The structure of all different Steiner triple systems S(2 (m) -1, 3, 2) of rank 2 (m) -m+2 over is described. This induces a natural recurrent method for constructing Steiner triple systems of any rank. In particular,...
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The structure of all different Steiner triple systems S(2 (m) -1, 3, 2) of rank 2 (m) -m+2 over is described. This induces a natural recurrent method for constructing Steiner triple systems of any rank. In particular, the method gives all different such systems of order 2 (m) - 1 and rank a parts per thousand currency sign 2 (m) - m + 2. The number of such different systems of order 2 (m) - 1 and rank less than or equal to 2 (m) - m + 2 which are orthogonal to a given code is found. It is shown that all different triple Steiner systems of order 2 (m) - 1 and rank a parts per thousand currency sign 2 (m) - m + 2 are derivative and Hamming. Furthermore, all such triples are embedded in quadruple systems of the same rank and in perfect binary nonlinear codes of the same rank.
This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results sho...
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This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results show that in some cases, over sufficiently large fields, the minimum distance of the code corresponding to a set S will be the same as that of the code corresponding to the convex hull conv(S). In an example, we will also discuss a [49,12,28] generalized toric code over F-8, better than any previously known code according to M. Grassl's online tables, as of December 2012. (C) 2013 Elsevier Inc. All rights reserved.
In this paper, we give several new constructions of write-once-memory (WOM) codes. The novelty in our constructions is the use of the so-called Wozencraft ensemble of linear codes. Specifically, we obtain the followin...
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In this paper, we give several new constructions of write-once-memory (WOM) codes. The novelty in our constructions is the use of the so-called Wozencraft ensemble of linear codes. Specifically, we obtain the following results. We give an explicit construction of a two-write WOM code that approaches capacity, over the binary alphabet. More formally, for every epsilon > 0, 0 < p < 1, and n = (1/epsilon)(O(1/p epsilon)), we give a construction of a two-write WOM code of length n and capacity H(p) + 1 - p - epsilon. Since the capacity of a two-write WOM code is max(p)(H(p) + 1 - p), we get a code that is epsilon-close to capacity. Furthermore, encoding and decoding can be done in time O(n(2) . poly(log n)) and time O(n . poly(log n)), respectively, and in logarithmic space. In addition, we exhibit an explicit randomized encoding scheme of a two-write capacity-achieving WOM code of block length polynomial in 1/epsilon (again, epsilon is the gap to capacity), with a polynomial time encoding and decoding. We obtain a new encoding scheme for three-write WOM codes over the binary alphabet. Our scheme achieves rate 1.809 - epsilon, when the block length is exp(1/epsilon). This gives a better rate than what could be achieved using previous techniques. We highlight a connection to linear seeded extractors for bit-fixing sources. In particular, we show that obtaining such an extractor with seed length O(log n) can lead to improved parameters for two-write WOM codes. We then give an application of existing constructions of extractors to the problem of designing encoding schemes for memory with defects.
FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coo...
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FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coolant circuit into the containment building. The results contribute to validation of models and computer codes used to calculate the source term for a severe accident with core meltdown in light water reactors. Unlike the previous tests, FPT3 used B4C as absorber material in the pre-irradiated (24.5 GWd/tU) fuel bundle, while featuring a steam-poor period as in FPT2, which used Ag/In/Cd absorber. The main FPT3 containment results are summarised: the source term of FPs, fuel and structural materials from the experimental circuit into the containment;the composition, morphology and deposition processes of aerosols in the containment atmosphere;the specific behaviour of the radiologically significant FP iodine;and finally the performance of passive autocatalytic recombiner (PAR) coupons exposed to the containment atmosphere just after the transient. The major elements contributing to the aerosol mass in the containment are the volatile FPs Cs and Mo, the control rod material B, the cladding material Sn, and the instrumentation materials Re and W (specific to Phebus tests). The fractional compositions, leaving aside the control rod materials, were very similar in FPT2 and FPT3. After reactor shutdown, homogenisation of the aerosol size in the containment led to only one aerosol population, similar to the previous tests. Long-term aerosol deposition in the containment was dominated by gravitational settling and diffusiophoresis, but significant deposits were also measured on the vertical wall, consisting of multi-component aerosols, again comparable with FPT2. A significant result of FPT3 was that iodine is mainly in gaseous form in the atmosphere up to containment isolation;the rest in aerosol form. Another important result was the fast decrease of the iodin
In this paper, we study the following two hypercube coloring problems: given n and d, find the minimum number of colors, denoted as chi(d)'(n) (resp. chi(d)(n)), needed to color the vertices of the n-cube such tha...
