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.

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.

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.

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.

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.

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.

탄성 저장관과 스마트 밸브가 일체화된 주입 포트와 이동식 주입기를 이용한 콘크리트 구조물의 균열보수 주입공법 (TPS 공법)(건설신기술 제 822호)

김경민,신재경,박용준,Kim, Kyoung-Min,Shin, Jae-Kyung,Park, Yong-Jun 한국건설순환자원학회 2018 한국건설순환자원학회지 Vol.13 No.1

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.1997 No.0

Gluconacetobacter sp. gel_SEA623-2를 이용한 Bacterial Cellulose 생산에 초산농도 및 유산균 혼합배양이 미치는 영향

김경민,김지현,양경월,Kim, Kyung min,Kim, Jihyeon,Yang, Kyong Wol 한국미생물학회 2014 미생물학회지 Vol.50 No.3

In this study, Gluconacetobacter sp. gel_SEA623-2 isolated from citrus that produces bacterial cellulose was used to examine the effect of initial concentration of acetic acid and mixed culture inoculated with Lactobacillus plantarum KCCM 80077 on productivity of bacterial cellulose. In mixed culture added with 0.5% acetic acid, the viable cell count increased from $2.4{\times}10^6CFU/ml$ to $1.1{\times}10^7CFU/ml$ after 14 days of culture, and total acidity was about 0.3% higher than single culture added with 0.5% acetic acid, which implies that additional lactic acid was produced by L. plantarum KCCM 80077. In single culture, although bacterial cellulose productivity was higher when the initial concentrations of acetic acid were 0.0% and 0.5%, than when it was 1.0%, there was no significant difference. However, in mixed culture, adding 0.5% acetic acid resulted in dry weight of $37.83{\pm}6.81g/L$ and thickness of $10.33{\pm}0.58mm$, showing a significant difference from that of single culture added with 1% acetic acid, $28.40{\pm}1.23g/L$ and $7.50{\pm}0.50mm$ (P<0.05). 본 연구에서는 bacterial cellulose를 생산하는 감귤에서 분리된 Gluconacetobacter sp. gel_SEA623-2를 이용하여 초기 초산농도 및 Lactobacillus plantarum KCCM 80077 유산균을 접종한 mixed culture가 bacterial cellulose 생산성에 미치는 영향을 알아보았다. 0.5%의 초산을 첨가한 mixed culture의 경우 초기 생균수가 $2.4{\times}10^6CFU/ml$에서 14일 동안 배양한 이후에 $1.1{\times}10^7CFU/ml$까지 증가하였고 total acidity가 0.5%의 초산을 첨가한 single culture와 비교하여 0.3% 가량 높게 측정되어 유산균에 의해 추가적으로 젖산이 생성된 것으로 판단된다. Single culture에서는 초기 초산농도가 0.0 및 0.5%일 때 1.0% 농도와 비교하여 상대적으로 높은 bacterial cellulose 생산성을 나타내기는 하였으나 유의적인 차이는 보이지 못하였다. 하지만 mixed culture에서는 0.5%의 초산을 첨가하였을 때 $37.83{\pm}6.81g/L$의 dry weight과 $10.33{\pm}0.58mm$의 thickness를 나타냄으로써 1%의 초산을 첨가한 single culture의 $28.40{\pm}1.23g/L$와 $7.50{\pm}0.50mm$의 생산량과 비교하여 유의적인 차이를 나타내었다(P<0.05).

선행조건이 명세되어 있지 않은 복합 리팩토링에 대한 조립성 검사

김경민,장필재,김태공,Kim, Kyung-Min,Jang, Pil-Jae,Kim, Tae-Gong 한국정보처리학회 2011 정보처리학회논문지D Vol.18 No.1

최근의 소프트웨어 개발에서는 리팩토링이 활발하게 이용되고 있다. 리팩토링에 대한 관심이 높아지면서 요소 리팩토링을 정의해서 이들의 조립을 통해 더 큰 종류의 복합 리팩토링을 처리하려는 연구들이 많이 진행되고 있다. 복합 리팩토링은 조합된 요소 리팩토링의 순서대로 처리되기 때문에 프로그램에 실제 적용하기에 앞서 적용 가능성을 판단하는 것이 중요하다. 기존 연구들에서는 요소 리팩토링들의 선 후행조건들로부터 복합 리팩토링에 대한 선행조건을 계산하여 적용 가능성을 판단하고 있다. 이것은 선행조건이 정의되어 있는 복합 리팩토링만 판별할 수 있으며 선행조건이 정의되어 있지 않은 복합 리팩토링에 대해서는 적용 가능성을 판단할 수 없는 문제점이 있다. 본 연구에서는 복합 리팩토링의 명세를 추가로 정의 하지 않고 요소 리팩토링만으로 조립 가능 여부를 판단하고자 한다. 이를 위해 요소 리 팩토링을 명세하는 방법과 조립성 검사 방법을 제안한다. 이를 기반으로 프로토타입 도구를 개발해 보고, 적용사례를 통해 선행조건이 명세되어 있지 않은 복합 리팩토링들의 조립성 검사를 확인해봄으로써 본 연구의 효용성을 검토해본다. Refactoring has been actively used in recent software developments. Many studies on the processing of more large scaled composite refactorings have been conducted through the composition of elementary refactorings. It is important to verify the possibility of composition before the refactoring is performed, because the composite refactorings are processed to the sequence of composed elementary refactorings. In conventional studies, they verify the possibility of composition using the precondition of composite refactorings which are computed from the precondition and postcondition of elementary refactorings. They can not verify the possibility of composition in case which composite refactorings do not have a specification of precondition. Thus, we plan to verify the possibility of composition by using the elementary refactorings only without any additional definitions of the preconditions of composite refactorings. To achieve this goal, we proposes a specification method of elementary refactorings and a method for the composition check of refactorings. Then, we develop a prototype tool based on these methods. In addition, we verify the efficiency of our methods through case studies.