• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.2
• /
• pp.123-134
• /
• 2000

This paper addresses a new triangulation method for constructing surface model from a set of wire-frame contours. The most important problem of contour triangulation is the branching problem, and we provide a new solution for the double branching problem, which occurs frequently in real data. The multiple branching problem is treated as a set of double branchings and an algorithm based on contour merging is developed. Our double branching algorithm is based on partitioning of root contour by Toussiant's polygon triangulation algorithml[14]. Our double branching algorithm produces quite natural surface model even if the branch contours are very complicate in shape. We treat the multiple branching problem as a problem of coarse section sampling in z-direction, and provide a new multiple branching algorithm which iteratively merge a pair of branch contours using imaginary interpolating contours. Our method is a natural and systematic solution for the general branching problem of contour triangulation. The result shows that our method works well even though there are many complicated branches in the object.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.6
• /
• pp.740-747
• /
• 2019

In this paper, an antenna applicable to WLAN and WiMAX frequency bands is designed, fabricated, and measured. The proposed antenna is designed to have two branch strip line in the patch plane and a rectangular slit in the ground plane based on microstrip feeding for triple band characteristics and added a vertical strip in the ground plane to enhance impedance bandwidth characteristics. The proposed antenna is designed on a substrate with a relative permittivity of 4.4, a thickness of 1.0 mm, and has a size of $18.0mm(W1){\times}37.3mm$ (L4+L5+L7). From the fabricated and measured results, impedance bandwidths of 480 MHz (2.32 to 2.80 GHz) for 2.4/2.5 GHz band, 810 MHz (3.22 to 4.03 GHz) for 3.5 GHz band, and 1,820 MHz (5.05 to 6.87 GHz) for 5.0 GHz band were obtained based on the impedance bandwidth. Measured 3D pattern and gains are displayed.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.4
• /
• pp.441-448
• /
• 2015

In this paper, a CPW-fed dual-band monopole antenna with two branch strips for WLAN(Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a CPW-feeding structure, and composed of two branch strips and then designed and tuned the length of two branch lines to obtained required frequencies bands. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and carried out simulation about parameters $L_5$, $L_8$, $W_3$, $W_5$, $W_9$. The proposed antenna is fabricated on the FR-4 substrate using the obtained parameters. The numerical and experiment results demonstrated that the proposed antenna obtained the -10 dB impedance bandwidth 1,095 MHz (1.57~2.665 GHz) for 2.4 GHz band and 1,680 MHz (4.99~6.67 GHz) for 5 GHz band satisfied requirement while simultaneously covering the WLAN bands. And characteristics of gain and radiation patterns are determined for WLAN operating bands.

• The KIPS Transactions:PartB
• /
• v.14B no.6
• /
• pp.413-422
• /
• 2007

This paper addresses a new technique for constructing surface model from a set of wire-frame contours. The most difficult problem of this technique, called contour triangulation, arises when there are many branches on the surface, and causes lots of ambiguities in surface definition process. In this paper, the branching problem is reduced as the surface reconstruction from a set of virtual belts and virtual canyons. To tile the virtual belts, a divide-and-conquer strategy based tiling technique, called the BPA algorithm, is adopted. The virtual canyons are covered naturally by an iterative convex removal algorithm with addition of a center vertex for each branching surface. Compared with most of the previous works reducing the multiple branching problem into a set of tiling problems between contours, our method can handle the problem more easily by transforming it into more simple topology, the virtual belt and the virtual canyon. Furthermore, the proposed method does not involve any set of complicated criteria, and provides a simple and robust algorithm for surface triangulation. The result shows that our method works well even though there are many complicated branches in the object.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.1
• /
• pp.241-250
• /
• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and synchronizations and secure communication of a lossy equivalent transmission are investigated. Since the synchronization of the lossy equivalent transmission system is impossible by coupled synchronization, theory having both the drive-response and the coupled synchronization is proposed. The proposed method is synthesizing the desired information with the chaos circuit by adding the information signal to the chaos signal in the lossy equivalent transmission system.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.10
• /
• pp.3300-3309
• /
• 2000

