Statistical analysis and comparison of 2T and 3T1D e-DRAM minimum energy operation

Bio-medical wearable devices restricted to their small-capacity embedded-battery require energy-efficiency of the highest order. However, minimum-energy point (MEP) at sub-threshold voltages is unattainable with SRAM memory, which fails to hold below 0.3V because of its vanishing noise margins. This paper examines the minimum-energy operation point of 2T and 3T1D e-DRAM gain cells at the 32-nm technology node with different design points: up-sizing transistors, using high- V th transistors, read/write wordline assists; as well as operating conditions (i.e., temperature). First, the e-DRAM cells are evaluated without considering any process variations. Then, a full-factorial statistical analysis of e-DRAM cells is performed in the presence of threshold voltage variations and the effect of upsizing on mean MEP is reported. Finally, it is shown that the product of the read and write lengths provides a knob to tradeoff energy-efficiency for reliable MEP energy operation.Peer ReviewedPostprint (author's final draft

The public investment rule in a simple endogenous endogenous growth model with public capital: active or pasive?

In dynamic settings with public capital, it is common to assume that the government claims a constant fraction of public investment to total output each period, which is clearly a restrictive assumption. The goal of the paper is twofold: first, to find out a more reasonable rule for public investment, consistent with US data, than the constant-ratio rule; second, to analyze the impact of that rule on welfare and judge the public investment downsizing process held in US since the end of the sixties. Calibrating for US, the model simulation captures the public investment downsizing process held during 1960-2001, as well as the post-1970 slowdown in private factors productivity. Downsizing would be optimal whenever the public capital elasticity is approximately smaller than 0.09, a lower level than the general consensus in the literature. Thus, it is more likely that our result be consistent to Aschauer (1989) and Munnell (1990), which put forth that policymakers would have reduced the stock of public capital below its optimum level along this time.Public investment rule, Policy coordination, Transitional dynamics, Endogenous growth, Public capital elasticity

Enforcement of Employment Protection and the hiring behaviour of firms. Evidence from a large Italian region.

This paper investigates the effect of the Employment Protection Legislation (EPL) on the hiring behaviour of the firms when the level of EPL is differentiated by firms size. In this respect, Italy represents an interesting case because workers hired by bigger firms enjoy a stronger protection than workers hired by small firms; the threshold size is fixed by law at 15 employees. A model derives the conditions under which firms decide whether to upsize or not and, in case of upsizing, whether to hire temporary (i.e. workers who are not counted in the threshold, as apprentices in Italy) or permanent workers. The model has been tested using data drawn from the VWH (Veneto Workers History) registered data for firms and workers, from 1982 to 1997, for a large Italian region (i.e. Veneto). Firms close to the threshold are not scared to growth but they are more likely to hire apprentices than permanent workers.Employment Protection, Hiring, Random Effects, Regression Discontinuity Design.

Family Management, Family Ownership and Downsizing: Evidence from S&P 500 Firms

Little is known about the relationship between family firms and their employees. This paper aims to close this gap. We distinguish between family management and family ownership as two dimensions of family firms and analyze their respective influence on downsizing. Our findings show that family management decreases the likelihood of downsizing, whereas the extent of family ownership decreases the likelihood of downsizing only with regard to deep job cuts (above 6%). We conclude that family managers have a strong long-term perspective, which is in line with both agency and stewardship theory. Yet, the idea that reputation concerns lead family owners to shy away from downsizing is only partially supported.Family firms, family management, family ownership, job cuts, downsizing; layoffs

Job Creation by Firms in Denmark

In this paper we will look at job creation and destruction in firms. We will answer the question if it is the large companies that create jobs, while the smaller companies are contributing much less. Or is it the young companies that create jobs? And who destroys the most jobs? In the crisis Denmark lost 186,000 jobs in the private sector. The question is where and how could these jobs be recreated. Are these issues specific to industries or are they universal? The data used is register data on workplaces and firms for the period 1980-2007. The base unit of data is the workplace. The company (firm) is the legal entity. A company can have many sites, and one of the ways companies can grow is by expanding with multiple sites. This can happen by mergers and acquisitions but can also happen by creating "daughter workplaces". It is therefore essential to look at workplaces and firms at the same time. A complication here is that firms switch ID over time because of change of ownership, mergers and divisions. Data must be corrected so that these administrative issues will not affect the survival of firms. The data are used in a way where we can cover firm birth and firm death, spin-offs and mergers. The analysis will make it possible to differentiate between net and gross creation of jobs because we can follow each single individual in and out of jobs. We have for Denmark found that size on its own does not have a big impact, but young firms are much more likely to contribute to a positive growth. For the U.S. it has been found that the growth in jobs comes from small businesses. A closer analysis though shows that the main factor here is the firm age. Thus, it is found that young firms net create the most jobs, but they are also responsible for the most job destructions.job creation, job destruction, firm age, firm size, education, employer-employee data

On the mass assembly of low-mass galaxies in hydrodynamical simulations of structure formation

Cosmological hydrodynamical simulations are studied in order to analyse generic trends for the stellar, baryonic and halo mass assembly of low-mass galaxies (M_* < 3 x 10^10 M_sun) as a function of their present halo mass, in the context of the Lambda-CDM scenario and common subgrid physics schemes. We obtain that smaller galaxies exhibit higher specific star formation rates and higher gas fractions. Although these trends are in rough agreement with observations, the absolute values of these quantities tend to be lower than observed ones since z~2. The simulated galaxy stellar mass fraction increases with halo mass, consistently with semi-empirical inferences. However, the predicted correlation between them shows negligible variations up to high z, while these inferences seem to indicate some evolution. The hot gas mass in z=0 halos is higher than the central galaxy mass by a factor of ~1-1.5 and this factor increases up to ~5-7 at z~2 for the smallest galaxies. The stellar, baryonic and halo evolutionary tracks of simulated galaxies show that smaller galaxies tend to delay their baryonic and stellar mass assembly with respect to the halo one. The Supernova feedback treatment included in this model plays a key role on this behaviour albeit the trend is still weaker than the one inferred from observations. At z>2, the overall properties of simulated galaxies are not in large disagreement with those derived from observations.Comment: 19 pages, 12 figures. Accepted for publication in MNRAS: 6th August 2013. First submitted: 7th July 201