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In this paper, we study the following two hypercube coloring problems: given n and d, find the minimum number of colors, denoted as chi(d)'(n) (resp. chi(d)(n)), needed to color the vertices of the n-cube such that any two vertices with Hamming distance at most d (resp. exactly d) have different colors. These problems originally arose in the study of the scalability of optical networks. Using methods in coding theory, we show that chi(5)'(2(r+1)) = 4(r+1) for any odd number r >= 3, and give two upper bounds on chi(d)(n). The first upper bound improves on that of Kim, Du and Pardalos. The second upper bound improves on the first one for small n. Furthermore, we derive an inequality on chi(d)(n) and chi(d)'(n). (C) 2013 Elsevier B.V. All rights reserved.
TASS/SMR-S is thermal-hydraulic design code for safety analysis of SMART plant. SBLOCA is considered as the design basis accident in the SMART. The capability of TASS/SMR-S for SBLOCA analysis was assessed using LOFT ...
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TASS/SMR-S is thermal-hydraulic design code for safety analysis of SMART plant. SBLOCA is considered as the design basis accident in the SMART. The capability of TASS/SMR-S for SBLOCA analysis was assessed using LOFT L3-7 as TMI action plan. Because TASS/SMR-S has been developed only for SMART, which is an integral reactor with helical steam generator heat exchanger, the steam generator model of TASS/SMR-S cannot be used directly for LOFT experiment that involves the use of U-tube steam generator. Therefore, the general heat structure model of TASS/SMR-S was used for modeling the SG heat exchanger. Nevertheless, TASS/SMR-S predicted important thermal-hydraulic parameters such as system pressure, fluid temperatures, and cladding temperature of reactor within reasonable error ranges. Further, TASS/SMR-S was applied to simulate SBLOCA in the SMART plant. In this simulation, thermal hydraulic parameters similar to those predicted in LOFT L3-7 were predicted. (c) 2012 Elsevier B.V. All rights reserved.
A group of subroutines, designed to extend the application range of the fuel performance code DIONISIO to high burn up, has recently been included in the code. The new calculation tools, which are tuned for UO2 fuels ...
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A group of subroutines, designed to extend the application range of the fuel performance code DIONISIO to high burn up, has recently been included in the code. The new calculation tools, which are tuned for UO2 fuels in LWR conditions, predict the radial distribution of power density, burnup, and concentration of diverse nuclides within the pellet. The balance equations of all the isotopes involved in the fission process are solved in a simplified manner, and the one-group effective cross sections of all of them are obtained as functions of the radial position in the pellet, burnup, and enrichment in U-235. In this work, the subroutines are described and the results of the simulations performed with DIONISIO are presented. The good agreement with the data provided in the FUMEX II/III NEA data bank can be easily recognized. (c) 2012 Elsevier B.V. All rights reserved.
作者：
Amabili, M.McGill Univ
Dept Mech Engn Canada Res Chair Tier 1 Montreal PQ H3A 0C3 Canada
A consistent higher-order shear deformation nonlinear theory is developed for shells of generic shape allowing for thickness variation by using six variables;geometric imperfections are also taken into account. The ge...
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A consistent higher-order shear deformation nonlinear theory is developed for shells of generic shape allowing for thickness variation by using six variables;geometric imperfections are also taken into account. The geometrically nonlinear strain-displacement relationships are derived retaining full nonlinear terms in the in-plane displacements. They are presented in curvilinear coordinates in a formulation that can be readily implemented in computer codes. This new theory is applied to laminated circular cylindrical shells complete around the circumference and simply supported at the ends. Linear (natural frequencies) and geometrically nonlinear (large-amplitude forced response) vibrations are studied by using the present theory and results are compared to those obtained by using the refined Amabili-Reddy higher-order shear deformation nonlinear shell theory, which neglects thickness variations. (C) 2013 Elsevier Ltd. All rights reserved.
We show that the free distance, as a function on a space parameterizing a family of convolutional codes, is a lower semicontinuous function and that, therefore, the property of being maximum distance separable (MDS) i...
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We show that the free distance, as a function on a space parameterizing a family of convolutional codes, is a lower semicontinuous function and that, therefore, the property of being maximum distance separable (MDS) is an open condition. For a class of convolutional codes, an algorithm is offered to compute the free distance. The behavior of the free distance by enlargements of the alphabet and by increasing the length is also studied. As an application, the algebraic equations characterizing the subfamily of MDS codes are explicitly computed for families of 1-D convolutional Goppa codes.
The paper proposes a new data hiding method based on deoxyribonucleic acid (DNA) coding, using the Word document as carrier. The plain message becomes a cipher sequence after being encoded to a DNA sequence and encryp...
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The paper proposes a new data hiding method based on deoxyribonucleic acid (DNA) coding, using the Word document as carrier. The plain message becomes a cipher sequence after being encoded to a DNA sequence and encrypted by the addition operation. The cipher sequence is attached to a random DNA primer sequence and circularly shifted for finite times, then hide the whole sequence into a Word document through substituting each character's color. The plaintext can be extracted according to the keys, and the key space is large enough to resist brute force attacks. Experimental results show the feasibility of the scheme. (C) 2013 Elsevier Ltd. All rights reserved.
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