디스크 배열

元裕憲,金鍾勳,盧三赫 弘益大學校 科學技術硏究所 1995 科學技術硏究論文集 Vol.6 No.-

Disk arrays were proposed in the 1980`s as a way to allow parallelism between multiple disks to improve aggregate I/O performance. Today they appear in the product lines of most major computer manufactures. This paper gives a comprehensive overview of disk arrays and provides a framework in which to organize current and future work. First, this paper introduces disk arrays in general, and reviews the driving forces that have popularized disk arrays : performance and reliability. It discusses the two architectural techniques used in disk arrays, striping across multiple disks to improve performance and redundancy to improve reliability. Next, this paper describes 6 disk array architectures, namely RAID levels 0∼5. It goes on to discuss advanced research and implementation topics such as the way in which parity is distributed in a RAID, and the means of refining the basis RAID levels to improve performance. Finally, this paper describes software disk arrays which allow writing data redundantly across an array of disks in workstations distributed across the network.

동진강 유역 비점오염원 정밀조사

원찬희,정팔진,김민정,조선영,김세훈,김종천 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

Nonpoint source pollution(NSP) arises due to agriculture activity and it is quite an extensive and complicated problem in order to control and has received a great deal of concern during the recent years, whereas point source are known to originate from an estimated volume of contaminant discharged from a distinguishable source. Extensive research work have been conducted and presented in the past with regard to the various characteristics of watershed on Dong Jin River(DJR), however there are certain drawbacks of existing survey for determining important polluting sources, distribution features of pollutants and estimated load of the organic and nutrients from the creeks. Unfortunately, investigation for loadings originating due to agricultural drainage was not satisfactory, although the regional consideration for DJR across Kim Je Field(KJF) as an agricultural area receives a reasonable source point in the agri-pollution management. Therefore it was necessary to carry out a thorough investigation into the diffuse sources resulting, to form the pollution-developing estimation and to evaluate the output roperties and determining various factors in the generation of non-point pollution. Eventually, this research work would serve as an useful tool for the development of predictive pollution management for DJR. Non-point sources in the present work were classified as municipal non-treated sewage water discharged into the river, loadings through agricultural drainages in the dry/wet field and inadequate treatment of wastewater generated from livestocks. The entire duration of the research work was from December-2001 to July-2002. Site measurement were conducted during various season, in a dry season(December), in rainfall, in seed-sowing time and also collecting data from the rural public organizations related to water management was done and examined and examined during the mid of research work. Similarly, domestic wastewater loadings due to population was based on area unit, as City, Country, Up, Myon, Dong, Ri. The Dong Jin River watershed contains small three Creeks, KoBu(KB), DongJin(DJ, including JeongEup(JE) and ChilBo(CB), WonPyong(WP). It was further divided into 32 sub-watersheds which comprises of further 5,18,9 watersheds in the creeks respectively. The results obtained from research work are presented as follows. Animal productions have marked differences in the rate of pollutant loadings reported in the following sequence: DJ(only CE)>WP>CB>KB, in a case of Korean cow and milk cow. However, it was revealed that WP creek became significantly higher than any other livestocks. According to statistical data for land use, rice field(369.0㎢) and forest(378㎢) have much occupation prior to dry paddies(125.0㎢), residential land(32.0㎢) and others(5.0㎢). Especially, rice fields receives 2.5∼3 times than dry paddies in size.

수액 세트의 Drip Chamber를 이용한 상부소화관의 이물 제거 1예

서종훈,양미진,이진성,이상호,김정원 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.2

In the upper gastrointestinal tract, in particular, there are parts consisting of esophageal sphincter muscles to carry out physiologic functions, which causes impairments when removed, as well as such complications as mucosal injuries, bleeding and even perforations in the case of foreign bodies with large size and/or sharp angles. Therefore, it is essential to use an appropriate type of supplementary instrument for a safe procedure. Frequently utilized supplementary instruments are overtube, protector hood, latex glove and transparent cap. We report a case in which authors were successful in removing a watch bend consisting of metal ring from gastric body while using a modification of a widely available drip chamber of fluid set attached to vertical end of endoscopic device.

내시경적 절제로 진단된 폴립 형태의 심재성 낭종성 위염 2예

허종현,조영화,성용완,유재훈,구동영,김갑식,노지훈,문원 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.2

Gastritis cystica profunda (GCP) is a disease characterized by hyperplastic and significant extension of cystic dilatation of the gastric mucous glands, which results in a cystic lesion in gastric submucosa. It often occurs on the part of gastroenterostomy, but can be found in the stomach without any previous surgery. GCP has variable gross finding including solitary polyps, diffuse ones, submucosal tumors, and rare giant gastric mucosal fold. It is difficult to tell GCP from a cancerous lesion by gross finding that the disease demands a necessary tissue biopsy, though GCP is commonly showed as a benign in the progress. We report a case of GCP in polypoid types diagnosed by endoscopic polypectomy.

