• Title/Summary/Keyword: Radiations

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Soft Error Susceptibility Analysis for Sequential Circuit Elements Based on EPPM

  • Cai, Shuo;Kuang, Ji-Shun;Liu, Tie-Qiao;Wang, Wei-Zheng
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.2
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    • pp.168-176
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    • 2015
  • Due to the reduction in device feature size, transient faults (soft errors) in logic circuits induced by radiations increase dramatically. Many researches have been done in modeling and analyzing the susceptibility of sequential circuit elements caused by soft errors. However, to the best knowledge of the authors, there is no work which has well considerated the feedback characteristics and the multiple clock cycles of sequential circuits. In this paper, we present a new method for evaluating the susceptibility of sequential circuit elements to soft errors. The proposed method uses four Error Propagation Probability Matrixs (EPPMs) to represent the error propagation probability of logic gates and flip-flops in current clock cycle. Based on the predefined matrix union operations, the susceptibility of circuit elements in multiple clock cycles can be evaluated. Experimental results on ISCAS'89 benchmark circuits show that our method is more accurate and efficient than previous methods.

Musculoskeletal Ultrasound Intervention: Principles & Cautions (초음파를 이용한 침습적 치료: 원칙과 주의점)

  • Oh, Gun-Myung;Lee, Kyung Jae;Min, Byung-Woo;Kim, Dong-Wan
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.6 no.1
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    • pp.38-44
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    • 2013
  • The ultrasound can be used primarily to guide exact needle placement for aspirations of fluids, injections of steroid, and biopsies in musculoskeletal field. Recently, ultrasound-guided intervention is widely used because of several advantages such as real-time performance, relatively inexpensiveness, and getting multiple images without additional radiations. However, the modality is operator dependent and requires detailed knowledge of the relevant anatomy and there have been also reported serious complications related to the procedure. So, authors will discuss about the basic techniques, principles and cautions for the use of ultrasound-guided intervention in musculoskeletal field.

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Effects of Ionizing Radiation on Postharvest Fungal Pathogens

  • Jeong, Rae-Dong;Shin, Eun-Jung;Chu, Eun-Hee;Park, Hae-Jun
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.176-180
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    • 2015
  • Postharvest diseases cause losses in a wide variety of crops around the world. Irradiation, a useful nonchemical approach, has been used as an alternative treatment for fungicide to control plant fungal pathogens. For a preliminary study, ionizing radiations (gamma, X-ray, or e-beam irradiation) were evaluated for their antifungal activity against Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer through mycelial growth, spore germination, and morphological analysis under various conditions. Different fungi exhibited different radiosensitivity. The inhibition of fungal growth showed in a dose-dependent manner. Three fungal pathogens have greater sensitivity to the e-beam treatment compared to gamma or X-ray irradiations. The inactivation of individual fungal-viability to different irradiations can be considered between 3-4 kGy for B. cinerea and 1-2 kGy for P. expansum and R. stolonifer based on the radiosensitive and radio-resistant species, respectively. These preliminary data will provide critical information to control postharvest diseases through radiation.

Electromagnetically Excited Audible Noise in Electrical Machines

  • Hameyer, Kay;Henrotte, Francois;Delaere, Koen
    • Journal of KSNVE
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    • v.13 no.2
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    • pp.109-118
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    • 2003
  • With the rising utilisation of electrical machines to increase the output-Power of the device several problems occur. Next to probable additional losses and other parasitic effects, aspects concerning the audible noise radiated by the device are of particular interest. This contribution is intended to give an overview to the problematic of the analysis of vibrations and audible noise radiated by electrical machines. It is not the intention of the authors to set off a scientific firework with various complicated equations in this contribution. The paper should rather give an insight in a complicated technical matter and should help to understand the mechanism of vibration and parasitic noise generation in electrical machines. Rotating machines, such as the induction motor as well as non-rotating electrical machines, such as inductors or transformers are studied. The origin of vibrations leading to noise radiations is studied and discussed to illustrate the way in which the analysis of the governing effects can be performed. Magnetically generated radial pullout force waves in rotating electrical machines are the main cause of the excited audible noise, whereas magnetostriction plays an important role in transformers.

Ultrasonic Backward Radiation on Randomly Rough Surface (무작위로 거친 표면에서의 후방복사 초음파)

  • Kwon, Sung-D.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.1
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    • pp.9-14
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    • 2005
  • The angular dependence(profile) of backward radiated ultrasound was measured for glass specimens with random surface roughness using ultrasonic goniometer that ran changes the incident angle continuously. It was concluded that the roughened region had greater acoustic impedance than the unperturbed region. The comparison of backward radiations showed that the amplitude of peak and the area of radiation profile were increased with surface roughness. It was suggested from the sensitive dependence of the profile area that the profile of backward radiation could be applied to in the nondestructive evaluation of sulfate region. Inclined C-scan technique with the transducer inclined at Rayleigh angle showed the reverse of luminosity and the high signal to noise ratio so that it provided high resolution.

