• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.15-20
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• 2008

Provable security has widely been used to prove a cryptosystem's security formally in crpytography. In this paper, we analyze the Cramer-Shoup public key cryptosystem that has been known to be provable secure against adaptive chosen ciphertext attack and argue that its security proof is not complete in the generic sense of adaptive chosen ciphertext attack. Future research should be directed toward two directions: one is to make the security proof complete even against generic sense of adaptive chosen ciphertext attack, and another is to try finding counterexamples of successful adaptive chosen ciphertext attack on the Cramer-Shoup cryptosystem.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1535-1540
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• 2006

하천의 평형상태를 판단하기위해 필요한 두가지 관점은 첫째, 대상 하천이 현재 평형상태에 있는 가이고 둘째, 하천에 하상변동을 일으킬 수 있는 인위적인 영향을 가한 후에 하천반응을 통해 궁극적으로 결정되는 평형상태를 예측하는 것이다. 따라서 본 연구는 하도의 특성을 토대로 하여 현 하도의 평형상태를 정성적인 측면에서 검토하고, 흐름과 유사 이송에 관련된 수학모형을 수치적으로 해석하는 하상변동모형의 분석을 통한 현하도의 안정성 및 하상변동 양상을 파악하는데 그 목적이 있다. 본 연구는 임진강 유역의 충적하천인 문산천을 대상으로 지배유량을 산정한 후 지배유량 유하시의 마찰속도와 무차원 소류력 등의 하도특성량을 산정하여 토사이송이 크게 발생하는 구간을 정성적으로 예측하였다. 예측된 구간의 현장조사결과 $No.29{\sim}No.35$ 구간의 하상의 상승은 개수공사와 수해복구공사로 인한 인위적인 굴착에 대한 퇴적으로 하천이 평형상태로 환원하고자 하는 것으로 판단되었고, $No.41{\sim}No.54$ 구간의 하상저하는 문산천 상류구간의 큰 하상경사와 보의 영향인 것으로 조사되었다. 또한 1, 2차원 모형에 의한 장 단기 하상변동 분석결과 하도특성량을 이용한 하도의 안정성 평가와 유사한 결과를 보였다. 따라서 문산천의 경우 하상변동의 양상 파악 및 하도의 안정성 판단을 하는데 있어 하도특성량을 근거로 판단하는 방법의 적용가능성을 파악할 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1179-1184
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• 2014

Reliability allocation is generally used during the early stage of system development to apportion the system reliability target to its individual modules. This paper presents a comprehensive method for performing the reliability allocation of KTX door systems. Nine criteria for reliability allocation include failure criticality, operating time, risk, complexity, failure rate, maintenance, manufacturing technology, working condition, and reliability cost. For satisfying the system reliability target, the allocated $B_{10}$ lives of four modules are provided.

• Korean Journal of Cognitive Science
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• v.19 no.3
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• pp.257-281
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• 2008

The expression 'kes' is one of the most widely used ones in the language whose uses are highly dependent upon the context. These highly-context dependent uses make it hard to determine its grammatical properties. As a way of examining the properties in a rather controlled context, this paper collects a series of speeches made by government officials and examines the grammatical properties of the expression in the corpus. In particular, the paper, based on the 539 instances of 'kes' uses extracted from the corpus, focuses on the 7 types of 'kes' constructions most widely used in the collected speech corpus.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.373-378
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• 2008

