2-Fluorenyl chalcone 유도체의 합성과 가수분해반응에 관한 연구

이기창,황성규,윤철훈,오세영 명지대학교 자연과학연구소 1995 자연과학논문집 Vol.12 No.-

Fluorenyl chalcone 유도체를 합성하였고 25 ±1℃의 20% dioxane-H?O 혼합용매 중에서 자외선 분광광도법을 이용하여 pH 1.0~13.0까지의 넓은 pH범위에서 가수분해 반응속도를 측정하였다. 또한 Fluoreny chalcone 유도체의 pH변화에 따른 반응속도로 측정하고, 일반염기효과, 치환기효과 및 가수 분해 생성물 확인 등으로부터 Fluorenyl chalcone 유도체에 대한 가수분해 반응속도상수를 구하였다. 이들 유도체들은 pH와 무관한 부분과 수산화 이온농도에 비례하며, pH와 무관한 부분에서는 중성의 물분자가 첨가된다. 반응속도 상수 측정으로부터 Fluorency chalcon 유도체의 가수분해 반응은 비가역 1차 반응임을 확인하였고, 치환기효과로부터 전자유인성기에 의해 반응이 촉진되는 것을 알 수 있었다. 또한, 가수분해 최종 생성물은 확인 결과 2 ~acetyl fluorene과 벤즈알데히드였다. 이러한 실험결과를 토대로 하여 Fluorenyl chalcone 유도체에 대한 가수분해 반응 메카니즘을 제안하였다. Fluorenyl chalcone derivatives were synthesis, it was measured that hydrolysis made use of ultraviolet spectrophotometry at a wide pH 1.0 ~ 13.0 range in 20% dioxane-H?O solution, 25±1℃. On the basis of general base catalysis, substitutent effect and confirmation of hydrolysis product, it was measured the reaction rate of fluorenyl chalcone derivatives for the pH change. It maybe concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion: Above pH 10.0, It was in propotion to concentration of hydroxide ion, a part having no concern with pH was added to the neutral H?O molecule. From the result of measurement the reaction rate, hydrolysis of fluorenyl chalcone derivatives confirmed to the irreversible first order through measurement the substituent effect, It was found that reaction rate was accelerated first order through measurement the substituent effect, It was found that reaction rate was accelerated by electron attracting group. Also, from the result of final product, there were 2-acetyl fluorene benzaldehyde.On the basis of these findings, Hydrolysis for the fluorenyl chalcone derivative was proposed a fitting mechanism.

중복 허용 범위를 고려한 서바이벌 네트워크 기반 안드로이드 저자 식별

황철훈 ( Cheol-hun Hwang ),신건윤 ( Gun-yoon Shin ),김동욱 ( Dong-wook Kim ),한명묵 ( Myung-mook Han ) 한국인터넷정보학회 2020 인터넷정보학회논문지 Vol.21 No.6

안드로이드 저자 식별 연구는 좁은 범위에서는 출처를 밝히기 위한 방법으로 해석할 수 있으나, 넓은 범위에서 본다면 알려진 저작물을 통해 유사한 저작물을 식별하는 통찰력을 얻기 위한 방법으로 해석할 수 있다. 안드로이드 저자 식별 연구에서 발견되는 문제점은 안드로이드 시스템 상 중요한 코드이지만 의미가 없는 코드들로 인하여 저자의 중요한 특징을 찾기 어렵다는 것이다. 이로 인해 합법적인 코드 또는 행동들이 악성코드로 잘못 정의되기도 한다. 이를 해결하기 위하여 서바이벌 네트워크 개념을 도입하여 여러 안드로이드 앱에서 발견되는 특징들을 제거하고 저자별로 정의되는 고유한 특징들을 생존시킴으로써 문제를 해결하고자 하였다. 제안하는 프레임워크와 선행된 연구를 비교하는 실험을 진행하였으며, 440개의 저자가 식별된 앱을 대상으로 실험한 결과에서 최대 92.10%의 분류 정확도를 도출하였고 선행된 연구와 최대 3.47%의 차이를 보였다. 이는 적은 양의 학습데이터를 이용하였으나 저자별 중복된 특징 없이 고유한 특징들을 이용하였기에 선행 연구와 차이가 나타났을 것으로 해석하였다. 또한 특징 정의 방법에 따른 선행 연구와의 비교 실험에서도 적은 수의 특징으로 동일한 정확도를 보일 수 있으며, 이는 서바이벌 네트워크 개념을 통한 지속적으로 중복된 의미 없는 특징을 관리할 수 있음을 알 수 있었다. The Android author identification study can be interpreted as a method for revealing the source in a narrow range, but if viewed in a wide range, it can be interpreted as a study to gain insight to identify similar works through known works. The problem found in the Android author identification study is that it is an important code on the Android system, but it is difficult to find the important feature of the author due to the meaningless codes. Due to this, legitimate codes or behaviors were also incorrectly defined as malicious codes. To solve this, we introduced the concept of survival network to solve the problem by removing the features found in various Android apps and surviving unique features defined by authors. We conducted an experiment comparing the proposed framework with a previous study. From the results of experiments on 440 authors' identified apps, we obtained a classification accuracy of up to 92.10%, and showed a difference of up to 3.47% from the previous study. It used a small amount of learning data, but because it used unique features without duplicate features for each author, it was considered that there was a difference from previous studies. In addition, even in comparative experiments with previous studies according to the feature definition method, the same accuracy can be shown with a small number of features, and this can be seen that continuously overlapping meaningless features can be managed through the concept of a survival network.

