준안정상 기반의 질화철계 영구자석소재 제조연구동향

김경민,이정구,김경태,백연경,Kim, Kyung Min,Lee, Jung-Goo,Kim, Kyung Tae,Baek, Youn-Kyoung 한국분말야금학회 2019 한국분말재료학회지 (KPMI) Vol.26 No.2

Rare earth magnets are the strongest type of permanent magnets and are integral to the high tech industry, particularly in clean energies, such as electric vehicle motors and wind turbine generators. However, the cost of rare earth materials and the imbalance in supply and demand still remain big problems to solve for permanent magnet related industries. Thus, a magnet with abundant elements and moderate magnetic performance is required to replace rare-earth magnets. Recently, $a^{{\prime}{\prime}}-Fe_{16}N_2$ has attracted considerable attention as a promising candidate for next-generation non-rare-earth permanent magnets due to its gigantic magnetization (3.23 T). Also, metastable $a^{{\prime}{\prime}}-Fe_{16}N_2$ exhibits high tetragonality (c/a = 1.1) by interstitial introduction of N atoms, leading to a high magnetocrystalline anisotropy constant ($K_1=1.0MJ/m^3$). In addition, Fe has a large amount of reserves on the Earth compared to other magnetic materials, leading to low cost of raw materials and manufacturing for industrial production. In this paper, we review the synthetic methods of metastable $a^{{\prime}{\prime}}-Fe_{16}N_2$ with film, powder and bulk form and discuss the approaches to enhance magnetocrystalline anisotropy of $a^{{\prime}{\prime}}-Fe_{16}N_2$. Future research prospects are also offered with patent trends observed thus far.

불안 관련 장애의 신경생물학적 이해

김경민,김민경,이상혁,Kim, Kyung-Min,Kim, Min-Kyoung,Lee, Sang-Hyuk 대한생물정신의학회 2014 생물정신의학 Vol.21 No.4

Anxiety disorders are characterized by dysregulation of neuroendocrine, neurotransmitter and neuroanatomical functions. Substantial advances in research method offered new insights into the neurobiologic mechanisms in anxiety disorders. Advances in molecular biology have enabled illumination of hormone and neurotransmitters that have important roles in anxiety. The neuroanatomic circuits related to anxiety are also being elucidated by improvements in neuroimaging technology such as structural and functional magnetic resonance imaging. This article reviews the research data in relation to the neurobiology underlying fear and pathologic anxiety and discusses their implications for development of biological treatments for anxiety disorders.

초기 성 학대 경험이 있는 여성 공황장애 환자의 임상적 특성

김경민,김민경,이강수,최태규,이상혁,Kim, Kyung Min,Kim, Min-Kyoung,Lee, Kang Soo,Choi, Tai Kiu,Lee, Sang-Hyuk 대한생물정신의학회 2016 생물정신의학 Vol.23 No.4

Objectives The objective of this study is to investigate differences of clinical characteristics between a healthy female control group and female panic disorder (PD) patients with early sexual abuse history (PD+S) and without early sexual abuse history (PD-S). Methods We examined data from 83 patients diagnosed with PD and 20 healthy control subjects. We divided the patients with PD into PD+S (32 patients) and PD-S (51 patients) to compare demographic and clinical characteristics. The following instruments were applied: the Stress coping strategies, the Beck Depression Inventory (BDI), the Panic Disorder Severity Scale, the Anxiety Sensitivity Index-Revised (ASI-R), the Albany Panic and Phobia Questionnaire (APPQ) and the NEO-neuroticism. Results Compared to the PD-S, the PD+S group showed higher scores in neuroticism and the APPQ. And, in the PD+S group, the scores of neuroticism were correlated with the ASI-R and APPQ subscale scores and the APPQ total scores were associated with the scores of BDI. Conclusions This study shows that female PD+S patients have higher scores in neuroticism and the APPQ than the PD-S group, and these factors are associated with the panic-related symptoms severity. It emphasizes the need of specific strategies considering the childhood abuse history such as early sexual abuse in clinical approach among patients with PD.

