질소, 산소, 인 주개 리간드를 갖는 몰리브덴 (Ⅲ) 및 (Ⅳ) 착물의 합성과 특성 (제 3 보)

김은기,유은영,박유철,Kim, Eun Gi,Yu, Eun Yeong,Park, Yu Cheol 대한화학회 1994 대한화학회지 Vol.38 No.2

$MoCl_4(MeCN)_2$과 N, P, O주개 리간드를 반응시켜 새로운 몰리브덴(Ⅲ) 및 (Ⅳ)착물을 합성하였으며 원소분석과 적외선 및 전자 흡수스펙트럼 등을 이용하여 그 특성을 조사하였다. 사용한 리간드는 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine 과 1,2-bis(diphenylphosphino)ethane이다. 합성된 몰리브덴(Ⅳ) 착물의 Mo-Cl 신축진동은 몰리브덴(Ⅲ)착물보다 증가한 영역에서 나타나므로, M-Cl 신축진동의 위치는 금속의 산화수에 비례한다는 사실과 잘 일치한다. 한자리 리간드의 착물에서는 Mo-Cl신축진동에 의해 강한 한 개의 흡수띠가 나타나는 반면, 두자리 리간드의 착물에서는 강한 네 개의 흡수띠가 나타나므로 이들 각각 trans($D_{4h}$)및 cis($C_{2v}$) 대칭임을 알 수 있다. 몰리브덴(Ⅲ)착물에서 acetonitrile의 C≡N 신축진동은 자유 리간드(2260 $cm^{-1}$)보다 약 30 $cm^{-1}$ 증가한 위치에서 나타나므로 이들 착물은 acetonitrile이 배위된 것을 알 수 있다. 이상의 분광학적 분석 결과를 종합해 보았을 때 $[MoCl_4(L)_2]$,[Mo$Cl_4$(L^L)], $[MoCl_3(L)_2MeCN]$ 및 [Mo$Cl_3$(L^L)MeCN]과 같은 팔면체 구조의 착물임을 알 수 있었다. Some molybdenum(III) and (IV) complexes have been prepared from the reaction of $MoCl_4$·2MeCN with N, P, O-donating ligands and characterized by elemental analysis, infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine and 1,2-bis(diphenylphosphino)ethane were chosen as coordinating ligands. Stretching frequencies $\upsilon$ (Mo-Cl) of Mo(IV) appear at higher frequencies than those of Mo(III) complexes due to the increasing oxidation number of metal. $MoCl_4(L)_2$ exhibit one Mo-Cl stretching frequency, whereas Mo$Cl_4$(L^L) exhibit four Mo-Cl stretching frequencies. The number of Mo-Cl stretching frequency suggestes the former complexes have trans($D_{4h}$) and the latter complexes have cis($C_{2v}$) symmetry. Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in Mo(III) complexes are shifted to about 30 $cm^{-1}$ higher frequency compared with that of a free ligand (2260 $cm^{-1}$). These spectral data indicates that Mo(III) complexes are in the octahedral geometries with the coordinated acetonitrile. Finally each molybdenum(III) and (IV) complexes showed the following formulation; $[MoCl_4(L)_2]$,[Mo$Cl_4$(L^L)], $[MoCl_3(L)_2MeCN]$ and [Mo$Cl_3$(L^L)MeCN].

소아에서의 갑상선설관낭종의 임상적 고찰

김은기,김재천,Kim, Eun-Gi,Kim, Jae-Chun 대한소아외과학회 1997 소아외과 Vol.3 No.1

Thirty-four consecutive cases of thyroglossal duct lesions in children were reviewed at the Department of Surgery, Chonbuk National University Hospital. Twenty patients were males, and the most prevalent age of discovering was 2 to 4 years (52.9%). Resection was performed within 2 years after discovering the lesions in 19 cases, but was delayed untill 4 to 10 years in 6 cases. Cystic lesions (85.3%) were 5.8 times more common than fistulas. A midline upper neck mass was found in every cystic cases, and a draining sinus at hyoid region was noticed in fistula patients. The location of the lesion was on the hyoid bone in 34 cases, at the midline in 31 cases, slightly to the left in 2 cases, and slightly to the right in 1. Two cases were misdiagnosed as lymphadenopathy, and a single case of ectopic thyroid gland was misinterpreted as a thyroglossal duct cyst. Modified Sistrunk operation was performed in twenty-three cases(67.6%), Sistrunk operation in 9(26.5%), and cyst excision in 2(5.9%). Postoperative complications occurred in 4 cases(11.8%); 2 wound infections and 2 recurrences. One of recurrences was a fistula treated by modified Sistrunk operation, and the other was a cyst treated by cyst excision.

