• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.221-229
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• 2023

Urbanization and industrialization have significantly increased the amount of solid waste produced in recent decades, posing considerable disposal problems and environmental burdens. The practice of waste utilization in concrete has gained popularity among construction practitioners and researchers for the efficient use of resources and the transition to the circular economy in construction. This study employed Lytag aggregate, an environmentally friendly pulverized fuel ash-based lightweight aggregate, as a substitute for natural coarse aggregate. At the same time, fly ash, an industrial by-product, was used as a partial substitute for cement. Concrete mix M20 was experimented with using fly ash and Lytag lightweight aggregate. The percentages of fly ash that make up the replacements were 5%, 10%, 15%, 20%, and 25%. The Compressive Strength (CS), Split Tensile Strength (STS), and deflection were discovered at these percentages after 56 days of testing. The concrete cube, cylinder, and beam specimens were examined in the explorations, as mentioned earlier. The results indicate that a 10% substitution of cement with fly ash and a replacement of coarse aggregate with Lytag lightweight aggregate produced concrete that performed well in terms of mechanical properties and deflection. The cementitious composites have varying characteristics as the environment changes. Therefore, understanding their mechanical properties are crucial for safety reasons. CS, STS, and deflection are the essential property of concrete. Machine learning (ML) approaches have been necessary to predict the CS of concrete. The Artificial Fish Swarm Optimization (AFSO), Particle Swarm Optimization (PSO), and Harmony Search (HS) algorithms were investigated for the prediction of outcomes. This work deftly explains the tremendous AFSO technique, which achieves the precise ideal values of the weights in the model to crown the mathematical modeling technique. This has been proved by the minimum, maximum, and sample median, and the first and third quartiles were used as the basis for a boxplot through the standardized method of showing the dataset. It graphically displays the quantitative value distribution of a field. The correlation matrix and confidence interval were represented graphically using the corrupt method.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.124-132
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• 2013

An influx of the population to the city has soared due to industrialization. As times go by, cities become densely populated so Korean government started to construct a number of buildings including apartment housings. Because they have become functionally, structurally, esthetically deteriorated over the past two decades. some improvements are needed. There are mainly two ways to improve old buildings: remodeling and reconstruction. Between the two, the first one is more popular as it is less time-consuming and more eco-friendly. Demolition work comes first for both of them and it should not give negative effects since it is regarded as a CP(Critical path) in the overall process. For this reason, a thorough construction management must be done. The reality, however, demolition is managed by the construction manager's experiences and decisions. If the key factor of demolition which is the planning of manpower and machine equipment, is determined by unscientific and subjective judgments, its period and risk also will increase. In particular, eco-friendly demolition can be more risky because it's been rarely conducted. Therefore, scientific and objective ways of demolition management are needed. In this context, this paper aims at analyzing productivity in each process of demolition focusing on manpower and machinery equipment which are the main parts of demolition assuming that the demands of eco-friendly remodeling demolition projects will be increasing. At the same time, by estimating working period through the output, this paper would be helpful to set up the plans for overall project in earlier stage.

• International Journal of Highway Engineering
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• v.4 no.3 s.13
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• pp.43-49
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• 2002

Asphalt pavements have to perform under the conditions of heavily-loaded vehicles due to the industrialization and large temperature variance between the summer and the winter. Due to these factors, a characteristics change of early permanent deformation becomes a big issue, and to remedy this problem many research to use modified asphalt are being widely conducted. However, most of the modified asphalt is being paved after milling the surface course and applying tackcoating, and it is being used mostly for the repair and maintenance purpose rather than pavement of new national road. The purpose of this investigation is to obtain some fundamental data for the evaluation of the performance and long-term performance of the construction material mixtures by the laboratory test and field experiments. For the field experiment, 200m of two-lanes national road, that is being paved for the new national road under the direction of Pusan Regional Construction Management Office, was paved with SBS PMA and PSMA asphalt mixtures, which are an modified asphalt mixtures used for the surface course, on top of the base course paved with other modified asphalt mixtures. The remaining section of the new national road was paved with dense grade mixture. The laboratory tests assessed and analyzed the mixture characteristics by Marshall's stability test, strength tests and wheel-tracking test. On the basis of the evaluation result of the temperature control and roughness of the newly constructed road at the field experiment site, it is desired to evaluate and identify the most economic modified asphalt mixtures by long-term performance evaluation and LCC(Life Cycle Cost) analysis in order to apply the test result to the design of new road construction in the future.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.180-186
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• 2016