연구 논문 : 전기화학적 마이크로머시닝 기술을 이용한 균일한 니오븀 표면 에칭 연구

김경민 ( Kyung Min Kim ),유현석 ( Hyeon Seok Yoo ),박지영 ( Ji Young Park ),신소운 ( So Woon Shin ),최진섭 ( Jin Sub Choi ) 한국공업화학회 2014 공업화학 Vol.25 No.1

본 연구에서는 micro-contact printing을 통하여 니오븀 호일 표면 위에 균일한 에칭 pits를 형성하였다. 균일한 보호층을 형성하고자 전해연마의 효과를 확인하였으며, 기존의 O2 플라즈마 공정 없이 손쉽게 균일한 에칭 pits를 형성시킬 수 있는 조건을 확인하였다. 메탄올 혼합 전해질을 사용하여 10 min 동안 에칭을 진행한 결과 니오븀 호일 표면 위에 지름과 간격이 각각 10 μm와 5 μm로 잘 정렬된 에칭 pits를 관찰하였다. We describe the preparation of highly-ordered etching pits on the Nb foil through a micromachining. The effects of electro-chemical polishing on the formation of uniformly-patterned protective epoxy layer was investigated. Unlike the previous proc-ess using O2 plasma, well-ordered etched pits were prepared without any dry processes. As a result, the Nb foil with the well-ordered pits of 10 μm × 5 μm could be obtained by electrochemical etching in methanolic electrolytes for 10 min.

지하철 차량운용 문제에 대한 수리적 해법에 관한 연구

김경민(Kyung Min Kim),홍순흠(Soon-Heum Hong) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

This paper considers subway routing problem. Given a schedule of train to be routed by a railway stock, the routing problem determines a sequence of trains while satisfying turnaround time and maintenance restrictions. Generally, the solution of routing problem is generated from set partition formulation solved by column generation method, a typical integer programming approach for train-set. However, we find the characteristics of metropolitan subway which has a simple rail network, a few end stations and 13 departure-arrival patterns. We reflect a turn-around constraint due to spatial limitations has no existence in conventional railroad. Our objective is to minimize the number of daily train-sets. In this paper, we develop two basic techniques that solve the subway routing problem in a reasonable time. In first stage, we formulate the routing problem as a Min-cost-flow problem. Then, in the second stage, we attempt to normalize the distance covered to each routes and reduce the travel distance using our heuristic approach. Applied to the current daily timetable, we could find the subway routings, which is an approximately 14% improvement on the number of train-sets reducing 15% of maximum traveling distance and 8% of the standard deviation.

한국과 일본의 노인장기요양보험에 관한 문헌고찰

김경민,김남희,이정화,윤현서,박혜영,김혜진,Kim, Kyung-Min,Kim, Nam-Hee,Lee, Gung-Hwa,Yoon, Hyun-Seo,Park, Hye-Young,Kim, Hye-Jin 한국치위생학회 2017 한국치위생학회지 Vol.17 No.5

Objectives: The purpose of this study is to look into the health insurance systems and application in Korea and Japan in order to improve elderly people's quality of life. Their quality of life can be improved by upgrading the long term care systems; and extending treatment and prevention. Methods: This study is to examine long term care systems articles through content analysis in the National Health Insurance Service. Data were collected from the printed Internet and analyzed. Results: A part-time dentist system in elderly care facilities has trouble in taking care of old people's oral health due to both lack of time and operational difficulties. It is urgent to arrange dental experts who can permanently stay in care facilities and to build systems which can be managed periodically and continually. Conclusions: As having staff training for the efficiency and using the manpower in care facilities (care workers), it is necessary to solve the unequal medical service in oral health care for the elderly in Korea.

