• Journal for History of Mathematics
• /
• v.20 no.4
• /
• pp.61-70
• /
• 2007

Combinatorics, often called the 21 st century mathematics, has turned out a very important subject for the present information era. Modern combinatorics has started from some mathematical works, for example, Pascal's triangle and the binomial coefficients, and Euler's problems on the partitions of integers and Konigsberg's bridge problem, and so on. In this paper, we investigate the origin of combinatorics by looking over some interesting ancient combinatorial problems and some important problems which have started various subfields of combinatorics. We also discuss a little on the role of combinatorics in mathematics and mathematics education.

• Journal for History of Mathematics
• /
• v.27 no.3
• /
• pp.197-210
• /
• 2014

Species like insects and fishes have, in many cases, non-overlapping time intervals of one generation and their descendant one. So the population dynamics of such species can be formulated as discrete models. In this paper various discrete population models are introduced in chronological order. The author's investigation starts with the Malthusian model suggested in 1798, and continues through Verhulst model(the discrete logistic model), Ricker model, the Beverton-Holt stock-recruitment model, Shep-herd model, Hassell model and Sigmoid type Beverton-Holt model. We discuss the mathematical and practical significance of each model and analyze its properties. Also the stability properties of stationary solutions of the models are studied analytically and illustratively using GSP, a computer software. The visual outputs generated by GSP are compared with the analytical stability results.

• Journal of Educational Research in Mathematics
• /
• v.18 no.1
• /
• pp.51-62
• /
• 2008

In the 7th-curriculum, only basic arithmetics of complex numbers have been taught. They are taught formally like literal manipulations. This paper analyzes mathematically essential relations between algebra of complex numbers and plane geometry. Historical analysis is also performed to find effective methods of teaching complex numbers in school mathematics. As a result, we can integrates this analysis with school mathematics by help of Viete's operations on right triangles. We conclude that teaching geometric interpretation of complex numbers is possible in school mathematics.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.623-629
• /
• 2007

In the study of Art History and Archaeology, the paintings, sculptures, relief, and applied arts provide a vivid description of religious and historical events and everyday life. Through these descriptions it is possible to gain a greater understanding of things such as the customs, culture, and architectural styles of that period. However, if Art History and Archaeological images are very old, distorted or underexposed, it is difficult to analyze them. Using Levels and Curves is one way to tonally correct professional photographs. It is an effective method for tonal correction because of the exact numeric values which are calculated and displayed as the image is adjusted. In this paper, the usefulness of this method for correcting a distorted archaeological image was examined.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.9 no.1
• /
• pp.137-152
• /
• 1998

The purpose of this study was to review today's development trends of library bibliographic instruction through historical assessment of U.S. university library bibliographic instruction development pattern. And the results of this study may be used in implementing the university library bibliographic instruction program in Korea. The major conclusions of this study are summarized as follows: . The bibliographic instruction had been affected by changing trend of higher education. . Early leaders had been understanding of higher education and were active in the library organization. . Related books and articles were much published continuously. . Library professional organizations supported and assisted these effort. . Received financial aid from the government and non-profit organization. . Effective educational techniques were developed. . Implemented computer-aided education together with audio-visual technique.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.5
• /
• pp.241-250
• /
• 2021

This study reviewed details and case studies of district unit planning to preserve and develop urban tissues concerning a historic urban environment and provide implications for future practice. In particular, this case study examined the role of the district unit planning in city conservation rooted in the experience of Incheon's old town. The old town begins with the opening of Incheon Port and concessions, including Japanese, Qing Dynasty, and multinational settlements. Second, the study established land subdivision planning and reviewed the institutions to encourage urban tissue. Third, the conservation guidelines influenced the conservation and utilization of the streets, such as alleys and old coastlines, the form of parcels called deep and narrow lots, and the exterior elements of buildings. This study also derived implications for the future. First, the street with historical value in the settlement should be excavated further. Second, the parcels in the settlement limit redevelopment to maintain the unique morphological characteristics. Third, the exterior of the buildings should be provided with planning incentives to induce conservation and utilization.

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.251-254
• /
• 2002

Poly(ethylene 2,6-naphtalenen dicarboxylate)(PEN)에 관한 연구는 1948년 Cook 등에 의해 처음으로 PET의 benzene ring을 naphthalene ring으로 대체하는 새로운 합성방법이 보고되었다[1]. 그 역사는 비교적 오래 되었지만 1980년대까지 PEN의 구조에 관한 연구는 거의 이루어지지 않았다. 그러나 1980년대 후반이 되면서 소위 "high performance polymers"에 관한 관심의 증가로 매우 좋은 기계적 물성과 열 안정성을 가지고 있는 PEN은 매우 중요한 소재로 인식되었다[2]. (중략)

• Tribology and Lubricants
• /
• v.12 no.3
• /
• pp.26-32
• /
• 1996

오랜 역사에 걸쳐 연구자들은, 마찰력은 주로 접착에 의한 것으로 믿어 왔으며, 이러한 주장은 실험적으로 증명되지 못했다. 한편, 미끄럼 두 표면 사이의 건식 마찰력은 두 표면 사이의 기계적인 상호작용에 의한 것으로 알려져 있다. 이 연구에서는 두 표면 사이의 기계적 상호작용을 제거함으로써 마찰계수를 감소시키는 방법을 제시하였다. 매끄러운 경한 표면에 얇은 elastomer층을 입힌 비윤활 최소 마찰계수에 대한 본 실험결과는 앞으로 정밀기계부품의 충격을 받는 부위에 응용할 수 있을 것으로 기대된다.

• Proceedings of the Korea Contents Association Conference
• /
• 2004.05a
• /
• pp.109-120
• /
• 2004

As the Korea history have developed and media have changed, Korea commercial animation assumes different aspects, formative and technical image from production method. But, both will advance suit each characters base on good point and characteristic of Korea commercial animation.

• Journal of the Korean Professional Engineers Association
• /
• v.16 no.1
• /
• pp.4-12
• /
• 1983

Data communication has historically evolved from leased lines, to use of the public telephone network, and eventually to dedicated(exclusive) data networks. It requires an enormous amount of money for establishing a separate and independent data network at the beginning stage. No country has ever adopted this method In the Republic of Korea too the age of leased circuits is passing and it is scheduled to open the public telephone network to the data transmission and to install packet mode processor in the last half of 1983. This paper presents a survey on characteristics of the public telephone network in Seoul and a future development of the data communication of Korea.