조절반응량 측정을 통한 노안 가입도와 원근거리 난시 분석

심현석 한국안광학회 2007 논문집 Vol.2007 No.1

안드로이드 악성코드 분류를 위한 Flow Analysis기반의 API 그룹화 및 빈도 분석 기법

심현석,박정수,단티엔북,정수환 한국정보보호학회 2019 정보보호학회논문지 Vol.29 No.6

While several machine learning technique has been implemented for Android malware categorization, there is stilldifficulty in analyzing due to overfitting problem and including of un-executable code, etc. In this paper, we introduce ourimplemented tool to address these problems. Tool is consists of approximately 1,500 lines of Java code, and perform Flowanalysis on set of APIs, or on control flow graph. Our tool groups all the API by its relationship and only perform analysison actually executing code. Using our tool, we grouped 39032 APIs into 4972 groups, and 12123 groups with result ofincluding class names. We collected 7,000 APKs from 7 families and evaluated our feature reduction technique, and we alsoreduced features again with selecting APIs that have frequency more than 20%. We finally reduced features to 263-numbersof feature for our collected APKs. 본 논문에서는 머신러닝 기반의 악성코드 분류에 있어 오버피팅 문제를 비롯하여 실제로 실행되지 않는 코드가APK에 포함되는 문제 등을 해결하기 위해 모든 API들의 연관성을 통해 그룹화하며, 제어 흐름 분석을 통해 실제로실행되는 코드에 대한 분석을 수행하는 툴을 개발하였다. 툴은 약 1,500라인으로 이루어진 자바 기반의 소프트웨어로, 전체 API에 대한 빈도 분석을 수행하거나 생성된 제어 흐름 그래프를 바탕으로 빈도 분석을 수행한다. 툴을 이용하여 모든 버전에서의 총 39032개의 메서드에 대해 4972개의 그룹으로 축소할 수 있으며, 클래스를 포함한 결과로는 총 12123개의 그룹으로 축소할 수 있다. 결과 분석을 위해서 본 논문에서는 총 7개의 패밀리에서 7,000개의APK를 랜덤으로 수집하였으며, 수집된 APK를 이용하여 feature를 축소하는 기법을 검증하였다. 또한, 추출된 데이터에서 빈도가 20% 이상으로 나타난 API만을 선별하여 feature를 더욱 축소하여 최종적으로 263개의 feature로 축소하였다.

갑상선 편평상피세포암의 메타분석

심현석,권오진,고준석,박정제,김진평,정찬열,우승훈 대한이비인후과학회 2013 대한이비인후과학회지 두경부외과학 Vol.56 No.7

Background and Objectives Primary squamous cell carcinoma (SCC) of thyroid is an unusual tumor, accounted for approximately 1.1% of all neoplasms of the thyroid gland. It is highly lethal, like anaplastic thyroid carcinoma, in terms of aggressive clinical behavior. In the literature, the best treatment of this tumor is by surgery and the use of combination therapy that includes postoperative radiation, chemotherapy and radioiodine therapy; however, the effect of treatment is very poor. This study aims to identify the clinical features of SCC of thyroid, and to devise a better treatment method. Subjects and Method Journals citing SCC of thyroid were identified from Pubmed, Korea Med, and Google and the clinical records reported therewithin from 1990 to 2013 were reviewed. A total of 40 patients were analyzed from 21 well-organized papers by searching the following keywords: squamous cell carcinoma, primary, thyroid, excerpt of the patient’s age, sex, clinical features, pathologic findings, therapy, course and prognosis. Results We analyzed the treatment results of 40 patients from a total of 21 papers. Patients, consisting of 17 men and 23 women, were found in the age range of 24-88, with the mean age of 63.2. The follow-up period ranged from one to 96 months, with the mean being 15 months, and the size of the mass varied from 1 cm to 15 cm. Histopathologically, we found 13 patients with only SCC mixture of SCC and 22 patients with papillary thyroid carcinoma (PTC). Each of the following diseases were identified with one patient: a mixture of SCC and Hashimoto thyroiditis, a mixture of follicular thyroid carcinoma (FTC), SCC and FTC and mixed Hurtle cell cancer, SCC and PTC and mixed Hashimoto thyroiditis, and SCC, PTC with mixed insula cancer. Thirty-two patients underwent total thyroidectomy, and 30 patients underwent total thyroidectomy accompanied by neck dissection. Twelve patients received postoperative radiation therapy, and five patients received postoperative chemotherapy. Nineteen patients were observed without recurrence of the disease, and ten patients were found to be in stage III or less. Conclusion SCC of the thyroid showed aggressive clinical characteristics, however, good results can be expected with early diagnosis and treatment. If tumor is found only within the thyroid, we expect good therapeutic results after the same treatment as PTC.

