• Title/Summary/Keyword: 기초 수학

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FEM Electrical Resistivity Modeling in Cylindrical Coordinates (원통 좌표계에서의 전기비저항 유한요소 모델링)

  • Choi Wonseok;Kim Jung-Ho;Park KwonGyu;Kim Hak-Soo;Suh Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.5 no.3
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    • pp.206-216
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    • 2002
  • The finite element method (FEM), a powerful numerical modeling tool for solving various engineering problems, is frequently applied to three-dimensional (3-D) modeling thanks to its capability of discretizing and simulating the shape of model with finite number of elements. Considering the accuracy of the solution and computing time in modeling of engineering problems, it is preferable to construct physical continuity and simplify mesh system. Although there exist systematic mesh generation systems for arbitrary shaped model, it is hard to model a simple cylinder in terms of 3-D coordinate system especially in the vicinity of the central axis. In this study I adopt cylindrical coordinate system for modeling the 3-D model space and define the origin of the coordinates with mathematically clear coordinate transformation. Since we can simulate the whole space with hexahedral elements, the cylindrical coordinate system is effective in handling the 3-D model structure. The 3-D do resistivity modeling scheme developed in this study provides basie principle for borehole-to-surface resistivity survey, which can be a useful tool for the application to environmental problem.

Multiple Intelligences, Creative Home Environment, Social economic status, and Leadership of Children (유아의 다중지능, 창의적 가정환경 및 사회인구학적 변인이 유아의 리더십에 미치는 영향)

  • Kim, Min Young;Moon, Hyuk Jun
    • Korean Journal of Childcare and Education
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    • v.7 no.3
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    • pp.259-284
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    • 2011
  • This thesis examined the effects of social demographical variables, multiple intelligences, and creative home environment on the child leadership. Study samples are 5 years old children at the kindergartens located in Seoul and metropolitan areas as well as their parents and (homeroom) teachers. 173 copies were analyzed. Results of this study are as follows: First, in terms of difference of multiple intelligences, creative home environment and child leadership depending on social demographical background, The second child showed significantly different interpersonal intelligence among other multiple intelligences from the first child with regard to the birth order. In terms of mother's education level and creative home environment, mothers with education more than universities showed big difference in family pressure. In terms of effects of total income, the children from families with total income over 4 million won showed significant difference in logical, mathematical, naturalist intelligence. and language intelligence. In terms of creative home environment, significant difference was found with regard to learning environment and child respect. Second, multiple intelligences, creative home environment, and child leadership showed correlated strongly. Third, total income in social demographic variables, language intelligence in multiple intelligences, and family pressure in creative home environment were found to have effects on it. Total income in social and demographical variables and family pressure in creative home environment were found to have effects on it. Interpersonal relation intelligence in multiple intelligences and learning environment in creative home environment were found to have effects on it. Total leadership had effects on family pressure only in creative home environment.

A Study on Modelling and Tracking Control System Design of RTGC(Rubber-Tired Gantry Crane) (RTGC의 모델링 및 주행제어기 설계에 관한 연구)

  • Jeong, Ji-Hyun;Lee, Dong-Seok;Jeong, Jeong-Soon;Kim, Young-Bok
    • Journal of Navigation and Port Research
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    • v.34 no.6
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    • pp.479-485
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    • 2010
  • To handle container effectively is one of the most important factors in a port because working time is linked soon into cost. Since the middle of 1990s, RMGC(Rail-Mounted Gantry Crane) and RTGC(Rubber-Tired Gantry Crane) have been developed and widely used to operate containers in the yard. The RTGC is more difficult than RMGC in the automatic control system design. Although, the RTGC is largely advantaged to free driving environment, it has some considerable disadvantages in the system operating. In general, the problems are due to tire slip and lack of tire pressure etc. Therefore, a desirable research result has not been shown in this time. So, in this paper, we propose a new approach to design tracking control system for the RTGC in which the mathematical modeling is included. From the simulation results, the control performance of the designed control systems is evaluated.

