• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.2
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• pp.177-184
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• 1998

The equation of motion on the vehicle-bridge system is established as the simultaneous equations which are combined the equation of vehicle and bridge by the interaction elements. A vehicle element is modeled as lumped masses supported by springs and dashpots, and a bridge element with pavement roughness is modeled as beam elements. An interaction element is defined to consist of a bridge element and the suspension units of the vehicle resting on the element. By the dynamic condensation method, the degrees of the freedom are eliminated, and compared with all the degrees of freedom on the bridge, the efforts of calculation is decreased. Thus, although a very small computational error is occured, the present technique appears to be computationally more efficient. It is particularly suitable for the simulation of bridges with a series of vehicles moving on the deck.

• Journal of Korean Association for Spatial Structures
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• v.22 no.3
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• pp.41-48
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• 2022

The purpose of this study is to evaluate seismic performances of a modular house system developed by a simple 4-clip fastening method and double metal assembly made of lightweight metals. In order to evaluate structural and non-structural seismic performances of the system. Shaking table test was carried out with full-scale modular units, and a nonlinear pushover analysis was performed to obtain suitable seismic responses for story drifts, displacements, force resistances and dynamic properties of the system. Through 3D analysis and shaking table test, the current method of lightweight modular metal unit assembly and systems with seismic performance of a 4-clip fastening type modular house were demonstrated safe and effective to seismic design.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.435-442
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• 2017

A lateral load resisting system is a necessary structural element for the mid- to high-rise modular buildings and concrete cores are known as the most typical lateral load resisting systems in 10- to 20-story modular buildings. It is difficult to construct a concrete core simultaneously with the installation and finishing work of modular units because concrete placed using wet methods might contaminate or destroy the modular unit. Therefore, we have developed a hybrid PC (precast concrete) panel construction method that can construct a concrete core together with the installation of modular units. The hybrid PC panel is a load-bearing element in which a pair of C-shaped beams are combined at the top and bottom of a concrete wall. Concrete cores can be constructed by dry method to connect the hybrid PC panels with bolts. In this study, the details and connection of hybrid PC panels are improved to have the lateral performance comparable to reinforced concrete structural walls and are verified through FE analysis.

• Journal of Practical Engineering Education
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• v.13 no.3
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• pp.533-544
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• 2021

The purpose of this study is to investigate the structural relationship among psychological contract violation, job burnout, and turnover intention of MZ generation workers in small and medium enterprises. The sample collected through online and offline was 144 units of millennial generation and 140 units of Z generation. The results of analysis using structural equations showed that psychological contract violation had a positive (+) effects on turnover intention and job burnout, and job burnout also had a positive (+) effect on turnover intention. In the relationship between psychological contract violation and turnover intention, job burnout had a partial mediating effect.

• Journal of Korean Critical Care Nursing
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• v.17 no.1
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• pp.30-43
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• 2024

Purpose : Post-intensive care syndrome (PICS) is characterized by a constellation of mental health, physical, and cognitive impairments, and is recognized as a long-term sequela among survivors of intensive care units (ICUs). The objective of this study was to explore the impact of intensive care experience (ICE) on the development of PICS in individuals surviving critical care. Methods : This secondary analysis utilized data derived from a prospective, multicenter cohort study of ICU survivors. The cohort comprised 143 survivors who were enrolled between July and August 2019. The original study's participants completed the Korean version of the ICE questionnaire (K-ICEQ) within one week following discharge from the ICU. Of these, 82 individuals completed the PICS questionnaire (PICSQ) three months subsequent to discharge from hospital. The influence of ICE on the manifestation of PICS was examined through Partial Least Squares-Structural Equation Modeling (PLS-SEM). Result : The R² values of the final model ranged from 0.35 to 0.51, while the Q² values were all greater than 0, indicating adequacy for prediction of PICS. Notable pathways in the relationship between the four ICE dimensions and the three PICS domains included significant associations from 'ICE-awareness of surroundings' to 'PICS-cognitive', from 'ICE-recall of experience' to 'PICS-cognitive', and from 'ICE-frightening experiences' to 'PICS-mental health'. Analysis found no significant moderating effects of age or disease severity on these relationships. Additionally, gender differences were identified in the significant pathways within the model. Conclusion : Adverse ICU experiences may detrimentally impact the cognitive and mental health domains of PICS following discharge. In order to improve long-term outcomes of individuals who survive critical care, it is imperative to develop nursing interventions aimed at enhancing the ICU experience for patients.

