Hee-Sung Cha

A Proposal for Optimizing Unit Modular System Process to Improve Efficiency in Off-site Manufacture, Transportation and On-site Installation

A unit modular system is a construction method which installs on site by manufacturing 50%~90% of the whole process in the factory. This method can minimize the process in the site and maximize the operation, which will reduce the duration and improve the overall quality. The recent paradigm of construction is to be sustainable building. Modular system can be regarded as a sustainable building construction method because it can reduce the amount of construction waste by recycling partial or whole part of overdue building be torn down. A unit modular system is the answer to cope with the increasing market of small size housings. A unit modular system is the most appropriate option at this point. This research proposes the standard operation and construction process of modular system, which enable to optimal system. A case study of reconstructing small-size housing was introduced to support this proposal. Finished unit modular is the reasonable way. However, 80% of complication rate of the modular is the most rational when a defect occurrence during delivery is considered.

Evaluation Method of Green Construction Technologies Using Integrated LCC and LCA Analysis

Green technologies of buildings are spreading for saving resource and energy consumption during life cycle of buildings. However, selection of optimized the technologies for applying projects is needed a lot of time and costs. Therefore prioritization is necessary to apply the technologies for buildings. An evaluation of economic value for the technologies is significant for prioritization of the technologies, however, the current evaluation system of economic value for technologies is not reflected the accurate features of the technologies. Green technologies have the objectives for reducing the emission of CO2 and saving the cost during the whole lifecycle of buildings. Thus the evaluation of economic feasibility for green technologies is needed to include the economic value from improving the environment. This paper developed the economic evaluation method integrated with LCC and LCA to accurately analyze the economic value for green technologies. Moreover, this paper drew the priority of the technologies by conducting case studies with the integrated method and analyzing the results with AHP. The conclusion of case studies, Green technologies is worth more if to include the economic value from improving the environment. Then in analysis of priority, Green intelligent component technologies were rated the highest. The conclusion of the study is able to utilize the supporting tool for making decision to select the optimized technologies for the projects and precedence study for developing future research of prioritization for green technologies. The future study for improving the developed method will supplement the various evaluation factors and apply the detailed weight to analyze the priority of green technologies.

To Improve Production Process of the Modular Using the Conveyor System

Republic of Korea is recently becoming an advanced country with increasing standard of living. This is causing a lack of employment in the construction industry because of high labor costs and it is resulting rapid increase in foreign labors. Modular Method of Construction can be defined as 50%~90% of the entire process is completed in factory, and transferred to construction field to install. The main purpose of this process is to minimize the entire process that possibly can be done at construction field in order to maximize the quality. The current local usage of Modular Method of Construction started at Shin Ki Elementary School during 2003 and it is widely used for military facilities. It should be used more because it has strengths of spending short time period to complete and low production costs. It can make a change if Modular Method of Construction is applied. Toyota is currently producing vehicle with conveyor system and if Modular Method of Construction is applied, then it is possible to reduce the waste of labor, and automatic production time. Expansion of the modular Market can be expected by applying this method because it will improve producing costs, high quality, and enforced process. This research tried to solve the problem of factory`s manufacturing production by applying local Modular Method of Construction to provide suggestions and analyze the profitability with applied conveyor system. It is depending on produced model, but this research`s model will take 20 months including assessment of payback period.

Development of Construction Project Performance Management System(PPMS) Considering Project Characteristics

In the construction industry, there are so many qualitative factors affecting the performance of a project. So it is crucial to measure the factors in an effective way in order to analyze the interrelationship among the various factors. To improve the performance level of a project, it is also important to identify the most appropriate management practices which are inter-linked with the subject project. The purpose of this study is to develop a project performance management system (PPMS) to quantitatively analyze the variety of project performance data and identify the best management practice to increase the potential level of a particular performance area. Using a comparative statistical method, this study developed a quantification method and web-based computerized system to enhance the usage of the system. The system, however, is still under the validation stage because of the shortage of data set. In the future, when more and more completed project data are stored in the system, the system would play a crucial role in predicting the performance level and matching the best management practice for a subject project. In addition, the system can also be modified as a tool for a business- or industry-level system by incorporating the existing enterprise resource programs.

A Study on Duration Calculation Method for Eco-Friendly Remodeling Demolition Work Using Productivity Analysis

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.

