1,997 research outputs found

    Layered Steered Space-Time Codes and their capacity

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    A capacity analysis of a multifunctional multiple-input multiple-output system that combines the benefits of vertical Bell Labs space-time scheme, space-time block codes and beamforming is presented

    Measurement of the magnetic anisotropy energy constants for magneto-optical recording media

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    Measurement of the magneto-optical polar Kerr effect is performed on rare earth-transition metal (RE-TM) amorphous films using in-plane fields. From this measurement and the measurement of the saturation magnetization using a vibrating sample magnetometer (VSM), the magnetic anisotropy constants are determined. The temperature dependence is presented of the magnetic anisotropy in the range of -175 to 175 C. The results show a dip in the anisotropy near magnetic compensation. This anomaly is explained based on the finite exchange coupling between the rare earth and transition metal subnetworks

    EXPLORING A NEW HOUSING DESIGN PARADIGM FOR POST PANDEMIC MULTI-STORY BUILDINGS IN LEBANON

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    When the fast-spreading COVID-19 was announced as a pandemic by the World Health Organization (WHO), people around the world rushed to go home. This worldwide widespread altogether affected our individual and proficient lives and features a coordinate bearing upon the exceptionally establishments of design hypothesis. As a result, the pandemic has contributed to concerns about how architects and designers should view and install antivirus-related ideas or redesign current spaces, as well as at what point our physical and built environment could be impacted by the pandemic. In forecasting the post-pandemic style and visualizing the appropriate antivirus scheme, the answers to these questions may help. This paper aims to develop a new paradigm of housing design. And especially, a new functional layout for residential unit in a multi-story building in Lebanon. In this order, a literature study and a survey has been conducted. One of the main goal of the literature study is to highlight on previous pandemic and residential experiences. In the other hand, the survey serves on analysing nowadays residential unit users. These two ways will lead for the future of residential units in multi-story buildings

    Characterization of magneto-optical media

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    Amorphous rare earth-transition metal (RE-TM) alloys and compositionally modulated TM/TM films were characterized in terms of their magnetic, magneto-optic, and galvanomagnetic properties. The loop tracer, vibrating sample magnetometer (VSM), and Rutherford Backscattering (RBS) facility were used to characterize and analyze the various properties of these magneto-optical storage media. Kerr effect, ellipticity, coercivity, and anisotropy at various temperatures, magnetoresistance, and resistivity are among the properties measured in Co/Pt films, Co/Pd films, and TbFeCo films

    Downlink Steered Space-Time Spreading Assisted Generalised Multicarrier DS-CDMA Using Sphere-Packing-Aided Multilevel Coding

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    This paper presents a novel generalised Multi-Carrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) system invoking smart antennas for improving the achievable performance in the downlink, as well as employing multi-dimensional Sphere Packing (SP) modulation for increasing the achievable diversity product. In this contribution, the MC DS-CDMA transmitter considered employs multiple Antenna Arrays (AA) and each of the AAs consists of several antenna elements. Furthermore, the proposed system employs both time- and frequency- (TF) domain spreading for extending the achievable capacity, when combined with a novel user-grouping technique for reducing the effects of Multiuser Interference (MUI). Moreover, in order to further enhance the system’s performance, we invoke a MultiLevel Coding (MLC) scheme, whose component codes are determined using the so-called equivalent capacity based constituent-code rate-calculation procedure invoking a 4-dimensional bit-to-SP-symbol mapping scheme. Our results demonstrate an approximately 3.8 dB Eb/N0 gain over an identical throughput scheme dispensing with SP modulation at a BER of 10?5

    On the performance of key pre-distribution for RPL-based IoT Networks

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    A core ingredient of the the Internet of Things (IoT) is the use of deeply embedded resource constrained devices, often connected to the Internet over Low Power and Lossy Networks. These constraints compounded by the need for unsupervised operation within an untrusted environment create considerable challenges for the secure operation of these systems. In this paper, we propose a novel method to secure an edge IoT network using the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of distributed sensor networks. First, we investigate the performance of the unmodified algorithm in the Internet of Things setting and then analyse the results with a view to determine its performance and thus its suitability in this context. Specifically, we investigate how ring size influences performance in order to determine the required ring size that guarantees full connectivity of the network. We then proceed to propose a novel RPL objective function and associated metrics that ensure that any node that joins the network can establish secure communication with Internet destinations. , N., , H., , Th., , Th., , A., , P

