• Title/Summary/Keyword: linear network

Search Result 1,826, Processing Time 0.029 seconds

Generalization by LoD and Coordinate Transformation in On-the-demand Web Mapping (웹환경에서 LoD와 좌표변형에 의한 지도일반화)

  • Kim, Nam-Shin
    • Journal of the Korean association of regional geographers
    • /
    • v.15 no.2
    • /
    • pp.307-315
    • /
    • 2009
  • The purpose of map generalization is a method of map making to transmit the concise cartographic representation and geographic meaning. New generalization algorithm has been developed to be applied in the digital environments by the development of computer cartography. This study aims to look into possibilities of the multiscale mapping by generalization in application with the coordinate transformation and LoD(level of detail) in the web cartography. A method of the coordinate transformation is to improve a transmission of spatial data. Lod is a method which is making web map with selection spatial data by zoom level of users. Layers for test constructed contour line, stream network, the name of a place, a summit of mountain, and administrative office. The generalization was applied to zoom levels by scale for the linear and polygonal features using XML-Based scalable vector graphics(SVG). Resultantly, storage capacity of data was minimized 41% from 9.76mb to 4.08mb in SVG. Generalization of LoD was applied to map elements by stages of the zoom level. In the first stages of zoom level, the main name of places and administrative office, higher order of stream channels, main summit of mountain was represented, and become increase numbers of map elements in the higher levels. Results of this study can help to improve esthetic map and data minimization in web cartography, and also need to make an efforts to research an algorithm on the map generalization over the web.

  • PDF

Implementation of Web-based Remote Multi-View 3D Imaging Communication System Using Adaptive Disparity Estimation Scheme (적응적 시차 추정기법을 이용한 웹 기반의 원격 다시점 3D 화상 통신 시스템의 구현)

  • Ko Jung-Hwan;Kim Eun-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.1C
    • /
    • pp.55-64
    • /
    • 2006
  • In this paper, a new web-based remote 3D imaging communication system employing an adaptive matching algorithm is suggested. In the proposed method, feature values are extracted from the stereo image pair through estimation of the disparity and similarities between each pixel of the stereo image. And then, the matching window size for disparity estimation is adaptively selected depending on the magnitude of this feature value. Finally, the detected disparity map and the left image is transmitted into the client region through the network channel. And then, in the client region, right image is reconstructed and intermediate views be synthesized by a linear combination of the left and right images using interpolation in real-time. From some experiments on web based-transmission in real-time and synthesis of the intermediate views by using two kinds of stereo images of 'Joo' & 'Hoon' captured by real camera, it is analyzed that PSNRs of the intermediate views reconstructed by using the proposed transmission scheme are highly measured by 30dB for 'Joo', 27dB for 'Hoon' and the delay time required to obtain the intermediate image of 4 view is also kept to be very fast value of 67.2ms on average, respectively.

Evaluation of Adhesion Property with Pot Life and Curing Humidity of GFRC and Epoxy Adhesive (유리섬유강화 복합재료와 에폭시 접착제의 가사시간과 경화습도에 따른 접착 강도 평가)

  • Yoo, Ji-Hoon;Shin, Pyeong-Su;Kim, Jong-Hyun;Lee, Sang-Il;Park, Joung-Man
    • Journal of Adhesion and Interface
    • /
    • v.21 no.2
    • /
    • pp.65-70
    • /
    • 2020
  • Epoxy adhesive was mainly used to combine different composite materials. Epoxy adhesive was a typical thermosetting resin that can be bonded by changing from a linear structure to a three-dimensional network structure by curing reaction of epoxy and hardener. The curing conditions of epoxy adhesive were different with different types of hardener such as mixing ratio, curing time, and temperature. These curing conditions affected to the adhesive property of epoxy adhesive. In industry, it was difficult to proceed the applying epoxy adhesive and combining two parts immediately. The adhesive property decreased by humidity and pre-curing of epoxy adhesive in waiting time between two processes. In this paper, the glass fiber reinforced composite (GFRC) was combined with epoxy adhesive and adhesion property between epoxy adhesive and GFRCs was evaluated using single lap shear test. The different waiting times and humidity conditions were applied to epoxy adhesive in room temperature and adhesive property decreased as the waiting time increased. In small amount of humidity, the adhesive property increased because a small amount of moisture in the surroundings accelerated the curing reaction. In certain amount of humidity, however, the adhesion property decreased.