본 논문에서는 변전소에서 수용가까지의 전력공급설비를 나타내는 도면인 배전설비도면의 주요 기호인 전주와 전선인식 방법에 과하여 기술한다. 제안하는 방법은 원형성에 근거하여 전주후보를 추출한 후 이들 사이의 연결성에 근거하여 전선을 인식한 다음, 전주후보들 중에서 전주를 확인하는 방법으로 다음과 같이 네 개의 단계로 구성된다. 첫 번째는 히스토그램 분석을 통하여 얻어진 임계값을 사용하여 입력영상에서 배전설비영역을 추출하는 단계이고, 두 번째는 추출된 배전설비영역을 세선화 하는 단계이다. 세 번째는 세선영상의 분기점 근처에 정의된 탐색영역에서 원형성을 측정하여 전주후보를 추출하는 단계이다. 네 번째는 전주후보들이 가지는 분기점들 간의 연결성을 측정하여 전선을 인식하는 단계이다. 전선인식이 완료되면 전주후보들 중에서 전선을 가지는 후보들만을 추출하여 전주를 인식한다. 제안된 방법은 한국전력공사의 배전설비도면들 중에서 무작위로 추출한 표본 약 30매를 대상으로 실험하고 그 결과를 제시한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.3
• /
• pp.475-482
• /
• 2019

In this paper, we propose a triple band antenna for GPS / DCS / WLAN system. The proposed antenna has the characteristics required by considering the interconnection of two strip lines and various slits on the ground place. The total substrate size is $31mm(W1){\times}50mm(L1)$, thickness (h) 1.6 mm, and the dielectric constant is 4.4, which is made of $22mm(W7+W12+W8){\times}43mm(L4+L3)$ antenna size on the FR-4 substrate. From the fabrication and measurement results, bandwidths of 340 MHz (1.465 to 1.805 GHz), 480 MHz (2.155 to 2.635 GHz) and 1950 MHz (4.975 to 6.925 GHz) were obtained on the basis of -10 dB. Also, gain and radiation pattern characteristics are measured and shown in the frequency triple band as required.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.236-236
• /
• 2011

진천지역의 지하수 유동체계를 분석하기 위해 진천지역 내 530개 공의 지하수위를 1년간 관측하였다. 이중 360개 공에서는 분기별로 한번씩 총 4회, 130개 공에서는 월1회씩 총 12회 지하수위를 관측하였으며, 40개 공에 대해서는 1시간 간격으로 자동관측을 실시하였다. 관측결과를 수집하여 지하수위의 변동특성, 지하수위 분포, 지하수 심도분포 등을 실시하였으며, 이와 같은 지하수위 분석 결과를 바탕으로 지하수 유동체계를 분석하였다. 조사지역의 평수기 지하수위 분포에 대해 수리학적인 접근법(hydraulic approach) 및 동수역학적 접근법(hydrodynamic approach)에 근거하여 수리수두(hydraulic head) 및 전수두(total head)를 분석하여 2차원 및 3차원 수리경사도를 작성하였다. 이러한 지하수위 분포에 따른 분석 성과와 지형 및 수문지질을 고려하여 함양 및 배출지역을 분류하였으며, 이와 함께 기분석된 지하수위 등고선에 따른 유선망도를 작성하였다. 지하수는 지하수위의 표고 및 압력에 따른 위치 에너지 차에 의하여 대수층 매질을 통하여 유동하며 수두가 높은 곳에서 낮은 곳으로 일정한 수리경사를 갖고 지하수 등수위선에 연직 방향으로 형성된 유선을 따라 이동한다. 따라서 지하수의 유동방향은 지하수 수리경사 분석이 이루어진 8개 방향의 지하수위 경사 중 최대경사를 갖는 방향으로 지하수 유동이 발생하므로, 이를 지하수위 유동방향으로 결정하였다. 이와 같이 분류된 지하수 함양 중간 및 배출 지역과 지하수의 함양과 배출의 양적인 측면에 서 유동체계의 규모를 고려하여 조사 지역을 8단계로 구분하였다. 또한 조사지역의 지하수 유동체계를 종합적으로 규명하기 위하여 기 분석한 조사지역의 지하수위 등고선, 지하수위 등심도선, 지하수 수리경사, 지하수 유동방향 및 지하수 함양-배출체계와 지형기복, 그리고 주요 하천 등의 제반 요소를 중첩 분석하여 종합적으로 규명하고, 그 결과를 지하수 유동체계도로 작성하였다. 지하수 유동체계 분석결과는 수문지질 평가와 오염취약성 평가 및 지하수 관리 방안 수립에 활용될 수 있을 것으로 기대된다.