• ETRI Journal
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• v.25 no.6
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• pp.437-444
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• 2003

We derive a new joint power and rate control rule with which we can minimize the mean transmission delay in CDMA networks for a given mean transmission power. We show that it is optimal to respectively control the power inverse-linearly and the rate linearly to the square root of channel gain while maintaining the signal-to-interference ratio at a constant. We also show that the proposed joint power/rate control rule achieves excellent performance results in terms of the probability of the instantaneous delay being within a target delay against one-dimensional control schemes.

• Journal of Internet Computing and Services
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• v.3 no.1
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• pp.1-10
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• 2002

A remote image transmission apparatus combines robot technology and image transmission there is safe problem or place that a person can not go. Recently, control apparatus that use wire and RF between web server and robot for remote control are developed. But, there is problem that must install Internet line and communication distance. Transmission distance problem can solve when using the equipment of RF, but price of RF router is problem that is very high cost. In this paper, we developed remote control system using the cellular phone communication network that can control image transmission and image transmission apparatus to solve these problem. Developed system could solve defects of methods that use existent RF and internet. And could transmit the most suitable image and voice under limited condition include current communication network.

• Journal of Drive and Control
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• v.17 no.3
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• pp.47-56
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• 2020

As a shift control of automatic transmission was managed with the electronic control unit (ECU), shift quality which is a measure of shift shock during gear change has markedly improved. However, the initial clutch pressure control of the clutch filling phase should continue to rely on the predetermined control input since the input and output speeds are unchanged until the shifting process attains the inertia phase. It is critical to minimize the clutch response time and control the clutch pressure accurately at the end of clutch fill to achieve quick shift response and smoothness. Advanced transmission companies have adopted an auto calibration method which establishes the databases for the clutch piston fill-up attributes and the frictional characteristics of the disks. In this study, a distinctive auto calibration algorithm for forklift transmission under development is proposed and verified with the real-vehicle test. The experimental calibration results showed consistent turbine dynamics at the initial stage of shifts with the properly calibrated clutch-fill control parameters. By using this technique, it is necessary to finalize the shift control for the various operation conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.301-306
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• 2008

Drivers are becoming more fatigued and uncomfortable with increase in traffic density, and this condition can lead to slower reaction time. Consequently, they may face the danger of traffic accidents due to their inability to cope with frequent gear shifting. To reduce this risk, some drivers prefer automatic transmission (AT) over manual transmission (MT). The AT offers more superior drivability and less shifting shock than the MT; therefore, the AT market share has been increasing. The AT is controlled by an electronic control unit (ECU), which provides better shifting performance. The transmission control unit (TCU) is a higher-value-added product, so the companies that have advanced technologies end to evade technology transfer. With more cars gradually using the ECU, the TCU is expected to be faster and more efficient for organic communication and arithmetic processing between the control systems than the l6-bit controller. In this paper, the model of an automatic transmission vehicle using MATLAB/Simulink is developed for the Hardware in-the-Loop (HIL) simulation with a 32-bit embedded system, and also the AT control logic for shifting is developed by using MATLAB/Simulink. The developed AT control logic, transformed automatically by real time workshop toolbox, is loaded to a 32-bit embedded system platform based on Freescale's MPC565. With both vehicle model and 32-bit embedded system platform, we make the HIL simulation system and HIL simulation of AT based on real time operating system (RTOS) is performed. According to the simulation results, the developed HIL simulator will be used for the performance test of embedded system for AT with low cost and effort.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.403-408
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• 2010

The sensor nodes can be installed in the environment in which the temperature change is considerable, such as desert, urban, and data center. Particularly, because the output power becomes less than the targeted power if a temperature is increasing, link quality is degraded and packet losses are occurred. In order to compensate the temperature changes, existing schemes detect the change of the link quality between nodes and control transmission power through a series of feedback process. However, these approaches can cause heavy overhead by additional control packets. In this paper, we propose the T2PC(Temperature-aware Transmission Power Control) to keep up the link quality despite temperature variation. At each node, T2PC compensates the attenuated link quality by controlling the transmission power based on the local temperature measurement. In addition, the packet reception ratio can be improved with less control packets than ones required in existing transmission power control methods based on the feedback control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.811-816
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• 2011

This study includes investigation on sound transmission phenomena through a structural panel including structural vibration and feedback control methodology to minimize the transmission. Focus is placed on finding the relation between vibration pattern and sound transmission, and on finding optimal sensor and actuator location. A simple analog feedback control circuit is designed and implemented to verify the approach.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.45-48
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• 2002

This paper presents a QoS-guaranteed traffic control system which supports QoS of realtime packet transmission for the multimedia communication. The traffic control system presented in this paper applies the integrated service model and provides QoS o(packet transmission by means of determining the packet transmission rate with the policy of network manager and the optimal resource allocation according to the end-to-end traffic load. It also provides QoS for the realtime packet transmission through the AWF2Q+ Scheduling algorithm and per-class queuing method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.82.1-82
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• 2001

It is known that existence of irregular transmission time delay is a major bottleneck for application of advanced robot control schemes to internet telerobotic systems. In the internet teleoperation system, the irregular transmission time delay causes a critical problem, which is unstable and inaccurate. This paper suggests a practical internet teleoperation system with streaming buffer system, which consists of a buffer, a buffer manager, and a control timer. The proposed system converts the irregular transmission time delay to constant. So, the system effectively transmits the control input to a remote site to operate a robot stably and accurately. This feature enables short control input interval. That means the entire system has ...

• Journal of Korea Multimedia Society
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• v.19 no.5
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• pp.924-931
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• 2016

In this paper, Various network adaptive MAC scheduling technique is proposed to effectively overcome limits of narrow bandwidth and low transmission speed in underwater. UPFC(Underwater Packet Flow Control) is a technique to reduce both the number of transmission and transmission time using three types (Normal, Blocked, Parallel) of data transmission. In this technique, the load information, in which a transmission node have, is transmitted to destination node using marginal bit in reserved header. Then the transmitted information is referred to determine weighting factor. According to the weighting factor, scheduling is dynamically changed adaptively. The performance of UPFC is analyzed and flow control technique which can be applied to Cluster Based Network and Ad Hoc network as well.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.72-77
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• 2011

Dynamic Line Rating (DLR) techniques have been greatly worthy of notice for efficiently increasing transmission capacity as well as controlling load-flow in overhead transmission lines, in comparison with the existing power system operating with Static Line Rating (SLR). This paper describes an utilization method to implement DLR control system for old transmission lines built in the first stage using the ground clearance design standard with lower dips. The suggested DLR system is focused on designing as temperature control system rather than current/load control system. Based on several performance for conductor temperatures, it is shown that DLR system with efficiency can be implemented.