• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2603-2605
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• 2001

In this paper, we introduce the concept and construction of a web-based bidirectional remote laboratory system. In this configuration, students build and test circuits using internet at home, and the circuit components and experimental equipments at the school are interconnected following student's design. This means that it is possible to choose components, build circuits, connect experiment equipments, control the equipment. and receive measurement results at home in real-time. Labview and Java are used to control this system efficiently and to provide user-friendly environments. Computer-based function generator, DMM, and oscilloscope are used and switch module is used to change interconnections. It was found that a system adopting computer-based instruments, which include PXI/CompactPCI modules and PC plug-in board, provide better performance than that adopting stand-alone instruments connected with GPIB. It is believed that, if this system is installed, the real experiments, not the virtual experiments based on simulation, can be done at home effectively, resulting in revolutional change in engineering education.

• 아동학회지
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• 제10권2호
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• pp.19-31
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• 1989

The purpose of this research was to examine the concurrent validity of the Nalongyee children's achievement motivation test by studying its relationship to a children's school readiness test. The subjects were 335 preschool children (171 urban and 164 rural) selected from 8 public and 7 private kindergartens located in two metropolitan areas (Seoul and Pusan) and 5 rural counties in Kyungsang Nam Do. Instruments included the Nalongyee Children's Achievement Motivation Test by the author and the School Readiness "Lest by Unhai Rhee. Data were analyzed by Pearson r and Z-test. Readiness was positively related to the total score and sub-areas of achievement motivation (.10-.43). Sub-areas of the achievement motivation test were related to each of the 4 factors of the readiness test. The correlations ranged from .00-.35 with the personal-social response factor, .00-.26 with the associative vocabulary factor, .05-.31 with the number concept factor, and .03-.37 with the perception factor. Significant differences in correlations were found between urban and rural areas for self-confidence, interest in learning, interest in kindergarten and physical competence.

• 한국수학교육학회지시리즈A:수학교육
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• 제42권3호
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• pp.403-417
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• 2003

The purpose of this study is to analyze the effects of the use of calculators in elementary school mathematics education. For this purpose, we established the subject matters of the research as folloows; (1) to develop the lesson plan and the students' activity sheet related to the use of calculators. (2) to analyze the effects of the use of calculators when we applied the materials developed. Four classes of sixth grade students were sampled two elementary schools in D city. Two of them were assigned to the calculator group and the others to traditional group. The experiment was conducted for 10 class times. Two kinds of test instruments were used: pretest and post test. The pretest scores guaranteed that both groups were homogeneous. Post-test was used to identify the effect of use of calculator and the post-test scores were analyzed by t-test. We also used questionnaire to identify the students' change of attitude toward mathematics. The results of this study as fellows: (1) The calculator group got scores significantly higher than the traditional group on the test. (2) The students' attitude in calculator group was changed a little positively.

• 천문학회보
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• 제36권2호
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• pp.156-156
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• 2011

VPH (Volume Phase Hologram) grating is one of the transmission gratings and is known as its remarkable efficiency (>90%). It has two different densities of gelatins causing interference patterns. The VPH grating is favored in many astronomical instruments these days and also IGRINS, which is up coming near infrared high-resolution spectroscope expected to see the first light next year, uses the VPH grating as its cross-disperser. The infrared astronomical instruments operate at cryogenic temperature (~100K) in order to cut down thermal noise and the optical components of IGIRNS will be operated at 130K. The VPH grating is sandwiched in between fused silica or glass and glued together using optical adhesive. IGRINS is expected to go through 50 times of thermal cycling in 10 years including the performance test and this research is to check whether the physical characteristic such as the adhesion or dichromatic gelatin does not break and change from the several cryogenic thermal cycling. The two identical test gratings provided from Kaiser Optical System, Inc. are used in this test. One VPH grating is cooled down to 100K for 2 hours with maximum dT/dt = 5 and warmed up to the room temperature and another grating is kept stored in the room temperature and used as a control sample. In order to check the change, we inspected the grating with eyes and checked its efficiency and transmission at the room temperature every 10 cycling. From the 40 times of cryogenic temperature cool down cycling, the VPH grating showed no signs of change within the error compared to the control sample. We concluded the VPH grating is durable through several cryogenic thermal cycling.

• 대한의용생체공학회:의공학회지
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• 제14권4호
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• pp.341-348
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• 1993

Automated system to analyze liver function test results is presented based on fuzzy logic knowledge. Clinician's knowledge and experience was first expressed in linguistic terms fol- lowed by conversion to numerical values to create membership functions of disease possibility for each test item and liver disease. Membership functions were then compensated for different relative importances of test items. Liver diseases considered were acute viral hepatitis (AVH), chronic persistent hepatitis(CPH), chronic active hepatitis(CAH), and liver cirrhosis(LC), Liver function test results of alanine aminotransferase(ALT), aspartate amino- transferase(AST) , glutamate dehydrogenase(GDH), ornithine carbamyltransferase(OCT) , ALT/AST, and 10* GDH/ALT in 218 patients were analyzed by the present system, welch resulted in 80% accuracy. AVH and CAH showed the highest 93 % and the lowest 58% ac- curacies, respectively, which was similar to the clinician's expectation. The simple mathemat- ical formulation of the present system would enable an easy implementation in commercial analysis instruments. Also, the identical fuzzy logic can be applied to similar diagnostic envi- ronments in general.

