• 제목/요약/키워드: Over-the-head

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무한궤도 수차의 성능시험 (Performance Test of a Catapillar Track-Hydroturbine)

  • 이현구;김현진;김현수
    • 대한기계학회논문집B
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    • 제20권1호
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    • pp.237-243
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    • 1996
  • Current low head and small scale hydroturbines have limitations in the minimum required head and flow rate for efficient operation. This study attempts to develop a new concept hydroturbine which is expected to run efficiently even in very low head and small flow rate, so that the limitations on the conventional small scale hydropower could be alleviated and competition with other alternative energy sources in the economic respect could be attained. A small scale catapillar track- hydroturbine was fabricated and the performance test was carried out in a water tunnel over the head range of H = 0.8 m ~ 1.26 m. The peak turbine efficiency was 41.3% at the speed ratio of 0.6, and the turbine loss was mostly due to the friction at the chain drive used for power transmission from the runner to the shafts. This type of turbine is expected to become competitive when some improvement in the power transmission mechanism is made.

동의보감(東醫寶鑑) 외형편(外形篇) 권(卷)1 [두(頭)]부분 관련처방의 재해석 (A Study of Prescriptions of Head Part in DongEuiBoGam)

  • 박선동
    • 대한한의학방제학회지
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    • 제15권1호
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    • pp.37-47
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    • 2007
  • 許浚(Heo Jun), the best physician on his day, wrote 東醫寶鑑(DongEuiBoGam, 1613) based on his clinical experience as a court doctor and life-long study of over 500 medical books. Now most clinicians consult 東醫寶鑑(DongEuiBoGam) for its practicality. And it is also considered as one of the most valuable medical books for basic medical studies. As 許浚(Heo Jun) mentioned on the 東醫寶鑑(DongEuiBoGam) preface. we should practice flexibility on the interpretation of the medical classics instead of binding ourselves to the precedents. But worship of 東醫寶鑑(DongEuiBoGam) may hinder the studying of new pathways. The treatment and its understandings of a disease should be based on objectivity of observation. Finding the common traits of the recipes in 東醫寶鑑(DongEuiBoGam) is important for the study of 東醫寶鑑(DongEuiBoGam). Accordingly, group synthesis of symptoms and resultant classification of recipes are vital. In this research, symptoms listed in the head part(頭門) of External Shape vol. I(外形篇 卷1) of 東醫寶鑑(DongEuiBoGam) are synthesized into 3 different parts: head-wind syndrome(頭風證), dizziness(眩暈), headache(頭痛). Classification of prescriptions according to these 3 parts is also suggested.

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광역상수도용 펌프의 전양정 결정에 관한 연구 (A Study on the Total Head Decision of Pump for Regional Water Supply Facilities)

  • 김경엽;서상호;이정우;노형운;김상균
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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    • pp.165-170
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    • 2001
  • An extensive range of pumping facilities are employed in the regional water supply system in metropolitan areas, and optimization and the systematic combination of the Pump facilities have direct bearing on the stability and economy of the water supply system concerned. These systems must be able to guarantee stability, efficiency and offer high reliability. Preparation of metropolitan area regional water supply system construction project must include a basic plan which takes into account the suitability of pumping facilities to be used, the environment in which facilities will be installed, man-power requirements and basic operational and management policies. This paper contains over-all analysis of the management of metropolitan area regional water supply systems as like Jayang, Paldang 1st pump station. In the study, it aims to prepare counterplan which will be operated and managed the pump upon the operational conditions and to suggest the proposal for water facilities codes to decides total head of pump in Korea.

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프로골퍼의 4m 퍼팅시 퍼터 헤드형태에 따른 운동학적 특성 (Kinematic Characteristics according to Types of Putter Head on Pro Golfer's 4 Meter Putts)

  • 이근혁;소재무
    • 한국운동역학회지
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    • 제23권4호
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    • pp.319-326
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    • 2013
  • The objective of this study is to help golfers to select adequate putters and to provide golfers basic scientific data for improving athletic performance by showing differences of kinematic variables according to the shape of putter head. In this research three right-handed male pro-golfer who are listed at KPGA were studied and three video camera (GR-HD1KR, JVC, Japan) were used and recording speed was 60 frame/sec during the research. In this study kinematic variables were calculated using Kwon3D XP program and analysed on the 4 events and 3 phases. This study showed the following results : (1) The swing of heel-toe putter showed longer time than that of face balanced putter, and there are statistical significant difference of kinematic variables of each objective (2) As of the trajectory of putter head, heel-toe putter showed more approximating curve trajectory than that of in-between, face balanced putter on the X-axis (3) heel-toe putter showed longer distance follow-through than that of other putters by statistically significant difference on the Y-axis (4) Heel-toe putter showed longer distance swing trajectory over the ground than that of other putters by statistically significant difference on the Z-axis.