멀티미디어 서버에서 효율적인 승인 제어 알고리즘 설계

元裕憲,朴勇,金鍾勳 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-

A server of client-server environments has to not only minimum delay time, but also realtime processing of job. Specially, multimedia systems are need to an efficient admission control algorithm, because of clients of big-size data need to maximum processing and realtime processing. In this paper, we propose an admission control algorithm that considers both realtime requests and non-realtime requests. The proposed algorithm minimizes delay time about requests of client and efficiently uses resources of system. Using comparisons between a previously proposed algorithm and the proposed algorithm we show that the proposed algorithm improves performance in the aspect of the delay time and consumed buffer size.

신뢰성을 제공하는 효율적인 분산 파일 시스템

元裕憲,金鐘勳,安柔貞 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.2

Current network file system protocols rely heavily on a central server to coordinate file activity among client workstations. This central server can become a bottleneck that limits scalability for environments with large numbers of clients. In central server systems such as NFS and AFS, all client writes, cache misses, and coherence messages are handled by the server. To keep up with this workload, expensive server machines are needed, configured with high-performance CPUs, memory systems, and I/O channels. Since the server stores all data, it must be physically capable of connecting to many disks. This reliance on a central server also makes current systems inappropriate for wide area network use where the network bandwidth to the server may be limited. In this paper, we investigate the software RAID file system, writing data redundantly across an array of disks in each of the workstations on the network. By striping across enough disks, each workstation can appear to have disk bandwidth limited only by the network link bandwidth. Availability of a software RAID file system could be better than in other distributed file systems, because there is no central host to be a single point of failure. If one workstation crashes, any other can take its place in controlling the RAID. We present results from a trace-driven simulation study of the network file system protocol. We find that the software RAID file system improves the performance in the aspect of the av, age response time when compared with NFS protocol.

알레르기성 진균성 부비동염 1예

동헌종,윤성원,정승규 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.7

CMS에서 전력제어를 위한 AGC의 성능 개선에 관한 연구

이원구,이철희,천종훈,박수봉,박종안,신용길 조선대학교 동력자원연구소 1996 動力資源硏究所誌 Vol.18 No.1

CDMA 시스템에서는 이동국이 Open-loop 전력제어 및 Close-Loop 전력제어를 할 때 비 선형적인 AGC의 특성으로 인해 수신기의 감도가 현저히 낮아진다. 본 논문에서는 AGC의 비선형적인 특성 곡선값을 S/W로 선형화 시켜 RAS RAMDATA를 생성하고 이를 RAS RAM에 넣어 선형적으로 보상된 AGC특성을 얻는 알고리즘을 제안하였다. 그리고 실험을 통하여 그 유효성을 증명한다. In CDMA system, the sensitivity of receivers is lowered significantly due to characteristics of non-linear AGC when the mobile station implements open-loop power control and closed-loop power control. In this paper, We propose a algorithm that obtains linearly conpensated AGC characteristic by inserting the RAS RAM DATA in RAS RAM, which linearizes the value of non-linear characteristic graph in AGC by S/W, and the experimental results shows the validity.

