• Title/Summary/Keyword: 실시간 용량

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A Study on Effective Solution for Priority Inversion in MicroC/OS-II Real-time Operation Systems (MicroC/OS-II 실시간 운영체제에서의 우선순위 역전현상 해결 방법에 관한 효율적인 연구)

  • Jeon, Young-Sik;Heu, Shin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.627-630
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    • 2009
  • MicroC/OS-II에서는 우선순위 역전 현상에 대한 해결 기법으로 뮤텍스를 사용한 기본적인 우선순위 상속(Basic Priority Inheritance)을 사용한다. 뮤텍스를 구현하려면 리얼타임 커널이 우선순위가 같은 여러 태스크를 지원해야 한다. 하지만 MicroC/OS-II는 우선순위가 같은 여러 태스크를 지원하지 않는다. 이를 해결하기 위해 MicroC/OS-II는 우선순위 예약을 사용할 수밖에 없었으며 이로 인해 불필요한 메모리공간 및 우선순위 자원을 낭비하게 된다. 본 논문에서는 MicroC/OS-II에서의 불필요한 메모리 낭비와 우선순위 낭비를 줄여, 적은 용량의 메모리를 가지는 임베디드 장비에 효율적으로 운영되도록 제안 하고자 한다.

A Study on the need for a Digital Twin-based Real-time Flood Forecasting and Alarm Monitoring System (디지털 트윈 기반 실시간 침수 예·경보 모니터링 시스템 필요성 연구)

  • Kim, Young-Hwi;Tian-Feng Yuan
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2022.10a
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    • pp.421-422
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    • 2022
  • 최근 들어 집중호우와 긴 장마기간으로 인해 침수피해가 많이 발생하고 있다. 행정안전부 재해연보 2020에 따르면, 2020년 자연 재난 피해액 중 83%인 1조 952억이 호우로 인한 피해로 집계 되었다. 국내의 하수 관로 설계는 관로와 맨홀등의 용량을 검토하는 1차원 해석으로 수행 하지만, 재난 시는 설계에서 예측한 강우량 이상이 발생하고 월류한 물의 영향을 분석하기 위해서는 2차원 해석이 필요하다. 따라서 본 연구에서는 2차원 해석 기반의 모의 침투해석을 기반으로 풍수해저감대책의 대응대책인 침수 예·경보 모니터링 시스템을 구축 한 국내·외 사례를 분석하고 필요성에 대해서 알아보도록 한다.

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Design and Implementation of HA(High-Availability) Clustered Stream Server System (고성능 클러스터드 스트림 서버 시스템 설계 및 구현)

  • Jeon, Jin-Han;Yang, Hyun-Jong;Nam, Ji-Seung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.05a
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    • pp.648-650
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    • 2008
  • 스트리밍 서비스를 위한 서버 시스템은 실시간 데이터를 서비스하기 위한 충분한 용량을 가져야 하며 많은 클라이언트들에게 비디오 파일을 전송할 수 있어야 한다. 또한 지속적으로 늘어나는 사용자수와 추가되는 새로운 저장 공간에 대한 우수한 확장성을 제공하여야 한다. 그러나 현재의 범용 스트리밍 서버시스템은 이러한 요구사항을 충분히 반영하지 못할 뿐만 아니라 늘어나는 사용자의 부하와 시스템 요구에 대한 확장성 및 고화질 고용량의 미디어 데이터에 대한 반영이 이루어지지 못하여 점차 증가되는 사용자의 서비스 요구에 대한 사항을 충족시키지 못하고 있다. 본 논문에서는 이러한 사용자의 요구에 대하여 효과적인 QoS와 효율적인 Management 정책을 제시하고 이에 따라 개발된 우수한 병렬 미디어 스트리밍 서버(PMSS)를 소개한다.

