Goal-directed weakening of abstract interpretation results

Seo, Sunae,Yang, Hongseok,Yi, Kwangkeun,Han, Taisook Association for Computing Machinery 2007 ACM transactions on programming languages and syst Vol. No.

흐름 그래프 형태를 이용한 함수형 프로그램 유사성 비교

서선애(Sunae Seo),한태숙(Taisook Han) 한국정보과학회 2005 정보과학회논문지 : 소프트웨어 및 응용 Vol.32 No.4

컴퓨터와 소프트웨어의 사용이 증가하면서, 프로그램 소스의 도용(표절)이 사회적인 문제로 부각되고 있다. 이런 문제를 해결하고자 프로그램의 문법 구조를 비교하여 표절을 찾아내는 방법론이 제안되었지만, 간단한 프로그램 수정에도 표절을 찾아내지 못하는 한계를 가지고 있다. 이 연구에서는, 문법 구조적인 정보 뿐 아니라, 프로그램식 간의 수행시 의존 관계를 드러내는 그래프를 이용한 프로그램 표절 감지 시스템을 제안한다. 이 방법론은 문법 정보 뿐 아니라, 수행시 의존 관계까지 비교 대상에 올림으로써, 수행시 의존 관계를 변화시키지 못하는 프로그램 수정에 대해서도 프로그램 표절을 판별할 수 있다. 또한, 이 연구에서는 표절 프로그램이란 무엇인가를 엄밀하게 정의하고 이 표절 프로그램의 정의와 연구에서 제안된 표절 감별 그래프와의 관계를 보였다. 즉, 두 프로그램이 표절이라는 것은 표절 감별 그래프가 일치한다는 것과 필요 충분 관계가 있음을 증명하였다. 또한 제안된 표절 감별 방법론을 실제적인 프로그래밍 언어인 nML 에 대해서 구현하였다. 구현된 도구를 통해서 실제 표절된 프로그램들을 감별한 결과, 기존의 방법에서 찾기 어려운 프로그램 표절을 제안된 방법론이 다룰 수 있음을 확인하였다. Stealing the source code of a program is a serious problem not only in a moral sense but also in a legal sense. However, it is not clear whether the code of a program is copied from another or not. There was a program similarity checker detecting code-copy by comparing the abstract syntax trees of programs. However this method has a limitation that it cannot detect the code-copy attacks when the attacker modifies the syntax of the program on purpose. We propose a program similarity check by program control graph, which reveals not only syntax information but also control dependancy. Our method can detect the code-copy attacks that do not change control dependancy. Moreover, we define what code-copy means and establish the connection between code-copy and similarity of program control graph: we prove that two programs are related by copy congruence if and only if the program control graphs of these programs are equivalent. We implemented our method on a functional programming language, nML. The experimental results show us that the suggested method can detect code similarity that is not detected by the existing method.

정확한 정수 합동 분석을 위한 역방향 요약 연산자 정의

서선애(Sunae Seo) 한국정보과학회 2002 한국정보과학회 학술발표논문집 Vol.29 No.2Ⅱ

정수 합동 분석(integer congruence analysis)은 프로그램 변수들이 의미 영역을 정수 합동(integer congruence) 집합으로 정의하여 분석한다. 정수 합동 분석을 위한 합동 격자(lattice of integer congruences)와 순방향 요약 산술 연산자에 대한 정의는 이미 P. Granger에 의해 소개되었다. 하지만, 분석의 정확도에 영향을 미치는 역방향 요약 산술 연산자에 대한 연구가 아직 되어 있지 않다. 이 논문에서는 정수 합동 분석을 위한 역방향 요약 산술 연산자를 정의한다. 역방향 요약 산술 연산자를 정의하는 방법은 정수 방정식을 푸는 방법을 기반으로 고안되었다. 정의된 역방향 요약 산술 연산자는 프로그램 분석의 정확도를 높이는데 기여를 할 수 있는데, 이 논문에서는 예제를 통해서 이 사실을 보인다.

