• 제목/요약/키워드: evaluation errors

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유치원과 초.중등학교 교과서 내 산림 교육 현황 및 개선 방안 (The Current Status of Forest Education in K-10 School Levels and Recommendations for the Future Innovative Approach)

  • 이재영;전정일;주형선;곽정난;조경준;박효인;조찬희;박정순;황은실;류미
    • 한국환경교육학회지:환경교육
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    • 제23권1호
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    • pp.13-26
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    • 2010
  • As an effort to realize the results of last two years of study, this study had three distinguished purposes: 1) confirming whether some requests for corrections had been accepted or not 2) making a list of possible errors found in newly written textbooks and asking to fix them, and 3) classifying forest related contents identified in the textbooks according to the 150 topics included in information material, so called Forest IQ 200. Among 94 errors associated trees, forest or forest education, only thirteen of them were found to be fixed according to the request made in previous study of 2008. Especially, most of the fixed errors were identified to be in natural and social science subject textbooks and nothing was found in art and language areas. Total of 1,320 forest related items were found in the textbooks at the level of kindergarten to 10th grade(freshman in highschool). Korean student was expect to have a chance to learn forest related items 1.64 times a week for 10 years(First to 10th grade). Analyzing 1,109 contents in terms of four topic areas of forest education, the forest culture area was found to have most content of 348 including painting and recreation. Some suggestions were made to make school forest education better, and publishing the forest textbook for elementary schools was one of them.

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차세대 자기기록 채널을 위한 LDPC-LDPC 곱 부호의 성능 평가 (Performance Evaluation of LDPC-LDPC Product Code for next Magnetic Recording Channel)

  • 박동혁;이재진
    • 전자공학회논문지
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    • 제49권11호
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    • pp.3-8
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    • 2012
  • 2차원 곱 부호는 저장장치 시스템에서 연집 오류를 정정하기 위해 연구되었다. RS-LDPC 곱 부호는 횡 방향의 RS 부호와 종 방향의 LDPC 부호로 이루어져 있다. 먼저 횡 방향의 RS 부호를 이용하여 연집 오류를 검출하며, 이 연집 오류의 위치 정보를 활용하여 종 방향의 LDPC 부호로 오류를 정정한다. 저장장치에서는 여러 가지 요인에 의해 연집 오류가 발생할 수 있다. 따라서 저장장치 시스템에서는 연집 오류에 강한 부호가 필요하다. RS-LDPC 곱 부호는 연집 오류에 강하다. 하지만 저장 밀도가 커지면서 연집 오류의 길이는 더 길어지게 된다. 따라서 본 논문에서는 긴 연집 오류에도 강한 특성을 보이는 LDPC-LDPC 곱 부호를 제안한다. 또한, RS-LDPC 곱 부호와 비교하여 LDPC-LDPC 곱 부호는 횡 방향으로 LDPC 부호를 사용하여 많은 램덤 오류가 발생 하였을 때 안정적인 성능 이득이 있다.

일대비교에 의한 관능평가능력의 동작판별 (Dynamic discrmination of sensory evaluation capability using a paired-comparison method)

  • 김정만;이상도
    • 대한인간공학회지
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    • 제12권2호
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    • pp.85-91
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    • 1993
  • Data obtained for sensory evaluation have a wide dispersion and fuzziness since human sensory organs are used as a means of measuring sensation instead of measuring instruments. Such dispersion and fuzziness are caused by all kinds of time error and have a great influence on the sensory evaluation, but most of previous papers not consider time errors. In this study, the comparative judgement capability of the evaluator was discriminated by means of the eigen- structure analysis on the premise that evaluation values of sensory evaluators obtained by a paired-comparison become different by the order of sample presentation.

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이동속도와 방향을 고려한 수치모델의 태풍진로 예측성 평가 (Evaluation of the Numerical Models' Typhoon Track Predictability Based on the Moving Speed and Direction)

  • 신현진;이우정;강기룡;변건영;윤원태
    • 대기
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    • 제24권4호
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    • pp.503-514
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    • 2014
  • Evaluation of predictability of numerical models for tropical cyclone track was performed using along-and cross-track component. The along-and cross-track bias were useful indicators that show the numerical models predictability associated with cause of errors. Since forecast errors, standard deviation and consistency index of along-track component were greater than those of cross-track component, there was some rooms for improvement in alongtrack component. There was an overall slow bias. The most accurate model was JGSM for 24-hour forecast and ECMWF for 48~96-hour forecast in direct position error, along-track error and cross-track error. ECMWF and GFS had a high variability for 24-hour forecast. The results of predictability by track type showed that most significant errors of tropical cyclone track forecast were caused by the failure to estimate the recurvature phenomenon.

