Selection-Based Learning: The Coevolution Of Internal And External Selection In High-Velocity Environments

To understand the effects of selection on firm-level learning, this study synthesizes two contrasting views of evolution. Internal selection theorists view managers in multiproduct firms as the primary agents of evolutionary change because they decide whether individual products and technologies are retained or eliminated. In contrast, external selection theorists contend that the environment drives evolution because it determines whether entire firms live or die. Though these theories differ, they describe tightly interwoven processes. In assessing the coevolution of internal and external selection among personal computer manufacturers across a 20-year period, we found that (1) firms learned cumulatively and adaptively from internal and partial external selection, the latter occurring when the environment killed part but not all of a firm; (2) internal and partial external selection coevolved, as each affected the other's future rate and the odds of firm failure; (3) partial external selection had a greater effect on future outcomes than internal selection; and (4) the lessons gleaned from prior selection were reflected in a firm's ability to develop new products, making that an important mediator between past and future selection events.Managemen

Premise Selection and External Provers for HOL4

Learning-assisted automated reasoning has recently gained popularity among the users of Isabelle/HOL, HOL Light, and Mizar. In this paper, we present an add-on to the HOL4 proof assistant and an adaptation of the HOLyHammer system that provides machine learning-based premise selection and automated reasoning also for HOL4. We efficiently record the HOL4 dependencies and extract features from the theorem statements, which form a basis for premise selection. HOLyHammer transforms the HOL4 statements in the various TPTP-ATP proof formats, which are then processed by the ATPs. We discuss the different evaluation settings: ATPs, accessible lemmas, and premise numbers. We measure the performance of HOLyHammer on the HOL4 standard library. The results are combined accordingly and compared with the HOL Light experiments, showing a comparably high quality of predictions. The system directly benefits HOL4 users by automatically finding proofs dependencies that can be reconstructed by Metis

Basel II, External Ratings and Adverse Selection

This paper will describe and analyse the development of Basel II Capital Accord and will focus on the use of external ratings in the Standardized Approach in Basel II. Furthermore it will examine the problem of adverse selection which appears in Basel II as a result from the proposal for the use of external ratings in determining the risk weights in the standardized approach. The paper will also attempt to find possible solutions to the adverse selection problem by discussing two similar models, and derive implications from them.Basel II, external ratings, adverse selection, rating agencies, standardized approach

Cost of External Finance and Selection into Entrepreneurship

This paper examines the extent to which the positive relationship between personal wealth and entry into entrepreneurship is due to financing constraints. I exploit a tax reform and use unique micro-data from Denmark to study how exogenous changes in the cost of external finance shape both the probability of entering entrepreneurship and the characteristics of those who become entrepreneurs. As expected, differences-in-differences estimates show that the entry rates for individuals who faced an increase in the cost of finance fell by 40% relative to those whose cost of external finance was unchanged. However, while some of the fall in entry was due to less wealthy individuals with high human capital (confirming the presence of financing constraints), the greatest relative decline in entry came from individuals with lower human capital, many of whom were above median wealth. This finding suggests that an important part of the positive relationship between personal wealth and entrepreneurship may be driven by the fact that wealthy individuals with lower ability can start new businesses because they are less likely to face the disciplining effect of external finance.financing constraints, entrepreneurship, entry.

Interference-filter-stabilized external-cavity diode lasers

We have developed external-cavity diode lasers, where the wavelength selection is assured by a low loss interference filter instead of the common diffraction grating. The filter allows a linear cavity design reducing the sensitivity of the wavelength and the external cavity feedback against misalignment. By separating the feedback and wavelength selection functions, both can be optimized independently leading to an increased tunability of the laser. The design is employed for the generation of laser light at 698, 780 and 852 nm. Its characteristics make it a well suited candidate for space-born lasers.Comment: 12 pages, 5 figure

DO EXTERNAL FUNDS YIELD LOWER RETURNS ? RECENT EVIDENCE FROM EAST ASIAN ECONOMIES

Using a large firm level panel data set from four Asian countries, this paper compares the returns to various internal and external funds. A novel feature of our analysis is that we distinguish between financially constrained and unconstrained firms and determine selectivity-corrected estimates of rates of return to internal and external funds in markets characterised by information problems. Results derived from a unique random effects panel data model with selection and unobserved heterogeneity suggest evidence of significant misallocation, especially in external financing of investment. While these results contrast some of the existing results, they seem to complement the moral hazard arguments put forward by the macro literature on the recent Asian crisis.Efficiency, Misallocation of capital, Returns to internal and external funds, Debt and equity, Financial constraint, Random effects model with selection

Selection of sampling rate for digital control of aircrafts

The considerations in selecting the sample rates for digital control of aircrafts are identified and evaluated using the optimal discrete method. A high performance aircraft model which includes a bending mode and wind gusts was studied. The following factors which influence the selection of the sampling rates were identified: (1) the time and roughness response to control inputs; (2) the response to external disturbances; and (3) the sensitivity to variations of parameters. It was found that the time response to a control input and the response to external disturbances limit the selection of the sampling rate. The optimal discrete regulator, the steady state Kalman filter, and the mean response to external disturbances are calculated

How Do Young Innovative Companies Innovate?

This paper discusses the determinants of product innovation in young innovative companies (YICs) by looking at in-house and external R&D and at the acquisition of external technology in embodied and disembodied components. These input-output relationships are tested on a sample of innovative Italian firms. A sample-selection approach is applied. Results show that in-house R&D is linked to the propensity to introduce product innovation both in mature firms and YICs; however, innovation intensity in the YICs is mainly dependent on embodied technical change from external sources, while − in contrast with the incumbent firms − in-house R&D does not play a significant role.R&D, product innovation, embodied technical change, CIS 3, sample selection