Profile control in distributed parameter systems using lexicographic optimization based MPC

Process equipment that exhibits significant spatial variation of system properties, such as temperature or concentration in a fixed bed reactor, are typically modeled as distributed parameter systems. While some properties of the final product exiting the equipment may depend on the states concerning the endpoint, others may be a function of the history of processing within the equipment. In such instances, control of the spatial property profile may be beneficial. In this work, we explore the idea of profile control using extended MPC and outline the additional challenges that must be addressed in this context. In case that the target profile is unachievable, we present an MPC formulation that uses lexicographic optimization to prioritize the different sections of the profile. Simulation of a simple representative system namely a hypothetical plug flow reactor is used to demonstrate that the lexicographic optimization based MPC provides a systematic approach to profile control and spans between the endpoint control strategy and the whole profile control strategy. The benefits of lexicographic optimization based MPC were also demonstrated on a large-scale distributed parameter system of industrial size, namely the continuous pulp digester.     

W3-privacy: understanding what, when, and where inference channels in multi-camera surveillance video

Huge amounts of video are being recorded every day by surveillance systems. Since video is capable of recording and preserving an enormous amount of information which can be used in many applications, it is worth examining the degree of privacy loss that might occur due to public access to the recorded video. A fundamental requirement of privacy solutions is an understanding and analysis of the inference channels than can lead to a breach of privacy. Though inference channels and privacy risks are well studied in traditional data sharing applications (e.g., hospitals sharing patient records for data analysis), privacy assessments of video data have been limited to the direct identifiers such as people’s faces in the video. Other important inference channels such as location (Where), time (When), and activities (What) are generally overlooked. In this paper we propose a privacy loss model that highlights and incorporates identity leakage through multiple inference channels that exist in a video due to what, when, and where information. We model the identity leakage and the sensitive information separately and combine them to calculate the privacy loss. The proposed identity leakage model is able to consolidate the identity leakage through multiple events and multiple cameras. The experimental results are provided to demonstrate the proposed privacy analysis framework.     

Water Resources Under Climate Change in Himalayan Basins

Water Resources Management - Climate change has significant implications for glaciers and water resources in the Himalayan region. There is an urgent need to improve our current knowledge and...     

An improved method using factor division algorithm for reducing the order of linear dynamical system

An improved method is proposed to determine the reduced order model of large scale linear time invariant system. The dominant poles of the low order system are calculated by clustering method. The selection of pole to the cluster point is based on the contributions of each pole in redefining time moment and redefining Markov parameters. The coefficients of the numerator polynomial for reduced model are obtained using a factor division algorithm. This method is computationally efficient and keeps up the stability and input output characteristic of the original arrangement.     

Analysis of a metal hydride reactor for hydrogen storage

In this paper a two-dimensional model of an annular cylindrical reactor filled with metal hydride suitable for hydrogen storage is presented. Comparison of the computed bed temperatures with published experimental data shows a reasonably good agreement except for the initial period. Effects of hydrogen pressure and external fluid temperatures on heat transfer and entropy generation are obtained. Results show that the time required for hydrogen charging and discharging is higher when the thermal capacity of the reactor wall is considered. The time required for absorption and desorption can be reduced significantly by varying the hydrogen gas pressure and external fluid temperatures. However, along with reduction in time the entropy generated during hydrogen storage and discharge increases significantly. Results also show that for the given input conditions, heat transfer between the external fluid and hydride bed is the main source of entropy generation.     

Critical current density and stability of Tube Type Nb3Sn conductors

The critical current densities (J_c) and stabilities of Tube Type Nb₃Sn conductors have been measured. The strands had superconducting subelement counts ranging from 192 to 744, and flat-to-flat filament sizes (for 0.7 mm OD wire) of from 35 μm down to 15 μm. These Tube Type conductors had a very simple structure: prior to heat treatment the filaments consist of a Sn core surrounded by a thin Cu tube, itself surrounded by a Nb or Nb alloy tube. Eight different strand types were investigated using various techniques including SEM, residual resistance ratio (RRR), transport J_c, and stability measurement. Most strands were studied at 0.7 mm OD, with one representative at 0.42 mm. The transport measurements were made at 4.2 K in fields up to 14 T. Numerous heat treatment schedules were investigated, with reaction temperatures ranging from 615 °C to 650 °C, and times ranging from 36–500 h. The highest J_cs were seen for the lowest reaction temperatures, with 12 T transport J_c values as high as 2450 A/mm² observed. The RRRs were lower for longer time and higher temperature reactions and ranged from 4 to 180. Strand stability was a strong function of the effective filament diameter, d_eff, and RRR. The most stable strands showed stability currents, J_s, of 8700 A/mm² and 15,300 A/mm² for 0.7 mm OD and 0.42 mm OD conductors, respectively.     

Hierarchical WSN protocol with fuzzy multi-criteria clustering and bio-inspired energy-efficient routing (FMCB-ER)

Multimedia Tools and Applications - Wireless Sensors Network (WSN) is used for monitoring and recording the physical environment and to transfer the sensed data to a central location by means of...     

Crisis Management

Multiple recent disasters have put crisis management in the limelight. Consequently, many IT-related research efforts are under way to bring transformational changes to first responder and response organizations’ ability to contain and mitigate crises.