Nanomechanical Thermal Analysis of Photosensitive Polymers

Yun, Minhyuk,Yim, Changyong,Jung, Namchul,Kim, Seonghwan,Thundat, Thomas,Jeon, Sangmin American Chemical Society 2011 Macromolecules Vol.44 No.24

<P>A few nanograms of poly(methyl methacrylate) (PMMA) or poly(vinyl cinnamate) (PVCN) was coated onto one side of a silicon cantilever, and the photodegradation of PMMA or photo-cross-linking of PVCN was investigated as a function of UV irradiation time. After UV irradiation, the resonance frequency and deflection of the polymer-coated silicon cantilevers were measured as a function of temperature, and these properties were found to be related to changes in the modulus and surface stress of the coated polymers, respectively. A decrease in the modulus and tensile surface stress was observed for PMMA under UV exposure due to photodegradation, whereas an increase in the modulus of PVCN was observed due to photo-cross-linking. In addition, the influence of UV exposure on the glass transition of the PMMA and PVCN was investigated using deflection measurements. Whereas a single glass transition was observed for PMMA, two distinctive glass transitions were observed for PVCN due to the copresence of cross-linked and un-cross-linked of PVCN. Variations in the polymer structures were also investigated as a function of UV irradiation time using Fourier transform infrared spectroscopy and compared with the results obtained using the cantilever measurements.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2011/mamobx.2011.44.issue-24/ma202194e/production/images/medium/ma-2011-02194e_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma202194e'>ACS Electronic Supporting Info</A></P>

Facile Phase Transition Measurements for Nanogram Level Liquid Samples Using Suspended Microchannel Resonators

Yun, Minhyuk,Lee, Il,Jeon, Sangmin,Lee, Jungchul Institute of Electrical and Electronics Engineers 2014 IEEE SENSORS JOURNAL Vol.14 No.3

Enhanced sensitivity of a microfabricated resonator using a graphene-polystyrene bilayer membrane

Yun, Minhyuk,Lee, Eunho,Cho, Kilwon,Jeon, Sangmin American Institute of Physics 2014 Applied Physics Letters Vol.105 No.7

Development Status of Operation Concept and Procedures for KASS

Minhyuk Son,Youngsun Yun,Byungseok Lee 사단법인 항법시스템학회 2022 Journal of Positioning, Navigation, and Timing Vol.11 No.1

Korea Augmentation Satellite System (KASS) is a Satellite Based Augmentation System (SBAS) system under development in South Korea and aims to provide air navigation services after 2023. In order to provide reliable service, detailed design for the operation of this system is required. This paper proposes a detailed operation-based designs based on mission, architecture, operation definition of the system. For the stable operation of the system, an operation organization was designed and operation activities were classified in consideration of the architecture and function of the system. Detailed operation procedures were designed according to this classification and operation procedures related to the command and configuration of subsystem were verified on the Integration, Verification and Qualification (IVQ) platform for integrated testing and verification. The proposed operation concepts and procedures will be continuously confirmed and verified during verification, qualification and service preparation, and will be updated event after official KASS service.

차량 안정성 제어 시스템을 위한 차량 모델의 안정성 영역 해석

손민혁(Minhyuk Son),윤득선(Duksun Yun),부광석(Kwangseok Boo),김흥섭(Heungseob Kim) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

This paper describes the design of a unified chassis control system and study of control input affects the vehicle dynamic stability. As the vehicle stability enhancement, unified chassis control system is developed by integration of a individual controller. Moreover original ability, these systems are used for vehicle behavior control by brake pressure control, superimposed steering, active damping control. Most of these systems composes that choice the reference parameter and control that minimize the error between reference and actual parameter, but effects of control input to vehicle stability is still unclear. This paper examine the parameter affects the vehicle stability with Lyapunov’s direct method and Topological method under several driving condition. Consequently, these control input guarantee the stability region, while satisfying all actuator constraints.

리모트 콘트롤러를 이용한 모바일 카메라 제어 및 응용 시스템 구현

박민혁 ( Minhyuk Park ),윤현준 ( Hyunjune Yun ),이예슬 ( Yeseoul Lee ),임승호 ( Seung-ho Lim ) 한국정보처리학회 2015 한국정보처리학회 학술대회논문집 Vol.22 No.1

모바일 시스템의 카메라 응용 어플리케이션은 기본적인 이미지 저장 및 영상 촬영뿐만 아니라 카메라 기반의 증강현실 및 위치 기반 서비스 등 다양한 응용 분야에 활용할 수 있다. 특히, 셀프 활동에 많이 활용되는데, 이때 발생하는 문제점은 셀프 촬영이 힘들다는 것이다. 스마트폰 카메라를 자유롭게 제어하고, 나아가서는 카메라 촬영 및 다양한 이미지 프로세싱을 보조해줄 수 있는 시스템 및 장치가 필요하다. 본 논문에서는 안드로이드 스마트폰 기반의 카메라 제어 모듈과 카메라 제어 모듈을 활용한 이미지 프로세싱 보조 시스템을 구현해보도록 한다. 카메라 제어 모듈은 리모트에서 안드로이드 스마트폰의 카메라 촬영을 제어할 수 있으며, 여러 대의 안드로이드 스마트폰과 연동해서 다양한 각도에서 하나의 피사체에 대한 카메라 촬영이 가능하도록 통신 제어 시스템이다. 이를 활용하면 모바일 카메라 응용 서비스를 좀 더 폭넓게 활용할 수 있을 것이다.

