• 제목/요약/키워드: hand-off

검색결과 573건 처리시간 0.031초

Y형태의 급전 구조를 이용한 편파 변환 재구성 패치 안테나 (Reconfigurable Polarization Patch Antenna with Y-Shaped Feed)

  • 이다애;성영제
    • 한국전자파학회논문지
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    • 제25권1호
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    • pp.1-9
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    • 2014
  • 본 논문에서는 Y자 형태의 급전 구조를 사용한 두 개의 편파 변환 재구성 패치 안테나를 제안하였다. 제안된 안테나는 정사각형 형태의 패치, Y자 형태의 급전 구조, 하나의 핀 다이오드, 다이오드를 동작시킬 DC bias 회로로 구성되어 있다. 구조적인 대칭/비대칭은 두 갈래로 갈라지는 Y자 형태의 급전부 왼쪽 라인에 삽입된 핀 다이오드의 on/off 상태에 의해 결정된다. 제안된 재구성 안테나는 핀 다이오드가 on 상태이면 급전부의 갈라지는 두 마이크로스트립 라인의 길이가 같아지게 되어 안테나는 선형 편파 특성을 나타낸다. 반면에, 핀 다이오드가 off 상태이면 급전부의 갈라지는 두 마이크로스트립 라인 중 한 쪽 라인의 길이가 나머지 한 쪽 라인의 길이보다 상대적으로 짧아지게 된다. 그러므로 안테나는 원형 편파 특성을 나타낸다. 측정 결과로부터 제안된 안테나는 좋은 임피던스 매칭과 축비 특성을 나타내며, 같은 주파수 대역에서 쉽게 편파 변환할 수 있다는 것을 확인할 수 있다.

장외영향평가 및 공정안전관리제도의 통합 안전환경관리방안에 관한 연구 (Offsite Consequence Analysis and safety management system process integration plan of safety management system)

  • 김동준;이인복;문진영;천영우
    • 대한안전경영과학회지
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    • 제18권3호
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    • pp.63-70
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    • 2016
  • The main point of this study is to find out duplicates and differences among various regulations from different organizations. Also, it focuses on creating a reasonably unified regulation system to standardize safety & environment management. In this study, I analyzed the commonalities and the differences of two systems which are typical korean Process Safety Management System and off-site Consequence Analysis. It is confirmed that there are 25 species of overlapped material of those two systems and assessment like handling material information, facilities lists, hazardous substances and list of machine power. Process safety report focuses on onsite workers and facility protect. On the other hand, off-site Consequence Analysis focuses on design, arrangement and management of handling facility from off-site influence. I found difference two system of Enforcement purposes and way. Contradiction of Harmful information of Chemicals Control Act and occupation safety and health acts from same material. To be specific, There are no unit rule of occupation safety and health acts. so it permit inch, psi etc. But Chemicals Control Act provides that m, Mpa units. Therefore, Each regulatory duplication of items for chemicals management, standardization is writing so that you can coordinate overlapping items in the measures the need to be presented.

A Study on Characteristic Improvement of IGBT with P-floating Layer

  • Kyoung, Sinsu;Jung, Eun Sik;Kang, Ey Goo
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.686-694
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    • 2014
  • A power semiconductor device, usually used as a switch or rectifier, is very significant in the modern power industry. The power semiconductor, in terms of its physical properties, requires a high breakdown voltage to turn off, a low on-state resistance to reduce static loss, and a fast switching speed to reduce dynamic loss. Among those parameters, the breakdown voltage and on-state resistance rely on the doping concentration of the drift region in the power semiconductor, this effect can be more important for a higher voltage device. Although the low doping concentration in the drift region increases the breakdown voltage, the on-state resistance that is increased along with it makes the static loss characteristic deteriorate. On the other hand, although the high doping concentration in the drift region reduces on-state resistance, the breakdown voltage is decreased, which limits the scope of its applications. This addresses the fact that breakdown voltage and on-state resistance are in a trade-off relationship with a parameter of the doping concentration in the drift region. Such a trade-off relationship is a hindrance to the development of power semiconductor devices that have idealistic characteristics. In this study, a novel structure is proposed for the Insulated Gate Bipolar Transistor (IGBT) device that uses conductivity modulation, which makes it possible to increase the breakdown voltage without changing the on-state resistance through use of a P-floating layer. More specifically in the proposed IGBT structure, a P-floating layer was inserted into the drift region, which results in an alleviation of the trade-off relationship between the on-state resistance and the breakdown voltage. The increase of breakdown voltage in the proposed IGBT structure has been analyzed both theoretically and through simulations, and it is verified through measurement of actual samples.

