• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.93-101
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• 2018

A city is like a living organism that is born, grows and become extinct within an ecosystem. In recent years, more and more cities have been planned by designers rather than spontaneously growing over time. This planning means that if a city is not appropriately designed at the beginning, it is very hard to fix or adjust it later. A poor urban design inconveniences many people, and forces them to adjust to it. For this reason, it is important to design a city as optimally as possible at the design phase. One of the reasons why a city is not designed optimally is complexity. Previous urban design methods have attempted to resolve the complexity by using a top-down problem-solving method based on the experience and knowledge of the urban planner. However, such an approach does not have the organic characteristics of a bottom-up problem-solving method of an artificial life, based on the creation principle of the ecosystem. Therefore, in this study the general principle of artificial life, which can provide a solution to the bigger problems that accumulate as a result of the solutions to small units of problems, is adopted. This enables us to draw various urban design alternatives, and it proves that the alternatives, despite being drawn through a limited modeling method, have almost no differences from those designed by an expert, and its possibilities of future development has also been verified.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.12-20
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• 2018

As facilities have become larger, more complex, and advanced, the importance of the facility management in the operation phase of the building is increasing. As a result, the scope of the facility management function is expanding, and the requirements of information are ever-increasing. However, inefficient exchange of information occurs due to duplicated tasks and lack of collaboration among the construction life cycle phases, resulting in cost loss. These low interoperability issues can be complemented by construction information management from a life cycle perspective. Efficient construction information management at each life-cycle stage is derived from the owner's will and is materialized through the construction information handover requirements by the owner. The purpose of this study is to develop an evaluation method of construction information handover requirements for facility management. In order to develop the method, facility management types and business functions are also classified and defined in this paper. Using the methodology proposed by this study, a case-study of evaluating the 'takeover items' submitted by contractors was performed for the purpose of research validation. The results of the case-study found that the most effective areas are in the order of 'legal informations', 'drawings', 'guides', etc. This study can be used as a reference data for deriving handover requirements for construction information at the early stage of the project.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1330-1335
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• 2012

Foot and mouth disease (FMD) is one of the acute infectious diseases in hoofed and even-toed mammals, including pigs, and it occurs via acute infection by Aphthovirus. When FMD is suspected, animals around the location of origin are typically slaughtered and buried. Other methods such as rendering, composting, and incineration have not been verified in practice in Korea. After the FMD incident, the regular monitoring of the microbial community is required, as microorganisms greatly modify the characteristics of the ecosystem in which they live. This is the result of their metabolic activities causing chemical changes to take place in the surrounding environment. In this study, we investigated changes in the microbial community during a 24 week period with DNA extracts from leachate, formed by the decomposition of buried pigs at a laboratory test site, using denaturing gradient gel electrophoresis (DGGE) with a genomic DNA. Our results revealed that Bacteroides coprosuis, which is common in pig excreta, and Sporanaerobacter acetigenes, which is a sulfur-reduced microbe, were continuously observed. During the early stages (0~2 weeks) of tissue decomposition, Clostridium cochlearium, Fusobacterium ulcerans, and Fusobacterium sp., which are involved in skin decomposition, were also observed. In addition, various microbes such as Turicibacter sanguinis, Clostridium haemolyticum, Bacteroides propionicifaciens, and Comamonas sp. were seen during the later stages (16~24 weeks). In particular, the number of existing microbial species gradually increased during the early stages, including the exponential phase, decreased during the middle stages, and then increased again during the later stages. Therefore, these results indicate that the decomposition of pigs continues for a long period of time and leachate is created continuously during this process. It is known that leachate can easily flow into the neighboring environment, so a long-term management plan is needed in burial locations for FMD-infected animals.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.732-741
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• 2001

In the relational database systems the join operation is one of the most time-consuming query operations. Many parallel join algorithms have been developed 개 reduce the execution time Multiple hash join algorithm using allocation tree is one of the most efficient ones. However, it may have some delay on the processing each node of allocation tree, which is occurred in tuple-probing phase by the difference between one page reading time of outer relation and the processing time of already read one. This delay problem was solved by using the concept of synchronization of page execution time with we had proposed In this paper the effects of the performance improvements in each node of the allocation tree are extended to the whole allocation tree and the performance evaluation about that is processed. In addition we propose an efficient algorithm for multiple hash joins in limited number of processor environments according to the relationship between the number of input relations in the allocation tree and the number of processors allocated to the tree. Finally. we analyze the performance by building the analytical cost model and verify the validity of it by various performance comparison with previous method.