안드로이드 애플리케이션 개발을 위한 UML 프로파일

고민혁(Minhyuk Ko),국승학(Seunghak Kuk),윤상필(Sangpil Yun),김현수(Hyeon Soo Kim) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.1B

UML은 표준화된 소프트웨어 모델링 언어이다. UML은 잘 정의된 풍부한 모델링 개념들과 표기법을 제공하기 때문에, 어떠한 시스템이라도 쉽게 모델링을 가능하게 해준다. 그렇지만 UML은 시스템 개발을 위한 모델링 시 개발자간의 의사소통을 원활하게 이루어지도록 하기 위한 메커니즘을 제공하지만, 특정 시스템에서 사용하는 요소들에 대한 개념까지 제공하는 것은 아니다. UML은 이런 사항을 충족할 수 있도록 하기 위한 확장 메커니즘을 제공한다. UML의 확장 메커니즘은 새로운 UML 모델링 요소를 정의하여 표준 UML에서는 표현할 수 없는 새로운 개념을 표현할 수 있도록 해준다. 본 논문에서는 UML의 확장 메커니즘을 사용하여 안드로이드 애플리케이션 개발을 위한 프로파일을 구현한다. 표준 UML로는 표현 할 수 없는 안드로이드의 특정 요소들을 UML 확장 메커니즘을 사용하여 나타내고, 이를 이용하여 안드로이드 애플리케이션 개발 시 효과적인 모델링을 가능하게 한다.

최소 침습 수술과 척추의 거동 안정화를 위한 척추 인공삽입물 설계

허민혁(Minhyuk Heo),윤지환(Jihwan Yun),박성훈(Seonghun Park) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

The purpose of the present study is to design a novel lumbar spine implant that allows a minimally invasive surgery that can avoid soft tissue removal as much as possible in the device installation procedure and that makes the lumbar behavior similar to normal lumbar behavior even after the procedure, so that the drawbacks of conventional lumbar spine implants may be overcome. The lumbar spine implant developed in this study was designed to include spike and ratchet elements in the fixed part of the device in order to minimize removal of soft tissue. Also, the part that connects the interspinous process was designed as a spring element to enable normal lumbar movement after the lumbar support installation process. In order to analyze the structural stability of the device, a load of 250 N was applied to the lumbar spine implant. As a result of the analysis, it was evaluated that the lumbar spine implant was structurally stable. When the lumbar spine implant was inserted, the disc pressure decreased by 80 - 92% compared to the defect model and the flexion movement was also recovered to the normal behavior range reported in previous studies. These results suggest that the currently designed the lumbar spine implant could provide the minimization degenerative diseases at the adjacent lumbar segment.

Fabrication of complete denture by stereolithography-based 3D printing: a case report

Yina Yun,Minhyuk Park,박상원,박찬,장우형,Seon-Ki Lee 조선대학교 치의학연구원 2021 Oral Biology Research (Oral Biol Res) Vol.45 No.4

The conventional complete denture has disadvantages such as multiple visits to the dental clinic, including definitive impression and intermaxillary relationship records after taking preliminary impressions and making individual trays and reduced adaptation of the denture base due to the shrinkage of the heat-cured resin. The MAGIC Denture system (Cozahn, Seoul, Korea) requires only a few visits because of intermaxillary relationship records and definitive impression at the first visit and has reduced shrinkage after additive manufacturing of 3D printing. In this case, a 3D-printed denture by MAGIC Denture of Cozahn was manufactured, which required a minimum number of visits for a patient who had difficulty in treatment due to poor cooperation and intended to determine the clinical usefulness. The patient was satisfied with the functional and aesthetic aspects after the final denture was delivered.

안드로이드 애플리케이션의 UI 단위 테스트 방법

윤상필(Sangpil Yun),서용진(Yongjin Seo),고민혁(Minhyuk Ko),김현수(Hyeon Soo Kim) 한국정보과학회 2012 정보과학회 컴퓨팅의 실제 논문지 Vol.18 No.12

세계 스마트폰 OS 시장의 절반 이상을 차지한 안드로이드는 향후 태블릿, 스마트 TV, 자동차 등으로 시장의 확대가 전망된다. 현재 안드로이드 OS를 기반으로 수 많은 애플리케이션이 개발되고 있지만 애플리케이션의 신뢰성을 보장하기 위한 연구들은 부족한 상태이다. 이는 안드로이드 애플리케이션이 GUI를 기반으로 동작하기 때문에 기존의 테스트 방법을 적용하기 어렵기 때문이다. 구글에서 애플리케이션 테스트를 위한 환경을 제공하지만 개발자가 이를 활용하여 효율적인 테스트 코드를 작성하는 것은 쉽지 않다. 이 논문에서는 안드로이드 앱 개발에서 GUI 구현의 기본 단위인 액티비티에 대한 단위 테스트 방법을 제시한다. 이를 위해 테스트 케이스 설계 방법과 테스트 수행코드의 자동 생성 방법을 제안한다. 이 방법을 통해 개발자는 쉽게 테스트 코드를 생성할 수 있으며 신뢰성 있는 앱을 개발할 수 있을 것이다. More than half of the world’s Smartphone OS market is occupied by Android. In the future Android market will be enlarged to tablet, smart TV, car, etc. Currently, based on the Android OS, many applications are being developed. However, researches to ensure the reliability of the application are insufficient. Since the Android applications are operated through the GUI, it is difficult to apply the existing test methods. Though Google provides the test environments for applications, but it is not easy for developers to utilize them efficiently. In this paper, we propose a unit testing method for the activities which are the basic implementation unit of the GUI in Android app development. To do this, the test case design methods and the automatic creation methods of the test code are proposed. With this testing method, developers can easily generate the test code and will be able to develop the reliable apps.