SHS 공정으로 합성된 TiC 계 cermet 미세구조에 미치는 바인더 금속의 영향

박민우,한유동,전재호,김명진 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.11

Microstructural evolution of Ti-C-metal binder powder mixtures during SHS process was investigated by combustion-wave arresting technique. Al, Fe, Co, Ni and Cu were selected as binder metals of TiC-based cermet. The characteristics of SHS reaction occurred in different mode, depending on the binder metals. SHS reaction resulted in the three distinct regions; such as unreacted, partially reacted, and fully reacted parts. The intermediate phases of Ti and the metal binder were formed in the partially reacted region. The resulting cermet in the fully reacted region consisted of round shaped carbide particles and metal binder phase.

전자부품 리드프레임용 Cu-Sn-P 합금의 미세구조에 미치는 합금조성 및 열가공 변형 영향연구

박민우 경성대학교 공학기술연구소 2003 공학기술연구지 Vol.10 No.-

Miicrostructure and mechanical properties of Cu-Sn and Cu-Sn-P (phosphor alloys) alloys were studied for the leadframe application of electronics packaging. The as-cast alloys were thermomechanically processed(TMP) by swaging to increase the alloy strength and grain refinement. Microstructure of the alloys were studied by Transmission Electron Microscopy. Brittle Cu₃Sn compounds were formed in the as-cast condition, however, the compound were dissolved during the subsequent TMP. Tensile strength increases as the addition of Sn and P increase. Electrical resistivity and workability of Cu-Sn alloys are further discussed as a function of alloy composition and deformation.

간섭에 강인한 OFDM 기반의 W-LAN시스템 연구

박민우,최정희 대구대학교 정보통신연구소 2003 情報通信硏究 Vol.1 No.2

OFDM 기반의 시스템은 다중경로 환경에 우수한 특성이 있기 때문에 WLAN과 같은 광대역 멀티미디어 통신시스템의 표준으로 채택되어왔다. 본 논문에서는 802.11a 광대역 OFDM시스템과 Chirp pulse radar 시스템간에 5㎓ 대역의 주파수를 공유할 때 발생하는 간섭을 분석하고 Block Interleaving과 Convolutional coding기술을 적용하여 OFDM시스템에 미치는 간섭경감을 시도하였다. 또한 Walsh code를 사용하여 각각의 부반송파를 확산시킴으로써 간섭경감을 시도하였다. 최종적으로 Convolutional coding 기법과 확산기법을 연쇄적으로 적용하여 간섭신호의 전력과 대역폭에 따른 성능을 분석함으로 OFDM시스템과 Radar시스템간의 주파수 공유가능성을 제시한다. OFDM-based system has been standard wide-band multimedia communication system such as WLAN, due to it's superiority of multipth fading environment. In this paper, we analyzed interference when such a wide-band OFDM system and conventional radar system coexist in the same frequency band, e.g,2/5㎓. Using burst type characteristic of radar signal and system, we attempted to reduce interference on OFDM system by applying interleaving and convolutional coding technique. We also attempted to reduce radar interferences by applying spreading technique using walsh code for each subcarrier. Finally, we propose the possibility of frequency sharing between OFDM system and radar system via analysis of system performance based on power and bandwidth of interferences when convolutional coding and spreading scheme are concatenated.

Viscoelastic-flow assisted materials patterning

박민우,김봉수,정운룡 한국고분자학회 2011 한국고분자학회 학술대회 연구논문 초록집 Vol.2011 No.1

현대자동차와 기아자동차의 기업결합은 왜 허용되었을까? - 도산법과 공정거래법의 역할을 중심으로 -

박민우 한국상사법학회 2015 商事法硏究 Vol.34 No.1

This paper aims to explore the reasons why Korean Fair Trade Commission (hereinafter KFTC) allowed the Hyundai Motor Company to merge with the Kia motor Company. Under the Monopoly Regulation and Fair Trade Act, no one shall practically suppress competition in a particular business area by conducting practices except that where the effect of efficiency promotion attainable through the combination of enterprises is more than the negative effect produced by restricted competition(efficiency effects defense); or where such combination is made with non-viable company whose total capital in a balance sheet is less than its paid-up capital for a reasonable period of time(the failing firm defense). To succeed with an efficiency defense under Monopoly Regulation and Fair Trade Act, a dominant company would need to show that: the efficiency gains that are likely to result from the potentially abusive conduct offset any likely negative effects on competition and consumer welfare generated by that conduct; those efficiency gains have been, or are likely to be brought about as a result of the potentially abusive conduct; the potentially abusive conduct is necessary for the achievements of those efficiency gains; and the potentially abusive conduct does not eliminate effective competition by removing all or most existing sources of actual or potential competition. Also the failing firm can be applied only if it can be shown that there are no alternative less anticompetitive mergers. And the law goes further and requires evidence that if the merger were prohibited, the assets of the failing firm would leave the market. Actually, Hyundai Motor Company did not show efficiency effect or failing firm defense which was needed for acquisition. However they got the permission of the KFTC. The systemic risk is a key to find an answer the reason that why KFTC allowed the Hyundai Motors Company to merge with the Kia Motor Company during Asian Financial Crisis. While the Asian financial crisis, the Korean government had not many choices except to resolve market disaster as soon as possible. Therefore KFTC gave the permission to the Hyundai Motor Company. Besides, before the Asian Financial Crisis, economic recessions in history were always accompanied by relaxation or abandon of competition policy in many countries. And the law(Monopoly Regulation and Fair Trade Act) also supported this decision by this clause which “the purpose of this Act is to strive for balanced development of the national economy.” Development of national economy required not only competition in the market but also stabilization of the market which obtained by Hyundai and Kia's merger.