Reliable Multivalued Conductance States in TaO_<i>x</i> Memristors through Oxygen Plasma-Assisted Electrode Deposition with in Situ-Biased Conductance State Transmission Electron Microscopy Analysis

Lee, Myoung-Jae,Park, Gyeong-Su,Seo, David H.,Kwon, Sung Min,Lee, Hyeon-Jun,Kim, June-Seo,Jung, MinKyung,You, Chun-Yeol,Lee, Hyangsook,Kim, Hee-Goo,Pang, Su-Been,Seo, Sunae,Hwang, Hyunsang,Park, Sung American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.35

<P>Transition metal oxide-based memristors have widely been proposed for applications toward artificial synapses. In general, memristors have two or more electrically switchable stable resistance states that device researchers see as an analogue to the ion channels found in biological synapses. The mechanism behind resistive switching in metal oxides has been divided into electrochemical metallization models and valence change models. The stability of the resistance states in the memristor vary widely depending on: oxide material, electrode material, deposition conditions, film thickness, and programming conditions. So far, it has been extremely challenging to obtain reliable memristors with more than two stable multivalued states along with endurances greater than ∼1000 cycles for each of those states. Using an oxygen plasma-assisted sputter deposition method of noble metal electrodes, we found that the metal-oxide interface could be deposited with substantially lower interface roughness observable at the nanometer scale. This markedly improved device reliability and function, allowing for a demonstration of memristors with four completely distinct levels from ∼6 × 10<SUP>-6</SUP> to ∼4 × 10<SUP>-8</SUP> S that were tested up to 10<SUP>4</SUP> cycles per level. Furthermore through a unique in situ transmission electron microscopy study, we were able to verify a redox reaction-type model to be dominant in our samples, leading to the higher degree of electrical state controllability. For solid-state synapse applications, the improvements to electrical properties will lead to simple device structures, with an overall power and area reduction of at least 1000 times when compared to SRAM.</P> [FIG OMISSION]</BR>

A hot-water extract of <i>Sanguisorba officinalis</i> ameliorates endotoxin-induced septic shock by inhibiting inflammasome activation : HSO attenuates inflammasome activation

Seo, Dong-Won,Cho, Yong-Il,Gu, Suna,Kim, Da-Hee,Yi, Young-Joo,Lee, Sang-Myeong Center for Academic Publications Japan 2018 Microbiology and immunology Vol.62 No.1

<P>The inflammasome is a multiprotein signaling complex that mediates inflammatory innate immune responses through caspase 1 activation and subsequent IL-1 secretion. However, because its aberrant activation often leads to inflammatory diseases, targeting the inflammasome holds promise for the treatment of inflammation-related diseases. In this study, it was found that a hot-water extract of Sanguisorba officinalis (HSO) suppresses inflammasome activation triggered by adenosine 5-triphosphate, nigericin, microbial pathogens, and double stranded DNA in bone marrow-derived macrophages. HSO was found to significantly suppress IL-1 production in a dose-dependent manner; this effect correlated well with small amounts of caspase 1 and little ASC pyroptosome formation in HSO-treated cells. The anti-inflammatory activity of HSO was further confirmed in a mouse model of endotoxin-induced septic shock. Oral administration of HSO reduced IL-1 titers in the serum and peritoneal cavity, increasing the survival rate. Taken together, our results suggest that HSO is an inhibits inflammasome activation through nucleotide-binding domain and leucine-rich repeat pyrin domain 3, nucleotide-binding domain and leucine-rich repeat caspase recruitment domain 4 and absent in melanoma 2 pathways, and may be useful for treatment of inflammasome-mediated diseases.</P>

원격고등교육에서 성인학습자의 중도탈락에 관한 로지스틱 회귀분석

권선아(Suna Kyun),김명진(Myungjin Kim),서희정(Heejeong Seo),김민정(Min-Jeong Kim) 한국방송통신대학교 미래원격교육연구원 2020 평생학습사회 Vol.16 No.4

