플라즈마 조사에 의한 전기분무합성 SiO₂ 코팅층의 물접촉각 변화

김재훈,이준성,김지영,김상섭,Kim, Jae-Hun,Lee, Junseong,Kim, Ji Yeong,Kim, Sang Sub 한국재료학회 2014 한국재료학회지 Vol.24 No.11

Hydrophilic $SiO_2$ layers were obtained by the atmospheric-pressure plasma treatment. Superhydrophobic $SiO_2$ layers were first deposited by the electrospray deposition method. The electrospunable solution that was prepared based on the solgel method was sprayed on Si (100) substrates. The surface of the electrosprayed $SiO_2$ layers consisted of the agglomeration of nano-sized grains, which led to a very high roughness and revealed a very high contact angle to water droplets over $162^{\circ}$. After having been exposed to the atmospheric $Ar/O_2$ plasma, the observed superhydrophobicity of the $SiO_2$ layers were greatly changed: a dramatic variation of the water contact angle from $162^{\circ}$ to $3^{\circ}$, namely realization of superhydrophillicity. Interestingly, the surface microstructure was almost preserved. According to the XPS analysis, it is more likely that thanks to the plasma exposure, the surface of $SiO_2$ layers will be cleaned in terms of organic species that are hydrophobic-inducing, consequently leading to the hydrophilic nature observed for the plasma-exposed $SiO_2$ layers.

RFCVD 장치를 이용하여 성장한 실리콘 나노와이어의 특성

김재훈,이형주,신석승,김기영,고춘수,김현숙,황용규,이충훈,Kim, Jae-Hoon,Lee, Hyung-Joo,Shin, Seok-Seung,Kim, Ki-Young,Go, Chun-Soo,Kim, Hyun-Suk,Hwang, Yong-Gyoo,Lee, Choong-Hun 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.2

We have synthesized silicon nanowires by using RFCVD(Radio Frequency Chemical Vapor Deposition) system on Au deposited p-type Si(100) wafers, and investigated their physical and electrical properties. The silicon nanowires had been grown in the atmospheres of $H_{2},\;N_{2}\;and\;SiH_{4}$ at 10 Torr at the substrate temperatures of $700{\pm}5^{\circ}C\;and\;810{\pm}5^{\circ}C$ respectively. FE-SEM analysis revealed that diameters of the silicon nanowires are $50{\sim}60nm$ with the length of several ${\mu}m$. XRD analysis showed that the growth direction of the nanowires is Si[111]. Field emission characteristics showed that the turn-of voltages at the current of $0.01\;mA/cm^{2}$ are $10\;V/{\mu}m\;and\;8.5\;V/{\mu}m$ for the wires grown at $700{\pm}5^{\circ}C\;and\;810{\pm}5^{\circ}C$, respectively.

고로슬래그 미분말을 함유한 고유동 모르터의 유동성상에 미치는 영향 요인에 관한 연구

김재훈,윤상천,지남용,Kim, Jae-Hun,Yoon, Sang-Chun,Jee, Nam-Yong 한국건축시공학회 2002 한국건축시공학회지 Vol.2 No.4

High fluid concrete unlike OPC concrete is made with various material, and the phase of fresh concrete is considerably different. In order to understand fluidity phase and mix properties of high fluid concrete, concrete is required to access as suspension structure which consists of aggregate and paste. The focus of this paper is to analyze the test results and quantify the effect of mix proportions of mortar and fineness modulus of sand on the properties of fresh mortar. The effect of water-binder ratio. sand-binder ration. contents of ggbs (by mass of total cementitious materials). and various contents of water reducing agent on the yield stress and plastic viscosity of the mix is studied. Based on the experimental results, the fellowing conclusions can be drawn: (1) The mixing time needed for high fluid mortar was approximately two times more than that of ordinary portland mortar. (2) The fluidity phase of mortar could be explained by yield stress of mix and the fluidity of mortar. (3) As the content of ggbs increased, yield stress of mortar was decreased and plastic viscosity of it was increased. (4) For the high fluid mortar, it was appeared that sand-binder ratio should be below 1.5.

