Sensors and Machine Learning Models to Prevent Cooktop Ignition and Ignore Normal Cooking

Fire Technology - Cooking equipment is involved in nearly half of home fires in the United States, with cooktop fires the leading cause of deaths and injuries in cooking-related fires. In this...     

Generating sub-1V reference voltages from a resistorless CMOS bandgap reference circuit by using a piecewise curvature temperature compensation technique

A piecewise curvature compensated CMOS voltage reference that is able to generate a sub-1V reference voltage is presented. The presented voltage reference circuit is operated at a minimum operating voltage of 1.5 V (theoretically 1.408 V) and generates a stable 0.658 V reference voltage with a temperature coefficient of 9.617 ppm/°C over the temperature range of −10 °C to 130 °C. When implemented in a 0.18 μm CMOS technology, the presented design occupies a compact silicon area of 0.022 mm². Spectre SPICE simulation showed that the presented design achieves a line regulation of 0.89%, a power supply rejection ratio of −42.3 dB, a power consumption of 0.449 mW at 1.8 V power supply and a high immunity to process variation.     

A comparison of stochastic programming and bi-objective optimisation approaches to robust airline crew scheduling

A prominent problem in airline crew scheduling is the pairings or Tour-of-Duty planning problem. The objective is to determine a set of pairings (or Tours-of-Duty) for a crew group to minimise the planned cost of operating a schedule of flights. However, due to unforeseen events the performance in operation can differ considerably from planning, sometimes causing significant additional recovery costs. In recent years there has been a growing interest in robust crew scheduling. Here, the aim is to find solutions that are “cheap” in terms of planned cost as well as being robust, meaning that they are less likely to be disrupted in case of delays. Taking the stochastic nature of delays into account, Yen and Birge (Transp Sci 40:3–14, 2006) formulate the problem as a two-stage stochastic integer programme and develop an algorithm to solve this problem. Based on the contradictory nature of the goals, Ehrgott and Ryan (J Multi-Criteria Decis Anal 11:139–150, 2002) formulate a bi-objective set partitioning model and employ elastic constraint scalarisation to enable the solution by set partitioning algorithms commercially used in crew scheduling software. In this study, we compare the two solution approaches. We improve the algorithm of Yen and Birge (Transp Sci 40:3–14, 2006) and implement both methods with a commercial crew scheduling software. The results of both methods are compared with respect to characteristics of robust solutions, such as the number of aircraft changes for crew. We also conduct experiments to simulate the performance of the obtained solutions. All experiments are performed using actual schedule data from Air New Zealand.     

Sodium molybdate—a possible alternate additive for sodium dichromate in the electrolytic production of sodium chlorate

Sodium dichromate is commonly used in sodium chlorate production to maintain high current efficiency; however, it is also a well documented carcinogen. To reduce the environmental impact, identification of a suitable alternative with similar buffering characteristics to dichromate and without adverse effect on the electrolytic performance of sodium chlorate production is important; sodium molybdate is a good candidate. Molybdate ion and its conjugated acid work as a buffer pair at pH 5–6, a lower and slightly narrower pH window than the typical buffer region of dichromate. Nonetheless, the molybdate buffer works effectively during the electrolytic process by maintaining pH at 5.9. Although the use of molybdate buffer will lower the overpotential of hydrogen evolution reaction (HER) by 100 mV, the average off-gas oxygen content is noticeably compromised at 3.6–4.6%, measured using a pilot cell operated at 3 kA m⁻²and 80 °C during a 3-day trial. The resulting current efficiency of 91 92% is significantly lower than when dichromate is employed as the process additive (> 96%). Mixtures of different dichromate and molybdate ratio were also investigated in terms of the resulting cathode surface potential.     

Minor components in the sex pheromone of legume podborer: Maruca vitrata development of an attractive blend

The legume podborer, Maruca vitrata (syn. M. testulalis) (F.) (Lepidoptera: Pyralidae) is a pantropical pest of legume crops. Sex pheromone was collected by gland extraction or trapping of volatiles from virgin female moths originating in India, West Africa, or Taiwan. Analysis by GC-EAG and GC-MS confirmed previously published findings that (E,E)-10,12- hexadecadienal is the most abundant EAG-active component with 2–5% of (E,E)-10,12-hexadecadienol also present. At least one other EAG response was detected at retention times typical of monounsaturated hexadecenals or tetradecenyl acetates, but neither could be detected by GC-MS. Laboratory wind-tunnel bioassays and a field bioassay of blends of (E,E)-10,12-hexadecadienal with (E,E)-10,12-hexadecadienol and a range of monounsaturated hexadecenal and tetradecenyl acetate isomers indicated greatest attraction of males was to those including (E,E)-10,12-hexadecadienol and (E)-10-hexadecenal as minor components. In subsequent trapping experiments in cowpea fields in Benin, traps baited with a three-component blend of (E,E)-10,12-hexadecadienal and these two minor components in a 100:5:5 ratio caught significantly more males than traps baited with the major component alone, either two-component blend, or virgin female moths. Further blend optimization experiments did not produce a more attractive blend. No significant differences in catches were found between traps baited with polyethylene vials or rubber septa, or between lures containing 0.01 and 0.1 mg of synthetic pheromone. Significant numbers of female M. vitrata moths, up to 50% of total catches, were trapped with synthetic blends but not with virgin females. At present there is no clear explanation for this almost unprecedented finding, but the phenomenon may improve the predictive power of traps for population monitoring.     

Price elasticity and the growth of computer spending

The price of computers is a key factor in explaining the growth of computer spending. However, it remains unclear whether the price elasticity of the demand for computers is constant over time. Findings on the pattern of price elasticity will have important implications in the study of information technology (IT) innovation diffusion. To test the hypothesis of dynamic price elasticity, we extend existing growth models to include a price factor with different elasticity specifications. Nested specifications of three growth models were tested using spending data from 1955 to 1984 adjusted by a quality price index for computers. The results indicate that three out of four competing models depict dynamic price elasticity over the investigated period. A similar pattern is also observed when the models are estimated using more recent data on mainframe computer spending. Our results underscore the dynamic behavior of price sensitivity in computer spending over time. They offer a new perspective to study innovation attributes and to examine their impacts empirically over time. Implications for information systems (IS) management and IT suppliers are also discussed     

Trainable blotch detection on high resolution archive films minimizing the human interaction

Film archives are continuously in need of automatic restoration tools to accelerate the correction of film artifacts and to decrease the costs. Blotches are a common type of film degradation and their correction needs a lot of manual interaction in traditional systems due to high false detection rates and the huge amount of data of high resolution images. Blotch detectors need reliable motion estimation to avoid the false detection of uncorrupted regions. In case of erroneous detection, usually an operator has to remove the false alarms manually, which significantly decreases the efficiency of the restoration process. To reduce manual intervention, we developed a two-step false alarm reduction technique including pixel- and object-based methods as post-processing. The proposed pixel-based algorithm compensates motion, decreasing false alarms at low computational cost, while the following object based method further reduces the residual false alarms by machine learning techniques. We introduced a new quality metric for detection methods by measuring the required amount of manual work after the automatic detection. In our novel evaluation technique, the ground truth is collected from digitized archive sequences where defective pixel positions are detected in an interactive process.