• Title/Summary/Keyword: real-life materials

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A Study on the Development and Application of the Learning Material for Mathematics Optional Activities. - Focused on 8-ga Grade - (수학 교과 재량활동에 대한 학습자료 개발 및 적용에 관한 연구 -8-가 단계를 중심으로-)

  • 유희식;박달원
    • Journal of the Korean School Mathematics Society
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    • v.5 no.2
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    • pp.71-82
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    • 2002
  • This study purported to develop the learning materials for the optional activities of mathematics, apply them to the students, and examine the effect on the learner's interest and attitude to mathematics. In order to conduct this study, the learning materials for the mathematics optional activities were developed according to the units of grade 8-Ga and the developed learning materials of the mathematics optional activities were inputted in two classes for 18 units after the second grade middle school students in Daejeon area received the questionnaire regarding the learning attitude and the interest in the mathematics. After that, the questionnaire regarding the learning attitude and the interest in the mathematics and the examination regarding the response to the application of the learning materials for mathematics optional activities were conducted and did t-test. The results of the study as follows : First The learning materials applied exciting games for mathematics optional activities aroused interest in mathematics and made the learners have confidence in mathematics learning. Second, There was affirmative change in the interest and attitude to the mathematics learning with the application of the mathematics optional learning materials. Third The leaning materials of the mathematics optional activities made the learners think mathematical questions connected with the real life and try various ways to solve the questions. Here are some suggestions to study the development of the learning materials such as story, game, quiz and craft. First it is necessary to develop the learning materials applied the games or the real life matters connected with mathematics for all grade middle school students and use them in the mathematics optional activities. Second, many students feel a great interest in animation. moving picture, sound graphic, etc. If the multimedia learning materials included the real life matters or the games are developed, the learners will feel more interest in mathematics. Third, the systematic and economical support is continuously needed in order that teachers are given much time to study and the opportunity to attend the training course for the understanding of the optional activities and the development of the various learning materials.

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Development of Life Test Equipment with Real Time Monitoring System for Butterfly Valves

  • Lee, Gi-Chun;Choi, Byung-Oh;Lee, Young-Bum;Park, Jong-Won;Nam, Tae-Yeon;Song, Keun-Won
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.1
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    • pp.40-46
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    • 2017
  • Small valves including ball valves, gate valves and butterfly valves have been adopted in the fields of steam power generation, petrochemical industry, carriers, and oil tankers. Butterfly valves have normally been applied to fields where in narrow places installing the existing valves such as gate valves and ball valves have proven difficult due to the surrounding area and the heavier of these valves. Butterfly valves are used to control the mass flow of the piping system under low pressure by rotating the circular disk installed inside. The butterfly valve is benefitted by having simpler structure in which the flow is controlled by rotating the disc circular plate along the center axis, whereas the weight of the valve is light compared to the gate valve and ball valve above-mentioned, as there is no additional bracket supporting the valve body. The manufacturing company needs to acquire the performance and life test equipment, in the case of adopting the improving factors to detect leakage and damage on the seat of the valve disc. However, small companies, which are manufacturing the industrial valves, normally sell their products without the life test, which is the reliability test and environment test, because of financial and manpower problems. Furthermore, the failure mode analysis of the products failed in the field is likewise problematic as there is no system collecting the failure data on sites for analyzing the failures of valves. The analyzing and researching process is not arranged systematically because of the financial problem. Therefore this study firstly tried to obtain information about the failure data from the sites, analyzed the failure mode based on the field data collected from the customers, and then obtained field data using measuring equipment. Secondly, we designed and manufactured the performance and life test equipment which also have the real time monitoring system with the naked eye for the butterfly valves. The concept of this equipment can also be adopted by other valves, such as the ball valve, gate valve, and various others. It can be applied to variously sized valves, ranging from 25 mm to large sized valves exceeding 3000 mm. Finally, this study carries out the life test with square wave pressure, using performance and life test equipment. The performance found out that the failures from the real time monitoring system were good. The results of this study can be expanded to the other valves like ball valves, gate valves, and control valves to find out the failure mode using the real time monitoring system for durability and performance tests.