포스터 발표 - 무기재료분과 / 전기화학분과 / 촉매분과 : 제4급 인산염을 이용한 과염소산 이온 선택성 PVC 막 전극

김경민,박상희,김용렬,강안수 ( Kyung Min Kim,Sang Hee Park,Yong Ryul Kim,An Soo Kang ) 한국공업화학회 1997 한국공업화학회 연구논문 초록집 Vol.1990 No.3

생활 실천형 녹색 에너지 주택 '에코하우스'

김경민,Kim, Kyung-Min 한국과학기술단체총연합회 2010 과학과 기술 Vol.497 No.-

벼의 Doubled-haploid 집단육성과 SSR 마커를 이용한 유전자 지도작성

김경민,남우일,권용삼,손재근,Kim, Kyung-Min,Nam, Wu-Il,Kwon, Yong-Sham,Sohn, Jae-Keun 한국식물생명공학회 2004 식물생명공학회지 Vol.31 No.3

본 연구에서는 1998년부터 2003년 하계까지 약배양 기법 및 콜히친 처리를 이용하여 개발한 '삼강벼/낙동벼' DH(doubled-haploid) 183계통의 주요 농업 형질을 조사$.$분석하였다. DH 집단의 주요 농업형질을 조사한바 초장, 간장, 수장, 삼절간장, 수수 및 출수일수는 양적형질의 특징인 넓은 범위의 변이폭, 연속적인 빈도 분포양상 및 양친을 초월하는 초월분리 현상을 보였다. SSR 마커를 이용한 유전자지도의 작성에는 양친에 다형성을 나타내는 136개의 마커를 사용하였다. 작성된 유전자 지도는 전체 길이가 1,909cM이었으며, 마커간 평균길이는 14 cM을 나타내었다. A doubled-haploid (DH) population was developed through anther culture of F$_1$ plants obtained from a cross between a japonica cultivar, 'Nagdongbyeo', as male parent and a indica cultivar, 'Samgangbyeo', as female parent. Segregation modes for plant length, culm length, panicle length, third internode length, and days to heading in the DH lines showed nearly normal distribution with wide range of variation. A molecular map with 136 simple sequence repeat (SSR) markers was constructed using the DH population. The total map distance was 1,909 cM and the average interval of marker distance was 14 cM.

QoS가 보장된 멀티캐스트 서버스를 위한 Blocking Avoidance 셀 할당 기법과 Virtual Threshold 기법을 이용한 CICQ 스위치 구조

김경민,정현덕,이재용,Kim, Kyung-Min,Jung, Hyun-Duk,Lee, Jai-Yong 한국통신학회 2011 韓國通信學會論文誌 Vol.36 No.2B

최근 다양한 멀티미디어 서비스의 등장으로 멀티캐스트를 통한 컨텐츠의 전송이 빠르게 늘어나고 있으며 이를 처리하기 위한 스위치 기술의 중요성이 높아지고 있다. CICQ 스위치 구조는 cross point의 버퍼를 이용하여 HoL blocking 확률을 낮출 수 있으며 스케줄링이 간단하다는 장점이 있지만 트래픽의 부하가 높아짐에 따라 멀티캐스트 트래픽의 처리율이 급격히 떨어질 수 있다는 단점이 있다. 이를 해결하기 몇몇의 멀티캐스트 셀 할당 기법들과 입력 포트와 cross point 사이의 스케줄링 기법들이 제안되었지만 여전히 멀티캐스트 트래픽의 충분한 처리율을 보장하지 못한다. 따라서 본 논문에서는 BA 셀 할당 기법과 VT 기법을 제안하여 멀티캐스트 트래픽의 HoL blocking 확률을 낮추고 cross point 버퍼의 전용 공간을 확보하여 멀티캐스트 트래픽의 처리율을 보장 할 수 있도록 하였다. 또한 시뮬레이션을 통해 제안된 방법을 이용하여 QoS를 향상시킬 수 있음을 확인하였다. Recently the multicast based contents transmission is rapidly increasing due to the various multimedia services and the importance of switching technology to handle it is increasing as a consequence. Though the CICQ architecture has advantages that reduction of HoL blocking probability and simple scheduling using cross point buffer, it has disadvantage that the processing rate of multicast traffic can be significantly degraded corresponds to the traffic load increment. Several schemes have been proposed to solve this problem however they still can't provide enough processing ratio for multicast traffic. Therefore this paper proposes the BA cell assignment scheme and the VT scheme, and the processing rate of multicast traffic can be guaranteed by reducing the HoL blocking probability of multicast traffic and reservation of cross point buffer. Also simulation results verify that using the proposed scheme, the QoS of multicast service can be improved.