• Title/Summary/Keyword: mathematical assessment

Search Result 517, Processing Time 0.024 seconds

Review of Instant Release Fractions of Long-lived Radionuclides in CANDU and PWR Spent Nuclear Fuels Under the Geological Disposal Conditions

  • Choi, Heui Joo;Koo, Yang-Hyun;Cho, Dong-Keun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.20 no.2
    • /
    • pp.231-241
    • /
    • 2022
  • Several countries, including Korea, are considering the direct disposal of spent nuclear fuels. The radiological safety assessment results published after a geological repository closure indicate that the instant release is the main radiation source rather than the congruent release. Three Safety Case reports recently published were reviewed and the IRF values of seven long-lived radionuclides, including relevant experimental results, were compared. According to the literature review, the IRF values of both the CANDU and low burnup PWR spent fuel have been experimentally measured and used reasonably. In particular, the IRF values of volatile long-lived nuclides, such as 129I and 135Cs, were estimated from the FGR value. Because experimental leaching data regarding high burnup spent nuclear fuels are extremely scarce, a mathematical modelling approach proposed by Johnson and McGinnes was successfully applied to the domestic high burnup PWR spent nuclear fuel to derive the IRF values of iodine and cesium. The best estimate of the IRF was 5.5% at a discharge burnup of 55 GWd tHM-1.

A Berth Assignment Planning for a Public Terminal (공공터미널의 선석배정계획에 관하여)

  • Keum, J.S.;Lee, H.G.;Lee, C.Y.
    • Journal of Korean Port Research
    • /
    • v.10 no.2
    • /
    • pp.7-15
    • /
    • 1996
  • A berth assignment problem has a direct impact on assessment of charges made to ships and goods. A berth can be assigned to incoming vessels and operated in tow different ways: as a common user berth, as a preference berth. A common user berth is a berth that any ship calling at a port may be permitted to use according to her time of arrival and to priorities as determined by the port authority. In this paper, we concerned with various types of mathematical programming models for a berth assignment problem to achive an efficient berth operation. In this paper, we focus on a reasonable berth assignment programming in a public container terminal in consideration of trade-off between server and user. We propose a branch and bound algorithm & heuristic algorithm for solving the problem. We suggest three models of berth assignment to minimizing the objective functions such as total port time, total berthing time and maximum berthing time by using a revised Maximum Position Shift(MPS) with which the trade-off between servers and users can be considered. The berth assignment problem is formulated by min-max and 0-1 integer programming and developed heuristic algorithm to solve the problem more easily instead of branch and bound method. Finally, we gave the numerrical solutions of the illustrative examples.

  • PDF

Development of Medical Cost Prediction Model Based on the Machine Learning Algorithm (머신러닝 알고리즘 기반의 의료비 예측 모델 개발)

  • Han Bi KIM;Dong Hoon HAN
    • Journal of Korea Artificial Intelligence Association
    • /
    • v.1 no.1
    • /
    • pp.11-16
    • /
    • 2023
  • Accurate hospital case modeling and prediction are crucial for efficient healthcare. In this study, we demonstrate the implementation of regression analysis methods in machine learning systems utilizing mathematical statics and machine learning techniques. The developed machine learning model includes Bayesian linear, artificial neural network, decision tree, decision forest, and linear regression analysis models. Through the application of these algorithms, corresponding regression models were constructed and analyzed. The results suggest the potential of leveraging machine learning systems for medical research. The experiment aimed to create an Azure Machine Learning Studio tool for the speedy evaluation of multiple regression models. The tool faciliates the comparision of 5 types of regression models in a unified experiment and presents assessment results with performance metrics. Evaluation of regression machine learning models highlighted the advantages of boosted decision tree regression, and decision forest regression in hospital case prediction. These findings could lay the groundwork for the deliberate development of new directions in medical data processing and decision making. Furthermore, potential avenues for future research may include exploring methods such as clustering, classification, and anomaly detection in healthcare systems.

Comparison of event tree/fault tree and convolution approaches in calculating station blackout risk in a nuclear power plant

  • Man Cheol Kim
    • Nuclear Engineering and Technology
    • /
    • v.56 no.1
    • /
    • pp.141-146
    • /
    • 2024
  • Station blackout (SBO) risk is one of the most significant contributors to nuclear power plant risk. In this paper, the sequence probability formulas derived by the convolution approach are compared with those derived by the conventional event tree/fault tree (ET/FT) approach for the SBO situation in which emergency diesel generators fail to start. The comparison identifies what makes the ET/FT approach more conservative and raises the issue regarding the mission time of a turbine-driven auxiliary feedwater pump (TDP), which suggests a possible modeling improvement in the ET/FT approach. Monte Carlo simulations with up-to-date component reliability data validate the convolution approach. The sequence probability of an alternative alternating current diesel generator (AAC DG) failing to start and the TDP failing to operate owing to battery depletion contributes most to the SBO risk. The probability overestimation of the scenario in which the AAC DG fails to run and the TDP fails to operate owing to battery depletion contributes most to the SBO risk overestimation determined by the ET/FT approach. The modification of the TDP mission time renders the sequence probabilities determined by the ET/FT approach more consistent with those determined by the convolution approach.

