Kyungrai Kim

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.

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.

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.

Pulsed boundary layers observed during a Geotail magnetopause skimming orbit

On January 8, 1996, the Geotail satellite skimmed along the dayside magnetopause from the dawnside to the duskside and observed a series of quasi-periodically recurring pulsed boundary layers in the prenoon (∼0900–1000 LT) and the postnoon (∼1400–1500 LT) sectors. For both intervals the interplanetary magnetic field observed by the Wind satellite upstream of the bow shock was inferred to be southward from an estimated convection time between Wind and Geotail. During the pulsed events, Geotail observed bipolar signatures in the magnetic field component normal to the nominal magnetopause. In the prenoon sector the bipolar variation had the inward-then-outward polarity, while in the postnoon sector the polarity was opposite (i.e., outward-then-inward). The plasma flows normal to the nominal magnetopause showed bipolar signatures with the inward-then-outward polarity in the prenoon and postnoon sectors. They were accompanied by sunward flows for the lower-density pulsed events and by tailward flows for the higher-density pulsed events. We have interpreted the sunward flow as the local plasma response to a tailward moving flux tube. This may imply that the sunward plasma flow near the magnetopause does not always reflect the direction of the motion of the flux tube. On the basis of these observations, we suggest that the observed pulsed boundary layers are attributed to the passage of a train of flux transfer events propagating tailward.

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

An Administration Model for Causes of Delay in Construction Projects to Decide Time Extension Responsibility

Since the cases of time extension have continuously transpired in the public construction project, the potential of economical loss and claims is increasing because the concerned parties such as an owner or a contractor have not properly performed their own responsibility for time extension. One of the main reasons is that the present planning and scheduling do not support the method to apportion the proper responsibility to the right party. This problem has repeatedly led to time extension and made it difficult for the concerned parties to perform the responsibility for time extension. In order to overcome this problem, a framework of delay administration is required as the method to apportion the proper responsibility to the right party. To solve this problem, this paper aimed to develop the conceptual model and prototype system as the practical method to administrate delay causation. Furthermore, the verification result for the reliability and applicability throughout the case studies on real construction projects shows that the conceptual model and prototype system developed would help efficiently to administrate the delay causation.

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.

Theoretical Studies of Plasma Wave Coupling: A New Approach

New numerical and analytical methods are applied to wave coupling in inhomogeneous plasma. It is found that the X-mode feeds energy into the upper hybrid resonance at plasma inhomogeneities oriented perpendicular to the ambient magnetic field. The results are consistent with previous studies using other methods. When a finite pressure is introduced, the upper hybrid waves are no longer stationary and start propagating. They can form cavity modes and emit a small fraction of O (or X) waves. Limitations of the present study are the neglect of collisions and plasma pressure effects which might limit the growth of the upper hybrid waves; furthermore, this study concentrates on the case for which the density gradient is perpendicular to the magnetic field, a condition that is valid near the equator.

Spacecraft potential variations inside the magnetopause during transient events: Geotail observations

We examine the spacecraft potential (SP) variations near the magnetopause. In the magnetosphere the Geotail satellite often observed transient SP increase accompanied by magnetic field enhancements. This signature (SP increase and magnetic field increase) was also observed inside the magnetopause during the outbound (from the magnetosphere to the magnetosheath) and/or inbound (from the magnetosheath to the magnetosphere) magnetopause crossings. For the interval of the SP increase, the plasma density and temperature were intermediate between those of the magnetosheath and the magnetosphere, and strong enhancements of the field-aligned bidirectional electron fluxes were observed mainly in the medium energy (∼300–450 eV) range. These observations are consistent with previous studies in the inner part of the low-latitude boundary layer (LLBL). Thus we suggest that the transient SP increase in the magnetosphere may be a good indicator of the entry into the inner LLBL.