• Earthquakes and Structures
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• v.20 no.2
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• pp.133-148
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• 2021

The paper presents a simplified force-based seismic design procedure for the preliminary design of steel haunch retrofitting for the seismic upgrade of deficient RC frames. The procedure involved constructing a site-specific seismic design spectrum for the site, which is transformed into seismic base shear coefficient demand, using an applicable response modification factor, that defines base shear force for seismic analysis of the structure. Recent experimental campaign; involving shake table testing of ten (10), and quasi-static cyclic testing of two (02), 1:3 reduced scale RC frame models, carried out for the seismic performance assessment of both deficient and retrofitted structures has provided the basis to calculate retrofit-specific response modification factor Rretrofitted. The haunch retrofitting technique enhanced the structural stiffness, strength, and ductility, hence, increased the structural response modification factor, which is mainly dependent on the applied retrofit scheme. An additional retrofit effectiveness factor (ΩR) is proposed for the deficient structure's response modification factor Rdeficient, representing the retrofit effectiveness (ΩR=Rretrofitted /Rdeficient), to calculate components' moment and shear demands for the retrofitted structure. The experimental campaign revealed that regardless of the deficient structures' characteristics, the ΩR factor remains fairly the unchanged, which is encouraging to generalize the design procedure. Haunch configuration is finalized that avoid brittle hinging of beam-column joints and ensure ductile beam yielding. Example case study for the seismic retrofit designs of RC frames are presented, which were validated through equivalent lateral load analysis using elastic model and response history analysis of finite-element based inelastic model, showing reasonable performance of the proposed design procedure. The proposed design has the advantage to provide a seismic zone-specific design solution, and also, to suggest if any additional measure is required to enhance the strength/deformability of beams and columns.

• Journal of the Earthquake Engineering Society of Korea
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• v.26 no.1
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• pp.13-22
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• 2022

This study proposes a low-cycle fatigue life derived from measurement points on pipe elbows, which are components that are vulnerable to seismic load in the interface piping systems of nuclear power plants that use seismic isolation systems. In order to quantitatively define limit states regarding leakage, i.e., actual failure caused by low-cycle fatigue, in-plane cyclic loading tests were performed using a sine wave of constant amplitude. The test specimens consisted of SCH40 6-inch carbon steel pipe elbows and straight pipes, and an image processing method was used to measure the nonlinear behavior of the test specimens. The leakage lines caused by low-cycle fatigue and the low-cycle fatigue curves were compared and analyzed using the relationship between the relative deformation angles, which were measured based on each of the measurement points on the straight pipe, and the moment, which was measured at the center of the pipe elbow. Damage indices based on the combination of ductility and dissipation energy at each measurement point were used to quantitatively express the time at which leakage occurs due to through-wall cracking in the pipe elbow.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.91-103
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• 2023

This study aims to investigate the dynamic fracture characteristics of rocks and rock-like materials subjected to the Nonex Rock Cracker (NRC), a vapor pressure crushing agent that produces vapor pressure by instantaneously vaporizing a liquid mixture crystallized through the thermite reaction. Furthermore, the study seeks to develop an analytical technique for predicting the fracture pattern. A dynamic fracture test was performed on a PMMA block, an artificial brittle material, using the NRC. High-speed cameras and dynamic pressure gauges were employed to capture the moment of vapor pressure generation and measure the vapor pressure-time history, respectively. The 2-dimensional Dynamic Fracture Process Analysis (2D DFPA) was used to simulate the fracture process caused by the vapor pressure, with the applied pressure determined based on the vapor pressure-time history. The proposed analytical method was used to examine various fracture patterns with respect to granite material and high-performance explosives.

• Korean Journal of Child Education & Care
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• v.18 no.2
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• pp.1-15
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• 2018

The purpose of this study was to determine if teachers' perception of professionalism, teaching intentions, and the quality of teacher-child interactions differed by teachers' education and career and how those variables were associated with one another. It was conducted in 50 teachers who were in charge of two- to five-year-olds at 22 national/public, private, and employer-supported childcare centers in Seoul and Gyeonggi Province. Arnett's (1989) Caregiver Interaction Scale (CIS) translated by Choi and Shin (2015) was used to measure the quality of teacher-child interactions, and the Current Status and Self-Desire for Professional Competence scale developed by Wang (2005) and translated and revised by Jeong (2016) was used to measure a teacher's perception of professionalism. The Teaching Intention Scale (TIS) developed by Wilcox-Herzog and Ward (2004) and translated and revised by the researcher was used to measure teaching intentions. The researcher and the research assistant personally visited the centers to observe the teachers for the quality of teacher-child interactions and a questionnaire for teachers was used to determine a teacher's perception of professionalism and teaching intentions. For data analysis, t-test and Pearson's product-moment correlation analysis were performed on the basis of the questions. The results of this study can be summarized as follows: First, the quality of teacher-child interactions differed insignificantly by education or career. Second, teacher's perception of professionalism differed significantly by teachers' career but differed insignificantly by education: the longer career, the better perception of professionalism. Third, teaching intentions differed insignificantly by education or career. Fourth, teachers with better perception of professionalism showed higher quality of teacher-child interaction. Fifth, The higher level of teaching intentions teachers showed the more sensitive interactions they made with children.

