• 한국수학교육학회지시리즈C:초등수학교육
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• 제6권1호
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• pp.41-54
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• 2002

The purpose of this study is to find out what mathematical situation means, how to pose a meaningful situation and how situation-centered teaching could be done. The obtained informations will help learners to improve their math abilities. A survey was done to investigate teachers' perception on teaching-learning in mathematics by elementary teachers. The result showed that students had to find solutions of the textbook problems accurately in the math classes, calculated many problems for the class time and disliked mathematics. We define mathematical situation. It is artificially scene that emphasize the process of learners doing mathematizing from physical world to identical world. When teacher poses and expresses mathematical situation, learners know mathematical concepts through the process of mathematizing in the mathematical situation. Mathematical situation contains many concepts and happens in real life. Learners act with real things or models in the mathematical situation. Mathematical situation can be posed by 5 steps(learners' environment investigation step, mathematical knowledge investigation step, mathematical situation development step, adaption step and reflection step). Situation-centered teaching enhances mathematical connections, arises learners' interest and develops the ability of doing mathematics. Therefore teachers have to reform textbook based on connections of mathematics, other subject and real life, math curriculum, learners' level, learners' experience, learners' interest and so on.

• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.177-197
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• 2020

Colleges have been forced to take non-face-to-face classes this year due to the COVID-19, and the situation is expected to continue unless the development of treatments and vaccines is carried out as soon as possible. In the situation where non-face-to-face classes are required under compulsion, two methodologies have been suggested as most representative alternatives to face-to-face classes: online real-time classes and on-demand contents classes. The purpose of this study is to compare the perceived convenience, self-fidelity, and preference of students between online real-time and on-demand contents classes by gender, school year grade, mostly using class media, and number of courses taken. Comparative results between online real-time and on-demand contents classes were statistically analyzed by surveying students at a university.

• 한국학교수학회논문집
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• 제16권3호
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• pp.561-582
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• 2013

그동안 수학교육에서 의미는 강조되었지만 의미가 뜻하는 것이 무엇인지, 어떻게 분류될 수 있는지는 명확하게 규정되지 못하였다. 이러한 입장에서 의미를 표현적 의미와 인지적 의미로 구분하였으며, 두 의미도 수학적 상황과 현실적 상황으로서의 의미로 다시 재분류 하였다. 의미의 분류를 기반으로, 본 연구에서는 수학적 모델링문제 해결에서 보이는 학생의 의미 인식에 대해 살펴보았다. 그 결과 다른 의미의 이해에 비해 현실적 상황의 인지적 의미 이해에서는 상대적으로 어려움을 겪는다는 것을 알게 되었으며, 식을 세우는 단계에서의 의미보다 풀이과정에서의 의미 이해에 더 어려움을 겪는다는 것을 알게 되었다. 따라서 수학적 모델링의 전 과정에서 의미의 이해를 돕기 위해, 학생이 실생활 상황과 수학을 연결 지어 사고하도록 지도하여야 하며, 측정과 단위를 통한 지도 방법이 실생활 상황과 수학의 연결을 위한 하나의 방안이 됨을 알 수 있었다. 이러한 현실 상황과 수학의 연결을 강조한 지도를 통해 더 폭넓은 수학의 활용이 가능하리라 생각된다.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2001년도 제19회 하계학술발표회 논문집
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• pp.117-130
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• 2001

R&D is the core competence of an enterprise. Furthermore, R&D requires huge capital investment and has very risky characteristics. Therefore, to be successful in R&D process, several approaches of engineering economics are used prior to decision-making. Until now, typical approaches of engineering economics such as NPV(net present value) or DCF(Discounted cash flow) have been used. But, they cannot properly capture managerial flexibility to adapt and revise later decisions in response to unexpected market development. In a constantly changing and always uncertain marketplace, managerial operation flexibility and strategic adaptability have become vital in order to successfully capitalize on favorable future investment opportunities and limit losses from adverse market development. For the alternatives of conventional static decision-making approaches, new concept of using real options is introduced. Real option theory is based on financial option's characteristics and checks every revision interval whether situation have changed favorable to decision maker or not. In advantageous situation, the decision maker has only to go on. In contrast, with unfavorable situation, he abandons the investment immediately. In this aspect, real option model is more suitable in very uncertain and dynamic business environment in that it can provide the opportunity to cope with flexibility. This paper suggests efficient and effective R&D investment strategy by using real options model. In addition, this paper compares financial options and real options.

• 한국정보통신학회논문지
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• 제21권9호
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• pp.1771-1776
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• 2017

최근 IoT(Internet of Things)는 다양한 분야에 활용되어 특정 장소에 스마트 환경을 구성함으로써 사용자들에게 서비스를 제공하고 있다. 그러나 기존 시스템은 주변 환경의 변화에 따라 디바이스의 동작과 작업이 변화하지 않기 때문에 사용자는 환경 및 상황이 변화할 때마다 수동적으로 동작해야 한다. 이에 본 논문에서는 실시간 데이터 분류 기반 상황별 작업 제어 시스템을 제안한다. 센서 데이터를 서버로 전송하고 실시간, 비 실시간 데이터로 분류한 뒤 의사 결정 트리에 삽입하여 상황에 따른 작업을 식별한다. 또한 위험상황을 가스 누출 및 화재 발생과 같이 2단계로 나눠 경고 메시지를 전송한다. 이에 따라 전력의 낭비와 오작동 발생을 감소시킬 수 있으며 작업 효율이 증대된 서비스를 제공받을 수 있을 것으로 사료된다.

