축사 난방용 할로겐램프의 위험성 및 화재 예방에 관한 연구

이재경,서승현,이재욱,Lee, Jae kyung,Seo, Seong Hyeon,Lee, Jae Wook 국제문화기술진흥원 2021 The Journal of the Convergence on Culture Technolo Vol.7 No.3

본 연구에서는 돈사에서의 난방용 할로겐램프의 위험성과 화재 예방에 대하여 분석하였다. 할로겐램프는 경제성과 편의성이 뛰어나 축사 보온에 사용된다. 하지만 안전관리가 허술하고 동물의 움직임에 노출돼 때문에 화재 위험성이 높다. 실제로 오래된 돈사와 축사를 둘러본 결과 화재위험에 노출되어 있음을 쉽게 확인할 수 있었다. 이 점에 주목하여 할로겐램프와의 가연성 물질 접촉 및 사용 부주의로 인한 화재 가능성을 실험을 통해 연구하였다. 실험은 실제 사용환경과 유사한 조건에서 실시되었다. 실제 축사로 사용되는 높이까지 할로겐램프를 설치한 후 바닥에 짚과 톱밥, 왕겨를 두고 적외선 카메라로 온도변화를 관찰했다. 그리고 비정상적인 조건을 가정하여 램프가 바닥에 떨어지거나 인화성 물질이 램프 내부의 유리관에 접촉하는 상태에서 실험을 진행하였다. 할로겐램프를 정상 상태로 사용하면 화재위험은 없었다. 그러나 비정상적인 사용 환경에서는 연기가 나거나 발화하기도 한다. 사용이 편리하거나 활용도가 높은 경우에도 화재위험이 높기 때문에 화재 예방대책이나 사용 규제가 필요하다. 철저한 화재조사와 연구를 통해 화재위험을 알리고 인명피해와 재산피해를 최소화하는 화재 예방을 위해 노력해야 한다. This study analyzed the the risk of halogen lamp for pigsty heating and its fire prevention. Halogen lamps are used for keeping warm in pen because of their excellent economy and convenience. However, there is a high risk of fire due to poor safety management and exposure to animal movements. In fact, after exploring old pigsty and cattle shed, it was easy to confirm that they were exposed to fire risks. We noted this point and studied the possibility of fire by experiment due to combustible contact with halogen lamp and carelessness in use. The experiment was conducted under conditions similar to the actual use environment. After installing halogen lamps to the height used in actual pen, the temperature change was observed with infrared camera with straw, sawdust and rice husks on the floor. And assuming abnormal conditions, the experiment was also conducted under conditions the lamp dropped on the floor or combustible material came into contact with the glass tube inside the lamp. If halogen lamps were used in normal condition, there was no risk of fire. However, in abnormal use environments, smoke comes out or even ignited. Even if it is convenient for use or highly utilized, high risk of fire will require setting up fire prevention measures or regulation of use. Through in-depth fire investigation and research, we should promote the risk of fire and make efforts to prevent fire to minimize human life and property damage.

FDM 에 의한 응고해석시 계산기간 단축을 위한 Algorithm 연구

이재경,전주매,전기찬 ( Jae Kyung Lee,Ju Mae Jeon,Ghi Chan Jun ) 한국주조공학회 1994 한국주조공학회지 Vol.14 No.5

N/A Efficient algorithm for the solidification simulation by FDM is described from the practical point of views. If a proper time step Δt is selected, the calculation is accelerated by implicit algorithm with the temperature recovery method of latent heat method. The implicit routine in the calculation is processed by SOR method(relaxation factor=1.5, truncation error=l0^(-4)). The calculation is more accelerated by linear-interpolated explicite algorithm with a time step larger than the minimum value of the time step. This explicit method, which is applicable to the practical casting simulation problems, produces almost same results with about 40% faster calculation speed compared with the conventional explicit method.

PECL을 이용한 소형 세라믹 VCXO 개발

이재경,윤달환,Lee, Jae-Kyung,Yoon, Dal-Hwan 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.2a

본 논문에서는 통신소자의 경박 단소화 추세에 따라 적층 세라믹 SMD(surface mounted device) 패키지기술을 통하여 소형화한 $5{\times}7mm$의 크기의 VCXO를 개발한다. 이때 안정된 입력신호를 공급하기 위하여 양의 이미터결합논리(PECL)를 이용하고, 역메사형 HFF(high frequency fundamental) 기법을 이용하여 제작한 수정소자로 IC에 설계함으로써 동작전압은 3.3 V, 저전력하에서 120MHz-180MHz 범위의 주파수에서 발진하며, Q인자는 5 K이상, 3.5 ps rms의 낮은 지터(Jitter)와 위상잡음 특성 및 일정기간의 경화실험에서도 안정된 출력특성을 보인다. In this paper, we have developed the miniature ceramic PECL(positive emitter-coupled logic) VCXO of the $5{\times}7mm$ size for gratifying the requested specifications and the multilayer ceramic SMD(surface mounted device) package technology. The ceramic SMD PECL VCXO designed by the inverted Mesa type HFF is operating at the 3.3 Voltage and have the frequency range of 120MHz-180MHz. The Q factor is over 5K and it has the low jitter characteristics of 3.5 ps and low phase noise.

