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.

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.

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].

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.

발전 산업 기술동향 및 전망 II

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

Continuous Water Toxicity Monitoring Using Immobilized Photobacterium phosphoreum

김은기,서형준,Se Kwon Kim,Baek Seok Lee,이정건 한국생물공학회 2003 Biotechnology and Bioprocess Engineering Vol.8 No.2

Water toxicity monitoring based on the continuous cultivation of Photobacterium phosphoreum is presented. Normally, after 10 days of operation, a dark variant, which emits no light, appears and dominates the population, resulting in a rapid decrease in bioluminescence. Therefore, to overcome this problem, a fluidized-bed reactor is used in which alginate-immobilized cells are grown and leaking cells are continuously released into the effluent. Experimental results revealed that the dominance of dark variants was suppressed inside the immobilized beads, thereby mitigating the rapid loss of bioluminescence. Plus, a high dilution rate (1.2 h-1) prevented the occurrence of other microbial contamination in the reactor. The concentration and bioluminescence of the released cells were sufficient to measure the water toxicity for more than 4 weeks.

Long-term preservation of high initial bioluminescence of lyophilized Photobacterium phosphoreum: Effect of skim milk and saccharose at various temperatures

김은기,Thuan-Hieu Tran,Young-Bum Kim,Woo-Jin Chang,구윤모,Joo-Young Yoon,Jin-Hwan Kim 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.6

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.

보조 및 관리 단말을 갖는 새로운 시공간 협동 다이버시티 중계 전략

김은기,김영주,이인성,Kim, Eun-Ki,Kim, Young-Ju,Lee, In-Sung 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.1A

본 논문에서는 다중-홉(multi-hop) 무선통신시스템에서 보조 및 관리단말을 추가로 갖는 시공간 협동 다이버시티 중계 시스템을 제안한다. 한 협동그룹에 1개 이상의 중계단말을 추가하여, 프레임 에러여부 및 채널정보 등의 상태정보만을 공유한다. 상태가 좋은 수신신호를 가지는 단말을 선택하여, 선택된 각 중계단말은 같은 시공간 부호로 다중안테나 송신다이버시티 중계전송을 한다. 그리고 협동그룹 내에 중계단말 간의 교신 프로토콜을 제안한다. 이 방식에 대해, 수신신호 대 송신신호 비($E_r/E_s$)를 측정하여 성능개선 됨을 증명하였으며, 플랫 페이딩 (flat-fading) 채널에서의 시뮬레이션은 기존의 협동다이버시티에 비해 혁신적인 성능향상을 보인다. A new space-time cooperative communication relaying strategy with assistant or management terminals is proposed in multi-hop wireless communication systems. More than one relaying terminals are included in one cooperative group to share the state information such as frame error rate and channel information. Among the cooperative group, the best ones are selected to send bit information using space-time codes. An implementation for the proposed scheme is also presented using a TDMA cooperative protocol. Receive signal to transmit signal ratio($E_r/E_s$) and computer simulation show the strategy outperform the conventional cooperative system.

A Comparative Analysis of Research on LIS Information Behavior and Health Information Seeking Behavior

김은기,Kim, Eungi Korean Biblia Society for Library and Information 2019 한국비블리아학회지 Vol.30 No.2

본 논문은 정보행동 분야에 상당한 연구가 진척된 문헌정보분야의 정보행동에 관한 연구와 의학분야의 건강정보탐색행동 연구를 비교하였다. 이 연구는 계량서지학적 접근으로 진행하였다. 연구 실행을 위해 Scopus 데이터베이스를 사용하여 서지기록들을 문헌정보학과 건강과의학 분야별로 데이터 세트를 구성하였다. 계량서지학적 분석은 다음과 같은 영역으로 실행하였다: 출판된 논문, 인용, 논문지, 저자키워드, 제목에서 고유한 단어, 제목에서 "information" 앞에 이용되는 단어들, 제목에서 "study" 앞에 이용되는 단어들, 제목에서 국가명을 표기한 단어들, 저자 키워드와 색인 키워드. 결과적으로, 두 분야에서 드러난 정보행동에 관한 연구영역에서의 주요차이점은 정의, 주된 초점, 일반적인 인구통계학적 그룹에서 분명하게 나타났다. 이러한 다양한 차이점은 두 학계 연구자들에게 정보 탐색과 정보행동을 연구하는데 있어 학계별 특수한 차이와 상황들에 따라 유연하게 접근하고 적용해야 함을 시사하였다. Information behavior (IB) research in LIS and Health Information Seeking Behavior (HISB) in Health Medicine are two subject areas of research that have matured in the past few decades. This research aimed to compare these two research areas using a bibliometric approach. To conduct this study two distinct datasets were created using the Scopus database: a) bibliographic records of IB in the LIS domain, and b) bibliographic records of the HISB domain. The bibliometric analysis was performed according to the following criteria: published papers, citations, journal articles, author keywords, unique words in the title, words preceding "information" in the title, words preceding "study" in the title, and author keywords along with index keywords. As a result, the major differences in the two IB research areas were evident in terms of definitions, main focus, and general demographic groups. These varying types of differences suggest that researchers of the two areas should have flexibility when examining issues related to IB by considering the context and the unique distinction between the two fields.