• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.1
• /
• pp.128-132
• /
• 1996

In [1], it is shown that a subclass of ETBFs, which are self-dual ETBFs, can be expressed as a weighted average of median subfiltered outputs. In this paper, we extend this result to general ETBFs. In particular, we show that any ETBF can be represented as a weighted average of minimum (or maximum) subfiltered outputs. These representations naturally lead to a subclass of ETBF, called the K-th order ETBF (K-ETBF) that employs only those subfilters whose window sizes are less than or equal to K. By designing K-ETBFs under the mean square error criterion for various values of K and applying them to restore noisy signals, the tradeoff between the performance and the complexity of this class of filters is examined.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.643-646
• /
• 2007

As increase of the land price at downtown area, it makes people more and more interested of improving the space utilization such as makes buildings bigger, deeper and higher. Therefore, the importance of the underground construction which is the basic principle has been increased. As constructors have to complete underground construction as soon as possible with the minimum costs, they concentrate on the whole process of underground structure. Although they makes every these efforts, construction failure still happen because of the uncertainty of the condition of soil and the unexpected danger of underground construction. To make matter worse, there are only some examples without detailed information like 'how much this breakdown damage to the construction?' so it is the anther problem that most of people doesn't recognize the economical negative impact of underground structure breakdown. This report would make people understood the importance and risk of the underground construction by showing some analysis which was assumed from the real accidents.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.22 no.4
• /
• pp.33-38
• /
• 1985

By the complemental frequency characteristics of directional filter in passband and stopband the method of isolation between microwave RF and low frequency If is derived. And when this characteristic of microstrip directional filter is applied to MIC balanced mixer from 3.7 to 4.2 GHz, the experimental results of isolation and return loss are more than 20 65 in this band. This balanced mixer with the microstrip coupled directional filter is suitable for the DBS microwave receiver system.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.8 no.5
• /
• pp.20-26
• /
• 1971

A function relationship between the envlope rise time and Q v91ue of band pass filter is studied by using the time response to the step and sinusodal inputs. It is discovered that the above relationship is linear in the very low frequency band. The filter was constructed by the Analog computer so as to do the function of 2nd order RC active band pass.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.10
• /
• pp.1855-1861
• /
• 2017

In this paper, the gain enhancement of an SDPA using a director and two parasitic patches is studied. The modified balun is used to increase the bandwidth, whereas the director and two parasitic patches are appended to the SDPA to enhance the gain in the middle and high frequency bands. The effects of the distance between the director and parasitic patches on the antenna performance are analyzed, and the SDPA with a gain over 7 dBi at 1.54-2.99 GHz band is designed. The proposed SDPA is fabricated on an FR4 substrate with a dimension of $90mm(L){\times}135mm(W)$ in order to validate its performance. The fabricated antenna shows a frequency band of 1.56-3.10 GHz for a VSWR < 2, and it is confirmed by measurement that gain maintains over 7 dBi in the frequency range of 1.54-3.00 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.59-60
• /
• 2017

In this paper, the bandwidth and gain enhancement of a series-fed dipole pair antenna (SDPA) using a modified balun., a director, and two parasitic patches is studied. The proposed SDPA consists of two strip dipoles with different lengths, a ground reflector, which are connected through a coplanar strip line, a director, and two parasitic patches. The modified balun is used to increase the bandwidth, whereas the director and two parasitic patches are appended to the SDPA to enhance the gain in the middle and high frequency band. A prototype of the proposed SDPA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.56-3.10 GHz for a VSWR < 2, and measured gain maintains over 7 dBi in the frequency range of 1.55-3.00 GHz.

• Journal of Digital Convergence
• /
• v.10 no.8
• /
• pp.149-157
• /
• 2012

Recently, many corporations and public institutions are busy preparing and providing measures in dealing with new privacy information law. This study reviews privacy impact assessments in order to perform preventing and diagnosis against potential threats focus on the K-hospital case. The quality of protection in K-hospital shows that the corporations itself is 79.0, the system is 97.0, the life cycle of the privacy is 67.4 and CCTV is 90.0. The lowest levels are saving and keeping 50.0, usage and offer 64.1 and destruction 66.7 among the life cycle of the privacy. The result of risk analysis shows that the highest levels are controlling for privacy 11.0, saving and keeping 12.5 and destruction 13.0. From the result, dangerous duplications are saving and keeping and destructions.

• Journal of Korea Society of Industrial Information Systems
• /
• v.17 no.6
• /
• pp.73-82
• /
• 2012

This paper reviews Privacy Impact Assessments in order to perform preventing and diagnosis against potential threats focused on the C-Shopping mall case. The quality of protection in C-shopping mall shows that the corporations itself is 29.2, the system is 68.8, the life cycle of the privacy is 25.5 and CCTV is 60.0. The lowest levels are the corporation's management 16.7, the life-cycle's saving and keeping 12.5, usage and offer 11.5 and destruction 16.7 among the life cycle of the privacy. The result of risk analysis shows that the highest levels are saving and keeping 13.3 and destruction 13.0. From the result, dangerous duplications are saving and keeping and destructions.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.15 no.3
• /
• pp.243-250
• /
• 2009

The expression of signal to noise ratio (SNR) is derived for the individual echo sounder and for the general specifications of commercial echo sounder. The SNR is depicted by several factors on transmitting and receiving, sound propagation, scattering by fishes, and mainly self ship noise. The detection ranges of echo sounders in depth and breadth are derived by finding the border of an acceptable SNR. The detection ranges are computed for the echo sounders of individual and general specifications. Generally, the detection range is lager for low frequencies. Increasing an electrical power and a diameter of transducer is not as effective for high frequencies as for low frequencies to increase the detection range. The theoretical results of the detection range can be applied to design low electrical power echo sounder for coastal use, to select an appropriate echo sounder, to know the capability of a sounder, and to interpret echograms. A method for evaluating and designing low electrical power echo sounder is developed. A universal diagram for the basic design of the low electrical power echo sounder where SNR is plotted against frequency is developed. An appropriate frequency, transducer diameter, and beam width are easily determined by using the diagram.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.52-54
• /
• 2011

In this paper, efficient framework design to construct electromagnetic simulator is proposed and examined. Especially computing time for example problem is enhanced to be shorted than computed time for single task corresponding to increasing the number of network PCs. As a result, design and analysis for antenna, cavity, and waveguide problems with large scale complex structure can be applied.