• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.205-214
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• 2008

To transfer large amount of packets fast in sensor network, it is necessary that the delay between successive packet transmissions should be minimized as possible. In Sensor network, since the Operating Systems are worked on the event driven, the Timer Event is used to transfer packets successively. However, since the transferring time of packet completely is varies very much, it is very hard to set appropriate interval. If interval is too long, delay also becomes too long but if interval is too short, the fail of transfer request would increase. In this paper, we propose ESTEO which reduces the delay between successive packet transmissions by using SendDone Event which informs that a packet transmission has been completed. In ESTEO, the delay between successive packet transmissions is shortened very much since the transmission of next Packet starts at the time when the transmission of previous packet has completed, irrespective of the transmission time. Therefore ESTEO could provide high packet transmission rate given large amount of packets.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1218-1219
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• 2011

본 논문은 KA555 Timer을 이용한 PWM회로로 구성된 아날로그 방식의 DC-DC Buck Converter와 AVR ATmega128를 이용한 PWM회로로 구성된 디지털 방식의 Buck Converter을 설계하여 각각의 특성을 비교 분석하였다. 제안된 컨버터들은 공통적으로 전원을 공급받아 전압분압회로를 통해 DC-DC Buck Converter의 PWM 제어회로부에 공급되며, 아날로그방식 컨버터의 제어부는 KA555 timer을 이용하여 구형파회로와 미분회로를 구성하고, 출력된 삼각파와 정현파를 KA555 timer을 이용하여 PWM파형으로 제어한다. 디지털방식의 컨버터는 AVR RISC 8-bit 마이크로프로세서 ATmega128을 이용하여 PWM 제어부를 구성하고 이를 LCD창을 통해 그 값을 확인할 수 있도록 설계하였다. 본 논문에서는 두 가지 방식의 제어부를 구성하여 제작 및 실험함으로써, 각각의 장단점을 비교하여 시스템 구성시 요구조건인 소형경량, 단가저감, 효율 등을 비교하여 그 상황에 맞는 설계가 가능할 것이다.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.142-151
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• 1995

The trend of compact size, light weight, low power consumption in the portable telecommunication equipments demands large scale integration and low voltage operation of chips and the minimization of the number of the components in the telecommunication terminal. According to the trend, existing chip components are modulized and are integrated as a part into a bigger chip. This paper is about the development of the peripheral units of micro-controller for mobile telecommunication terminal. Peripherals consist of DMA controller, Interrupt controller, timer, watchdog timer, clock generator, and power management unit. They are designed to be integrated with EU(Execution Unit) and BIU(Bus Interface Unit) into a 16 bit micro-controller which will be used as a core of an ASIC for next generation digital mobile telecommunication terminal. At first, whole block of the micro-controller was described by VHDL behavioral model and simulated to verify its overall operation. Then, watchdog timer, clock generator and power management unit were directly synthesized by using VHDL synthesis tool. Rest of the pheriperal units were designed and simulated by using Compass Design Tool.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.2
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• pp.5-13
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• 2000

Most networks for automation are tuned to an expected traffic condition ar their design stage. During their actual operations, however, the networks experience considerable changes in traffic from time to time. These traffic changes caused by common events like machine failure and production schedule change may adversely affect th network performance and, in turn , the performance of the connected devices. This paper presents experimental results for performance management of a Profibus-FMS network. The performance management aims to maintain a uniform level of network performance at all stations under changing network traffic. The performance management algorithm monitors the performance of individual network stations and commands the stations to change their timer values in order to have comparable performance at all stations. In order to determine the amount of timer change, the algorithm employs a set of fuzzy rules. The algorithm has been evaluated on a Profibus network.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.539-545
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• 2011

This paper describes an intelligent service robot system for managing a store in an unmanned environment. The robot can be a good replacement for humans because it is possible to work all day and to remember lots of information. We design a system architecture for configuring many intelligent functions of intelligent service robot system which consists of four layers; a User Interaction Layer, a Behavior Scheduling Layer, a Intelligent Module Layer, and a Hardware Layer. We develop an intelligent service robot 'Part Timer' based on the designed system architecture. The 'Part Timer' has many intelligent function modules such as face detection-recognition-tracking module, speech recognition module, navigation module, manipulator module, appliance control module, etc. The 'Part Timer' is possible to answer the phone and this function gives convenient interface to users.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.1
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• pp.1-6
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• 1988

For the purpose of making the detection range of fish detection system more longer and computerizing the system a parametric sound source, a timer and a digitizing circuit for the Apple II computer have been studied. The parametric sound of 5 KHz generated by passing AND gate two signals from carrier signal generator of 200KHz with modulator of 5KHz. This parametric acoustic source of 5KHz difference frequency had more higher directional resolution of 10 degrees than single frequency sound of 200KHz. Peripheral interface adaptor MC 6821 was adopted for interfacing to the Apple II personal computer. The timer consisted of six decade binary coded decimal counters (74 LS 190), and the digitizing circuit consisted of a sample and hold (LF 398) and an A/D converter(ADC 0808). The timer with 10KHz clock pulse had the measuring time from 0.1msec to 100sec. This time measuring range was satisfactory for the aim of the fish finding acoustic system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.551-555
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• 2015

Dementia of the country due to the aging population of 59 thousand people has reached serious territory. To increase the number of future dementia doubled every 20 years until 2050, in 2020 about 84 thousand people, about 127 thousand people in 2030, 2050 are estimated at 271 thousand people. If you have a gas stove when using dementia patients at home, Voice Support breaker is required in a fire can automatically block the gas valve because of a risk. In this paper, we develop a gas-timer demented patients using S3F8S19 8bit processor to use the gas safely.

• The Transactions of the Korea Information Processing Society
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• v.1 no.3
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• pp.357-366
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• 1994

The IEEE 802.4 token bus has been widely accepted as the standard for factory local area networks. The priority option of the 802.4 standard supports multiple classes of traffic by using a set of timers to control information exchange. The performance of the 802.4 priority mechanism in industrial real time control is examined. A timer assignment technique is presented for such applications. The timers are set to satisfy the worst case access delay requirements of real time control applications. Other applications that are not time constrainted can be supported simultaneously. In fact under certain conditions, such applications can also be guaranteed a minimum bandwidth allocation. Simulation results are used to evaluate the timer assignment and utililization.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1992.06a
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• pp.108-111
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• 1992