• Earthquakes and Structures
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• v.18 no.5
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• pp.543-553
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• 2020

Past earthquakes experience shows that serious damage or collapse of buildings have dramatically accrued when sufficient separation distance has not been provided between two adjacent structures. The majority of past studies related to the pounding topic indicate that obtaining the gap size between two buildings is able to prevent collision and impact hazards during seismic excitations. Considering minimization of building collisions, some relationships have been suggested to determine the separation distance between adjacent buildings. Commonly, peak lateral displacement, fundamental period and natural damping as well as structural height of two adjacent buildings are numerically considered to determine the critical distance. Hence, the aim of present study is to focus on all mentioned parameters and also utilizing the main characteristic of earthquake record i.e. PGA to examine the lateral displacement of irregular structures close to each other and also estimate the sufficient separation distance between them. Increasing and decreasing the separation distance is inherently caused economical problems due to the land ownership from a legal perspective and pounding hazard as well. Therefore, a new equation is proposed to determine the optimum critical distance. The accuracy of the proposed formula is validated by different models and various earthquake records.

• Korean Management Science Review
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• v.12 no.3
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• pp.17-44
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• 1995

The changing business environment requires that firms reengineer their fundamental processes in order to retain their competitive advantage. Most Business Proess Reengineering (BPR) projects, however, have failed partly because the essential enabler, ie. information technology, was unable to perpetuate the original vision. The information systems were unable to support the collaboration among the workers participating in the process. Workflow Management Systems (WfMS) have the potential to enhance not only individual performance as did traditional information systems, but also the group performance essential to the success of BPR by providing an effective means of communications through connectivity. It also enhances productivitiy through proceduralization of the fundamental processes, thus making it possible to empower the employee even while it controls the flow, and ultimately the delaly that originally made the BPR effort necessary. Therefore, though it is not a panacea, WfMS's can improve chances for the success of BPR projects. Managers who have realized this are faced with another obstacle - that of selecting the WfMS that best meets the particular organization's needs. This paper provids an evaluation structure of WfMS functions with emphasis on those functions that are essential for BPR, classifying the functions into an attribute hierarchy according to the Analytic Hierarchy Process (AHP) approach. It also suggests specific evaluation criteria for the main workflow functions provided by most vendors today, thus providing managers with a comprehensive guideline to facilitate the decision process.

• Journal of Power Electronics
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• v.7 no.2
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• pp.146-158
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• 2007

A multi-pulse GTO based voltage source converter (VSC) topology together with a fundamental frequency switching mode of gate control is a mature technology being widely used in static synchronous compensators (STATCOMs). The present practice in utility/industry is to employ a high number of pulses in the STATCOM, preferably a 48-pulse along with matching components of magnetics for dynamic reactive power compensation, voltage regulation, etc. in electrical networks. With an increase in the pulse order, need of power electronic devices and inter-facing magnetic apparatus increases multi-fold to achieve a desired operating performance. In this paper, a competitive topology with a fewer number of devices and reduced magnetics is evolved to develop an 18-pulse, 2-level $\pm$ 100MVAR STATCOM in which a GTO-VSC device is operated at fundamental frequency switching gate control. The inter-facing magnetics topology is conceptualized in two stages and with this harmonics distortion in the network is minimized to permissible IEEE-519 standard limits. This compensator is modeled, designed and simulated by a SimPowerSystems tool box in MATLAB platform and is tested for voltage regulation and power factor correction in power systems. The operating characteristics corresponding to steady state and dynamic operating conditions show an acceptable performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.4
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• pp.58-64
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• 2006

In this age of infinite competition, quality control plays a huge part in deciding whether companies survive or not. In order to successfully solve the fundamental questions of quality in corporate management under the given circumstances, I suggest that the followings are vital: 1) continuous training of employees and competence development; 2) advocating employees' voluntary involvements and their will to work; 3) revitalizing quality circle activities. Activities of quality circles, which are organized to work out fundamental problems within the corporation, are important in renovating the existing administration. Thus, the purpose of this study is to understand the degree of influence quality circle activities have on the management outcome of the corporation by analyses of actual proofs, and to raise the importance of these activities. Moreover, it purports to provide the foundation for domestic companies to move toward becoming competitive advantage organizations by endowing them with the motivation to activate quality circles.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.1
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• pp.155-162
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• 2020

