• Communications of Mathematical Education
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• v.31 no.2
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• pp.103-121
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• 2017

Taxicab geometry was a typical non-Euclid geometry for mathematically gifted. Most educational material related quadratic curves on taxicab geometry for mathematically gifted served them to inquire the graph of the curves defined by focis and constant. In this study, we provide a shape of quadratic curves on taxicab geometry by applying three definitions(geometric algebraic definition, eccentricity definition, conic section definition).

• Communications of Mathematical Education
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• v.24 no.3
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• pp.659-689
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• 2010

Taxicab distance function is a practical distance notion which gives us information of real world pathway distance that really taxi can go through. As one of the non-Euclidean geometry, this study of an ideal city with all roads running horizontal or vertical, was introduced by the Russian Mathematician H. Minkowski and synthetically reported by the E. F. Kraus in 1986. After that, there were many reports and papers on this topic and still being researched. At this point of view, our research about taxicab geometry provides its differences from Euclidean plane geometry, and considers about several theorems on plane geometry using the taxicab distance function.

• Journal of Science Education
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• v.47 no.3
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• pp.263-272
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• 2023

We consider how a pre-service teacher can understand and utilize various concepts of Euclidean geometry by learning conic sections using mathematical definitions in non-Euclidean geometry. In a third-grade class of D University, we used mathematical definitions to demonstrate that learning conic sections in non-Euclidean space, such as taxicab geometry and Minkowski distance space, can aid pre-service teachers by enhancing their ability to acquire and accept new geometric concepts. As a result, learning conic sections using mathematical definitions in taxicab geometry and Minkowski distance space is expected to contribute to enhancing the education of pre-service teachers for Euclidean geometry expertise by fostering creative and flexible thinking.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.295-295
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• 1998

고속도로에서 교통류의 특성에 파악하여 교통류의 특성을 파악하여 동적행태로 교통상황을 분석하고 효과적인 제어전략, 시뮬레이션, 그리고 기하구조 개선등의 효율적이고 실용적인 적용을 위해서는 교통류의 정확한 모사가 필요하다. 시공간으로 표현되는 상태방정식을 포함하는 거시적 시뮬레이션 모델에 사용되는 연속류 모델은 이러한 교통류 특성을 모사하는데 적절하다. Lighthill과 Whitham(1955), Richard(1956)에 의해 일계도함수의 형태를 가지는 단순모델이 제시된 이후 모델의 결점을 보완하기 위해 많은 고계도 모델이 제시되었지만 고계도 모델이 가진 이론적인 결점에 대해서는 여러 연구들이 제시되어 있다. 또한 고계도 모델은 운동량 방정식의 유도, 정산, 구현의 어려움으로 널리 사용되기 힘들다는 단점을 가지고 있다. 만일 적절히 구현할 수 있다면 적용이 간단한 단순모델로도 보다 정확한 교통류 상황 모사가 가능하다. Ansorge는 혼잡교통류상황을 보다 정확하게 모사하기 위해 단순모델에 엔트로피 조건을 결합시킨 모델을 제시했다. Bui는 이 제안된 모델이 적절한 시뮬레이션 결과를 나타낸다는 것을 밝혔다. 그러나 이 모델은 차량의 재가속이 이루어지는 교통상황-stop-start wave의 경우 비현실적인 값을 가진다. 엔트로피조건에 의해 구해진 해는 실제보다 과다한 교통량을 추정하게 되는데 이런 결과는 위와 같은 교통상황에서 중요한 요소로 작용하는 가속효과가 무시되고 있기 때문이다. 따라서 본 연구에서는 stop-start wave 조건에서 가속도에 경계치를 부여하여 교통류율을 상한경계조건을 제시함으로써 교통상황에 맞는 교통류율을 산정하는 방법에 대해 제안하고자 한다.환승이라는 특정대안변수(Specific alternative variable)를 첨가하여 그것이 수단선택에 미치는 영향을 분석한다. 또한, 대중교통의 속성을 가지고 있는 지하철과 버스를 하나의 대안으로 묶어서 효용함수를 구한 다음 다시 승용차, 택시, 대중교통을 독립된 대안으로 두고 모형을 정립하는 NESTED LOGIT모형으로 파라메타를 추정하여 대중교통의 효용에 관해 분석·비교하였다. 본 논문에 이용된 자료는 공항을 이용하는 이용객들을 대상으로 직접 설문·면접조사한 자료이며 대상 교통수단은 승용차, 택시, 지하철, 버스로 설정하였다. 결과 적응형 알고리즘이 개개인의 최단시간 경로를 제공하는 사용자 평형 경로안내전략에 비해 교통혼잡도와 정체시간의 체류정도에 따라 3%에서 10%까지 전체통행시간을 절약할 수 있다는 결론을 얻었다.출발참, 구성대외개방선면축심, 실현국제항선적함접화국내항반적전항, 형성다축심복사식항선망; 가강기장건설, 개피포동제이국제기장건설, 괄응포동개발경제발전적수요. 부화개시일은 각 5월 26일과 5월 22일이었다. 11. 6월 중순에 애벌레를 대상으로 처리한 Phenthoate EC가 96.38%의 방제가로 약효가 가장 우수하였고 3월중순 및 4월중순 월동후 암컷을 대상으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was result