Effect of Untreated Water Flow Rate at Certain Temperature on the Discharge of Treated Water

  • Ullah, Muhammad Arshad;Aslam, Muhammad;Babar, Raheel
    • The Korean Journal of Food & Health Convergence
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    • v.5 no.6
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    • pp.5-9
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    • 2019
  • Desalination requires large energy. This experiment deals to desalinate brackish water through solar panels. The discharge from desalination plants is almost entirely water, and .01 percent is salt. Desalination is a process that extracts minerals from saline water. Solar-powered desalination technologies can be used to treat non-traditional water sources to increase water supplies in rural, arid areas. Water scarceness is a rising dilemma for large regions of the world. Access to safe, fresh and pure clean drinking water is one of the most important and prime troubles in different parts of the world. Among many of water cleansing technologies solar desalination/distillation/purification is one of the most sustainable and striking method engaged to congregate the supply of clean and pure drinkable water in remote areas at a very sound cost. Six types of dripper having discharge 3 - 8 lh-1 were installed one by one and measured discharge and volume of clean water indicated that at 6 lh-1 untreated water discharge have maximum evaporation and volume of clean water was 19.2 lh-1 at same temperature and radiations. Now strategy was developed that when increased the temperature the intake discharge of untreated water must be increased and salt drained water two times more than treated water.

Propagation of the ionizing radiations leaked out of bright H II regions into the diffuse interstellar medium

  • Seon, Kwang-Il
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.33.2-33.2
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    • 2009
  • Diffuse ionized gas (DIG or warm ionized medium, WIM) outside traditional regions is a major component of the interstellar medium (ISM) not only in our Galaxy, but also in other galaxies. It is generally believed that major fraction of the Halpha emission in the DIG is provided by OB stars. In the "standard" photoionization models, the Lyman continuum photons escaping from bright H II regions is the dominant source responsible for ionizing the DIG. Then, a complex density structure must provide the low-density paths that allow the photons to traverse kiloparsec scales and ionize the gas far from the OB stars not only at large heights above the midplane, but also within a galactic plane. Here, I present Monte-Carlo models to examine the propagation of the ionizing radiation leaked out of traditional H II regions into the diffuse ISM applied to two face-on spirals M 51 and NGC 7424. We find that the "standard" scenario requires absorption too unrealistically small to be believed, but the obtained scale-height of the galactic disk is consistent with those of edge-on galaxies. We also report that the probability density functions of the Halpha intensities of the DIG and H II regions in the galaxies are log-normal, indicating the turbulence property of the ISM.

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Prediction of Stratification Model for Diffusers in Underfloor Air Distribution System using the CFD (CFD를 활용한 바닥공조시스템 디퓨저의 성층화 모델 예측)

  • Son, Jeong-Eun;Yu, Byeong-Ho;Pang, Seung-Ki;Lee, Kwang Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.3
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    • pp.105-110
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    • 2017
  • Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings. UFAD systems use the underfloor plenum beneath a raised access floor to provide conditioned air through floor diffusers that create a vertical thermal stratification during cooling operations. Thermal stratification has significant effects on energy, indoor air quality, and thermal comfort performance. The purpose of this study was to characterize the influence of a linear bar grille diffuser on thermal stratification in both interior and perimeter zones by developing Gamma-Phi based prediction models. Forty-eight simulations were carried out using a Computational Fluid Dynamics (CFD) technique. The number of diffusers, the air flow supply, internal heat gains, and solar radiations varied among the different cases. Models to predict temperature stratification for the tested linear bar grille diffuser have been developed, which can be directly implemented into dynamic whole-building simulation software such as EnergyPlus.

Theory of Radiative Transfer for 3.3-micron $CH_4$ emissions from the Auroral Regions of Jupiter

  • Kim, Sang Joon;Sohn, Mirim
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.66.1-66.1
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    • 2014
  • Radiative transfer programs to simulate the 3-micron auroral $CH_4$ emissions of Jupiter have been developed. The formalism of the radiative transfer calculations including the thermal, fluorescent, and auroral emissions of the $CH_4$ bands for an atmospheric layer having an optical depth of ${\tau}_v$ is given by: ${\mu}dI_v/d{\tau}_v=I_v-{\varpi}_v{^*}J_v(1-{\varpi}_v{^*})B_v-{\varpi}{^*}F_{ov}{e}{x}{p}(-{\tau}_v/{\mu}_o)4{\pi}-hv{\varpi}{^*}V/4{\pi}$ where ${\varpi}_v{^*}$ is the single scattering albedo of $CH_4$ consisting of Einstein A coefficient and collisional deexcitation rate. Other terms are usual radiative transfer parameters appearing in textbooks including the terms for scattered ${\varpi}_v{^*}J_v$, thermal $(1-{\varpi}_v{^*})B_v$, and attenuated solar radiations $F_{ov}$ at the certain atmospheric layer. For auroral excitations, we include V, which is the number of excited states per $cm^3$ persec by auroral particle bombardments. We apply this formalism to the high-resolution spectra of the auroral regions observed with GNIRS/Gemini North, and will present preliminary results for the 3 micron auroral processes of Jupiter.

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Shielding Calculations of Accelerator Facility for Medical Isotope Production using MCNPX Code (MCNPX 코드를 이용한 의료용 방사성동위원소 생산을 위한 가속기 시설의 방사선차폐 및 선량 계산)

  • Seo Kyu-Seok;Kim Chan-Hyeong
    • Progress in Medical Physics
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    • v.15 no.4
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    • pp.210-214
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    • 2004
  • Since production of radioactive isotope for using PET, a lot of neutrons were produced. The produced neutrons were mainly shielded by concrete facility. Secondary photons are generated and emitted from the concrete shielding wall of the PET cyclotron since the proton-generated neutrons are thermalized and absorbed in the concrete wall and emit secondary radiations, i.e., photons. This study calculated neutron dose and photon dose at outside of the accelerator facility using MCNPX code. As results of the calculation, total dose were calculated less than limited dose by law.

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