• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.9-16
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• 2019

Recently, precast PSC girder bridges have been widely applied for short and middle span bridges. The construction of the spliced girder bridges has been increasing to overcome the length limit of girder and transportation restrictions. In case of the spliced girder, the integrity of the segmental joints is very important to secure the structural soundness of bridge because the discontinuity on the segmental joints between adjacent segments could be vulnerable point. The study of segmental joint behavior with different influence factors of joint type, shear key installation, confining force is very important. In this research, finite element analysis and scaled model test with different shear key shapes and confining forces were carried out and the comparative study was performed to evaluate the segmental joint behavior of precast spliced PSC girder bridge. It was confirmed that the installation of shear key with height and depth ratio of 1/2~1/3 and applying of confining force of 1/2 of the concrete strength at the joint was effective in improving the integrity of segmental joint. In addition, the field loading test for existed precast spliced PSC girder bridge was performed and the measurement of the difference of deflection between adjacent segments at segmental joint was proposed as the assessment solution of the integrity of segmental joint.

• Journal of the Korean Solar Energy Society
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• v.39 no.5
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• pp.1-10
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• 2019

Recently, the installation capacity of PV (photovoltaic) systems has been increasing not only field installation but also floating PV, farm land, BIPV/BAPV. For this reason, the new design and materials of PV module are needed. In particular, in order to apply a PV system to a building, lightweight of the PV module is essential. PV modules made of generally used texturing glass are excellent in output and reliability, but there is a limit to the weight that can be reduced. For the lightweight of the PV module, it necessary to use a film instead of a glass. However, the application of film rather than a glass may cause various problems such as decrease in photocurrent by decrease in transmittance and a increase of CTM (cell to module) loss, a degradation of the reliability, and so on. In this paper, PV modules using Ultra barrier film, which is recently a lot of interest as a substitute for a glass, its characteristic analysis and reliability test were conducted. The transmittance and UV characteristics of each material were verified, and the output of the fabricated 1 cell PV module was measured. In addition, 24 cell PV modules were fabricated at the lab-scale and its reliability tests were conducted. As a result of the experiment, the reliability characteristics of the ultra barrier film PV module were excellent, and it was confirmed that it could be used as the front material of the PV module instead of glass

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.725-733
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• 2018

With urbanization projects involving trunk roads progressing, many simple interchanges, which separate passing traffic into the main traffic and access subtraffic, are being constructed to maximize the traffic capacity. Under the current Road Connection Rule, the access-prohibited section in an interchange is determined based on the access lane and limit distance in the complete interchange road, but separate criteria for the simple interchange are not defined. This may cause confusion in the Road Management Office's determination of the access-prohibited section in the simple interchange, or lead to the application of the criteria for the access-prohibited section in the complete interchange without considering the features of such interchange. This study conducted a comparative analysis of the domestic and overseas systems related to the installation of access section in trunk roads, such as general national roads. This paper presents a survey of the methods for applying the access-prohibited section in the interchange along with the actual cases and proposes improvement measures for a rational calculation of the access prohibited installation section in the simple interchange to minimize the downsides associated with the application of the extremely strict criteria. The proposed road connection rule improvement measures based on the consideration of the purpose of installing the simple interchange and on the consideration the features of the simple interchange are expected to prevent administration confusion by the field road management offices as well as the waste of unnecessary efforts and costs by petitioners so they can boost the service satisfaction for people and the administrative reliability.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.46-53
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• 2019

Recently, the need for emergency medical facilities is increasing due to a large-scale disaster. The Ministry of the Interior and Safety has completed the development of Disaster Resource Sharing System (DRSS). In this system, only air tent and negative pressure tent, which are classified and managed as equipment are resources related to emergency medical facility at disaster site. However, the characteristics of resources for the facility such as the time of input, a period of stay, transportation, and installation methods were not reflected. So, The purpose of this study is to propose improvements of management of resources for emergency medical facility at disaster site, that classified to materials and equipment in DRSS. This study analyzed the state of resources for facilities and the attributes of resources based on literature and disaster medical consultation of mobile hospitals. The resources for emergency medical facility are required to be linked to medical support resources and reflected in the DRSS, since emergency medical facility resources at the disaster site should be managed through a combination of medical resources classified as equipment. And future research on installation of emergency medical facilities plan considering the cost of the disaster management resources should be carried out.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.438-443
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• 2022

In this study, the lateral loading test was performed to analyze structural performance of multi-span plastic greenhouse through full-scale experiment and numerical analysis. In order to analyze the lateral stiffness and stress, we installed 9 displacement sensors and 19 strain gauge sensors on the specimen, respectively, and load of l mm per minute was applied until the specimen failure. In the comparison between the full-scale experiment and the structural analysis results of a multi-span greenhouse with venlo-type roof according to bracing installation, there was a large difference in the lateral stiffness of the structure. By installing a brace system, the lateral stiffness measured near the side elevation of the specimen increased by up 44%. As the bracing joint used in the field did not secure sufficient rigidity, the external force could not be transmitted to the entire structure properly. Therefore, it is necessary to establish a bracing construction method and design standards in order for a greenhouse to which bracing applied to have sufficient performance.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.37-49
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• 2021

