• Structural Engineering and Mechanics
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• v.31 no.5
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• pp.507-526
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• 2009

Based on numerical and experimental methods, a systematic structural evaluation of a steel natatorium in service was carried out in detail in this paper. Planning of inspection tasks was proposed firstly according to some national codes in China in order to obtain the economic and reliable results. The field visual inspections and static computation were conducted in turn under in-service environmental conditions. Further a three-dimensional finite element model was developed according to its factual geometry properties obtained from the field inspection. An analytical modal analysis was performed to provide the analytical modal properties. The field vibration tests on the natatorium were conducted and then two different system identification methods were used to obtain the dynamic characteristics of the natatorium. A good correlation was achieved in results obtained from the two system identification methods and the finite element method (FEM). The numerical and experimental results demonstrated that the main structure of the natatorium in its present status is safe and it still satisfies the demand of the national codes in China. But the roof system such as purlines and skeletons must be removed and rebuilt completely. Moreover the system identification results showed that field vibration test is sufficient to identify the reliable dynamic properties of the natatorium. The constructive suggestion on structural evaluation of the natatorium is that periodic assessment work must be maintained to ensure the natatorium's safety in the future.

• PNF and Movement
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• v.18 no.2
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• pp.183-194
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• 2020

Purpose: Functional ankle instability (FAI) causes tension in the joints, ligaments, and tendons, and the impact on visual and vestibular organs leads to imbalance. This study compared the effects of a traditional balance training program to virtual reality training to improve FAI. Methods: Twenty-four participants with FAI (CAIT score < 24) were assigned to a virtual reality training group (n = 13) and a traditional balance training group (n = 11). Both groups pursued their respective training program for four weeks. After a ten-minute warm-up, participants completed a 30-minute training session, three times per week. The traditional balance training group underwent static and dynamic training using a balance board and a stability trainer pad while the virtual reality group underwent balance training using a virtual reality program. Biorescue was used to measure changes in the speed and length of center of pressure (COP) for single-leg stance pre- and post-training. Results: The speed and length of COP improved significantly in both groups after training as compared to before (p < 0.05). However, there were no significant differences in these outcomes between the virtual reality training group and the traditional balance training group (p>0.05). Conclusion: The study findings confirm the effectiveness of both virtual reality training and traditional balance training in reducing ankle instability, with no difference in treatment effects.

• Journal of Korean Physical Therapy Science
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• v.11 no.3
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• pp.28-37
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• 2004

Background: Lumbar joint dysfunction is reported to be the main cause of lower back pain (LBP). The purpose of this study was to evaluate the effect of joint dysfunction on the postural balance of the lower hack and pelvis in different normal activities such as walking or stair management. Also it was studied whether the status of LBP (intensity and duration of LBP, length of treatment) contributes to die pelvic height difference (PHD) in various postures. Subjects: 28 patients with LBP and 32 normal adult volunteers, 60 years of age or younger, who came to the Community Health Center and orthopedic clinics in Incheon, South Korea. Methods: In order to determine the accuracy of the manual angulometer method in measuring the PHD, it was compared to the pelvic x-ray method in selected subjects. In the manual angulometer method, the arm of the angulometer was placed on the top of both iliac crests. The PHD was measured in static upright stance, then one-legged stance, on the affected leg or unaffected leg each time. Information regarding the disease status was obtained through interviews. Visual assessment scale was used to grade the intensity of LBP. Data analysis was performed using SPSS 10.0/PC program. Homogeneity between the two groups was tested by 2-test and t-test. To compare the PHD of the subgroups, we used t-test, F-test and two-way ANOVA. Relationships among dependent variables were analyzed by Pearson correlation analysis. Conclusion: In patients with LBP, lumbar joint dysfunction causes lumbar and pelvic postural asymmetry during normal activities.

• Genomics & Informatics
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• v.2 no.4
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• pp.191-194
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• 2004

Exponentially increasing biopathway data in recent years provide us with means to elucidate the large-scale modular organization of the cell. Given the existing information on metabolic and regulatory networks, inferring biopathway information through scientific reasoning or data mining of large scale array data or proteomics data get great attention. Naturally, there is a need for a user-friendly system allowing the user to combine large and diverse pathway data sets from different resources. We built a data warehouse - BIOWAY - for analyzing and visualizing biological pathways, by integrating and customizing resources. We have collected many different types of data in regards to pathway information, including metabolic pathway data from KEGG/LIGAND, signaling pathway data from BIND, and protein information data from SWISS-PROT. In addition to providing general data retrieval mechanism, a successful user interface should provide convenient visualization mechanism since biological pathway data is difficult to conceptualize without graphical representations. Still, the visual interface in the previous systems, at best, uses static images only for the specific categorized pathways. Thus, it is difficult to cope with more complex pathways. In the BIOWAY system, all the pathway data can be displayed in computer generated graphical networks, rather than manually drawn image data. Furthermore, it is designed in such a way that all the pathway maps can be expanded or shrinked, by introducing the concept of super node. A subtle graphic layout algorithm has been applied to best display the pathway data.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1017-1026
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• 2009

