• Title/Summary/Keyword: Full density

Search Result 683, Processing Time 0.03 seconds

Sensor Density for Full-View Problem in Heterogeneous Deployed Camera Sensor Networks

  • Liu, Zhimin;Jiang, Guiyan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.15 no.12
    • /
    • pp.4492-4507
    • /
    • 2021
  • In camera sensor networks (CSNs), in order to better identify the point, full-view problem requires capture any facing direction of target (point or intruder), and its coverage prediction and sensor density issues are more complicated. At present, a lot of research supposes that a large number of homogeneous camera sensors are randomly distributed in a bounded square monitoring region to obtain full-view rate which is close to 1. In this paper, we deduce the sensor density prediction model in heterogeneous deployed CSNs with arbitrary full-view rate. Aiming to reduce the influence of boundary effect, we introduce the concepts of expanded monitoring region and maximum detection area. Besides, in order to verify the performance of the proposed sensor density model, we carried out different scenarios in simulation experiments to verify the theoretical results. The simulation results indicate that the proposed model can effectively predict the sensor density with arbitrary full-view rate.

Consolidation of Iron Nanopowder by Nanopowder-Agglomerate Sintering at Elevated Temperature

  • Lee, Jai-Sung;Yun, Joon-Chul;Choi, Joon-Phil;Lee, Geon-Yong
    • Journal of Powder Materials
    • /
    • v.20 no.1
    • /
    • pp.1-6
    • /
    • 2013
  • The key concept of nanopowder agglomerate sintering (NAS) is to enhance material transport by controlling the powder interface volume of nanopowder agglomerates. Using this concept, we developed a new approach to full density processing for the fabrication of pure iron nanomaterial using Fe nanopowder agglomerates from oxide powders. Full density processing of pure iron nanopowders was introduced in which the powder interface volume is manipulated in order to control the densification process and its corresponding microstructures. The full density sintering behavior of Fe nanopowders optimally size-controlled by wet-milling treatment was discussed in terms of densification process and microstructures.

Innovative Approach to Sintering Aluminum and Aluminum Alloy Powders for Rapid Manufacturing Applications

  • Liu, Jianxin;Kuhn, Howard A.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2006.09a
    • /
    • pp.246-247
    • /
    • 2006
  • A new approach to sintering loose packed, coarse aluminum alloy powder to full or near full density is presented. A controlled amount of water vapor is introduced into the sintering atmosphere, which disru pts the oxide film and allows metallurgical contact between particles. In addition, supersolidus liquid phase sintering is used to sinter the part to full density. Since the method is particularly applicable to uncompacted powders, it is potentially useful for sintering aluminum powder preforms manufactured by 3DPrinting and powder injection molding.

  • PDF

A Study on the Comparision of Performance between Three-phase Full-wave and Single-phase Full-wave X-ray Generators (삼상(三相)12펄스 전파정류장치(全波整流裝置)와 단상(單相) 전파정류장치(全波整流裝置)의 성능(性能) 비교(比較))

  • Kim, Young-Ill;Kim, Chang-Kyun;Huh, Joon
    • Journal of radiological science and technology
    • /
    • v.3 no.1
    • /
    • pp.81-86
    • /
    • 1980
  • To compare three-phase 12-pulse full-wave X-ray generators with single-phase full-wave X-ray generators on their performance of outputs, authors studied the generating X-ray by means of exposure dose and radiographic density. The results were as follows; 1. The exposure doses of three-phase full-wave X-ray generators showed a 30%-60% increase as compared against of single-phase full-wave generators. 2. The transmitted doses of three-phase full-wave generators were more increased than single-phase full-wave X-ray generators. 3. To obtain the same density, 60kVp in three-phase full-wave generators were equivalent to $60{\sim}65kVp$ in single-phase full-wave generators, and 100kVp in those generators were equivalent to $100{\sim}125kVp$ in these generators.

  • PDF

A Study on the Variety of Lung Field by Respiration Methods (호흡상태(呼吸狀態)에 의(依)한 폐야(肺野)의 변화(變化))

  • Jun, Kwang-Suk
    • Journal of radiological science and technology
    • /
    • v.2 no.1
    • /
    • pp.55-57
    • /
    • 1979
  • Author had an experiment on the size and density of the lung field by respiration methods in taking chest roentgenogram, and obtained the results as follows; 1. General density of chest film in full inhalation was higher than the other respiration methads. a. Apex length of the lung was $2.49{\pm}0.54cm$ in full inhalation, $2.30{\pm}0.53cm$ in normal respiration, and $1.97{\pm}0.58cm$ in full exhalation respectively. 3. Size of the lung in full inhalation was the largest as $21.95{\pm}1.83cm$ in length and $26.37{\pm}1.22cm$ in width.

