• KOREAN ASSOCIATION OF OCCUPATIONAL HEALTH NURSES
• /
• 제19권3호
• /
• pp.49-49
• /
• 2012

• Journal of Environmental Health Sciences
• /
• 제23권2호
• /
• pp.89-97
• /
• 1997

Most of urban streams in Korea have been changed channel forms and suffered from direct inflow of domestic sewage, etc. Therefore, maintenance of structure and function of those ecosystem are hard. The present study was carried out to examine the life survival maintenance ability of the stream by community analysis of aquatic animals in typical urban stream (Jungrang stream) in Seoul. The aquatic animals were composed of 31 species, 18 families, 8 orders, 5 classes in 4 phyla. Seasonal species number showed big fluctuation between 8 species in Winter and 24 species in Autumn. Major dominant species in Jungrang stream were Tubificidae sp.1, Chironomidae sp.1, Chironomidae sp.2 and Physa acuta, and above endurance species for water pollution occupied very high dominance indices. But, Cercion hieroglyphicum, Ischnura asiatica, Rantra chinensis, Herochares striatus, Agabus japonicus in benthic macroinvertebrates of a few individuals are appeared. Also, fry of Carassius auratus and Silurus asotus in fish are occurred. Therefore, we can be inferred on posibility of growth and spawning of above species in the stream. Jungrang stream has a small quantity of natural riffle areas, ponds and watergrass areas by channel form of water course. Aquatic animals in Jungrang stream has been suffered by reduction of self-purification reaction ability and have mass production of attached algae on the stream bed. For analysis of fluctuation of life survival maintenance ability in Jungrang stream, long-term survey is needed.

• Journal of the Korea Institute of Military Science and Technology
• /
• 제27권2호
• /
• pp.294-303
• /
• 2024

The objective of condition-based maintenance plus(CBM+) is to improve the availability and maintenance efficiency of missiles, bolstering national defense capabilities. This study proposes an application of CBM+ to enhance the reliability and the safety of missiles, which are the devices typically stored for long durations. CBM+ CBM+ does not only contribute to defense capabilities, but it also aims to reduce maintenance costs. This study focuses particularly on the dormant stage of the missile life-cycle, in which various failure modes and environmental impacts on failure mechanisms are investigated. The effectiveness of maintenance strategies and the implementation of CBM+ is evaluated using simulation data.

• Journal of the Korean Society for Nondestructive Testing
• /
• 제35권6호
• /
• pp.421-428
• /
• 2015

An important trend in the sustainment of military aircraft is the transition from preventative maintenance to condition based maintenance (CBM). For CBM, it is essential that the actual system condition can be measured and the measured condition can be reliably extrapolated to a convenient moment in the future in order to facilitate the planning process while maintaining flight safety. Much research effort is currently being made for the development of technologies that enable CBM, including structural health monitoring (SHM) systems. Great progress has already been made in sensors, sensor networks, data acquisition, models and algorithms, data fusion/mining techniques, etc. However, the transition of these technologies into service is very slow. This is because business cases are difficult to define and the certification of the SHM systems is very challenging. This paper describes a possibility for fielding a SHM system on legacy military aircraft with a minimum amount of certification issues and with a good prospect of a positive return on investment. For appropriate areas in the airframe the application of SHM will reconcile the fail-safety and slow crack growth damage tolerance approaches that can be used for safeguarding the continuing airworthiness of these areas, combining the benefits of both approaches and eliminating the drawbacks.

• Korean Journal of Occupational Health Nursing
• /
• 제21권1호
• /
• pp.18-26
• /
• 2012

Purpose: This study tried to explore factors influencing on job maintenance of the mentally disabled who employed before. The subjects of this study were the mentally disabled who participated in community mental health center and social rehabilitation center, there had experienced a job in the past. Methods: The number of community centers were 27 places, there were located in different region. The number of participants were 221 persons agreed to this study. Data was analyzed by Mean, SD and logistic regression analyzation using SPSS/WIN 14.0. Results: General character such as age was significant factor. Monthly pay and working a day in the midst of job related factors were significant. Moreover, job rehabilitation program satisfaction rate and social support revealed significant factors. Conclusion: On the basis of results, Job rehabilitation programs for job maintenance of the mentally disabled should be development and establish mediate strategies to improve social support to them.

• Smart Structures and Systems
• /
• 제5권4호
• /
• pp.357-367
• /
• 2009

Structural Health Monitoring (SHM), particularly remote monitoring, is an emerging field with great potential to help infrastructure owners obtain more and up-to-date knowledge of their structures. The methodology could provide supplemental information to guide the frequency and extent of visual inspections, and the possible need for maintenance. The instrumentation for a SHM system needs to be developed with longevity and the objectives for the system in mind. Sensors need to be selected for reliability and durability, sited where they provide the maximum information for the objectives, and where they can be accessed and replaced should the need arise over the monitoring period. With the rapid changes now occurring with sensors and software, flexibility needs to be in place to allow the system to be upgraded over time. Damage detection needs to be considered in terms of the type of damage that needs to be detected, informing maintenance requirements, and how detection can be achieved. Current vibration analysis techniques appear not yet to have achieved the necessary sensitivity for that purpose. Societal factors will influence the design of a SHM system in terms of the sophistication of the instrumentation and methodology employed.