A Study of the Assessment Model for Math Clinic Program (수학학습클리닉 프로그램 평가 모형 개발에 관한 연구)

  • Kim, Jeong Hyun;Ko, Ho Kyoung;Huh, Nan;Hwang, Hye Jeang
    • Communications of Mathematical Education
    • /
    • v.31 no.3
    • /
    • pp.313-329
    • /
    • 2017
  • Recently, 'students who gave up mathematics' became social problems. The need for systematic support for spreading and seating mathematics clinics was recognized. The mathematics clinic emphasizes the change of the affective aspects by constantly meeting the students and listening to the worries of the students. It is also a program that guides students in the future to see mathematics in a positive way. However, at school, mathematics clinics are operated in various forms at the discretion of teachers. Therefore, it is difficult to confirm whether the purpose of the mathematics clinic is being achieved properly. It is necessary to prepare a plan that can act as a guideline to check the necessary basic items for the runs of the math clinic and to check the necessary parts in the course of runs The purpose of this study is to develop a model for evaluating mathematics clinic programs which can be a guideline for the operation of mathematics clinic programs in a systematic way and to reduce the confusion of operation of mathematics clinics at the schools. We expect that this evaluation model could provide a direction for the operation of a math clinic.

Research on Teachers' Recognition about the Introduction of Mathematics Workbook and the Suggestion of Its Organization (수학 워크북 도입에 대한 교사들의 인식 조사 및 구성 방안 제안)

  • Kim, Bu-Mi
    • Journal of Educational Research in Mathematics
    • /
    • v.17 no.3
    • /
    • pp.271-293
    • /
    • 2007
  • Mathematics workbook is developed according to the amendment of the 7th national curriculum of mathematics. This study polled 300 national mathematics teachers in the elementary school, middle school, and high school to find out what they think in conjunction with the introduction of mathematics workbook such as needs for mathematics workbook, teachers' recognition about the system of mathematics textbook and workbook which are proper for lesson of achievement level and organization of mathematics workbook before using the mathematics workbook in school. As a results, mathematics teachers want the introduction of workbook because it helps students' self-regulated learning of mathematics and it is material very valuable for teachers to give lessons of achievement level. Also, we suggest the organization and contents of mathematics workbook on the base of our survey. Mathematics workbook has a lot of exercises assessing into the upper, intermediate, lower level in the contents, concepts of mathematics learning. It has the items developed with various problem solving methods and emphasis on performance tests, an essay-type examination and a periodical assessment. It has the problem posing items and the corner that helps students revise their mathematical errors and proposes useful, interesting mathematical activities and the commentary of a correct answer to questions at the tail of the book.

  • PDF

Longitudinal Study on the Relationship and Effects of Internal and External Factors on Mathematics Academic Achievement -For Middle and High School Students- (수학 학업성취도에 대한 내·외적요인의 관계 및 영향에 대한 종단연구 -중·고등학생을 대상으로-)

  • Kim, Yongseok;Han, Sunyoung
    • Communications of Mathematical Education
    • /
    • v.34 no.3
    • /
    • pp.325-354
    • /
    • 2020
  • This study utilized longitudinal data from the 2013 year (Secondary Middle School) to 2017 year (Secondary High School) of the Seoul Education Termination Study. Using the latent growth model and the piecewise growth model, we investigated the changes in mathematics academic achievement, internal factors(self-concept, self-control, self-assessment of life satisfaction), and external factors(school climate, guardians) as students' grades increased, and examined whether internal factors and external factors influence the changes in mathematics academic achievement. We examined whether internal and external factors influence the change in academic achievement. As a result of analysis, it was found that mathematics academic achievement remained unchanged from the first grade of middle school to the second grade of middle school, and steadily increased from the second grade of middle school to the first grade of high school, and then decreased slightly in the second grade of high school. The internal and external factors had little change. It has been found that self-concept, self-control as internal factors, and school climate as external factors influence changes in mathematics academic achievement.

