클러스터 컴퓨터를 위한 단일 I/O 공간 서비스의 구현 및 성능분석

김태규,김방현,김종현,Kim, Tae-Kyu,Kim, Bang-Hyun,Kim, Jong-Hyun 한국정보처리학회 2006 정보처리학회논문지 A Vol.13 No.6

클러스터 컴퓨터에 있어서 I/O 중심적인 응용을 효과적으로 처리하기 위해서는 통합 I/O 하부 구조를 지원하는 단일 I/O 공간(SIOS)이 필수적으로 구현되어야 한다. SIOS 서비스는 클러스터 컴퓨터 내의 어느 노드에서든지 자신 혹은 원격 노드에 위치한 주변기기 및 하드 디스크들을 직접 액세스할 수 있도록 전역 I/O 주소 공간을 구축해준다. 본 논문에서는 리눅스 클러스터에서 프리웨어들만을 이용하여 SIOS를 구현하는 방법을 제안하였다. 이 방법은 ENBD를 이용한 디바이스 드라이버 레벨과 S/W RAID 및 NFS를 이용한 파일 시스템 레벨에서 구현되었다. 이 방법의 주요 장점은 프리웨어들만을 이용하기 때문에 구현이 용이하고 비용이 거의 들지 않는다는 것이다. 또한 본 연구에서 사용한 프리웨어들은 공개 소스이기 때문에 다른 플랫폼에서도 약간의 수정을 통하여 적용이 가능하다는 장점이 있다. 이러한 장점을 가지면서도 실험 결과에서 나타난 I/O 처리율은 커널 수준에서 별도로 개발된 디바이스 드라이버를 사용하는 CDD보다 쓰기 동작에서는 최대 5.5배, 읽기 동작에서는 2.3배정도 더 높게 나타났다. In cluster computers, it is essential to Implement the single I/O space(SIOS) supporting integrated I/O substructure to efficiently process I/O intensive applications. SIOS service provides with global I/O address space to directly access peripherals and hard disks in its own or remote nodes from any node in the cluster computer In this thesis, we propose the implementation method of SIOS in Linux clusters by using only freewares. This method is implemented at device driver level that uses Enhanced Network Block Device(ENBD) and file system level that uses S/W RAID and NFS. The major strengths of this method are easiness of implementation and almost no cost due to using freewares. In addition, since freewares used are open sources, it is possible to apply this method to other platforms with only slight modification. Moreover, experiments show that I/O throughputs are up to 5.5 times higher in write operations and approximately 2.3 times higher in read operations than those of CDD method that uses the device driver developed at kernel level.

선체 교류 전자장 제거를 위한 능동 축 접지 시스템 설계

김태규,안호균,윤태성,박승규,곽군평,Kim, Tae-kue,Ahn, Ho-kyun,Yoon, Tae-sung,Park, Seung-kyu,Kwak, Gun-pyong 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.6

최근 선박의 부식을 방지할 목적으로 전기적인 방식 장치를 이용하여 선체와 프로펠러의 부식을 방지하는 장치가 많이 이용되고 있는 추세이다. 그러나 전기적 방식 방법은 선체 내부의 전원장치에 의해 선체 주위의 해수로 전류를 방사하여 선체와 프로펠러가 부식이 되지 않는 상태로 인위적으로 만들어 주는 방법을 사용하는데, 해수에 방사되는 방식전류로 인하여 선체 외부에서 전자장 신호가 발생하게 된다. 본 논문에서는 선체 외부의 수중에서 발생하는 전자장 신호를 분석하고, 이에 대한 감소 대책에 대한 연구를 수행하는 것을 목표로 하였다. 기존의 축 접지 시스템에서는 축 전위가 100[mV] 이상 이며, 교류 전류 성분이 전체의 10% 이상을 차지하였으나, 본 논문에서는 방식전류내에서 교류전자장을 발생하는 교류 전류 성분과 축 전위가 각각 1% 와 2[mV]이내로 유지되게 하는 제어 시스템을 설계하고, 모의 실험을 통하여 그 성능을 입증하였다. Recently, for the purpose of preventing the corrosion of a vessel, the electrical corrosion protection device that prevents the corrosions of the hull and the propeller is widely used. However, the electrical corrosion protection method artificially emits the current into the seawater around the hull using the power supply in order to make the hull and propeller be in the state of not being corrosion, so that electromagnetic field is generated outside the hull by the current emitted into the seawater. In this paper, the static and alternating constituents of the electromagnetic field generated in underwater outside the hull are analyzed and a countermeasure is investigated to reduce the strength of the electromagnetic field. In conventional shaft grounding system, the shaft potential is maintained above at least 100mV and the alternating current component constitutes more than 10% of the total current. However, in this paper, a control system was designed in order that the alternating current component and the shaft potential which generate electromagnetic field are maintained within 1% and 2mV respectively, and the performance was verified by simulation.

