• Journal of Korean Association for Spatial Structures
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• v.20 no.4
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• pp.177-184
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• 2020

This study evaluates safety assessment before and after repair of Seonamsa temple seungseon bridge, which refer to the representative Hongye bridge in Korea. In this approach natural frequency of the structure were considered in the modeling procedure. Trial & error method is applied to obtain the approximate natural frequency before and after retrofit construction. Stiffness of the actual structure was examined to account for the dynamic characteristics of Hongye bridge measured in the field and adjusting parameters in computer modeling. The safety and usability of the stone structure in terms of load bearing capacity and displacement were examined.

• The Journal of Internal Korean Medicine
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• v.41 no.6
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• pp.959-966
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• 2020

Objectives: To examine the fundamental characteristics of interventional clinical trials registered in the CRIS (Clinical Research Information Service) database. Methods: We systematically analyzed the status of Korean medical interventions using the search function of the CRIS database. Results: From 2010 to January 2020, 267 Korean medicine-related clinical trials were registered with CRIS. The studies, which included many randomized trials (80.14%), focused primarily on demonstrating the effectiveness and safety of acupuncture and Korean herbal remedies. Most of these studies were government-sponsored and researcher-led clinical trials, but a few were company-sponsored trials. All trials were small and need improvement. Conclusion: This study reviews the current status of clinical trials in the field of Korean medicine and the basic data that can be used to create evidence-based Korean medicine.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.565-578
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• 2022

Among Generation IV reactors, the sodium-cooled fast reactor (SFR) is attracting attention as a system having great potential for commercial use. Gas entrainment is a thermal-hydraulic issue related to the safety problem of the reactor core in the SFR. Typically, a dipped plate or baffles are installed under the free surface to suppress gas entrainment. However, these approaches can cause gas entrainment in other locations and require many trial-and-error and verifications. In this study, a new strategy using magnetohydrodynamics to suppress gas entrainment in the SFR is proposed. In a counter-flow model, a judgment criterion of gas entrainment occurrence was developed for both water and liquid metal. Moreover, the gas entrainment can be completely suppressed by applying a magnetic field.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.238-239
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• 2021

This study presented the development of a user centered school facility fire safety evaluation model that would support fire safety evaluation, which is globally recognized as being important in terms of school safety, to be more efficiently implemented in the school field mainly by students. The study consisted of five steps. First, actual condition survey tools were developed based on the major fire safety evaluation items derived through literature review. Second, the characteristics of domestic school facilities in terms of fire safety were developed using the survey tools. Third, an evaluation model at a level utilizable by students was developed based on the foregoing characteristics. Fourth, the applicability of the model was verified through a trial application of the model to elementary school students. Finally, legal and institutional improvement plans and fire safety education materials were presented through a policy proposal.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.151-152
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• 2020

There is a possibility of failure as a result of field application in the planning and execution process to change the operating policy for operating terminals, so a lot of time and effort are required to reduce trial and error. In the planning stage to change the terminal operation policy, simulation technology can be used to support decision making. This study introduces a case of using a virtual terminal system among simulation technologies.

• Geomechanics and Engineering
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• v.37 no.5
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• pp.499-510
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• 2024

In northern China, abundant summer rainfall and a higher water table can weaken the soil due to salt heave, collapsibility, and increased moisture absorption, thus the chlorine saline soil (silty clay) needs to be stabilized prior to use in road embankments. To optimize chlorine saline soil stabilizing programs, unconfined compressive strength tests were conducted on soil treated with five different stabilizers before and after soaking, followed by field compaction test and unconfined compressive strength test on a trial road embankment. In situ testing were performed with the stabilized soils in an expressway embankment, and the results demonstrated that the stabilized soil with lime and SH agent (an organic stabilizer composed of modified polyvinyl alcohol and water) is suitable for road embankments. The appropriate addition ratio of stabilized soil is 10% lime and 0.9% SH agent. SH agent wrapped soil particles, filled soil pores, and generated a silk-like web to improve the moisture stability, strength, and stress-strain performance of stabilized soil.

