Hiring Costs of Skilled Workers and the Supply of Firm-Provided Training

This paper analyzes how the costs of hiring skilled workers from the external labor market affect a firm's supply of training. Using administrative survey data with detailed information on hiring and training costs for Swiss firms, we find evidence for substantial and increasing marginal hiring costs. However, firms can invest in internal training of unskilled workers and thereby avoid costs for external hiring. Controlling for a firm's training investment, we find that a one standard deviation increase in average external hiring costs increases the number of internal training positions by 0.7 standard deviations.hiring costs, apprenticeship training, firm-sponsored training

Online monitoring of coffee roasting by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS): towards a real-time process control for a consistent roast profile

A real-time automated process control tool for coffee roasting is presented to consistently and accurately achieve a targeted roast degree. It is based on the online monitoring of volatile organic compounds (VOC) in the off-gas of a drum roaster by proton transfer reaction time-of-flight mass spectrometry at a high time (1Hz) and mass resolution (5,500m/Δm at full width at half-maximum) and high sensitivity (better than parts per billion by volume). Forty-two roasting experiments were performed with the drum roaster being operated either on a low, medium or high hot-air inlet temperature (= energy input) and the coffee (Arabica from Antigua, Guatemala) being roasted to low, medium or dark roast degrees. A principal component analysis (PCA) discriminated, for each one of the three hot-air inlet temperatures, the roast degree with a resolution of better than ±1 Colorette. The 3D space of the three first principal components was defined based on 23 mass spectral profiles of VOCs and their roast degree at the end point of roasting. This provided a very detailed picture of the evolution of the roasting process and allowed establishment of a predictive model that projects the online-monitored VOC profile of the roaster off-gas in real time onto the PCA space defined by the calibration process and, ultimately, to control the coffee roasting process so as to achieve a target roast degree and a consistent roasting. Figure Online monitoring of coffee roasting by real-time analysis of the roaster off-gas using PTR-ToF-MS. In a first phase, 42 calibration experiments were conducted at three different roasting temperatures and to three final roast degrees, to generate the 3D space defined by the three first principle components PC1, PC2 and PC3. Inverted triangles mark the dark roast degree, square medium and circle light, respectively. The hot-air inlet temperature is marked as follows: high (black), medium (grey), low (white). The different hot-air inlet temperatures and roast degrees are clearly separated. In a second phase, an online monitored PTR-ToF-MS spectrum of a roasting process was projected onto the 3D space, allowing following in real-time the roasting process and halting the roasting with a precision better that ± 1 Colorette roast degre

Antioxidant generation during coffee roasting : a comparison and interpretation from three complementary assays

Coffee is a major source of dietary antioxidants; some are present in the green bean, whereas others are generated during roasting. However, there is no single accepted analytical method for their routine determination. This paper describes the adaption of three complementary assays (Folin-Ciocalteu (FC), ABTS and ORAC) for the routine assessment of antioxidant capacity of beverages, their validation, and use for determining the antioxidant capacities of extracts from coffee beans at different stages in the roasting process. All assays showed a progressive increase in antioxidant capacity during roasting to a light roast state, consistent with the production of melanoidins having a higher antioxidant effect than the degradation of CGAs. However, the three assays gave different numbers for the total antioxidant capacity of green beans relative to gallic acid (GA), although the range of values was much smaller when chlorogenic acid (CGA) was used as reference. Therefore, although all three assays indicated that there was an increase in antioxidant activity during coffee roasting, and the large differences in responses to GA and CGA illustrate their different sensitivities to different types of antioxidant molecule

Modelling the fraction of Lyman Break Galaxies with strong Lyman alpha emission at 5 < z < 7

