• Title/Summary/Keyword: Real - time

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Adaptive Packet Scheduling Scheme to Support Real-time Traffic in WLAN Mesh Networks

  • Zhu, Rongb;Qin, Yingying;Lai, Chin-Feng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.9
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    • pp.1492-1512
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    • 2011
  • Due to multiple hops, mobility and time-varying channel, supporting delay sensitive real-time traffic in wireless local area network-based (WLAN) mesh networks is a challenging task. In particular for real-time traffic subject to medium access control (MAC) layer control overhead, such as preamble, carrier sense waiting time and the random backoff period, the performance of real-time flows will be degraded greatly. In order to support real-time traffic, an efficient adaptive packet scheduling (APS) scheme is proposed, which aims to improve the system performance by guaranteeing inter-class, intra-class service differentiation and adaptively adjusting the packet length. APS classifies incoming packets by the IEEE 802.11e access class and then queued into a suitable buffer queue. APS employs strict priority service discipline for resource allocation among different service classes to achieve inter-class fairness. By estimating the received signal to interference plus noise ratio (SINR) per bit and current link condition, APS is able to calculate the optimized packet length with bi-dimensional markov MAC model to improve system performance. To achieve the fairness of intra-class, APS also takes maximum tolerable packet delay, transmission requests, and average allocation transmission into consideration to allocate transmission opportunity to the corresponding traffic. Detailed simulation results and comparison with IEEE 802.11e enhanced distributed channel access (EDCA) scheme show that the proposed APS scheme is able to effectively provide inter-class and intra-class differentiate services and improve QoS for real-time traffic in terms of throughput, end-to-end delay, packet loss rate and fairness.

Characterization of Differentiation of the Supernumerary Dental Pulp Stem Cells toward the Odontoblast by Application Period of Additives (과잉치 치수유래 줄기세포의 분화제 처리 기간에 따른 상아모세포 발현 특성)

  • Kim, Jongsoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.42 no.4
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    • pp.312-318
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    • 2015
  • The aim of this study was to investigate the possibility of the supernumerary teeth for the stem cell source in dentistry. The Real Time Quantitative Reverse Transcription Polymerase Chain Reaction (Real Time qRT-PCR) method was used to evaluate the differentiation toward the odontoblast of the supernumerary dental pulp stem cells (sDPSCs). Supernumerary dental pulp stem cells were obtained from 3 children (2 males and 1 female, age 7 to 9) diagnosed that the eruption of permanent teeth was disturbed by supernumerary teeth. The common genes for odontoblasts are alkaline phosphatase (ALP), osteocalcin (OC), osteonectin (ON), dentin matrix acidic phosphoprotein 1 (DMP-1), dentin sialophosphoprotein (DSPP). The sDPSCs were treated for 0 days, 8 days and 14 days with additives and then Real Time qRT-PCR was performed in intervals of 0 days, 8 days and 14 days. The alizarin-red solution staining was performed to visualize the stained color for the degree of calcification at 7 days, 14 days, 21 days and 28 days after treating additives to the sDPSCs. From the result of the Real Time qRT-PCR, the manifestation exhibit maximum value at 8 days after additive treatment and shifted to a decrease trend at 14 days. Alizarin-red solution staining exhibit light results at 7 days after staining and generalized dark result at 14 days. Consequently, in studies with sDPSCs, appropriate treatment time of additives for Real Time qRT-PCR is 8 days. Also, a suitable period of Alizarin-red solution staining is 14 days.

