• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.4
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• pp.41-54
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• 2020

This study was conducted to provide basic data for a transparent and fair bidding system by identifying problems and suggesting improvement measures through an analysis of the bidding status for construction projects and service-related landscaping of multi-family housing. To this end, we used the data from the "Multi-Family Housing Management Information System (K-apt)" that provides the history of apartment maintenance, bidding information, and the electronic bidding system to examine the winning bid status and amount, along with the size and trends of the winning bids by year, and the results of the selection of operators by construction type. As a result, it was found that out of the total number of successful bids (36,831), 4.4% (16,631) were in the landscaping business, and the average winning bid value was found to be about 24 million won. According to the data, 73% of the landscaping cases were valued between 3 million won and 30 million won, and 58.6% of the cases were in the field of "pest prevention and maintenance". 36% of the total number of bids were awarded from February to April, with "general competitive bidding" accounting for 59.8% of the bidding methods. As for the method of selecting the winning bidder, 55% adopted the "lowest bid" and "electronic bidding method," and 45% adopted the "qualification screening system" and "direct bidding method." As an improvement to the problems derived from the bidding status data, the following are recommended: First, the exception clause to the current 'electronic bidding method' application regulations must be minimized to activate the electronic bidding method so that a fair bidding system can be operated. Second, landscaping management standards for green area environmental quality of multi-family housing must be prepared. Third, the provisions for preparing design books, such as detailed statements and drawings before the bidding announcement, and calculating the basic amount shall be prepared so that fair bidding can be made by specifying the details of the project concretely and objectively must be made. Fourth, for various bidding conditions in the 'business operator selection guidelines', detailed guidelines for each condition, not the selection, need to be prepared to maintain fairness and consistency. These measures are believed to beuseful in the fair selection of landscaping operators for multi-family housing projects and to prepare objective and reasonable standards for the maintenance of landscaping facilities and a green environment.

• Journal of the Korean GEO-environmental Society
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• v.21 no.12
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• pp.35-41
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• 2020

Recently, underground spaces have been developed variously due to the concentration of the building structure in downtown area and reconstruction of the apartment. However, various problems such as differential settlement are occurring in the waterproof and reinforcement construction. In grouting method, which is frequently used for the ground reinforcement, quality control was performed by measuring the injection quantity of grouting materials and performing laboratory tests using boring samples, but it is difficult to determine whether the ground reinforcement has been performed properly during the construction stage. In order to solve this problem, a research is needed to carry out quality control by measuring electric resistivity after grouting is performed using grouting materials mixed with conductive materials. In this research, as a basic study of the new grouting method using conductive materials, uniaxial compression tests were performed using cement specimen with 0, 3, 5, 7% of carbon fiber to evaluate the effect of conductive material on the performance of grouting material. Based on the test results, the uniaxial compressive strength is increased with the mixed proportion of the carbon fiber increase. Furthermore, the carbon fiber can also affect on the early-strength of the grouting materials.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.271-279
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• 2010

We conducted a quantitative human health risk assessment with respect to inhalation of heavy metals for residents of housing developments in "new towns" where an incinerator will be operated within the area scheduled for construction thereof. To assess potential human health risk we calculated the amount of heavy metals emitted from the incinerator, and then forecasted the potential health impact on adjoining areas where new housing is to be developed (i.e. "new towns") at different altitudes by a using SCREEN-3 model. We assessed Cancer Risk (CR) caused by known carcinogens using the Inhalation Unit Risk criteria developed by the US Environmental Protection Agency. Notably, we assessed risk by determining concentrations of heavy metals on a floor by floor basis, as apartment buildings are to be constructed near the incinerator according to a pre-devised plan. Results indicated that cancer risk for most carcinogens exceeded US EPA standards for the highest locations at each collection point. This result indicates that construction of high buildings in areas adjoining incinerators is undesirable, and that measures to lower carcinogens are needed. The results of this study, which assessed health risk from exposure to heavy metals emitted from a nearby incinerator, can be useful in land use planning with respect to the location of housing developments in new towns, as well as the heights of any buildings constructed. Furthermore, the methodology deployed herein with respect to risk assessment can be helpful for policy makers and the general public in the event of conflicts regarding incinerator projects in the future. The results herein may also be of merit in determining priorities when establishing harm reduction measures for carcinogens at incinerators. However, the study does contain several limitations. The SCREEN-3 model, a kind of screening model that provides conservative results, can provide higher forecasted concentrations of air pollutants than other models. Moreover, although the incinerator in question is set to be a thermoselect type, domestic data for emissions from these incinerators is not available, and assumptions were based on a stoker type incinerator. Insufficient domestic data likewise compelled the use of data of USA, resulting in possible errors in results. Continued research will thus be required to develop systematic methodologies that address the foregoing factors and produce more reliable outcomes.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.55-67
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• 2010

