• Title/Summary/Keyword: Interaction model

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Analytical Study of Geometric Nonlinear Behavior of Cable-stayed Bridges (사장교의 기하학적 비선형 거동의 해석적 연구)

  • Kim, Seungjun;Lee, Kee Sei;Kim, Kyung Sik;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1A
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    • pp.1-13
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    • 2010
  • This paper presents an investigation on the geometric nonlinear behavior of cable-stayed bridges using geometric nonlinear finite element analysis method. The girder and mast in cable-stayed bridges show the combined axial load and bending moment interaction due to horizontal and vertical forces of inclined cable. So these members are considered as beam-column member. In this study, the nonlinear finite element analysis method is used to resolve the geometric nonlinear behavior of cable-stayed bridges in consideration of beam-column effect, large displacement effect (known as P-${\delta}$ effect) and cable sag effect. To analyze a cable-stayed bridge model, nonlinear 6-degree of freedom frame element and nonlinear 3-degree of freedom equivalent truss element is used. To resolve the geometric nonlinear behavior for various live load cases, the initial shape analysis is performed for considering dead load before live load analysis. Then the geometric nonlinear analysis for each live load case is performed. The deformed shapes of each model, load-displacement curves of each point and load-tensile force curves for each cable are presented for quantitative study of geometric nonlinear behavior of cable-stayed bridges.

Interactions between pre-existing large pipelines and a new tunnel (기존 대구경 파이프라인과 신설터널간의 상호작용)

  • Jeong, Sun-Ah;Choi, Jung-In;Hong, Eun-Soo;Chun, Youn-Chul;Lee, Seok-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.2
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    • pp.175-188
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    • 2009
  • When a new tunnel is excavated by the drill and blast method near pre-existing underground structures or tunnels due to the region restricted condition such as urban area, the ground will be relaxed by the excavation. In this case, issues can be created in terms of stability of pre-existing underground structures. One of major factors determining the stability of pre-existing underground structures can be a separation distance between pre-existing underground structures and a newly excavated tunnel. The region of ground relaxation defined by the plastic zone due to new excavation can be varied by separation distance. In this study, in other to estimate an influence of new tunnel excavation in terms of separation distance on the stability of pre-existing large pipelines, two-dimensional scaled model tests using plaster were performed for six models which have a different separation distance, The results show that based on the analysis of induced displacement during tunnel construction, the displacement decreases as the separation distance between large pipeline and new tunnel is increased until the distance is 2.5 times of pipeline diameter. Beyond this point, however, the displacement has become stabilized.

A study on longitudinal interaction of resilience of adolescents in poverty: psychological resilience, social resilience, school resilience (빈곤 청소년의 적응유연성 영역간 종단적 상호관계 : 심리, 사회, 학교 영역을 중심으로)

  • Jwa, Hyun-suk
    • Korean Journal of Social Welfare Studies
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    • v.41 no.2
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    • pp.247-278
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    • 2010
  • There are three main purposes of this study: (a) to investigate the developmental trajectories of psychological resilience, social resilience, and school resilience of adolescents in poverty, (b) to identify the longitudinal relationship of three resiliences and (c) to examine the protective factors that help adolescents to develop successfully in the face of poverty. Data were drawn from Korea Youth Panel Survey(KYPS), a longitudinal panel study on Middle school students in the second grade. Sample consists of 648 adolescents in poverty who particiipated in the KYPS. Latent Growth Curve Model(LGM) was used to analyze intraindividual changes in resiliences and interindividual differences in these changes. And AMOS 7.0 and SPSS 15.0 were used. In this study, it is concluded that the resilience of adolescents in poverty is the construct that has uni-dimensionality and multi-dimensionality at the same time. Therefore, in order to improve resilience of adolescents in poverty, protective factors associated with each resilience have to be increased. Those findings have provided various theoretical and practical implications for social workers and professionals helping adolescents in poverty.

