• Research in Mathematical Education
• /
• v.16 no.1
• /
• pp.67-77
• /
• 2012

This study aimed to explore teachers' perceived beliefs regarding teaching practice in the context of three-year Professional Development Project (ProDev) implementing lesson study incorporating Open Approach. The data were collected through questionnaire distributing to the teachers in three schools. Qualitative data were collected through participatory observation on teaching practice and interviewing members of lesson study team. The findings revealed that teacher's perceived beliefs regarding teaching practice could be categorized into three categories according to 3 phases of lesson study as the followings: 1) Perceived beliefs related to collaboratively designing research lessons 2) Perceived beliefs related to collaboratively observing their friend teaching the research lesson 3) Perceived beliefs related to collaboratively doing post-discussion or reflection on the activities of the two phases.

• ETRI Journal
• /
• v.29 no.2
• /
• pp.162-168
• /
• 2007

A new scheme for bi-directional HDTV/Gigabit Ethernet/CATV transmission over a hybrid dense-wavelength-division-multiplexing passive optical network (DWDM-PON) is proposed and demonstrated. It is based on injection-locked vertical-cavity surface-emitting lasers and distributed-feedback laser diodes as transmitters. Services with 129 HDTV channels, a 1.25 Gbps Gigabit Ethernet connection, and 77 CATV channels are successfully demonstrated over 40 km single-mode fiber links. Good performance of bit error rate, carrier-to-noise ratio, composite second order, and composite triple beat is achieved in our proposed bidirectional DWDM-PON.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.798-802
• /
• 2003

The robustness and reliability of vision algorithms is the key issue in robotic research and industrial applications. In this paper, the robust real time visual tracking in complex scene is considered. A common approach to increase robustness of a tracking system is to use different models (CAD model etc.) known a priori. Also fusion of multiple features facilitates robust detection and tracking of objects in scenes of realistic complexity. Because voting is a very simple or no model is needed for fusion, voting-based fusion of cues is applied. The approach for this algorithm is tested in a 3D Cartesian robot which tracks a toy vehicle moving along 3D rail, and the Kalman filter is used to estimate the motion parameters, namely the system state vector of moving object with unknown dynamics. Experimental results show that fusion of cues and motion estimation in a tracking system has a robust performance.

• Proceedings of the IEEK Conference
• /
• 2004.06a
• /
• pp.135-138
• /
• 2004

Mobile phone antenna needs a small size and light weight for carrying and handling. In case of receiving a wide band TV signal, it would be difficult to obtain a good impedance matching between the antenna and the circuit due to a large capacitive reactance of antenna. Buffer amplifier was established on the teflon( ${\varepsilon}_r=3.38$, h=20mils) substrate by using GaAs FET( CPY30 ) and Silicon RF Transistor( BFP540 ) produced by Infineon and experimented.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.1109-1112
• /
• 2005

The software reliability is defined, and not only the relations between testing time and reliability, but also the relation between duration following failure fixing and reliability are studied in this paper. The release time making the testing cost to be minimum is determined through evaluating the cost for each condition. Also, the release time is determined depending on the conditions of the first reliability, considering the specified reliability. The optimum release time is determined by simultaneously studying two optimum release time issues that determine both the cost related time and the specified reliability related time. And, each condition and limitation are studied. The trend of the optimum time is also examined.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.115-118
• /
• 1999

One of the typical methods to design a codebook is K-means algorithm. This algorithm has the drawbacks that converges to a locally optimal codebook and its performance is mainly decided by an initial codebook. D. Lee's method is almost same as the K-means algorithm except for a modification of a distance value. Those methods have a fixed distance value during all iterations. After many iterations. because the distance between new codevectors and old codevectors is much shorter than the distance in the early stage of iterations, the new codevectors are not affected by distance value. But new codevectors decided in the early stage of learning iterations are much affected by distance value. Therefore it is not appropriate to fix the distance value during all iterations. In this paper, we propose a new algorithm using each different distance value between codevectors for a limited iterations in the early stage of learning iteration. In the experiment, the result show that the proposed method can design better codebooks than the conventional K-means algorithms.

• Proceedings of The KACE
• /
• 2017.08a
• /
• pp.51-54
• /
• 2017

본 연구의 목적은 오픈 러닝과 소셜 러닝 플랫폼의 핵심요소 비교분석 결과를 바탕으로 학습자와 학습 환경 개선을 위해 고려해야 할 핵심 요소와 방향에 대한 시사점을 고찰하는 데 있다. MOOC로 대변되는 오픈 러닝 사례들의 핵심요소를 분석하여 각각의 공통점과 차이점은 무엇인지 알아보고자 했다. 소셜 러닝 플랫폼을 활용한 사례들을 살펴봄으로써 소셜 러닝 플랫폼의 정의와 특이사항을 살펴보았다. 오픈 러닝과 소셜 러닝 플랫폼의 특이사항은 서로 어떤 상호작용을 가질 수 있을지 비교분석 내용을 바탕으로 오픈 러닝에서 발견 된 장단점과 소셜 러닝 플랫폼의 장단점으로 대치하여 서로 보완해줄 수 있는 진화한 러닝 플랫폼을 구상해보는 것은 유의미 할 것이다.

• Journal of the Korean Mathematical Society
• /
• v.54 no.3
• /
• pp.1015-1030
• /
• 2017

This paper is concerned with the following Klein-Gordon-Maxwell system: $$\{-{\Delta}u+{\lambda}V(x)u-(2{\omega}+{\phi}){\phi}u=f(x,u),\;x{\in}\mathbb{R}^3,\\{\Delta}{\phi}=({\omega}+{\phi})u^2,\;x{\in}\mathbb{R}^3$$ where ${\omega}$ > 0 is a constant and ${\lambda}$ is the parameter. Under some suitable assumptions on V (x) and f(x, u), we establish the existence and multiplicity of nontrivial solutions of the above system via variational methods. Our conditions weaken the Ambrosetti Rabinowitz type condition.

• Clinical and Experimental Pediatrics
• /
• v.63 no.3
• /
• pp.115-116
• /
• 2020

• Proceedings of the Society of Korea Industrial and System Engineering Conference
• /
• 2002.05a
• /
• pp.151-161
• /
• 2002

This paper presents the business model and system functionalities of a B2B e-marketplace solution that not only can overcome some problems of the public e- marketplace, but also can be applicable to both public and private types of e-marketplaces. This solution is different from the most of the public e-marketplace solutions that their main sources of revenue are transaction commissions or transaction fees through the third-party intermediation. Instead, this solution provides an ASP (Application Service Provider) functionality for direct, dis-intermediated purchasing and sales-related transactions between suppliers and buyers. With this functionality, suppliers and buyers electronically commerce with each other without the disclosure of their transactions as well as transaction commissions.