• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.5
• /
• pp.85-91
• /
• 2011

A grounding system is generally composed of several vertical, horizontal electrodes or grids. Excessive ground potential rises due to adjacent grounding electrodes can cause failures or misoperation of electronic devices and control systems. It is therefore necessary for computer-related and information-oriented equipment to be placed at a sufficient distance from the areas influenced by grounding electrodes. In this paper, in order to propose a method for evaluating the ground potential rise and interference in the vicinity of vertical grounding electrodes, the experimental and theoretical results on the potential interference between vertical grounding electrodes and its frequency dependence were described. The ground potential rise is sharply decreased with increasing the distance between grounding electrodes. In case that the separation of vertical grounding electrodes is less than 1.5[m], the potential interference coefficient was greater than 0.1 and linearly increased with the frequency of the test current within the frequency of 1[MHz].

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.11
• /
• pp.66-73
• /
• 2015

AC-based power systems, having the advantages that voltage transformation and long distance transmission are easy, have been constructed since the last 19th century. However, DC-based power system is paid attention these days because of the development of power electronic devices as well as the increase of digital loads and distributed generation. For instance, the transmission systems using High Voltage DC (HVDC) are commercially operated in the world and the researches on distribution system using Low Voltage DC (LVDC) are gradually increased. This paper analyzes voltage sag, resulted from faults, in LVDC distribution system according to the number of poles. Modeling and simulation with various conditions are conducted by using ElectroMagnetic Transients Program (EMTP). Moreover, some countermeasures to reduce voltage sag in LVDC distribution system are suggested briefly.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.765-767
• /
• 2010

In this paper, the variations of threshold voltage characteristics for ratio of channel length and thickness have been alanyzed for DG(Double Gate)MOSFET having top gate and bottom gate. Since the DGMOSFET has two gates, it has advantages that contollability of gate for current is nearly twice and SCE(Short Channel Effects) shrinks in nano devices. The channel length and thickness in MOSFET determines device size and extensively influences on SCEs. The threshold voltage roll-off, one of the SCEs, is large with decreasing channel length. The threshold voltage roll-off has been analyzed with various ratio of channel length and thickness for DGMOSFET in this study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.214-215
• /
• 2010

UPnP Protocol is protocol for home networking that extends PnP to IP based network. It is able to remote control, transfer video and audio. However, It is only used simple devices. In this paper, UPnP is applied to Non IP Network and Extended its function. also, it Implements the System that is capable of updating firmware and realtime monitoring, and therefore it suggestions application possibility of UPnP Protocols that for efficiently management In environment of network on IP or Non-IP.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.833-835
• /
• 2010

The SPARTAN-3E development kit is equipped with an FPGA which holds 500 thousand logic gates and a bus system platform using MicroBlaze microprocessor system. This kind of embedded systems can be used to gather information from sensor nodes and send over to the main server periodically through the network gateway, using the microprocessor-based embedded system, so that edlers living alone under sensor coverage can send their moving information and can be applied to get help in the event of emergency situations. In this paper, we designed a simple embedded system based on a CPU and flash memories using such FPGAs which can be used to monitor those elderlies living alone. The developed hardware system can be directly combined with the web-based elders-living-alone monitoring system, making the system more efficient.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.809-811
• /
• 2010

In most floating-point operations related with 3D graphic applications for mobile devices, properly approximated data calculations with reduced complexity and low power are preferable to exactly rounded floating-point operations with unnecessary preciseness with cost. Among all the sophisticated floating-point arithmetic operations, multiplication and division are the most complicated and time-consuming, and they can be transformed into addition and subtraction repectively by adopting the logarithmic conversion. In this process, the most important factor for performance is how high we can make an approximation of the logarithm conversion. In this paper, we cover the trends in studying the logarithm conversion circuit designs. We also discuss the important factor in design issues and the applicable fields in detail.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.10a
• /
• pp.125-127
• /
• 2012

With the progress of electronics and radio communication technology, human enjoys greater freedom in communication. However, EMW (Electro-Magnetic wave) environments have became complicate and more difficult to control. Thus, international organizations, such as the American National Standard Institution (ANSI), Federal Communications Commission (FCC), the Comite Internationale Special des Perturbations Radio electrique (CISPR), etc, have provided standard for controlling the EM wave environments and for the countermeasure of the electromagnetic compatibility (EMC). In this paper, the status of EMW absorber and the goal of smart EMW absorber ifor the future were described. Furthermore, design method of the smart EM wave Absorber with heat radiating function was suggested. The designed smart EM wave Absorber has the absoption ability of more than 5 dB from 2 GHz to 2.45 GHz band, one optimum aperture (hole) size of which was 6 mm, 9 mm in adjacent hole space, and 6.5 mm in thickness, respectivly. Thus, it is repected that these results can be applied to various EMC devices in electronic, communication, and controlling systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.473-476
• /
• 2017

As the society has developed into a digital information age society, a lot of electronic communication equipments are popularized. However, there are various causes of noise during signal transmission between communication devices. The noise generated in the communication system is a white noise that is distributed evenly in all frequency bands. This white noise causes system errors and lowers reliability. Therefore, in this paper, the existing Gaussian filter, Median filter, Alpha trimmed mean filter, and min/max filter for removing white noise are described and the characteristics and performance of each filter are compared with each other.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.2
• /
• pp.1364-1369
• /
• 2015

As the wire bonding process has been converted into BUMP process due to the high density integration of semiconductor chip, the telecommunication line connecting to semiconductor chip and external devices have become finer. As a result, a more precise work is necessary. However, it is difficult to control quantity given the nature of high viscosity of PSPI and the yield rate continues to decline due to the inflow of bubble. Therefore, this paper developed the D&P(degassing and pumping) system to remove and supply gas that is generated from coating the high viscosity photosensitive polyimide(PSPI) in the semiconductor BUMP process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.4
• /
• pp.1812-1816
• /
• 2011

This research developed chemical flow control system(CFCS) essential for spinner equipment in nano semiconductor manufacturing process under the 100nm to prevent complex process defect due to missing spread after chemical injection. The devices developed in this research, which can be swiftly replaced in case abnormal state element changes or wafer manufacturing defect occurs, are anticipated to improve module yield as well as real-time monitoring on the state element. In addition, as a result of mounting H/W and S/W system to control detailed operation sequence in production line and executing performance check and verification, we can be exactly detected in five abnomal process type.