• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.129-138
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• 2011

Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.101-109
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• 2011

As climate change is becoming the main issue, various efforts are focused on saving building energy consumption both at home and abroad. In particular, it is very important to save energy by maintenance, repair and rehabilitation of existing multi-family housing complex, because energy consumption in residential buildings is not only forming a great part of gross energy consumption in Korea but the number of deteriorated complexes is also sharply increasing. However, energy saving is not considered as a main factor in decision making on rehabilitation project. Also, any supporting tool is not appropriately prepared in existing process. As the first step for development of decision support system on rehabilitation, this paper developed a breakdown structure, which makes clusters of multi-family housing complexes. Decision tree, one of data mining methods, was used to make clusters based on the characteristics and energy consumption data of multi-family housing complexes. Energy saving and CO2 reduction will be maximized by considering energy consumption during rehabilitation process of multi-family housing complex, based on these results and following research.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.281-289
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• 2018

The Korean environmental impact assessment(EIA) system, and explored ways to improve it as a more efficient and viable institution relevant to the demand of our time and conditions in study. The first problem this study identified is found in the fact that the party to write up the assessment report is itself the business operator or the one who is planning to work out the business plan. This structure translates into placing an order with an agent for EIA report. The reporting job may br subcontracted to the agent at a cost far below the rate specified in the 'Standard for Estimate of Agency Fee for Environmental Impact Assessment.' This practice also causes the vicious circle of producing a report that is written to justify the project or business in question or it leads to rough-and ready and poor documentation to minimize the time required. Second, in order to achieve the goal of the plan or business, which is the target of EIA, the local residents tend to ve regarded as an obstacle. This means elimination of the local people from participating in the EIA or their opinion being frequently ignored. This is the seed of distrust and hostility that sometimes provoke disagreements or fierce conflicts. The first proposal to improve these problem is to improve the factors that cause poor documentation of the assessment report as well as improve the understanding of the EIA system. This study proposes the following measures for improvement. The agency cost for EIA should be paid by the business operator or a third party that can ensure faithful implementation of the payment. A system should be established to verify transparent estimation of the agency cost. In order to enhance the professional quality of EIA agents, there should be implementation of qualification test for industrial engineer of related engineers in addition to the current EIA Qualification Test. The second proposal for improvement is to improve the citizen participation process by instituting a legal framework to make clear the purpose of the briefing session for local residents, which is held as a procedure of EIA, and to ensure more positive publicity during the stage of listening to the opinion of the local community. For a smooth and rational communication process, a moderator and a communicator of opinion, as is the case in a public hearing, could be instituted to clearly get the purpose of the briefing session across to the residents and to help to carry out the explanation and Q & A sessions according to the categories of the opinion of the residents. At present, the notification of the public inspection of the draft of the assessment report and briefing session for the residents is made on the newspaper and internet network. But some people have difficulty with access to this method of announcement. A higher participation rate could be secured if a legal provision is added to specify putting up placards in specific places such as the entrance to the place for the briefing session for residents or the building of administrative agencies of the area concerned.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.427-434
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• 2017

The generation of construction waste can be divided into a decommissioning phase and a new construction phase, and most of the waste is generated at the decommissioning stage. However, recently, domestic new construction construction has expanded to 150 trillion yards per year, so construction work is increasing rapidly. Especially, as the size of the construction work with much waste of construction waste exceeds 100 trillion, the management of the amount of construction waste in the new construction site is required. Unlike the dismantling work site, the new construction site can separate waste generated by each property, and relatively low foreign matter content is generated. The purpose of this study was to investigate the amount of construction waste generated by new construction sites and to calculate the unit amount of construction waste based on this. In addition, since the existing unit cost is centered on concrete and mixed waste, we set the basic unit by setting synthetic resin, waste wood, and waste board as additional items. The basic unit survey was carried out to investigate the wastes according to the characteristics of each construction period. As a result of the survey, the new construction site showed that most wastes were discharged in the first 30% and after 70% of the process, and the ratio of mixed construction waste was as high as 45%. As a result of this study, it was found that about twice as much waste was produced as compared with the conventional standard product.

