• Korean Journal of Construction Engineering and Management
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• v.25 no.5
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• pp.32-40
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• 2024

In the construction industry, lack of reliability in the quality of recycled aggregates, harmful substance problems, and negative consumer perceptions limit the expansion of the use of recycled aggregates. In this respect, existing studies mainly focus on the use of recycled coarse aggregates in concrete in consideration of durability. On the other hand, in the case of recycled fine aggregates, not only are there insufficient cases applied to major structures, but the scope of application is very limited due to lack of awareness. Therefore, the main purpose of this study is to present the possibility of their application in bearing and non-bearing wall structures through physical characteristics experiments of concrete bricks for masonry according to various mixing ratios of recycled fine aggregates and cement amounts. To this end, the compressive strength and absorption rate of concrete bricks were measured focusing on the mixing ratio of the recycled fine aggregate and the crushed fine aggregate and the amount of cement. As a result, it is found that it is possible to use 100% of recycled fine aggregate for 200kg/m³ of cement or 25% of crushed fine aggregate mixed with 75% of recycled fine aggregate for the same amount of cement to achieve the compressive strength of 13MPa, witch is one of the quality requirements for concrete bricks for bearing walls. In addition, it is found that to meet the strength of 8MPa, one of the quality requirements for non-bearing walls, it is sufficient to use 100% of the recycled fine aggregate for 100kg/m³ of cement. Through the absorption rate tests, it is also confirmed that the absorption rate of the concrete brick is 13% or less by meeting the required performance criteria. This means that even if recycled fine aggregate is used in the manufacture of concrete bricks, the quality standards required by KS F 4004 (concrete bricks) can be sufficiently met.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.12
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• pp.1098-1125
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• 2000

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1189-1194
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• 2011

The Maglev train is operated by levitating from a power of a large number of magnets and moving without direct contact to railway track so that reduces noise and vibration due to mechanical friction. Also, the Maglev passes sharp curves and steep hill without any difficulties. The Maglev has a potential to be an alternative transport system urban areas. For successful commercializing of Maglev, the organization of interface for safety and reliability of third rail system are one of the key considerations. Especially, the components of the third rail system, such as power rail, expansion joints, FRP section insulator, and supporter with epoxy insulator, should be durable, convenient for construction, and easy to maintenance. This paper analyzes the characteristics of the third rail system components and proposes organization of interface for system engineering. The operating tests of KIMM for the proposed third rail system verify the safety. Also, this paper analyzes the life cycle of the system components to improve the system reliability and evaluation.

• Journal of the Korean association of regional geographers
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• v.21 no.3
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• pp.427-449
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• 2015

Network governance can be defined as collaborative process to develop a new socio-political order through civil society centered networking with government and market, and the term 'collaborative governance' can be used in a sense that the basis of governance is collaborative process. In particular, it can be stressed that collaborative governance between regions need double collaborative processes, that is, collaboration between local governments and collaboration between local government and local civil society within a region. Yet, the collaboration as a core element of collaborative governance should not be seen as a pure normativity presupposing confidence and reciprocity, but as a strategy based on competition and antagonism. The normativity implied in the concept of collaborative governance may not realized in actual process, and tends to be mobilized as a rationale for justifying neoliberal strategies. In order to overcome such limits of collaborative governance, the concept of collaborative governance should be reconstructed. This paper suggests that collaborative governance can be seen as hegemonic governing process in a Gramcian sense operating in the government plus civil society, and that, radicalizing Ostrom's concept, it also can be seen as a governing process producing polycentricity by self-regulating subjects. Finally, collaborative governance between regions needs expansion of material basis for economic complementarity and construction of infrastructure as well as a discursive process in order to enhance connectivity between them.