A Balanced Piggybacking Techniques with Minimizing Average Errors in Near-VOD Service Environment (Near-VOD 서비스 환경에서 평균 오류의 최소화를 고려한 Balanced piggybacking 기술)

  • Choi, Sung-Wook
    • Journal of the Korea Computer Industry Society
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    • v.5 no.9
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    • pp.911-920
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    • 2004
  • Intensive studies have been made in the area of VOD server. Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Bu11er size and disk bandwidth. we propose a efficient user-grouping policy for multi-casting services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and QOS change of proposed scheme are about 23% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

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A Pattern Matching Method of Large-Size Text Log Data using In-Memory Relational Database System (인메모리 관계형 데이터베이스 시스템을 이용한 대용량 텍스트 로그 데이터의 패턴 매칭 방법)

  • Han, Hyeok;Choi, Jae-Yong;Jin, Sung-Il
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.837-840
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    • 2017
  • 각종 사이버 범죄가 증가함에 따라 실시간 모니터링을 통한 사전 탐지 기술뿐만 아니라, 사후 원인 분석을 통한 사고 재발 방지 기술의 중요성이 증가하고 있다. 사후 분석은 시스템에서 생산된 다양한 유형의 대용량 로그를 기반으로 분석가가 보안 위협 과정을 규명하는 것으로 이를 지원하는 다양한 상용 및 오픈 소스 SW 존재하나, 대부분 단일 분석가 PC에서 운용되는 파일 기반 SW로 대용량 데이터에 대한 분석 성능 저하, 다수 분석가 간의 데이터 공유 불가, 통계 연관 분석 한계 및 대화형 점진적 내용 분석 불가 등의 문제점을 해결하지 못하고 있다. 이러한 문제점을 해결하기 위하여 고성능 인메모리 관계형 데이터베이스 시스템을 로그 스토리지로 활용하는 대용량 로그 분석 SW 개발하였다. 특히, 기 확보된 공격자 프로파일을 활용하여 공격의 유무를 확인하는 텍스트 패턴 매칭 연산은 전통적인 관계형 데이터베이스 시스템의 FTS(Full-Text Search) 기능 활용이 가능하나, 대용량 전용 색인 생성에 따른 비현실적인 DB 구축 소요 시간과 최소 3배 이상의 DB 용량 증가로 인한 시스템 리소스 추가 요구 등의 단점이 있다. 본 논문에서는 인메모리 관계형 데이터베이스 시스템 기반 효율적인 텍스트 패턴 매칭 연산을 위하여, 고성능의 대용량 로그 DB 적재 방법과 새로운 유형의 패턴 매칭 방법을 제안하였다.

An Efficient Buffering and Disc Scheduling for VCR-Like N-VOD Services (N-VOD 서버에서 VCR 서비스를 위한 효율적인 버퍼 및 디스크 스케쥴링)

  • Choi Seong-Wook
    • Journal of the Korea Computer Industry Society
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    • v.7 no.3
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    • pp.217-226
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    • 2006
  • Intensive studies have been made in the area of N-VOD server Multimedia files in the N-VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Buffer size and disk bandwidth. we propose a efficient VCR-LIKE operations and buffer, disk scheduling policy for multimedia services with management of VOD sever resources. Simulation results show that the rate of buffer usage and service time of proposed scheme are about 18% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

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An Efficient Pre-Fetching Service for Multi-media Server based on Disc Partition Scheduling (멀티미디어 서버에서 효율적인 선반입 서비스를 위한 디스크 파티션 스케쥴링)

  • Choi Sung-Wook
    • Journal of the Korea Computer Industry Society
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    • v.6 no.3
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    • pp.379-390
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    • 2005
  • Intensive studies have been made in the area of VOD server Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Buffer size and disk bandwidth. we propose a efficient $pre\_fetching$ policy for multimedia services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and service time of proposed scheme are about $28\%$ performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

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Analysis of Effects of Nonideal Channels on the Throughput of CR Systems (인지 무선 시스템에서 전송 오류가 전송 용량에 미치는 영향에 대한 분석)

  • Lee, Sang-Wook;Lim, Chang-Heon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.9A
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    • pp.719-726
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    • 2009
  • CR systems performs spectrum sensing operation to detect the appearance of primary users. However, since it is not feasible to do spectrum sensing and data transmission simultaneously, they typically operate alternatively in a time domain. There have been an effort(8) to investigate the optimal spectrum sensing duration for maximum throughput for the scheme with cooperative spectrum sensing. This is based on an assumption that the communication channels between each secondary user and the fusion center are ideal and does not consider the effects of transmission error. Motivated by this, we here model the channels as binary symmetric channels and examined its effect on the maximum throughput and the associated optimal sensing duration. Analysis shows that the performance degradation due to the transmission error is smaller for the case of using the AND fusion rule than for the OR fusion rule.

