• 제목/요약/키워드: time coordination

검색결과 596건 처리시간 0.024초

A Civilian Reporting Service to Guide Converging Resources for Search and Rescue in Disaster Response

  • Chen, Albert Y.;Han, Sang-Uk;Lee, Sang-Hyun;Pena-Mora, Feniosky
    • Journal of Construction Engineering and Project Management
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    • 제1권3호
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    • pp.45-51
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    • 2011
  • During disaster response, prioritization of limited resources is one of the most important but challenging tasks. At the same time, it is imperative to timely provide to the rescuers with the adequate heavy equipment to facilitate lifesaving operations. However, supply of high demand equipment is usually insufficient during the initial phase of disaster response, challenging lifesaving operations. At the same time, resources outside of the disaster affected zone converge into the area to assist the response efforts, which is the effect of convergence that often made resource coordination challenging in large scale disasters. Meanwhile, the initial condition of the disaster is usually best known by civilians already at the area before and during impact of the disaster. The knowledge of the civilians is not always received and considered by the responding organizations. With the help of these civilians, critical information such as victim location, infrastructure damage, and risk condition could be better know before any response actions are taken. To efficiently collect information and utilize the converging resources, this paper proposes a geospatial information repository for initial condition reporting and update to guide search and rescue operations and deployment of equipment with safety considerations for the rescuers in large scale disaster response scenarios.

A New Battery Approach to Wind Generation System in Frequency Control Market

  • Nguyen, Minh Y.;Nguyen, Dinh Hung;Yoon, Yong Tae
    • Journal of Electrical Engineering and Technology
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    • 제8권4호
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    • pp.667-674
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    • 2013
  • Wind power producers face many regulation costs in deregulated environment, which remarkably lowers the value of wind power in comparison with conventional sources. One of these costs is associated with the real-time variation of power output and being paid in frequency control market according to the variation band. This paper presents a new approach to coordination of battery energy storage in wind generation system for reducing the payment in frequency control market. The approach depends on the statistic data of wind generation and the prediction of frequency control market price to determine the optimal variation band which is then kept by the real-time charging and discharging of batteries, ultimately the minimum cost of frequency regulation can be obtained. The optimization problem is formulated as trade-off between the decrease in the regulation payment and the increase in the cost of using battery, and vice versus. The approach is applied to a study case and the results of simulation show its effectiveness.

추출가능 상황에서 전자기기 사용유형에 따른 상대적 위험성평가: 운전 시뮬레이션 연구 (Relative Risk Evaluation of Front-to-Rear-End Collision when Drivers Using Electronic Devices: A Simulation Study)

  • 이세원;이재식
    • 한국안전학회지
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    • 제24권4호
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    • pp.104-110
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    • 2009
  • In this driving simulation study, the impairing effects of various types of electronic devices usage(i. e., destination search by using in-vehicle navigation system, TV watching and dialing cellular phone) during driving on front-to-rear-end collision avoidance were investigated. Percentage of collisions, driving speeds when the drivers collided, and initial reaction time for collision avoidance were analyzed and compared as the dependent measures. The results indicated that (1) any types of electronic devices usage during driving induced more serious collision-related impairment than control condition where no additional task was required, and (2) in general, destination search task appeared to impair drivers collision avoidance performance more than the other task requirements in terms of percentage of collisions and initial reaction time for collision avoidance, but TV watching induced most serious collision impact. These results suggested that any types of electronic device usage could distract drivers attention from the primary task of driving, and be resulted in serious outcome in potentially risky situation of front-to-rear-end collision. In particular, mandatory use of eye-hand coordination and receiving feedback seemed to one of essential factor leading the drivers visual attentional distraction.

VANET을 위한 지연 최적화 적응적 멀티 채널 백오프 메카니즘 (Delay-Optimized Adaptive Multichannel Backoff Mechanism for VANET)

  • 이정재
    • 한국전자통신학회논문지
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    • 제14권5호
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    • pp.837-844
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    • 2019
  • 본 논문에서는 VANET(: Vehicular Ad Hoc Networks)환경에서 비-안전 애플리케이션을 위한 낮은 지연을 제공하기 위해 AMBM(: Adaptive Multi-channel Backoff Machisum)-MAC 프로토콜을 제안한다. 제안된 프로토콜은 우선 순위가 다른 비-안전 패킷간의 처리량의 극대화를 위해 WSA(: WAVE Service Advertisement)의 CW(: C hannel window)를 동적으로 조정하여 비-안전 패킷의 서비스품질을 보장한다. 또한 SC(: Service Channel)를 위한 채널조정 및 타임슬롯예약을 하기 위해 많은시간을 할당하고 CW 및 최적 CCI(: CC Interval)를 동적으로 조정함으로서 IEEE 1609.9, C-MAC(: Coordinated multi-channel MAC), Q-VCI(QoS Variable CCH Interval) 프로토콜보다 노드가 증가할 때 전송지연이 감소됨을 보인다.

