• 제목/요약/키워드: Evaluation Formula

검색결과 664건 처리시간 0.028초

초등학생의 과학적 가설생성능력 평가를 위한 서술형 지필과제 및 가설생성능력지수 산출식의 개발 (Development of a Descriptive Paper Test Item and a Counting Formula for Evaluating Elementary School Students' Scientific Hypothesis Generating Ability)

  • 조은별;신동훈
    • 한국초등과학교육학회지:초등과학교육
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    • 제35권2호
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    • pp.137-149
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    • 2016
  • The purpose of this study is to develop a descriptive paper test item which can evaluate elementary school students' HGA (scientific Hypothesis Generating Ability) and to propose a counting formula that can easily assess student's HGA objectively and quantitatively. To make the test item can possibly evaluate all the students from 6th graders to 3rd graders, the 'rabbit's ear' item is developed. Developed test item was distributed to four different elementary schools in Seoul. Total 280 students who were in the 6th grade solved the item. All the students' reponses to the item were analyzed. Based on the analyzed data evaluation factors and evaluation criteria are extracted to design a Hypothesis Generating ability Quotient (HGQ). As the result 'Explican's Degree of Likeness' and 'Hypothesis' Degree of Explanation' are chosen as evaluation factors. Also precedent evaluation criteria were renewed. At first, Explican's Degree of Likeness evaluation criterion was turned four levels into three levels and each content of evaluation criterion is also modified. Secondly, new evaluation factor 'Hypothesis' Degree of Explanation' was developed as combined three different evaluation criteria, 'level of explican', 'number of explican' and 'structure of explican'. This evaluation factor was designed to assess how the suggested hypothesis can elaborately explain the cause of one phenomenon. Newly designed evaluation factors and evaluation criteria can assess HGA more in detail and reduce the scoring discordant through the markers. Lastly, Developed counting formula is much more simple than precedent Kwon's equation for evaluating the Hypothesis Explanation Quotient. So it could help easily distinguish one student's scientific hypothesis generating ability.

EVALUATION FORMULA FOR WIENER INTEGRAL OF POLYNOMIALS IN TERMS OF NATURAL DUAL PAIRINGS ON ABSTRACT WIENER SPACES

  • Chang, Seung Jun;Choi, Jae Gil
    • 대한수학회보
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    • 제59권5호
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    • pp.1093-1103
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    • 2022
  • In this paper, we establish an evaluation formula to calculate the Wiener integral of polynomials in terms of natural dual pairings on abstract Wiener spaces (H, B, 𝜈). To do this we first derive a translation theorem for the Wiener integral of functionals associated with operators in 𝓛(B), the Banach space of bounded linear operators from B to itself. We then apply the translation theorem to establish an integration by parts formula for the Wiener integral of functionals combined with operators in 𝓛(B). We finally apply this parts formula to evaluate the Wiener integral of certain polynomials in terms of natural dual pairings.

Sample size calculation for comparing time-averaged responses in K-group repeated binary outcomes

  • Wang, Jijia;Zhang, Song;Ahn, Chul
    • Communications for Statistical Applications and Methods
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    • 제25권3호
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    • pp.321-328
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    • 2018
  • In clinical trials with repeated measurements, the time-averaged difference (TAD) may provide a more powerful evaluation of treatment efficacy than the rate of changes over time when the treatment effect has rapid onset and repeated measurements continue across an extended period after a maximum effect is achieved (Overall and Doyle, Controlled Clinical Trials, 15, 100-123, 1994). The sample size formula has been investigated by many researchers for the evaluation of TAD in two treatment groups. For the evaluation of TAD in multi-arm trials, Zhang and Ahn (Computational Statistics & Data Analysis, 58, 283-291, 2013) and Lou et al. (Communications in Statistics-Theory and Methods, 46, 11204-11213, 2017b) developed the sample size formulas for continuous outcomes and count outcomes, respectively. In this paper, we derive a sample size formula to evaluate the TAD of the repeated binary outcomes in multi-arm trials using the generalized estimating equation approach. This proposed sample size formula accounts for various correlation structures and missing patterns (including a mixture of independent missing and monotone missing patterns) that are frequently encountered by practitioners in clinical trials. We conduct simulation studies to assess the performance of the proposed sample size formula under a wide range of design parameters. The results show that the empirical powers and the empirical Type I errors are close to nominal levels. We illustrate our proposed method using a clinical trial example.