• Structural Monitoring and Maintenance
• /
• 제6권3호
• /
• pp.219-235
• /
• 2019

Scheduled inspections of common crossings are one of the main cost drivers of railway maintenance. Prognostics and health management (PHM) approach and modern monitoring means offer many possibilities in the optimization of inspections and maintenance. The present paper deals with data driven prognosis of the common crossing remaining useful life (RUL) that is based on an inertial monitoring system. The problem of scheduled inspections system for common crossings is outlined and analysed. The proposed analysis of inertial signals with the maximal overlap discrete wavelet packet transform (MODWPT) and Shannon entropy (SE) estimates enable to extract the spectral features. The relevant features for the acceleration components are selected with application of Lasso (Least absolute shrinkage and selection operator) regularization. The features are fused with time domain information about the longitudinal position of wheels impact and train velocities by multivariate regression. The fused structural health (SH) indicator has a significant correlation to the lifetime of crossing. The RUL prognosis is performed on the linear degradation stochastic model with recursive Bayesian update. Prognosis testing metrics show the promising results for common crossing inspection scheduling improvement.

• Perspectives in Nursing Science
• /
• 제2권1호
• /
• pp.37-47
• /
• 2005

Biobehavioral nursing research is focused on generating knowledge that examines relations among biological, behavioral, and social dimensions of health to improve outcomes. In this paper we review the findings of a biobehavioral nursing study of individuals with fibromyalgia (FM) that was framed from the perspective of an individual human response model, the FM literature, and our previous studies in midlife women. We were particularly interested in the studying the role of 'arousal' secondary to pain or to dysregulated hypothalamic-pituitary-adrenal (HPA) axis hormones during sleep and the impact on symptom expression. Unexpectedly, we did not find evidence of, arousal' or abnormal amounts of HPA axis hormones but we did find reduced amounts of growth hormone (GH) and prolactin (PRL) and of sleep spindle activity, a biomarker of sleep maintenance. We discuss these new findings and how our thinking was re-shaped to better understand the role that disturbed sleep plays in symptom expression in FM. It is argued that disturbed sleep maintenance mechanisms coupled with dysregulated somatotrophic-growth hormone axis and sleep-related PRL render individuals vulnerable to the development of or exacerbations of FM symptoms.

• Journal of The Korea Institute of Healthcare Architecture
• /
• 제27권4호
• /
• pp.41-50
• /
• 2021

Purpose: This study is aimed at the case of the cognitive health design pilot projects promoted by the Seoul Metropolitan Government since 2014 in terms of design to solve social problems in accordance with the aging population of our society. The purpose of this study is to analyze the maintenance and management of the projects and to suggest implications for the promotion and expansion of sustainable cognitive health design in the future. Method: It set the analysis frame by dividing management into maintenance-damage-demolition for the spatial types and spatial elements suggested in the Seoul Cognitive Health Guidelines. And it analyze the actual conditions of four pilot projects based on the field survey. Results: First, the ratio of damage and demolition was higher than maintenance. Second, designs and techniques with low durability were applied. Most of the cases where floor marks were applied to the external environment were lost or difficult to recognize, and their functions were limited due to storage of goods and parking of vehicles and motorcycles. Third, there was a large variation according to the type of residence. The project contents that can be applied to the low-rise residential area were also limited, and more elements were demolished than in the apartment type. Implications: First, it should limit project contents of space types and space elements that can be maintained even over time. Second, it should seek sustainable design and technical solutions. Third, it should seek alternatives to cognitive health design in low-rise residential areas where a large number of elderly people live.

• International Journal of Reliability and Applications
• /
• 제8권2호
• /
• pp.183-197
• /
• 2007

There is a growing trend for asset intensive industries to outsource maintenance services of their complex assets since outsourcing through service contract reduces upfront investments in infrastructure, expertise and specialised maintenance facilities. Estimation of costs for such contracts is complex and it is important to the user and the service providers for economic variability. The service provider's profit is influenced by many factors such as the terms of the contract, reliability of asset, and the servicing strategies, costs of resources needed to carryout maintenance. There is a need to develop mathematical models for understanding future costs to build it into the contract price. Three policies for service contracts are proposed in this paper considering the concepts of outsourcing maintenance service of assets to the service providers. Conceptual models are developed for estimating servicing costs of outsourcing through service contracts by considering time dependent failure mode.