• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.347-355
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• 2017

The purpose of this study was to investigate the effects of pelvic adjustment on low back pain and spino-pelvic parameters in middle-aged women. Thirty-eight middle-aged women with chronic low back pain were randomly assigned to the pelvic adjustment (n = 20) oruntreated control (n = 18) group. Pelvic adjustment interventionswereperformed four times a week for 8 weeksin the former group. At baseline and after 8 weeks, the back pain and back function were evaluated using the visual analogue scale (VAS), Oswestry disability index (ODI), and back flexibility. Additionally, the spino-pelvic radiographic parameters and serum C-reactive protein (CRP) levels were assessed. After 8 weeks, the VAS, ODI, and back flexibility significantly improved in the pelvic adjustment group compared with the control group. It was found that the changes from baseline in the lumbar lordotic angle, sacral slope, pelvic crest unleveling, and femoral head height inequality were significantly greater in the pelvic adjustment group than in the control group. There were no significant changes in the pelvic incidence or serum CRP levels in either group. In conclusion, pelvic adjustment has beneficial effects on chronic low back pain and back function, suggesting that the effects of pelvic adjustment on back pain may at least in part result from changes in the spino-pelvic alignment.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.11
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• pp.53-62
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• 1994

This paper presents a new approach of analyzing errors resulting from nonideal general-purpose lighting environment when the Photometric Stereo Method (PSM) is applied to estimate the surface-orientation of a three-dimensional object. The approach introduces the explicit modeling of the lighting environment including a circular-disk type irradiance object plane and the direct simulation of the error distribution with the model. The light source is modeled as a point source that has a certain amount of beam angle, and the luminance distribution on the irradiance plane is modeled as a Gaussian function with different deviation values. A simulation algorithm is devised to estimate the light source orientation computing the average luminance intensities obtained from the irradiance object planes positioned in three different orientations. The effect of the nonideal lighting model is directly reflected in such simulation, because of the analogy between the PSM and the proposed algorithm. With an instrumental tool designed to provide arbitrary orientations of the object plane at the origin of the coordinate system, experiment can be performed in a systematic way for the error analysis and compensation. Simulations are performed to find out the error distribution by widely varying the light model and the orientation set of the object plane. The simulation results are compared with those of the experiment performed in the same way as the simulation. It is confirmed from the experiment that a fair amount of errors is due to the erroneous effect of the general-purpose lighting environment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1175-1183
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• 2013

Even if some CFD software developers and its users think that a state-of-the-art CFD software can be used to reasonably solve at least single-phase nuclear reactor safety problems, there remain limitations and uncertainties in the calculation result. From a regulatory perspective, the Korea Institute of Nuclear Safety (KINS) is presently conducting the performance assessment of commercial CFD software for nuclear reactor safety problems. In this study, to examine the prediction performance of commercial CFD software with the porous model in the analysis of the scale-down APR (Advanced Power Reactor Plus) internal flow, a simulation was conducted with the on-board numerical models in ANSYS CFX R.14 and FLUENT R.14. It was concluded that depending on the CFD software, the internal flow distribution of the scale-down APR was locally somewhat different. Although there was a limitation in estimating the prediction performance of the commercial CFD software owing to the limited amount of measured data, CFX R.14 showed more reasonable prediction results in comparison with FLUENT R.14. Meanwhile, owing to the difference in discretization methodology, FLUENT R.14 required more computational memory than CFX R.14 for the same grid system. Therefore, the CFD software suitable to the available computational resource should be selected for massively parallel computations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.87-94
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• 2017

Because the cavitation flow driven by an underwater propeller corrodes the materials around it and generates a high level of noise, it has become an important topic in engineering research. In this study, computational fluid dynamics techniques are applied to simulate cavitation flow, and the noise in the flow is predicted by applying the acoustic analogy to the predicted flow. The predicted results are compared with measurement results and other predictions in terms of surface pressure distribution and the temporal variation in liquid volume fraction. The predicted results are found to be in good agreement with the measured results. The source of the noise attributed to the time rate of change in the liquid volume fraction around the hydrofoil is modeled as a monopole source, and the source of the noise due to unsteady pressure perturbations on the hydrofoil surface is modeled as a dipole source. Then the predicted noise results are analyzed in terms of directivity and SPL spectrum. The noise caused by unsteady pressure perturbations was dominant in the entire frequency range considered in the study.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.296-304
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• 2007

Background : The main aim of this study was to analyze the factors that could be used to predict job satisfaction of assistant nurses in general hospitals. Material and Methods : This study was based on a survey of assistant nurses in the Daegu region from January 1, 2006 to January 31, 2006. Originally 300 questionnaires were distributed and among them 291 were completed. The data was collected and used for the statistical analysis. Descriptive and inferential statistics, such as the frequency, t-test and one-way ANOVA were used for the analysis. Results : Among the respondents, the average score for job satisfaction was lowest in the university-trained nurses and highest in the nurses who had only graduated from high school. Conclusion : The working conditions, work place and motivation are significantly associated with job satisfaction. In particular, there was lower job satisfaction in those nurses who wanted to change their occupation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4523-4530
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• 2011

