• 제목/요약/키워드: Four-component

검색결과 1,367건 처리시간 0.025초

PIV를 이용한 선박 프로펠러 후류의 속도장 계측 (PIV Velocity Field Measurements of Flow around a Ship with Rotating Propeller)

  • 이상준;백부근
    • 대한조선학회논문집
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    • 제40권5호
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    • pp.17-25
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    • 2003
  • Velocity field behind a container ship model with a rotating propeller has been investigated using PIV (particle image velocimetry) system. Four hundred instantaneous velocity fields were measured at 4 different blade phases and ensemble-averaged to investigate the spatial evolution of vortical structure of near wake within one propeller diameter downstream. The phase-averaged mean velocity fields show the potential wake and the viscous wake formed due to the boundary layers developed on the blade surfaces. The interaction between bilge vortex developed along the hull surface and the tangential velocity component of incoming flow causes to have asymmetric flow structure in the transverse plane.

노년 여성의 연령집단별 동체부 형태 분석 (An Analysis of Torso somatotype according to age group of Elderly Women)

  • 최인순
    • 대한가정학회지
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    • 제33권6호
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    • pp.255-268
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    • 1995
  • The purpose of this study is to provide basic information for elderly women's clothing construction and to develop dress form that can reflect the characteristics of their bodies. Three hundred twenty subjects, between the ages of 60∼85, were chosen and the data were collected from 59 anthropometric measurements of each subject. Data were analyzed by factor analysis of principal component model, cluster analysis, analysis of variance and duncan test. The results are as follows : 1. A decrease in height, an enlargement of the waist and abdomen area, and a dropped bustline are characteristics of elderly women. The upper-torso droops as a ge increase 2. Seven factors were extracted from anthropometric measurements. Factor components were obesity, height, shoulder shaper, the center front bodice length, the center back bodice length, the bust and neck shape, the degree and level of scapular protusion. 3. After analyzing seven factors, four types were categorized.

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Comparative Analysis of Volatile Flavor Compounds from Zanthoxylum pipperitum A.P. DC

  • Chang, Kyung-Mi;Kim, Gun-Hee
    • Preventive Nutrition and Food Science
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    • 제13권1호
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    • pp.33-39
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    • 2008
  • The volatile flavor components of Zanthoxylum pipperitum A.P. DC. produced in Korea and China were isolated using a Clevenger-type apparatus by steam distillation extraction, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yields of oils from Korean and Chinese Z. pipperitum A.P. DC. were 2.0 and 1.2% (w/w), respectively. From the two Z. pipperitum A.P. DC. oils, sixty and fifty-four volatile flavor compounds were tentatively identified, and they constituted 94.78 and 87.34% of the total peak area, respectively. Piperitone(p-menth-1-en-3-one) (13.48%) was the most abundant compound in the Chinese Zanthoxylum pipperitum A.P. DC. oil, followed by $\beta$-phellandrene, sabinene, terpinen-4-ol and linalool (each >5%). Whereas, the most abundant compound in the Korean Zanthoxylum pipperitum A.P. DC. oil was limonene (18.04%), followed by geranyl acetate, cryptone, citronellal, cuminal and phellandral (each >5%).

Single-molecule fluorescence measurements reveal the reaction mechanisms of the core-RISC, composed of human Argonaute 2 and a guide RNA

  • Jo, Myung Hyun;Song, Ji-Joon;Hohng, Sungchul
    • BMB Reports
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    • 제48권12호
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    • pp.643-644
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    • 2015
  • In eukaryotes, small RNAs play important roles in both gene regulation and resistance to viral infection. Argonaute proteins have been identified as a key component of the effector complexes of various RNA-silencing pathways, but the mechanistic roles of Argonaute proteins in these pathways are not clearly understood. To address this question, we performed single-molecule fluorescence experiments using an RNA-induced silencing complex (core-RISC) composed of a small RNA and human Argonaute 2. We found that target binding of core-RISC starts at the seed region of the guide RNA. After target binding, four distinct reactions followed: target cleavage, transient binding, stable binding, and Argonaute unloading. Target cleavage required extensive sequence complementarity and accelerated core-RISC dissociation for recycling. In contrast, the stable binding of core-RISC to target RNAs required seed-match only, suggesting a potential explanation for the seed-match rule of microRNA (miRNA) target selection.

내부공생 켈프 배우체의 숙주 선택 (Host Specificity of Endophytic Kelp Gametophytes)

  • 김광용;최태섭;이영호
    • ALGAE
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    • 제19권1호
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    • pp.31-37
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    • 2004
  • Farmed kelp gametophytes were previously observed to be living endophytically in filamentous red algae. The interactions of two farmed kelp species and six red algae were examined in laboratory culture. Undaria pinnatifida (Harvey) Suringar and Laminaria religiosa Miyabe demonstrated the differing abilities of zoospores to become endophytic in four host red algae and neither kelp became endophytic in two non-filamentous red algae. There was a strong seasonal component regarding infectiousness that is associated with the changes in fron erosion in U. pinnatifida from April to June. At the same time, L. religiosa showed no significant changes in frond erosion, and there were no apparent changes in infection levels in the two species they were able infect. This study indicated clear differences between two keip species with regard to their symbiotic relationship to red algae in terms of host specificity and preference of kelp gametophytes.

