Social networks and regional economic development: The Los Angeles and Bay Area metropolitan regions, 1980–2010

Social capital is widely recognized as an important aspect of regional economies, and social networks in particular have recently been the focus of research in economic sociology and economic geography. Building on this body of work, this research explores the role of social networks in the divergent economic fortunes of two highly advance Californian metropolitan regions over the past three decades, Los Angeles and the Bay Area. Proxies for the two regions’ industrial social structures are constructed and analysed at three cross sections over the divergence period: 1982, 1995 and 2010. Network analysis shows that the Bay Area’s industrial social structure maintains a high level of connectivity, bridging relations across industrial boundaries, and by 2010 has a highly connected and central business-civic organization, the Bay Area Council. The LA region’s social structure, on the other hand, fragments substantially over the period

The ambiguity of blogging: beneficial and believable? (guest blog)

The Ambiguity of Blogging by Polis Summer School Student, Nadine Makarem An international celebrity “Tweeted” in May 2009: “Laying in bed this morning contemplating how amazing it would be if somehow Oscar Wilde and Mae West could twitter from the grave”

How friendships and networks matter for urban economic development

Why do some cities perform so much better than others? According to new research from, Naji P. Makarem, it’s not just down to their resources – both human and physical – but also how people and organizations interact and work together. In studying social relations in business communities, he finds that while San Francisco’s diverse and connected social structure has allowed the Bay Area to withstand new economic challenges, Los Angeles’ comparable regional network has not been able to maintain its connectivity, which has led to relatively poorer economic outcomes for the city

Designing, modeling, manufacturing, and testing an atomic layer deposition system

There are multiple techniques for depositing thin films in nanoelectronics and semiconductor industries. Each technique has its own advantage and disadvantage. Of the many techniques, chemical deposition is the most favorable since materials can be deposited in high aspect ratios and give full coverage across uneven surfaces. However the most conventional technique in chemical deposition, named chemical vapor deposition (CVD), has some limiting properties like high temperature and uncontrollable film growth. T have the advantage of chemical deposition and also being able to control film growth in monolayer resolution, a new technique has been introduced, named Atomic Layer Deposition (ALD). This technique gives a very good control on layer-by-layer film growth. It can work at low temperatures and high pressures. In manufacturing nanoantennas and MIM diodes there is a need, for having an ultra thin film with full coverage across select areas. ALD is a promising solution for ultra-thin film fabrication problems. In this work we designed, modeled, manufactured, and tested a novel ALD system. Our system is designed to do more exotic film depositions than the small-range accessible with industrially available ALDs A typical ALD process starts with entraining a precursor in a carrier gas that brings it inside the reactor where it adsorbs on the substrate's surface. The second step is removing the extra precursor from the chamber by purging it. The third step is adding another precursor gas to the reactor. The two precursors will react with each other on the substrate's surface. In the fourth step a purge is used to remove excessive precursors and by-products from the reactor chamber. A well-designed reactor for this process needs to have the ability to operate under high vacuum, high temperatures, and intense reactions. In the designed reactor within this project, a showerhead, a stage heater, a ceramic spacer, and stage holder were designed and manufactured. There are four gas inlets from a top flange that feed into showerhead, which helps better gas dispersion. Also in the showerhead each of the inlets can be used to bring different gases inside the reactor for CVD processes. The designed reactor is a cross reactor, which minimizes the gas entrapment. All the flanges were designed in a way to have good ability to control the system. The tubing in this system is used to bring precursors inside the reactor. To have a good control on the flow rate of precursors, individual mass flow controllers, i.e. four ALD Solenoid Valves, are used to regulate the flow of each precursor. Bubblers are used to contain precursors at the entry point of the gas delivery line. Each bubbler has a dipping tube that extends the length of the bubbler container to give the carrier gas the ability to entrain precursors and bring them inside reactor. ALD Valve-4 is designed in a way that can switch the system from ALD to CVD. This gives us the ability to have multiple depositions in different techniques ina single run. ALD Valve-3 is designed for vacuum bubblers in case there is a precursor with very low volatility or very sensitive to high temperatures. Controlling the entire system, all at the same time, is crucial to the success of ALD. The parameters that needed to be controlled are temperature, pressure, gas flow, and each of the ALD Valves. There are five parts in the designed system that have separate thermocouples and heaters. Each of bubblers, tubings, the reaction chamber's body, and substrate stage can get to a separate temperature using PID controllers. Finally a box designed for all the PID controllers and relays to read all the temperatures side-by-side. In addition, there is a terminal box that connects all the tubings' heaters and chamber heaters together. Low vacuum pressure can be read by either of the two thermocouple gauges installed on the system. One of the thermocouple gauges reads the pressure of the reaction chamber and the other reads the pressure inside turbopump. Also there is an ion gauge, which has the ability to read pressures less than 10-3 Torr. To control gas flow and ALD Valves, a software program was developed that can send digital signals to DAQcards and the cards can change it to analog signal and send to MFCs and Valves. A control box is designed that contains all the four DAQ cards and a circuit that gives us the ability to control the valves by low currents. Finally, the manufactured ALD was tested for process of depositing Al2O3 on top of silicon substrate. The test were performed in two batches, EDS test were performed to prove the deposition of Al2O3 also AFM test showed very flat films with 1.2 nm RMS were fabricated. The results of tests ensured the ability of the ALD to deposit films

