• Structural Engineering and Mechanics
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• 제26권3호
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• pp.315-341
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• 2007

A sudden change of stiffness in a structure, associated with the events such as weld fracture and brace breakage, will cause a discontinuity in acceleration response time histories recorded in the vicinity of damage location at damage time instant. A new damage index is proposed and implemented in this paper to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. The proposed damage index is suitable for online structural health monitoring applications. It can also be used in conjunction with the empirical mode decomposition (EMD) for damage detection without using the intermittency check. Numerical simulation using a five-story shear building under different types of excitation is executed to assess the effectiveness and reliability of the proposed damage index and damage detection approach for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also examined. The results from this study demonstrate that the damage index and damage detection approach proposed can accurately identify the damage time instant and location in the building due to a sudden loss of stiffness if measurement noise is below a certain level. The relation between the damage severity and the proposed damage index is linear. The wavelet-transform (WT) and the EMD with intermittency check are also applied to the same building for the comparison of detection efficiency between the proposed approach, the WT and the EMD.

• 산업융합연구
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• 제22권7호
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• pp.43-48
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• 2024

이 연구는 비처치군, 대조군, 처치군 간의 Visual Analog Scale (VAS)와 Disability Index (Disa)의 변화를 비교하여 요통(LBP) 완화를 위한 테이핑 방법의 효과를 평가하였다. 결과는 대조군과 처치군 모두에서 테이핑의 효과를 확인했다. VAS의 ANOVA 분석에서는 그룹 간 유의미한 차이가 나타났으며, 사후 검정에서는 비처치군과 대조군, 비처치군과 처치군 간에 유의미한 차이가 나타났으나, 대조군과 처치군 간에는 유의미한 차이가 없었다. 이는 두 테이핑 방법이 요통 완화에 유사한 효과를 나타낸다는 것을 의미한다. Disa의 경우, ANOVA에서는 유의미한 차이가 나타났지만, 사후 검정에서는 이러한 차이를 확인하지 못했다. 그룹 내 t-검정에서는 대조군과 처치군에서 VAS와 Disa의 처치 전후 차이가 유의미하게 나타났지만, 비처치군에서는 유의미하지 않았다. 이 연구는 요통 완화를 위한 테이핑의 효과를 강조하며, 두 방법이 임상에서 활용될 수 있음을 시사한다. 향후 연구에서는 더 큰 샘플과 다양한 조건을 사용하여 이러한 결과를 검증해야 한다.

• 한국국방경영분석학회지
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• 제5권1호
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• pp.37-72
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• 1979

This paper presents the FORTRAN program for expected damage by surface-to-surface weapons. One of the methods can be used to determine the effectiveness of general purpose (GP) bombs and cluster weapons against single unitary targets, linear targets, area targets, and areas of unitary target elements, The effectiveness index is in terms of fractional damage ($F_D$) or the number of volleys ($N_V$).

• 산업경영시스템학회지
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• 제17권30호
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• pp.81-87
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• 1994

Productivity relates output to input and also integrates performance aspects of quality, efficiency and effectiveness. Productivity improvement are associated with efficiency and effectiveness, productivity index involved quality and flexibility, integrated productivity measurement system, and other factors. This study focused on the productivity improvement that involved the opportunity costs such as qualify costs and flexibility effects.

• 기업가정신과 벤처연구
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• 제20권2호
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• pp.35-50
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• 2017

