• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.9
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• pp.1027-1038
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• 1988

This paper, the last part of these three companion papers treated the electromagnetic diffraction by a dielectric wedge, presents the correction to the physical optics approcomation by the sheet currents of the Neumann expansion. Those expansion coefficients obtained by solving dual series equation amenable to simple numerical calculation may provide the asymprotically corrected solution. The validity of this result, satisfying both the edge condition near the tip of the dielectric wedge and the boundary condition along dielectric interfaces, is assured by approach of the corrected diffraction pattern to that of a perfectly conducting wedge for large permittivity of dielectric wedge.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.247-252
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• 2016

In this paper, we propose a new defect detection technology for micro-defect on the surface of steel products. Due to depth and size of microscopic defect, slop of surface and vibration of strip, the conventional optical method cannot guarantee the detection performance. To solve the above-mentioned problems and increase signal to noise ratio, a novel retro-schlieren method that consists of retro reflector and knife edge is proposed. Moreover dual switching lighting method is also applied to distinguish uneven micro defects and surface noise. In proposed method, defective regions are represented by a black and white pattern. This pattern is detected by a defect detection algorithm with Gabor filter. Experimental results by simulator for sample defects of cold rolled steel show that the proposed method is effective.

• Asian Journal of Turfgrass Science
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• v.8 no.1
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• pp.47-52
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• 1994

Attempts were made to investigate the antagonistic activity of soil borne microorganisms Pseudomonas spp. and Trichoderma spp. against to the pathogens of turf diseases Rhizoctionia solani spp. and Pythiom spp. in vitro by a dual culture bioassay. Inhibition zone between the edge of the my-celium and the margin of each antagonistic bacteria, Pocudontonas, on potato dextrose agar was measured 3 days after incubation at 28˚C. Psudomonas spp. showed relatively high inhibition of mycelium growth of R. solani AG-i and Pythium spp. which cause brown patch and pythium blight, respectively. Antagonistic fungi Trichodenma spp. also showed effective inhibition against mycelium growth of both pathogens, more proper methods of measuring the inhibition effects were required because of fast growth of Trichodenna hypae. Brown patch and pythium blight both, re-quire most higher rate of fungicide use to control in golf curses in Korea. Application of antagon-istic microorganisms are useful as biological resources an approach to sole environmental contamination.

• Journal of Communications and Networks
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• v.6 no.2
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• pp.173-181
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• 2004

This paper shows a technique for regulating the rate emitted by UWB mobile terminals. This technique is designed to adapt the emission rate to the effects of channel capacity variations. We assume that individual flows are shaped at edge routers by means of dual leaky buckets. The proposal is based on the evaluation of certain parameters, which reflect the channel status, sent to the application layer. This information is generated by the scheduler designed to guarantee appropriate channel sharing for the various traffic components. We describe some results which highlight how performance depends on the specific operating conditions, as well as on the traffic descriptors of the flows, their reciprocal difference, and performance requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1521-1528
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• 2000

In this paper we analyze the performance of a DS/CDMA system in LEO mobile satellite channels. The channel uses the Extended Suzuki model which is the product of a Rician distribution having a LOS component and a lognormal distribution due to shadowing. We assume that the signal transmitted from the satellite to the mobile undergoes the same fading for the whole coverage of signal's beam. The average bit error probabilities of double coverage system is calculated in this paper. The interference resulting from the reference satellite is calculated for mobile located in the middle of the double coverage region whereas the additive interference from next-satellite is included for mobile located in the edge of the double coverage region. The performance of the mobile's receiving signal is dependent on shadowing and the interference of the next-satellite. We can obtain an obtain an improved average bit error probability by using dual diversity over the conventional correlated receiver for similar shadowing conditions in the coverage area of the satellite channel.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.1
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• pp.75-82
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• 2000

