• Korean Journal of Construction Engineering and Management
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• v.21 no.3
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• pp.11-19
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• 2020

Since an accident in construction industry has been higher than others for decades, the accident in construction industry should be decreased. To prevention this problem, the work breakdown structure (WBS) and risk breakdown structure (RBS) are presented. the WBS and RBS, are hierarchy structure which can find fatal incident considering type of building and type of work easily and quickly. So, this study aims to develop framework for the integrated WBS-RBS to prevent fatal incident on construction industry. The research process is conducted by following 3 steps: (I) collection of data; (II) classification of data; and (III) development of the integrated WBS-RBS. The result of this study can propose the most dangerous fatal incident aspect of type of building, type of work, and type of accident. Through the result, the decision maker can reduce or eliminate fatal incident considering type of building, type of work and type of accident in construction industry.

• Journal of the Korean Vacuum Society
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• v.8 no.1
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• pp.36-42
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• 1999

Field emission behaviors from diamond-like carbon films were investigated. The films were deposited on n-type Si wafer by ion beam sputtering method using 3 cm Kaufman type ion source. Regardless of the film thicknesses and atomic bond structure, the emission current was much enhanced by electrical breakdown between anode and the film surface. The effective work function was estimated to be about 0.1 eV. In order to identify the emission site, tungsten tip was scanned the damaged region damaged region but localized to a specific site. Analysis using Auger electron spectroscopy and SEM shows that SiC compound was not a sufficient condition for the electron emission. This result showed that the enhanced emission was mainly due to the changes in the chemical bond of the damaged region rather than the enhanced electric field caused by the morphological change.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1310-1310
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• 2024

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.213-219
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• 2010

The research, based on 200 cases of small interior works in6 different floor area types of apartment in Busan, intended to compare the architectural work with the breakdown structure and analyze the cost of general small-scale interior work, by work type. The outcome of the research is outlined as follows. (1) Given the cost of small interior works for apartmentsranges from 10 million to 15 million won, which correspond to apartments ranging in size from $79.2m^2$ (24PY) to $105.6m^2$, it is necessary to implement a cost analysis for material cost and labor cost for these two types. (2) Given that small interior work for apartments comprises mostly finishing work, unlike the categoriesof general architectural work, it is more reasonable to classify the works into 9 categories,which include embellishment, wood, tile, paint, metal, toilet, sink & furniture, electric & mechanical and other works, instead of the 22 divisions stipulated in the Korean Architectural Standard Specification. (3) After reviewing the average cost of small interior work and rate by floor area, it was found thatthe average cost of 24PY was 10.5 million won, of which metal work accounts for 12.8%, embellishment work 17.8%, and toilet 19.7%, while sink & furniture appeared to be the highest with 22.1%, while for 32PY, average cost was 12.5 million won,which comprises 7.4% wood work, sink & furniture 20.2%, toilet 23.4% and embellishment work the highest at 28.6%, indicating that embellishment work accounts for the greater portion.

• Journal of KIBIM
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• v.11 no.2
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• pp.1-16
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• 2021

Since entering the 21st century, the construction industry has developed faster and faster, and more and more technologies have been applied in the construction industry. BIM technology (Building Information Modeling) was born in this environment. The application of BIM technology can greatly improve the efficiency of cost management and help achieve the goal of cost management. But through BIM to realize project cost management, there is still no good solution. In order to solve this problem, this paper puts forward the concept of WBS structure applied to construction projects by studying the BoQ (Bill of Quantities) list based on BIM, and proposes the numbering method of the structure. The WBS (Work Breakdown Structure) structure proposed in this paper divides more than 5000 cost objects into 133 projects according to the type of work and project schedule. This structure helps to realize the application of BIM in project cost management. Although this article has studied more than 5000 data of three projects, it does not think that it can cover all cost objects in the existing construction industry. The purpose of this article is to propose a solution for cost and Process Control using BIM-based BoQ data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.67-71
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• 2001

