• Title/Summary/Keyword: written test

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Identification of motion error sources in NC machine tools by a circular interpolation test (원호보간시험에 의한 수치제어 공작기계의 운동오차원인 진단에 관한 연구)

  • Hong, Seong-Wook;Shin, Young-Jae;Lee, Hu-Sang
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.2
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    • pp.126-137
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    • 1993
  • This paper presents an efficient method for the identification of motion error sources in NC machine tools by making use of the circular interpolation test, which is often used in estimating the motion accuracy of NC machine tools. Mathematical formulae are described for motion errors due to various kinds of error sources. Two identification formulae are proposed: one is based on the frequency analysis and the other is formulated with the weithted residual method. Motion error signal is classified into two patterns, mean errors(mean of CW and CCW test signals from mean errors). The sources of the mean errors are identified by using the frequency analysis technique and the sources of the deviation errors by the weighted residual formulaltion. A menu driven, user oriented, computer program is written to realize the full steps of the proposed identificationprocedure. Then, the identification method is applied to two NC machine tools.

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A study of the Development of Ship Integrated Combat Capability Operational Test and Evaluation using Missile Live-Fire and Reaction Time Analysis (유도탄 실사격 및 반응시간 분석보고서를 활용한 함정 통합전투성능 운용시험평가 발전방안 제시)

  • Kim, Byungjun;Kang, Jeongseok;Hur, Jangwan;Ko, Jangsoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.3
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    • pp.259-266
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    • 2022
  • This study aims to introduce missile live-fire during the ship operational test and evaluation(T&E) as a means of verifying the integrated combat capability(ICC) of various systems installed on naval ships. The research method identified domestic and foreign T&E systems and cases, and reports related to ICC, which were written during the ship's design stage. As a result of research, Republic of Korea is not conducting the missile live-fire at the ship T&E stage due to the lack of relevant systems, while the U.S. is conducting it based on the mission-based T&E and the end-to-end test system. As a way to improve within the current domestic ship acquisition systems, the reaction time analysis, a quantitative analysis result of ICC calculated at the ship basic design stage, was proposed to be verified by missile live-fire during ship operational T&E.

Dynamic Analysis of Underwater Test Collector on Extremely Soft Soil (해저연약지반 시험집광기의 동적거동 해석)

  • Kim, Hyung-Woo;Hong, Sup;Choi, Jong-Su;Yeu, Tae-Yeong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.3
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    • pp.222-228
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    • 2008
  • We conducted a dynamic analysis of an underwater test collector, which operates on extremely soft soil of deep-seafloor. The underwater test collector consists of nodule pick-up device, vehicle tracks, nodule crusher, loading frame and electric-electronic system. The weight of underwater test collector is about 8600 kg. The average normal pressure, that the underwater test collector supports, is about 6.0 kPa. The dynamic analysis model of underwater test collector is developed using commercial software RecurDyn-LM and Visual Fortran 90. A terramechanics model of extremely soft soil is implemented to the software based on user-written subroutine and applied to the dynamic analysis of the underwater test collector model. The dynamic responses of test collector are studied with respect to track velocities, terrain conditions, and coefficients of added mass and drag.

A Study on Teaching-Learning and Evaluation Methods of Environmental Studies in the Middle School (중학교 "환경" 교과의 교수.학습 및 평가 방법 연구)

  • 남상준
    • Hwankyungkyoyuk
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    • v.7 no.1
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    • pp.1-17
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    • 1994
  • This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

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A Study on the Propagation of Measurement Uncertainties into the Result on a Turbine Performance Test

  • Cho, Soo-Yong;Park, Chanwoo
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.689-698
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    • 2004
  • Uncertainties generated from the individual measured variables have an influence on the uncertainty of the experimental result through a data reduction equation. In this study, a performance test of a single stage axial type turbine is conducted, and total-to-total efficiencies are measured at the various off-design points In the low pressure and cold state. Based on an experimental apparatus, a data reduction equation for turbine efficiency is formulated and six measured variables are selected. Codes are written to calculate the efficiency, the uncertainty of the efficiency, and the sensitivity of the efficiency uncertainty by each of the measured quantities. The influence of each measured variable on the experimental result is figured out. Results show that the largest uncertainty magnification factor (UMF) value is obtained by the inlet total pressure among the six measured variables, and its value is always greater than one. The UMF values of the inlet total temperature, the torque, and the RPM are always one. The uncertainty percentage contribution (UPC) of the RPM shows th, lowest influence on the uncertainty of the turbine efficiency, but the UPC of the torque has the largest influence to the result among the measured variables. These results are applied to find the correct direction for meeting an uncertainty requirement of the experimental result in the planning or development Phase of experiment, and also to offer ideas for preparing a measurement system in the planning phase.