SVM 기반 유전 알고리즘을 이용한 컴파일러 분석 프레임워크 : 특징 및 모델 선택 민감성

황철훈(Cheol-Hun Hwang),신건윤(Gun-Yoon Shin),김동욱(Dong-Wook Kim),한명묵(Myung-Mook Han) 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.4

악성코드 기술 발전으로 변이, 난독화 등의 탐지 회피 방법이 고도화되고 있다. 이에 악성코드 탐지 기술에 있어 알려지지 않은 악성코드 탐지 기술이 중요하며, 배포된 악성코드를 통해 저자를 식별하여 알려지지 않은 악성코드를 탐지하는 악성코드 저자 식별 방법이 연구되고 있다. 본 논문에서는 바이너리 기반 저자 식별 방법에 대해 중요 정보인 컴파일러 정보를 추출하고자 하였으며, 연구 간에 특징 선택, 확률 및 비확률 모델, 최적화가 분류 효율성에 미치는 민감성(Sensitive)을 확인하고자 하였다. 실험에서 정보 이득을 통한 특징 선택 방법과 비확률 모델인 서포트 벡터 머신이 높은 효율성을 보였다. 최적화 연구 간에 제안하는 프레임워크를 통한 특징 선택 및 모델 최적화를 통해 높은 분류 정확도를 얻었으며, 최대 48%의 특징 감소 및 51배가량의 빠른 실행 속도라는 결과를 보였다. 본 연구를 통해 특징 선택 및 모델 최적화 방법이 분류 효율성에 미치는 민감성에 대해 확인할 수 있었다. Advances in detection techniques, such as mutation and obfuscation, are being advanced with the development of malware technology. In the malware detection technology, unknown malware detection technology is important, and a method for Malware Authorship Attribution that detects an unknown malicious code by identifying the author through distributed malware is being studied. In this paper, we try to extract the compiler information affecting the binary-based author identification method and to investigate the sensitivity of feature selection, probability and non-probability models, and optimization to classification efficiency between studies. In the experiment, the feature selection method through information gain and the support vector machine, which is a non-probability model, showed high efficiency. Among the optimization studies, high classification accuracy was obtained through feature selection and model optimization through the proposed framework, and resulted in 48% feature reduction and 53 faster execution speed. Through this study, we can confirm the sensitivity of feature selection, model, and optimization methods to classification efficiency.

비정복성 관절원판 변위환자들에서 악관절세척술의 술후 예측 인자들에 관한 연구

김철훈(Cheol-Hun Kim),황희성(Hie-Seong Hwang),신상훈(Sang-Hun Sin) 대한구강악안면외과학회 2003 대한구강악안면외과학회지 Vol.29 No.6

Purpose: The purpose of this study was to find the predictors for successful arthrocentesis for anterior disc displacement without reduction(ADD without Reduction) of the temporomandibular joint (TMJ). Patients and Methods: Arthrocentesis and lavage was carried out in 25TMJs of 22patients whose MRI findings were all anterior disc displacement without reduction. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of postoperative pain score. Predectors which was analyzed were age, duration of painful locking, MMO, the degree of pain, perioperative clicking and the amounts of irrigation fluid. Results: 18cases (72%) was included to criteria for success. There were no significant differences in age, duration of locking, MMO and the degree of pain statistically. But In 15cases(83%) of successful cases, amouts of irrigated solution recovered to normal MMO were less than 150ml. And In 8cases (44%) of successful cases, perioperative clicking was appeared. Conclusion: Amounts of irrigated solution recovered to normal MMO and the appeareance of perioperative clkicking may be predictors of the successful results of arthrocenetesis of ADD without reduction of TMJ.