Micropiles are widely used in construction field to enhance bearing capacity and reduce settlement of existing foundation. It has various benefits such as low construction expense, simple installation process, and small construction equipment. Recently, new microple equipped with the base expansion structure at the end has been developed to improve the foundation bearing capacity. The improvement of load capacity can be conceptually achieved by expanding the base expansion structure when a load is applied to the micropile. However, the expansion mechanism of the base expansion structure and the improvement of load capacity of the micropile were not yet experimentally validated. Therefore, in this study, a series of centrifuge model tests was performed to evaluate the effect of the base expansion structure on the improvement of load capacity. Two types of soil, sand and weathered rock, were prepared and the loading tests were performed using the real micropile with the base expansion structure. During the tests, the earth pressures surrounding the base expansion structure were monitored. As a result, when a load of 30 kN was applied to the micropile, the increase in the ratio of the horizontal to vertical pressure increment (∆σ_h/∆σ_𝜈) ranged from 0.4 to 0.58 in sand and ∆σ_h/∆σ_𝜈 = 0.19 in weathered rock, respectively. Therefore, it can be concluded that the increase in the horizontal earth pressure adjacent to the base expansion structure will improve the bearing capacity of the micropile.

• Journal of the Korean Geotechnical Society
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• v.26 no.6
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• pp.29-38
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• 2010

Micro-piles have been used to increase the bearing capacity or to restrain settlement of existing shallow foundation. Recently, micro-piles are used to support the shallow foundation, to stabilize the slope and to resist the sliding of retaining wall. Using the micro-piles in geotechnical engineering, some investigators have studied the effective installing method by model test or field test. But most of previous studies are chiefly focused on the micro-piles in sand or clay layer. If a rock layer exists in soil, the installing length of micro-piles may be determined by the depth of rock layer. In this case, the stiffness of pile may be changed by the installing length of pile, and so the installing method has to be altered by the changed stiffness of pile. Model tests have been conducted to study the installation method of micro-pile in soil with rock layer. As a result, when the ratio of length of pile is below 50 ($L/d{\leq}50$), installing of micro-piles in vertical position is effective regardless of the depth of rock layer. If the depth of rock layer is deeper than soil failure zone and the ratio of the length of pile exceeds 50 (L/d>50), installing of the micro-piles in sloped position is effective.

• The Journal of Bigdata
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• v.6 no.2
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• pp.125-137
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• 2021

The number of CCTV installed in Korea is over 1.3 million, increasing by more than 15% annually. However, due to the limited budget compared to the installation demand, the infrastructure is composed of 500,000 pixel low-quality CCTV, and there is a limits on identification of objects in the video. Public CCTV has high utility in various fields such as crime prevention, traffic information collection (control), facility management, and fire prevention. Especially, since installed in high height, it works as its role in solving diverse crime and is in increasing trend. However, the current public CCTV field is operated with potential problems such as inability to identify due to environmental factors such as fog, snow, and rain, and the low-quality of collected images due to the installation of low-quality CCTV. Therefore, in this study, in order to remove the typical low-quality elements of public CCTV, the method of attenuating scattered light in the image caused by dust, water droplets, fog, etc and algorithm application method which uses deep-learning algorithm to improve input video into videos over quality over 4K are suggested.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.792-800
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• 2012

The study was performed to simulate the reduction efficiency of suspended solids (SS) for cultivated land located at riverine area at the Namhan River and the Bukhan River watershed sites (site A, B, C) under the rainfall conditions using HUFF & SCS UH-based VFS Design module of Web GIS-based VFSMOD System. The study indicates that the field 5% sloped, located at Bukhan River watershed (site A), requires at least 0.5 m width of Vegetative Filter Strip (VFS) to reduce 70% of SS while the field 10% sloped requires the at least 1.0~1.5 m width of VFS to reduce 70% SS, under the condition 106.2 mm of rainfall event and bell pepper or corn of crops. Against the conditions 95.1 mm of rainfall event and sweet potato or soy bean of crops, the field 5% sloped, located at Namhan River watershed (site B) requires at least 0.5 m width of VFS to reduce 70% of SS while the field 10% sloped requires at least 1.0 m width of VFS to reduce 50% SS. The crops sweet potato and soy bean are cultivated in the site C, located at Namhan River watershed, 1 m of VFS is capable of 64.0% and 62.0% of SS reduction against 102.6 mm and 151.2 mm rainfall conditions respectively, for the 5% sloped field. The result supports that VFS is one of most potential methods to reduce SS from cultivated area, which is environment-friendly hydrologic structure. The VFS design, however, needs to be simulated before its installation in the field, the simulation needs to consider not only various characteristics of the field but also different conditions affecting the VFS, using a model capable to consider a lot of factors.