• Culinary science and hospitality research
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• v.22 no.7
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• pp.267-280
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• 2016

Customer Experience Management (CEM) appeared as a complementary solution to overcome CRM limitations. CEM enhances profitability through building long-term relations with customers by understanding their experiences. This study aims at investigating the impact of customer experience quality on the willingness to pay more through customer satisfaction in the hotel businesses. The survey for this study was carried out on customers who had domestic hotel experience s within the last 6 months. Out of the 306 questionnaires retrieved, 225 valid responses were used for the empirical analysis that utilizied the statistical package programs SPSS 18.0 and AMOS 18.0. The research findings may be summarized as follows. First, as an outcome of the research hypothesis that each component of customer experience management would influence satisfaction, 'the peace of mind' & 'the moment of truth' were shown to have a significantly positive (+) impact on it. On the other hand, 'the product experience' was shown not to significantly influence it in a positive (+) way. Second, as an outcome of the research hypothesis that satisfaction would influence willingness to pay more. From the findings of the study, theoretical implications are as follows. It can be predicted that customer experience management will likely make customers more profitable because customers are willing to pay more with a sense of loyalty built through satisfaction of the hotel industry. In the practical implications, the dimension of experience quality examined by the study can be used as an index to measure and manage customer experience in the hotel industry.

• Journal of The Korean Association For Science Education
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• v.39 no.5
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• pp.599-611
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• 2019

The purpose of this study is to analyze the systems thinking level of pre-service teachers using rubrics of evaluating systems thinking. For this purpose, systems thinking level model, which can be applied to education or science education, was selected through literature analysis. Eight pre-service teachers' systems thinking were investigated through the systems thinking analysis tool used in domestic research. The systems thinking presented by the pre-service teachers were transformed into the box type causal map using Sibley et al. (2007). Two researchers analyzed the systems thinking using rubrics of evaluating systems thinking. For data analysis, quantitative analysis was performed through correlation analysis using SPSS. In addition, the qualitative analysis of the box type causal map was conducted and the consistency with the quantitative analysis results was verified. The results indicated that the correlation between the 5-Likert systems thinking measurement instrument and the rubrics score was highly correlated with the Pearson product-moment of .762 (p <.05). In the hierarchical correlation of the systems thinking level, the STH model was analyzed with a very high correlation with the Pearson product-moment of .722~.791, and 4-step model was analyzed .381~.730. The qualitative analysis suggested the concept to be included in the low level of system thinking, the higher the level, the less the concept that is presented properly. In conclusion, the level of systems thinking can be derived as a result of research that there is clearly, a hierarchical part. Based on the results of this study, it is necessary to develop a systems thinking level model applicable to science education and develop and validate items that can measure the level of systems thinking.

• Journal of Gifted/Talented Education
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• v.21 no.1
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• pp.57-81
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• 2011

The purpose of this study was to explore the quality of life of musically talented students as measured by their external experiences (e.g., activities, companions) and internal experiences (e.g., flow, emotion). The participants in this study were 33 musically talented students (10 males, 23 females) aged 13 to 19. Study data were collected for 7 consecutive days using the Experience Sampling Method (ESM), which employs a cellular-phone as a signaling device. The results were as follows: First, in response to the 1625 random signals, musically talented students reported that 40.9% of their time was spent on productive activities. An additional 33.4% of time was used for maintenance activities and the rest of their time was spent on leisure/social activities. Also, musically talented students reported that 48.5% of their time was spent alone. When they were alone, they spent a lot of time engaging in productive activities (44.3%). Second, in order to measure the flow of their life, two methods were used. One used a 4-channel flow model (i.e. apathy, boredom, flow, anxiety) and the other used 8 dimensions and conditions of the flow experience (i.e. concentration, self-consciousness disappears, action and awareness merge, distorted sense of time, freedom from worry about failure, clear goals, immediate feedback, balance between challenges and skills). According to the former, when engaged in music-related activities, musically talented students usually reported flow (54.0%), while they felt apathy (41.3%) for daily routines activities. According to the latter method, musically talented students experienced flow for most productive activities, while they experienced flow least for maintenance activities. Emotional variables of ESF are comprised of 10 semantic scales (i.e. happy-sad, strong-weak, active-passive, sociablelonely, proud-ashamed, involved-detached, excited-bored, clear-confused, relaxed-worried, cooperative-competitive). Musically talented students reported experiencing the most positive emotion for social activities and experiencing the most negative emotion for maintenance activities. Results of this study assert that musically talented students had to trade off immediate enjoyment for developing their special gifts. They could not afford as much time for socializing with friends, and they had to spend more time alone compared to their peers without such gifts. Consequently, they were found to deprive themselves of the spontaneous good times that teenagers usually thrive on. They were helped in this respect by their autotelic personality traits, especially their strong need for achievement and endurance. The downside, however, is that the moment-to-moment quality of their moods suffered. The argument concerning musically talented students applies for all adolescents. The choices that talented students must make between immediate gratification and long-term development, and between solitude and companionship, are the same choices every young person must make, regardless of her or his level of talent. All of us have gifts that are potentially useful and worthy of being appreciated. But to develop these latent talents we must cultivate them, and this takes time and the investment of mental energy. The lifestyle that musically talented students develop can show us some of the choices all of us must make in order to cultivate our gifts.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.183-189
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• 2014