Unconventional Three-Armed Luminogens Exhibiting Both Aggregation-Induced Emission and Thermally Activated Delayed Fluorescence Resulting in High-Performing Solution-Processed Organic Light-Emitting Diodes

Park, Seo Yeon,Choi, Suna,Park, Gi Eun,Kim, Hyung Jong,Lee, Chiho,Moon, Ji Su,Kim, Si Woo,Park, Sungnam,Kwon, Jang Hyuk,Cho, Min Ju,Choi, Dong Hoon American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.17

<P>In this work, three-armed luminogens <B>IAcTr-out</B> and <B>IAcTr-in</B> were synthesized and used as emitters bearing triazine and indenoacridine moieties in thermally activated delayed fluorescence organic light-emitting diodes (OLEDs). These molecules could form a uniform thin film via the solution process and also allowed the subsequent deposition of an electron transporting layer either by vacuum deposition or by an all-solution coating method. Intriguingly, the new luminogens displayed aggregation-induced emission (AIE), which is a unique photophysical phenomenon. As a nondoped emitting layer (EML), <B>IAcTr-in</B> showed external quantum efficiencies (EQEs) of 11.8% for the hybrid-solution processed OLED and 10.9% for the all-solution processed OLED with a low efficiency roll-off. This was evident by the higher photoluminescence quantum yield and higher rate constant of reverse intersystem crossing of <B>IAcTr-in</B>, as compared to <B>IAcTr-out</B>. These AIE luminogens were used as dopants and mixed with the well-known host material 1,3-bis(<I>N</I>-carbazolyl)benzene (mCP) to produce a high-efficiency OLED with a two-component EML. The maximum EQE of 17.5% was obtained when using EML with <B>IAcTr-out</B> doping (25 wt %) into mCP, and the OLED with EML bearing <B>IAcTr-in</B> and mCP showed a higher maximum EQE of 18.4% as in the case of the nondoped EML-based device.</P> [FIG OMISSION]</BR>

토픽 모델링 기반의 사이버대학교 학습자 중도탈락 개선을 위한 교육요구 탐색

서희정(Seo, Heejeong),권선아(Kyun, Suna) 숭실대학교 영재교육연구소 2021 Global Creative Leader Vol.11 No.3

이 연구의 목적은 사이버대학교 학습자의 교육요구를 탐색하여 교육과정 개선 및 개발을 위한 기초자료로 확보하고, 궁극적으로 중도탈락 개선에 기여하는 것이다. 이를 위하여, H 사이버대학교에 재학 중인 신·편입생들의 학업계획서 4,880건이 분석되었다. 4,880건의 학업계획서는 계열별(공학계열, 인문사회계열, 예술계열) 및 성별(남, 여)로 구분되어 ① 핵심 단어의 빈도분석, ② LDA(Latent Dirichlet Allocation) 기반 토픽 모델링의 2단계에 걸쳐 분석되었다. 분석결과는 다음과 같다. 첫째, 빈도분석 결과, 가장 많이 언급된 키워드는‘지식’, ‘직무’, ‘실무’, ‘전문성’, ‘졸업’, ‘자격증’, ‘학위취득’ 등 경력개발과 관련된 내용이었다. 둘째, 토픽 모델링 결과, 공학계열의 남녀학생과 인문계열 남학생의 분석 결과에서는‘전공 분야의 직무 역량 향상’, 인문계열 여학생은 ‘전공 분야 기초 학습’, 예술계열 남녀학생은‘전공 분야 심화학습’이 가장 중요한 토픽으로 도출되었다. 마지막으로, 이상과 같이 본 연구를 통해서 확인된 학습자 교육요구 분석결과가 주는 시사점이 논의되었다. The purpose of the present study is to explore the educational needs of cyber university learners, in order to obtain the basic data for curriculum improvement or development, which contributes to the improvement of learners’ dropout rates in the cyber university. To do this, 4,880 study plans of H cyber university s 1st year and transfer students were analyzed. 4,880 study plans were analyzed over two stages by faculties (Engineering, Humanities & Social Sciences, and Arts) and gender (male, female): ① frequency analysis of keywords, ② LDA-based topic modeling. The results are as follows. First, as a result of frequency analysis, the most frequently mentioned keywords were those related to career development such as ‘knowledge’, ‘job’, ‘practice’, ‘professionalism’, ‘graduation’, ‘certificate’, and ‘acquisition of degree’. Second, as a result of topic modeling, in the case of male and female students from the Engineering department and male students from the Humanities & Social Sciences department, ‘improving job competency in the major field’ was derived as the most important topic. Also, while female students from Humanities & Social Sciences department, showed ‘basic learning in their major’ as the most important topic, male and female students from the Arts department showed ‘intensive learning in their major’. Finally, based on these results of the learner s’ educational needs analysis confirmed through this study, the implications were discussed.

