• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.124-135
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• 2015

As many countries have been raising awareness of environmental issues, greater efforts for eco-friendly construction have been made in both governmental and private sectors. However, assessment circumstances for building energy performance and green building standard of legislation are still based on two dimension and handwork. This takes time, cost and labor, and makes assessment inaccurate and inefficient. Therefore, this study suggests methods to improve eco-friendly construction permission process and to automatize open BIM-based assessment of Energy Performance Index (EPI) among several eco-friendly construction certification standards. First, it analyzes the relations between assessment criteria and IFC data, and provides solutions to problems and limitations. Second, it applies the solutions to assessment program in order to automatize open BIM-based assessment for EPI. The eco-friendly construction permission process with these solutions applied will reduce time, cost, and labor by simplifying and automatizing the tasks. Also, the simplified process of design revision will improve not only productivity and efficiency but also accuracy and reliability.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.83-91
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• 2014

The problems of environmental pollutions and resources depletion 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, systematic approach to manage wastes has been rarely made, and most construction wastes from construction sites are being land-filled or incinerated. In this study, a system is proposed to predict 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 project schedule, (2) to categorize the types of wastes, (3) to determine the timing of taking out wastes from sites, and (4) to share information 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 features of the system, along with functions to share wastes information with other agencies outside the site, are expected to enhance the level of wastes recycling to a great extent. By saving construction materials through wastes recycling, the system also contributes in reducing $CO_2$ emission.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.971-976
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• 2007

In the U.S., utility damages or utility delay caused by conflicts during the underground utility relocation is one of the weighty problem in the construction industry. Also, in domestic case, delay and additional cost caused by underground utility(i.e, electricity, communication, gas, water supply and sewerage) relocation has been happened so that there is an increase of claims for responsibility between owners and contractors. However, there is insufficient survey for the recent circumstance of additional cost for delay and design changes caused by utility relocation and shortage of enough research for solving and analyzing of causes and their ripple effect. This research presents a result of the study about the best practices of FHWA(Federal Highway Administration), SHAs(State Highway Agencies) and the utility companies managing utility relocation. Also, it presents the basic concept of SUE(Subsurface Utility Engineering), the most reliable tool of FHWA presented, and investigates the developing status about SUE in Korea. At the end of this paper, this research proposes a practical and more applicable study about the efficient utility relocation focusing on local industry.

• Korean Journal of Construction Engineering and Management
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• v.14 no.3
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• pp.146-156
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• 2013

Recently, to reflect the various needs of customers in the apartment field, the customized apartment has emerged. From the point of the customer, customized apartments have the definite advantage of being able to guarantee more customer options. On the other hand, from the point of the project manager, there are significant risk factors, with increase of management factors, construction delays, etc. The reasons for this are, to date, the insufficient systematic analysis of the project, and the lack of experience of similar projects. This study provides the waste factors of each phase in a customized apartment project. A survey and interview are conducted to achieve the waste factors using MUDA methodology; a process of the project was analyzed; and a factor of each process was identified. Also, AHP(Analytic Hierarchy Process) are used, to evaluate the waste factors in project stages. The AHP results show that "Design change" and "Inappropriate intervention in construction process" ranked highly in the waste factors. The results of our research will provide a countermeasure that addresses waste factors in similar projects, and contributes to reducing the extra cost and time in new projects.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.21-33
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• 2018

In 2018, the real estate markets have hardly been transacted according to the government's tight regulations of real estates, and have the high possibility to reach a low hit due to the hike of loan interest rates following the U. S rise of base money rate. The key profits for the large construction companies mainly come from the overseas plant projects and the domestic non-governmental construction projects. They suffered a lot such as the lowering of their credit ratings due to the large losses caused by the frquent design changes and work delay. Even in the domestic non-governmental construction projects, the general business risks are on the rise due to the property marketing moving over to the decreasing phase. The small and medium sized security companies has realized a lot of operaring profits as they participated in the PF market to make up for the losses in the securities trading business. But, now as the housing market is not so good around the nation except Seoul and the financial states of large construction companies are not good enough, they can face the liquidity crisis if there happens the problems in the PF backed securities which they have handled. As Korean economy experienced the crisis in the savings banks before, it is recommended that Financial Supervisory Service proposes the preemptive control method and supervision direction to overcome the crisis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.1015-1026
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• 2002

