• Journal of agricultural medicine and community health
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• v.18 no.2
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• pp.173-183
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• 1993

This study reports the relationship between life-style and physical, mental health status in college students. The questionnaire survey was carried out from September to October, 1991. The questionnaire included life-style, physical health condition centered on unhealthy habits and complaints about physical symptoms, and mental condition which was assessed by Zung's self-rating depression scale(SDS). Days absent from school during the last year in males(3.6) were significantly more than those in females (1.0). Days catching the common cold were more in females than in males. The amount of complaints and the SDS score were significantly higher in females than in males. In the relationship between physical and mental health status and individual health habits, abscence-days from school significantly correlated with regular life, snacking, physical exercise, smoking, drinking. The amount of complaints and the SDS score were significantly associated with regular life, regular meal-time, eating breakfast, nutritional balance and physical exercise. In the relationship between health practice index to health status, the group having good habits showed significantly less days catching the common cold, less complaints, less SDS score and less amount of stress. It was also shown that life-style correlated with physical and mental health status.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.69-76
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• 2015

PURPOSES : Performance evaluation of four types of asphalt concrete overlays for deteriorated national highways. METHODS : Pavement distress surveys for crack rate and rut depth have been conducted annually using an automated pavement survey vehicle since 2007. Linear and non-linear performance prediction models of the asphalt concrete overlays were developed for 43 sections. The service life of the asphalt overlays was defined as the number of years after which a crack rate of 30% or rut depth of 15mm is observed. RESULTS : The service life of the asphalt overlays was estimated as 17.4 years on an average. In 90.7% of the sections, the service life of the overlays was 15 years or more which is 1.5 times the life of conventional asphalt concrete overlays used in national highways. The performance of the overlays was dependent on the type of asphalt mixture, traffic volume levels, and environmental conditions. CONCLUSIONS : The usage of stone mastic asphalt (SMA) and polymer-modified asphalt (PMA) for the overlays provided good resistance to cracking and rutting development. It is recommended that appropriate asphalt concrete overlays must be applied depending on the type of existing pavement distress.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.120-125
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• 2004

Fatigue life of welded joints are governed by the propagation of multiple collinear surface cracks distributed randomly along weld bead. These cracks propagate in mutual interaction and coalescence of them. To estimate the fatigue life, the influences of above two mechanisms on the fatigue life should be taken into account. These two mechanisms appear through the stress intensity factors disturbed mutually. However, it is difficult to calculate the stress intensity factors of multiple surface cracks located in vicinity of weld toe. The stress intensity factors are calculated normally by using the Mk-factors, but such Mk-factors are very rare in literature. In this study, the Mk-factors were obtained from a parametric study on crack length and depth, in which a finite element method is used. A fatigue test for a cruciform welded joint was conducted. The fatigue life of the tested specimen was estimated through present method with the informations obtained from the test, e.g. the number, size and locations of the cracks. The estimated and measured fatigue life showed a good agreement.

• Food Science and Preservation
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• v.5 no.4
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• pp.392-395
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• 1998

This study was to reveal consumer attitudes about open shelf-life dating method of the packaged foods. Consumers consider that open shelf-life dating to the packaged foods gives good information to choose the products to buy, but also confusion with unclear open shelf-life dating marked on the package. For the perishable foods, consumers tended to get more attention to the open shelf-life dates. Consumers prefer the dating method of edible periods better than sellable periods to the packaged foods. The female consumers consider that open shelf-life dating is more important to buy the packaged foods than male consumers do.

• Steel and Composite Structures
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• v.32 no.6
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• pp.701-715
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• 2019

Using first-order shear deformation theory (FSDT), a semi-analytical solution is employed to analyze creep damage and remaining life assessment of 304L austenitic stainless steel thick (304L ASS) cylindrical pressure vessels with variable thickness subjected to the temperature gradient and internal non-uniform pressure. Damages are obtained in thick cylinder using Robinson's linear life fraction damage rule, and time to rupture and remaining life assessment is determined by Larson-Miller Parameter (LMP). The thermo-elastic creep response of the material is described by Norton's law. The novelty of the present work is that it seeks to investigate creep damage and life assessment of the vessels with variable thickness made of 304L ASS using LMP based on first-order shear deformation theory. A numerical solution using finite element method (FEM) is also presented and good agreement is found. It is shown that temperature gradient and non-uniform pressure have significant influences on the creep damages and remaining life of the vessel.