A Study on Improving the Precision of Quantitative Prediction of Cold Forging Die Life Cycle Through Real Time Forging Load Measurement (실시간 성형하중 계측을 통한 냉간단조 금형수명 정량예측 정밀도 향상 연구)

  • Seo, Y.H.
    • Transactions of Materials Processing
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    • v.30 no.4
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    • pp.172-178
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    • 2021
  • The cold forging process induces material deformation in an enclosed space, generating a very high forging load. Therefore, it is mainly designed as a multi-stage process, and fatigue failure occurs in forging die due to cyclic load. Studies have been conducted previously to quantitatively predict the fatigue limit of cold forging dies, however, there was a limit to field application due to the large error range and the need for expert intervention. To solve this problem, we conducted a study on the introduction of a real-time forging load measurement technology and an automated system for quantitative prediction of die life cycle. As a result, it was possible to reduce the error range of the quantitative prediction of die life cycle to within ±7%, and it became possible to use the die life cycle calculation algorithm into an automated system.

The Development of Teaching-learning Materials based on Real life and the Investigation of Students's cognition change about Mathematics class using Developed materials (실생활 중심의 교수-학습 자료 개발과 이를 활용한 수학 수업에 대한 학생들의 인식 변화 고찰)

  • Lee, Shin-Deuk;Kwean, Hyuk-Jin
    • Journal of the Korean School Mathematics Society
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    • v.10 no.1
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    • pp.45-69
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    • 2007
  • In the 21st century, knowledge-based and information-based society requires not just the capability of applying mathematics simply but mathematical power such as problem-solving ability which composes and solves problems using mathematical knowledge in real-life and fields of various subjects. However, to develop mathematical power, we need various teaching and learning methods which raise basic mathematical knowledge, the inference capability, problem- solving ability, the flexibility of thinking, the expressing and transforming ability of mathematical ideas, perseverance, interest, intellectual curiosity, and creativity. In this paper, we develop the teaching-learning plans based on real life using the various methods of learning and then we analyze the change of students's cognition of mathematics and the students's reaction of the class.

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Using Mean Residual Life Functions for Unique Insights into Strengths of Materials Data

  • Guess Frank M.;Zhang Xin;Young Timothy M.;Leon Ramon V.
    • International Journal of Reliability and Applications
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    • v.6 no.2
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    • pp.79-85
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    • 2005
  • We show how comparative mean residual life functions (MRL) can be used to give unique insights into strengths of materials data. Recall that Weibull's original reliability function was developed studying and fitting strengths for various materials. This creative comparing of MRL functions approach can be used for regular life data or any time to response data. We apply graphical MRL's to real data from tests of tensile strength of high quality engineered wood.

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Establishment of accreditation criteria for nutrition and dietary education materials (영양.식생활 교육자료의 인증 심사기준 개발 연구)

  • Lee, Kyoung Ae;Kim, Ji-Myung;Park, Yoo Kyoung;Lee, Kyung-Hea;Oh, Sang Woo;Lee, Hee Seung
    • Journal of Nutrition and Health
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    • v.46 no.5
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    • pp.470-481
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    • 2013
  • This study provides standardized scientific criteria for education materials on nutrition and diet that could be used in schools, workplaces, and health and medical facilities. The study was conducted from April 2011 to October 2011. Literature reviews, institutional visits, and telephone interviews were conducted for the first draft of the accreditation criteria. Expert meeting and advisory councils were conducted in order to obtain feedback after development of the first draft of accreditation criteria. In order to verify the validity and reliability of the first draft on certification criteria, a survey was sent out to 143 professionals, including professors, researchers, health and medical experts, teachers, nutrition teachers, dietitians, and clinical nutritionists. After several modifications, the final accreditation criteria were established for 1) printed materials (authority, credibility, objectivity, organization, editing, real-life usability, activities and participation, and public interest), 2) web-sites (authority, credibility, objectivity, design, real-life usability, accessibility, currency, and public interest) and 3) materials with activities (credibility, organization, design, convenience of utilizing, safety, and public interest). Out of several criteria, contents (authority, credibility. and objectivity) and publicity (public interest) areas are mandatory requirements. For the accreditation, books for learning and materials with activities are required to meet more than six evaluation components, and the other materials are required to meet more than five evaluation components, including the required area. Accreditation criteria developed in this study could be used as a standard for development or selection of good education materials for nutrition and dietary life.