A Visual-Based Logic Minimization Method

김은기,Kim, Eun-Gi Korea Society of Industrial Information Systems 2011 한국산업정보학회논문지 Vol.16 No.5

In many instances a concise form of logic is often required for building today's complex systems. The method described in this paper can be used for a wide range of industrial applications that requires Boolean type of logic minimization. Unlike some of the previous logic minimization methods, the proposed method can be used to better gain insights into the logic minimization process. Based on the decimal valued matrix, the method described here can be used to find an exact minimized solution for a given Boolean function. It is a visual based method that primarily relies on grouping the cell values within the matrix. At the same time, the method is systematic to the extent that it can also be computerized. Constructing the matrix to visualize a logic minimization problem should be relatively easy for the most part, particularly if the computer-generated graphs are accompanied.

TCP 혼잡제어를 위한 RTT(Round trip time) 측정

김은기,Kim, Eun-Gi 한국정보처리학회 2000 정보처리논문지 Vol.7 No.5

TCP congestion control algorithm prevents network congestion through the control of outgoing traffic size. The network, therefore, should monitor the incoming traffic size of a TCP to determine whether or not a TCP follows standard congestion control algorithms. Some TCP friendly test algorithms are proposed, But, these algorithms cannot be used in real environments because a router in a network does not know the RTT of a TCP flow. In this study, we propose a new RTT determination algorithm that can be used in a router. Our proposed algorithms is validated through the simulation studies. TCP 프로토콜의 혼잡 제어 알고리즘은 인터넷 망 내로 들어오는 트래픽 량을 조정하여 망이 혼잡 상태에 빠지는 것을 방지하는 기능을 수행한다. 따라서, 망에서는 어떤 TCP에서 발생하는 트래픽이 표준 TCP 흐름 제어 알고리즘을 따르고 있는지 감시할 필요가 있다. 이러한 기능르 수행할 수 있는지 감시할 필요가 있다. 이러한 기능을 수행할 수 있는 몇 가지 방안들이 제안되었으니 이들은 TCP 플로우(flow)의 RTT(round trip time)를 얻지 못하여 실제로 사용될 수 없는 문제를 갖고 있다. 본 연구에서는 인터넷 망 내 라우터에서 각 TCP 플로우의 RTT 값을 측정할 수있는 알고리즘을 제안하고, 시뮬레이션을 통하여 알고리즘의 올바른 동작을 확인하였다.

발전 산업 기술동향 및 전망 II

김은기,Kim, Eun-Gi 한국전기기술인협회 2007 電力技術人 Vol.293 No.-

심마비용액의 삼투압을 유지하기위한 첨가 물질들의 차이가 심근보호에 미치는 영향

김은기,이종국,이상헌,Kim, Eun-Gi,Lee, Jong-Guk,Lee, Sang-Heon 대한흉부심장혈관외과학회 1991 Journal of Chest Surgery (J Chest Surg) Vol.24 No.11

High potassium cardioplegia is a widely accepted procedure to enhance myocardial protection from ischemic injuries associated with open heart surgery. Maintaining optimum osmolarity of the cardioplegic solution is one of the required conditions for an ideal cardioplegic solution Albumin is an frequently added component for maintaining optimum osmolarity of clinically used cardioplegic solutions. But the source of albumin is human blood so that the supply is limited and the cost of manufacturing is relatively high. Recently there are moves to minimized the use of blood product for fear of blood-associated infections or immunological disorders. In this experiment, we substituted mannitol or glucose for albumin added to the cardioplegic solution which has been used at the Wonju Medical College, To determine whether addition of mannitol or glucose instead of albumin in the cardioplegic solution can produce satisfactory myocardial protection during ischemia, three different groups of isolated rat heart perfused by modified Langendorff technique were studied. Wonju Cardioplegic Solution was selected as a standard high potassium[18mEq/L of K+] cardioplegic solution. Three kinds of cardioplegic solution were made by modifying the composition maintaining the same osmolarity[339$\pm$1mOsm/Kg] Isolated rat heart were perfused initially with retrograde nonworking mode and then changed to working mode. After measuring the heart rate, systolic aortic pressure, aortic flow, coronary flow, ischemic arrest by aorta cross clamp and cardioplegia was made maintaining the temperature of water jacket at 10oC. The heart was rewarmed and reperfused after 60min of ischemic arrest with intermittent cardioplegia at the 30min interval. The time to return of heart beat and the time required to get. Regular heart beat were observed after reperfusion. The recovery rate of the functional variables-heart rate, systolic aortic pressure, aortic flow, coronary flow and cardiac output were calculated and compared among the three groups of different cardioplegia-albumin, mannitol, and glucose. The wet weight and dry weight was measured and the water content of the heart as figured out for comparison. The time to return of heart beat was fastest in the albumin group, The functional recovery rates were best in the albumin group also. In the above conditions, albumin was the best additive to the cardioplegic solution compared to the mannitol or glucose.

