기반 기술 : 소형 광대역 L-형 슬롯 안테나

장민규 ( Min Gyu Jang ),이영순 ( Young Soon Lee ),장민규 ( Min Gyu Jang ),이영순 ( Young Soon Lee ) 한국항행학회 2014 韓國航行學會論文誌 Vol.18 No.4

본 논문에서는 광대역 특성을 가지는 기울어진 L-형 모노폴 슬롯안테나를 새롭게 제안하였다. 안테나의 소형화 및 광대역화를 위해 접지면의 모서리에 위치하여 슬롯의 양 끝단이 개방되는 L-형 슬롯을 사용하였다. 그리고 낮은 주파수 대역에서 대역폭 증가를 위해 L-형 슬롯의 하단 구조를 기울어진 형태로 하였고, 반면에 높은 주파수 대역에서의 대역폭 증가를 위해 L-형 슬롯의 상단 구조를 테이퍼 형태로 하였다. 급전 구조는 일반적으로 개방 종단보다 대역폭 증가에 유리한 것으로 알려진 단락 종단된 마이크로스트립 급전선을 사용하였다. 제안된 안테나의 제작 및 측정 결과, 임피던스 대역폭(-10 dB)이 4.72 GHz (2.28~7 GHz)인 광대역 특성을 얻을 수 있었으며, 안테나 이득의 경우 전 대역에서 약 3dBi 이상의 높은 이득을 얻을 수 있었다. In the present study, oblique L-shaped monopole slot antenna with broadband characteristic is newly proposed. For bandwidth enhancement as well as size reduction, L-shaped slot with two open-terminations on the ground edge is used. The lower part of L-shaped slot comprises oblique form for bandwidth enhancement in low frequency band, whereas its higher part comprise tapered form for its enhancement in high frequency band. The short-circuit terminated microstrip line which is generally known to be more useful for bandwidth enhancement than open-circuit termination is used. The measured impedance bandwidth(-10 dB) and gain of the fabricated antenna have been observed to be 4.72 GHz (2.28~7 GHz) and more than 3dBi over the passband respectively.

Smart GPS 모듈용 슬롯과 결합된 패치안테나 설계

장민규 ( Min Gyu Jang ),이영순 ( Young Soon Lee ),조동균 ( Dong Kyun Cho ) 한국항행학회 2013 韓國航行學會論文誌 Vol.17 No.2

본 논문에서는 L1주파수대역(1.575GHz)을 사용하는 보안등제어기 내장형 무선 모듈에 적용 가능한 PCB(Printed Circuit Board) 인쇄형 GPS안테나를 제안하였다. 제안된 안테나는 삽입형 급전(insertion feeding)을 가지는 마이크로스트립 패치안테나를 기본구조로 하였다. 특히 임피던스 매칭을 위해 윗면에 좌/우 2개의 비대 칭형 슬롯을 삽입하였으며, 아랫면에는 대역폭 증가와 주파수설정을 위하여 한 쪽 끝이 개방된 슬롯과 단락점(shorting point)을 적용하였다. 측정 결과 설계 목표로 한 GPS주파수 L1대역에서 90%의 방사효율과 4.8dBi 이상의 이득을 얻을 수 있었다. In this paper, printed antenna which can be applied to a built-in wireless module of the security controller operating at global positioning system(GPS) L1 frequency band(1.575GHz) is proposed. The proposed antenna is basically composed of a microstrip patch antenna with inserting feed. In particular left and right slots which are respectively asymmetric are used for impedance matching, whereas slot with one open-end and shorting point are used on the bottom plane to set operating frequency and enhance bandwidth. It is observed at the desired GPS L1 frequency band that the radiation efficiency and gain of the proposed antenna are 90% and more than 4.8dBi respectively.

MR 유체를 이용한 햅틱 디스플레이의 질감 반응 특성

장민규(Min-Gyu Jang),최재영(Jea-Young Choi),이철희(Chul-Hee Lee) 한국트라이볼로지학회 2010 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.26 No.3

In this paper, tactile response characteristics in medical haptic interface are investigated to characterize the feeling of contact between the finger skin and the organic tissue when a finger is dragged over tissue. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR) fluid has been developed. Tactile display devices simulate the finger's skin to feel the sensations of contact such as compliance, curvature and friction. Thus, the tactile display provides the surface information of organic tissue to the surgeon using different actuating mechanisms ranging from the conventional mechanical motor to the smart material actuators. In order to investigate the compliance feeling of human finger's touch, vertical force responses of the tactile display under the various magnetic fields have been assessed. Also, frictional resistive force responses of the tactile display are investigated to simulate the action of finger's dragging. From the results, different tactile feelings are observed as the applied magnetic field is varied and arrayed magnetic poles combinations. This research gives a smart technology of tactile displaying.