• Spatial Information Research
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• v.13 no.4 s.35
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• pp.365-372
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• 2005

In North Korea, there has been the considerable loss of human lives every year due to the deficiency of foods. Thus, in order to reduce such damages, a research project should be launched to provide various information for cooperation with North Korean government, and to develop proper agricultural information management system. Therefore, this research is mainly to develop North Korean Agricultural Information Management System (NKAIMS), which can collect, manage and analyze agricultural information and water resources utilization status of North Korea, and further support to make relevant decisions and establish the agricultural land-use plans. This research has three phases. The major outcome of the first phase is collecting the agricultural and water resources utilization data such as soils, rivers, streams, collective farms, etc., designing and building database, and developing integrated management system considering the users' requirements. The main work of the second phase is improving and reinforcing database such as adding the information of dams, land-over data, bridges, tunnels, satellite images, etc., inspecting and renewing such as importing detail attribute information of reservoirs, and improving system for more conveniently using. The third phase will be to supplement more useful functions such as statistic analysis, continually inspecting and improving database, and developing web-based system. The product of this research supports collecting and analyzing relevant data to facilitate easier agricultural activities and support effective decision making for food production in the preparation of unification. Moreover, through designing database considering sharing information and system expendability, it can support systematic data usability of agricultural information and save cost for data management.

• Spatial Information Research
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• v.17 no.1
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• pp.131-144
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• 2009

Recently, a lot of local autonomous entities are promoting Ubiquitous City(U-City) Construction by integrating Information Communication Technology(ICT) with city development, and also internationally, a lot of cities are making efforts to develop U-City to intensify a city's competitive strength and improve life quality of city dwellers. In keeping with such a stream of the times, each local autonomous entity and project developer are developing a lot of methodologies to establish optimal U-City in corresponding cities and also inquiring into a variety of development procedures, such as connecting existing urban development methods with information establishment methods. The method used usually is to establish Information strategy Plan(ISP) for a city which will be developed through consulting in the stage of city development planning. ISP is to establish vision & strategy for building the ubiquitous city and is a methodology including city vision, strategy, goal, and implementation method, etc. However, due to a lot of variables, such as a variety of city environment, establishment period, budget, information technology, and etc., it is difficult to contain establishment plans for every occasion in a similar method, in reality. Therefore, it is naturally necessary to suggest plans for city vision & strategy, and selection of element technology/service. Thus, this paper suggests models for vision & strategy establishment of U-City and suggests Top-Down Approach and Bottom-Up Approach method as a plan for U-City establishment. In addition, this paper analyzes general promotion methodologies for constructing U-City and analyzes how these two strategic methods [Top-Down Approach and Bottom-Up Approach] for city vision establishment are composed in such a methodology, to define and analyze its constituent plan.

• Information Systems Review
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• v.18 no.1
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• pp.79-103
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• 2016

The Korean Army has to construct a system that will enable it to cope immediately with the flexible military relationships in Northeast Asia by systematizing and improving the efficiency of operations. These improvements include building a smart and strong army, concentrating on cost-effective combat skills, maximizing the utilization of private resources, and establishing a military structure based on information and technology. Accordingly, this study proposes solutions to solve the problems affecting the success of outsourcing in the defense industry. Unlike outsourcing in other government ministries, outsourcing in the national defense sector may be unrealistic because this strategy is related to the renovation project of the Ministry of the National Defense. In general, the objective of outsourcing in the defense industry, similar to other businesses, is to improve efficiency and not to reduce troops and national defense budget. Several factors, such as identification and security guarantee, risk reduction, cost saving, quality improvement, the reliability of enterprise, and professional technology, are necessary to ensure outsourcing success in the national defense sector. In terms of effectiveness, the improvement in service quality significantly influences outsourcing success in the national defense sector. Eventually, the national defense forces must be strengthened to prevent the provocative actions of North Korea and other threats by improving identification, sense of national security, and quality unlike the current outsourcing of the government, as well as emulating German GEBB or PMC, which utilizes social capital.