중국 소비자의 라이프스타일이 애슬레저웨어 추구혜택과 구매의도에 미치는 영향 (Effect of Chinese Consumers' Lifestyle on Pursuing Benefits and Purchase Intention for Athleisure Wear)

  • 장분용;오경화
    • 한국의상디자인학회지
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    • 제25권1호
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    • pp.1-13
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    • 2023
  • This study examines the effects of Chinese consumers' lifestyles on pursuing the benefits and purchase intentions for athleisure wear. Chinese female consumers aged 20 to 40 in Shanghai and Chengdu, who have purchased athleisure wear were selected for a survey, and 510 questionnaires were collected. Data was analyzed using SPSS 26.0 software. Factor analysis, reliability verification, regression analysis, and discrete analysis were performed. As a result, Chinese consumers' lifestyles were classified into three categories: 'personality orientation', 'show-off orientation', and 'health orientation'. There were four benefits: 'situation pursuit', 'practicality pursuit', 'fashion style pursuit', and 'appearance pursuit' for athleisure wear. Among the lifestyle types of Chinese consumers, "individuality-oriented" showed a positive effect on "pursuit of practicality", "pursuit of situation", "pursuit of fashion style", and "pursuit of appearance" among the benefits of pursuing athleisure wear. Next, among lifestyle types, 'show-off orientation' showed a positive effect on 'individuality' and 'appearance pursuit'. Finally, among lifestyle types, 'health-oriented' showed a positive effect on 'pursuit of practicality' and 'pursuit of appearance'. On the other hand, Chinese consumers' lifestyle types of "show-off," "health-oriented," and "individuality-oriented" all exhibited a significant impact on their purchase intention for athleisure wear. According to age groups and location, there is no significant difference in terms of 'lifestyle', 'athleisure wear pursuit benefits' and 'purchase intention'. Compared married women and unmarried women, it was found that unmarried women value their health and leisure, while those with a lower their educational background, considered the lifestyle of "individuality-oriented" and "show-off-oriented", as well as "situation-pursuit", "practicality", and "fashion style pursuit".

PIN 다이오드를 이용한 다중 편파 재구성 마이크로스트립 안테나 (A Multi-Polarization Reconfigurable Microstrip Antenna Using PIN Diodes)

  • 송태호;이영기;박대성;이석곤;김형주;최재훈
    • 한국전자파학회논문지
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    • 제24권5호
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    • pp.492-501
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    • 2013
  • 본 논문에서는 S-밴드에서 하나의 급전 회로로 4개의 편파(수직 편파, 수평 편파, 좌선회 편파, 우선회 편파)를 선택적으로 사용할 수 있는 다중 편파 재구성 마이크로스트립 안테나를 제안하였다. 제안된 안테나는 십자 슬롯과 원형 슬롯을 포함하는 정사각형 형태의 마이크로스트립 패치와 4개의 PIN 다이오드로 구성되어 있으며, 커플링을 통한 급전 방식을 이용한다. 각각의 PIN 다이오드에는 직류 전압을 인가하기 위한 바이어스 단이 있으며, 직류 전압의 인가에 따른 다이오드 ON / OFF 동작으로 편파를 재구성할 수 있다. 제작된 안테나는 수직 편파(3.17~3.21 GHz), 수평 편파(3.16~3.20 GHz), 좌선회 편파(3.08~3.19 GHz), 우선회 편파(3.10~3.20 GHz)에서 VSWR 2:1을 만족하며, 선형 편파에서는 20 dB 이상의 교차 편파 및 5 dBi 이상의 이득 특성을 갖고, 원형편파에서는 50 MHz 이상의 3 dB 축비 특성을 나타낸다.

