• Earthquakes and Structures
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• v.19 no.4
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• pp.287-301
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• 2020

Fragility as one of the most effective methods to evaluate seismic performance, which is greatly affected by damage index. Taking a multi span continuous rigid frame offshore bridge as an example. Based on fragility and reliability theory, considering coupling effect of time-varying durability damage of materials and time-varying attenuation effect of damage index to analyze seismic performance of offshore bridges. Results show that IDA curve considering time-varying damage index is obviously below that without considering; area enclosed by IDA of 1# pier and X-axis under No.1 earthquake considering this effect is 96% of that without considering. Area enclosed by damage index of 1# pier and X-axis under serious damage with considering time-varying damage index is 90% of that without considering in service period. Time-varying damage index has a greater impact on short pier when ground motion intensity is small, while it has a great impact on high pier when the intensity is large. The area enclosed by fragility of bridge system and X-axis under complete destruction considering time-varying damage index is 165% of that without considering when reach designed service life. Therefore, time-varying attenuation effect of damage index has a great impact on seismic performance of bridge in service period.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.93.1-93
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• 2002

In this paper, an efficient robust control method for chaotic system introducing the concept, the edge of chaos (:boundary status between chaos and non-chaos), is proposed. To realize this concept, we introduce an extended performance index which consists of two parts. One is for achievement of the system's objects, another is for keeping the system edge of chaos. Parameters of the neural network controller are adjusted to minimize the value of the extended performance index and achieve the above two objects using Random...

• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1221-1227
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• 2019

This paper describes a low-density parity-check (LDPC) coded index modulated orthogonal frequency division multiplexing with quasi-orthogonal sequence (IM-OFDM-QOS) and provides performance evaluations of the proposed system. By using QOS as the spreading code, IM-OFDM-QOS scheme can improve the reception performance than IM-OFDM-SS scheme for a given data rate. On the other hand, LDPC code is widely used to the latest wireless communication systems as forward error correction (FEC) scheme and has Shannon-limit approaching performance. Therefore, by applying LDPC code to IM-OFDM-QOS system as FEC scheme, the reception performance can be further improved. Simulation results show that significant signal-to-noise ratio (SNR) gains can be obtained for LDPC coded IM-OFDM-QOS system compared to the LDPC coded IM-OFDM-SS system and the SNR gain increases with the higher code rate.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.117-123
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• 2020

This study intended to develop the Performance Evaluation system for the modern pentathlon such as an Olympic sporting event. The performance evaluation index system for the modern pentathlon was developed by Microsoft Excel 2016 with Visual Basic for Application that it is able to be understandable for the practical field in sport. Consequently, the system for the performance evaluation index is able to be developed within the concept of performance analysis of sport such as a notational analysis of sport. And the performance indicators for the performance evaluation index were selected by the skills to make successful outcomes. Finally, the simulation with big data gathering by the developed system would be requested that systematic reviews on successful outcomes in other sporting events would be necessary.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.618-622
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• 2010

The damages from DDoS attacks are increasing as DDoS attacks are taking various forms. This has resulted not only in decreased reliability of organizations and corporations but also in the threat of national security. Organizations and corporations are making significant efforts in developing a system through which they can appropriately correspond to DDoS attacks. However, the studies on objective index for evaluating the performance of DDoS correspondence are lacking. The majority of the existing studies have been on the information protection & management system on a large scale. Accordingly, the scope of this thesis will be limited to DDoS correspondence to propose correspondence index for quantitatively measuring and managing them. The statistical techniques such as SMART technique and factor analysis will be utilized accordingly.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.5
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• pp.360-366
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• 1987

The design problem of optimal constant PIDM (proportional-integral-derivative and measurable variable) feedback controller for linear time-invariannt systems is investigated with the time-weighted quadratic performance index. Necessary conditions for an optimality of the controller are derived and an algorithm for computing the optimal feedback gain is presented. It is shown via example that the design mithod using the time-weighted quadratic performance index improves the transient responses of the closed-loop system.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.323-326
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• 2008

Data Envelopment Analysis (DEA) is a theoretically sound framework for performance analysis that offers many advantages over traditional methods such as performance ratios and regression analysis. Largely the result of multidisciplinary research during the last three decades in economics, engineering and management, DEA is best described as an effective new way of visualizing and analyzing performance data. Besides, overseas information technology companies have aggressively tried to enter the domestic market. In the age of globalization and high competition, it is imperative that the system integration (SI) companies need to introduce the performance evaluation models of SI projects, including Capability Maturity Model and Software Process Improvement and Capability Determination, to gain a competitive advantage. Therefore, it makes our research regarding evaluation of SI projects very opportune. The purpose of the study is not only to evaluate efficiency of each project by DEA but also to gain insight into various factors such as project complexity, team members' man-months structure, and process index(project management index) that link to the projects performance.

• Knowledge Management Research
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• v.10 no.1
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• pp.71-100
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• 2009

Recently, many of organizations build up their performance measurement system (PMS) to measure their knowledge management performance. However, the system that doesn't well reflect the organization's strategies as well as surroundings could obstruct their performance improvement, instead. Therefore, It is really important to establish the PMS to reflect organization's surroundings and strategies. The purpose of this study is to make a diagnosis of a performance measurement practice of a domestic university's knowledge management. To serve this research purpose, we examine the uptight performance index and PMS from existing references. And we diagnose the specific practices and maturity rates of measuring performances, and the recognition of the performance index at "D" university recently adopting balanced scorecard to performance evaluation through the survey on academic affairs committee members, performance evaluation committee members, and administration members. The method analyzing data from the survey is a gap analysis which includes alignment analysis, congruence analysis, consensus analysis, and confusion analysis. We make a diagnosis of performance measurement practices at "D" university, raise several points of this performance measurement system, and present the improvement plans from these problems.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.12
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• pp.41-49
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• 2018

The current housing performance rating system displays the performance rating of the houses supplied by the housing construction company, approved by the Housing Law. This system is intended to provide accurate information to the consumers in the announcement of the tenant recruitment, thereby improving the quality of the housing. This system was revised in January 2005 and implemented from January 2006. It is obligatory for companies with a scale of more than 1,000 households (energy performance rating is over 300 households), but there is currently no content on the waterproofing field. Therefore, this study suggests the revision plan proposes the necessity of the inclusion of the performance grade for the waterproofing field which is not currently implemented in the apartment house performance rating system, and to understand how to secure an adequate living environment. As a result, according to survey results, the performance score based on the difficulty of the maintenance method according to future leaks was selected and the revised system was prepared. Based on this, the performance grade for the virtual apartment was evaluated, and the results show that the performance of various grades is presented accordingly.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.984-987
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• 1996

We consider a feedback control system including interval plant where uncertain parameters expressed in the hyperrectangular box X. Here we define the maximum value of the integral of the error(ISE) as the worst performance index(WPI) due to the plant parameter uncertainty. Suppose that the closed loop system retains robust stability and it belongs to type I. Then we show that the WPI occurs only on the exposed edges of Q. In particular, it is also shown that if ISE is a convex function relative to X, the WPI is attained at one of vertices of X. Some examples are given.