Combining technology and work organization : an analysis of complementarity between IT and decentralization across firms of different size

This paper examines whether information technology (IT) and decentralized work organization are complementary only for large firms or also for smaller firms. Empirical evidence, which suggests complementarity between IT and decentralization, is mainly based on large firms. Using data from a sample of 3292 SMEs and of 598 larger firms from the manufacturing and service sector in Germany, I can observe firms’ IT intensity in terms of enterprise software and computer use and whether firms have a decentralized work organization. I find that SMEs with decentralized work practices tend to use IT more intensively. Moreover, for the sample of SMEs, IT and decentralized work organization are individually associated with higher productivity but the combination of IT and decentralization does not yield a productivity premium. Contrarily, for the sample of larger firms, the results show that the productivity of IT depends positively on decentralization. The findings suggest that combining IT and decentralized work organization seems to be a successful strategy only for larger firms

An Evaluation of Computer Aided Learning (BRAC-CAL) in Secondary Schools in Bangladesh.

BRAC initiated Computer Aided Learning (CAL) programme, the first ever in Bangladesh, to introduce ICT based materials in teaching-learning in 2004 Along with digital contents of Science, English and mathematics of secondary level, this programme provided basic ICT and content delivery training to the teachers of programme schools. A qualitative evaluation following the Realist Evaluation framework was designed to evaluate the programme mechanism, context and outcome. Data were collected from six secondary schools selected purposively. Findings showed that both teachers and students enjoyed the CAL materials and also believed that those materials had changed classroom scenario by improving learners’ attention and participation in classroom activities. However, significant difference was not observed between CAL and non-CAL classrooms. Teachers struggled to organise collaborative learning tasks such as group and pair works. Students also had limited participation in teaching-learning process. Irregular electricity supply sometimes hampered use of CAL materials. Furthermore, students had limited access to these materials. Bearing this context the recommendations were to focus more on teachers’ pedagogic improvement and to create more scopes for students’ self use of these materials

Light shifts in atomic Bragg diffraction

Bragg diffraction of an atomic wave packet in a retroreflective geometry with two counterpropagating optical lattices exhibits a light shift induced phase. We show that the temporal shape of the light pulse determines the behavior of this phase shift: In contrast to Raman diffraction, Bragg diffraction with Gaussian pulses leads to a significant suppression of the intrinsic phase shift due to a scaling with the third power of the inverse Doppler frequency. However, for box-shaped laser pulses, the corresponding shift is twice as large as for Raman diffraction. Our results are based on approximate, but analytical expressions as well as a numerical integration of the corresponding Schr\"odinger equation.Comment: 6 pages, 5 figure

Double Bragg diffraction: A tool for atom optics

The use of retro-reflection in light-pulse atom interferometry under microgravity conditions naturally leads to a double-diffraction scheme. The two pairs of counterpropagating beams induce simultaneously transitions with opposite momentum transfer that, when acting on atoms initially at rest, give rise to symmetric interferometer configurations where the total momentum transfer is automatically doubled and where a number of noise sources and systematic effects cancel out. Here we extend earlier implementations for Raman transitions to the case of Bragg diffraction. In contrast with the single-diffraction case, the existence of additional off-resonant transitions between resonantly connected states precludes the use of the adiabatic elimination technique. Nevertheless, we have been able to obtain analytic results even beyond the deep Bragg regime by employing the so-called "method of averaging," which can be applied to more general situations of this kind. Our results have been validated by comparison to numerical solutions of the basic equations describing the double-diffraction process.Comment: 26 pages, 20 figures; minor changes to match the published versio

ICT and global sourcing - evidence for German manufacturing and service firms

This paper analyses the relevance of information and communication technologies (ICT) for firms’ robability of global sourcing of inputs. Using firm-level data from Germany in 2009, which include mainly small and medium-sized firms, the empirical analysis differentiates between the manufacturing and service firms. The results show some differences between the manufacturing and service sector. Controlling for various sources of firm heterogeneity, the global sourcing probability is increasing in the firms’ share of employees with Internet access in the manufacturing sector. E-commerceintensive firms are more likely to source inputs from abroad but generally, this relationship between e-commerce and global sourcing is only robust in services and much stronger there than in manufacturing. In both sectors, it is strongest in industries with higher upstream industry diversity. Moreover, labour productivity is positively linked to global sourcing. The findings support arguments for the importance of the Internet for global trade and they confirm the productivity advantage of importing in comparison to non-importing firms that is stated in the literature

Trade and technology: new evidence on the productivity sorting of firms

Using a unique German firm-level data set, we provide empirical evidence for a productivity sorting along two dimensions: international activity and technology choice. We consider domestic and exporting firms and measure technology choice by firms’ actual use of advanced information technology (IT). For manufacturing firms, the observed sorting pattern is consistent with recent theories of heterogeneous firms and technology choice: Only the relatively more productive ones among internationally active firms are also highly technology intensive. For service sector firms we find similar evidence, yet the results seem to depend on the trade cost of certain services. In general, recent theoretical advances regarding trade and technology adoption thus seem to better fit the manufacturing sector

Regimes of atomic diffraction: Raman versus Bragg diffraction in retroreflective geometries

We provide a comprehensive study of atomic Raman and Bragg diffraction when coupling to a pair of counterpropagating light gratings (double diffraction) or to a single one (single diffraction) and discuss the transition from one case to the other in a retroreflective geometry as the Doppler detuning changes. In contrast to single diffraction, double Raman loses its advantage of high diffraction efficiency for short pulses and has to be performed in a Bragg-type regime. Moreover, the structure of double diffraction leads to further limitations for broad momentum distributions on the efficiency of mirror pulses, making the use of (ultra) cold ensembles essential for high diffraction efficiency.Comment: 16 pages, 14 figure

A compact dual atom interferometer gyroscope based on laser-cooled rubidium

We present a compact and transportable inertial sensor for precision sensing of rotations and accelerations. The sensor consists of a dual Mach-Zehnder-type atom interferometer operated with laser-cooled $^{87}$Rb. Raman processes are employed to coherently manipulate the matter waves. We describe and characterize the experimental apparatus. A method for passing from a compact geometry to an extended interferometer with three independent atom-light interaction zones is proposed and investigated. The extended geometry will enhance the sensitivity by more than two orders of magnitude which is necessary to achieve sensitivities better than $10^{-8}$rad/s/$\sqrt{\rm Hz}$.Comment: 9 pages, 8 figure