• Title/Summary/Keyword: 홀 효과

Search Result 260, Processing Time 0.03 seconds

Efficient Busbars for Distribution Boards and Distribution Boards R & D Laser Cutting Machine (전기 접속장치인 분전반과 배전반의 효율적인 부스바 절연 피복 레이저 커팅기 연구 개발)

  • Lim, Yeon-Jeong;Lim, Sang-Ho
    • Industry Promotion Research
    • /
    • v.4 no.2
    • /
    • pp.1-8
    • /
    • 2019
  • This research is a technology for cutting the insulation of the busbar (busbar) installed in the distribution panel or switchboard, the results of the study, first, the cutting unit and frame of the cutting unit including a housing attached to the upper and lower cutters, respectively Busbar coating laser cutting machine is installed on the top, characterized by consisting of a stopper for adjusting the coating cutting distance of the busbar. Second, the frame is installed with the guide bar in the longitudinal direction at the top so as to be located at the rear side end of the table, the post is installed vertically at the front and rear at the upper middle part, respectively, and cut to the table at the outer side of the front post. It is characterized by the formation of holes. Third, the supporter is fixedly installed on the upper part of the guide bar arranged in the frame, and is characterized by consisting of a cylinder and a support plate. The meaning of this study is to prevent the safety accidents of workers, to improve the efficiency of cutting work, and to prevent the occurrence of scratches on the surface of the busbar.

Parenting Stress among Dual- and Single-Earner Families : The Interaction Effect of Marital Relationship and Father's Child-Rearing Involvement on the Parenting Stress (맞벌이 가구와 남성홀벌이 가구 부모의 양육스트레스 연구 : 부부관계와 아버지 양육참여의 상호작용 효과 분석)

  • Kim, Yuna;Park, Aely
    • Journal of Family Relations
    • /
    • v.21 no.1
    • /
    • pp.51-76
    • /
    • 2016
  • Objectives: This study aims to investigate the effect of marital relationship on parenting stress among dual- and single-earner families. In particular, this study focuses on the interaction effect of marital relationship and father's child-rearing involvement on the parenting stress. To access factors associated with parenting stress, we included marital satisfaction and marital conflict as the dimensions of marital relationship in this study. Method: We employed data from the 5th wave of the Panel Study of Korean Children(PSKC) data. Our analysis sample consisted of 1,515 parents having at least one child aged under 4 years. Also, this study conducted descriptive statistics and multiple regression analysis. Results: First of all, marital satisfaction and marital conflict were significantly related to parenting stress for both mother and father in dual-earner families. While both indicators were significantly related to parenting stress for father, marital conflict only was a significant predictor for mother in single-earner families. Second, father involvement was a significant predictor for parenting stress for father in both dual- and single-earner families. Third, interaction effects were found between father involvement and marital conflict in the dual-earner families and between father involvement and marital satisfaction in the single-earner families. Conclusions: Based on the results, we recommended programs designed to enhance father's child-rearing involvement such as parenting education and community-based campaign. In addition, we recommended that policy and practice need to identify marital relationship dynamics to promote father's involvement and to reduce marital conflict in both dual- and single-earner families accordingly.

A Study on the Development of Fire Extinguishing Agent and Extinguishing System for ESS Fire (ESS 화재전용 소화약제 및 소화시스템 개발에 관한 연구)

  • Lee, Yeon-Ho;Lee, Joo-Hyung;Kim, Soo-Jin;Chon, Sung-Ho;Choi, Byoung-Chul;Oh, Seung-Ju;Kim, Si-Kuk
    • Fire Science and Engineering
    • /
    • v.34 no.2
    • /
    • pp.147-155
    • /
    • 2020
  • This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.

