712 research outputs found
On-line learning in multilayer neural networks
We present an analytic solution to the problem of on-line gradient-descent learning for two-layer neural networks with an arbitrary number of hidden units in both teacher and student networks. The technique, demonstrated here for the case of adaptive input-to-hidden weights, becomes exact as the dimensionality of the input space increases
Optimization of Friction Stir Welding Parameters of Al 6061 and Al 7075 Using GRA
لحام الخلط الاحتكاكي هو تكنولوجيا واعدة لربط سبائك الألومنيوم غير المتشابهة. سبائك الالمنيوم تستخدم بصورة شائعة في صناعات الفضاء مثل ابدان الطائرات والالواح والأجنحة نظرا لمتانته العالية نسبه الى وزنه. لذلك هنالك محاوله للوصول الى أمثليه متغيرات عمليه اللحام الاحتكاكي عند لحام سبيكتين من الالمنيوم هما6061 و7075 باستخدام برنامجMinitab 16 من اجل تحسين خصائص الشد مثل اجهاد الخضوع (YS) ومتانة الشد القصوى(UTS) ونسبة الاستطالة(E) . طريقه Taguchi استخدمت كأساس لتحليل العلاقة الرمادية (GRA) باستخدام عاملين هما سرعه دوران الاداة (TRS) وسرعه اللحام (WS بأربع مستويات. النتائج اظهرت ان المتغيرات التي هي سرعه دوران الاداة وسرعه اللحام لها تأثير كبير على اجهاد الخضوع ومتانة الشد القصوى ونسبة الاستطالة. كما اظهرت النتائج ان طريقه Taguchi المستخدمة كأساس لتحليل العلاقة الرمادية تحسن المخرجات لسبيكتي الالمنيوم 6061 7075 الملحومتان.Friction stir welding (FSW) is proved as a promising welding technology for joining dissimilar aluminium alloys. Aluminium alloys are used extensively within the aerospace industry for applications such as fuselage and wing skin panels due to their high strength to weight ratio. Therefore, an effort is made to optimize the process parameters of FSW using Al 6061 and Al 7075 alloys by the Minitab 16 program in order to enhance tensile properties such as elongation (E), yield stress (YS), and ultimate tensile strength (UTS). Grey relational analysis (GRA) based on the Taguchi method is applied using two factors tool rotational speeds (TRS) and welding speed (WS) with four levels. Results show that the variables, namely the tool rotation speed and welding speed have a significant effect on yield stress, ultimate tensile strength and elongation. Results also show that the Taguchi based grey relational approach improved properties of output response of welded Al 6061 and Al 7075 aluminum alloys
Semantic Clustering of Search Engine Results
This paper presents a novel approach for search engine results clustering that relies on the semantics of the retrieved documents rather than the terms in those documents. The proposed approach takes into consideration both lexical and semantics similarities among documents and applies activation spreading technique in order to generate semantically meaningful clusters. This approach allows documents that are semantically similar to be clustered together rather than clustering documents based on similar terms. A prototype is implemented and several experiments are conducted to test the prospered solution. The result of the experiment confirmed that the proposed solution achieves remarkable results in terms of precision
Genetic causes for iron deficiency
The genetic causes of iron deficiency, real or functional, occur due to defects in many proteins involved in the absorption and metabolism of iron. In this chapter we briefly describe the genetic causes of iron deficiency in the synthesis of hemoglobin, resulting in hypochromic or microcytic anemia. These alterations are rare with few descriptions in the literature. In some cases, functional iron is not available for erythroblasts to synthesis hemoglobin, or erythroblasts may be incapable of capturing iron from the circulation although iron is accumulated in tissues and mitochondrias. Many discoveries have been made over the last few years, mainly resulting from the description of human or animal models, which have elucidated the implications of the components in iron metabolism in hereditary iron deficiency involving all processes from intestinal absorption to the final inclusion into heme.As causas genéticas de deficiência de ferro, real ou funcional, ocorrem por defeitos em muitas proteínas envolvidas na absorção e metabolismo de ferro. Neste capítulo descreveremos sucintamente causas genéticas de carência de ferro para a síntese de hemoglobina, que cursa então com anemia microcítica e hipocrômica. Ressalto que estas são alterações raras, com poucas descrições na literatura. Em alguns casos, o ferro funcional não está disponível para os eritroblastos sintetizarem hemoglobina, ou o eritroblasto é incapaz de captar ferro da circulação, mas o ferro está acumulado em tecidos ou nas mitocôndrias. Nos últimos anos, várias descobertas, principalmente oriundas de descrições em humanos ou de modelos animais, ajudaram a elucidar a implicação dos componentes do metabolismo do ferro na deficiência de ferro hereditária, que afetam desde a absorção intestinal até sua inclusão final no heme.9910
Penyingkiran racun siput gondang emas menggunakan granulasi aerobik (Removal of Gondang Emas Pesticide using Aerobic Granulation) / Azlina Mat Saad … [et al.]
