• Journal of Mechanical Science and Technology
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• v.18 no.2
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• pp.246-252
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• 2004

The modal characteristics of rotating structures vary with the rotating speed. The material and the geometric properties of the structures as well as the rotating speed influence the variations of their modal characteristics. Very often, the modal characteristics of rotating structures need to be specified at some rotating speeds to meet their design requirements. In this paper, rotating cantilever beam is chosen as a design target structure. Optimization problems are formulated and solved to find the optimal shapes of rotating beams with rectangular cross section.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.252-255
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• 1999

Feed rate in the fed-batch reactor is the most important control variable in optimizing the reactor performance. Exact solution can be obtained only for limited cases of simple reactor. The complexity of the model equations makes it extremely difficult to solve fur the general class of system models. Evolutionary programming method is proposed to get the information of the profile types, and the final profile is calculated by that information. The modified evolutionary programming method is used to get the more optimal profiles and it is demonstrated that proposed method can solve a wide range of optimal control problems.

• Journal of Communications and Networks
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• v.14 no.3
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• pp.252-256
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• 2012

We consider resource allocation in femto-cell networks to maximize the throughput while minimizing interference to macro-users nearby. This can be achieved by allocating spectrum resource in a cognitive radio way. The proposed resource allocation is performed in two steps; spectrum sensing and resource scheduling. The femto base station detects idle frequency assignments (FAs) free from the occupation by macro-users and then allocates sub-channels in an idle FA to femto-users, effectively managing the interference problem. Finally, the effectiveness of the proposed scheme is verified by computer simulations.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.250-252
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• 2005

경영환경변화가 가속화되고 있는 이즈음, 마르게 적응하기 위한 인프라, 업무처리 생산성 향상, 내부의 역량강화, 경쟁력 확보 등에 기업들은 관심을 집중시키고 있다. 대기업을 중심으로 기술과 경영혁신으로 RTE(Real Time Enterprise)시스템에 대하여 본격 시도되고 있다. 그래서 기업들은 생존을 위하여 연속적인 성과 개선이 필요하다. 기존 조직구조와 시스템으로부터 할 수 있는 기술도구로서 BPM을 연구하였다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.252-254
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• 2001

A great deal of effort has been put into the identification of Alexandrium tamarense/fundyense/catenella complex by understanding correlation between morphological and subcellular characteristics. To date, the most promising tool for the study of these species is sequence analyses of rRNA genes that have been useful for various organisms' taxonomy and phylogeny, and its application such as in situ hybridization. (omitted)

• Journal of Korean Elementary Science Education
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• v.34 no.2
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• pp.252-263
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• 2015

This study analyzed the effects of science outdoor activity applying a Brain-Based Evolutionary (ABC-DEF) approach on elementary school students' interest and academic achievement. Samples of the study were composed of 3 classes of 67 sixth graders in Seoul, Korea. Unit of 'Ecosystem and Environment' was selected as a object of the research. Textbook- and teachers' guidebook-based instruction was implemented in comparison group, brain-based evolutionary approach within classroom in experimental group A, and science outdoor learning by a brain-based evolutionary approach in experimental group B. In order to analyze the quantitative differences of students' interests and achievements, three tests of 'General Science Attitudes', 'Applied Unit-Related Interests', and 'Applied Unit-Related Achievement' were administered to the students. To find out the characteristics which would not be apparently revealed by quantitative tests, qualitative data such as portfolios, daily records of classroom work, and interview were also analyzed. The major results of the study are as follows. First, for post-test of interest, a statistically significant difference between comparison group and experimental group B was found. Especially, the 'interests about biology learning' factor, when analyzed by each item, was significant in two questions. Results of interviews the students showed that whether the presence or absence of outdoor learning experience influenced most on their interests about the topic. Second, for post-test of achievement, the difference among 3 groups according to high, middle, and low levels of post-interest was not statistically significant, but the groups of higher scores in post-interest tends to have higher scores in post-achievement. It can be inferred that outdoor learning by a brain-based evolutionary approach increases students' situational interests about leaning topic. On the basis of the results, the implications for the research in science education and the teaching and learning in school are discussed.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.252-263
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• 2016

Road sign is an important street furniture that gives some information such as road conditions, driving direction and condition for a driver. Thus, road sign is a major target of image recognition for self-driving car, ADAS(autonomous vehicle and intelligent driver assistance systems), and ITS(intelligent transport systems). In this paper, an enhanced road sign recognition system is proposed for MMS(Mobile Mapping System) using the single camera and GPS. For the proposed system, first, a road sign recognition scheme is proposed. this scheme is composed of detection and classification step. In the detection step, object candidate regions are extracted in image frames using hybrid road sign detection scheme that is based on color and shape features of road signs. And, in the classification step, the area of candidate regions and road sign template are compared. Second, a Geo-marking scheme for geo-content that is consist of road sign image and coordinate value is proposed. If the serious situation such as car accident is happened, this scheme can protect geographical information of road sign against illegal users. By experiments with test video set, in the three parts that are road sign recognition, coordinate value estimation and geo-marking, it is confirmed that proposed schemes can be used for MMS in commercial area.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.252-257
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• 2011

Tests were carried out on domestic wood samples to modify the formula which had previously been developed to predict the withdrawal strength of screw on the face of lumber. Screw sizes were No. 6, 8 and 10 used in this study. Predicted equations were fitted to the results of different length of No. 8 wood screw. The withdrawal strength of screws was enabled to predicted as a function of screw diameter, depth of penetration, and specific gravity of wood. Predicted equation was under-predicted the withdrawal strength of 25 and 30 mm length of screw within 5% and over-predicted withdrawal strength of 18 and 38 mm length of screw.

• Journal of the korean veterinary medical association
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• v.14 no.4
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• pp.239-252
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• 1978

Two diotinot lymphomatous diseases occur in the field in domestic fowl: Lymphoid leukosis, which is caused by an oncornavirus and Marek's disease, which is caused by a herpesvirus. They are the most common neoplastic diseases of the chicken, and Marek's d

• Bulletin of the Korean Mathematical Society
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• v.45 no.2
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• pp.241-252
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• 2008

By means of a Riccati transform and averaging technique some oscillation criteria are established for perturbed nonlinear differential equations of second order $(P_1)\;(p(t)x'(t))'+q(t)|x({\phi}(t)|^{{\alpha}+1}sgnx({\phi}(t))+g(t,\;x(t))=0$ $(P_2)$ and $(P_3)$ satisfying the condition (H). A comparison theorem and examples are given.