• 제목/요약/키워드: Statistical efficiency

검색결과 1,203건 처리시간 0.026초

영구자석의 착자방향을 고려한 브러시리스DC 전동기의 효율 최적화 설계 (Efficiency Optimal Design of a Brushless DC Motor Considering the Magnetization Direction of Permanent Magnet)

  • 송정현;김병택
    • 제어로봇시스템학회논문지
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    • 제17권3호
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    • pp.241-247
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    • 2011
  • This paper is intended to improve efficiency of two-phase BLDC motor using analytical and statistical methods, and then the stability of the starting for the designed model is investigated. The characteristics of the motor according to magnetization directions of permanent magnet are analyzed through the analytical method, and design variables that affect the efficiency are selected. Preliminary optimal design is performed using the analytical method with the design variable. The RSM (Response Surface Method) based on the FEA (Finite Element Analysis) is applied to complement errors of the analytical method. As a result, the optimal design is determined. Finally, the stability of the starting for the optimal designed model is evaluated by analyzing cogging torque, and it is verified through the FEA.

RDF발전에 의한 열효율향상 및 $CO_2$삭감효과에 대한 평가 (An Evaluation on the Effect of the MSW-RDF Power Generation on the Thermal Efficiency and $CO_2$ Reduction)

  • 최갑석;최연석;김석준;권영배
    • 연구논문집
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    • 통권31호
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    • pp.45-51
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    • 2001
  • One of emerging technologies under development in the advanced countries is considered as RDF(Refuse Derived Fuel) power generation, which could meet both the requirement of an alternative energy resource utilization and $CO_2$ reduction. This paper deals with the effect to the thermal effiency and CO2 reduction of RDF firing power generation. The statistical data of domestic MSW generation in last year in small and medium cities for evaluating the merits of the RDF power generation were used. The analysis for RDF power generation compared to the existing incinerator w/o(or w/) power generation shows around 20.6%(10.0%) up in the total thermal efficiency and 57.0%(31.4%) up in the $CO_2$ reduction respectively.

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췌셰픽만 꽃게의 예망에 의한 채집효율성 추정 (Estimation of Dredge Sampling Efficiency for Blue Crabs in Chesapeake Bay)

  • 장창익
    • 한국수산과학회지
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    • 제26권4호
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    • pp.369-379
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    • 1993
  • 1992년 동계에 췌셰픽만의 꽃게자원에 대하여 예망을 사용한 연속채집법에 의한 어획 효율성을 조사하였다. 일반선형모델 분석에 따르면 26회에 걸친 야외시험 결과 어획효율성은 저질이나 수심, 사용된 조사선박에 따라 통게학적으로 유의한 차이가 나타나지 않았다. 예망효율(즉, 어획율)은 Leslies방법과 단순히 개조된 방법 등의 두 방법을 사용하여 추정하였다. 평균 어획율은 0.26 (표준오차:0.03)으로 추정되었는데 이는 한번의 예망을 사용하여 채집장소에 존재하고 있는 꽃게 가운데 단지 $26\%$($95\%$ 신뢰한계 : $20{\sim}32\%$)를 잡을 수 있다는 의미이다. 예망효율은 꽃게의 밀도가 증가함에 따라 지수적으로 감소하였다.

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사이버 강좌에서 학습 효과를 높이기 위한 사례 연구 (Case Study for Increasing the Learning Effect In Cyber Lecture)

