• School Mathematics
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• v.15 no.4
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• pp.847-866
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• 2013

The purpose of this study was to analyze students' various solution methods revealed in the lessons of finding out the area of plane figures, and to explore instructional implications on how to draw meaningful formalization out of such multiple methods. The teacher in this study tended to select a few solution methods that were easy for students to understand and to induce formalization. An analysis of students' solution methods and the process of formalization showed that students need to understand what parts of the length of the given plane figure they should know, and to identify the base, height, and diagonal line of the figure. The analysis also showed that it was effective to choose the solution methods that were used by many students and that could be easily transformed into a concise formula. Based on these results, this paper provides instructional suggestions for a teacher to orchestrate classroom discussion toward formalization based on students' multiple solution methods.

• Elastomers and Composites
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• v.49 no.2
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• pp.134-143
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• 2014

Polymers are introduced to neat asphalt to prepare self-healing asphalt. The polymers are Surlyn, Nylon and polyethyleneterephtalate(PET). Since they are known as having high intermolecular force, they have high processing temperature. Therefore they are hardly introduced into the asphalt as bulk state. So in this study, they are introduced as solutions. Polymer-modified asphalts showed excellent modification effect and also healing effect. 5% polymer added asphalt showed more than 18% increased tensile strength. This tensile strength increment can be explained by polymer's intermolecular forces. Especially Surlyn interacts with asphalt molecules by hydrogen bonding and also with metals in asphalt by ionic bonding. When it comes to healing aspect the healing efficiency of Surlyn increased to 138% based on tensile strength. That of PET increased to 141% based on complex modulus and in case of Nylon it increased to 131% based on impact strength. This tells that in dealing with healing efficiency the important considering factors are not only the intermolecular forces of the polymers but also the interaction between the polymer and asphalt molecules.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.205-205
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• 2019

우리나라에서 강우의 시간분포를 위해 보편적으로 사용되고 있는 방법은 Huff 4분위법으로 강우의 시간적 분포특성을 나타내는 무차원 시간분포곡선을 제시한 것으로, 강우의 지속기간을 4분위로 구분하여 각 분위의 강우량 중 가장 큰 값이 속해 있는 구간을 선택하여 그 구간의 위치에 따라 분위를 정하는 방법이다. 현재 실무에서는 Huff의 분위별 곡선에 대한 회귀식은 지속기간 전반에 걸쳐 정확도가 높은 이유로 6차식을 적용하고 있으나, 통계 모델링에서 간결함의 원리에 따라 회귀식이 간결할 필요가 있으며, 통계적 유의수준에 기초하여 회귀계수를 결정하여야 하므로 유의성 검정 방법을 통한 검정결과를 비교할 필요가 있다. 따라서 본 연구에서는 다중회귀분석 방법에 따른 회귀계수 유의성 검정결과 비교를 위하여 구미지역의 무차원 누가우량 백분율을 이용한 시간분포 회귀식을 이용하여 유의성 검정 방법인 분산분석 방법(Analysis of Variance)과 변수선택 방법(Backward Selection)의 검정 결과를 도출 및 비교하였다. 통계프로그램인 프로그래밍 R을 이용하여 변수선택 방법 중 후방제거법 함수를 이용하여 최종 회귀식을 도출하고 또한 7차 회귀식을 분산분석을 이용한 후방제거법으로 회귀계수를 제거하는 방법으로 최종 회귀식을 산정하였다. 분산분석을 이용한 후방제거법의 유의성 검정결과는 프로그래밍 R을 이용한 후방제거법의 결과와 동일한 것으로 분석되었다. 일반적으로 설계강우량의 시간분포를 위한 방법으로 사용되고 있는 Huff의 4분위 방법의 시간분포 회귀식은 회귀계수의 유의성 검정이 이루어지고 있지 않으므로 본 연구결과를 통해 설계강우량 시간분포 회귀식의 유의성 검정방법 제시 및 결과도출과정을 통해 시간분포 회귀식 산정기법으로 활용할 수 있을 것으로 사료된다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.298-300
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• 2003

최근의 임베디드 시스템 분야에서 실시간 운영체제를 탑재하여 개발 된 제품들이 점차 늘어 증가하는 추세이다. 실시간 운영체제는 다른 범용 운영체제와는 달리 시간 결정성을 보장하는 운영체제이다. 그리고 실시간 운영체제를 포함하는 임베디드 시스템은 특정 목적을 위해 간결하게 만들어지기 때문에 한정된 자원을 효율적으로 사용해야 한다. 본 논문에서는 실시간 운영체제 iRTOS$^{TM}$에서 태스크의 우선순위를 64 에서 256 으로 확장하면서 발생하는 메모리의 낭비를 줄이는 스케줄링 방법을 설계하고 구현한 내용을 설명한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.160-166
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• 2018

This paper proposes an advanced suspension system and reports its performance in the framework of the preview control algorithm based on the RPS (road profile sensing) system and MSD system with the multi-stage damping characteristics. Typical disturbance inputs that cause excessive vibration and steering instability of an automobile are irregular obstacles that protrude or sink into the road surface to be driven. The control performance can be improved if information on the existence and shape function of its obstacle is known. Based on the results of the previous study, advanced research that uses the actuating system has been processed to be commercialized practically. For this purpose, a switching algorithm between the control logic and the multi-stage damping system was developed and its connectivity is presented. To verify the applicability of an actual vehicle, the proposed control system was implemented in full vehicle models and simulations were performed. The proposed system using the 3-DS actuator system, which is applied for structural simplicity, can improve the ride comfort and steering stability. In addition, the results indicate the feasibility of the intelligently controlled suspension system.