자외선 조사된 Magnesium Aluminum Spinel의 Supralinearity

김태규,Kim, Tae-Kyu 한국의학물리학회 2005 의학물리 Vol.16 No.4

Magnesium Aluminum Spinel ($MgAl_2O_4$)은 자외선 선량계에로 응용성을 가지고 있는 Aluminum oxide와 유사한 물리 화학적 특성을 가지고 있다. $MgAl_2O_4$의 자외선 선량계로 응용하기 위한 열자자극발광 특성을 조사하였다. 자외선 조사된 $MgAl_2O_4$의 3차원 열자극발광 스펙트럼을 300${\~}$600 K 및 300${\~}$800 nm 범위에서 측정하였다. 자외선 조사시간의 증가함에 따라 열자극발광 곡선의 정점 온도는 낮은 쪽으로 이동하였다. 476 K 정점의 열자극발광 곡선은 second-order kinetics이고, 활성화 에너지 및 이탈진동수는 각각 0.85 eV 및 $1.92{\times}10^6\;sec^{-1}$이다. 열자극발광 스펙트럼은 530 nm 및 700 nm 방출 스펙트럼으로 나눠지고, 이들은 각각 $V^{2+}$와 $Cr^{2+}$에 포획된 양공에 기인한다. 700 nm 열자극발광의 선형성이 530 nm 보다 작은 반면, 700 nm 열자극발광의 포화는 530 nm 보다 더 많은 조사시간에서 나타난다. Three-dimensional thermoluminescence (TL) spectra from $MgAl_2O_4$ irradiated with UV light were measured over 300${\~}$600 K and 300${\~}$800 nm. The peak positions of TL glow curves were shifted to lower temperature with increasing the exposure time of UV light. The 476 K TL glow curve is due to the second kinetics and its activation energy and escape frequency factor are calculated to be 0.85 eV and $1.92{\times}10^6 sec^{-1}$, respectively The TL spectra were split into 530 nm and 700 nm emission bands which were associated with $V^{2+}$ and $Cr^{2+}$, respectively. The linearity range of 700 nm omission band is smaller than that of 530 nm emission band, but the saturation time of 700 nm emission band is longer than that of 530 nm omission band.

Gore-Tex^TMmembrane과 COLLACOTE^®를 이용한 골유도 재생술의 조직학적 비교 연구

김태규,장창덕,김철훈,Kim, Tae-Kyu,Jang, Chang-Dug,Kim, Cheol-Hun 대한악안면성형재건외과학회 1997 Maxillofacial Plastic Reconstructive Surgery Vol.19 No.1

The principle of guided tissue regeneration (GTR), as applied to bone healing, is based on the prevention of connective tissue from entering the bony defect during the healing phase. This allows the slower bone producing cells to migrate into and reproduce bone within the defect. GTR has demonstrated a level of success in regenerating bone defect. Several types of membrane barrier have been utilized to apply this principle in bone regeneration. The purpose of this study was to evaluate whether improved bone regeneration can be achieved with different membrane barriers ($Gore-Tex^{TM}$membrane, $COLLACOTE^{(R)}$). In the 10 NewZealand white rabbits, full-thickness bone defects on three sites of each rabbit calvaria were made. Experimental group 1 was covered with $COLLACOTE^{(R)}$, and group 2 was covered with $Gore-Tex^{TM}$membrane. Macroscopic, microscopic examinations were made serially on 1, 2, 3, 6, 12 weeks after operation. The results were as follows : 1. Macroscopically, both of experimental group 1, 2 were filled with bone-like mass but the defects of experimental group 1 disclosed markedly thinner than the original bone. 2. Microscopically, the defect of experimental group 1, 2 was filled with bony trabeculae without infection and adverse reaction. But multinucleated giant cell infiltration around $COLLACOTE^{(R)}$ was seen till 6th week. 3. Resorption of $COLLACOTE^{(R)}$ started from 3rd week and it was completely resorped on the 12th week.

Taxonomy of the Genus Eudectus Redtenbacher (Coleoptera: Staphylinidae: Omaliinae) in Korea

김태규,안기정,Kim, Tae-Kyu,Ahn, Kee-Jeong Korean Society of Applied Entomology 2014 한국응용곤충학회지 Vol.53 No.2

한국 미기록속인 넓은가슴네눈반날개속(Eudectus Redtenbacher) (신칭)의 분류학적 연구 결과, 넓은가슴네눈반날개(E. japonicus Zerche) (신칭)와 배무늬넓은가슴네눈반날개(E. rufulus Weise) (신칭) 두 종을 국내에 처음 보고한다. 두 종에 대한 재기재, 진단 형질의 그림, 그리고 검색표를 제시한다. A taxonomic study of the genus Eudectus Redtenbacher in Korea is presented. Two species, E. japonicus Zerche and E. rufulus Weise, are newly added to the Korean fauna. Redescriptions, illustrations of the diagnostic features, and a key to the species are provided.