• Journal of the Korean Geographical Society
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• v.51 no.4
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• pp.491-508
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• 2016

This study has taken the Myeongjidong island, which has experienced spatial change due to various reasons ranging from the Japanese colonial era until today, as an instance in order to comprehend macroscopic spatial change of the Nakdonggang Delta and the adaptation process of the locals in a microscopic point of view. Spatial change of the Myeongjidong has been confirmed by collecting maps such as the atlas of late period of Chosun published in 1910, topographic map, regional geography, city records, and by applying coordinates with geographic reference function of GIS program, then checking for time sequential space change of individual regions. Space change driven by the Japanese government-general of Korea, Gimhae Irrigation Association, and by national policy or planning brought about environmental and humanistic changes unlike ever before, and land usage, housing and industry of the region and the locals experienced various adaptation processes. Such processes were compiled through collection and comparison of literature, and supplementation from interview of the locals during field study. As for the research region, it ranged from the construction of Nakdonggang bank and Myeongji seawall of 1935, agricultural rural landscape formed after the area expansion project by Gimhae Irrigation Association in 1940, to landscape that are becoming mercantile and urban due to the developmental plans of national and local governments.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.68-81
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• 2014

This study aims to apply and evaluate the automatic DAD analysis method, which is able to establish the depth-area relationship more efficiently and accurately for point-to-areal rainfall conversion. First, the proposed automatic DAD analysis method tracks the expansion route of area from the storm center, and it is divided into Box-tracking, Point-tracking, Advanced point-tracking according to tracking method. After applying the proposed methods to 10 events occurred in Yongdam-watershed area, we confirmed that the Advanced point-tracking method makes it possible to estimate the maximum average areal rainfal(MAAR) more accurately with consideration of the storm movement and the multi-centered storm. In addition, Advanced point-tracking could reduce the errors of the estimated MAAR induced by increasing the area because it can estimate MAAR for each storm center and compare them at the same time. Finally, the DAD curve for the study area could be derived based on the DAD analysis of the selected 10 events.

• International Commerce and Information Review
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• v.18 no.3
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• pp.205-226
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• 2016

As knowledge workers have increased and information interchanges become more diverse, only the resources of internal enterprise is not longer useful, and the practical use of external information through information public sharing network is even more crucial. But, few studies that use both internal and external information sharing systems together have been conducted. In this research, we carried on the depth interview to analyze the main factors that intend to utilize outside information as well as to share inside information voluntarily. In conclusion, sharing internal information is directly involved with the performance of their job exchanging simple data, past documents, and technical materials. On the other hand, using the external information belonged to several other organizations is mostly caused by the voluntary participants' satisfaction sharing their individual experience through the network systems. Based on the study, we propose the idea that can activate both internal and external information sharing network through the system with user feedback function regarding the customized information, and with the space expansion where people can freely raise their private opinion. We also introduce the plan of the construction of communication systems with various experts, and the development of compatible devices with diverse interfaces.

• Journal of the Korean Geosynthetics Society
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• v.17 no.3
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• pp.19-32
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• 2018

Gravel Compaction Pile (GCP) method is currently being designed and constructed by empirical method because quantitative design method has not been developed, leading to various types of and frequent destruction such as expansion failure and shear failure and difficulties in establishing clear cause and developing measure to prevent destruction. In addition, despite the difference with domestic construction equipment and material characteristics, the methods applied to the overseas ground is applied to the domestic as it is, leading to remarkable difference between applied values and measured values in variables such as bearing capacity and the settlement amount. The purpose of this study was, therefore, to propose a reasonable and safe design method of GCP method by analyzing the settlement and stress behavior characteristics according to ground strength change under GCP method applied to domestic clay ground. For the purpose, settlement amount of composite ground, stress concentration ratio, and maximum horizontal displacement and expected location of GCP were analyzed using ABAQUS. The results of analysis showed that the settlement and Settlement reduction rate of composite ground decreased by more than 60% under replacement ratio of 30% or more, that the maximum horizontal displacement of GCP occurred at the depth 2.6 times pile diameter, and that the difference in horizontal displacement is slight under replacement ratio of 30%.

