Data mining and game sounds classification prerequisite to find a compact but effective set of features in the overall problem-solving process. As a preprocessing step of data mining, feature selection has tuned to be very efficient in reducing its dimensionality and removing irrelevant data at hand. In this paper we cast a feature selection problem on rough set theory and a conditional entropy in information theory and present an empirical study on feature analysis for classical instrument classification. An new definition of a significance of each feature using rough set theory based on rough entropy is proposed. Our results suggest that further feature analysis research is necessary in order to optimize feature selection and achieve better results for the musical instrument sound classification problem through Weka’s classifiers. The results show that the performance of the best 17 selected features among 37 features has 3.601 compared to 2.332 in standard deviation and 94.667 compared to 96.935 in average with four classifiers.

본 연구는 유아들에게 악기연주의 기초가 되는 신체악기, 무선율 타악기 연주를 통하여 악기연주 능력과 창의적인 표현능력을 증진시킬 수 있는 효과적인 악기연주의 지도방법을 제시하는 데 목적이 있다.이를 위해 문헌을 중심으로 유아의 악기연주 능력 발달단계를 고찰하고 악기연주 지도에 관한 Orff의 이론을 기초로 하여 유아기 악기연주의 교수방법과 프로그램을 단계별로 제시하였다.악기연주 프로그램은 단계별로 신체 타악기, 신체 타악기 Ostinato, 무선율 타악기, 무선율 타악기 Ostinato를 제시하였다. 신체 타악기에서는 ‘박자’를 제시하였으며 신체 타악기 Ostinato에서는 ‘신체’, ‘말하기’를 제시하였다. 또한 무선율 타악기에서는 ‘모방’, ‘동화’를 제시하였으며 무선율 타악기 Ostinato에서는 ‘합주’를 제시하였다.악기연주 프로그램을 현장에 적용하기 위해서는 유아에게 적절한 음악환경을 제공하고 신체 타악기와 무선율 타악기를 활용한 단계적이고 체계적인 악기연주가 이루어져야 한다. 또한 악기연주 지도 자료가 현장에 보급되어야 하고 유아교사 자신이 악기연주 능력을 계발하기 위한 노력이 필요하다.

The current standard solutions for somatic cells used for calibration of electronic somatic cell counts as reference material in raw milk are preserved with bronopol, boric acid, sodium azide, or potassium dichromate, and have a shelf-life of only up to 6 days at 4 ± 2℃. In the present study, a set of somatic cell standard solutions (SCSS) with a stability of 5 months for calibration of electronic instruments was developed. Somatic cells collected from cow’s milk and stored in a bulk tank at a dairy plant were treated with 10% formaldehyde in order to improve stability, and then separated by centrifugation. The resulting somatic cell suspension was preserved with glycerin, thimerosal, and dimethyl sulfoxide, and diluted in 3% processed skim milk solution ranging from 200,000～250,000 (low level), 350,000～ 450,000 (medium level), and 550,000～650,000 (high level) cells/㎖. Each SCSS was verified by direct microscope somatic cell counting (DMSCC), C-reader, and commercial standard samples. The average somatic cell count determined by DMSCC was 248, 214, 226 × 103 cells/㎖, 436, 382, 420 × 103 cells/㎖, and 612, 595, 609 × 103 cells/㎖. The coefficient of variation representing the repeatability of DMSCC decreased as the number of cells increased, and was <10.0% in almost all SCSS samples (range 4.6～7.1%). No statistically significant difference in somatic cell concentration was observed after storage at refrigeration temperature (2～6℃) over a period of 22 weeks (5 months). The stabilized SCSS may be useful as a reference material for determination of somatic cell count and quality control in testing of bovine raw milk.

The Ganui (簡儀, simplified armillary sphere) is a representative of astronomical instruments in Joseon Dynasty of Korea, as well as Yuan Dynasty and Ming Dynasty of China. In early 15th century, Joseon's scientists and engineers uniquely developed the Soganui (小簡儀, small simplified armillary sphere) and the Ilseongjeongsiui (日星定時儀, sun-and-star time determining instrument) from the structural characteristic of Ganui. These two astronomical instruments had a new design by the miniaturization and felt convinced a similar performance of Ganui in the harmony with Korean Astronomy and Astrology Cultures. Since mid-18th century after the enforcement of shixian-li (時憲曆), the Soganui and Ilseongjeongsiui handed over the Jeokdogyeongwiui (赤道經緯儀, equatorial armilla) by a change of the observational framework such as the time and angle measures. The Jeokdogyeongwiui made by Gwansanggam (觀象監, Bureau of Astronomy in Joseon Dynasty) adopted the new observational framework. We studied the structural characteristics and scientific values of these 3 astronomical instruments with theirs observation methods.

