• Journal of Power System Engineering
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• v.8 no.3
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• pp.58-66
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• 2004

The sway motion control problem of a container hanging on the trolly is considered in the paper. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, many trolley motion control strategies are introduced and applied. In this paper, we introduce and synthesize a swing motion control system in which a small auxiliary mass is installed on the spreader made by ourselves. In this control system, the actuator reacting against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. Especially, we apply the $H_{\infty}$ based gain-scheduling control technique the anti-sway control system design problem of the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the simulation result shows that the proposed control strategy is shown to be useful to the case of time-varying system and, robust to disturbances like winds and initial sway motion.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.166-171
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• 2003

This paper presents the algorithms and Matlab Toolbox for co-simulation of distributed real-time control system based on OSEK-OS and CAN protocol. This toolbox enables the developers to analyze the timing uncertainty, which is caused by resource sharing including shared memories and networks, and to take the timing uncertainty into consideration in the early design phase. Furthermore, this toolbox helps the developers to model the behaviors of a control system by providing graphical user interface for objects of OSEK-OS and CAN. To prove the feasibility of this toolbox, a vehicle body network system is modeled with this toolbox, and the timing uncertainties are analyzed.

• The KIPS Transactions:PartA
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• v.18A no.4
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• pp.143-150
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• 2011

This paper presents an EDF based scheduling algorithm for scheduling imprecise computation model where each task consists of mandatory part and optional part. Imprecise computation is useful to manage overload condition. In overload situation, some optional parts should be removed. The proposed DOP algorithm removes optional parts of earlier deadline tasks to enhance flexibly for newly arriving tasks. A simulation result shows that DOP has better performance than other algorithms.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.39-47
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• 2010

As vehicles become intelligent for convenience and safety of drivers, in-vehicle networking (IVN) systems are essential components of intelligent vehicles. Recently, the chassis networking system which require increased network capacity and real-time capability is being developed to expand the application area of IVN systems. Also, FlexRay has been developed for the chassis networking system. However, FlexRay needs a complex scheduling method of static segment, which is a barrier for implementing the chassis networking system. Especially, if we want to migrate from CAN network to FlexRay network using CAN message database that was well constructed for the chassis networking system by automotive vendors, a novel scheduling method is necessary to be able to reduce design complexity. This paper presents a node-based scheduling method for FlexRay network system. And, in order to demonstrate the method's feasibility, its performance is evaluated through an experimental testbed.

• The Journal of Information Technology
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• v.4 no.2
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• pp.25-36
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• 2001

In this paper, we present the development of distributed dual real-time kernel system. This paper proposed that real-time applications should be split into small and simple parts with real-time constraints, Following this concept we have designed to preserve the properties of both hard real-time kernel and general kernel. To satisfy these properties, we designed real-time kernel and general kernel, that have their different properties. In real-time tasks, interrupt processing should be un. In general kernel, non real-time tasks or general tasks are run. We compared the results of this study for performance of the proposal real-time kernel with both RT Linux 0.5a and QNX 4.23A, that is, of interrupt latency scheduling precision and message passing.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.8
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• pp.343-348
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• 2013

We proposes a power-aware fixed-priority real-time scheduling algorithm for multimedia service, called static voltage scaling algorithm with multi-granularity resource reservation (STATIC-MULTIRSV). The multi-granularity resource reservation was introduced to deliver higher system utilization and better temporal isolation than the traditional approaches in [2]. Based on this, our STATIC-MULTIRSV is designed to reduce the power consumptions while guaranteeing that all I-frames of each video stream meet their deadlines. We implemented the proposed algorithm on top of ChronOS Real-time Linux [6]. We experimentally compared STATIC-MULTIRSV with other existing methods which showed that STATIC-MULTIRSV reduce power consumption by maximum 15% compared to its experimental counterparts.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.5
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• pp.218-225
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• 2001

This paper analyses the performance of network system using the CAN(Controller Area Network) protocol. Given messages are assumed to be scheduled by the DMS(Deadline Monotonic Scheduling) algorithm. The mathematical models for time-delay that can be occurred between CAN nodes are defined. The effectiveness of modeling is shown by comparing the difference of time-delay between simulations and practical experiments. We analyse the results according to the variation of factors, such as the number of nodes, the transmission speed, the message size and the number of aperiodic messages through simulation and confirm the real-time performance of lower priority messages. We also investigate the real-time performance of periodic messages when aperiodic message generates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.137-139
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• 2012

This paper presents a system architecture and database of construction quality management system which encourages real time information tracking and monitoring. It improves the real time quality record tracking by using QR code technology in the project delivery. The advantages and issues relative to QR code and the database structures of the tracking system are presented. Conventional project scheduling system, operation modeling and analysis system, and quality management system are hybridized using QR code technology. The system improves project quality management by tracking the atomic tasks which consists of a construction process at the lowest level of construction hierarchy. It analyzes the quality records to determine the causes of abnormality and/or nonconformity. Using QR code technology, the construction quality management system may be more effective than the conventional one. It was confirmed that the quality management processes in construction project delivery can be more visible and controllable by integrating QR code technology, project scheduling system, and quality management system.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1225-1232
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• 2001

In this paper, we investigate the scheduling algorithm of router system for Internet services on large scale ATM networks based on the quality-of-service(QoS) level of the input source traffics. We suggest an approprite scheduling algorithm in order to satisfy their QoS requirements. For this purpose, we first study the service requirements of the multiplexer in Internet. Second, we suggest functional architecture of the multiplexer for real time services and the scheduling algorithm to satisfy various QoS requirements. Finally, the performance measures of interest, namely steady-state average delay time and fairness of network resources, are discussed by simulation results.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.249-252
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• 2004

The automatic determination of vehicle operation status as well as continuous tracking of vehicle location with intelligent management is one of major elements to achieve the goals. Especially, vehicle operation status can only be analyzed in terms of expert experiences with real-time location data with scheduling information. However the scheduling information of individual vehicle is very difficult to be interpreted immediately because there are hundreds of thousand vehicles are run at the same time in the national wide range workplace. In this paper, we propose the location-based knowledge management system(LKMs) using the active trajectory analysis method with routing and scheduling information to cope with the problems. This system uses an inference technology with dispatching and geographic information to generate the logistics knowledge that can be furnished to the manager in the central vehicle monitoring and controlling center.