• 한국IT서비스학회지
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• 제13권1호
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• pp.209-220
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• 2014

Most of monitoring systems in logistics industry have limitations on monitoring container information in real-time. And customers only could check information gathered from certain points through web browser. That is why it is very hard to take actions in advance when emergency situation has happened. But if customers could check information such as position and status of freight in real-time through their mobile devices, they could take prompt actions. So, in this study, mobile application based on mobile devices is developed to monitor position and status information of the container in real-time. Entire devices monitoring container in aspect of logistics security are handled by workers in the field. So it is strongly required to develop monitoring system operated in mobile devices. For that reason this study aims to develop mobile application in order to monitor information related to container security and safety in real-time.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (1)
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• pp.433-435
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• 2002

최근 real-time 시스템들이 많이 개발되어 상용화되고 있고, 여러 산업분야에 적용되고 있다. 한편 리눅스 운영체제의 사용이 증가하고 안정화됨에 따라, 이 시스템에 real-time 기능을 추가하기 위한 노력으로 여러 프로젝트가 진행 중에 있다. 이 가운데 시스템간에 네트웍 패킷을 송수신하고 이를 처리하는 과정에 대해 본 논문은 soft real-time을 적응하고자 한다. 기존 방식은 TOP HALF와 BOTTOM HALF로 인터럽트 처리과정을 나누어 BOTTOM HALF의 크기와 시스템 콜의 사용 빈도에 비례하여 종료시간을 예측할 수 없다. 이에 본 논문에서는 real-time 네트웍 패킷을 좀더 신속히 처리할 수 있도록 네트웍 인터럽트 처리 방안을 소개하고자 한다.

• International journal of advanced smart convergence
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• 제11권1호
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• pp.28-35
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• 2022

This paper presents a performance evaluation of real-time Linux for industrial real-time platforms. On industrial platforms, multicore processors are popular due to their work distribution efficiency and cost-effectiveness. Multicore processors, however, are not designed for applications with real-time constraints, and their performance capabilities depend on their core configurations. In order to assess the feasibility of a multicore processor for real-time applications, we conduct a performance evaluation of a general processor and a low-power processor to provide an experimental environment of real-time Linux on both Xenomai and RT-preempt considering the multicore configuration. The real-time performance is evaluated through scheduling latency and in an environment with loads on the CPU, memory, and network to consider an actual situation. The results show a difference between a low-power and a general-purpose processor, but from developer's point of view, it shows that the low-power processor is a proper solution to accommodate low power situations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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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.

• 디지털산업정보학회논문지
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• 제9권4호
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• pp.127-134
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• 2013

While there are many services that can check current traffic condition and application program such as bus arrival alarm are developed, since it only provide simple alarm and check level of information, it is still insufficient in many senses. Therefore, the program that try to develop in this study is the system that predict arrival time to destination and inform the bus passengers by applying real time traffic information. The system developed related to this study is still very inadequate. In the system developed in this thesis, when the user input the current bus number and destination using smart-phone, relevant server acquire the bus route information from bus information DB, and analyze real time traffic information based on the information from traffic information DB, and inform customer of expected arrival time to destination. In this thesis, traffic congestion can be eased off and regular operation of public transportation can be improved with reliable destination arrival alarm. Also, it is considered that pattern of bus users can be analyzed by using these information, and analyzing average transport speed and time of public transportation, travel time depending on various situation can give a boost to study related to transportation information and its development.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.134-142
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• 2021

This paper proposes a probabilistic method in analyzing timing measurements to determine the periodicity of real-time tasks. The proposed method fills a gap in existing techniques, which either concentrate on the estimation of worst-case execution times, or do not consider the stochastic behavior of the real-time scheduler. Our method is based on the Z-test statistical analysis which calculates the probability of the measured period to fall within a user-defined standard deviation limit. The distribution of the measured period should satisfy two conditions: its center (statistical mean) should be equal to the scheduled period of the real-time task, and that it should be symmetrical with most of the samples focused on the center. To ensure that these requirements are met, a data adjustment process, which omits any outliers in the expense of accuracy, is presented. Then, the Z-score of the distribution according to the user-defined deviation limit provides a probability which determines the periodicity of the real-time task. Experiments are conducted to analyze the timing measurements of real-time tasks based on real-time Linux extensions of Xenomai and RT-Preempt. The results indicate that the proposed method is able to provide easier interpretation of the periodicity of real-time tasks which are valuable especially in comparing the performance of various real-time systems.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (D)
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• pp.291-296
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• 2008

Wireless network technologies are becoming more widely used in industrial environment. The industrial communication system requires a real-time delivery of messages. The sensors periodically senses the physical environment and wants to deliver the data in real-time to the sink. This paper proposes a real-time protocol for periodic messages on wireless sensor and actor networks to be used in industrial communications. The proposed protocol delivers the data message using the shortest path from the source and the nearest actor. The protocol considers the energy consumption by reducing the number of broadcast messages during flooding. We have evaluated the performance of the proposed protocol using QualNet simulator. The simulation results show that the data messages have been delivered in real-time and the number of broadcast messages is reduced from 90% to 35% compared the existing protocols.

• 대한임베디드공학회논문지
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• 제2권2호
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• pp.95-100
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• 2007

Recently ubiquitous application services are developed plentifully using RFID techniques in the field of distribution and security industries. However, except these field the applications using RFID are not mature yet. In this study, we proposed a real-time context service model of the u-conference based on the real-time contextual information acquired from conference and exposition. With collection of real-time contextual information for u-conference, the model can provide a lot of information services on the state of session attendee, doorway control, affairs, user certification, presentation progress etc. For the verification of proposed real-time context service model of u-conference, we design and implement the conference progress state service included the state of session attendee, user certification and presentation progress etc. This service provides the presentation state information included the current presenter, the paper list, the number of session attendee, the schedule and place of each session using the collecting RFID tag and the related information.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.69-72
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• 1999

In this paper, the implementation method for the extending real-time execution in MMS Implementation is proposed. For this, the method of MMS over ATM(Asynchronous Transfer Mode) and IEEE 802.12 network is analyzed. By the analysis of service response time, making the ASIC of encoding and decoding parts are proposed for one of the real time extension in MMS. The main goals of this paper to analyze and propose suitable methods to meet the real time requirements in MMS applied system.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.281-291
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• 2019

In order to reflect complex and diverse building types, resident characteristics and disaster factors, it is necessary to introduce a flexible situation-based response system based on real-time information. Intelligent CCTV, hybrid sensor, location scanner, and customized broadcasting device were examined to introduce for the real-time response intelligent response system and its feasibility was verified through field test. In addition, based on the real-time information, the evacuation simulation was executed by assuming the dormitory building and the resident of the school, and the safety of the evacuation and the shortening of the pinnacle time were confirmed. The feasibility of real time information based evacuation comparing with the existing evacuation system were verified in the case of evacuation.