The main purpose of this study is to develop a system and data model extracted from the TO-BE process model of rental apartments to promote information exchange based on knowledge obtained through maintenance status analysis. Currently, it is difficult to find examples suggesting a data model through a process analysis of maintenance in rental apartments. Thus, this study intends to suggest a process as well as a data model to promote the development of a maintenance system for rental apartments by using building management knowledge, utilization of standardized tools, and existing FM (Facility Management) techniques to break through limitations in actual application. Ultimately, this study aims to show examples of document-oriented analysis and information technology for middle managers in charge of the maintenance of rental apartments, as well as work analysts developing the maintenance system. In further research beyond this study, complex issues on the maintenance of rental apartments, legal restrictions on customary practices of maintenance activities, effects of the scales of maintenance practices, requirements to perform maintenance activities, evaluation on the status of maintenance, life cycle cost and risks will be investigated.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.42-48
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• 2013

The present study assessed the amount of $CO_2$ uptake owing to concrete carbonation through a case study for an apartment building with a principal wall system and an office building with Rahmen system under different exposed environments during use phase and recycling application. The $CO_2$ uptake assessment owing to concrete carbonation followed the procedure established by Yang et al. As input data necessary for the case study, actual surveys conducted in 2012 in Korea, which included data about the climate environments, $CO_2$ concentration, lifecycle inventory database, life expectancy of structures, and recycling activity scenario, were used. From the comparisons with the $CO_2$ emissions from concrete production, the $CO_2$ uptake during the lifetime of structures was estimated to be 5.5~5.7% and that during recycling activity after demolition was 10~12%; as a result, the amount of $CO_2$ uptake owing to concrete carbonation can be estimated to be 15.5~17% of the $CO_2$ emissions from concrete production, which roughly corresponds to 18-21% of the $CO_2$emissions from cement production as well.

• Journal of the Korean Geotechnical Society
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• v.34 no.1
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• pp.47-57
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• 2018

In recent years, vertical extension remodeling of apartment building is considered as one of the efficient ways to broaden and enhance the utilization of existing buildings due to the rapid development of population and decrement of land resources. The reinforcement of foundation is of great importance to bearing the additional load caused by the added floors. However, because of the additional load, the carried load by the existing piles would be in excess of its allowable bearing capacity. In this study, a conceptual construction method called preloading method was presented. The preloading method applies force onto the reinforcing pile before vertical extension construction. The purpose of preloading is to transfer partial load applied on the existing piles to reinforcing piles in order to keep each pile not exceeding the allowable capacity and to mobilize resistance of reinforcing pile by developing relative settlement. The feasibility and effect of preloading method was investigated by using finite numerical method. Two simulation models, foundation reinforcement with preloading and without preloading, were developed through PLAXIS 3D program. Numerical results showed that the presented preloading method is capable of sharing partial carried load of existing pile and develops the mobilization of reinforcing pile's frictional resistance.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.97-104
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• 2010

This study evaluated the energy efficiency of a windows system using built-in blinds, with regard to their insulation performance and their blocking of solar radiation. The study took advantage of the "Physibel Voltra" program as a physical simulation of heat transfer. To simulate the "Physibel Voltra" program, I practiced a mock-up test to determine heating quality and translation condition. I analyzed the propensity to annual energy consumption, the annual quantity of heat transfer, and the annual cooling and heating cost through a computer simulation for one general household in an apartment building. In the test, it was found that compared to a general windows system, a windows system with built-in blinds reduced the annual heat transfer by 10% in cooling states and by 11% in heating states when the blind was up. When the blind was down, the windows system with built-in blinds reduced the annual heat transfer by 25% in cooling states and 30% in heating states. When a windows system with built-in blinds is compared with a general windows system, the quantity of cooling and heating loads is reduced by 283.3kw in cooling states and 76.3kw in heating states. This leads to a reduction in the required cooling and heating energy of 359.6kw per house. It is thus judged that the use of a windows system with built-in blinds is advantageous in terms of reducing greenhouse gas emissions, because the annual TOE (tons of oil equivalent) per house is reduced by 0.078TOE, while $tCO_2$ is reduced by $0.16tCO_2$. In addition, compared with a general windows system, the cost of cooling and heating loads in the system reduces the annual cooling cost by 100,000won, and the annual heating cost by 50,000won. Ultimately, this means that cooling and heating loads are cut by 150,000won per year.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.656-663
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• 2012