면내 조합하중과 횡압을 받는 선박 이중판의 강도 평가 (Strength Evaluation of a Doubler Plate of Ship Structure subjected to the In-plane Combined Load and Lateral Pressure Load)

  • 함주혁
    • 대한조선학회논문집
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    • 제40권6호
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    • pp.37-48
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    • 2003
  • A study for the structural strength evaluation of doubler plates subjected to the in-plane combined load and lateral pressure load has been performed through a systematic evaluation process. In order to properly estimate the static strength of doubler plate, elasto-plastic large deflection analysis is introduced including the contact effect between main plate and doubler. The characteristics of stiffness and strength variation are discussed based on the analysis results. Also, in order to compare the doubler structure with the original strength of main plate without doubler, a simple formula for the evaluation of the equivalent flat plate thickness is derived based on the additional series analysis of fiat plate structure. Using this derived equation, the thickness change of a equivalent flat plate is analyzed according to the variation of various design parameters of doubler plate and some design guides are suggested In order to maintain the original strength of main plate without doubler reinforcement. Finally, correlation between derived equivalent plate thickness formula and the developed buckling strength formulas for intact plates by author et al. is discovered and these relations are formulated for the future development of simple strength evaluation formula of doubler plate structure.

Evaluating website performance using formula and balanced scorecard methods

  • Hou, Liyao;Hong, Jong-Yi;Suh, Eui-Ho
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2007년도 International Conference
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    • pp.764-769
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    • 2007
  • This paper proposes a new model to· evaluate the effectiveness of websites using balanced scorecard (BSC) and weighted formula based methods.fisrt, we Use BSC method to find out the cause-and-effect relationships between the measure and website activities, and our proposed model evaluates website performance from six perspectives: business value, operational excellence, customer value, website interface, management, maintenance, and learning and innovation. Next, we usedformula-based approach to identify what makes website performance low by developing the evaluation formula through investigating website users; finally, case studies of two famous websites are given to show how our method can be used Our evaluation model can not only evaluate website performance but also suggest how to improve performance.

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엔진 커넥팅로드의 좌굴평가에 대한 연구 (Study of Buckling Evaluation for the connecting rod of the engine)

  • 이문규;문희욱;이형일;이태수;신성원;장훈
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.677-680
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    • 2004
  • This study investigates the buckling evaluation of connecting rods used in the diesel engine through finite element analysis. The Rankine formula, which is modified from classical Euler‘s formula, has been widely accepted in automotive industry to evaluate the buckling of connecting rods. Apparently, this formula is most suitable for the straight and idealized rod shape, and over-simplifies the geometric complexity associated with connecting rods. The subspace iteration method in FEA is used to predict the critical buckling stress of a connecting rod with certain slenderness ratio. To create models with various slenderness ratios for shank portion in the rod, the automatic meshing preprocessor was implemented. Results from FEA were verified by the experiments, in which the embedded strain gages measured for the connecting rod running at 4000rpm. The result indicates that the buckling prediction curve through FEA and experiment is effectively different from the curve of classical Rankine formula.

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한옥의 내진설계를 위한 비틀림비정형 평가 방안 (An Evaluation Scheme of Torsional Irregularity for Seismic Design of Hanok)

  • 김영민
    • 대한건축학회논문집:구조계
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    • 제35권10호
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    • pp.191-198
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    • 2019
  • In this paper the evaluation scheme for determining torsional irregularity of Hanok has been proposed. The proposed method can evaluate torsional irregularity of Hanok easily only with characteristics of Hanok shapes, arrangement of lateral load resisting frames and their lateral stiffness without time consuming and complicate 3-dimensional structural analysis. The proposed formula is expressed as allowable maximum eccentricity, and torsional irregularity is evaluated by comparing this value with actual eccentricity. The applicability of the proposed scheme was evaluated by applying it to the line shape plan Hanok with two symmetrically arranged walls and the result was expressed by formula and graph. The results showed that the allowable maximum eccentricity is 10% of plan dimension perpendicular to the seismic load when the walls are placed at the extreme end. The proposed formula was expressed as a generalized formula so it can be applied generally to the various plan shape and wall arrangement of Hanok.