Peningkatan jumlah populasi siput gondang emas dalam sawah padisecara langsung telah meningkatkan penggunaan racun perosak iaitu metaldehyde. Sisa racun perosak yang telah digunakan akan berakhir di dalam sistem air yang merupakan sumber air dan habitat kepada hidupan akuatik. Manusia dan haiwan lain turut menerima impak negatif dengan pencemaran ini. Sisa racun terkumpul di dalam badan mampu merosakkan sistem saraf dan hati. Sebagai penyelesaian, kajian ini akan memantau keupayaan granul aerobik untuk menyingkirkan metaldehyde dari air sisa.Sebuah bioreaktor yang dikenali sebagai reaktor kumpulan penjujukan telah digunakan untuk membangunkan butiran aerobik. Sampel enapcemar diaktifkan diambil dari loji rawatan air sisa telah digunakan sebagai enapcemar benih untuk memulakan pembentukan granul aerobik.Biomas dalam enapcemar benih diberi makan air sisa sintetik yang terdiri daripada beberapa bahan kimia sebagai sumber karbon dan nutrien
Dynamics of on-line gradient descent learning for multilayer neural networks
We consider the problem of on-line gradient descent learning for general two-layer neural networks. An analytic solution is presented and used to investigate the role of the learning rate in controlling the evolution and convergence of the learning process
Learning with noise and regularizers in multilayer neural networks
We study the effect of two types of noise, data noise and model noise, in an on-line gradient-descent learning scenario for general two-layer student network with an arbitrary number of hidden units. Training examples are randomly drawn input vectors labeled by a two-layer teacher network with an arbitrary number of hidden units. Data is then corrupted by Gaussian noise affecting either the output or the model itself. We examine the effect of both types of noise on the evolution of order parameters and the generalization error in various phases of the learning process
Cross-Linked Carboxymethylcellulose Adsorbtion Membranes from Ziziphus lotus for the Removal of Organic Dye Pollutants
The goal of this study is to assess Ziziphus lotus’s potential for producing carboxymethylcellulose adsorption membranes with the ability to adsorb methyl green from wastewaters by the revalorization of its cellulosic fraction. The cellulose from this feedstock was extracted by an alkaline process and TAPPI standard technique T 203 cm-99 and afterwards they were carboxymethylated. The obtained carboxymethylcelluloses were deeply characterized, being observed that the carboxymethylcellulose produced from the alkaline cellulose presented the higher solubility due to its lower crystallinity degree (53.31 vs. 59.4%) and its higher substitution degree (0.85 vs. 0.74). This carboxymethylcellulose was cross-linked with citric acid in an aqueous treatment in order to form an adsorption membrane. The citric acid provided rigidity to the membrane and although it was hydrophilic it was not soluble in water. By evaluating the potential of the produced membrane for the removal of pollutant dyes from wastewater, it was observed that the adsorption membrane prepared from the carboxymethylcellulose’s produced from the Ziziphus lotus was able to remove 99% of the dye, methyl green, present in the wastewater. Thus, this work demonstrates the potential of the Ziziphus lotus for the production of a novel and cost-effective carboxymethylcellulose adsorption membrane with high capacity to treat wastewaters.This research was funded by Ministry of Higher Education and Scientific Research of Tunisia, I. Dávila would like to thank the University of the Basque Country (UPV/EHU) for their financial support (Grant reference DOCREC19/47)
Hepatic complications in sickle cell disease
