• Journal of Cadastre & Land InformatiX
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• v.49 no.1
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• pp.29-43
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• 2019

In this study, to solve the problem of the Association-led Housing Reconstruction Business (AHRB), as an alternative to the AHRB, the reliability of the Trust company-led Housing Reconstruction Business (THRB) is verified. To this end, the AHRB and the THRB comparison analyses were performed for the project period, income and expenditure, and the calculation of the Reconstruction Charges (RC). The results of the study are as follows: First, the THRB's business period is shorter than the AHRB's. Second, the THRB's business value is likely to be superior to the AHRB's. Third, due to differences in the calculation period of excess profit for housing reconstruction and the cost items related to implementer, the THRB's RC will be less than the AHRB's RC. Thus, the stability of the THRB has been partially verified as an alternative to the AHRB. The THRB is expected to expand further in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.150-159
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• 2015

This study was conducted for the purpose of presenting basic data for calculating a more reasonable landscaping project cost in the future through the construction cost calculation ratio of scenic planting and facilities and their time series trend analysis targeting 'J' corporation, a representative Korean public institution that creates apartment complexes. This study targeted scenic planting and the facility construction costs of 37 apartment complexes in the capital area from 2004 to 2012, using statistical analysis methods such as technical analysis, correlation analysis, and regression analysis to analyze the characteristics of the time series change. The conclusion was drawn as follows. First, breaking down the cost of overall landscaping projects to scenic planting and facility construction, the ratio of the average cost of scenic planting to that of facility construction showed 56.1% to 43.9% from 2004 to 2012. Second, the costs of planting construction and facility construction both showed a fluctuation range of about ${\pm}3%$, implying relatively steady costs considering the inflation rate. Third, the landscape construction cost for each type of construction resulted in a fluctuation range from minimum ${\pm}3%$(exercise facility) to maximum ${\pm}5%$(packing facility), reflecting that among the landscaping projects, the facility construction costs tended to show relatively large fluctuations in accordance with the change of time series. Fourth, the comprehensive indication of the ratio of landscaping project costs by time series and landscaping construction type implies that the regional characteristics and positional condition of the apartment complexes were not reflected sufficiently. Fifth, the high level of correlation of landscaping construction types and landscaping construction elements imply that the entire construction costs were controlled through partial adjustment of cost components within the overall frame of construction cost. These results reveal the problems of standardized landscaping cost irrespective of user satisfaction or environmental traits such as the conditions of the apartment complexes.

• Journal of Construction Engineering and Project Management
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• v.3 no.3
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• pp.23-34
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.83-89
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• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.218-226
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• 2016

In the original design of K2 tank the Vertical Sensor Unit(VSU) was mounted to measure the attitude of the main gun to enhance the hit probability. In this research, as a part of efforts to reduce the cost of K2, it was theoretically simulated and evaluated to use the data from Inertial Navigation System(INS) for the calculation of the gun attitude instead of the direct measurement using VSU. It was found that the negative effect of INS approach is negligible and the elimination of VSU is technically possible and beneficial to the system.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.375-385
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• Spatial Information Research
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• v.22 no.3
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• pp.47-58
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• 2014

The credible measurement, reporting and verification (MRV) is among the most critical elements in UN-REDD (United Nations programme on Reducing Emissions from Deforestation and forest Degradation in Developing Countries). This study is intended to explore MRV potential in terms of UN-REDD opportunity cost estimation using satellite image for Mt. Geum-gang of North Korea. A visual interpretation were conducted to evaluate MRV conditions by sub-dividing or decomposing the images with different pixel size into a three types of hierarchical tree structure that helps dealing with spatial variability within each subarea. The permanent record of standard satellite remote sensing system demonstrated its capability of presenting area-wide visual evidences of MRV conditions in Mt. Geum-gang (such as the identification of forested area, degradation trends for forest space, three types of hierarchical land-cover and land use tree structure, carbon density in the landscape). Satellite data could be accepted as legally binding proof when it comes to REDD opportunity cost estimation since several cases exist where remote sensing has been used as legal evidence in ICJ (International Court of Justice) and UN resolution. It doesn't seem very difficult to comply with MRV requirements for UN-REDD opportunity cost calculation due to the probative value of satellite data. It is anticipated that this research output could be used as a valuable reference for Korea-based enterprises exploring REDD project sites and the carbon traders to ensure MRV potentials using satellite image in UN-REDD Opportunity Cost estimation.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.147-157
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• 2009

Recently, there has been continued research on UCP from the development effort estimation method to a software development project applying object oriented development methodology. Current research proposes a linear model estimating the developmenteffort by multiplying a constant to AUCP which applies technical and environmental factors. However, the fact that a non-linear regression model is more appropriate as the software size increases, the development period increases exponentially. In addition, in the UCP calculation process the occurrence of FP errors due to the application of TCF and EF, it is unrealistic to estimate the size with AUCP. This paper presents the issue of current research based on UCP without considering problems of the research, for example, TCF and EF and expresses the models (linear, logarithmic, polynomial, power and exponential type) estimating the development effort directly from UUCP. Consequently, the exponential model within non-linear models exhibit more accurate results than the current linear model. Therefore, after calculating the UUCP of the developing software system, using the proposed model to estimate the development effort, it is possible to estimate the direct cost required in development.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.115-126
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• 2009

A software size estimation has to be analyzed in the beginning of the software life-cycle and helpful to the prediction of its size and cost. The software cost has been calculated by estimating software size from the user's point of view since the function point method based on international standards was introduced for the estimation of software size in 2004. However, the current function point method is not easy to be exploited for unfamiliar user, and has a problem that it cannot estimate the proper size for software such as engineering software, scientific calculations and simulation with complicated internal computational logic. This paper presents an improved model which can simplify the existing function point measurement procedure, and perform the estimation of software size in easy and fast way at the initial stage of project. Moreover, it presents a mathematical weighted value calculation model which can solve the problem of the fixed complexity weighted value and reflect the characteristics of organization as its data is pilled up. Our evaluation shows that the presented model has advantage that it can measure the size more rapidly than the existing FPA methods and has more correlation with LOC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4176-4184
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• 2015

Cost Estimate for alternative in design phase of construction become criterion for profitability and feasibility analysis of projects. Initial design phase performed schematic estimate based on similar data in the past. The quantity take-off according to estimators experience and calculation method are occurred different or missing. IT (Information Technology) technology evolution has been promoting BIM technology in construction. It is changing the paradigm of planning, design, construction and maintenance phase throughout the construction project. A number of studies have been attempted to apply BIM technology in the construction. In this paper, we propose schematic estimation framework linking standard format IFC (Industry Foundation Classes) and estimate related knowledge. As a result, it performs a cost prediction for decision-making in the design phase, and expected to overcome the limitations of previous studies. In addition, it is possible actively coping with changes.