• Journal of the Korean Geographical Society
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• v.49 no.6
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• pp.917-934
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• 2014

Geographically weighted regression(GWR) model has been widely used to estimate spatially heterogeneous real estate prices. The GWR model, however, has some limitations of the selection of different price determinants over space and the restricted number of observations for local estimation. Alternatively, the geographically weighted LASSO(GWL) model has been recently introduced and received a growing interest. In this paper, we attempt to explore various local price determinants for the real estate by utilizing the GWL and its applicability to forecasting the real estate price. To do this, we developed the three hedonic models of OLS, GWR, and GWL focusing on the sales price of apartments in Seoul and compared those models in terms of model fit, prediction, and multicollinearity. As a result, local models appeared to be better than the global OLS on the whole, and in particular, the GWL appeared to be more explanatory and predictable than other models. Moreover, the GWL enabled to provide spatially different sets of price determinants which no multicollinearity exists. The GWL helps select the significant sets of independent variables from a high dimensional dataset, and hence will be a useful technique for large and complex spatial big data.

• 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 Energy Engineering
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• v.28 no.4
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• pp.82-93
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• 2019

In this study, a new model is proposed to improve the problem of the decline of predict rate of heat demand on a particular date, such as a public holiday for the conventional heat demand forecasting system. The proposed model was the Four Season Mixed Heat Demand Prediction Neural Network Model, which showed an increase in the forecast rate of heat demand, especially for each type of forecast date (weekday/weekend/holiday). The proposed model was selected through the following process. A model with an even error for each type of forecast date in a particular season is selected to form the entire forecast model. To avoid shortening learning time and excessive learning, after each of the four different models that were structurally simplified were learning and a model that showed optimal prediction error was selected through various combinations. The output of the model is the hourly 24-hour heat demand at the forecast date and the total is the daily total heat demand. These forecasts enable efficient heat supply planning and allow the selection and utilization of output values according to their purpose. For daily heat demand forecasts for the proposed model, the overall MAPE improved from 5.3~6.1% for individual models to 5.2% and the forecast for holiday heat demand greatly improved from 4.9~7.9% to 2.9%. The data in this study utilized 34 months of heat demand data from a specific apartment complex provided by the Korea District Heating Corp. (January 2015 to October 2017).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.113-120
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• 2020

Safety accidents, called industrial accidents in construction work, are causing a lot of casualties, property damage and social controversy in the event of an accident, causing the construction to lose public confidence. The risk of safety accidents at construction sites may continue to increase as the construction of high-rise, large-scale, and multi-purpose complex buildings has increased in recent years. In particular, the most frequently constructed apartment construction among reinforced concrete buildings is designed and constructed with a wall-like structure with no beams for each floor, while the lower floors are made of lamen with columns and beams. As a result, the transfer beam or transfer slab to withstand the upper load is installed on the upper part of the Ramen structure, so the system Dongbari, which is installed as a temporary material during concrete laying construction, may collapse at any time during plowing and curing. The purpose of this study is to apply IT convergence technology to prevent the collapse of the system Dongbari during concrete installation, and to apply many of the variables that may occur during construction on a case-by-case basis to check the stability of the system Dongbari and to propose a model of the anti-conducting prediction system.

• Archives of design research
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• v.17 no.3
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• pp.353-362
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• 2004

This research has been done to evaluate the interior environmental factors in Gyungro-dang to suggest the advanced recommendations for them. For this research, the essential interior elements influencing on elderly's behavior were examined with the developed checklist, the lighting and color conditions of main hall at 14 facilities in Seoul area were analysed, and 124 subjects staying at Gyungro-dang were participated in questionaire survey for color preferences. Results showed that 1.The average installation rate of 39 items in checklist was 59%, the mandatory items such as accessible dimension were considered, but several items related to mobility and safety were not properly installed. Therefore not only guiding handrail and floor block to destination but also elimination of obstacles should be reconsidered. 2.The average of illuminances was 289 Lux dose to standard 300 Lux, but lighting quality was too low to support the activities of elderly users. The lighting control devices, combined lighting sources, and suitable lighting techniques should be applied for those facilities. 3.Most facilities were predominantly in warm colors in hue, medium or high value, low saturation, and natural atmosphere with similarity harmony. The color applications in those facilities were not functional, but similar as color preferences for the elderly except overall atmosphere. It is recommendable to include contrast harmony with classic or romantic mood.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.243-254
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• 2019

In this study, problems of the waterproofing methods in which water leakage occurs in the upper slab of the underground parking lot of apartment houses and the requirements considering the characteristics of the upper slab, and selected the appropriate performance(proposal) for the composite polyurea process are reviewed. As a result of the study, it is necessary to review performance such as responsiveness to upper slab of the multi-unit underground parking lot that is comprised of (1) crack and behavior responsiveness, (2) surface integrity, (3) vertical watertight stability, (4) pressure layer construction, (5) impact and pressure response and (6) vehicle moving load. As a result of evaluating 5 items corresponding to the requirements for the soft and hard complex polyurea, all of them were found to meet the conditions, and each materials were improved by compounding the materials that had problems when applying a single-ply method, thereby clarifying the advantages and disadvantages of the material property. However, in order to apply to the actual site, additional evaluation on site applicability such as mock-up evaluation should be conducted, and subsequent studies on the applicability of the market through review of economic feasibility and maintenance is required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.426-433
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• 2019

