3,239 research outputs found

    Correlation of microwave dielectric properties and normal vibration modes of xBaMg1Õ3Ta2Õ3O3– 1ÀxBaMg1Õ3Nb2Õ3O3 ceramics: I. Raman spectroscopy

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    [[abstract]]Micro-Raman measurements of xBa~Mg1/3Ta2/3)O3–(12x)Ba~Mg1/3Nb2/3)O3 perovskite ceramics, with x50, 0.25, 0.50, 0.75, and 1.0, were taken at room temperature. Raman results clearly show the 1:2 ordered structures of these compounds. Four A1g and five Eg Raman modes were unambiguously assigned. The A1g(O) phonon of the oxygen-octahedron stretch mode, which possesses the largest energy and width of all the observed Raman phonons, significantly influences the microwave dielectric properties of the materials. A higher vibration frequency of A1g(O) mode results in a lower dielectric constant, and a wider width of the mode corresponds to a lower Q3f value.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]US

    Life-style orientation and contents of websites in personas industry

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    Electronic commerce challenges personas companies to design electronic system to increase interaction which leads to retain customers and increase sales. This exploratory study examines the correlation between lifestyle and emphasis on contents of website in personas industry. The study finds that market segment of lifestyle can be divided into four groups: ‘opinion leader’, ‘opinion follower’, ‘conservative’ and ‘challenger’. This paper tries to suggest a checklist to a vendor. We conclude that AIO can be a base of market segment in personas industry. We suggest some important factors which are included of the customized services, the safety of use factors, the store information and the menu illustration. Finally, we also conclude that the first three important factors of websites have significant influences on market segments of personas industry except for the store information factor.AIO, market segmentation, personas industry.

    An investigation of a deep learning based malware detection system

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    We investigate a Deep Learning based system for malware detection. In the investigation, we experiment with different combination of Deep Learning architectures including Auto-Encoders, and Deep Neural Networks with varying layers over Malicia malware dataset on which earlier studies have obtained an accuracy of (98%) with an acceptable False Positive Rates (1.07%). But these results were done using extensive man-made custom domain features and investing corresponding feature engineering and design efforts. In our proposed approach, besides improving the previous best results (99.21% accuracy and a False Positive Rate of 0.19%) indicates that Deep Learning based systems could deliver an effective defense against malware. Since it is good in automatically extracting higher conceptual features from the data, Deep Learning based systems could provide an effective, general and scalable mechanism for detection of existing and unknown malware.Comment: 13 Pages, 4 figure

    Metastatic Cardiac Angiosarcoma to the Lung, Spine, and Brain: A Case Report and Review of the Literature

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    Background Metastatic angiosarcoma to the brain is a rare entity without an established management protocol. Case Description A man with primary cardiac angiosarcoma presented with a rare brain metastasis. The patient underwent successful resection of the brain metastasis and was initiated on chemotherapy only for his systemic disease. The patient did not develop local recurrence. A review of primary and metastatic central nervous system angiosarcoma, its pathologic features, clinical disease course, treatment strategies, and genomics is also provided. Conclusions Angiosarcomas are rare tumors that are difficult to treat. Gross total resection of a central nervous system metastasis is recommended before initiation of adjuvant chemotherapy or radiation therapy. Close follow-up is still required given the propensity for continued metastasis of these tumors. Future treatments may be developed based on the genomics of angiosarcomas

    Disordered Fe vacancies and superconductivity in potassium-intercalated iron selenide (K2-xFe4+ySe5)

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    The parent compound of an unconventional superconductor must contain unusual correlated electronic and magnetic properties of its own. In the high-Tc potassium intercalated FeSe, there has been significant debate regarding what the exact parent compound is. Our studies unambiguously show that the Fe-vacancy ordered K2Fe4Se5 is the magnetic, Mott insulating parent compound of the superconducting state. Non-superconducting K2Fe4Se5 becomes a superconductor after high temperature annealing, and the overall picture indicates that superconductivity in K2-xFe4+ySe5 originates from the Fe-vacancy order to disorder transition. Thus, the long pending question whether magnetic and superconducting state are competing or cooperating for cuprate superconductors may also apply to the Fe-chalcogenide superconductors. It is believed that the iron selenides and related compounds will provide essential information to understand the origin of superconductivity in the iron-based superconductors, and possibly to the superconducting cuprates

    A CMOS digital temperature sensor for ASIC VLSI standard cell design

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    This thesis describes the design of a CMOS digital temperature sensor cell including the physical layout database.This cell is designed for implementation within an ASIC VLSI chip as a standard cell . The digital temperature sensor can trigger an alarm signal and turn off power for preventing fatal damage in the VLSI chip if overheating occurs.A digital output also permits measurement of temperature over the 0 - 120°C range with ±3.4°C accuracy using standard VLSI foundry processing. Two sensing elements are implemented in a differential mode within the temperature sensor cell. An operational amplifier is used in the successive approximation ADC as a comparator. The level shifter is also used for voltage summation in the ADC design. The error due to simulated device temperature dependence, and power supply voltage ±10% swing are ±1.40% 1.68°C) and ±1.41% ( 1.69°C) respectively over the 0 - 120°C range. This CMOS digital temperature sensor cell measures 48mi1 x 55mi1 using MOSIS 3μ CMOS layout rules for single level metal and single level polysilicon. The calculated analog power dissipation is 15mW. The digital circuits dissipate 0.2mW per MHz clock. This circuit is simulated by using UC Berkeley SPICE 2(4.5 and designed using Mentor Graphics Corporation tools
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