• Title/Summary/Keyword: Real time

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Real-Time Peak Shaving Algorithm Using Fuzzy Wind Power Generation Curves for Large-Scale Battery Energy Storage Systems

  • Son, Subin;Song, Hwachang
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.14 no.4
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    • pp.305-312
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    • 2014
  • This paper discusses real-time peak shaving algorithms for a large-scale battery energy storage system (BESS). Although several transmission and distribution functions could be implemented for diverse purposes in BESS applications, this paper focuses on a real-time peak shaving algorithm for an energy time shift, considering wind power generation. In a high wind penetration environment, the effective load levels obtained by subtracting the wind generation from the load time series at each long-term cycle time unit are needed for efficient peak shaving. However, errors can exist in the forecast load and wind generation levels, and the real-time peak shaving operation might require a method for wind generation that includes comparatively large forecasting errors. To effectively deal with the errors of wind generation forecasting, this paper proposes a real-time peak shaving algorithm for threshold value-based peak shaving that considers fuzzy wind power generation.

Tramsmission Method of Periodic and Aperiodic Real-Time Data on a Timer-Controlled Network for Distributed Control Systems (분산제어시스템을 위한 타이머 제어형 통신망의 주기 및 실시간 비주기 데이터 전송 방식)

  • Moon, Hong-ju;Park, Hong-Seong
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.7
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    • pp.602-610
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    • 2000
  • In communication networks used in safety-critical systems such as control systems in nuclear power plants there exist three types of data traffic : urgent or asynchronous hard real-time data hard real-time periodic data and soft real-time periodic data. it is necessary to allocate a suitable bandwidth to each data traffic in order to meet their real-time constraints. This paper proposes a method to meet the real-time constraints for the three types of data traffic simultaneously under a timer-controlled token bus protocol or the IEEE 802.4 token bus protocol and verifies the validity of the presented method by an example. This paper derives the proper region of the high priority token hold time and the target token rotation time for each station within which the real-time constraints for the three types of data traffic are met, Since the scheduling of the data traffic may reduce the possibility of the abrupt increase of the network load this paper proposes a brief heuristic method to make a scheduling table to satisfy their real-time constraints.

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Method of Real-time Communication in Android OS (안드로이드 운영체제 상에서 실시간 통신 방법)

  • Woo, Sang-Ho;Lee, Sang-Gil;Lee, Cheol-Hoon
    • The Journal of the Korea Contents Association
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    • v.21 no.1
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    • pp.475-484
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    • 2021
  • The Android OS has quickly established itself with the smartphone market and is being applied in a variety of ways such as navigation and refrigerator panels. Existing terminals can implement services that require high precision while using RTOS that requires accurate execution time, but Android OS has a disadvantage in that it cannot provide high-precision real-time performance. In this paper, we propose a real-time communication method that operates in the Android OS. Real-time communication reduces the load using the UDP protocol, and configures the real-time operating system time tick through a high-precision timer in the kernel area. An Android application level library was created to implement real-time communication and compared with the existing Android library for real-time performance verification.

Correlation between Real-Time and Off-Time Subjective Assessments and Physiological Responses for Visual Picture Stimulus (시각자극에 대한 실시간 및 비 실시간 주관적 평가와 생리반응과의 상관관계)

  • Jeong, Sun-Cheol;Min, Byeong-Chan;Min, Byeong-Un;Kim, Sang-Gyun;O, Ji-Yeong;Kim, Yu-Na;Kim, Cheol-Jung;Park, Se-Jin
    • Journal of the Ergonomics Society of Korea
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    • v.18 no.3
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    • pp.27-39
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    • 1999
  • The purpose of this study was to approve the capability of human sensibility evaluation based on physiological responses and real-time subjective assessments. Three well-trained healthy human subjects were participated in the experiments. We measured physiological responses such as Heart Rate Variability(HRV), Galvanic Skin Response(GSR) and skin temperature under rest and visual stimulation conditions, respectively. Off-time subjective assessments were recorded before and after visual stimulations. Real-time subjective assessments were recorded during visual stimulations. The results of physiological responses and off-time and real-time subjective assessments were quantified and compared. The results showed that the correlation between physiological responses and real-time subjective assessments was high (83%) for both the positive and negative visual stimulation. The correlation between the physiological responses and off-time subjective assessments was high (83%) for the negative visual stimulation but was low (15%) for the positive visual stimulation. Although the current observation is preliminary and requires more careful experimental study, it appears that the correlation between real-time subjective assessment and physiological responses is higher than that of the off-time subjective assessment and physiological responses.

