• 제목/요약/키워드: action functional

검색결과 445건 처리시간 0.027초

한국형 틸팅열차의 신뢰성기반 유지보수 체계 구축에 관한 연구 (A Study on the Construction of Reliability Centered Maintenance System for Korean Tilting Train)

  • 서승일;문형석;엄기영
    • 한국철도학회논문집
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    • 제10권5호
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    • pp.520-526
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    • 2007
  • 본 논문에서는 한국형 틸팅열차의 유지보수 활동을 위해 신뢰성기반유지보수체계를 제안하였다. 열차시스템을 3단계의 교체 부품 단위로 분류하고, 각 단위에 대해 기능블록도를 작성한 후 고장모드 영향 분석을 실시하였다. 각 단위의 심각도를 결정한 후 유지보수 정책을 제안하였으며, 틸팅열차를 위한 유지보수 기준을 정하고, 실제 사례를 제시하였다. 제안된 신뢰성기반유지보수체계는 기존 유지보수 체계와도 호환성을 갖고 있으며, 안전성 향상과 유지보수 활동 효율화에 기여할 수 있다.In this paper, a reliability centered maintenance (RCM) system is proposed to perform maintenance action for Korean Tilting Train. The train system was divided into line replaceable units up to three steps. Functional block diagrams were drawn and failure mode effect analysis for the units was carried out. The criticality of each unit was determined and a maintenance policy was proposed. Maintenance and repair criteria for the tilting train were determined and an example was presented. The proposed RCM system is compatible with the previous maintenance system and contributes to improvement of safety and efficiency of maintenance action.

Sclerotiorin: a Novel Azaphilone with Demonstrated Membrane Targeting and DNA Binding Activity against Methicillin-Resistant Staphylococcus aureus

  • Dasagrandhi, Chakradhar;Pandith, Anup;Imran, Khalid
    • 한국미생물·생명공학회지
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    • 제48권4호
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    • pp.429-438
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    • 2020
  • The emergence of multi-drug resistant, pathogenic methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health and has created a need for novel functional therapeutic agents. In this study, we evaluated the underlying mechanisms of the anti-MRSA effect of an azaphilone pigment, sclerotiorin (SCL) from Penicillium sclerotiorum. The antimicrobial activity of SCL was evaluated using agar disc diffusion, broth microdilution, time-kill assays and biophysical studies. SCL exhibits selective activity against Gram positive bacteria including MRSA (range, MIC = 128-1028 ㎍/ml) and exhibited rapid bactericidal action against MRSA with a > 4 log reduction in colony forming units within three hours of administration. Biophysical studies, using fluorescent probes and laser or electron microscopy, demonstrated a SCL dose-dependent alternation in membrane potential (62.6 ± 5.0.4% inhibition) and integrity (> 95 ± 2.3%), and the release of UV260 absorbing materials within 60 min (up to 3.2 fold increase, p < 0.01) of exposure. Further, SCL localized to the cytoplasm and hydrolyzed plasmid DNA. While in vitro checkerboard studies revealed that SCL potentiated the antimicrobial activity of topical antimicrobials such as polymixin, neomycin, and bacitracin (Fractional Inhibitory Concentration Index range, 0.26-0.37). Taken together these results suggest that SCL targets the membrane and DNA of MRSA to facilitate its anti-MRSA antimicrobial effect.

다채널전극으로 기록한 토끼 망막신경절세포의 활동전위 파형 구분 (Waveform Sorting of Rabbit Retinal Ganglion Cell Activity Recorded with Multielectrode Array)

  • 진계환;이태수;구용숙
    • 한국의학물리학회지:의학물리
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    • 제16권3호
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    • pp.148-154
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    • 2005
  • 망막에서 나오는 활동전위와 같이 복잡한 신경망을 거쳐 처리되는 전기신호를 분석하기 위해서는 기존의 단일 전극 기록법으로는 어렵다. 단일 전극을 통한 활동전위의 기록은 개개의 신경세포 특성을 알아내는 데에는 유용한 방법이나 신경세포 간의 시간적, 공간적인 관계는 알아낼 수 없다는 한계를 가지고 있으므로 이같은 한계를 극복하기 위하여 다채널 전극을 이용한 신경신호 기록방법이 최근에 개발되어 널리 이용되고 있다. 다채널전극 기록 방식인 MEA60 시스템은 세포 밖에 위치한 60개의 전극이 생체신호를 동시에 기록한다. 세포 fi에 위치한 각각의 전극이 포착한 신경 신호는 하나의 망막신경절세포 반응이라기보다는 여러 세포의 반응이 동시에 기록될 가능성이 높다. 그러므로 여러 세포의 반응이 함께 기록된 신호로부터 각각의 세포로부터 나오는 파형을 구분하는 작업이 반드시 필요하다. 본 연구에서는 다채널 전극으로 기록한 망막 신경절세포 신호로부터 MATLAB을 이용하여 활동전위 파형을 검출하고 분류하는 과정을 구현하여 보았다. 이러한 분류과정은 추후 진행되는 신호분석방법인 자극 후 시간 히스토그램(poststimulus time histogram, PSTH), 자기상관관계(autocorrelogram), 상호상관관계(cross-correlogram)를 보기 위하여 반드시 거쳐야 하는 전처리(preprocess) 과정이다. 본 연구에서는 MATLAB을 이용한 파형 구분 프로토콜을 확립하였을 뿐만 아니라 이러한 프로토콜이 신경절 세포의 활동전위 파형을 검출하는 데 유용한 방법임을 입증하였다

