• Journal of Korea Society of Digital Industry and Information Management
• /
• v.10 no.3
• /
• pp.11-21
• /
• 2014

In this paper, concerning the various advertising and policy advertising of the election with respect to whether to deliver a message to a large number of people, we design and implement an automative system what enables sending the text messages directly from the server to the client and also fast feedback is enabled by utilizing a number of operational programs to connect to the server. Therefore, we design and implement the automative communication system which enables delivering message to each user mobile terminal from a plurality of relay mobile terminals by utilizing the mobile instant messenger, not to deliver a message from the server to the mobile instant messenger user directly. In result of comparative analysis on the number of times of data transmission, this automative communication system utilizing mobile instant messenger shows the result that it enables transmitting five times per minute as it can copy and paste in the automation system regardless of the size of the data loading, otherwise in case of transmitting manually it show the result that the number of times of data transmission is reduced if the size of the data is larger.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.127-128
• /
• 2008

전력계통 구성의 복잡함에 따라 보다 다양한 기능이 요구되는 디지털 보호 계전기는 구성 모듈이 점점 다양해지고, 상호 복합적으로 설계된다. 그러한 결과로 개발 시, 공인 인증된 디지털 보호 계전기의 외란에 대한 신뢰성은 예상치 못한 오류 등으로 인하여 신뢰를 상실하는 경우가 있고, 최악의 경우 오동작을 유발하여 전체 전력 계통의 정전을 초래할 수 있다. 특히 디지털 보호 계전기의 시스템 이상 감시에만 그치던 자기 감시 기능은 반복되는 잘못된 이상 감지 판단으로 관리자 및 실무자의 계통 보호에 대한 신뢰의 혼동을 가져올 수 있으며, 일반적인 자기 감시 주기인 $1{\sim}2$초는 그 순환 주기 시간이 너무 길어서 제대로 된 시스템 감시를 행하지 못할 수 있다. 물론 고속의 자기 감시가 필요한 부분은 특별히 존재하지 않지만, 이는 오동작 시 전체 시스템에 미치는 영향을 고려하면, 고속 감시 항목을 미리 지정하여 자기 감시의 신뢰도를 높이는 것도 매우 중요하다. 그렇지만 일반적으로 그 주기를 고속으로 매우 짧게 가져간다면 전체적인 시스템에 무리한 부담을 유발하여 기본 기능에 대한 안정성을 악화시킬 수 있다. 그러나 가장 위험한 현상은 자기 감시 실패 시 디지털 보호 계전기 뿐 아니라 전체 계통에 막대한 피해를 유발하는 것이다. 본 논문에서는 이러한 경우 오동작을 사전에 예방할 수 있는 추가 상시 감시 Tool을 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.9
• /
• pp.3449-3467
• /
• 2015

A broadcast operation is the fundamental transmission technique in mobile ad-hoc networks (MANETs). Because a broadcast operation can cause a broadcast storm, only selected forwarding nodes have the right to rebroadcast a broadcast message among the one-hop and two-hop neighboring nodes of a sender. This paper proposes the maximum intersection self-pruning (MISP) algorithm to minimize broadcasting redundancy. Herein, an example is given to help describe the main concept of MISP and upper bounds of forward node have been derived based on induction. A simulation conducted demonstrated that when conventional blind flooding (BF), self-pruning (SP), an optimized link state routing (OLSR) multipoint relay (MPR) set, and dominant pruning (DP), are replaced with the MISP in executing Strong duplicate address detection (DAD), the performances in terms of the energy consumption, upper bounds of the number of forward nodes, and message complexity have been improved. In addition, to evaluate the performance in reference to the link error probability, P_e, an enhancement was achieved by computing a proposed retransmission limit, S, for error recovery based on this probability. Retransmission limit control is critical for efficient energy consumption of MANET nodes operating with limited portable energy where Strong DAD reacts differently to link errors based on the operational procedures.

• The Korean Journal of Physiology
• /
• v.28 no.1
• /
• pp.99-103
• /
• 1994

Single neuronal activities were recorded in the cuneate nucleus of awake rats during rest and running behavior. Movement-induced changes in somatic sensory transmission were tested by generating post-stimulus time histograms of these neurons' responses to stimulation through eleetrodes chronically implanted under the skin of the forepaw, during control resting behavior and during two standardized speeds of locomotor movement: slow (1.0 steps/s), fast (2.0 steps/s). The magnitudes of firing during these responses were measured and normalized as percentage increases over background firing. The averaged evoked unit responses were facilitated by $+59.3{\pm}12.5%\;and\;+25.6{\pm}5.4%$ (SEM) as compared with resting behavior, during slow and fast movement respectively. This is to be compared with the movement-induced sensory suppressions observed previously in the ventrobasal thalamus $(-31.0%{\pm}1.9%)$ and in the primary somatosensory cortex $(-71.2%{\pm}3.8%)$ of slowly running rats. These results suggest that afferent somatosensory information may be uniquely modulated at each sensory relay, such that it may be facilitated at brainstem level and then subjected to suppression at higher somatosensory nuclei during movement.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.2A
• /
• pp.134-141
• /
• 2010