• Women's Health Nursing
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• v.15 no.3
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• pp.231-241
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• 2009

Purpose: This study was designed to construct and test a structural equation model for life satisfaction in grandmothers who were parenting grandchildren Methods: Grandmothers assuming part-time parenting responsibilities for grandchildren were recruited in four cities in South Korea. They were asked to complete a questionnaire through face to face interviews or self reports, and 248 data units were analyzed with Structural Equation Modeling. Results: Model fit indices for the final model revealed a fit at an excellent level, and all of the 12 paths were statistically significant explaining 51% of the variance. Predictors of life satisfaction in the final model were parenting efficacy, perceived health status, parenting stress, amount of parenting, and demographic factors. The new findings of this study were as follows: First, the satisfaction with life of part-time parenting grandmothers was less than that of non-parenting grandmothers. Second, parenting stress and parenting efficacy revealed determinants to life satisfaction. Third, motivation of parenting and amount of parenting affect both parenting stress and parenting efficacy. Conclusion: The value of parenting and the grandmother-adult children relationship quality should also be considered in developing a grandmothers' educational program, because these are the factors which strengthen parenting efficacy and alleviate parenting stress.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.419-424
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• 2002

The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality In February, 1995. Many experiments should be safely performed to activate the utilization of the HANARO. A flow simulation facility is being developed for the endurance test of reactivity control units for extended life times and the verification of structural integrity of those experimental facilities prior to loading in the HANARO. This test facility is composed of three major parts; a half-core structure assembly, flow circulation system and support system. The flow circulation system is composed of a circulation pump, a core flow pipe, a core bypass flow pipe and instruments. The system is to be filled with de-mineralized water and the flow should be met the design flow to simulate similar flow characteristics in the core channel of the half-core test facility to the HANARO. This paper, therefore, describes an analytical analysis to study the flow behavior of the system. The computational flow analysis has been performed for the verification of system pressure variation through the three-dimensional analysis program with standard k-$\epsilon$ turbulence model and for the verification of the structural piping integrity through the finite element method. The results of the analysis are satisfied the design requirements and structural piping integrity of flow circulation system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.24-29
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• 2007

Low-speed Diesel Engine, 7K60MC-S, in Power Plant have been experienced high vibration frequently since these units were completed the construction works, but they did not have any fundamental vibration solutions up to date. Therefore, several vibration tests and analyses are conducted to identify the root cause of high vibration and to suggest the optimal countermeasures for diesel engine. The 9.25Hz & 25.4Hz vibrations have been observed on main body during operation. The magnitude of engine upper structural vibration is generally similar in horizontal transverse direction. However, differences in the 'Fore' and 'After' vibration magnitude at 9.25Hz occurs due to the inertia momentum added by SCR duct system with the same vibration phase angle. It is analyzed that the excess structural vibration be occurred when the natural frequency of engine body is accessed the exciting sources due to the explosion pressure and the discharge pulsation of 7 cylinders in resonance range.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.393-408
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• 2004

There exists a clear need to monitor the performance of civil structures over their operational lives. Current commercial monitoring systems suffer from various technological and economic limitations that prevent their widespread adoption. The wires used to route measurements from system sensors to the centralized data server represent one of the greatest limitations since they are physically vulnerable and expensive from an installation and maintenance standpoint. In lieu of cables, the introduction of low-cost wireless communications is proposed. The result is the design of a prototype wireless sensing unit that can serve as the fundamental building block of wireless modular monitoring systems (WiMMS). An additional feature of the wireless sensing unit is the incorporation of computational power in the form of state-of-art microcontrollers. The prototype unit is validated with a series of laboratory and field tests. The Alamosa Canyon Bridge is employed to serve as a full-scale benchmark structure to validate the performance of the wireless sensing unit in the field. A traditional cable-based monitoring system is installed in parallel with the wireless sensing units for performance comparison.

• Journal of KIISE:Databases
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• v.31 no.1
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• pp.48-60
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• 2004

XML documents consist of elements that are basic units of information. When the structure of XML documents is changed dynamically, we need to update structure information efficiently without changing the information of the index structure for fast retrieval. In this paper, we propose a dynamic indexing model scheme that updates the index structure in real time as the structure of XML documents is changed by insertion and deletion of elements. Our dynamic indexing model consists of a structure information representation method and a dynamic index structure. The structure information representation method supports various types of structure retrievals. Our dynamic index structure processes various structural queries efficiently. We show through various experiments that our method outperforms existing ones in processing various types of queries such as content based queries, structural queries and hybrid queries.