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.

MPEG-2에서 H.264로의 Transcoding 과정에서 DCT 계수를 H.264 변환 계수로 변환하는 효율적인 알고리듬

김용재,이창우,Kim, Yong-Jae,Lee, Chang-Woo 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.8c

가장 최근에 표준화된 H.264/AVC 동영상 압축 부호화 방식은 기존의 방법인 MPEG-2에 비해 우수한 압축 효율을 보이지만, 아직 많은 응용분야에서 MPEG-2가 적용되고 있기 때문에 MPEG-2에서 H.264/AVC로의 변환 기법 개발이 필요하다. 본 논문에서는 이러한 변환을 위해 가장 첫 번째 단계로 볼 수 있는 DCT 계수에서 H.264 변환 계수로의 변환을 위한 효율적인 방법을 제안한다. 이러한 변환은 영상의 압축을 위한 변환기술로 MPEG-2에서는 $8{\times}8$ discrete cosine transform(DCT)를 사용하고 있고, H.264/AVC 표준안에서는 $4{\times}4$ integer transform을 사용하고 있기 때문에 필수적이다. 제안하는 알고리듬에서는 부호화 성능을 유지하면서 효율적으로 계산량을 감소시킬 수 있는 방법을 제시하고 계산량 분석과 모의실험을 통해서 이를 입증한다. The H.264/AVC video coding standard provides higher coding efficiency compared to the conventional MPEG-2 standard. Since a lot of videos have been encoded using MPEG-2, the format conversion from MPEG-2 to H.264 is essential. In this paper, we propose an efficient method for the conversion of DCT coefficients to H.264/AVC transform coefficients. This conversion is essential, since $8{\times}8$ DCT and $4{\times}4$ integer transform are used in MPEG-2 and H.264/AVC, respectively. The mathematical analysis and computer simulation show that the computational complexity of the proposed algorithm is reduced compared to the conventional algorithm, while the loss caused by the conversion is negligible.

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.

남부지방에서 벼 재배형태별 분얼체계 및 수량구성형질의 차이에 관한 연구 I. 묘종류와 육묘시기에 따른 묘소질 및 본답 생육의 변화

김용재,신해룡,장강연,Kim, Yong-Jae,Shin-Hae-Ryong,Chang, Gang-Yeon 한국작물학회 1992 한국작물학회지 Vol.37 No.3

To study the effects of different nursing methods and transplanting on the growth of the rice plant(Oriza sativa L.hn southern region of Korea, Kumo-byeo, Palgong-byeo and Dong-jinbyeo were transplanted from April 20 to July 20 with 15 days intervals as 8 days seedling (infant rice), 25 days box seedling for machine transplanting and 45 days conventional seedling, respectively. No. of leaves at transplanting were in order of 45 days seedling>25 days seedling>8 days seedling. In 25 days seedling, they were increased as transplanting dates were later from April 20 to June 5, and in 45 days seedling, it showed same tendency until June 5 with Dongjinbyeo, June 20 with Palgong-byeo and Kumo-byeo. Root activity according to the $\alpha$-naphthylamine oxidation activity and rooting activity were higher in order of 8 days seedling>25 days seedling>45days seedling. Panicle formation initiated after maximum tillering stage as transplanting at April 20 with 8 days seedling and 25 days seedling, but it intiated before maximum tillering stage as transplanting at July 20 in Kumo-byeo. and in Palgong-byeo intiations of panicle formation were shown after maximum tillering stage as transplanting until May 20, but June 5 in Dongjin-byeo. However, there was no significant tendency with 45 days seedling. Missing hill ratio were less than 5% as transplanting with 8 days seedling and 25 days seedlingregardless of transplanting periods or varieties.

임하호에서의 (臨河湖) 식물성플랑크톤 군집의 (群集) 생태학적 고찰

김용재,최재신,김도한,정준 ( Yong Jae Kim,Jae Sin Choi,Do Han Kim,Jung Chung ) 한국하천호수학회 1995 생태와 환경 Vol.28 No.1

