• Title/Summary/Keyword: Gradients

Search Result 1,176, Processing Time 0.029 seconds

Truck Classification System Using HOG Feature - based SVM (HOG 특징 기반 SVM 을 활용한 화물차 분류 시스템)

  • Kang, Keon-Woo;Kang, Suk-Ju
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2018.06a
    • /
    • pp.345-346
    • /
    • 2018
  • 차종 별 교통량 자료는 도로의 유지관리나 분석 등의 행정 처리 업무에 필요한 기본 자료임과 동시에 각종 연구에 활용된다. 본 시스템은 그 일환으로서 화물차나 일반차량을 구분하여 특정 도로의 화물차 비율이나 교통량을 파악하는데 활용할 수 있다. 머신 러닝 알고리즘 중에서 높은 성능을 보이는 Support Vector Machine (SVM) 알고리즘을 이용하여 도로 위의 일반차량과 화물차를 구분하였다. 우선, 화물차와 일반차량의 차이를 구분하고자 각각의 영상에 대해 Histogram of Oriented Gradients (HOG) 기반 특징점을 추출하고 이에 따라 1 차원 벡터로 표현된 데이터를 SVM 으로 분류하여 구분한다.

  • PDF

COMPUTATION OF DIVERGENCES AND MEDIANS IN SECOND ORDER CONES

  • Kum, Sangho
    • Nonlinear Functional Analysis and Applications
    • /
    • v.26 no.4
    • /
    • pp.649-662
    • /
    • 2021
  • Recently the author studied a one-parameter family of divergences and considered the related median minimization problem of finite points over these divergences in general symmetric cones. In this article, to utilize the results practically, we deal with a special symmetric cone called second order cone, which is important in optimization fields. To be more specific, concrete computations of divergences with its gradients and the unique minimizer of the median minimization problem of two points are provided skillfully.

Complexity Control Method of Chaos Dynamics in Recurrent Neural Networks

  • Sakai, Masao;Homma, Noriyasu;Abe, Kenichi
    • Transactions on Control, Automation and Systems Engineering
    • /
    • v.4 no.2
    • /
    • pp.124-129
    • /
    • 2002
  • This paper demonstrates that the largest Lyapunov exponent λ of recurrent neural networks can be controlled efficiently by a stochastic gradient method. An essential core of the proposed method is a novel stochastic approximate formulation of the Lyapunov exponent λ as a function of the network parameters such as connection weights and thresholds of neural activation functions. By a gradient method, a direct calculation to minimize a square error (λ - λ$\^$obj/)$^2$, where λ$\^$obj/ is a desired exponent value, needs gradients collection through time which are given by a recursive calculation from past to present values. The collection is computationally expensive and causes unstable control of the exponent for networks with chaotic dynamics because of chaotic instability. The stochastic formulation derived in this paper gives us an approximation of the gradients collection in a fashion without the recursive calculation. This approximation can realize not only a faster calculation of the gradient, but also stable control for chaotic dynamics. Due to the non-recursive calculation. without respect to the time evolutions, the running times of this approximation grow only about as N$^2$ compared to as N$\^$5/T that is of the direct calculation method. It is also shown by simulation studies that the approximation is a robust formulation for the network size and that proposed method can control the chaos dynamics in recurrent neural networks efficiently.

Altitudinal Variation in Species Composition and Soil Properties of Banj Oak and Chir Pine Dominated Forests

  • Kumar, Munesh;Singh, Harpal;Bhat, Jahangeer A.;Rajwar, G.S.
    • Journal of Forest and Environmental Science
    • /
    • v.29 no.1
    • /
    • pp.29-37
    • /
    • 2013
  • The study was carried out in two different forest types viz., Banj oak and Chir pine forests to assess the variation in forest species composition and soil properties along altitudinal gradients in the Garhwal Himalayas. The results of the study showed that between the forests soil moisture was higher in Banj oak forest because of closed canopy and dense forest compared to Chir pine forest. The sand particles were reported higher in Banj oak forest which might be due to the addition of organic matter favouring coarse structure of soil, helping in holding maximum water in soils. However in the Chir pine forest low amount of soil organic matter and presence of clayey soil, develops soil compactness which reduces the penetration of water resulting in high soil bulk density. The higher accumulation of litter and presence of moisture in Banj oak forest favours higher nutrient level of nitrogen, phosphorus and potassium compared to Chir pine forest. The soil organic carbon also reduced with increasing altitude at both gradients. While bulk density has reverse trend with soil organic carbon in both the forests at different peaks of same region. In Banj oak forest, the highest density and total basal cover was reported 1,100 tree $ha^{-1}$ and 58.86 $m^2\;ha^{-1}$ respectively. However, the highest values of density and total basal cover of Chir pine forest was 560 tree$ha^{-1}$ and 56.94 $m^2\;ha^{-1}$ respectively. The total density and basal cover of both the forests reduced with increasing altitude. The study concludes that Banj oak forest has better nutrient cycling ability, well developed foest floor and has a greater protective and productive features compared to the Chir pine forest which is without lower vegetation cover and having only pine litter accumulation which does not allow any other species to grow.

