109 research outputs found

    The effects of six weeks of training on physical fitness and performance in teenage and mature top-level soccer players

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    The main aim of the present study was to investigate the effects of soccer-specific training on physical fitness components in adolescent elite soccer players and make comparisons with older counterparts. Twenty two male soccer players from the Serbian First Division team were allocated to two assigned trials according to age – young group (YG) and mature group (MG). Players in their teenage years (19 years and younger) were assigned to YG (10 subjects) and others to MG (12 subjects). Between the first and second test session, all subjects followed six weeks of soccer-specific periodized training programme. There were no differences between groups at pre- and post-training trial for body mass, vertical jump height, average anaerobic power and VO2max (P>0.05). Body fat was significantly lower in YG before and after training program as compared to MG (P<0.05). Body mass and fat dropped significantly in both groups after training program (P<0.05). Furthermore, average anaerobic power and VO2max along with vertical jump height, were significantly improved in both groups (P<0.05) at post-training performance. Finally, the magnitude of change in VO2max was significanty superior in MG as compared to YG after training program (18.3 vs. 7.8�20P<0.05). The findings of the present study indicate that the trainability indices are not highly influenced by age in top-level soccer players

    Key recovery attacks on Grain family using BSW sampling and certain weaknesses of the filtering function

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    A novel internal state recovery attack on the whole Grain family of ciphers is proposed in this work. It basically uses the ideas of BSW sampling along with employing a weak placement of the tap positions of the driving LFSRs. The currently best known complexity trade-offs are obtained, and due to the structure of Grain family these attacks are also key recovery attacks. It is shown that the internal state of Grain-v1 can be recovered with the time complexity of about 2662^{66} operations using a memory of about 258.912^{58.91} bits, assuming availability of 2452^{45} keystream sequences each of length 2492^{49} bits generated for different initial values. Moreover, for Grain-128 or Grain-128a, the attack requires about 21052^{105} operations using a memory of about 282.592^{82.59} bits, assuming availability of 2752^{75} keystream sequences each of length 2762^{76} bits generated for different initial values. These results further show that the whole Grain family, due to the choice of tap positions mainly, does not provide enough security margins against internal state recovery attacks. A simple modification of the selection of the tap positions, as a countermeasure against the attacks described here, is given

    Termination Casts: A Flexible Approach to Termination with General Recursion

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    This paper proposes a type-and-effect system called Teqt, which distinguishes terminating terms and total functions from possibly diverging terms and partial functions, for a lambda calculus with general recursion and equality types. The central idea is to include a primitive type-form "Terminates t", expressing that term t is terminating; and then allow terms t to be coerced from possibly diverging to total, using a proof of Terminates t. We call such coercions termination casts, and show how to implement terminating recursion using them. For the meta-theory of the system, we describe a translation from Teqt to a logical theory of termination for general recursive, simply typed functions. Every typing judgment of Teqt is translated to a theorem expressing the appropriate termination property of the computational part of the Teqt term.Comment: In Proceedings PAR 2010, arXiv:1012.455

    On Hardware Implementation of Tang-Maitra Boolean Functions

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    In this paper, we investigate the hardware circuit complexity of the class of Boolean functions recently introduced by Tang and Maitra (IEEE-TIT 64(1): 393 402, 2018). While this class of functions has very good cryptographic properties, the exact hardware requirement is an immediate concern as noted in the paper itself. In this direction, we consider different circuit architectures based on finite field arithmetic and Boolean optimization. An estimation of the circuit complexity is provided for such functions given any input size n. We study different candidate architectures for implementing these functions, all based on the finite field arithmetic. We also show different implementations for both ASIC and FPGA, providing further analysis on the practical aspects of the functions in question and the relation between these implementations and the theoretical bound. The practical results show that the Tang-Maitra functions are quite competitive in terms of area, while still maintaining an acceptable level of throughput performance for both ASIC and FPGA implementations
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