In this paper, we propose a scheduling algorithm to improve the performance of IEEE 802.16 based wireless mesh networks using directional antenna. The performance is presented in terms of throughput of system and delay between each node by varying number of users. The result show that proposed scheduling algorithm improving the performance by reducing the delay of mesh network system. Our work may be useful as a guideline to control the fairness between SSs for multi-hop systems such as multi-hop relay and mesh networks.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.48-53
• /
• 2008

The performances of the building service equipment relay on the individual superintendent's share for the assessment of performance, fault detection, deterioration diagnosis of the building service equipment. A major use of building energy management system(BEMS) is for monitoring plant and building's energy consumption. National building management system (N-BMS) presented in this study links buildings into a network group in order to monitor and control the buildings. How to construct the N-BMS was considered to save energy resource and to conserve performance of building service equipment. The FEMIS, facility, energy/environmental management & information system, for building service offer management process integrated with BAS, FMS and EMS and so on.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.11
• /
• pp.1554-1560
• /
• 2017

Prepare a lose of 765kV transmission route in power system operation condition, there are some Special Protection Scheme(SPS)s in Korean power system. These SPS can make some preselected generators are tripped to avoid generator overspeed. Because of many of the new large power plants are installed to existing power generation sites due to the siting problem, the number of generator tripped by SPS should be increased. But that can be a cause of system frequency change under the Under Frequency Relay(UFR) 1st pickup level 59.0Hz. Therefore generation constraint should be considered until new transmission lines are installed. In this paper, we propose the ESS application for generation constraint mitigation by frequency damping control of ESS. To analysis an effect of ESS application, we use PSS/E dynamic simulation tool, CBEST model and controller model. The proposed ESS application is applied to the empirical Korean power system.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.5
• /
• pp.728-733
• /
• 2010

The conventional electro-mechanical circuit break and relay are widely used in large-sized DC power system. However, recently due to high reliability, remote controllability and small power dissipation of a RSSPC(Remote Solid State Power Controller), high-friendly DC power systems have increasingly adopted the RSSPC as a essential element. In this paper, we have conducted a mathematical modeling to analyze the performance of the proposed RSSPC system with the optimal signal range for $I^2t$. Based on the calculation, the RSSPC system has been implemented by DSP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.683-686
• /
• 2000

The chargers for DC power supply of the contro1lers, which have been installed in the relay rooms in 345/154kV substations of KEPCO, lag in both aspects of technique and performance. Moreover, as they are SCR-based, they dont meet the performance requirements of todays digital and automated controllers. Now two controllers are running in pair and one of those is for reservation. There are lots of troubles because the patrol engineering team has to replace them manually whenever they are out of order. So it is expected to bring convenience if the charger replacement is automated. Also, the existing chargers take much space, weight and cost - which have increased the need of development to make them smaller, less expensive, and have high quality. We will develop a charger system which has one fifth of the weight of the existing system by double-integrating the volume. The new system will be ready for a future full unmanned system with integrated pores for remote control, state-of-the-art digital features, and more than 90% efficiency/power factor against 80% efficiency/power factor of the existing system.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.53 no.2
• /
• pp.70-76
• /
• 2004

The purpose of interlocking system in railway is to prevent the route for a train being set up and its protecting signal cleared if there were already another, conflicting route set up and the protecting signal for that route cleared. Recently, conventional relays circuitry in industrial field is replaced to computer-based control systems according to the advance of computer and communication technology. Therefore, interlocking systems in railway field are rapidly changing from existing relay-based interlocking system to computer-based electronic ones that executes the vital interlocking logic to assure the safety train routes at trackside signaling equipment room using electronic circuits. So it is very important to verify the performance of developed electronic interlocking system by plentiful laboratory testing before actually application in the railway system. However the laboratory testing in the present state of railway signaling is preformed individually by manual, so very much test time and cost are required. To solve these problems, we are developed the simulator for automatic interlocking inspection in this research. This simulator is able to operate on general personal computer and has following beneficial functions : automatic test sheet generation for inspection, automatic inspection execution and et al. The experiments are executed to test the feasibility of the developed simulator the experimental results have good agreements with the anticipated ones.