초임계 Tetrahydrofuran 을 이용한 Polystyene 의 분획

김형진,박경애,정일현,홍인권 ( Hyung Jin Kim,Kyung Ai Park,Il Hyun Jung,In Kwon Hong ) 한국공업화학회 1995 공업화학 Vol.6 No.1

기능성 고분자 제조에는 여러 가지 방법이 있으나 본 연구에서는 다분산 고분자 물질을 단분산화시키는 `용매 추출 분획` 방법에 이론적 배경을 두고 연구하였다. 온도와 압력 조절이 가능한 고압반응기에 0.5w/v%로 용해된 polystyrene용액을 충진하고 THF의 임계온도(T_C=540.2K)와 임계압력(P_c=752.64psi) 이상에서 같은 농도의 용액을 정량펌프를 이용해 20㎖/min으로 공급하여 반응기의 압력을 일정한 간격으로 증가시키면서 연속적으로 시료를 추출하고 추출된 시료를 GPC로 분석하였다. 분석한 결과를 토대로 Schulz 분포 함수를 이용해 분자량별로 연속 분포함수를 표현하였다. 또한 UV-vis. spectrophotometer를 이용하여 각 압력에서 추출된 시료의 농도를 측정하여 분자량에 대한 누적 무게 분율을 도시하였다. 본 연구의 결과에 의하면 polystyrene의 녹는점(533.15K) 이상에서 분획이 잘됨을 알 수 있었고, 녹는점 이상인 548.15K에서 압력이 증가함에 따라 추출된 고분자의 분자량은 증가하고 분산도는 감소함을 알 수 있었다. 그러나 polystyrene의 녹는점 이하인 518.15K에서는 압력 증감에 따른 추출된 고분자의 분자량과 분산도와의 관계는 그 의존성이 작게 나타남을 알 수 있었다. There are many methods for manufacturing of functional polymer, but solvent elution fractionation is the theoretical background which can obtain the monodisperse polymer from the polydisperse polymer in this study. The high pressure reactor which can tune temperature and pressure was filled with 0.5w/v% polystyrene solution, and the same concentration solution was feed to reactor at the rate of 20㎖/min using a metering pump above critical pressure of tetrahydrofuran. The extracted samples of each pressure were collected continuously and analyzed by GPC. Continuous distribution function was predicted as a function of molecular weight using a Schulz` distribution function on the basis of acquired data. Also, cumulative weight fraction was predicted as a function of molecular weight on the basis of concentration data of sample which was obtained by UV-vis. spectrophotometer. It was predicted that the fractionation efficiency was improved, and molecular weight of extract was increased and polydispersity was decreased with increasing pressure above the melting temperature of polystyrene. But molecular weight of extract, and polydispersity had small dependency on pressure below the melting temperature of polystyrene.

광물성 섬유의 새로운 용융 방사법

김형진,양희원,전경진,허유,Kim, Hyung-Jin,Yang, Hee-Won,Jeon, Kyung-Jin,Huh, You 한국섬유공학회 2009 한국섬유공학회지 Vol.46 No.3

Nowadays many kinds of inorganic fibers are used in various industry fields. However, their superior mechanical and thermal properties are utilized in a limited way due to the environmental regulations that become tighter and stronger with time. This motivates to develop new environment-friendly inorganic material especially for the field, where the high performance material under a wide range of operation circumstances is required. This research reports on the a super-high temperature melt spinning method applicable for manufacturing mineral fibers. The spinning system is composed of a furnace, a crucible along with a refractory system, and a take-up device. Results show that the new crucible spinning system can be used for spinning mineral fibers effectively. The basalt rocks as a test raw material could be molten and transformed into fibers through the direct spin-drawing procedure. The form and size of the raw material affected the spinnability. The device playing the role as the forehearth bushing is very important to assure a !continuous process. The fiber diameter and the drawing speed could be described by a reciprocal relationship.