• 음성과학
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• 제6권
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• pp.219-233
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• 1999

This paper presents a real-time implementation of a speaker independent speech recognition system based on a discrete hidden markov model(DHMM). This system is developed for a car navigation system to design on-chip VLSI system of speech recognition which is used by fixed point Oak DSP core of DSP GROUP LTD. We analyze recognition procedure with C language to implement fixed point real-time algorithms. Based on the analyses, we improve the algorithms which are possible to operate in real-time, and can verify the recognition result at the same time as speech ends, by processing all recognition routines within a frame. A car noise is the colored noise concentrated heavily on the low frequency segment under 400 Hz. For the noise robust processing, the high pass filtering and the liftering on the distance measure of feature vectors are applied to the recognition system. Recognition experiments on the twelve isolated command words were performed. The recognition rates of the baseline recognizer were 98.68% in a stopping situation and 80.7% in a running situation. Using the noise processing methods, the recognition rates were enhanced to 89.04% in a running situation.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제3권1호
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• pp.57-68
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• 1999

In this paper, we investigate the comparative effectiveness of two kinds of instructional methods in transfer of mathematics learning: one based on the situated cognition, i.e. situated learning (SL) and the other based on traditional learning (TL). Both classes (of grade 2) studied addition and subtraction of 3-digit numbers. After that, they completed two written tests (Written Test 1 included computation problems, Written Test 2 included computation problems and story problems) and a real situation test. As a result, no significant differences were found between the two groups' performance on computation skill in Written Tests 1 and 2. But the SL group performed significantly better on the performance of story problem and real situation test than TL group. This result indicated that the SL made improvement in transfer of mathematics learning. As a result of interviews with 12 children of the SL group were able to use contextual resources in solving real situation as well as story problems.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제3권1호
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• pp.37-45
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• 1999

This paper investigates the comparative effectiveness of two kinds of instructional methods in transfer of mathematics learning: one based on the situated cognition, ie. situated learning and the other based on traditional learning. Two classes of second graders studied the instruction about 3-digit addition and subtraction. After that, they completed two written tests and a real situation test. As a result. no significant differences were found between the two group's performance on the written test 1 and real situation test. But the situated learning group performed significantly better on the performance of story problem than traditional group. This result indicated that the situated learning made improvement in transfer of mathematic loaming. As a result of interviews with 12 children, the situated loaming group's children were able to use contextual resources in solving real situation as well as story problems.

• 수산해양기술연구
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• 제44권3호
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• pp.218-228
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• 2008

This paper describes on the real-time tracking of ship's dynamic behavior by AIS information in the coastal waters. The AIS data was received at a land station by using the antenna of AIS receiver mounted on the rooftop of the laboratory, Pukyong National University (PKNU), Busan, Korea, and stored as a NMEA format of serial output sentence of VDM(VHF Data-Link Message) and displayed on the ENC(Electronic Navigational Chart) of a PC-based ECDIS. In this study, the AIS receiver was mainly used to obtain the dynamic information that is necessary to evaluate and track the movement situation of training ship "KAYA" of PKNU in the coastal waters. The change of position with time for the ship turning under the rudder angle of port $30^{\circ}$ was correctly tracked with the turning circle of 940 m in diameter on the ENC of a PC-based ECDIS. Then, the dynamic information of the AIS system was updated every 6.29 seconds under the turning situation for the speed of 10.9 knots and every 21.65 seconds under the situation running at the speed of 11.05 knots on the straight line route of $155^{\circ}$, respectively. In case of AIS target tracking in the inshore zone behind large topographical obstructions, such as mountain and apartment buildings, the update rate of dynamic information was irregularly changed by the existence of land obstacles. However, the position tracking by AIS information under the situation existing no sea obstructions was achieved in real or near real-time and the instant presentation of course alternations for the ship was correctly monitored by using a PC-based ECDIS. From these results, we concluded that the PC-based ECDIS technology and methodology combined with the AIS information can be easily extended and applied to the surveillance and management for the fishing operation of fishing vessels in the coastal zone and in the EEZ fishing grounds.

• 한국자동차공학회논문집
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• 제21권3호
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• pp.142-147
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• 2013

Over the past few years, intelligent tire is developed very actively for more accurate measurement of real-time tire forces generated during vehicle driving situation. Information on the force of intelligent tire could be used very usefully to chassis control systems of a vehicle. Intelligent tire is based on deformation of tire's inner surface from the waveform of a SAW, or Surface Acoustic Wave. The tire vertical force is estimated by using variance analysis of sensor signals. The estimated tire vertical force is compared with the tire vertical force generated during vehicle driving situation in real-time environment. The scope of this paper is a correlation study between the measured sensor signals and the tire vertical force generated during vehicle driving situation.