카본블랙에 의한 천연고무 물성치와 피로수명 변화에 대한 실험적 연구

김재훈,김영학,정현용,Kim, Jae-Hun,Kim, Yeong-Hak,Jeong, Hyeon-Yong 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.11

The effects of carbon black on the material properties and the fatigue life of the carbon-black filled natural rubbers were investigated. Different kinds of carbon blacks resulted in different fatigue lives, hysteresis, and critical J-values. It was noticed that the hysteresis was inversely proportional to the difference between DBPA and CTAB, and the critical J-value was almost the same regardless of the length of a precrack. In addition, different kinds of carbon blacks resulted in different fracture morphologies, and micro-scale and macro-scale roughnesses. The critical J-value was proportional to the micro-scale roughness. and it seemed relate to the size distribution of carbon black particles. By reviewing all the experimental data. it was finally noticed that the logarithmic value of the fatigue life could be linearly expressed by a multiplication of the critical J-value and the logarithmic value of the hysteresis.

플렉시블 LCD 모드

김재훈,Kim, Jae-Hun 한국정보디스플레이학회 2006 인포메이션 디스플레이 Vol.7 No.3

시간지연과 입력포화를 갖는 T-S 퍼지 카오스 시스템의 동기화

김재훈,신현석,김은태,박민용,Kim Jae-Hun,Shin Hyunseok,Kim Euntai,Park Mignon 대한전자공학회 2005 電子工學會論文誌-SC (System and control) Vol.42 No.1

본 논문에서는 시간지연과 입력포화를 갖는 카오스 시스템에 대한 퍼지 모텔 기반의 동기화 기법을 제안한다. 시간지연을 갖는 카오스 마스터 시스템과 슬레이브 시스템을 모델링하기 위해 Takagi-Sugeno(T-S) 퍼지 모델을 이용한다. 특히 슬레이브 시스템은 제어 입력이 제한되는 입력포화 특성을 갖는다고 가정한다. 선형 오차 피드백과 병렬 분상 보상(PDC) 방법에 따라 퍼지 카오스 동기화 시스템을 설계하고 동기화 오차 시스템의 국소 안정도 조건을 해석한다. 신호 전송 채널에는 시간지연이 항상 존재하므로 채널 시간지연 또한 고려한다. 입력포화와 시간지연을 갖는 퍼지 동기화 시스템의 국소 안정도에 대한 충분 조건은 Lyapunov-Krasovskii 이론을 적용하여 선형 행렬 부등식 (LMI) 문제의 해를 통해 얻어진다. 제안된 동기화 기법의 효과를 확인하기 위해서 모의 실험을 수행한다. This paper presents a fuzzy model-based approach for synchronization of time-delay chaotic system with input saturation. Time-delay chaotic drive and response system is respectively represented by Takagi-Sugeno (T-S) fuzzy model. Specially, the response system contains input saturation. Using the unidirectional linear error feedback and the parallel distributed compensation (PDC) scheme, we design fuzzy chaotic synchronization system and analyze local stability for synchronization error dynamics. Since time-delay in the transmission channel always exists, we also take it into consideration. The sufficient condition for the local stability of the fuzzy synchronization system with input saturation and time-delay is derived by applying Lyapunov-Krasovskii theory and solving linear matrix inequalities (LMI's) problem. A numerical example is given to demonstrate the validity of the proposed approach.

돼지 질병 진단은 어떻게 하나?

김재훈,Kim, Jae-Hun 대한양돈협회 1997 養豚 Vol.19 No.9

Markov process 및 상태천이확률 행렬 계산을 통한 사격통제장치 전처리필터 신뢰성 산출 기법

김재훈,유준,Kim, Jae-Hun,Lyou, Joon 한국군사과학기술학회 1999 한국군사과학기술학회지 Vol.2 No.2

An easy and efficient method is proposed for a computation of reliability of preprocessing filters in the fire control system when the sensor data are frequently unreliable depending on the operation environment. It computes state transition probability matrix after modeling filter states as a Markov process, and computing false alarm and detection probability of each filter state under the given sensor failure probability. It shows that two important indices such as distributed state probability and error variance can be derived easily for a reliability assessment of the given sensor fusion system.

