• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.6-12
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• 2018

Recently, The use of the curtain wall method is increasing in construction. The curtain wall construction is widely applied to the exterior wall of the building for shortening construction period and economical efficiency. However, the replacement of deterioration of the weather resistance and structural behavior of the sealing material connecting the curtain wall method and the glass frame is necessary for introduction of the stable curtain wall method and quality improvement in accordance with KS F 4910 standard. In this study, the elastic restoring force test was performed in the external environment. In this study, the deterioration of the sealant was evaluated for structural sealants. In Korea, studies on the variable displacement behavior of structural sealants are lacked. In this study, the reproduced results in laboratory conditions are compared with the deteriorating conditions exposed to the external environment, and they are reflected in the design of sealing materials in the future. According to the results of the study, it was confirmed that the existing structure sealant meets the quality standard of KS F 4910, but in the conditions performed in this study, adhesion failure of the specimen and cracking of the surface occurred. Especially, in the weather resistance test, it is necessary to evaluate the long-term durability performance of the structural sealant used in the curtain wall method by checking the insoluble state of all the test pieces. Therefore, in order to apply a conventional structural sealant to the site, it is necessary to introduce another durability performance evaluation.

• The Journal of Engineering Geology
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• v.30 no.2
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• pp.185-198
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• 2020

High-density rapid expansion material is a method that increases the solid volume of injection materials due to hydration and foam reactions at the same time as spraying. It is an effective method for securing ground stability, restoring subsidence, and loading during construction of structures. In this regard, through the mechanical experiments of injection materials, the stability of the foundation ground of the structure and the effect of increasing the endurance using site construction were analyzed. The results of the experiment showed that the unit weight of soil decreased by 10.5% after injection of the filling material, and the allowable support for the structure was deemed safe, and the subsidence by each section after ground improvement was determined to be safe at 2.28, 1.55 and 0.46 cm, respectively, with an acceptable subsidence of less than 5 cm. After the field test, five inclinometers were installed on the top floor of the target building to measure the displacement of the X and Y axes. As a result of the measurement, no displacement related to the phenomenon of inequality or subsidence cracks of the structure was measured for about 16 months (509 days) after construction. This can be judged to be a sufficient increase in the stability of the ground after the injection of rapid expansion.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.61-76
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• 2018

Everything is coming into the world of network where modern people are living. The Internet of Things that attach sensors to objects allows real-time data transfer to and from the network. Mobile devices, essential for modern humans, play an important role in keeping all traces of everyday life in real time. Through the social network services, information acquisition activities and communication activities are left in a huge network in real time. From the business point of view, customer needs analysis begins with SNS data. In this research, we want to build an automatic collection system of SNS contents of web environment in real time using Python. We want to help customers' needs analysis through the typical data collection system of Instagram, Twitter, and YouTube, which has a large number of users worldwide. It is stored in database through the exploitation process and NLP process by using the virtual web browser in the Python web server environment. According to the results of this study, we want to conduct service through the site, the desired data is automatically collected by the search function and the netizen's response can be confirmed in real time. Through time series data analysis. Also, since the search was performed within 5 seconds of the execution result, the advantage of the proposed algorithm is confirmed.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.81-92
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• 2017

According to the revision of the Housing Act in 2013, it has been possible to carry out an apartment remodeling project involving two to three floor vertical extension. The remodeling project with vertical extension requires foundation reinforcement because structural safety due to additional load and enhanced seismic criteria must be met. In this case, structural analysis is performed to analyze the load distributed to existing PC pile and reinforced additional pile. The vertical stiffness ($K_v$) of the pile is required for structural analysis, but the research on the 20~30 year old PC pile stiffness is very limited. In this paper, the stiffness of the PC pile in accordance with the change of diameter and length was analyzed by examining the results of 38 field pile load tests performed during the construction of the apartments in the 1990's. As a result of the analysis, the pile stiffness decreases with the increase of the length-diameter ratio (L/D). In addition, the results of on-site pile load test are compared with the coefficient 'a' for estimating pile stiffness proposed in Korea Highway Bridge Design Standard (2008) and the Pile Foundation Design Guideline of Korea Railroad Corporation (2012). It shows that 'a' obtained through the estimation of the literature is very similar to the field test results in the range of 10

