1,318 research outputs found

    Position-Dependent Performance in 5 nm Vertically Stacked Lateral Si Nanowires Transistors

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    In this work, we investigated the performance of vertically stacked lateral nanowires transistors (NWTs) considering the effects of series resistance. Also, we consider the vertical positions of the lateral nanowires in the stack and diameter variation of the lateral NWTs as new sources of process variability

    Variability-Aware Simulations of 5 nm Vertically Stacked Lateral Si Nanowires Transistors

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    In this work, we present a simulation study of vertically stacked lateral nanowires transistors (NWTs) considering various sources of statistical variability. Our simulation approach is based on various simulations techniques to capture the complexity in such ultra-scaled device

    Graphics technology to model the problems of calculus using analytical geometry

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    The paper contains some general background and someof the visualization methods that have been used to bring computer graphics technology to model mathematical problems of Calculus with Analytical Geometry. Computer-generated images have been length and breath of the paper as a source of additional background information on visual mathematics and an overview of selected animations concerned with mathematical visualization.Ця стаття містить опис деяких методів візуалізації, що дають можливість використовувати технології комп'ютерної графіки для моделювання задач математичного аналізу та аналітичної геометрії. Детально розглядаються питання використання комп'ютерних зображень та робиться огляд використання комп'ютерної анімації для цієї візуалізації

    Graphics technology to model the problems of calculus using analytical geometry

    Get PDF
    The paper contains some general background and someof the visualization methods that have been used to bring computer graphics technology to model mathematical problems of Calculus with Analytical Geometry. Computer-generated images have been length and breath of the paper as a source of additional background information on visual mathematics and an overview of selected animations concerned with mathematical visualization.Ця стаття містить опис деяких методів візуалізації, що дають можливість використовувати технології комп'ютерної графіки для моделювання задач математичного аналізу та аналітичної геометрії. Детально розглядаються питання використання комп'ютерних зображень та робиться огляд використання комп'ютерної анімації для цієї візуалізації

    The performance of robust estimator on linear regression model having both continuous and categorical variables with heteroscedastic errors

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    The ordinary least squares (OLS) technique is often used in practice to estimate the parameters of a multiple linear regression model with both continuous and categorical variables. It has been the most popular technique due to its optimal properties and ease of computation. Nevertheless, in the presence of outliers, the OLS can result in very poor estimates. Outliers which arise from bad data points may have unduly effect on the OLS estimates. The problem is further complicated when both outliers and heteroscedasticity or non-constant error variances are present in the data. The influence of outliers and heteroscedasticity cannot be removed or reduced by simply transforming the data using known transformation such as logarithmic transformation. In this paper, we proposed a robust technique to deal with these two problems simultaneously. A robust estimate of scales for each level of categorical variables are first estimated by using robust distance S and M (RDSM) estimates. Then we determine the weighting scheme for each level of the categorical variables and transform the model. The reweighted least squares based on RDSM (RLSRDSM) is then applied to the transformed model. The empirical evidence shows that the proposed method has reduced the heteroscedastic effect to a greater extent

    Linerboard made from Soda-Anthraquinone (Soda-AQ) treated coconut coir fiber and effect of pulp beating

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    The performance of coir fiber in the production of linerboard made from soda-anthraquinone (soda-AQ) pulp was evaluated. Based on chemical analysis, the composition of coir fiber is suitable for the pulping process. Out of nine pulping conditions characterized, a pulping condition of 18% active alkali for 90 min cooking time was chosen. These conditions provided the highest screened yield (48.99%), a low rejection yield (0.27%), high viscosity (11.73 cP), and a kappa number (41) that is acceptable for unbleached linerboard production. Beating strengthened the coir pulp. Analyzing the beating revealed that coir pulp was optimized at 1000 to 2000 revolutions, based on a graph of freeness vs. burst index. For all beating conditions (1000 to 8000 revolutions), FESEM micrographs showed the presence of internal and external fibrillation of the fiber, which gradually increased fiber conformability and improved the inter-fiber bonding within the paper formation. Based on its burst strength of 4.57 kPa.m2/g and ring crush test of 1.76 Nm2/g, which complies with the minimum requirement of the industry standard, coir fiber can be considered an alternative fiber source for linerboard production

