• Korean Journal of Radiology
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• 제20권6호
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• pp.880-893
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• 2019

Objective: To assess the technical performance of two-dimensional shear wave elastography (2D-SWE) for measuring liver stiffness. Materials and Methods: The Ovid-MEDLINE and EMBASE databases were searched for studies reporting the technical performance of 2D-SWE, including concerns with technical failures, unreliable measurements, interobserver reliability, and/or intraobserver reliability, published until June 30, 2018. The pooled proportion of technical failure and unreliable measurements was calculated using meta-analytic pooling via the random-effects model and inverse variance method for calculating weights. Subgroup analyses were performed to explore potential causes of heterogeneity. The pooled intraclass correlation coefficients (ICCs) for interobserver and intraobserver reliability were calculated using the Hedges-Olkin method with Fisher's Z transformation of the correlation coefficient. Results: The search yielded 34 articles. From 20 2D-SWE studies including 6196 patients, the pooled proportion of technical failure was 2.3% (95% confidence interval [CI], 1.3-3.9%). The pooled proportion of unreliable measurements from 20 studies including 6961 patients was 7.5% (95% CI, 4.7-11.7%). In the subgroup analyses, studies conducting more than three measurements showed fewer unreliable measurements than did those with three measurements or less, but no intergroup difference was found in technical failure. The pooled ICCs for interobserver reliability (from 10 studies including 517 patients) and intraobserver reliability (from 7 studies including 679 patients) were 0.87 (95% CI, 0.82-0.90) and 0.93 (95% CI, 0.89-0.95), respectively, suggesting good to excellent reliability. Conclusion: 2D-SWE shows good technical performance for assessing liver stiffness, with high technical success and reliability. Future studies should establish the quality criteria and optimal number of measurements.

• 시스템엔지니어링학술지
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• 제5권2호
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• pp.27-34
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• 2009

This paper analyze technical review entry criteria and review process based on system property, and review checklist to conform technical review is also showed. The execution of review is determined according to the preparation of review item and identification for risk element. Risk level should be mitigated before technical review by appropriate plan. This paper described the entering condition of technical review for developmental phase, and tailoring consideration for technical review condition. Described technical review entry criteria, review process, and tailoring consideration is applied to development of test equipment for ground ant-air missile system. Applied system specific technical review process, tailored entry condition for test equipment for ground ant-air missile system and review check list is showed and the effectiveness of described system specific technical review process is presented.

• Asia pacific journal of information systems
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• 제15권3호
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• pp.163-186
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• 2005

When firms are confronted with IT investment decision-makings, technical or financial factors are widely considered. However, based on sociotechnical systems theory, it is argued that in addition to the traditional factors, social issues must be considered in the IT investment decision-makings. Even though the strategic criteria of social issues within organization are important for IT investment decision-makings, the social or organizational issues are hardly considered in IT implementation and adoption(Ryan and Harrison, 2000). The objective of this study is to empirically verify how the comprehensive consideration of both of technical and organizational issues related with IT investment affects firm performance through its impact on IT technical capability and IT personnel skills. Senior managers of 153 Korean firms were surveyed, and the collected data were analyzed with PLS technique. The results of the PLS path analysis show that the comprehensive consideration of the technical and social issues affected indirectly firm performance through IT technical capability and IT personnel skills. It is found that the comprehensive consideration had a significant impact on IT technical capability and IT personnel skills, and that IT technical capability and IT personnel skills affected firm performance. IT personnel was also found to affect IT technical capability. Finally, this study found that the consideration of social factors had greater impacts on firm performance than that of technical factors.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.806-810
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• 2005

Slope was necessarily formed by development of hilly district for human living. At present slope is distributed about sixteen thousand in state road and expressway. Nevertheless, rule of preservation management for slope is overlapping or diffuse. In this study it analyze condition evaluation for slope.

• 한국안전학회지
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• 제21권5호
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• pp.72-76
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• 2006

This study deals with problems of technical assistance through accidents analysis and questionnaires on small-sized construction sites which are difficult to understand real condition and administrate legally and indicated following efficient methods of technical assistance. (1) Ensuring access to the small-sized construction sites. (2) Delegation technical assistance service to civilian and supporting selected. (3) Raising of the person's safe consciousness concerned with the small-sized construction sites. (4) Safety consulting for the head office of small-sized construction sites.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.423-430
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• 2000

With speed-up of existing railway, a greater attention is paid to the riding safety and the comfort of the passengers. They are combined to some technical factors related to track such as alignment, derailment coefficient, and track bearing capacity, A quantitative analysis method for those technical factors is presented in this study. Calculating the allowable transit speed, the technical reviews of speed-up of Janghang-Line(Chunan∼Janghang) are conducted. And the alternatives for improving train speed in existing railway are proposed.

