전자제어 스로틀을 이용한 자동차의 통합제어시스템의 구축

정강,심한섭 麗水水産大學校 産業技術硏究所 1996 産業基術硏究所 論文集 Vol.5 No.-

The ECT(Electronic Control throttle) has improved capabilities of several types of control devices and been recognized as a very important technology securing safety and convenience. In this system, servo-motor connected with throttle valve control engine rpm. Applicability of integrated control system and its effects were investigated by discussing the control methods and characteristics of technology related to control system of the ECT. From the experimental results, the control system of the ECT using stepping motor has been found to have an excellent ability to control, and to be expected to be an important fundamental technology to construct integrated control system with the technology related to it.

大學 男女 球技選手들의 最大無機的 Power

김태운,유재충,안덕균,선우섭,이한,손두욱,박충서 慶熙大學校 社會體育硏究所 1994 體育科學論叢 Vol.- No.7

The purpose of the present research is to compare characteristics of maximal anaerobic power observed in different types of sports and player's sex differences. We have reached the following conclusions from the results we obtained by measuring maximal anaerobic power and blood lactate concentration of 60 elite university male and female players during the exercise of bicycle ergometer: 1. As to absolute and relative values of maximal anaerobic power, male players are higher in the order of rugby and handball, whereas female players are higher in the order of hockey and soccer, but no significant differences are observed between types of sports. 2. Male players are noticably higher in absolute values of maximal anaerobic power(p<0.001), but relative value is very simi1ar to that of female players. 3. It is estimated that the fact, that female players show obvious higher mean anaerobic power(p<0.001) during the 3,4KP excercise is due to sex differences in ocdurrence work load of maximal anaerobic power. 4. Comparison of blood lactate concentration at each work load in different types of sports and player's sex differences show an increase in proportion to mean anaerobic power. The results given above clearly show the differences between the type of sports such as rugby and hockey requiring power and speed, and the type of sports such as handball and soccer requiring edurance.

균열크기 측정기법 개발에 관한 연구

남민우,조찬희,정한섭,김홍덕,신기석 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

본 연구는 증기발생기 건전성 향상기술 개발 과제 일환으로 진행중인 고리 1호기 구 증기발생기 인출 전열관을 대상으로 하는 Round Robin Test의 사전 시험을 위해 수행하였다. 균열결함에 대한 검출 및 크기측정의 기준을 설정하기 위해 SGMP Mock-Up를 제작하였고 신호수집한 Data를 증기발생기 전열관 가동중검사 업무를 수행하고 있는 와전류신호평가자들 4개조가신호평가에 참여하였으며, 그 결과를 요약 정리하였다. 본 연구에서 SGMP Mock-Up Data Crack Sizing의 목적은 고리 1호기 구 증기발생기 전열관을 대상으로 시행될 Round Robin Test 전에 결함 기구별 균열결함의 특성 이해 및 균열결함이 여러 유형의 외부 환경에서 나타나고 있을 때의 균열결함에 대한 정량적인 크기 측정값의 바람직한 모델 적용을 확인하기 위함이다. SGMP Mock-Up에 적용한 와전류검사는 Robbin 및 MRPC 검사를 포함하였다. 본 연구의 주 목적인 MRPC 데이터를 이용한 균열깊이 평가에 2개조는 위상각-깊이 분석법을 적용하여 신호평가를 수행하였고, 2개조는 위상각-깊이 분석법 이외에 진폭-깊이 평가 기법을 적용하여 SGMP Mock-Up에 대한 최적의 기법을 설정하였다.

Horizontal-to-Vertical Transition of 2D Layer Orientation in Low-Temperature Chemical Vapor Deposition-Grown PtSe₂ and Its Influences on Electrical Properties and Device Applications

Han, Sang Sub,Kim, Jong Hun,Noh, Chanwoo,Kim, Jung Han,Ji, Eunji,Kwon, Junyoung,Yu, Seung Min,Ko, Tae-Jun,Okogbue, Emmanuel,Oh, Kyu Hwan,Chung, Hee-Suk,Jung, YounJoon,Lee, Gwan-Hyoung,Jung, Yeonwoong American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.14

