• Title/Summary/Keyword: Gradient 방법

Search Result 1,224, Processing Time 0.028 seconds

A Study on the Performance Improvement of Image Segmentation by Selective Application of Structuring Element in MPEG-4 (MPEG-4 기반 영상 분할에서 구조요소의 선택적 적용에 의한 분할성능 개선에 관한 연구)

  • 이완범;김환용
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.41 no.5
    • /
    • pp.165-173
    • /
    • 2004
  • Since the conventional image segmentation methods using mathematical morphology tend to yield over-segmented results, they normally need postprocess which merges small regions to obtain larger ones. To solve this over-segmentation problem without postprocess had to increase size of structuring element used marker extraction. As size of structuring element is very large, edge of region segments incorrectly. Therefore, this paper selectively applies structuring element of mathematical morphology to improve performance of image segmentation and classifies input image into texture region, edge region and simple region using averaged local variance and image gradient. Proposed image segmentation method removes the cause for over-segmentation of image as selectively applies size of structuring element to each region. Simulation results show that proposed method correctly segment for pixel region of similar luminance value and more correctly search texture region and edge region than conventional methods.

GIS Technology for Soil Loss Analysis (금강유역 토양 유실 분석을 위한 GIS응용연구)

  • 김윤종;김원영;유일현;이석민;민경덕
    • Spatial Information Research
    • /
    • v.2 no.2
    • /
    • pp.165-174
    • /
    • 1994
  • Soil loss was estimated by using universal soil loss equation(USLE) through GIS technique in Buyeu area. The expected soil loss is determined from six environmental factors: rainfall, erodibility of selected soil, length and steepness (gradient) of ground slope, crop grown in soil, and land practices used. A scoring system for assessing soil lossrisk has been developed for calculating SLI(Soil Loss Index) by GIS. The scores of six factors multiplied to give a total score which was compared with an chosen classification system to categorize areas of low, moderate and high risk. Finally, a soil loss assessment map was produced by GIS cartographic simulation technique, and this map could be applied in the establishment of regional land use planning.

  • PDF

The Feasibility of Event-Related Functional Magnetic Resonance Imaging of Power Hand Grip Task for Studying the Motor System in Normal Volunteers; Comparison with Finger Tapping Task

  • Song, In-Chan;Chang, Kee-Hyun;Han, Moon-Hee
    • Proceedings of the KSMRM Conference
    • /
    • 2001.11a
    • /
    • pp.111-111
    • /
    • 2001
  • 목적: To evaluate the feasibility of the event-related functional MR study using power grip studying the hand motor system 대상 및 방법: Event-related functional MRI was performed on a 1.5T MR unit in seven norm volunteers (man=7, right-handedness=2, left-handedness=5, mean age: 25 years). A single-shot GRE-EPI sequence (TR/TE/flip angle: 1000ms/40ms/90, FOV = 240 mm matrix= 64$\times$64, slice thickness/gap = 5mm/0mm, 7 true axial slices) was used for functiona MR images. A flow-sensitive conventional gradient echo sequence (TR/TE/flip angl 50ms/4ms/60) was used for high-resolution anatomical images. To minimize the gross hea motion, neck-holders (MJ-200, USA) were used. A series of MR images were obtained in axial planes covering motor areas. To exclude motion-corrupted images, all MR images wer surveyed in a movie procedure and evaluated using the estimation of center of mass of ima signal intensities. Power grip task consisted of the powerful grip of all right fingers and hand movement ta used very fast right finger tapping at a speed of 3 per 1 second. All tasks were visual-guid by LCD projector (SHARP, Japan). Two tasks consisted of 134 phases including 7 activatio and 8 rest periods. Active stimulations were performed during 2 seconds and rest period were 15 seconds and total scan time per one task was 2 min 14 sec. Statistical maps we obtained using cross-correlation method. Reference vector was time-shifted by 4 seconds an Gaussian convolution with a FWHM of 4 seconds was applied to it. The threshold in p val for the activation sites was set to be 0.001. All mapping procedures were peformed usin homemade program an IDL (Research Systems Inc., USA) platform. We evaluated the activation patterns of the motor system of power grip compared to hand movement in t event-related functional MRI.

