Web shops today needs to be more and more responsive, where one part of this responsivenessis fast product searches. One way of getting faster searches are by searching against anindex instead of directly against a database. Network Expertise Sweden AB (Net Exp) wants to explore different methods of implementingan index in their future web shop, building upon the open-source web shop platformSmartStore.NET. Since SmartStore.NET does all of its searches directly against itsdatabase, it will not scale well and will wear more on the database. The aim was thereforeto find different solutions to offload the database by using an index instead. A prototype that retrieved products from a database and made them searchable through anindex was developed, evaluated and implemented. The prototype indexed the data with aninverted index algorithm, and was made searchable with a search algorithm that mixed typeboolean queries with normal queries. / Webbutiker idag behöver vara mer och mer responsiva, en del av denna responsivitet ärsnabb produkt sökningar. Ett sätt att skaffa snabbare sökningar är genom att söka mot ettindex istället för att söka direkt mot en databas. Network Expertise Sweden AB vill utforska olika metoder för att implementera ett index ideras framtida webbutik, byggt ovanpå SmartStore.NET som är öppen käll-kod. Då Smart-Store.NET gör alla av sina sökningar direkt mot sin databas, kommer den inte att skala braoch kommer slita mer på databasen. Målsättningen var därför att hitta olika lösningar somavlastar databasen genom att använda ett index istället. En prototyp som hämtade produkter från en databas och gjorde dom sökbara genom ettindex var utvecklad, utvärderad och implementerad. Prototypen indexerade datan med eninverterad indexerings algoritm, och gjordes sökbara med en sök algoritm som blandar booleskafrågor med normala frågor. / <p></p><p></p><p></p>

<p>Conventional multiple description coding (MDC) is a source coding technique which provides resilience against packet loss. On the other hand, the correlation introduced between descriptions can be used to combat bit errors as well. While the latter feature of MDC has been attested and exploited in prior work, only few attempts have been made to design MDC with higher bit error resilience ability.</p> <p>This thesis makes some progress in the latter direction by addressing the problem of robust (i.e., bit error resilient) index assignment (IA) design for two description scalar quantizers. Our approach is to start from an initial IA which is known to be good for the conventional two description problem, and then apply permutations to indices in each description to increase a minimum Hamming distance-like performance measure.</p> <p>The criterion of increasing the minimum Hamming distance between valid index pairs (d_min), has been considered in prior work, however an efficient IA construction was presented only for the case of d_min = 2 and low redundancy.</p> <p>The contribution of this thesis is the following. For the scenario when one description is known to be error free, a new measure for IA robustness is proposed, which is termed minimum side Hamming distance (d_side,min). This quantity is defined as the minimum Hamming distance between valid indices of one description for fixed index of the other description. It is further shown that the problem of robust permutations design under the new criterion is closely connected to the anti-bandwidth problem in a certain graph derived from a hypercube. Leveraging this connection, permutations achieving d_side,min = 2 are proposed for all redundancy levels. Furthermore, for general values of d_side,min, a simple construction of permutations achieving d_side,min is presented, based on channel codes of appropriate block length and rate, and with minimum distance d_side,min + 1, respectively, d_side,min, for two types of initial IA (diagonal, respectively, square-based). The application of this result to achieve IA with d_side,min = 3 is further discussed for a wide range of redundancy levels.</p> <p>Finally, for the scenario when both descriptions may carry bit errors, simple constructions of permutations achieving d_min = 3 are proposed for the high redundancy case.</p> / Master of Applied Science (MASc)

<p> The fire weather index (FWI), useful as a measure of forest fire danger, is calculated from precipitation and other weather variables. In the present environmental study, precipitation, fuel moisture codes, and fire behavior indices were available for a reference site and 4 higher elevation sites around Smithers, British Columbia. The objective of the study was to determine whether the use of local precipitation would lead to a different FWI than obtained from precipitation at the reference site.</p> <p> The features of the series of daily FWI values which needed to be taken into account were: peaks following dry periods, serial correlation, and heteroscedasticity. Two types of models were developed to characterize the record as a smooth component, for the upward and downward movements of the index, and a component of correlated error terms. The first type was a parametric Fourier series in a context of a generalized linear model (GLS) that allowed for serial correlation and heteroscedasticity. The second form was a smoothing cubic spline with a bootstrap procedure for estimation of standard errors and confidence bands. The question, of whether FWI on a particular day differed between a higher elevation station and the reference station, was addressed by adding a station effect to the GLS model and by graphical comparison of the smooth curves with confidence bands for the spline method.</p> <p> The Model-3 for the combined station effect is not able to capture the sharpness of the peak and found insignificant while cubic spline smoothing curves fitted to the bootstrap behave well to capture peaks and troughs in the index but it encounter some difficulties for few lower index values.</p> / Thesis / Master of Science (MSc)

No description available.