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.301-310
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• 2020

The purpose of paper is to find index for building digital database of bike infrastructure statistics by analyzing the existing design standards and manuals. The design standards and guides of both central and local governments which designates the design elements of bikeway were investigated to find the primary index, and then the attribute data of bikeway were grouped into four categories including transportation, geometry, pavement, safety and utility facility, and were analyzed to find the secondary index. A FGI(Focus Group Interview) was conducted with experts in the arena of transportation to collect the opinions on the selected index. It is found that the final twenty four design elements were selected and additional six elements were added. The proposed twenty four index of bikeway design elements are considered to be included when building the digital bikeway register database.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.1-17
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• 2018

Over the past five years (2010-2014), the total number of traffic accidents has decreased from 226,878 to 223,552 with decrease of 0.37 percent each year. The death toll has also decreased from 5,505 to 4,762. However, the number of rental car accidents and fatalities has been steadily increased. Despite of its growth, no previous study has been conducted on rental car accident severity. This study analyzed data of 18,050 rental car accidents in South Korea collected from 2010 to 2014 and then processed in order to identify which factors could affect the accident severity. Seventeen factors related to rental car accident severity were grouped into four categories: driver, vehicle, roadways and environment. As a result of the ordered probit model analysis, fourteen variables excluding age, intersection, and day of week were found to affect the severity of rental car accidents. The results of the study summarized as follows. First of all, violation of traffic regulations such as speeding increase the severity of rental car accidents. Secondly, rental accident severity is higher at curved sections of complicated roadway, which the driver's field of view is impaired. The results of this study can be used to reduce the severity of rental car accidents in transportation safety.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.3
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• pp.38-49
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• 2015

Seoul has 424 traffic fatalities in 2010 and 227 of them related to pedestrian crashes. In addition, it revealed that 40% of pedestrian fatalities occurred during jaywalking. Through the effective methods preventing jaywalking can save lots of people, and it can reduce social costs pertinent to pedestrian crashes. Therefore, this study is to suggest the methods preventing jaywalking through conducting literature reviews, human factors with pedestrian and vehicle characteristics, as well as geometric features of accident site or spot. Firstly, in order for examining the contributing factors of accident, this research conducts statistical analysis on pedestrian accidents specifically in jaywalking. Secondly, the analysis on human factors about pedestrian and drivers revealed that drivers with high speed play pivotal roles in pedestrian fatalities. Thirdly, Road and environment factors showed both expected and contradictory results through analyzing total numbers of lane or dry/icy pavement conditions. Consequently, this study can be used to prevent and alleviate pedestrian accidents as well as expected to be applied to future researches about pedestrian safety facilities.