• Title/Summary/Keyword: 통신장애

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Technology Development for Non-Contact Interface of Multi-Region Classifier based on Context-Aware (상황 인식 기반 다중 영역 분류기 비접촉 인터페이스기술 개발)

  • Jin, Songguo;Rhee, Phill-Kyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.6
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    • pp.175-182
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    • 2020
  • The non-contact eye tracking is a nonintrusive human-computer interface providing hands-free communications for people with severe disabilities. Recently. it is expected to do an important role in non-contact systems due to the recent coronavirus COVID-19, etc. This paper proposes a novel approach for an eye mouse using an eye tracking method based on a context-aware based AdaBoost multi-region classifier and ASSL algorithm. The conventional AdaBoost algorithm, however, cannot provide sufficiently reliable performance in face tracking for eye cursor pointing estimation, because it cannot take advantage of the spatial context relations among facial features. Therefore, we propose the eye-region context based AdaBoost multiple classifier for the efficient non-contact gaze tracking and mouse implementation. The proposed method detects, tracks, and aggregates various eye features to evaluate the gaze and adjusts active and semi-supervised learning based on the on-screen cursor. The proposed system has been successfully employed in eye location, and it can also be used to detect and track eye features. This system controls the computer cursor along the user's gaze and it was postprocessing by applying Gaussian modeling to prevent shaking during the real-time tracking using Kalman filter. In this system, target objects were randomly generated and the eye tracking performance was analyzed according to the Fits law in real time. It is expected that the utilization of non-contact interfaces.

Active Fault Tolerant Control of Quadrotor Based on Multiple Sliding Surface Control Method (다중 슬라이딩 표면 제어 기법에 기반한 쿼드로터의 능동 결함 허용 제어)

  • Hwang, Nam-Eung;Kim, Byung-Soo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.1
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    • pp.59-70
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    • 2022
  • In this paper, we proposed an active fault tolerant control (AFTC) method for the position control of a quadrotor with complete loss of effectiveness of one motor. We obtained the dynamics of a quadrotor using Lagrangian equation without small angle assumption. For detecting the fault on a motor, we designed a fault detection module, which consists of the fault detection and diagnosis (FDD) module and the fault detection and isolation (FDI) module. For the FDD module, we designed a nonlinear observer that observes the states of a quadrotor based on the obtained dynamics. Using the observed states of a quadrotor, we designed residual signals and set the appropriate threshold values of residual signals to detect the fault. Also, we designed an FDI module to identify the fault location using the designed additional conditions. To make a quadrotor track the desired path after detecting the fault of a motor, we designed a fault tolerant controller based on the multiple sliding surface control (MSSC) technique. Finally, through simulations, we verified the effectiveness of the proposed AFTC method for a quadrotor with complete loss of effectiveness of one motor.

Development of Series Connectable Wheeled Robot Module (직렬연결이 가능한 소형 바퀴 로봇 모듈의 개발)

  • Kim, Na-Bin;Kim, Ye-Ji;Kim, Ji-Min;Hwang, Yun Mi;Bong, Jae-Hwan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.5
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    • pp.941-948
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    • 2022
  • Disaster response robots are deployed to disaster sites where human access is difficult and dangerous. The disaster response robots explore the disaster sites prevent a structural collapse and perform lifesaving to minimize damage. It is difficult to operate robots in the disaster sites due to rough terrains where various obstacles are scattered, communication failures and invisible environments. In this paper, we developed a series connectable wheeled robot module. The series connectable wheeled robot module was developed into two types: an active driven robot module and a passive driven robot module. A wheeled robot was built by connecting the two active type robot modules and one passive type robot module. Two robot modules were connected by one DoF rotating joint, allowing the wheeled robot to avoid obstructions in a vertical direction. The wheeled robot performed driving and obstacle avoidance using only pressure sensors, which allows the wheeled robot operate in the invisible environment. An obstacle avoidance experiment was conducted to evaluate the performance of the wheeled robot consisting of two active driven wheeled robot modules and one passive driven wheeled robot module. The wheeled robot successfully avoided step-shaped obstacles with a maximum height of 80 mm in a time of 24.5 seconds using only a pressure sensors, which confirms that the wheeled robot possible to perform the driving and the obstacle avoidance in invisible environment.