An Exploratory Study on Work Conflict Experience (직장 내 갈등경험의 과정에 대한 탐색적 연구)

  • Dawon Rhee;Sunhee Lee;Min Han
    • Korean Journal of Culture and Social Issue
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    • v.20 no.3
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    • pp.205-233
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    • 2014
  • This study aims to identify work conflicts in Korean socio-cultural context by applying grounded theory. Survey has been conducted through in-depth interviews with 11 different employees from various occupational categories. Data collected from the survey were then analyzed based on the grounded theory of Strauss and Corbin (1998), thus resulted in a paradigm model consisting of 31 categories, 63 subcategories, and 100 concepts by open coding. Axial coding was then conducted and the results were as follows. The causal condition was the 'character of an opponent'. Contextual conditions which affect the causal condition were 'situational characteristics', 'character of an opponent', 'character of oneself', and their 'mutuality'. 'Negative feeling' was the central phenomena of work conflict and action/interaction strategies were verified to be 'avoidance', 'expression', 'effort toward solving problems' and 'increasing conflict'. Intervening conditions were 'interrelation', 'intervention', and 'group/task characteristics'. The consequences were organized as 'conflict continuance', 'personnel change' and 'positive effect'. Through selective coding, 'managing with the conflict' was derived as core-category and three different types of management were classified. Ultimately, this study shows how employees work in Korea experience the work conflicts and what kinds of socio-cultural factors have influence on the work conflicts, which can supplement previous inadequate empirical research. Also, this study can provide implications and suggestions as a fundamental integrated model for the future empirical research on work conflicts.

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Design of a Decentralized Controller for Deep-sea Mining System (심해저 채광시스템에 대한 분산제어기 설계에 관한 연구)

  • Yeu, Tae-Kyeong;Park, Soung-Jea;Hong, Sup;Kim, Hyung-Woo;Choi, Jong-Su
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.3
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    • pp.252-259
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    • 2008
  • The deep-sea mining system is generally composed of surface vessel, lifting system, buffer, flexible pipe and miner. The mining system can be regarded as a large-scale system in which each subsystem is interconnected to other ones. In order to control a large-scale system, decentralized control approaches have been proposed recently. In this paper, as a basic study on application of decentralized control, firstly, the mining system was modeled in a simplified way. Lifting system and buffer were regarded as a spherical pendulum and the flexible pipe was taken as a two-dimensional linear spring connection. Based on the simplified model dynamics, the mining system can be decentralized two subsystems, the one consisting of surface vessel, lifting system and buffer, and the other, the miner. Next, this paper proposed the design of controller for each decentralized subsystem by regarding the interacting terms as disturbances. The controllers kept the constant distance between two subsystems during the miner was moving on the specified track. Finally, the efficiency of proposed controller was proven through the numerical simulation of the derived model.

Developing Measurement Items for the Service Quality of Clinical Trials based on the Brady & Cronin Model (Brady & Cronin의 모델에 기반한 임상시험 서비스 질 측정 문항 개발)

  • Go-Eun Lee;Sanghee Kim;Sue Kim;Sang Hui Chu;Jeong-Ho Seok;So Yoon Kim
    • The Journal of KAIRB
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    • v.6 no.1
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    • pp.17-31
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    • 2024
  • Purpose: This study aims to develop preliminary items for measuring the perceived service quality of clinical trials among participants and to verify content validity. Methods: This study was designed as a methodological study. A conceptual framework was established based on Brady and Cronin's hierarchical model, and preliminary items were prepared through translation-back-translation, a review of existing instruments, and in-depth interviews with clinical trial participants and clinical research coordinators. The final items were completed through content validity testing by experts and a review of items by clinical trial participants for the prepared preliminary items. Results: Through this study, a set of 58 items across four domains (quality of interaction with researchers, the physical environment, performance procedures, and performance results) and 9 components (information·education·communication, trust, respect for participant preferences, securing facilities and space, accessibility, comfortability, informed consent, coordination of care, subjective understanding of clinical trials) on the service quality of clinical trials were completed. The scale content validity index of all preliminary items was 0.96, meeting the recommended standards. The individual-item content validity index also meets the recommended criteria for most items, excluding four items. Conclusion: This study holds significance in developing items to measure the quality of clinical trial execution from the perspective of participants. By verifying the reliability and validity of these items through subsequent research, it is expected that they can be utilized as a valuable instrument to devise strategies for improving the quality of clinical trials.