Yes / Coherent subspaces spanned by a finite number of coherent states are introduced, in a quantum system with Hilbert space that has odd prime dimension d. The set of all coherent subspaces is partitioned into equivalence classes, with d 2 subspaces in each class. The corresponding coherent projectors within an equivalence class, have the 'closure under displacements property' and also resolve the identity. Different equivalence classes provide different granularisation of the Hilbert space, and they form a partial order 'coarser' (and 'finer'). In the case of a two-dimensional coherent subspace spanned by two coherent states, the corresponding projector (of rank 2) is different than the sum of the two projectors to the subspaces related to each of the two coherent states. We quantify this with 'non-addditivity operators' which are a measure of quantum interference in phase space, and also of the non-commutativity of the projectors. Generalized Q and P functions of density matrices, which are based on coherent projectors in a given equivalence class, are introduced. Analogues of the Lorenz values and the Gini index (which are popular quantities in mathematical economics) are used here to quantify the inequality in the distribution of the Q function of a quantum state, within the granular structure of the Hilbert space. A comparison is made between Lorenz values and the Gini index for the cases of coarse and also fine granularisation of the Hilbert space. Lorenz values require an ordering of the d 2 values of the Q function of a density matrix, and this leads to the ranking permutation of a density matrix, and to comonotonic density matrices (which have the same ranking permutation). The Lorenz values are a superadditive function and the Gini index is a subadditive function (they are both additive quantities for comonotonic density matrices). Various examples demonstrate these ideas.

Yes / Lorenz values and the Gini index are popular quantities in Mathematical Economics, and are used here in the context of quantum systems with finite-dimensional Hilbert space. They quantify the uncertainty in the probability distribution related to an orthonormal basis. It is shown that Lorenz values are superadditive functions and the Gini indices are subadditive functions. The supremum over all density matrices of the sum of the two Gini indices with respect to position and momentum states is used to define an uncertainty coefficient which quantifies the uncertainty in the quantum system. It is shown that the uncertainty coefficient is positive, and an upper bound for it is given. Various examples demonstrate these ideas.

yes / An expansion of row Markov matrices in terms of matrices related to permutations with repetitions, is introduced. It generalises the Birkhoff-von Neumann expansion of doubly stochastic matrices in terms of permutation matrices (without repetitions). An interpretation of the formalism in terms of sequences of integers that open random safes described by the Markov matrices, is presented. Various quantities that describe probabilities and correlations in this context, are discussed. The Gini index is used to quantify the sparsity (certainty) of various probability vectors. The formalism is used in the context of multipartite quantum systems with finite dimensional Hilbert space, which can be viewed as quantum permutations with repetitions or as quantum safes. The scalar product of row Markov matrices, the various Gini indices, etc, are novel probabilistic quantities that describe the statistics of multipartite quantum systems. Local and global Fourier transforms are used to de ne locally dual and also globally dual statistical quantities. The latter depend on off-diagonal elements that entangle (in general) the various components of the system. Examples which demonstrate these ideas are also presented.

The purpose of this study was to develop an explanation for the volatile behavior of the Local Composite Index, Virginia's measure of public school division fiscal capacity. This study documented and analyzed the behavior of the mathematical and structural components of the current formula over the period inclusive of Biennia 1984-86 through 1996-98. It was implemented in five phases: 1. Literature Review. Literature related to public school division fiscal capacity was reviewed: a) To identify normative and procedural concepts important to the philosophical development of fiscal capacity. b) To delineate the various models used across the United States in the determination of public school fiscal capacity. c) To examine components of indices, their application, and criteria for evaluating their behavior. 2. Local Composite Index Review. Information was collected from various sources regarding the Local Composite Index and its components for all school divisions in the Commonwealth. 3. Database Development. A relational database was developed to facilitate exploratory trend analyses of the LCI and its components. 4. Analysis. An identification and analysis of three trends was selected, defined, and undertaken: a) Biennial Change Rate of the Indicators, Local and State b) Biennial Change Rate of the Standardized Indicators, Local and State c) Net Biennial Change Rate of the Local to State Ratio for the Standardized Indicators 5. Case Studies. Five case studies of public school divisions and the Commonwealth of Virginia were performed to provide an in-depth and quantitative analysis of the interaction of the various component trends of the Local Composite Index and their resultant effects. The study identified specific phenomena and their percentage contribution to the volatility of the Local Composite Index. The study found three interactive effects of the LCI ratio structure that contribute to its volatility: * The Ratio structure can enhance the LCI value. * The Ratio structure can dampen the LCI value. * The ratio structure allows for Synthetic Change within the Local or State Standardized Indicators, which stimulates unpredictable patterns of volatility. / Ph. D.

In this work we investigate multi-variable Toeplitz operators and their relationship with KK-theory in order to apply this relationship to define and analyze embedded Toeplitz problems. In particular, we study the embedded Toeplitz problem of the unit disk into the unit ball in C^2. The embedding of Toeplitz problems suggests a way to define Toeplitz operators over singular spaces. / Ph. D.

Pavement friction have become a characteristic of interest due to its impact on road safety. The demand of the transportation agencies for equipment to measure the friction of their pavements grew. Different companies developed in parallel way different devices to satisfy that demand. This generate that the different transportation agencies are using different devices to measure the same characteristic. In order to determine a threshold for the adequate friction levels, the need to compare those data was created. Several attempts to harmonize those measurements have been developed, but have demonstrate that not produce harmonious results among some devices. Also, there are new equipment like the Continuous Friction Measurement Equipment (CFME) that offer some advantages compared to the traditional Locked Wheel Trailer (LWST) that also generate the need to compare historical data to the collected with the new device. This thesis is proposing an interconversion method between the measurements from a CFME as the SCRIM and the LWST. / Master of Science