• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.606-608
• /
• 1999

본 논문에서는 이동 로봇의 유연하고 짧은 경로 계획을 위하여 기존의 그리드 셀(grid cell)로 구성되는 지도 대신에 삼각형을 이용하여 지도를 구성하는 새로운 방법을 제안한다. 기존의 그리드 셀로 구성되는 지도의 경우 이동 로봇가 현재 셀에서 다음 셀로 진행시 진행 방향이 8 방향이나, 본 논문에서 제안한 방법에 의해 구성된 새로운 지도는 셀을 삼각형으로 표현함으로써, 이동 로봇의 진행 방향이 12 방향이 된다. 이와 같이 이동 로봇의 진행 방향이 증가한다는 것은 이동 로봇이 더욱 유연하게 장애물을 회피하며 더욱 짧은 경로로 주행할 수 있는 가능성을 의미한다. 한편, 본 논문에서 제안한 삼각형 지도 작성 방법의 효율성을 기존의 그리드 셀을 이용한 경로 계획 알고리즘인 거리 변환(path transform) 경로 계획을 통하여 증명한다. 또한 새로운 삼각형 지도 구성이 메모리의 효율성 위해 이동 로봇의 주행 환경을 장애물이 비어있는 공간을 가능한 하나의 셀로 병합하는 4진트리 방법(quadtree method)에도 적용 가능함을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.8A
• /
• pp.796-804
• /
• 2002

This paper presents a new algorithm of fingerprint image analysis and processing using directional filter bank(DFB). The directional components of ridge is very important in pre-processing steps of fingerprint image processing such as image enhancement by directional filtering followed by estimationg the directional image of ridge patterns. The DFB analyzes input image into directional subband images and synthesizes them to the perfectly reconstructed image. In this paper, a new fingerprint processing algorithm using the DFB is proposed. The algorithm decomposes the fingerprint image into directional subband images and performs directional map generation, foreground segmentation, singular points extraction and image enhancement based on local directional energy estimate.

• KOMUNHWA
• /
• no.66
• /
• pp.57-86
• /
• 2005

이 논문은 미국의 남서부지역(대략, 애리조나 주, 뉴-멕시코 주, 콜로라도 주, 그리고 유타 주 등에 해당)에서 발굴 조사된 수혈주거지들의 방향을 열효율과 연계하여 연구한 것이다. 이 지역 선사시대 수혈주거지에 거주했던 사람들은 주거지 내부에 있었던 작은 노지(爐址) 이외에 다른 난방시설이 없었기 때문에 고고학자들은 이 지역 주민들이 주거지를 설계할 때 자연난방인 태양열을 이용하였을 것이라고 추정하고 있다. 이 아이디어를 고고학 자료를 통하여 검증하기 위하여 기원 전후부터 기원 후 미국 남서부 지역에서 가장 주도적인 역할을 하였던 원주민들의 호호캄(Hohokam, 남부 애리조나 지역), 아나사지(Anasazi, 북부 애리조나, 뉴-멕시코, 남서 콜로라도와 남동 유타에 걸쳐져 있던 四隅지역), 그리고 머기욘(Mogollon, 남동 애리조나와 남서 뉴-멕시코 지역) 문화 유적지에서 발굴조사된 수혈주거지들의 깊이, 모양, 그리고 방향에 대해서 검토하여 보았다. 동시에 수혈주거지의 방향의 해석과 관련된 하부구조적 측면과 관념적 측면의 두 가지 상반되는 견해에 대해서 검토하여 보았다. 이들 지역에서 발굴조사된 주거지들의 방향을 분석하여 보아 일관성 있게 남쪽으로 난 주거지들의 방향이 초자연적인 의미를 내포한 것 이라기보다는 적응의 전략으로서 태양열의 이용을 염두에 두었을 가능성이 더 높다는 것을 주장하였다. 주제어: 선사시대, 미국 남서부 지역, 고고학, 건축, 수혈주거지, 방향, 태양열, 실용성, 상징성ン?⨀⣳?⨀㋳?⨀?⨀

• Journal of KIISE:Software and Applications
• /
• v.32 no.11
• /
• pp.1121-1135
• /
• 2005

