멀티코어시스템에서의 예측 기반 동적 온도 관리 기법

김원진,정기석,Kim, Won-Jin,Chung, Ki-Seok 대한임베디드공학회 2009 대한임베디드공학회논문지 Vol.4 No.2

The power consumption of a high-end microprocessor increases very rapidly. High power consumption will lead to a rapid increase in the chip temperature as well. If the temperature reaches beyond a certain level, chip operation becomes either slow or unreliable. Therefore various approaches for Dynamic Thermal Management (DTM) have been proposed. In this paper, we propose a learning based temperature prediction scheme for a multi-core system. In this approach, from repeatedly executing an application, we learn the thermal patterns of the chip, and we control the temperature in advance through DTM. When the predicted temperature may go beyond a threshold value, we reduce the temperature by decreasing the operation frequencies of the corresponding core. We implement our temperature prediction on an Intel's Quad-Core system which has integrated digital thermal sensors. A Dynamic Frequency System (DFS) technique is implemented to have four frequency steps on a Linux kernel. We carried out experiments using Phoronix Test Suite benchmarks for Linux. The peak temperature has been reduced by on average $5^{\circ}C{\sim}7^{\circ}C$. The overall average temperature reduced from $72^{\circ}C$ to $65^{\circ}C$.

장거리 벨트 컨베이어의 기동 및 정지시의 동적거동 해석

김원진,박태건,이신섭,Kim, Won-Jin,Park, Tae-Geon,Lee, Shin-Sup 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.2

According to the considerable increase of the length of belt conveyors, the dynamic analysis of systme becomes necessary to consider the variation of tensions and transient motion of components during starting and stopping of conveyor. The mathematical model of system is derived using the lumped parameter method. The input driving force is represented with two functions of time and pulley speed to count the characteristics of motor and fluid coupling. An example system was studied with 14 km in the distance of carrying. At head, it has two drivers and one gravity take-up and at tail ond driver and one power winch take-up. In the example, the transient tensions and responses, calculated using two cases of driving force, are mutually compared in starting mode. Also, the position of maximum tension and the braking force of take-up are obtained in stopping mode.

부정기적 발생 신체이상 모니터링 블랙박스 프로그램 구현

김원진,윤광렬,Kim, Won-Jin,Yoon, Kwang-Yeol 한국전자통신학회 2012 한국전자통신학회 논문지 Vol.7 No.3

수면 중에 부정기적으로 발생하는 인체 이상유형을 모니터링하기 위한 블랙박스 프로그램을 구현하였다. 인체 블랙박스 시스템은 생체 신호를 계측하는 센서와 알람, 전등, 네트워크 카메라와 같은 보조 장치 및 신호를 모니터링 하는 컴퓨터로 구성되어 있다. 신체 이상 증상의 원인을 정확하게 규명하기 위하여 PPG, EOG, EEG, 호흡센서, 온도센서, G-센서 및 마이크로폰과 같은 다양한 센서를 이용하였다. 이상 증상이 발생하면 시스템은 치료에 활용할 수 있는 정보를 제공하기 위해서 환자의 상태를 기록한다. 신체 이상유형을 감지하게 위하여 적절한 센서 위치를 선정한다. 측정 데이터의 유형별 정상 범위에 근거하여, 신체 이상유형을 구별하기 위한 신호 수준을 선정하였다. 이상 신호가 계측되면 전등 및 알람, 네트워크 카메라가 동시에 작동하고, 센서 신호 및 비디오 데이터가 저장된다. A black-box program was implemented in order to monitor abnormal symptoms of human body irregularly occurring during sleep. The system consists of sensor probing body signals, auxiliary devices such as the alarm, lamp, network camera, and signal monitoring computer. Various types of sensors, PPG, ECG, EEG, temperature, respiration sensor, G-sensor, and microphone were used to more exactly identify the causes of abnormal symptoms. If a symptom occurs, the system records the patient's condition to provide information being utilized in the treatment. The sensors are attached on some locations of body being proper to check a specific type of abnormal reaction. Based on the normal range and type of measurement data, criteria of signal levels were set to distinguish abnormal reaction. An abnormal signal being probed, the program starts to operate the lamp, alarm, and network camera at the same time and stores the signal and video data.

