AFM을 이용한 데이터 저장 소자 연구

최정환,박근형,Choi Jung-Hwan,Park Kun-Hyung 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.5

A new reading technology for the ultra-high density data storage device utilizing AFM technology was proposed and its experimental results were discussed in this paper. For the experiments, an about $2{\mu}m$ thick conductive polymer layer was spin-coated on the heavily doped n-type Si wafer and an about $0.1{\mu}m$ thick PMMA layer was also been spin-coated on it. After then, the $5{\times}5$ memory way was fabricated by making indents on the surface of the wafer with the heated AFM tip, and the data reading was performed by scanning the surface with the tip biased at 10 V and the measuring the current flowing out at the end of the tip. The experimental results clearly showed that the new data reading technology worked superbly. The current measured was about 0.92 pA at the cell with the indent, and it was not only below 0.31 pA at the cell without the indent, but also at the cell where the indent was erased.

기름기록부 실효성 확보에 관한 연구

최정환,이상일,Choi, Jung-Hwan,Lee, Sang-Il 해양환경안전학회 2014 海洋環境安全學會誌 Vol.20 No.4

The purpose of this thesis is studying for a legal basis and definition of Oil Record Book. In the thesis, comparing with the laws related to punishment for false entry of Oil Record Book of the maritime countries and korea Act. Studying the improvement marine pollutants from ships by suggesting legal and institutional proposal which are able to make themselves increase effectiveness for recording and inspection of Oil Record Book. Suggest the solution of the problems raised in this thesis, First, The Oil Record Book should not be the evidence which is having the effectiveness simply after the accident of marine pollution, but take sanction on pre-inspection of Oil Record Book as establish the concrete administrative punishment for each contents-based record of Oil Record Book. Second, It should set up of judgement criteria of false entry of Oil Record Book by port state control officer. Third, It should strengthen the legal effectiveness of Oil Record Book contents such as Code(c) ; oil residue, Code(d); relating to bilge discharge by including premeditation for false entry of Oil Record Book. Also, The enhancement of role for marine pollution prevention manager raise the effectiveness of Oil Record Book as recognizing the importance of Oil Record Book. 본 연구에서는 기름기록부의 정의 및 법적근거를 살펴보며, 우리나라 및 주요 해양국가의 기름기록부 허위기재에 대한 법령을 비교 고찰하여, 우리나라 기름기록부의 기록과 점검에 대한 실효성을 높이기 위한 법률적 제도적 방안을 제시함으로써 선박으로부터 발생하는 해양오염을 사전에 예방할 수 있는 개선책을 연구하고자 하였다. 본 연구결과에서 제시된 문제점 개선을 위한 방안으로서 첫째, 기름기록부의 각 항목별 기록사항에 대한 구체적 행정처분의 규정을 제정하여 해양오염 발생 후 단순 증거로서 효력을 가지는 기름기록부가 아닌 사전조사를 통한 엄격한 제재조치가 될 수 있도록 해야 할 것이다. 둘째, 항만국통제관의 기름기록부 허위기재에 대한 판단의 기준을 설정하여 통일된 규제가 될 수 있도록 해야 할 것이다. 셋째, 기름기록부 제I부 (C) Code 11. 유성잔류물 및 (D) Code 저장구역 빌지의 선외배출과 관련한 단순 기록 불일치 사항도 고의성여부를 포함시켜 엄격함을 유지시켜나가야 할 것이다. 또한 해양오염방지관리인의 기름기록부 기록사항에 대한 사전점검 역할을 강화하여 기름기록부의 기록사항의 중요성 인식을 제시함으로써 기름기록부의 실효성을 높이고자 한다.

Craniosynostosis Occurring between Siblings

최정환,김명훈,김민수,정규용,이근철,김석권,Choi, Jeong-Hwan,Kim, Myung-Hoon,Kim, Min-Su,Jung, Gyu-Yong,Lee, Keun-Cheol,Kim, Seok-Kwun Korean Cleft Palate-Craniofacial Association 2013 Archives of Craniofacial Surgery Vol.14 No.2

Craniosynostosis is a congenital anomaly in which cranial sutures close prematurely and restrict skull growth. In this paper, the case of two siblings, a male and a female, who were both diagnosed as craniosynostosis is reported. They underwent corrective osteotomy for cranial vault remodeling. A 22-month-old female infant who was brought to the department of plastic and reconstructive surgery of the authors' hospital was diagnosed with plagiocephaly. At the same time, her 7-month-old brother was diagnosed with brachycephaly. In the case of the female infant, corrective coronal osteotomy and supraorbital bar advancement were performed. Her brother underwent frontal advancement osteotomy using Tessier's tongue in the groove procedure. After the correction of the craniosynostosis, the two patients recovered in several days later, and the results were good in both cases cosmetically and functionally. They showed normal head circumference increasing curves and no symptom of functional disorder in their last follow-up. Isolated or nonsyndromic craniosynostosis is sporadic but mostly autosomal dominant. This paper presents a case of craniosynostosis with a genetic tendency; and although it occurred between siblings, the affected lesions differed. Thus, appropriate diagnosis and management in patients are needed.