  • 엄종석;조세홍
    • 한국멀티미디어학회논문지
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    • 제16권10호
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    • pp.1230-1237
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    • 2013
  • 사이버 강의는 전통적인 수업의 대안으로써 주목을 받았으나, 교육의 효율성이 떨어진다는 비판을 받아왔다. 하지만 교육 공학이 접목된 사이버 강좌의 기획력과 최근 컴퓨터 및 네트웍 등의 기술 발전의 결합은 사이버 강좌 교육의 효율성을 상당히 제고하는 것으로 보고되고 있다. 본 논문의 지향점은 사이버 강좌 교육의 학습 효율성을 높이기 위하여 사이버 강좌 제작에 있어서 중점이 되는 요소들을 파악하는데 있다. 본 연구를 위하여 제작된 사이버 강좌는 강좌의 학습 효율성을 극명하게 나타내기 위하여 일반적인 이론교육이 아닌 소프트웨어 실습이 중심이 되는 컴퓨터 교과목이다. 제작된 강좌의 학습 효율성을 위하여 강의를 수강한 학생들에 설문 조사를 통하여 데이터를 수집한 후 통계적인 처리를 통하여 사이버 강좌의 학습 효율성에 유의미한 영향을 주는 요소들을 분석하였다.

Cementing Efficiency of Fly-ash in Mortar Matrix According to Binder-Water Ratio and Fly-ash Replacement Ratio

  • Cho, Hong-Bum;Jee, Nam-Yong
    • 한국건축시공학회지
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    • 제12권2호
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    • pp.194-202
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    • 2012
  • This paper predicts the cementing efficiency of fly-ash(FA) based on mortar test considering binder-water ratio and FA replacement ratio as experimental variables. The cementing efficiency prediction model proposed by statistical analysis enables us to estimate the value according to the binder-water ratio and FA replacement ratio of matrix. When FA replacement ratio is the same, the lower the binder-water ratio, the higher the estimated cementing efficiency. There are significant differences in the values according to binder-water ratio at FA replacement ratios of 15% or less, but there are almost no differences when FA replacement ratio is more than 15%. As the binder-water ratio increases, the variations in the values according to FA replacement ratio are great at FA replacement ratios of 15% or less. As the FA replacement ratios increase, the values increase for FA replacement ratios of 15% or less, but decrease for more than 15%. The values range from -0.71 to 1.24 at binder-water ratio of 1.67-2.86 and FA replacement ratio of 0-70%. The RMSE of the 28-day compressive strength predicted by modified water-cement ratio is 2.2 MPa. The values can be trusted, as there is good agreement between predicted strength and experimental strength.

Soft computing techniques in prediction Cr(VI) removal efficiency of polymer inclusion membranes

  • Yaqub, Muhammad;EREN, Beytullah;Eyupoglu, Volkan
    • Environmental Engineering Research
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    • 제25권3호
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    • pp.418-425
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    • 2020
  • In this study soft computing techniques including, Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were investigated for the prediction of Cr(VI) transport efficiency by novel Polymer Inclusion Membranes (PIMs). Transport experiments carried out by varying parameters such as time, film thickness, carrier type, carier rate, plasticizer type, and plasticizer rate. The predictive performance of ANN and ANFIS model was evaluated by using statistical performance criteria such as Root Mean Standard Error (RMSE), Mean Absolute Error (MAE), and Coefficient of Determination (R2). Moreover, Sensitivity Analysis (SA) was carried out to investigate the effect of each input on PIMs Cr(VI) removal efficiency. The proposed ANN model presented reliable and valid results, followed by ANFIS model results. RMSE and MAE values were 0.00556, 0.00163 for ANN and 0.00924, 0.00493 for ANFIS model in the prediction of Cr(VI) removal efficiency on testing data sets. The R2 values were 0.973 and 0.867 on testing data sets by ANN and ANFIS, respectively. Results show that the ANN-based prediction model performed better than ANFIS. SA demonstrated that time; film thickness; carrier type and plasticizer type are major operating parameters having 33.61%, 26.85%, 21.07% and 8.917% contribution, respectively.

잣나무 차대검정(次代檢定)에 있어서의 효율적(效率的)인 Plot Sampling에 관(關)한 연구(硏究) (Statistical Efficiency of Sampling Plot Size in Half-sib Progeny Test of Korean Pine (Pinus koraiensis S. et Z.))

