Dynamic mechanical analysis of poly(vinyl chloride) compounds and blends

PVC is one of the most versatile and cost effective commercial polymers. A main limitation of PVC is optimizing its fabrication characteristics and end use properties with minimum adverse effect on either. PVC compounding technology is supersensitive due to effect of subtle variations in formulations causing “inspec” products during one production run and “out-of-spec” products in another. Large variations in properties are frequently due to improper mixing. Dynamic mechanical analyses provides a method of monitoring variations in mixing and their affect on morphological structure deviations which can lead to poor processing and end use properties.     

D2D pervasive communication system with out-of-band control autonomous to 5G networks

Wireless Networks - D2D (device-to-device) communication is one of the developments of 5G networks (5th generation mobile networks) that reduce mobile traffic load, reduce energy consumption and...     

Wind-induced pressure distribution on a large grain storage shed: Prediction of wind-driven ventilation rates

The wind-induced pressure distribution over a typical, large grain storage shed (rectangular low rise building, 30° pitched roof) is presented for different wind orientations. The distribution was determined from a wind tunnel model study using a simulated atmospheric boundary layer. The overall pattern was similar to that expected, showing, in particular, a prominent leeward vortex for some wind incidence angles. As an example of the use of the pressure distribution data in ventilation modelling and design studies, the ventilation rate was calculated for three different dispositions of vent in the storage. Two of these incorporated rectangular vents in the roof; the third being the common open eave vent system. The three dispositions investigated gave similar calculated ventilation rates showing that, for an equal area of vent, the open eave system could be replaced by suitably placed and more easily sealed rectangular vents.     

The properties of MOVPE grown 1.3 μm DFB MQW lasers infilled with semi-insulating InP fabricated on semi-insulating substrates

The use of optoelectronic integrated circuits (OEICs) is now emerging as a practical technology for a variety of applications, particularly in advanced telecommunications. OEICs consist of a range of devices such as lasers, waveguides, modulators, amplifiers, transistors, detectors, etc. fabricated on the same substrate. When a semi-insulating substrate is used, these devices can be electrically isolated by channel etching, resulting in a low capacitance structure with reduced electrical interference between the subcomponents. One of the devices which is particularly advantageous for this type of integration scheme is the distributed feedback (DFB) laser. The laser can be made to function more efficiently by minimizing the current flowing outside the active region. This can be achieved by surrounding the active region with semi-insulating iron doped InP. This work describes for the first time, the MOVPE growth, fabrication, and device characterization of 1.3 um buried heterostructure DFB MQW lasers, which combine the advantages of using both a semi-insulating substrate and a semi-insulating infill region in the same device structure. The potential advantage of this design scheme is improved OEIC performance as a result of, reduced capacitance and electrical crosstalk, enhanced laser output power, higher speed, increased efficiency, wider operating temperature and reduced threshold current. The laser active region consists of 8 x 140 Å quantum wells of GalnAsP (λ = 1.3 μm) and 110 Åbarriers of GalnAsP (λ= 1.07 μm). Single mode 1.3 urn devices of length 250 μm operating at room temperature produced threshold currents of 8 mA, efficiencies of up to 25%, output powers of 18 mW at 80 mA (pulsed), and a frequency response greater than 12GHz. The parasitic capacitance was estimated to be less than 3 pF.     

Multimodal acting in mixed reality interactive storytelling

In this paper, an experimental mixed reality using a multimodal approach is introduced which lets users play characters in interactive narratives as though acting on a stage. Users interact with characters through speech, attitude, and gesture, enhancing their immersion in the virtual world. This system provides a small-scale but complete integration of multimodal communication in interactive storytelling. It uses a narrative's semantic context to focus multimodal input processing-that is, the system interprets users' acting (the multimodal input) in the mixed reality stage in terms of narrative functions representing users' contributions to the unfolding plot.     

Design and fabrication of monolithically integrated DFB laser-wavelength duplexer transceivers for TPON/BPON access links

The fabrication and characterisation of monolithically integrated OEIC transceivers for use in optical subscriber access links are reported. A design incorporating DFB lasers, wavelength duplexers and a monitor photodiode, specific to the TPON/BPON passive optical network configuration is presented.<>     

Standardization of a multi-configuration medium access protocol for broadband ISDN

This paper examines the current work within various standards bodies to define a multi-configuration medium access control (MAC) protocol for operation between broadband ISDN terminals. To begin, the configurations in which the MAC protocol is expected to operate are introduced. The relation between the MAC protocol and the broadband ISDN resource allocation schemes is then discussed. Several MAC protocol proposals currently being discussed in various standards bodies, each with unique assumptions regarding resource allocation in broadband ISDN, are then described and compared. Finally, areas for future work on this topic are identified.     

Evaluation of Corn/Soybeans Separability Using Thematic Mapper And Thematic Mapper Simulator Data

Multitemporal Thematic Mapper, Thematic Mapper Simulator, and detailed ground truth data were collected for a 9-by 1-km sample segment in Webster County, Iowa, in the summer of 1982. Three dates were acquired each with Thematic Mapper Simulator (June 7, June 23, and July 31) and Thematic Mapper (August 2, September 3, and October 21). The Thematic Mapper Simulator data were converted to equivalent TM count values using TM and TMS calibration data and model based estimates of atmospheric effects. The July 31, TMS image was compared to the August 2, TM image to verify the conversion process. A quantitative measure of proportion estimation variance (Fisher information) was used to evaluate the corn/soybeans separability for each TM band as a function of time during the growing season. The additional bands in the middle infrared allowed corn and soybeans to be separated much earlier than was possible with the visible and near-infrared bands alone. Using the TM and TMS data, temporal profiles of the TM principal components were developed. The greenness and brightness exhibited behavior similar to MSS greenness and brightness for corn and soybeans.     

Fast and scalable parallel layout decomposition in double patterning lithography

For 32/22 nm technology nodes and below, double patterning (DP) lithography has become the most promising interim solutions due to the delay in the deployment of next generation lithography (e.g., EUV). DP requires the partitioning of the layout patterns into two different masks, a procedure called layout decomposition. Layout decomposition is a key computational step that is necessary for double patterning technology. Existing works on layout decomposition are all single-threaded, which is not scalable in runtime and/or memory for large industrial layouts. This paper presents the first window-based parallel layout decomposition methods for improving both runtime and memory consumption. Experimental results are promising and show the presented parallel layout decomposition methods obtain upto 21× speedup in runtime and upto 7.5×reduction in peak memory consumption with acceptable solution quality.     

Cryptographic Hash Functions from Expander Graphs

We propose constructing provable collision resistant hash functions from expander graphs in which finding cycles is hard. As examples, we investigate two specific families of optimal expander graphs for provable collision resistant hash function constructions: the families of Ramanujan graphs constructed by Lubotzky-Phillips-Sarnak and Pizer respectively. When the hash function is constructed from one of Pizer’s Ramanujan graphs, (the set of supersingular elliptic curves over with ℓ-isogenies, ℓ a prime different from p), then collision resistance follows from hardness of computing isogenies between supersingular elliptic curves. For the LPS graphs, the underlying hard problem is a representation problem in group theory. Constructing our hash functions from optimal expander graphs implies that the outputs closely approximate the uniform distribution. This property is useful for arguing that the output is indistinguishable from random sequences of bits. We estimate the cost per bit to compute these hash functions, and we implement our hash function for several members of the Pizer and LPS graph families and give actual timings.