• 소음진동
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• 제4권4호
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• pp.459-467
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• 1994

Various maintenance programs and techniques have been implemented for roating machineries, since machines were invented for commerical use. The earliest type of maintenance was run-to-failure, where the machine was run until a fault caused to fail in service. It was obviously an expensive approach due to the unpredictability of the machine condition. Another type is the periodic maintenance, where machines are disassembled and overhauled on regular schedules. With the advent of reliable data collectors including FFT analyzer and developing of versatile supporting software such as ExpertALERT system, the predictive maintenance is known to be the most feasible maintenance type these days. The vibration analysis enables for a maintenance crew to find the exact cause of fault on a machine and to make a proper maintenance schedule with a trend analysis. The predicitive maintenance is considered to be the most important part of pro-active maintenance.

• Smart Structures and Systems
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• 제30권5호
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• pp.463-477
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• 2022

In this paper, a hybrid vibration-impedance-based damage monitoring approach is experimentally evaluated for prestressed concrete (PSC) structures with local strand breakage. Firstly, the hybrid monitoring scheme is designed to alert damage occurrence from changes in vibration characteristics and to localize strand breakage from changes in impedance signatures. Secondly, a full-scale PSC anchorage is experimented to measure global vibration responses and local impedance responses under a sequence of simulated strand-breakage events. Finally, the measured data are analyzed using the hybrid monitoring framework. The change of structural condition (i.e., damage extent) induced by the local strand breakage is estimated by changes in a few natural frequencies obtained from a few accelerometers in the structure. The damaged strand is locally identified by tomography analysis of impedance features measured via an array of PZT (lead-zirconate-titanate) sensors mounted on the anchorage. Experimental results demonstrate that the strand breakage in the PSC structure can be accurately assessed by using the combined vibration and impedance features.

• Journal of Korean Biological Nursing Science
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• 제16권4호
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• pp.259-266
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• 2014

Purpose: The purpose of this study was to analyze risk factors in predicting medical patients transferred to Intensive Care Unit (ICU) on the general ward. Methods: We reviewed retrospectively clinical data of 120 medical patients on the general ward and a Modified Early Warning Score (MEWS) between ICU group and general ward group. Data were analyzed with multivariate logistic regression and the area under the receiver operating characteristic curves using SPSS/WIN 18.0 program. Results: Fifty-two ICU patients and 68 general ward patients were included. In multivariate logistic regression, the MEWSs (Odds Ratio [OR], 1.91; 95% confidence interval [CI], 1.32-2.76), sequential organ failure assessment score (OR, 1.28; 95% CI, 1.10-1.72), $PaO_2/FiO_2$ ratio (OR, 0.98; 95% CI, 0.98-0.99), and saturation (OR, 0.93; 95% CI, 0.88-0.99) were predictive of ICU transfer. The sensitivity and the specificity of the MEWSs used with a cut-off value of six were 80.8% and 70.6% respectively for ICU transfer. Conclusion: These findings suggest that early prediction and treatment of patients with high risk of ICU transfer may improve the prognosis of patients.

• 한국화재소방학회논문지
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• 제23권2호
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• pp.41-48
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• 2009

기존 유선망에 의한 화재 감지와 경보시설의 문제점을 해결하고자 새로운 대안으로 제시되고 있는 USN기반의 화재감시시스템의 실시간 온도데이터를 GIS의 공간 모델링 기법을 활용하여 건물 내부온도의 시공간 특성을 분석 하였다. 즉 시간적으로 일별, 월별로 공간적으로는 장소별로 온도데이터의 분포 특성을 분석하여, 건물 내부에 USN기반의 온도센서 설치 시 단순히 면적이나 높이에 의존할 것이 아니라 공간구조에 따라 다르게 설치하여야 한다는 것을 제시하였다. 이러한 결과는 앞으로 USN기반 화재 감시용 온도 센서 설치에 대한 객관적 기준과 현실성 확보에 기여 할 수 있을 것이다.

