• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.317-324
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• 2020

In this study, a simplified equation for settlement evaluation suitable for the special conditions of a counter facility is suggested. Recently, counter facilities, especially breakwaters, are constructed on soft ground in distant seas as new-port development projects. A counter facility that resists the external forces by self-weight settles easily when constructed on soft ground. Settlement in a counter facility and breakwater is not an important factor for maintenance than a land facility. On the other hand, the current settlement evaluation criteria are excessive for conducting a safety inspection. A settlement evaluation from a safety inspection followed by "Detailed Guidelines for a safety inspection on a counter facility" is used. A simplified equation was proposed to calculate the maximum settlement by applying the allowable residual settlement or settlement stability evaluation results. The suitability of the simplified equation was assessed compared to the assessed rating from the settlement survey results. The proposed simplified equation showed that the settlement evaluation rating had been upgraded. The proposed simplified equation is expected to be used to evaluate the practical structural stability and functional performance.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.1
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• pp.40-50
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• 2016

A BIM, which is being applied actively to the construction and civil construction industries, is a technology that can maximize efficiency of various sectors from initial planning and design, construction, and maintenance, to demolition; however, it is in the introductory phase in the field of domestic landscaping. In order to introduce and promote BIM in the field of landscape design, this study developed a prototype of a library and template and analyzed the performance of trial application. For the development of a prototype, annotations and types were analyzed from floor plans of existing small parks, and components of landscape template were deduced. Based on this, play facilities, pergola, and benches were madeintofamily and templates, making automatic design possible. In addition, annotations and tags that are often used in landscape design were made, and a 3D view was materialized through visibility/graphic reassignment. As for tables and quantities, boundary stone table, mounding table, summary sheet of quantities, table of contents, and summary sheet of packaging quantities were grouped and connected with floor plans; regarding landscaping trees, classification criteria and name of trees that are suitable for domestic situations were applied. A landscape template was created to enable the library file format(rfa) that can be mounted on a building with BIM programs. As for problems that arose after the trial application of the prepared template, some CAD files could not be imported; also, while writing tables, the basis of calculation could not be made automatically. Regarding this, it is thought that functions of a BIM program and template need improvement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.322-329
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• 2016

This study is about the method to control the quality of material used to repair leakage and crack of concrete structure and suggests the "Temperature Stability Test Method" as a follow-up study. In the result of performance evaluation for 45 samples of 15 types in 5 series, the temperature stability test showed different material changes including rolling down, volume change, and color change as they are frozen and melt repeatedly in the somewhat extreme conditions at low($-20^{\circ}C$) and high($60^{\circ}C$) temperatures, where 13 samples (approx. 29%) and 32 samples (approx. 71%) showed leakage, respectively, in the permeability test to evaluate leakage. This result shows the enough importance of setting the quality control criteria of leakage repair material currently used to maintain concrete structures considering the temperature conditions, and proves the applicability of the Temperature Stability Test Method as a standard test method to ensure long-term durability of concrete structure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.4
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• pp.429-435
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• 2020

North Korea declared itself complete with nuclear force after its sixth nuclear test in 2017. Despite efforts at home and abroad to denuclearize the Korean Peninsula, the prospects for the denuclearization are not bright. Along with political and diplomatic efforts to deter NK's WMD threats, the government is required to strengthen its consequence management capabilities against 'catastrophic situations' expected in case of emergency. Accordingly, this study was conducted to present measures to strengthen follow-up management against CBRN threats. The research model was partially supplemented and utilized by the THIRA process adopted and utilized by the U.S. Department of Homeland Security among national-level disaster management plan development models. Korea's consequence management (CM) system encompasses risk and crisis management on disaster condition. The system has been carried out in the form of a civil, government and military integrated defense operations for the purpose of curbing the spread or use of CBRNs, responding to threats, and minimizing expected damages. The preventive stage call for the incorporation of CBRN concept and CM procedures into the national management system, supplementing the integrated alarm systems, preparation of evacuation facilities, and establishment of the integrated training systems. In the preparation phase, readjustment of relevant laws and manuals, maintenance of government organizations, developing performance procedures, establishing the on-site support systems, and regular training are essential. In the response phase, normal operations of the medical support system for first aid and relief, installation and operation of facilities for decontamination, and development of regional damage assessment and control guidelines are important. In the recovery phase, development of stabilization evaluation criteria and procedures, securing and operation of resources needed for damage recovery, and strengthening of regional damage recovery capabilities linked to local defense forces, reserve forces and civil defense committees are required.

• Land and Housing Review
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• v.8 no.1
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• pp.23-29
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• 2017

The BIM design is expected to expand to the domestic and overseas construction industries, depending on the effect of construction productivity and quality improvement. However, with the obligation of Public Procurement Service to design the BIM design, it includes a design error and the problem of utilization of 3D design by choosing a simple 2D to 3D remodelling method that can not be modelled in 3D modeling or use of the construction and maintenance phases. The results reviewed by BIM design results were largely underutilized and were not even performed with the verification of the error. In order to resolve this, one must develop the check system that secures the quality of BIM design and ensure that the reliability of BIM results are available. In this study, it is designed to develop a program that can automatically verify the design of the BIM design results such as violation of the rules of the BIM design, design flaws, and improve the usability of the BIM design. In particular, this programs were developed not only to identify programmes that were not commercially available, but also to validate drawings in low-light computer environments. The developed program(LH-BIM) store the information of attribute extracted from the Revit file(ArchiCAD, IFC file included) in the integrated DB. This provides the ability to freely lookup the features and properties of drawings delivered exclusively by the LH-BIM Program without using the Revit tools. By doing so, it was possible to resolve the difficulties of using traditional commercial programs and to ensure that they operate only with traditional PC performance. Further, the results of the various BIM software can be readily validated, which can be solved the conversion process error of IFC in the case of SMC. Additionally, the developed program has the ability to automatically check the error and design criteria of the drawings, as well as the ability to calculate the area estimation. These functions allow businesses to apply simple and easy tasks to operate tasks of BIM modelling. The developed system(LH-BIM) carried out a verification test by reviewing the review of the BIM Design model of the Korea Land & Housing Corporation. It is hoped that the verification system will not only be able to achieve the Quality of BIM design, but also contribute to the expansion of BIM and future construction BIM.