There are many apartment buildings with the government's policy of increasing the supply of residential houses in Korea. Roughly 60% of the Korea population are living in apartment buildings. Since the 1970s, the Korean economy has grown enormously, the economic and social structure was radically transformed to industrialization and urbanization step. A village has grown into a large town in Korea and apartment buildings was constructed to solve national housing shortage by the Korean government and the construction company. Since the 2000s, this apartment buildings which was built in the 1970s and 1980s had become gradually deteriorated. So, reconstruction and remodeling project of apartment buildings have been come into request in Korea. There are two way to improve the residential environment. The one is remodeling of apartment buildings and the other is reconstruction of that. Therefore, we carried out questionnaire and survey study of the preference on the reconstruction and remodeling of old aged apartment which were located in daejeon province. As a result, the preference rate of remodeling is increasing instead of reconstruction because reconstruction of apartment buildings takes more money and needs long construction period.

• Journal of the Korean association of regional geographers
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• v.1 no.1
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• pp.23-43
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• 1995

This paper is the first part of a research which looks into the regional development process and the quality of life of Youngnam area, and which suggests a prospect and tasks for the future development of the region. Youngnam region has grown rapidly on the basis of labor-intensive light industries and standardized Fordist lage-scale heavy industries through the industrialization and urbanization of South Korea from the 1960s; but recently it has shown a relatively downward trend. The recent economic stagnation of Youngnam region can be seen as a result of uneven regional development in the national scale, which has brought out the increasing subcontracting relation within the region, the geographically excessive concentration of firms, the lack of growth potentiality of high-tech industries, the weakness of producer service, and the shortage of financial activities for capital flows. In addition, construction of physical and social infrastructures and management of urban central functions could not meet properly the rapid economic and urban growth of the region. Because of these problematics inherent in the economy of Yougnam region, the occupational status of regional dwellers is more or less unstable, and the wage level of employee as a whole in Youngnam region is lower than those of Seoul, although the wage level of labourers in manufacturing is relatively high. Moreover, the quality of life of dwellers in the region has some difficulties in the use of resources and ecological environment as well as the unequal provision of means of living and welfare facilities, even though it has been improved materially.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.1
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• pp.1-27
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• 2014

This paper aims at exploring the multi-scalar processes through which the Gumi Industrial Complex was developed in the late 1960s and the early 1970s. Existing studies, influenced by the "Developmental State Thesis", tend to see the industrialization processes of South Korea either by focusing on the socio-politico-economic processes at the national scale or in terms of the plan rationality of the national bureaucrats. This paper, however, denies this perspective on the basis of the strategic relational approach to the state and the multi-scalar perspective. In particular, it argues that the state actions for national industrialization have been the outcome of complex interactions, conflicts and negotiations among social forces, acting in and through the state, and at diverse geographical scales. This paper attempts to empirically prove this argument on the basis of a case study on the construction processes of Gumi Industrial Complex. The development of Gumi Industrial Complex cannot be solely explained in terms of either the plan rationality of the national bureaucrats or the political motivation related to the fact that Gumi was the hometown of President Park Jung-Hee. This paper argues that the development of Gumi Industrial Complex was heavily influenced by the role of the following actors; place-dependent local actors in Gumi and the multi-scalar agents, such as the Korean-Japanese businessmen and the national parliament members elected in the Gumi electoral district.

• Resources Recycling
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• v.17 no.2
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• pp.55-62
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• 2008

Amount of waste is always generated in industrialization process and it is gradually increasing. Domestic and industrial waste in 2003 increased by 9.5 percent than that of the last year(2002), whereas the amount of construction waste increased largely by 21 percent. Recently construction waste of total waste accounts for nearly 50 percent, waste concrete and Ascon from the construction waste takes up to 73 percent. Furthermore, amount of natural materials are gradually decreasing, that is, they are not sufficient any more. Owing to these reasons, the importance of recycling construction waste has been emphasized. The use of recycling aggregate makes the disposal of construction waste easier as well as protects environment from gathering raw aggregate. Also, it has the alternative effect economizing the insufficient new natural aggregate. This study employs the cost-benefit model to analyze the economic effect of construction waste recycling of Ascon which takes relatively high part of the total waste. The cost-comparison between raw aggregate and recycling aggregate were analyzed. With the model, the economic effect of Ascon recycling in 2003 and 2004 in capital area of Korea were analysed. Cost comparison between raw aggregate and recycling aggregate were also carried out. The result showed that the economic effect of Ascon recycling increased to 0.0808 for 2004 as compared 0.0694 for 2003. We could not conclude using above data, but this result shows that the economic benefit of Ascon recycling of construction waste has increased.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.379-387
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• 1999