Motor Skill Learning on the Ipsi-Lateral Upper Extremity to the Damaged Hemisphere in Stroke Patients

  • Son, Sung Min;Hwang, Yoon Tae;Nam, Seok Hyun;Kwon, Yonghyun
    • The Journal of Korean Physical Therapy
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    • 제31권4호
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    • pp.212-215
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    • 2019
  • Purpose: This study examined whether there is a difference in motor learning through short-term repetitive movement practice in stroke survivors with a unilateral brain injury compared to normal elderly participants. Methods: Twenty-six subjects who were divided into a stroke group (n=13) or sex-aged matched normal elder group (n=13) participated in this study. To evaluate the effects of motor learning, the participants conducted a tracking task for visuomotor coordination. The accuracy index was calculated for each trial. Both groups received repetitive tracking task training of metacarpophalangeal joint for 50 trials. The stroke group performed a tracking task in the upper extremity insi-lesional to the damaged hemisphere, and the normal elder group performed the upper extremity matched for the same side. Results: Two-way repetitive ANOVA revealed a significant difference in the interactions ($time{\times}group$) and time effects. These results indicated that the motor skill improved in both the stroke and normal elder group with a tracking task. On the other hand, the stroke group showed lesser motor learning skill than the normal elder group, in comparison with the amount of motor learning improvement. Conclusion: These results provide novel evidence that stroke survivors with unilateral brain damage might have difficulty in performing ipsilateral movement as well as in motor learning with the ipsilateral upper limb, compared to normal elderly participants.

국가 온실가스 통계 산정을 위한 임목축적 재계산 (Recalculation of Forest Growing Stock for National Greenhouse Gas Inventory)

  • 이선정;임종수;손영모;김래현
    • 한국기후변화학회지
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    • 제7권4호
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    • pp.485-492
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    • 2016
  • For reporting national greenhouse gas inventory in forest sector, the forest growing stock from the National Forest Inventory (NFI) system has used as activity data sources. The National Forest Inventory system was changed from rotation system by province to annual system by 5 years across the country. The forest growing stocks based on the new inventory system produced a different trend compared to the previous estimations. This study was implemented to recalculate previous forest growing stocks for time series consistency at a national level. The recalculation of forest growing stock was conducted in an overlap approach by the IPCC guideline. In order to support the more consistency data, we used calibration factors between applied stand volumes in 1985 and 2012, respectively. As a result, the time series of recalculated forest growing stock was to be consistency using the overlap approach and the calibration factor with the lower middle/middle site index. According to the applied overlap period, however, we will recalculate activity data using more complete data from national forest inventory system.

메타버스 리얼리티를 위한 공유 모빌리티 기반 국부적 미세먼지 관측 기술 연구 (A Study on the Local Particulate Matter Monitoring Technology using Shared-Use Mobilities for Metaverse Reality)

  • 정인택;장봉주
    • 한국멀티미디어학회논문지
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    • 제24권8호
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    • pp.1138-1148
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    • 2021
  • In this study, we developed a 'shared-use mobility'-mounted local particulate matter monitoring terminal technology to measure the actual particulate matter concentration around me. As a mobile terminal device in the form of an IoT sensor platform, it is designed to be separated into a control module and a sensor module to minimize interference between sensors and to consider the optimal observation position of each sensor. As a result of the field test, it was confirmed that particulate matter was locally different depending on time and space even within the same area. In addition, it was confirmed that the concentration of particulate matter in the relevant section differed by up to 100 times compared to the surrounding area due to specific sources of particulate matter such as unpaved roads. In addition, we positively reviewed the applicability of the service in the real-time metaverse environment using this result. Through technological advancement and application of multiple shared-use mobilities, we expect to be able to provide new services for practical smart city air environment monitoring, such as localized particulate matter information, air pollution event information, and identification of causes of particulate matter.

