임하호의 (臨河湖) 식물성 플랑크톤 군집 분석

김용재,정준 ( Yong Jae Kim,Jun Chung ) 한국하천호수학회 1993 생태와 환경 Vol.26 No.3

This study investigated to the composition of phytoplankton community and its ecological factors in the Imha lake changed from the stream environment to the lake environment as the result by the construction of a multiple-purpose dam from Mar. to Dec. in 1992. Phytoplankton community was total 234 taxa composed of 7 class, 14 orders, 6 suborders, 39 families, 95 genera, 199 species, 25 variaties, 3 forma and 7 unidendifed species. The occurred taxa at each station and season ranged from 25 taxa at station 2 on May to 62 taxa at station 4 on May, which were very the wide variations at each station and season. The changes of standing crops were the maximum as 1.5×10^7unit/ℓat station 1 on Mar. and the minimum as 2.9×10^5unit/ℓat station 3 on Mar. Dominant Species were Achnanthes minutissima, Aulacoseira granulata var. angustissima, Cyclotella stelligera, Cymbella minuta var. silesiaca, Coelastrum cambricum, Phacotus lenticularis and Synedra delicatissima var. angustissima. The dominance index ranged from 0.15 to 0.76, and the diversity was very wide as the range from 0.23 to 1.05, also evenness diversed such as two index. The cluster analysis by similarity appeared the high relations with Aug. and Sept. at station 2 and the index was 0.88. Of the relationships between standing crops and physico-chemical factors, it was not the regularity between standing crop and chlorophyll concentration, and ranged from 0.89 at station 2 to negative index at other stations. Of dominant species, the relationships between Cyclotella stelligera and chlorophyll concentrations were the positive relations as up to 0.65 at all stations except to station 4.

대학신문의 진로

김용재,Kim, Yong-Jae 한국대학교육협의회 1986 大學敎育 Vol.23 No.-

임하호의 식물 플랑크톤 군집구조

김용재,최재신,김한순 ( Yong Jae Kim,Jae Shin Choi,Han Soon Kim ) 한국하천호수학회 1997 생태와 환경 Vol.30 No.4

Phytoplankton communities are investigated at four stations in Lake Imha from March, 1992 to November, 1994. Phytopalnkton are identified from 234 taxa in 1992 to 302 taxa, in 1994. Standing crops are the highest value in 1992 and the lowest value in 1993, and slowerly increased in 1994. Dominant species are Cyclotella pseostelligera and 13 taxa. Among them, Anabaena solitaria f. planctonica is bloomed during the season the high Total-N/Total-P ratio. This result is guessed the difference between the water environment of Korea and other nations.

임플랜트 표면 처리 방법에 따른 골조직 반응에 대한 연구

김용재,조인호,Kim, Yong-Jae,Cho, In-Ho 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.1

Statement of problem: Implant surface characteristics plays an important role in clinical success and many studies have been made for improvement of success by changing surface roughness. Purpose: Appropriate increase of surface roughness increases the activity of osteoblast and enhance contact and retention between bone and implant. Material and method- Machined, SLA and RBM surface implants, which are the most commonly used implants were implanted into the tibia of rabbits and after 1 week, 4 weeks, 8 weeks and 12 weeks there were histologic and histomorphometric analysis and study for bone gradient and change of Ca/P ratio using EDS(Energy Dispersive X-ray Spectroscope). Results: Comparison of bone-implant contact showed no significant difference among each implant. In comparison of bone area rates, SLA showed higher value with significant difference at 1 week and 4 weeks, and SLA and RBM at 8 weeks than Machined implant (p<0.05). In analysis of bone constituents with EDS, titanium was specifically detected in new bones and the rates were constant by surface treatment method or period. In case of Ca/P ratio, according to surface treatment method, each group showed significant difference. Lots of old bone fragments produced during implantation remained on the rough surface of RBM implant surface and each group showed histological finding with active synthesis of collagen fibers until 12 weeks. In transmission electronic microscopic examination of sample slice after elapse of twelve weeks, tens nm of borderline (lamina limitans like dense line)was seen to contact the bone, on the interface between bone and implant. Conclusion: SLA and RBM implant with rough surface shows better histomorphometrical result and the trend of prolonged bone formation and maturation in comparison with Machined implant. In addition, implant with rough surface seems to be helpful in early stage bone formation due to remaining of old bone fragments produced in implantation. From the results above, it is considered to be better to use implant with rough surface in implantation.

