Improved decision support for engine-in-the-loop experimental design optimization

Experimental optimization with hardware in the loop is a common procedure in engineering and has been the subject of intense development, particularly when it is applied to relatively complex combinatorial systems that are not completely understood, or where accurate modelling is not possible owing to the dimensions of the search space. A common source of difficulty arises because of the level of noise associated with experimental measurements, a combination of limited instrument precision, and extraneous factors. When a series of experiments is conducted to search for a combination of input parameters that results in a minimum or maximum response, under the imposition of noise, the underlying shape of the function being optimized can become very difficult to discern or even lost. A common methodology to support experimental search for optimal or suboptimal values is to use one of the many gradient descent methods. However, even sophisticated and proven methodologies, such as simulated annealing, can be significantly challenged in the presence of noise, since approximating the gradient at any point becomes highly unreliable. Often, experiments are accepted as a result of random noise which should be rejected, and vice versa. This is also true for other sampling techniques, including tabu and evolutionary algorithms. After the general introduction, this paper is divided into two main sections (sections 2 and 3), which are followed by the conclusion. Section 2 introduces a decision support methodology based upon response surfaces, which supplements experimental management based on a variable neighbourhood search and is shown to be highly effective in directing experiments in the presence of a significant signal-to-noise ratio and complex combinatorial functions. The methodology is developed on a three-dimensional surface with multiple local minima, a large basin of attraction, and a high signal-to-noise ratio. In section 2, the methodology is applied to an automotive combinatorial search in the laboratory, on a real-time engine-in-the-loop application. In this application, it is desired to find the maximum power output of an experimental single-cylinder spark ignition engine operating under a quasi-constant-volume operating regime. Under this regime, the piston is slowed at top dead centre to achieve combustion in close to constant volume conditions. As part of the further development of the engine to incorporate a linear generator to investigate free-piston operation, it is necessary to perform a series of experiments with combinatorial parameters. The objective is to identify the maximum power point in the least number of experiments in order to minimize costs. This test programme provides peak power data in order to achieve optimal electrical machine design. The decision support methodology is combined with standard optimization and search methods – namely gradient descent and simulated annealing – in order to study the reductions possible in experimental iterations. It is shown that the decision support methodology significantly reduces the number of experiments necessary to find the maximum power solution and thus offers a potentially significant cost saving to hardware-in-the-loop experi- mentation

1997 FIU Cuba Poll

Results from the 1997 FIU Cuba Pollhttps://digitalcommons.fiu.edu/cuba_poll/1007/thumbnail.jp

The 2000 FIU Cuba Poll

Results from the 2000 FIU Cuba Pollhttps://digitalcommons.fiu.edu/cuba_poll/1008/thumbnail.jp

Fruit, vegetables and the prevention of cancer: research challenges

OBJECTIVE: A great deal of epidemiologic evidence has indicated that fruits and vegetables are protective against numerous forms of cancer. However, there are many gaps in our knowledge. METHODS: In this pilot study we reviewed more than 200 cohort and case-control studies to determine the shape of the dose–response relationship (i.e., how the risk reduction per extra serving of fruits and vegetables changes with the actual intake of these foods). We found major barriers to investigating this. As part of this pilot study we also investigated whether specific fruits and vegetables are responsible for the anticancer action of these foods or whether a wide variety is required for optimal protection. If the former is correct, then fruits and vegetables may contain one or a small number of "magic bullets"; if the latter is correct, then a "teamwork" concept may be valid. RESULTS: Different findings suggested that the teamwork concept is much more likely. Many studies, especially older ones, have ignored potential confounding variables such as energy intake, alcohol consumption, physical activity, body mass index, smoking, and socioeconomic status (although many recent studies have adjusted for education). Other potential confounders that have generally been ignored are consumption of whole grain cereals and the use of vitamin and mineral supplements. CONCLUSIONS: The inverse association between intake of fruits and vegetables and the risk of cancer of the colon, breast, and stomach has generally been much stronger in case-control than in cohort studies. We have no clear explanation for this

The 1995 FIU Cuba Poll: Views on Policy Options Toward Cuba Held by Cuban-American Residents of Dade County, Florida and Union City, New Jersey

Results from the 1995 FIU Cuba Pollhttps://digitalcommons.fiu.edu/cuba_poll/1006/thumbnail.jp

A Multiobjective G.A./Fuzzy Logic augmented flight controller for an F16 aircraft.