<P>Two-dimensional (2D) transition-metal dichalcogenides (2D TMDs) in the form of MX<SUB>2</SUB> (M: transition metal, X: chalcogen) exhibit intrinsically anisotropic layered crystallinity wherein their material properties are determined by constituting M and X elements. 2D platinum diselenide (2D PtSe<SUB>2</SUB>) is a relatively unexplored class of 2D TMDs with noble-metal Pt as M, offering distinct advantages over conventional 2D TMDs such as higher carrier mobility and lower growth temperatures. Despite the projected promise, much of its fundamental structural and electrical properties and their interrelation have not been clarified, and so its full technological potential remains mostly unexplored. In this work, we investigate the structural evolution of large-area chemical vapor deposition (CVD)-grown 2D PtSe<SUB>2</SUB> layers of tailored morphology and clarify its influence on resulting electrical properties. Specifically, we unveil the coupled transition of structural-electrical properties in 2D PtSe<SUB>2</SUB> layers grown at a low temperature (i.e., 400 °C). The layer orientation of 2D PtSe<SUB>2</SUB> grown by the CVD selenization of seed Pt films exhibits horizontal-to-vertical transition with increasing Pt thickness. While vertically aligned 2D PtSe<SUB>2</SUB> layers present metallic transports, field-effect-transistor gate responses were observed with thin horizontally aligned 2D PtSe<SUB>2</SUB> layers prepared with Pt of small thickness. Density functional theory calculation identifies the electronic structures of 2D PtSe<SUB>2</SUB> layers undergoing the transition of horizontal-to-vertical layer orientation, further confirming the presence of this uniquely coupled structural-electrical transition. The advantage of low-temperature growth was further demonstrated by directly growing 2D PtSe<SUB>2</SUB> layers of controlled orientation on polyimide polymeric substrates and fabricating their Kirigami structures, further strengthening the application potential of this material. Discussions on the growth mechanism behind the horizontal-to-vertical 2D layer transition are also presented.</P> [FIG OMISSION]</BR>

Structural Evolutions of Vertically Aligned Two-Dimensional MoS₂ Layers Revealed by in Situ Heating Transmission Electron Microscopy

Wang, Mengjing,Kim, Jung Han,Han, Sang Sub,Je, Minyeong,Gil, Jaeyoung,Noh, Chanwoo,Ko, Tae-Jun,Lee, Kyu Seung,Son, Dong Ick,Bae, Tae-Sung,Ryu, Hyeon Ih,Oh, Kyu Hwan,Jung, YounJoon,Choi, Heechae,Chung, American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol.123 No.45

<P>Benefiting from a large density of layer edges exposed on the surface, vertically aligned two-dimensional (2D) molybdenum disulfide (MoS<SUB>2</SUB>) layers have recently harvested excellent performances in the field of electrochemical catalysis and chemical sensing. With their increasing versatility for high-temperature, demanding applications, it is vital to identify their thermally driven structural and chemical stability, as well as to clarify its underlying principle. Despite various ex situ and in situ characterizations on horizontally aligned 2D MoS<SUB>2</SUB> layers, the direct in situ heating of vertically aligned 2D MoS<SUB>2</SUB> layers and the real-time observation of their near-atomic-scale dynamics have never been approached, leaving their thermal stability poorly understood. Moreover, the geometrical advantage of the surface-exposed vertically aligned 2D MoS<SUB>2</SUB> layers is anticipated to unveil the structural dynamics of interlayer van der Waals (vdW) gaps and its correlation with thermal energy, unattainable with 2D MoS<SUB>2</SUB> layers in any other geometry. Herein, we report a comprehensive in situ heating TEM study on cleanly transferred, vertically aligned 2D MoS<SUB>2</SUB> layers up to 1000 °C. Several striking phenomena were newly observed in the course of heating: (1) formation and propagation of voids between the domains of vertical 2D MoS<SUB>2</SUB> layers with distinct grain orientations starting at ∼875 °C; (2) subsequent decompositions of the 2D MoS<SUB>2</SUB> layers accompanying a formation of Mo nanoparticles at ∼950 °C, a temperature much lower than the melting temperature of their bulk counterpart; and (3) initiation of decomposition from the surface-exposed 2D layer vertical edge sites, congruently supported by molecular dynamics (MD) simulation. These new findings will offer critical insights into better understanding the thermodynamic principle that governs the structural stability of general vdW 2D crystals as well as providing useful technological guidance for materials design and optimization in their potential high-temperature applications.</P> [FIG OMISSION]</BR>

Zr-V-Mn-Ni계 라브스상 합금의 미세 구조와 전기 화학적 특성

정치규(Chi Gyu Jeong),한동수(Dong Soo Han),정원섭(Won Sub Chung),김인곤(In Gon Kim),김원백(Won Baek Kim) 한국수소및신에너지학회 1997 한국수소 및 신에너지학회논문집 Vol.8 No.3

