• Title/Summary/Keyword: Diffusion Patterns

Search Result 302, Processing Time 0.032 seconds

Sap Temperature Distribution of the Xylem and Leaf Water Status of Apple Trees in Relation to Soil Oxygen Diffusion Rates

  • Ro, Hee-Myong
    • Journal of Applied Biological Chemistry
    • /
    • v.43 no.3
    • /
    • pp.170-175
    • /
    • 2000
  • A pot-lysimeter experiment was conducted with 3-year-old 'Tsugaru' apple (Malus domestica Borkh) trees to examine the changes in oxygen diffusion rate (ODR) with lateral flow velocity of water through soil. The influence of lateral water flow velocity on water relations and elemental content in leaf, and sap temperature distribution patterns of the xylem of trees were also determined. Trees were grown under four soil water regimes: (1) fast laterally flowing (FWT, $2.50{\times}10^{-4}cm\;s^{-1}$), (2) slow laterally flowing (SWT, $0.25{\times}10^{-4}cm\;s^{-1}$), and (3) stagnant water table (WLT) at 60-cm, and (4) drip-irrigation at -40 kPa of soil matric potential as a control. The rate of $O_2$ diffusion converged near $2{\times}10^{-3}g\;m^{-2}\;min^{-1}$ for FWT and control soils, but decreased below $1{\times}10^{-3}g\;m^{-2}\;min^{-1}$ 40 days after treatment (DAT) for WLT soils. For SWT soils, however, the ODR at 15 cm below the soil surface was similar to that of control, but at 45 cm below the soil surface, ODR was similar to that of the WLT treatment. Leaf water potential of FWT and SWT plants was similar to that of control plants, but the values for SWT plants declined by 98 DAT. Leaf water potential of WLT plants decreased from -1.86 MPa (9 DAT) to -2.41 MPa (59 DAT) and finally down to -2.70 MPa. The sap temperature measured at 1100-hr was lowest at top and highest at bottom for FWT and control plants, but this pattern of SWT and WLT plants was disturbed from 29 DAT. However, for SWT plants, such thermal disturbance of sap temperature disappeared from 63 DAT.

  • PDF

Edge Enhanced Error Diffusion with Blue Noise Mask Threshold Modulation (청색잡음 마스크 임계값변조를 이용한 경계강조 오차확산법)

  • Lee, Eul-Hwan;Park, Jang-Sik;Park, Chang-Dae;Kim, Jae-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.36S no.10
    • /
    • pp.72-82
    • /
    • 1999
  • The error diffusion algorithm is excellent for reproducing continuous gray-scale images to bianry images and also has good edge characteristics. However, it is well known that artifacts with objectionable patterns can occur in the halftoned images. On the other hand, a halftone algorithm using blue noise mask has been proposed. where the halftoning is achieved by a pixelwise comparison of gray-scale image with an array, the blue noise mask. It doesn't have pattern artifacts, but the halftoned image looks unclear because the quantization errors are not feedbacked compared to the error diffusion. In this paper, edge enhanced error diffusion which dithers the threshold with the blue noise mask is proposed. We show that the proposed algorithm can produce unstructured and edge enhanced halftone images. This algorithm is analyzed by the concept of an equivalent input image. The performace of the proposed algorithm is compared with that of the conventional halftoning by measuring the radially averaged power spectrum and edge correlation.

  • PDF

Characteristics of Damage on Photosensor Irradiated by Intense Illumination : Thermal Diffusion Model (고섬광에 노출된 광센서의 손상 특성 : 열확산 모델)

  • Kwon, Chan-Ho;Shin, Myeong-Suk;Hwang, Hyon-Seok;Kim, Hong-Lae;Kim, Seong-Shik;Park, Min-Kyu
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.15 no.2
    • /
    • pp.201-207
    • /
    • 2012
  • Pulsed lasers at the 613 nm and 1064 nm wavelengths on nanoseconds have been utilized to characterize the damage on Si photodiode exposed to intense illumination. Morphological damages and structural changes at sites on the photodiode irradiated during microseconds of laser pulses were analyzed by FE-SEM images and XRD patterns, respectively. The removal of oxide coating, ripple, melting marks, ridges, and crater on photodiodes were definitely observed in order of increasing the pulse intensities generated above the damage threshold. Then, the degradation in photosensitivity of the Si photodiode irradiated by high power density pulses was measured as a function of laser irradiation time at the various wavelengths. The free charge carrier and thermal diffusion mechanisms could have been invoked to characterize the damage. The relative photosensitivity data calculated using the thermal diffusion model proposed in this paper have been compared with the experimental data irradiated above the damage threshold.