• 한국환경과학회지
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• 제18권8호
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• pp.919-926
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• 2009

Renewable energy or green energy is a hot issue in theses days. Since wind resource can be endlessly supplied by nature, researchers and common people are interested in study how to use that resource at home or company. Especially, many architects have tried to integrate wind power generator for a part of building. So in this paper, three buildings installed wind power turbine are targed to CFD analysis and these buildings are Bahrain trade center, Discovery tower, and Pearl river tower. Bahrain trade center is the first building installed real wind turbine, Discovery tower is constructing at Texas, and Pearl river tower is designed and proved by china researchers. These buildings have very different type of wind power turbine and each turbine has different conditions f3r best power generation. Therefor this paper will focus on characteristic shape of buildings, wind power turbine type, and expected purpose of construction. Moreover, CFD analysis will show wind flow pattern and wind speed while wind is passing through wind turbine of three tall buildings. CFD analysis for three buildings make comparison the wind flow patterns with experimental result.

• Earthquakes and Structures
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• 제9권1호
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• pp.145-171
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• 2015

Due to earthquakes, many structures suffered extensive damages that were attributed to the torsional effect caused by mass, stiffness or strength eccentricity. Due to this type of asymmetry torsional moments are generated that are imposed by means of additional shear forces developed at the vertical resisting structural elements of the buildings. Although the torsional effect on the response of reinforced concrete buildings was the subject of extensive research over the last decades, a quantitative index measuring the amplification of the shear forces developed at the vertical resisting elements due to lateral-torsional coupling valid for both elastic and elastoplastic response states is still missing. In this study a reliable index capable of assessing the torsional effect is proposed. The performance of the proposed index is evaluated and its correlation with structural response quantities like displacements, interstorey drift, base torque, shear forces and upper diaphragm's rotation is presented. Torsionally stiff, mass eccentric single-story and multistory structures, subjected to bidirectional excitation, are considered and nonlinear dynamic analyses are performed using natural records selected for three hazard levels. It was found that the proposed index provides reliable prediction of the magnitude of torsional effect for all test examples considered.

• Earthquakes and Structures
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• 제6권1호
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• pp.1-18
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• 2014

The main focus of this paper is the analysis of the different components of the variability for strong ground motions recorded from earthquakes produced by the Vrancea subcrustal seismic source. The analysis is performed for two ground motion prediction equations: Youngs et al. (1997) and Zhao et al. (2006), recommended within the SHARE project for the Vrancea subcrustal seismic source and which are proposed in the work of Delavaud et al. (2012) and graded best in Vacareanu et al. (2013c). The first phase of the analysis procedure consists of a grading procedure. In the second phase, the single station sigma procedure is applied for both attenuation models in order to reduce some parts of ground motion models' variability produced by the ergodic assumption. The strong ground motion database which is used throughout the study consists of over 400 accelerograms recorded from 9 Vrancea intermediate-depth seismic events. The results of the single station sigma analysis show significant reduction of the standard deviations, especially in the case of the Youngs et al. (1997) attenuation model, which is also graded better than the other selected GMPE.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.831-837
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• 2005

In this study, a computer program to predict the behavior of laterally loaded single pile and pile groups was developed by using a beam-column analysis in which the soils are modeled as nonlinear springs by a family of p-y curves for subgrade modulus. The special attention was given to the lateral displacement of a single pile and pile groups due to the soil condition and the cap rigidity. The analysis considering group effect was carried out for $2\;{\times}\;2\;and\;3\;{\times}\;3$ pile groups with the pile spacing 3.0B, 4.0B and 5.0B. Based on the results obtained, it is found that the overall distributions of deflection, slope, moment, and shear force in a single pile give a reasonable results irrespective of cap connectivity conditions. It is also found that even though there are some deviations in deflection prediction compared with the observed ones, the prediction by present analysis simulates much better the general trend observed by the centrifuge tests than the numerical solution predicted by PIGLET.