• Journal of Global Scholars of Marketing Science
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• v.15 no.3
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• pp.93-116
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• 2005

This study explored factors affecting consumer's external information search effort on online shopping malls through three approaches(cost-benefit approach, psychological motivation approach, and web-site theory approach) respectively, and designed the integrative model through searching the relationships among them. In this study search motivation are designed to be explained by search benefit and search cost that are explained by factors related to the web site and search efforts are designed to be explained by search benefit, search cost and search motivation. The results from our empirical research showed that search motivation, search benefits and prior knowledge on online shopping malls have a direct effect on consumer external information search effort. On the other hand, it was verified that the search motivation was affected by search benefits and purchase involvement, and the search benefits are directly influenced by purchase involvement, constructive simplicity, search convenience and trust. In addition, purchase involvement, time press, constructive simplicity and search convenience had direct effects on the search cost.

• Design Convergence Study
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• v.15 no.4
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• pp.1-16
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• 2016

Healthcare service helps users' health management by collecting an individual user's activity and biometric data from mobile devices and by providing them to the user. As a result, it has become necessary to perform a research on how to show the collected data. According to information visualization, the same data can have various interpretations depending on how they are represented. Healthcare data must be elivered to information acceptors without errors or distortion as they are directly related to people's health. With the expansion of healthcare service by the development of technology, this study could measure various data from users and was started to provide a necessary guideline for the visualization of measured numerical data. To propose a specific visualization by applying the visualization direction, 5 types of data including present value, measured value, relative value, relation data, and prediction value were set as the values necessary for the continuous use of mobile healthcare. Visualization was proposed concretely by applying clarity, variable comparison, brevity, relation, reliability, independence, and contextuality, which are the criteria for vitalizing the healthcare service.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.243-248
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• 2017

This study set the standard for label standardization of foreign sports apparel. Based on the theory of labels, the labels were scanned around the internal T-shirt of sports apparel brands. Based on the plan, 32 young men and women surveyed 32 tentative labels. As a result, The survey revealed that the respondents preferred the information of size, fit, washing symbol mark, and function. Based on these results, the complementary labels were designed for balance, simplicity, coherency, cognitive, and harmonization. The study interviewed 12 men and women in their 20s and 30s. As a result, the subjects indicated that they selected cognitive preference for labels because of the maximum, minimum spacing, and emphasis on information representative.

• 한국디지털정책학회:학술대회논문집
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• 2006.06a
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• pp.431-441
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• 2006

본 연구는 모바일 비즈니스(Mobile-business)에서 모바일 서비스 특성이 고객충성도와 재구매에 미치는 영향에 관하여 연구하고자 한다. 모바일 서비스를 제공하는 기업들이 성공하기 위해서 사용자의 서비스에 대한 충성도를 높일 수 있는 확실한 콘텐츠를 개발하는 것은 매우 중요하다. 모바일 비즈니스의 기존연구를 살펴보면 고객의 충성도와 재구매를 높이기 위해 구체적 어떠한 서비스 특성이 영향을 미치는 가에 대한 연구는 미진한 편이다. 따라서 본 연구는 선행연구에서 연구된 모바일 비즈니스의 특성과 인터넷 특성을 고려하여 모바일만의 서비스 특성을 제시하고, 이를 실증 분석하여 주요한 영향요인을 도출하고자 한다. 본 연구에 제시하고자 하는 모바일 특성의 3가지 유형은 모바일 정보 특성과 인터페이스 특성, 모바일 이용 특성으로 분류하고 있다. 본 연구를 수행하는 방법은 모바일 특성을 선행변수로 하고, 재구매 의도와 고객충성도를 결과변수로 하는 연구 모형을 설정하여 실증연구를 수행하였다. 모바일 사용 주계층인 10대에서 30대를 대상으로 총 226부을 연구에 사용하였다. 연구 결과 첫째, 고객충성도와 재구매 의도간에 강한 영향정도가 있었고, 둘째, 고객충성도에 영향을 미치는 요인으로는 정보 특성 요인과 인터페이스 요인 중 간결성으로 나타났으며, 셋째, 재구매 의도에 영향을 주는 요인은 정보 특성 요인 중 정확성과 최신성과 인터페이스 특성 요인으로 나타났다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.69-74
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• 2015

In this paper the patterns of information system is reduced so that control rules can guarantee fast response of queries in database. Generally an information system includes many kinds of necessary and unnecessary attribute. In particular, inconsistent information system is less likely to acquire the accuracy of response. Hence we are interested in the simple and understandable rules that can represent useful patterns by means of rough entropy and Bayesian posterior probability. We propose an algorithm which can reduce control rules to a minimum without inadequate patterns such that the implication between condition attributes and decision attributes is measured through the framework of rough entropy. Subsequently the validation of the proposed algorithm is showed through test information system of new employees appointment.