    Secure routing in IoT networks with SISLOF

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    In this paper, we propose a modification of the RPL routing protocol by introducing the SISLOF Objective Function ensuring that only motes that share a suitable key can join the RPL routing table. This will ensure that all IoT network motes connect in a secure method. SISLOF uses the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of the Internet of Things. First, we discuss related work that provide evidence that the key pre-distribution scheme in the context of the IoT with default RPL metrics fails to achieve the full network connectivity using the same ring size, however full time connectivity can be achieved but with a great cost in term of the large rings sizes. We introduce the SISLOF Objective Function and explain the modification it does to the RPL messages (DIO and DAO). We finally show the performance of the key pre-distribution in the context of the Internet of Things when SISLOF is used as the Objective Function of the RPL routing protocol

    Iteratively Decoded Irregular Variable Length Coding and Sphere-Packing Modulation-Aided Differential Space-Time Spreading

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    In this paper we consider serially concatenated and iteratively decoded Irregular Variable Length Coding (IrVLC) combined with precoded Differential Space-Time Spreading (DSTS) aided multidimensional Sphere Packing (SP) modulation designed for near-capacity joint source and channel coding. The IrVLC scheme comprises a number of component Variable Length Coding (VLC) codebooks having different coding rates for the sake of encoding particular fractions of the input source symbol stream. The relative length of these source-stream fractions can be chosen with the aid of EXtrinsic Information Transfer (EXIT) charts in order to shape the EXIT curve of the IrVLC codec, so that an open EXIT chart tunnel may be created even at low Eb/N0 values that are close to the capacity bound of the channel. These schemes are shown to be capable of operating within 0.9 dB of the DSTS-SP channel’s capacity bound using an average interleaver length of 113, 100 bits and an effective bandwidth efficiency of 1 bit/s/Hz, assuming ideal Nyquist filtering. By contrast, the equivalent-rate regular VLC-based benchmarker scheme was found to be capable of operating at 1.4 dB from the capacity bound, which is about 1.56 times the corresponding discrepancy of the proposed IrVLC-aided scheme

    APLIKASI SISTEM AKADEMIK PADA LBPP LIA PALEMBANG

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    Semakin berkembangnya ilmu pengetahuan dan teknologi sekarang ini yang dirasakan semakin canggih, akan menuntut lembaga pendidikan agar mampu menguasai dan meningkatkan pengetahuan lembaga pendidikan dalam bidang teknologi. Dengan kemampuan tersebut lembaga pendidikan dapat bersaing di dunia pendidikan yang semakin ketat. Teknologi Informasi khususnya komputer yang dilengkapi berbagai program aplikasi sangat berpengaruh dan bermanfaat guna mempermudah melakukan segala kegiatan lembaga pendidikan. Kebutuhan program aplikasi di semua bidang pendidikan sangat tinggi, salah satunya dalam melakukan pengolahan data-data akademik yang bergantung besar pada program aplikasi, dikarenakan data-data akademik tersebut adalah inti utama kegiatan dalam lembaga pendidikan. Dan dengan adanya aplikasi sistem akademik pada LBPP LIA Palembang dapat mempermudah dalam penyusunan jadwal dan pengajar serta membantu mengurangi tingkat kesalahan dalam perhitungan nilai sehingga mampu meningkatkan pelayanan di LBPP LIA Palembang

    Inflammation in Atherosclerosis and Implications for Therapy

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    Atherosclerosis is now understood to be a disease characterized by inflammation that results in a host of complications, including ischemia, acute coronary syndromes (unstable angina pectoris and myocardial infarction), and stroke. Inflammation may be caused by a response to oxidized low-density lipoproteins, chronic infection, or other factors; and markers of this process, such as C-reactive protein, may be useful to predict an increased risk of coronary heart disease. Thus, we believe that inflammatory processes may be potential targets of therapy in preventing or treating atherosclerosis and its complications
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