• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1658-1663
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• 2021

Research on climate change and global warming on the power generation systems are rapidly increasing because of the Importance of the sustainable energy supply, thus the electricity supply since its growing share, in the end, uses energy supply. However, some researchers conducted this field, but many research gaps are not mentioned and filled in this field's literature since the lack of general statements and the quantitative models and formulation of the issue. In this research, an exergy-based model is implemented to model a set of six power generation technologies (combined cycle, gas turbine, nuclear plant, solar PV, and wind turbine) and use this model to simulate each technology's responses to climate change impacts. Finally, using these responses to define and calculate a formulation for the relationship between the system's energy performance in different environmental situations and a dimensionless index to quantize each power technology's reliability against the climate change impacts called the Pahlev reliability index (P-index) of the power technology. The results have shown that solar and nuclear technologies are the most, and wind turbines are the least reliable power generation technologies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권1호
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• pp.53-76
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• 2020

The synchronous phasor measurement algorithm is the core content of the phasor measurement unit. This manuscript proposes a dynamic synchronous phasor measurement algorithm based on compressed sensing theory. First, a dynamic signal model based on the Taylor series was established. The dynamic power signal was preprocessed using a least mean square error adaptive filter to eliminate interference from noise and harmonic components. A Chirplet overcomplete dictionary was then designed to realize a sparse representation. A reduction of the signal dimension was next achieved using a Gaussian observation matrix. Finally, the improved orthogonal matching pursuit algorithm was used to realize the sparse decomposition of the signal to be detected, the amplitude and phase of the original power signal were estimated according to the best matching atomic parameters, and the total vector error index was used for an error evaluation. Chroma 61511 was used for the output of various signals, the simulation results of which show that the proposed algorithm cannot only effectively filter out interference signals, it also achieves a better dynamic response performance and stability compared with a traditional DFT algorithm and the improved DFT synchronous phasor measurement algorithm, and the phasor measurement accuracy of the signal is greatly improved. In practical applications, the hardware costs of the system can be further reduced.

• 품질경영학회지
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• 제44권1호
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• pp.77-94
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• 2016

Purpose: This paper reviews Type 1 Gage study, Gage R&R study, and procedure of ISO 22514-7 for assessing a measurement system, and discusses some relationships between the measurement capability indices. Methods: The gage capability index $C_g$ of Type 1 Gage study, precision-to-tolerance ratio PTR of Gage R&R study, and measurement performance ratio $Q_{MS}$ and $Q_{MP}$ of ISO 22514-7 are considered in this paper. Results: This paper derives the relationships between $C_g$ and $Q_{MS}$, PTR and $Q_{MP}$, and $Q_{MS}$ and $Q_{MP}$, respectively, and discusses the acceptance conditions for each procedures. Conclusion: The measurement capability analysis is the first step for the quality improvement of the manufacturing processes. Therefore the result of this study provides a helpful guidelines for assessing the measurement system, enabling proper evaluation of manufacturing processes.

• 사회복지연구
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• 제42권1호
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• pp.151-177
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• 2011

바우처 사회서비스가 확대되면서 서비스 성과가 강조됨에 따라 성과평가에 대한 학문적·실천적 관심도 증가하고 있다. 이에 이용자들의 서비스 만족도 조사가 확대되고 있으나 아직 바우처 서비스 이용자들을 대상으로 한 만족도에 대한 연구는 체계적으로 진행되지 못하고 있다. 이에 본 연구는 보건복지부에서 시행하고 있는 지역사회서비스투자사업(지역개발형)의 바우처 서비스 이용자를 대상으로 하여 서비스 만족도 지표를 개발하려는 연구목적으로 진행되었다. 분석자료는 2009년 5월 현재 지역개발형 바우처 서비스 이용자 1800명을 대상으로 한 설문을 활용하였다. 기존의 만족도 연구에서 사용되고 있는 만족도의 유형과 측정방식, 측정도구를 정리하고 바우처 특성을 반영한 요소만족도 지표를 구성하였다. 우선 요소만족도 구성문항들은 문항분석과 신뢰도 분석을 통해 동질적인 문항들로 구성되어 있음이 확인되었다. 요소만족도와 체감만족도를 활용하여 종합만족도를 도출하였으며 수렴타당도와 판별타당도 평가를 통해 만족도 평가도구로서의 타당성을 확인하였다. 본 연구 결과, 종합만족도를 산출하는 방식에 있어 체감만족도를 요소만족도의 가중치 선정에만 활용하는 방식과 체감만족도를 요소만족도의 가중치 선정뿐만 아니라 종합만족도 합산시에도 중복적으로 사용하는 방식 간에 있어서 만족도 지수의 차이가 거의 없음이 확인되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.65-70
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• 2001