초정밀 직선 스테이지에서 5 자유도 운동의 정적 및 동적 성능 평가 (Performance Evaluation of Five-DOF Motion under Static and Dynamic Conditions of Ultra-precision Linear Stage)

  • 이재창;이광일;양승한
    • 한국정밀공학회지
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    • 제31권5호
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    • pp.423-430
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    • 2014
  • In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.

집광 열유속 측정과 모델링의 비교를 통한 집광 오차 평가 (Concentration Error Assessment by Comparison of Solar Flux Measurement and Modeling)

  • 채관교;윤환기;이현진;이성욱;김시석
    • 한국태양에너지학회 논문집
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    • 제33권3호
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    • pp.82-90
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    • 2013
  • Concentration errors critically affect the performance of solar concentrator, so their evaluation is important to the concentrated solar power technology. However, the evaluation is very challenging because error sources are various and not easy to measure individually. Therefore, the integrated effect of concentration errors is often more interesting and useful for large-scale applications. In the present work, we analytically investigate and classify various concentration error sources and then explain that the effect of various concentration errors can be represented in terms of a root mean square value of reflector surface slope error. We present an indirect approach to assessing the reflector surface slope error by comparing solar flux measurement data with modeling calculations. We apply the approach for solar furnaces with different thermal capacity and investigate its advantages and disadvantages.

A Study on Nonresponse Errors in the Internet Survey

  • Namkung, Pyong;Kim, Min Jung
    • Communications for Statistical Applications and Methods
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    • 제9권3호
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    • pp.665-674
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    • 2002
  • The advantage of internet survey compared to the traditional survey methods are speedy in data collection, cost-effective, high performed design and able to data process and analysis at the same time. The other side are difficult to select sample, come from serious nonresponse errors. We suggest the new internet survey method to the questionnaire design that have the high response rate, enough to advanced preparations and system stability.

문자와 식, 함수 영역에서 보이는 중학생의 수학적 오류 분석: 2013년 국가수준 학업성취도 평가 서답형 문항을 바탕으로 (Analysis of Errors by Response Assessments of Korean Middle School Students on the 2013 National Assessment of Educational Achievement in Mathematics)

  • 조윤동;고호경
    • 대한수학교육학회지:수학교육학연구
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    • 제25권3호
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    • pp.281-302
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    • 2015
  • 본 연구에서는 국가수준 학업성취도 서답형 문항의 문제해결 과정에서 나타나는 오류를 살펴보기 위하여 236개 학교 8007명의 답안지를 추출하여 분석하였다. 분석에 사용한 문항은 국가수준 학업성취도 평가 중학교 수학 서답형 문항으로 내용 영역은 '문자와 식', '함수'이고 행동 영역은 '문제해결'과 '계산'이다. 두 문항 모두 주어진 문제 상황에 알맞은 식을 세우고 조건에 맞는 결과를 산출하는 문제이다. 분석 결과 각 문항에 따라 문제 상황을 파악하여 식을 세우고, 풀며, 결과를 기술하는 세가지 과정에서 다양한 오류들이 나타났다. 본 연구에서는 이에 대한 원인을 추론하여 교수학적 시사점을 이끌어 내고자 하였다.

Robust finite element model updating of a large-scale benchmark building structure

  • Matta, E.;De Stefano, A.
    • Structural Engineering and Mechanics
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    • 제43권3호
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    • pp.371-394
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    • 2012
  • Accurate finite element (FE) models are needed in many applications of Civil Engineering such as health monitoring, damage detection, structural control, structural evaluation and assessment. Model accuracy depends on both the model structure (the form of the equations) and the model parameters (the coefficients of the equations), and can be generally improved through that process of experimental reconciliation known as model updating. However, modelling errors, including (i) errors in the model structure and (ii) errors in parameters excluded from adjustment, may bias the solution, leading to an updated model which replicates measurements but lacks physical meaning. In this paper, an application of ambient-vibration-based model updating to a large-scale benchmark prototype of a building structure is reported in which both types of error are met. The error in the model structure, originating from unmodelled secondary structural elements unexpectedly working as resonant appendages, is faced through a reduction of the experimental modal model. The error in the model parameters, due to the inevitable constraints imposed on parameters to avoid ill-conditioning and under-determinacy, is faced through a multi-model parameterization approach consisting in the generation and solution of a multitude of models, each characterized by a different set of updating parameters. Results show that modelling errors may significantly impair updating even in the case of seemingly simple systems and that multi-model reasoning, supported by physical insight, may effectively improve the accuracy and robustness of calibration.