• Research in Community and Public Health Nursing
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• v.18 no.4
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• pp.662-672
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• 2007

Purpose: In recent years, the problem of runaway youths, which is rapidly increasing and worsening in nature, has emerged as a serious problem to individuals, home and the society as a whole. Against this back drop, this study was designed to illuminate the danger signals through extensive analysis of factors influencing the running away of middle-school students and, on this basis, build a forecast model on runaway middle-school students. Method: The subjects of this descriptive survey on the causal relation were 592 subjects enrolled in middle schools selected through convenience sampling. The data collected from June 19 to July 19, 2003 were analysed through the SPSS 10.0 program. The differences between the runaway group and the non-runaway group were determined through chi-square and t-test. Also logistic regression analysis was conducted on the basis of the purposeful selection method for constructing the forecast model. Result: The findings are as follows: Individual-related factors predicting runaway middle-school students were smoking experience, delinquent experience, psychosomatic symptoms and stress. A home-related factor was attachment to family. A society-related factor was the number of delinquency friends. Conclusion: The findings of this study suggest that a broad intervention program should be provided to middle-school students' culture related to runaway group. It is also recommended that a variety of individual, home and society-related programs should be developed for the runaway group.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.173-179
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• 2018

Estimating reliability of a non-repairable system using the degradation data, variance assumption such as homogeneity (constant) or heteroscedasticity (time-variant) could affect accuracy of reliability estimation. This paper showed reliability estimation and comparison results under normal conditions using accelerated degradation data obtained from destructive measurements, according to variance assumption of the data at each measurement time. Degradation data from three accelerated conditions with stress factors of temperature and humidity were used to estimate reliability. The $B_{10}$ lifetime was estimated as 1243.8 years by constant variance assumption, and 18.9 years by time-variant variance. And variance assumption provided different analysis results of important stresses to reliability. Thus, accurate assumption of variance at each measurement time is required when estimating reliability using degradation data of a non-repairable system.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.17 no.3
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• pp.179-188
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• 2013

Objectives This study was designed to development the diagnosis indicators for the fatigue group without disease using analysis of questionnaire data. Methods The subjects were divided into three groups, the fatigue group with disease, the fatigue group without disease, non-fatigue group without disease. Thirteen kinds of questionnaire (Fatigue visual analogue scale, Fatigue severity scale, Pain visual analogue scale, Short-form McGill pain questionnaire score, Headache impact Test-6, Neck disability index, Oswestry low back pain disability questionnaire score, Blood stasis assessment scale, Physical activities questionnaire score, Beck depression inventory, Anger expression inventory score, Mood disability scale, Job stress scale) were carried out for the subjects. Results The results of this study are ; 1) The weight, the systolic and diastolic blood pressure were different among three groups. 2) Among nine questionnaires related to the physical or life conditions, the averages of eight questionnaires were not same one another. 3) Among four questionnaires related to the mental condition or autonomic nervous system, the averages of Beck depression inventory were not same one another. Conclusion The fatigue group without disease can be diagnosed through using the both the questionnaires related to the physical or life condition and the those related to the mental condition or autonomic nervous system.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.69-74
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• 2011

Despite most of tasks in manufacturing, construction and agriculture, etc., were currently mechanized and automated, manual materials handling still existed in atypical working condition. In case of manual materials handling, repetitive work, inappropriate working posture, excessive force, contact stress might cause overload, which could lead to work-related musculoskeletal disorders and low back pains. On this basis, the goal of this study is to reveal the effects of various lifting postures of trunk angles and lower extremity postures on maximum holding time(MHT). Twenty two subjects were recruited from a university population. The experiment was designed by a combination of three trunk angle ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) and three lower extremity postures(straight, bent, kneeling). Before experimental trials, subjects performed MVC(maximum voluntary contraction) exertions in three trunk angles ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) to calculate 30%MVC at designated postures. In each trial, they were required to hold the handheld load(30%MVC) for a designated posture as long as they could. The results of MVC by trunk angles were measured in $0^{\circ}$ > $20^{\circ}$ > $60^{\circ}$ orders, but those of MHT measured in $20^{\circ}$ > $0^{\circ}$ > $60^{\circ}$ orders. These results showed that straight posture is the ideal working posture in work exerted a strong force for a short time, but the ability to work might be improved in the trunk angle $20^{\circ}$ in work required 30%MVC for a long time. Also, results of MVC and MHT by lower extremity postures measured in straight > bent > kneeling orders.

• Journal of Korean Society of Steel Construction
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• v.19 no.5
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• pp.483-492
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• 2007

Pre-Engineering Building (PEB) system is one of the most economical structural systems. Tapered members can resist a maximum stress at a single location, whereas stresses of the rest of the members are considerably low. This results in appreciable savings both in terms of materials and construction costs. However, it was appreciated that special consideration would be required for certain aspects of this structural form. In particular, because of their slenderness, webs would buckle laterally and torsionally under the combined action of excessive axial, bending and shear forces. In this study, a total of four large-scale rafters with simple ends were tested. The main parameters were the width-thickness ratio of the web, the stiffener, and the flange brace. The purpose of this experiment is to evaluate the structural stability and to offer back-data on PEB design.