주형하강식 일방향 응고시 결정성장에 미치는 Grain Selector 의 영향

이재경,최학규,홍준표 ( Jae Kyung Lee,Hack Kyu Choi,Chun Pyo Hong ) 한국주조공학회 1989 한국주조공학회지 Vol.9 No.2

N/A This study was carried out on single crystal growth in the mold-withdrawal type unidirectional solidification. The effects of grain selectors on the microstructural morphology were investigated. A two-dimensional heat transfer model was developed to simulate the relationship between thermal parameters and growth morphology. Single crystal can be grown by proper design of grain selector in this method.

신재생에너지 연계형 마이크로그리드의 하이브리드시스템 최적 설계 연구

이재경,한용찬,권성기,박계춘,Lee, Jae-Kyung,Han, Yong-Chan,Kwon, Sung-Gi,Park, Gye-Choon 한국전기전자재료학회 2022 전기전자재료학회논문지 Vol.35 No.6

Microgrid, which enables the production and consumption of electricity to be done independently on a small scale, has been studied on one of the solutions of reinforcement for flexibility of electronic system. This study examined the application effect of new microgrid by applying hybrid battery in electric power storage device. We designed the system to highlight the advantage of each battery and complement the disadvantage by using hybrid system with Lithium-ion battery and interval Redox flow battery. It runs with lithium-ion battery during the initial startup while the Redox flow battery operates for a long time at the end of excessive period, and it enables a discharge of Lithium-ion and Redox flow battery at the same time when the load has a large output. We chose Maldives as a subject of this study for organizing and optimizing independent microgrid. Maldives is the country to accomplish 100% domestic electricity in South Asia, but the whole electric power is supplied through diesel generation imported fossil fuel. We organized and optimized microgrid for energy independence on Malahini island to solve Maldives energy cost problem and global energy environment matters. We analyzed the daily power supply and accumulated the power supply from September 18, 2018~February 11, 2019. The accumulated power supply was about 120.4 MWh and the daily power supply was about 800~1000 kWh. Based on the collected information, we divided the cases into three models which are only diesel generator, solar generator as well as diesel generator, and solar+ESS+diesel generator. We analyzed the amount of oil consumption compared to the cost of construction and power output. The result showed that solar+ESS+diesel generator was most economically feasible. As well, we obtained that our considering hybrid battery system reduced the fuel consumption for diesel power generation about 10~15%.

파라메트릭 모델에 의한 주강의 수축공 결함 예측의 Quality Criteria

이재경,최정길,홍준표 ( Jae Kyung Lee,Jeong Kil Choi,Chun Pyo Hong ) 한국주조공학회 1998 한국주조공학회지 Vol.18 No.1

N/A Criteria functions using the prediction parameters, such as t_f, G and G/√R which can be evaluated from the heat transfer and solidification analyses of castings, are of great importance in the prediction of shrinkage defects in steel castings. The critical values of these prediction parameters are found to be dependent upon the shape and size of castings. A new additional parameter, shrinkage potential, was proposed to evaluate the formation of shrinkage defects quantitatively. A coupling method of the prediction parameters with shrinkage potential was adopted to predict shrinkage defects in steel castings. The calculated results on several castings were compared with the experimental castings. (Received January 14, 1998)

두 가지 곤충 세포주에 대한 배양 및 바이러스 증식을 위한 최적 FBS 농도 결정

이재경,구현나,우수동,Lee, Jae-Kyung,Koo, Hyun-Na,Woo, Soo-Dong 한국응용곤충학회 2007 한국응용곤충학회지 Vol.46 No.2

곤충 세포주 Sf21과 Bm5 세포주에 대해 세포 배양과 바이러스의 증식을 위한 최적 FBS 의 농도를 결정하기 위하여 다양한 FBS 농도에서 세포 및 바이러스의 증식 곡선을 비교하였다. 세포의 생존율, 증식속도, 증식량 그리고 FBS 함량을 모두 고려할 때 Sf21 에 대해서는 7%가, Bm5에 대해서는 5% FBS 가 최적 농도로 결정되었다. 바이러스의 증식은 감염 후 5일째에 두 세포주 모두 모든 FBS 농도에서 유사한 증식량을 보였으나, 감염 후 2 일과 3일에 있어서는 Sf21 은 각각 10%와 3%가 Bm5 에 대해서는 양일 모두 5% FBS 농도에서 가장 증식량이 높았다. 이러한 결과는 목적에 따라 세포 및 바이러스 증식을 위한 적정 FBS 농도의 결정이 필요함을 제시하는 것이다. To determine the optimal concentration of fetal bovine serum (FBS) on the growth of insect cells and the multiplicity of viruses, the growth of cells (Sf21 and Bm5) and viruses were examined on the various concentrations of FBS. In view of the viability, growth speed, proliferation of cells and the amount of FBS, the most proper concentration for the cell culture were 7% and 5% for Sf21 and Bm5, respectively. The multiplicity of viruses at the various concentrations of FBS was similar in both cell lines at 5 days post-infection (p.i.). However, it differed significantly at 2 and 3 days p.i. The proper concentration of FBS were 10% and 3% for Sf21 at 2 and 3 days p.i., respectively, and 5% for Bm5 at both 2 and 3 days p.i. These results suggested that the optimal concentration of FBS should be determined according to the used cell lines and viruses for their optimum production.