The solar cell system operates by facing the sun-light. Minor cracks, static discharge, and thermal shock that can happen during production/testing phase can lead to degradation in performance during operation, since solar cells are exposed to extreme thermal/mechanical environment in space. In order to detect small cracks and internal damages in the solar cells due to thermal shocks, which are the core units of a solar cell system, expensive equipment, complicated test process, and much time are required. Therefore, a qualitative method for easily and quickly testing the 'health' of solar cell functionality is required. This dissertation describes a theoretical and technical grounds for quickly and easily evaluating the health of solar cells using electroluminescence effect of Gallium-Arsenide solar cells that are most widely used by spacecrafts in recent years. Also described in the dissertation is the technical issues and constraining factors for applying the proposed method to actual space-rated solar cell systems.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.83-90
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• 2002

Control point survey by GPS can save labor and time and can obtain result of high accuracy, but if excessive error is contained to Control point that is used to GPS relative positioning, the error that has influence on new point is propagated to various configuration. therefore poor triangulation points that are caused by careless management are existed, a product of the triangulation points still are in many case. In order to select new point, this study carried out error-analysis of surrounding-control-points and performed selective process of control point. The propriety parts of control points that are used to verify precision is identified by means of comparing existing product with or GPS product about some control points after directly observe each baseline by using EDM. As the error is analyzed by static positioning the optimum control point is selected, the precision of survey data by EDM is improved than GPS data.

• The Mathematical Education
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• v.60 no.1
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• pp.1-19
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• 2021

This study investigates students' conceptions of fractions from a measurement approach while providing a technological environment designed to support students' understanding of the relationships between quantities and adjustable units. 13 third-graders participated in this study and they were involved in a series of measurement tasks through task-based interviews. The tasks were devised to investigate the relationship between units and quantity through manipulations. Screencasting videos were collected including verbal explanations and manipulations. Drawing upon the theory of semiotic mediation, students' constructed concepts during interviews were coded as mathematical words and visual mediators to identify conceptual profiles using a fine-grained analysis. Two students changed their strategies to solve the tasks were selected as a representative case of the two profiles: from guessing to recursive partitioning; from using random units to making a relation to the given unit. Dragging mathematical objects plays a critical role to mediate and formulate fraction understandings such as unitizing and partitioning. In addition, static and dynamic representations influence the development of unit concepts in measurement situations. The findings will contribute to the field's understanding of how students come to understand the concept of fraction as measure and the role of technology, which result in a theory-driven, empirically-tested set of tasks that can be used to introduce fractions as an alternative way.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.4
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• pp.29-38
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• 2020

Purpose : The purpose of this research was to investigate the effects of barefoot walking on the sandy beach on pain intensity, disability, motor function, sleep satisfaction, and quality of life in the elderly with low back pain (LBP). Methods : A single-blinded randomized controlled trial was conducted involving 32 elderly with LBP who underwent sand walking barefoot (intervention, n=16) or with sneakers (control, n = 16). Both walking methods were carried out for 30 minutes per day, three times a week for four weeks. Pain intensity and disability were assessed using the visual analog scale and Oswestry disability index, respectively. Balance and gait were evaluated using the Berg balance scale and timed up and go test, respectively. Sleep satisfaction was quantified with the Verran and Snyder-Halpern sleep scale. Finally, quality of life was assessed through the WHO quality of life scale's abbreviated Korean version. Results : Compared with the control group, the intervention group showed significant differences in pain intensity (p=.005), disability due to LBP (p=.002), static balance ability (p=.003), dynamic balance ability (p=.002), and sleep satisfaction (p=.017). There was no significant difference in the quality of life between the two groups. Conclusion : Barefoot walking on a sandy beach is significantly effective in improving pain, disability due to LBP, balance ability, and sleep satisfaction in the elderly with LBP. Further studies with larger sample sizes and longer intervention periods must to be conducted to generalize using barefoot walking in LBP management.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.49-57
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• 2020

This paper analyzed maximized the tension not by functional restriction but by psychological response inducement to form the tension of the horror game from the point of space time view. In order that, We arranged three major situations inducing the tension in the horror game and prepared space time analysis base. Pure fiction time of game itself is applied on game time excluding the time creating the cut-scene and the game space is organized with various combination of three space types. This analysis result can help horror game design by discovering the relationship between space time structure and tension forming of the horror game. These analysis results allow us to find guidelines for the time and space design of horror games that can be flexibly linked to game events and contexts by controlling the player's dynamic/static tension and temporary/continuous tension.