The tensor product of two good codes is not necessarily robustly testable

Given two codes R and C, their tensor product $R?C$ consists of all matrices whose rows are codewords of R and whose columns are codewords of C. The product $R?C$ is said to be robust if for every matrix M that is far from $R?C$ it holds that the rows and columns of M are far on average from R and C respectively. Ben-Sasson and Sudan (RSA 28(4), 2006) have asked under which conditions the product $R?C$ is robust.Addressing this question, Paul Valiant (APPROX-RANDOM 2005) constructed two linear codes with constant relative distance whose tensor product is not robust. However, one of those codes has a sub-constant rate. We show that this construction can be modified such that both codes have both constant rate and constant relative distance. We also provide an alternative proof for the non-robustness of the tensor product of those codes, based on the inverse direction of the “rectangle method” that was presented by the second author (ECCC TR07-061). We believe that this proof gives an additional intuition for why this construction works.     

Ground-penetrating radar measurement of crop and surface water content dynamics

Ground-penetrating radar (GPR) with a suspended 1 GHz horn antenna was deployed for measurement of soil water contents and crop canopy properties over bare and electrically terminating surfaces. Surface reflection (SR) and signal propagation times (PT) were used to independently determine dielectric permittivity and water content of soil and canopy. Measured surface reflection coefficients progressively decreased with increasing canopy biomass according to Beer-Lambert type relationships. In contrast, PT measurements remained unaffected by canopy, and hence provided an accurate account of soil water content dynamics. Immediately after canopy removal, SR-based soil water content measurements were in close agreement with PT values. Canopy dielectric properties were inferred from canopy water contents (?_c-CWC) and canopy propagation times (?_c-CPT). Distinct canopy reflections were correlated with key canopy biophysical parameters. The study demonstrates the usefulness of a horn antenna GPR for characterization of vegetation canopy scattering, and for subcanopy water content measurements within a well-defined footprint, thereby offering a potential for calibration and verification of radar data collected from air- and spaceborne platforms.     

Alternative crystal field parameters for rare-earth ions obtained from various techniques: I. Reanalysis of Mössbauer spectroscopy studies of Tm3+ ions in TmBa2Cu4O8 and TmBa2Cu3O7−δ high Tc superconductors

In this series of papers, implications of two major properties of orthorhombic crystal field (CF) Hamiltonians for interpretation of CF data for rare-earth ions obtained from various experimental techniques are considered. These properties, i.e. existence of alternative (physically equivalent) CF parameter (CFP) sets and incorrectness of comparison of such alternative yet disparate CFP sets, appear not fully utilized in literature. The CFP sets for Tm³⁺ in orthorhombic high T_c superconductors TmBa₂Cu₄O₈ and TmBa₂Cu₃O_7?δ are reanalysed applying standardization and closeness of CFP sets. Correlated CFP sets are transformed to the same nominal standard axis system. Standardization transformations are used to generate alternative (standard and non-standard) CFP sets, which may be utilized in the multiple correlated fitting technique to improve reliability of final fitted CFPs. The discrepancies concerning orthorhombic CFPs, identified in Mössbauer spectroscopy studies of Tm³⁺ ion in TmBa₂Cu₄O₈, are clarified. Misinterpretations of CF and structural data arising from usage of intrinsically incomparable CFP sets for similar ion–host systems are discussed.     

Borreliosis--Lyme disease--a growing clinical problem

Neovascularization on the center of rabbit cornea was induced by 5N.NaOH alkali burns. We studied the change in localization of acidic fibroblast growth factor (a-FGF) and basic fibroblast growth factor (b-FGF) through corneal neovascularization with immunohistochemistry, using eyes which we enucleated on the 3rd, 7th, and 14th day. Moreover, by co-cultivation of rabbit corneal stromal cells and adrenal cortical vascular endothelium of bovine, a capillary-like code was induced, in which we also studied the localization of a-FGF and b-FGF on the 3rd, 7th, and 14th day. On the 14th day after the alkali burn we recognized intrastromal neovascularization and positive staining of a-FGF and b-FGF around it. Strong staining of a-FGF was observed in goblet cells through the experimental period. In control eyes we recognized positive reaction of a-FGF in corneal and conjunctival epithelium. In co-cultured cells, we recognized positive staining of both a-FGF and b-FGF around the capillary-like code which was induced among the corneal stromal cells.     