• 한국게임학회지
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• v.6 no.1
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• pp.70-72
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• 2009

This research is focused on defining interaction within the context of digital media and creating a multi cultural definition of interactivity. The concept of multi digital culture and a definition of interaction in digital media have often been overlooked by other researchers and this has caused the emergence of many different notions on this issue. As a result of these varied notions of the concept, public confusion has arisen regarding interactivity. The main purpose of this research is to find a suitable multi definition of interaction through examining local digital culture. In order to analogise multi digital culture, the video game culture is employed as a metaphor to interpret local digital culture. The reason for this is that a specific national culture can be easily identified within the video game culture. Four countries, South Korea, Japan, the U.S. and the UK have been chosen for comparison purposes. Case study, questionnaire and publicly accessible video game related data, such as, video game charts, are used for formalising and analysing unique local digital culture. The Heyri POP UP IMAGE Festival, S. Korea, was also used as a pilot study, with some of the above research methods being employed to analyse South Korean digital culture. In relation to western cases, interview and questionnaire were primarily used. The data from the case countries was carefully compared and analysed and then it became the basis of a theory of multi definition of interaction in digital media. The case study employed the cultural metaphor for this research and in addition video game culture related questionnaires and interviews with experts of interactive art genre, regarding new notions of digital interaction were utilised. The survey was conducted simultaneously in the four different cultural case nations of this research. Twenty respondents from each case nation participated in the survey, in order to investigate firstly, the existence of 'local digital culture' and secondly, the trends and phenomena of 'digital culture' in these four different 'local digital cultural areas'. In terms of interviews with experts of the interactive art genre, these were focused on obtaining their understanding of contemporary digital culture in their research. Using gathered data from the observation of local digital culture, the basic theory of interaction and the terminology of interaction are reformed. Localised definitions of interaction on digital media, control based interaction and communication based interaction are presented, in order to identify a 'locality' in terms of various contemporary digital cultures. As a result of analysing digital culture, new definitions of 'multi definition of digital interaction' were formulated. As mentioned above, 'control' and 'communication' based interaction were initiated, based on 'user to media' relationships. Based on the degree of physical interaction, 'liminal' and 'transitive' interactions were initiated. Less physical digital interaction is named 'liminal' interaction and more physical digital interaction is named' transitive' interaction. These new definitions of interaction were applied to the real world examples of uses of digital interaction, such as, digital interactive installation artworks and video games. The newly defined meaning of digital interaction can be applied to analysing digital interactive installation artworks and possibly indicate their future development and the prospects of future electronic games. Three leading digital interactive artists were selected for this analysis and their works were studied in terms of the implementation of 'multi definition of digital interaction'. Throughout these processes, the meaning of 'communication' in digital interactive media was emphasised. Many of the selected artists' digital installations were focused on 'communication' or 'interaction between each user through digital media', rather than the concept of 'control' in digital interaction, otherwise termed, 'communication with digital media'. In their artworks, interaction between each audience was digitally engaged within the physical interactive environment which was created by the digital media. Both the audience's action and all the reaction throughout the interaction between the audiences, triggered the digital media' s reaction. This audience-audience-media interaction is the key to understanding the concept of 'communication' in physical digital media and it is the main interactive concept upon which the selected digital interactive installation artists for this research and many other artists from similar fields, are concentrating their efforts. In the case of the video game, a similar trend was noticed to that of digital interactive installations. Based on this research's 'multi definition of digital interaction', the video game has evolved from the early stage of being conventional game, which was focused on control based interaction, to the on-line game which was focused on communication based interaction, to physical interactive games, such as, Nintendo Wii, which are focused on more physical interaction and finally, the ubiquitous interactive game, which is mainly concentrated on the concept of 'communication' in physical digital interaction. It is possible that this evolution of the video game concept of interaction is comparable to the progress of digital interactive artworks. This view is based on the fact that both genres show evidence that they are developing in the direction of the concept of 'communication', in terms of physical digital interaction. The important emphasis of this research's results is 'locality' and 'communication' in physical digital interaction. The existence of different digital culture trends, which were assessed by the 'multi definition of digital interaction', can explain the concept of 'locality' in digital interaction. This meaning of 'locality' may assist in understanding contemporary digital culture and can reduce possible misunderstanding as regards 'local' digital culture. In the application of the concept of digital interaction to the field of either artworks or video games, it is possible to form the opinion that an innovative concept of physical digital interaction is 'communication' within this context. This concept and its applications can improve the potential of both digital interactive culture and technology.