Dimensionality Reduction for Fast Similarity Search in Large Time Series Databases

The problem of similarity search in large time series databases has attracted much attention recently. It is a non-trivial problem because of the inherent high dimensionality of the data. The most promising solutions involve first performing dimensionality reduction on the data, and then indexing the reduced data with a spatial access method. Three major dimensionality reduction techniques have been proposed: Singular Value Decomposition (SVD), the Discrete Fourier transform (DFT), and more recently the Discrete Wavelet Transform (DWT). In this work we introduce a new dimensionality reduction technique which we call Piecewise Aggregate Approximation (PAA). We theoretically and empirically compare it to the other techniques and demonstrate its superiority. In addition to being competitive with or faster than the other methods, our approach has numerous other advantages. It is simple to understand and to implement, it allows more flexible distance measures, including weighted Euclidean queries, and the index can be built in linear time. Received 16 May 2000 / Revised 18 December 2000 / Accepted in revised form 2 January 2001     

Usability principles and best practices for the user interface design of complex 3D architectural design and engineering tools

This study proposes usability principles for the user interfaces (UI) design of complex 3D parametric architectural design and engineering tools. Numerous usability principles have been developed for generic desktop or web applications. The authors tried to apply existing usability principles as guidelines for evaluating complex 3D design and engineering applications. However, the principles were too generic and high-level to be useful as design or evaluation guidelines. The authors, all with more than 10 or 30 years of experience with various CAD systems, selected and reviewed 10 state-of-the-art 3D parametric design and engineering applications and captured what they thought were best practices, as screenshots and videos. The collected best practices were reviewed through a series of discussion sessions. During the discussion sessions, UI design principles underlying the collected best practices were characterized in the line of existing UI principles. Based on the best practices and the derived common UI principles, a new set of refined and detailed UI principles were proposed for improving and evaluating 3D parametric engineering design tools in the future.     

Plaster of Paris activated supersulfated slag cement

Hydration and strength behavior of supersulfated cement produced by activating a granulated Indian blastfurnace slag by plaster of Paris has been investigated. It is shown that plaster of Paris is a better activator than the conventional hard burnt gypsum (anhydrite) at least for a class of blastfurnace slags which are ordinarily considered less than ideal for this purpose. The setting characteristics of the plaster of Paris activated slag were controlled by small additions of a set retarder which does not adversely affect the strength properties of the cement. X-ray analysis and DTA have been used to identify the hydration products, interpret the strength data, and to compare the plaster of Paris activated cement with anhydrite activated slag cement.     

POLYELECTROLYTE MULTILAYER STAMPING IN AQUEOUS PHASE AND NON-CONTACT MODE

Polyelectrolyte multilayer (PEM) transfer printing has been previously achieved by stamping under dry conditions. Here, we show for the first time, that PEM can be transferred from a stamp to the base substrate under aqueous conditions whereby the two surfaces are in a non-contact mode. Degradable multilayers of (PAA/PEG)(10.5) followed by non-degradable multilayers of (PDAC/SPS)(80.5) were fabricated under acidic pH conditions on either PDMS or glass (stamp), and subsequently transferred over top of another multilayer prepared on a different substrate (base substrate), with a spacing of ~ 200 μm between the stamping surface and the base substrate. This multilayer transfer was performed under physiological pH conditions. This process is referred to herein as non-contact, aqueous-phase multilayer (NAM) transfer. NAM transfer can be useful for applications such as fabricating three-dimensional (3-D) cellular scaffolds. We attempted to create a 3-D cellular scaffold using NAM transfer, and characterized the scaffolds with conventional and fluorescence microscopy.     

Anaerobic Degradability: Effect of Particulate COD

Batch bioassay tests were conducted to evaluate the effect of particulate chemical oxygen demand (COD) (CODP) on anaerobic digestion of wastewater at different ratio of food to microorganism (F/M). Synthetically prepared soluble and complex wastewaters were used. Experiments were conducted in seven sets of serum bottles maintained at F/M ranging from 0.18 to 2.0. Each set contained six bottles having a total COD (CODT) of 500 mg and CODP from 0 to 100%. Methane generation conforms to the first order rate kinetics. At all F/M, k?(day?1) decreased linearly with increase in fraction of CODP?(CODPF = CODP/CODT). Biomethane potential (BMP), and substrate and sludge activities also exhibited declining trend with increasing CODPF. The optimum value of F/M ranged from 0.57 to 0.68. The two variables, CODPF and F/M, were compounded to yield the ratio of CODP to microorganisms [M, measured as volatile suspended solids (VSS)]. On increasing the CODP/VSS from 0 to 0.9, the rate constant for methane generation is reduced by 81%. BMP30, percent sludge activity, and substrate utilization rate are lowered by 52–55%. These correlations could serve as useful guidelines to quantitatively assess the impact of particulate COD on biodegradability parameters.     

Manufactured Housing Production Layout Design

This paper presents exploratory research work in facility layout design of a manufactured housing production plant. Manufactured homes are built in a factory on an assembly line that consists of activity stations, subactivity stations, feeder stations, and storage areas. This research developed systematic process steps for the layout design of manufactured housing production plants with a qualitative approach. The qualitative approach takes into account space requirements and proximity parameters. For this purpose, the tools and techniques available in industrial and manufacturing engineering were investigated. Data related to the space and proximity requirements in the two case study production plants were collected, and alternative layouts were developed. These layouts were analyzed to suggest the best possible layout. Finally, layout design steps for the qualitative analysis of the facility design were presented in the form of a process flowchart.     

An inverse solution methodology for estimating the diffusion coefficient of gases in Athabasca bitumen from pressure-decay data

An inverse solution methodology is developed for the estimation of diffusion coefficient of gases in highly viscous, oil-sands bitumens from isothermal, pressure-decay measurements. The approach involves modeling the rate of change in pressure using the diffusion equation for the liquid phase coupled with a mass balance equation for the gas phase. The inverse solution framework is utilized to arrive at two graphical techniques for estimating the diffusion coefficient. Both techniques involve the determination of the slope of a straight line resulting from plotting the experimental data in accordance with the developed model. An advantage of the proposed techniques is that the diffusion coefficient is estimated directly, i.e. without making it an adjustable parameter. The novelty of the proposed method is in its simplicity as well as its ability to isolate portions of the pressure-decay data affected by experimental fluctuations. The effect of the initial pressure on the predicted diffusion coefficient and pressure-decay profile was also investigated. The diffusion coefficients of CO₂, CH₄, C₂H₆ and N₂ in Athabasca bitumen at 50–90 °C and about 8 MPa were estimated and compared with literature values.