• 제목/요약/키워드: Dual-Level

검색결과 766건 처리시간 0.024초

골다공증 여성의 자기효능감과 생활양식의 관계 연구 (Life Style and Self-efficacy in Osteoporosis Women)

  • 변영순;김옥수
    • 대한간호학회지
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    • 제29권3호
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    • pp.530-540
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    • 1999
  • The purpose of this study was to investigate the life style, self-efficacy, and Bone Marrow Density (BMD) in osteoporosis female patients. The subjects were recruited at the four Osteoporosis Clinics. A convenience sample of 190 women completed a survey instrument which included the Osteoporosis Self-Efficacy Questionnaire, Life Style Questionnaire and demographic items. BMD of L$_4$ was measured by Dual Photon Absor photiometry. The sample ranged in age from 40 to 82 years (Mean=60.28). Eighty-one percent were married and 14.9% were widowed. Forty-four percent lived with their spouse and children. Excercise, diet, medication, alcohol consumption, and smoking were measured to investigate the life style. Fifty-seven percent of the subjects exercised regularly. Mountain climbing, brisk walking, and free gymnastics were frequently cited excercises by the subjects in this study. Sixty percent drank one cup of milk and 34.7% had 1.13 cups of coffee in a day. Thirty-nine percent used calcium supplements, 9.5% drank alcohol, and 3.2% smoked cigarettes. Economic status and education level were related to self-efficacy. Age, economic status, and education level were related to BMD. As a life style, exercise, diet(milk, ice cream, and coffee), and medication(calcium) were associated with self-efficacy. The subjects who exercised regularly and took calcium supplements for a longer time had a higher level of self-efficacy than those who did not. Smoking and alcohol consumption had no relationship with self-efficacy. Excercise, medication(calcium), and alcohol consumption were related to BMD. The subjects who took calcium supplements for a longer time had a higher level of BMD. Alcohol consumption was not related to self-efficacy but related to BMD. The subject who drank alcohol had a higher level of BMD than those who did not drink. The amount of alcohol consumption was positively related to BMD.

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Characterization of stacked geotextile tube structure using digital image correlation

  • Dong-Ju Kim;Dong Geon Son;Jong-Sub Lee;Thomas H.-K. Kang;Tae Sup Yun;Yong-Hoon Byun
    • Computers and Concrete
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    • 제31권5호
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    • pp.385-394
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    • 2023
  • Displacement is an important element for evaluating the stability and failure mechanism of hydraulic structures. Digital image correlation (DIC) is a useful technique to measure a three-dimensional displacement field using two cameras without any contact with test material. The objective of this study is to evaluate the behavior of stacked geotextile tubes using the DIC technique. Geotextile tubes are stacked to build a small-scale temporary dam model to exclude water from a specific area. The horizontal and vertical displacements of four stacked geotextile tubes are monitored using a dual camera system according to the upstream water level. The geotextile tubes are prepared with two different fill materials. For each dam model, the interface layers between upper and lower geotextile tubes are either unreinforced or reinforced with a cementitious binder. The displacement of stacked geotextile tubes is measured to analyze the behavior of geotextile tubes. Experimental results show that as upstream water level increases, horizontal and vertical displacements at each layer of geotextile tubes initially increase with water level, and then remain almost constant until the subsequent water level. The displacement of stacked geotextile tubes depends on the type of fill material and interfacial reinforcement with a cementitious binder. Thus, the proposed DIC technique can be effectively used to evaluate the behavior of a hydraulic structure, which consists of geotextile tubes.

전산망 보호를 위한 혼합형 방화벽 시스템 구현 (Implementation of Hybrid Firewall System for Network Security)

  • 이용준;김봉한;박천용;오창석;이재광
    • 한국정보처리학회논문지
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    • 제5권6호
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    • pp.1593-1602
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    • 1998
  • 본 논문에서는 스크리닝 라우터, 듀열-홈드 게이크웨이, 스크린드 호스트 게이트웨이, 그리고 응용 레벨 게이트웨이를 사용한 혼합형 방화벽 시스템을 제안하였다. 스크린드 호스트 게이트웨이는 스크리닝 라우터와, DMZ, 그리고 베스쳔 호스트로 구성되었으며, 외부의 모든 트랙픽은 프로토콜 필터링 기능을 가진 스크리닝 라우터에서 필터링되고, 그리고 응용 레벨 필터링을 수행하기 위하여 베스쳔 호스트로 전송된다. 듀얼-홈드 게이트웨이는 외부의 사용자가 내부 네트워크를 직접 접근을 못하도록 중개 역할을 한다. 응용 레벨 게이트웨이는 프럭시 서버를 통해서만 트래픽 전송이 가능하도록 한다. 외부 사용자는 DMZ에 있는 고개 서버를 통해서만 내부 네트워크로의 접근이 가능하지만 내부 사용자는 외부 네트워크를 용이하게 사용할 수 있다. 그리고 DMZ에 있는 시스템의 효율적인 관리를 위하여 시스템 관리자만 Telnet 접속이 가능하도록 규칙기반을 적용하였다. 실험 결과, 접근 거부는 Web, Mail, FTP, Telnet 순으로 나타났으며, DMZ에 있는 공개 서버릴 제외한 나머지 시스템에 대한 접근은 거부되었다. 프로토콜별 접근 거부는 모든 네트워크에 broadcast하는 BOOTP와 NETBIOS를 사용하는 호스트가 많았기 때문에 TCP보다 UDP가 많이 나타났다. 또한 내부 네트워크에 불법적인 Telnet이나 FTP는 거의 없었다.