무선 센서 네트워크에서 에너지 효율적 클러스터 헤드 선정 기법 (Energy-Efficient Cluster Head Selection Method in Wireless Sensor Networks)

  • 남춘성;장경수;신호진;신동렬
    • 한국인터넷방송통신학회논문지
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    • 제10권2호
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    • pp.25-30
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    • 2010
  • 무선 센서 네트워크는 제한된 자원을 가지고 특정한 지역에 임의로 뿌려진 센서 노드가 자가 구성적으로 형성하는 네트워크를 말한다. 센서 네트워크의 확장성(scalability), 로드 밸런싱(load balancing) 그리고 네트워크 라이프타임(network lifetime)을 보장하기 위해서 네트워크를 지역적으로 관리하는 클러스터링 알고리즘이 필요하다. 이전의 클러스터링 알고리즘에서 클러스터 헤드를 선정할 때 노드의 위치 및 에너지를 알아내기 위해 추가적인 통신비용이 발생하고, 클러스터 간 불균형이 클러스터 헤드에게 과부하를 유발한다. 따라서 본 논문은 이러한 문제점들을 해결하기 위해 추가적인 통신비용과 클러스터 불균형을 고려하는 새로운 클러스터 헤드 선정 알고리즘을 제안한다. 제안된 알고리즘은 실험결과를 통해 기존의 방법보다 에너지 측면에서 효율적임을 보여준다.

Survivability Evaluation Model in Wireless Sensor Network using Software Rejuvenation

  • Parvin, Sazia;Thein, Thandar;Kim, Dong-Seong;Park, Jong-Sou
    • 융합보안논문지
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    • 제8권1호
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    • pp.91-100
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    • 2008
  • The previous works in sensor networks security have focused on the aspect of confidentiality, authentication and integrity based on cryptographic primitives. There has been no prior work to assess the survivability in systematic way. Accordingly, this paper presents a survivability model of wireless sensor networks using software rejuvenation for dual adaptive cluster head. The survivability model has state transition to reflect status of real wireless sensor networks. In this paper, we only focus on a survivability model which is capable of describing cluster head compromise in the networks and able to switch over the redundant cluster head in order to increase the survivability of that cluster. Second, this paper presents how to enhance the survivability of sensor networks using software rejuvenation methodology for dual cluster head in wireless sensor network. We model and analyze each cluster as a stochastic process based on Semi Markov Process (SMP) and Discrete Time Markov Chain (DTMC). The proof of example scenarios and numerical analysis shows the feasibility of our approach.

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RF-Coverage를 고려한 에너지 효율적인 클러스터 헤드 선출 알고리즘 (Energy Efficient Cluster Head Election Algorithm Considering RF-Coverage)

  • 이두완;한연희;장경식
    • 한국정보통신학회논문지
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    • 제15권4호
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    • pp.993-999
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    • 2011
  • 무선 센서노드들은 초기에 대량으로 랜덤하게 배치되어 스스로 클러스터를 구성하고, 각 클러스터 헤드 노드를 선출하여 정상적인 통신이 이루어져야 한다. 이러한 일련의 작업을 무선 센서노드 설치시 관리자가 직접적으로 관여할 수 없기 때문에 자가 구성 라우팅 기능이 가능하여야 한다. 논문에서 제안하는 통신영역을 고려한 클러스터 헤드 노드 선출 알고리즘은 계층구조를 형성하는 무선센서 네트워크 환경에서 적용되며, 베이스 스테이션의 통신 영역을 계산하여 클러스터 헤드 노드를 선정하고 클러스터를 구성한다.

