• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.6 s.97
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• pp.563-570
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• 2005

In this paper, a small-sized planar square-spiral monopole antenna is proposed by using parasitic elements. The Parasitic element is composed of a crossed strip and additional right-angle folded(L-type) stirps. And these parasitic elements are printed on a substrate which is the opposite side of a radiation element . When the parasitic elements are used, the size of the square-spiral monopole antenna is reduced by $32\%$ for the same operating frequency compared to the antenna without parasitic elements. The radiation pattern of the proposed antenna is nearly omni-directional in azimuth. The designed antenna can be used in the application of channel 12 digital mulimedia broadcasting(DMB) handset.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.3
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• pp.32-40
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• 1991

A modified transmission line model is proposed for input impedance analysis of a square microstip antenna with single-circularly-polarized. Alog-periodic arrangement with microstrip antenna (LPMA) which consists of 3 resonant element ($3\times1$) is designed for broadband operation ranging from 11.2 GHz to 12.4 GHz, based on this pro- posed model from transmission line model. Aplanar array ($3\times4$array), in which 4sets of the above LPMA are in the same plane, is fabricated for high gain X-band satellite communication antennas. The optimum spacing between each LPMA is determined using computer simulation for the minimum bariation of far field pattern and null. This $3\times4$array has a measured values of gain greater than 8dBi, VSWR les then 2.3, and bandwidth greater than 7% respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.451-460
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• 2008

Gregorian offset dual-shaped reflector antennas have been widely used in the satellite communication systems for their high gain and low sidelobe characteristics. However, in this paper, it is designed as the CATR(Compact Antenna Test Range) reflector system, and its near-field characteristics are investigated. The CATR facility needs to provide an uniform plane wave with the minimum amplitude and phase ripple and the low cross polarization to the test region. Therefore, the reflector near-field patterns are calculated and presented with the variations of the aperture power distribution, the feed horn pattern, and the distance from the aperture to the test zone. Also, the offset dual-shaped reflector is fabricated at 30 GHz, and its near-field patterns are measured. The measured results are in good agreement with the calculated results. From theses results, we confirm that the designed offset dual-shaped reflector can be used as the reflector system for the compact antenna test range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2773-2778
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• 2015

In this paper, the compact antenna with three folded patches for use in a number of bands of LTE, WCDMA, US-PCS, and WLAN at the same time is proposed. As the changes in widths of the 3 patches to widen the insufficient bandwidth are given, it is optimized for $S_{11}$<-6dB(VSWR<3). The CPW with a number of advantages is used in the proposed antenna. The proposed antenna is designed and fabricated with FR4 substrate to the size of $44.9{\times}35{\times}1mm^3$. Fabricated antenna has within $S_{11}$<-6dB under operating bands. And measured characteristics of radiation patterns and gains are shown under operating bands.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.79-86
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• 1999

Traffic jams of our country are due to the shortage of roadway as compared with the traffic, however. they are sometimes due to inconsistency of the roadway capacity. Inconsistency of the roadway capacity comes from the difference of cycle length, phase length and number of Phase between major intersection and minor intersection. Specialty increasing number of Phase due to left-turn movements bring out decrease of the arterial capacity, deterioration of the arterial offset. The Purpose of this research is to introduce and analyze the continuous flow intersection to solve the bottleneck of the major intersection. The major contents of this research introduce the concept and design consideration for the continuous flow intersection and also analyze delay, fuel consumption and emissions among multiphase intersection, grade separated intersection and continuous flow intersection. This research analyze the sensitivities according to change of the left-turn traffic volume and also evaluate the cost-effectiveness through the total cost analysis among three of them.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.3
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• pp.220-224
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• 2017

In this paper, a method of feeding for the near field beam scanning array antenna with three dimensional focal point has been studied. The conventional array antenna theory is mostly about the far field points. The basic idea is to feed the transmitted signal so that it is in phase at the desired point. In this study, a method is proposed to compensate the phase to have the maximum received power at the point where the measurement point distance is near to the array antenna size. In the proposed method, 11 point source antennas are arrayed in three ways in free space. And the contour map is plotted by calculating the radiation patterns in the three dimensional space and the received signal intensities in the plane within the near space. As a result, it was confirmed that 3 dimensional beam scanning is possible also in the near field of the array antenna.