APPLICATION OF HF COASTAL OCEAN RADAR TO TSUNAMI OBSERVATIONS

  • Heron, Mal;Prytz, Arnstein;Heron, Scott;Helzel, Thomas;Schlick, Thomas;Greenslade, Diana;Schulz, Eric
    • Proceedings of the KSRS Conference
    • /
    • v.1
    • /
    • pp.34-37
    • /
    • 2006
  • When tsunami waves propagate across open ocean they are steered by Coriolis force and refraction due to gentle gradients in the bathymetry on scales longer than the wavelength. When the wave encounters steep gradients at the edges of continental shelves and at the coast, the wave becomes non-linear and conservation of momentum produces squirts of surface current at the head of submerged canyons and in coastal bays. HF coastal ocean radar is well-conditioned to observe the current bursts at the edge of the continental shelf and give a warning of 40 minutes to 2 hours when the shelf is 50-200km wide. The period of tsunami waves is invariant over changes in bathymetry and is in the range 2-30 minutes. Wavelengths for tsunamis (in 500-3000 m depth) are in the range 8.5 to over 200 km and on a shelf where the depth is about 50 m (as in the Great Barrier Reef) the wavelengths are in the range 2.5 - 30 km. It is shown that the phased array HF ocean surface radar being deployed in the Great Barrier Reef (GBR) and operating in a routine way for mapping surface currents, can resolve surface current squirts from tsunamis in the wave period range 20-30 minutes and in the wavelength range greater than about 6 km. There is a trade-off between resolution of surface current speed and time resolution. If the radar is actively managed with automatic intervention during a tsunami alert period (triggered from the global seismic network) then it is estimated that the time resolution of the GBR radar may be reduced to about 2 minutes, which corresponds to a capability to detect tsunamis at the shelf edge in the period range 5-30 minutes. It is estimated that the lower limit of squirt velocity detection at the shelf edge would correspond to a tsunami with water elevation of less than 5 cm in the open ocean. This means that the GBR HF radar is well-conditioned for use as a monitor of small and medium scale tsunamis, and has the potential to contribute to the understanding of tsunami genesis research.

  • PDF

A Design on Face Recognition System Based on pRBFNNs by Obtaining Real Time Image (실시간 이미지 획득을 통한 pRBFNNs 기반 얼굴인식 시스템 설계)

  • Oh, Sung-Kwun;Seok, Jin-Wook;Kim, Ki-Sang;Kim, Hyun-Ki
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.16 no.12
    • /
    • pp.1150-1158
    • /
    • 2010
  • In this study, the Polynomial-based Radial Basis Function Neural Networks is proposed as one of the recognition part of overall face recognition system that consists of two parts such as the preprocessing part and recognition part. The design methodology and procedure of the proposed pRBFNNs are presented to obtain the solution to high-dimensional pattern recognition problem. First, in preprocessing part, we use a CCD camera to obtain a picture frame in real-time. By using histogram equalization method, we can partially enhance the distorted image influenced by natural as well as artificial illumination. We use an AdaBoost algorithm proposed by Viola and Jones, which is exploited for the detection of facial image area between face and non-facial image area. As the feature extraction algorithm, PCA method is used. In this study, the PCA method, which is a feature extraction algorithm, is used to carry out the dimension reduction of facial image area formed by high-dimensional information. Secondly, we use pRBFNNs to identify the ID by recognizing unique pattern of each person. The proposed pRBFNNs architecture consists of three functional modules such as the condition part, the conclusion part, and the inference part as fuzzy rules formed in 'If-then' format. In the condition part of fuzzy rules, input space is partitioned with Fuzzy C-Means clustering. In the conclusion part of rules, the connection weight of pRBFNNs is represented as three kinds of polynomials such as constant, linear, and quadratic. Coefficients of connection weight identified with back-propagation using gradient descent method. The output of pRBFNNs model is obtained by fuzzy inference method in the inference part of fuzzy rules. The essential design parameters (including learning rate, momentum coefficient and fuzzification coefficient) of the networks are optimized by means of the Particle Swarm Optimization. The proposed pRBFNNs are applied to real-time face recognition system and then demonstrated from the viewpoint of output performance and recognition rate.

The Strategies for Forming Governance System to Raise Industrial Competitiveness of Metal and Machinery Industrial Clusters in South-East Region, Korea (동남권 기계.금속산업클러스터의 광역적 지원체계 구축전략)

  • Kwon, O--Hyeok
    • Journal of the Economic Geographical Society of Korea
    • /
    • v.9 no.3
    • /
    • pp.297-317
    • /
    • 2006
  • This article is aimed to find a more successful way to build a metropolitan-wide governance for enhancing industrial cluster in South-East region, Korea. We begin a research with reviewing a current study of regional cluster and its governance. New industrial system and agglomeration changed regional growth theory and urban system. In traditional system, a central city dominated economy of the metropolitan area. However, with development of new transportation and communication technology, a central city lost their superiority to suburban cities. In other words, growing competition between central and suburban cities changed traditional concentration and diffusion theory of urbanization which dominated urban geography for last decades. Next, current situation of development of industrial cluster in South-East region is examined to suggest policy for more competitiveness. South-East region has grown as the most prominent cluster of mechanical engineering and metal industry in Korea since the late 1970s. In the form of agglomeration and network of a specific and its related industry, South-East region has formed a linear industrial belt along with the inter-regional South Coast Highway and contain about ten industrial cities. Accompanying with this growing South-East region, a problem has risen from geographic mismatch between metropolitan-wide industrial cluster and its administrative boundary. Since industrial cluster has no specific administrative boundary, adequate government support for developing industrial cluster has not been provided. Responding to the problem, academics and policy makers maintain need in establishing a metropolitan-wide governance for supporting a cluster. At the end, this paper provides some implication to planners and policy makers.