Detection of Hepatitis B Virus Using Micro-PCR and Real-Time PCR Methods (Micro-PCR과 Real-Time PCR을 이용한 B형 간염 바이러스 검출)

  • Kang, Won;Park, Sang-Bum;Nam, Youn-Hyoung;An, Young-Chang;Lee, Sang-Hyun;Jang, Won-Cheoul;Park, Su-Min;Kim, Jong-Wan;Chong, Song-Chun
    • Journal of the Korean Chemical Society
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    • v.51 no.1
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    • pp.36-42
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    • 2007
  • Hepatitis B is a serious public health problem leading to chronic infection and liver cancer. Quantitation of circulating hepatitis B virus (HBV) is important for monitoring disease progression and for assessing the response to antiviral therapy. In this study, by using Real-Time PCR and novel Micro-PCR assay method, we measured HBV concentration in the clinical sample. A total of 120 serum samples from patients with HBV infection collected was in Dankook university hospital to compare the detection limit, sensitivity, specificity and reproducibility of the two assay methods. These findings of this study suggest that Micro-PCR and Real-Time PCR assay methods are comparable to each other in there detection limit, sensitivity, and reproducibility for HBV DNA quantitation. However, Micro-PCR assay is more efficient than Real-Time PCR method, because Real-Time PCR is not so time - consuming, technically easy and need to reagent of a small quantity. It will be useful for rapid and reliable clinical diagnosis of HBV in many countries.

Detection of Salmonella Using the Loop Mediated Isothermal Amplification and Real-time PCR (등온 증폭법과 Real-time PCR을 이용한 Salmonella 검출)

  • Ahn, Young-Chang;Cho, Min-Ho;Yoon, Il-Kyu;Jung, Duck-Hyun;Lee, Eun-Young;Kim, Jin-Ho;Jang, Won-Cheoul
    • Journal of the Korean Chemical Society
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    • v.54 no.2
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    • pp.215-221
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    • 2010
  • Salmonella is an important food-and water-borne pathogen associated with acute gastrointestinal illnesses around the world. The most common serotypes isolated from humans are Salmonella enterica serotype Typhimurium (S. Typhimurium) and S. Enteritidis. Traditional detection methods for Salmonella are based on cultures using selective media and characterization of suspicious colonies by biochemical and serological tests. These methods are generally time-consuming and not so highly sensitive. Recently, the Loop Mediated Isothermal Amplification and real-time PCR has been used as a highly sensitive, specific, and rapid test for the presence of pathogenic bacteria. In this study, a LAMP and real-time PCR was used to detect S. Typhimurium and S. Enteritidis. We selected target genes, which were the in invA and a randomly cloned sequence specific for the genus Salmonella. With LAMP and real-time PCR, random sequence was detected from Salmonella spp, invA were detected from all strain of S. Typhimurium and S. Enteritidis. This assay indicate that the specificity, sensitivity and rapid of the LAMP and real-time PCR make them potentially valuable tools for detection of S. Typhimurium and S. Enteritidis.

Decentralized Output Feedback Robust Passive Control for Linear Interconnected Uncertain Time-Delay Systems

  • Shim, Duk-Sum
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.2
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    • pp.140-146
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    • 2002
  • We consider a class of large-scale interconnected time delay systems and investigate a decentralized robust passive control problem. sufficient conditions for unforced interconnected uncertain systems with time delay to be robustly stable with extended strictly passivity is given in terms of algebraic Riccati inequality and linear matrix inequality. The decentralized robust passive control problem for norm-bounded and positive real uncertainty is shown to be converted to extended strictly positive real control problem for a modified system which contains neither time delay nor uncertainty.

Real-time simulation and control of indoor air exchange volume based on Digital Twin Platform

  • Chia-Ying Lin;I-Chen Wu
    • International conference on construction engineering and project management
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    • 2024.07a
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    • pp.637-644
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    • 2024
  • Building Information Modeling (BIM) technology has been widely adopted in the construction industry. However, a challenge encountered in the operational phase is that building object data cannot be updated in real time. The concept of Digital Twin is to digitally simulate objects, environments, and processes in the real world, employing real-time monitoring, simulation, and prediction to achieve dynamic integration between the virtual and the real. This research considers an example related to indoor air quality for realizing the concept of Digital Twin and solving the problem that the digital twin platform cannot be updated in real time. In indoor air quality monitoring, the ventilation rate and the presence of occupants significantly affects carbon dioxide concentration. This study uses the indoor carbon dioxide concentration recommended by the Taiwan Environmental Protection Agency as a reference standard for air quality measurement, providing a solution to the aforementioned challenges. The research develops a digital twin platform using Unity, which seamlessly integrates BIM and IoT technology to realize and synchronize virtual and real environments. Deep learning techniques are applied to process camera images and real-time monitoring data from IoT sensors. The camera images are utilized to detect the entry and exit of individuals indoors, while monitoring data to understand environmental conditions. These data serve as a basis for calculating carbon dioxide concentration and determining the optimal indoor air exchange volume. This platform not only simulates the air quality of the environment but also aids space managers in decision-making to optimize indoor environments. It enables real-time monitoring and contributes to energy conservation.