Full HD 비디오를 위한 고성능, 저비용 히스토그램 평활화 방법

최정환,박종식,이성수,Choi, Jung-Hwan,Park, Jong-Sik,Lee, Seong-Soo 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.5

Image Signal Processor(ISP)의 한 블록인 Auto Exposure(AE)는 입력 영상의 밝기가 전체적으로 어둡거나 밝으면 적정 밝기로 조절하여 적당한 평균 밝기를 유지하는 기능을 한다. 하지만 AE는 영상의 전체 평균 밝기만 조절하기 때문에 영상의 명암대비 향상까지 기대하기는 어렵다. 특히 물체 인식이 필요한 분야에서는 ISP의 AE 만으론 명암대비가 낮은 영상에서는 물체 인식이 어려워져 명암대비 향상 기술이 필요하다. 이러한 문제를 해결하기 위해 본 논문에서는 ISP의 AE를 대체할 방법으로 Histogram Equalization(HE)를 제안한다. 또한 기존의 HE 문제점을 간단한 연산만으로 보완하고 하드웨어 구현에도 적합한 방법을 제안한다. Auto exposure (AE) in image signal processor (ISP) controls brightness of input image to the proper brightness when it is too dark or bright. But conventional AEs often fail to get proper brightness since AE controls only average brightness of image. Especially in applications that require object recognition, it cannot be solved the problem by AE of ISP. In this paper proposes Histogram Equalization (HE) processes that is the alternative of AE. It also proposes proper method to realize hardware and compensate HE problems conventional by using simple calculation.

국가 에너지안보 추진전략 분석에 관한 연구 - 혁신시스템 관점에서의 분석 및 추진전략을 중심으로 -

최정환,이홍훈,Choi, Jeong-Hwan,Lee, Hong-Hoon 해양환경안전학회 2015 海洋環境安全學會誌 Vol.21 No.6

에너지자원의 안정적인 확보는 국가발전을 위한 가장 중요한 요소 중 하나이다. 본 연구는 혁신시스템 관점에서 우리나라의 에너지관련 정책결정시스템을 분석하고 그 문제점을 도출하였다. 혁신시스템의 구성요소 중 혁신주체 측면에서는 에너지의 안정적인 수송을 위한 전략적인 강화방안이 미흡하다는 한계를 가지고 있었으며, 연계측면에서는 국방영역을 제외한 혁신주체들 간의 연계는 비교적 양호하였으나 안보적 관점에서 중요한 역할을 담당하는 국방영역과 타 혁신주체들 간의 연계는 미흡한 것으로 분석되었다. 하부구조 측면에서는 에너지안보 관점에서 국방영역의 하부구조인 전력건설 논의가 미흡한 것으로 나타났으며, 마지막으로 제도적 측면에서는 에너지안보에 관한 국방영역의 역할에 대한 제도적 정립이 미흡하여 향후 국가 에너지안보와 관련된 거버넌스에서 국방영역의 참여가 제도적으로 명시될 필요가 있는 것으로 분석되었다. Stability and security of energy resources are one of the most important factors for a national-development. In this research, we analyzed the Republic of Korea's policy making system on energy security and identified the problems from an innovation system perspective. In terms of the actors, they had limitations that ROK's navy do not have enough strategic plan for energy transportation. The links between innovation actors except defense area were relatively good, but links between the military area(navy) and other innovation actors had weak linkage. The infrastructure did't have enough consideration for military force development. For the institution; the role of the military area on energy security was not completely established. Therefore, participation of the defense area(navy) is required to be stated institutionally.

멀티 코어 프로세서의 온도관리를 위한 방안 연구 및 열-인식 태스크 스케줄링

최정환,Choi, Jeong-Hwan 한국정보과학회 2008 정보과학회논문지 : 시스템 및 이론 Vol.35 No.7

최신의 마이크로프로세서 설계에서는 전력 관련 문제들이 중요한 고려사항이 되었다. 온-칩(On-chip) 온도 상승은 이와 관련하여 중요한 요소로 부각되었다. 이를 적절하게 처리하지 않을 경우 냉각 비용과 칩 신뢰성에 부정적인 결과를 초래한다. 이 논문에서 우리는 시간적/공간적인 핫 스폿(Hot spot) 완화를 위한 설계들과 열 시간 상수, 작업부하 변동, 마이크로프로세서의 전력 분배 사이의 보편적인 상충관계(Trade off)들을 조사한다. 우리의 방안은 작업부하의 실행위치/순서를 변경하고 동시실행 스레드의 수를 조절하여 시스템의 공간 및 시간적인 열 틈새(Heat slack)에 영향을 줌으로써, 운영체계(OS)와 이미 시스템에 존재하는 하드웨어의 지원만으로 적절한 시간제한내에 작업부하를 조절함으로써 온-칩 온도를 낮출 수 있다. Power-related issues have become important considerations in current generation microprocessor design. One of these issues is that of elevated on-chip temperatures. This has an adverse effect on cooling cost and, if not addressed suitably, on chip reliability. In this paper we investigate the general trade-offs between temporal and spatial hot spot mitigation schemes and thermal time constants, workload variations and microprocessor power distributions. By leveraging spatial and temporal heat slacks, our schemes enable lowering of on-chip unit temperatures by changing the workload in a timely manner with Operating System (OS) and existing hardware support.