수종의 세멘트가 근관 치료된 치아의 포스트 유지에 미치는 영향

김종원,이청희,조광헌 慶北大學校 齒科大學 1993 慶北齒大論文集 Vol.10 No.2

근관치료된 치아에 포스트를 할 경우 세멘트의종류와 포스트의 직경이 포스트의 유지력에 어떠한 영향을 주는지 알아보기 위하여, 하악절치 33개와 견치 17개를 이용하여 법랑-백악질 경계선상에서 치아장축에 수직되게 절단한 후 근관치료 및 근관충전을 하였다. 기성품의 parallel Para-post를 샌드브라스팅하여 깊이 7mm로 하여, Ⅰ에는 Z,P,C., Ⅱ에는 Panavia, Ⅲ군에는 All-Bond 및 복합레진으로 세멘트하였다. 1주일간의 레진 세멘트 경화시간을 준 후 인스트론 만능시험기에 치아를 거상하고 cross head speed 1mm/min로 인장력을 가하여 유지력을 측정하고, 치근 내부를 주사 전자 현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1. 하악절치에서 평균 파단하중은 Ⅲ군에서 48.49±13.51Kg중, Ⅱ군에 서 21.47±9.32Kg중, Ⅰ군에서 21.34±7.85Kg중의 순서로 나타났으며 Ⅲ군이 Ⅰ군과 Ⅱ군에 비해 통계적으로 유의성있는 차이를 나타내었다(P<0.01). 2. 견치에서 평균 파단하중은 Ⅲ군에서 42.99±7.87Kg중,Ⅰ군에서 29.58±7.47Kg중, Ⅱ군에서 28.55±4.37Kg중으로 Ⅲ군이 Ⅰ군과 Ⅱ군에 비하여 통계적으로 유의성있는 차이를 나타내었다(P<0.05). 3. 포스트 직경의 크기에 따른 파단하중의 비교에 있어서, 각각의 실험군 내에서 Φ1mm의 하악절치와 Φ 1.25mm의 견치 사이에는 통계적 으로 유의성이 없었다(P>0.05). 4. 레진의 기계적 결합을 관찰하기 위한 주사전자 현미경 관찰에서 Ⅱ군에서는 상아질 세관내에 레진 tag가 관찰되지 않았으며, Ⅲ군 에서는 상아질 세관내에 레진tag가 상당히 관찰되었으나, 일부 치아에서는 관찰되지 않은 경우도 있었다. The prupose of this study was to evaluate the effect of various cements and the diameter of posts to retention of the post in endodontically treated teeth. Thirty three mandibular incisors and seventeen canines were used. The coronal portion of the teeth were removed at the cemento-enamel junction. Every tooth was made with a Para-post drill to the depth of 7mm(P-42-4 in mandibular incisors, P-42-5 in canines). The teeth were divided into three groups. Group Ⅰ was composed of 11 mandibular incisors & 6 canines, and posts were cemented with zinc phosphate cement. Group Ⅱ was composed of 11 mandibular incisors & 6 canines, and posts were cemented with Panavia cement. Group Ⅲ was composed of 11 mandibular incisors & 5 canines, and posts were cemented with All-Bond & composite luting cement. A special retention jig was made. After 1 week, teeth with cemeted posts were mounted on a retention jig and the failure loads of the specimens were measured by an Instron Universal Testinng Machine. Scanning electron microscopy examined the internal surface of the roots. The results were as follows; 1. There was a statistically significant difference between the failure loads of group Ⅲ and the others in the mandibular incisors(P<0.01). 2. There was a statistically significant difference between the failure loads of group Ⅲ and the others in canines(P<0.05). 3. There was no statistically significant difference between degrees of diameter of post in each experimental group(P>0.05). 4. In examination by scanning electron microscopy, group Ⅱ had no resin tags on the dentinal tubules. Group Ⅲ had resin tags on the dentinal tubules, though not present in some parts.

Baculovirus를 利用한 Canine Parvovirus VP2蛋自質의 發現

朴鍾賢,宋載永,玄芳動,安動濬,姜永源,全茂炯,安壽煥 충남대학교 생물공학연구소 1998 생물공학연구지 Vol.6 No.-

국내에서 分離된 개파보바이러스주(V20주)의 VP2 遺傳子를 baculovirus system을 이용하여 발현시켜 다음의 結果를 얻었다. 1. 개파보바이러스의 VP2 유전자를 PCR에 의해 增幅하여 1755bp의 VP2遺傳子를 pUC19에 클로닝하여, 클로닝된 遺傳子를 polyhedrin promoter를 가지는 baculovirus expression vector인 pVL1393에 옮겨 VP2 발현벡터인 pVL1393-VP2를 얻을 수 있었다. 2. pVL1393-VP2 plasmid와 baculovirus DNA와의 homologous recombination에 의해 재조합바이러스인 VP2-BV를 얻을 수 있었으며, 그 발현효율은 2.000-5.000 HAU/0.05 ml이었다. 3. 免疫沈澱法에 의해 발현된 단백질은 개파보바이러스의 VP2단백질과 유사한 64 kb에 달하는 것이었으며, 血球凝集能을 지니고 있었다 4. 血球凝集能을 지닌 蛋白質이 여러 陽性血淸에 있어서 抗體수준을 測定할 수 있는지 개파보바이러스항원과의 相關性을 比較한 바 0.94 (n=125. p<0.01)의 相關係數를 보였다 5. 발현 VP2白은 virus-like particles를 形成하였으며, 그 크기로는 개파보바이러스와 비슷한 25 ㎚의 크기를 갖았다. Canine parvovirus(CPV) is a member of autonomous replicating parvoviruses and is aetiologically associated with enteritis and mycoarditis in puppies. The capsids of CPV are composed of three structural proteins: VP1, VP2 and VP3. The VP2 protein is the major component of capsid. The VP2 gene of a canine parvovirus. V20 strain isolated in Korea was cloned into baculovirus expression vector, and subsequently the VP2 protein was expressed by a recombinant baculovirus under the control of polyhedrin promoter. The recombinant VP2 protein expressed in Spodoptera frugiperda 9(Sf9) cells was detected by haemagglutination(HA) test and immunofluorescent antibody assay. Molecular weight of the recombinant VP2 protein expressed was estimated as 64Kd when tested by immunoprecipitation test using anti-CPV monoclonal antibody. In haemagglutination inhibition(Ⅲ) test. 8 HA units of the recombinant VP2 protein antigen was successfully utilized to determine a level of antibody against CPV in various positive sera. The recombinant VP2 protein showed also the capability to form virus like particles similar in size and appearance to the CPV virions.