• Journal of Advanced Navigation Technology
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• v.3 no.2
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• pp.139-146
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• 1999

A flight simulator is composed of engine, navigation systems and instrument modules. However, two problems exist here. First, the coordinate of each independent module is not same. To solve this problem, we design a method that mutual coordinates are capable of transformation each other. Second, the distance and bearing between two points on the earth are computed in a sphere shape using the spherical trigonometry. However, the computing time is very severe. In this paper, we project the sphere into the planar to reduce the computing time. An experimental result shows that the performance of the proposed method is excellent to both distance and bearing calculations in close region. Also, the computing time is reduced from $4.95{\times}10^{-4}$ seconds to $1.648{\times}10^{-4}$ seconds.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.229-236
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• 2005

This paper is contribute to Inverse continuous wavelets transform(ICWT) which permits to determine real 'time-scale' plan. The application of ICWT is not yet represented because of the numerical difficulty. If the signal can be reconstructed stably by ICWT, the multi scale filter bank system which composed by analysis and synthesis process can be designed. In this work, we represent the ICWT which leads to nearly perfect reconstruction of signal and the multi-scale filter bank system.

• Journal of Advanced Navigation Technology
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• v.17 no.2
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• pp.183-188
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• 2013

In this paper, the TE (Transverse Electric) scattering problems by a perfectly conducting strip grating over a grounded two dielectric layers with edge boundary condition are analyzed by applying the FGMM (Fourier Galerkin Moment Method). For the TE scattering problem, the induced surface current density is expected to the zero value at both edges of the strip, then the induced surface current density on the strip is expanded in a series of the multiplication of the Chebyshev polynomials of the second kind and the functions of appropriate edge boundary condition. The numerical results shown the fast convergent solution and good agreement compared to those of the existing papers.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.1-8
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• 1999

A complete electromagnetic simulation for a ground-penetrating radar(GPR) is implemented by employing 3-dimensional dispersive finite-difference time-domain(FDTD) method. The presented simulation model includes the cavity-backed bow-tie antennas, which are terminated by resistors. And an equivalent cirvuit consisting of the input impedance of the antenna and the characteristic impedance of the feed line is used to calculate the response in the receiving antenna. Actual emasurements of a GPR system including our manufactured bow-tie antenna pair are performed just above dry sand contained in a PVC tank. It is confirmed that the FDTD simulation results agree well with the actual measurement data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.968-977
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• 2008

In this paper, an analysis of TE-wave scattering from transversal-shifted tandem slits using fourier transform analysis and Wiener-Hopf technique are derived and the electrical performances have been compared with a commercially availabel software. In Fourier transform analysis, it is shown that a fast-convergent series solution can be obtained when the distance between the slits is very narrow, while in Wiener-Hopf technique, it is found that the highly-accurate approximation can be obtained when the gap between the slits becomes wider. In addition, this paper has dealt with a good agreement between two analytical solutions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.696-706
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• 1992

In sheet metal fabrication using NCT(numerically controlled turret), the automatic tool selection for the NCT operation is the major problem to be solved first to improve its production performance. However, the punching tool selection has been done by human experts either manually or semi-automatically. In this paper, we have introduced the shape-index-set to handle the shape of sheet metal parts and developed an algorithm through which one can find easily the successive matching curves between two curve lists, one from the punching tool and the other from the boundaries of the sheet metal part. Based on this algorithm, we have also devised the method that can select automatically the tools to punch out the boundaries of sheet metal parts. The result of several computational experiments shows the successful tool selection without any fail.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.6
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• pp.23-29
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• 1981

By using a slot-line in combination with microstrip lines, a coplanar wide-band balun is designed and fabricated. The slot-line of balun junction is compensated to be operated in C-band(4~8GHz), and therefore the results are agreement with theoritical prediction. Experimental data are given for a 3-section Chebyshev transformer-matched balun with a balanced-to-unbalanced line impedance ratio of 2 : 1. A bandwidth from 3.5GHz to 7.0GHz is obtained with V.S.W.R. of below 1.2 : 1. Maximum insertion loss is measured as 0.9dB, and the phase difference varies linearlly within 180$^{\circ}$$\pm$5$^{\circ}$.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.403-406
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• 2007

발전소 온배수의 원활한 배수를 위한 설계 낙차와 함께 남서해안의 조위변화에 따른 낙차의 이용가능성을 인지하고 소수력 발전 방식과 조력발전 방식의 특정을 동시에 활용하는 해양소수력 발전소를 삼천포 화력발전소 배수로에 최초로 건설하여 운전함으로써 청정 재생에너지 개발 및 $CO_2$ 저감효과 창출에 이바지하고 있다. 본 연구에서는 삼천포 해양소수력 발전소의 운전실적 자료를 토대로 조위 및 방류량의 변화에 따른 해양소수력의 효율 특성을 분석하고자 한다. 해양소수력 발전소의 효율은 방류량과 유효 낙차의 영향을 직접적으로 받기 때문에 관측한 수위 및 방류량, 해양소수력발전소 운전실적 자료를 토대로 효율분석을 실시하였다. 우선, 소수력 가동 이후 배수로에서의 수위 상승이 명확히 나타났으며, 배수로내 위어에서의 흐름구조가 완전월류 상태에서 불완전월류로 바뀌면서 배수로 전체의 수면 불안정성이 크게 증가하였으나, 배수로의 범람이나 순환수 계통에의 큰 영향을 초래할 만한 수준은 아니었다. 성능시험 결과, 최대출력, 평균출력, 최소출력 모든 부분에서 설계 보증치 이내의 값을 보였으며, 효율 또한 설계 보중치를 상회하는 결과를 보였다. CWP 유량 분석결과, 소수력 발전소에서의 유량이 과소 측정되고 있음을 확인하였으며, 최대낙차에서 최대효율을 보이고, 저낙차일 때는 보증치보다 효율이 낮게 나타나는 결과를 보였다. 또한 조위조건을 고려한 유량을 이용하여 산정한 효율 곡선이 보증치와 가장 일치하였으며, 전체 시스템 효율은 비교적 양호한 상태임을 알 수 있었다.

• Animal Systematics, Evolution and Diversity
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• v.12 no.2
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• pp.91-99
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• 1996

The complete larval development of Philyra pisum De Hann, 1841 from hatching to the megalopal stage was obtained by culture in the laboratory. Two zoeal and one megalopal stages are described and illustrated . The frist zoea of the present species is very similar to those of other two Philyra species except for the reduced carapace spines. The first zoeae belonging to the subfamily Philyrinae can be divided into two groups based on the zoeal characteristics: the first group is composed of Arcania septemspinosa, A. undecimspinosa elongata, and Myra fugax, whereas the second group is composed of Philyra corallicola, P. syndactyla, and P. pisum.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.558-562
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• 2000

A strain of non-sulfur photosynthetic bacteria possessing large amount of ubiquinone-10 in the cell mass, was isolated from waste water collected from the Nakdong River. It was identified as Rhodobacter sp. N-2 by a series of studies on its morphological. cultural and physiological characteristics. The organism appeared to got higher cell mass under circumstances of anaerobic growth conditions than under photosynthetic aerobic cultures. Biotin and thiamin and niacin could be used as good growth factors.