Optimal Networks from Error Correcting Codes

To address growth challenges facing large Data Centers and supercomputing clusters a new construction is presented for scalable, high throughput, low latency networks. The resulting networks require 1.5-5 times fewer switches, 2-6 times fewer cables, have 1.2-2 times lower latency and correspondingly lower congestion and packet losses than the best present or proposed networks providing the same number of ports at the same total bisection. These advantage ratios increase with network size. The key new ingredient is the exact equivalence discovered between the problem of maximizing network bisection for large classes of practically interesting Cayley graphs and the problem of maximizing codeword distance for linear error correcting codes. Resulting translation recipe converts existent optimal error correcting codes into optimal throughput networks.Comment: 14 pages, accepted at ANCS 2013 conferenc

On the interdiffusion-based quantum cascade laser

Design procedure for the active region of current pumped quantum cascade laser is proposed, so to achieve maximal gain. Starting with an arbitrary smooth potential, a family of isospectral Hamiltonians with predefined energy spectrum is generated using the inverse spectral theory. By varying the relevant control parameter the potential shape is varied, inducing changes in transition dipole moments and electron–phonon scattering times, and the optimal potential which gives the largest gain is thus found. For purpose of realization, a simple step quantum-well structure with just a few layers is then designed so that in the post-growth heating-induced layer interdiffusion, it will acquire a shape as close as possible to the optimal smooth potentia

Quantized Indexing: Beyond Arithmetic Coding

Quantized Indexing is a fast and space-efficient form of enumerative (combinatorial) coding, the strongest among asymptotically optimal universal entropy coding algorithms. The present advance in enumerative coding is similar to that made by arithmetic coding with respect to its unlimited precision predecessor, Elias coding. The arithmetic precision, execution time, table sizes and coding delay are all reduced by a factor O(n) at a redundancy below 2*log(e)/2^g bits/symbol (for n input symbols and g-bit QI precision). Due to its tighter enumeration, QI output redundancy is below that of arithmetic coding (which can be derived as a lower accuracy approximation of QI). The relative compression gain vanishes in large n and in high entropy limits and increases for shorter outputs and for less predictable data. QI is significantly faster than the fastest arithmetic coders, from factor 6 in high entropy limit to over 100 in low entropy limit (`typically' 10-20 times faster). These speedups are result of using only 3 adds, 1 shift and 2 array lookups (all in 32 bit precision) per less probable symbol and no coding operations for the most probable symbol . Further, the exact enumeration algorithm is sharpened and its lattice walks formulation is generalized. A new numeric type with a broader applicability, sliding window integer, is introduced.Comment: Submitted to DCC-200

Factorial Structure of the Existence Scale

Existential meaning in life is becoming an increasingly important measure of personal assessment. In search of a suitable instrument to measure existential meaning, the authors reviewed several measures. Eventually, they selected the Existence Scale (ES), doing so on theoretical grounds. The ES is a fairly new self-rating instrument that assesses the degree of personal search for existential meaning in life. The aim of the current study is to examine the construct validity of the ES empirically by analyzing the factor structure of the scale. Confirmatory factor analysis was applied. Inventory responses from 1,187 participants were used as the overall sample, which was based on four samples, consisting of elementary school teachers (N = 215), elementary school principals (N = 514), pastors (N = 266), and social workers (N = 192). The results show that confirmatory factor analysis did not confirm the construct validity of the ES. The ES has been developed to measure existential meaning in life. There is no evidence in the current study that the ES is a valid, and acceptable measure of existential meaning

Safety profile od allergen specific imunotherapy of allergic rhinitis

Background: The aim of the presentation is to determine the safety profile of allergen specific immunotherapy, the frequency of local and/or systemic reactions, including subcutaneous (SCIT) and sublingual (SLIT) administrations. Methods: Our research was carried out in the diagnostic polyclinic section of the Allergology and Immunology Clinic of the Clinical Center of Serbia in Belgrade. We looked at retrospective insights into medical documentation, and all statistics was processed in the SPSS software. Results: Allergen specific immunotherapy (ASIT) is an effective treatment in IgE mediated allergic diseases: a) allergic rhinitis, with or without conjunctivitis, b) allergic asthma and c) hypersensitivity to venomas, with a range of patients from very good tolerance of AIT (no local, no systemic reactions 67.5 % ) to patients with very poor tolerance of AIT (there was not one case with anaphylactic shock, 0 % ). Conclusion: Its advantage as immunomodulatory treatment versus conventional pharmacological is that it alleviates the clinical picture, prevents the development of new symptoms, sensitizations and progression of rhinitis in asthma or a more severe disease. The quality of life is remarkably improved and also exhibits long term effects after the discontinuation of therapy

Period Batch Control - A Production Planning System Applied to Virtual Manufacturing Cells

Period Batch Control (PBC) system has been known for its implementation with the classical group technology (GT) cells, and it has been known for its simplicity. The main production planning decisions concern the choice of the period length and the stage number and contents. Also, in order to better integrate the production planning with the application of GT cells at the shop floor, the concept of virtual manufacturing cells has been applied. Since virtual cells configurations are changing periodically, a model for implementing the PBC system into virtual manufacturing cells environment is developed. The model enables alignment of the PBC principles and rules with virtual cell design goals. Model is tested on the case study of furniture production. With the use of scheduling software, different scheduling rules were simulated for four production weeks. The experimental results from these for production weeks show how the choice of PBC parameters impacts the virtual cells configurations, machine sharing and utilization

Resonant inelastic x-ray scattering probes the electron-phonon coupling in the spin-liquid kappa-(BEDT-TTF)2Cu2(CN)3

Resonant inelastic x-ray scattering at the N K edge reveals clearly resolved harmonics of the anion plane vibrations in the kappa-(BEDT-TTF)2Cu2(CN)3 spin-liquid insulator. Tuning the incoming light energy at the K edge of two distinct N sites permits to excite different sets of phonon modes. Cyanide CN stretching mode is selected at the edge of the ordered N sites which are more strongly connected to the BEDT-TTF molecules, while positionally disordered N sites show multi-mode excitation. Combining measurements with calculations on an anion plane cluster permits to estimate the sitedependent electron-phonon coupling of the modes related to nitrogen excitation