• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.26.3-26
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• 2001

Van de Vusse reactor is known as a highly nonlinear chemical process and has been considered by a number of researchers as a benchmark problem for nonlinear chemical process. Various identification methods for nonlinear system are also verified by applying these methods to Van de Vusse reactor. From the point of view of identification, only the Volterra kernel of second order has been obtained until now. In this paper, the authors show that Volterra kernels of nonlinear Van de Vusse reactor of up to 3rd order are obtained by use of M-sequence correlation method. A pseudo-random M-sequence is applied to Van de Vusse reactor as an input and its output is measured. Taking the cross correlation function between the input and the output, we obtain up to 3rd order Volterra kernels, which is ...

• 한국전자거래학회지
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• 제5권2호
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• pp.127-142
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• 2000

Lately, electronic commerce through the Internet has been rising in attention. An important element in such commerce is EDI. EDI is mainly used with VAN but its use is not common due to the high cost of EDI transfer. Thus, only large corporations with frequent use of EDI are able U benefit from it, To smaller companies that have small usage, EDI is becoming a burden. Considering this fact as well as current changes within the enterprise environment, it is apparent that a new generation of EDI is required. To resolve the problems of VAN EDI, the proposed Internal EDI was implemented. Internet EDI deals with the use of the widely spread Internet instead of VAN. By using Internet EDI, it is possible to reduce the high cost that came when using VAN. There would be no extra transfer cost since transmission will be done through the Internet. Also, electronic commerce that is mostly used today between an individual and a company may grow to become a true electronic commerce between companies.

• 한국해안해양공학회지
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• 제15권3호
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• pp.186-189
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• 2003

방파제 피복석의 중량 산정을 위하여 여러 가지 경험식들이 개발되어져 왔다 Hudson 식은 많은 결함이 있음에도 불구하고, 형태가 간결하기 때문에 가장 널리 사용되고 있다. van der Meer 식은 가끔 크로스체크 용으로 사용되고 있지만, 식의 복잡성과 관련 변수들의 불확실성 때문에 아주 널리 사용되지는 않고 있다 한편 최근에 유(2003)는 'action slope'라는 새로운 무차원수를 사용하여 형태가 간결한 식을(이후 Yoo 식이라고 부름) 제안하였다. 본 연구에서는, 해안공학 기술자들에게 이 공식들의 사용에 대한 판단 기준을 제공하기 위하여, van der Meer가 1987년과 1988년에 보고한 실험 자료와 비교하여 이들의 정밀도를 평가하였다. 검토 결과, van der Meer 식이 가장 높은 정밀도를 보였으며, Hudson 식은 정밀도가 매우 낮아서 사용에 신중을 기해야 하는 것으로 나타났다. 한편, van der Meer 식보다 정밀도가 약간 낮기는 하지만 형태가 간결한 Yoo 식은 안전율을 약간 높게 잡으면 실무에 사용해도 무방한 것으로 판단된다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제18권2호
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• pp.103-128
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• 2014

This paper presents the Global van Hiele (GVH) questionnaire as a tool for mapping knowledge and understanding of plane and solid geometry. The questionnaire facilitates identification of the respondents' mastery of the first three levels of thinking according to van Hiele theory with regard to key geometrical topics. Teacher-educators can apply this questionnaire for checking preliminary knowledge of mathematics teaching candidates or pre-service teachers. Moreover, it can be used when planning a course or granting exemption from studying in basic geometry courses. The questionnaire can also serve high school mathematics teachers who are interested in exposing their students to multiple-choice questions in geometry.

• Journal of Microbiology
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• 제39권2호
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• pp.116-120
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• 2001

The prevalence resistance genotype and antibiotic susceptibility of vancomycin-resistant enterococci (VRE) were determined. Prevalence of VRE in chickens, healthy children and intensive care unit (ICU) patients was 43.0%, 12.7% and 24.1%, respectively. Forty out of 56 isolates from chicken intestines were identified as Enterococcus faecium, and 12 were E. faecalis. All the isolates contained the vanA gene. Nine out of 13 VRE isolates from patients and two out of 21 from healthy young children were identified as E. faecium. The resistance types of E. faecium, E. gallinarium and E. casseliflavus were VanA, VanCl, and VanC2, respectively. The minimum inhibitory concentrations (MICs) of E. faecium, E. gallinarium, and E. casseliflavus to vancomycin were 512,8 and 4 g/ml, respectively. Specifically, E. faecium isolates were resistant to most of antibiotics except ampicillin and gentamicin. This is the first report of high VanA type VRE prevalence in nonhospitalized young children in Korea.