WAVE Packet Transmission Method for Railroad WAVE Communication (철도 WAVE 통신을 위한 WAVE 패킷 전송방법)

  • Cho, Bong-Kwan;Ryu, Sang-Hwan;Kim, Keum-Bee;Kim, Ronny Yongho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6604-6610
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    • 2015
  • In this paper, an efficient Wireless Access in Vehicular Environment (WAVE) packet transmission scheme for railroad communication is proposed. WAVE communication is a wireless local area network (WLAN) based communication and it is developed to be suitable for vehicular communication. There has been a lot of study on WAVE's applicability to Intelligent Transport System (ITS). As one of main transportation methods, by using WAVE, quality of railroad communication including WLAN based Communication Based Train Control (CBTC) can be enhanced and variety of railroad communication systems can be integrated into WAVE. However, there are technical challenges to adopt WAVE in railroad communications. For the simplest single-PHY WAVE, time division alternation of 50ms between Control Channel (CCH) and Service Channel (SCH) is required. Since there are delay sensitive railroad traffic types, alternation operation of CCH and SCH may cause performance degradation. In this paper, after identifying a couple of problems based on detailed analysis, a novel packet transmission scheme under railroad environment is proposed. In order to verify if the proposed scheme meets the requirement of railroad communication, WAVE transmission is mathematically modeled.

A Study on Improving the Quality of General Education at an Engineering College - Hongik University, College of Science and Technology - (공과대학의 소양교육 개선 방안 연구 - 홍익대학교 과학기술대학을 중심으로 -)

  • Baek Hyun-Deok;Park Jin-Won;Sim Soo-Man;Shin Pan-Seok
    • Journal of Engineering Education Research
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    • v.8 no.1
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    • pp.84-98
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    • 2005
  • This study is on improving the general engineering education for enhancing the quality of engineers at a local engineering school in which the students are not highly qualified for engineering education. Based on the analysis on the current engineering education by asking questions to professors, students and alumni of Hongik College of Science and Engineering, we have set the basic educational philosophy as educating practical engineers and have decided the goals of basic engineering education as changing to student oriented education, enhancing the field adaptation capability, improving the problem solving ability and introducing engineering design courses. For achieving the foregoing goals, we have changed several basic engineering courses. Mathematics, science courses, computer related courses, English, communication skill related courses are strengthened, but general college education courses are reduced. We also have encouraged students to participate the classes actively and study efficiently, think logically and creatively. For the operational details, we have tried to impose less courses to freshmen and sophomores, to impose the prerequisite courses, to activate summer and winter schools. Finally, we have tried to find the ways to support continuous improvement on the basic engineering education.

The Study on Proper Way for Engineering University Education: Based on the Perception of Current Competencies and Expected Competencies of Engineering Freshmen (공과대학 신입생의 핵심역량 인식수준을 통한 공학교육방향 연구)

  • Lee, Gyeoung-Hee;Kwon, Hyuk-Hong;Lee, Jeong-Rye;Lee, Sung-Jin
    • Journal of Engineering Education Research
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    • v.13 no.6
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    • pp.57-71
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    • 2010
  • This paper is a study on the perception of current competency and expected competency of engineering freshmen by extracting core competencies acquired from university education. It also aims to suggest proper way for engineering university education. This study extracts competencies in the following five areas as core competencies: 'knowledge on major area', 'cultural ability', 'foreign language ability', 'basic learning ability', 'intercommunication ability'. To achieve this purpose, this study surveyed 'C' university engineering department freshmen (584 students) with questionnaires about their perception of core competencies. The results are as follows. First, engineering freshmen perceived current competencies were weak in every area, especially their capacities in 'foreign language ability' area were perceived to be weakest. Their demand for education is the highest in 'foreign language ability' area, and the second higher in 'knowledge on major area'. Secondly, there exists meaningful difference between perception of current competency and expected competency depending on the gender, high school department (science/liberal arts), high school location, types of college admissions, and types of mathematics in NAST. According to these results, this study suggests enhancement of foreign language (English) education in engineering department, design and implementation of various educational program to overcome individual difference, promoting importance of competencies in the 'cultural abilty' and 'intercommunication abilty', necessity of continuous adjustment and complementation for engineering educational program through accumulation of feedback processes, activation of career education through engineering education and special programs.

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The effects of S-STEAM program on creativity and multiple intelligences of young children (과학 중심 융합인재교육(S-STEAM) 프로그램이 유아의 창의성 및 다중지능에 미치는 영향)

  • Song, Min-Seo;Kim, Hyoung-Jai
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.361-372
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    • 2016
  • The purpose of this study was to develop a STEAM-based science education program for children and to verify its effectiveness. An S-STEAM-based science education program for young children was developed through careful analysis of prior research on science education for young children and S-STEAM. The participants were 29 four-year-old children from daycare centers located in Seoul (an experimental group of 14 and comparative group of 15). The S-STEAM program was applied to the experimental group, while the control group went through a general science education course provided by the government. TTCT of Creative Thinking (TTCT: Figures A and B) was used as a research tool, and a multiple intelligence test tool was applied to teachers of the groups. Afterwards, analysis of covariance was implemented to find the S-STEAM program's effects. First, the results showed positive effects on overall creativity, as well as in fluency, originality, abstractness, elaboration, and openness components of creativity. Second, the results showed positive effects on overall multiple intelligences and its components of linguistic, musical, spatial, logical/mathematical, physical exercise, interpersonal, and naturalist intelligence.