This study was investigated the ecological study of phytoplankton community from eight stations of Imha lake on May, July, September and November in 1993. Phytoplankton was identified the total 297 taxa, which was composed of 261 species, 29 varieties, 3 forma and 4 unidentified taxa. Standing crops were ranged from 6.Ox10^5unit/l at st. 1 on May to 1.4×10^7unit/l at st. 2 on July. Dominant species were Anabaena soilitaria f. planctonica, Cyclotella comta, Cyclotella meneghiniana, Cyclotella ocellata, Cyclotella stelligera and Synedra delicatissima var. angustissima. Dominant index, diversity index and evenness index were 0.068∼0.750, 0.341∼1.367, 0.183∼0.716, respectively. In relationships between community and physico-chemical factors, chlorophyll-a concentration was showed a law coefficient with the total standing crops but a high with standing crop of C. stelligera. Water temperature was a positive relations with the total standing crops. T-P was showed a low relation with the total standing crops and a negative with A. solitaria f. planctonica. T-N and conductivity were a positive with the total standing crops and standing crop of Bacillariophyceae. This lake was the oligotrophic or mesotrophic type on May but converted from mesotrophic to eutrophic type at all stations on July, September and November by comparison with phytoplankton community and physico-chemical factors.

Bifurcating을 적용한 집중권 PMLSM의 보조극 설치에 관한 연구

김용재,Kim, Yong-Jae 한국전자통신학회 2012 한국전자통신학회 논문지 Vol.7 No.5

Recently, linear motors have been widely researched and have been increasingly used in various industrial applications. Especially, permanent magnet linear synchronous motors(PMLSMs) have been getting the spotlight in the transportation system. A PMLSM is structurally simple and has a lot of merits such as high speed, high thrust force, etc. However, in case of a long stator system which arranges armature to the full length of transportation lines, a PMLSM has some disadvantages such as the material cost increase and long manufacturing time. Hence, in order to overcome these problems, the PMLSM with stationary discontinuous armature structure and concentrated windings was proposed. However, this method occurs undesirable cogging force by outlet edge effect. The cogging force causes thrust force ripples and generates noise and vibration. Therefore, in this paper, we proposed installation method of auxiliary pole PMLSM with concentrated winding applying bifurcating in order to reduce cogging force by the outlet edge when the armature is placed in a discontinuous arrangement. Also, we have examined characteristics of outlet edge cogging force using 2-D finite element analysis(FEA). 현재 선형 전동기는 많은 연구가 진행되어 그 응용분야가 산업전반에 확대되고 있다. 이중 반송장치 분야에서 영구자석 선형 동기 전동기(Permanent Magnet Linear Synchronous Motor:이하 PMLSM)가 각광을 받고 있다. 영구자석 선형 동기 전동기는 구조적으로 간단하며 고속화 고추력화 등의 장점을 가지고 있지만 전기자를 반송경로 전장에 배치하는 지상 1차측 시스템을 장거리 반송장치에 적용하면 재료비용의 증가 및 제작시간 증가 등의 문제점이 발생한다. 따라서 전기자를 분산(불연속) 배치하는 방식이 제안되고 있다. 하지만 이러한 전기자 분산배치 방식은 구조적으로 단부가 존재하고 이러한 단부에 의해 코깅력이 발생한다. 이는 추력 맥동의 원인이 되며, 소음과 진동을 발생시킨다. 따라서, 본 연구에서는 전기자를 분산배치 할 경우 필연적으로 생기는 단부에 의한 코깅력을 저감하기 위해 Bifurcating을 적용한 집중권 PMLSM에 보조극 설치법을 제안한다. 또한 그에 따른 단부 코깅력 특성을 2차원 유한요소법(FEA)을 이용하여 분석하였다.

보행자보호 시험용 Flex-PLI의 특성 및 소형차 대응 구조 연구

김용재,진욱,김동선,Kim, Yong Jae,Jin, Wook,Kim, Dong Sun 한국자동차안전학회 2012 자동차안전학회지 Vol.4 No.2

In 2014 Flex-PLIfor the pedestrian protection will be applied to NCAP test. The most significant feature of Flex-PLI is constructed with segmental bone cores for the femur and tibia regions. So it can be more reproducible by representing pedestrian injuries such as knee ligament and tibia injury during the pedestrian crash against vehicle. In this paper, Analyzed the characteristics of Flex-PLI through the structural analysis and the test results by using Flex-PLI for our compact vehicles. Finally countermeasures into compact vehicle were proposed to fulfill the injury criteria of Flex-PLI.