The influence of temperature gradient and rotation rate on Bi4Ge3O12 crystal growth by czochralski method (쵸크랄스키법에 의한 $Bi_4Ge_3O_{12}$ 단결정 육성에서 온도구배와 회전속도가 미치는 영향)

  • 배인국;황진명
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.9 no.6
    • /
    • pp.585-589
    • /
    • 1999
  • In order to grow $Bi_4Ge_3O_{12}$ crystals by the Czochralski method equipped with the auto-diameter control system, we used the resistance heater of our own design. We measure the temperature gradients under-arious thermal configurations. The relation between the critical rotation rate corresponding to the flat interface and the temperature gadient was investigated, and the importance of the axial temperature gradient was pointed out. The results from this work were compared with those obtained by other authors when RF heating was used. The optimal conditions for the crystal growth were determined as follows; under $O_2$ atmosphere with the pulling rate fixed at 2 mm/hr, rotation rate changed from 30 to 23 rpm as the crystal growth proceeded, radial and axial temperature gradients were 50 and $40^{\circ}C$/cm near melts respectively, and the composition was chemically stoichiometric.

  • PDF

ROI Based Object Extraction Using Features of Depth and Color Images (깊이와 칼라 영상의 특징을 사용한 ROI 기반 객체 추출)

  • Ryu, Ga-Ae;Jang, Ho-Wook;Kim, Yoo-Sung;Yoo, Kwan-Hee
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.8
    • /
    • pp.395-403
    • /
    • 2016
  • Recently, Image processing has been used in many areas. In the image processing techniques that a lot of research is tracking of moving object in real time. There are a number of popular methods for tracking an object such as HOG(Histogram of Oriented Gradients) to track pedestrians, and Codebook to subtract background. However, object extraction has difficulty because that a moving object has dynamic background in the image, and occurs severe lighting changes. In this paper, we propose a method of object extraction using depth image and color image features based on ROI(Region of Interest). First of all, we look for the feature points using the color image after setting the ROI a range to find the location of object in depth image. And we are extracting an object by creating a new contour using the convex hull point of object and the feature points. Finally, we compare the proposed method with the existing methods to find out how accurate extracting the object is.

Dynamics of Carbon Sequestered in Concentric Layers of Soil Macroaggregates

  • Park, Eun-Jin;Smucker, Alvin J.M.
    • The Korean Journal of Ecology
    • /
    • v.28 no.4
    • /
    • pp.181-188
    • /
    • 2005
  • Methods used to study carbon sequestration by soil aggregates have often excluded the concentric spatial variability and other dynamic processes that contribute to resource accessibility and solute transport within aggregates. We investigated the spatial gradients of carbon (C) and nitrogen (N) from the exterior to interior layers within macroaggregates, $6.3\sim9.5$ mm, sampled from conventional tillage (CT) and no tillage (NT) sites of a Hoytville silt clay loam. Spatial gradients in C accumulation within macroaggregates were related to the differences in C dynamics by determining the sizes and the turnover rates of fast C and slow C pools in the concentric layers of aggregates. Aggregate exteriors contained more labile C and were characterized by greater C mineralization rates than their interiors in both management systems. In contrast, C in the interior layers of aggregates was more resistant in both systems. These results indicated the spatial differentiation of C dynamics within macroaggregates, i.e., exterior layers as a reactive site and interior layers as a protective site. Greater total C distribution in the exterior layers of NT aggregates indicated more influx of C from the macropores in interaggregate space than C. mineralization (net gain of C), whereas lower C distribution within the exterior layers of CT aggregates indicated net loss of C by greater C mineralization than C influx. We found total C increased approximately 1.6-fold by the conversion of CT soils to NT management systems for a period of 36 years. Differences in total accumulation and the spatial distribution of C within aggregates affected by management were attributed to the differences in aggregate stability and pore networks controlling the spatial heterogeneities of resource availability and microbial activity within aggregates.