• Journal of Science and Technology Studies
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• v.3 no.2 s.6
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• pp.29-60
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• 2003

Inter-Korean Cooperation in Science and Technology will contribute to building the trust between S.K and N.K as a leading factor and cut down the cost of unification by diminishing the technology lag and the gap of economic level. This study has shown that we can increase the productivity of unified Korea Innovation system if we systematically analyse the present condition of the Inter-Korean Cooperation and promote Inter-Korean Cooperation. In this study, the author analyses the present condition of the Inter-Korean Cooperation with integrated framework of three aspects to clear up the policy of Inter-Korean Cooperation. First, in the national aspect, we make use of the notion of international cooperation and multilateral mechanism of an international organization. Thereafter, we make out the alternatives in the aspects of international relationship and legal and institutional view Second, in the unification aspect, we consider the Inter-Korean Cooperation by the notion of national innovation system. Thereafter, we make out the alternative in the aspect of a phase-dependent approach. Finally, in technology aspect, we consider the Inter-Korean Cooperation by the notion of technology gap, the framework of technology transfer, and technology dependency theory. As a conclusion, through this study, the author have tried to integrate the various theoretical backgrounds. As a result, the author could analyse the present condition of ter-Korean Cooperation in Science and Technology and team a good lesson from it; Therefore, we can use it as a means of evaluation on a cooperation program and prediction for the future status of cooperation.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.79-90
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• 2021

In domestic public construction, disputes are increasing due to differences among stakeholders regarding contract price adjustment. In particular, the actual cost-plus fee for overhead costs due to the schedule extension cannot be agreed upon at the administrative phase, and most of them seek judicial judgment. Thus, this study aims to propose a 'sufficiently satisfactory' alternative to reach an agreement before disputes in order to minimize disputes related to the calculation of additional overhead costs. To this end, this study proposes three alternatives based on the rate method. Firstly, when calculating additional overhead costs, it is not calculated as an actual cost-plus-fee method, but as a rate compared to direct labor costs among net direct costs. Secondly, the calculated indirect labor costs are compensated for up to the legal maximum of legal limit costs such as general management costs, profits and so on. Thirdly, it reflects overhead costs increased or decreased due to change orders. Risks were analyzed by collecting expert opinions on the proposed methods and applying actual cases. Finally, as a result of investigating the level of consensus for each stakeholder, it was confirmed that all stakeholders could agree regardless of the size of the company. The result of this study is expected to as a useful tool among stakeholders in the construction fields that can be able to easily agreed upon.

• Smart Media Journal
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• v.9 no.4
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• pp.152-161
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• 2020

In the construction, VR(Virtual Reality) is simply used by users to implement and experience 3D modeling in virtual reality, such as safety, practical education, and promotion. The VR related research includes content development and visualization simulation such as disaster safety evacuation simulation and design education contents. Research on developing suitable VR and presenting directionality is insufficient, which is required in practice. Therefore, in this study, prior to the development of VR suitable for the construction, quantitative evaluation, and analysis based on the judgment of experts are performed. However, the research was conducted on the design stages, which are believed to have high needs and application effects of VR during the lifecycle of construction. There are nine tasks that can be applied to VR in the design stage, and these tasks were evaluated and analyzed using IPA(Importance Performance Analysis) by surveying the level of expectations, importance, and performance. As a result, it was evaluated and analyzed that VR and content development was necessary for the review of member interference and collaboration work for decision making among related stakeholders. The results of this study are expected to be used as basic data for the development of VR to be applied in the design stage to the future.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.1-13
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• 2011

