Real and imaginary-time quarkonium correlators in a hot plasma

The possibility of describing the behavior of a $Q\overline{Q}$ pair in a hot plasma in terms of an effective potential is investigated. It is shown that as long as medium effects can be embodied in a gaussian action, like in the QED case, the $Q\overline{Q}$ propagator obeys a closed temporal evolution equation whose large-time behavior is governed by an effective potential. The latter, beside screening, displays also an imaginary part related to collisions.Comment: Talk given at the 8-th Conference "Quark Confinement and the Hadron Spectrum", Mainz, Germany, 1-6 September 200

An Approximate analytical method to evaluate the performance of multi-product assembly manufacturing systems

The automotive industry is characterized by the continuous and frequent adoption of cutting edge technologies in manufacturing. The introduction of new technology often entails a system level investigation to determine whether it meets expected production requirements. Many system design alternatives are usually considered at this stage, and a fast performance evaluation tool is desired to quickly obtain the optimum system configuration. In this paper, we introduce an analytical tool that was developed for this specific purpose

An automated approach to reuse machining knowledge through 3D – CNN based classification of voxelized geometric features

The enhanced digitalization in the manufacturing sector is claimed to facilitate the generation or the use of the existing process data incorporating the production variations and offers a significant increase in the productivity and efficiency of a system. Moreover, manufacturing companies possess substantial knowledge while designing a product and manufacturing procedures. The primary requirement is to link and organize all the information sources related to the operation design and production. This research is concerned with the reuse of machining knowledge for existing and new parts having similarities in geometric features and operational conditions. The proposed methodology starts by extracting each machining operation's geometric information and cutting parameters using industrial part programs in the numerical control (NC) simulator VERICUT. The removed material between two consecutive operations is obtained through mesh comparison in the simulator to analyze the feature interactions. A deep learning approach based on 3D convolutional neural networks (CNN) is applied to classify similar geometries to reuse the process design knowledge by creating a library of operations. The proposed approach is implemented on actual machining data, and the results demonstrate the effectiveness of the proposed solution. The obtained knowledge clusters in the operations library assist in making propositions related to operational parameters for similar geometric features during the process planning phase reducing the planning and designing time of operations

Standardizing the Process Information for Machining Operations Through Self-Contained Structures

A mechanical product is manufactured through multiple processes and procedures. The process information is coded in a part program, and a large amount of unstructured information comes from the shop floor. This results in the loss of logic formulated for the creation of a code. Moreover, it is impossible to track the modifications carried out during these processes. Thus, the unavailability of appropriate and standard knowledge of part processing leads to the situation where the information must be recreated every time a similar part is manufactured, hence, increasing the process planning time. One solution is to divide it into two steps: first, by fetching the information and coding it in a standardized structure; second saving it in a suitable form, facilitating in improving the efficiency and effectiveness of process design for available parts as well as anticipating the new parts. This was achieved by using the previous information related to the process combined with the one obtained from the shop floor. The proposed work concerns capturing the unstructured information from the existing part programs and regaining it using process simulation (VERICUT). Through the extraction of theoretical and graphical geometric data, the interactions between the operations were analyzed. The operational knowledge in this work includes: origin, feed-rate, rotating speed of the tool, rapid movement, cutting tool, material knowledge, and some geometric information of the process. The proposed approach based on simulations and mathematical programming logic is a way to improve flexibility at process and system level by formalizing the available operational knowledge. To illustrate the applicability of the proposed approach, a case study was carried out on a real industrial part program

Modeling urban-level impact of a shared taxi market

Taxi systems are being challenged by alternative, emerging services like Uber, Lyft, and Sidecar, which increasingly offer the option of ride sharing. While the enormous potential of ride sharing has been unveiled in a number of recent papers, it also raised legitimate concerns about the potentially disruptive impact on other transportation modes. In this paper, we introduce a framework for estimating the urban-level impact of ride sharing applied to the current taxicab service. First, we extend a representative economic model of regulated taxi markets to include ride sharing. The model allows predicting the interactions between demand and supply of a shared taxi service based on a few representative parameters, and is rooted on data analytical results. Then, we apply our model to the case study of the New York taxi market. The analysis highlights the dramatic impact of the pricing policy and taxi fleet management on the urban-level, systemic outcomes of a shared taxi system

Pulse of the city: Visualizing Urban Dynamics of Special Events

How does a city perform during a special event? How can we inform local authorities and urban dwellers of public happenings? Until today it has been difficult to monitor urban dynamics in real time. Traditional methods, like head counts, surveys, and aerial inspection, are costly and limited. In this paper we present our twofold approach to the processing and visualization of real time information gathered from the telecommunication infrastructures that percolate modern cities

An Evaluation of Furniture Making Methods for Yachts

There are mainly three different methods of furniture making for yachts as on-site method, mock-up method and computerized method. On-site method is the oldest and traditional way which has been developed by old talented wooden boat builders. In fact, the method is still alive in many small boatyards where the artisans apply the techniques learned by their masters. Mock-up method separates the construction process into two: boat building and furniture making. Hull, bulkheads, engines installation, mechanical and electrical infrastructure, all are made by a boatyard and furnitures are made by a sub- contractor, which indicates the furniture making is a specialization. Computerized method is the advanced way, developed in the last decade. All furnitures are drawn phase by phase by the sub-contractor's design team in detail and after the drawings are approved, production starts. Time planning, a clear definition of work sharing and responsibility are the key issues of this contemporary system. Within the scope of this study, all methods are explained widely. This study depends on an empirical research realized in furniture making companies and boatyards. Knowledge gained by both unstructured observations of making processes and interviews with responsible persons. Data is evaluated by qualitative methods. It is an attempt to understand the case and in line with its complementary understanding approach, a deductions set is given together with the observations and interviews in each making method. Then, four variables are determined to evaluate the furniture making methods: a. boat size and purpose of use, b. equipment and organizational capacity of furniture company, c. making time, and d. tolerance for decision changes. As a conclusion, three different methods of furniture makingdemonstrate three different work scales, but not the quality of end product

Acute idiopathic pericarditis with transient constriction [4]

The etiology and the clinical pattern of acute pericarditis change frequently and some classic assumption and descriptions are outdated. We report on a case of transient constrictive pericarditis in a healthy young man

THE EVALUATION OF TWO MASTER PROGRAMS CONTRIBUTING TO THE DEVELOPMENT OF INDUSTRY: IZMIR UNIVERSITY OF ECONOMICS AND POLITECNICO DI MILANO

This paper evaluates yacht design master programs in Izmir University of Economics (IUE) and Politecnico di Milano (POLIMI) in terms of where each institution is in the partnership with the industry. Therefore, vision and educational structure of both programs are summarized and projects as the cases are exhibited to understand in which ways each contributes to the development of yacht industry. A table of university - industry links typology prepared by The Innovation Policy Platform is used as a tool for evaluation and both programs are considered as two institutions in collaboration not only to the industry, but also to each other as an example of a collaborative development vision