• 간호행정학회지
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• 제23권2호
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• pp.139-150
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• 2017

Purpose: The purpose of this study was to identify nursing service costs associated with all health care costs incurred by the institution. Methods: This study was an empirical case study research in which the nursing cost was separated from total medical cost. The nursing cost index was calculated through a cost allocation method after summarizing costs for personnel, raw materials and administration of each department in one public hospital. The 2014 budget plan, published in 'Public Hospitals Alert', was used as data and the data were analyzed using the Microsoft Office EXCEL 2013 program. Results: When comparing total medical costs and nursing costs, the nursing cost were 27.14% of the total medical cost. The nursing cost per nurse per hour was calculated as \29,128 The nursing cost per inpatient per day was calculated as \157,970, and the administration cost per patient was calculated as \133,710. Conclusion: The results of the research present the process of cost allocation of specific cost elements in the hospital and evidence for administrative costs which in the past have been only vaguely formulated. These are the significant implications of this study.

• 한국정밀공학회지
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• 제30권7호
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• pp.673-678
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• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• 한국항행학회논문지
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• 제16권1호
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• pp.163-170
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• 2012

본 논문에서는 안드로이드 운영체제를 기반으로 하는 스마트폰 사용자가 스마트폰을 휴대할 수 없는 수영장이나 찜질방 등 제한된 공간에서 스마트폰으로 수신되는 전화 및 SMS를 중계기와 디스플레이를 이용하여 확인할 수 있는 어플리케이션 설계를 제안하였다. 어플리케이션 설계는 사용자의 기본적인 정보를 저장하고, 전화 및 SMS를 수신 하였을 때, PhonStateListener와 SmsReceiver를 이용하여 발신자 번호와 사용자 기본정보를 데이터화 한다. 데이터는 블루투스를 이용하여 중계기로 데이터를 전송한다. 스마트폰 사용자는 수신정보를 중계기를 통해 디스플레이 장치로 확인할 수 있다.

• Journal of Astronomy and Space Sciences
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• 제33권4호
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• pp.247-256
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• 2016

An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs). We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV) yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT) has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV). We also found that peak luminosity is positively correlated with peak energy.

• 정신간호학회지
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• 제27권4호
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• pp.415-426
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• 2018

Purpose: This study aimed to explore the essentials of psychiatric and mental health nursing by identifying the care experience of the psychiatric nurses. Methods: Eleven psychiatric nurses were recruited across five geographical areas in the Korea. Data were collected using semi-structured interviews from two focus groups, which were analyzed with an inductive content analysis. Results: Participants constructed two categories including 'nursing tasks for the client' and 'nursing tasks for the organization'. Subcategories of nursing tasks for the client are 'staying alert on crisis prevention', 'leading them to be real with eager and persistent will', 'nursing beyond role boundaries', 'tuning the needs of clients' family', 'taking journey with clients' personal life history', and 'doing invisible but recognizable nursing'. Subcategories of nursing tasks for the organization are 'working as a responsible team member', 'integrating team competencies at the center of team', and 'balancing protection and control'. Conclusion: Psychiatric nurses played professional and holistic care roles for the clients, and managerial roles for the organizations. This study provides essential data for defining psychiatric nursing and estimating the appropriate ratio of psychiatric nursing staffing.

• 스마트미디어저널
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• 제12권10호
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• pp.38-46
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• 2023

Farming activities are transforming from traditional skill-based agriculture into knowledge-based and technology-driven digital agriculture. The use of intelligent information and communication technology introduces the idea of smart farming that enables farmers to collect weather data, monitor crop growth remotely and detect crop diseases easily. The introduction of Plantix, a pest and disease management tool in the form of a mobile application has allowed farmers to identify pests and diseases of the crop using their mobile devices. Hence, this study collected the reviews of Plantix to explore the response of the users on the Google Play Store towards the application through Latent Dirichlet Allocation (LDA) topic modeling. Results indicate four latent topics in the reviews: two positive evaluations (compliments, appreciation) and two suggestions (plant options, recommendations). We found the users suggested the application to additional plant options and additional features that might help the farmers with their difficulties. In addition, the application is expected to benefit the farmer more by having an early alert of diseases to farmers and providing various substitutes and a list of components for the remedial measures.