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중국의 대북지원 결정요인에 관한 연구: 양면게임이론을 중심으로 (Analysis of China's Aid to North Korea: Focusing on The Two-level game theory)

  • 김현정;박선화
    • 한국과 국제사회
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    • 제2권1호
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    • pp.113-136
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    • 2018
  • 본 연구는 국제사회의 대북제재가 왜 큰 효과를 나타내지 못했는가에 대한 문제인식에서 출발하고 있으며, 이러한 질문의 답을 찾기 위해 중국의 대북지원에 주목하고서 대북지원의 결정요인을 분석한다. 국제사회의 강경한 대북제재에도 불구하고 중국은 북한에 대해 제재와 지원이라는 이중적 자세를 취하고 있다. 이러한 중국의 이중적 자세에 대해 본 연구는 양면게임이론에 이론적 근거를 두고서 대북지원이 대한 대내외적 상황에 접근하였다. 중국의 대북지원에 대한 결정요인은 국외요인, 국내요인으로 구분할 수 있다. 이들 요인들은 중국의 패권강화, 미국 견제, 중국의 책임있는 강대국 역할 수행, 북한의 자원 확보, 중국의 안정적인 성장 지속, 중국의 사회주의정치체제 정당성 유지, 베이징 컨센서스의 확산 등이 있다. 해당 요인들에 대한 분석을 토대로 살펴보면 향후 중국의 대북지원은 공식적 또는 비공식적 모두 지속적으로 이루어질 것이고 대북지원이 중단되거나 북 중 관계가 악화되는 상황이 발생하는 것은 어려울 것이라고 전망할 수 있다.

Alternative Alert System for Cyanobacterial Bloom, Using Phycocyanin as a Level Determinant

  • Ahn, Chi-Yong;Joung, Seung-Hyun;Yoon, Sook-Kyoung;Oh, Hee-Mock
    • Journal of Microbiology
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    • 제45권2호
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    • pp.98-104
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    • 2007
  • Chlorophyll ${\alpha}$ concentration and cyanobacterial cell density are regularly employed as dual criteria for determinations of the alert level for cyanobacterial bloom. However, chlorophyll ${\alpha}$ is not confined only to the cyanobacteria, but is found universally in eukaryotic algae. Furthermore, the determination of cyanobacterial cell counts is notoriously difficult, and is unduly dependent on individual variation and trained skill. A cyanobacteria-specific parameter other than the cell count or chlorophyll ${\alpha}$ concentration is, accordingly, required in order to improve the present cyanobacterial bloom alert system. Phycocyanin has been shown to exhibit a strong correlation with a variety of bloom-related factors. This may allow for the current alert system criteria to be replaced by a three-stage alert system based on phycocyanin concentrations of 0.1, 30, and $700\;{\mu}g/L$. This would also be advantageous in that it would become far more simple to conduct measurements without the need for expensive equipment, thereby enabling the monitoring of entire lakes more precisely and frequently. Thus, an alert system with superior predictive ability based on highthroughput phycocyanin measurements appears feasible.

The Production and Enzymatic Properties of Extracellular Chitinase from Pseudomonas stutzeri YPL-1, as a Biocontrol Agent

  • Lim, Ho-Seong;Kim, Sang-Dal
    • Journal of Microbiology and Biotechnology
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    • 제4권2호
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    • pp.134-140
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    • 1994
  • An antagonistic bacterium Pseudomonas stutzeri YPL-1 liberated extracellular chitinase and $\beta$-1,3-glucanase which are key enzymes in the decomposition of fungal hyphal walls. The lytic enzymes caused abnormal swelling and retreating at the hyphal tips of plant pathogenic fungus Fusarium solani in a dual culture. Scanning electron microscopy revealed the hyphal degradation of F. solani in the regions interacting with P. stutzeri YPL-1. The production of chitinase and properties of a crude preparation of the enzyme from P. stutzeri YPL-1 were investigated. Peak of the chitinase activity was detected after 4 hr of cultivation. The enzyme had optimum temperature and pH of 50$^{\circ}C$ and pH 5.3, respectively. The enzyme was stable in the pH range of 3.5 to 6.0 up to 50$^{\circ}C$. The enzyme was significantly inhibited by metal compounds such as $HgCl_2$, but was stimulated by $CoCl_2$. P. stutzeri YPL-1 produced high levels of the enzyme after 84 hr of incubation. Among the tested carbon sources, chitin was the most effective for the enzyme production, at the concentration level of 3%. As a source of nitrogen, peptone was the best for the enzyme production, at the concentration level of 4%. The maximum amount of enzyme was produced by cultivating the bacterium at a medium of initial pH 6.8.