  • PDF

Full-Chip Power/Performance Benefits of Carbon Nanotube-Based Circuits

  • Song, Taigon;Lim, Sung Kyu
    • Journal of information and communication convergence engineering
    • /
    • v.13 no.3
    • /
    • pp.180-188
    • /
    • 2015
  • As a potential alternative to the complementary metal-oxide semiconductor (CMOS) technology, many researchers are focusing on carbon-nanotube field-effect transistors (CNFETs) for future electronics. However, existing studies report the advantages of CNFETs over CMOS at the device level by using small-scale circuits, or over outdated CMOS technology. In this paper, we propose a methodology of analyzing CNFET-based circuits and study its impact at the full-chip scale. First, we design CNFET standard cells and use them to construct large-scale designs. Second, we perform parasitic extraction of CNFET devices and characterize their timing and power behaviors. Then, we perform a full-chip analysis and show the benefits of CNFET over CMOS in 45-nm and 20-nm designs. Our full-chip study shows that in the 45-nm design, CNFET circuits achieve a 5.91×/3.87× (delay/power) benefit over CMOS circuits at a density of 200 CNTs/µm. In the 20-nm design, CNFET achieves a 6.44×/3.01× (delay/power) benefit over CMOS at a density of 200 CNTs/µm.

A Study on the Determination of Density and Moisture Content of Asphalt Concrete Pavement and Subgrade Using Nuclear Density Meter (방사선측정치를 이용한 아스콘 포장 및 노상의 현장밀도와 함수비 측정에 관한 연구)

  • 진성기;도덕현
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.36 no.4
    • /
    • pp.103-116
    • /
    • 1994
  • The objective of this study was to determine the criteria for density and moisture content measurements made with a nuclear density meter on common materials in the construction field. The study also sought to test a full-type nuclear density meter in controlling the density of overlay layers( 2.5~5.0cm). In order to determine the accuracy and reliablility of nuclear guage measurements made on construction materials, laboratory and field tests were conducted. Wooden blocks( 65 x 45 ${\times}$ 50 cm) and a special steel compactor( 4.7kg) were constructed in order to carry out tests which were conducted on three different materials; coarse gramed soil, fine grained soil, and AC material. Throughout all laboratory and field tests, the nuclear density and moisture content were determined using Humboldt 5OOLP nuclear gauge. The tests on subgrade material entailed obtaining density measurements by means of both the sand replacement method and the nuclear density meter. The results of the sand replacement method were then compared to the readings recorded bu the meter. As in the subgrade material tests, density measurements made during AC pavement tests were also determined using the unclear meter in addition to a second means; through the core method. The meter readings and core densties were compared as was done in the tests on subgrade materials. The correlation between the results of the sand replacement test( also, the core method) and meter readings on subgrade material was then determined. Sirnilarly, the observed results were then analyzed through linear regression. The tests to determine thin-lift density by means of a full-type nuclear density meter also conducted on the overlay layers( about 4. 8cm thickness) above AC pavements at road construction sities in Korea.

  • PDF

OFDMA FD-MAC Protocol Based on the Channel Information (채널정보 기반 OFDMA FD-MAC 프로토콜)

  • Cheon, Hye-Rim;Kim, Jae-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.3
    • /
    • pp.451-458
    • /
    • 2015
  • The deployment density of AP increases as well as the density WLAN stations due to increase of WLAN use and the real performance of WLAN is degraded. To improve the performance, there are many PHY/MAC technologies and OFDMA and full duplex are promising technologies among them. In conventional OFDMA WLAN MAC relate works, there are some limitations in terms of channel utilization and collision probability. Thus, it need to research for effective channel allocation protocol. Full duplex can transmit data on the same time and same frequency resource so it can allocate channel more flexible than half duplex. In this paper, we prose the OFDMA FD-MAC(Full Duplex MAC) protocol that it allocates the sub-channels based on the idle channel information for full duplex pair. In addition, it shows the throughput improvement by performance analysis.

Comparison of CME mean density based on a full ice-cream cone structure and its corresponding ICME one

  • Na, Hyeonock;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.43 no.1
    • /
    • pp.54.1-54.1
    • /
    • 2018
  • For space weather forecast, it is important to determine three-dimensional parameters of coronal mass ejections (CMEs). To estimate three-dimensional parameters of CMEs, we have developed a full ice-cream cone model which is a combination of a symmetrical flat cone and a hemisphere. By applying this model to 12 SOHO/LASCO halo CMEs, we find that three-dimensional parameters from our method are similar to those from other stereoscopic methods. For several geoeffective CME events, we determine CME mass by applying the Solarsoft procedure (e.g., cme_mass.pro) to SOHO/LASCO C3 images. CME volumes are estimated from the full ice-cream cone structure. We derive CME mean density as a function of CME height for these CMEs, which are approximately fitted to power-law functions. We find that the ICME mean densities extrapolated from the power law functions, are correlated with their corresponding ICME ones in logarithmic scales.

  • PDF