• Journal of Environmental Policy
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• v.10 no.3
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• pp.21-48
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• 2011

The paper affirms the weight proportion concept as an element, which could be empirically analyzed quantitatively through the developmental expansion of qualitative empirical analysis on taxonomy that is required for the construction Low-Carbon Green Cities and their eco-friendly elements, such as a pleasant residential environment The weight proportion concept is proposed as a new measure to identify eco-friendly elements and as an objective assessment indicators. To perform an empirical analysis, surveys were first given to the residents of Metropolitan Newtown (50 persons) and outside experts (50 persons) for the total of 100 persons. Second, the paper surveyed 74 sites of Eco-Environmental Certified Apartment Housing Complexes. Upon analysis of eco-friendly elements by their type and total weight, the largest weight proportion was expressed in the interior and eco-environmental elements, carbon-decrease types, and carbon-absorption types. The results of this paper confirm recent positive sentiments and preference toward a variety of future-oriented and sustainable eco-friendly elements like the eco-housing and new renewable energy, In addition, the paper affirmed the new housing trend towards constructing eco-friendly elements, such as carbon-decrease and carbon-absorption, that induce long-term investments, despite their need for higher investments.

• Journal of Families and Better Life
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• v.19 no.4
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• pp.49-68
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• 2001

The purpose of this study was 1) to review communal housing in the UK, 2) to consider the policy implications for elderly communal housing in Korea. The research methods used were 1) literature review about communal housing and related policy in the UK 2) field survey in the UK 3) interpretative suggestion for the proper policy implication to develope communal housing for the elderly in Korea. Sheltered housing in the UK had been developed as communal housing for the elderly with special needs since the 1970s. The type of sheltered housing were category 1 and category 2. Very sheltered housing with more facilities and meal services was added in 1980s. Sheltered housing was evaluated as the most humanistic solution for older people in the UK in 1980s. Because of the policy of moving institutional care to community care, sheltered housing became less in demand because of more options for older people including being able to stay in their own home. So new completion of sheltered housing by registered social landlords reduced saliently. Sheltered housing already totalled over half million units in which 5% of all elderly over 65 still lived and a small quantity of private sector for sale schemes emerged in the 1990s. The reason why the residents moved to sheltered housing was for sociable, secure, and manageable living arrangements. In general the residents were satisfied with these characteristics but dissatisfied with the service charge and quality of meals, especially in category 2.5 schemes. The degree of utilisation of communal spaces and facilities depended on the wardens ability and enthusiasm. Evaluation of sheltered housing indicated several problems such as wardens duty as a \"good neighbour\" ; difficult-to-let problems with poor location or individual units of bedsittiing type with shared bathroom ; and the under use of communal spaces and facilities. Some ideas to solve these problems were suggested by researchers through expanding wardens duty as a professional, opening the scheme to the public, improving interior standards, and accepting non-elderly applicants who need support. Some researchers insisted continuing development of sheltered housing, but higher standards must be considered for the minority who want to live in communal living arrangement. Recently, enhanced sheltered housing with greater involvement of relatives and with tied up policy in registration and funding suggested as an alternative for residential care. In conclusion, the rights of choice for older people should be policy support for special needs housing. Elderly communal housing, especially a model similar to sheltered housing category 2 with at least 1 meal a day might be recommended for a Korean Model. For special needs housing development either for rent or for sale, participation of the public sector and long term and low interest financial support for the private sector must be developed in Korea. Providing a system for scheme managers to train and retrain must be encouraged. The professional ability of the scheme manager to plan and to deliver services might be the most important factor for the success of elderly communal housing projects in Korea. In addition the expansion of a public health care service, the development of leisure programs in Senior Citizens Centre, home helper both for the elderly in communal housing and the elderly in mainstream housing of the community as well. Providing of elderly communal housing through the modified general Construction Act rather than the present Elderly Welfare Act might be more helpful to encourage the access of general people in Korea. in Korea.