한국 포장디자인의 전통성에 관한 연구

  • 최동신
    • 디자인학연구
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    • 제9권
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    • pp.1101-1114
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    • 1994
  • As of today-half a century has passed after 1945, the liberation from Japanese imperialism-it's significant to introspect our culture. On the one hand our culture has succeeded due to the peculiar history, but on the other hand it hasn't. So to speak, it has gained in Quantity but lost in Quality. There are keen, international competition and exchange in the modern culture. So the Qualitive success of modern design depends on if it had an original character or not. According to Korean rapid industrialization, technological extence, and economic growth, the export has increased greatly, but package design hasn't been match for them. Korean expoters have been meeting with cutthroat competition in world market. Under these circumstances it's very important that we have a real understand and interest in our culture, we strengthen the competitive power of home products with good package design. This is our age of not home market but world market. We live in an age when design wins, so that we have to develop the good design native to Korea. Many designers have proposed their opinions with the characteristic designs, but it has been only a fragmentary and passive method. We must seek for the new method more positively. The effective and proper method resolves itself into the following four points. First, to understand Korean history and culture. Second, to have the exact grip of this economic situation. Third, to promote the national emotion. Fourth, in conclusion, to accord the package design with them. We cannot put off this task to overcome the cultural subordination, to place Korea on a firm cultural basis in the world, and to contribute to the cultural exchange of package design. First, to understand Korean history and culture. Second, to have the exact grip of this economic situation. Third, to promote the national emotion. Fourth, in conclusion, to accord the package design with them. We cannot put off this task to overcome the cultural subordination, to place Korea on a firm cultural basis in the world, and to contribute to the cultural exchange of package design.

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다중 키 교환 알고리즘을 이용한 무선 보안 전송 기법 (Wireless Security Transmission Using Algorithm of Multiple-Key Exchange)

  • 류동주;김광현;노봉남
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2005년도 추계종합학술대회
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    • pp.807-810
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    • 2005
  • 본 논문에서는 무선 네트워크 환경의 모바일 노드에서 전송되는 데이터의 기밀성 모장 및 안전한 전송을 위한 무선 기반의 네트워크 시험환경을 구축하고, 모바일 환경 중 IPv6에 기본으로 내장되어 있는IPSec를 이용한 효율적인 보안전송을 위한 IKEv2의 다중 키 교환 메카니즘에 관한 연구를 진행하였다. 무선망에서 모바일 노드의 핸드오프 패킷 전송 과정에서 끊김과 빈번하게 발생하는 키에 대한 재설정 및 재교환 문제를 해결하기 위해 하나의 단말에 여러 개의 키를 가지고 이동하는 기술을 연구하였다. 실험을 위해 사용된 키 교환 프로토콜은 MIPv6에서 기본적으로 탑재하고 양단간의 신뢰성 있는 암호화키의 관리와 분배를 위해 사용되는 IKEv2 프로토콜을 사용하였다. 본 논문에서는 SSFNet(Scalable Simulation Framework Network Models)이라는 네트워크 보안 시뮬레이터를 이용하여 IKEv2의 보안전송의 키 교환 지연 값을 비교 분석하여 성능을 측정하고 그에 따른 문제점과 개선 방안에 대해 연구하였다.

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주변 전기장 측정센서를 이용한 손동작 신호 검출을 위한 신호처리시스템 연구 (Study on Signal Processing Method for Extracting Hand-Gesture Signals Using Sensors Measuring Surrounding Electric Field Disturbance)

  • 천우영;김영철
    • 스마트미디어저널
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    • 제6권2호
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    • pp.26-32
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    • 2017
  • 본 논문에서는 지구전기장 왜란신호를 전위차로 변환하는 EPIC(Electric Potential Integrated Circuit) 센서를 이용한 NUI(Natural User Interface) 기술의 요소기술인 신호검출 전자회로를 기반으로 LED 조명을 제어하는 시스템을 구현하였다. 기존에는 CIB 개발 장비를 통해서만 제한적인 형태로 이용 가능했던 신호를 모든 EPIC 센서 각각의 신호를 추출할 수 있도록 개발된 신호검출 전자회로를 이용하였다. 이렇게 추출한 신호는 이후 손동작 인식프로세스에서 특징추출 등의 과정에서 더 많은 자유도와 성능개선 효과를 보여준다. 설계되어 제작된 회로의 실제 응용시스템으로서 적용성을 검증하기 위하여 4개의 손동작으로 LED 조명의 on/off 와 밝기를 조정할 수 있는 시스템을 설계하였다. 기존의 EPIC 센서를 이용하여 명령체계를 구축하고 인터페이스 제어신호를 이용하여 보다 빠른 패턴인식 처리 속도를 얻을 수 있었다.

