• Wind and Structures
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• 제32권2호
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• pp.81-87
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• 2021

The aim of the current study is to compare the performance of large 2 MW and 3 MW wind turbines operating on existing onshore wind farms using Blade Element Momentum (BEM) theory and Angular Momentum (AM) theory and illustrate the performance characteristic curves of the turbines as a function of wind speed (U∞). To achieve this, the measurement data obtained from two different Wind Energy Power Plants (WEPPs) located in the Hatay region of Turkey was used. Two different horizontal-axis wind turbines with capacities of 2 MW and 3 MW were selected for evaluation and comparison. The hub-height wind speed (UD), turbine power output (P), atmospheric air temperature (Tatm) and turbine rotational speed (Ω) data were used in the evaluation of the turbine performance characteristics. Curves of turbine power output (P), axial flow induction factor (a), turbine rotational speed (Ω), turbine power coefficient (CP), blade tip speed ratio (λ), thrust force coefficient (CT) and thrust force (T) as a function of U∞ were obtained for the 2 MW and 3 MW wind turbines and these characteristic curves were compared. Results revealed that, for the same wind speed conditions, the higher-capacity wind turbine (3 MW) was operating at higher turbine power coefficient rates, while rotating at lower rotational speed ratios than the lower-capacity wind turbine (2 MW).

• Journal of Information Science Theory and Practice
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• 제2권4호
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• pp.20-30
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• 2014

This study examines the foremost concerns related to most noted research performance index. The most popular and widely acceptable h-index underestimates the highly visible scientist, the middle order group, due to citation distribution issues. The study addresses this issue and uses 'Corrected Quality Ratio' (CQ) to check the implicit underpinnings as evident in h-index. CQ helps to incorporate the aspects of a good research performance indicator. This simple revision performs more intimately and logically to gauge the broader research impact for all groups and highly visible scientists with less statistical error.

• 한국비블리아학회지
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• 제33권4호
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• pp.93-114
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• 2022

본 연구는 올바른 연구문화 정착지원을 위한 대학의 연구업적평가 개선방안을 도출하고자 하였다. 이를 위해 국내외 연구업적평가와 관련한 사례를 조사·분석하고, 대학 교원과 연구업적평가 관계자를 대상으로 각각 설문조사와 면담조사를 실시하였다. 이를 통해 연구업적평가 원칙 수립 방향, 연구업적물 유형의 범주화 방안, 연구업적평가 방식과 절차, 필요 서류 등을 제안하였다. 구체적으로 첫째, 정량평가의 한계점을 보완하면서 평가의 타당성과 신뢰성, 투명성을 확보하기 위해 연구업적평가 시 고려해야 하는 8가지 원칙을 제시하였다. 둘째, 연구업적물의 주요 유형을 학술논문, 저서, 학술대회 발표로 범주화하였다. 셋째, 연구업적평가 방식으로는 정량 및 정성, 복수의 계량지표를 활용하는 하이브리드 평가를 제안하였다. 넷째, 연구업적평가의 절차로 총 11단계(필수 7단계)를 제시하였다. 다섯째, 연구업적 평가를 위한 주요 서류로 출판물, 평가서, 위원장 보고서 등을 제안하였다. 본 연구에서 제시된 연구업적평가 개선방안은 학문 및 연구 분야와 대학의 특성을 고려하여 유연하게 적용되어야 할 것이다.

• Animal Bioscience
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• 제34권5호
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• pp.914-921
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• 2021

Objective: The objective of this study was to compare growth performance, carcass traits and meat quality in young bulls, steers and heifers produced by crossing Limousin bulls with Holstein-Friesian cows, fattened semi-intensively and slaughtered at 18 months of age. Methods: Thirty-one young calves were reared in a conventional production system, and were fed milk replacer, hay and concentrate. At 6 months of age, the animals were divided into groups based on gender, and were fed a total mixed ration composed of grass silage, concentrates I and II in a semi-intensive production system. At the end of the fattening period (18 months), the animals were slaughtered, carcass quality was evaluated, and samples of musculus longissimus thoracis were collected to determine the proximate composition and quality of meat. Results: Bulls were characterized by the highest percentage share of the most valuable cuts in the carcass, and three-rib sections from bull carcasses had the highest lean meat content with low intramuscular fat content (0.93%). No significant differences in carcass conformation, dressing percentage or the percentage share of round in the right half-carcass were found between bulls vs. steers and heifers. Heifers and steers had higher carcass fat content than bulls, which had a positive influence on the sensory properties of beef. In comparison with the meat of bulls, the meat of steers and heifers was characterized by more desirable physical properties and sensory attributes (water-holding capacity, shear force, color lightness, aroma, juiciness, tenderness, flavor). Conclusion: Under the semi-intensive production system, heifers and steers had higher carcass fat content than bulls, which had a positive effect on the sensory properties of beef. Bulls are better suited for intensive systems, which contribute to improving the quality of their meat. The results of this study may encourage producers to breed steers and heifers for beef.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1654-1659
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• 2003

In this paper, the performance evaluation of the JADE-MUSIC estimation based on the indoor channel is presented. By means of the JADE-MUSIC algorithm, DOA and time delay can be obtained simultaneously. In the JADE-MUSIC method, the channel impulse response is first estimated from the received samples and then this impulse response is employed to estimate DOAs and time delays of multipath waves. Moreover, according to the JADE-MUSIC characteristics, it can work in cases when the number of impinging waves is more than the number of antenna elements, unlike the traditional parametric subspace-based method, such a case is not true. Therefore, we employ the JADE-MUSIC algorithm applying for the real indoor environment where is rich of the multipath propagation waves and can imply that the number of waves is very possibly higher than that of the array element. The experiment is carried out in our laboratory considered to be the real indoor environment. The performance of the JADE-MUSIC algorithm is evaluated in terms of the comparison between the simulation and experiment results by using the simulated channel model and the real indoor channel model, respectively. It is clear that the joint angle and delay estimation using the simulated channel model are in good agreement with the estimation using the real indoor channel model. Therefore, we can say that the JADE-MUSIC algorithm accomplishes the high performance to jointly estimate the angle and delay of the arriving signal for the indoor environment.