After the construction of waterworks automatic meter reading with 15 mm diameter digital water mater with magnetoresistance sensor developed in this study at 96 households of apartment complexes located in Incheon-City B-Gu S-Dong, the feasibility of field application of waterworks automatic meter reading was evaluated. The field application of waterworks automatic meter reading was performed from July to December in 2011, and average reception rate was as low as 84.6% due to the instable wibro networks, the existence of communication blackout and temporary malfunction of router. After the extraction of 10 households with one to five residents out of 96 households by using stratified random sampling method and analysis of domestic water use, it was found that domestic water use was significant at August and showed a decreasing trend at September, followed by increase in domestic water use at November and decrease in domestic water use at December. This phenomenon should be attributed to weather factors (temperature, humidity, etc.), which significantly affected domestic water use. Similar trend in domestic water use in terms of weather factors was obtained in case of Liter per capita day of water use after the extraction of 30 households out of 96 households by using stratified random sampling method. After analysis of Liter per capita day for 96 households, single residents increases resulted in reduction of domestic water usage by about 14% of Liter per capita day. These results might be due to the fact that domestic water usage such as laundry, beverages, catering, cleaning, etc. should be required for even the household with one resident, whereas domestic water usage for those common utilization can be significantly saved for the household with more than one resident.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.577-592
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• 1996

The forming process of poverty region in Taegu and the feature of its spatial distribution which are reviewed hitherto can be summarized like this. 1) In the froming porcess of poverty region in Taegu, during the soverignty of Japanese Empire petty farmers became tenantry by the colonial agricultural policy of Japanes Empire and some of those came into the city and g\became urban poor class. They generally lived in poor houses or dugouts in the city, and 6.6$\circ$ of poor house and dugouts of the whole country were in Taegu and 4.9$\circ of the popolatio in Taegu resided there. During the period of disorder, because of the historic accidents, such as the restoration of independence and Korean War, the returnees from aboad and refugees converged into the big city so that those who need the country's relief stood out as new poor class. They generally made their dwellings with tents and straw-bags on vacant grounds in suburbs living form hand to mouth and shaped the poor houses area, so-clalled "Liberated Village". During the developing period, the number of those who need aid gradually decreased, but the problem of poor people by the city-concentration of the poeple who shifted from agricultrual jobs by economic development came to the front. They mostly lived in squatter area forming large poor class area, and generally located near the center of Taegu consisiting of West. South. East Ward. 2) Reviewing the the feature of spatial distribution, the proportion of poor class are highest within 1~2km from the center of the city and also high within 2~3km form the center and suburbs. The poor class area in the center of the city are mostly cleared and removed area and in suburbs by the construction of permanently leased, and leased apartments large grouped poor class areas are forming. In Taegu, 16 low-income class group residence areas and residential environement improving areas are dispersed so that they came under the so-called poor class area. But by the improvement of dewelling environment and living the poor people who lived in groups dispersed or bettered their living for themselves, so the poverty area is greatly chaning into average-levelled residence area, and on the other hand, large poor people's apartment complexes are being constructed in suburbs. 3) Up to now, the distribution of poverty area could be limited its scale to generally the area within 1~3km because the poverty region which had been in suburbs relatively came near the center of the city by the rapid urbanization and poor people preferred that area because of the living convenience facilities as well as the transportation facilities and job-hunting being near the center of the city. But now poor people's apartment complex is being constructed regardless of their zone of job sites, so the low proportion of occupation is pointed as a new problem.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.63-76
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• 2022

This study was conducted to compare the perceptions of the park use status, importance, and satisfaction of users in the first implemented and completed Uijeongbu Jikdong Neighborhood Park among the private park special projects carried out as a countermeasure for long-term non-execution of urban parks. To this end, in the initiated project, apartment residents and non-residents were classified according to the promotion plan, and a questionnaire research on importance and satisfaction was conducted to analyze the park use status and IPA(importance-performance analysis). First, as a result of the analysis of the current situation in terms of locational characteristics that occur during the promotion of special projects for private parks, unlike the mountainous areas, the targeted site was close to flat land, indicating that users' satisfaction with the landscape was high. Second, the access of the apartment residents in the initiated project site was easy. Thus, the use rate of residents was relatively higher than that of the non-residents. Third, differences in perception by item were identified through the analysis of IPA and the establishment of strategies. In quadrant I, among the facilities and services, installing restrooms was the priority for residents, and parking facilities and rest facilities were the priority than installing restrooms for non-residents. In quadrant II, overall scores for residents and non-residents were similar, but the distance to the park was in quadrant III due to the low level of satisfaction among non-residents. In this study, the difference in perception between residents and non-residents may cause problems in access and facilities in managing the park in the future. Therefore, it would be necessary to find a way to improve it by establishing a management strategy that takes into account the difference in the perception of residents after construction. In addition, through the results of this study, it was judged that the purpose of park development, the selection of types of parks, and the selection of plans and management indicators for each kind would be significant in the promotion of initiated projects in the planning of park development.