• ETRI Journal
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• v.39 no.3
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• pp.345-352
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• 2017

Traffic management is a highly beneficial mechanism for satisfying quality-of-service requirements and overcoming the resource scarcity problems in networks. This paper introduces an optimal connection admission control mechanism to decrease the packet loss ratio and end-to-end delay in cognitive radio sensor networks (CRSNs). This mechanism admits data flows based on the value of information sent by the sensor nodes, the network state, and the estimated required resources of the data flows. The number of required channels of each data flow is estimated using a proposed formula that is inspired by a graph coloring approach. The proposed admission control mechanism is formulated as a semi-Markov decision process and a linear programming problem is derived to obtain the optimal admission control policy for obtaining the maximum reward. Simulation results demonstrate that the proposed mechanism outperforms a recently proposed admission control mechanism in CRSNs.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.423-428
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• 1999

A high precision hot strip width control method has been developed in this study by applying interstand looper tension measuring system at finishing mill stands. As with deviation of hot rolled steel strip is closely related to abnormal increase in the interstand strip tension, on-line measuring device of looped tension and data analyzing system was developed in this study. To determine dominant factors that will cause local width shortage, the logged data sets of bar width, bar thickness, looper tension, and strip thickness along the strip length were correlated with the data set of strip width change. With the result of the correlation analysis, existing sequence control logic and parameters for looper actuator were modified for strip width quality and the gains of the looper control were refined for the stable operation during the full passage of rolled strip. The on-line tension measurement and tension feedback control for looper system improved strip travelling stability and reduced strip width deviation in the srip top end region.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.79-84
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• 1990

Analog systems could not fully deal with instrumentation and control facilities in power plants since these facilities have become more and more complex on account of various needs for large power generation capacity highly cost effective operation to conserve energy and operation management to prevent pollution. Digitalizations of control device and augmentations of control informations increased the necessity of fiber optic data networks which have excellent noise immunity and high quality wide-band with information transfer capability. The goal of this study is to offer a fiber optic data-way system which has high reliabilities, high data transmission rates and small cable ducts with large transmission capacities for the instrumentation and control of power plants.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.894-900
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• 1998

In this paper, a communication method is proposed for the development of a main engine remote control system. The main engine control system compriese three subsystems such as RCS (Remote Control System) BCS (Bridge Control System) and SS (Safety System), Thus it is required to exchange data each other among these subsystems. The communication method has simplified hardware through the minimization of communication components where the interrupt method are employed for receiving and the polling method for transmitting. We discuss a methodology of using a ring buffer for data storage physically which has two buffers virtually for the effective use of memory. This communication method presents a good performance in the system which has rather small numbers of communication data.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.2
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• pp.32-38
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• 2006

A vehicle adaptive cruise control strategy based on human drivers' driving characteristics has been investigated. Human drivers driving characteristics have been analyzed using vehicle test data obtained from 125 participants. The control algorithm has been designed to incorporate the driving characteristics of the human drivers and to achieve natural vehicle behavior of the controlled vehicle that would reduce the workload of the human driver. Vehicle following characteristics of the cruise controlled vehicle have been compared to real-world driving radar sensor data of human drivers using a validated vehicle simulator. and compare nominal cruise control and adaptive cruise control.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.78-84
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• 2006

This paper describes UAV (Unmanned Aerial Vehicle) control system which employs PC104 modules. It is controlled by application program based on Linux OS. This application consists of both Linux device driver in kernel-space and user application in user-space. In order to get data required in the unmanned flight, external devices are connected to PC104 modules. We explain how Linux device drivers deal with data transmitted by external devices and we account for how the user application controls UAV on the basis of data processed in the device driver as well. Furthermore we look into the role of GCS (Ground Control Station) which is to monitor the state of UAV.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2140-2142
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• 2003

Recently, TCP/IP on Ethernet protocol is in use environment of LAN have developed a single chip by hardware. Therefore, the study about the single chip applies to the system control application like information electronic appliances, manufacturing automation machine has been made progress. This paper is the development of experimental Client node and Serve node that can transfer input-output data needed on Network Control System Client node is a sensor part of control system, that is, an analog signal is applicable to output data convert AD through LAN. Server node data sended in client convert DA, and then it is applicable to driver of Control System, so it achieves its part. In this study, is prove that using TCP/IP construct Network Control System.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.750-753
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• 2003

In this paper, we have developed the web-based management system for greenhouse teleoperation. The remote control system consists of database, web-server, controller in greenhouse, and clients. The database in the server stores user informations and greenhouse conditions, and is used to manage user login and conditioning data. The management system developed by using Java applet, which is a client program for effective and easy management of greenhouse, monitors the greenhouse in real time. Master and driver boards installed in greenhouse control unit. Database on flowering to collect and analyze data exchanges data with the server. The greenhouse can be managed effectively by timer routine, repeat control within setting time, and algorithm of setting points. Also, the greenhouse conditions can be controlled by manual or remote controller (PC) through web browser in internet. Furthermore, all of the control devices of the greenhouse are managed by remote control using PC and checked via camera installed in greenhouse.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.3
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• pp.185-190
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• 2022

We propose a high speed data communication method for motor drive systems with fast control cycle in order to collect state variables of motor control without degrading control performance. Ethernet is chosen for communication device, and multi-core DSP architecture is exploited for communication processing load distribution. The communication program including network protocol stack and motor control program are assigned to two separate cores, and data between two cores are exchanged using interrupt-based inter-process communication mechanism, which enables to achieve a high-speed communication performance without degrading the motor control performance. The performance of developed communication method is demonstrated by real experiments using TCP, UDP and Raw Socket protocols in an experimental setup consisting of TI's TMS320F28388D motor control card and MS Windows PC.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.140-149
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• 2004

Data broadcast has received much attention as a very efficient method for disseminating data items in mobile environment with large number of mobile clients. In this approach, a database server periodically and continuously broadcasts data items through wireless channels and clients perform read-only transactions by accessing necessary data items from the air. While broadcasting, the server must also process update transactions on the database, which raises an obstacle for client's accessing consistent data. In this research, we propose a new algorithm SCDSC(Serialization Checking with DirtySet on Commit) which is an alternative for solving the concurrency control problem efficiently. The SCDSC is a kind of optimistic concurrency control in that a client checks the consistency of data using a DirtySet as a part of data broadcast when it commits its transaction. In each broadcast cycle, the server updates and disseminates the DirtySet with newly changed data items for last few cycles in the sliding window approach. We perform an analysis and a simulation study to evaluate the performance of our SCDSC algorithm in terms of data consistency and data currency.