• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1486-1491
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• 2010

Recently, the frequency and magnitude of the earthquake have increased. The structural safety of the public facilities such as bridges and tunnels etc. which were not concerned for earthquake resistant design are increased. Fiber reinforcement polymer that has been frequently studied for seismic retrofit has advantage as seismic reinforcement material, but it has disadvantage of the brittleness. Therefore, the investigation of safety and seismic reinforcement are required. In this study, new FRP-ductile material layered composites proposed to seismic performance reinforced of subway tunnel. Tensile test of FRP-ductile material layered composites showed that Maximum tensile force of FRP-ductile using Aluminum is similar to existing FRP reinforcement material and maximum strain was increased. In case of application of domestic subway tunnel which need ductility, layered composites of FRP-Aluminum is estimated effectively for increase of seismic performance.

• Korean Journal of Optics and Photonics
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• v.15 no.3
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• pp.241-247
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• 2004

The collimator is necessary for the assembly and evaluation of high resolution satellite telescope. Traditionally, the off-axis paraboloid has been used as a collimator. However, it has some disadvantages in that it can suffer from air turbulence when the focal length of a collimator is long, which may result in some error in the measurement. In contrast, since the Cassegrain type collimator folds the beam, it occupies smaller space compared to the off-axis paraboloid for the same focal length. This can reduce the air turbulence, which can improve the measurement accuracy. In this paper, we explain the process of design and manufacturing of a diameter 450 mm Cassegrain type collimator, to evaluate the diameter 300 mm satellite telescope. After assembly of primary and secondary mirrors, the final wavefront error of the collimator was 0.07λ(λ=633 nm), which is the diffraction limit.

• Health Policy and Management
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• v.24 no.4
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• pp.312-321
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• 2014

Background: To evaluate the quality of chronic care provided by public health centers located in a South Korean metropolitan city using a modified Assessment of Chronic Illness Care (ACIC). Methods: We conducted self-evaluation surveys and collected data using a modified ACIC from twenty five public health centers. Cultural validity of the original ACIC was examined by the public health and nursing science experts. Based on expert reviews, cognitive interviews, pre-test results, five items of the original ACIC that were not relevant were deleted. The response scale was changed from twelve-point Likert scale to Guttman scale but its scoring system was maintained. Results: Eighty eight percent of public health centers in this study reported that their overall quality of chronic care was at a limited or basic level. About 68% of the centers reported that the organization was as reasonably good or fully developed to provide chronic care. On the other hand, 96% of the public health centers reported that the clinical information system was at a very limited or basic support level. The decision support, the integration of Chronic Care Model components, the delivery system design, the community linkages, and the self-management support were evaluated as limited or basic level of support by more than half of the public health centers, respectively. Conclusion: In a metropolitan area of South Korea, quality of chronic care in public health centers was not found to reach acceptable levels of services. It is critical to enhance the quality of chronic care in public health centers.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.4
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• pp.9-17
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• 1994

It is well recognized recently that ultrasonic technique is one of the most widely used methods of nondestructive evaluation to characterize material properties of nonconventional engineering materials. Therefore it is very important to understand physical phenomenon on propagation behavior of elastic wave in these materials, which is directly associated with ultrasonic signals in the test. In this study, the theoretical analysis on multi-scattering of harmonic elastic wave due to the particulate with interface between matrix and fiber in metal matrix composites(MMCs) was done on the basis of Lax's quasi-crystalline approximation and extinction theorem. SiC particulate (SiCp) reinforced A16061-T6 composite material was chosen for this analysis. From this analysis, frequency dependences of phase velocity and amplitude attenuation of effective plane wave due to the change of volume fraction of SiC particulate were clearly found. It was also shown that the interface condition between matrix and fiber in MMCs gives a direct effect on the variation of phase velocity of plane wave in MMCs.

• Journal of Korean Society of Steel Construction
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• v.27 no.2
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• pp.181-193
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• 2015

High-frequency staircases are widely used nowadays to meet aesthetics and functionality needed in modern architecture. Unfortunately, no design guide is available in domestic practice to predict response or evaluate the vibration performance of high-frequency staircases. SCI-P354 published by the Steel Construction Institute of UK provides the formula for effective impulsive force. However, this formula was shown to overestimate the response of high-frequency staircases excited by fast ascending and descending over 2.2Hz pace frequency because it was developed based on the walking test in a slow pace frequency. This study proposes a semi-analytical formula to predict the response of stiff staircases based on analytical and experimental studies of response acceleration for various walking frequencies covering 1.4~4.5Hz.