나선 홈을 가진 공기 동압베어링의 강성 해석

최정환(J.H. Choi),박근형(K.H. Park),최우천(W.C. Choi),김권희(K.H. Kim),우기명(K.M. Woo),최환영(H.Y. Choi) 한국정밀공학회 1998 한국정밀공학회 학술발표대회 논문집 Vol.1998 No.11월

유비쿼터스 환경에서 상황 인지 정보를 이용한 적응형 추천 서비스 기법

최정환(Jung Hwan Choi),류상현(Sanghyun Ryu),장현수(Hyunsu Jang),엄영익(Young Ik Eom) 한국정보과학회 2010 정보과학회논문지 : 소프트웨어 및 응용 Vol.37 No.3

최근 유비쿼터스 시대의 도래와 함께 개인화된 서비스를 제공하기 위한 다양한 서비스 모델들이 제안되어 왔으며, 특히, 사용자에게 개인화된 서비스를 선응적으로 제공하기 위한 다양한 추천 서비스 기법들이 고안되었다. 그러나, 기존의 기법들은 수 많은 데이터를 여과 과정 없이 분석함으로써 추천의 효율성이 떨어지며, 한정된 상황 인지 정보만을 추천 요소로 고려하기 때문에 사용자에게 개인화된 서비스를 제공하기에 적합하지 않다. 본 논문에서는 유비쿼터스 환경에서 사용자의 현재 상황에 가장 적합한 서비스를 제공하는 적응형 추천 서비스 기법을 제안한다. 본 기법은 사용자의 선호도 예측을 위해 누적된 사용자와 장치 간의 상호작용 상황 정보들을 이용하며, 군집 및 협업 필터링 기법을 이용하여 사용자에게 현재 상황에 적응적인 서비스를 추천한다. 군집 기법을 통해 사용자의 현재 위치에 근접한 데이터만을 분석함으로써, 추천의 효율성을 높이며, 협업 필터링을 이용하여 누적된 정보들이 충분하지 않은 상황에서도 정확한 추천을 보장한다. 끝으로, 시뮬레이션을 통해 본 기법의 성능 및 신뢰성을 평가한다. With the emergence of ubiquitous computing era, various models for providing personalized service have been proposed, and, especially, several recommendation service schemes have been proposed to give tailored services to users proactively. However, the previous recommendation service schemes utilize a wide range of data without any filtering and consider the limited context-aware information to predict user preferences so that they are not adequate to provide personalized service to users. In this paper, we propose an adaptive recommendation service scheme which proactively provides suitable services based on the current context. We use accumulated interaction contexts (IC) between users and devices for predicting the user’s preferences and recommend adaptive service based on the current context by utilizing clustering and collaborative filtering. The clustering algorithm improves efficiency of the recommendation service by focusing and analyzing the data that is collected from the locations nearby the users. Collaborative filtering guarantees an accurate recommendation, even when the data is insufficient. Finally, we evaluate the performance and the reliability of the proposed scheme by simulations.

권무관의 개념에 대한 재검토

최정환(Jeong Hwan Choi) 한국중세사학회 2001 한국중세사연구 Vol.- No.11

N/A

특수체육 교사의 교육과정 운영분석

최정환(Jung Whoan Choi) 한국체육교육학회 2000 한국체육교육학회지 Vol.5 No.1

The purpose of this research was to analyze the activities in teaching of the special school physical Teacher. To achieve the purpose of this study, the research method used in this study was the qualitative case study. Participants of this study were consisted of four special school physical teachers(2 males and 2 female)in Seoul Province, Korea. In order to collect the data needed for the study, qualitative research data collection methods were used: in-depth interview. and documents gathering. The collected materials were analyzed by using the encoding and inductive category analysis, and the trustworthiness, morality were ascertained. The analysis resulted in the fact that the activities in teaching of the special school physical Teachers were core-categorized into curriculum management. The results of the analyses and interpretation on the study are as follows. First, curriculum managements were sub-categorized into curriculum plan, sub-curriculum process, evaluation. Curriculum plan were curriculum process, composition and Indiviualized Education Plan(I E P) recognition, goal. Special school physical teacher recognized that the curriculum difficult to apply in field and Indiviualized Education Plan(I E P) was formal curriculum that the charge of teacher. The annual teaching plan was made out at the beginning of each semester, but formal curriculum and modified the current curriculum in field. Indiviualized Education Plan(I E P) goal was consider student level and speciality. Sub-curriculum process sub-categorized into minute-curriculum, estimate time and special activity. Minute-curriculum management was to difficult that the lack of athletic facilities such as locker room and gymnasium, many student, multiful specialty and of the subject of physical education. but the class was to managing smoothly that the student centered in field. Estimate time was going to primary teacher only play. Special activity was difficult for reason why facility and administrative order. Curriculum evaluation was composed of conformability and application. but the conformability to be lacked validity level. and description was limited.