In this paper, a new low power 16-bit ALU has been designed, fabricated and tested at the transistor level. The designed ALU performs 16 instructions and has a two-stage pipelined architecture. For the reduction of switched capacitance, the ELM adder of the proposed ALU is inactive while the logical operation is performed and P(propagation) block has a dual bus architecture. A new efficient P and G(generation) blocks are also proposed for the above ALU architecture. ELM adder, double-edge triggered register and the combination of logic style are used for low power consumption as well. As a result of simulations, the proposed architecture shows better power efficient than conventional architecture$^{[1,2]}$ as the number of logic operation to be performed is increased over that of arithmetic to logic operation to be performed is 7 to 3, compared to conventional architecture. The proposed ALU was fabricated with 0.6${\mu}m$ single-poly triple-metal CMOS process. As a result of chip test, the maximum operating frequency is 53MHz and power consumption is 33mW at 50MHz, 3.3V.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.415-420
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• 2007

In this paper, we have designed and fabricated a new type of bandpass-filter that used rectangular ring and interdigital capacitive feeding-structure. The filter is applied the modified rectangular ring and interdigital capacitive feeding-structure in patch, which reduce rho size of filter and IEEE 802. 11 correspond to wireless LAN domain(2.45GHz and 5.2GHz) for operating. As a result, the design and fabrication process of the filter become simple and the size of it is reduced more than 60% compared with RF filter are available conventional PEMBF(Parallel Edge-coupled Microstrip Bandpass Filter) of accounted circuit by minimum stage, measurement result of fabricated filter, center frequence is down 2.408GHz and 5.075GHz. input return loss is -39.169dB at 2.408GHz, -40.922dB at 5.075GHz. insertion loss is -0.437dB at 2.408GHz, -1.669dB at 5.075GHz.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.4
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• pp.433-448
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• 2012

A source-synchronous receiver based on a delay-locked loop is presented. It employs a shared global calibration control between channels, yet achieves channel expandability for high aggregate I/O bandwidth. The global calibration control accomplishes skew calibration, equalizer adaptation, and phase lock of all the channels in a calibration period, resulting in the reduced hardware overhead and area of each data lane. In addition, the weight-adjusted dual-interpolating delay cell, which is used in the multiphase DLL, guarantees sufficient phase linearity without using dummy delay cells, while offering a high-frequency operation. The proposed receiver is designed in the 90-nm CMOS technology, and achieves error-free eye openings of more than 0.5 UI across 9-28 inch Nelco4000-6 microstrips at 4-7 Gb/s and more than 0.42 UI at data rates of up to 9 Gb/s. The data lane occupies only $0.152mm^2$ and consumes 69.8 mW, while the rest of the receiver occupies $0.297mm^2$ and consumes 56.0 mW at the 7- Gb/s data-rate and supply voltage of 1.35 V.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.59-68
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• 2009

This paper addresses a hybrid multi-focus image fusion scheme using the recent curvelet transform constructions. Hybridization is obtained by combining the MS fusion rule with a novel "copy" method. The proposed scheme use MS rule to fuse the m most significant terms in spectrum of an image at each decomposition level. The scheme is dubbed in this work as m-term fusion in adherence to its use of the MSC (most significant coefficients) in the transform set at any given scale, orientation, and translation. We applied the edge-sensitive objective quality measure proposed by Xydeas and Petrovic to evaluate the method. Experimental results show that the proposed scheme is a potential alternative to the redundant, shift-invariant Dual-Tree Complex Wavelet transforms. In particular, it was confirmed that a 50% m-term fusion produces outputs with no visible quality degradation.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.461-466
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• 2019

In this paper, we have studied the improvement of gain and bandwidth characteristics by using double feeding and L-shaped inset feed line matching circuit in microstrip stacked patch antenna which is widely used to broaden the gain of general microstrip antenna. The proposed structure is composed of two feeding edges of the main patch antenna, each of them are connected to a feeding line having an L shaped inset feeder. And the parasitic patch is placed at a proper distance above the main patch. The size of the main patch is designed so that the resonance frequency is close to the center frequency of the target frequency band. The experimental results show that the bandwidth was increased more than 180MHz in the 2.3-2.7 GHz band, which is more interesting than the single feed, and the gain improvement of 2.5dBi was obtained at 2.7GHz.