• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1423-1436
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• 1992

In the paper, a CAT interface supporting multitask is realized. To interface a computer with measuring instruments, a GPIB card is designed and implemented. Controlling and displaying software using OOP and GUI are programmed with C++. A spectrum analyzer and a power meter are chosen as object instrument to be controlled. Total 9 modules are configured to manage the various resources and each module in integrated system. Also in case that several instruments are used, the system is realized to be capable of multitasking to exchange the data mutually. The multitasking is implemented under the time-sharing DOS environment. Thread-based method is used for processing, and Round Robin method for scheduling. Provided proper software modules for other object instruments are integrated, the system can control more measuring instruments simultaneously by the computer. Users can save the time and errors even without expert knowledge.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.154-158
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• 2008

Autonomous business card exchange system using ZigBee with low power and short range was configured In the autonomous business card exchange system characterized as full mesh network in which every node exchanges each information one by one, it is necessary to reduce the time taken for information to be exchanged. In this paper, the novel method where the node ID is exchanged based on CSMA/CA and then the information of each node is broadcast to other nodes according to the ID list based on FIFO. The time required for exchanging information using the proposed method was analyzed and compared with the direct exchange method based on CSMA/CA. The results show that it takes less time in the proposed method than the direct exchange time.

• Current Photovoltaic Research
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• v.5 no.3
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• pp.100-104
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• 2017

This paper analyzes the correlation between Net Benefit Test (NBT) and System marginal price (SMP), which has a significant impact on the allocation of demand response (DR) resources in resource scheduling and commitment (RSC) process, based on the performance data of the demand resource market which has been established in 2014. Demand resources compete with generation resources in the RSC process, and it is prescribed to use demand resources only when net benefit occurs. Analysis result shows that the larger the SMP than the Net Benefit Threshold Price (NBTP), the more the winning bid of demand response resource was. It is interpreted that the introduction of NBT in DR market is justified. The demand resource market has been steadily growing. It is required to expand the scope of resources up to the small-sized DR, and to expand the functionalities of demand resources not only in the current energy market but also in the reserve market in the future. In order for that, institutional improvements are required.

• International Journal of Control, Automation, and Systems
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• v.2 no.3
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• pp.279-288
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• 2004

This paper presents a novel design for a tubular linear brushless permanent-magnet motor. In this design, the magnets in the moving part are oriented in an NS-NS―SN-SN fashion which leads to higher magnetic force near the like-pole region. An analytical methodology to calculate the motor force and to size the actuator was developed. The linear motor is operated in conjunction with a position sensor, three power amplifiers, and a controller to form a complete solution for controlled precision actuation. Real-time digital controllers enhanced the dynamic performance of the motor, and gain scheduling reduced the effects of a nonlinear dead band. In its current state, the motor has a rise time of 30 ms, a settling time of 60 ms, and 25% overshoot to a 5-mm step command. The motor has a maximum speed of 1.5 m/s and acceleration up to 10 g. It has a 10-cm travel range and 26-N maximum pull-out force. The compact size of the motor suggests it could be used in robotic applications requiring moderate force and precision, such as robotic-gripper positioning or actuation. The moving part of the motor can extend significantly beyond its fixed support base. This reaching ability makes it useful in applications requiring a small, direct-drive actuator, which is required to extend into a spatially constrained environment.

• ETRI Journal
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• v.37 no.3
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• pp.480-490
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• 2015

The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.42-49
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• 2007

For electricity markets to function in a truly competitive and efficient manner, it is not enough to focus solely on improving the efficiencies of power supply. To recognize price-responsive load as a reliability resource, the customer must be provided with price signals and an instrument to respond to these signals, preferably automatically. This paper attempts to develop the Windows-based load management system in competitive electricity markets, allowing the user to monitor the current energy consumption or billing information, to analyze the historical data, and to implement the consumption strategy for cost savings with nine possible scenarios adopted. Finally, this modeling framework will serve as a template containing the basic concepts that any load management system should address.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3113-3118
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• 2000

A framework proposed in this paper includes representations of multi-objectives rule-basd constraint satisfaction problem(RCSP) and especially, flexible structure of RCSP which provides adequate solution sithin an expectation time and adaptively considers some change of constratraints on the RCSP. In this study, the power system implemented by above framework is entirely programmed by using a modeling system for the quantitative model and a rule-based constraint programming tool for the qualitative model. The results of an exemplary cse show how the structure that involves the problem representation gives the scheduler an effective decision and what are the advantages of the easy and diverse representation for considering the techmical characteristics of the units on the RCSP over the traditional problem.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.1-21
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• 2003

In this research, we developed a Multi-Agent based Negotiation Support System to be able to increase the competitive power of a company in dynamic environment and correspond to various orders of customers by diffusion of electronic commerce. The system uses the agent technology that is being embossed as new paradigm in dynamic environment and flexible system framework. The multi-agent technology is used to solve these problems through cooperation of agent. The system consists of six sub agents: Mediator, manufacturability Analysis Agent, Process Planning Agent, Scheduling Agent, Selection Agent, Negotiation-strategy Building Agent. In this paper, the proposed Multi-Agent based Negotiation Support System takes aim at the automation of transaction process from ordering to manufacturing plan through the automation of negotiation that is the most important in order-taking transaction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2382-2388
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• 2014

To provide network reliability in indoor wireless communication systems, we should resolve the problem of unexpected network failure rapidly. In this paper, we propose an adaptive resource management (ARM) scheme to support seamless connectivity to users. In consideration of system throughput and user fairness simultaneously, the ARM scheme adaptively determines the set of healing channels, and performs scheduling and power allocation iteratively based on a constrained non-convex optimization technique. Through intensive simulations, we demonstrate the superior performance results of the proposed ARM scheme in terms of the average cell capacity and user fairness.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.11 s.104
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• pp.1311-1317
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• 2005

In environmental Impact assessment, noise impact assessment usually consists of three stages-surveying the existing noise levels by measurements, predicting noise levels induced by construction works and predicting noise levels after the completion of a project. The distance-attenuation relation of a point source, which has been used to predict the noise level due to its simplicity does not consider complex acoustic phenomena like multi-reflection, -diffraction and -absorption due to complex topographic configuration of buildings and terrains. For the consideration of such physical complexities. a noise mapping tool is adopted to produce a series of noise maps, which are those for the present, tot the works of construction and for the future. For accurate noise mapping, acoustical and topographic Information is used. Standard sound power levels and directivities of various construction equipments are need and scheduling of construction processes and locations of the equipments should be provided. In the case of exceeding legal limit, mitigation measures are applied to satisfy the legal limits and subsequent noise map is obtained and checked.