Purpose : Intravenous contrast medium is a substance used to enhance the contrast of normal tissues or malignant tissues within the body. For this reason, intravenous contrast media have been extensively used form treatment-planning CT. However, when the patient is receiving proton therapy, there is no contrast medium in that moment. In this study, evaluate the influence of intravenous contrast medium on proton range and Spread-Out Bragg peak(SOBP) in Treatment Planning System(TPS). Materials and Methods : Hounsfield Unit(HU) value were measured by 20 liver cancer patients with phase change. and evaluate the proton range and SOBP on 5 liver proton treatment plan. By using the hand made water phantom measure the proton range and SOBP on proton treatment plan with changing HU and Depth. Results : Changing value(Pre contrast, Arterial phase, Portal phase) in liver cancer patient were ($58{\pm}5.7$, $75{\pm}9.5$, $117{\pm}14.6$ for liver tissue) and ($40{\pm}6.1$, $279{\pm}49.0$, $154{\pm}22.8$ for aorta), respectively. The mean difference of range was 2.5mm and SOBP was 1.4mm according to HU change. In phantom study, proton range was shorter and SOBP was narrowed with increasing HU. Conclusion : We verify that HU change lead to range and SOBP change in TPS. Additional study is required to verify that change of HU make range and SOBP be changed in actual substance.

• Journal of dental hygiene science
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• v.12 no.4
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• pp.437-442
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• 2012

The current research examines the aching part and the muscle activity that happens during scaling practice subject to 20 dental hygienic students and therefore propose a basic data according to the working attitude of the Dental Hygienist. During the scaling we used the free EMG (BTS Inc., Milan, Italy) to measure the muscle activity, and in order to check the musculoskeletal pain area we used the Nordic-style questionnaire, and the measured research results are as following: At the moment of scaling according to posture the occurrence of the pain showed no difference among the groups elbow, back, leg, knee, ankle/foot but in the neck, shoulder, wrist/hand, waist showed a high difference in the degree of pain according to posture. Results from measuring the muscular activity according to posture, in the group that had a good posture, the trapezius and brachial muscles showed a change according to time, and in the group that had a bad posture a high muscle activity was shown in larynx, trapezius and brachial muscles. In the muscle activity, the changing aspect between the two parts, the group that fulfilled a scaling in a good posture showed a low muscle activity, but in the group that fulfilled the scaling in a bad posture the muscle activity increased excessively. Therefore we examined that when fulfilling a scaling maintaining a bad posture can help in using more effectively the activity of the muscle, in the future I think there is a need to raise the office efficiency by subjecting to dental hyginiest that are in the clinics and performing experiments.

• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.73-81
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• 2018

In this paper, we present a motion-driven rowing simulation framework that allows multiple players to row a boat together by their harmonized movements. In the actual rowing game, it is crucial for the players to synchronize their rowing with respect to time and pose so as to accelerate the boat. Inspired by this interesting feature, we measure the motion similarity among multiple players in real time while they are doing rowing motions and use it to control the velocity of the boat in a virtual environment. We also employ game components such as catching an item which can accelerate or decelerate the boat depending on its type for a moment once it has been obtained by synchronized catching behaviors of the players. By these components, the players can be encouraged to more actively participate in the training for a good teamwork to produce harmonized rowing movements Our methods for the motion recognition for rowing and item catch require the tracking data only for the head and the both hands and are fast enough to facilitate the real-time performance. In order to enhance immersiveness of the virtual environment, we project the rowing simulation result on a wide curved screen.