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.

Segmenting sport video gamers by motivation: a cluster analysis

김용재,Soojin Kim 한국마케팅과학회 2013 마케팅과학연구 Vol.23 No.1

Using the Uses and Gratifications paradigm, the present study examines motives for playing sport video games (SVG). Based on motivations, this study identifies segments of SVG users using a cluster analysis, and then explores potential similarities and differences between segments based upon demographic and behavioral variables. With a sample of 378 SVG users from four popular video game websites, the cluster analysis yielded two distinct clusters: Fun seekers and Fantasy seekers. Results indicated that the members of each cluster seek various gratifications from SVG use. Each cluster also was further distinguished based upon gender, marital status, and media consumption behaviors. Implications are discussed relative to virtual sport experience in the mediated environment and its corresponding marketing strategies.

권선방식 차이에 따른 영구자석 선형 동기 전동기의 단부 코깅력 해석

김용재,김성진,Kim, Yong-Jae,Kim, Sung-Jin 한국전자통신학회 2011 한국전자통신학회 논문지 Vol.6 No.6

PMLSM is structurally simple and it have a lot of merits such high speed, high thrust force etc., but cogging force by slot-teeth structure of armature and cogging force by outlet edge effect occurs. This is the cause of thrust force ripple and generate the noise and vibration. Therefore, in this paper we proposed installation of an auxiliary pole to mover of the PMLSM in order to decrease cogging force by the outlet edge which came necessarily into being discontinuous arrangement of the armature. Also, outlet edge cogging force designed a form of the auxiliary pole which the minimum became, and we compared a outlet edge cogging force characteristic along a winding method of an armature as we used 2-D of finite element analysis. 영구자석 선형 동기 전동기(Permanent Magnet Linear Synchronous Motor:이하 PMLSM)는 구조적으로 간단하며 고속화 고추력화 등의 많은 장점을 가지고 있지만 전기자 권선부의 슬롯-치 구조로 인한 코깅력과 단부효과에 의한 코깅력이 발생한다. 이는 추력 맥동의 원인이 되며, 소음과 진동을 발생시킨다. 따라서, 본 연구에서는 전기자를 분산배치 할 경우 필연적으로 생기는 단부에 의한 코깅력을 저감하기 위해 PMLSM의 가동자에 보조극의 설치를 제안하였다. 또한 2차원 유한요소법(Finite Element Analysis)을 이용하여 단부 코깅력이 최소가 되는 보조극의 형태를 설계하고 전기자의 권선 방식에 따른 단부 코깅력 특성을 비교하였다.

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.

전기자 분산배치 집중권 PMLSM의 전기자 간격에 따른 단부 코깅력 최소화

김용재,Kim, Yong-Jae 한국전자통신학회 2013 한국전자통신학회 논문지 Vol.8 No.8

현재 일반적인 반송 장치에서는 전기자를 반송 경로 전장에 배치하는 지상 1차측 시스템이 적용되고 있다. 하지만 이러한 시스템을 장거리 반송 장치에 적용하면 초기 설치비용과 제작시간이 상승하는 문제점이 발생한다. 이러한 문제점을 해결하기 위해 전기자를 분산시켜 배치하는 방식이 제시되고 있다. 하지만 전기자 분산배치 방식은 전기자가 존재하지 않는 구간에서 외란 발생 시 가동자가 정지할 수 있으며 이 때 전기자에 의한 제어가 불가능하게 되어 가동자를 이동 시킬 수 없는 문제점을 내재하고 있다. 따라서 이러한 문제점을 해결하기 위한 전기자 간격 결정이 매우 중요하다. 또한 전기자를 분산배치 할 경우 단부가 발생하게 된다. 이는 가동자가 전기자에 진입 또는 반출 시에 코깅력을 크게 발생시켜 추력 맥동의 원인이 되며, 소음과 진동을 발생시키므로 저감하여야 한다. 따라서 본 논문에서는 전기자를 분산 배치함에 따라 존재하는 단부 코깅력을 유한요소법을 이용한 2-D 수치해석을 통해 파악하고 이를 최소화하기 위한 전기자 간격을 도출하고자 한다. Currently, The general transportation system arranges the armature on the full length of transportation lines. However, when this method is applied to the long distance transportation system, it causes an increase of material cost and manufacturing time. Thus, in order to resolve this problem, discontinuous arrangement method of the armature has been proposed. However, in the method of using stationary discontinuous armatures, mover can stop in the freewheeling section which is non-installations section when disturbance is generated and the mover can not be moved because armature control is impossible. Thus, the distance determination of armature is very important. Also, when the armature is arranged discontinuously the edge always exists due to the structure. Due to this edge, the cogging force is greatly generated during the entry and ejection of the mover to the armature. This cogging force causes thrust force ripple generating noise, vibration and decline of performance, it must be reduced. Therefore, in this paper, we examined the end edge cogging force generated by the stationary discontinuous armatures through 2-D numerical analysis using finite element method (FEM) and we figured out distance of armature for end edge cogging force minimization.

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.

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.

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.

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.

MgO 증착률에 따른 PDP 보호막 물성 및 방전 특성 분석

김용재,권상직,Kim, Yong-Jae,Kwon, Sang-Jik 한국진공학회 2007 Applied Science and Convergence Technology Vol.16 No.3

본 연구에서는 플라즈마 디스플레이 패널의 방전 특성과 MgO 보호막 물성에 영향을 미치는 MgO 증착률에 대해 분석을 하였다. 물성 특성으로 결정 방향과 표면 거칠기 결정 구조 및 음극선 발광을 XRD (X-ray Diffraction), AFM (Atomic Force Microscopy), Mono-CL (Mono Cathode Luminescence analysis)등을 이용하여 측정하였고, 방전 특성으로는 방전개시전압과 방전 전류, 휘도를 진공 챔버와 오실로스코프 (TDS 540C), 전류 프로브 (TCP 312A), 휘도 색차계 (CS-100A)를 이용하여 측정하였다. 실험 결과 $5{\AA}/sec$의 증착률이 최적의 증착률임을 확인하였고, 또한 MgO의 증착률에 따라서 MgO 보호막의 물성특성이 변화하고 이에 의해서 전기적 광학적 특징이 영향을 받는 것을 확인하였다. 즉, 증착률 $5{\AA}/sec$을 기준으로 증착률이 증가할수록 (200) 결정 방향 및 음극선 발광의 밀도가 감소되고, 동작 전압은 증가하며 점차 효율이 나빠지는 경향을 보인다. We have investigated and analyzed the effects of the evaporation rate of MgO films on the MgO properties and the discharge characteristics of a plasma display panel(PDP). The MgO properties such as the crystal orientation, the surface roughness, the film structure, and cathode-luminescence (CL) spectra were inspected using XRD (X-ray diffraction), AFM(atomic force microscopy). And the discharging characteristics of the PDP such as the firing voltage, discharging current, and luminescence were measured using a vacuum chamber with oscilloscope (TDS 540C), current probe (TCP-312A), color meter (CS-100A) and etc. From the experiments results we confirmed the optimum evaporation rate at $5{\AA}/sec$, the MgO properties were shown to be strongly dependent on the evaporation rate, and the MgO properties had an effecton the optical and electrical characteristics. In other words, if the evaporation rates increase than $5{\AA}/sec$, the intensity of (200) orientation and cathode-luminescence (CL) spectra reduce, and the firing vlotage was increased. So the luminuous efficiency grows worse.