    Measurement of some Air Pollutantsin Printing Units and Copy Centers Within Baghdad City

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    إن انبعاث المواد الدقائقية من الأوراق المتناهية الصغر فضلا عن الأحبار والمذيبات العضوية خلال عملية تشغيل ماكينات الطباعة والاستنساخ تشكل خطرا على صحة الإنسان بالأخص بعد التعرض طويل الأمد في بيئات العمل المغلقة . أجريت الدراسة الحالية في بعض دور الطباعة ومراكز الاستنساخ في مدينة بغداد خلال شهري شباط ونيسان، وأثبتت الدراسة حدوث مشكلة تلوث الهواء فيما يتعلق بمحتويات الرصاص والزنك في جميع مواقع الدراسة .تم تحديد تركيز الرصاص والزنك والنحاس من خلال جمع العينات بوساطة جهاز جمع عينات الهواء وبعدها تم ترشيح العينات وهضمها وتحديد نسبة العناصر الثقيلة بوساطة جهاز المطياف الذري اللهبي، أما المواد الدقائقية تم قياسها بوساطة جهاز قياس الدقائق العالقة في الهواء ، واستعمل جهاز قياس الغازات الملوثة للهواء لقياس غاز ثنائي أكسيد لنتروجين وثنائي أكسيد الكبريت وأول أكسيد الكربون والمركبات العضوية المتطايرة . سجل أعلى تركيز للرصاص والزنك في هواء المطابع (2.75 مايكرو غرام/م3 ) و (51.95 مايكرو غرام /م3) على التوالي . بالمقابل سجل أعلى قيمة معنوية نحاس في  هواء مكاتب الاستنساخ (0.65 مايكرو غرام /م3) مقارنة بدور الطباعة . سجل أعلى تركيز للمواد الدقائقية الناعمة (PM2.5) التي يكون قطرها أقل من 2.5 مايكرو متر(44.50 مايكرو غرام /م3) في دور الطباعة يليها أعلى تركيز للمواد الدقائقية الخشنة المستنشقة(PM10)  التي يتراوح قطرها بين 2.5 الى 10 مايكرو متر والدقائق الكلية العالقة (477.66 و667.00 مايكرو غرام /م3) في دور الطباعة على التوالي . أظهرت النتائج أعلى تركيز لغاز أول أكسيد الكربون CO (6.13 جزء في المليون) والمركبات العضوية المتطايرة ((VOCs (21.88 جزء في المليون) في دور الطباعة بينما سجل أعلى تركيز لغاز ثنائي أكسيد النتروجين(NO2)  (1.44 جزء في المليون) في مراكز الاستنساخ . تجاوزت تركيز الرصاص والزنك والنحاس والمواد الدقائقية PM2.5و PM1والدقائق الكلية العالقة المستويات المسموح بها في جميع مواقع الدراسة على عكس مستويات أول أكسيد الكربون وثنائي أكسيد النتروجين وثنائي أكسيد الكبريت والمركبات العضوية المتطايرة التي كانت ضمن محددات جودة الهواء المسموح بها .Emissions of particulate matter from nanopapers as well as inks and organic solvents during the printing operationand copying machines constitute a threat to human health, especially with long time exposure in closed working environments. The present study was conducted in some printing houses and copying centers of Baghdad city during February and April  .The studyproved the occurrence of an air pollution problem concerning lead and zinc contents in all the study sites. The levels of Pb, Zn and Cu were collected by low volume sampler from the air of the study sites then filter papers digested and determined the heavy metals by flame atomic spectrophotometer. Particulate matter was measured by Aerocet, Microtector  meter device was used to measure nitrogen dioxide, sulphur dioxide, carbon monoxide and volatile organic compounds . The highest concentrations of lead and zinc were recorded in the printing houses air (2.75μg/m3) and (51.95μg/m3) respectively. In contrast,copper concentration in the copying offices air recorded a significantly higher value (0.65μg/m3) (P>0.05) as compared to that in printing houses. Fine particulate matter(PM2.5)(particles diameter < 2.5 μm) hasrecorded the highest concentration (44.50μg/m3) in printing houses, followed by the highest concentrations of inhalable coarse particulate matter (PM10)  (particles with diameter  of 2.5 to 10 μm)  and total suspended particulates (TSP)(the total of solid particles) (477.66 and 667.00μg/m3) respectively in printing houses. The results obviously showed the highest concentrations of carbon monoxide (CO) (6.13 ppm) and volatile organic compounds (VOCs) (21.88 ppm) in  printing houses, while nitrogen dioxide (NO2) recorded its highest concentration (1.44 ppm) in copy centers. Lead, zinc, copper, PM2.5, PM10 and TSP concentrations exceeded the permissble levels in all study sites converselywith the levels of carbon monoxide , nitrogen dioxide, sulphur dioxide(SO2) and volatile organic compounds that were within permissible air quality standards