Design and Implementation of Game Server using the Efficient Load Balancing Technology based on CPU Utilization (게임서버의 CPU 사용율 기반 효율적인 부하균등화 기술의 설계 및 구현)

  • Myung, Won-Shig;Han, Jun-Tak
    • Journal of Korea Game Society
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    • v.4 no.4
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    • pp.11-18
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    • 2004
  • The on-line games in the past were played by only two persons exchanging data based on one-to-one connections, whereas recent ones (e.g. MMORPG: Massively Multi-player Online Role-playings Game) enable tens of thousands of people to be connected simultaneously. Specifically, Korea has established an excellent network infrastructure that can't be found anywhere in the world. Almost every household has a high-speed Internet access. What made this possible was, in part, high density of population that has accelerated the formation of good Internet infrastructure. However, this rapid increase in the use of on-line games may lead to surging traffics exceeding the limited Internet communication capacity so that the connection to the games is unstable or the server fails. expanding the servers though this measure is very costly could solve this problem. To deal with this problem, the present study proposes the load distribution technology that connects in the form of local clustering the game servers divided by their contents used in each on-line game reduces the loads of specific servers using the load balancer, and enhances performance of sewer for their efficient operation. In this paper, a cluster system is proposed where each Game server in the system has different contents service and loads are distributed efficiently using the game server resource information such as CPU utilization. Game sewers having different contents are mutually connected and managed with a network file system to maintain information consistency required to support resource information updates, deletions, and additions. Simulation studies show that our method performs better than other traditional methods. In terms of response time, our method shows shorter latency than RR (Round Robin) and LC (Least Connection) by about 12%, 10% respectively.

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Relation between Dietary Habit and Nutrition Knowledge, and Attention Deficit Hyperactivity Disorder (ADHD) in the Middle School Students in Seoul (서울시내 일부 중학생의 식습관, 영양지식과 주의력결핍 과잉행동장애와의 관계)

  • Choi, Jin-Young;Lee, Sang-Sun
    • Journal of Nutrition and Health
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    • v.42 no.8
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    • pp.682-690
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    • 2009
  • The purpose of this study is to analyse the relation between dietary habit and nutrition knowledge, and ADHD (Attention Deficit Hyperactivity Disorder) in the middle school students in Seoul, Korea. Total study subjects were 631 students, 51.8% was male and 48.2% was female. In the assessment of predisposition of ADHD, 93% was normal group and 7% was ADHD group. As for the gender in ADHD group, 56.8% was male and 43.2% was female. Normal group showed the higher breakfast consumption rate than ADHD group (p < 0.05). Dietary habits were better in normal group than ADHD group. Nutrition knowledge scores of normal group was 7.38 out of 15 and scores of ADHD group was 5.77 out of 15 (p < 0.01). The nutrition knowledge score and the dietary habits score showed a positive correlation (p < 0.01). The nutrition knowledge score and snack meal purchasing frequency showed a negative correlation (p < 0.05). There are significant negative correlation between attention deficit hyperactivity score and nutrition knowledge score (p < 0.01). In conclusion, ADHD group showed lower level of nutrition knowledge and worse dietary habits than the normal group.

A Study of Efficient Spare Capacity Planning Scheme in Mesh-Based Survivable Fiber-Optic Networks (생존성을 갖는 메쉬기반 광전송망에서의 효율적인 예비용량 설계방안에 관한 연구)

  • Bang, Hyung-Bin;Kim, Byung-Gi
    • The KIPS Transactions:PartC
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    • v.10C no.5
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    • pp.635-640
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    • 2003
  • Due to the development of information technology and widespread use of telecommunications networks, the design of mesh-survivable net works has received considerable attention in recent years. This paper deals with spare capacity planning scheme in mesh-based fiber-optic networks. In this study, a new spare capacity planning scheme is proposed utilizing path restoration with maximal sharing of share capacity that is traced by the spare capacity incremental factor (after this, we called "SCIF"). We compare it with three other spare capacity planning scheme : link capacity of IP (Integer Programming), SLPA(Spare Link Placement Algorithm) and GA(Genetic Algorithm). The approach shows better performance with heuristics algorithm for determining the spare capacity assignment and the computational time is easily controlled allowing the approach to scale to large networks. The major advantages of the new approach are reduction of spare capacity and a polynomial time complexity.omplexity.