서바이벌 네트워크 개념을 이용한 저자 식별 프레임워크: 의미론적 특징과 특징 허용 범위

황철훈(Cheol-Hun Hwang),신건윤(Gun-Yoon Shin),김동욱(Dong-Wook Kim),한명묵(Myung-Mook Han) 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.6

악성코드 저자 식별은 알려진 악성코드 저자의 특징을 이용하여 알려지지 않은 악성코드의 저자 특징과 비교를 통해 악성코드를 식별하기 위한 연구 분야이다. 바이너리를 이용한 저자 식별 방법은 실질적으로 배포된 악성코드를 대상으로 수집 및 분석이 용이하다는 장점을 갖으나, 소스코드를 이용한 방법보다 특징 활용 범위가 제한된다. 이러한 한계점으로 인해 다수의 저자를 대상으로 정확도가 저하된다는 단점을 갖는다. 본 연구는 바이너리 저자 식별에 한계점을 보완하기 위하여 ‘바이너리로부터 의미론적 특징 정의’와 ‘서바이벌 네트워크 개념을 이용한 중복 특징에 대한 허용 범위 정의’ 방법을 제안한다. 제안한 방법은 바이너리 정보로부터 Opcode 기반의 그래프 특징을 정의하며, 서바이벌 네트워크 개념을 이용하여 저자별 고유 특징을 선택할 수 있는 허용범위를 정의하는 것이다. 이를 통해 저자별 특징 정의 및 특징 선택 방법을 하나의 기술로 정의할 수 있으며, 실험을 통해 선행연구보다 5.0%의 정확도 향상과 함께 소스코드 기반 분석과 동일한 수준의 정확도 도출이 가능함을 확인할 수 있었다. Malware Authorship Attribution is a research field for identifying malware by comparing the author characteristics of unknown malware with the characteristics of known malware authors. The authorship attribution method using binaries has the advantage that it is easy to collect and analyze targeted malicious codes, but the scope of using features is limited compared to the method using source code. This limitation has the disadvantage that accuracy decreases for a large number of authors. This study proposes a method of ‘Defining semantic features from binaries’ and ‘Defining allowable ranges for redundant features using the concept of survival network’ to complement the limitations in the identification of binary authors. The proposed method defines Opcode-based graph features from binary information, and defines the allowable range for selecting unique features for each author using the concept of a survival network. Through this, it was possible to define the feature definition and feature selection method for each author as a single technology, and through the experiment, it was confirmed that it was possible to derive the same level of accuracy as the source code-based analysis with an improvement of 5.0% accuracy compared to the previous study.

측두하악장애환자에서 악관절 세척술후 관절활액의 전구염증성 Cytokines의 발현

김철훈(Cheol-Hun Kim),황희성(Hie-Sung Hwang),신상훈(Sang-Hoon Shin),정인교(In-Kyo Chung),황태호(Tae-Ho Hwang) 대한구강악안면외과학회 2005 대한구강악안면외과학회지 Vol.31 No.5