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.1-9
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• 2013

Education and training is an important means of promoting safety culture and enhancing the level of competence of radiation worker in radiation protection. The existing international nuclear education and training of short duration has been carried out on the high-level officials and focussed on the classroom based training. The developing countries has been asking for support to cultivate their own technical experts to Korea which is a donor country exporting nuclear power plants. This paper summarizes the results of developing and operating the international education and training course to froster technical experts in radiation protection that emphasized practical training sessions and technical visits using the excellent domestic radiation facilities and infrastructure of education and training. It mentions the procedures of assessment and feedback as well. In an effort to maximize teaching-learning effects and to maintain consistency of the learning objectives, methods and assessment, SAT methodology has been applied on the processes of developing and operating the course. In the comparative and final assessment which were conducted at the beginning or at the end of training course, participants' average score increased around 2 points. The questionnaire of participants showed a high level of satisfaction of 4.0 points or above for the most of the questions. These imply teaching-learning methods applied to it might be effective. The teaching-learning methodologies may provide the opportunity to develop the customized training course for bringing up international technical experts and to shift educational paradigm from theory-oriented to on-site practice-based education.

• Management & Information Systems Review
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• v.29 no.3
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• pp.71-96
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• 2010

This article firstly reviewed Permanent Established(PE) concept of OECD and UN model tax treaty and compared it with that of Korean Corporate Income Tax Law(CITL). The various factors regarding profit like ways of deciding the local source profit, scope and calculation method which will be imputed to PE were also reviewed. Based on above, standard PE judgement basis and calculation method of local source profit were also studied by using actual cases in foreign corporation which performs plant construction & sales in Korea. Accordingly to properly solve the conflict regarding international tax and to protect the tax authority against the foreign corporation in Korea, by standing on equality, I now propose followings for the better concept of PE in Korea. Firstly, the article that a building site or construction or installation project constitutes a PE only if it lasts more than 6 months should be modified to reflect OECD model convention's criteria of 12 months. Second, the scope of 'subordinate attorney' which is regarded as PE under CITL is now including 'holding-delivery attorney', 'order attorney', and 'assurance attorney' as well as 'contract attorney'. This is overly limit the activities of foreign corporation. It had better be loosened only to include 'contract attorney' as OECD provisions. Third, the CITL limits the cases of preparatory and/or auxiliary place which is not regarded as PE, thus limit the foreign corporations' business by expanding the concept of PE. This had better be eased. Fourth, in deciding the amount of local source profits, the CITL stipulates to split the profits by the relevant contribution of transaction parties through 'profit split method'. To solve the conflict, the ways of profit split must be better clarified through providing object and detailed standard and basis.

• Journal of the Korean Institute of Educational Facilities
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• v.25 no.1
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• pp.13-24
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• 2018