A study on the research scheme and the education of e-trade marketing in Korea (전자무역 해외마케팅 교육과 연구체계 수립에 관한 연구)

  • Kang, Hyo-Won
    • International Commerce and Information Review
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    • v.15 no.3
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    • pp.411-430
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    • 2013
  • Overseas marketing before the conclusion of a contract is a huge obstacle to enter the global market because it has needed the company's maximum capacities which are some cost, time and human resources. Thus it required a reestablishment about the education fields and research schemes. Due to the advancements in ICT and internet, a subject of e-trade is becoming a critical issue with a subject of a practice of international trade. However, since the mid-2000s, e-trade research articles and educational materials such as textbooks, research papers are being gradually reduced. Therefore the purpose of this study, from an oversea marketing point of view among the various e-trade fields, is to measure an education performance and an academic research scheme. And this study will suggest direction of improvement about research scheme and educational performance in the overseas marketing. According to the result, to establish the education and research scheme about SEM(Search Engine Marketing), SEO(Search Engine Optimization) and SNA(Social Network Analysis) which are introduced in the industry among the education and research field related the e-trade is urgent. And some subjects need a capstone-design reconcile theory and practice.

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An Indoor Localization and Guidance System for the Visually Impaired Person Based on Bluetooth 4.0 (시각 장애인을 위한 Bluetooth 4.0 기반의 실내 위치 추정 및 안내 시스템)

  • Bae, Sun-Young
    • The Journal of the Korea Contents Association
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    • v.16 no.8
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    • pp.202-208
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    • 2016
  • The scope of activities of the visually impaired is increasing. But they are not easy to visit the destination safely because the building was complicated and larger than ever. There is a guide system for visually impaired such as GPS and Audio alerts, Braille guide block, Acoustic signaller, etc. But they are not suitable for indoor because most of them are the outdoor guide system. Therefore, in this paper, I propose a system that provides guidance information to the visually impaired using Voice Technology, TTS (Text to Speech) and Haptic Technology, Beacon based on the wireless sensor networks. It informed the visually impaired of guidance information about destination such as distance, height, and obstacle to the destination using the generalized smart phone. The user could be received guide info about searches for the optimal route to the destination using the TTS technology and Haptic technology in test result of the proposed system.

Mobile Contents Adaptation Network using Active Network Mechanisms (액티브 네트워크 메커니즘을 이용한 이동 컨텐츠 적응형 네트워크)

  • 김기조;이준호;임경식;오승희;남택용;손승원
    • Journal of KIISE:Information Networking
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    • v.31 no.4
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    • pp.384-392
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    • 2004
  • Mobile contents service providers have some difficulties to timely and proper service deployment due to rapid development cycle of diverse portable devices with different capabilities. A way to resolve the problem is to introduce a mobile contents service paltform that can adapt original mobile contents to diverse devices dynamically and automatically. In this paper, we propose a mobile contents service platform based on active network mechanisms, called Mobile Content Adaptation Network(MobiCAN). The MobiCAN node provides effective service deployment, execution, and maintenance features and accommodates service layering and service customization capabilities for easy deployment. The basic functional units of the MobiCAN node are micro services with well-defined service interfaces and service layering features. For reliable services among the MobiCAN nodes, we design new distributed and robust Overlay Management Protocols(OMPs). As an example of practical MobiCAN applications, we finally describe Dynamic Contents Customization Proxy(DCCP) service.

A Study on Development of Enhancement Guidelines of Smart Application Accessibility for the Disabled (장애인을 위한 스마트 애플리케이션 접근성 향상 가이드라인 개발 연구)

  • Jun, Woochun
    • Journal of The Korean Association of Information Education
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    • v.19 no.1
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    • pp.69-76
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    • 2015
  • In current information society, there is a barrier called digital divide. Due to this barrier, the disabled have difficulties to communicate with the world. Recently, with advanced smart techniques, smart devices become necessity for the disabled. Currently improvements of smart application accessibility become a great concern for the disabled. The purpose of this paper is to present some guidelines for enhancing smart application accessibility for the disabled. The enhancement guidelines are developed based on the existing mobile accessibility guidelines and modified for better adaptability for the disabled. Our principles are as follows: minimizing blue light emission from smart devices, automatic focus on input window, action trace, font color change, emergency notification by motion, gesture recognition, control location, scrolling avoidance, auditory service for visual warning, and icon literation.