• 제목/요약/키워드: interruptions

Search Result 158, Processing Time 0.024 seconds

Design of INS/Image Sensor Integrated Navigation System (INS/영상센서 결합 항법시스템 설계)

  • Oh Seung-Jin;Kim Woo-Hyun;Lee Jang-Gyu;Lee Hyung-Keun;Park Chan-Gook
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.12 no.10
    • /
    • pp.982-988
    • /
    • 2006
  • The errors of INS (Inertial Navigation System) are known to grow in time. To compensate the accumulated errors, measurements of external or onboard sensors are extensively utilized to form an integrated navigation system. Recently, INS/GPS integrated navigation systems have become popular since exact position and velocity information can be utilized by low cost GPS receivers. Unfortunately, this configuration cannot be trusted at all times especially when there are intentional or unexpected jammings and interruptions. To aid INS irrespectively of these cases, an INS/Image sensor integrated navigation system configuration is designed only based on the information of image sensor gimble angles. The performance of the INS/Image sensor integrated navigation system is evaluated by Monte Carlo simulation.

Horner's Syndrome after a Fracture of the First Rib Caused by a Crushing Injury (충돌 손상에 의한 첫 번째 늑골 골절에 동반된 Horner 증후군)

  • Ma, Dae Sung;Cho, Hyun Jin;Lee, Jung Nam;Jeon, Yang Bin
    • Journal of Trauma and Injury
    • /
    • v.27 no.4
    • /
    • pp.201-203
    • /
    • 2014
  • Patients with Horner's syndrome exhibit a variety of symptoms, including miosis, palpebral ptosis, and anhidrosis. This syndrome is caused by interruptions of the sympathetic neural pathways. This paper describes two cases of patients with Horner's syndrome who experienced a first rib fracture after crushing injuries.

Cognitive Routing for Multi-hop Mobile Cognitive Radio Ad Hoc Networks

  • Lee, Jae-Joon;Lim, Jaesung
    • Journal of Communications and Networks
    • /
    • v.16 no.2
    • /
    • pp.155-161
    • /
    • 2014
  • Mobility can lead to continual loss of data and service interruptions during communications in multi-hop cognitive radio networks. Mobility of primary users (PUs) or cognitive users (CUs) requires adjustment of multi-hop communications among CUs to avoid any interference to PUs. To provide durable and reliable data routing that ensures continuous network service, we propose mobility-aware cognitive routing (MCR) for multi-hop cognitive radio networks. MCR examines the risk level of each node against interference regions and selects the most reliable path for data delivery using a Markov predictor. Through simulation, we verify that the proposed scheme can avoid route destruction preemptively and achieve reliable data delivery.

The Concept and International Standards of Power Quality (전력 품질의 개념 정립과 국제 표준 비교)

  • Lim, Su-Saeng;Lee, Eun-Woong;Sohn, Hong-Kwan;Joh, Hyun-Kil;Jeong, Jong-Ho;Kim, Jun-Ho
    • Proceedings of the KIEE Conference
    • /
    • 2001.04a
    • /
    • pp.174-177
    • /
    • 2001
  • The dependence of modern life upon the continuous supply of electrical energy makes system reliability and power quality topics of the utmost importance in the power systems. Power quality is the combination of voltage quality and current quality. But in this paper, voltage quality and harmonic distortion are focused. Transient phenomena and current quality are not included. Voltage quality is split into voltage sags. voltage swells, and short interruptions. These voltage variations are studied on their definitions, origins, the effect on electric equipment. Related industrial standards and guidelines are summarized. Harmonic voltage and current distortion are strongly linked. The concepts and contributions of harmonic distortions are studied. Typical symptoms of harmonic problems and a summary of the trends and guidelines are given.

  • PDF

Applications of Seismic Disaster Simulation Technology on Risk Management

  • Yeh, Chin-Hsun
    • 한국방재학회:학술대회논문집
    • /
    • 2010.02a
    • /
    • pp.16-24
    • /
    • 2010
  • This paper introduces the applications of Taiwan Earthquake Loss Estimation System (TELES), which is developed by the National Center for Research on Earthquake Engineering (NCREE). Seismic disaster simulation technology (SDST) integrates geographical information system to assess the distribution of ground shaking intensity, ground failure probability, building damages, casualties, post-quake fires, debris, lifeline interruptions, economic losses, etc. given any set of seismic source parameters. The SDST may integrate with Taiwan Rapid Earthquake Information Release System (TREIRS) developed by Central Weather Bureau (CWB) to obtain valuable information soon after large earthquakes and to assist in decision-making processes to dispatch rescue and medical resources more efficiently. The SDST may also integrate with probabilistic seismic source model to evaluate various kinds of risk estimates, such as average annual loss, probable maximum loss in one event, and exceeding probability curves of various kinds of losses, to help proposing feasible countermeasures and risk management strategies.