Experimental Study on the Characteristics of Combustion in Middle Size-direct Moxibustion (중주(中炷) 직접구(直接灸)의 연소특성에 관한 실험적 연구)

  • Choi, Youn-Sung;Kim, Do-Ho;Lee, Geon-Hui;Lee, Geon-Mok
    • Journal of Acupuncture Research
    • /
    • v.26 no.1
    • /
    • pp.111-119
    • /
    • 2009
  • Objectives : The purpose of this study is to investigate the mechanism and effect of moxa bucket moxibustion, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxa bucket moxibustion. Methods : We have selected the moxa bucket moxibustion. We have made a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We have examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : 1. We could design the moxa bucket moxibustion so that it has $57.6^{\circ}C$ maximum temperature with 7g weight and 10mm height, if we use more weight of moxa or lower height of moxa, we can observe relatively elevated maximum temperature. We observed the maximum temperature following the measuring position of moxa bucket and we could see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket. 2. We could design the moxa bucket moxibustion with 5g moxa and 10mm height so that it has 0.12 $1^{\circ}C/sec$ of maximum temperature gradient, and it has relatively high temperature gradient at lower weight and height condition. 3. We could design the moxa bucket moxibustion with 7g moxa and 15mm height so that it has 4,135sec of the longest effective temperature combustion time. If we use more weight of moxa or higher height of moxa, we can observe relatively extended effective temperature combustion time. Conclusions : We observed the longest effective combustion time following the measuring position of moxa bucket. We can see a higher temperature at the center of the moxa bucket and a lower temperature at the side of the moxa bucket.

  • PDF

Recognition of Symbolic Road Marking using HOG-SP and Improved Lane Detection (HOG-SP를 이용한 방향지시기호 인식 및 향상된 차선 검출)

  • Lee, Myungwoo;Kwak, Sooyeong;Byun, Hyeran
    • Journal of Broadcast Engineering
    • /
    • v.21 no.1
    • /
    • pp.87-96
    • /
    • 2016
  • Recently, there is a need for automatic recognition of a variety of symbols on roads because of activation of information services using digital maps on the Web or mobile devices. This paper proposes a method which automatically recognizes 11 kinds of symbolic road markings on the road surface with HOG-SP(Histogram of oriented Gradients-Split Projection) descriptor and shows improvement of lane position detection with recognized symbolic road markings. With the proposed method, recognition rate of 81.99% has been proven on NAVER road view images and the experiments proves the superiority of proposed method by comparisons with other existing methods. Moreover, this paper shows 7.64% higher lane position detection rate by recognizing road surface marking beforehand than only detecting lanes' positions.

A Study on the Clinical Application of Intelligent Replenishment System of Automatic X-ray Film Processor Based on Film Density (자동현상 지능화 보충방식의 임상적응에 관한 연구)

  • Lee, W.H.;Suh, S.S.;In, K.H.;Lee, H.J.;Kim, K.C.;Yoon, C.H.;Auh, Y.H.
    • Journal of radiological science and technology
    • /
    • v.22 no.1
    • /
    • pp.49-53
    • /
    • 1999
  • To inquire its usefulness of the clinical application of intelligent replenishment system of automatic X-ray film processor based on film density, we processed the serial 300 sheets of radiographic film of chest [$14{\times}14"$, HR-C type] and bone [elbow & ankle($8{\times}10"$), skull($10{\times}12"$), hand & foot($11{\times}14"$), pelvis($14{\times}17"$), HR-G type, 68, 70, 77, 85 sheets respectively]. We analyzed the characteristic corves, relative speeds, average gradients and base plus fog densities every twenty five sheets. We also evaluated the developer and fixer replenishment volumes every that time. In the chest and bone radiograph two all, the characteristic curves were little change, and the relative speeds, average gradients and base plus fog densities were within the maximum control limits. The average developer replenishment volumes were about 43m1/sheet and 39m1/sheet respectively. It brings decreased results about 29% in comparison with the conventional replenishment system. In our experiences, we conclude that the intelligent replenishment system of automatic X-ray film processor based on film density maintains image quality consistently, decreases also the replenishment volumes. Therefore, this system will be resulted in economic and environmental effects, and solve problems of over and low replenishment volume.

  • PDF