MR 유체를 이용한 햅틱 디스플레이의 질감 특성

장민규(Min-Gyu Jang),김찬기(Chan-Ki Kim),최재영(Jae-Young Choi),이철희(Chul-Hee Lee) 한국트라이볼로지학회 2009 한국트라이볼로지학회 학술대회 Vol.2009 No.11

In this research, tactile characteristics in medical haptic interface are investigated to characterize the feeling of contact between the finger skin and the organic tissue when a finger is dragged over tissue. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR) fluid has been developed. Tactile display devices simulate the finger's skin to feel the sensations of contact such as compliance, curvature and friction. Thus, the tactile display provides the surface information of organic tissue to the surgeon using different actuating mechanisms ranging from the conventional mechanical motor to the smart material actuators. In order to investigate the compliance feeling of human finger's touch, vertical force responses of the tactile display under the various magnetic fields have been assessed. Also, frictional resistive force responses of the tactile display are investigated to simulate the action of finger's dragging. From the results, different tactile feelings are observed as the applied magnetic field is varied and arrayed magnetic poles combinations. This research gives a smart technology of tactile displaying.

인산화 전분 ER 유체의 댐퍼 내구 특성

장민규(Min-Gyu Jang),이철희(Chul-Hee Lee),손정우(Jung Woo Sohn),한영민(Young-Min Han),최승복(Seung-Bok Choi) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.11

In this work, durability characteristics of electrorheological (ER) fluid for damper application are experimentally investigated. ER fluid is prepared by using phosphorated starch particles and silicone oil. The field-dependent Bingham characteristics and response time for the proposed ER fluids are experimentally obtained. Experimental apparatus of durability test for ER fluid is established with cylindrical ER cylinder for mid-sized passenger vehicle. In order to evaluate the durability characteristics of ER fluid as a function of time, damping force and temperature variations are measured until one million cycles. After durability test, Bingham characteristics and response time of ER fluid are measured and compared to the initial properties. Microscopic pictures of ER fluid are taken to validate the changes of properties. The results indicate that the ER fluid can be commercially utilized in vehicle damper system with its durability performance. Moreover, the understanding of durability characteristics is essential to predict the service life ofER fluid as well as to design its applications.

지그비 송신 단말기용 CPW급전 슬롯 안테나

장민규(Jang Min Gyu),이영순(Lee Young Soon) 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.6

인산화 전분 ER 유체의 트라이볼로지 특성

장민규(Min-Gyu Jang),이철희(Chul-Hee Lee),최재영(Jea-Young Choi),손정우(Jung Woo Sohn),최승복(Seung-Bok Choi) 한국트라이볼로지학회 2010 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.26 No.1

This experimental study presents tribological characteristics under boundary lubrication contacts associated with electrorheolocal (ER) fluid. ER fluid is prepared by using phosphorated starch particles and silicone oil. Experimental apparatus of tribological tester is designed and constructed to evaluate tribological characteristics of pin specimens. Wear tests under boundary lubrication of ER fluid are experimentally performed under consideration of several operational factors such as normal load, sliding distance, sliding speed and specimen materials: steel, copper and aluminum. After wear test, microscopic surface changes of the worn pin specimens are analyzed in order to investigate measured wear characteristics by using the scanning electron microscope (SEM) as well as surface profilometer. In addition, the chemical wear characteristics are investigated by using energy dispersive x-ray spectroscopy (EDS). Moreover, friction coefficient measurements under different materials of pin specimens are conducted for the tribological investigations. In order to verify the effect of starch phosphate particles in ER fluid, the wear test results with ER fluid are compared with test results with only silicone oil. The results clearly present that the phosphorated starch based ER fluid shows the stabilized wear as well as friction characteristics after run-in operations, but the wear rate under ER fluid is increased.

인산화 전분 ER 유체의 트라이볼로지 특성

장민규(Min-Gyu Jang),최재영(Jae-Young Choi),이철희(Chul-Hee Lee),손정우(Jung-Woo Sohn),최승복(Seung-Bok Choi) 한국트라이볼로지학회 2009 한국트라이볼로지학회 학술대회 Vol.2009 No.6

This experimental study presents tribological characteristics under boundary lubrication contacts associated with electrorheolocal(ER) fluid. ER fluid is prepared by using phosphorated starch particles and silicone oil. Experimental apparatus of tribological tester is designed and constructed to evaluate tribological characteristics of pin specimens. Wear tests under boundary lubrication of ER fluid are experimentally performed under consideration of several operational factors such as normal load, sliding distance, sliding speed and specimen materials: steel, copper and aluminum. After wear test, microscopic surface changes of the worn pin specimens are analyzed in order to investigate measured wear characteristics by using the scanning electron microscope (SEM) as well as surface profilometer. Moreover, friction coefficient measurements under different materials of pin specimens are conducted for the tribological investigations. In order to verify the effect of starch phosphate particles in ER fluid, the wear test results with ER fluid are compared with test results with only silicone oil. The results clearly present that the phosphorated starch based ER fluid shows the stabilized wear as well as friction characteristics after run-in operations, but the wear rate under ER fluid is increased.

