• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.65-73
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• 2008

Retaining large stability margin is essential in designing a feedback control system to deal with the uncertainties inherently existing in the mathematical model and the control apparatus. The LQG controller in general loses the stability margin due to the embed Kalman filter. The performance of a control system called LTR with a DUOX structure(LTR/DOUX) to overcome the demerit of LQG controller is to be investigated from the responses in both the time and the frequency domain. The results indicated that the LTR/DOUX recovered the gain margin of 30dB approximately 20 times more than that of LQG/DOUX, resulting in a robust stable control system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.117-123
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• 2022

Recently, due to COV ID-19, many people are spending most of their time indoors. So, there is a rising interest on the indoor air quality in the field of building construction. The main sources for the indoor air pollution are human indoors activity, building materials, living supplies and the polluted air from outdoor. The Korean government has designated 17 indoor air pollutants including fine dust, total airborne bacteria, fungi and carbon dioxide, etc.. Most people are always exposed to assorted bacteria and molds in our daily life, because indoor environment for human, moderate temperature are humidity, it is favourable to the growth of most of bacteria and fungi. Pine needles have an antibacterial effect against bacteria and fungi. In this study, the antibacterial activity against bacteria and fungi was tested by cement matrix using pine needle extract. As a result, the cement matrix using pine needle extract showed antibacterial activities against bacteria, but in the case of fungi, it did not show antifungal activity.

• Journal of Korean Society of Archives and Records Management
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• v.1 no.1
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• pp.19-35
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• 2001

After almost one century of discontinuity in the archival tradition of Chosun dynasty, Korea entered the new age of records and archival management by legislating and executing the basic laws (The Records and Archives Management of Public Agencies Ad of 1999). Annals of Chosun dynasty recorded major historical facts of the five hundred years of national affairs. The Annals are major accomplishment in human history and rare in the world. It was possible because the Annals were composed of collected, selected and complied records of primary sources written and compiled by generations of historians, As important public records are needed to be preserved in original forms in modern archives, we had to develop and establish a modern archival system to appraise and select important national records for archival preservation. However, the colonialization of Korea deprived us of the opportunity to do the task, and our fine archival tradition was not succeeded. A centralized archival system began to develop since the establishment of GARS under the Ministry of Government Administration in 1969. GARS built a modem repository in Pusan in 1984 succeeding to the tradition of History Archives of Chosun dynasty. In 1998, GARS moved its headquarter to Taejon Government Complex and acquired state-of-the-art audio visual archives preservation facilities. From 1996, GARS introduced an automated archival management system to remedy the manual registration and management system complementing the preservation microfilming. Digitization of the holdings was the key project to provided the digital images of archives to users. To do this, the GARS purchased new computer/server systems and developed application softwares. Parallel to this direction, GARS drastically renovated its manpower composition toward a high level of professionalization by recruiting more archivists with historical and library science backgrounds. Conservators and computer system operators were also recruited. The new archival laws has been in effect from January 1, 2000. The new laws made following new changes in the field of records and archival administration in Korea. First, the laws regulate the records and archives of all public agencies including the Legislature, the Judiciary, the Administration, the constitutional institutions, Army, Navy, Air Force, and National Intelligence Service. A nation-wide unified records and archives management system became available. Second, public archives and records centers are to be established according to the level of the agency; a central archives at national level, special archives for the National Assembly and the Judiciary, local government archives for metropolitan cities and provinces, records center or special records center for administrative agencies. A records manager will be responsible for the records management of each administrative divisions. Third, the records in the public agencies are registered in the computer system as they are produced. Therefore, the records are traceable and will be searched or retrieved easily through internet or computer network. Fourth, qualified records managers and archivists who are professionally trained in the field of records management and archival science will be assigned mandatorily to guarantee the professional management of records and archives. Fifth, the illegal treatment of public records and archives constitutes a punishable crime. In the future, the public records find archival management will develop along with Korean government's 'Electronic Government Project.' Following changes are in prospect. First, public agencies will digitize paper records, audio-visual records, and publications as well as electronic documents, thus promoting administrative efficiency and productivity. Second, the National Assembly already established its Special Archives. The judiciary and the National Intelligence Service will follow it. More archives will be established at city and provincial levels. Third, the more our society develop into a knowledge-based information society, the more the records management function will become one of the important national government functions. As more universities, academic associations, and civil societies participate in promoting archival awareness and in establishing archival science, and more people realize the importance of the records and archives management up to the level of national public campaign, the records and archival management in Korea will develop significantly distinguishable from present practice.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.29-38
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• 2022

Recently, seismic design for anchors is required, which are used for connecting structural members and non-structural and structural members. In this study, pull-out tests on the new expansion anchors which have been developed for cracked concrete. The anchors of 12 mm and 20 mm diameters were tested which are commonly used. Experiments were conducted on non-cracked concrete and cracked concrete to evaluate the seismic performance of the post-installed anchor. The experimental method complies with the specified test protocol (KCI, 2018). Three experimental variables are included in this study: presence of cracks, concrete compressive strength, and effective embedment depth. The strength of the anchors was evaluated with the characteristic capacity K_5% determined from the test results incorporated with the safety of 5% fractile. The characteristic capacity K_5% of the non-cracked and cracked concrete specified in KDS 14 20 54 are 9.8 and 7.0, respectively. Test results show that all groups except the three groups have higher characteristic capacity K_5% than the KDS code and the nominal strengths of the tested anchors can be determined with the obtained characteristic capacity K_5%.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.101-112
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• 2005