During the past several decades, electricity generating plant increased with remarkable rapidity in Korea. Recently the increase has been much more rapid as the rate of industrialization has accelerated. Construction of nuclear power plants in coastal areas inevitably caused the perturbation of critical coastal habitats and thus influenced marine algal species composition. Particularly, an increase in the building of nuclear power plants led the amounts of heat discharged to increase exponentially. As far as the effects of cooling water and thermal discharges are concerned, benthic marine algae are likely to be vulnerable to a discharge. Heated effluents from nuclear power plants, with the temperature rises of 7~12$^{\circ}C$ under normal operating and design conditions, are discharged through the discharge canal and into natural water bodies. It is clear that the characteristic marine algal community is developed in the area affected by the thermal discharges; i.e. low species richness and low species diversity. Nevertheless, it is worthwhile to note that elevated temperatures exert differential effects depending on the algal populations. Benthic marine algae grown at the discharge canal can be regarded as warm tolerant species. 35 species (4 blue-green, 9 green, 8 brown and 14 red algae) of marine algae occurred more than 20eye frequency at discharge canal of three nuclear power plants in the east coast during 1992 ~ 1998 and thus can be categorized as warm tolerant species in Korea. To minimize the ecological impacts of waste heat on benthic marine algae, it is recommended that, in the future, nuclear power plants will have to employ some form of closed-cycle cooling for the condensers.

• Land and Housing Review
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• v.5 no.3
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• pp.151-167
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• 2014

Urban space structure in South Korea when through drastic changes ever since public housing policies began their full-fledge implementation. That is, public housing policies represent the main cause for formation of the current urban space structure, as the public houses are constructed in accordance with changes of demographic/social structure, considering changes of housing demand, in urban spaces demanded by the end users. After rapid industrialization and urbanization in the 1960's, each government in different periods have implemented housing supply policies through massive urban developments, to resolve the issue of housing shortage and residential instability. Phase 1 New Towns were developed in the 1980's resulting in suburbanization of the Seoul Area, followed by urban sprawl due to construction of small-size New Towns after deregulation in the 1990's, and construction of Phase 2 New Towns for resolution of housing shortage in the early 2000's and the resulting urban problems. In the mid-2000's, construction of Bogeumjari houses in GB areas led to insufficient housing supply in downtown areas, and the period after 2010 witnessed continuous deterioration of existing urban areas and acceleration of the rental housing crisis caused by rental housing shortage in downtown areas. Moreover, the residentially vulnerable classes consisting of young, 1~2-member households is expanding, with the real estate market in recess. Therefore, the government is trying to achieve urban regeneration through public housing policies so as to resolve the urban space problem and the housing problem at the same time, and the Happiness Housing Project has been implemented as a policy to achieve that goal. The Happiness Housing Project for young, residentially vulnerable classes in downtown areas, is going through diversification aimed at conjunction with urban regeneration projects in downtown areas, as exemplified by conversion of rental houses in residential environment improvement project districts and redevelopment/reconstruction project districts into happiness housing, and supply of happiness housing in conjunction with small reorganization projects for deteriorated residential areas in such areas as those excluded from New Town designation. Continuous supply of Happiness Housing in conjunction with urban regeneration requires mixed-use residential development which includes convenience facilities and public facilities, along with improvement of rental conditions (rental period/rent) and diversification of project methods, considering that the project is implemented in downtown areas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.2
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• pp.157-163
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• 2007

Recently, industrialization of a country is accelerated and request of society infrastructure is raised so national land development is activity view. Accordingly, the search for a wide-ranging buried heritage do acted in large construction region. Because the buried heritage get buried in land that it is necessary to the precision search and research for a record and a preservation. Until now, Surveying techniques of a historic site have made status map, profile and cross section map through leveling survey, total-station survey and sketch of specialist. So, to solve problems existing relic survey or drawing making method have using digital camera these researches rapidly and economically obtain stereo image of object and present a technique that constructs 3D image model for digital photogrammetry method. Also, these researches construct 3D image model for record and preservation of a historic site through site test and in 3D and graphical express a historic site and support works that produce other maps if we need it. offer base data of GIS (Geographic Information System) to collect and analyze overall, information of a historic site.