자동차용 등속 조인트의 내부 마찰 모델 개발

장민규(Min-Gyu Jang),이철희(Chul-Hee Lee) 한국트라이볼로지학회 2008 한국트라이볼로지학회 학술대회 Vol.2008 No.6

An internal friction model was developed to model the frictional behavior of automotive Constant Velocity (CV) joints by using the test data from an instrumented CV joint friction apparatus with actual driveshaft assemblies. Experiments were conduced under different realistic operating conditions of oscillatory speeds, CV joint articulation angles, lubrication, and torque. The experimental data were used to develop a physics-based semi-empirical CV joint internal friction coefficient model as a function of different CV Joint operating parameters. It was found that the proposed friction model captures the experimental results well not only the static behavior of friction coefficient, but also the dynamic friction terms, which is the main source of force that causes vehicle vibration problems.

자본시장법 제162조 제1항 및 제170조 제1항의 손해배상의 범위 및 손해액 추정의 복멸

장민규(Min-Gyu Jang) 경희법학연구소 2023 KHU 글로벌 기업법무 리뷰 Vol.16 No.1

대상판결(대법원 2022.9.7. 선고 2022다228056 판결)은 거짓기재로 인한 손해배상의 요건에 대해서 다루고 있으며, 특히 자본시장법 제162조 제1항 및 제170조 제1항의 손해배상의 범위와 손해액 추정의 복멸에 대해 종래와는 다른 새로운 기준을 제시하였다. 구체적으로 대법원은 손해배상의 요건으로 중요사항의 거짓기재, 손해 인과관계과 거래 인과관계를 제시하였으며, 손해액 추정의 복멸을 위한 정상주가의 증명과 관련하여 ’정상공시직후 형성된 주가를 정상주가로 보려면 허위공시로 부양된 부분이 남아있는지가 부분명한 정도에 그쳐서는 아니 되고 반드시 피고 회사 측에서 부실공시의 주가에 대한 영향이 제거되었음을 분명하게 증명해야 한다‘는 구체적인 기준을 제시하였다. 생각건대, 대상판결의 보고서는 특정 자료에 인용된 자료가 거짓기재된 것에 불과하고, 그 내용 또한 과거의 대손충당금과 관련된 것으로 한정되어있으므로 ‘중요사항의 거짓기재’에 해당한다고 볼 수 없다. 이에 설령 중요사항의 거짓기재에 해당한다고 하더라도 거래 인과관계 및 손해 인과관계가 인정된다고 할 수 없다. 이에 1심의 판단은 타당하지 않으며 이에 대한 원심과 대법원의 판단이 타당하다. 정상주가의 시점을 정하는데 있어서는 원칙적으로 배상책임자가 어느 시점에 대해 손해액의 추정을 복멸시킬 수 있을 정도로 증명하는지 여부에 따라 달라지겠지만, 배상책임자의 증명이 없는 경우에는 그 손해배상액의 추정을 계속해서 이어가는 것이 타당하다고 할 것이다. 사안의 경우에는 1심법원이 판단했던 것처럼 분식회계 사실이 공표된 직후로 봄이 타당하다. The target judgment (Supreme Court Decision 2022Da228056 Decision) deals with the requirements for compensation for damages due to false statements, and in particular, it proposed new standards different from the previous ones for the scope and destruction of damages under Articles 162 (1) and 170 (1) of the Capital Markets Act. Specifically, the Supreme Court presented false statements of important matters, cause-and-effect relationships, and the proof of normal stock prices to destroy the estimation of damages, 'To see the stock price formed immediately after the normal disclosure, it must be clearly proved that the impact on the stock price of the poor disclosure remains.' presented specific criteria. Presumably, the report of the target judgment is only a false entry of the data cited in the specific data, and its contents are also limited to those related to the provisions for bad debts in the past, so it cannot be considered as a “false entry of important matters.” Therefore, even if it falls under a false entry of important matters, it cannot be said that the transaction causal relationship and the damage causal relationship are recognized. Therefore, the judgment of the first trial is not valid, and the judgments of the lower court and the Supreme Court are valid. In principle, determining the timing of the normal stock price depends on when the compensation manager proves enough to destroy the estimation of the amount of damage, but if there is no proof from the compensation manager, it is reasonable to continue estimating the amount of damage. In the case of the case, it is reasonable to regard it as immediately after the fact of accounting fraud was announced, as judged by the first trial court.