• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.195-202
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• 2011

The study interprets each of three classification models based on Bath-Tub Failure Rate (BTFR), Extreme Value Distribution (EVD) and Conjugate Bayesian Distribution (CBD). The classification model based on BTFR is analyzed by three failure patterns of decreasing, constant, or increasing which utilize systematic management strategies for reliability of time. Distribution model based on BTFR is identified using individual factors for each of three corresponding cases. First, in case of using shape parameter, the distribution based on BTFR is analyzed with a factor of component or part number. In case of using scale parameter, the distribution model based on BTFR is analyzed with a factor of time precision. Meanwhile, in case of using location parameter, the distribution model based on BTFR is analyzed with a factor of guarantee time. The classification model based on EVD is assorted into long-tailed distribution, medium-tailed distribution, and short-tailed distribution by the length of right-tail in distribution, and depended on asymptotic reliability property which signifies skewness and kurtosis of distribution curve. Furthermore, the classification model based on CBD is relied upon conjugate distribution relations between prior function, likelihood function and posterior function for dimension reduction and easy tractability under the occasion of Bayesian posterior updating.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.324-333
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• 2001

The purpose of this cross-sectional study was to explore fear of falling in relation to activity restriction of in the community dwelling elderly. Two hundred ninety-nine community dwelling elderly residing in Seoul and Kyonggi-do were interviewed using a structured questionnaire. The results were as follows : 1. Subjects were predominantly women$(70.6\%)$, an average 72.5 years old; the incidence of falls in last one year was $45.5\%$. 2. The highest level of fear found for activity in those who say they do engage and those who do not engage in the activity was 'going out when it is slippery '(m=2.53, 2.81) and 'reach for something over your head'(m=1.66, 2.60). Fear of falling scores were significant lower for those who say they do engage in eight kinds of activities (excluded activities of given were 'go to the store', 'take a tub bath', 'get out of bed') than for those who do not engage in the activities. 3. Among those who did not perform the activity, the three activities, when it is slippy(n=80), reaching overhead(n=70), and walk outside(n=59),were most often avoided because fear alone as well as for reasons in addition to fear. 4. The significant variables associated with fear of falling were female(p=0.0000), 1 educational status(p=0.000l), poor economic condition(p=0.0007), and experience of falls in last one year(p=0.0007). Fear of falling is common in the community dwelling elderly in Korea and is associated with several demographical variables. Therefore, to prevent falls and to reduce fear of falling, further study for development of education program for the elderly is needed.

• Korean Institute of Interior Design Journal
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• v.26 no.5
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• pp.3-15
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• 2017

The study on bathroom plan for the elderly who use wheelchair has been done continuously. However, the elderly's behaviour at the bathroom and consideration for the caregiver has been underestimated. In this perspective, the purpose of this study is to find out how much more bathroom size is needed for the elderly who use wheelchair and the caregiver based on their behaviours. The study method is as follows: First, behaviours which occur at bathroom were collected from the previous research. Second, the size needed was calculated based on the elderly and caregiver's movement. Third, the size of bathroom enough for the impaired elderly with caregivers was suggested. The room next to shower booth and bath tub should be expanded for the caregiver. In addition, the room beside the basin should be added as much as $600{\times}600$ to let the caregiver stand and support the elderly when they are needed to wash their hair. As a result, the size of bathroom should be at least planed as follow; $1.3m^2$ more for type A, $1.5m^2$ more for type B, $1.6m^2$ more for type C, and $1.1m^2$ more for type D. As the bathroom is the room that the elderly want to modify for their rest of the lives, the room should be reserved enough from the early stage of design, so that this will make the elderly be possible stay at the place until they want to stay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.11
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• pp.2191-2198
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• 2017

The PME(precision measurement equipment) used in the measurement to check the performance of the equipment in military weapon system is periodically calibrated to maintain measurement reliability during the life cycle. Previous studies suggest that reliability models are determined by considering sample size and characteristics of equipment. However, it may not be fit well to apply a single model assuming the same characteristic distribution for the maintenance date of many kinds of PMEs. This paper proposes that the most suitable calibration interval for maintenance data is selected through the F-test and the performance index evaluation among the calibration intervals estimated from the measurement reliability models assuming the characteristic of the bath-tub curve during the life cycle of various PMEs. The research results show that the reliabilities of various types of equipment are maintained during calibration intervals.