Cheongpyeongsa Temple was originally built in the early years of Goryeo Dynasty, but its current structural framework was made by the Lord Jinrakgong Lee Ja Hyeon(1061-1125) of the middle Goryeo period based on the Zen thought after he began living in the Cheongpyeong mountain around the temple in 1089. The purpose of this study is to conceptualize, based on old documents, historical changes of the appearance and survival of man-made structures with in the Zen garden formed and developed after Lee Ja Hyeon laid the foundation for Munsuwon Zen garden. Among the eight, outside-the-temple hermitages built at the time of Lee Ja Hyeon's Munsuwon Zen garden, only three hermitages, which are Sik-am, Gyeonseong-am, Yangshin-am had been remaining thanks to restoration and repair until late Joseon Dynasty and preserved as symbolic hermitages. Also, the Yeongji Pond built at the time of Lee Ja Hyeon still remains as precious landscape relics which is meaningful as a genuine Goryeo-period pond. The nine pine trees said to be planted by Lee Ja Hyeon remained until middle 1800s through their descendant trees. When the Buddhist monk Bowoo Daesa(1509-1565)changed the name to Cheongpyeongsa Temple in middle Joseon based on the Munsuwon Zen garden built by Lee Ja Hyeon and greatly expanded it, he newly built and expanded all buildings inside the temple except for Neunginjeon(main temple building), resulting in the present temple structure. In addition, by greatly enhancing the level of scenery by reconstructing Yeongji Pond outside the temple area and transplanting garden plants from the royal court, he made Cheongpyeongsa Temple the most prosperous Zen garden in its history. But after the mid-1800s, which is late Joseon period, Cheongpyeongsa Temple failed to thrive further and began to decline, and so currently most buildings of the Zen garden have disappeared except for some parts of the temple and other facilities are neglected.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.23-38
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• 2021

In this paper, we analyzed the possibility of utilizing LX-PPS GNSS permanent stations whose antennas are installed on the building rooftop for the purpose of high-precision GNSS positioning services. We picked 15 pairs of adjacent GNSS permanent stations operated by LX-PPS and NGII, and then produced 3-year-long time series using the high-precision data processing software called GIPSY. Patterns and trends of position estimates were compared and analyzed. Horizontal and vertical deviations including the linear velocities coincide with the well-known crustal deformation rates of the Korean peninsula. We also observed almost the same annual or seasonal patterns from those nearby sites. After detrending the linear velocity, the amplitude and phase of annual signals almost perfectly match each other within the baseline length of 2 km. By subtracting seasonal signals, the RMS and standard deviations in LX-PPS PPGR with respect to NGII KANR are about 1, 2, and 5 mm in the north-south, east-west, and vertical directions, respectively. From this analysis it can be concluded that the rooftop-installed LX-PPS sites show similar level of stability and positioning performance comparable to those ground-mounted NGII stations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.371-383
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• 2021

Steel-concrete single-leaf blast-resistant doors, having steel box and slab inside, are installed on the wall using supporting members such as hinges and latches. Several studies have been conducted on their deflection behavior in the same direction as that of the blast pressure, but studies on their deflection behavior in the opposite direction, that is, studies on negative deflection behavior are relatively insufficient. In this study, we conducted a parameter analysis using finite element analysis on blast-resistant doors, on their rebound behavior in the negative deflection phase. Results revealed that the plastic deformation of the door, and the change in momentum and kinetic energy during rebound, were major factors influencing the rebound behavior. Greater rebound force was developed on the supporting members in the impulsive region, than in the quasi-static region; due to the characteristics in the impulsive region, where the kinetic energy developed relatively greater than the strain energy. In the design process, it is necessary to consider excessive deformation that could occur in the supporting members as the rebound behavior progresses. Additionally, it was found that in the case of steel-concrete blast doors, the rebound force increased relatively more, when the effects of both rebound and negative blast pressure contributed to the negative deflection of the door. Since conditions for the occurrence of this superposition effect could vary depending on structural characteristics and explosion conditions, further investigation may be required on this topic.