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Identification and Organization of Task Complexity Factors Based on a Model Combining Task Design Aspects and Complexity Dimensions

  • Ham, Dong-Han
    • 대한인간공학회지
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    • 제32권1호
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    • pp.59-68
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    • 2013
  • Objective: The purpose of this paper is to introduce a task complexity model combining task design aspects and complexity dimensions and to explain an approach to identifying and organizing task complexity factors based on the model. Background: Task complexity is a critical concept in describing and predicting human performance in complex systems such as nuclear power plants(NPPs). In order to understand the nature of task complexity, task complexity factors need to be identified and organized in a systematic manner. Although several methods have been suggested for identifying and organizing task complexity factors, it is rare to find an analytical approach based on a theoretically sound model. Method: This study regarded a task as a system to be designed. Three levels of design ion, which are functional, behavioral, and structural level of a task, characterize the design aspects of a task. The behavioral aspect is further classified into five cognitive processing activity types(information collection, information analysis, decision and action selection, action implementation, and action feedback). The complexity dimensions describe a task complexity from different perspectives that are size, variety, and order/organization. Combining the design aspects and complexity dimensions of a task, we developed a model from which meaningful task complexity factors can be identified and organized in an analytic way. Results: A model consisting of two facets, each of which is respectively concerned with design aspects and complexity dimensions, were proposed. Additionally, twenty-one task complexity factors were identified and organized based on the model. Conclusion: The model and approach introduced in this paper can be effectively used for examining human performance and human-system interface design issues in NPPs. Application: The model and approach introduced in this paper could be used for several human factors problems, including task allocation and design of information aiding, in NPPs and extended to other types of complex systems such as air traffic control systems as well.

유백피(楡白皮) 추출물이 인간의 피부 세포 재생 및 악성 흑색종 세포에 미치는 영향 (Effects of Cortex Ulmi pumilae on Human HaCaT keratinocyte and its antioxidant and anti-cancer effect)

  • 한진근;박수연;김종한;최정화
    • 한방안이비인후피부과학회지
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    • 제20권3호
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    • pp.82-97
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    • 2007
  • Objective : Cortex of Ulmi pumilae(CUP) has been used to treat several diseases including boil, swelling, and scabies etc. Recently, CUP was known to have wrinkle care and whitening actions. But, It's exact mechanisms are unclear. Methods : The present study was designed to investigate effects of CUP on Human HaCaT keratinocyte and malignant melanoma cells such as SK-MEL-2 and B16F10 in terms of cell viabilities, proliferations, DPPH free radical scavenging activities, oxygen free radical productions and inhibitory action on elastase activities. Results : CUP accelerated proliferation of HaCaT keratinocytes in the lower concentration. CUP also prevented cell death of HaCaT induced by Hydrogen peroxide, which products oxygen free radicals. On the contrary, CUP did not affect proliferations of SK-MEL-2 or B16F10. Futhermore, CUP showed inhibitory action against SK-MEL-2 proliferation at the concentration of $500{\mu}g/m{\ell}$ In addition, CUP was shown to have DPPH free radical scavenging activities and also have inhibitory effects on elastase activities too. On the fluorescent examinations, the present author knows that CUP elevated production levels of oxygen free radicals in malignant melanoma cell, SK-MEL-2. Conclusions : These results suggest that CUP has possibilities of usage for functional cosmetics which have wrinkle care and whitening activities and related mechanisms are involved in inhibition of elastase action and acceleration of oxidative stress in melanoma cell.

