• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.27-28
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• 2023

Currently, the Off-Site Construction (OSC) construction method, which emphasizes the minimization of field work, is being emphasized at construction sites due to the lack of construction skilled manpower, extreme weather, and the Severe Disaster Punishment Act. In this study, we developed a stacked PC modular, which is a method of stacking PC modules, and solved the lifting problem by reducing the weight of the unit module, which is emerging as the biggest disadvantage of PC modules, to around 20 tons. For the connection between modules, structural safety was secured through repeated history tests of the wall and slab connection. Walls and slabs satisfied all statutory fire resistance times through fire resistance tests, and residential performance was evaluated to be satisfactory through mock-up demonstration. The developed PC modular has been applied to the construction of commercial houses, detached houses, shopping malls, churches, etc., and has design results for many buildings such as dormitories, detached houses with 4 floors or more, and resorts, so it is expected that an atmosphere of revitalization of construction methods will be created.

• Computers and Concrete
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• 제33권6호
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• pp.643-658
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• 2024

To date, shell-solid and fibre element model analysis are the most commonly used methods to investigate the seismic performance of concrete-filled steel tube (CFST) bridge piers. However, most existing research does not consider the loss of bearing capacity caused by the fracture of the outer steel tube. To fill this knowledge gap, a refined finite element (FE) model considering the ductile damage of steel tubes and the behaviour of infilled concrete with cracks is established and verified against experimental results of unidirectional, bidirectional cyclic loading tests and pseudo-dynamic loading tests. In addition, a parametric study is conducted to investigate the seismic performance of CFST bridge piers with different concrete strength, steel strength, axial compression ratio, slenderness ratio and infilled concrete height using the proposed model. The validation shows that the proposed refined FE model can effectively simulate the residual displacement of CFST bridge piers subjected to highintensity earthquakes. The parametric analysis indicates that CFST piers hold sufficient strength reserves and sound deformation capacity and, thus, possess excellent application prospects for bridge construction in high-intensity areas.

• Transactions on Control, Automation and Systems Engineering
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• 제2권1호
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• pp.40-46
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• 2000

In this paper, a transient identification based on a Hidden Markov Model (HMM) has been suggested and evaluated experimentally for the classification of transients in the dynamic process. The transient can be identified by its unique time dependent patterns related to the principal variables. The HMM, a double stochastic process, can be applied to transient identification which is a spatial and temporal classification problem under a statistical pattern recognition framework. The HMM is created for each transient from a set of training data by the maximum-likelihood estimation method. The transient identification is determined by calculating which model has the highest probability for the given test data. Several experimental tests have been performed with normalization methods, clustering algorithms, and a number of states in HMM. Several experimental tests have been performed including superimposing random noise, adding systematic error, and untrained transients. The proposed real-time transient identification system has many advantages, however, there are still a lot of problems that should be solved to apply to a real dynamic process. Further efforts are being made to improve the system performance and robustness to demonstrate reliability and accuracy to the required level.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1987년도 춘계학술발표회 논문집
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• pp.27-30
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• 1987

Some modification of laplacian pyramidal coding have been done and tested for a test image, From our studies, its apperar that 3-D redictor which exploits inter and intra plane redundancy simultaneously somewhat imporves the image quality, We also have tried to reduce the bit rate by only sending zeroth plane image values that correstpond to estimated dege points which can be obtained from the first plane For both cases the feedback of quantization errof in the previous plane has been in the reconstruction of each plane. Subjective and SNR tests show the better performance of the studied methods oner the conventional one.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.596-602
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• 2008

Recently, there are increasing social needs for safe operation of trains and comforting for passengers. But lightning surges are responsible for serious disturbances such as damage, permanent degradation or temporary erratic operation of sensitive electronics circuits and systems. The purpose of this paper is to identify the requirements for Surge Protective Devices(SPDs) used in protecting railway signalling system. In this paper, we describes tests and requirements which establish methods for testing SPDs and determining their performance.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.23-29
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• 2018