An investigation is made in this paper of the pos- sibility of enhancing the performance of controllers of unstable systems while retaining safety critical function. In this case, a General Dynamics F16 fighter is considered in simulation. A fuzzy logic controller is designed and its membership functions tuned by Multiobjective Genetic Algorithms in order to design an augmented flight controller with enhanced manouverability which still retains safety critical operation. The controller is assessed in terms of pilot effort and thus reduction of pilot fatigue. The controller is incorporated into a six degree of freedom real-time flight simulator, and flight tested by a qualified pilot instructor

Measurement and characterisation technique for real-time die temperature prediction of MOSFET-based power electronics

This paper presents a technique to predict the die temperature of a MOSFET based on an empirical model derived following an offline thermal characterization. First, a method for the near-simultaneous measurement of die temperature during controlled power dissipation is presented. The method uses a linear arbitrary waveform power controller which is momentarily disconnected at regular intervals to allow the forward voltage drop of the MOSFET's antiparallel diode to be measured. Careful timing ensures the power dissipation is not significantly affected by the repeated disconnection of the power controller. Second, a pseudorandom binary sequence-based system identification approach is used to determine the thermal transfer impedance, or cross coupling between the dice of two devices on shared cooling using the near-simultaneous measurement and control method. A set of infinite impulse response digital filters are fitted to the cross-coupling characteristics and used to form a temperature predictor. Experimental verification shows excellent agreement between measured and predicted temperature responses to power dissipation. Results confirm the usefulness of the technique for predicting die temperatures in real time without the need for on-die sensors

Cuba Poll 2014 : Full Survey Results

The full survey results include the full list of questions and tables with results for each question.https://digitalcommons.fiu.edu/cuba_poll/1004/thumbnail.jp

A prospective randomised study comparing different approaches to intraoperative management of diabetes mellitus: The Vellore regimen VS intermittent IV bolus regimen.

Diabetes mellitus is a common metabolic disorder with relevant anaesthetic implications. The large number of trials aiming to arrive at an ideal protocol for intraoperative management of the disease have so far not lead to a widely accepted and agreeable solution. This might be due, in part, to poor adherence because of inconvenient strategies. In this study, I aim to conclude whether the simple and easy intermittent intravenous insulin bolus regimen can stand up to the mostly followed Vellore regimen in efficiency and safety. Method: This was a unicentric randomised prospective trial in vascular surgery patients who have type 2 diabetes mellitus. 70 patients were chosen based on predefined criteria and randomly divided into 2 groups .Patients from each group were subjected to hourly intraoperative monitoring and insulin dosing depending on the group .Statistical approach- Primary outcome measures- The mean with standard deviation of glycaemic readings of each hour were calculated within each group and then compared across the groups for statistical significance .Secondary outcome measures -The difference in the percentage of people with uncontrolled sugars (defined as blood glucose values outside 100 - 200 mg %) between hour 0 and hour 3 was calculated and compared across both the groups. Tertiary outcome measure-The approach used for primary outcome measure was applied only to patients with poor pre operative glycaemic control. Results: The groups were well balanced for baseline characteristics except for the slightly higher mean PPBS in the intermittent iv bolus group. Since the FBS in both groups was comparable, the confounding factor of preoperative blood glucose control can be taken as insignificant in this case. It was seen that the decreased mean blood glucose measurement in Vellore Regimen Group compared to the Insulin Bolus Regimen Group is statistically significant as the p value is 0.0367 at 2 hours and 0.0383 at 3 hours intraoperatively as per unpaired t- test indicating a true difference among study groups.For the secondary outcome , in comparing the difference between the number of patients who were outside the target range at hour 0 and hour 3 between both the groups every hour , we find that for the Vellore regimen , the percentage dropped from 63% to 0% , while for the insulin bolus regimen it decreased from 17 % to 5 % . Although the Vellore Regimen takes the upper hand here, the finding was not found to be statistically significant .Coming to the tertiary outcome, In patients belonging to Insulin Bolus Regimen Group, the mean Blood Glucose Monitoring of Patients who had Poor Control at Assessment ( FBS≥126, PPBS≥200) ranged from 211 mg/dl at baseline to 160.60 mg/dl at the end of hour 3. The comparison turned out to be insignificant although it was in favour of the Vellore regimen Conclusion: Based on the above findings, I conclude that the Vellore regimen is marginally more efficacious as well as safer than the intermittent intravenous insulin bolus regimen

Effects of Threat and Sleep Deprivation on Action Tendencies and Response Inhibition

The ability to control action is crucial for adaptive responding, but may be compromised in situations involving strong emotions (e.g., threat) or when people are deprived of resources (e.g., sleep). As compromised action control can have large consequences in threatening situations, for example when police officers face a potentially armed suspect, we experimentally investigated how acute threat and partial sleep deprivation affect the ability to control impulsive responses, in 52 healthy young adults performing a simulated shooting task. The results showed that acute threat increased the tendency to act quickly (i.e., reduced response times; Coef = 9.46, 95% CI [3.49, 15.29], p = .001) and impaired response inhibition (i.e., increased stop signal reaction times; Coef = -4.91, 95% CI [-9.47, -0.44], p = .035). In addition, three nights of partial sleep deprivation (five hours [n = 28] vs. eight hours [n = 24] of sleep), led to a significant decrease in overall response accuracy (Coef = -0.22, 95% CI [- 0.40, -0.05], p = .025). Contrary to expectations, our results did not show increased threat sensitivity in sleep-deprived individuals (all p > .13). Nevertheless, they may have important implications for professionals who are required to maintain behavioral control under high levels of threat and who experience disturbed sleep due to e.g. shift work, as both factors negatively affected performanc