Patients with sickle cell disease may present acute or chronic hepatopathy. The acute syndrome is characterized by right upper quadrant abdominal pain and jaundice. The differential diagnoses include acute sickle hepatic crises, hepatic sequestration, sickle cell intrahepatic cholestasis, cholecystitis, choledocholithiasis and acute viral hepatitis. These alterations can be differentiated by a careful history, liver function tests and hepatobiliary imaging studies. The specific treatment must be promptly initiated. Red blood cell transfusion is essential for the treatment of the clinical syndromes caused by the sickling process such as hepatic sequestration and sickle cell intrahepatic cholestasis. Chronic liver disease is frequently caused by chronic hemolysis and multiple transfusions. In an attempt to prevent, early diagnosis and treatment of chronic liver disease, sickle cell disease patients must be routinely submitted to liver function tests, serologic tests for hepatitis B and C, serum ferritin levels and abdominal ultrasound. Liver biopsy may be indicated in patients with virus hepatitis and in patients with persistent and accentuated alterations in liver function tests, out of acute sickle cell hepatic crises.Doentes falciformes podem apresentar alterações hepáticas agudas ou crônicas. As agudas são caracterizadas por dor no quadrante superior direito e icterícia. O diagnóstico diferencial inclui crise aguda de falcização hepática, seqüestro hepático, colestase intra-hepática, colelitíase, coledocolitíase, colecistite e hepatite viral aguda. Estas complicações devem ser diagnosticadas precocemente, através de história clínica, testes de função hepática e exames radiológicos, e o tratamento deve ser prontamente iniciado. Transfusão sangüínea é essencial para o tratamento das manifestações agudas causadas pelo processo de vaso-oclusão, como seqüestro hepático e colestase intra-hepática. As alterações hepáticas crônicas são freqüentemente causadas pela hemólise crônica e múltiplas transfusões. Para prevenção, diagnóstico precoce e orientação terapêutica da alteração hepática crônica, os doentes falciformes devem ser submetidos a exames de rotina: testes de função hepática, sorologia para hepatite B e C, dosagem sérica de ferritina e ultra-sonografia de abdômen. A biópsia hepática deve ser realizada em pacientes com hepatite viral e em pacientes com alterações hepáticas crônicas acentuadas e persistentes, afora das manifestações agudas.29930
Cell-Free Massive MIMO Energy Efficiency Improvement by Access Points Iterative Selection
Cell-free massive multiple-input multiple-output (CF-MIMO) system has been considered a promising technology for 5G and 6G networks for its ability to handle the rise in demand effectively. With CF-MIMO, improved energy efficiency can be obtained from straightforward signal processing. One of the potential problems in CF-MIMO systems is high power consumption due to the large numbers of distributed Access Points (APs), which decrease energy efficiency. This research proposes a modified algorithm to improve overall energy efficiency by reducing total power consumption via using the APs selection technique while maintaining the system's sum of rate. The technique used for APs selection is the largest large-scale-based selection, where each user is served by a subset of APs that offer the best channel condition rather than by all of APs. Total energy efficiency has been calculated for three cases: without APs selection, fixed APs selection, and dynamic APs selection (proposed approach). The simulation result shows that the proposed approach significantly improves energy efficiency by 45% at the signal-to-noise ratio (SNR) equal to 6 dB than the case where the selection of APs is fixed due to the optimal APs selection for each user
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