  • PDF

Study on Improvement of Target Tracking Performance for RASIT(RAdar of Surveillance for Intermediate Terrain) Using Active Kalman filter (능동형 Kalman filter를 이용한 지상감시레이더의 표적탐지능력 향상에 관한 연구)

  • Myung, Sun-Yang;Chun, Soon-Yong
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.46 no.3
    • /
    • pp.52-58
    • /
    • 2009
  • If a moving target has a linear characteristics, the Kalman filter can estimate relatively accurate the location of a target, but this performance depends on how the dynamic status characteristics of the target is accurately modeled. In many practical problems of tracking a maneuvering target, a simple kinematic model can fairly accurately describe the target dynamics for a wide class of maneuvers. However, since the target can exhibit a wide range of dynamic characteristics, no fixed SKF(Simple Kalman filter) can be matched to estimate, to the required accuracy, the states of the target for every specific maneuver. In this paper, a new AKF(Active Kalman filter) is proposed to solve this problem The process noise covariance level of the Kalman filter is adjusted at each time step according to the study result which uses the neural network algorithm. It is demonstrated by means of a computer simulation that the tracking capability of the proposed AKF(Active Kalman filter) is better than that of the SKF(Simple Kalman Filter).

An Adaptive Temporal Suppression for Reducing Network Traffic in Wireless Sensor Networks (무선 센서 네트워크에서 통신량 감소를 위한 적응적 데이터 제한 기법)

  • Min, Joonki;Kwon, Youngmi
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.49 no.10
    • /
    • pp.60-68
    • /
    • 2012
  • Current wireless sensor networks are considered to support more complex operations ranging from military to health care which require energy-efficient and timely transmission of large amounts of data. In this paper, we propose an adaptive temporal suppression algorithm which exploits a temporal correlation among sensor readings. The proposed scheme can significantly reduce the number of transmitted sensor readings by sensor node, and consequently decrease the energy consumption and delay. Instead of transmitting all sensor readings from sensor node to sink node, the proposed scheme is to selectively transmit some elements of sensor readings using the adaptive temporal suppression, and the sink node is able to reconstruct the original data without deteriorating data quality by linear interpolation. In our proposed scheme, sensing data stream at sensor node is divided into many small sensing windows and the transmission ratio in each window is decided by the window complexity. It is defined as the number of a fluctuation point which has greater absolute gradient than threshold value. We have been able to achieve up about 90% communication reduction while maintaining a minimal distortion ratio 6.5% in 3 samples among 4 ones.

A Study on Polynomial Pre-Distortion Technique Using PAPR Reduction Method in the Next Generation Mobile Communication System (차세대 이동통신 시스템에 PAPR 감소기법을 적용한 다항식 사전왜곡 기법에 관한 연구)

  • Kim, Wan-Tae;Park, Ki-Sik;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
    • /
    • v.14 no.5
    • /
    • pp.684-690
    • /
    • 2010
  • Recently, the NG(Next Generation) system is studied for supporting convergence of various services and multi mode of single terminal. And a demand of user for taking the various services is getting increased, for supporting these services, many systems being able to transmit a large message have been appeared. In the NG system, it has to be supporting the CDMA and WCDMA besides the tele communication systems using OFDM method with single terminal An intergrated system can be improved with adopting of SoC technique. For adopting SoC technique on the intergrated terminal, we have to solve the non linear problem of HPA(High Power Amplifier). Nonlinear characteristic of HPA distorts both amplitude and phase of transmit signal, this distortion cause deep adjacent channel interference. We adopt a polynomial pre-distortion technique for this problem. In this paper, a noble modem design for NG mobile communication service and a method using polynomial pre-distorter with PAPR technique for counterbalancing nonlinear characteristic of the HPA are proposed.

Development a Downscaling Method of Remotely-Sensed Soil Moisture Data Using Neural Networks and Ancillary Data (신경망기법과 보조 자료를 사용한 원격측정 토양수분자료의 Downscaling기법 개발)

  • Kim, Gwang-Seob;Lee, Eul-Rae
    • Journal of Korea Water Resources Association
    • /
    • v.37 no.1
    • /
    • pp.21-29
    • /
    • 2004
  • The growth of water resources engineering associated with stable supply, management, development is essential to overcome the coming water deficit of our country. Large scale remote sensing and the analysis of sub-pixel variability of soil moisture fields are necessary in order to understand water cycle and to develop appropriate hydrologic model. The target resolution of coming Global monitoring of soil moisture field is about 10km which is not appropriate for the regional scale hydrologic model. Therefore, we need a downscaling scheme to generate hydrologic variables which are suitable for the regional hydrologic model. The results of the analysis of sub-pixel soil moisture variability show that the relationship between ancillary data and soil moisture fields shows there is very weak linear relationship. A downscaling scheme was developed using physically-based classification scheme and Neural Networks which are able to link the nonlinear relationship between ancillary data and soil moisture fields. The model is demonstrated by downscaling soil moisture fields from 4km to 0.2km resolution using remotely-sensed data from the Washita'92 experiment.