Structural features and Diffusion Patterns of Gartner Hype Cycle for Artificial Intelligence using Social Network analysis (인공지능 기술에 관한 가트너 하이프사이클의 네트워크 집단구조 특성 및 확산패턴에 관한 연구)

  • Shin, Sunah;Kang, Juyoung
    • Journal of Intelligence and Information Systems
    • /
    • v.28 no.1
    • /
    • pp.107-129
    • /
    • 2022
  • It is important to preempt new technology because the technology competition is getting much tougher. Stakeholders conduct exploration activities continuously for new technology preoccupancy at the right time. Gartner's Hype Cycle has significant implications for stakeholders. The Hype Cycle is a expectation graph for new technologies which is combining the technology life cycle (S-curve) with the Hype Level. Stakeholders such as R&D investor, CTO(Chef of Technology Officer) and technical personnel are very interested in Gartner's Hype Cycle for new technologies. Because high expectation for new technologies can bring opportunities to maintain investment by securing the legitimacy of R&D investment. However, contrary to the high interest of the industry, the preceding researches faced with limitations aspect of empirical method and source data(news, academic papers, search traffic, patent etc.). In this study, we focused on two research questions. The first research question was 'Is there a difference in the characteristics of the network structure at each stage of the hype cycle?'. To confirm the first research question, the structural characteristics of each stage were confirmed through the component cohesion size. The second research question is 'Is there a pattern of diffusion at each stage of the hype cycle?'. This research question was to be solved through centralization index and network density. The centralization index is a concept of variance, and a higher centralization index means that a small number of nodes are centered in the network. Concentration of a small number of nodes means a star network structure. In the network structure, the star network structure is a centralized structure and shows better diffusion performance than a decentralized network (circle structure). Because the nodes which are the center of information transfer can judge useful information and deliver it to other nodes the fastest. So we confirmed the out-degree centralization index and in-degree centralization index for each stage. For this purpose, we confirmed the structural features of the community and the expectation diffusion patterns using Social Network Serice(SNS) data in 'Gartner Hype Cycle for Artificial Intelligence, 2021'. Twitter data for 30 technologies (excluding four technologies) listed in 'Gartner Hype Cycle for Artificial Intelligence, 2021' were analyzed. Analysis was performed using R program (4.1.1 ver) and Cyram Netminer. From October 31, 2021 to November 9, 2021, 6,766 tweets were searched through the Twitter API, and converting the relationship user's tweet(Source) and user's retweets (Target). As a result, 4,124 edgelists were analyzed. As a reult of the study, we confirmed the structural features and diffusion patterns through analyze the component cohesion size and degree centralization and density. Through this study, we confirmed that the groups of each stage increased number of components as time passed and the density decreased. Also 'Innovation Trigger' which is a group interested in new technologies as a early adopter in the innovation diffusion theory had high out-degree centralization index and the others had higher in-degree centralization index than out-degree. It can be inferred that 'Innovation Trigger' group has the biggest influence, and the diffusion will gradually slow down from the subsequent groups. In this study, network analysis was conducted using social network service data unlike methods of the precedent researches. This is significant in that it provided an idea to expand the method of analysis when analyzing Gartner's hype cycle in the future. In addition, the fact that the innovation diffusion theory was applied to the Gartner's hype cycle's stage in artificial intelligence can be evaluated positively because the Gartner hype cycle has been repeatedly discussed as a theoretical weakness. Also it is expected that this study will provide a new perspective on decision-making on technology investment to stakeholdes.

