• Title/Summary/Keyword: Over-the-head

Search Result 1,195, Processing Time 0.024 seconds

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

  • Lee, Hyeon-Gu;Kim, Hyeon-Jin;Kim, Hyeon-Su
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.20 no.1
    • /
    • pp.237-243
    • /
    • 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.

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

  • Park, Sun-Dong
    • Herbal Formula Science
    • /
    • v.15 no.1
    • /
    • pp.37-47
    • /
    • 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.

  • PDF

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

  • Kim, Kyung-Yup;Suh, Sang-Ho;Lee, Jung-Woo;Roh, Hyung-Woon;Kim, Sang-Gyun
    • 유체기계공업학회:학술대회논문집
    • /
    • 2001.11a
    • /
    • pp.165-170
    • /
    • 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.

  • PDF

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

  • Lee, Geun-Hyuk;So, Jae-Moo
    • Korean Journal of Applied Biomechanics
    • /
    • v.23 no.4
    • /
    • pp.319-326
    • /
    • 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.

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

  • Nam, Choon-Sung;Jang, Kyung-Soo;Shin, Ho-Jin;Shin, Dong-Ryeol
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.10 no.2
    • /
    • pp.25-30
    • /
    • 2010
  • Wireless sensor networks is composed of many similar sensor nodes with limited resources. They are randomly scattered over a specific area and self-organize the network. For guarantee of network life time, load balancing and scalability in sensor networks, sensor networks needs the clustering algorithm which distribute the networks to a local cluster. In existing clustering algorithms, the cluster head selection method has two problems. One is additional communication cost for finding location and energy of nodes. Another is unequal clustering. To solve them, this paper proposes a novel cluster head selection algorithm revised previous clustering algorithm, LEACH. The simulation results show that the energy compared with the previous clustering method is reduced.

Survivability Evaluation Model in Wireless Sensor Network using Software Rejuvenation

  • Parvin, Sazia;Thein, Thandar;Kim, Dong-Seong;Park, Jong-Sou
    • Convergence Security Journal
    • /
    • v.8 no.1
    • /
    • pp.91-100
    • /
    • 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.

  • PDF

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

  • Lee, Doo-Wan;Han, Youn-Hee;Jang, Kyung-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.15 no.4
    • /
    • pp.993-999
    • /
    • 2011
  • In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. Specially, in WSN environment, in which the administrator's intervention is restricted, the self-configuration capability is essential to establish a power-conservative WSN which provides broad sensing coverage and communication coverage. In this paper, we propose a communication coverage-aware cluster head election algorithm for Herearchical WSNs which consists of communication coverage-aware of the Base station is the cluster head node is elected and a clustering.

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
    • /
    • v.13 no.3
    • /
    • pp.975-978
    • /
    • 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.

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

  • Kim, Tae-Im
    • Child Health Nursing Research
    • /
    • v.8 no.2
    • /
    • pp.204-216
    • /
    • 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.

  • PDF

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

  • Kang, Seok-Min;Paik, Chae-Hoon;Lee, Geon-Hwi;Choi, Man-Young;Sengottayan, Senthil-Nathan;Hwang, Chang-Yeon
    • Korean journal of applied entomology
    • /
    • v.48 no.2
    • /
    • pp.165-170
    • /
    • 2009
  • This study was conducted to investigate specific stages and distribution of overwintering nymphs of green rice leafhopper, Nephotettix cincticeps by measuring head capsule width. The nymphal head capsule width of the 1st instar to the 5th instar was 0.381, 0.502, 0.673, 0.979 and 1.128 mm, respectively. lts coefficient variation was 5.3, 4.0, 3.0, 4.5 and 5.3%, respectively. Growth ratio of each instar was not significantly different among 2nd to 4th instars as 1.31 to 1.34, but for the 5th instar it decreased as 1.28. The logarithm of the nymphal head capsule width was regressed as a function of the stage number of insects, resulting in LogY = 1.4627 + 0.1192X ($r^2= 0.9993$). Also fitness to the Dyar's law for the nymphal head capsule width of each instar was 98% or over and the Dyar's constant (K) was 1.316. The occurrence of N. cincticeps was maximum at the end of January with 195 individuals/0.25 $m^2$. The most abundant instar in the overwintering N. cincticeps population was 4th instar accounting for over 90%. Population of the 5th instar began to increase from mid-March, and adults began to occur in early April.