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Real-Time Scheduling Facility for Video-On-Demand Service (주문형 비디오 서비스를 위한 실시간 스케쥴링 기능)

  • Sohn, Jong-Moon;Kim, Gil-Yong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2581-2595
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    • 1997
  • In this paper, the real-time facility of the operating system for a VOD(Video On Demand) server have been analyzed and implemented. The requirements of the real-time scheduling have been gathered by analyzing the model of the video-data-transfer-path. Particularly, the influence of the bottleneck subsystem have been analyzed. Thus, we have implemented the real-time scheduler and primitives which is proper for processing the digital video. In performance measurements, the degree of the guarantee of the real-time scheduler have been experimented. The measured data show that the most time constraints of the process is satisfied. But, the network protocol processing by the interrupt is a major obstacle of the real-time scheduling. We also have compared the difference between the real-time scheduler and the non-real-time scheduler by measuring the inter-execution time. According to the measured results, the real-time scheduler should be used for efficient video service because the processor time allocated to the process can't be estimated when the non-real-time scheduler is used.

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Comparison of Loop-Mediated Isothermal Amplification and Real-Time PCR for the Rapid Detection of Salmonella Typhimurium, Listeria monocytogenes and Cronobacter sakazakii Artificially Inoculated in Foods (식품에 인위접종된 Salmonella Typhimurium, Listeria monocytogenes, Cronobacter sakazakii의 신속검출을 위한 Real-time PCR과 Loop-mediated isothermal amplification 비교)

  • Kim, Jin-Hee;Oh, Se-Wook
    • Journal of Food Hygiene and Safety
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    • v.34 no.2
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    • pp.135-139
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    • 2019
  • The objective of this research was to compare loop-mediated isothermal amplification (LAMP) with real-time polymerase chain reaction (PCR) for the rapid detection of pathogens in foods. In this study, the limits of detection (LODs) for Salmonella Typhimurium, Listeria monocytogenes, and Cronobacter sakazakii were evaluated in various foods. Among 11 samples tested for S. Typhimurium, LAMP and real-time PCR had the same LODs in beef and duck meat whereas real-time PCR was more sensitive than the LAMP in 8 samples. However, S. Typhimurium in chocolate samples was not detected by real-time PCR. The sensitivity of real-time PCR was high in all samples inoculated with L. monocytogenes and C. sakazakii whereas LAMP was more sensitive than real-time PCR in oil-rich foods. Therefore, LAMP can be shown as an easrer, more convenient method, as well as effective analytical method for testing difficult samples when employed in PCR.

Rapid detection and quantification of porcine circovirus type 2 (PCV 2) DNA in Real-time PCR (Real-time PCR을 이용한 돼지써코바이러스 감염증 진단법 연구)

  • Kim, Eun-Gyeong;Hwang, Bo-Won;Lee, Jong-Min;Son, Byeong-Guk;Park, Ho-Jung;Kim, Tho-Kyoung
    • Korean Journal of Veterinary Service
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    • v.32 no.4
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    • pp.299-306
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    • 2009
  • Assay for the detection and quantification of porcine circovirus type 2 (PCV 2) with the real-time PCR were developed. TaqMan probe real-time using a set of primer/probe was developed for detection of PCV 2. In this study we applied real-time PCR assay to 320 samples, collected from pig farms. In 151 of 320 samples, PCV 2 DNA was detected by conventional PCR assay. All samples positive for PCV 2 DNA in conventional PCR assay were also positive in Real-time PCR assay, but 69 of 169 samples that tested negative for PCV 2 DNA in conventional assay were tested positive in TaqMan probe real-time PCR assay. The test of TaqMan probe real-time PCR resulted in detection and quantification limits of 101 copies per sample. TaqMan probe real-time PCR assay increased the number of samples in which PCV 2 was detected by 21%. TaqMan probe real-time PCR assay is very efficient method in contrast to the conventinal PCR, becoming increasingly important method for gene analysis.

