• Journal of the Korean Mathematical Society
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• v.39 no.6
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• pp.881-898
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• 2002

Our aim in this paper is to introduce a generalization of some notions in homological algebra. We define the concepts of chain U-complex, U-homology, chain (U, U')-map, chain (U, U')-homotopy and $\mu$-functor. We also obtain some interesting results. We use these results to find a generalization of Lambek Lemma, Snake Lemma, Connecting Homomorphism and Exact Triangle.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.428-435
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• 2017

In this paper, we propose a novel motion field estimation algorithm for which a U-disparity map and forward-and-backward error removal are applied in a vehicular environment. Generally, a motion exists in an image obtained by a camera attached to a vehicle by vehicle movement; however, the obtained motion vector is inaccurate because of the surrounding environmental factors such as the illumination changes and vehicles shaking. It is, therefore, difficult to extract an accurate motion vector, especially on the road surface, due to the similarity of the adjacent-pixel values; therefore, the proposed algorithm first removes the road surface region in the obtained image by using a U-disparity map, and uses then the optical flow that represents the motion vector of the object in the remaining part of the image. The algorithm also uses a forward-backward error-removal technique to improve the motion-vector accuracy and a vehicle's movement is predicted through the application of the RANSAC (RANdom SAmple Consensus) to the previously obtained motion vectors, resulting in the generation of a motion field. Through experiment results, we show that the performance of the proposed algorithm is superior to that of an existing algorithm.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.1
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• pp.1-8
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• 2006

In this paper, we obtain some unique common fixed point theorems for four self-maps and pair of maps in D-metric space using orbitally lower semi continuity conditions.

• Journal of Astronomy and Space Sciences
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• v.9 no.1
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• pp.1-10
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• 1992

Isophote map and luminosity profile of the barred spiral galaxy NGC 7755 are obtained from PDS scanning of PAL 0-471 plate. From the isophote map, NGC 7755 can be classified SBbc(r) with asymmetric bar ring. We get several physical parameters $({M_T}^\circ,U(R)_{CB},U(R)_{CD},D/B,C_{jj},M/L)$ of NGC 7755 from the analysis of the luminosity distribution.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.257-260
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• 2020

본 논문은 단일의 옷감 이미지로 가상의 그래픽 렌더링을 위해 Pix2Pix 방법을 이용하여 Normal map 을 생성하는 방법을 제시한다. 구체적으로 단일의 이미지를 이용해서 Normal map 를 생성하기 위해, Color image 와 Normal map 쌍의 training dataset 을 Pix2Pix 방법을 이용해서 학습시킨다 또한, test dataset 의 Color image 를 입력으로 넣어 생성된 Normal map 결과를 확인한다. 그리고 선행연구에서 사용되어오던 U-Net 방식의 방법과 본 논문에서 사용한 Pix2Pix 를 이용한 Normal map 생성 결과를 SSIM(Structural Similarity Index)으로 비교 평가한다. 또한, 생성된 Normal map 을 렌더링하고자 하는 가상 객체의 사이즈에 맞게 사이즈를 조정하여 OpenGL 로 렌더링한 결과를 확인한다. 본 논문을 통해서 단일의 패턴 이미지를 Pix2Pix 로 생성한 Normal map 으로 옷감의 디테일을 사실감 있게 표현할 수 있음을 확인할 수 있었다.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.63-72
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• 2005

In order to understand regional wind characteristics and to estimate offshore wind resources, a wind map of the Korean Peninsula was established using remote-sensing data from the satellite, U.S. NASA Quik SCAT which has been deployed for the Sea Winds Project since 1999. According to the linear regression result between the wind map data and in-situ marine-buoy data, the correlation factor was greatly improved up to 0.87 by blending the remote-sensing data of Quik SCAT with U.S. NCEP/NCAR CDAS reanalysis data to eliminate precipitation interference and to increase temporal resolution. It is found from the established wind map that the wind speed in winter is prominent temporally and the South Sea shows spatially high energy density over the wind class 6. The reason is deduced that the north-west winds through the Yellow Sea and the north-east winds through the East Sea derived by the low pressure developed in Japan are accelerated passing through the Korea Channel and formed high wind energy region in the South Sea; the same trends are confirmed from the statistical analysis of the meteorological observation data of KMA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3780-3797
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• 2022