Current instrumentation activities and the open user status of Okayama Astrophysical Observatory (OAO) are reviewed. There are two telescopes in operation and one telescope under reforming at OAO. The 188cm telescope is provided for open use for more than 200 nights in a year. The typical over-subscription rate of observation proposals for the 188cm telescope is ~ 1.5 - 2. The 50cm telescope is dedicated to ɤ-ray burst optical follow-up observation and is operated in collaboration with Tokyo Institute of Technology. The 91cm telescope will become a new very wide field near-infrared camera in two years. The high-dispersion echelle spectrograph (HIDES) is the current primary instrument for the open use of the 188cm telescope. Two new instruments, an infrared multi-purpose camera (ISLE) and an optical low-dispersion spectrograph (KOOLS), are now under development. They will be open as common use instruments in 2006.

어군탐지기, 계량어군탐지기, 바이오텔레메터리등 음향을 이용하여 해중의 어군의 정보를 탐색하는 수산음향계측장치의 탐지범위와 그 음향특성에 대해 검토, 분석할 결과를 요약하면 다음과 같다. 1. 탐지범위는 송 · 수파기 직경, 송파음의 강도의 증가와 함께 저주파로 이동하여 어군탐지기의 경우 20~50kHz, 바이오텔레메터리의 경우 40~80kHz에서 최대치를 나타내었다. 2. 탐지거리는 주파수의 증가와 함께 증가하였지만, 고주파에서는 흡수계수의 영향으로 급격하게 감소하였다. 즉, 송 · 수파기 직경, 송파음의 강도, TS의 증가 효과는 저주파에서는 크고 고주파에서는 적은 경향을 나타내었다. 3. 바이오텔레메터리에서는 어군탐지기와 같은 송파의 지향성 이득을 얻을 수 없기 때문에 탐지체적의 최대치가 수파기의 직경과 함께 미소하게 감소하였다. 4. 탐지범위는 주파수 특성에 의한 어군탐지기의 음향산란신호를 분석하건, 수산음향계측장치의 설계 및 성능평가에 유효하게 사용될 수 있다.

The characteristics of the BOES (Bohyunsan Observatory Echelle Spectrograph) CCD camera is presented. In order to get optimum gain and readout noise of the CCD, we examine the variation of the gain and readout noise by changing the value of output drain voltage of the CCD and measuring the gain using transfer curve, which is defined as the plot of variance versus mean exposure level of a homogeneous light onto the CCD surface. The gain and readout noises are optimised to be 0.5e −/ADU and 3e−, which is good for highest signal-to-noise ratio and contrast for the low light level characteristics of the BOES. We also measure the dark count of the CCD by getting five dark images with 3600 seconds exposure time. The mean dark count from median stacked dark images is essentially zero. A table of positions of defected pixels is also presented.

A CCD camera for the BOES (Bohyunsan Observatory Echelle Spectrograph) has been developed. The camera consists of a 2048 × 4096 format CCD, a SDSU Gen-I CCD controller, and a continuous flow cryostat (CFC) designed by the ESO. In order to control the CCD under SDSU Gen-I controller, the voltage level of all the biases and clocks were lowered by -6V. The CFC showed cooling time of about 10 hour, after which the chip temperature settled down with variation less than ±1°C. The final chip temperature is around -105 °C with the setting value for the CFC as -170 °C

최근 개발 도입되고 있는 첨단항해계기와 관련된 새로운 기술, 관련 국제기준과 세계주요해양대학의 항해계기 관련 교육현황을 분석하였다. 그리고, 분석결과를 바탕으로 새로운 전자항해교육을 위한 교과목의 세부 요목을 제시하였다. 이것은 시대적 흐름을 반영한 해기교육과정의 편성과 해기면허시험의 세부요목을 설정하는데 참고 자료로서 충분히 활용할 수 있을 것이다.

The investigation of the space environment requires the use of experimental and theoretical tools and resources in order to perform the research task. Understanding of these research tools is imperative for proper interpretation of the results. In this paper, we discuss on research tools that are widely used in the field of aeronomy; Fabry-Perot interferometer and Michelson interferometer. These instruments have been used extensively as passive optical devices, spectrally monitoring the natural atmospheric emissions (airglow). This function has made both instruments valuable tools in upper atmospheric studies since they provide the ability to determine the dynamic and thermodynamic properties of the upper atmosphere by monitoring naturally-occuring emission.