341 research outputs found

    Perfect 3-colorings of the Cubic Graphs of Order 10

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    Perfect coloring is a generalization of the notion of completely regular codes, given by Delsarte. A perfect m-coloring of a graph G with m colors is a partition of the vertex set of G into m parts A_1, A_2, ..., A_m such that, for all i,j{1,...,m} i,j \in \lbrace 1, ... , m \rbrace , every vertex of A_i is adjacent to the same number of vertices, namely, a_{ij} vertices, of A_j. The matrix A=(aij)i,j{1,...,m}A=(a_{ij})_{i,j\in \lbrace 1,... ,m\rbrace }, is called the parameter matrix. We study the perfect 3-colorings (also known as the equitable partitions into three parts) of the cubic graphs of order 10. In particular, we classify all the realizable parameter matrices of perfect 3-colorings for the cubic graphs of order 10

    Reduction the Effect of Mobility in Link Transmitting Using Efficient DSR Route Cache for MANETs

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    Communication between mobile users is becoming more popular than ever before due to the recent technological advances in wireless communication devices. Ad hoc networks are generally closed in that, it’s a collection of two or more devices equipped with wireless communications and networking capability; they do not connect to the Internet and are typically created between participants. This means that a formed network can be de-formed on-the-fly without the need for any system administration. Many routing protocol methods have been proposed in Mobile Ad-Hoc Network but still the challenges are to improve the routing performance. The DSR (Dynamic Source Routing) routing protocol dependent on the cache memory for every node to store the routing path from source to destination. This paper presented a new algorithm using DSR routing cache technique to improve the routing between mobile nodes to reduction the effect of mobility in link transmitting that can solve link broken problem. The simulation results show a low delay, stable link in routing and better performance in terms of Route Discovery Time. It indicates that DSR cache outperforms DSR standard and had a high quality of packet delivery

    Photostablization and Antioxidant Activity of Some New Bis(Indazole-6-Imino) Subsituted-9,10-Anthracene Compounds

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    Four series of some new compounds composed from diamine and anthraquinone have been prepared and characterized by elemental analysis and spectroscopic techniques. The photostablizer activities of these compounds against low density polyethylene after exposure to Xenon U.V light were measured and compared with standard photostablizer (BHT). The antioxidant properties of these compounds were also studied using scavenger technique. Photostablization and antioxidant results for the prepared compounds indicate that these materials are very effective. Keywords: Imino-Indazole, synthesis, photostablization, Antioxidan

    From template to anchors: transfer of virtual pendulum posture control balance template to adaptive neuromuscular gait model increases walking stability

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    Biomechanical models with different levels of complexity are of advantage to understand the underlying principles of legged locomotion. Following a minimalistic approach of gradually increasing model complexity based on Template & Anchor concept, in this paper, a spring-loaded inverted pendulumbased walking model is extended by a rigid trunk, hip muscles and reflex control, called nmF (neuromuscular force modulated compliant hip) model. Our control strategy includes leg force feedback to activate hip muscles (originated from the FMCH approach), and a discrete linear quadratic regulator for adapting muscle reflexes. The nmF model demonstrates human-like walking kinematic and dynamic features such as the virtual pendulum (VP) concept, inherited from the FMCH model. Moreover, the robustness against postural perturbations is two times higher in the nmF model compared to the FMCH model and even further increased in the adaptive nmF model. This is due to the intrinsic muscle dynamics and the tuning of the reflex gains. With this, we demonstrate, for the first time, the evolution of mechanical template models (e.g. VP concept) to a more physiological level (nmF model). This shows that the template model can be successfully used to design and control robust locomotor systems with more realistic system behaviours

    An Experimental Study to Demonstrate the Effect of Alumina Nanoparticles and Synthetic Fibers on Oil Well Cement Class G

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        In the drilling and production operations, the effectiveness of cementing jobs is crucial for efficient progress. The compressive strength of oil well cement is a key characteristic that reflects its ability to withstand forceful conditions over time. This study evaluates and improves the compressive strength and thickening time of Iraqi oil well cement class G from Babylon cement factory using two types of additives (Nano Alumina and Synthetic Fiber) to comply with the American Petroleum Institute (API) specifications. The additives were used in different proportions, and a set of samples was prepared under different conditions. Compressive strength and thickening time measurements were taken under different conditions. The amounts of Nano Alumina (0.5%, 1%, and 1.5% by weight of cement (BWOC)) were selected with synthetic fiber (0.5 g, 1 g, and 1.5 g, respectively). The results show a significant improvement in compressive strength, with all values meeting the API requirements, and a decrease in the thickening time of Iraqi oil well cement, depending on the proportions of additives. The most significant improvement in compressive strength was achieved in the sample containing 1.5% Nano Alumina by weight of cement (BWOC) and 1.5 g Synthetic Fiber (Barolift), where the compressive strength increased by 40.7% and 33.8% at a temperature of 38 °C and 60 °C, respectively, while the thickening time decreased by 26.53% at this ratio of additives. The results demonstrate the feasibility of using these additives to enhance the performance of Iraqi oil well cement, expanding its potential application in Iraqi oil fields

