantially to public subscriptions.

• The Korean Journal of Financial Management
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• v.11 no.2
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• pp.223-257
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• 1994

본 연구는 최초공모주식의 저가발행 원인에 대한 보험가설을 미국에서의 실제 소송사례를 중심으로 실증분석한다. Tinic(1988)은 최초공모주의 저가발행이 공모에 따르는 법률적 소송위험과 소송으로 인한 간사회사의 명예손상에 대한 일종의 보험효과를 가지고 있으며, 따라서 저가발행의 크기는 소송위험과 음의 관계에 있다고 주장한다. 또한 보험가설에 의하면 실제 소송이 발생했을 경우에도 저가발행의 크기는 소송결과에 유리하게 작용한다고 한다. 본 연구에서 는 1933-1990 기간동안 미국증권법 제 11조 조항을 위반하여 소송이 제기되었던 사례가운데 실제소송의 결과가 알려진 판례를 중심으로 보험가설의 주장을 실증분석 하였다. 또한 최초공모이후의 공모시장을 통한 기업자금 조달시에 주간사회사의 변경여부를 분석함으로써 소송으로 인한 간사회사의 명예손상의 정도를 파악하고자 했다. 연구결과에 따르면 투자자들에 의한 집단소송의 결과와 최초공모주의 저가발행의 크기에는 유의적인 관계가 있음이 실증적으로 제시되었다. 또한 간사회사의 명성과 실제 현금으로 환원한 소송위험간에도 유의적인 관계가 있음을 보여주고 있다. 한편 소송에 관련된 최초공모주의 경우에는 일단 소송이 제기된 후의 공모를 통한 추가기업자금 조달시에 기존의 간사회사를 전원 교체하는 등 통제집단과는 다른 형태를 보여 줌으로써 보험 가설의 주장을 지지하고 있다.

• The Korean Journal of Financial Management
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• v.12 no.1
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• pp.187-210
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• 1995

본고(本槁)에서는 영국기업의 최초공모주를 이용하여 최초공모주(最初公募株) 시장(市場)에 나타나는 3가지 이례현상(異例現象) 즉 단기(短期)에 있어 최초공모주의 저가발행현상(低價發行現象), 장기(長期)에 있어 최초공모주의 저성과현상(低成果現象) 그리고 hot issue market 존재를 분석하고 있다. 이러한 분석은 주로 미국(美國) 발행시장(發行市場)을 대상으로 이루어져 왔는바, 시장의 효율성 측면에서 비슷한 수준을 유지하고 있는 영국(英國)의 증권시장(證券市場)에서도 이러한 현상이 나타나는지를 조사해보는 것은 의미가 있을 뿐만아니라 이러한 현상이 다른 시장에서도 통상 나타나는 현상인지를 밝히는데도 의의가 있다고 보여진다. 영국(英國)의 최초공모주(最初公募株) 시장(市場)에서의 3가지 이례현상(異例現象)을 분석하기 위해 우선 거래 첫날의 시장조정수익률(市場調整收益率)을 계산하여 신규공모주가 시장가격에 비해 할인(割引)되어 발행되는지를 조사한 결과 시장가격에 비해 12.88% 정도 할인발행되고 있음이 밝혀졌다. 단기의 저가발행현상(低價發行現象)과는 달리 신규공모주가 시장에 상장된지 3년이 경과한 후 추정된 장기투자수익률(長期投資收益率)은 12.05%의 부(負)의 누적초과수익률(累積超過收益率)을 시현하고 있는데 이는 과잉반응가설(過剩反應假說)에 의해 설명되고 있다. 끝으로 1987년의 최초공모주가 다른 연도에 비해 다섯배 정도로 저가발행되고 있음을 밝힘으로써 영국발행시장(英國發行市場)에도 hot issue market 현상이 나타남을 분석하고 있다.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.83-93
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• 2013

This study has been performed to analyze and consider the problems after 30 years in terms of landscape design competition process in Korea, so that it can provide the basic data, which can improve the future landscape design competition. We have used Delphi Investigation to carry out a survey that targets professionals and identifies problems. The results are summarized as follows. Firstly, the results of the analysis of Landscape Design Competition for institution theory and case studies showed that there is an issue from four perspectives which are 'method of design competition', 'guidelines for design competition', 'winner selection process', and 'design changes after winning' Secondly, the process by professional Delphi performed expert analysis, and agree with expert opinion. As a result, we derived the problems of a landscape design competition system with the 12 items. Third, in the 'design competition style', two items, the 'design competition style' and 'problem of design public offering period' had become a problem. Fourth, the 'Guidelines for design competition', 'non-hierarchical excess of the amount of instructions', 'directive determined the guidelines', and the 'provision of confusion' three items had also become a problem. Fifth, 'sex expert committee review selection process winning work', 'Problems of participation', 'examination scoring system experts lack', and 'non-landscaping' had become a problem. Sixth, 'The design of the original order' as much as possible 'design changes after the winning work' Four 'order to Comments to reduce the creativity of the design of the climate', 'original extension', 'contractor feedback of excess without the promise of frequent personnel changes', design period of the person in charge is reflected in excess item has become a problem. I considered that a continuous research on the improvement of the problems of the landscape design competition system based on the results must be performed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.6
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• pp.1-7
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• 2010

This paper presents a novel implementation on multimedia fingerprinting algorithm based on BCH (Bose-Chaudhuri-Hocquenghem) code. The evaluation is put in force the colluder detection to n-1. In the proposed algorit hm, the used collusion attacks adopt logical combinations (AND, OR and XOR) and average computing (Averaging). The fingerprinting code is generated as below step: 1. BIBD {7,4,1} code is generated with incidence matrix. 2. A new encoding method namely combines BIBD code with BCH code, these 2 kind codes are to be fingerprinting code by BCH encoding process. 3. The generated code in step 2, which would be fingerprinting code, that characteristic is similar BCH {15,7} code. 4. With the fingerprinting code in step 3, the collusion codebook is constructed for the colluder detection. Through an experiment, it confirmed that the ratio of colluder detection is 86.6% for AND collusion, 32.8% for OR collusion, 0% for XOR collusion and 66.4% for Averaging collusion respectively. And also, XOR collusion could not detect entirely colluder and on the other hand, AND and Averaging collusion could detect n-1 colluders and OR collusion could detect k colluders.