The estimation of radio map (RM) is a fundamental and critical task for the network planning and optimization performance of mobile communication. In this paper, a RM estimation method is proposed based on a deep dual learning structure. This method can simultaneously and accurately reconstruct the urban building map (UBM) and estimate the RM of the whole cell by only part of the measured reference signal receiving power (RSRP). Our proposed method implements UBM reconstruction task and RM estimation task by constructing a dual U-Net-based structure, which is named RadioCycle. RadioCycle jointly trains two symmetric generators of the dual structure. Further, to solve the problem of interference negative transfer in generators trained jointly for two different tasks, RadioCycle introduces a dynamic weighted averaging method to dynamically balance the learning rate of these two generators in the joint training. Eventually, the experiments demonstrate that on the UBM reconstruction task, RadioCycle achieves an F1 score of 0.950, and on the RM estimation task, RadioCycle achieves a root mean square error of 0.069. Therefore, RadioCycle can estimate both the RM and the UBM in a cell with measured RSRP for only 20% of the whole cell.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.86-96
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• 2010

In this paper, we propose stereo vision-based obstacle detection and vehicle verification methods using U-disparity map and bird's-eye view mapping. First, we extract a road feature using maximum frequent values in each row and column. And we extract obstacle areas on the road using the extracted road feature. To extract obstacle areas exactly we utilize U-disparity map. We can extract obstacle areas exactly on the U-disparity map using threshold value which consists of disparity value and camera parameter. But there are still multiple obstacles in the extracted obstacle areas. Thus, we perform another processing, namely segmentation. We convert the extracted obstacle areas into a bird's-eye view using camera modeling and parameters. We can segment obstacle areas on the bird's-eye view robustly because obstacles are represented on it according to ranges. Finally, we verify the obstacles whether those are vehicles or not using various vehicle features, namely road contacting, constant horizontal length, aspect ratio and texture information. We conduct experiments to prove the performance of our proposed algorithms in real traffic situations.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.75-91
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• 2015

This study aims to analyse the U-City characteristics through the U-City historical mapping. The U-City characteristics were analysed by building the U-City historical map in terms of STIM model which consists of service, technology, infrastructure and management. The data for analysis is the National Informatization White Paper published by the NIA (National Information Society Agency) from 2002 to 2013. As a result, first, the U-City service were evolved from administration informatization, enterprise informatization, administration/living informatization and administration/space/private informatization through the intelligence facilities and space. Second, the U-City technology were changed through wire network, sensor/network, processing/super-highway network, convergence of network/security. Third, the U-City infrastructure have had evolutionary process such as wire computer network, wire/wireless network, intellectualization facility and intelligent facility space. Forth, the U-City management were carried out with making the unit network/infrastructure management, information connection/operating management and information integration/participation management. Therefore, the history of U-City has been making rapid development in government computerization, computer oriented society, information city and ubiquitous city.

• ETRI Journal
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• v.14 no.4
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• pp.165-178
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• 1992

본 고는 Mini-MAP 네트워크의 접속장치를 구현한 내용이다. 이 접속장치는 공장자동화 네트워크 시스팀에서 Mini-MAP 노드로 동작하며, PLC, CNC, robot와 같은 프로그래머블 디바이스를 MAP 네트워크 환경에 접속하여 원격제어가 가능하도록 하는 네트워크 구축을 위한 핵심 장치이다. 이 접속장치는 MAP 3.0의 Mini-MAP으로 구현하고 실현하였다. MAC 부계층은 Token Bus Controller(TBC)가 담당하며, LLC 부계층은 class 3로 설계하였고, MMS는 implementaton class MAP3를 설계하였다. 구현된 모든 소프트웨어는 Mini-MAP의 실시간 정보 전송 성능을 보증하기 위해 real-time 멀티 태스크 OS로 운영하도록 설계하였으며, 보드에 firmware로 탑재하였다. 프로토콜 분석기를 이용하여 LLC 수준의 오류검출과 전송기능을 확인하였으며, MMS는 적합성 시험을 이미 받은 MMS를 탑재한 상용 제품과의 통신 실험을 통해 적합성을 확인하였다.