Antimicrobial Resistance Profiles of eae Positive Escherichia coli (eae+ Escherichia coli의 항생제 감수성 및 내성 패턴)

  • Lee, Min-Hwa;Choi, Chang-Sun
    • Journal of Food Hygiene and Safety
    • /
    • v.22 no.2
    • /
    • pp.116-119
    • /
    • 2007
  • The antimicrobial susceptibility and antibiotic resistance patterns of 67 eae positive Escherichia coli strains isolated from pigs were investigated by disc diffusion method. Sixty-seven E. coli isolated from pigs showed susceptibility to Ceftiofur (98.5%), Lincomycin+Spectinomycin (74.6%), Danofloxacin (73.1%), Enrofloxacin (64.2%), and Neomycin (41.8%). However, the multiple resistance patterns were also seen in eae+E. coli isolates. Neomycin+Tylosin+Penicillin+Tetracycline, Tylosin+Penicillin+Tetracycline, and Neomycin+Tylosin+Danofloxacin+Penicillin+Tetracycline+Enrofloxacinwere the most prevalent patterns of multiple antibiotic resistance.

Forming Properties of Micro Random Pattern Using Micro Abrasive Paper Tool by Roll to Plate Indentation Method (미세 지립 페이퍼 공구와 롤투플레이트 압입공정을 이용한 마이크로 랜덤 패턴의 성형특성)

  • Jeong, Ji-Young;Je, Tae-Jin;Moon, SeungHwan;Lee, Je-Ryung;Choi, Dae-Hee;Kim, Min-Ju;Jeon, Eun-chae
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.33 no.5
    • /
    • pp.385-392
    • /
    • 2016
  • Recently in the display industry, demands for high-luminance and resolution of display devices have been steadily increasing. Generally, micro linear patterns are applied to an optical film in order to improve its properties of light. However, these patterns are easily viewed to eyes and moire phenomenon can be occurred. Micro random patterns are proposed as a method to solve these problems, increasing light-luminance and light-diffusion. However, conventional pattern manufacturing technologies have long processing times and high costs making it difficult to apply to large area molds. In order to combat this issue, micro-random patterns are formed by using a roll to plate indentation method along with abrasive paper tools composed of AlSiO2, SiC, and diamond grains. Also, forming properties, such as size and fill-factor of random patterns, are analyzed depending on type, mesh of abrasive paper tools, and indentation forces.

Diffusion-weighted MR imaging findings of intracerebral hematoma (뇌실질내의 확산강조영상 소견)

  • 박창숙;최순섭;오종영;박병호;김기욱;남경진;이영일
    • Investigative Magnetic Resonance Imaging
    • /
    • v.6 no.1
    • /
    • pp.21-27
    • /
    • 2002
  • Purpose : To evaluate diffusion-weighted imaging findings of intracerebral hematoma according to the time sequence. Materials and methods : Seventeen patients with intracerebral hematoma were studied. Diffusion weighted images using 1.5 tesla MRI machine were obtained with b-value of $1000{\;}sec/\textrm{mm}^2$. The patients were grouped as hyperacute stage(within 12 hours, 5 patients), acute stage(within 3 days, 4 patients), subacute stage(within 3 weeks, 4 patients), and chronic stage(after 3 weeks,4 patients). The signal intensities were analysed as bright, high, iso, low and dark at the central and peripheral portions of the hematoma in each stage, and compared with those of T2 and T1 weighted images. Results : The signal intensities of the central and peripheral portion of the intracerebral hematoma on diffusion-weighted images were high and dark in hyperacute stage, dark and high-bright in acute stage, and high-bright and dark in subacute and chronic stages. The patterns of signal change of hematoma on diffusion-weighted image according to the time sequence were similar to those on T2-weighted image, but changed early and prominently. Conclusion : The intracerebral hematoma on diffusion-weighted image showed unique central and peripheral signal intensity according to the time sequence. Central portions show high to bright signals in hyperacute, subacute and chronic stage, and dark signal in acute stage, and peripheral portions show dark signals in hyperacute, subacute and chronic stage, and high to bright signal in acute stage.