Open-Top chamber 내(內)에서 오존에 노출(露出)시킨 현사시 5개(個) 클론의 생장량(生長量)과 오존에 대(對)한 민감성(敏感性)과의 관계(關係)

김태규,이경준,김군보,구영본,Kim, Tae Kyu,Lee, Kyung Joon,Kim, Goon Bo,Koo, Yong Bon 한국산림과학회 2000 한국산림과학회지 Vol.89 No.1

본 연구는 수목의 오존에 대한 피해정도가 수목 고유의 생장속도와 관련되어 있는지를 검증하기 위하여 실시하였다. 생장이 우수한 현사시(Populus alba ${\times}$ P. glandulosa) 4호 품종 중에서 두 개 클론(72-30, 72-16)과 생장이 비교적 저조한 현사시 2호 품종 중에서 3개 클론(72-28, 72-27, 72-19)을 본 실험에서 비교하였다. 위의 5개 클론의 삽수를 4월초 $2{\ell}$ 화분에 삽목하여 증식시킨 후, 8월 하순에 야외에서 3개의 open top chamber(직경 2.5m, 높이 2.0m) 내에서 30일 동안 70ppb와 130ppb의 오존에 1일 5시간씩 노출하였다. 대조구는 활성탄으로 여과하여 오존의 농도가 30ppb이하로 유지되도록 하였으며, 각 클론별, 처리별로 20개의 화분을 반복으로 사용하였다. 대조구에서 두 품종간의 생장비교는 현사시 4호가 현사시 2호보다 잎 건중량에서 73%, 뿌리 건중량에서 64%, 총건중량에서 38% 더 우수하여 현사시 4호의 생장속도가 2호보다 우수함을 입증하였다. 오존에 의한 가시적 피해는 70ppb 오존처리에서는 나타나지 않았으며, 130ppb 처리에서 현사시 4호에서만 관찰되었으며, 성숙잎에서 전형적인 작은 갈색 반점들로 나타났으며, 성숙잎의 조기낙엽을 가져왔다. 70과 130ppb 오존처리는 5개 모든 클론의 수고생장, 잎과 뿌리의 건중량과 총건중량을 감소시켰는데, 이 중에서 뿌리생장을 가장 크게 감소시켰다. 70ppb 오존에서 뿌리의 감소량은 현사시 4호가 39.7%이고, 현사시 2호는 13.8%이었다. 130ppb 오존에서도 현사시 4호의 뿌리감소량은 47.4%이고, 현사시 2호는 34.9%이었다. 이로 인하여 shoot/root율은 130ppb에서 현사시 4호는 63.4% 증가한 반면, 현사시 2호는 22.1% 증가에 그쳤다. 오존에 의한 가공전도도와 순광합성량의 변화에서도 현사시 4호가 현사시 2호보다 더 많이 감소하였다. 특히 130ppb 오존에서 현사시 4호의 순광합성량은 69.5% 감소한 반면에, 현사시 2호는 31.5% 감소하였다. 따라서 위의 여러 가지 생리적 반응을 근거로 하여 생장이 우수한 현사시 4호가 생장이 상대적으로 적은 현사시 2호보다 오존에 더 민감하다고 판단할 수 있으며, 수목의 오존에 대한 피해정도는 수목 고유의 생장속도가 관련되어 있다고 결론 짓는다. This study was conducted to test a hypothesis that sensitivity of trees to ozone exposure was related to their growth rates. Two cultivars of Populus alba ${\times}$ P. glandulosa with different genetic growth potential were used for the comparison. Two clones(72-30, 72-16) of cultivar No. 4 with fast growing potential and three clones(71-28, 72-27, 72-19) of cultivar No. 2 with slow growing potential were propagated in early spring by cutting in $2-{\ell}$ plastic pots. They were grown outdoor for 5 months and exposed in late August for 30 days to 70 and 130ppb ozone in a open-top chambers(2.5m in diameter and 2m in height). Ozone concentration in a control chamber was maintained below 30ppb by filtering with activated charcoal. Each treatment was replicated twenty times. In a control chamber, cultivar No. 4 grew 73%, 64%, and 38% faster than cultivar No. 2 in leaf weight, root weight, and total dry weight, respectively. Visible injury was observed only in cultivar No. 4 in 130ppb treatment. Ozone treatment at both 70 and 130ppb decreased height growth, dry weight of leaf, root, and entire plants in all five clones. Particularly root growth was reduced by 39.7% and 13.8% in cultivar No. 4 and No. 2, respectively, in 70ppb treatment. Consequently, shoot/root ratio of cultivar No.4 was increased by 63.4%, while that of cultivar No.2 was increased by 22.1%. Stomatal conductance decreased more in cultivar No.4 than in cultivar No.2. Net photosynthesis of cultivar No.4 at 130ppb ozone decreased by 69.5%, while that of cultivar No.2 decreased by 31.5%. Above mentioned physiological responses of two cultivars to ozone strongly suggested that fast growing cultivar No.4 was more sensitive to ozone than slow growing cultivar No.2. It was concluded that sensitivity of trees to ozone exposure was closely related to their growth rates.