본 연구는 기업의 재무상태 및 지원규모에 따른 정책금융지원의 효과를 파악하기 위하여 일반화가법모형을 적용하여 실증분석 하였다. 이를 위해 이자보상배율과 총자산 대비 신규보증금액 비율을 이용하여 업종별로 분석대상을 구분하였으며, 수익성, 성장성지표를 사용하여 경영성과를 측정하였다. 또한 분석기간에 여러 번의 정책금융을 지원받은 기업의 경우 표본선택편의로 인한 결과의 왜곡이 발생할 수 있으므로 중복지원 효과를 최소화하기 위해 지원연도를 기준으로 이전 3년 동안 보증잔액 및 신규보증이 없으며, 이후 2년 동안 신규보증이 없는 기업을 선정하였다. 분석 결과, 보증시점의 이자보상배율이 1 미만이라 하더라도 지원규모에 따라 성과는 차별화되는 것을 확인할 수 있었다. 또한 한계기업의 기준으로 사용되는 이자보상배율이 0에 근사한 기업이더라도 경영성과는 향상될 수 있음을 확인할 수 있다. 결국 본 연구에서는 정책금융 지원정도에 따른 차별적인 경영성과를 확인함으로써 기술력이나 성장 잠재력을 고려한 평가가 요구되며 이를 통해 정책금융을 지원하는 담보가 부족한 중소기업의 자금조달 문제를 완화할 수 있는 유인책으로서의 작용할 수 있음을 시사하고 있다.

• 전기학회논문지
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• 제58권10호
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• pp.2047-2051
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• 2009

In this paper, we propose the localization method on WSN(Wireless Sensor Network) using fuzzy model and Kalman filter. The proposed method is as follows: First, we estimate the distance of RSSI(Receive Signal Strength Index) by using fuzzy model in order to minimize the distance error. Second, we use a triangulation measurement for estimating the localization. And then, we minimize the localization error using a Kalman filter. Finally, we show the effectiveness and feasibility of the proposed method through some experiments.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.465-473
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• 2015

The increasing need to improve transient security assessment of existing or forecasted operating conditions of networks by power system operators is major concern of the power system security monitoring problem at the Energy Management Systems. This paper proposes a preventive control of transient stability with generation rescheduling based on rotor trajectory index obtained using time domain simulations. This index may help power engineers in making operational decision and to obtain a generation configuration with better transient security dispatch. The effectiveness of the proposed methodology is demonstrated on IEEE 39-bus New England system for a three phase fault at different loading conditions with single and multiple line outage cases.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.803-808
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• 2007

LCCA module enabling to estimate LCC and analyze time-variant reliability index of a plate girder bridge was developed. The developed module was based on the designed data structure following the standardized methodology of ISO/STEP, LCCA module consisted of LCC estimation module, which is composed of six sub modules according to the cost category, and reliability index analysis module, which is composed of time-variant corrosion sub module, time-variant live load sub module, and element reliability analysis sub module, The effectiveness of the developed LCCA module was verified by estimating LCC and analyzing time-variant reliability index of a plate girder bridge on the basis of the constructed test database.

• 대한전기학회논문지:전력기술부문A
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• 제49권2호
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• pp.56-61
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• 2000

In the paper, the system loss sensitivity index that implies the incremental system loss with respect to the change of bus power is derived using optimization technique. The index λ reaches $\infty$ at critical loading point and can be applied to actual power systems for following purposes. 1) Evaluation of system voltage stability 2)Optimal investment of reactive power focused on minimizing system loss and maximizing system voltage stability 3)Optimal re-location of reactive power focused on minimizing system loss and maximizing system voltage stability 4)Optimal load shedding in case of severe system contingency focused on minimizing system loss and maximizing system voltage stability. Case studies for each application have proved their effectiveness.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.1-8
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• 2023

Smart IoT over high speed network and high performance smart devices explodes the ubiquitous services and applications. Nearest Neighbor(NN) query is one of the important type of queries that have to be supported for ubiquitous information services. In order to process efficiently NN queries in the wireless broadcast environment, it is important that the clients determine quickly the search space and filter out NN from the candidates containing the search space. In this paper, we propose a hybrid index of Voronoi and grid partition to provide quick search space decision and rapid filtering out NN from the candidates. Grid partition plays the role of helping quick search space decision and Voronoi partition providing the rapid filtering. We show the effectiveness of the proposed index by comparing the existing indexing schemes in the access time and tuning time. The evaluation shows the proposed index scheme makes the two performance parameters improved than the existing schemes.