    Suitability of coir fibers as pulp and paper

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    This study was to investigate the suitability of coir fibers as an alternative material in making pulp and paper. Maceration process was used to characterize the fiber. Soda-AQ pulping with various combinations of active alkali (18-22%) and cooking time (90- 150 minutes) at fixed temperature was done. Physical properties evaluated were density, brightness, opacity, scattering coefficient, tear, burst and tensile index. As concentration of active alkali and cooking time increased, the physical properties values also increased, except for the opacity and scattering coefficient. The optimum condition for producing the strongest paper is using 22% active alkali in 120 minutes

    Scalability Improvement Of Multicast Source Movement Over Mobile Ipv6 Using Clustering Technique

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    Mobile IPv6 (MIPv6) describes how a mobile node can change its point of attachment to the Internet. While MIPv6 focuses on unicast communications, it also proposes two basic mechanisms, known as bi-directional tunnelling and remote subscription, to handle multicast communications with mobile members. In the mean time, the deployment of Source-Specific Multicast (SSM) is of great interest, using the Protocol Independent Multicast-Sparse Mode (PIM-SM) and Multicast Listener Discovery (MLDv2) protocols. In the particular case of mobile IPv6 SSM sources, the mechanism proposed in MIPv6 to support multicast communications introduced a number of problems that need to be addressed. First, in most scenarios the MIPv6 solution leads to suboptimal routing by setting up a tunnel to forward packets between the home agent in its home network and the current location in the foreign network. The use of a third party when roaming which is the home agent leads to suboptimal routing. Second, it introduces a central point of failure (i.e. the Home Agent (HA)) that is not to be neglected. The proposed MIPv6 solution also induces a great traffic concentration around this central point. Third, the processing task of the central point increases with the number of mobile sources it serves, thus reducing the efficiency of multicast delivery. The objective of this thesis is to remove some of the obstacles encountered in the way of multicast deployment in the Internet, thereby making Mobile IPv6 better equipped to support mobile SSM sources. Recent proposals to provide multicasting over mobile IP focuses mainly on recipient mobility but little attention has been given to the case of source mobility. This thesis attempts to address this problem. The basic essence of the problem is that while the effect of receiver movement on the multicast tree is local, the effect of source movement may be global and it may affect the complete multicast delivery tree. The initial design was motivated by the need to support one-to-many and many-to-many applications in a scalable fashion. Such applications cannot be serviced efficiently with unicast delivery. As the overall problem statement of “Scalability Improvement of Multicast Source Movement over IPv6 Using Clustering Technique” is extremely complex, we divide the problem into the following components: build the multicast delivery tree for source specific multicast which is a routing issue; clustering receivers based on their IPv6 addresses; improve the state scalability of these clusters which is a deployment issue; find an efficient way for service distribution which is a deployment issue as well; and finally, the seamless integration of the work with Mobile IPv6 allowing it to support multicast efficiently for mobile nodes. The combined solution provides a comprehensive procedure for planning and managing a multicast-based IPv6 network. The outcome of this thesis are: a software to represent an architecture of a multicast delivery tree for one-to-many type of group communication, a group management scheme that could handle the end nodes subscription/un-subscription process with the required updates, an average subscription delay of between 0.255 ms-0.530 ms and un-subscription delay of between 0.0456 ms-0.087 ms for up to 50000 nodes, an approach to multicast forwarding state reduction that could support small-size groups as well as large-size groups, and finally the integration of the work with Mobile IPv6 to handle the multicast source movement
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