  • 김대은;전상근
    • 한국산림과학회지
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    • 제80권4호
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    • pp.379-382
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    • 1991
  • 난괴법 3반복(反復)으로 배치(配置)한 잣나무 10년생(年生) 반형매차대검정림(半兄妹次代檢定林)에서 plot당(當) 임의(任意)로 2-10본(本)의 표본목(標本木)을 선정(選定)한 후(後), 분산분석(分散分析)을 통하여 가계평균(家系平均) 수고(樹高)의 오차(誤差)를 나타내는 C.V. 값을 각(各) sampling size 별(別)로 추정(推定), 비교(比較)하였다. plot당(當) 표본목수(標本木數)를 증가(增加)시킴에 따라 C.V.값은 점차 감소(減少)되었으며, plot당(當) 4본(本)부터 안정(安定)된 C.V. 값(6.97%)을 나타내었으나, plot당(當) 7본(本)부터는 실험오차(實驗誤差)가 증가(增加)됨을 알 수 있었다. 이들 두 변량간(變量間)에 ${\hat{Y}}=10.425e-^{0.073x}$ ($R^2$=0.840)의 관계식(關係式)을 추정(推定)할 수 있었다.

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Combination of Brain Cancer with Hybrid K-NN Algorithm using Statistical of Cerebrospinal Fluid (CSF) Surgery

  • Saeed, Soobia;Abdullah, Afnizanfaizal;Jhanjhi, NZ
    • International Journal of Computer Science & Network Security
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    • 제21권2호
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    • pp.120-130
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    • 2021
  • The spinal cord or CSF surgery is a very complex process. It requires continuous pre and post-surgery evaluation to have a better ability to diagnose the disease. To detect automatically the suspected areas of tumors and symptoms of CSF leakage during the development of the tumor inside of the brain. We propose a new method based on using computer software that generates statistical results through data gathered during surgeries and operations. We performed statistical computation and data collection through the Google Source for the UK National Cancer Database. The purpose of this study is to address the above problems related to the accuracy of missing hybrid KNN values and finding the distance of tumor in terms of brain cancer or CSF images. This research aims to create a framework that can classify the damaged area of cancer or tumors using high-dimensional image segmentation and Laplace transformation method. A high-dimensional image segmentation method is implemented by software modelling techniques with measures the width, percentage, and size of cells within the brain, as well as enhance the efficiency of the hybrid KNN algorithm and Laplace transformation make it deal the non-zero values in terms of missing values form with the using of Frobenius Matrix for deal the space into non-zero values. Our proposed algorithm takes the longest values of KNN (K = 1-100), which is successfully demonstrated in a 4-dimensional modulation method that monitors the lighting field that can be used in the field of light emission. Conclusion: This approach dramatically improves the efficiency of hybrid KNN method and the detection of tumor region using 4-D segmentation method. The simulation results verified the performance of the proposed method is improved by 92% sensitivity of 60% specificity and 70.50% accuracy respectively.

DEA를 이용한 한방병원의 경영효율성 분석: 환자수를 기준으로 (Analysis of the Efficiency of the Oriental Hospital using the DEA(Based on the Number of Patients))

  • 김영식;이우천
    • 벤처창업연구
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    • 제11권1호
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    • pp.75-84
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    • 2016
  • 본 연구는 DEA를 이용하여 한방병원의 경영효율성을 분석하고, 효율성 점수를 종속변수로 사후분석을 실시하여 한방병원의 경영효율성 향상방안을 제시하고자 한다. 투입변수는 의사수, 간호사수, 의료기사수와 병상수이고, 산출변수는 연외래환자수와 연입원환자수이며 분석도구는 EnPas와 IBM SPSS 19.0을 사용하였다. 연구결과, 설립형태별 효율성 분석에서는 학교법인 소속 병원의 효율성 점수가 가장 높았고 개인병원이 가장 낮았다(p<.05). 그리고 병상규모별 분석에서는 101-150병상 범주의 효율성 점수가 가장 높았고 100병상 이하의 한방병원들이 대체로 낮은 효율성을 보였다(p<.05). 또한 소재지별 분석에서는 서울지역 한방병원의 효율성이 가장 높았으며 광역시 소재병원의 효율성이 가장 낮게 나타났으나 통계적으로 유의한 차는 없었다(p<.05). 그리고 효율성 결정요인 파악을 위한 이항로지스틱 분석결과로 간호사 1명이 증가하면 효율성이 약 1.045배 증가함을 알 수 있었다.

