17,285 research outputs found
PC-RED for IPv6: Algorithm and Performance Analysis
Full text linkThis paper presents a Priority Checking Random Early Detection (PC-RED) gateway for ensuring the Quality of Service (QoS) of high priority dataflow in IPv6 networks. A bit in the IP header is used in PC-RED to label the current status of the QoS that the dataflow is being treated in, which is determined by the difference between the packet average-dropping rate and the fixed desired limit dropping rate of the dataflow. PC-RED would perform dissimilarly to every dataflow corresponding to the different QoS status throughout congestions. PC-RED has been modeled and the parameter setting has been studied. Simulation result shows remarkable contrast between the High-Priority and Non-Priority dataflow throughput under PC-RED mechanism
Reduced-Rank MMSE Detection in Space-Time Coded Space-Division Multiple-Access Systems
No full textA multiple-input multiple-output (MIMO) space-division multiple-access (SDMA) system is presented and investigated, when the space-time block coded (STBC) user signals are transmitted over Rayleigh fading channels. In the proposed SDMA system each mobile uses two transmit antennas, while the base-station (BS) receiver employs multiple receive antenna arrays and each receive antenna array consists of several array elements. The MIMO SDMA signals at the BS are detected with the aid of various reduced-rank MMSE schemes. Specifically, three classes of reduced-rank MMSE techniques are investigated in conjunction with the proposed SDMA system. The three classes of reduced-rank MMSE algorithms are derived, respectively, based on the principles of principal components (PC), cross-spectral metric (CSM) and Taylor polynomial approximation (TPA). Our study and simulation results show that the reduced-rank MMSE detection is capable of achieving a satisfactory trade-off between the affordable detection complexity and the achievable detection BER performance
The physiological and morphological characteristics of interneurons caudal to the trigeminal motor nucleus in rats.
No full textA PC parallel port button box provides millisecond response time accuracy under Linux
Full text linkFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Exposure to a mixture of polychlorinated biphenyls and polychlorinated dibenzofurans resulted in a prolonged time to pregnancy in women.
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SISTEM PAKAR PEMILIHAN HARDWARE PC YANG KOMPATIBEL DENGAN FORWARD CHAINING
Full text linkKegunaan sebuah personal computer (PC) sangat krusial. Untuk dapat
memiliki sebuah PC, para calon pembeli umumnya mempercayakan proses
pembangunan PC mereka pada toko-toko PC tanpa paham mengenai detail
hardware pada PC tersebut dan seringkali mendapatkan PC yang melebihi
anggaran dan/atau tidak sesuai kebutuhan. Selain itu, dalam memilih hardware PC
juga memerlukan mekanisme untuk menjaga kompatibilitas antara hardware. Maka
dari itu diperlukan sebuah sistem untuk membantu masyarakat awam dalam
memilih hardware PC, yaitu sistem pakar pemilihan hardware PC dan mekanisme
pembatasan kompatibiltas dengan forward chaining.
Penelitian dimulai dengan mengumpulkan landasan teori tentang hardware
PC, sistem pakar dan metode inferensi forward chaining. Teori-teori yang
didapatkan dijadikan dasar pembuatan algoritma sistem. Setelah itu,
mengumpulkan data hardware PC yang dijual mulai Januari 2015 hingga April
2016 sekaligus harganya. Pengumpulan data hardware dilakukan di Hi-Tech Mall
Surabaya. Daftar hardware tersebut dijadikan pilihan untuk direkomendasikan.
Lalu, melakukan wawancara kepada pakar untuk mendapatkan data perilaku calon
perakit PC, jenis spesifikasi hardware yang mempengaruhi kompatibiltas, dan tipe
hardware yang direkomendasikan. Hasil wawancara digunakan sebagai dasar
pembuatan pertanyaan yang akan diberikan kepada pengguna ketika
mendefinisikan kebutuhan. Selain itu, dijadikan rule dalam mesin inferensi sistem
pakar dan algoritma untuk mekanisme pembatasan kompatibiltas. Sistem dirancang
menggunakan sisflow, dibangun menggunakan bahasa pemrograman PHP dengan
sistem pengelolaan database MySQL, dan dieksekusi menggunakan browser
internet. Sistem dievaluasi dengan cara membuat semua kemungkinan skenario
kebutuhan pengguna lalu menjalankannya di sistem yang telah dibuat lalu
membandingkan hasil rekomendasi dari sistem dengan hasil rekomendasi pakar.
Hasil evaluasi menunjukkan bahwa sistem yang dibangun dalam penelitian
menghasilkan rekomendasi yang sesuai dengan pakar. Maka dari itu, dapat
disimpulkan bahwa sistem pakar pemilihan hardware PC yang kompatibel dapat
dibangun menggunakan metode pendekatan inferensi forward chaining
Mellin Transform Based Performance Analysis of FFH M-ary FSK Using Product Combining Against Partial Band Noise Jamming
No full textWe propose a novel bit error ratio (BER) analysis technique for fast frequency hopping (FFH) assisted M-ary frequency shift keying (MFSK) using product combining (PC), when the channel is contaminated by partial band noise jamming (PBNJ). Exploiting the fact that the Mellin transform of the product of independent random variables is the product of their Mellin transforms, we derive the probability density function (PDF) of the PC’s output, when communicating in uncorrelated Rayleigh fading channels contaminated by PBNJ. Derivation of the PDF thus allows computation of the system’s BER. It is shown that the Mellin transform substantially simplifies the analysis of the PC receiver and facilitates for the first time the analysis of FFH-MFSK PC receiver for modulation orders of M > 2
Chronological evolution of IgM, IgA, IgG and neutralisation antibodies after infection with SARS-associated coronavirus
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