  • PDF

Characterization and Distribution of Transferrin from the Last Larval Haemolymph of Papilio xuthus (호랑나비 유충 혈림프 Transferrin의 특성과 분포)

  • Shin, Myung-Ja;Kim, Kyoung-Keun;Kim, Jeong-Sook;Lim, Jae-Hwan;Seo, Eul-Won
    • Journal of Life Science
    • /
    • v.17 no.8 s.88
    • /
    • pp.1046-1052
    • /
    • 2007
  • Transferrin is a molecule carrying iron to store and maintain for iron homeostasis of living organisms. In this study, we have purified transferrin, as an iron-binding protein, from the last larval haemolymph of Papilio xuthus by KBr density gradient ultracentrifugation and gel filtration (superose 6 HR) using fast protein liquid chromatography (FPLC) and transferrin containing iron was identified by Ferene S staining. The purified haemolymph transferrin was shown to have molecular mass of 78 and 80 kDa and amino acid composition of transferrin was rich in aspartic acid, valine, leucine and glutamic acid. With immuno-diffusion assay, we confirmed the existence of the transferrin in the haemo-lymph and fat body by detection of visible and clear positive reaction. From the quantitative comparison by rocket immuno-electrophoresis process, the amount of transferrin were increased in the haemolymph of 3 days after pupation and the whole 5 days after pupation. Here, with biochemical and immunohistochemical analysis, we speculate the relationship of transferrin between the physical characteristics and distribution during metamorphosis of P. xuthus.

Modeling of the Optimal Operation Pattern for Energy Saving of The Trains (전동열차의 운행에너지 절감을 위한 최적 운행 패턴 모델링)

  • Kim, Jung-Hyun;Lee, Se-Hoon;Jun, Sang-Pyo
    • Journal of the Korea Society of Computer and Information
    • /
    • v.19 no.12
    • /
    • pp.187-196
    • /
    • 2014
  • In this paper, Minimize driving energy for operation within a defined distance yeokgan fixed time-resolved and determine the nature of the train is traveling, and to model mathematically. Urban rail car cruise in general by the PID controller is used instead of automatically tracking a target value while traveling in energy consumption to be minimized by using optimal control model railroad charyangreul was designed under real operating conditions the same. The actual track conditions apply to the minimum value or a separate listing of cars around the track facility without a driving energy of the automatic operation and to reduce the driving energy. Therefore, actual route chosen straight line 8 / gradient segment / curve for the measured data analysis, such as sections within the city-minute drive each section and presented how the trains to save energy, depending on the pattern of the train station in the region.

Half-metallicity and Magnetism at the (001) Surfaces of the Quaternary Heusler Alloys CoFeCrZ (Z = Ga, Ge): A First-principles Study (4원 호이슬러 합금 CoFeCrZ(Z = Ga, Ge)의 (001) 표면에서의 자성과 반쪽금속성: 제일원리 계산 연구)

  • Kim, Dong-Chul;Lee, Jae Il
    • Journal of the Korean Magnetics Society
    • /
    • v.25 no.2
    • /
    • pp.31-38
    • /
    • 2015
  • Recently, a first-principles study led to a prediction that quaternary Heusler compounds, CoFeCrZ (Z = Ga, Ge) are excellent half-metallic ferromagnets. In this study, we investigate the electronic and the magnetic properties at the (001) surfaces of CoFeCrGa and CoFeCrGe by means of the full-potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation. We considered two types of surface termination: CoFe-terminated and CrZ-terminated surfaces, Z being either Ga or Ge. From the calculated total magnetic moments and the local density of states, we found that half-metallicity is not preserved for all the surfaces. But the calculated atomic density of states showed that CrGa-terminated surface of the CoFeCrGa is almost half-metallic. The magnetic moment of the Co, Fe, or Cr atoms at the surface or subsurface layers in each system had very different values.

Optimal Design of Viscoelastic Dampers and Support Braces (점탄성 감쇠기와 설치용 가새의 최적설계)

  • 박지훈;이상현;강경수;황재승;김진구
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.5 no.3
    • /
    • pp.45-55
    • /
    • 2001
  • The purpose of this paper is to present the optimal design method of viscoelastic dampers and support brace stiffnesses. The dynamics of visco-elastic dampers and support braces connected in series is modeled by state equation. A constraint on maximum story drifts which are computed using RMS\`s of story drifts and peak factors is added to the optimization problem. The number of variables is reduced by including the constraint associated with the dynamic behavior of the structure in the procedure to compute the gradient of the inequality equation about constraint on the maximum story drifts. In the design example, it is confirmed that the design of dampers considering support brace stiffnesses is necessary when sufficient brace stiffnesses cannot be supplied. It is also found that unnecessary brace stiffnesses can be removed by adding brace stiffnesses to optimal design variables and that the increase of damper volumes to compensate for the variation of maximum story drifts is pretty small.