The purpose of this study is that evaluate the distribution and biological roles of TNF-a, interleukin-1β(IL-1β), interleukin-6(IL-6) and tissue inhibitors of metalloproteinase-1(TIMP-1) in the synovial fliud of patients with non-inflammatory chronic temporomandibular joint(TMJ) disorders in relation to pain during joint movements and magnetic resonance imaging(MRI) findings. TMJ synovial fluids aspirates were obtained from 36 patients (36 joints) with chronic TMJ disorders and from 8 controls(8 joints). Patients were divided to four groups. The control group was from healthy volunteers(8 joints), group I(18 joints) was patients with anterior disc displacement with reduction, group II(5 joints) was patients with disc displacement without reduction and group III (5 joints) was osteoarthritis. The TNF-α, IL-1βand IL-6 levels in the aspirates were determined by using an enzyme-linked immunosorbent assay and the TIMP-1 level was measured by an enzyme immunoassay. Following examinations for pain during joint movements and MRI observations, these cytokines’level and frequencies of detection were compared. The level of IL-1βwas not significant different in all groups. but the level of TNF-α, IL-6 and TIMP-1 were significant different among groups. The level of IL-6 and TIMP-1 were correlated to pain during movement(p〈0.01) and the level of TNF-a(p〈0.05). Also, the level of IL-6 was correlated to the level of TIMP-1(p〈0.01). Especially, The level of the TIMP-1 level was significantly correlated to the pain during movement and showed very high levle of Pearson’s correlation coefficient (r=0.833)(p〈0.001). The results indicated that the TNF-α, IL-6 and TIMP-1 levels in the TMJ aspirates of patients with chronic TMJ disorders have been raised. Especially, IL-6 and TIMP-1 were very high levels in the patients who were degraded in the TMJ. Also, TNF-α, IL-6 and TIMP-1 showed the significant correlation in the chronic temporomandibular joint disorders. Therefore I suggest that these cytokines were also correlated to the pain during movement in the chronic temporomandibular joint disorders

Piezoelectrically modulated touch pressure sensor using a graphene barristor

Hwang, Hyeon Jun,Kim, So-Young,Kang, Soo Cheol,Allouche, Billal,Yang, Jin Ho,Lee, Byoung Hun Institute of Pure and Applied Physics 2019 Japanese Journal of Applied Physics Vol.58 No.2

Aspergillosis in a Korean Native Goat

Cheol Jeong,In-Jin Hwang,Ha-Hyun Kim,Su-Jin Park,Sang-Ik Park,Young-Ju Jeong,Mun-Il Kang,Bang-Hun Hyun,In-Joong Kim,Dong-Kun Yang,Chang-Hee Kwon,Kyoung-Oh Cho 한국실험동물학회 2007 Laboratory Animal Research Vol.23 No.4

Pulmonary pyogranuloma due to aspergillosis was observed in a young Korean native goat raised in Korea. At necropsy, multiple cheese-like white nodules were detected throughout all lung lobes, with diffuse mild lung edema. Microscopically, pyogranulomatous lesions consisted of central necrotic debri and peripheral layers including inner layer of neutrophils and lymphocytes, and outer fibrosis layer. Giant cells were scattered between inner and outer layers in the periphery of this lesion. Some parts of pyogranulomatous lesions had necrosis in the peripheral lesions, resulting in spreading the Aspergillus into the adjacent alveoli. Aspergillus hyphae were detected in the central and peripheal areas of pyogranulomas by Periodic acid Schiff reaction. From these results, this case was diagnosed as pulmonary aspergillosis in a Korean native goat. This is the first report about pulmonary pyogranuloma due to aspergillosis in Korean native goat raised in Korea. Since over 60 species of Aspergillus cause diverse diseases into varied organs and tissues of many animals, further characterization of Aspergillus will need to perform using the isolates from the pulmonary pyogranulomas in the goats.

Thermally driven homonuclear-stacking phase of MoS₂ through desulfurization

Hwang, Young Hun,Yun, Won Seok,Cha, Gi-Beom,Hong, Soon Cheol,Han, Sang Wook The Royal Society of Chemistry 2019 Nanoscale Vol.11 No.23

<P>Engineering phase transitions or finding new polymorphs offers tremendous opportunities for developing functional materials. We reveal that the thermally driven desulfurization of single-crystalline MoS2 samples improves transport properties by reducing the band gap and further induces metallization. Semi-desulfurization, <I>i.e.</I>, removal of the topmost S layer, results in the placement of the exposed Mo layers directly on top of the following sub-layers, together with the bottom S layer of the top layer. This homonuclear (AA) stacking derived from the AA′ stacking of the hexagonal (2H) phase is retained even after further desulfurization of the remaining bottom S layer, <I>i.e.</I>, full desulfurization of the top layer. Our findings fundamentally explain why the 2H phase of TMDs is characterized by AA′ stacking.</P>

Optimal path planning for the capturing of a moving object

Cheol-Ho Hwang,Sang-Hun Lee,Jae-Pyung Ko,Jang-Myung Lee 제어로봇시스템학회 2003 제어로봇시스템학회 국제학술대회 논문집 Vol.2003 No.10