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임상실습교육의 교수효율성과 임상실습만족도에 관한 상관성 연구 (대구지역을 중심으로) (A study on correlation of teaching efficiency and satisfaction of clinical training in Daegu)

  • 김정숙;정영해
    • 대한치과기공학회지
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    • 제28권1호
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    • pp.121-142
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    • 2006
  • Collecting materials for study on teaching efficiency and satisfaction of clinical training, it changes. Dental technology's educational procedure to many ways of a prospect. In a circumstance that needed higher level of education, this study is aimed on realizing an importance of clinical training through the various materials that previously carried out and offering basic knowledge to take better clinical training for the students. Study results below 1. This Investigation conducted on 123 of sophomores(70.3%) and 52 of juniors(29.7%) who have been taken clinical training, and men's proportion(51.45%)is a bit higher than girls(48.6%). The 64% of respondents taken largest proportion were 20 to 24 years old. As 67.9% of respondents attended daytime school and 30.3% of them attended nighttime one, their school time shows a little difference. In a question about relation ship, one answered "Harmonious" took largest proportion by 72.6% during training, and about the degree of satisfaction of campus life who answered "normal" were the most with 59.4%. 2. About the reason choosing dental technology as a major, 41.1% taken the most answered "due to the specialized job", "Getting job easily" was second with 26.9%, and third was "recommended from around" with 18.3%. 50.3% of the respondents answered "normal" about the Satisfaction of their major, student marked in grade "B" most with 51.4% 3. In a investigation result about clinical training statues and preference, most(72.6%) choose place less than 10 for clinical training, and 60.6% of them resided own home. About their commuting time from home to training place, 44% was under 30min, 40% took time 30-60min. It shows students prefer shotter distance in terms of choosing training place. 4. Each part manager took large proportion as a clinical trainer with 33.7%, Training curriculum reform and developing method were most answer as a improvement measure after completing training with 30%. 5. The average of total score about clinical training was 3.15 of 5. In the detailed question, 'satisfaction of clinical training' got 3.38 as a highest score, the lowest score was 2.86 that is about satisfaction of clinical training period. The average score about efficiency of study was 2.86 and in detailed question, 'a Role model' got 3.26 as a highest score and participation of student got 3.05 as a lowest score. 6. The result of T-test to see the difference of the satisfaction according to the general character and clinic training condition between teaching efficiency is that the degree of satisfaction of clinical training showed statistical significance only in the degree of satisfaction of campus life(p<0.05), and teaching efficiency has a statistical significance with their age, grade, and satisfaction of campus life (p<0.05). 7. The relation between of teaching efficiency of clinical training and satisfaction of clinical training of dental technologic student has a statistical meaning in significance leveler 0.01. Now, therefore we suggest following based on these result. 1. To elevate satisfaction of clinical training, it agentry needs development of consistent clinical training curriculum. 2. To grasp the satisfaction and requirement, in needs to measure anxiousness and satisfactory degree after completing training 3. To train efficiently and evaluate efficiency over the teaching activities, it needs to develop measuring tools for teaching efficiency in terms of teacher's important rules in a clinical training. 4. Strengthen the relations with the study developing and managing curriculum gathering theoretical knowledge and practice. And make an effort to apply to their students. 5. Let the trainee take a class setting a belief, sense of value, function and obtain behavior by making the students comfort over clinical training as increasing teaching efficiency.

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