하절기 가두리양식 참돔의 절식에 따른 성장과 혈액성상의 변화

김원진,원경미,신윤경,이정용,Kim, Won Jin,Won, Kyoung Mi,Shin, Yun Kyung,Lee, Jeong Yong 한국어류학회 2017 韓國魚類學會誌 Vol.29 No.3

본 연구는 하절기에 지속적으로 발생하는 고수온, 적조와 같은 피해를 최소화하기 위한 방안으로 해상가두리 ($6m{\times}6m{\times}6m$) 절식 사육을 통해 참돔의 생존율, 성장, 성장 회복 그리고 생리반응을 조사하였다. 6주간의 절식 후 4주간의 먹이 공급을 통한 연구결과 생존율은 섭식구 94.4%, 절식구 98.1%로 나타났다. 체중 성장률은 절식구에서 $-12.4{\pm}3.2%$ 성장을 보여 체중의 유의한 감소를 보였지만, 먹이 공급 후 $36.7{\pm}6.8%$의 빠른 성장 회복을 나타냈다. 혈액분석을 통한 절식구의 영양상태 또한 섭식구에 비해 유의하게 감소하였지만 먹이 공급 후 개시 시 수준으로 빠르게 회복하였다. 또한 스트레스 지표를 분석한 결과 절식기간 섭식구의 Hb, Ht의 수치가 증가하였으며, 섭식구의 급격한 혈액성상의 변화는 하절기 해상가두리 환경에서 절식구보다 섭식구가 스트레스에 더 민감한 것으로 나타났다. 따라서 본 연구의 생존율, 성장 회복, 혈액성상을 통한 결과를 토대로, 고수온과 적조에 노출되는 하절기에 피해를 최소화하기 위한 가두리 양식어류 관리 방안으로 일정기간 절식이 활용 가능할 것으로 여겨진다. To minimize the damage caused by summer season such as high temperature and red tide, this study was conducted to investigate the effect of feeding and starvation on the survival rate, growth, growth restoration and physiological response of red seabream Pagrus major which were reared in marine net cage ($6m{\times}6m{\times}6m$). The feeding group was fed throughout the experiment for 10 weeks, whereas starvation group was not fed for 6 weeks and subsequent refeeding for 4 weeks. Survival rates of feeding and starvation groups were 94.4% and 98.1% respectively. The growth rate of starvation group was significantly lower than feeding group during starvation period, but recovered rapidly after feeding. The nutritional status such as albumin, total protein, total cholesterol, triglyceride also showed similar tendency to the growth data. Hematocrit and hemoglobin levels were higher in the feeding group than the starvation group during starvation period. Aspartate aminotransferase, glucose and total cholesterol were rapidly increased at the same time (in 5 week) in feeding group, whereas starvation group did not significant difference during starvation period. It was shown that the feeding group is more sensitive to stress than the starvation group. Thus, starvation can be applied as a rearing management plan of net cage fish farm in summer season.

유한요소모델을 이용한 비선형 시스템의 매개변수 규명

김원진,이부윤,Kim, Won-Jin,Lee, Bu-Yun 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.6

A method based on frequency domain approaches is presented for the nonlinear parameters identification of structure having nonlinear joints. The finite element model of linear substructure is us ed to calculating its frequency response functions needed in parameter identification process. This method is easily applicable to a complex real structure having nonlinear elements since it uses the frequency response function of finite element model. Since this method is performed in frequency domain, the number of equations required to identify the unknown parameters can be easily increased as many as it needed, just by not only varying excitation amplitude but also selecting excitation frequencies. The validity of this method is tested numerically and experimentally with a cantilever beam having the nonlinear element. It was verified through examples that the method is useful to identify the nonlinear parameters of a structure having arbitary nonlinear boundaries.