Six recycling plants have started operation for recycling scrap home appliances since the spring of 2000 in Taiwan. The performance of the plants has not yet been measured during the 18-month period. The performance measurement, however, can be looked in several aspects. Because of the nature of these recycling plants, at least three aspects, namely government (representing general public), appliance manufacturers and owners of the recycling plants themselves should be considered in the performance evaluation. This study proposes various performance indices categorized in four groups: profitability, recyclability, automation and environment. The indices are different from the productivity and cost measures that are used in conventional manufacturing plants. Performances of three existing plants in Taiwan are evaluated as illustrative examples to demonstrate the use of the proposed measures. The practical implications of the performance indices are also discussed.

• 한국환경과학회지
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• 제24권4호
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• pp.371-381
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• 2015

In the mountain streams in Jeju Island, strong turbulence and roughness usually made it nearly impossible to utilize most of intrusive instrumentation for streamflow discharge measurements. Instead, a non-intrusive fixed electro-magnetic wave surface velocimetry (fixed EWSV: Kalesto) became alternatively popular in many representative streams to measure stream discharge seamlessly. Currently, Kalesto has shown noteworthy performance with little loss in flood discharge measurements and also has successfully provided discharge for every minute. However, Kalesto has been operated to regard its measured one-point velocity as the representative mean velocity for the given cross-section. Therefore, it could be highly possible to potentially encompass discharge measurements errors. In this study, we analyzed the difference between such Kalesto discharge measurements and other alternative concurrent discharge measurements such as Acoustic Doppler Current Profiler (ADCP) and mobile EWSV which were able to measure velocity in multi-points in the cross-section. Consequently, Kalesto discharge deviated from ADCP discharge in amount of 48% for relatively low flow, and more than 20% difference for high flow compared with mobile EWSV discharge measurements. These results indicated that the one-point velocity measured by Kalesto should be used as a cross-sectional mean velocity, rather it should be accounted for as an index-velocity in conjunction with directly measured cross-sectional mean velocity by using more reliable instrumentations. After inducing Kalesto Discharge Correction Coefficient (KDCC) that actually means relationship between index velocity and cross-sectional mean velocity, the corrected discharge from Kalesto was significantly improved. Therefore, we found that index velocity method should be applied to obtain better accuracy of discharge measurement in case of Kalesto operation.

• 한국유통학회지:유통연구
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• 제11권4호
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• pp.71-96
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• 2006