Perception of safe robot speed in virtual and real industrial environments

The purpose of this project was to study the influences of dynamic virtual objects in an Internet‐based virtual industrial environment. The main objectives of this study were to investigate perception of safe robot speed and perception of acceptability. Virtual industrial environments were designed and developed to conduct the experiment. The hypotheses specifying the relationships between perceptions of the robot size, type, different robot starting speed conditions, and gender were tested through data collected from 32 participants. The results indicated that the perception of safe speed was significantly different depending on robot sizes and the initial robot speed conditions. This was consistent with results shown in previous literature for tests in a real industrial environment. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 369–383, 2006.     

PECOM--工业报纸生产的支柱

报纸印刷生产线每天必须在较短的时间内印刷报纸,许多年都很稳定可靠。客户期待他们投资的印刷机在很长的时间内能够运行稳定,而印刷系统中每个组件之间的兼容性对此起到很大的作用。老的印刷生产线必须在较长的时间内保持功能稳定并且有一定的可扩展性,所添加的新组件也必须容易操作。然而如果电器的控制不同,供应商不同,就很难满足这些要求,很快就会出现问题。例如,当一个电器的供应商不能再生产某种元件时,就会发生这种现象。但是如果     

Biomaterial with chemically engineered surface for protein immobilization

The last 3 decades have been a revolution in the area of sol-gel-derived materials. They can be used to encapsulate biomolecules such as enzymes, antibodies, hormones, and proteins retaining their functional state. Proteins can be immobilized in many ways but it is crucial that they retain their native conformational structure and, therefore, bioactivity. Porous silica gel matrixes with modified surfaces offer unlimited possibilities to control the protein-solid interaction behavior. The bioimmobilization process on sol-gel biomaterials with chemically engineered surface has driven applications on solid-phase materials, affinity chromatography, biosensors and many others. In the present work, we have aimed to produce surface-modified silica glass materials obtained via sol-gel route to be used as solid support on drug delivery systems and as solid-phase in immunodiagnostic. The functionalization process was carried out by reacting alkoxysilanes with 5 different silane surface modifying chemical groups: tetraethoxysilane (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and 3-aminopropyltriethoxysilane (APTES), 3-glycidoxypropyltrimethoxysilane (GPTMS) and 3-isocyanatopropyltriethoxysilane (ICPES). The bioactivity assays were based on two main tests: (a) An in vivo bioresponse of rats with sol-gel disk implants with insulin protein incorporated. In vivo tests with adult male rats were used to verify the immobilized insulin bioactivity after implantation of different biomaterial with functionalized surfaces. All surface modified materials have presented hypoglycemic peak response associated with the insulin bioactivity. (b) The produced solid-phase sol-gel disks with protein substrates were tested through Enzyme Linked Immuno Sorbent Assay (ELISA). The immunoassay results have showed that glasses with chemically functionalized surfaces regulated the extent of bioimmobilization of protein. The amine, thiol and hydroxyl terminated porous gels have showed significant interaction with the antibody-antigen, during the coupling process. We believe that it is due to balance of forces associated with Van der Waals interaction, hydrophilic and hydrophobic forces and steric hindrance acting at the surface. Therefore, such novel biomaterial could be advantageously used in drug delivery systems and in immunoassays of diagnostic kits.     

Elastic-plastic deformation of a centrally heated cylinder

Summary Subject of the investigation is the deformation of a perfectly plastic cylinder with uniform temperature inside its cylindrical core and zero surface temperature. The calculation is based on Tresca's yield condition and the flow rule associated to it. For small radii of the hot core, a plastic region appears at the center expands towards the surface of the cylinder with increasing core temperature. The other possibility is that, depending on the core radius, two plastic regions form one after the other or simultaneously, in the core and at the surface and join in the fully plastic state. The image points of the cylinder lie on different edges and sides of the Tresca-prism in stress space.     

A decision support tool for the analysis of pricing,investment and regulatory processes in a decentralized electricity market

After the liberalization of the electricity generation industry, capacity expansion decisions are made by multiple self-oriented power companies. Unlike the centralized environment, decision-making of market participants is now guided by price signal feedbacks and by an imperfect foresight of the future market conditions (and competitor actions) that they will face. In such an environment, decision makers need to better understand long-term dynamics of the supply and demand sides of the power market. In this study, a system dynamics model is developed, to better understand and analyze the decentralized and competitive electricity market dynamics in the long run. The developed simulation model oversees a 20-year planning horizon; it includes a demand module, a capacity expansion module, a power generation module, an accounting and finance module, various competitors, a regulatory body and a bidding mechanism. Many features, singularities and tools of decentralized markets, such as; capacity withholding, enforced divestment, long-term contracts, price-elastic demands, incentives/disincentives, are also incorporated into the model. Public regulators and power companies are potential users of the model, for learning and decision support in policy design and strategic planning. Results of scenario analysis are presented to illustrate potential use of the model.