• 한국정밀공학회지
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• 제19권12호
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• pp.179-184
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• 2002

In this study, we developed a portable device which can monitor and analyze vibration signals from machines. This system consists a PDA loading the program for vibration analysis and A/D board for vibration acquisition. A PDA is smaller than the palm of the hand, but it has a powerful computing ability as much as an IBM compatible PC with a Pentium 100MHz CPU. The A/D board developed in this study supports LAN interface using TCP/IP communication protocol. The application program for vibration analysis includes signal processing module, fault diagnosis module, data store module, and plot display module. MS visual embedded C＋＋ 3.0 was used to developed the program.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.895-896
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• 2015

With the development of sensor, wireless mobile communication, embedded system and cloud computing, the technologies of Internet of Things have been widely used in logistics, Smart devices security, intelligent building and o on. Bridging between wireless sensor networks with traditional communication networks or Internet, IoT gateway plays n important role in IoT applications, which facilitates the integration of wireless sensor networks and mobile communication networks or Internet, and the management and control with wireless sensor networks. The IoT Gateway is a key component in IoT application systems but It has lot of security issues. We analyzed the trends of security and privacy matters.

• 융합보안논문지
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• 제8권1호
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• pp.27-33
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• 2008

본 연구에서는 센서네트워크 기반의 컴퓨팅 기술이 혼합된, 개별난방 제어 시스템을 제안한다. 지그비 RF 기술과 임베디드 하드웨어 기술의 조합을 통하여, 주택 및 아파트 등에서 각 방별로 온도 및 습도를 취합하여 난방을 관리할 수 있다. 또한 제안된 시스템은 체감온도 기반으로 난방을 관리하여 인간에게 쾌적한 환경을 제공하기 위한 최적의 선택이라 할 수 있다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.365-372
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• 2006

A new meshfree formulation is developed for material discontinuity problems. A local interfacial jump function which is defined as hyperplane function is embedded in the meshless approximation and the approximation accurately models functions with jumps in the displacement and the derivative fields. Diffuse derivative technique copes with difficulty due to complexity of derivative computation of meshfree approximation. Collocation method with diffuse derivative accelerates computing speed for numerical solution. By solving inclusion and composite material problems, the robustness and effectiveness of the method are verified.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.248-268
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• 2018

The performance of smartphone applications are usually constrained in user interactions due to resource limitation and it promises great opportunities to improve the performance by exploring the smartphone built-in and embedded sensing techniques. However, heterogeneity in techniques, semantic gap between sensor data and usable context, and complexity of contextual situations keep the techniques from seamless integration. Relevant studies mainly focus on feasibility demonstration of emerging sensing techniques, which rarely address both general architectures and comprehensive technical solutions. Based on a proposed functional model, this investigation provides a general architecture to deal with the dynamic context for context-aware automation and decision support. In order to take advantage of the built-in sensors to improve the performance of mobile applications, an ontology-based method is employed for context modelling, linguistic variables are used for heterogeneous context presentation, and semantic distance-based rule matching is employed to customise functions to the contextual situations. A case study on mobile application authentication is conducted with smartphone built-in hardware modules. The results demonstrate the feasibility of the proposed solutions and their effectiveness in improving operational efficiency.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.1-6
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• 2008

The ubiquitous sensor network technique is widely applied to variety of information fields such as home automations, logistics, traffic controls, public administrations, health and environment monitoring and etc. It is particularly useful in the areas where energy consumption is minimal and where continuous monitoring of the surrounding environments, which generates streams of data, are required. In this study, we have designed and implemented a living environment automatic control system which collects the streams of temperature, humidity, light and noise data of a simulated house setting in real-time fashion, then controls the home environment based on the collected data according to the users favorites. In order to differentiate the proposed system from the currently existing similar system, we have demonstrated not only the feasibility of collecting data using sensor network in the controlled environment but also the ability to control the various household equipments through wireless communications.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.140-144
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• 2001

This paper describes to extend the MLFMA(Multi-Level Fast Multipole Algorithm) for three-dimensional capacitance computation in the case of conductors embedded in an arbitrary dielectric medium. The triangular meshes are used and refined in the area which has heavy charge density. This technique is applied to the capacitance extraction of three-dimensional structures with multiple dielectrics. The results show good convergence with the comparable accuracy, and this adaptive technique coupled with MLFMA is useful to reduce computing time and the number of elements without additional computational efforts in large three dimensional problems.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권11호
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• pp.1101-1105
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• 2010

본 논문에서는 웹 환경에서 컨텐츠의 내용을 시각적으로 보조하는 2D 애니메이션의 생성 인터페이스를 제안한다. 제안된 인터페이스를 이용하여, 애니메이션 생성에 대한 경험이 없는 사용자들도 움직임, 현상의 설명이나 시각적인 효과들을 친숙한 스케치방식으로, 인터렉티브하게 생성하고 공유할 수 있다. 또한, 컷아웃(Cutouts) 인터페이스 방식은 스케치 환경에서 양질의 결과들에서 생성하는데 기여하며, 기존 스케치기반 애니메이션 접근들에서 다루기 어려웠던, 이미지나 관절 객체를 간결한 방식으로 지원할 수 있게 한다.

• Journal of Computing Science and Engineering
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• 제11권3호
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• pp.100-108
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• 2017

In the field of Internet of Things (IoT), smarter embedded devices offer functions via web services. The Quality-of-Service (QoS) prediction is a key measure that guarantees successful IoT service applications. In this study, a collaborative filtering method is presented for predicting response time of IoT service due to time-awareness characteristics of IoT. First, a calculation method of service response time similarity between different users is proposed. Then, to improve prediction accuracy, initial similarity values are adjusted and similar neighbors are selected by a similarity threshold. Finally, via a densified user-item matrix, service response time is predicted by collaborative filtering for current active users. The presented method is validated by experiments on a real web service QoS dataset. Experimental results indicate that better prediction accuracy can be achieved with the presented method.

• 대한기계학회논문집A
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• 제20권1호
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• pp.206-213
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• 1996

Third order correlation funciton is to be advantageous to detect unique features embedded in various random signals that are undetectable with second order correlation or power spectrum. In this paper, we will introduce optical modulator which consists of a laser light source, 2-dimensional ultrasonic diffractor cell with signal controlling circuitry, and a CCD camera connected to personal computer for image processing. With this modulator, the third order correlaiton pattern of signal can be immediately obtained at the camera due to parallel nature of optical computing.