• Smart Structures and Systems
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• v.4 no.2
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• pp.221-232
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• 2008

This paper represents the final results of a research program sponsored by the European Commission through project WIND-CHIME ($\underline{W}$ide Range Non-$\underline{IN}$trusive $\underline{D}$evices toward $\underline{C}$onservation of $\underline{HI}$storical Monuments in the $\underline{ME}$diterranean Area), in which the possibility of using advanced seismic protection technologies to preserve historical monuments in the Mediterranean area is investigated. In the current research, the dynamic characteristics of two outstanding Mamluk-Style minarets, which similar minarets were reported to experience extensive damage during Dahshur 1992 earthquake, are investigated. The first minaret is the Qusun minaret (1337 A.D, 736 Hijri Date (H.D)) located in El-Suyuti cemetery on the southern side of the Salah El-Din citadel. The minaret is currently separated from the surrounding building and is directly resting on the ground (no vaults underneath). The total height of the minaret is 40.28 meters with a base rectangular shaft of about 5.42 ${\times}$ 5.20 m. The second minaret is the southern minaret of Al-Sultaniya (1340 A.D, 739 H.D). It is located about 30.0 meters from Qusun minaret, and it is now standing alone but it seems that it used to be attached to a huge unidentified structure. The style of the minaret and its size attribute it to the first half of the fourteenth century. The minaret total height is 36.69 meters and has a 4.48 ${\times}$ 4.48 m rectangular base. Field investigations were conducted to obtain: (a) geometrical description of the minarets, (b) material properties of the minarets' stones, and (c) soil conditions at the minarets' location. Ambient vibration tests were performed to determine the modal parameters of the minarets such as natural frequencies and mode shapes. A $1/16^{th}$ scale model of Qusun minaret was constructed at Cairo University Concrete Research Laboratory and tested under free vibration with and without SMA wire dampers. The contribution of SMA wire dampers to the structural damping coefficient was evaluated under different vertical loads and vibration amplitudes. Experimental results were used along with the field investigation data to develop a realistic 3-D finite element model that can be used for seismic risk evaluation of the minarets. Examining the updated finite element models under different seismic excitations indicated the vulnerability of such structures to earthquakes with medium to high a/v ratio. The use of SMA wire dampers was found feasible for reducing the seismic risk for this type of structures.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.212-222
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• 2011

Estuaries have been used competitively and exploited for the past decades in Korea. To preserve the environment of the estuaries from the integrated perspective, new policies have started to change such exploitative development in 2000s. Due to the poor knowledge-base, however, there has been a lack of support system which enables to execute such policies effectively. The present study was conducted to figure out the limits of the estuarine management research projects in Korea, which is being performed to overcome these limitations. It was studied through Gap Analysis between domestic and foreign advanced practices as well as Analytical Hierarchy Process on expert survey in terms of the three aspects: how well the estuarine management research projects in Korea meets the demands of policy making and administration; raises the awareness of citizens about the merit of environmental preservation; and establishes knowledge-based support system. This project turned out to reflect adequately the development of programs for building estuarine management systems. But consideration of other ministries was relatively scarce. But the contents which directly support community-based activities and educational programs to improve citizens' awareness were judged to be insufficient. According to the results of Gap Analysis, research about the structure and function of estuarine ecosystems, which can support to develop policy alternatives in detail, was relatively more necessary. Therefore, to support estuarine policy management effectively, the development of a realistic plan, which can overcome fundamental issues inherent in the Korean environmental management system and the limitation of the estuarine management research projects in Korea itself, is needed.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.441-450
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• 2013

With the recent increase in BIM orders in civil engineering, project owners are supplied with BIM-based products. Due to the lack of related guidelines, however, and the vague regulations on the creation and level of drawings as well as on the products list, many owners receive BIM-based products along with the existing 2D products. This can lead to task overlapping by designers or contractors and can cause the owners to have more data to maintain. If the existing 2D-based electronic supply system is changed to a BIM ordering system to reduce such a burden, it is necessary to examine the 2D products that can be extracted from or substituted for the BIM model so as to minimize the overlapping products. Therefore, in this study, BIM modeling of road construction projects whose enforcement plan by the Ministry of Land and Transportation has been completed was conducted, and based on the study results, the possibility of extracting 2D drawings from a total of 3,767 drawing items was determined. The results showed that 2,549 drawing items (67%) could be extracted as 2D drawings from the BIM model, and in particular, drawing items related to general connection work, earthwork, and amenities work could be most effectively substituted. The results of this study can be used as the base data for reducing the number of 2D drawings or substituting them in developing a BIM-based product supply system in the future.