ZrV_0.1Mn_0.7Ni_1.2 alloy ingot (bulk alloy) made by the arc melting was found to be consisting of mostly of ZrV_0.2Mn_0.98Ni_1.04 matrix alloy and ZrV_0.01Mn_0.13Ni_1.2 2nd phase alloy. The former alloy had the form of the C15 type Laves alloy structure and the latter one had the intermetallic compound structure of Zr₉sNi₁₁. In order to investigate the effect of these two phases on the electrochemical charge-discharge characteristics of bulk ZrV_0.1Mn_0.7Ni_1.2 alloy, the matrix and the 2nd phase alloys were fabricated separately by arc melting method and their electrochemical characteristics were studied and compared with the bulk alloy. It was found that the discharge capacity was the lowest of 160 mAh/g in the 2nd phase alloy. The matrix alloy exhibited 200 mAh/g. Both were lower than that of the bulk alloy of 250 mAh/g. The matrix and the bulk alloys showed a similar properties in the activation stage, the high rate dischargeability and the self discharge characteristics. Also a signigicant capacity decrease was observed after activation in both alloys. Whereas the 2nd phase alloy showed the very different characteristics. This alloy was found to be difficult to activate. However the capacity was remained constant after the activation. Also the self discharge rate was seen to be better than those of the matrix and the bulk alloys.

Ferroelectric Tunnel Junction for Dense Cross-Point Arrays

Lee, Hong-Sub,Han, Wooje,Chung, Hee-Yoon,Rozenberg, Marcelo,Kim, Kangsik,Lee, Zonghoon,Yeom, Geun Young,Park, Hyung-Ho American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.40

<P>Cross-point array (CPA) structure memories using a memristor are attracting a great deal of attention due to their high density integration with a 4<I>F</I><SUP>2</SUP> cell. However, a common significant drawback of the CPA configuration is crosstalk between cells. To date, the CPA structure using a redox-based memristor has restrictions to minimize the operating current level due to their resistive switching mechanism. This study demonstrates suitable characteristics of a ferroelectric tunnel junction (FTJ) for the memristor of the CPA structure using an electrostatic model. From the FTJ of the Au/<I>p</I>-type Pr<SUB>0.98</SUB>Ca<SUB>0.02</SUB>MnO<SUB>3</SUB> (4 nm)/ BaTiO<SUB>3</SUB> (4.3 nm)/<I>n</I>-type Ca<SUB>0.98</SUB>Pr<SUB>0.02</SUB>MnO<SUB>3</SUB> (3 nm)/ Pt(111) structure, which has a higher and thicker potential barrier, a good memristive effect for the CPA structure with a high nonlinear current–voltage curve and low current operation, was obtained by Δ Fowler–Nordheim tunneling with effectively blocked direct tunneling and thermionic emission. The FTJ demonstrated reduced sneak current and the possible for high nonlinearity.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-40/acsami.5b06117/production/images/medium/am-2015-06117d_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b06117'>ACS Electronic Supporting Info</A></P>

Multifunctional Two-Dimensional PtSe₂-Layer Kirigami Conductors with 2000% Stretchability and Metallic-to-Semiconducting Tunability

Okogbue, Emmanuel,Han, Sang Sub,Ko, Tae-Jun,Chung, Hee-Suk,Ma, Jinwoo,Shawkat, Mashiyat Sumaiya,Kim, Jung Han,Kim, Jong Hun,Ji, Eunji,Oh, Kyu Hwan,Zhai, Lei,Lee, Gwan-Hyoung,Jung, Yeonwoong American Chemical Society 2019 NANO LETTERS Vol.19 No.11