• Journal of Korean Society of Steel Construction
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• v.23 no.1
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• pp.61-72
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• 2011

In this study, the structural details of steel girder-abutment joints with shear connectors and tie bars were suggested to improve the rigid behavior and crack-resisting capacity of the joints in integral bridges. Experimental loading tests of steel girder-abutment joint specimens with the proposed and empirically constructed structural details were carried out, and the capacities and behavioral characteristics of the joints were evaluated through loading tests. Based on the results of the loading tests, it was estimated that all types of tested joints can be applied to the steel girder-abutment joints because they have sufficient stiffness and crack-resisting capacity under the required design and yield loads. According to the initial stiffness, crack propagations, and load-strain relationships, however, the joints with shear connectors and tie bars showed better structural behaviors compared to the empirically constructed joint.

• The Korean Journal of Food And Nutrition
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• v.18 no.2
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• pp.115-126
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• 2005

This Quantitative study was investigated to examine the relationship between self-esteem on body image and disordered eating patterns in some university students. This study used a cross-sectional study design. Total 347 students participated in this study (88 male and 259 female) among three universities. The assessment of eating disorder was conducted by Eating Attitudes Test (EAT-26), a score of >or=20 identified individuals likely have an eating disorder, including anorexia nervosa and bulimia nervosa. Ideal body weight and current body weight were completed with self-evaluation. A distorted body image was independently related to the eating problem in the Logistic regression analysis. There were stronger relationships between their EAT-26 scores and their expected weight changes and weight control behaviors. Compared with the men, women showed highly wishful to loss for current body weight. In the relationship between score of EAT-26 and BMI distance by sex, levels of eating disorder showed linearly elevated toward increased BMI distance (Ideal BMI-Current BMI) (F-value=18.794, p<0.0001) in women, but there were not significant in men (F-value=2.028, p>0.05). In estimate on state-trait anxiety inventory according to quartile of BMI distance by sex, levels of state-trait anxiety were not significant difference by degree of body dissatisfaction in all sex. In addition, higher distorted body image was significantly increased numbers of weight control method and experience of side effects in female, but there were not showed significant relation between two variables in male.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.111-117
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• 2017

The National Competency Standards (NCS) was designed to implement a competence-based society and solve the problem of inconsistency between the industrial field and education, training, and certification system. This study designed and developed the Korean NCS core vocational competence system, in accordance with the NCS, as an infrastructure to solve fundamental problems such as re-education and the social costs that are incurred in the workplace. Further, this study designed and developed standard indicators to evaluate the technical performance of the system for the global advancement of the Korean NCS core vocational competence system. The NCS core vocational competence system has been developed as an appropriate response type for multiple devices such as computers, tablet PCs, and cellular phones. For the global advancement of the Korean NCS core vocational competence system, this study designed and developed 10 performance evaluation indicators in accordance with 10 global standards, such as linkage-target operating system, interface protocol, packet format, encryption, class component, simultaneous access number, supervisor-to-testtaker response speed, server-to-admin response speed, auto-recovery speed for test answers, and real-time answer transmission speed.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.603-613
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• 2015

In current design codes, minimum shear reinforcement is required for reinforced concrete flexural members, and the use of steel fiber reinforced concrete is permitted to replace the minimum shear reinforcements. In the present study, to estimate the effects of shear reinforcements and fibers on shear strength, simply supported beams were tested under transverse loading. The test results showed that the shear strength was significantly increased by the use of fibers. Particularly, the effect of fiber reinforced concrete was pronounced when high-strength concrete was used. The performance of fiber reinforced concrete for minimum shear reinforcement was evaluated using results of the present study and existing tests.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.239-243
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• 2017

PURPOSE. The purpose of this study is to compare single and three-unit metal frameworks that are produced by micro-stereolithography. MATERIALS AND METHODS. Silicone impressions of a selected molar and a premolar were used to make master abutments that were scanned into a stereolithography file. The file was processed with computer aided design software to create single and three-unit designs from which resin frameworks were created using micro-stereolithography. These resin frameworks were subjected to investment, burnout, and casting to fabricate single and three-unit metal ones that were measured under a digital microscope by using the silicone replica technique. The measurements were verified by means of the Mann-Whitney U test (${\alpha}=.05$). RESULTS. The marginal gap was $101.9{\pm}53.4{\mu}m$ for SM group and $104.3{\pm}62.9{\mu}m$ for TUM group. The measurement of non-pontics in a single metal framework was $93.6{\pm}43.9{\mu}m$, and that of non-pontics in a three-unit metal framework was $64.9{\pm}46.5{\mu}m$. The dimension of pontics in a single metal framework was $110.2{\pm}61.4{\mu}m$, and that of pontics in a three-unit metal framework was $143.7{\pm}51.8{\mu}m$. CONCLUSION. The marginal gap was smaller for the single metal framework than for the three-unit one, which requires further improvement before it can be used for clinical purposes.