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Relationship between Social Network and Stage of Adoption of Gastric Cancer Screening among the Korean Population

  • Lee, Myung Ha;Choi, Kui Son;Lee, Yoon Young;Suh, Mina;Jun, Jae Kwan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.6095-6101
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    • 2013
  • Few studies have examined the relationship between social support and stages of adoption of cancer screening. Here we investigated associations between both structural and functional aspects of social support and stages of adoption of gastric cancer screening in the general population of Korea. The study population was derived from the 2011 Korean National Cancer Screening Survey (KNCSS), an annual cross-sectional survey that uses nationally representative random sampling to investigate cancer screening rates. Data were analyzed from 3,477 randomly selected respondents aged 40-74 years. Respondents were classified according to their stage of adoption of gastric cancer screening: precontemplation (13.2%), contemplation (18.0%), action/maintenance (56.1%), relapse risk (8.5%), and relapse stage (4.1%). Respondents with larger social networks were more likely to be in the contemplation/action/maintenance, or the relapse risk/relapse stages versus the precontemplation stage (OR=1.91, 95%CI: 1.52-2.91; p for tend=0.025). Emotional and instrumental supports were not associated with any stage of adoption of gastric cancer screening. However, respondents who reported receiving sufficient informational support were more likely to be in the relapse risk/relapse stages versus the precontemplation, or the contemplation/action/maintenance stage (p for trend=0.016). Interventions involving interactions between social network members could play an important role in increasing participation in gastric cancer screening.

Effects of Pahs and Pcbs and Their Toxic Metabolites on Inhibition of Gjic and Cell Proliferation in Rat Liver Epithelial Wb-F344 Cells

  • Miroslav, Machala;Jan, Vondracek;Katerina, Chramostova;Lenka, Sindlerova;Pavel, Krcmar;Martina, Pliskova;Katerina, Pencikova;Brad, Upham
    • 한국환경성돌연변이발암원학회지
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    • 제23권2호
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    • pp.56-62
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    • 2003
  • The liver progenitor cells could form a potential target cell population fore both tumor-initiating and -promoting chemicals. Induction of drug-metabolizing and antioxidant enzymes, including AhR-dependent CYP1A1, NQO-1 and AKR1C9, was detected in the rat liver epithelial WB-F344 "stem-like" cells. Additionally, WB-F344 cells express a functional, wild-type form of p53 protein, a biomarker of genotoxic events, and connexin 43, a basic structural unit of gap junctions forming an important type of intercellular communication. In this cellular model, two complementary assays have been established for detection of the modes of action associated with tumor promotion: inhibition of gap junctional intercellular communication (GJIC) and proliferative activity in confluent cells. We found that the PAHs and PCBs, which are AhR agonists, released WB-F344 cells from contact inhibition, increasing both DNA synthesis and cell numbers. Genotoxic effects of some PAHs that lead to apoptosis and cell cycle delay might interfere with the proliferative activity of PAHs. Contrary to that, the nongenotoxic low-molecular-weight PAHs and non-dioxin-like PCB congeners, abundant in the environment, did not significantly affect cell cycle and cell proliferation; however both groups of compounds inhibited GJIC in WB-F344 cells. The release from contact inhibiton by a mechanism that possibly involves the AhR activation, inhibition of GJIC and genotoxic events induced by environmental contaminants are three important modes of action that could play an important role in carcinogenic effects of toxic compounds. The relative potencies to inhibit GJIC, to induce AhR-mediated activity, and to release cells from contact inhibition were determined for a large series of PAHs and PCBs and their metabolites. In vitro bioassays based on detection of events on cellular level (deregulation of GJIC and/or proliferation) or determination of receptor-mediated activities in both ?$stem-like^{\circ}{\times}$ and hepatocyte-like liver cellular models are valuable tools for detection of modes of action of polyaromatic hydrocarbons. They may serve, together with concentration data, as a first step in their risk assessment.

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혐오자극에 대한 정서조절전략이 얼굴표정 및 정서경험에 미치는 영향 (The Effects of the Emotion Regulation Strategy to the Disgust Stimulus on Facial Expression and Emotional Experience)

