LAN 환경하에서 효율적인 원격강의 시스템의 설계 및 구현

유종훈,이병수 순천향대학교 부설 산업기술연구소 1998 순천향 산업기술연구소논문집 Vol.4 No.2

In this thesis. we present a multimedia tele-lecturing system that supports a real-time bidirectional learing through the computer networks. The proposed system, which is a multimedia tele-lecturing system based on a model of real classroom, consists of the multimedia authoring tool, the BBS system and the remote lecture system. A instructor can build conveniently educational materials such as examination papers by using the authoring tool, Through the BBS, learners can communicate the questions and answers with their instructor. The remote lecture system provides an environment in which the instructor and learners can navigate the courseware prepared for the lecture. This ability can be carried out though the real-time video conferencing, the shared workspace and the monitoring tools. In this thesis, we fist analyze the functional requirements, and then describe the design specification and the implementation details of the system.

PLL에서의 루프필터 특성에 관한 연구

유종훈,이병수 순천향대학교 부설 산업기술연구소 1998 순천향 산업기술연구소논문집 Vol.3 No.3

In this paper, a phase-locked loop(PLL) designed and simulated with todays general simulation, PSPICE PLL consists of a phase detector(PD), a voltage-controlled oscillator(VCO), and a low-pass filter(LPF). LPF out of them does a great deal of effect to the frequency characteristics of PLL. By using a RC LPF, a Butterworth, and a Chebyshev LPF in turn, the frequency characteristics of the outputs according to the variations of the inputs are analyzed respectively. When 2.5KHz is selected as specified free running frequencies in VOC block, the characteristics of the outputs show that in case of 3rd order Chebyshev LPF, the capture and lock range are 1076Hz and 2112Hz respectively. Besides, this paper shows some validity that this macromodeling technique is one of the easy and accurate methods in analyzing the frequency characteristics, and useful in simplifying the circuits.

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.

Vector 合成法을 이용한 Booming Noise 低減에 關한 硏究

김재열,유신,오성민,장종훈,김갑중 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

Booming Noise of a Automotive can be divided in Air Borne Noise and Structure Borne Noise. In this study, Booming Noise is reduced by the vector Synthesis method. The vibration that transferred by the engine is managed. The car that by the used model is composed of Mount system supported to three point with 2000 cc 14 engine FR vehicle. The vibration that is transmitted from propeller sharft and Differential Gear to Sub Frame and Suspention effect Booming Noise. but, The vibration that generated by the Mount has Booming Noise more than it. So, We research that sound generated by the Mount and reduce that Booming Noise used the Dynamic Damper. The Booming. Noise by the vector Synthesis. is reduced in 2000 ~ 4000 rpm front of vehicle. We know that Booming Noise is reduced into hoped for rpm by the vector Synthesis.

제주도 동부 연안역의 생물생태학적 기초연구(ll) 우도주변 식물 플랑크톤 군집동태와 일차생산력

이준백,좌종헌,고유봉,최영찬 濟州大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.7 No.1

제주도 동부연안역인 우도해역에서 1991년 9월부터 1992년 6월까지 격월로 식물플랑크톤 동태와 일차생산력의 수평적 및 수직적 정성, 정량자료를 분석하였다. 조사기간중 출현한 총 출현종수는 89종이며 규조류가 가장 많았고 그 외 와편모조류와 규질편모조류가 출현하였다. 이중 Chaetoceros diadema, C. socialis, Skeletonema costatum, Prorocentrum micans가 계절적 천이경향을 보이면서 우점하였다. 개체수의 월변화는 4,116∼588.68cells/l의 범위로써 11월에 최소치, 3월에 최대치를 보였다. 개체수의 수직분포는 수괴의 수직혼합 및 성층과 밀접한 관계를 보이고 있다. 수층의 평균 일일 일차생산력은 연안역 (정점1)에서 210.17(4.34∼588.68)mgC/m²/day, 외해역(정점7)에서 309.35(4.25∼804.55)mgC/m²/day를 나타내었다. 미세식물플랑크톤 (<20㎛)의 총 일차생산력에 대한 비율은 연안에서 37.6%와 외해에서 67.6%를 차지하며 외해역에서 더 높은 생산력을 보였다. 식물플랑크톤의 동화계수는 표층에서 0.17∼12.05mgC/mgChl-a/hr의 범위로써 춘계와 하계에서 높았다. 와편모조류중 Prorocentrum micans의 대발생은 하계의 저염현상과 밀접한 관계를 보였다. This study has been carried out to understand the dynamics and primary productivity of phytoplankton around U-do, eastern part of Cheju Island from September 1991 to June 1992. During the survey a total of 89 species were identified, comprising mainly diatom, and dinoflagellate and silicoflagellate as minority. Of these, Chaetoceros diadema, C. socialis, Skeletonema costatum, Prorocentrum micans predominated with seasonal succession. The cell number ranged from 4,116 to 812,748cell/l, showing the minimum in November and the maximum in March. The vertical distribution of cell number related closely with the vertical mixing and stratification of the water mass. The mean depth-integrated primary productivity was 210.17 (4.34∼588.68)mgC/㎡/day at st.1 (nearshore) and 309.36 (4.25∼804.55)mgC/㎡/day at st. 7 (offshore). The nanoplankton fraction (<20㎛)accounted for 37.4% and 67.6% of total primary productivity at st. 1 and st.7, respectively, representing higher productivities at offshore than at nearshore. Assimilation number by phytoplankton at the surface ranged from 0.17 to 12.05mgC/mgChl-a/hr, showing higher values in spring and summer. Dinoflagellate bloom of Prorocentrum micans may have a close relationship with the presence of lower salinity in summer.

