• Journal for History of Mathematics
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• v.29 no.3
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• pp.173-190
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• 2016

Luca Pacioli was a Franciscan friar, a prolific writer, a devoted teacher, a mathematician and a close friend of Leonardo da Vinci. He is also known to be the"father of accounting". He is best remembered for his two books on mathematics: "Summa de Arithmetica Geometria Proportioni et Proportionalita" and "De divina proportione". These two books, which were printed in the field of mathematics for the first time by using Gutenberg's printing technology, contributed to the development of mathematics in Europe. In this paper, we investigate various aspects of his life and mathematical contribution of Pacioli based on these two books.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.101-102
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• 2016

본 논문에서는 차량의 특징점들 사이의 간격과 크기의 비례식으로 자동차의 차종을 식별하는 방법을 제시한다. 자동차 관련 영상은 그 편의성을 위하여 기본 RGB모델에서 Gray색상 모델로 변환시켜 사용한다. 자동차의 배경 제거는 Canny Edge Direction을 통하여 수행하고 외곽선 검을을 통하여 원하는 특징 점을 얻는다.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.133-143
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• 2007

Previous studies on the transit assignment hardly show its achievement in research but have many limitations not only in theory but also in practice. This paper presents an integrated transit assignment model taking into account cost functions of multiple modes, such as auto, bus and subway, which represent an integrated network. An integrated transit network including cost functions and in-vehicle congestion needs to be developed. In addition, a link fare calculation model needs to be developed and applied to the model to calculate path travel costs. Based on these sub-models, a path-based traffic assignment model, which considers in-vehicle congestion and an integrated distance-based fare system in the integrated traffic network, is developed.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.101-108
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• 2004

The new transit fare in the Seoul Metropolitan is basically determined based on the distance-based fare system (DBFS). The total fare in DBFS consists of three parts- (1) basic fare, (2) transfer fare, and (3) extra fare. The fixed amount of basic fare for each mode is charged when a passenger gets on a mode, and it proceeds until traveling within basic travel distance. The transfer fare may be added when a passenger switches from the present mode to another. The extra fare is imposed if the total travel distance exceeds the basic travel distance, and after that, the longer distance the more extra fare based on the extra-fare-charging rule. This study proposes an algorithm for finding minimum fare route in DBFS. This study first exploits the link-label-based searching method to enable shortest path algorithms to implement without network expansion at junction nodes in inter-modal transit networks. Moreover, the link-expansion technique is adopted in order for each mode's travel to be treated like duplicated links, which have the same start and end nodes, but different link features. In this study, therefore, some notations associated with modes can be saved, thus the existing link-based shortest path algorithm is applicable without any loss of generality. For fare calculation as next steps, a mathematical formula is proposed to embrace fare-charging process using search process of two adjacent links illustrated from the origin. A shortest path algorithm for finding a minimum fare route is derived by converting the formula as a recursive form. The implementation process of the algorithm is evaluated through a simple network test.

• Journal of the Korean Magnetics Society
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• v.4 no.3
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• pp.249-255
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• 1994

Magneto-optical disks with dielectric layers for optical tunning are useful for maximizing the SNR. We have developed a computer program based on characteristic matrix to investigate the best combination of the film thicknesses. We have optimized the thicknesses of the multilayers which were composed of TbFeCo, dielectric, and AI layers at the wavelengh of 830nm. The criterion for the optimization of the film thickness was to maximize the figure of merit with maintaining the low ellipticity and rmre than 10% reflectivity.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.673-675
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• 2011

본 연구에서는 매립 구간의 길이가 유도초음파 신호 강도에 미치는 영향을 분석하였다. 유도초음파 모드 해석을 통해 가진 모드와 주파수를 결정하였으며, 유도초음파의 가진 및 수진은 경사각 입사 방식의 Pitch-Catch 법을 이용하였다. 또한, 비 매립된 배관에서 유도초음파 신호를 획득하여, 이를 기준으로 매립된 배관에서 획득한 유도초음파 신호를 분석하였다. 실험 결과 매립 구간의 길이가 유도초음파의 신호 강도에 매우 큰 영향을 미칠 뿐만 아니라, 매립 구간의 길이와 신호 강도의 변화가 선형 비례적인 관계를 보이지 않는다는 것을 확인할 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.107-108
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• 2016

Our study proposes the methods of distinguishing vehicle types using the interval and size of the car. The car videos converts the basic RGB model to Gray model for use and through Canny Edge Direction, it eliminates the background of the car while obtaining feature points through the detection of contours.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.488-489
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• 2019

We propose a method to identify vehicle type by the formula of distance between feature points of vehicle and proportional rate of size. Car images are converted from the basic RGB model to the gray color model. Perform Canny Edge Direction to remove the background image of the car. The desired feature points are obtained through contour extraction.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.165-173
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• 2013

The purpose of this study was to investigate the effects of customer's innovation and usefulness on the use intention of Service Robots by potential customers. Based on Davis(1989)'s Technology Acceptance Model, this study formulated three hypotheses, which were about relationships between customer's innovation, usefulness, and use intention of Service Robots. For this study, structured questionnaires were used and data were collected from the 171 people in Seoul and Cheonan. To test three hypotheses, collected data were analyzed using hierarchical regression technique. The results showed that customer's innovation has no influence on usefulness, whereas customer's innovation and usefulness have effects on use intention.

• The Korean Journal of Rheology
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• v.11 no.2
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• pp.67-72
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• 1999

A magneto-rheological(MR) fluid based rotary loading and braking device is developed. The loading and braking forces of the device are accurately adjustable by controlling the yield stress of MR fluid, so that the vibration control, the precision position control and the speed control of rotating machines equipped with the device can be achieved. As an engineering application, constant rotational speed regulation is conducted using the device manufactured in laboratory, introducing PI control action not only with varying torque due to gravitation, with initial angular speed, but also with constant external torque made by hand. To do this, first, mathematical model was obtained via experiments. And then, simulation was carried out, based on the experimentally identified model. Its result was confirmed through experiment. It is identified by simulation and experimental results that PI action leads to satisfactory control performance in both cases that varying torque due to gravitation, with initial angular speed, and constant external torque are applied.