A Scheme to Reduce the Transmission Delay for Real-Time Applications in Sensor Networks (센서 네트워크에서 실시간 응용을 위한 전송 지연 개선 기법)

  • Bin, Bong-Uk;Lee, Jong-Hyup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.8
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    • pp.1493-1499
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    • 2007
  • Real-time applications in a wireless sensor network environment require real-time transmissions from sensing nodes to sink nodes. Existing congestion control mechanisms have treated congestion problems in sensor networks, but they only adjust the reporting frequency or the sending rate in intermediate nodes. They were not suitable for real-time applications from the transmission delays point of view. In this paper, we suggest a new mechanism that can reduce the transmission delay and can increase the throughput for real-time applications in sensor network. This mechanism classifies data on the real-time characteristics, processes the data maintaining the real-time characteristics prior to the other data such as the non real-time data or the data lost the real-time characteristics. A modified frame format is also proposed in order to apply the mechanism to IEEE 802.15.4 MAC layer. The simulation based on ns-2 is accomplished in order to verify the performance of the suggested scheme from transmission delay and throughput standpoints. The simulation results show that the proposed algorithm has a better performance specifically when It applies to the real-time applications in sensor networks.

qPALS: Quality-Aware Synchrony Protocol for Distributed Real-Time Systems

  • Kang, Woochul;Sha, Lui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.10
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    • pp.3361-3377
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    • 2014
  • Synchronous computing models provided by real-time synchrony protocols, such as TTA [1] and PALS [2], greatly simplify the design, implementation, and verification of real-time distributed systems. However, their application to real systems has been limited since their assumptions on underlying systems are hard to satisfy. In particular, most previous real-time synchrony protocols hypothesize the existence of underlying fault tolerant real-time networks. This, however, might not be true in most soft real-time applications. In this paper, we propose a practical approach to a synchrony protocol, called Quality-Aware PALS (qPALS), which provides the benefits of a synchronous computing model in environments where no fault-tolerant real-time network is available. qPALS supports two flexible global synchronization protocols: one tailored for the performance and the other for the correctness of synchronization. Hence, applications can make a negotiation flexibly between performance and correctness. In qPALS, the Quality-of-Service (QoS) on synchronization and consistency is specified in a probabilistic manner, and the specified QoS is supported under dynamic and unpredictable network environments via a control-theoretic approach. Our simulation results show that qPALS supports highly reliable synchronization for critical events while still supporting the efficiency and performance even when the underlying network is not stable.

An expanded Matrix Factorization model for real-time Web service QoS prediction

  • Hao, Jinsheng;Su, Guoping;Han, Xiaofeng;Nie, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.3913-3934
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    • 2021
  • Real-time prediction of Web service of quality (QoS) provides more convenience for web services in cloud environment, but real-time QoS prediction faces severe challenges, especially under the cold-start situation. Existing literatures of real-time QoS predicting ignore that the QoS of a user/service is related to the QoS of other users/services. For example, users/services belonging to the same group of category will have similar QoS values. All of the methods ignore the group relationship because of the complexity of the model. Based on this, we propose a real-time Matrix Factorization based Clustering model (MFC), which uses category information as a new regularization term of the loss function. Specifically, in order to meet the real-time characteristic of the real-time prediction model, and to minimize the complexity of the model, we first map the QoS values of a large number of users/services to a lower-dimensional space by the PCA method, and then use the K-means algorithm calculates user/service category information, and use the average result to obtain a stable final clustering result. Extensive experiments on real-word datasets demonstrate that MFC outperforms other state-of-the-art prediction algorithms.