재생 아스팔트 혼합물을 다량 혼입한 중온 아스팔트의 현장적용 특성

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

보문호에서의 (普門湖) Pediastrum clathratum ( Schroeter ) Lemmermann ( 녹엽망 (綠葉綱) 의 천이와 (遷移) 생태형

김용재,정준 ( Yong Jae Kim,Jun Chung ) 한국환경생물학회 1993 환경생물 : 환경생물학회지 Vol.11 No.1

According to the environmental fluctuations, it was changed with not only physico-chemical factors but also biological species composition and standing crops. In this water system, the authors investigated the total standing crops, standing crops and composition ratio of each morphotype of Pediastrum clathratum from Nov. 1990 to Oct. 1991 and established the ecotype. Physico-chemical factors were changed uniformly in the steady state water system, but changed dramatically as the nonsteady state from June to Oct. 1991 by a torrential rain. Changes of standing crops of P. clathratum were ranged from the 7.0×10 exp (4)unit/ℓ in Nov. 1990 to 1×10 exp (2)unit/ℓ in Aug. and Sept. 1991. Of seasonal changes of each morphotype, A-2 morphotype occurred during the all months and showed the highest standing crops and composition ratio. Therefore, the authors treat A -2 morphotype as the ecotype (e.g. P. biwae form) by the seasonal changes of steady state, eury-adaptation, the highest standing crops and composition ratio.

Effects of Cell-free Culture Fluids for the Expression of Putative Acyltransferase in Corynebacterium glutamicum

김용재,이흥식,하운환,Kim, Yong-Jae,Lee, Heung-Shick,Ha, Un-Hwan The Microbiological Society of Korea 2012 미생물학회지 Vol.48 No.3

이 연구의 목적은 코리네형 균주(Corynebacterium glutamicum)에 존재하는 acyltransferase 유전인자의 발현에 관여하는 autoinducer에 대한 정보를 얻기 위해 다양한 종류의 균주에서 얻은 세포배양액(cell-free culture fluids)을 처리하여 발현에 미치는 효과를 조사하는 것이다. 다양한 배양시간동안 얻은 Agrobacterium tumefaciens의 세포배양액은 acyltransferase의 발현을 전혀 증가시키지 못하는 것으로 관찰되었다. 반면 AI-1과 AI-2를 분비하는 것으로 알려진 Vibrio harveyi BB120($AI-1^+$, $AI-2^+$)을 지수성장기까지 배양시켜 얻은 세포배양액은 acyltransferase의 발현을 증가시키는 것으로 관찰되었다. 이들 autoinducer가 미치는 효과를 조사하기 위하여 돌연변이 균주인 MM77 ($AI-1^-$, $AI-2^-$)과 BB152 ($AI-1^-$, $AI-2^+$)를 사용하여 조사한 결과, 이들 균주에서 얻은 세포배양액은 BB120와는 달리 acyltransferase의 발현을 증가시키지 않는 것으로 나타났다. 이러한 결과로 보아 acyltransferase의 발현은 AI-1에 의한 효과로 보이며, 이를 확인하기 위해 V. harveyi BB152와 같이 AI-2만을 분비하는 것으로 알려진 Escherichia coli ($AI-1^-$, $AI-2^+$)를 사용하였다. 하지만 E. coli 세포배양액은 acyltransferase의 발현을 증가시키는 것으로 관찰되었다. 이들 결과는 코리네형 균주에 존재하는 autoinducer는 기존에 알려진 형태의 신호분자와 차이가 있을 것이며, 코리네형 균주외에 V. harveyi와 E. coli에도 존재하여 종간 상호작용(interspecies communication)에 관여할 것으로 보인다. Autoinduction is mediated by signaling molecules known as autoinducers (AIs) that are produced, released and detected by bacterium itself. We recently reported that Corynebacterium glutamicum possesses an autoinduction system which secretes autoinducers during the stationary-phase of growth, triggering the expression of acyltransferase gene. However, it is still not clear what may act as autoinducers for the autoinduction in C. glutamicum. In this study, we compared the inducing effects of cell-free culture fluids obtained from a number of microbes including Agrobacterium tumefaciens, Vibrio harveyi, and Escherichia coli. Fluids from A. tumefaciens did not increase the expression of acyltransferase, whereas fluids from V. harveyi BB120 ($AI-1^+$, $AI-2^+$) did. Interestingly, the expression was increased by the fluids obtained from the early exponential-phase culture of BB120. Furthermore, this induction was not observed by the fluids from autoinducer mutants of V. harveyi MM77 ($AI-1^-$, $AI-2^-$) and BB152 ($AI-1^-$, $AI-2^+$). Unlike the effect shown by BB152, fluids from E. coli ($AI-1^-$, $AI-2^+$) still induced the acyltransferase expression. Taken together, these results suggest that C. glutamicum autoinducers seem to be unidentified molecules which do not belong to AI-1 or AI-2.