• Structural Engineering and Mechanics
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• 제41권2호
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• pp.243-262
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• 2012

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

• ETRI Journal
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• 제31권5호
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• pp.500-505
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• 2009

The detrimental effect of short-term fading and shadowing can be mitigated using microdiversity and macrodiversity systems, respectively. In this paper, implementation of selection combining at both micro and macro levels to improve system performance is analyzed. An assessment of the performance of such a system is carried out by considering the desired signal as Rician fading with lognormal shadowing and cochannel interference signal as Rayleigh fading superimposed over lognormal shadowing. The proposed analysis is complemented by various performance evaluation results, including the effects on overall system performance of fading severity, shadowing spreads and branch correlation existing at the base station, and correlation between base stations.

• Steel and Composite Structures
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• 제12권5호
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• pp.445-464
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• 2012

In order to evaluate the dynamic behavior of passive energy dissipation system, two steps need to be considered for prediction of structural response in the presence of ductile element in an off-centre bracing system. The first is a detailed analysis of the proposed ductile element and the second is the effect of this ductile element on an off-centre bracing system. The use of ductile bracing system is expanding in steel structures in order to increase the force reduction factor. Therefore, regarding the nonlinear behavior of steel material used in an off-centre bracing systems and using ductile element in OBS bracing systems, the seismic evaluation of the mentioned systems seems to be necessary. This paper aims to study linear and nonlinear behavior of steel frames with off-centre bracing system and ductile element, in order to get the best position of these bracing elements. To achieve this purpose, the modeling has been done with ANSYS software. The optimum eccentricity has been obtained by modeling three steel frames with different eccentricities and evaluating the results of them. The analytical results showed that the model OBS-C with 0.3 eccentricities has higher performance among the models.

• Clinical Endoscopy
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• 제55권2호
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• pp.279-286
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• 2022

Background/Aims: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a standard procedure for obtaining tissue from lesions near the gastrointestinal lumen. However, there is a scarcity of information on the diagnostic performance of EUS-FNA for abdominal lymphadenopathy of unknown causes. To assess the accuracy of EUS-FNA in diagnosing abdominal lymphadenopathy of unknown etiology. Methods: The EUS records of patients with undiagnosed abdominal lymphadenopathy between 2010 and 2015 were reviewed. Results: A total of 42 patients were included in this study. Adequate specimens were obtained from 40 patients (95%). The final diagnoses were metastatic cancer (n=16), lymphoma (n=9), tuberculosis (n=8), inflammatory changes (n=6), and amyloidosis (n=1). For diagnosing malignancy, EUS-FNA had a sensitivity of 84.6%, specificity of 95.7%, positive predictive value of 91.7%, negative predictive value of 91.7%, and area under the receiver operating characteristic curve (AUROC) of 0.901. For the diagnosis of lymphoma, EUS-FNA was 100% accurate when combined with cytologic evaluation and immunohistochemical staining. The diagnostic sensitivity decreased to 75%, whereas the specificity remained 100%, for tuberculosis. The overall AUROC was 0.850. No procedure-related complications occurred. Conclusions: EUS-FNA showed high diagnostic performance for abdominal lymphadenopathy of unknown causes, especially malignancy, lymphoma, and tuberculosis. Therefore, it is a crucial diagnostic tool for this patient population.

• 한국빅데이터학회지
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• 제9권1호
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• pp.197-208
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• 2024

오늘날 대학에서 소속 교원을 종합적으로 평가하기 위해 실시하고 있는 교원업적평가는 제도의 취지와는 달리 정량적 평가 중심 시스템으로 인해 제도의 취지와 다른 결과가 나타나고 있다. 특히 연극예술분야는 다른 학문분야에 비해 성과물의 주관적인 성격이 강해 기존의 정량적 평가 방법으로는 연구 및 창작업적의 성과를 공정하고 객관적으로 측정하기 어렵다는 특성이 있다. 이에 본 연구에서는 연극예술분야 연구 및 창작업적평가 개선을 위해 빅데이터 활용 방안을 제안하였다. 먼저 국내 주요 대학의 연극예술 관련 학과에서 시행 중인 연구 및 창작업적평가 기준과 방법을 조사하고, 현재 국내 연극예술분야 연구 및 창작업적평가 시스템과 관련한 주요 쟁점을 분석한 다음, 공연예술통합전산망(KOPIS)의 빅데이터를 활용한 연극예술분야 연구 및 창작업적평가 시스템의 개선 방안을 제시하였다. 본 연구를 통해 연극예술분야 교원들의 연구와 창작활동을 보다 효과적으로 지원하고, 대학 경쟁력을 강화할 수 있는 방안이 마련될 수 있기를 기대한다.