  • PDF

Multilevel Location Trigger in Distributed Mobile Environments for Location-Based Services

  • Min, Kyoung-Wook;Nam, Kwang-Woo;Kim, Ju-Wan
    • ETRI Journal
    • /
    • v.29 no.1
    • /
    • pp.107-109
    • /
    • 2007
  • In location-based services, most trigger technologies have been implemented on the server side by periodically requesting the locations of mobile phones from mobile network servers. However, bottlenecks and communication interruptions occur when the servers are overloaded by trigger requests. In this letter, we propose a new multilevel location trigger specification which distributes the event detecting role to mobile phones and redesigns the location triggering into a multilevel step. Our suggested location trigger specification can reduce bottlenecks caused by triggers in a mobile core network and reduce power consumption caused by embedded GPS devices in mobile phones.

  • PDF

An Analysis of the throughput performance of some continuous A.R.Q, Schemes

  • Jung, Doo-Young;Kim, Sung-Chun
    • Proceedings of the IEEK Conference
    • /
    • 2000.07a
    • /
    • pp.73-76
    • /
    • 2000
  • In the basic continuous ARQ schemes (Go-Back-N or Selective Repeat ARQ), each block is continuously transmitted without interruptions. Only when the transmitter receives NAK from the receiver side, the transmitter stops sending current data block and retransmit the erroneous block (Naked block). When channel error rate increases and become sufficiently high, there exists a point at which each block of message is transmitted, on average, more than once. Under such conditions, it will be more efficient to send continuously two or more copies(generally $\ell$ copies) of each block from the first transmission over noisy channel. A request for repeat will be made again only when none of $\ell$ duplicates are received correctly. By this way, the proposed scheme yields a better throughput efficiency and holds nearly constant throughput as compared to others continuous A.R.Q schemes under wide error rate variations (0 < P < 0.3).

  • PDF

Fault Current Calculation and Coordination by IEC Standards (IEC 표준에 의한 고장전류 계산과 보호협조)

  • Son, Seok-Geum
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.28 no.12
    • /
    • pp.6-12
    • /
    • 2014
  • The safety and reliability of the power system short-circuit current, the short-circuit current depends on the failure to obtain the objective is to quickly eliminate the breaking capacity of the circuit-breaker selection of the cable, the insulation of electrical equipment and protective relay an important factor in determining the level correction and protective relay selection scheme to be meaningful. Standards used in the domestic circuit breaker is applied to the production of IEC standard, but the American National Standards (ANSI / IEEE) by NEMA specification of the fault current calculations and the application of the asymmetric coefficient Korea. Therefore, in this paper, the IEC 60909 standard IEC breaker fault current calculation method and the method for selection of system configurations reviewed and protection system for reviewing the configuration of various protective relays appropriate correction and the correction value is main protection, back-up protection the equipment so that the period of protection relay coordination to minimize accidents and accident protection to minimize interruptions proposed for cooperation.

Investigating delay factors in construction industry: A Korean perspective

  • Acharya, Nirmal Kumar;Im, Hae-Man;Lee, Young-Dai
    • Korean Journal of Construction Engineering and Management
    • /
    • v.7 no.5
    • /
    • pp.177-190
    • /
    • 2006
  • Construction projects are facing delay problems. Delays in construction have been immense effect on performance or satisfactory delivery of the project. Delays have been causing project cost overrun as well as it is a source of dispute hence damaging the relationship between the project participants. The purpose of this study was to explore the causes of delay risk through a field survey study. Data were collected from construction professionals working in owner, consultant and contractor organizations. All together 208 questionnaire instruments were used and analyzed by employing statistical tools (SPSS computer program). 19 delay factors were identified by this study, out of which following factors were critical: Frequent interruptions from public (local people, pressure group etc.), changed site condition, failure to provide required construction site, unrealistic project time estimation and design errors.

Design of Adaptive Population-size on Bias in Genetic Algorithms (유전자 알고리즘에서 bias에 의한 adaptive한 개체군 크기의 설정)

  • 김용범;오충환
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.18 no.36
    • /
    • pp.133-141
    • /
    • 1995
  • One of the problems brought up in the effective execution of genetic algorithms is that if they come under any influences according as the population size is large or small. In the case of small population size the opportunities of premature convergence are increased when the greatly powerful or no good individual is generated during search of the solution space. And searching the solution space in the case of large population size, the difficulties under the execution cause to searching all for one by one individual in every generation applied is limited, this gives the many interruptions to the convergence of final solution. Now this paper gives a suggestion to set up the adaptive population size which could compute the more correct solution and simplify the development of computation performance.

  • PDF