코팅 처리된 카멜리나 종자의 발아율 분석

박민우,이상협 한국종자연구회 2015 종자과학과 산업 Vol.12 No.1

기존의 도산제도를 통해 본 우리나라 지방자치단체의 도산

박민우 한국상사법학회 2013 商事法硏究 Vol.32 No.3

What has happened when a city goes bankrupt? As this question suggest, the bankruptcy of a municipality raises fundamental issues regarding the nature of the city. Do the creditors take over city hall and the city’s streets and alleys? Can the creditors obtains a lien on the city’s primary source of income: taxes? What is the goal of the municipal bankruptcy laws? Although cities are legally classified as municipal corporations, the purposes of U.S. federal municipal bankruptcy laws resemble individual bankruptcy more than corporate bankruptcy: municipal bankruptcy is based on the idea of the fresh start rather than the efficient reconfiguration of assets. Based on this idea, filing for bankruptcy can be a useful tool in alleviating financial distress: It allows municipalities to make use of bankruptcy's automatic stay provisions to negotiate payments with creditors in U.S. However, municipal bankruptcies are rare and are generally met with political disfavor. The financial constraints of local governments here in Korea, mostly caused by the mismanagement of the authorities and the economic slowdown, have been intensified. In recent years many municipalities, including major metropolitan centers, have been confronted with skyrocketing expenses, a declining tax revenue base and a resulting dependence on intergovernmental aid. As prospects for financial distress have grown, it is evident that this system which deals with local government financial status has been rendered archaic and incapable of providing an adequate remedy for municipal insolvencies. The local borrowing system in Korea is regulated by the central government according to the nature of projects and the repaying ability of local governments. While projects benefit the public and are reflected in the mid-term financial planning, issuing authorities should be capable of redeeming principle amount and interest. Also, the local bond market heavily relies on public funds, thus, crippling the market mechanism. This means there is no possibility of municipal bankruptcy cause systemic risk. However, municipal bankruptcy links with sovereign default because local government credit rank reflects central government's. This Article analyzes the ways in which the legal status of municipalities affects these aspects of bankruptcy law, compare the mechanisms of common bankruptcy system and a municipal bankruptcy system and recommend to create local bond market for operation of market discipline.

DC 및 RF 스퍼터링법으로 증착한 Cr 박막의 특성 비교

박민우,이종무,Park, Min-Woo,Lee, Chong-Mu 한국재료학회 2006 한국재료학회지 Vol.16 No.8

Chromium (Cr) films were deposited on plain carbon steel sheets by DC and RF magnetron sputtering as well as by electroplating. Effects of DC or RF sputtering power on the deposition rate and properties such as, hardness, surface roughness and corrosion-resistance of the Cr films were investigated. X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microcopy (SEM) analyses were performed to investigate the crystal structure, surface roughness, thickness of the Cr films. Salt fog tests were used to evaluate the corrosion resistance of the samples. The deposition rate, hardness, and surface roughness of the Cr film deposited by either DC or RF sputtering increase with the increase of sputtering power but the adhesion strength is nearly independent of the sputtering power. The deposition rate, hardness, and adhesion strength of the Cr film deposited by DC sputtering are higher than those of the Cr film deposited by RF sputtering, but RF sputtering offers smoother surface and higher corrosion-resistance. The sputter-deposited Cr film is harder and has a smoother surface than the electroplated one. The sputter-deposited Cr film also has higher corrosion-resistance than the electroplated one, which may be attributed to the smoother surface of the sputter-deposited film.

Trichophyton mentagrophytes에 의한 두부 독창

박민우,천보미,박훈,김상석,이정옥,이종주 대한의진균학회 2006 대한의진균학회지 Vol.11 No.4

Kerion celsi is an inflammatory type of tinea capitis. It is a deep, boggy swelling and is painful. Patchy hair loss and broken hairs, inflammation and scaling are characteristic. We report a case of kerion celsi caused by Trichophyton(T.) mentagrophytes in 4 year-old boy. He presented with 6 cm × 7 cm and 2cm × 2cm sized erythematous boggy masses with multiple pustules and crusts on the vertex. Cultures from a scalp lesion of the patient on Sabouraud dextrose agar media showed T. mentagrophytes. Treatment was done systemically with itraconazole and prednisolone for 14 weeks.

와우내 신경초종 2예

박민우,장정훈,박민현 대한이비인후과학회 2009 대한이비인후과학회지 두경부외과학 Vol.52 No.12

Intracochlear schwannoma is a rare tumor arising from Schwann cells limited to the cochlea. Most of the cases have been found incidentally at autopsies or during surgeries. Today, gadoliniumenhanced magnetic resonance imaging (MRI) has made the diagnosis possible before surgical intervention. Intracochlear schwannoma presents unilateral progressive hearing loss, tinnitus or vague unsteadiness, all of which are common otologic symptoms seen in the outpatient department. Therefore, a high index of suspicion to detect this tumor is needed. We report two cases of intracochlear schwannoma: one case was diagnosed at gadolinium-enhanced MRI and removed by modified transotic approach preserving external auditory canal; the other case was followed up closely without the intervention of surgery.