Hydraulic Resistance Characteristics of Compacted Weathered Granite Soil by Rotating Cylinder Test and Image Analysis (영상처리기법과 회전식 수리저항성능 실험을 이용한 다짐화강풍화토의 수리저항특성 분석)

  • Kim, Young Sang;Lim, Jae Seong
    • Journal of the Korean Geotechnical Society
    • /
    • v.32 no.7
    • /
    • pp.25-34
    • /
    • 2016
  • Recently, in Korea, problems related with unstability of slope or sinkhole in urban area due to erosion of compacted granite soil which was used as a backfill or embankment material have been treated as important issues. Small hole might develop inside of backfill area due to erosion of not only weathered granite soil but also clay, silt, fine sand size particles when underground water flows. Once erosion starts in a soil mass, erosion rate increases gradually to cause rapid destruction. In this study, a rotating cylinder test (RCT) was performed to evaluate the hydraulic resistance characteristics of compacted weathered granite soil under various relative densities and preconsolidation pressures. Meanwhile, an image analysis method was introduced to analyze radius of irregularly eroded sample. It was found that image analysis is an effective means of minimizing the error in calculating a critical shear stress and threshold shear stress on the irregularly eroded sample. Furthermore, in general, hydraulic resistance capacity increases with the increase of relative density and preconsolidation pressure.

A Study on the Reinforcement Case of Bridge Foundation in the Limestone Cavity with CGS Method (CGS 공법 적용 석회암 공동지역의 교량기초보강 사례 연구)

  • Park, Sungsu;Hong, Jongouk;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
    • /
    • v.14 no.12
    • /
    • pp.43-52
    • /
    • 2013
  • Limestone typically forms large caverns such as reticular caverns or limestone caves, and also forms sinkhole and doline. These caverns cause different settlement when constructing roads, dams, etc. because the foundation cannot sustain the upper structures. So it is necessary to reinforce foundation such as cavern filling method, etc. In this study, ground reinforcement for structure foundation was carried out using CGS method in limestone cavity area and evaluation of reinforcement effect from engineering viewpoint was conducted through the field test. Among others, boring test was carried out to identify the ground structure and engineering characteristics. After CGS reinforcement, boring test was conducted for supplementary verification, and with reinforcement core taken during boring test, rock test was carried out to identify the physical properties of reinforcement material. After applying CGS method, rock test of the typical specimen, among reinforcement cores, taken from boring test was carried out and physical properties of the reinforcement was identified. As a result of compressive test of core sample, material inside the cavity was filled properly, indicating compressive strength of 12.2~19.2(MPa) which was evaluated acceptable. Thus the limestone cavity proved to have been reinforced successfully.

Evaluation of Stiffness Profile for a Subgrade Cross-Section by the CAP(Common-Array-Profiling)-SASW Technique (CAP SASW 기법에 의한 지반단면의 전단강성구조 평가)

  • Joh Sung-Ho;Jang Dae-Woo;Kang Tae-Ho;Lee Il-Wha
    • Journal of the Korean Geotechnical Society
    • /
    • v.21 no.4
    • /
    • pp.71-81
    • /
    • 2005
  • Surface wave techniques were initially based on 2-D plane waves and were later improved to the techniques based the 3-D based cylindrical waves. However, body-wave interference, near-field effect and limited technology in surface wave measurements restricted the use of 3-D cylindrical waves to the 1-D evaluation of subgrade stiffness. In this study, by the numerical simulation of SASW measurements, the dispersion properties of surface waves including vertical, horizontal Rayleigh waves and Love waves were thoroughly investigated in the 3-D domain, and a new filter criteria to minimize the near-field effect was established, which led to CAP (common-array-profiling)-SASW technique. The CAP-SASW technique enabled the evaluation of subgrade stiffness fur a specific subgrade segment, not for a whole section of measurement array. Therefore, a contour plot of subgrade stiffness with a ground-truth quality can be obtained by the CAP-SASW technique. The procedure proposed in this study was verified by comparing the shear-wave velocity profiles with the shear-wave velocity profiles of downhole testing at two geotechnical sites.

