실시간 리눅스에서 Bit Masking 기법을 이용한 효율적인 고정 우선순위 기반의 태스크 스케줄러의 설계 및 구현

신귀매,오훈,김용석 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

We design and implement an efficient static priority based scheduler using bit masking technique and analyze how the scheduler overhead affects the scheduling of real-time tasks. The Real-time Linux used for experimental analysis in this paper uses a simple search method that costs O(n) in finding a task of the highest priority for n tasks in the ready queue. The cost is reduced to O(1) when bit masking technique is applied; however, it may constrain the range of priority. We show by experimental study that the reduced scheduler overhead largely increases the number of tasks that are scheduled successfully.

알루미나-실리카계의 Mullite 화합물의 제조에 관한 연구

백귀찬,김용욱 慶熙大學校 材料科學技術硏究所 1999 材料科學技術硏究論集 Vol.12 No.-

This study is to investigate into the preparation and the character of monolith gel and ceramics having the composition of mullite by sol-gel method. The results abtained are as follows : The optimal addition of HNO_(3) to abtain no cracking monolith was 0.07mol per 1mol of alkoxides. The gelling time became longer as increasing the H_(2)O content and the activation energy for gelling was 12 kcal/mol. The mullite crystalline phase was formed at 1230℃∼1600℃ and the activation energy was 100 kcal/mol.

고정원으로부터 회수한 CO₂를 이용한 메탄올 합성용 H₂제조에 관한 연구

백귀찬,김용욱 경희대학교 산학협력기술연구원 1999 산학협력기술연구논문집 Vol.5 No.-

The purpose of this work is to gain optimum process variables in terms of carbon dioxide catalytic reforming of methane using Rh-Al_2O_3 catalyst and Ni-Al_2O_3 catalyst. Ni- Al_2O_3 catalyst was more useful than Rh-Al_2O_3 catalyst in engineering sight. But carbon coaking effect on Ni-Al_2O_3 catalyst activity was more harmful than on Rh-Al_2O_3 catalyst, to contro1 carbon coaking by cycle split perform some verification. At low reaction temperature reaction Is hardly occurred, even though few hydrogen outbreak that were vanished from reverse reaction. When GHSV was more than 60000(h^-1), catalyst and reactants don't have enough time to reaction. But GHSV was less than 10000(h^-1), both catalysts have been high hydrogen yield. Low yields of hydrogen have been obtained at CO_2/CH_4 ratio less than 0.5, and high yields of hydrogen have been obtained at CO_2/CH_4 ratio less than 2, however both yields were lower than CO_2/CH_4 ratio 1.

온도 기울기(temperature gradient) 젤에서 Heteroduplex Analysis 기법을 이용한 돌연변이 DNA의 검출

조용석,구미자,박귀근,박영서,강종백 A.R. Liss 1998 ENVIRONMENTAL MUTAGENS AND CARCINOGENS Vol.18 No.2

저온소결 세라믹을 이용한 적층형 전압제어발진기의 설계제작

朴貴南,宋眞亨,金志均,李憲用 明知大學校 産業技術硏究所 2004 産業技術硏究所論文集 Vol.23 No.-

The circuit substrate was made from the LTCC that a ε_(r) was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimensions in the multilayer substrate circuit inside, and one structure integrated band-pass filter, resonator, a bias line and a matching circuit. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], harmonics characteristic -45[dBc] in control voltage 1.5[V]. A phase noise is -68.22[dBc/Hz] in 100 [kHz] offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA].

PDMS-PEI 복합막 제조와 투과증발법에 의한 휘발성 유기화합물 제거에 관한 연구

백귀찬,김용욱 경희대학교 산학협력기술연구원 1998 산학협력기술연구논문집 Vol.4 No.-

In this work, poly(dimethylsiloxane)(PDMS) dense membrane was made from room temperature vulcanizing(PTV) silicone rubber. PDMS-PEI composite membrane with polyetherimide(PEI) support was also prepared. These membranes were evaluated in terms of the removal of chlorinated organic hydrocarbons such as chloroform, trichloroethylene(TCE), perchloroethylene(PCE), 1,1,1-trichloroethane from water by pervaporation. PDMS-PEI composite membrane has remarkably greater flux than PDMS dense membrane with similar flux. However, the physical properties of dense membrane and composite membrane were not changed. PDMS-PEI composite membrane showed the best performances among the silicone polymeric membranes, and has better durability and mechanical strength than PDMS dense membrane. PDMS-PEI composite membrane should be a useful candidate for the removal of chlorinated organic hydrocarbons dissolved in water.

해상교량의 교각에 대한 설계선박 결정

이성로,배용귀 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

An analysis of the annual frequency of collapse(AF) is performed for each maritime bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgement. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. More researches on the allocation model of AF and the determination of impact resistance are required.

위장관 출혈을 일으킨 공장의 형활근종 1예

김병수,장성종,부귀범,조운택,박찬국,김만우,변주남,김정용,전호종 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.1

Small bowel leiomyoma is a rare tumor which may occur wherever smooth muscle is present. The small bowel is the most common site and it makes up 20~30% of all benign small intestinal neoplasms. A spectrum of symptoms are common ranging from nausea, vomiting, abdominal pain, to massive intestinal bleeding. Bleeding is the most common symptom and is usually gross and recurrent. Occasionally it may be life threatening. But, the most serious problem is both the absence of specific clinical symptoms, and the difficulties shown in radiological diagnostics of the small bowel. If conventional diagnostic methods fail to reveal any positive findings for gastrointestinal bleeding, the diagnosis of intestinal leiomyoma should be suspected and an SMA angiography shoud be performed. The angiographic criteria of small bowel leiomyoma is very characteristic. We present a case of leiomyoma with considerable and prolonged gastrointestinal bleeding, which was diagnosed by angiography. A 61-year old woman was admitted with a history of melena over the last 10 days. An SMA angiography showed a hypervascular mass with a diameter of 3×3cm. A segmental resection was performed under the impression of the gastrointestinal bleeding due to leiomyoma of the small bowel. Microscopic examination of the lesion shows interlacing or whorl bundles of spindle shaped ces and no mitosis.