체계적 브랜드 관리는 브랜드 가치의 측정에서 시작된다. 따라서 많은 선행 연구들은 브랜드 가치 측정 방안을 제안하고 있지만, 이들 연구의 대부분은 유형 제품을 측정 대상으로 한 것이다. 또한 대부분의 경우 브랜드 가치 측정이 일회 측정에 끝나거나, 반복 측정의 경우에는 측정 방법의 변화로 비교 가능성이 낮고 지식이 축적되지 않는 한계를 갖고 있다. 따라서.본 연구는 우리나라 소매점의 대표적인 형태라 할 수 있는 할인점과 백화점을 중심으로 이들의 소매점 브랜드 가치 지수의 변화를 2002년에서 2004년에 걸쳐 동태적으로 관찰하였다. 그 결과, 할인점의 경우 조사 대상에 포함된 모든 할인점의 브랜드 가치가 처음 측정 시점인 2002년부터 2004년까지 지속적으로 증진되고 있는 것으로 나타났다. 특히 국내 할인점 브랜드가 1위의 자리를 고수하고 있는 가운데 외자계 업체들의 두드러진 성장 추세도 확인할 수 있었다. 그러나 이와 달리 백화점의 경우 시장 내 확고한 1위 자리를 차지한 소매점 브랜드가 발견되지 않고, 서로 비슷한 역학 관계 속에서 선두 다툼을 하고 있는 것으로 나타났다. 특히 2003년을 지나서는 백화점 브랜드 가치의 성장이 전반적으로 둔화 또는 감소되는 현상을 확인할 수 있다. 또한 본 연구는 소매점 브랜드 가치지수의 동태적 측정과 더불어 소매점 브랜드 가치 구성요소와 시장성과간의 관계를 분석하여, 할인점과 백화점 각각에서 시장성과와 유의미한 관계에서 있는 브랜드 가치 구성요소를 규명하였다.

• 한국전문물리치료학회지
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• 제30권2호
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• pp.102-109
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• 2023

Background: While efforts have been made to differentiate fall risk in older adults using wearable devices and clinical methodologies, technologies are still infancy. We applied a decision tree (DT) algorithm using inertial measurement unit (IMU) sensor data and clinical measurements to generate high performance classification models of fall risk of older adults. Objects: This study aims to develop a classification model of fall risk using IMU data and clinical measurements in older adults. Methods: Twenty-six older adults were assessed and categorized into high and low fall risk groups. IMU sensor data were obtained while walking from each group, and features were extracted to be used for a DT algorithm with the Gini index (DT1) and the Entropy index (DT2), which generated classification models to differentiate high and low fall risk groups. Model's performance was compared and presented with accuracy, sensitivity, and specificity. Results: Accuracy, sensitivity and specificity were 77.8%, 80.0%, and 66.7%, respectively, for DT1; and 72.2%, 91.7%, and 33.3%, respectively, for DT2. Conclusion: Our results suggest that the fall risk classification using IMU sensor data obtained during gait has potentials to be developed for practical use. Different machine learning techniques involving larger data set should be warranted for future research and development.

• 한국정밀공학회지
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• 제22권7호
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• pp.200-207
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• 2005

This study compares two different methods of measuring brain-BOLD activation. By comparing two different methods of measurement i.e., one method calculating the neural activation area (the number of activated voxels), while the other measured the neural activation intensity (the mean intensity of selected activated yokels), this study identified the more precise method of measuring brain activation which results from the completion of a visuospatial task. 16 right-handed male college students (mean age 23.2 years) participated in this study as subjects. Functional brain images were scanned on them using a 3T MRI single-shot EPI method. No correlation was found between the levels of cognitive performance and number of activated yokels in the activated brain areas. However, a significant correlation was found between the levels of cognitive performance and the mean intensity of selected activated yokels in the parietal, frontal, and other areas. In conclusion, the method of mean intensity was considered a better index of brain activity rather than the activated yokels measurement method.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.72-76
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• 2015

Capital project benchmarking requires an effective cost normalization process to compare cost performance of projects accomplished in different time and location. Existing cost normalization approaches have been established based on the assumption that all required information for cost normalization is fully identified once a project is completed. Cost normalization, however, is sometimes required to evaluate phase-level outcomes of an ongoing project where the required information is not fully available. This paper aims to provide a cost normalization procedure for phase-based performance assessment. The procedure consists of three normalization steps: currency conversion, location adjustment, and time adjustment considering various scenarios where the required information is not fully identified. This paper also presents how the cost normalization procedure has been applied to the 10-10 Performance Assessment Program, which is a phase-based performance assessment system developed by the Construction Industry Institute (CII). Both researchers and industrial professionals can apply the cost normalization procedure to studies and practices regarding to cost estimation, feasibility analysis, and performance assessment.