• Journal of KIISE:Software and Applications
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• v.36 no.10
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• pp.786-792
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• 2009

A kernel in support vector machines can be described as a similarity measure between data, and this measure is used to find an optimal hyperplane that classifies patterns. It is therefore important to effectively incorporate the characteristics of data into the similarity measure. To find an optimal similarity between amino acid sequences, we propose a real exponent exponential form of the two metrices, which are derived from the evolutionary relationships of amino acids and the hydrophobicity of amino acids. We prove that the proposed metric satisfies the conditions to be a metric, and we find a relation between the proposed metric and the metrics in the string kernels which are widely used for the processing of amino acid sequences and DNA sequences. In the prediction experiments on the cleavage site of the signal peptide, the optimal metric can be found in the proposed metrics.

• Korean Journal of Human Ecology
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• v.21 no.5
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• pp.975-988
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• 2012

Although the pattern development for tight-fitting clothing has been carried out using 3D data on humans, the pattern development using 3D scan data obtained for various postures still remains an interesting subject. In this study, we have developed the 2D pattern using the 3D human body reflecting standing and cycling postures. The 3D scan data of a subject was obtained using Cyberware. 2C-AN program(Triangle simplification and the Runge-Kutta method) was used in the system to reduce the 3D scan data points and to make segmented triangular patches in a plane from 3D data. As results, surface distance and area of each body part of standing and cycling postures were also provided for the future application of the functional clothing construction. The area of center piece on the front (c.front) decreased by $106.45cm^2$(-13.08%) and that of lateral piece(s.back) on the back increased by $144.96cm^2$(18.69%) in the patterns of cycling posture. The girth of neck and waist for the cycling posture increased by 0.88cm (3.92%) and 1.56cm(4.40%) respectively, and the that of thigh decreased by 1.01cm(-2.24%). The differences between the area in the 2D pattern obtained from the 3D scan data and that in the 3D scan surface data for standing and cycling postures were very small($-10.34cm^2$(-0.32%) and $-44.33cm^2$(-1.32%)).

• Tunnel and Underground Space
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• v.28 no.4
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• pp.343-357
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• 2018

Algorithm which can analyze the slope failure behavior utilizing the comprehensive information of the dense point of joint poles and the joint set orientations, both of which are obtained statistically, and the defect pattern of pole distribution has been developed. This method overcomes the potential incorrectness of the hemispheric projection method utilizing the joint set orientations only and also enhances the reliability of slope failure analysis. To this end a method capable of calculating the joint dispersion index directly from the joint pole distribution, instead of contour map, has been devised. The representative orientations for the slope failure analysis has been determined by considering the number and orientations of cone angle-dependent joint sets as well as the joint dispersion index. By engaging these representative orientations to the hemispheric projection analysis more reliable slope failure examination has been carried out. Sensitivity analysis for the potentially unstable slope of plane failure mode has been performed. Significance of joint strength index and the external seismic loading on the slope stability has been fully analyzed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.4 s.334
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• pp.29-36
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• 2005

Many novel designs of planar antennas for related applications such as internal mobile phone antennas, base station antennas, WLAN or Bluetooth antennas, and so on, have been reported very recently, especially since the year 2000. In this thesis, Dualband internal antenna for GSM/DSC handset is proposed. The antenna has a size of about 38mm$\times$90mm$\times$1mm, giving a total mobile phone PCB for support and fold type Patch of about 30mm$\times$8mm$\times$3.2mm. This antenna characteristic facilitates the fine-tuning of the two operating frequencies of 909MHz and 1762MHz in this dualband design. The measured radiation pattern in the E-plane and H-plane for operating frequencies of 909MHz and 1762MHz is compared and analyzed. The designed and fabricated two band internal antenna for GSM/DSC handset have a gain between 0dBi and 2.0dBi at all bands.