원거리와 근거리에서의 대칭난시와 비대칭난시의 분포

심현석,김영청 대한시과학회 2019 대한시과학회지 학술대회 Vol.2019 No.07

Hard coating film for in-mold processing using thermal curing and EB curing dual reaction systems

심현석,손재명,이은지,이광희 한국고분자학회 2010 한국고분자학회 학술대회 연구논문 초록집 Vol.2010 No.4

플립칩 접합용 초음파 혼의 CFD 열유동 해석

심현석,리광훈(Hyun suk Shim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

This paper introduce the CFD analysis for predicting the heat transfer at the Ultrasonic horn. Approximately Ultrasonic horn separates two part. One is preheating part and the other is cooling part. Temperature of preheating part rise up by 260℃ that make it possible to attach a chip to a semiconductor. Also there is a piezo material in the cooling part. When piezo work, it generates heat of 100℃. It can stand by 150℃. But the high temperature conducted from the preheating part has a bad affect on the piezo. These situation make it necessary cooling at piezo. Previously except of the piezo, all of them are composed of the SUS440c that has good thermal conductivity. This study shows way that not only cooling the piezo but also cutting off the conduction between preheating part and cooling part by using the Ti and Duralumin that have low thermal conductivity compare with the SUS440c. Conclusion of CFD analysis that the heat coming from the piezo can`t be transferred the horn cause of the Ti and Duralumin.

Numerical Investigation on Hydrodynamic Characteristics of a Centrifugal Pump with a Double Volute at Off-Design Conditions

심현석,김광용 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.3

Severe radial thrust under off-design operating conditions can be a harmful factor for centrifugal pumps. In the present work, effects of geometry of a double volute casing on the hydrodynamic performance of a centrifugal pump have been investigated focusing on off-design conditions. Three-dimensional steady Reynolds-averaged Navier-Stokes analysis was carried out by using shear stress transport turbulence model. Numerical results for the hydrodynamic performance of the centrifugal pump were validated compared with experimental data. The hydraulic efficiency and radial thrust coefficient were used as performance parameters to evaluate the hydrodynamic characteristics of the centrifugal pump. The cross-sectional area ratio of the volute casing, the expansion coefficient of the rib structure, the distance between the rib starting point and volute entrance, and radius and width of the volute entrance, and length of the rib structure, were selected as geometric parameters. Results of the parametric study show that the performance parameters are significantly affected by the geometric variables and operating conditions. Optimal configurations of the double volute casing based on the design of experiments technique show outstanding performance in terms of the efficiency and radial thrust coefficient.

Fabrication of Hard Coating Layer for In-mold Decoration (IMD) Foil and The Characteristics of IMD Foil Layers with EB irradiation