기존에는 잠재위험도와 해당지역 하나의 강우관측소에서의 기왕최대강우량을 이용하여 계획빈도를 결정하였다. 그러나 기왕최대강우량은 이미 발생한 최대강우량이기 때문에 안전치를 고려해 산정한 계획빈도를 따라가지 못하였고, 잠재위험도에 따른 계획빈도의 범위가 매우 작은 문제점이 있었다. 따라서 본 연구에서는 문산천 유역의 기왕최대강우량과 잠재위험도를 이용하여 계획빈도를 산정하는데 필요한 가중치를 결정하였다. 본 연구에서는 수도권지역 6개의 기상청 강우관측소 강우량 자료를 사용하여 크리깅기법으로 공간분포를 시키고자 하였다. 또한, 기왕최대강우량으로 계획빈도를 연결시키는데 있어서 발생하는 문제점을 해결하기 위하여 계획빈도의 가중치를 산정하고자 하였다. 문산천 유역에 잠재위험도 산정에 따라 계획빈도를 결정한 결과, 크리깅기법으로 문산천 유역에 기왕최대강우량에 해당하는 계획빈도는 160년 정도이며, 회귀식으로 각 소유역별로 계획빈도를 산정한 결과 약 110년에서 120년까지 분포하였다. 이렇게 산정된 계획빈도를 공시지가와 홍수량으로 가중치를 구하여 소유역별로 분포시킨 계획빈도 값은 대략 100년에서 200년으로 산정되었다. 잠재위험도와 피해액 산정기법을 이용하여 문산천에 최적 홍수방어대안을 선정하고자 하였다. 최적 대안을 선정하기 위한 방법론을 제시하고 이에 따라 잠재위험도를 산정하고 유역 분담량을 결정하여 적합한 구조적 홍수방어시설물을 Decision Tree라는 의사결정을 통하여 계획하고 조합하여 3개의 적정 홍수방어대안을 선정하였다.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.375-379
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• 2016

In this study, the structure and diversity of bacterial community were investigated in the surface and subsurface marine sediments using a NGS method (i.e. illumina sequencing technology). The bacterial community in the surface was distinct from that in the subsurface of marine sediment; with the exception of the phylum Proteobacteria, the relative abundance of Bacteroides phylum were higher in the surface than subsurface, whereas the sequences affiliated to the phyla Chloroflexi and Acidobacteria were relatively more copious in the subsurface than surface sediment. Moreover, interestingly, we observed that the phyla Nitrospinae and Nitrospirae contribute to nitrogen cycle in the marine sediment. This study may present the possibility for the presence of novel microorganisms as unexplored sources and provide basic information on the microbial community structure.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.55-67
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• 2008

This paper presents the assignment motion algorithm unrestricted for code optimization computationally. So, this algorithm is suppressed the unnecessary code motion in order to avoid the superfluous register pressure, we propose the assignment motion algorithm added to the final optimization phase. This paper improves an ambiguous meaning of the predicate. For mixing the basic block level analysis with the instruction level analysis, an ambiguity occurred in Knoop's algorithm. Also, we eliminate an ambiguity of it. Our proposal algorithm improves the runtime efficiency of a program by avoiding the unnecessary recomputations and reexecutions of expressions and assignment statements.

• Korean Journal of Logic
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• v.18 no.3
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• pp.337-358
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• 2015

Vann Mcgee produced "counterexamples" to Modus Ponens in "A Counterexample to Modus Ponens". Discussions about the examples tended to focus on a probabilistic reading of conditional statements. This article attempts to establish both (1) Modus Ponens is a deductively valid rule of inference, and (2) the counterexample-like appearance of Mcgee's example can be (and should be) explained without making a reference to the notion of conditional probability. The reason why his examples seem to counter Modus Ponens is found rather within the ambiguity a conditional statement exhibits. That is, Mcgee's examples are cases of equivocation on the conditional statements involved.

• The KIPS Transactions:PartA
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• v.8A no.1
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• pp.27-35
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• 2001

This paper presents the assignment motion algorithm unrestricted for code optimization computationally. So, this algorithm is suppressed the unnecessary code motion in order to avoid the superfluous register pressure, we propose the assignment motion algorithm added to the final optimization phase. This paper improves an ambiguous meaning of the predicated. For mixing the basic block level analysis with the instruction level analysis, an ambiguity occurred in knoop’s algorithm. Also, we eliminate an ambiguity of it. Our proposal algorithm improves the runtime efficiency of a program by avoiding the unnecessary recomputations and reexecutions of expressions and assignment statements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.86-88
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• 2017

The digital door lock is an electronic door lock that uses a password system and has the function of automatically locking the door when the door is closed, thus eliminating the worry about the door lock. As the technology has gradually developed, various authentication technologies such as semiconductor key system, RFID, and fingerprint recognition have been introduced. However, there is a danger of copying the door lock key, and there are password stealing and infringement. In this paper, we develop a remote control system that can unlock or open a smartphone to supplement the user's risk. The system you are going to develop can use WiFi to check if the door is locked or open on your smartphone, and you can lock or unlock the door remotely.