주파수영역방법에 의한 비선형 모델변수의 실험적 규명

김원진,Kim, Won-Jin 대한기계학회 1998 大韓機械學會論文集A Vol.22 No.2

In this work, a frequency domain method is tested numerically and experimentally to improve nonlinear model parameters using the frequency response function at the nonlinear element connected point of structure. This method extends the force-state mapping technique, which fits the nonlinear element forces with time domain response data, into frequency domain manipulations. The force-state mapping method in the time domain has limitations when applying to complex real structures because it needd a time domain lumped parameter model. On the other hand, the frequency domain method is relatively easily applicable to a complex real structure having nonlinear elements since it uses the frequency response function of each substurcture. Since this mehtod is performed in frequency domain, the number of equations required to identify the unknown parameters can be easily increased as many as it needed, just by not only varying excitation amplitude bot also selecting excitation frequency domain method has some advantages over the classical force-state mapping technique in the number of data points needed in curve fit and the sensitivity to response noise.

전자레인지 포장품의 낙하충격 해석 및 설계

김원진(Won Jin Kim),이부윤(Boo Youn Lee),손병삼(Byung Sam Son) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.5

Dynamic behaviour of a package of a microwave oven under the drop-impact conditions is evaluated by the finite element analysis and tests. PAM-CRASH software is used for the finite element analysis and the tests are performed according to the ISTA(International Safe Transit Association) specification. Results of the analyses are compared with those of the tests and accuracy is shown to be favourable. Under the drop-impact condition of the original design, severe deformation occurs and an improved design is proposed to reduce it. The approach presented in this research can be successfully applied to reduce costs and time required to develop new models of the microwave oven.

천식 환자에서 우울과 천식의 중증도 및 조절과의 관련성

김원진 ( Won Jin Kim ),배현숙 ( Hyun Sook Bae ),최보경 ( Bo Kyung Choi ),황종민 ( Jong Min Hwang ),신경화 ( Kyung Hwa Shin ),김미현 ( Mi Hyun Kim ),이광하 ( Kwang Ha Lee ),김기욱 ( Ki Uk Kim ),전두수 ( Doo Soo Jeon ),박혜경 ( Hye 대한결핵 및 호흡기학회 2010 Tuberculosis and Respiratory Diseases Vol.69 No.4

Background: Psychological factors are increasingly recognized for their influence on the course of asthma, on a worldwide basis. The aim of this study was to assess the presence of depression, anxiety, and asthma-related quality of life in patients with asthma and to evaluate their impact on severity and control of asthma. Methods: We assessed the severity of asthma by comparing patients` current medications to GINA guideline. The patients were classified into the controlled group (asthma patients with controlled disease) or into the uncontrolled group (asthma patients with uncontrolled disease), which included partly controlled and uncontrolled patients, again based on GINA guideline 2004. Patient-reported depressive symptoms, anxiety, and asthma-related quality of life were evaluated using the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), and Korean asthma quality of life (KAQLQ). Results: One hundred and twenty patients were enrolled (mean age, 55±1 years; 65% women). Among the 120 patients, 14 (12%) patients were classified as having mild asthma, 88 (73%) as having moderate asthma, and 18 (15%) as having severe asthma. Eighty-one (67%) of the 120 patients were controlled. The asthma-related quality of life showed the difference according to severity of asthma (p=0.002). The prevalence of depression was lower (10% vs 26%, p=0.024) and the asthma-related quality of life was higher (59.951 (29∼75) vs 35.103 (18∼72), p≤0.001) in the controlled group. Higher trait anxiety score and lower asthma-related quality of life were associated with depression (p<0.001, p=0.002, respectively). Conclusion: Psychological factors, such as anxiety and depression, are strongly associated with asthma control. Therefore, screening and management of depression is needed in patients with asthma.

화력발전소의 소음지도 모델링 및 해석

김원진(Won-Jin Kim),윤준호(Jun-Ho Yun) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.10

This study proposes an analysis model to simulate a noise map and estimate noise distribution for a location and its surroundings of a power plant. The noise map analysis was executed by using ENPro that is a commercial program for environmental noise prediction. Experimental evaluation for the proposed analysis model was carried out by comparing the results from noise analysis and measurement at several major points of the power plant and residential areas.

세탁기 기본형 형성과 디자인 발전에 관한 연구

김원진(Kim Won-Jin),채승진(Chae Sung-Zin) 한국디자인학회 2002 디자인학연구 Vol.- No.50