대한불교조계종 중앙기록관 역사기록전시 - 기록으로 보는 한국불교와 조계종 -

김재훈,이경훈,Kim, Jae-Hun,Lee, Kyung-Hoon 한국기록학회 2006 기록학연구 Vol.0 No.13

기록을 관리하는 궁극의 목적은 이용 제공에 있다. 기록물전시회는 기록관 및 기록관리에 대한 대중적 인지도를 높이고, 이에 대한 관심을 제고시킬 수 있는 기회가 된다. 또한, 미지의 이용자에게 적극적으로 접근하여 서비스를 제공할 수 있다. 아울러, 아키비스트에게는 소장하고 있는 기록물에 대한 개괄적인 분류 및 평가를 할 수 있는 기회를 제공하기도 한다. 이러한 기록전시의 기능과 중요성에도 불구하고 기록물전시회를 개최한 기관 및 단체는 아직 많지 않은 형편이다. 본고에서는 대한불교조계종 중앙기록관의 역사기록전시 사례를 바탕으로 전시기획, 기록물 선별 및 전시 실제에 대하여 소개함으로써 기록전시의 참고 유형을 제시하고자 한다. The ultimate purpose of records management is for reference service. Archival exhibition provides an opportunity to raise the public's interest at archives and maintain records management and to offer the reference service to unknown users. As for archivists, archival exhibition allows to summarize generally the archives that he may have and to appraise its value. At the opening of the Memorial hall for the history and culture of Korean buddhism, the Archives of Jogye Order of Korean Buddhism held an archival exhibition by showing archives of Korean Buddhism History to the public. The exhibition mainly consists in 2 themes: History of Jogye Order of Korean Buddhism and its activities. Over 300 archives were selected in accordance with historicity, rarity and particularity of each archives that the Jogye Order of Korean Buddhism posses. The present paper aims to suggest different models of Archival Exhibition with the help of detailed explanation on Exhibition planning, Selection of archives and the practice.

소프트 실시간 시스템을 위한 두 단계 스케쥴링 알고리즘

김재훈,Kim, Jae-Hun 한국정보처리학회 1999 정보처리논문지 Vol.6 No.2

본 논문은 소프트 실시간 시스템을 위한 스케쥴링을 간단히 하기 위하여 "두 단계 데드라인" 방법을 제안하였다. 각각의 작업은 두 개의 데드라인을 갖는데, 첫 번째 데드라인과 두 번째 데드라인이라 부른다. 첫 번째 데드라인은 일반 실시간 시스템의 데드라인과 같다. 두 번째 데드라인은 첫 번째 데드라인 보다 늦은 시각인데, 늦은 결과가 아직은 사용할 만한 가장 늦은 시각이다. 첫 번째 데드라인 이내에 끝난 일은 만점을 주지만, 첫 번째 데드라인을 놓치고 두 번째 데드라인 이내에 끝난 일에 대해서는 부분 점수만 인정한다. 본 논문에서, 첫 번째 데드라인, 두 번째 데드라인, 부분 점수 등을 고려하여 다이나믹하게 일들의 우선 순위를 정하는 방법을 고안하였다. 시뮬레이션 결과를 통하여 두 단계 스케쥴링 알고리즘이 소프트 실시간 시스템과 일시적으로 과부하가 걸린 하드 실시간을 처리하는데 적절한 방법임을 확인하였다.법임을 확인하였다. This paper presents an algorithm for scheduling jobs in soft real-time systems. To simplify the scheduling for soft real-time systems, we introduce two-level deadline scheme. Each job in the system has two deadlines, which we call first-level and second-level deadlines, respectively. The first-level deadline is the same as the deadline in traditional real-time systems. The second-level deadline is later than the first-level deadline, and defines the latest point in time when the result is still acceptable. Partial-credit is given for jobs meeting the second-level deadline but missing the first-level deadline, whereas jobs meeting the latter are given full credit. We heuristically compute priorities of jobs in a dynamic way by combining the first-level adn second-level deadlines with the partial-credit. Simulation results indicate that our two-level scheduling algorithm is a viable approach for dealing with both soft real-time systems and temporary overloaded hard real-time systems.