A study on the left/right brain utilization tendency of information prodigies (정보영재 학생의 좌·우뇌 활용 성향 연구)

  • Nam, Seun Kwon;Choi, Won Sik;Lim, Byoung Ung
    • 대한공업교육학회지
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    • v.33 no.1
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    • pp.23-43
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    • 2008
  • The purpose of this study is to provide some necessary baseline data to the information prodigy related research through the study on the brain left/right tendency of information prodigies. Subjects were 298 gifted students(59 information, 79 mathematics, 80 science, 40 invention, 40 social science) and 114 general students summing up 412 in the schools of Daejeon metropolitan area. 'Brain Tendency Test' developed by Torrance and modified by Ko in Korean was used as a tool to measure the prodigies' brain tendencies. Data analysis has been done with the $x^2$ test of frequency with the alpha = .05. The results of this study are as follows. 1) The information gifted students have tendencies of utilizing right brain hemisphere at the most, both left/right brain(whole brain) utilization at the second, and left brain utilization at the last. 2) There was statistically no difference between information prodigies and general students in the left/right brain tendency. 3) There was statistically mild evidence to support the notion that there are some differences in the brain tendency between the group of information prodigies and the group of other area of the prodigies. The degree of inclination to utilize the whole brain hemisphere for the prodigies of the other area was the highest compare to other left/right brain utilization while the information prodigies tend to utilize the right brain hemisphere at the most. 4) The female information prodigies have tendencies of utilizing while brain area at the most, right brain utilization at the second, and left brain utilization at the last contrary to the brain utilization tendencies in the male information prodigies which are the same as the brain utilization tendencies of the information prodigies. However there was no difference in brain tendencies statistically between the two groups since the female subjects were too small.

Speed Control of Marine Gas Turbine Engine using Nonlinear PID Controller (비선형 PID 제어기를 이용한 선박용 가스터빈 엔진의 속도 제어)

  • Lee, Yun-Hyung;So, Myung-Ok
    • Journal of Navigation and Port Research
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    • v.39 no.6
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    • pp.457-463
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    • 2015
  • A gas turbine engine plays an important role as a prime mover that is used in the marine transportation field as well as the space/aviation and power plant fields. However, it has a complicated structure and there is a time delay element in the combustion process. Therefore, an elaborate mathematical model needs to be developed to control a gas turbine engine. In this study, a modeling technique for a gas generator, a PLA actuator, and a metering valve, which are major components of a gas turbine engine, is explained. In addition, sub-models are obtained at several operating points in a steady state based on the trial running data of a gas turbine engine, and a method for controlling the engine speed is proposed by designing an NPID controller for each sub-model. The proposed NPID controller uses three kinds of gains that are implemented with a nonlinear function. The parameters of the NPID controller are tuned using real-coded genetic algorithms in terms of minimizing the objective function. The validity of the proposed method is examined by applying to a gas turbine engine and by conducting a simulation.

EEG Recording Method for Quantitative Analysis (정량적 분석을 위한 뇌파 측정 방법)

  • Heo, Jaeseok;Chung, Kyungmi
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.4
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    • pp.397-405
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    • 2019
  • Quantitative electroencephalography (QEEG) has been widely used in research and clinical fields. QEEG has been widely used to objectively document cerebral changes for the purpose of identifying the electrophysiological biomarkers across various clinical symptoms and for the stimulation of specific cortical regions associated with cognitive function. In electroencephalography (EEG), the difference in quantitative and qualitative analyses is discriminated not by its measurement methods and relevant clinical or research environments, but by its analysis methods. When performing a qualitative analysis, it is possible for a medical technologist or experienced researchers to read the EEG waveforms to exclude artifacts. However, the quantitative analysis is still based on mathematical modeling, and all EEG data are included for the analysis, leading the results to be affected by unexpected artifacts. In the hospital setting, the case that the medical technologists in charge of the EEG test perform academic research has been little reported, compared to other clinical physiological measurement-based research. This is because there are few laboratories specialized in clinical physiological research. In this respect, this study is expected to be utilized as a basic reference material for medical technologists, students, and academic researchers, all of whom would like to conduct a quantitative analysis.