Sequence Analysis and Functional Expression of the Structural and ]Regulatory Genes for Pyruvate Dehydrogenase

  • Hwan Youn;Jangyul Kwak
    • Journal of Microbiology
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    • 제40권1호
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    • pp.43-50
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    • 2002
  • A cluster of genes encoding the pyruvate dehydrogenase complex (PDC) of Streptomyces seoulensis, a Gram-positive bacterium, was cloned and sequenced. The genes of S. seoulensis consist of four open reading frames. The first gene, lpd, which encodes a lipoamide dehydrogenase, is followed by pdhB encoding a dihydrolipoamide acetyltransferase (E2p), pdhR, a regulatory gene, and pdhA encoding a pyruvate dehydrogenase component (Elp). Elp had an unusual homodimeric subunit, which has been known only in Gram-negative bacteria S. seoulensis E2p contains two lipoyl domains like those of humans and Streptomyces faecalis. The pdhR gene appears to be clustered with the structural genes of S. seoulensis PDC. The PdhR-overexpressed S. seoulensis howed growth retardation and the decrease of Elp, indicating that PdhR regulates the function of PDC by repressing the expression of Elp. A strain of Streptomyces licidans overexpressing S. seoulensis PdhR showed a significant decreasein the level of actinorhodin, implying a regulatory role for Streptomyces PDC in antibiotic biosynthesis.

동시 3축 가진에 의한 자동차 의자류의 승차감 평가 (Ride Quality Assessment of Automative Seats by Simultaneous 3-Axis Excitation)

  • 정완섭;우춘규;박세진;김수현
    • 소음진동
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    • 제7권1호
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    • pp.143-152
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    • 1997
  • This paper introduces experimental results of the ride qulaity characteristics of automotive seats fixed on the vibration table that is noving simultaneously to the three-axis in a similar way to the real running condition. Vibration experiment was carried out for five different automotive seats and four Korean individuals. The assessment of the ride quality characteristics for each seat and indiviual was made not only from the analysis of vibration measurements but also from the evaluation of weighied vibration signals, which were obtained using the frequency weighting function and the multiplication factor dependent on the position and axis of vibration exposure to wehole-body. The usefulness of those assessment results in analysis of the ride quality of seats is discussed and their limitation is also pointed out in this paper.

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펠티어 냉난방시스템 최적화 기술에 관한 연구 (A Study on Optimization Development of Peltier Air-conditioning System)

  • 박상훈;정수진;박영우;박유경;송범중
    • 융복합기술연구소 논문집
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    • 제3권1호
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    • pp.19-23
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    • 2013
  • This study is concerned with air-conditioning system in use of thermoelectric device. It is introduced that the well designed structures for better cooling & heating performance with high efficiency. And also it is performed that the system performance test of four types trial products for the use of hybrid commercial vehicle. System performance is affected by many component parts, especially heat sink design & power control method. It is applied that dual extrusive fin tube with buffer zone for the effective radiating of circulating liquid in tube. And also it is applied that power supply method with constant-current system. It is attained that system cooling capacity is 1.2kW, COP is 0.95.

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Expression and Preparation of Periostin FAS1 Domains for NMR Structure Determination

  • Yun, Hyosuk;Kim, Jae Il;Lee, Chul Won
    • 한국자기공명학회논문지
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    • 제20권1호
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    • pp.17-21
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    • 2016
  • Periostin, a component of extracellular matrix (ECM) protein, is produced and secreted by the fibroblasts that are involved in chronic allergic inflammation diseases and various types of human cancers. Periostin protein is composed of multiple domains including four FAS1 domains which play important roles in cell adhesion and tumor metastasis by interacting with integrins. In spite of their important biological role, the structural information of periosin FAS1 domains was not revealed yet. Recently we systemically prepared various constructs of the FAS1 domains and tried to express them in E. coli. Of them, only single FAS1-II and -IV domains were highly soluble. Circular dichroism (CD) and nuclear magnetic resonance (NMR) studies revealed that the FAS1-IV domain might be suitable for three-dimensional structure determination using NMR spectroscopy.

Review of Multifunctional Inverter Topologies and Control Schemes Used in Distributed Generation Systems

  • Teke, Ahmet;Latran, Mohammad Barghi
    • Journal of Power Electronics
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    • 제14권2호
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    • pp.324-340
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    • 2014
  • Recent developments in power electronics technology have spurred interest in the use of renewable energy sources as distributed generation (DG) generators. The key component in DG generators is a grid-connected inverter that serves as an effective interface between the renewable energy source and the utility grid. The multifunctional inverter (MFI) is special type of grid-connected inverter that has elicited much attention in recent years. MFIs not only generate power for DGs but also provide increased functionality through improved power quality and voltage and reactive power support; thus, the capability of the auxiliary service for the utility grid is improved. This paper presents a comprehensive review of the various MFI system configurations for single-phase (two-wire) and three-phase (three- or four-wire) systems and control strategies for the compensation of different power quality problems. The advances in practical applications and recent research on MFIs are presented through a review of nearly 200 papers.