Severe myocardial dysfunction and coronary revascularization

Severe myocardial dysfunction, characterized by global hypokinesis, or akinetic areas with hypokinesis of the remaining wall, and a very low ejection fraction (EF), has been considered to be a contraindication for coronary revascularization (CABG). However, myocardial scintigraphy and echo-stress data have shown that hypo- or akinetic areas can regain their contractility. Therefore, we expanded the indications for CABG, and performed operations even upon patients who were waiting for a heart transplant. Between January 1993 and June 1995, among 352 patients who underwent CABG, 85 had highly depressed left ventricular function. Their resting EF was lower than 0.35, and in 27 it was lower than 0.25. Viable areas of myocardium were found in all of the patients through the combination of scintigraphy and dobutamine-echocardiography: these areas depended on significant coronary lesions. The mean age of the patients was 48.2 years (range 33-62 years); angina was present in 62 patients. A mean of 3.1 grafts/patient were implanted; enoximone was used in all but 5 patients upon weaning from cardiopulmonary bypass; intra-aortic balloon pump was used in 9 cases. Operative mortality was 10.6% (9 patients), due to low-output syndrome in 5, acute myocardial infarction in 2, cerebral damage in 1, and respiratory failure in 1. At the 6-month follow-up, EF was improved in all but 7 patients, in whom it remained unchanged. Scintigraphic and echocardiographic tests revealed good function in most of the areas that had been previously recognized as hypo- or akinetic. These results suggest that the indications for standard myocardial revascularization can be expanded, and a promising option can be offered to patients who may otherwise be destined to wait for an uncertain transplantation.     

On the numerical modelling of the multiphysics self piercing riveting process based on the finite element technique

The development of reliable numerical models permits to investigate the manufacturing processes with very low incremental costs or prototyping efforts hence it provides a relevant help in process optimisation and gives great opportunity for making maximum use of sparse process data [Shercliff HR, Lovatt AM. Selection of manufacturing process in design and the role of process modelling. Prog Mater Sci 2001;46:429–59].

Among others the metal forming processes have heavily benefited from the finite element numerical computing technology [Chenot JL, Massoni E. Finite element modelling and control of new metal forming processes. Int J Machine Tool Manuf 2006;46:1194–200].

The self piercing riveting (SPR) is a cold forming process which creates a strong mechanical interlock between two or more sheets by means of a semi-tubular rivet, which, pressed by a punch, pierces the upper sheet and flares into the bottom one. It is governed by complex multiphysics phenomena whose governing equations can be resolved using the finite element method.

In this paper all the governing equations are fully reported along with the mathematics of the resolving method needed for setting up and simulate a finite element model of the self piercing riveting of an aluminium alloy. A case study of the SPR of two sheets of the 6060T4 aluminium alloy using a steel rivet was investigated. The calculations were performed using the LsDyna finite element commercial code. The problems encountered and the solutions applied for the preparation of the model and the run of the calculation were presented and discussed. The obtained results were validated by comparison with data coming from a laboratory experiment.     

Smart City L’Aquila: An Application of the “Infostructure” Approach to Public Urban Mobility in a Post-Disaster Context

Ever since the earthquake of April 6, 2009 hit the city of L’Aquila, Italy, the city has been facing major challenges in terms of social, physical, and economic reconstruction. The system of public urban mobility, the bus network, is no exception with its old bus fleet, non-user-friendly information, and poor scheduling. This paper argues that the public transportation system of L’Aquila could be improved towards smart mobility models without large infrastructure investment by leveraging the “infostructure” approach, digital technologies, open data, and open source software. This work presents the digitization and geo-referencing procedure, software architecture, and the web and mobile apps that have been developed to improve the information flow available to citizens and to increase the user-friendliness of the transportation system. Future research will seek to make use of the data and develop applications to perform a public transport accessibility analysis of major points of interest throughout the city.     