The objective of this paper is to evaluate the reliability of a volute pump and presents test results through performance and life tests. The performance and life test methods were presented by analyzing the failure modes of the volute pump. Zero failure test time was calculated to evaluate the reliability of the volute pump and then, the test was performed under accelerated conditions. The test was also carried out to check the failure modes of the field conditions. This study can be provided to improve the product reliability through failure analysis of the volute pump. And failure cause of typical failure case has been investigated and improvement design has been presented. The performance test results of before and after the accelerated life test were presented to confirm the improved reliability of the volute pump.

• 간호행정학회지
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• 제22권5호
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• pp.471-479
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• 2016

Purpose: This study was conducted to evaluate the level of safety climate, fatigue, and safety performance and to identify the impact of safety climate and fatigue on the safety performance of operating room nurses. Methods: The study design was a descriptive survey. Participants were 174 operating room nurses from two general hospitals and two university hospitals in S and D cities. Three structurally designed questionnaires were used to evaluate their safety climate, fatigue, and safety performance. Collected data were analyzed using descriptive analysis, t-tests, ANOVAs, Pearson correlation coefficient, and stepwise multiple regression. Results: Safety performance of operating room nurses had a mean of 3.26 on a 5-point scale. 'Current department career'(${\beta}=.17$, p=.006) and 'safety climate (work-unit contribution) (${\beta}=.63$, p<.001) accounted for 39% of the variance in operating room nurses' safety performance. Conclusion: Findings indicate that work-unit contribution towards safety climate is an important factor in increasing operating room nurses' safety performance. Therefore, it is essential to find motivational properties consistent with the characteristics of the operating room environment.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.112-119
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• 2000

the shaking table tests for 5 different model sections are performed to investigate the behaviors of quay walls during earthquakes and to evaluate the seismic performance of quay walls with countermeasures. 5 different model sections describe the cases of dense soil and loose soil in the foundation repectively the case to which gravel backfill was applied and the cases to which light material replacement method and sand compction pile method was applied repectively for sesmic countermeasure methods. Pore water pressures accelerations and deformations in quay walls and grounds are analyzed. As a result the softening of foundation and backfill soils have much influence on the behaviors of quay walls. Also light material replacement method and sand compaction pile method are effective in improving the seismic performance of quay walls.

• 멤브레인
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• 제1권1호
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• pp.59-59
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• 1991

A theoretical and experimental study made in order to determine the performance of mem-brane contactors in water carbonation is presented. In particular on the basis of experimental results pre-viously obtained it has been derived an expression in which the effect of some parameters as temprera-ture water and CO₂ flow rate CO₂ pressure trans-membrane pressure on the performance of the process is taken into account. The study refers to hollow fiber membrane contactors used for the experimental tests. The main scope has been to verify if by membrane contactors it is possible to reach the same de-gree of water carbonation as by trditional methods (1-5 g/1) and to derive for the module used a cor-relation able to describe the performance of the process at several operating conditions. The high CO₂ removal observed confirms the interesting potentialties of membrane contactors also in gas streams purification.

• 국제초고층학회논문집
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• 제9권4호
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• pp.343-349
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• 2020

This research aimed to clarify the long-term mechanical performance of a steel truss member strengthened by a carbon fiber-reinforced polymer (CFRP) without protective coating through exposure testing. Strengthening and repair methods using CFRP have been developed in recent years; however, there is a lack of durability research for CFRP-strengthened members, especially mechanical performance investigation according to actual exposure testing. In this study, 10 CFRP-strengthening steel specimens were created in 2015, and elastic bending tests were conducted biannually. Eventually, although resin loss occurred due to environmental effects, the mechanical performance of CFRP-strengthened steel was not degraded, and we propose a calculation method of bending stiffness to evaluate the lower value of stiffness for design.