Implementation of the multi-target tracker for MIROSOT

  • In, Chu-Sik;Choi, Yong-Hee;Lee, Ja-Sung
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.828-831
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    • 1997
  • One of the most important design factor for the image tracker is the speed of the data processing which allows real-time operation of the system and provides reasonably accurate performance at the same time. Use of powerful DSP alone does not guarantee to meet such requirement. In this paper, a simple efficient algorithm for real-time multi-target image tracking is suggested. The suggested method is based on a recursive centroiding technique and color table look-up. This method has been successfully implemented in a image processing system for Micro-Robot Soccer Tournament(MIROSOT). This tracker can track positions of a ball, 3 enemies, and 3 agents at the same time. The experimental results show that the processing time for each frame of image is less than 7ms, which is well within the 60Hz sampling interval for real-time operation.

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Real- Time Estimation of the Ventricular Relaxation Time Constant

  • Chun Honggu;Kim Hee Chan;Sohn Daewon
    • Journal of Biomedical Engineering Research
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    • v.26 no.2
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    • pp.87-93
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    • 2005
  • A new method for real-time estimating left ventricular relaxation time constant (T) from the left ventricular (LV) pressure waveform, based on the isovolumic relaxation model, is proposed. The presented method uses a recursive least squares (RLS) algorithm to accomplish real-time estimation. A new criterion to detect the end-point of the isovolumic relaxation period (IRP) for the estimation of T is also introduced, which is based on the pattern analysis of mean square errors between the original and reconstructed pressure waveforms. We have verified the performance of the new method in over 4,600 beats obtained from 70 patients. The results demonstrate that the proposed method provides more stable and reliable estimation of τ than the conventional 'off-line' methods.

Exploiting Static Non-Uniform Cache Architectures for Hard Real-Time Computing

  • Ding, Yiqiang;Zhang, Wei
    • Journal of Computing Science and Engineering
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    • v.9 no.4
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    • pp.177-189
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    • 2015
  • High-performance processors using Non-Uniform Cache Architecture (NUCA) are increasingly used to deal with the growing wire delays in multicore/manycore processors. Due to the convergence of high-performance computing with embedded computing, NUCA caches are expected to benefit high-end embedded systems as well. However, for real-time systems that use multicore processors with NUCA caches, it is crucial to bound worst-case execution time (WCET) accurately and safely. In this paper, we developed a WCET analysis approach by considering the effect of static NUCA caches on WCET. We compared the WCET in real-time applications with different topologies of static NUCA caches. Our experimental results demonstrated that the static NUCA cache could improve the worst-case performance of realtime applications using multicore processor compared to the cache with uniform access time.

Multimicrocomputer Network Design for Real-Time Parallel Processing (실시간 병렬처리를 위한 다중마이크로컴퓨터망의 설계)

  • 김진호;고광식;김항준;최흥문
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.10
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    • pp.1518-1527
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    • 1989
  • We proposed a technique to design a multimicrocomputer system for real-time parallel processing with an interconnection network which has good network latency time. In order to simplify the performance evaluation and the design procedure under the hard real-time constraints we defined network latency time which takes into account the queueing delays of the networks. We designed a dynamic interconnection network following the proposed technique, and the simulation results show that we can easily estimate the multimicrocomputer system's approximate performance using the defined network latency time before the actual design, so this definition can help the efficient design of the real-time parallel processing systems.

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