Betriebliche Determinanten formeller und informeller Weiterbildung im Vergleich

Der Beitrag behandelt die Frage, ob sich betriebliche Determinanten informeller Weiterbildung von denen formalisierter Weiterbildung unterscheiden. Grundlage ist eine Befragung von über 1.700 Betrieben. Empirisch zeigt sich auf der Grundlage von ordered-logit-Schätzungen, dass (1) viele der betrachteten Faktoren, die einen signifikanten Einfluss auf formelle betriebliche Weiterbildung haben, auch einen signifikanten Einfluss auf informelle Weiterbildung ausüben; markante Ausnahme sind Merkmale der Arbeitsorganisation, die oft mit informellen Lernformen, aber nicht mit formellen Lernformen zusammenhängen, und dass (2) jene Faktoren, die sowohl für die formelle als auch die informelle Weiterbildung signifikant sind, in der gleichen Richtung wirken. Informelles Lernen wird von den Betrieben nicht deshalb genutzt, weil sie darin eine günstige Alternative zur formellen Weiterbildung sehen. Beide Formen der Weiterbildung sollten vielmehr als Komplemente betrachtet werden.Our paper concerns whether the organizational determinants of formal further training are different from those of informal further training. The study is based on a survey of more than 1,700 firms. Empirically, it can be shown on the basis of ordered-logit-estimations that firstly many of the factors that have a significant effect on formal further training also exert a significant influence on informal further training; important exceptions being the characteristics of work organization which are often related to informal but not to formal further training. Secondly, those factors which have a significant effect on formal as well as on informal further training act in the same direction. Firms do not use informal further training as a cheap alternative to formal learning. Both forms of training should rather be understood as complements

Modulational Instability in Equations of KdV Type

It is a matter of experience that nonlinear waves in dispersive media, propagating primarily in one direction, may appear periodic in small space and time scales, but their characteristics --- amplitude, phase, wave number, etc. --- slowly vary in large space and time scales. In the 1970's, Whitham developed an asymptotic (WKB) method to study the effects of small "modulations" on nonlinear periodic wave trains. Since then, there has been a great deal of work aiming at rigorously justifying the predictions from Whitham's formal theory. We discuss recent advances in the mathematical understanding of the dynamics, in particular, the instability of slowly modulated wave trains for nonlinear dispersive equations of KdV type.Comment: 40 pages. To appear in upcoming title in Lecture Notes in Physic

Making Password Authenticated Key Exchange Suitable For Resource-Constrained Industrial Control Devices

Connectivity becomes increasingly important also for small embedded systems such as typically found in industrial control installations. More and more use-cases require secure remote user access increasingly incorporating handheld based human machine interfaces, using wireless links such as Bluetooth. Correspondingly secure operator authentication becomes of utmost importance. Unfortunately, often passwords with all their well-known pitfalls remain the only practical mechanism. We present an assessment of the security requirements for the industrial setting, illustrating that offline attacks on passwords-based authentication protocols should be considered a significant threat. Correspondingly use of a Password Authenticated Key Exchange protocol becomes desirable. We review the signif-icant challenges faced for implementations on resource-constrained devices. We explore the design space and shown how we succeeded in tailoring a partic-ular variant of the Password Authenticated Connection Establishment (PACE) protocol, such that acceptable user interface responsiveness was reached even for the constrained setting of an ARM Cortex-M0+ based Bluetooth low-energy transceiver running from a power budget of 1.5 mW without notable energy buffers for covering power peak transients

Hyper-precarious lives : Migrants, work and forced labour in the Global North

This paper unpacks the contested inter-connections between neoliberal work and welfare regimes, asylum and immigration controls, and the exploitation of migrant workers. The concept of precarity is explored as a way of understanding intensifying and insecure post-Fordist work in late capitalism. Migrants are centrally implicated in highly precarious work experiences at the bottom end of labour markets in Global North countries, including becoming trapped in forced labour. Building on existing research on the working experiences of migrants in the Global North, the main part of the article considers three questions. First, what is precarity and how does the concept relate to working lives? Second, how might we understand the causes of extreme forms of migrant labour exploitation in precarious lifeworlds? Third, how can we adequately theorize these particular experiences using the conceptual tools of forced labour, slavery, unfreedom and precarity? We use the concept of ‘hyper-precarity’ alongside notions of a ‘continuum of unfreedom’ as a way of furthering human geographical inquiry into the intersections between various terrains of social action and conceptual debate concerning migrants’ precarious working experiences

FourQ on Embedded Devices with Strong Countermeasures Against Side-Channel Attacks

This work deals with the energy-efficient, high-speed and high-security implementation of elliptic curve scalar multiplication, elliptic curve Diffie-Hellman (ECDH) key exchange and elliptic curve digital signatures on embedded devices using FourQ and incorporating strong countermeasures to thwart a wide variety of side-channel attacks. First, we set new speed records for constant-time curve-based scalar multiplication, DH key exchange and digital signatures at the 128-bit security level with implementations targeting 8, 16 and 32-bit microcontrollers. For example, our software computes a static ECDH shared secret in 6.9 million cycles (or 0.86 seconds @8MHz) on a low-power 8-bit AVR microcontroller which, compared to the fastest Curve25519 and genus-2 Kummer implementations on the same platform, offers 2x and 1.4x speedups, respectively. Similarly, it computes the same operation in 496 thousand cycles on a 32-bit ARM Cortex-M4 microcontroller, achieving a factor-2.9 speedup when compared to the fastest Curve25519 implementation targeting the same platform. A similar speed performance is observed in the case of digital signatures. Second, we engineer a set of side-channel countermeasures taking advantage of FourQ\u27s rich arithmetic and propose a secure implementation that offers protection against a wide range of sophisticated side-channel attacks, including differential power analysis (DPA). Despite the use of strong countermeasures, the experimental results show that our FourQ software is still efficient enough to outperform implementations of Curve25519 that only protect against timing attacks. Finally, we perform a differential power analysis evaluation of our software running on an ARM Cortex-M4, and report that no leakage was detected with up to 10 million traces. These results demonstrate the potential of deploying FourQ on low-power applications such as protocols for the Internet of Things

What determines the motivation for further training? Results from a factorial survey among jobseekers

Publically sponsored further trainings for the unemployed are an important measure of active labour market policies (ALMP) in Germany. Current discussions within this context also focus on the willingness to participate, which is an important prerequisite for the success of the programs. Financial incentives may foster both participation and successful completion, thereby reducing opportunity costs of these measures. We investigate the question what factors determine the motivation to participate by conducting a CATI survey among around 4000 unemployed persons from the unemployment insurance system (Social Code III) and the means-tested basic income support system for needy recipients (Social Code II). We use a factorial survey - also known as vignette analysis - in combination with administrative data of the Federal Employment Agency (FEA), the latter providing detailed information about the individual labour market history. Multivariate analyses suggest that a program's duration, monthly bonus payments in addition to regular unemployment benefits, future job prospects and gratifications for successful completion influence the probability of participation mostly in the theoretically expected way