• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.3
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• pp.63-74
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• 1999

In this paper we present a Hangul Encryption Algorithm (HEA) which encrypts composition Hangul syllables into composition Hangul syllables using the non-linear structure of Hangul. Since ciphertexts generated by HEA are displayable characters HEA can be used in applications such as Privacy Enhanced mail (PEM) where ciphertexts should be displayable characters. HEA is based on DES and it can be shown that HEA is as safe as DES against the exhaustive key search differential cryptanalysis and linear cryptanalysis. HEA also has randomness of phonemes of ciphertexts and satisfies plaintext-ciphetext avalanche effect and key-ciphertext avalanche effect.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.203-211
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• 2023

A Markov chain Monte Carlo (MCMC) simulation is proposed for probabilistic full waveform inversion (FWI) in a layered half-space. Dynamic responses on the half-space surface are estimated using the thin-layer method when a harmonic vertical force is applied. Subsequently, a posterior probability distribution function and the corresponding objective function are formulated to minimize the difference between estimations and observed data as well as that of model parameters from prior information. Based on the gradient of the objective function, a proposal distribution and an acceptance probability for MCMC samples are proposed. The proposed MCMC simulation is applied to several layered half-space examples. It is demonstrated that the proposed MCMC simulation for probabilistic FWI can estimate probabilistic material properties such as the shear-wave velocities of a layered half-space.

• Annual Conference on Human and Language Technology
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• 2023.10a
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• pp.648-653
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• 2023

관계 추출 태스크는 주어진 텍스트로부터 두 개체 간의 적절한 관계를 추론하는 작업이며, 지식 베이스 구축 및 질의응답과 같은 응용 태스크의 기반이 된다. 최근 자연어처리 분야 전반에서 생성형 거대 언어모델의 내재 지식을 활용하여 뛰어난 성능을 성취하면서, 대표적인 정보 추출 태스크인 관계 추출에서 역시 이를 적극적으로 활용 가능한 방안에 대한 탐구가 필요하다. 특히, 실 세계의 추론 환경과의 유사성에서 기인하는 저자원 특히, 제로샷 환경에서의 관계 추출 연구의 중요성에 기반하여, 효과적인 프롬프팅 기법의 적용이 유의미함을 많은 기존 연구에서 증명해왔다. 따라서, 본 연구는 한국어 관계 추출 분야에서 거대 언어모델에 다각적인 프롬프팅 기법을 활용하여 제로샷 환경에서의 추론에 관한 비교 연구를 진행함으로써, 추후 한국어 관계 추출을 위한 최적의 거대 언어모델 프롬프팅 기법 심화 연구의 기반을 제공하고자 한다. 특히, 상식 추론 등의 도전적인 타 태스크에서 큰 성능 개선을 보인 사고의 연쇄(Chain-of-Thought) 및 자가 개선(Self-Refine)을 포함한 세 가지 프롬프팅 기법을 한국어 관계 추출에 도입하여 양적/질적으로 비교 분석을 제공한다. 실험 결과에 따르면, 사고의 연쇄 및 자가 개선 기법 보다 일반적인 태스크 지시 등이 포함된 프롬프팅이 정량적으로 가장 좋은 제로샷 성능을 보인다. 그러나, 이는 두 방법의 한계를 지적하는 것이 아닌, 한국어 관계 추출 태스크에의 최적화의 필요성을 암시한다고 해석 가능하며, 추후 이러한 방법론들을 발전시키는 여러 실험적 연구에 의해 개선될 것으로 판단된다.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.121-128
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• 2014

Purpose: To compare the clinical characteristics and laboratory finding between adenoviral and group A streptococcal (GAS) pharyngitis. Methods: A retrospective review of medical records was performed in the patients with adenovirus infection among those who were admitted for febrile respiratory disease from January 2011 to July 2013 and GAS pharyngitis among those who visited for symptoms of scarlet fever from August 2006 to July 2013. Results: 179 patients (AV1 group) were diagnosed with adenoviral pharyngitis and 37 (AV2 group) of these patients had adenovirus single infection. 26 patients (GAS group) were diagnosed with scarlet fever. Adenoviral infection (AV2 group) developed in younger patients compared to GAS group ($2.8{\pm}2.1$ years vs. $5.4{\pm}1.8$ years, P =0.000). Total durations of fever and admission were longer in AV2 ($6.3{\pm}2.6$ days vs. $3.3{\pm}1.9$ days, P =0.000; $4.1{\pm}1.2$ days vs. $1.9{\pm}1.8$ days, P =0.000, respectively). WBC counts were higher in AV2 ($11,449{\pm}5,680$ cells/$mm^2$ vs. $6,722{\pm}6,941$ cells/$mm^2$, P =0.000). CRP was not significantly different between AV2 and GAS group ($3.8{\pm}3.2$ mg/dL vs. $5.2{\pm}5.1$ mg/dL, P =0.368). No difference was found between two groups in the percentage of antibiotics use (91.9% vs. 100%, P =0.261). Conclusion: Clinical characteristics and measures of inflammation in the laboratory findings were similar between adenoviral and GAS pharyngitis group. It is necessary to conduct the test for respiratory virus and bacteria in early stage to differentiate in the pharyngitis patients with leukocytosis and elevation of CRP level.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.79-84
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• 2002