High School Mathematics Teachers' Conception of Mathematics Textbooks Based on Storytelling (고등학교 수학 교사의 스토리텔링 수학 교과서에 대한 이해)

  • Kwon, Oh-Nam;Ju, Mi-Kyung;Park, Kyoo-Hong;Oh, Hye-Mi;Park, Ji-Hyun;Cho, Hyung-Mi;Lee, Ji-Eun;Park, Jung-Sook
    • The Mathematical Education
    • /
    • v.51 no.3
    • /
    • pp.223-246
    • /
    • 2012
  • Korean Ministry of Education Science, and Technology(MEST) has recommended the introduction of mathematics textbooks based on storytelling to improve the teaching and learning of mathematics in school. As part of the mathematics textbooks based on storytelling development, this research has investigated school mathematics teachers' perspectives on mathematics textbooks based on storytelling in order to identify implications for the development and the implementation of it. For the purpose, we have developed survey questionnaire and administered it to 113 high school mathematics teachers. The survey asked the teachers to address their conception of mathematics textbooks based on storytelling, its contribution to school mathematics, challenges and obstacles for the implementation. The survey shows that the mathematics teachers' conception of mathematics textbooks based on storytelling was not clear or limited. Most of them replied that they received information about mathematics textbooks based on storytelling from the materials provided by workshop or materials of school district office. While the teachers heard about that school will implement mathematics textbooks based on storytelling, they rarely had idea of how to use them in class. In the survey, the teachers identified which type of storytelling is effective for which purpose of mathematics education. They also identified the positive effect and the difficulties in the implementation of mathematics textbooks based on storytelling. The mathematics teachers pointed out that textbook is not enough. They urged that the implementation of mathematics textbooks based on storytelling should be integrated into classroom teaching and assessment to make a significant change in the educational practice of mathematics in school. Thus, mathematics teachers need support to implement mathematics textbooks based on storytelling into their teaching practice. Teacher workshop and teacher manuals need to be developed to help teachers understand educational visions and values of mathematics textbooks based on storytelling. These results of the survey would form the worthwhile base information for the development and the implementation of mathematics textbooks based on storytelling.

Effects of Professional Development for Equity: Focusing on High School Students' Attitudes toward Mathematics (교육 형평성을 위한 고등학교 수학 교사 교육 시행 효과: 학생들의 수학 정의적 영역을 중심으로)

  • Kim, Yeon
    • School Mathematics
    • /
    • v.19 no.4
    • /
    • pp.751-774
    • /
    • 2017
  • Having mathematics for everyone in terms of students' mathematics achievement and attitudes toward mathematics is challenging in high school in South Korea. To gain such purpose, teachers are supposed to have a considerable amount of knowledge and develop mathematical and pedagogical reasoning and insight because equity can be fulfilled in mathematics classroom when any student share their ideas and have mathematical discussions. As a part of a large project aimed to develop and enact professional development for equity and examine its effects and, finally, to propose the direction of professional development to help students cognitively and affectively balanced grow in mathematics, the current study briefly introduces how such professional development was designed and implemented. This study reports its effect based on the statistical analysis of students' responses for the three different surveys, which are parts of the National Assessment of Educational Achievement study, TIMSS Advanced, and the survey about classroom interaction. The data collected in all students in school whose three mathematics teachers had participated in the professional development for two years. The findings consistently indicate the strong and impressive growths in students' attitudes toward mathematics, which are statistically significant. Furthermore, their attitudes toward mathematics are also related to interactions in a mathematics classroom. Based on such results, this study claims expansion of professional development for equity.

Exploring factors in terms of school and social environment that affect high school student's affective attitude on mathematics according to the student's academic level, grade, gender, and school location (고등학생의 학업성취도, 학년, 성별, 학교 소재지에 따른 수학에 대한 정의적 태도에 영향 미치는 학교와 사회 환경적 측면의 요인 탐색)

  • Jung Hye-Yun
    • The Mathematical Education
    • /
    • v.62 no.1
    • /
    • pp.151-173
    • /
    • 2023
  • In this study, we explored factors that affect high school student's affective attitude on mathematics with respect to the school mathematics instructoin, school mathematics assessment, mathematics textbook, private mathematics education, college entrance and career, and social atmosphere. Considering students' grade, major, academic level, gender, and school location, 1,029 high school students participated in the survey. To analyze the survey results, descriptive statistics, t-test, ANOVA, and chi-square test were conducted using SPSS ver 29.0. Results are as follows. First, generally, college entrance and career and school mathematics instruction affected students' affective attitude on mathematics. Second, according to student's academic level and gender, there was a statistically significant difference in the factors affecting the affective attitude on mathematics. Third, according to students' background, there was a statistically significant difference in students' responses to sub-categories of each factor. We suggested that to improve student's affective attitude on mathematics, diversity of the school mathematics instruction, improvement of the mathematics textbook, student's appropriate participation in the private mathematics education, improvement of student's perception of the utilization of the mathematics in the future and the importance of the mathemaitcs in the society, and parents' emotional support are needed.