Optimal control with constrained total variance for Markov jump linear systems with multiplicative noises

We consider in this paper the stochastic optimal control problem of discrete-time linear systems subject to Markov jumps and multiplicative noises (MJLS-mn for short). Our objective is to present an optimal policy for the problem of maximising the system's total expected output over a finite-time horizon while restricting the weighted sum of its variance to a pre-specified upper-bound value. We obtain explicit conditions for the existence of an optimal control law for this problem as well as an algorithm for obtaining it, extending previous results in the literature. The paper is concluded by applying our results to a portfolio selection problem subject to regime switching.     

Age and productivity as determinants of firm survival over the industry life cycle

This paper contributes to fill the gap between the literature on the determinants of firm survival and the empirical works on the industry life cycle (ILC). Using a representative sample of Spanish firms with 10 or more employees over the period 1993–2009, the role played by firm age and productivity in firm survival is empirically analysed across three stages of the life cycle of forty-seven 3-digit manufacturing sectors. In the ‘early’ stage of the ILC, firm age is negatively correlated with hazard rates while firm productivity is not. Firm productivity is associated with lower hazard in the ‘mature’ stage of the ILC, when competition is primarily efficiency-driven, while firm age does not play a significant role for firm survival. In the ‘intermediate’ stage, both age and productivity play a role in reducing firms’ hazard rates.     

Assessment of intradialysis calcium mass balance by a single pool variable‐volume calcium kinetic model

Introduction: A reliable method of intradialysis calcium mass balance quantification is far from been established. We herein investigated the use of a single‐pool variable‐volume Calcium kinetic model to assess calcium mass balance in chronic and stable dialysis patients. Methods: Thirty‐four patients on thrice‐weekly HD were studied during 240 dialysis sessions. All patients were dialyzed with a nominal total calcium concentration of 1.50 mmol/L. The main assumption of the model is that the calcium distribution volume is equal to the extracellular volume during dialysis. This hypothesis is assumed valid if measured and predicted end dialysis plasma water ionized calcium concentrations are equal. A difference between predicted and measured end‐dialysis ionized plasma water calcium concentration is a deviation on our main hypothesis, meaning that a substantial amount of calcium is exchanged between the extracellular volume and a nonmodeled compartment. Findings: The difference between predicted and measured values was 0.02 mmol/L (range ?0.08:0.16 mmol/L). With a mean ionized dialysate calcium concentration of 1.25 mmol/L, calcium mass balance was on average negative (mean ± SD ?0.84 ± 1.33 mmol, range ?5.42:2.75). Predialysis ionized plasma water concentration and total ultrafiltrate were the most important predictors of calcium mass balance. A significant mobilization of calcium from the extracellular pool to a nonmodeled pool was calculated in a group of patients. Discussion: The proposed single pool variable‐volume Calcium kinetic model is adequate for prediction and quantification of intradialysis calcium mass balance, it can evaluate the eventual calcium transfer outside the extracellular pool in clinical practice.     

HCI and education: a blended design experience

Teaching HCI in an undergraduate course for computer scientists is often a challenging experience, because the skills that characterize HCI are different from scientific and computational thinking that are the focus of most subjects of the curriculum. Often HCI teaching is organized as a set of lectures that are useful to learn concepts, but don’t increase the design skills of the students. This work reports the results of an educational experience where both learners and teachers were actively involved in a process of knowledge construction and design. This process usually happens in other domains, such as architecture or industrial design, but is not part of most computer science curricula. We chose as project a challenging theme: the design of eco-feedback interfaces that inform people about the consequences of their actions for the environment and help to take decisions for lowering energy consumption. Eco-feedback interfaces are also representative of the gap between the products available on the market and the results of scientific studies, evidenced also by a recent workshop about HCI education. The workshop evidenced a number of pitfalls in HCI education that in our educational experience we tried to overcome with appropriate methodologies. An additional challenging task was the attempt to organize all the design activities taking advantage of a platform for remote learning, stressing its limits. The paper will discuss all these issues, evidencing where the applied methodologies gave good results and where they need further improvements, with the final goal of giving useful advices for HCI educational experiences to come.     

3D floor plan recovery from overlapping spherical images

Computational Visual Media - We present a novel approach to automatically recover, from a small set of partially overlapping spherical images, an indoor structure representation in terms of a 3D...     

Mac-A-Mal: macOS malware analysis framework resistant to anti evasion techniques

Journal of Computer Virology and Hacking Techniques - With macOS increasing popularity, the number, and variety of macOS malware are rising as well. Yet, very few tools exist for dynamic analysis...     

Scheduling links for heavy traffic on interfering routes in wireless mesh networks

We consider wireless mesh networks and the problem of scheduling the links of a given set of routes under the assumption of a heavy-traffic pattern. We assume some TDMA protocol provides a background of synchronized time slots and seek to schedule the routes’ links to maximize the number of packets that get delivered to their destinations per time slot. Our approach is to construct an undirected graph G and to heuristically obtain node multicolorings for G that can be turned into efficient link schedules. In G each node represents a link to be scheduled and the edges are set up to represent every possible interference for any given set of interference assumptions. We present two multicoloring-based heuristics and study their performance through extensive simulations. One of the two heuristics is based on relaxing the notion of a node multicoloring by dynamically exploiting the availability of communication opportunities that would otherwise be wasted. We have found that, as a consequence, its performance is significantly superior to the other’s.     

Bimorph actuator with monolithically integrated CMOS OFET control

We present an electrostrictive polymer bimorph controllable with low voltage through an integrated CMOS OFET control system. We have actuated the device by applying voltages up to 400 V to the control system, and can actuate the control with 60 V switching. The electrostrictor material was used both as the substrate for the transistors and as the dielectric layer for the control circuitry. This allows for a reduction in the number of layers in the structure, minimizing the clamping effect that would compromise the strain capabilities of the device. We have characterized the macroscopic displacement of the structure through a radius of curvature measurement, ranging from 11.4 mm to 7.5 mm depending on the supply voltage provided. The architecture proposed can be scaled to larger system with higher supply voltages.     

Colour features and pigment composition of Italian carbonic macerated red wines

Thirty commercially available Italian carbonic macerated young red wines, have been analysed by HPLC–DAD–MS with the aim to characterise their pigment composition and find possible correlations with the colour features evaluated by means of spectrophotometric measurements. The composition in anthocyanin monoglucosides, acetates, p-coumarates as well as that in pyranoanthocyanins and direct and ethyl-bridged adducts with flavanols, was studied. Because of the peculiar maceration process, carbonic macerated wines demonstrated to be qualitatively rich in pyranoanthocyanins and pigment adducts. A number of ethyl-bridged anthocyanin isomers was found, together with significant contents of vitisin A and vitisin B (up to 15.5 mg/L as a sum). Malvidin-3-glc-4-vinylphenol was the main pyranoanthocyanin-vinylphenol adduct (up to 1.10 mg/L). The colour features of the wines were broadly distributed as a consequence of the percentage of carbonic macerated wine present in the marketed product. The statistical treatment of the entire data set revealed that pyranoanthocyanins are positively correlated with colour density (while no correlation was found for monoglucosides) and that direct adducts and/or ethyl-bridged compounds can play a role for what concerns the hue of carbonic macerated wines.