의사와 간호사의 외과적 손씻기에 관한 지식, 태도 및 실천에 대한 조사 연구 (A Survey on the Performance of Surgical Hand Scrubs)

  • 윤혜상
    • 대한간호학회지
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    • 제26권3호
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    • pp.591-604
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    • 1996
  • The surgical hand scrub (SHS) is the single most important procedure in the prevention of post-operative wound infections and yet it remains the most violated of all infection control procedures. The purpose of this study was to gain an overview of SHS habits in operative th atre personnel and to determine knowledge and attitudes to identify whether there is a need for improvement. The subjects for this study included 79 doctors and 94 nurses working in the operative th atres of four hospitals in Incheon City and Kyungki Province. Related data were collected from July 25 to August 10, 1995 by the author. The data were analyzed using descriptive stat-istics and Chi-squre test. The results of the study are summarized as follows : 1. Nurses felt that they conducted SHS for a longer period of time than doctors did(X=20.1, P=.005). 2. Nurses and doctors had some knowledge of slip-ping rings off fingers and the length of nails, but they lacked knowledge on the duration of SHS, handwashing after an operation and on manicure. 3. There were many reasons given for insufficient SHS included : 1) because they were so busy (38%). 2) brushes were too harsh(19.7%). 3) operations were very simple(18.7%). 4) surgical latex gloves provide functional barrier(11.6%). 5) SHSs were troublesome(7.4%) 6) there were no clocks near the sinks(2.5%) and 7) the operative patients were administered antibiotics after operartion(2.1%). 4. Most of nurses and doctors considered SHS to be important in prevention against post operative infections. 5. Nurses were found to do a thorough SHS, but residents were found to neglect SHS. 6. Considering prevention against postoperative infections, most nurses and doctors considered aseptic techniques, environment-sanitary management and SHS more important than the use of antibiotics, the resistance of patients or the method of operation. 7. Half of the nurses and doctors(54.3%) considered surgical latex gloves to function well as a barrier. 8. Half of the nurses (56.4%) and doctors(51.9%) learned SHS as part of the curriculum in their school education and the rest(nurses : 95.7%, doctors : 74.7%) learned SHS as part of their In Service Education. In conclusion, these findings suggest a need to develop an educational program on surgical hand scrub and hospital infection control for surgical personnels, to install clocks near the hand scrub sinks, to consider a violation report for negligent surgical hand scrubs, and to develop a soft brush for hand scrubs in order to increase performance of the surgical hand scrub.

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제조공법에 따른 디스플레이 소자용 silver-grid 투명전극층의 특성 비교 (Comparison of characteristics of silver-grid transparent conductive electrodes for display devices according to fabrication method)

  • 최병수;최석환;류정호;조현
    • 한국결정성장학회지
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    • 제27권2호
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    • pp.75-79
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    • 2017
  • 고밀도 플라즈마 식각 및 lift-off 두 가지 공정으로 honeycomb 형상의 Ag-grid 투명전극층을 제작하였고 제조 공법에 따른 광학적 및 전기적 특성을 비교하였다. 플라즈마 식각 조건 선정을 위하여 Ag 박막의 $10CF_4/5Ar$ 유도결합 플라즈마 식각특성을 조사하였다. 비교적 낮은 ICP source power 또는 rf chuck power 영역에서는 power 증가에 따라 Ag 식각속도가 증가하였고, 높은 power 조건에서는 $Ar^+$ 이온 에너지 감소 또는 $Ar^+$ 이온에 의한 F radical 제거로 인해 식각속도가 감소하였다. $10CF_4/5Ar$ 플라즈마 식각 공정에 의해 제작된 Ag-grid 전극층은 lift-off 공정으로 제작된 전극층에 비해 grid 패턴 형상의 왜곡이나 단절이 없는 더 우수한 grid 패턴 전사 효율과 가시광선 영역에서 더 높은 83.3 %(pixel 크기 $30{\mu}m$/선폭 $5{\mu}m$)와 71 %(pixel 크기 $26{\mu}m$/선폭 $8{\mu}m$)의 광투과율을 각각 나타내었다. 반면에 lift-off 공정으로 제작된 Ag-grid 전극층은 플라즈마 식각 공정 시편보다 더 우수한 $2.163{\Omega}/{\square}$(pixel 크기 $26{\mu}m$/선폭 $8{\mu}m$)과 $4.932{\Omega}/{\square}$(pixel 크기 $30{\mu}m$/선폭 $5{\mu}m$)의 면저항 특성을 나타내었다.