고층 아파트 단지의 동선 유형 및 적용 패턴에 관한 연구 - '90년대 이후 공영 아파트 설계 경기 당선안을 중심으로 -

김형진,김영석,박찬규,Kim, Hyung-Jin,Kim, Young-Suk,Park, Chan-Kyu 한국주거학회 2008 한국주거학회 논문집 Vol.19 No.6

The street system in multi-family housing is an important design element to control the circulation of vehicles and pedestrians, and to form the spatial organization of the projects. In particular, in the case of high-rise apartments, the street patterns have an influence on the safety, amenity, and convenience of facilities. Until now, however, the design of street patterns in most high-rise multi-family housing projects has diminished the quality of residential environments because priority of design consideration has primarily been given to planning road ways and parking areas. Nevertheless, the design competitions introduced for the first time in the 1980s have played a significant role in developing fresh ideas and concepts in housing design. Because street patterns have been respectably modified as a result of the generalizing of design competitions, it is important to review the ideas that have been proposed in competitions over the recent past. In this context, this study classified the types of street patterns and analyzed their design characteristics for the proposals of housing design competitions since the 1990s. As a result of this analysis, the road patterns are classified into 4 types: 1) serial type, 2) isolated type, 3) mixed type, and 4) not a road pattern due to the system of connection. In addition, these were further divided into 8 types: 1) loop, 2) ring, 3) penetration, 4) tree, 5) direct entry, 6) ring and penetration, 7) loop and penetration, 8) not a road pattern due to appearance and the collector.

합성곱 네트워크 기반의 Conv1D 알고리즘에서 시간 종속성을 반영한 선박 연료계통 장비의 고장 진단 모델

김형진,김광식,황세윤,이장현,Kim, Hyung-Jin,Kim, Kwang-Sik,Hwang, Se-Yun,Lee, Jang Hyun 한국항해항만학회 2022 한국항해항만학회지 Vol.46 No.4

본 연구는 자율운항 선박의 연료 계통 펌프와 청정기를 대상으로 고장을 진단 사례를 제시하였다. 계측된 신호의 시간종속성을 반영한 심층학습(Deep learning) 알고리즘 적용 절차를 구성하고, 장비의 정상 운전상태와 고장 상태에서 계측한 진동 신호를 고장 패턴 학습에 사용하였다. 특히, 진동 신호에 내포된 열화의 시간 종속성을 반영할 수 있는 방법을 찾고자 하였으며, 슬라이딩 윈도우 연산 과정을 가진 Conv1D를 이용하여고장의 시간 종속성을 반영하였다. 또한 계측된 신호의 차수를 2차원에서 3차원으로 확장하여 시간 영역의 특징을 반영할 수 있는 데이터 전처리과정을 고안하였다. Conv1D 알고리즘의 적층과 변수를 결정하는 과정에서 그리드 탐색 기법을 사용하여 초매개변수의 최적 값을 결정하였다. 마지막으로 제안한 데이터 전처리 방법과 시계열 데이터의 시간 종속성을 반영한 Conv1D 모델이 이상 감지 및 고장 진단에 타당성이 있음을 확인하였다. The purpose of this study was to propose a deep learning algorithm that applies to the fault diagnosis of fuel pumps and purifiers of autonomous ships. A deep learning algorithm reflecting the time dependence of the measured signal was configured, and the failure pattern was trained using the vibration signal, measured in the equipment's regular operation and failure state. Considering the sequential time-dependence of deterioration implied in the vibration signal, this study adopts Conv1D with sliding window computation for fault detection. The time dependence was also reflected, by transferring the measured signal from two-dimensional to three-dimensional. Additionally, the optimal values of the hyper-parameters of the Conv1D model were determined, using the grid search technique. Finally, the results show that the proposed data preprocessing method as well as the Conv1D model, can reflect the sequential dependency between the fault and its effect on the measured signal, and appropriately perform anomaly as well as failure detection, of the equipment chosen for application.