Developing the mathematics model textbook based on storytelling with real-life context - Focusing on the coordinate geometry contents - (실생활 연계형 스토리텔링 수학 교과서 개발 -도형의 방정식 단원을 중심으로-)

  • Kim, Yujung;Kim, Ji Sun;Park, Sang Eui;Park, Kyoo-Hong;Lee, Jaesung
    • Communications of Mathematical Education
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    • v.27 no.3
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    • pp.179-203
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    • 2013
  • The purpose of this study was to discuss the example that developed geometry model textbook based on storytelling using real-life context. To achieve this purpose, we first elaborated the meaning of the textbook based on storytelling with real-life context, and then we discussed the outline of the story and the summary of each lesson. This study defined the storytelling textbook with real-life context as the textbook consisting of activities that explored and organized mathematical concepts by using real-life situations as materials of stories. The geometry textbook we developed employed two real-life materials, a map and a set square: we used a map for the coordinate geometry and a set square for the equation of a line. To attract students' interest, we introduced confrontation between a teacher and two students and a villain. We implemented experimentation with the textbook based on storytelling in order to verify its validity. The participants were 25 students that were enrolled in a high school in Seoul. Among them, 17 participants were surveyed. Students' answers from the survey questionnaire suggested that the geometry textbook we developed based on storytelling helped them learn mathematics and that the instruments such as a map and a set square helped them understand mathematical concepts. However, their opinion implied that the story of the textbook needed to be improved so that the story reflected more realistic contexts that were familiar with students.

Life Prediction and Stress Evaluation of Hydraulic Winch Drum by Finite Element Analysis and Experiment (유한요소해석과 실험에 의한 유압 윈치 드럼의 응력 계산 및 수명 예측)

  • Lee, Gi-Chun;Park, Jane;Nam, Tae-Yeon;Choi, Jong-Sik;Park, Jong-Won;Lee, Yong-Bum;Je, Yeong-Gi;Lee, Jae-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.57 no.5
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    • pp.254-261
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    • 2020
  • The structural safety of hydraulic winch drum and the gears are estimated by the Finite Element Analysis (FEA) and the winch operation experiment. The mesh convergence test is performed and the applied force is the pressure on the drum converted from the rope tension in working condition. The stress of the drum calculated from the strain values of the winch operation experiment shows the agreement with that from the FEA. Most stress values are under the yield strength except for the small hole made for the wire rope fixation. The life of bearings in the drum is calculated using the life prediction formula with the reaction forces from the operation load. One of the two ball bearings shows the short life for impact condition, yet the real prototype winch system shows more life than the numerical value.

Technology for Fatigue Life Prediction of Mechanical Components using Multibody Dynamics (다물체동력학을 이용한 기계 부품의 피로수명 예측 기술)

  • Han, Hyeong-Seok
    • 연구논문집
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    • s.27
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    • pp.47-55
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    • 1997
  • Fatigue life prediction of mechanical components is necessary to develop new products, which is very expensive and time-consuming. This paper reviews technologies proposed for computation of dynamic stress in mechanical components. The methods based on multibody dynamics are considering more real operational conditions than other methods. The technology for fatigue life prediction without the prototype for experiment results in cost and time saving. This technology can be applied to design of various mechanical components like carbody.

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Label-Free and Real-Time Monitoring of Phosphatase Reactions Using a Phosphate-Specific and Fluorescent Probe

  • Lee, Ji-Hoon;Ahn, Hee-Chul;Shin, Dong-Yun;Ahn, Dae-Ro
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.943-947
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    • 2008
  • A phosphate-specific and fluorescent probe was prepared for label-free phosphatase assays based on fluorescence polarization. By using the probe, dephosphorylation reactions of DNA and protein substrates by calf intestinal alkaline phosphatase (CIP) could effectively be monitored in real-time. Since this assay method does not require additional materials such as labeled substrates and phosphospecific antibodies to obtain fluorescence polarization signals, it is simple, cost-effective, and expected to be useful not only for measuring activity of phosphatases but also for high-throughput screening of phosphatase inhibitors.