A Study on the Strategy for Creating Demand of Modular Construction through Case Analysis by Building Type

It has been seriously difficult to create demand of modular construction because Korean modular method has been considered as container house or lightweight steel house. Actually, barrier factor of modular construction for activation was difficult to produce modular continuously in factories based on stable amount of demands. So, this research found successive factors of modular construction and proposed the method of demand creation through a plethora of case analysis by building types. In addition, this research found the scale of modular potential market. Owners will be able to use this strategy that is proposed in this research when they make a decision about construction system. Also, the modular construction can make potential market in Korea. As a result, modular system producer can make their business strategies and make continuous demand by conjugating the method of creating demand for modular construction which is proposed in this research.

Construction Waste Management System for Improving Waste Treatment on the Construction Site

Abstract: The problems of environmental pollutions and resources depletio n have been growing issues in global construction recently. Efforts to reduce CO 2 emission have been also made in all sectors of construction industry these days. As one of the biggest industries that consume a huge amount of resources and generate complex construction wastes, the construction industry has significant impacts on environment issues. However, systema tic approach to manage wastes has been rarely made, and most construction wastes from construction sites are being land-fill ed or incinerated. In this study, a system is proposed to predi ct the amount of wastes in visual formats, and to control the process of wastes management. The system’s main functions include : (1) to estimate the amount of wastes to be generated in proje ct schedule, (2) to categorize the types of wastes, (3) to determine the timing of taking out wastes from sites, and (4) to share in formation regarding wastes for recycling. A huge amount of wastes are generated in construction process, but most of the wastes have been discharged in forms of mixed wastes, which make them hardly reused. The system not only provide information on wastes to be generated, but also prevent mixing various wastes by classifying them by types and schedules. This feature s of the system, along with functions to share wastes information with other agencies outside the site, are expected to enhance t he level of wastes recycling to a great extent. By saving construction materials through wastes recycling, the system also contributes in reducing CO

A Study on Analyzing Success Factors of Project Financing Within Small and Middle Scale Development Project

Recently, the Project Financing industry has appeared the various change of the development environment in the rapid growth. So the Project Financing company has been trying to search Project Financing able to success and they are performing diversified researching to prepare the judgment ground of success from initial stage of development. The aim of this study is to find success factors which is in the Project Financing through collecting opinion of specialist and talking survey to people employed in Project Financing development field. Consequently, we indicate success factors using Analytic Hierarchy process (AHP) and make out success factors for the Project Financing. Furthermore, we suggest the way which is able to apply factors objectified so that exceed the development success Project Financing objectively.

A Business Model for Application of the Modular Building in the Rental Market

The current real estate market is in a state that is considerably shrink due to the recession and long-term reduction of trading. In response, the government recently announced an innovative way for the middle-class residential housing and it is taking the lead to activate the real estate market. Meanwhile, the domestic housing market is entering a transition period, including structural changes of household structure, changes from joeonse to rent increasingly. Also single-member households will rise steeply, so that makes the high demand of small houses. In addition, the domestic construction industry is interested in new technology called Modular building. The Modular construction is an off-site construction system that shorten construction period, eco-friendly building technology and mobility etc, which can be used in various field. Overall, there are two major issues of the current market, one is the change of the real estate market, and the other is the modular construction. This study will propose modular business model in the rental market through the analysis the profitability of the modular business scenarios and IRR analysis.

Developing Countermeasure Model to Prevent Planned Lawsuit on Apartment Construction Defects

Abstract: The proportion of apartment housing has been increased to solve the housing problems resulted from rapid growth in urban population and urban economy. With the increase in apartments proportions and the concern about quality of housing, the contractors have made efforts to satisfy the customers in i mproving the quality of housing. Despite these efforts, the conflicts between the contractor and the customers are getting serious. A lso the disputes and the litigation of defect are increasing because of the contractors negative treatment and inadequate c ountermeasure. In this study the defect lawsuits which bring actions against the contractors are collected and analyzed. And then the strategic countermeasures are proposed according to t he classifying the type of defect and size. The suggested countermeasure model before the defects are resulted is expected to contribute in developing the contractors strategies to reduce the conflicts against customers.Keyword : Apartment house, Defect, Planned Lawsuit, Countermeasure Model , Checklist