• Geomechanics and Engineering
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• v.13 no.5
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• pp.715-742
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• 2017

Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

• Journal of Ocean Engineering and Technology
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• v.32 no.6
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• pp.502-510
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• 2018

In order to accumulate data to lower the friction coefficient of a press mold, tribological tests were performed before and after coating SM45C with a PVC/PO film and plasma coating (CrN, concept). The ultrasonic nanocrystal surface modification (UNSM)-treated material had a nano-size surface texture, high surface hardness, and large and deep compressive residual stress formation. Even when the load was doubled, the small amount of abrasion, small weight of the abrasion, and width and depth of the abrasion did not increase as much as those of untreated materials. A comparison of the weight change before and after the tribological test with the CrN and the concept coating material and that of the untreated material showed that the wear loss of the concept coating material and P-UNSM treated material (that is, the UNSM treated material treated with the concept coating) showed a tendency to decrease by approximately 55-75%. Concept 100N had a lower friction coefficient of about 0.6, and P-UNSM-30-100N showed almost the same curve as concept 100N and had a low coefficient of friction of about 0.6. The concept multilayer coating had a thickness of $5.32{\mu}m$. In the beginning, the coefficient of friction decreased because of the plasma coating, but it started to increase from about 250-300 s. After about 350 s, the coefficient of friction tended to approach the friction coefficient of the SM45C base metal. The SGV-280F film-attached test specimen was slightly pushed back and forth, but the SM45C base material was not exposed due to abrasion. The friction coefficient was 0.22, which was the lowest, and the tribological property was the best in this study.

• The Journal of Korean Obstetrics and Gynecology
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• v.32 no.2
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• pp.87-99
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• 2019

Objectives: The aim of this study was to analyse the domestic trends of Chuna manual therapy on Obstetrics and Gynecological Diseases in Korean literature. Methods: We searched for papers which had Chuna manual therapy through 2 related journals and 5 Korean web databases. All relevant papers were selected and extracted to be analyzed according to their study designs, academic journals, and target disease. Results: Nine papers belonged to four types of study designs, systematic review, randomized or non-randomized controlled trial and case report. And they were published in four kinds of academic journals. There were four papers about postpartum pain, two low back pain during pregnancy, and a stress urinary incontinence. The exact Chuna techniques were explained in only seven papers. All of papers have been shown that Chuna manual therapy is useful for obstetrics and gynecological diseases. Conclusions: It has been identified that Chuna manual therapy could be a good treatment for obstetrics and gynecological diseases. However, more clinical and well-designed studies with Chuna manual therapy will be needed.

• (The)Study of the Eastern Classic
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• no.68
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• pp.319-344
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• 2017

Saam Park Sun(1523-1589) holds a very important position in history of 16th century $d{\grave{a}}oxu{\acute{e}}$ politics. Starting from King Seonjo's accession in 1567, he took a lead in changing the former Politics by Hoonchuck(勳戚政治) to $d{\grave{a}}oxu{\acute{e}}$ politics. He served a prime minister alone for 14 years. Following philosophy of $d{\grave{a}}oxu{\acute{e}}$ politics that Jo Gwang-jo(趙光祖, 1482-1519) had advocated a generation earlier, he sought reformative politics by rising elites. He pursued ideal politics of $d{\grave{a}}oxu{\acute{e}}$ in which principles and public opinion agreed with each other and to realize it, he was in the forefront of correcting 'shìdào(世道)' and improving 'qīngyì(淸議).' It is why $d{\grave{a}}oxu{\acute{e}}$ politics is called shìdào politics(世道政治). He emphasized 'old manners(古禮)' as standard to criticize wrong reality and to realize ideals. The 'old' in his mind was ideals, principles and traditions. The most meaningful reform was to go back to spirit of 'old.' It is why he put stress on and stuck to practice of 'old manners' in national liturgy.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.4
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• pp.185-192
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• 2022

Variations in the microstructure and mechanical properties of API X70 steel processed by piping, electrical resistance welding (ERW), and post seam annealing (PSA) are investigated in this study. In the welding zone, some elongated pearlites are formed and grains coarsening occurs due to extra heat caused by the ERW and PSA processes. After the piping, the base metal shows continuous yielding behavior and a decrease in yield and impact strengths because mobile dislocation and back stress are introduced during the piping process. On the other hand, the ERW and PSA processes additionally decreased the impact strength of welding zone at room and low temperatures because some elongated pearlites easily act as crack initiation site and coarse ferrite grains facilitate crack propagation. As a result, the fracture surface of the welding zone specimen tested at low temperature revealed mostly cleavage fracture unlike the base metal specimen.