  • PDF

Rapid Detection Methods for Food-Borne Pathogens in Dairy Products by Polymerase Chain Reaction (PCR 방법을 이용한 우유 및 유제품에서 발생하는 식중독 균의 신속 검출법)

  • Kwak, Hyelim;Han, Seonkyeong;Kim, Eiseul;Hong, Yeun;Kim, Haeyeong
    • Journal of Dairy Science and Biotechnology
    • /
    • v.31 no.2
    • /
    • pp.171-177
    • /
    • 2013
  • The dairy industry has consistently grown via the expansion of dairy-based food categories. Dairy product consumption is stable since the nutrient composition in dairy products is ideal for human health. However, dairy products are highly susceptible to food-borne pathogens. Controlling the safety of dairy products is thus important when considering the nutrient-rich matrix of this food category. Currently, immunoassays or molecular biology techniques have been used to evaluate the safety of dairy products in Korea. These methods are based on the detection of proteins and thus have low reproducibility and sensitivity. Recent techniques to detect food-borne pathogens have focused on genetic analyses. Rapid detection methods for food-borne pathogens in milk and dairy products using polymerase chain reaction (PCR) techniques, such as conventional PCR, real-time PCR, repetitive sequence-based (rep)-PCR, PCR-denaturing gradient gel electrophoresis (DGGE), and digital PCR, are reviewed in this article. The aim of this review was to contribute knowledge of the relationship between microflora and the quality of dairy products. This study will also assist in the immediate monitoring of food-borne pathogens in milk and dairy products when an outbreak related to this food category occurs.

  • PDF

The effect of gap between ingot and crucible on the distribution of initial melt concentration in Bridgman crystal growth (Bridgman 결정성장시 장입 주괴와 도가니 사이의 틈이 용액이 초기농도에 미치는 영향)

  • Seung-Mo Chung;Man-Sug Kang;Zin-Hyoung Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.4 no.2
    • /
    • pp.169-177
    • /
    • 1994
  • Dilute Al-Cu and Al-Mg alloys were solidified unidirectionally upward by Bridgman method. It is necessary that solute concentration of initial melt is uniform to be able to control the concentration of crystal. When solute concentration is not uniform, it can cause unusual macro-segregation in grown solid. A non-steady state solidification was observed where the solute concentration in the grown solid decreased with the progress of solidification, when a dilute Al-Cu melt with positive axial temeprature gradient was solidified. This was caused by leaking out of Cu-rich melt into the gap between ingot and crucible during melt-down and its sedimentation after complete melting. In the case of Al-Mg alloy, the solute concentration has a minimum in the middle of grown specimen because Mg-rich melt flowed down the gap between ingot and crucible and floated after complete melting. Uniform initial melt concentration can be achieved by the homogenization of the ingot or by the absence of the gap between ingot and crucible.

  • PDF

ON THE BONE TISSUE REACTION TO IMPLANTS WITH DIFFERENT SURFACE TREATMENT METHODS (임플랜트 표면 처리 방법에 따른 골조직 반응에 대한 연구)

  • Kim, Yong-Jae;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.45 no.1
    • /
    • pp.71-84
    • /
    • 2007
  • Statement of problem: Implant surface characteristics plays an important role in clinical success and many studies have been made for improvement of success by changing surface roughness. Purpose: Appropriate increase of surface roughness increases the activity of osteoblast and enhance contact and retention between bone and implant. Material and method- Machined, SLA and RBM surface implants, which are the most commonly used implants were implanted into the tibia of rabbits and after 1 week, 4 weeks, 8 weeks and 12 weeks there were histologic and histomorphometric analysis and study for bone gradient and change of Ca/P ratio using EDS(Energy Dispersive X-ray Spectroscope). Results: Comparison of bone-implant contact showed no significant difference among each implant. In comparison of bone area rates, SLA showed higher value with significant difference at 1 week and 4 weeks, and SLA and RBM at 8 weeks than Machined implant (p<0.05). In analysis of bone constituents with EDS, titanium was specifically detected in new bones and the rates were constant by surface treatment method or period. In case of Ca/P ratio, according to surface treatment method, each group showed significant difference. Lots of old bone fragments produced during implantation remained on the rough surface of RBM implant surface and each group showed histological finding with active synthesis of collagen fibers until 12 weeks. In transmission electronic microscopic examination of sample slice after elapse of twelve weeks, tens nm of borderline (lamina limitans like dense line)was seen to contact the bone, on the interface between bone and implant. Conclusion: SLA and RBM implant with rough surface shows better histomorphometrical result and the trend of prolonged bone formation and maturation in comparison with Machined implant. In addition, implant with rough surface seems to be helpful in early stage bone formation due to remaining of old bone fragments produced in implantation. From the results above, it is considered to be better to use implant with rough surface in implantation.