After an earthquake, fire and gas explosions are more likely to cause more casualties in cities with many apartment buildings and large complex buildings. In order to prevent this, seismic design is necessary for the fire protection sprinkler system. However, most systems currently use stainless-steel pipes, although synthetic resin pipes are used in some special places. These materials are susceptible to vibration and earthquakes. This study evaluated the displacement absorption flexibility of polyethylene (PE) and aluminum (Al) multi-layered composite pipes to increase the seismic performance in a vibration environment and during earthquakes. The seismic performance was compared with that of a stainless-steel and PE pipes. The seismic characteristics can be measured by measuring the amount and extent of vibration transmitted by the sprinkler pipe. This method can be used to judge the seismic characteristics to attenuate the vibration during an earthquake. The seismic characteristics of the pipe were verified by comparing the logarithmic attenuation rate to the initial response displacement of the vibration generated by the transverse vibration measurement method.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.879-891
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• 2018

In this study, the effects of urban redevelopment and building construction on the change of the detailed flows around the Pukyong National University (PKNU) campus located in the building-congested area was investigated using a CFD (computational fluid dynamics) model and GIS (geographic information system). For the analysis of the detailed flows before and after the constructions of the buildings around and within the campus, numerical simulations for the 16 inflow directions were performed before and after the construction. We used, as reference wind speeds at the inflow boundaries, the averaged wind speeds observed at the Gwangan light beacon (962) where there is no surrounding obstacle (i.e., building and terrain) acting as friction. We analyzed the area fractions in which wind speeds at z = 2.5 m changed after the construction for 16 inflow directions. The area fractions were relatively large in the east-south-easterly and southerly cases, because of the high-rise buildings constructed at the east and the apartment complex and the Engineering buildings constructed at the south of the PKNU campus. In the case of the easterly of which frequency is highest among the wind directions observed at the Daeyeon AWS (AWS 942) located inside the PKNU campus, the wind-speed change was not significant even after the constructions. It is shown that the building construction has affected the detailed flows around as well as even in the far downwind region of the constructed buildings. Also, it is shown that the GIS and CFD model are useful for analyzing the detailed flows in planning the urban redevelopment and/or building construction.

• Clean Technology
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• v.27 no.1
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• pp.39-46
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• 2021

A road structure washing vehicle equipped with a 4 HP, 80 LPM ultrafine bubble generator was used to clean a tunnel wall and the surface of the surrounding structure, consisting of concrete and tiles, in a heavy traffic area around an apartment complex in the city. Ultrafine bubbles were generated by supplying air at 2 to 3 LPM and using a specially designed nozzle, whereas fine bubbles made by an impeller in a gas-liquid mixing self-priming pump were produced with an average diameter of 165.4 nm and 6.81 × 107 particles mL-1. Using a high pressure washer gun that can perform high-pressure cleaning at 150 bar and 30 LPM, ultrafine bubbles were used to wash dust adsorbed on the surface of the road structures. The experimental analysis was divided into before and after washing. The samples were analyzed by applying ISO 8502-3 to measure surface contamination of dust adsorbed on the surface. Using the transparent tape attached to the surface, the removal rate was calculated by measuring the weight of the dust, and the number of particles was calculated using the gravimetric method and the software, ImageJ. The results of the experiment showed that the number of dust particles adsorbed on the tile wall surface before and after washing were 3,063 ± 218 particles mL-1 and 20 ± 5 particles mL-1, respectively, with weights of 580 ± 82 mg and 13 ± 4 mg. Particles on the surface of the concrete structure before and after washing were 8,105 ± 1,738 particles mL-1 and 39 ± 6 particles mL-1, respectively, with weights of 1,448 ± 190 mg and 118 ± 32 mg.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.150-163
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• 2022

Recently, the gated community has been increasing due to various reasons such as demand for differentiated areas and security, but various problems have been raised, including regional conflicts, traffic restrictions and disconnection of surrounding areas. Therefore, this study empirically considered what kind of spatial effect the gated community has on the surrounding area by analyzing the vitality using floating population big data and analyzing pedestrian accessibility using network analysis and social network analysis. As a result, it was found that the overall vitality in the study area was greatly affected by the land use and the building use. However, focusing on apartment complexes, even in the same land use, when the form of the complex is open to the outside, there is a lot of floating population, so the vitality is high. In terms of accessibility, assuming that the gated community is open, it was found that as the physical connectivity improved, there were more roads for pedestrians to choose from, and the accessibility improved as traffic and exchanges occurred in the disconnected space. The value of improving property rights and residential environment is also precious, but it is necessary to review how to reflect the improvement of local permeability in enhancing the publicness of cities and the value and direction of communities that can coexist with the region.