• Korean Journal of Construction Engineering and Management
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• v.9 no.1
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• pp.87-95
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• 2008

The government wants to apply the construction cost estimating method based on historical data published in the first six months of 2004. Construction companies, however, require the proposed cost estimation model, to be improved which makes it difficult to predict a reasonable construction costs. This paper presents an improved historical data selection model after analyzing the problem of previous method throughout comparing contracted unit prices of reinforced concrete works selected by the previous model to market prices. The model which can select more feasible data would assist participates such as general contractors and sub-contractors to earn a proper profits.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.369-372
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• 2001

The processes for verification of performance records in construction have many problems according to construction firm's participating in some of the processes. This study analyzed about current processes and provided improved processes with IDEF method. As the result of this study, it was found that 'As-Is' model has many repetition of activities and 'To-Be' model has three times more effective than 'As-Is' model has. The data modeling which is available for 'To-Be' model was also suggested.

• The Journal of Society for e-Business Studies
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• v.18 no.4
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• pp.145-167
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• 2013

This paper proposes a method to compare planned processes with actual processes of bock assembly operations in shipbuilding industry. Process models can be discovered using the process mining techniques both for planned and actual log data. The comparison between planned and actual process is focused in this paper. The analysis procedure consists of five steps : 1) data pre-processing, 2) definition of analysis level, 3) clustering of assembly bocks, 4) discovery of process model per cluster, and 5) comparison between planned and actual processes per cluster. In step 5, it is proposed to compare those processes by the several perspectives such as process model, task, process instance and fitness. For each perspective, we also defined comparison factors. Especially, in the fitness perspective, cross fitness is proposed and analyzed by the quantity of fitness between the discovered process model by own data and the other data(for example, the fitness of planned model to actual data, and the fitness of actual model to planned data). The effectiveness of the proposed methods was verified in a case study using planned data of block assembly planning system (BAPS) and actual data generated from block assembly monitoring system (BAMS) of a top ranked shipbuilding company in Korea.

• Korean Journal of Construction Engineering and Management
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• v.3 no.2 s.10
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• pp.107-113
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• 2002

The processes for management of historical data in construction have many problems according to construction firm$^{\circ}{\phi}$s participating in some of the processes. This study analyzed about current process and provided improved processes with IDEF method and simulation. The proposed $\lceil$To-Be$\rfloor$ model is more effective than $\lceil$As-Is$\rfloor$ model according to the result of simulation performance. It is revealed that the productivity in the construction company is more improved than that of the owner from the results of the system simulation.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.137-143
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• 2018

Korea's air passenger traffic has been growing steadily. In this paper, we propose a forecasting model of air passenger demand to ascertain the growth trend of air passenger transportation performance in Korea. We conducted a simulation based on System Dynamics with the demand as a dependent variable, and international oil prices, GDP and exchange rates as exogenous variables. The accuracy of the model was verified using MAPE and $R^2$, and the proposed prediction model was verified as an accurate prediction model. As a result of the demand forecast, it is predicted that the air passenger demand in Korea will continue to grow, and the share of low cost carriers will increase sharply. The addition of the Korean transportation performance of foreign carriers in Korea and the transportation performance of Korean passengers due to the alliance of airlines will provide a more accurate forecast of passenger demand.

• Journal of the Korea Computer Graphics Society
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• v.10 no.3
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• pp.1-8
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• 2004

본 논문은 한 장 혹은 여러 장의 실세계의 사진 영상을 입력으로 받아 영상 기반 모델링 방법 중 하나인 영상 분할 모델링 방법을 통해 환경을 3차원으로 모델링을 하고 주어진 실세계 사진 영상을 비사실적 렌더링하여 환경 탐색시 환경맵으로 사용하도록 하여 비사실적 탐색 영상을 생성하는 방법을 제안하였다. 제안된 방법은 세밀한 3차원 환경 메쉬 모델을 생성하여 2차원 환경맵의 비사실적 랜더링 과정을 통해 비사실적 애니메이션 효과를 손쉽게 만들어 낼 수 있다는 장점을 가지고 있다. 또한, 환경맵의 비사실적 렌더링을 통한 환경 매핑방법으로 각 프레임 간의 유사성을 유지하며 렌더링하는 특징을 가지고 있어 자연스러운 비사실적 탐색 영상을 생성 할 수 있다.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.81-89
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• 2010

Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget.

• Korean Journal of Construction Engineering and Management
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• v.3 no.1 s.9
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• pp.83-90
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• 2002

Actual construction data are unsystematically handled and uselessly hoarded after completion of the project although actual construction data can be applied to the various works of the future projects. Many researches have been carried out by several engineers and scholars of construction firms and research institutes, but the level of the application is not plausible yet. The objective of this paper is to propose a web-based data model and application system for commercial buildings in order to enhance the usability of the actual construction data on line. The principal factors of commercial building project data and the user$^{\circ}{\phi}s$ requirements in various areas, such as planning, design, procurement and construction and so on are analyzed to implement the database structure of the proposed system. The application of resource Information focused on cost, manpower, equipment is included in the system, which is expected to enhances the usability of actual database application system compared with other researches proposed so far.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.58-73
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• 2022

The purpose of this study is to construct a predictable estimation model that reflects the relationship between the variables of mobile app performance and to verify how app reviews affect app performance. In study 1 and 2, the relationship between app performance indicators was derived using correlation analysis and random forest regression estimation of machine learning, and app performance estimation modeling was performed. In study 3, sentiment scores for app reviews were by using sentiment analysis of text mining, and it was found that app review sentiment scores have an effect one lag ahead of the number of daily installations of apps when using multivariate time series analysis. By analyzing the dissatisfaction and needs raised by app performance indicators and reviews of apps, companies can improve their apps in a timely manner and derive the timing and direction of marketing promotions.

• Korean Journal of Construction Engineering and Management
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• v.1 no.2 s.2
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• pp.89-97
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• 2000

This research has been Initiated to provide an effective management tool for budget control of the public projects using EVMS. Barriers to implementing the tool for the domestic public projects are identified : no PMB (Performance Measurement Baseline) for budget control, management by BOQ(bill of quantity), no systematic planning and control. To eliminate these barriers, an integrated cost and schedule management process model using EVMS is proposed. This model is composed of six sub processes : organizing, scheduling, budget allocating, establishing PMB, managerial analysis, change incorporation.