Variation in Larvae Development and Moth Emergence of Striped Rice Borer (Chilo suppressalis Walker) and Damages in Rice Cultivars under Different Levels of Nitrogen and Silicate Fertilizers (질소 및 규산시비수준에 따른 수도품종간 이화명충의 발육ㆍ우화 및 피해정도의 변이)

  • 손상목;김기준
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.1
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    • pp.11-19
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    • 1982
  • The average weight of larvae, the percentage of survival larvae and the percentage of moth emergence in first and second generation of striped rice borer showed lower values in Akibare(Japonica variety) compared with those in Milyang 23 (Indica variety). At higher nitrogen level the larvae weight in second generation of striped borer was increased. The percentage of survival larvae in second generation was gradually decreased by applying the silicate fertilizer in both cultivars. The moth emergences in both generations of striped rice borer were also lower at high levels of silicate fertilizer. The percentage of white head of rice plant was reduced by the application of silicate fertilizer. The ratio of SiO$_2$ to T-N of the rice stem was related negatively with the percentage of survival larvae and the moth emergence in second generation of striped rice borer, and also with the percentage of white head of rice plant.

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Evaluation of Varietal Difference and Environmental Variation for Some Characters Related to Source and Sink in the Rice Plants (벼의 Source 및 Sink형질의 품종간차이와 환경변이의 평가)

  • Choi, Hae-Chun;Kwon, Yong-Woong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.30 no.4
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    • pp.460-470
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    • 1985
  • Experiments were carried out to evaluate the standard gravity in determining potential kernel size and to determine the effective sampling way by analyzing intra - and inter - plant variations for some source and sink characters using eleven semi-dwarf indica and three japonica cultivars including four semi-dwarf indica nearisogenic lines. Also, additional experiments were conducted to understand yearly variation and variety x year interaction effects for ten characters related to source and sink and to characterize the varietal difference of pre- and post-heading self-competition employing three parental varieties and their F$\sub$5/ progenies in 1982 and 1983. It is desirable to determine the potential kernel size by average kernel wight of rice grains showing above 1.15 specific gravity. There was significant difference in leaf area per tiller, spikelets and sink capacity per panicle among vigorous, intermediate and inferior tillers classified by differentiated order and vigorousness. Although it was difficult to find out any significant difference in grain-fill ratio, ratio of perfectly ripened grain, potential kernel size and sink/source ratio between vigorous and intermediate tillers, there was big difference between them and inferior one. The coefficients of variation within each tiller-group for some characters related to source and sink were larger with the order of vigorous tillers < intermediate one '||'&'||'lt; inferior one, and the average heritability of all characters, evaluated by the ratio of varietal variance (equation omitted) to total variance (equation omitted), were higher with the order of inferior tillers '||'&'||'lt; intemediate one '||'&'||'lt; superior one. Therefore, it is desirable to sample the vigorous tillers to represent the varietal difference of these traits. '82-'83 year variations of three parental cultivars were significant for all traits except for leaf area/tiller, panicles/hill, leaf area index and rough rice yield. The characters showing highly significant variance of variety x year interaction were growth duration from transplanting to heading, leaf area/tiller, sink/source ratio, sink capacity/panicle and grain yield. Generalized yearly response of three parental varieties (Suweon 264, Raegyeong, IR1317-70-l) and their F$\sub$5/ progenies on the 1st and 2nd principal components extracted from ten source and sink characters generally exhibited reduction in both source and sink. However, there were diverse variety x year interactions such as progenies showing similar reaction with their parents and intermediate or recombinational yearly response with little or considerable yearly movement on the four-dimensional planes of the two upper principal components between 1982 and 1983. Sink characters revealing highly significant border effect were grain-fill ratio, spikelets and sink capacity per panicle. Among them the latter two especially showed significant variety x border effect interaction. Self-competition characterized by relative weakness of inside plant's sink characters compared to the border one was more severe during the reproductive stage before heading than maturing stage. Though the larger sink capacity per panicle generally disclosed the severer self-competition, some lines (like Suweon 264) revealed severe self-competition with small sink capacity while a few others showed tender self-competition in spite of big sink capacity per panicle.

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