Multi-Level Groupings of Minterms Using the Decimal-Valued Matrix Method

김은기(Eun-Gi Kim) 한국컴퓨터정보학회 2012 韓國컴퓨터情報學會論文誌 Vol.17 No.6

이 논문에서는 십진수의 매트릭스 방법 (DVM) 을 이용한 새로운 방법으로 불리언 논리를 최소화할 때 최소항을 그룹화 하여 표시하는 방법을 제안하고 있다. DVM 방법은 매트릭스 방법을 이용하여 최소항에 관한 이진수의 차이를 십진수 형태로 변환하는 과정을 거치고, 결합할 수 있는 최소항을 직접 확인할 수 있다. 십진수의 매트릭스 방법은 시각적 접근에 따른 새로운 매트릭스이지만, 경우에 따라 주어진 셀 값을 그룹화 하는데 있어서 도형이 복잡해지기도 하는 문제점이 있다. 이 논문은 이러한 문제점을 해결하기 위한 연구로, 십진수의 매트릭스 방법에 최소항의 다단계 그룹을포함하는 기법을 제안하고 있다. 이 연구에서 제시하는 방법은 최소항의 그룹을 간결한 시각적인 방법으로 표현 하였으므로, 관련된 최소항을 구체적으로 파악하는 수단으로 사용할 수 있다. This paper suggests an improved method of grouping minterms based on the Decimal-Valued Matrix (DVM) method. The DVM is a novel approach to Boolean logic minimization method which was recently developed by this author. Using the minterm-based matrix layout, the method captures binary number based minterm differences in decimal number form. As a result, combinable minterms can be visually identified. Furthermore, they can be systematically processed in finding a minimized Boolean expression. Although this new matrix based approach is visual-based, the suggested method in symmetric grouping cell values can become rather messy in some cases. To alleviate this problem, the enhanced DVM method that is based on multi-level groupings of combinable minterms is presented in this paper. Overall, since the method described here provides a concise visualization of minterm groupings, it facilitates a user with more options to explore different combinable minterm groups for a given Boolean logic minimization problem.

최소차원 토크ㆍ관성 관측기를 이용한 전동기 극저속 운전

김은기(Eun-Gi Kim),전기영(Kee-Young Jeon),오봉환(Bong-Hwan Oh),정춘병(Choon-Byeong Chung),이훈구(Hoon-Goo Lee),김용주(Yong-Joo Kim),서영수(Young-Soo Seo),한경희(Kyung-Hee Han) 전력전자학회 2005 전력전자학술대회 논문집 Vol.- No.-

In this paper, an instantaneous speed observer with a reduced order is proposed to implement an indirect control for an motor with excellent dynamic stability and performance in a very low speed region. The proposed observer can estimate the instantaneous speed in very low speed region and simplify the system configuration by adopting a least order load torque-inertia observer to estimate the load torque and the rotor speed. Simulation are carried out to illustrate the performance of the proposed estimator at very low speed.

HPSK 를 사용하는 항공기용 위성 데이터링크 모뎀의 도플러 편이 보상 성능

김은기(Kim Eun Ki),김승완(Kim Seung Wan),송충호(Song Choong Ho),정병기(Jung Byung Gi) 한국통신학회 2011 한국통신학회 학술대회논문집 Vol.2011 No.6

HPSK 를 사용하는 항공기용 위성 데이터링크 모뎀의 가속 도플러 편이 보상 성능 향상을 위한 프레임 구조 및 AFC 설계

김은기(Kim Eun Ki),김승완(Kim Seung Wan),송충호(Song Choong Ho),정병기(Jung Byung Gi) 한국통신학회 2013 한국통신학회 학술대회논문집 Vol.2013 No.1