This study aimed to evaluate the effects of stretching management on musculoskeletal joint pain in community indwelling elderly farmers. The study included 28 residents who lived in a rural community. All participants were assigned randomly to either the stretching group (n=13, $59.67{\pm}4.77$ year-old) or the control group (n=15, $61.44{\pm}10.41$ year-old). Respondents were interviewed by means of a structured questionnaire. Pain severity of 6 body areas caused by symptoms of work-related musculoskeletal disorders and pain severity on day time variations were measured by the visual analogue scale on a self-assessed questionnaire. The stretching group was administered stretching therapy (45 min, 2 sets, warming up and cool down, main exercise; total 19 stretching kinds of subset 5 fields) for 12 times for 4 weeks. There were no significant difference between the two groups in general social and pain characteristics. After 4 weeks of stretching, the stretching group showed significant improvements at almost all joint pain scores except arm/elbow, and day time variation scores of pain compared to both baseline scores, and with control group scores. These results showed that stretching therapy is one of the most useful modalities to manage musculoskeletal pain in community-based elderly farmers.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.91-94
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• 2007

This research was investigated to find out the examinees' refractive problems within heterophoria using Torrington method. The number of subjects ware approximately 327 and subjects were sourced from the 12th grade student at high school in Kwang-Ju city. Result obtained shows 21.4% of emmetropia and 78.6% of ametropia. Most of refractive errors were myopia and due to it's condition, frequency of ametropia and emmetropia at the similar rate. However, one that consist of refractive problems, it's myopia contains 74.9% of heterophoria. Due to emmetropia, horizontal heterophoria have 45.7% of exophoria and 4.3% of esophoria. Myopia shows 11.4% of esophoria and 63.5% of exophoria. Hozizonda heterophoria shows 5.7% of emmetropia and myopia of 22.4%, than average of esophoria shows $4.3P{\Delta}$ and case of myopia, it was $3.4P{\Delta}$. Case of Exphoria, emmetropia have $8.8P{\Delta}$ and within myopia $8.0P{\Delta}$. Vertical heterophoria owns $2.2P{\Delta}$ within emmetropia and case of myopia $4.3P{\Delta}$ was shown. Which shows myopia result value higher than emmetropia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1318-1327
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• 2015

In this study, customer service representatives in call centers, the relevance of occupational stress, and turnover intention as well as the investigation of the relevance to that of demographic characteristics, health behaviors, and job-related characteristics is carried out. In particular, the relevance of occupational stress and turnover intention was attempted to be identified. From the response to the surveys of nine hospitals and five companies, there was a total of 158 people during the investigation. The collection of data was conducted by self-administered questionnaire in the period of February 1, 2013 to June 30, 2013. As the result of study, factors related to turnover intention involved age, sleep, job demands and job autonomy as significant variables. In particular, in the relevance of occupational stress and turnover intention, it was revealed that turnover intention decreases as job autonomy increases while turnover intention increases as job demands become higher. The ratio of danger of occupational stress on turnover intention eminently increased in the group of high job demands, low job autonomy, low support of supervisor and co-worker. Therefore, it is considered that efforts for improvement of occupational stress factors are required to decrease turnover intention.

• Journal of the Korean GEO-environmental Society
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• v.24 no.7
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• pp.5-14
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• 2023

Recently, earthquakes have occurred frequently in worldwide. These earthquakes cause various forms of natural and physical damage. In particular, liquefaction in which the ground shows liquid-like behavior causes great damage to the structure. Accordingly, various liquefaction damage reduction methods are being studied and developed. Therefore, in this study, a method of reducing liquefaction damage in the event of an earthquake applicable to existing structures was studied using the sheet pile method. The 1-G Shaking table test was performed and the ground was constructed with Jumunjin standard sand. A two-story model structure was produced by applying the similitude law, and the input wave applied a sine wave with an acceleration level of 0.6 g and a frequency of 10 Hz. The effect of reducing structure damage according to various embedded depth ratio was analyzed. As a result of the study, the structure settlement when the ground is reinforced by applying the sheet pile method is decreased by about 71% compared to when the ground is not reinforced, and the EDR with minimum settlement is "1". In addition, as the embedded depth ratio is increased, the calculation of the pore water pressure in the ground tends to be delayed due to the sheet pile. Based on these results, the relationship with structural settlement according to the embedded depth ratio is proposed as a relational equation with the graph. The results of this study are expected to be used as basic data in developing sheet pile methods applicable to existing structures in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.11-20
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• 2008

The spillway type of small and midsize dams in Korea is almost overflow weir. To examine flood control capacity of overflow spillway, FLOW-3D was applied to Daesuho dam and analysis was focused on the discharge of dam spillway by changing weir shape. Overflow phases and discharges of linear labyrinth weir and curved labyrinth weir were compared with those of existing linear ogee weir. Hydraulic model experiment was performed to verify numerical result. Verification results showed that overflow behaviors and flow characteristics in the side channel by hydraulic model experiment and numerical simulation are well matched, and water surface elevation at side wall coincides with each other. When the reservoir elevation was increased up to design flood level, in case of the linear ogee weir the flow over the crest ran through smoothly in the side channel, whereas in cases of linear labyrinth weir and curved labyrinth weirs, the flow discharge was increased by 40 cms, and the flow over the weir crest, rotating counter-clockwise, was submerged in the side channel. The results of the water level-discharge curve revealed that labyrinth weir can increase discharge by 71% compared to the discharge of linear ogee weir at low reservoir elevation since it can have longer effective length. But as water surface elevation rises, the slope of water level-discharge curve of labyrinth weir becomes milder by submergence and nappe interference in the side channel.