• 건축사
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• 통권640호
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• pp.120-121
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• 2022

• 한국컴퓨터정보학회논문지
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• 제6권1호
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• pp.51-59
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• 2001

본 논문에서는 pencil beam 형성에 적합하며, 특정 방향으로 예리한 지향특성을 갖는 이중 원형 배열 안테나의 성능을 분석하였다. N개의 등방성 점원을 평면상에 정방형, 원형 이중원형 구조를 갖도록 등간격으로 배열하여 각 배열 구조에 따른 방사패턴 특성을 비교ㆍ분석 하였다. 결과적으로 이중 원형 배열 안테나가 지향 특성 또는 SLL과 HPBW의 측면에서 정방형과 원형 배열 구조보다 우수한 특성을 나타내고 있음을 확인하였다.

• 한국응용과학기술학회지
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• 제28권1호
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• pp.15-21
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• 2011

Threelectrodes systems were used in stripping voltammetry (SW) and cyclic voltammetry (CV) instead of the expensive platinum and Ag/AgCl reference electrodes. Moreover, the electrolyte solution was used with deep seawater, which can reduce water pollution, is more eco-friendly, and has a lower cost. The analytical optimum parameters measured via CV and SW and with working ranges were obtained from 10 to 80 ug/L using fluorine immobilized on a graphite pencil electrode (FE). Under the optimum conditions, the analytical detection limit of 6.30 ug/LAu was obtained. The results of the study can be applied to diagnostic assay for natural minerals and human finger tissue.

• Smart Structures and Systems
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• 제4권5호
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• pp.565-582
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• 2008

This paper presents a feasibility study of flexible piezoelectric paint for use in wide-band low-profile surface-mount or embeddable ultrasonic sensor for in situ structural health monitoring. Piezoelectric paint is a piezoelectric composite with 0-3 connectivity. Because of its ease of application, piezoelectric paint can be readily fabricated into sensing element with complex pattern. This study examines the characteristics of piezoelectric paint in acoustic emission signal and ultrasonic guided wave sensing. A series of ultrasonic tests including pitch catch and pencil break tests were performed to validate the ultrasonic wave sensing capability of piezoelectric paint. The results of finite element simulation of ultrasonic wave propagation, and acoustic emission generated by a pencil lead break on an aluminum plate are also presented in this paper along with corresponding experimental data. Based on the preliminary experimental results, the piezoelectric paint appears to offer a promising sensing material for use in real-time monitoring of crack initiation and propagation in both metallic and composite structures.

• 한국CDE학회논문집
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• 제9권3호
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• pp.246-252
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• 2004

Presented in this Paper is a Micro Machining Service .(MIMS) based on the World Wide Web technologies. In order to ensure easy access to the service, the web browsers are used as the user interface. The pan geometry as an STL file is uploaded with process parameter for 3-axis CNC milling. Depending on the predefined user level, novice or expert, the user interface requires different parameters for process planning. An STL-based CAM resides in the server and automatically provides NC codes upon user's request. Tool-paths for scanning and pencil-cut, which are interference-free and precise, are created by the curve-based polyhedral machining method. A couple of sample parts were fabricated by a micro endmill with 127 fm diameter. From the tests, the parts fabricated by scanning followed by pencil-cut resulted in less error(within 2%) than the parts machined only by scanning tool-path.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.343-345
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• 2005

In the study, the noise involved on the active circuit is identified using correlation function. In order to figure out the unknown location of noise source, signals from each sections in the system are collected and the location is identified by a concept called "Noise Source SUI-face". Experiment is conducted to confirm the validity of the proposed method. Also a method to reduce and control the noise in the system signal by using Matrix Pencil Method is introduced. Experiment is attempted to prove that the total noise of system can be reduced by controlling the external noise.

• 수산해양교육연구
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• 제28권1호
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• pp.289-299
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• 2016

The purpose of the study was to develop evaluation methods which would measure student achievement and progress without traditional paper-pencil tests such as mid-term and final examinations. More specifically, the main research focus were to establish general directions of student assessment during free semester, to build evaluation models supporting student's participation and learning, and to report and record various student evaluation results. As research results, we found that student evaluation of free semester should be organized to improve a) experience learning activity, self-regulatory and collaboratory study, b) high-order thinking ability and character-building, and c) teacher-student-parent cooperation. Since traditional paper-pencil tests were restricted in free semester, student achievement should be provided by a way of performance descriptions on transcripts rather than quantitative grade points. Student performance descriptions had to show not only subject knowledge but also students efforts, motivation, and participation. These multiple and educationally meaningful information would be collected by teacher-student-parent communication and collaboration.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제11권1호
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• pp.75-85
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• 2007

This paper analyzes the difficulties with the learning of sequence and series of the second-year students who participated in a year long whole class at the university level. The research was carried out at the end of students' third semester. These students were randomly selected. They were applied to one paper and pencil test containing eight task items on sequence and series. In this study, qualitative method (case study design) was used to explore students' difficulties and misunderstandings in learning sequence and series. Students' responses to the questions were divided into three categories: These were "correct", "partial correct" and "false or no responses". Students' responses to the paper and pencil test were evaluated. The results show that students had difficulties and misunderstandings in series and sequence.

• 한국자동차공학회논문집
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• 제2권5호
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• pp.74-84
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• 1994

This paper discusses a method to generate the tool path for NC machining of automobile panel dies. The source data representing a panel die may be generated from digitizing machines, other CAD/CAM systems via IGES files, of compound surface models. From the source data, three types of interferencefree tool paths are generated automatically ; a parallel (Cartesian), an isometric, and a pencil cutting tool path. For the interference-free tool path, a polyhedral model composed of several triangles, and an 'offset triangle' approach are exploited. Finally, some practical examples are illustrated.

• 아동학회지
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• 제21권4호
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• pp.227-241
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• 2000

This study investigated the effectiveness of mathematical activities based on picture books for the development of children's problem-solving performance. Subjects were 72 children divided in two groups of 36 each; one group had mathematical activities based on picture books and the other group had of pencil-and-paper tasks. The problem-solving performance was measured in terms of the test by Ward(1993) with a few modification for pretest and posttest. Mathematical activities were performed 12 times over a 6 week period. The data was analyzed by Analysis of Covariance(ANCOVA). The group taught by picture books significantly improved mathematical problem-solving performance.