  • PDF

A Comparative Study on the Spatial Diffusion Patterns of Ailanthus altissima Communities (가죽나무군락의 공간별 분포특성에 관한 연구)

  • Lee, Chang-Woo;Hwang, Sun-Min;Kil, Jihyon;Kim, Youngha
    • Korean Journal of Plant Resources
    • /
    • v.25 no.5
    • /
    • pp.550-560
    • /
    • 2012
  • The aim of this study is to research spatial diffusion, a condition for spread of Ailanthus altissima, and conduct flora analysis to provide useful information for management of it. Three research spots where the community dominance value was found to be high and habitat was homogeneous according to a 2010 in-depth species study were selected, and census was conducted using a line-transect method. The diffusion area included 1,435 $m^2$ in Yangpyeong, 1,118 $m^2$ in Gimcheon and 760 $m^2$ in Sancheong, in order of increasing size, and a total of 510 trees were found to be randomly diffused in space. An average of 83.2% of Ailanthus altissima were found to be included in DBH classes I (1.0-3.4 cm) and II (3.5-6.4 cm), showing that young trees were dominant in Ailanthus altissima communities and there was an age diffusion pattern according to degree of disturbance in habitats. A total of 41 families 75 genera and 91 species of flora made up the list, and Therophytes were most widely found in all of the three areas. This shows that habitats in these areas have recently been disturbed. It was evaluated that elimination of roadside population and mountainous area population was necessary to prevent diffusion of Ailanthus altissima.

Estimation of Diffusion Direction and Velocity of PM10 in a Subway Station (For Gaehwasan Station of Subway Line 5 in Seoul) (지하철 역사 미세먼지(PM10)의 확산방향과 확산속도 추정 (서울 지하철 5호선 개화산역을 대상으로))

  • Park, Jong-Heon;Park, Jae-Cheol;Eum, Seong-Jik
    • Journal of Korean Society of Transportation
    • /
    • v.28 no.5
    • /
    • pp.55-64
    • /
    • 2010
  • In order to prepare an efficient solution for PM10 reduction in underground stations, the authors measured PM10 concentration levels every 30 minutes in the concourse, platform, and tunnel of Gaehwasan Station of Seoul's subway line 5. Through a correlation analysis of each changing pattern of PM10 concentration, the direction and velocity of diffusion in underground stations were estimated. The PM10 concentration levels were highest in the tunnel, followed by the platform and concourse. PM10 concentrations in the tunnel, platform, and concourse showed a pattern of increasing in the rush hours and decreasing in the non-rush hours. According to the statistical analysis of PM10 concentrations and changing patterns in each location, the higher PM10 concentration in the tunnel expanded to the platform, and some from the platform expanded to the concourse. Therefore, to efficiently reduce PM10 concentrations, it is essential to detect the centralized generation, diffusion factor, expanding route, expanding measure, and other variables and to remove or reduce the diffusion factor and level. Through operating the ventilation system in the right time frame while the PM10 concentration level increases, the power consumption and peak power consumption can be reduced.

A Study on Correlation between Extra Meridians and the nutritive Gi (營衛) & the defensive Gi (衛氣) (영위와 기경맥의 상관성 연구)

  • Cho, Yong-Ju;Kim, Jin-Ju
    • Korean Journal of Acupuncture
    • /
    • v.24 no.2
    • /
    • pp.1-17
    • /
    • 2007
  • Objectives : Extra Meridians are important conception for the proper comprehension of the defensive Gi & the defensive Gi, and the principle of the Gi (氣)‘s flow or diffusion. Methods : Extra Meridians could be explained by an anatomical feature and a functional stage. We should analyze the principle of samhap (三合) to have application to meridians. The study of the relationship between Extra Meridians and regular meridians (12正經) is useful to understand origination of the defensive Gi & the nutritive Gi. Results : The origination of the nutritive Gi & the defensive Gi could be interpreted by the principle of samhap correctly. The energic patterns in the flow of Gi (氣) are changed by cooperation with Extra Meridians and regular meridians (12正經). Conclusions : We could inferred that growth, disease, health, etc are controlled in cooperation with Extra Meridians (寄經脈) and the nutritive Gi & the defensive Gi (營衛). Extra Meridians take many parts in origination of the nutritive Gi & the defensive Gi, in the flow or diffusion of them but various energies are controlled basically by regular meridians (12正經). The defensive Gi is originated by Penetration Vessel (衝脈)) and it seems to be made by the principle of samhap (三合) in the process of the nutritive Gi flow (瀯氣流注).

  • PDF