Planning and designing training facilities has been developed from educational facilities, and increasingly diversified society has raised a need for facilities dedicated to training and education in a differentiated space separate from the one for regular works. This particular need of our times has led to the expansion of training facilities nationwide although they have something to be desired when it comes to planning and designing with sustainability associated with the locational characteristics of urban space as well as the unique types of facilities taken into account. Against this backdrop, this study will examined a variety of training facilities that have been established since 2000 through theoretical review and conduct intensive analysis on the characteristics of the planning aspects to suggest their significance and implications and to present the overall meanings and ramifications of planning approaches in consideration of new challenges modern training facilities are faced with, which have been revealed through architectural design competitions in recent years. The relevant implications are as follows. First, one of the locational advantages of training facilities, which is commanding beautiful scenery of the surrounding area, can be considered as intent to stress the aspect of a resort, one of the functions of any training facilities. As this study has demonstrated, many training facilities are located near around a beach or a lake. Second, training facilities can be classified into three different types in terms of their location: urban, suburban and resort and such locational characteristics are directly related to intended programs and differentiated links with target users. Third, the architectural styles of training institutes are differentiated in terms of harmonious arrangement between beautiful natural scenery and buildings in consideration of the layout characteristics of major facilities and the distance of ramps in and out of the facilities along with architectural features, including the transparency of building elevation and the type of slopes of roof structure. Fourth, the individual lodging buildings feature a variety of types depending on the design concept with different roles depending on the directional aspects such as the connection of ramps and the relations with the outside. Fifth, outdoor space plans are differentiated according to the intended purpose of training facilities. When it comes to gym facilities, for example, different outdoor space plans are found to be made depending on the original design concept such as outdoor playground-centered planning or golf facilities.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.55-70
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• 2020

This study aims to identify the influence of risk-inducing factors and safety inspection on the measures of reducing accidents among workers of building structures in small construction sites. The result can be summarized as follows: First, as for the influence of risk-inducing factors on human factors, preparation for work, disintegrating molds, taking follow-up measures, and keeping records, have statistically significant influences. Therefore, it can be said that safety inspection has a partial mediating effect in the relationship between risk-inducing factors and human factors. Second, as for the influence of risk-inducing factors on facility factors, preparation for work, and taking follow-up measures influenced significantly. This indicates that safety inspection has a partial mediating effect in the relationship between risk-inducing factors and facility factors. Third, as for the influence of risk-inducing factors on management factors, the installation of shores and risk assessment are found to have significant effects. This shows that safety inspection has a partial mediating effect in the relationship between risk-inducing factors and management factors. Fourth, the influence of risk-inducing factors on work factors was significant only in the installation of shores. This indicates that safety inspection has a completely mediating effect in the relationship between risk-inducing factors and work factors. Finally, in the relationship between risk-inducing factors and accident reduction measures, preparation for work, installation of shores, and taking follow-up measures showed significantly positive influences. In contrast, keeping records has a significant negative influence. Thus, safety inspection has a partial mediating effect in the relationship between risk-inducing factors and management factors.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.28-35
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• 2006

Recently, a number of equipments related with electricity, electronics, and communication in the same building are needed to the grounding system for safety from unexpected accidents. When the faulted electric current flows into a certain grounding system, the potential rise in that system takes place and it might induce the potential rise to other grounding system. This potential interference was strongly affected by the surface potential, which was deeply related with the electrode shape. In this paper, the fundamental formula was deduced on the basis of surface potential of two grounding electrodes. Which corresponds to source of the potential interference and other grounding electrode, respectively. Therefore, the degree of potential interference in this mesh grounding electrode system was verified by the simple model simulation. In addition, in order to identify the difference between the grounding resistance in the realistic construction site and the expected value from the corresponding simulation, the experiment was performed with model on a reduced scale about the realistic grounding system. It consists of stainless steel hemisphere electrodes in a water tank. From this work, the grounding resistance in the mesh grounding electrode showed the good coincidence results between those. Consequently, it is confirmed that the grounding resistance in the mesh electrode is possible to be estimated by performing the experiment using the water tank model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.559-562
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• 2017

In city, tracing of power transmission lines is difficult due to compound installation of overhead and underground lines, transposition, bad view caused by trees or big buildings. It is hard problem for electrical technician on site to trace power transformers or power lines to serve customers in 3 phase -4 wires power distribution systems. It is necessary that the correct and fast tracing method is required for load balancing among distribution lines. Old technology use to trace off-lines with high power impulse injection. Our proposed method use to trace live lines with very small power high frequency signal injection. Typical power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. Two end communication terminals are required to be synchronized between them for determination on electrically same phases. Challenging issue is to achieve synchronization without GPS providing synchronizing time. A novel power transformer and wire identification system is designed and implemented. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.