• 호남수학학술지
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• 제45권4호
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• pp.655-667
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• 2023

In this paper, we study quasi-Sasakian 3-dimensional manifolds admitting generalized 𝜂-Ricci solitons associated to the Schouten-van Kampen connection. We give an example of generalized 𝜂-Ricci solitons on a quasi-Sasakian 3-dimensional manifold with respect to the Schouten-van Kampen connection to prove our results.

• 한국학교수학회논문집
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• 제22권3호
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• pp.257-275
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• 2019

로봇은 4차 산업혁명 시대를 대표하는 테크놀로지로, 미래를 살아갈 학생들은 로봇을 유연하게 다룰 수 있는 역량을 갖출 필요가 있다. 따라서 로봇을 학교 수업에 효과적으로 도입하기 위한 교수학적 연구가 요구되며, 특히 로봇을 활용한 문제해결에서 필수적이라 할 수 있는 수학에 초점을 두어 로봇을 활용한 수업을 어떻게 설계하고 평가할 것인지에 대한 연구가 이루어질 필요가 있다. 본 연구는 이를 위한 기초 연구로, 로봇 활동의 수준을 정의하고자 시도하였다. 이를 위하여 학생의 학습 수준에 대한 대표적 연구인 Van Hiele의 기하 학습 수준 이론을 시작점으로 설정했으며, LEGO 마인드스톰 활동 수준을 설정하기 위한 매개로 LOGO를 선택하였다. Olson et al.(1987)의 연구에서는 Van Hiele의 기하학습 수준에 대응하는 LOGO 활동 수준을 정의했는데, 본 연구에서는 LOGO와 LEGO 프로그래밍의 태생적인 유사점에 주목하여 Van Hiele의 기하 학습 수준에 따른 LOGO 활동 수준에 LEGO 마인드스톰 활동 수준을 연계하여 로봇을 활용한 수학 수업에서의 활동 수준을 분석하고 정의하였다.

• 한국기계가공학회지
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• 제7권4호
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• pp.115-120
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• 2008

The fatalities of pedestrian accounted for about 40.0% of all fatalities in Korea (2005 year). In pedestrian involved accident, the most important data to inspect accident is throw distance of pedestrian. The throw distance of pedestrian can be influenced by many variables, such as vehicular frontal shape, vehicular impact speed, the offset of impact point, the height of pedestrian, and road condition. The trajectory of pedestrian after collision can be influenced by vehicular frontal shape classified into sedan type, box type, SUV type and van type. Many studies have been done about pedestrian accident with passenger car model and bus model for simple factors. But the study of pedestrian accident by van type vehicle was much insufficient, and even that the influence of multiple factors such as the offset of impact point was neglected. In this paper, a series of pedestrian kinetic simulation were conducted to inspect relationship between throw distance and multiple factors with using PC-CRASH s/w, a kinetic analysis program for a traffic accident for van type. By based on the simulation results, multi-variate regression was conducted, and regression equation was presented.

• International Journal of Internet, Broadcasting and Communication
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• 제15권1호
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• pp.113-119
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• 2023

This research analyzed the importance and influence of color expression on psychological and emotional changes of visual perception in the creation of art works. This research takes the element of the sky in the works of Vincent William Van Gogh, a Dutch post-Impressionist representative painter, as the basic research objective to prove the influence of color expression of the same thing on the inner emotional communication of the creator. After synthesizing the contents of previous research and investigation on Van Gogh, this research will summarize the works containing sky elements in Van Gogh's works according to his four creative stages, and select representative works for color analysis and comparison. In this paper, by comparing the colors of the same elements of the sky, we can find Van Gogh's guidance of psychological and emotional changes through the expression of colors in his works, which will play a certain inspiring role in the creation of painting art.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권4호
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• pp.229-245
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• 2015

In this study, I investigated how pre-service teachers (PSTs) proved three geometric problems by using Geometer's SketchPad (GSP) software. Based on observations in class and results from a test of geometric reasoning, eight PSTs were sorted into four of the five van Hiele levels of geometric reasoning, which were then used to predict the PSTs' levels of reasoning on three tasks involving proofs using GSP. Findings suggested that the ways the PSTs justified their geometric reasoning across the three questions demonstrated their different uses of GSP depending on their van Hiele levels. These findings also led to the insight that the notion of "proof" had somewhat different meanings for students at different van Hiele levels of thought. Implications for the effective integration of technology into pre-service teacher education programs are discussed.