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Down-regulation of the cyclin E1 oncogene expression by microRNA-16-1 induces cell cycle arrest in human cancer cells

  • Wang, Fu;Fu, Xiang-Dong;Zhou, Yu;Zhang, Yi
    • BMB Reports
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    • 제42권11호
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    • pp.725-730
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    • 2009
  • Cyclin E1 (CCNE1), a positive regulator of the cell cycle, controls the transition of cells from G1 to S phase. In numerous human tumors, however, CCNE1 expression is frequently dysregulated, while the mechanism leading to its dysregulation remains incompletely defined. Herein, we showed that CCNE1 expression was subject to post-transcriptional regulation by a microRNA miR-16-1. This was evident at protein level of CCNE1 as well as its mRNA level. Further evident by dual luciferase reporter assay revealed that two evolutionary conserved binding sites on 3' UTR of CCNE1 were the direct functional target sites. Moreover, we showed that miR-16-1 induced G0/G1 cell cycle arrest by targeting CCNE1 and siRNA against CCNE1 partially phenocopied miR-16-1-induced cell cycle phenotype whereas substantially rescued anti-miR-16-1- induced phenotype. Together, all these results demonstrate that miR-16-1 plays a vital role in modulating cellular process in human cancers and indicate the therapeutic potential of miR-16-1 in cancer therapy.

Theoretical Studies on Mechanism and Kinetics of the Hydrogen-Abstraction Reaction of CF3CH2CHO with OH Radicals

  • Ci, Cheng-Gang;Yu, Hong-Bo;Wan, Su-Qin;Liu, Jing-Yao;Sun, Chia-Chung
    • Bulletin of the Korean Chemical Society
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    • 제32권4호
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    • pp.1187-1194
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    • 2011
  • The hydrogen abstraction reaction of $CF_3CH_2CHO$ + OH has been studied theoretically by dual-level direct dynamics method. Two stable conformers, trans- and cis-$CF_3CH_2CHO$, have been located, and there are four distinct OH hydrogen-abstraction channels from t-$CF_3CH_2CHO$ and two channels from c-$CF_3CH_2CHO$. The required potential energy surface information for the kinetic calculation was obtained at the MCG3-MPWB//M06-2X/aug-cc-pVDZ level. The rate constants, which were calculated using improved canonical transitionstate theory with small-curvature tunneling correction (ICVT/SCT) were fitted by a four-parameter Arrhenius equation. It is shown that the reaction proceeds predominantly via the H-abstraction from the -CHO group over the temperature range 200-2000 K. The calculated rate constants were in good agreement with the experimental data between 263 and 358 K.

An Optimized Control Method Based on Dual Three-Level Inverters for Open-end Winding Induction Motor Drives

  • Wu, Di;Su, Liang-Cheng;Wu, Xiao-Jie;Zhao, Guo-Dong
    • Journal of Power Electronics
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    • 제14권2호
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    • pp.315-323
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    • 2014
  • An optimized space vector pulse width modulation (SVPWM) method with common mode voltage elimination and neutral point potential balancing is proposed for an open-end winding induction motor. The motor is fed from both of the ends with two neutral point clamped (NPC) three-level inverters. In order to eliminate the common mode voltage of the motor ends and balance the neutral point potential of the DC link, only zero common mode voltage vectors are used and a balancing control factor is gained from calculation in the strategy. In order to improve the harmonic characteristics of the output voltages and currents, the balancing control factor is regulated properly and the theoretical analysis is provided. Simulation and experimental results show that by adopting the proposed method, the common mode voltage can be completely eliminated, the neutral point potential can be accurately balanced and the harmonic performance for the output voltages and currents can be effectively improved.

우주용 냉각기의 미소진동을 이용한 에너지 수확 시스템의 실험적 성능검증 (Experimental Performance Verification of Energy-Harvesting System Using the Micro-vibration of the Spaceborne Cryocooler)

  • 정현모;권성철;오현웅
    • 항공우주시스템공학회지
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    • 제10권3호
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    • pp.15-22
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    • 2016
  • The on-board appendages of satellites with mechanical moving parts such as the fly-wheel, the control-moment gyro, the cryocooler, and the gimbal-type directional antenna can generate an undesirable micro-vibration disturbance, which is one of the main causes of the image-quality degradation that affects high-resolution observation satellites. Consequently, the isolation of the micro-vibration issue has always been considered as salient, and the micro-vibration is therefore the focus of this study wherein a complex system that can provide the dual functions of a guaranteed vibration-isolation performance and electrical energy harvesting is proposed. The vibration-isolation and energy-harvesting performances of the complex system are predicted through a numerical analysis based on the characteristics that are obtained from component-level tests. In addition, the effectiveness of the complex system that is proposed in this study is verified through an assembly-level functional-performance test.