The aim of the research is to investigate the fundamental properties and heat of hydration reducing performance of the fly ash incorporated concrete mixture when the coal gas slag (CGS) from integrated gasification combined cycle (IGCC) is used as fine aggregate. From the results of the experiment, the workability was generally increased and the air content was decreased up to one to four percent with increasing the replacing ratio of CGS to fine aggregate. The compressive strength was similar or increased within five percent to the Plain mixture when the CGS was used as a fine aggregate. When the CGS and fly ash were used same time, the heat of hydration reducing performance was improved than single using cases either CGS or fly ash. Based on the results, for the concrete mixture using CSG as a portion of the combined fine aggregate, the general properties were improved and heat of hydration was decreased approximately 16 % when the fly ash was replaced 30 % to cement and the CGS was replaced less than 50 % to fine aggregate.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.780-787
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• 2007

The Information and Communication Technologies (ICT) sector is undergoing a fundamental transformation. Determinant factors in this transformation process are deregulations and technological advancements. From the value chain perspective, industry convergence plays the most crucial role in the transformation of the established telecommunications and media industries. The objective of this paper is to validate the impact of convergence on the business performance using empirical data. To identify the various effects driven by industry convergence, we analyzed the relationships between firm's degree of convergence and the business performance using regression analysis. From the empirical result with the 2002-2005 data, it was found that the convergence across ICT sectors improves the business performance measured by Tobin's q significantly and this is only a recent phenomenon. These results are consistent with the conjecture that higher degree of convergence is becoming more associated with higher market value.

• Journal of KSNVE
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• v.11 no.2
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• pp.307-314
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• 2001

This study aims to provide fundamental data for enhancing the sound insulation performance of windows. For this study, windows composed of various types and thicknesses, were classified into five categories； fixed, single, double, triple and airtight, and then tested. In order to analyze their sound insulation characteristics and performances. test results were rated using methods such as D, STC, Ts and arithmetical mean. It was found that the sound insulation performance of windows is affected due to their type rather than the thickness of the glass. It was also found that when gap between the inner and outer frames was filled with caulking material, the sound transmission loss at high frequency bands was greatly improved. Therefore, the sound insulation performance of windows would be enhanced by minimizing the gap between frames.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.4
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• pp.352-356
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• 2011

The isolation performance of a linear vibration isolator is limited to the ratio of stiffness to mass it supports. The stiffness of the isolator must be large enough to hold the weight. This results in the deterioration of the isolation performance. Recently, to overcome this fundamental limitation, the HSLDS(high-static-low-dynamic-stiffness) magnetic vibration isolator was introduced and its isolation characteristic was investigated theoretically. In this paper, the isolation performance of the HSLDS magnetic isolator is examined experimentally. Considerable amount of experiments are performed by carefully considering nonlinear characteristics. The experimental results verify the practical usability promisingly and agree with the theoretical studies, i.e. its performance is largely dependent on the key design parameter.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.227-235
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• 2005

The earthquake-resistant structural systems have to ensure the sufficient stiffness and ductility for the stability. For those purposes, recently, the performance design concept to increase the degree of absorbed energy level of structures has been proposed. One practical way of the performance design in the spatial structures is to apply the isolation system to boundary parts of roof system and sub-structure to obtain the target performance. So, it is necessary to examine the characteristics of dynamic behavior of spatial structures governed by higher modes rather than lower modes different from the cases of high rise buildings. The objectives of this paper are to develop the equivalent model to simplify the analytical processes and to investigate the dynamic behavior of roof system according to the mass and the stiffness of sub-structures as a fundamental study of performance design for the spatial structures.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.73-78
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• 2003

In order to improve the safety performance oi construction projects, effective and corporative safety management program between head office and job site must be implemented. And its performance must be measured and analyzed for the identification of the problems in the safety management area. This study proposes a previous evaluation model of safety performance for the large construction firm in order to enhance their safety level. The fundamental data for proposed model is based on the past research(Son 2002), which is structured of evaluation criteria. weighted factor. statistical evaluation formula. The model would help the firm management in identifying the weak areas of safety performance in terms of the degree performing certain safety tasks. It is expected that the model could contribute to achieving the "zero accident" level.ot; level.