As per increasing research interest in the field of collaborative computing in recent year, the importance of security issues on that area is also incrementally growing. Generally, the persistency of collaborative system is facilitated with conventional authentication and cryptography schemes. It is however, hard to meet the access control requirements of distributed collaborative computing environments by means of merely apply the existing access control mechanisms. The distributed collaborative system must consider the network openness, and various type of subjects and objects while, the existing access control schemes consider only some of the access control elements such as identity, rule, and role. However, this may cause the state of security level alteration phenomenon. In order to handle proper access control in collaborative system, various types of access control elements such as identity, role, group, degree of security, degree of integrity, and permission should be taken into account. Futhermore, if we simply define all the necessary access control elements to implement access control algorithm, then collaborative system consequently should consider too many available objects which in consequence, may lead drastic degradation of system performance. In order to improve the state problems, we propose a novel access control framework that is suitable for the distributed collaborative computing environments. The proposed scheme defines several different types of object elements for the accessed objects and subjects, and use them to implement access control which allows us to guarantee more solid access control. Futhermore, the objects are distinguished by three categories based on the characteristics of the object elements, and the proposed algorithm is implemented by the classified objects which lead to improve the systems' performance. Also, the proposed method can support scalability compared to the conventional one. Our simulation study shows that the performance results are almost similar to the two cases; one for the collaborative system has the proposed access control scheme, and the other for it has not.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.12
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• pp.1185-1194
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• 2012

This paper proposes a new terrestrial 3DTV broadcasting standard specification based on synchronization with non-real-time contents in order to overcome quality limitations of the current 3DTV services that are arisen from the limited bandwidth of the legacy broadcasting channel. In the services using the proposed specification, one view sequence of a stereoscopic video content is delivered as a non-real-time content in idle time, and the other view sequence is transmitted in real time broadcasting signal, thereafter two sequences are synchronized in a receiver for display. Thus, it is possible to provide higher-quality stereoscopic video content services than the current 3DTV services. In order to realize these services, a new mechanism is required which enables synchronization between the data that are from different transmission media and time. Therefore, this paper suggests a solution by multiplexing the synchronization signals of non-real-time contents into broadcasting signals with real-time streams together. This solution can provide a accurate synchronization mechanism by minimum updates of legacy broadcasting systems while maintaining compatibility with legacy services.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.645-656
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• 2001

Recently, component-based development (CBD) is rapidly spreading as a way of improving the reusability, productivity, and quality of software. For CBD to be effective in achieving such design objectives, the creation and integration of components must be based on a well-defined architecture that guides the correct composition and cooperation of application components. Software architecture must be described using an architecture description language (ADL) to ensure the correctness and preciseness of architecture models. In this paper, we propose the system architecture of an ADL tool set that can effectively support the use of CBD based on the domain architecture and we describe each component of the proposed system architecture. We also modify and redefine C2SADL that was developed to support the use of the description of C2 architectural style by UCI (University of California in Irvine) to facilitate the integration of separately described architecture models, and introduce the method of design and implementation of our ADL processor that partially implements the proposed ADL system architecture.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.106-112
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• 2010

Due to the improvement and stabilization of the social environment, construction market in the urban region is under shrinking. According, researches to lengthen the service life of the existing building structures are under the way through the remodeling or maintenance of deteriorated structures other than the new constructions. Similar situations are widely discussed in the domestic building construction market and the social importance of the remodeling of the existing building structures is increased. Although the structural stability of the building is uncertain due to the frequent repairing and structural changing, the remodeling works are usually conducted. In general, documents such as drawings and calculations for the design of the deteriorated structure to be remodeled are not kept. Accident at the remodeling site frequently occur because of the lack of thorough understanding of changed situations such as loadings, loading paths, changing of the mechanical properties of material, etc. In this paper, using the finite element analysis method, we investigated the structural behaviors of slab in the remodeling building and the results are applied to remodeling construction, and the appropriateness of the remodeling works are evaluated.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1149-1158
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• 2000

A radioisotope tracer experiment was carried out in the submerged fixed bioreactor of a dye wastewater treatment facility to evaluate the flow behaviors in the 6 compartments of the reactor and to find any possible factors which may affect to the efficiency of the process. Approximately 20mCi of $^{131}I$ was injected into the system as a tracer and 8 radiation detectors were placed in the 6 compartments and at the inlet and the outlet of the system to measure the change of the tracer concentration with time. Using the Perfect Mixers in Series Model the measured data were analyzed to calculate the mean residence time and the characteristic parameters of the flow in the system. The mean residence time of the system was calculated as 17 hours which is 76% of the designed MRT(22.3hr). Among the 6 compartments, the first compartment doesn't show the characteristic of perfect mixer, whereas, the other 5 compartments are working as perfect mixers. The output response of the first compartment is fit well with the simulated output of a model which consists of a perfect mixer with an exchange volume. It indicates that a quarter of the tank volume is working as a dead volume or an exchange volume. From the measured residence time distributions in each compartment, the appropriate sampling times after the change of operational condition of the electron beam accelerator were evaluated.