• Journal of the Korean housing association
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• v.20 no.5
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• pp.31-39
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• 2009

The purpose of this study was to find out the residents' consciousness of the unit plan on condominium apartment and to contribute to develop a condominium apartment unit plan in Daejeon City. This research was performed by a questionnaire survey method, 464 data was collected from apartment residents lived in about $85\;m^2$ unit with 3 rooms and the apartments was limited to the complexes within 1-4 years of the length of building at Yuseong-gu and Seo-gu. By analyzing those data, findings are as follows: 1) Residents thought living room, kitchen and bathroom were importment space in a unit plan. They needed a storage function in an entrance and a intermediate room, and Anbang(mater bedroom) so did. 2) L-DK plan type was very popular and the type of front DK with L on the floor plan was preferred. This was unique results. 3) Sub-kitchen was needed for a refrigerator of Kimchi, the location of it was related to a main kitchen and a utility. the third room was needed for library, home office and storage space. 3) Bath-tub in An-bang and showe-booth in public bathroom was preferred. This was same to the popular trend of Korean condominium apartment. 4) The enlargment remodeling of balcony was showed livingroom balcony or personal bedrooms at the time of occupancy. They needed the balcony near a kitchen or an utility to equip a storage facility. Additionally, residents were preferred to their taste rather than a choice of interior concept package services.

• Korean Journal of Health Education and Promotion
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• v.27 no.1
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• pp.21-34
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• 2010

Objectives: The objective of this study was to investigate risk factors for falls in the elderly by life-cycle. Methods: This study used the data on 435 male and female elderly generated from a survey taken at 21 Welfare Centers for the Elderly in Seoul. The incidence of demographic characteristics, physical changes brought about with ageing, health-related behavior, chronic diseases, and environmental characteristics on falls in the elderly was analyzed. Hierarchical Logistic Regression analysis was also conducted to investigate the incidence by life-cycle (early-mid-late stage) and the results were used for predicting falls. Results: The incidence of risk factors on falls varied across life-cycle. Among the elderly in the early (ages from 65 through 74), marital status, the existence of a companion, the quality of sleep, the chronic diseases, and the condition of the bathroom floor were found to be related to falls. Among those in the mid-stage (ages from 75 through 84), sex, marital status, the existence of a companion, hearing capacity, sense of balancing, chronic diseases, the exclusive use of rooms, and the side bar with bath tub were found to affect falls. Finally, for the elderly in their late stage (85 years of age and older), drinking and vision were found to be related to falls. Conclusion: The incidence of risk factors on falls was found to vary according the stage in the elderly. A key implication of this finding is that falls prevention programs and interventions must be catered to specific age sub-groups.

• Journal of Venture Innovation
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• v.4 no.1
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• pp.101-118
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• 2021

Along with the rapid supply of apartments, bathtubs are becoming a must-have item for our lives, but research is very insufficient. This study is an empirical case study for formalization of taciturn as a long-time worker in the bathtub field. Bathtubs are developing different types of materials due to various factors, and we would like to draw characteristics based on their contents. The bathtub is characterized by its materials according to its manufacturing, housing structure and distribution process. First, it is a locally produced product because import and export is difficult. The second depends on the building soccer team, such as wet and dry. Third, it is different in relation to industries such as manufacturing and distribution. I would like to suggest the differences between the fourth countries. We hope this research will serve as a cornerstone for the study of bathtubs, and we hope it will be useful for those involved.

• Journal of Korea Water Resources Association
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• v.42 no.6
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• pp.445-455
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• 2009

In this paper proportional hazards models for the first through seventh break of 150 mm cast iron pipes in a case study area are established. During the modeling process the assumption of the proportional hazards for covariates on the hazards is examined to include the time-dependent covariate terms in the models. As a result, the pipe material/joint type and the number of customers are modeled as time-dependent for the first failure, and for the second failure only the number of customers is modeled as time-dependent. From the analysis on the baseline hazard functions the failure hazards are found to be generally increasing for the first and second failure, while the hazards of the third break and beyond showed a form of a bath-tub. Furthermore, the changes in the baseline hazard rates according to the time and number of break reflect that the general condition of the pipes is deteriorating. The factors causing pipe break and their effects are analyzed based on the estimated regression coefficients and their hazard ratios, and the constructed models are verified using the deviance residuals of the models.