CFRP 복합재료의 Mode Ⅰ 층간 파괴 인성치에 관한 연구

김형진,엄윤성,고성위 ( Hyung Jin Kim,Yoon Sung Um,Sung Wi Koh ) 한국복합재료학회 1994 Composites research Vol.7 No.4

필라멘트 링 코어사의 표면 피복 품질 평가

김형진,김종성,허유,Kim, Hyung-Jin,Kim, Jong-Seong,Huh, You 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.2

To evaluate the surface quality of ring core spun yarns, we set up a quality measurement system that operated on the basis of a CCD camera along with specific software programs that recognised the surfaced core filaments. The acquired images were transformed to binary states and filtered through a moving window. By defining a quantitative index by means of the number of defects per length of the specimen, the effects of the processing variables such as production speed and traveller mass on the surface quality of core spun yarns were investigated. Results demonstrated that the new measuring system could be applied effectively to assess the core coverage of yarns. There existed some optimal levels of yarn production speed and traveller mass that led to a minimum occurrence of the surface defects of core spun yarns.

초음파 에너지를 이용한 Polystyrene Latex 의 중합 특성

김형진,김원일,이승범,홍인권 ( Hyung Jin Kim,Won Il Kim,Seung Bum Lee,In Kwon Hong ) 한국공업화학회 1997 공업화학 Vol.8 No.6

Polystyrene latex를 제조하는 여러방법중에서 상업적으로는 유화중합기술이 가장 많이 사용되고 있다. 유화중합에서 사용되는 화학 개시제가 환경오염 유발의 원인이 될 수 있을 뿐만 아니라 고분자 중합 방법도 전통적 기술을 벗어나는 다양한 공정의 개발이 필요하다. 따라서 본 연구에서는 화학 개시제를 초음파 에너지 효과로 대체하여 초음파 조사시에 나타나는 공동현상에 의한 자유 라디칼(free radical)을 생성시켜 polystyrene latex를 제조하였다. 제조된 polystyrene latex를 GPC로 분석한 결과 초음파 조사시간이 증가할수록 평균분자량은 증가하였으며 분산도는 감소하였다. 또한 계면활성제로 사용된 sodium dodeccl sulfate(SDS)의 농도가 증가할수록 중합도는 증가하였으며, SDS의 농도가 전체의 2wt.%이고 반응온도가 40℃ 일때 중합도는 2.43×10⁴으로 최대값을 나타내었다. 중합이 진행되는 동안 해중합이 동시에 발생 하므로 평균분자량은 증가와 감소를 반복하는 경향을 나타내었으며, 초음파 조사시간과 계면활성제의 농도를 조절하므로써 분자량이 조절된 좁은 분자량 분포의 polystyrene latex를 제조할 수 있었다. There are many methods to synthesize polystyrene latex. Emulsion polymerization technique is commonly used commercially, but it requires a new technology to replace a traditional polymerization method because of the disadvantage of chemical initiator for environmental pollution. Since free radicals can be produced by ultrasound energy effect, polystyrene latex was synthesized using ultrasound energy instead of chemical initiator. As the ultrasonic irradiation time was increased, average molecular weight was increased and polydispersity was decreased. The degree of polymerization was increased with the concentration of SDS and maximum degree of polymerization was shown at 2 wt.% SDS concentration and the reaction temperature of 40℃. During the course of polymerization, molecular weight was repeatedly fluctuated because of occurrence of depolymerization. Narrow molecular weight distribution polystyrene latex having controlled molecular weight was synthesized by controlling ultrasonic irradiation time and the concentration of SDS.

CFRP 복합재료의 모드 Ⅱ 층간 파괴인성치에 관한 연구

김형진,엄윤성,김엄기,고성위 ( Hyung Jin Kim,Yoon Sung Um,Um Kee Kim,Sung Wi Koh ) 한국복합재료학회 1995 Composites research Vol.8 No.4

금속 산화물 촉매를 이용한 메탄의 Oxidative Coupling 반응

김형진,편무실,박홍수,함현식 ( Hyung Jin Kim,Moo Sil Pyun,Hong Soo Park,Hyun Sik Hahm ) 한국공업화학회 1993 공업화학 Vol.4 No.4