가정 정보화와 성별 분업

이재경(Lee Jae Kyung) 이화여자대학교 한국여성연구원 1993 여성학논집 Vol.9 No.-

The purpose of the present study is to examine the impact of an information technology on the gender division of household work. In doing so, the following questions were raised: 1) What are the actual situation of the application and the use of information technology in Korean homes? 2) How does the information technology influence domestic gender division of labor? Does the use of information technology at home increase or decrease women's domestic burden? 3) Therefore, will be the actual change in the gender role and women's scans in the future society? The data were obtained by documents from the government and various social institutions, and survey data were spplemented by in-edpth interviews. Main discussions of the study can be summarized as follows: First, the degree of informationalization of domestic affairs is relatively low in Korea, A number of women who are using home automation system and/or home information system are small. Housewives do not use these systems effectively, and hardly know about functions of the systems, even though they own the systems. Second, Korean middle-class housewives have shown more or less understanding of the information technology and its use of domestic affairs such as, the home automation system and the home information system. Despite the actual use of the computer is essential in the information society, however, housewives have shown the low level of knowledge about the computer. Only a few respondents have reported that they can use the computer. Third, respondents have recognized the necessity of information communication sevices through a computer terminal to homes. These services include information about shopping, banking, cultural events, tourism, the stock market, and so on. Fourth, housewives spend more time for domestic work than other household members and are not receiving help from others. Although a women employed outside less time, she remains the household member primarily responsible for the household. Electric home appliances and advanced home automations can rationalize and make domestic work efficient, but the primary responsibility for the work will be still held by women. Finally, respondents tend to show traditional attitudes toward the gender division of household work. They have predicted the doemstic gender division of labor will be maintained in the future information society. A compurterized household can liberate women from some household chores and yet impose on them the responsbility for other household work, including nuturing. We may conclude that women have not been or will not be freed from household labor and their housewife role. The most important thing is not the technology but the social structure that maintains the patriarchal social order and women's subordination.

능동형 인공표지를 이용한 이동로봇의 위치 인식

이재경(Lee, Jae-Kyung),박영환(Park, Young-Hwan) 한국산학기술학회 2008 한국산학기술학회논문지 Vol.9 No.1

이동로봇이 임의의 작업공간에서 임무를 수행하기 위해서는 주변 환경에 대한 위치 인식 능력이 있어야 한다. 본 논문에서는 새로운 능동형 인공표지를 이용하여 이동로봇의 위치를 인식할 수 있는 방법을 제안한다. 능동형 인공표지에는 이동로봇에서 무선통신으로 제어가 가능한 LED:가 부착되어 있는데, 제안한 방법은 CCD 카메라로인 공표지의 LED가 점등 및 소등된 두 영상의 차영상을 이용하여 인공표지 여부를 판별하기 때문에 주변 환경의 복잡 도에 관계없이 인식시간을 최소화할 수 있으며 인공표지의 특징점 정보를 이용하여 간단하게 위치를 인식할 수 있다. 제안한 방법의 성능을 평가하기 위하여 실험을 하였으며 실험 결과는 제안한 방법이 이동로봇의 위치 인식에 적용될 수 있음을 보였다. In order that a mobile robot can perform tasks in unknown environment localization of a mobile robot is essential task. In this paper, a new localization method for a mobile robot using an active landmark is proposed, which is very simple to implement. The landmark has a LED which can be controlled by a mobile robot via wireless communication. CCD camera gets two images of the landmark, one of which is with LED off and the other is with LED on. Because the landmark can be detected by using the difference image of the two images, detection time can be minimized. By using the characteristic points of the landmark, localization can be performed simply. A series of experiments are performed to evaluate the proposed method and the experimental results show that the proposed method can be applicable to the localization of a mobile robot.

원자로 핵계측 검출기 안내관 취급장치 개발

이재경(Jae-Kyung LEE),박준영(Joon-Young PARK),조병학(Byung-Hak CHO),변승현(Seung-Hyun BYUN) 한국에너지학회 2008 한국에너지공학회 학술발표회 Vol.2008 No.-