차원해석을 이용한 사용후 핵연료 수송용기의 충격력 실험식 공식화

김용재,최영진,이영신,Kim Yong-Jae,Choi Young-Jin,Lee Young-Shin 한국전산구조공학회 2005 한국전산구조공학회논문집 Vol.18 No.3

방사성물질은 다양한 분야에서 사용되고 있으며 이에 따른 국내 및 국제간 운반이 계속적으로 증가하고 있다. 방사성물질을 수송하기 위해서는 수송용기의 안전성이 확보되어야 한다. 방사성물질 수송용기의 안전규정에 관해서는 국내 원자력법 운반안전규정 및 IAEA 운반규정에서 규정하고 있다. 방사성물질 수송용기 중에서 사용후핵연료를 운반하는 수송용기는 본체와 충격완충제로 구성되어 있다. 본 논문에서는 사용후핵연료 수송용기의 충격완충제에 작용하는 충격력을 계산하는 간편한 실험식을 차원해석을 통하여 유도하였다. 해석결과는 기존의 충격면적법 및 유한요소해석과 비교를 통하여 그 타당성을 입증하였다. 본 실험식을 이용하여 수송용기의 낙하충격력을 쉽게 예측할 수 있다. Radioactive material is used in the various fields. The numbers of transport for radioactive material have been gradually increased in both domestic and International regions. The safety of the cask should be secured to safely transport of radioactive material. The korean atomic law and the IAEA safety standards prescribe regulations lot the safe transport of radioactive material The cask for spent fuel is comprised of the body and the impact limiter. In this study, the empirical equation of the cask impact force is proposed based on the dimensional analysis. Using this empirical equation the characteristics of the impact limiter are analyzed. The results are also validated by comparing with the previous results of the impact area method and the finite element analysis. The present method can be used to predict the impact force of the cask.

보문호에서의 훈장말 속 ( 녹조강 ) 에 대한 계절적 변화

김용재,정준 ( Yong Jae Kim,Jun Chung ) 한국하천호수학회 1992 생태와 환경 Vol.25 No.4

This study compared the seasonal variations of the species composition and standing crops of the genus Pediastrum in the steady state and the nonsteady state of water environment in the Pomun Lake from November, 1990 to October, 1991. It was identified 15 taxa which were 8 species, 7 varieties in the genus Pediastrum from this lake. The variations of monthly taxa numbers were from 11 taxa in November, 1990 to 4 taxa in August, 1991. The variations of standing crops were from 7.5×10^4 unit/l in November, 1990 to 8×10^2 unit/l in August, 1991, respectively. It was a positive correlation between the standing crops and physico-chemical factors (e.g. pH, water temperature, transparency, NH_4- N, PO_4- P). Also, the chlorophyll-a concentration was closely correlated with the changes of standing crops. In the steady state of water environment, the regular seasonal variations were the autogenic changes by the self-activity of the genus Pediastrum, but in the nonsteady state, the irregular seasonalities were the allogenic changes by the external factors(e. g. influx of external polluted material, and vertical and horizontal mixing by a localized torriential downpour), and retarded the velocity and disturbed the courses of succession.

재생 아스팔트 혼합물을 다량 혼입한 중온 아스팔트의 현장적용 특성

김용재,Kim, Yong-Jae 한국건설순환자원학회 2020 한국건설순환자원학회지 Vol.15 No.1

기업간(B2B) 전자결재

김용재,Kim, Yong-Jae 한국전자정보통신산업진흥회 2001 電子振興 Vol.21 No.11

전자문서 표준화 현황 및 추진방향

김용재,Kim, Yong-Jae 한국전자정보통신산업진흥회 2001 電子振興 Vol.21 No.5

멀티 콘센트용 변류기 및 과전류 검출 회로 설계

김용재,김민석,박규상,김재홍,Kim, Yong-Jae,Kim, Min-Seok,Park, Gyu-Sang,Kim, Jae-Hong 한국전자통신학회 2015 한국전자통신학회 논문지 Vol.10 No.8

멀티 콘센트의 과전류로 인한 과열을 방지하기 위한 보호방식으로는 주로 금속바이메탈 방식, 스위칭회로 방식, 마이크로컨트롤러(MCU)를 이용한 과전류 정밀제어 방식 등이 사용되어 오고 있다. 하지만 이러한 방식들은 보호회로가 과전류가 흐르는 전선에 병렬접속 함으로써 2차 화재의 위험이 있을 수 있으며 입력전압의 비선형 왜곡에 취약한 단점을 가지고 있다. 또한 기존의 방식들은 제품의 단가가 비교적 크게 올라가므로 충분한 시장성을 확보하기가 쉽지 않다. 본 논문에서는 이러한 문제를 해결하고자 과전류가 흐르는 전선에 비접촉식 관통형 변류기를 설계하고 변류기의 2차 유도전류를 이용하여 과전류를 감지하여 사용자가 과전류 상황을 인지할 수 있도록 LED 및 부저 회로를 통하여 시각 및 청각적 신호를 전달하는 기능을 구현한다. 실험 결과들로부터 제안된 회로는 매우 경제적이고 간단하면서도 안정적으로 동작함을 확인 할 수 있다. For the over-heat protection purpose in power strip devices, over-current detection/protection circuits, such as bimetal, switching circuit, and microprocessor-based relay circuit, have been widely setup in high-end products. Most of these circuits are connected to the power line in parallel and, thus, they are sensitive to the line voltage and current distortion. Moreover, these protection circuits are often costly and, therefore, it is hard to meet the commercial requirements. A low-cost over-current detection circuit with the contactless current transducer is designed and tested in this paper. The detection circuit is galvanically isolated from the power line and, thus, less sensitive to the line voltage distortion. The experimental results show that the proposed circuit accurately operates despite of its simple structure and low-cost electronic parts.