메탄의 직접 전환 기술 중 하나인 OCM(oxidative coupling of methane) 반응을 수행하였다. 사용한 금속 산화물 촉매는 Li/MgO와 Pb/MgO이었다. 온도에 따른 촉매의 반응성을 알아보기 위해 600, 700, 800℃에서 반응을 행하였으며, 반응물 혼합비(메탄:산소)에 따른 반응성, 전환율 및 선택도를 알아보기 위해 700℃에서 혼합비를 2:1 및 1:1로 하여 실험을 하였다. 그 결과 7wt% Li/MgO촉매의 경우 반응온도 700℃이고 혼합비가 2:1일 때 메탄의 전환율과 C_2화합물의 선택도가 각각 20%, 65% 정도로서 우수한 반응성을 보임을 알 수 있었다. 7wt% Li/MgO 촉매의 경우 700℃에서 혼합비가 1:1일 때 메탄의 전환율은 30%로 증가했으나 C_2화합물의 선택도는 45%로 감소하였다. Pb/MgO 촉매는 Li/MgO보다 낮은 선택도를(25%) 나타내었다. Oxidative coupling of methane(OCM), one of the methods of direct methane conversion, was performed. Metal oxide catalysts used were Li/MgO and Pb/MgO. To investigate the reactivity of the catalysts with temperature, the reaction was carried out at 600, 700 and 800℃; and to investigate the effect of the feed ratio of the reactants(CH_4:0_2) on reactivity, conversion, and selectivity the reaction was performed at 700℃ with the feed ratio of 2:1 and 1:1. The results indicate that 7wt% Li/MgO catalyst is a good catalyst for OCM reaction with 20% conversion and 65% selectivity at 700℃ with the feed ratio of 2:1. As feed ratio was 1:1, methane conversion was increased to 30% while C_2 selectivity decreased to 45% at 700℃ with 7wt% Li/MgO catalyst. The Pb/MgO catalyst showed less selectivity(25%) than Li/MgO did.

골프참여자의 건강신념과 환경관심도 및 운동지속의 관계

김형진,Kim, Hyung-Jin 한국응용과학기술학회 2019 한국응용과학기술학회지 Vol.36 No.2

본 연구는 골프연습장 이용객을 대상으로 골프 참여자의 건강신념과 환경관심도 및 운동지속에는 어떠한 관계가 있는지 규명하는데 목적이 있다. 본 연구의 목적을 달성하기 위하여 SPSS 18.0과 AMOS 18.0을 이용하여 빈도분석, 탐색적 요인분석, 확인적 요인분석, 신뢰도분석과 상관관계분석을 실시하였고 모형을 설정한 뒤 구조방적식모형(SEM)을 통하여 변인간의 인과적 관계를 규명하였다. 이상과 같은 연구방법과 연구모형 검증을 기초로 하여 본 연구에서 도출된 결과는 다음과 같다. 첫째, 골프 참여자들의 건강신념은 환경관심도에 정적인 영향을 미치는 것으로 나타났다. 둘째, 골프 참여자들의 환경관심도는 운동지속에 정적인 영향을 미치는 것으로 나타났다. 셋째, 골프 참여자의 건강신념은 운동지속에 정적인 영향을 미치는 것으로 나타났다. 넷째, 골프 참여자의 건강신념과 운동지속의 관계에서 환경관심도는 매개하는 것으로 나타났다. 골프참여자들이 골프를 통해 신체적, 심리적 건강효과를 증진시키고 나아가 골프 기술습득이나 기량향상 등의 성취감을 만들어 환경관심도가 높아진다면, 보다 나은 삶의 질을 영위할 수 있을 것이다. The purpose of this study was to investigate the relationship among health belief, environmental concern and continue exercise for golf participants. To achieve the goal of this study, a total of 270 questionnaires were distributed and 270 copies were collected back. Out of those returned questionnaires, insincerely replied or double-replied questionnaires were excluded and finally 255 questionnaires were analyzed for this study. For analysis of the data, frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, correlation analysis, and structural equating modeling were conducted using SPSS 18.0 and AMOS 18.0. Main findings were as follows: First health belief had a positive effect on environmental concern. Second, environmental concern had a positive effect on continue exercise. Third, health belief had a positive effect on continue exercise. Fourth, environmental concern mediated the relationship between golf participant health belief and continue exercise. If golf participants improve their physical and psychological health effects through golf and environmental concern increase from gaining a sense of accomplishment such as acquiring or improving golf skills, they will be able to lead a better quality of life.