This paper proposes a moving object extraction method using the contrast map and salient points. In order to make the contrast map, we generate three-feature maps such as luminance map, color map and directional map and extract salient points from an image. By using these features, we can decide the Attention Window(AW) location easily The purpose of the AW is to remove the useless regions in the image such as background as well as to reduce the amount of image processing. To create the exact location and flexible size of the AW, we use motion feature instead of pre-assumptions or heuristic parameters. After determining of the AW, we find the difference of edge to inner area from the AW. Then, we can extract horizontal candidate region and vortical candidate region. After finding both horizontal and vertical candidates, intersection regions through logical AND operation are further processed by morphological operations. The proposed algorithm has been applied to many video sequences which have static background like surveillance type of video sequences. The moving object was quite well segmented with accurate boundaries.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.4
• /
• pp.368-378
• /
• 2004

In this paper, we proposed the compensation structures for the enhanced directivity of CPW(Coplanar waveguide) directional couplers with finite-extent backed conductor. The proposed compensation structures are. realized by expanding the slot width between signal line and ground plane in center region of couplers. The CPW couplers with expanded slot have the same phase velocity for even and odd mode because of added inductance and changed capacitance appropriately, so the enhanced directivity is accomplished. The designed CPW directional couplers have good directivity and matching characteristic at center frequency in simulation and measurement.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.4
• /
• pp.1066-1071
• /
• 1998

This paper aims to examine the relationship between the directional characteristics and the quality for fingerprint image as preprocessing stage for adative image enchancement. In order to do that, we transformed the original images into directional images and set up the subimage size of 16, 32, 64 and the direction of 1, 2, 3, 4. Then we extracted the accumulated directional value as the measurement of quality for fingerprint images. By using the clustering algirthm, we performed an analytic experiemnt with the result. Finally, we could extract the optimal subimage size and directional characteristics of fingerprint image.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.2
• /
• pp.286-291
• /
• 2011

Directional couplers are widely used in RF and microwave applications to distribute or monitor signals. This paper presented a new structure of microstrip branch line directional coupler with coupled lines. The loose couplings of microstrip branch line directional couplers are impractical for the high characteristic impedance values required for the shunt branches. To overcome this limitation, the parallel coupled lines with the shorts were used for the high characteristic impedance. The results of the simulations and measurements were presented for the proposed branch line directional coupler. Measurement of the 10 dB branch line directional coupler shows that the return loss is higher than 30 dB over 10 % bandwidth and the isolation is 35 dB or better over 8 % bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.4A
• /
• pp.320-327
• /
• 2005

In this paper, compensation structures are proposed in the CPW directional couplers with finite-extent backed conductor for tight coupling. The proposed structures are realized T-shaped expanded slots and modified finite-extent backed conductor in CPW coupled structure. The T-shaped expanded slots was used to avoide reduced coupling and modified finite extent backed conductor of dumbbell shape was used to enhance directivity and matching. The designed CPW directional couplers at 1 GHz has good directivity without reducing coupling in simulation by EM solver based on full-wave analysis and measurements.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.5
• /
• pp.684-690
• /
• 2007

We describe our method to predict the direction of conditional probabilistic dependencies between clusters of random variables. Selected variables called 'gateway variables' are used to predict the conditional probabilistic dependency relations between clusters. The direction of conditional probabilistic dependencies between clusters are predicted by finding directed acyclic graph (DAG)-shaped dependency structure between the gateway variables. We show that our method shows meaningful prediction results in determining directions of conditional probabilistic dependencies between clusters.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.12
• /
• pp.1321-1328
• /
• 2003

In this paper, we demonstrate that the directivity of the CPW(Coplanar Waveguide) directional coupler with finite-extent backed conductor is enhanced by eliminating center region of backed conductor appropriately. If the backed conductor is removed at center region of couplers, the couplers have two backed conductors. If effective odd mode dielectric constant is decreased at center region, the electrical length for odd mode is changed and phase velocity is same at the directional couplers. Hence, directivity is improved. The eliminated length is solved by an odd and even mode analysis. The designed moderate CPW directional coupler with the proposed compensation structure has excellent directivity and matching characteristic at center frequency in simulation and measurement.