• Journal of The Korean Association For Science Education
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• v.9 no.1
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• pp.53-67
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• 1989

General Physics CAI Program was developed for university science and engineering student. The program was restricted in the field of mechanics and was mainly aimed for individual tutorial. This project was supported by Government. Department of Education, physics attending their general physics classes in university. The program was written in BASIC and constructed by frame, 4 professors and 6 graduate students were involved in the project. Summary of this study is as follows. 1. The theory of CAI was illuminated from a new point of view to enhance usefullness of CAI. Also the structure of frame type CAI was studied. 2. The program was developed as follows 1) The program consisted of main program, pretest routine, tutorial routine, final test routine, and several other routines for program control. Whole program was written in BASIC. 2) 20 problems for pretest, 90 problems and subsequent hints and solutions for tutorial, 20 problems for final test were developed. 3) According to student's pretest result, tutorial course was routed through several different courses which contain different number of problems 4) The expected rate of achievment for final test was set to 75%. 5) Data of students response to problems including number of tries and time used were recorded for the purpose of achievment analisys 3. 22 students went through whole course and the results were as follows. 1) Pretest marks were widly distributed from 20 points to 100. It means that achievement of high school physics course were not enough. 2) Throughout tutorial course, students who had got higher mark in pretest answered correctly in the first trial at a higher rate of 78 %. Overall rate of correct answer in the second trial was distributed appropriatly. 3) Average mark of final test was 78.8 points, rather a higher rate of achievement than expected. This means that the program was constructed well.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.322-332
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• 2011

In this paper, we introduce the 1st performance evaluation of VLBI Correlation Subsystem (VCS) main product, which is core system of Korea-Japan Joint VLBI Correlator (KJJVC). The main goal of the 1st performance evaluation of VCS main product is that the perfection of overall system will be enhanced after checking the unsolved part by performing the experiments towards various test items at the manufacturer before installation of field. The functional test was performed by including the overflow problem occurred in the FFT re-quantization module due to the insufficient of effective bit at the VCS trial product in this performance test of VCS main product. Through the performance test for VCS main product in the factory, the problem such as FFT re-quantization discovered at performance test of VCS trial product in 2008 was clearly solved and the important functions such as delay tracking, daly compensation, and frequency bining were added in this VCS main product. We also confirmed that the predicted correlation results (fringe) was obtained in the correlation test by using real astronomical observed data(wideband/narrow band).

• Smart Structures and Systems
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• v.9 no.5
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• pp.393-410
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• 2012

Conventional geotechnical instrumentation techniques available for monitoring of slopes, especially soil-nailed slopes have limitations such as electromagnetic interference, low accuracy, poor longterm reliability and difficulty in mounting a series of strain sensors on a soil nail bar with a small-diameter. This paper presents a slope monitoring system based on fibre Bragg grating (FBG) sensing technology. This monitoring system is designed to perform long-term monitoring of slope movements, strains along soil nails, and other slope reinforcement elements. All these FBG sensors are fabricated and calibrated in laboratory and a trial of this monitoring system has been successfully conducted on a roadside slope in Hong Kong. As part of the slope stability improvement works, soil nails and a toe support soldier-pile wall were constructed. During the slope works, more than 100 FBG sensors were installed on a soil nail, a soldier pile, and an in- place inclinometer. The paper presents the layout and arrangement of the instruments as well as the installation procedures adopted. Monitoring data have been collected since March 2008. This trial has demonstrated the great potential of the optical fibre monitoring system for long-term monitoring of slope performance. The advantages of the slope monitoring system and experience gained in the field implementation are also discussed in the paper.

• Journal of Science and Technology Studies
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• v.12 no.1
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• pp.45-78
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• 2012

What is a disaster? And what can science and technology studies tell us about it? There might be numerous definitions about disaster. In this article, we will posit that disaster is an incident when sociotechnical system actor-network broke down against the other force in their "trial of strength". This is a process that punctualized actor-network is depunctualized, and a status that readiness-to-hand of Being recedes while pesentness-at-hand of tool-being comes forward. Using the concept of disaster as a case study, we will consider how Latourian ontology overlaps with Heideggerian philosophy of technology. This STS approach which hasn't been previously studied might provide us with new theoretical framework that enables us to construe the assemblage of technoscience and nature-society in the field of PUS or NPSS.