A Quantitative Analysis of System-Level Performance of the Wireless LAN in Digital Home Environments

Byounghee Son,Hagbae Kim 대한전자공학회 2008 JUCT : Journal of Ubiquitous Convergence Technolog Vol.2 No.1

A digital home is a ubiquitous environment that is expected to be realized in the near future. All information appliances in a house are connected to each other through wired and/or wireless home networks. Authenticated user can access the various services provided by the digital home, and the access is not restricted by equipment, time, or location. The technologies that form the digital home can be grouped into two categories: wired networking technologies and wireless networking technologies. For the purpose of ubiquitous environments, wireless-networks offer suitable and seamless high-quality services. A wireless LAN can be created simply by equipping a single access point. For that reason, the cost of establishing such a network is low and using it is easy. Of course, there is an exciting new wireless technology. It is the Ultra Wide Band (UWB). However, it is not enough to bring wireless convenience, although offering a broad range of high-speed data transfer capabilities, Because of unstable. Thus, of the wireless-networking systems, we focus on the wireless LAN. We quantitatively analyze its capabilities. The dynamic and adaptive wireless LAN provides a foundation for the evolution toward the next generation of wireless and adaptive networks. The difference between wired LAN and wireless LAN in upload and download rates is small. Although the wireless LAN experiences a greater loss rate than the wired LAN, the difference is minimal. We conclude that a wireless LAN is suitable for use in an apartment environment.

A Quantitative Analysis of System-Level Performance of the Wireless LAN in Digital Home Environments

Son, Byoung-Hee,Kim, Hag-Bae The Institute of Electronics and Information Engin 2008 JUCT : Journal of Ubiquitous Convergence Technolog Vol.2 No.1

A digital home is a ubiquitous environment that is expected to be realized in the near future. All information appliances in a house are connected to each other through wired and/or wireless home networks. Authenticated user can access the various services provided by the digital home, and the access is not restricted by equipment, time, or location. The technologies that form the digital home can be grouped into two categories: wired networking technologies and wireless networking technologies. For the purpose of ubiquitous environments, wireless-networks offer suitable and seamless high-quality services. A wireless LAN can be created simply by equipping a single access point. For that reason, the cost of establishing such a network is low and using it is easy. Of course, there is an exciting new wireless technology. It is the Ultra Wide Band (UWB). However, it is not enough to bring wireless convenience, although offering a broad range of high-speed data transfer capabilities, Because of unstable. Thus, of the wireless-networking systems, we focus on the wireless LAN. We quantitatively analyze its capabilities. The dynamic and adaptive wireless LAN provides a foundation for the evolution toward the next generation of wireless and adaptive networks. The difference between wired LAN and wireless LAN in upload and download rates is small. Although the wireless LAN experiences a greater loss rate than the wired LAN, the difference is minimal. We conclude that a wireless LAN is suitable for use in an apartment environment.

독립제어구조를 갖는 N+1 모듈형 UPS 시스템의 병렬운전

조준석,한재원,최규하 전력전자학회 2002 전력전자학회 논문지 Vol.7 No.5

In this paper, a novel wireless parallel operation algorithm of N+1 redundant UPS system with no control interconnections for load-sharing is presented. The proposed control system eliminates the sensing noise and interconnection interference of conventional parallel operation system. To reduce a reactive power deviation in wireless control method, this technique automatically compensates for inverter parameter variation and line impedance imbalances with wireless auto-tuning method. In addition, to increase reliability on transient characteristics of parallel operation, a virtual injected impedance is adopted to eliminate a circulation current among inverter modules. Simulation results are provided in this paper to prove the proposed novel wireless algorithm. 본 논문에서는 N+1 모듈형 UPS 시스템의 병렬운전을 위해 기존에 사용된 부하분담용 신호선을 제거하고 독립적인 운전을 수행하는 새로운 형태의 wirelss 병렬제어 알고리즘을 제안하고자 한다. 제안된 제어시스템은 기존 방식이 갖는 센싱 노이즈나 상호간섭에 의한 문제를 제거할 수 있다. 또한 wireless방식의 단점을 보완하기 위해 인버터간 불평형요소 제거 알고리즘을 적용하여 무효전력편차의 발생을 최소화하는 구조를 가지며, 시스템의 불안정한 과도특성을 완충하는 가상의 임피던스를 삽입하여 과도순환전류를 저감하는 방식이 적용되었다. 제안된 알고리즘의 타당성을 검증하기 위해 시뮬레이션 결과를 제시하였다.

