• Journal of Power System Engineering
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• v.14 no.6
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• pp.61-66
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• 2010

Engineering asset management (EAM) requires the accurate assessment of current and the prediction of future asset health condition. Suitable mathematical models that are capable of predicting time-to-failure and the probability of failure in future time are essential. In general reliability models, lifetime of component and system is estimated using failure time data. This paper deals with the reliability assessment of elevators using life of main components. Especially this work is concerned with the stochastic nature of life of elevator components. First, we investigate the Weibull statistical analysis of lifetime data for the components. The final goal is to establish the mathematical model for reliability assessment. This work provides more perspectives to future research in the fields of reliability and maintainability.

• Korean Journal of Veterinary Research
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• v.46 no.2
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• pp.159-164
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• 2006

A stochastic simulation model incorporated with Reed-Frost approach was derived for evaluating diagnostic performance of a test used for a screening program of an infectious disease. The Reed-Frost model was used to characterize the within-herd spread of the disease using a hypothetical example. Specifically, simulation model was aimed to estimate the number infected animals in an infected herd, in which imperfect serologic tests are performed on samples taken from herds and to illustrate better interpreting survey results at herd-level when uncertainty inevitably exists. From a risk analysis point of view, model output could be appropriate in developing economic impact assessment models requiring probabilistic estimates of herd-level performance in susceptible populations. The authors emphasize the importance of knowing the herd-level diagnostic performance, especially in performing emergency surveys in which immediate control measures should be taken following the survey. In this context this model could be used in evaluating efficacy of a survey program and monitoring infection status in the area concerned.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.839-845
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• 2003

This paper introduces multichannel blind source separation (BSS) and multichannel blind deconvolution (MBD) based on higher order statistics of signals from convolutive mixtures. In particular, we are concerned with the case that the number of inputs is the same as the number of outputs. Simulations for two input two output cases are carried out and their performances are assessed. One of the major applications of those sequential algorithms (BSS and MBD) is demonstrated through the fault signal detection from only a single measurement of rotating machine, which offers a certain degree of practicability in the engineering field such as machine health monitoring or condition monitoring.

• YAKHAK HOEJI
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• v.18 no.1
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• pp.29-38
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• 1974

In order to study the residual amounts of absorbed organochlorine pasticides in vegetables, heptachlor and endrin were sprayed 2,4 and 6kg per 10a., respectively, before sowing the seeds in the station. The experiemental study is primarily concerned with the absorption in lettuce nad garland chrysanthemum. The absorption of each pesticide into lettuce and garland chrysanthemum, and residual pesticides in soil by timne have been analyzed by the gas chromtographic method, and the ratio of residual pesticides in vegetablesand soil were estimated. Heptachlor, heptachlor epoxide and endrin in lettuce nad garland chrysanthemum at the market in Seoul area hvae also analyzed and found extremely low level of pesticides in comparison with the level in above experimental vegetables as well as same vegetables in Japan.

• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.139-145
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• 2009

This study concerned with the characteristics and causes of musculoskeletal disorders (MSDs) for employees aged 50 years or older. In order to do this, based on 8,011 accident analysis reports, we analyzed the differences of characteristics between groups under 50 years and 50 years or more in terms of gender, occupation, duration of employment, part of body, industry, size of business and work-related factors. Results show that the distributions of the injuries aged 50 years or older are statistically different from those of the injuries under 50 years. Also, older employees have high relationship between repetition, or contact stress/vibration and upper extremity MSDs. These findings can be used to develop more effective MSD prevention programs for older employees.

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.63-70
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• 2007

There are something unreasonable, unsatisfactory on the law system for laboratorial safety enforced by the government from April 2006. Therefore, the system should be reviewed and revised to be satisfactory for current research condition. This study is to analyze research areas for improving laboratorial safety and to show safer ideas. With more detail, more practically improving ideas have been shown for systemizing safety assessment in advance, effective organization of laboratory, safety committee and their regulation. It is expected that better safety level all the concerned engagement, reasonable revision of safety regulation of laboratory, can be made by this research result.

• Journal of Families and Better Life
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• v.23 no.3 s.75
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• pp.103-114
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• 2005

The number of grandparents who have responsibility for raising their grandchildren is growing. The present study examines the extent of this phenomenon and some of the issues these grandparents face in surrogate parenting. The sample consists of 69 grandparents(63 grandmothers and 6 grandfathers) of grandchildren who have lived with them at least 6 months without their parents. The grandparents raising grandchildren reported that caregiving bought negative changes in relations with their own children, economic situation and health condition. They concerned most about the issue of good mannered behavior of grandchildren and making good friends and needed social supports in terms of house cleaning and cooking and transportation for after school activities. Caregiver burden was related to the number of family members, the degrees of life changes, economic hardship due to caregiving, grandchildren's school performance and the relations with granparents' own children.

• Journal of the Korean Society of Safety
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• v.15 no.3
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• pp.78-82
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• 2000

The flash point is an important property and hazardous index of a flammable liquid. The flash points are used by virtually all the environmental, health, and safety organizations in both government and industry to classify flammable liquids for safety and transportation regulations. The basics of all flash points behavior are concerned with the vapor pressure and explosive limits. The flash points of pure components and the mixture of solvents can be calculated with the use of the laws of Raoult, Dalton and Le Chatelier. In this paper, experimentally determined lower flash points of a p-xylene and epoxy resin system were compared with the calculated values by using Raoults law. Calculated lower flash points were in reasonable agreement with the observed values.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.3-9
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• 2003

The task for chromosome analysis and diagnosis by experienced cytogenetists are being concerned as repetitive, time consuming job and expensive. For that reason, intelligent agent based on chromosome knowledge base has been established to be able to analyze chromosomes and obtain necessary advises from the knowledge base instead of human experts. That is to say, knowledge base by IF THEN production rule was implemented to a knowledge domain with normal and abnormal chromosomes, and then the inference results by knowledge base could enter the inference data into the database. Experimental data were composed of normal chromosomes of 2,736 patients 'cases and abnormal chromosomes of 259 patients' cases that have been obtained from GTG-banding metaphase peripheral blood and amniotic fluid samples. The completed intelligent agent for chromosome knowledge base provides variously morphological information by analysis of normal or abnormal chromosomes and it also has the advantage of being able to consult with user on chromosome analysis and diagnosis.

• The Journal of Korean Physical Therapy
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• v.2 no.1
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• pp.113-122
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• 1990

Osteoporosis is a major underlying cause of bone fracture in postmenopausal women and older person in general, and so it is a major public health problem. It is a condition in which bone mass decreases, causing bones to be more susceptible to fracture. A trivial trauma can easily cause one or more bones to break in a person with severe osteoporosis. Physicians and patients alike are concerned with the optimum approach to the treatment and prevention of osteoporosis. The diagnostic method and proper use of agents, such as calcium, vitamin D, estrogen, and fluorides, as well as the role of exercise are issues that have generated major research efforts. So these are to be mentioned in this paper.