SCM415 침탄치차의 굽힘피로강도평가에 관한 연구 (A Study on Evaluation of Bending Fatigue Strength in SCM415 Carburized Spur Gear)

  • 류성기
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권6호
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    • pp.763-770
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    • 1998
  • This paper deals with evaluation of bending fatigue strength in SCM415 carburized spur gears. The constant stress amplitude fatigue test is performed by using an electrohydraulic servo-controlled pulsating tester. The S-N curves are obtained and the enhanvement of fatigue strength due to carburized treatment is clarified. In this study the improvement of fatigue strength is assumed to be caused by an increase of both hardness and residual stress and experimental formula has been proposed for the estimation of bending fatigue strength of carburized gears. The effect of surface conditions on the fatigue strength is evaluated quantitatively and it is close to the relative surface condition factor used in the ISO strength rating formula.

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Load-sharing ratio analysis of reinforced concrete filled tubular steel columns

  • Xiamuxi, Alifujiang;Hasegawa, Akira
    • Steel and Composite Structures
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    • 제12권6호
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    • pp.523-540
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    • 2012
  • It was clear from the former researches on reinforced concrete filled tubular steel (RCFT) structures that RCFT structures have different performance than concrete filled steel tubular (CFT) structures. However, despite of that, load-sharing ratio of RCFT is evaluating by the formula and range of CFT given by JSCE. Therefore, the aim of this investigation is to study the load-sharing ratio of RCFT columns subjected to axial compressive load by performing numerical simulations of RCFT columns with the nonlinear finite element analysis (FEA) program - ADINA. To achieve this goal, firstly proper material constitutive models for concrete, steel tube and reinforcement are proposed. Then axial compression tests of concrete, RC, CFT, and RCFT columns are carried out to verify proposed material constitutive models. Finally, by the plenty of numerical analysis with small-sized and big-sized columns, load-sharing ratio of RCFT columns was studied, the evaluation formulas and range were proposed, application of the formula was demonstrated, and following conclusions were drawn: The FEA model introduced in this paper can be applied to nonlinear analysis of RCFT columns with reliable results; the load-sharing ratio evaluation formula and range of CFT should not be applied to RCFT; The lower limit for the range of load-sharing ratio of RCFT can be smaller than that of CFT; the proposed formulas for load-sharing ratio of RCFT have practical mean in design of RCFT columns.

강철도 복합교량 케이블의 장력 평가기법에 관한 연구 (A Study on Evaluation Method of Cable Tension for Railway Steel Composite Bridge)

  • 최정열;이수재;정지승
    • 문화기술의 융합
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    • 제8권4호
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    • pp.407-413
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    • 2022
  • 본 연구에서는 약 3년간의 장기계측을 바탕으로 공용중인 복층 교량인 상부 도로교의 신축이음 신축량과 하부 철도교의 케이블 장력 간의 상관관계를 입증함으로서 온도변화에 따른 케이블 장력 평가 경험식을 제안하였다. 본 연구에서 제안한 케이블별 장력 평가 경험식을 이용한 장력 예측결과는 진동법을 이용한 장력과 3% 이내로 잘 일치하는 것으로 나타나 공용중인 케이블의 장력 예측 및 평가에 실험적인 기법인 진동법과 함께 적용이 가능할 것으로 판단되었다. 본 연구에서 제안한 신축량 경험식으로 산출한 추정온도를 케이블 경험식에 적용한 결과, 현장시험 진동법 측정결과와 비교시 높은 신뢰수준을 확보할 수 있을 것으로 분석되었다. 따라서 본 연구에서 제안한 추정온도를 반영한 장력 평가 경험식은 향후 기후변화에 따른 케이블의 장력 예측 및 유지관리방안 수립에 활용될 수 있을 것으로 판단된다.