  • 장성리;이장한
    • 한국심리학회지ㆍ건강
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    • 제15권3호
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    • pp.483-498
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    • 2010
  • 본 연구는 혐오정서 유발자극에 대한 선행사건초점 조절전략과 반응초점 조절전략이 얼굴표정 및 정서경험에 미치는 영향을 알아보고자 하였다. 연구는 여자 대학생 50명을 대상으로 실시되었고, 참여자들이 혐오정서 유발동영상을 시청할 때 서로 다른 정서조절전략(정서 표현, 표현 억제, 인지적 재평가, 표현 불일치)을 사용하도록 하여 얼굴표정과 정서경험을 측정하였다. 분석결과, 정서 표현집단에서 혐오표현단위의 빈도가 가장 높았고 표현 불일치, 인지적 재평가, 표현 억제집단의 순으로 빈도가 높게 나타났다. 그리고 실제 경험한 정서를 반영하는 얼굴 윗부분에서 인지적 재평가집단의 혐오관련표현단위의 빈도가 정서 표현집단과 표현 불일치집단보다 낮게 나타났다. 자기보고식 정서 상태 측정결과, 표현 불일치집단에서 가장 많이 긍정정서가 감소한 반면, 인지적 재평가집단에서는 긍정정서가 증가하는 경향을 보였다. 본 연구는 정서조절전략이 얼굴표정 및 정서경험에 미친 영향을 통해 인지적 재평가전략이 가장 기능적인 정서조절전략임을 확인하였다.

관절염 환자의 운동행위 예측모형 (Pender의 재개정된 건강증진 모형에 의한) (Prediction Model of Exercise Behaviors in Patients with Arthritis (by Pender's revised Health Promotion Model))

  • 임난영;서길희
    • 근관절건강학회지
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    • 제8권1호
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    • pp.122-140
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    • 2001
  • The aims of this study were to understand and to predict the determinent factors affecting the exercise behaviors and physical fitness by testing the Pender's revised health promotion model, and to help the patients with rheumatoid arthritis and osteoarthritis perform the continous exercise program, and to help them maximize the physical effect such as muscle strength, endurance, and functional status and mental effects including self efficacy and quality of life, and improve the physical and mental well being, and to provide a basis for the nursing intervention strategies. Of the selected variables in this study, the endogenous variables included the physical fitness, exercise score, exercise participation, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue) and the exogenous variables included personal sociocultural factor(education level), personal biologic factor(body mass index), personal psychologic factor(perceived health status) and prior related behavior factors(previous participation in exercise, life-style). We analyzed the clinical records of 208 patients with rheumatoid arthritis and degenerative arthritis who visited the outpatient clinics at H university hospital in Seoul. Data were composed of self reported qustionnaire and good of fitness score which were obtained by padalling the ergometer of bicycle for 9 minutes. SPSS Win 8.0 and Window LISREL 8.12a were used for statistical analysis. Of 75 hypothetical paths that influence on physical fitness, exercise participation, exercise score, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue), 40 were supported. The physical fitness was directly influenced by life-style, perceived health status, education level, family support, fatigue, which explained 12% of physical fitness. The exercise participation were directly influenced by life-style, education level, past exercise behavior, perceived benefits of action, perceived barriers of action, depression and duration of arthritis, which explained 47% of exercise participation. Exercise score were directly affected by perceived self efficacy. BMI, life-style, past exercise behavior, perceived benefits of action, family support, perceived health status. perceived barriers of action, and fatigue, which explained 70%. Perceived benefits of action was directly influenced by BMI, life-style, which explained 39%. Perceived barriers of action were directly influeced by past exercise behavior, perceived health status, which explained 7%. Perceived self efficacy were directly influeced by level of education, perceived health status, life-style, which explained 57%. Depression were directly influeced by past exercise behavior, BMI, life-style, which explained 27%. Family support were directly influeced by life-style, perceived health status, which explained 29%. Fatigue were directly influeced by BMI, life-style, perceived health status. which explained 41%. Duration of arthritis were directly influeced by life-style, past exercise behavior, BMI, which explained 6%. In conclusion, important variables for physical fitness were life-style, and variable affecting exercise participation were life-style. Perceived self-efficacy of exercise was a significant predictor of exercise score. BMI, Life-style, perceived benefits of action, family support, past exercise behavior showed direct effects on perceived self-efficacy. Therefore, disease related factor should be minimized for physical performance and well being in nursing intervention for patients with rheumatoid arthritis, and plans to promote and continue exercise should be seeked to reduce disability. In addition, Exercise program should be planned and performed by the exact evaluation of exercise according to the ability of the patients and the contents to improve the importance of exercise and self efficacy in self control program, dedicated educational program should be involved. This study suggest that the methods to reduce the disease related factors, the importance of daily life-style, recognition of benefit of exercise, and educational program to promote self efficacy should be considered in the exercise behavior promotion and nursing intervention for continous performance. The significance of this study is also thought to provide patients with chronic arthritis the specific data for maximal physical and mental well being through exercise, chronic therapeutic procedure, daily adaptation and confrontation in nursing intervention.

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유제품의 기능성 펩타이드 (Health Functional Peptides from Milk Products)

  • 이형주
    • Journal of Dairy Science and Biotechnology
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    • 제16권2호
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    • pp.98-105
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    • 1998
  • Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides(CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

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