Purpose : About 41% of obtained group A streptococci in the 1998 was reported as erythromycin-resistant streptococci in Seoul, Korea. The most common T serotype was T12, followed by T4 and T28. We'd like to monitor the serological changes and antibiotic sensitivity test of Streptococcus pyogenes obtained from the patients with pharyngotonsillitis and invasive diseases from 1999 through 2001. Also, it could be proposed to choose the proper antibiotic selection in the area where the rate of erythromycin-resistant streptococci is high. Methods : From Jan. 1999 to Oct. 2001, 208 isolates of group A streptococci were collected from inpatients and outpatients with pharyngotonsillitis, scarlet fever, and invasive infections in Seoul and Southern part of peninsula. All isolates were serotyped by T-agglutination, minimum inhibitory concentrations(MICs) which were determined by agar dilution methods, according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). Results : The most common T serotype was T12(29.8%), followed by T1(23.1%), T4 (14.9%). T1 was prominent serotype compared with previous year. T serotyping, among 25 isolates obtained from the patients with scarlet fever in Southern part of peninsula mostly, was T12, T1, and T4 in order of frequency. All the isolates tested were susceptible to penicillin, cefprozil, vancomycin, ceftriaxone, and chloramphenicol. However, 23 isolates(14.2%) was resistant to erythromycin and 18 isolates(11.1%) was resistant to clarithromycin. Serotype T12 was found to be the most resistant serotype to erythromycin and/or clarithromycin. Conclusion : High rate of erythromycin-resistant streptococci which surveyed in 1998 were reduced to 14.2% in this study. We should have to further evaluate the reason of decreased resistant strains and consider the resistant strains of streptococci in choosing the antibiotics. There was no serological characteristics according to the types of disease entities. Between the serologic distributions in Seoul and the Southern part of peninsula area are same, we could presume that the serological typing of strains obtained over the country may be not different.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1855-1869
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• 1993

For the traditional ALOHA system without capture, the Markov chain obtained using the number of backlogged users at each slot if shown to be non-ergodic. So the infinite population ALOHA with fixed retransmission probabilities is unstable for any choice of the arrival rates and retransmission probabilities. The capture ALOHA system of also shown to be unstable for any arrival rate unless it has perfect. In this paper, we study a stabilization policy for capture ALOHA system that controls the retransmission probabilities and prove the stability of its multidimensional Markovian model by empolying a continuous Lyapunov function, and thus identify the stability region. We also study a delay performance through computer simulation th show the stability for any input rate below the maximum achievable channel throughput.

• Korean Security Journal
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• no.6
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• pp.215-233
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• 2003

The Serial murder is a serious social phenomenon that gives a shock to community and society, because of it's habituate and scheme. We could identify a happening of serial killing crime at Western society, especially in U. S, but hardly to find many cases in Korea except some of cases. We can easily prospect the happening of serial killing crime at Korea in the future, at least it exists that home and social disorganization cause by divorcing and hasty economic development. There will be a reserve criminal who have distorted personality effected by undesirable surrounding, therefore he may become a serial murder. This study examines criminal psychological analysis of On Bo Hwan's serial murder case in 1994 at Korea, according to criminal records and press report and his statement and confession. This paper also show his domestic background and growing atmosphere and human relation between his parents.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.5-8
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• 2003

요오드화 아연과 수소화 요오드에 의해 개시되는 비닐에테르류 단량체의 양이온 리빙 중합이 보고$^{(1)}$ 된 이래 리빙 중합 개시계에 대한 연구가 많이 진행되어 왔다. 본 연구자들은 광양이온중합 개시제인 요오드화 디페닐요드늄과 할로젠화 아연 존재 하에서 비닐에테르 단량체의 광양이온중합을 실시하여 비극성 용매 하에서 연쇄이동이나 정지반응이 존재하지 않는 리빙중합을 보고한$^{(2-4)}$ 바 있는데 이 중합에서 비닐에테르 단량체와 프로톤산에 의하여 생성된 단량체 adduct의 C-I 결합이 안정한 공유결합을 형성하나 요오드화아연에 의해 C-I 결합의 분극화되어 활성화됨으로서 개시와 성장반응이 가능한 것으로 설명되었다. (중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.319-324
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• 2008

In this study the progressive collapse potential of special concentrically braced frames were investigated using the nonlinear static. All of seven different brace types were considered. According to the pushdown analysis results, most braced frames designed according to current design codes satisfied the design guidelines for progressive collapse initiated by loss of a first story mid-column; however most model structures showed brittle failure mode. This was caused by buckling of columns after compressive braces buckled. Among the braced frames considered, the inverted-V type braced frames showed superior ductile behavior during progressive collapse.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.307-312
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• 2008

Local damage may cause sequential collapse of structure, which is called progressive collapse. Current progressive collapse analysis is based on the mean value of design variables. This deterministic approach has a low reliability as it doesn't consider uncertainty of variables. In this study the sensitivity of design variables for progressive collapse of structure is evaluated by Monte Calro simulation and Tornado diagram. The analysis results show that the behaviour of model structures is highly sensitive to variation of the yield force of beams and the structural damping ratio.