An analysis of the time and activity of two pediatric head nurses at Boston Floating Hospital.

Thesis (M.S.)--Boston Universit

Earnings Management to Avoid Earnings Boosts

Acknowledgements The authors are thankful to Professor Frank Hong Liu for suggestions that improved the original draft of the article. The authors also appreciate the comments by two anonymous reviewers.Peer reviewedPostprin

Decentralized Control of Uncertain Multi-Agent Systems with Connectivity Maintenance and Collision Avoidance

This paper addresses the problem of navigation control of a general class of uncertain nonlinear multi-agent systems in a bounded workspace of $\mathbb{R}^n$ with static obstacles. In particular, we propose a decentralized control protocol such that each agent reaches a predefined position at the workspace, while using only local information based on a limited sensing radius. The proposed scheme guarantees that the initially connected agents remain always connected. In addition, by introducing certain distance constraints, we guarantee inter-agent collision avoidance, as well as, collision avoidance with the obstacles and the boundary of the workspace. The proposed controllers employ a class of Decentralized Nonlinear Model Predictive Controllers (DNMPC) under the presence of disturbances and uncertainties. Finally, simulation results verify the validity of the proposed framework.Comment: IEEE European Control Conference (ECC), Limassol, Cyprus, June 201

Dynamic Localizations in Structural Steel at High Strain Rates and Temperatures – COMPLAS XI

The proposed paper presents a numerical study on the formation of shear bands at localized regions in two ferrite steel alloys, HSLA-65 and DH-36, subjected to certain range of velocity impact. Constitutive relations developed by the author [1] for ferritic steels is utilized in simulating the thermal and athermal parts of the flow stress over a wide range of temperatures and strain rates. The proposed plasticity model is implemented into the commercially well-known finite element software ABAQUS through VUMAT user subroutine. This implementation enables studying the shear band formation over a wide range of initial temperatures and strain rates in a cylindrical hat-shaped specimen with certain dimensions where the location of shear localization preceding shear band formation is forced to be between the hat and the brim. Sensitivity analysis is performed on different mesh configurations in order to select the optimum mesh. Another sensitivity analysis is also performed on the constitutive plasticity model material parameters to study their effect on the shear bands formation. Several conclusions related to the width of the shear bands considering the velocity load and initial temperatures will be discussed throughout this work

Earnings management in the aftermath of the zero-earnings discontinuity disappearance

The authors are thankful to the participants and discussants at the British Accounting and Finance Association Annual Conference 2016 at University of Bath and the BAFA Scottish Area Group Conference 2016 at University of Strathclyde for constructive comments. The authors also appreciate the useful comments by two anonymous reviewers on the early version of this paper.Peer reviewedPostprin

Endotracheal Intubation of COVID-19 Patients

The novel coronavirus (COVID-19) emerged for the first time in China and then rapidly spread and swept the entire world like a tornado killing thousands of patients around the planet. People were advised to stay in-doors to prevent the spread of this deadly disease, and this slogan helped to a greater extent in containing the spread of the virus. Unfortunately, there is no treatment for the disease at present, but extensive research is going on to find a definitive treatment. Regarding endotracheal intubation (ETI) of COVID-19 patients, data are scarce and no randomized clinical trials are available to develop and formulate succinct and acceptable guidelines in tackling the problem of ETI in these highly risky and vulnerable patients