• 한국과학교육학회지
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• 제15권1호
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• pp.68-72
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• 1995

This is very important to know teachers' and children's scientific knowledge, scientific inquiry skills and cognitive abilities for better education of children. The subjects of this study are about 60-150 in each group. There are instruments used ; To test scientific knowledge a test is developed by the author. To test scientific inquiry skills, the test developed by Eun Kyung Yong is used. To test cognitive abilities, GALT, short version is used. There are results; Firstly, inservice teachers' scientific knowledge is better than preservice teachers', which is better than children'. Secondly, inservice teachers' scientific inquiry skills nearly equal preservice teachers', which are better than children'. Thirdly, preservice teachers' cognitive abilities nearly equal inservice teachers', which are better than children'. Fourthly, teachers' (special area-science) cognitive abilities are better than teachers' (special area-vidual art, music, physical education). Elementary teachers in Korea have fundamental abilities to teach elementary children.

• 아동학회지
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• 제21권4호
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• pp.243-257
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• 2000

This empirical test of the efficacy of the literature-based reading instruction was conducted with 63(31 male and 32 female) 2nd grade elementary school children. Subjects in the experimental group had 40-45 minutes literature-based reading instruction twice weekly; those in the control group had only basic text reading. Procedures included a pilot study, pre-test, experimental period, and post-test. Research instruments included the Basic Learning Skill Test(Park et al., 1988), the Qualitative Reading Inventory(Leslie & Caldwell, 1990), and the Elementary Reading Attitude Survey(Mckenna & Kear, 1990). Data were graded and scored by each research question and then analyzed with a t-test of differences between the groups. The experimental group showed higher word recognition, text comprehension, and story grammar strategies than the control group. They also showed more improvement in each of these categories than the control group.

• Restorative Dentistry and Endodontics
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• 제31권2호
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• pp.113-118
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• 2006

본 연구의 목적은 새로 시판된 NRT 기구의 근관 형태 유지 능력을 기존의 3종의 기구와 비교하는 것이다. 만곡된 레진 모형 근관을 ProFile, K3, ProTaper, NRT 기구를 이용하여 형성하였고 형성 전, 후의 상을 스캔한 후 중첩시켜 이미지 분석 프로그램을 이용하여 근관 만곡도의 변화와 근관 중심축에 대한 근관의 변이 정도를 근관 중심율의 변화로 계산하여 분석하였다. 근관 변이의 유의성 검정을 위해 one-way ANOVA분석을 시행하였으며 각 기구간의 유의성 검정은 Duncan's test로 사후 분석하였다. 근첨에서 1, 2 mm 상방 위치에서의 근관 중심율은 ProFile 군이 다른 군에 비해 우수한 것으로 나타났다. (p < 0.05). NRT기구의 근관 중심율 변화를 측정한 결과 근첨으로부터 5 mm 상방에서는 Profile에 비해서만 큰 것으로 나타났고 6, 7 mm 상방에서는 다른 모든 군들에 비해 큰 것으로 나타났다 (p < 0.05). 비록 NRT기구가 근첨 부위에서는 ProFile을 제외한 다른 기구에 비해 유의차 없는 중심률 유지 능력을 보였으나 근관 입구 및 중간부위의 형성에 사용되는 스테인레스-스틸 파일로 인해 coronal flaring시 다른 기구들에 비해 더 많은 중심률의 변화를 보이는 것으로 사료된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1854-1858
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• 2007

The reliability assurance with respect to the test procedure and results of the out-pile mechanical performance test for the nuclear fuel assembly is an essential task to assure the test quality and to get a permission for fuel loading into the commercial reactor core. For the case of vibration test, which is carried out to obtain basic dynamic characteristics of the fuel assembly, proper management and appropriate calibration of instruments and devices used in the test, various efforts to minimize the possible error during the test and signal acquisition process are needed. Additionally, the deep understanding both of the theoretical assumption and simplification cation for the signal processing/modal analysis and of the functions of the devices used in the test were highly required. Finally, to verify the test result to represent the accurate natural characteristics of the structure, the proper correlation analysis between the theoretical and experimental method has to be carried out. In this study, the overall procedure and result of lateral vibration test for the fuel assembly's mechanical characterization were briefly introduced. A series of measures to assure and improve the reliability of the vibration test were discussed.

• KSTLE International Journal
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• 제6권2호
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• pp.58-64
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• 2005

An OEM driven working group started in January 2004 to elaborate the philosophies, concepts and test procedures for testing piston ring and cylinder liner materials as well as engine oils outside the engine using the $SRV^{(R)}$ test equipment. The different $SRV^{(R)}$ test philosophies in use by OEMs are compiled. The working group focuses on a.) ASTM sequence VIB (Fuel economy by aging oils), b.) friction and wear in the top dead region under mixed/boundary lubrication, c.) extreme pressure load under mixed/boundary lubrication and d.) hydrodynamic friction. Tribological test result and precision data are presented.