W-TMS(Wireless-Threat Management System)에서의 효율적 관리를 위한 위협 분류기법

서종원,조제경,이형우 한국콘텐츠학회 2007 한국콘텐츠학회논문지 Vol.7 No.3

Internet had spread in all fields with the fast speed during the last 10 years. Lately, wireless network is also spreading rapidly. Also, number of times that succeed attack attempt and invasion for wireless network is increasing rapidly. TMS system was developed to overcome these threat on wireless network. Existing TMS system supplies active confrontation mechanism on these threats. However, existent TMS has limitation that new form of attack do not filtered efficiently. Therefor this paper proposes a new method that it automatically compute the threat from the imput packets with vector space model and detect anomaly detection of wireless network. Proposed mechanism in this research analyzes similarity degree between packets, and detect something wrong symptom of wireless network and then classify these threats automatically. 지난 10년 동안 인터넷은 빠른 속도로 모든 분야에 확산되어 왔으면 이와 비슷한 현상으로 최근 몇 년 동안 무선 네트워크의 확산 역시 빠른 속도로 보급되고 있는 추세이다. 그리고, 무선 네트워크 공격 시도 및 침입에 성공하는 공격의 횟수도 증가하고 있다. 이런 무선 네트워크 위협을 극복하기 위해 기존의 TMS는 필요에 따라 자동화되고 능동적인 대응 수단을 제공하기도 하지만, 새로운 형태의 무선 공격 등에는 효율적으로 대응하지 못한다는 취약점을 가지고 있다. 따라서 본 연구에서는 정보검색분야에서 사용되는 Vector Space모델을 이용해 실시간으로 유입되는 패킷과의 유사도를 비교하여, 분석된 유사도의 패턴을 분석해 무선 네트워크의 이상 징후를 탐지하고 자동으로 분류하는 기법을 설계했다.

신생아 인큐베이터 모니터링을 위한 저전력 원격 계측 시스템에 대한 연구

신동익,김인권,신길현,임경수,허수진 대한의료정보학회 2004 Healthcare Informatics Research Vol.10 No.1

As wireless network technology and various mobile communication equipments have widely used and rapidly developed, many research workers are studying about a measurable system for several medical data or bio-signals, such as electrocardiogram, pulse-oximetry and so forth, by wireless. And, even generic people who are in a good state of health as well as patients in the hospital, whose concern and care about healthcare has increased greatly, so many research workers are studying about Ubiquitous Healthcare of new technology. This technology will offer natural medical services freely in anywhere and in a quiet way, even if people can not go to hospital. Our research made a possibility to measure environment data in each infant incubator by using temperature and humidity sensor, prior to measure directly bio-signals of patients. Each sensor was composed of wireless network based on TinyOS, and that wireless network connected to Personal Digital Assistants(PDA). So we were studied about telemetry system by using wireless sensor network. It was researches about telemetry system to measure environment data in infant incubator before, by web-based RF modules. But they has problems that incubator's movement restriction by wire, wire net's limitation. We solved these problems by organizing wireless sensor network that connected together sensors and measurement devices. This wireless sensor network organization, based on TinyOS, is possible to receive sensor's data of long distance by a relay station and to save power. In future, this network will be basic of Ubiquitous Healthcare as well as medical information system in hospital.

A Feasibility Study of Damage Tracking through the Diffusive Communication of Wireless Sensors

Jeong, Min-Joong,Bae, Jong-Goo,Koh, Bong-Hwan 한국정밀공학회 2010 International Journal of Precision Engineering and Vol.11 No.1