Low-frequency capacitance measurements

The letter proposes a technique for the fast determination at extremely low frequencies of the capacitance and leakage components of capacitors. The proposed method permits the measurement of C and G in only a few cycles. An apparatus is described employing this technique for the automatic measurement of m.o.s. capacitance as a function of frequency and bias voltage.     

The Directors’ cut: a solution to collaborative multimedia management

Web 2.0 applications allow rich media contents to be exposed and shared by users. Nevertheless, usually, a multimedia is provided as an unicum, made by synchronized media items. Sound tracks, video sequences, captions, cannot be customized “on-the-fly” by users. Managing multimedia in a deep way would meet the expectations of nowadays Web prosumers (i.e. producers and consumers), and it would widen the audience. Describing and synchronizing each medium, as well as specifying different alternative contents for it, are the keystones of multimedia customization and of audience widening. This paper presents a multimedia collaborative system, which provides support to the arrangement of medium into a multi-views composed multimedia. Each prosumer can add medium by juxtaposition or by defining it as an alternative (audio, video, textual) version of an existing one. The implementation of such a system is based on SMIL 3.0 specification but implements a new and compact syntax to let users manipulate the original multimedia synchronization and their alternatives. The proposed approach has been put to test in two different scenarios.     

Optimized mobile thin clients through a MPEG-4 BiFS semantic remote display framework

According to the thin client computing principle, the user interface is physically separated from the application logic. In practice only a viewer component is executed on the client device, rendering the display updates received from the distant application server and capturing the user interaction. Existing remote display frameworks are not optimized to encode the complex scenes of modern applications, which are composed of objects with very diverse graphical characteristics. In order to tackle this challenge, we propose to transfer to the client, in addition to the binary encoded objects, semantic information about the characteristics of each object. Through this semantic knowledge, the client is enabled to react autonomously on user input and does not have to wait for the display update from the server. Resulting in a reduction of the interaction latency and a mitigation of the bursty remote display traffic pattern, the presented framework is of particular interest in a wireless context, where the bandwidth is limited and expensive. In this paper, we describe a generic architecture of a semantic remote display framework. Furthermore, we have developed a prototype using the MPEG-4 Binary Format for Scenes to convey the semantic information to the client. We experimentally compare the bandwidth consumption of MPEG-4 BiFS with existing, non-semantic, remote display frameworks. In a text editing scenario, we realize an average reduction of 23% of the data peaks that are observed in remote display protocol traffic.     

A technology transfer journey to a model-driven access control system

In the model-driven security domain, access control systems provide an application for handling access of persons through controlled gates. A gate, such as a door, can have a lock mechanism for securing the area from unauthorized access. Most commercial solutions for access control management offer pre-packaged software systems where customization of the authorization logic is either not allowed or subject to payment. Moreover, cross-platform development is a barrier for solution providers due to the high cost of development and maintenance that it implies. To overcome these limitations and further optimize the entire access control systems development process, we propose a model-driven approach that supports automatic code generation to enable communication between an IoT infrastructure and platforms for Facility Access Management. Specifically, the approach combines the benefits of Near-Field Communication (NFC) and Tinkerforge (i.e., an open-source hardware platform) with model-driven techniques. This allows the approach to exploit both behavioral and structural models for the modeling and the consequent code generation of part of the authorization mechanism, thus providing complete coverage of the code generated for the whole system. We implemented and evaluated our approach in a real-world case study within the premises of a fitness center with an IoT infrastructure consisting of several heterogeneous sensors by showing its practical applicability. Experimental results demonstrate the effectiveness of our approach in supporting abstraction and automation concerning traditional code-centric development through code generation features. Consequently, our approach makes the whole development process less time-consuming and error-prone, thus reducing the system’s time to market.

     

Design and Review of Water Management System Using Ethernet,Wi-Fi 802.11n,Modbus, and Other Communication Standards

Wireless Personal Communications - Sensors, actuators, and controllers communicate with each other in our Water Management Cyber Physical System (WM-CPS). This WM-CPS is also Internet of Things...