    An effective transmit packet coding with trust-based relay nodes in VANETs

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    ehicular ad-hoc networks (VANETs) are characterized by limited network resources such as limited bandwidth and battery capacity. Hence, it is necessary that unnecessary use of network resources (such as unnecessary packet transfers) is reduced in such networks so that the available power can be conserved for efficient multicast communications. In this paper, we have presented a Transmit Packet Coding (TPC) Network Coding in VANET to ensure reliable and efficient multicasting. With network coding, the number of transmitted packets over the network can be reduced, ensuring efficient utilization of network devices and resources. Here, the trust-based graph optimization is performed using Cuckoo search algorithm to select the secure relay nodes. The experimental results showed the superiority of the presented approach compared to the existing techniques in terms of throughput, latency, hop delay, packet delivery ratio, network decoder outage probability, and block error rate

    Diagnosis, Treatment, and Outcomes in Children With Congenital Nephrogenic Diabetes Insipidus: A Pediatric Nephrology Research Consortium Study

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    © Copyright © 2020 D\u27Alessandri-Silva, Carpenter, Ayoob, Barcia, Chishti, Constantinescu, Dell, Goodwin, Hashmat, Iragorri, Kaspar, Mason, Misurac, Muff-Luett, Sethna, Shah, Weng, Greenbaum and Mahan. Background and Objectives: Congenital or primary nephrogenic diabetes insipidus (NDI) is a rare genetic disorder that severely impairs renal concentrating ability, resulting in massive polyuria. There is limited information about prognosis or evidence guiding the management of these patients, either in the high-risk period after diagnosis, or long-term. We describe the clinical presentation, genetic etiology, treatment and renal outcomes in a large group of children (89%) and white (67%). Median age at diagnosis was 4.2 months interquartile range (IQR 1.1, 9.8). A desmopressin acetate loading test was administered to 46% of children at a median age of 4.8 months (IQR 2.8, 7.6); only 15% had a water restriction test. Genetic testing or a known family history was present in 70% of the patients; out of those genetically tested, 89 and 11% had mutations in AVPR2 and AQP2, respectively. No positive family history or genetic testing was available for 30%. The most common treatments were thiazide diuretics (74%), potassium-sparing diuretics (67%) and non-steroidal anti-inflammatory drugs (42%). At the time of first treatment, 70 and 71% of children were below −2 standard deviations (SD) for weight and height, respectively. At last follow-up, median age was 72.3 months (IQR 40.9, 137.2) and the percentage below −2 SD improved to 29% and 38% for weight and height, respectively. Adverse outcomes included inpatient hospitalizations (61%), urologic complications (37%), and chronic kidney disease (CKD) stage 2 or higher in 23%. Conclusion: We found the majority of patients were treated with thiazides with either a potassium sparing diuretic and/or NSAIDs. Hospitalizations, urologic complications, short stature, and CKD were common. Prospective trials to evaluate different treatment strategies are needed to attempt to improve outcomes

    New record of blunthead pufferfish, Sphoeroides pachygaster (Muller & Troschel, 1848 (Tetraodontiformes: Tetraodontidae) from Indian water along with DNA barcode and some biological aspects

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    Blunthead pufferfish, Sphoeroides pachygaster (Muller and Troschel 1848) was recorded for the first time in Indian seas. A single female specimen of S. pachygaster was caught in bottom trawl operation at 263 – 310 m depth of the Eastern Arabian Sea. Morphometric and meristic description are presented in detail and compared with the pertinent records available elsewhere. The specimen collected was fully matured with Gonado Somatic Index (GSI) of 17.9 %. Gonad occupied two-third of the abdominal cavity, ova diameters ranged between 0.45 and 0.6 mm and the absolute fecundity estimated was 0.238 million eggs. Histological studies revealed that, this species performs single spawning strategy and it is the first information on the reproduction of S. pachygaster in India. Available reports on the occurrence of this species indicated distribution in the Mediterranean Sea, Atlantic, Indian and Pacific Oceans; however, the present record confirms its distribution in the Arabian Sea. Wide variations in the meristic counts among the specimens of this species collected from various locations are also discussed. Molecular analysis of the present specimen using Mitochondrial 16S rRNA gene sequences, confirmed the identity as S. pachygaster with intra specific divergence of 00.0 – 0.04 %. This report is the first well documented, confirmed record and re-description of S. pachygaster from the Indian Ocean, which documents a new addition to the family, Tetraodontidae of the Indian ichthyofauna

    Reconsidering the aid relationship: International relations and social development

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    Recent rhetoric surrounding the contemporary aid relationship between donors and African states is couched in terms of a high level consensus between western and African political leaderships, a central pillar of which is adherence to liberal principles of governance and economic management. The paper argues that an analysis of the nature of this consensus and its prospects requires that we need to understand it as (i) encompassing specifically international-geopolitical dimensions (including state interests, bargaining and power); and (ii) social-developmental purposes and content. The paper uses Rosenberg's considerations on 'international sociology' and uneven and combined development to provide a framework for analysing the aid relationship. In doing this, the paper speaks to two related theoretical issues: conceptualisations of the relationship between the 'social developmental' and the 'geopolitical/international' within International Relations (IR); and the contemporary relevance or otherwise of the discipline of IR to analyses of Africa's place in the international system
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