THE POTENTIAL USE OF A PUBLIC WEB SERVICE TO GUIDE CONVERGING CONSTRUCTION EQUIPMENT IN US&R

  • Albert Y. Chen;Feniosky Pena-Mora
    • 국제학술발표논문집
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    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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    • pp.582-585
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    • 2011
  • During disaster response, prioritization of limited resources is one of the most important bust challenging tasks. At the same time, it is imperative to timely provide the rescuers with the adequate equipment to facilitate lifesaving operations. However, supply of high demand equipment was insufficient during the initial phase of disaster response, challenging lifesaving operations in the case of the 9-11 terrorist attacks. In respond to the Haiti Earthquake, spatial information of the geographic area was not sufficient to support the search and rescue operations in the early phase of disaster response. However, with the help of civilians, information such as road names, infrastructure damage, and victim locations were updated into the spatial data repository. At the same time, resource outside of the disaster affected zone converges into the area to assist the response efforts, which is the effect of convergence that often made resource coordination challenging in large scale disasters. To efficiently collect information and utilize the converging resources, this paper proposes a flexible data repository for information update for equipment utilization in large scale disaster response scenarios.

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에드혹 네트워크에서 다중 데이터률을 고려하는 분산 패킷 스케쥴링 (A Multi-Rate Aware Distributed Packet Scheduling in Ad-hoc Networks)

  • 노권문;진영천;유상조
    • 한국통신학회논문지
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    • 제31권7B호
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    • pp.642-651
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    • 2006
  • 에드흑 네트워크에서 패킷 스케줄링 기법들은 대부분 처리량에 기반한 공정성 (throughput-based fairness)를 제공한다. 처리량 기반 공정성을 제공하기 위해 기본적으로 가정하는 것은 채널 용량이 고정되어 있다는 것이다. 그러나 DCF(Distributed Coordination Function)를 제공하여 에드혹 네트워크를 구성하는데 대중적인 방법으로 사용하는 IEEE 802.11b와 802.11g는 채널 상태에 따라 다양한 데이터률을 적용할 수 있기 때문에, 채널 용량이 고정되어 있다는 가정은 실제 환경에서 적합하지 않다. 따라서, 본 논문에서는 이러한 디중 데이터률을 고려하기 위한 플로우별 시간 기반 공정성 (time-based fairness)를 정의하고, 정의한 시간 기반 공정성를 달성하는 패킷 스케쥴링 기법(MRADPS: Multi-Rate Aware Distributed Packet Scheduling)을 제안한다. 시뮬레이션 결과는 MRADPS가 정의한 시간 기반 공정성을 달성하면서 다중 데이터률을 제공하는 에드흑 네트워크의 전체 처리량을 크게 향상시키는 것을 보여준다.

배전자동화시스템 통신서비스를 위한 이중화 통신망 보호절체 알고리즘 연구 (A Study on the Protection Switching Mechanism for Distribution Automation System Ethernet Networks Service of Distribution Automation System)

  • 유남철;김재동;오재곤
    • 전기학회논문지
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    • 제62권6호
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    • pp.744-749
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    • 2013
  • The protection switching technology is widely adopted in the fiber-optical transmission equipments based on TDM(Time Division Multiplexing), such as PDH, SDH/SONET. A variety of protection switching algorithms for Ethernet networks and the progress of standardization are summarized in the document. There are several kinds of protection switching algorithms for Ethernet networks, such as STP, RSTP, MSTP and etc. However, since Ethernet signal move through detour route, it causes much time to recover. Accordingly, it is difficult to secure a usability of Ethernet networks and QOS(Quality of Service). Also, if the protection switching protocol standardized by IEEE and ITU-T is used, it remains a inherent network switching time for protection. Therefore, a specific protection switching algorithm for Ethernet are needed for seamless and stable operation of Ethernet networks service for Distribution Automation System(DAS). A reliable protection algorithm with no switching delay time is very important to implement Self-healing service for DAS. This study of FPGA based protection switching algorithm for Ethernet networks shows that in case of faults occurrence on distribution power network, immediate fault isolation and restoration are conducted through interaction with distribution equipments using P2P(Peer to Peer) communication for protection coordination. It is concluded that FPGA based protection switching algorithm for Ethernet networks available 0ms switching time is crucial technology to secure reliability of DAS.