제주도 문섬 산호서식지 주변의 생물생태학적 특성 Ⅱ. 식물플랑크톤의 군집동태와 1차생산력

이준백,좌종헌,강동우,고유봉,오봉철 제주대학교 방사능이용연구소 2000 연구보고 Vol.14 No.-

Community dynamics of phytoplankton and primary productivity have been investigated bimonthly from February 1997 to December 1997 in the coastal area around Moonsom of the southern Cheju Island, which is well-known for soft coral habitats in Korea. Average water temperature was 18.5℃ , being stratified from May to September by the seasonal thermocline, while vertically homogeneous in the winter. Euphotic depths ranged from 18.9 m to 45.9 m (average 33.7 m). Chlorophyll α concentrations varied from 0.02 to 0.92 ㎍ · ℓ-1 Standing crops of phytoplankton ranged from 2×103 to 3.9×105 cells · ℓ-1, showing a peak only in the spring. Diatoms occupied 67.5% of the total standing crops, while phytoflagellates, dinoflagellates and others 24.3%, 7.1% and 1%, respectively. However phytoflagellates and dinoflagellates were predominated with 36.6% and 38.7% in June, respectively. There was four dominant species in the study area. Chaetoceros sociales Lauder was dominant species from December to April, Prorocentrum micans Ehrenberg in June. In August, Chaetoceros socialis Lauder dominated in inshore but Paralia sulcata (Ehrenberg) Cleve in offshore. In October, Skeletonema costatum (Greville) Gran dominated the whole area. Daily primary productivity varied from 32.3 to 364.9 mg C · m-2 . day-1 (average 180.7 mgC · m-2 . day-1). Contribution of nanoplankton (<20 ㎛) to daily primary productivity was very high, accounting for 28.0-82.8%. Annual primary productivity is estimated 65.97 gC · m-2 ·yr-1, which is lower than those of the coast of Yellow Sea and the southern waters. Nanoplankton seemed to adopt higher irradiances with Ik values of 190-1,000 □· m-2·s-1 (mean 526.7 □ · m-2·s-1) than total phytoplankton with 140-850 □ ·m-2·s-1 (mean 466.7 □· m-2·s-1).

Dimecron 중독증 환자 6예

류하근,박봉안,류주성,유재등,김정수,김치훈,송종오 건국대학교 의과학연구소 2001 건국의과학학술지 Vol.11 No.-

The authors experienced 6 cases of Dimecron intoxication, an organophosphate, that required mechanical ventilator treatment. Among 6 cases, 4 cases were intoxication due to suicidal attempt and 2 cases were due to accidental exposure. Among 4 cases of intoxication due to suicidal attempt, only one patient recovered even after aggressive treatments using gastric lavage, mechanical ventilation, atropine and PAM(pralidoxime). Two cases of intoxications due to accidental exposure, 1 case needed mechanical ventilation. Both cases were recovered without any sequele, however. Organophosphate, especially Dimecron, showed high rates of resfiratory muscle paralysis and mechanical ventilator support. The mortality rate of organophosphate agents can be decreased by education, wearing protectors, and aggressive mechanical ventilator treatment when respiratory failure develops.

급성충수돌기염으로 발현된 방선균증 2예

조진원,송진영,김창억,민영훈,최창순,우흥정,현인규,김종현,유기철,채승완,손진희 대한화학요법학회 2001 대한화학요법학회지 Vol.19 No.1

The Actinomyces species are normal flora of oral cavity and upper intestine characterized as gram-positive, non-spore-forming anaerobic or mjcroaerophilic rods. Actinomycosis is a chronic suppurative and granulomatous disease characterized by abscess, sinus, abundant granulation and mass. The appendix is the commonly involved site among abdominal actinomycosis. Abdominal actinomycosis is often difficult to diagnose before operation because of no reliable clinical features and infrequency of the disease. We report two cases of abdominal actinomycosis which were manifested as acute appendicitis. Those were detected Incidentally tv the pathologist after routine appendectomy. Both patients were successfully treated with appendectomy followed by proper antibiotics use.

SIMD를 이용한 HEVC 하다마드 트랜스폼의 고속 구현

유종훈(Jong-Hun You),조현호(Hyun-Ho Jo),심동규(Dong-Gyu Sim) 한국방송·미디어공학회 2011 한국방송공학회 학술발표대회 논문집 Vol.2011 No.11

본 논문에서는 SIMD(Single Instruction Multiple Data) 프로세서를 사용한 HEVC 부호화기의 하다마트 트랜스폼 고속화를 제안한다. 본 논문에서는 MMX와 SSE 레지스터를 사용하여 하다마드 트랜스폼을 SIMD 연산으로 대체함으로써 메모리 접근 횟수와 명령어의 수를 줄여 부호화기를 고속화 하였다. 또한, HEVC의 10비트 입력에 따른 SIMD 구조의 비효율적인 구현을 해결하기 위하여 하다마드 트랜스폼의 입력 픽셀 비트수를 감소시키는 IBDD(Internal Bit Depth Decreasing)를 제안했다. HEVC 부호화기에 하다마드 트랜스폼을 SIMD 연산으로 대체한 결과 부호화 효율의 저하 없이, 부호화기의 수행 시간은 10% 감소되었다.

Effects of Gravity Wave Drags by Cumulus Convection on Seasonal Prediction in the Global Circulation Model

Jong-Hun Jeon,Song-You Hong,Hoon Park,In-Sun Song,Hye-Young Chun 한국기상학회 2007 한국기상학회 학술대회 논문집 Vol.2007 No.-