The objective of this paper is to investigate the feasibility of wireless sensors in the development of an autonomous structural health monitoring system. A collaborative searching algorithm is developed such that massively deployed wireless sensor nodes in a structure conveniently comprise a group and constitute a damage-surveillance perimeter. Wireless sensors in this perimeter spontaneously activate themselves for damage-tracking tasks by networking with neighboring sensors. When the damage-sensitive parameter that is measured by a sensor node exceeds a certain threshold, the process of damage-tracking begins. The proposed damage-tracking algorithm does not require any type of global control. Instead, sensor-networking and a pairwise-comparison algorithm that is implemented at each sensor node allows collaborative decision-making for tracking the changes, such as local strain, in structural properties. The extant autonomous, damage-tracking algorithms have been demonstrated through only numerical simulations for a single-damage case. Here, the study is further expanded to address the problem of simultaneously tracking multiple instances of damage in three-dimensional space by using improved algorithms for sensor networking. An event-based task-executing functionality of individual sensor nodes is successfully implemented and verified using four wireless strain sensors that are mounted on a cantilevered beam structure. Experimental results reveal that the overall capability of wireless sensor nodes is functional enough to enable a wireless-based autonomous structural health monitoring system.

대형 컨테이너 선박의 무선 상태 감시

심민찬 (M. C Shim ),양보석 (B. S. Yang ),공영모 (Y.M. Kong ) 한국동력기계공학회 2009 한국동력기계공학회 학술대회 논문집 Vol.2009 No.6

The wireless measurement system is developed for an effective vibration monitoring on the containership. Typically, Wi-Measys is deployed on a trial run of a constructed ship for measuring the ship's vibration. This development was performed as a solution for replacing existing wired instrumentations by wireless. The installations of wired DAQ system cause a manpower shortage, a cost prohibitive , limitation of measuring point and very susceptible to noise through coaxial cables in a complex structure of ship. However, these costs can be significantly reduced by utilizing a wireless system. Wi-Measys is applied on containership which conducted a vibration testing on an engine room, upper deck for estimating the new constructed ship's vibration limitation. This paper presented about how to apply a wireless measurement system and wireless local area network to a large ship have complex structure.

양방향으로 동작하는 DC-DC Converter를 이용하는 무선 전력 송수신기 개발

문영진(Young-Jin Moon),유창식(Changsik Yoo) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.7

A Tutorial for Key Problems in the Design of Hybrid Hierarchical NoC Architectures with Wireless/RF

Chunhua Xiao,Zhangqin Huang,Da Li 한국산학기술학회 2013 SmartCR Vol.3 No.6

As processing nodes scale up, it is difficult for traditional electronic networks to supply on-chip communication efficiently due to unacceptable latency, plus power and area consumption. Alternative interconnects, such as radio frequency interconnect (RF-I) and optical interconnect, have been explored as interconnection backbones. Hybrid hierarchical architectures with both traditional interconnects and emerging interconnects have been widely adopted to get excellent trade-off between latency and power. The hybrid hierarchical architecture with a wireless/RF-I backbone is more cost-efficient and feasible due to advantages in complementary metal oxide semiconductor compatibility, compared with other alternative interconnects, and has become one of the mainstreams of chip multi-processor systems. However, how to efficiently utilize the wireless/RF-I backbone is a new challenge for designers. Based on analysis of existing typical hybrid hierarchal wireless/RF-I architectures (HHWAs), the key problems in the Design of HHWAs are proposed here, and related potential solutions are provided. In particular, strategies for resource management of wireless/RF-I are explored in detail, and different solutions are discussed. This work is expected to serve as a basis for future HHWA designs.

원격계측을 위한 무선 통신 에러 검사 알고리즘 개발

김희식(H. S. Kim),김영일(Y. I. Kim),설대연(D. Y. Seol),남철(C. Nam),Odgerel 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

A data error inspection algorithm for wireless digital data communication was developed. Original data converted By wireless digital data error inspection algorithm. Wireless digital data is high possibility to get distortion and lose by noise and barrier on wireless. If the data check damaged and lost at receiver, can"t make it clear and can"t judge whether this data is right or not. Therefore, by wireless transmission data need the data error inspection algorithm in order to decrease the data distortion and lose and to monitoring the transmission data as real time. This study consists of RF station for wireless transmission, Water Level Meter station for water level measurement and Error inspection algorithm for error check of transmission data. This study is also that investigation and search for error inspection algorithm in order to wireless digital data transmission in condition of the least data"s damage and lose. Designed transmitter and receiver with one - chip micro process to protect to swell the volume of circuit. Had designed RF transmitter - receiver station simply by means of ATMEL one - chip micro processing the systems. Used 10mW of the best RF power and 448MHz-449MHz on frequency band which is open to public touse free within the limited power.