Diagnostic Utility of p63 (Ab-1) and (Ab-4) Tumor Markers in the Squamous Cell Carcinomas of Head and Neck

  • Khan, Nauman Rauf;Khan, Amna Nauman;Bashir, Saira;Khan, Ayyaz Ali;Suleman, Bilquis A.;Chaudhry, Saima
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.975-978
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    • 2012
  • P63 is a gene product required in cell cycle regulation which plays vital roles in tumor differentiation. Aims of the present study were to assess the frequency, pattern, sensitivity and specificity of two p63 protein clones P63 4A4 and P63 4A4+Y4A3 in squamous cell carcinomas (SCCs). Thirty cases of head and neck region SCC diagnosed on the basis of H&E staining were examined along with 60 cases of head and neck region biopsies other than squamous cell carcinoma, negative on H&E staining, were taken as control. Immunostaining was performed on slides according to the Thermo Scientific UltraVision LP detection System. P63 4A4+Y4A3 clone is more sensitive 96.6% in comparison to 86% in P63 4A4 with having greater NPV of 98.3%. The results signify the importance of P63 4A4+Y4A3 marker over the old markers and may be used as a confirmatory marker of squamous cell carcinoma.

마사지 요법이 시설 영아의 신체성장에 미치는 영향 (Effect of Massage Therapy on Growth Parameters of Instituted Infants)

  • 김태임
    • Child Health Nursing Research
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    • 제8권2호
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    • pp.204-216
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    • 2002
  • The purpose of this study was to investigate the effect of massage therapy on weight gain, length and head circumference in instituted infants. This study utilized nonequivalent control group with repeated measuring by quasi experimental design. Fifty eight instituted infants in Daejeon city were selected for the study. Fifty eight infants were randomly assigned two groups, one served as the control group and the other was experimental group to whom massage therapy was given. For the experimental group, massage protocol(developed by Field, 1986) was applied 2 times a day, mid-morning and early evening, for 4 weeks for each infants by researcher and trained research assistants. As a weight weighing instrument, electronic indicator scale (Cas Co., Korea) was used. The result of this study were summarized as follows; 1.A repeated measures ANOVA identified a significant group by time effect over the four weeks of intervention(F=14.69, p < .0001). Infants assigned to experimental group gained more weight than control group infants. 2. T-test identified that significant differences in length(t=2.60, P=.013) and head circumference(t=4.27, P=.000). Infants assigned to experimental group had more length and head circumference than control group infants. In conclusion, Massage therapy improved weight gain, length and head circumference of instituted infants. Therefore, it is recommended to utilize massage therapy as a nursing intervention for instituted infants.

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월동 끝동매미충(Nephotettix cincticeps)의 약충태별 두폭크기 및 밀도변화 (Head Capsule Width and Population Densities of Overwintering Nymphal Stages of the Green Rice Leafhopper, Nephotettix cincticeps Uhler (Hemiptera: Cicadellidae))

  • 강석민;백채훈;이건휘;최만영;;황창연
    • 한국응용곤충학회지
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    • 제48권2호
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    • pp.165-170
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    • 2009
  • 본 연구는 월동하는 끝동매미충의 충태별 분포를 두폭측정법을 활용하여 분석하였다. 끝동매미충 1령, 2령, 3령, 4령 및 5령 약충에 대한 두폭크기는 각각 0.381, 0.502, 0.673, 0.879 및 1.128mm였으며, 변이계수는 5.3, 4.0, 3.0, 4.5 및 5.3%였다. 성장률은 2령, 3령, 4령 약충에서는 1.31${\sim}$1.34로 큰 차이가 없었지만 5령에서 1.28로 약간 감소하였다. 두폭측정값의 회귀식을 구한 결과, LogY = 1.4627+0.1192X($r^2=0.9993$)으로 고도의 유의성이 인정되었고, Dyar 공식에 의한 적합도는 98% 이상으로 매우 적합하였으며, Dyar 계수(K)는 1.316이었다. 월동하는 끝동매미충의 밀도 및 충태 변화를 조사한 결과, 2006년 1월 하순에 0.25 $m^2$ 당 195마리가 채집되어 밀도가 가장 높았고, 월동 충태 조사에서는 90% 이상이 4령 약충이었다. 3월 중순부터 5령 약충의 발생량이 증가하였고, 월동 후 첫 성충발생은 4월 상순이었다.