Recently, a curtain wall construction is a exterior finishing components which is most used for shortening time in high-rise building as well as the class of key management factors in cost and schedule control. Also, it is recognized that an effective management for curtain wall process is a major subject to accomplish the project successfully. However, as the current management for curtain wall construction is focused on the construction stage, it makes problems such as errors in business performance, rework by mistakes and duplications, errors and omissions by ineffective information management and there has never been any efficient management from a view of the entire Curtain Wall Life-cycle process. Therefore, the aim of this study is to suggest a stage check point for process improvement in the curtain wall Life-cycle process through current curtain wall process analysis, and then to investigate the cause of waste factors using the Muda method from the Toyota Production System and extract the weighted effects of the waste factors using the analytical hierarchy process method. According to the result, Most of the inefficient factors happened in architectural design stage of the entire curtain wall Life-cycle process and my research identified that detail factors of them are a delay of decision making and an approval in changes, a deficit of engineering capacity and a delay of approval in architectural design drawings by owner, etc.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.115-121
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• 2015

As recent buildings have been enlarged and free-formed, it is hard to represent three-dimensional buildings with two-dimensional drawings and identify design errors, construction errors, difference of construction quantity and construction cost, clash with columns, beams, pipe machinery, and so on. In order to overcome the limitations, BIM(Building Information Modeling) has been used in construction industry. However, BIM in the construction site is not fully facilitated after practical implementation in process control including training, evaluation and analysis of the process. Therefore, in this study, the effect of BIM applied in the construction site is analyzed empirically throughout the survey at the construction site in accordance with the training, evaluation, and implementation of BIM.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.31-41
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• 2009

Under the Korea Building Act, anyone planning to build a building or buildings on a site over $200m^2$ must plant plants over a specific area. In large scale development this rule is adhered to well, but such is not the case in small scale development. Therefore, special attention must be given to small scale development. Thus, the purpose of this research is to analyze the current situation and practice of planting at small scale development sites in Seoul, and then suggest policies for improving them. In this study using the data covering Seongbuk-Gu and Gangnam-Gu, which was surveyed in 2002, the current situation and practice of planting at small scale development sites was analyzed. After a questionnaire survey was conducted with government officers and building owners, the same analysis was made. Then the policies for improvement were extracted. The results are as follows: 1. In superordinate planning stage, because the minimum standards are too low, those must be strengthened. Any district plan does not control planting in private building lots. This requests active application of planting in private building lots as a design control measure in district planning. 2. In the building design stage, there are no guidelines. The obligation of building set-back between adjacent buildings by the Korean Building Act produces mass shaded and inferior planting beds. The act also is blocking landscape architects' participation in small scale development. And wall installations deteriorate the streetscape and growth of plants with shading. Therefore guidelines must be made. 3. In each stage of the building permit, the permit for building completion, and maintenance the Korean Building Act is blocking landscape architects' participation in small scale development, so the planting plan is completely handled by nonprofessional persons. Therefore, the act should be amended in order to make way for landscape architects' participation in each stage of the small scale development process.

• Korean Journal of Construction Engineering and Management
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• v.20 no.2
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• pp.79-85
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• 2019

The policy introduced recently in order to promote small-size reconstruction housing projects for rehabilitating downtown area consists of aged multi houses has been little practiced, as preferential provisions for such projects are more likely applicable for large projects. Several expert interviews and surveys were conducted to find efficient clauses to overcome the problems and their relative weights. As the results, it is revealed that 'relation of floor area ratio' and 'relaxation of building height limit criteria' are the most effective whereas 'purchasing and operating of residents' common facilities with public fund' is little. The study results would be a great interests for public institutions to rebuild aged housing area without destroying local communities and to provide socially disadvantaged class with rental housing at the same time.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.3
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• pp.191-198
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• 2008

Pot life of two-component adhesives such as epoxy resin used in saturating FRP composite is defined as a certain time periods which can guarantee the bond performance and workability of epoxy resin. Therefore, adhesion procedure in strengthening RC members should be completed before chemical hardening is going on at job site. It has been known that there are two types of test method to evaluate the pot life of structural adhesive based on apparent viscosity or temperature change. This study is to verify the test methods how to assess pot life of structural adhesive for FRP composites by means of changing in apparent viscosity and means of exothermic reaction temperature proposed in existing test standards. Results of each test method were compared and analyzed, and reasonable test and evaluation method were suggested.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.73-82
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• 2022

Waste paint, one of the specified wastes in Korea, is currently treated entirely by incineration treatment method, and is hardly recycled compared to other wastes. Incineration treatment method also causes environmental problems such as air pollution. Thus, this study breaks away from the existing incineration treatment method of waste paint and switch to a method of pretreatment operation through evaporation, condensation, and thermal decomposition by temperature control. and then proposes a sustainable waste paint treatment process that can be recycled as an alternative energy heat source. If a new method of disposing of waste paint and technology for recycling are developed and disseminated, it is expected that the effect will be large from an economic and environmental point of view.