• Korean Journal of Construction Engineering and Management
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• v.7 no.6
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• pp.175-184
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• 2006

This study focused on developing Life Cycle Cost(LCC) analysis model for selecting sludge collectors in wastewater treatment system and applying the model to a case study. Cost items are examined through literature review and historical data of a facility. Analysis period, discount rate, energy cost escalation ratio are assumed to reasonable level. Monetary evaluation is performed using historical data and estimations from vendors. Sensitive analysis is executed using Monte Carlo Simulation for assumed factors. Interviews with operators, vendors, constructors, managers are conducted to define factors which indicates ease of maintenance, ease of delivery, technical performance, efficiency, environmental friendship. Factors are representing technical and social factors. Results from LCC analysis and qualitative analysis are evaluate together with Weighted Matrix Evaluation Methods for optimum alternative of sludge collectors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.86-93
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• 2020

The demand for maintenance in Korea infrastructure facilities constructed since the 1970s has increased significantly compared to the demand for new construction. Moreover, after the Gyeongju and Pohang earthquakes, seismic performance evaluation, repair, and retrofitting projects have been carried out. Therefore, in this study, a specimen was designed following the L-type GFRP Plate Externally Bonded Retrofit method, one among other retrofit methods. The L-type GFRP Plate was bonded to the specimen by epoxy and a washered steel nail. A four-point bending test was performed to confirm the strengthening effect of the Externally Bonded Retrofit method using an L-type GFRP Plate. The strengthening effect of the L-type GFRP plate was proven experimentally, and the behavior of the beam designed following the L-type GFRP Plate Externally Bonded Retrofit method was evaluated according to Korea's "Design Manual & Specification for Strengthening of RC Structures by Advanced Composites System". Furthermore, the effectiveness of the bonding method, a combination of epoxy and washered steel nail, was also checked. The results showed that the design, according to the guidelines mentioned above, predicted the strength of the member well, but the failure mode did not satisfy the design assumption because of unexpected damage to the GFRP plate due to the fixing method, washered steel nail.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.245-265
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• 2017

Recently, studies on cognitive control revealed that the optimal level of control is determined on the basis of reward and cost. The value of reward can be subjective and therefore, the optimal control strength can vary accordingly. The inconsistent effect of aging on cognitive control can be the result of flexible adjustment of control signal strength made by the older subjects. In other words, the elderly people maintains the ability to set the optimal level of control, which is known as the function of the dorsal anterior cingulate cortex. On the other hand, the age-related decline in cognitive control is obvious in rule maintenance and inhibition, which has to do with the function of lateral prefrontal cortex. In this study, we had young and old adults perform go-no go task and compared the behavioral and neural results for different reward conditions. Both age groups showed the best performance and the largest ERN amplitude when the reward was most appealing to them. And there was no age effect in ERN amplitude even though older adults' d' and accuracy was inferior to younger participants. These findings suggest that the effect aging on different cognitive control processes can be asymmetric.

• The KIPS Transactions:PartA
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• v.13A no.1 s.98
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• pp.45-52
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• 2006

To perform on-line maintenance for Distributed Information System, it is indispensable to disseminate files to participant nodes in the network. When users' requests for file deployment occur simultaneously in a short period a deployment server falls into overload phase, which is often called Flash Crowds. h common solution to avoid Flash Crowds is to increase hardware capacity. In this paper, we propose a software solution based on P2P, which does not cost any additional expense. In the proposed solution, nodes in the network are grouped into subnetworks one of which is composed of only neighboring nodes. In each subnetwork, copies of deployment files can be transferred to each other. Consequently, it brings about the effect of load balancing in deployment server. To raise the effectiveness, target files for deployment are packed into one package. Before being transferred, each package is divided into multiple equal-sized segments. A deployment server in a normal phase transmits a package requested from nodes in segment units. However a deployment server is overloaded, if segments already exist in the subnetwork participant nodes in the subnetwork receive necessary segments from neighboring nodes. In this paper, we propose data structures and algorithm for this approach and show performance improvement through simulation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.113-123
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• 2005

The removal of radioactive corrosion products from the reactor coolant through a magnetic filter system is one of the many approaches being investigated as a means to reduce radiation sources and exposures to the operational and maintenance personnel in a nuclear power plant. Many research activities in water chemistry, therefore, have been performed to provide a filtration system with high reliability and feasibility and are still in process. In this study, it was devised the magnetic filter system with permanent and electric magnets to remove the corrosion products in the coolant stream taking an advantage of the magnetic properties of corrosion particles. Permanent magnets were used for separation of corrosion products and electric magnets were utilized for flocculation of colloidal particles to increase in their size. Experiments using only permanent magnets, in the previous study, displayed the satisfactory outcome of filtering corrosion products and indicated that the removal efficiency was more than 90 $\%$ for above 5 $\mu$m particles. Experiments using electric magnets also showed the good performance of flocculation without chemical agents and exhibited that most corrosion particles were flocculated into larger aggregates about 5 $\mu$m and over in diameter. It is, thus, expected that the magnetic filter system with the arrangement of permanent and electric magnets will be an effective way for the removal of radioactive corrosion products with considerably high removal efficiency.