• Journal of KSNVE
• /
• v.4 no.4
• /
• pp.459-467
• /
• 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
• /
• v.30 no.5
• /
• pp.463-477
• /
• 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
• /
• v.16 no.4
• /
• pp.259-266
• /
• 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.

• Fire Science and Engineering
• /
• v.23 no.2
• /
• pp.41-48
• /
• 2009

In this paper, to overcome the limitation of the existing wired fire sensors and alert facilities, the real-time temperature data collected from the fire detectors applied USN is analyzed the time series and spacial features of temperature inside building using the GIS spatial modeling method. Resulting from the analysis of the distribution features by the spacial location and time series, the temperature sensors applied USN is installed by the consideration of the spacial structures features. This paper will suggest the objective and practical guideline of installation of fire sensors applied USN.

• Journal of Korean Academy of Nursing Administration
• /
• v.23 no.2
• /
• pp.139-150
• /
• 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.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.7
• /
• pp.673-678
• /
• 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.

• Journal of Advanced Navigation Technology
• /
• v.16 no.1
• /
• pp.163-170
• /
• 2012

This thesis suggests the application to the people who are using smart phone which is based on the Android operation system that makes it available to check their call and sms by a repeater and display in the limited places such as at the swimming pool or spa. This application is designed to save user's basic information. And when the user gets a call or a sms, it can make the sender number and fundamental information a data by PhonStateListener and SmsReceiver. The data is uploaded by bluetooth of a repeater. The smart phone user can use the repeater to check the received information by display.

• Journal of Astronomy and Space Sciences
• /
• v.33 no.4
• /
• pp.247-256
• /
• 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.

• Journal of Korean Academy of Psychiatric and Mental Health Nursing
• /
• v.27 no.4
• /
• pp.415-426
• /
• 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.

• Smart Media Journal
• /
• v.12 no.10
• /
• pp.38-46
• /
• 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.