• Smart Structures and Systems
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• v.30 no.6
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• pp.571-582
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• 2022

Optimal life-cycle management is a challenging issue for deteriorating regional bridges. Due to the complexity of regional bridge structural conditions and a large number of inspection and maintenance actions, decision-makers generally choose traditional passive management strategies. They are less efficiency and cost-effectiveness. This paper suggests a deep reinforcement learning framework employing double-deep Q-networks (DDQNs) to improve the life-cycle management of deteriorating regional bridges to tackle these problems. It could produce optimal maintenance plans considering restrictions to maximize maintenance cost-effectiveness to the greatest extent possible. DDQNs method could handle the problem of the overestimation of Q-values in the Nature DQNs. This study also identifies regional bridge deterioration characteristics and the consequence of scheduled maintenance from years of inspection data. To validate the proposed method, a case study containing hundreds of bridges is used to develop optimal life-cycle management strategies. The optimization solutions recommend fewer replacement actions and prefer preventative repair actions when bridges are damaged or are expected to be damaged. By employing the optimal life-cycle regional maintenance strategies, the conditions of bridges can be controlled to a good level. Compared to the nature DQNs, DDQNs offer an optimized scheme containing fewer low-condition bridges and a more costeffective life-cycle management plan.

• Research in Community and Public Health Nursing
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• v.33 no.1
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• pp.74-83
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• 2022

Purpose: The purpose of this study was to identify latent classes of health-related quality of life trajectories in middle-aged women and investigate predictors for latent classes. Methods: This study utilized data from the 2^nd, the 4^th to the 7^th Korean Longitudinal Survey of Women & Families. The subjects included 1,351 women aged 40~45 years. The data was analyzed using latent class growth analysis and logistic regression. Results: Two trajectories were identified for health-related quality of life in middle-aged women; 'persistently good' and 'increasing' groups. Predictors for the 'increasing' group were lower economic status, higher depression, and lower perceived health status. Conclusion: This study showed that characteristics of the individual, symptom status, and health perceptions were associated with health-related quality of life in middle-aged women. It is necessary to provide effective intervention for latent classes of health-related quality of life trajectories based on physical, mental, and social factors.

• Korean Journal of Culture and Social Issue
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• v.12 no.5_spc
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• pp.29-43
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• 2006

With longevity (75 years plus and still increasing) now commonly achievable, the new challenge for individuals and society is less concerned with adding more years to life, though that remains important, and more with adding life to years. To explore the quality of long life more fully, a concept broader than healthy ageing or active ageing is needed. For this purpose, the present article describes a framework of Positive Ageing, also known as Successful Ageing, which views the quality of long life as comprising good health, physical and cognitive functional independence, and meaningful engagement with life. Narrowly defined, it refers to old people ageing well in all these aspects. More broadly defined, it refers to ageing well from midlife on. The framework also identifiesvariables that may affect the process of ageing positively. These variables include the social-cognitive styles of control, humour and future-time perspective on the one hand, and on the other hand, resources based on finance, social network and lifestyle.

• The Korean Journal of Health Service Management
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• v.8 no.3
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• pp.103-112
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• 2014

The purpose of this study is to explore and classify the types of the attitude on a good death of nurses in long-term care hospitals. Q-methodology, which is effective in scientifically measuring individual subjectivity, was used. 151 Q-population were selected through the processes of review of research articles, newspaper articles and interviews. 34 Q-sample were selected from the 151 Q-population and 27 nurses in long-term care hospitals were invited as the P sample. The result of the Q-sort was analyzed using PC QUANL Program. The types of attitude on a good death of nurses in long-term care hospitals was categorized into three. 1) Death in supportive environment 2) a comfortable death in real life 3) Dignity guaranteed death By identifying 3 attitude patterns toward a good death of long-term hospital nurses, this study provides an opportunity for their reflection and recognition toward a good death based on this result and suggests to think about ways to improve the quality of nursing in the current increasing long-term hospitals.

• Journal of the Korean Society of Food Culture
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• v.14 no.2
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• pp.147-153
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• 1999

This study was conducted to investigate the sanitation status and food waste state from 220 restaurant owners in Taejon area by questionnaires. As a result, the restaurant owners had proper knowledges on the purposes of the good menu system which is to prove public sanitation and to reduce food waste by changing present food service style. According to the restaurant management characteristics study, the subjects recognized highly for the importance of cleanliness(4.6), taste(4.5) where diversity of portion size(3.9), attractiveness(4.0) were low. 86.3% of the subjects mentioned great reductions in food waste after practicing good menu system. Also the subjects recognized the necessity for further researches on this field. After practicing good menu system in restaurant, their food waste was reduced.