Fabrication of Temperature Responsive PNIPAAm-PEGDA Embolic Microspheres Using Microfluidic Device

Kyoung Duck Seo,Kyungsup Han,Sunae Hwang,Jonghwi Lee,Dong Sung Kim 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.4

공개 허가형 블록체인 및 스마트 컨트랙 기반의 대학교양교육체제 설계 및 타당화 연구

권선아(Kyun, Suna),서희정(Seo, Heejeong) 숭실대학교 영재교육연구소 2022 Global Creative Leader Vol.12 No.1

국내 대학교양교육은 대학학사구조의 개혁과 그 궤적을 같이하며 혁신의 과정을 통해 현재에 이르렀다. 특히 최근 ACE, PRIME, LINC+ 등의 정부지원 대학교육혁신 프로젝트의 일환으로 교양교육혁신의 큰 성과들이 보고되고 있다. 그러나 급속한 기술의 발전에 따라 빠른 속도로 변화해 가고 있는 우리 사회를 고려해 볼 때, 대학교양교육이 경쟁력을 갖추기 위해서는 좀 더 개선될 필요가 있다. 이에 본 연구는 설계·개발 연구방법론을 활용하여 기존 교양교육혁신의 한계점을 극복할 수 있게 하는 ‘공개 허가형 블록체인 기반 스마트 컨트랙에 의하여 작동되는 대학교양교육체제 모형’을 설계하고 타당화를 수행하였다. 구체적으로, ① 먼저 블록체인 기술 및 문헌 분석에 근거하여 공개 허가형 블록체인 기반 교양교육체제 모형을 설계하고, 이어서 ② 기술전문가들의 기술검토, ③ 대학 이해관계자들의 현장검토를 통한 타당화의 과정을 수행하였다. 타당화의 과정을 통하여, 본 연구가 제안하는 모형의 기술적 구현 가능성 및 대학 이해관계자들의 의견을 확인하였고, 이를 기반으로 모형의 정책적 보완점 및 구체적인 실행방안을 도출하였다. 본 연구는 대학교육혁신 및 교양교육혁신에 대하여 고민하는 국내의 많은 대학들이 참조할 수 있는 지침들을 구체적으로 제시하였다는 측면에서 큰 의의가 있다. Tertiary general education innovation in Korea has achieved the current level of innovation, following the trajectory of reform and innovation level of the university academic structure. In particular, it has been reporting great achievements in general education innovation, as a part of government-supported university education innovation projects such as ACE, PRIME, and LINC+. However, tertiary general education needs to be further improved to be competitive, considering that our society is rapidly changing with the rapid development of technology. Therefore, the current study designed and validated the‘tertiary general education model operated by public permissioned blockchain-based smart contract that can overcome the limitations of existing tertiary general education innovation by using the design & development research methodology. Specifically, first i) public permissioned blockchain-based general education system based on blockchain technology and literature analysis was designed. Next, technical review by technical experts was carried out, followed by validity through field review by university stakeholders. Through validation processes, technical feasibility of the model and opinions of university stakeholders were confirmed. Based on these, policy supplements for the model and specific implementation plans were proposed. This study has significant implications in that it provided guidelines that many universities in Korea are considering in tertiary general education innovation as well as tertiary education innovation.