We present theoretical results for the expected fraction of Lyman Break Galaxies (LBGs) to be detected as strong Lyman alpha emitters (LAEs) in the redshift range 5 < z < 7. We base our analysis on the 2-billion particle SPH simulation MareNostrum High-z Universe. We approximate galaxies as static dusty slabs with an additional clumpy dust distribution affecting stellar populations younger than 25 Myr. The model for the Lyman alpha escape fraction is based on the results of our Monte-Carlo radiative transfer code (CLARA) for a slab configuration. We also fix the transmission of Lyman alpha photons through the intergalactic medium to a constant value of 50% at all redshifts. From the results of this model we calculate xLya, the fraction of Lyman Break Galaxies with Lyman alpha equivalent width (EW) larger than 50 Angstrom. We find a remarkable agreement with observational data at 4.5 < z < 6. For bright (-22 < MUV < -20.5) and faint (-20.5 < MUV < -18.5) galaxies our model predicts xLya = 0.02 \pm 0.01 and xLya = 0.47 \pm 0.01 while observers report xLya = 0.08 \pm 0.02 and xLya = 0.47 \pm 0.16, respectively. Additional evolution of the extinction model at redshift z \sim 7, that decreases the intensity of transmitted Lyman alpha radiation by a factor of f_T = 0.4 as to match the LAE luminosity function at z \sim 6.5, naturally provides a good match for the recently reported xLya fractions at z > 6.3. Exploring different toy models for the Lyman alpha escape fraction, we show that a decreasing Lyman alpha escape fraction with increasing UV galaxy luminosity is a key element in our model to explain the of larger xLya fractions for fainter LBGs.Comment: 7 pages, 3 figures. Accepted for publication in MNRA

Personal trust between hierarchies within Chinese organizational settings

With the fast pace of globalization and knowledge-driven economy, the notion of trust in intra- and/or trans-organizational relations has attracted enormous attention both in academic research and business practices. It has been recognized that trust as a central mechanism within and between organizations plays a crucial role for economic performance. Trust relationship at personal levels is particular important in an environment where the institutional foundations for trust are still underdeveloped. China is commonly regarded as a country with low levels of institution-based trust. As a consequence, the quality of business relations, economic transactions and strategic alliances are strongly dependent on the degree of trust at personal levels. The objective of this study is to contribute to our understanding of trust relationships between hierarchies within Chinese organizational settings. In this paper, we present our empirical research on trust at personal levels carried out in a large Chinese state-owned enterprise. Three hypotheses that characterise the subordinate’s trust in the superior are developed and tested. Based on the statistical evaluations from 1216 samples collected, factors that influence the truster’s propensity to trust are outlined. The determinants for the trustee’s trustworthiness are analysed. In conclusion, we emphasis that further research on trust at personal levels in different enterprises, and trust at organizational levels are needed in order to draw a generalised picture on trust relationships in organizational settings

Potentialanalyse der BEMU-Nachladung mittels Direktstromnutzung aus EEA

Mit der Substitution von dieselbetriebenen Fahrzeugen durch Akkumulator-Triebfahrzeuge (englisch BEMU) wird durch begrenzte Reichweiten je nach Streckenanforderungen zusätzliche Ladeinfrastruktur, zum Beispiel in Form von Oberleitungsinselanlagen (OLIA), erforderlich. In einer vom Deutschen Zentrum für Schienenverkehrsforschung (DZSF) beim Eisenbahn-Bundesamt beauftragten Studie wurde die Direktversorgung von OLIA mit Erneuerbare-Energie-Anlagen mithilfe eines Optimierungsansatzes untersucht. Weiterhin wurden der Leistungsbedarf von BEMU sowie die Leistungsanforderungen des Ladeunterwerks an den Netzanschluss simulationsbasiert anhand von zwei OLIAStandorten analysiert

Hiring costs for skilled workers and the supply of firm-provided training

This article analyses how the costs of hiring skilled workers from the external labour market affect a firm’s supply of training. Using administrative survey data with detailed information on hiring and training costs for Swiss firms, we find evidence for substantial and increasing marginal hiring costs. However, firms can invest in internal training of unskilled workers and thereby avoid costs for external hiring. Controlling for a firm’s training investment, we find that a 1 standard deviation increase in average external hiring costs increases the number of internal training positions by more than half of a standard deviation