심현석,신지희,손재명,이은지,송권빈,이광희 한국고분자학회 2011 한국고분자학회 학술대회 연구논문 초록집 Vol.2011 No.2

정상안과 폭주부족안의 양안시기능 검사값 비교

심현석,김상현,심문식 한국안광학회 2010 한국안광학회지 Vol.15 No.3

Purpose: The aim of this study was to compare binocular functions such as near point of convergence (NPC), AC/A ratios, heterophoria, accommodation, accommodation lag, positive relative accommodation (PRA), negative relative accommodation (NRA), positive relative convergence (PRC), negative relative convergence (NRC) in normal subjects and convergence insufficiency. Methods: 86 subject (male n=45, female n=41, mean ageSD= 23.272.85 years) without amblyopia, strabismus, and ocular pathology were studied. Forty three patients each group were classified as normal subjects and convergence insufficiency group based on AC/A ratio and far and near phoria. Binocular function of the two groups was measured using phoropter. Results: The values between normal subjects and convergence insufficiency were 5.71cm and 7.07cm for NPC, 5.28 and 2.81 for Heterophria AC/A, 0.92exo/3.36exo and 2.17exo/10.84exo for far and near phoria, 15.49/23.30/13.30 and 13.50/20.02/9.09 for PRC, respectively. However, there were no significant differences between normal subjects and convergence insufficiency for accommodative amplitude, accommodative lag, PRA, NRA, BI vergence test, BO vergence test, NRC. Conclusions: Both groups were a significant difference for cover test, NPC, Heterophria AC/A, far and near phoria, break point of PRC, and recovery point of PRC. 목적: 정상안과 폭주부족안에서 폭주근점, AC/A비, 사위량, 조절력, 조절래그, 상대조절, 상대폭주 등의 양안시기 능 검사값을 비교해 보고자한다. 방법: 사시나 약시 및 안질환이 없는 86명(남 45명, 여 41명 평균연령 23.272.85 세)을 AC/A비와 원·근거리 사위량을 기준으로 정상안 43명과 폭주부족안 43명으로 분류하여 연구하였다. 두 그룹 의 양안시기능은 포롭터를 이용 측정하였다. 결과: 정상안과 폭주부족안은 폭주근점 5.71cm, 7.07cm로, 거리차 AC/ A비 5.28, 2.81, 원근거리 사위량 0.92 exo/3.36 exo, 2.17 exo/10.84 exo, 양성상대폭주 15.49/23.30/13.30, 13.50/ 20.02/9.09 등으로 차이가 있었으나, 조절력, 조절래그, 양성상대조절, 음성상대조절, 원거리 개산여력, 폭주여력, 음 성상대폭주 등은 현저한 차이가 없었다. 결론: 두 그룹은 차폐검사, 폭주근점, 거리차 AC/A, 원·근거리 사위량, 양 성상대폭주 파괴점과 회복점 등에서 유의한 차이가 있었다.

ICFGO : Inter-Procedural Control FlowGraph 난독화를 위한 UI 은닉 및 Dummy Flow 삽입 기법

심현석,정수환 한국정보보호학회 2020 정보보호학회논문지 Vol.30 No.3

For the obfuscation of Flow Analysis on the Android operating system, the size of the Flow Graph can be large enoughto make analysis difficult. To this end, a library in the form of aar was implemented so that it could be inserted into theapplication in the form of an external library. The library is designed to have up to five child nodes from the entry pointin the dummy code, and for each depth has 2n+1 numbers of methods from 100 to 900 for each node, so it consists of atotal of 2,500 entry points. In addition, entry points consist of a total of 150 views in XML, each of which is connectedvia asynchronous interface. Thus, the process of creating a Inter-procedural Control Flow Graph has a maximum of14,175E+11 additional cases. As a result of applying this to application, the Inter Procedure Control Flow Analysis tool generates an average of 10,931 edges and 3,015 nodes with an average graph size increase of 36.64%. In addition, in theAPK analyzing process showed that up to average 76.33MB of overhead, but only 0.88MB of execution overhead in theuser's ART environment. 안드로이드 운영체제에서 Flow Analysis의 난독화를 위해서는 실행되지 않는 흐름의 코드를 생성하여 FlowGraph의 크기를 크게 만들어 분석이 어렵게 만들 수 있다. 이를 위해 논문에서는 aar 형태의 라이브러리를 구현하여 외부 라이브러리의 형태로 애플리케이션에 삽입이 가능하도록 하였다. 라이브러리는 더미 코드에서의 진입점에서부터 최대 5개의 child node를 가질 수 있도록 설계되었으며, child node의 클래스는 각 node마다 100개부터900개까지 2n+1개의 메서드를 가지고 있으므로 총 2,500개의 진입점으로 구성된다. 또한 진입점은 XML에서 총150개의 뷰로 구성되며, 각각의 진입점은 비동기 인터페이스를 통해 연결된다. 따라서 Inter-Procedural 기반의Control Flow Graph를 생성하는 과정에서는 최대 14,175E+11개의 추가적인 경우의 수를 가지게 된다. 이를애플리케이션에 적용한 결과 Inter Procedural Control Flow Analysis 툴에서 평균 10,931개의 Edge와3,015개의 Node가 추가 생성되었으며 평균 36.64%의 그래프 크기 증가율을 갖는다. 또한 APK를 분석 시에는최대 평균 76.33MB의 오버헤드가 발생하였지만, 사용자의 ART 환경에서는 최대 평균 0.88MB의 실행 오버헤드만을 가지며 실행 가능한 것을 확인하였다.