A Study on Restaurant Workers' Knowledge about Food Hygiene and Safety (패밀리 레스토랑 직원들의 식품 위생 및 안전 지식에 관한 연구)

  • Eo, Geum-Hee;Hahm, Moon-Hoon
    • Culinary science and hospitality research
    • /
    • v.15 no.2
    • /
    • pp.268-281
    • /
    • 2009
  • The purpose of the study was to examine the restaurant workers' understanding of food hygiene and safety regulations using SPSS. From October 10th to 31st, 2008, a survey was conducted to those who work at family restaurants in Seoul and Gyeonggi-do. This program analyzed total 149 copies of the questionnaire. 79.9 percent of the respondents have completed college education; 76.7 percent out of them were domestic company workers and 82.9 percent were foreign company workers. The total average points turned out to be 14.03 points out of 20, 3.95 out of 5 for food poisoning, 2.37 out of 3 for personal hygiene, 6.41 out of 9 for food hygiene and environment, and 1.86 out of 3 for food safety. Foreign company employees scored higher points(14.3) compared to those of domestic companies. When comparing the points between domestic company workers and foreign company workers, the score of kitchen staff(p<0.001) and the score of a restaurant assistant(p<0.05) have influenced the overall points. In conclusion, people scored low points in areas as understanding of 'dangerous temperature level', 'bacterial multiplication', 'safe defrosting methods', 'cooling methods' and 'temperature control', indicating the necessity of the training on 'time/temperature control'.

  • PDF

수직형 발광다이오드의 표면패턴 밀도 증가에 따른 광추출 효율 향상에 관한 연구

  • Jeong, Ho-Yeong;Kim, Su-Jin;Kim, Gyeong-Heon;An, Ho-Myeong;Kim, Tae-Geun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.02a
    • /
    • pp.416-417
    • /
    • 2013
  • 최근 질화물계 발광다이오드(light emitting diode, LED) 소자는 핸드폰, 스마트 TV 등의 디스플레이 분야와 실내외조명, 감성조명, 특수조명 등의 조명분야에 그 응용분야가 급속히 확대되고 있다. 이러한 LED 소자는 에너지 절감과 친환경에 장점을 가지고, 가까운 미래에 조명시장을 대체할 것으로 예상된다. 이를 만족하기 위해서는 현재보다 더 높은 효율을 갖는 LED 개발이 요구되어지고 있는 상황이다. 일반적으로 질화물계 LED 소자의 효율은 내부양자 효율, 광추출 효율 등으로 나타낼 수 있다. 내부 양자효율은 성장된 결정의 질의 개선 및 다층의 이종접합 또는 다중양자우물 구조와 같이 활성층의 캐리어 농도를 높이는 접합구조로 설계되어 80% 이상의 효율을 나타낸다. 그러나 광추출 효율은 이에 미치지 못하고 있다. 이는 반도체 재료의 높은 굴절률로 인하여 빛이 외부로 탈출하지 못하고 내부로 반사되거나 물질 안에서 흡수가 일어나기 때문이다. 따라서 이러한 문제를 해결하기 위해 많은 연구 그룹들은, 표면에 패턴 형성하여 빛의 전반사를 줄여 그 효율을 올리는 연구결과를 보고하고 있다. 대표적인 방법으로는 wet etching, 전자빔 리소그라피, 나노임프린트 리소그라피, 레이저 홀로 리그라피, 나노스피어 리소그라피 등이 사용되고 있다. 이 중, 나노스피어 리소그라피는 폴리스틸렌 혹은 실리카 등과 같은 나노 크기의 bead를 사용하여 반도체 기판 표면에 단일층으로 고르게 코팅한 마스크로 사용하여 패턴을 주는 방법이다. 이 방법의 장점으로는 대면적에 균일한 패턴을 형성할 수 있고, 공정비용이 저렴하여 양산하기에 적합하다는 특징이 있다. 나노스피어 리소그라피를 통해서 표면에 생성된 패턴 모양의 각도에 따라서, 식각되는 깊이에 변화에 따라 실험한 결과들은 있지만, 아직까지 크기가 다른 나노입자들의 마스크 이용하여 형성된 패턴 밀도에 따른 광 추출 효과에 대한 연구가 많이 미흡하다. 따라서 본 연구에서는 다양한 크기의 실리카로 패턴을 형성시켜 패턴 밀도에 대한 광추출 효율의 효과에 대해서 조사하였다. 실험 방법으론, DI, 에탄올, TEOS, 암모니아의 순서대로 그 혼합 비율을 조정하여 100, 250, 500 nm 크기의 나노입자를 합성하였고 이것을 질화물계 LED의 표면 위에 단일층으로 스핀코팅 방법을 통해 코팅을 하였다. 그 후 ICP-RIE 방법으로 필라 패턴을 형성하였는데, 그 결과 100 nm SiO2 입자를 이용한 경우 $4.5{\times}10^9$/$cm^2$, 250 nm의 경우 $1.4{\times}10^9$/$cm^2$, 500 nm의 경우 $0.4{\times}10^9$/$cm^2$의 패턴의 밀도를 보여주었다(Fig. 1). 패턴의 밀도에 따라 전계광학적 특성을 확인하여 보았는데, 그 결과는 평평한 표면과 비교하였을 때 100 nm에서 383%, 250 nm에서는 320%, 500 nm에서는 244% 상승하는 결과를 보여주었다(Fig. 2). 이번 실험을 통해서 LED의 광추출 효율은 표면 모양과 깊이 뿐 아니라 밀도가 커질수록 그 효율이 올라간다는 사실을 알 수 있었다.