The Development of Boiler Fuel Control Algorithm and Distributed Control System for Coal-Fired Power Plant (석탄화력발전소 보일러 연료제어 알고리즘과 분산제어시스템의 개발)

  • Lim, Gun-Pyo;Lee, Heung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.1
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    • pp.36-44
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    • 2013
  • This paper is written for the development and application of boiler fuel control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. Fuel control algorithm has the upper algorithm and it is boiler master control algorithm that controls the fuel, feed water, air by generation output demand. Generation output demand by power load influences fuel control. Because fuel can not be supplied fast to the furnace of boiler, fuel control algorithm was designed adequately to control the steam temperature and to prevent the explosion of boiler. This control algorithms were coded to the control programs of distributed control systems which were developed domestically for the first time. Simulator for coal-fired power plant was used in the test step. After all of distributed control systems were connected to the simulator, the tests of the actual power plant were performed successfully. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

The Development of Boiler Furnace Pressure Control Algorithm and Distributed Control System for Coal-Fired Power Plant (석탄화력발전소 보일러 노내압력 제어알고리즘과 분산제어시스템의 개발)

  • Lim, Gun-Pyo;Hur, Kwang-Bum;Park, Doo-Yong;Lee, Heung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.3
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    • pp.117-126
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    • 2013
  • This paper is written for the development and application of boiler furnace pressure control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. The control algorithms were designed in the shape of cascade control for two parts of furnace pressure control and induced draft fan pitch blade by standard function blocks. This control algorithms were coded to the control programs of distributed control systems. The simulator for coal-fired power plant was used in the test step and automatic control, sequence control and emergency stop tests were performed successfully like the tests of the actual power plant. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

Utilization of Computer Pointing Game for Improving Visual Perception Ability of Children with Severe Intellectual Disability

  • Kim, Kyoung-Ju;Kim, Nam-Ju;Seo, Jeong-Man;Kim, Sung-Wan
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.4
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    • pp.41-49
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    • 2018
  • The purpose of this study is to investigate the effect of computer pointing game on the visual perception ability of children with severe intellectual disability. Based on a literature review, we developed a computer pointing game to improve visual perception ability, which consisted of three stages; catching a hamburger, catching a hamburger and a soda, and catching various foods. At each stage, different instructional models were applied by difficulty level of the contents. Experiments were performed among four children with severe intellectual disabilities for three weeks. They belonged to H public school in Kyeonggi, Korea. Their visual perceptions were quantitatively measured four times by utilizing the Korean Developmental Test of Visual Perception tool (K-DTVP-2). For qualitative evaluation, an observation assessment diary was written and analyzed. All four children at the fourth test showed better visual perception ability, compared with the ability at the first test. As a result of the analysis of the observation assessment, they were considered successful in their learning and ordinary life related to visual perception. It can be concluded that the computer pointing game may play a role in helping children with severe intellectual disabilities improve their visual perception ability.

Investigating the Regression Analysis Results for Classification in Test Case Prioritization: A Replicated Study

  • Hasnain, Muhammad;Ghani, Imran;Pasha, Muhammad Fermi;Malik, Ishrat Hayat;Malik, Shahzad
    • International Journal of Internet, Broadcasting and Communication
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    • v.11 no.2
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    • pp.1-10
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    • 2019
  • Research classification of software modules was done to validate the approaches proposed for addressing limitations in existing classification approaches. The objective of this study was to replicate the experiments of a recently published research study and re-evaluate its results. The reason to repeat the experiment(s) and re-evaluate the results was to verify the approach to identify the faulty and non-faulty modules applied in the original study for the prioritization of test cases. As a methodology, we conducted this study to re-evaluate the results of the study. The results showed that binary logistic regression analysis remains helpful for researchers for predictions, as it provides an overall prediction of accuracy in percentage. Our study shows a prediction accuracy of 92.9% for the PureMVC Java open source program, while the original study showed an 82% prediction accuracy for the same Java program classes. It is believed by the authors that future research can refine the criteria used to classify classes of web systems written in various programming languages based on the results of this study.

Study on EGS5 Based Test Code and Preliminary Results (EGS5 기반 사용자코드의 작성과 초기 계산결과)

  • Jeong Dong-Hyeok;Kim Jhin-Kee;Shin Kyo-Chul;Kim Ki-Hwan;Kim Jeung-Kee;Oh Young-Kee;Ji Young-Hun
    • Progress in Medical Physics
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    • v.17 no.2
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    • pp.123-129
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    • 2006
  • A test code was written to apply the EGS5 Monte Carlo code recently published to radiotherapy. This test code was designed to calculate the depth dose in cylindrical phantom for point source model. The evaluation of the test code was peformed by calculating the depth dose curves for high energy electrons of 5, 9, 12, and 15 MeV photons of Co-60 and 10 MV in water and comparing the results with DOSRZ/EGS4 results. In depth dose results, the differences between test code and DOSRZ/EGS4 were estimated to be less then ${\pm}1.5%\;and\;{\pm}3.0%$ approximately for electron and photon beams respectively.

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