PT of epoxy mold type have tendency to occur dielectric breakdown in high voltage system. These are using for measurement of voltage or protection of system and application voltage is 25.8kV. Therefore, for improving a lots of problems like as partial discharge, we had analyze on the destroyed Epoxy molded type PT and processing of production. As a results, we concluded that the reason of dielectric breakdown was defect of processing and degradation of insulation by electrical stress. In this work, We presented a method of solution in processing of production. which is reduction of the PO which was occurred at the insulation material. so we must many try to remove faults, these problems are mainly to winding methods of 1st coil. the other side, Reformation of 1st coil improved property of PD and we could prove it with experiments.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.6
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• pp.541-549
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• 2007

This work describes an investigation into the feasibility of using an acoustic emission (AE) technique to evaluate the integrity of a composite actuator with a PZT ceramic under electromechanical cyclic loading. AE characteristics have been analyzed in terms of the behavior of the AE count rate and signal waveform in association with the performance degradation of the composite actuator during the cyclic tests. The results showed that the fatigue cracking of the composite actuator with a PZT ceramic occurred only in the PZT ceramic layer, and that the performance degradation caused by the fatigue damage varied immensely depending on the existence of a protecting composite bottom layer. We confirmed the correlations between the fatigue damage mechanisms and AE signal types for the actuators that exhibited multiple modes of fatigue damage; transgranular micro damage, intergranular fatigue cracking, and breakdown by a short circuiting were related to a burst type signal showing a shortly rising and slowly decaying waveform with a comparably low voltage, a continuous type signal showing a gradual rising and slowly decaying waveform with a very high voltage and a burst and continuous type signal with a high voltage, respectively. Results from the present work showed that the evolution of fatigue damage in the composite actuator with a PZT ceramic can be nondestructively identified via in situ AE monitoring and microscopic observations.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1081-1084
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• 1995

Internal voids located within an insulation will arise partial discharge that causes local breakdown and even the entire insulation breakdown. For HV apparatuses, it is usual case that several voids are formed within non-uniform electric field condition rather than single void within uniform field, which can be solved analitically. The purpose of this work is to study partial discharge and breakdown characteristics of an insulation according to the distribution pattern of two disc-type voids that are located within non-uniform field. The results from numerical field analysis and experiments show that the electric field within the voids decreases as they are arranged more serially, which accordingly results in the increase of partial discharge inception field(PDIF) much higher than that of single void model. With parallel arranged voids, PDIF is almost the same as that of single void model. On the other hand, AC breakdown strength decreases as voids are arranged more serially, which is a natural result considering the reduction of effective insulation thickness. For parallel voids, this effect cannot he noticed where as they show different pattern compared with single void and serial void models in $\Phi$-Q-N analysis. Considering these results may leads us to the conclusion that, in the evaluation of insulating products through PD test, it is not sufficient to determine only PDIV or existence of PD at predetermined voltage level. We could evaluate more accurately by considering all the available data such as PDIV, PD magnitude, PD occurring phase, number of PD pulses, and etc.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.490-493
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• 2004

The purpose of this study is to construct technology product concept a deployment model on seeds type R&D projects. For this purpose, we have peformed the following studies : First, technology opportunities and market opportunities through ${\ulcorner}$perception analysis${\lrcorner}$ are captured by perceptional structure of technology experts and customers on the existing technologies and products. Second, the optimal technology product concept deployed by ${\ulcorner}$SAT(System Alternatives Tree)${\lrcorner}$ has been constructed by the ${\ulcorner}$PWBS(Project work Breakdown structure)${\lrcorner}$.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.38-45
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• 2017

A finite element analysis-based approach which investigates the causes of the breakdown in the outer ring of the choke at hot rod rolling mill is presented. Two-dimensional drawings of the whole vertical-type mill stand are transformed into three-dimensional CAD models. Non-linear elasto-plastic deformation analysis of material at the roll gap is performed for computing roll force and torque of the work roll. Then, the reaction forces of the bearing rings together with a set of roller bearings that support the work roll are obtained by means of rigid body motion analysis. Finally, stress behaviors in the bearing rings together with a set of roller bearings that support the work roll are investigated by linear elastic analysis. Results reveal that stress at the contact area between the outer ring and roller bearing is extraordinary high when an internal gap between an external surface of the outer ring and the internal surface of the chock due to wear of the inside of the chock occurs.