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A qualitative study of community college professors' experiences in career guidance: a grounded theory approach (전문대학 교수들의 학생진로지도 경험 연구: 근거이론을 중심으로)

  • Young Jee Woo;Ji Hee Lee
    • The Korean Journal of Coaching Psychology
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    • v.7 no.3
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    • pp.1-26
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    • 2023
  • This study aims to explore how professors at community colleges are experiencing career guidance for their students, uncovering key components related to causes, phenomena, contexts, coping strategies, etc., and deriving a paradigm model to structurally. To achieve this objective, focus group interviews were conducted with a total of 23 community college professors, and the results were analyzed using the grounded theory method (Strauss & Corbin, 1998). The analysis yielded 17 categories and 31 subcategories. The central phenomenon in the career guidance of community college professors was categorized into two groups: the distress experience in career guidance and attitude changes toward interactions with students..Three categories of causal conditions contributing to the occurrence of the central phenomenon were identified: professors' lack of expertise in career guidance, students' scope and needs for career guidance, and students' low interest and expectations. Additionally, four contextual conditions corresponding to special situations or circumstances that contributed to the central phenomenon were identified: increasing demand for career guidance, excessive burden and time constraints for career guidance, lack of communication about career guidance at the institutional level, and limitations within the career guidance support system. Furthermore, the study uncovered patterns of action-interaction, mediating conditions, and outcomes. This study is expected to contribute to a better understanding of the actual experiences of college professors in the career guidance process, and to stimulate consideration of the types of support required for effective career guidance for college professors in the future.

A Study on Production and Experience of Immersive Contents based on Mixed Reality and Virtual Reality using Meta Quest Pro (메타 퀘스트 프로를 활용한 혼합현실과 가상현실 기반의 몰입형 콘텐츠 제작 및 경험에 관한 연구)

  • Jongseon Kim;Sumin Kong;Moonsu Jang;Jinmo Kim
    • Journal of the Korea Computer Graphics Society
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    • v.30 no.3
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    • pp.71-79
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    • 2024
  • This study organizes an immersive content production pipeline using Meta Quest Pro as an asymmetric virtual environment where mixed reality(MR) and virtual reality(VR) users participate and interact together. Based on this, we compare and analyze the differences in presence and experience provided by the user's experience environment. The proposed production process is to build an integrated development environment using Meta XR All-in-One SDK based on the Unity 3D engine. This includes a real space analysis method using the Room Model function for organic and accurate interaction between MR users in the real world and VR users based on virtual scenes at fixed coordinates. Based on this, this study produces immersive table tennis content where MR and VR users participate together. Finally, we conduct survey experiments to compare and analyze the effects of differences in platform and participation methods on presence and experience using the produced content. As a result, this study confirmed that all users can feel a satisfactory presence and experience within an experience environment where real and virtual correspond.

The Effect of E-SERVQUAL on e-Loyalty for Apparel Online Shopping (재망상복장구물중전자(在网上服装购物中电子)E-SERVQUAL 대전자충성도적영향(对电子忠诚度的影响))