긴볼레기말의 항고지혈증 효과에 관한 연구 : Triton WR-1339 주사에 의한 고지혈증 유발 생쥐의 간세포내 지방 축적 감소를 중심으로 Based on the Decreasing Effect of Lipid Accumulation in Hepatocyte of Murine with Hyperlipidemia induced by Triton WR-1339

박인식,안상현,정재만,강윤호,이해풍,서귀문,홍용기,김호현,김진택 동국대학교 한의학연구소 1999 東國韓醫學硏究所論文集 Vol.7 No.2

본 연구는 긴볼레기말 추출물의 항고지혈증 효과를 조사하기 위해 ICR 생쥐에 TritonWR-1339(TX) 복강주사로 인위적인 고지혈증을 유발시킨 후 긴볼레기말 추출물(30㎎/㎏)를 복강주사하여 시간의 경과에 따른 간세포내에서의 지방 축적 변화를 조직화학적으로 관찰하였다. TX 주사후 그물구조의 세포질출 가진 간세포가 간엽 전체에서 관찰되었고, 일부 간소엽에서는 간세포 손상으로 인한 간세포판 소실이 나타났다. 또한 간세포내 지방축척도 증가하여 전체 간소엽의 간세포에서 지방의 과출현을 확인 할 수 있었고, 지방의 크기도 대조군에 비해 증가된 것으로 관찰되었다. 그러나 긴볼레기말 추출물 주사군에서는 그물구조의 세포질을 가진 간세포의 수가 TX 주사군에 비해 감소되었고, 대부분의 간소엽에서 정상적인 간세포판의 배열을 확인할 수 있었다. 간세포내의 지방 축적과 크기도 감소된 경향으로 관찰되었다. 이상의 결과로 볼 때 해조류 긴볼레기말 추출물은 고지혈증이 유발된 생쥐 간세포 내에서의 과도한 지방축적을 감소시키는 항고지혈증 효과를 하는 것으로 사료된다. Hepatic tissues of ICR mouse were intraperitoneally injeced with Colpomenia bullosa(CB) Extract after Triton WR-1339(TX) injection were observed to investigate the antihyperlipermic effect of CB extract for hyperlipidemic hepatic tissue caused by destruction of lipid metabolism. The hepatic tissues were obtained at hour-24, 48, and 72 after TX injection with CB extract treatment. And then these specimen were fixed in 10% neutral buffer solution and were cryocut. The tissue stained by H&E for general morphology and sudan black B for lipid distribution. The increase of hepatocyte having rneshlike cytoplasm were shown in all hepatic lobules after TX injection and the hepatic plates were disappeared in the region of meshlike hepatocyte aggregation, But the hepatocyte having meshlike cytoplasm were disappeared and hapatic plate were rearranged in CB extract injected mouse. The number of blue black colored lipid drop in hepatic cytoplasm of mouse injected with TX were increased and the size of lipid drop were enlarged. But the number of lipid drop in hepatic cytoplasm of mouse treated CB extract were decreased and the size of lipid drop were diminished. As results indicated that the accumulation of lipid drop caused by TX injection were mitigated by the antihyperlipidermic effect of CB extract.

표준화 환자를 이용한 가천의대 임상수행평가의 운영 경험

박귀화(Gwi Hwa Park),오재환(Jae Hwan Oh),박연호(Yeon Ho Park),임영희(Young Hee Lim),이선녀(Sun Neo Lee),박찬용(Chan Yong Park),김선숙(Sun Suk Kim),임용수(Yong Su Lim),이영돈(Young Don Lee),김용일(Yong Il Kim) 한국의학교육학회 2005 Korean journal of medical education Vol.17 No.2

Purpose: This study aims to abstract the differences of scores between the clinical instructors and standardized patients (SPs) in a clinical performance examination (CPX) using SPs and to correlate the concordance between the evaluation scores and the school records. Methods: The CPX was administered in 2003 to a total of thirty-six fifth year medical students at Gachon Medical School. The examination consisted of four cases, and four stations were duplicated, each requiring a total of 7.5 minutes per station. Evaluation of the student s performances was conducted by both clinical instructors and SPs using a formatted checklist. Results were analysed by t-test, agreement rates, and Pearson correlation. Result: The mean scores given out by the clinical instructors and the SPs for the newly developed case were significantly different, while those scores for pre-existing cases were not in the old cases. The correlation coefficients between these two evaluation groups were relatively high. And agreements between the two evaluation groups were 0.37~0.72. The mean scores among clinical instructors were not significantly different, but the correlation coefficients and agreement rates were relatively high. The correlation between the evaluation scores and school records did not correlate significantly. Conclusion: It is concluded that the CPX is a useful tool to measure the students essential competences in areas of knowledge, skills and attitude during the subinternship stage. In conducting a successful CPX, it is crucial to reconsider the recycling of cases and the selection and training of SPs aside from the development of an objective checklist.