<P>Two-dimensional transition-metal dichalcogenide (2D TMD) layers are highly attractive for emerging stretchable and foldable electronics owing to their extremely small thickness coupled with extraordinary electrical and optical properties. Although intrinsically large strain limits are projected in them (i.e., several times greater than silicon), integrating 2D TMDs in their pristine forms does not realize superior mechanical tolerance greatly demanded in high-end stretchable and foldable devices of unconventional form factors. In this article, we report a versatile and rational strategy to convert 2D TMDs of limited mechanical tolerance to tailored 3D structures with extremely large mechanical stretchability accompanying well-preserved electrical integrity and modulated transport properties. We employed a concept of strain engineering inspired by an ancient paper-cutting art, known as kirigami patterning, and developed 2D TMD-based kirigami electrical conductors. Specifically, we directly integrated 2D platinum diselenide (2D PtSe<SUB>2</SUB>) layers of controlled carrier transport characteristics on mechanically flexible polyimide (PI) substrates by taking advantage of their low synthesis temperature. The metallic 2D PtSe<SUB>2</SUB>/PI kirigami patterns of optimized dimensions exhibit an extremely large stretchability of ∼2000% without compromising their intrinsic electrical conductance. They also present strain-tunable and reversible photoresponsiveness when interfaced with semiconducting carbon nanotubes (CNTs), benefiting from the formation of 2D PtSe<SUB>2</SUB>/CNT Schottky junctions. Moreover, kirigami field-effect transistors (FETs) employing semiconducting 2D PtSe<SUB>2</SUB> layers exhibit tunable gate responses coupled with mechanical stretching upon electrolyte gating. The exclusive role of the kirigami pattern parameters in the resulting mechanoelectrical responses was also verified by a finite-element modeling (FEM) simulation. These multifunctional 2D materials in unconventional yet tailored 3D forms are believed to offer vast opportunities for emerging electronics and optoelectronics.</P> [FIG OMISSION]</BR>

Energy-Band-Engineered Unified-RAM (URAM) Cell on Buried <tex> $\hbox{Si}_{1 - y}\hbox{C}_{y}$</tex> Substrate for Multifunctioning Flash Memory and 1T-DRAM

Jin-Woo Han,Seong-Wan Ryu,Chung-Jin Kim,Sung-Jin Choi,Sungho Kim,Jae-Hyuk Ahn,Dong-Hyun Kim,Kyu Jin Choi,Byung Jin Cho,Jin-Soo Kim,Kwang Hee Kim,Gi-Sung Lee,Jae-Sub Oh,Myeong-Ho Song,Yun Chang Park,Je IEEE 2009 IEEE transactions on electron devices Vol.56 No.4

<P>A band-offset-based unified-RAM (URAM) cell fabricated on a Si/Si<SUB>1-y</SUB>C<SUB>y</SUB> substrate is presented for the fusion of a nonvolatile memory (NVM) and a capacitorless 1T-DRAM. An oxide/nitride/oxide (O/N/O) gate dielectric and a floating-body are combined in a FinFET structure to perform URAM operation in a single transistor. The O/N/O layer is utilized as a charge trap layer for NVM, and the floating-body is used as an excess hole storage node for capacitorless 1T-DRAM. The introduction of a pseudomorphic SiC-based heteroepitaxial layer into the Si substrate provides band offset in a valence band. The FinFET fabricated on the energy-band-engineered Si<SUB>1-y</SUB>C<SUB>y</SUB> substrate allows hole accumulation in the channel for 1T-DRAM. The band-engineered URAM yields a cost-effective process that is compatible with a conventional body-tied FinFET SONOS. The fabricated URAM shows highly reliable NVM and high-speed 1T-DRAM operations in a single memory cell.</P>

A REVIEW OF CANDU FEEDER WALL THINNING

Chung, Han-Sub Korean Nuclear Society 2010 Nuclear Engineering and Technology Vol.42 No.5

Flow Accelerated Corrosion is an active degradation mechanism of CANDU feeder. The tight bend downstream to Gray loc weld connection, close to reactor face, suffers significant wall thinning by FAC. Extensive in-service inspection of feeder wall thinning is very difficult because of the intense radiation field, complex geometry, and space restrictions. Development of a knowledge-based inspection program is important in order to guarantee that adequate wall thickness is maintained throughout the whole life of feeder. Research results and plant experiences are reviewed, and the plant inspection databases from Wolsong Units One to Four are analyzed in order to support developing such a knowledge-based inspection program. The initial thickness before wall thinning is highly non-uniform because of bending during manufacturing stage, and the thinning rate is non-uniform because of the mass transfer coefficient distributed non-uniformly depending on local hydraulics. It is obvious that the knowledge-based feeder inspection program should focus on both fastest thinning locations and thinnest locations. The feeder wall thinning rate is found to be correlated proportionately with QV of each channel. A statistical model is proposed to assess the remaining life of each feeder using the QV correlation and the measured thicknesses. W-1 feeder suffered significant thinning so that the shortest remaining life barely exceeded one year at the end of operation before replacement. W-2 feeder showed far slower thinning than W-1 feeder despite the faster coolant flow. It is believed that slower thinning in W-2 is because of higher chromium content in the carbon steel feeder material. The average Cr content of W-2 feeder is 0.051%, while that value is 0.02% for W-1 feeder. It is to be noted that FAC is reduced substantially even though the Cr content of W-2 feeder is still very low.