  • PDF

Effects of The Substrate Temperature and The Thin film Thickness on The Properties of The Ga-doped ZnO Thin Film (기판온도 및 박막두께가 Ga-doped ZnO 박막의 특성에 미치는 영향)

  • Cho, Won-Jun;Kang, Seong-Jun;Yoon, Yung-Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.47 no.1
    • /
    • pp.6-13
    • /
    • 2010
  • In this study, Ga-doped ZnO (GZO) thin films have been fabricated on Eagle 2000 glass substrates at various substrate temperatures $100{\sim}400^{\circ}C$ and thin film thickness by RF magnetron sputtering in order to investigate the structural, electrical, and optical properties of the GZO thin films. It is observed that all the thin films exhibit c-axis orientation and a (002) diffraction peak only. The GZO thin films, which were deposited at $T=300^{\circ}C$ and 400 nm, shows the highest (002) orientation, and the full width at half maximum (FWHM) of the (002) diffraction peak is $0.4^{\circ}$. AFM analysis shows that the formation of relatively smooth thin films are obtained. The lowest resistivity ($8.01{\times}10^{-4}\;{\Omega}cm$) and the highest carrier concentration ($3.59{\times}10^{20}\;cm^{-3}$) are obtained in the GZO thin films deposited at $T=300^{\circ}C$ and 400 nm. The optical transmittance in the visible region is approximately 80 %, regardless of process conditions. The optical band-gap shows the slight blue-shift with increase in doping which can be explained by the Burstein-Moss effect.

An Analysis on the Bleeding Effect of SCW Ground Heat Exchanger using Thermal Response Test Data (열응답시험 데이터를 이용한 SCW형 지중열교환기 블리딩 효과 분석)

  • Chang, Keun-Sun;Kim, Min-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.1
    • /
    • pp.512-520
    • /
    • 2020
  • Recently, the applications of the standing column well (SCW) ground heat exchanger (GHX) have increased significantly in Korea as a heat transfer mechanism of ground source heat pump systems (GSHP) because of its high heat capacity and efficiency. Among the various design and operating parameters, bleeding was found to be the most important parameter for improving the thermal performance, such as ground thermal conductivity and borehole thermal resistance. In this study, a bleeding analysis model was developed using the thermal response test data, and the effects of bleeding rates and bleeding locations on the thermal performance of anSCW were investigated. The results show that, when the ground water flows into the top of anSCW, the time variation of circulating water temperature decreased with increasing bleeding rate, and the ground thermal conductivity increases by as much as 179% with a 30% bleeding rate. When the ground water flows into the bottom of the SCW, the circulating water temperatures become almost constant after the increase in the beginning time because the circulating water exchanges heat with the ground structure before mixing with the ground water at the bottom.