  • Kim, Eun-Young;Jackson, Vanessa P.
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.4
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    • pp.57-63
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    • 2009
  • With an exponential increase in electronic commerce (e-commerce), marketers are attempting to gain a competitive advantage by emphasizing service quality and post interaction service aspects, which leads to customer satisfaction or behavioral consequence. Particularly for apparel, service quality is one of the key determinants in encouraging customer e-loyalty, and hence the success of apparel retailing in the context of electronic commerce. Therefore, this study explores e-service quality (E-SERVQUAL) factors and their unique effects on e-loyalty for apparel online shopping based on Parasuraman et al' s (2005) framework. Specific objectives of this study are to identify underlying dimension of E-SERVQUAL, and analyze a structural model for examining the effect of E-SERVQUAL on e-loyalty for online apparel shopping. For the theoretical framework of service quality in the context of online shopping, literatures on traditional and electronic service quality factors were comparatively reviewed, and two aspects of core and recovery services were identified. This study hypothesized that E-SERVQUAL has an effect on e-loyalty; customer satisfaction has a positive effect on e-service loyalty for apparel online shopping; and customer satisfaction mediates in the effect of E-SERVQUAL on e-loyalty for apparel online shopping. A self-administered questionnaire was developed based on literatures. A total of 252 usable questionnaires were obtained from online consumers who had purchase experience with online shopping for apparel products and reside in standard metropolitan areas, in the United States. Factor analysis (e.g., exploratory, confirmatory) was conducted to assess the validity and reliability and the structural equation model including measurement and structural models was estimated via LISREL 8.8 program. Findings showed that the E-SERVQUAL of shopping websites for apparel consisted of five factors: Compensation, Fulfillment, Efficiency, System Availability, and Responsiveness. This supports Parasuraman (2005)'s E-S-QUAL encompassing two aspects of core service (e.g., fulfillment, efficiency, system availability) and recovery related service (e.g., compensation, responsiveness) in the context of apparel shopping online. In the structural equation model, there are five exogenous latent variables for e-SERVQUAL factors; and two endogenous latent variables (e.g., customer satisfaction, e-loyalty). For the measurement model, the factor loadings for each respective construct were statistically significant and were greater than .60 and internal consistency reliabilities ranged from .85 to .88. In the estimated structural model of the e-SERVEQUAL factors, the system availability was found to have direct and positive effect on e-loyalty, whereas efficiency had a negative effect on e-loyalty for apparel online shopping. However, fulfillment was not a significant predictor for explaining consequences of E-SERVQUAL for apparel online shopping. This finding implies that perceived service quality of system available was likely to increase customer satisfaction for apparel online shopping. However, it was not supported that e-loyalty was determined by service quality, because service quality has an indirect effect on e-loyalty (i.e., repurchase intention) by mediating effect of value or satisfaction in the context of online shopping for apparel. In addition, both compensation and responsiveness were found to have a significant impact on customer satisfaction, which influenced e-loyalty for apparel online shopping. Thus, there was significant indirect effect of compensation and responsiveness on e-loyalty. This suggests that the recovery-specific service factors play an important role in maximizing customer satisfaction levels and then maintaining customer loyalty to the online shopping site for apparel. The findings have both managerial and research implications. Fashion marketers can establish long-term relationship with their customers based on continuously measuring customer perceptions for recovery-related service quality, such as quick responses to problem and returns, and compensation for customers' problem after their purchases. In order to maintain e-loyalty, recovery services play an important role in the first choice websites for consumers to purchase clothing. Given that online consumers may shop anywhere, a marketing strategy for improving competitive advantages is to provide better service quality, maximize satisfaction, and turn to creating customers' e-loyalty for apparel online shopping. From a researcher's perspective, there are some limitations of this research that should be considered when interpreting its findings. For future research, findings provide a basis for the further study of this important topic along both theoretical and empirical dimensions. Based on the findings, more comprehensive models for predicting E-SERVQUAL's consequences can be developed and tested. For global fashion marketing, this study can expand to a cross-cultural approach into e-service quality for apparel by including multinational samples.

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Evaluation of Tensions and Prediction of Deformations for the Fabric Reinforeced -Earth Walls (섬유 보강토벽체의 인장력 평가 및 변형 예측)

  • Kim, Hong-Taek;Lee, Eun-Su;Song, Byeong-Ung
    • Geotechnical Engineering
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    • v.12 no.4
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    • pp.157-178
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    • 1996
  • Current design methods for reinforced earth structures take no account of the magnitude of the strains induced in the tensile members as these are invariably manufactured from high modulus materials, such as steel, where straits are unlikely to be significant. With fabrics, however, large strains may frequently be induced and it is important to determine these to enable the stability of the structure to be assessed. In the present paper internal design method of analysis relating to the use of fabric reinforcements in reinforced earth structures for both stress and strain considerations is presented. For the internal stability analysis against rupture and pullout of the fabric reinforcements, a strain compatibility analysis procedure that considers the effects of reinforcement stiffness, relative movement between the soil and reinforcements, and compaction-induced stresses as studied by Ehrlich 8l Mitchell is used. I Bowever, the soil-reinforcement interaction is modeled by relating nonlinear elastic soil behavior to nonlinear response of the reinforcement. The soil constitutive model used is a modified vertsion of the hyperbolic soil model and compaction stress model proposed by Duncan et at., and iterative step-loading approach is used to take nonlinear soil behavior into consideration. The effects of seepage pressures are also dealt with in the proposed method of analy For purposes of assessing the strain behavior oi the fabric reinforcements, nonlinear model of hyperbolic form describing the load-extension relation of fabrics is employed. A procedure for specifying the strength characteristics of paraweb polyester fibre multicord, needle punched non-woven geotHxtile and knitted polyester geogrid is also described which may provide a more convenient procedure for incorporating the fablic properties into the prediction of fabric deformations. An attempt to define improvement in bond-linkage at the interconnecting nodes of the fabric reinforced earth stracture due to the confining stress is further made. The proposed method of analysis has been applied to estimate the maximum tensions, deformations and strains of the fabric reinforcements. The results are then compared with those of finite element analysis and experimental tests, and show in general good agreements indicating the effectiveness of the proposed method of analysis. Analytical parametric studies are also carried out to investigate the effects of relative soil-fabric reinforcement stiffness, locked-in stresses, compaction load and seepage pressures on the magnitude and variation of the fabric deformations.

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