바이오필터와 황-석회석을 이용한 마을하수 처리 공정 개발

김태규,Kim, Tae-Kyu 한국농공학회 2007 한국농공학회논문집 Vol.49 No.2

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

바이오필터와 황-석회석을 이용한 단일흐름 공정에서의 질산화와 탈질 연구

김태규,Kim, Tae-Kyu 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.5

When denitrification was connected with a single stream process by using biofilter and sulfur-limestone, it was found that such connection enabled highly efficient nitrification without special unit operation of microorganisms or injection of external carbon sources which is being shown in general biological treatment processes. It was observed that in the trickling filter bed, decomposition of organic substances and highly efficient nitrification by both the forced pressure feed trickling and the air fan were simultaneously done. In the denitrification tank where sulfur-limestone was mixed at a certain ratio, limestone was used by autotrophic microorganisms as a source of supply for alkalinity, and nitrate $NO_{3}^{-}$-N was denitrified into nitrogen gas. And in the sulfur-limestone autotrophic denitrification, $NO_{3}^{-}-N\;or\;NO_{2}^{-}-N$ was denitrified as a sulfur compound in reduction state was oxidized into a final output of $SO_{4}^{-2}$. The mean concentration of the discharge water was 8.6 mg/l for T-N and 0.8 mg/l for T-P, respectively, and their mean treatment efficiency was 79.2% and 80.8%, respectively. Implementing highly efficient denitrification without injection of an external organic carbon source or internal return, it is concluded that the proposed process is suitable for a sewerage in a small village with the merits of low power consumption and easy maintenance.

헤일레이션 방지 디스크를 이용한 소형 카메라 이미지 화질개선 연구

김태규,송인호,한찬호,Kim, Tae-Kyu,Song, In-Ho,Han, Chan-Ho 한국융합신호처리학회 2016 융합신호처리학회 논문지 (JISPS) Vol.17 No.1

본 논문에서는 소형 카메라 모듈의 화질을 분석하는 시스템을 제안하고 이를 이용하여 렌즈의 성능을 평가하며, 플레어 및 헐레이션 방지 디스크를 삽입하여 렌즈의 성능이 개선되는 효과를 검증한다. 카메라 모듈의 화질을 평가하는 카메라 모듈 화질검증 시스템과 이미지 신호 처리기(Image Signal Processor, ISP) 내부의 레지스터를 제어하는 카메라 모듈 제어 프로그램 및 화질분석 소프트웨어를 개발한다. 제안된 헐레이션 방지 디스크를 삽입된 카메라 모듈의 화질을 기존 카메라 모듈의 화질과 비교평가에서 획득된 영상의 해상도, 밝기, 색재현 등의 성능을 검증한다. In this paper, we propose an image quality evaluation system for compact camera module and assess the effect of optical performance improvement for proposed anti-halation disk in small lens. We develop a image quality evaluation system for quality estimation of camera module image. And we also develop a program to control register in image signal processor. Finally the resolution, brightness, and color reproduction performances were evaluated image quality comparison between conventional and proposed camera module using developed quality evaluation system and ISP register control program.

커먼레일 디젤엔진의 연료분사계 최적화 연구

김태규(Tae-Kyu Kim),이웅건(Woong-Gun Lee),강승천(Sung-Chon Kang),이동인(Dong-In Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The major purpose of this study is to find optimized Injector nozzle's hole-number, hole-hyd.flow and injection pressure, injection-timing in order to achieve their NOx reduction targets while minimizing smoke and fuel economy penalty. The tests were performed on a 6 ℓ Common Rail Diesel Engine to use commercial-vehicle, excavator, wheel-loader, fork-lift truck. In this study, two case of injector nozzle's hole-number(#7, #8) and three case of injector nozzle's hole-hyd.flow(Standard, +7%, -7%) were tested for their relation of NOx, BSFC, smoke by changing injection-pressure, injection-timing. From the test, we find that injector nozzle's hole-number, #8 and hole-hyd.flow, Standard are optimized at this engine. And we find engine performance and emission trend by changing injection-pressure and injection-timing.