Power Explorer – a casual game style for encouraging long term behavior change among teenagers

When it comes to motivating teenagers towards energy awareness, new approaches need to be considered. One such is the use of pervasive games connected to the players own energy consumption. Earlier work has confirmed this to be a highly effective approach. The question however remains if post game effects on behavior can be achieved. In this paper we try to answer this by trying out a slightly different design compared to previous work. The hypothesis is that a more casual game play and a richer learning interaction enabled by building the game on a real time sensor system could stimulate more lasting effects. Electric consumption data after the 7 days evaluation on a test group of 15 players shows tentative indications for a persistent post game effect compared to the control group of 20 households. Findings also show a statistically significant positive change in the players’ attitude towards saving energy compared to the same group. Findings, at the same time, also indicate a negative effect on the player’s attitude toward environmental questions in general

The Undercut Criterion of Pinion Shaper Cutters: And an Improvement by Modifying the Basic Rack Profile

The fillet of the gear tooth is highly stressed in operation; so for heavily loaded gears, the fillet geometry must be controlled. The manufacturer's task is to, within acceptable tolerances, produce the gear to the designer's specifications regardless of the manufacturing method. Most often gear cutting tools are used that work under generating conditions. The tool will form the gear tooth; so to produce the specified gear geometry and, especially, the fillet geometry, this tool must be conjugated to the same basic rack as the gear to cut. However, this gives a risk that the tooth tip of the tool will be undercut, and if this occurs the tool will not cut the intended gear fillet. In this report, novel analytical equations are derived, which predict the limit when the tool tip will be undercut. It is shown that if the gear tooth should be conjugated to the standard basic rack with a circular fillet, which is the normal case, very large tool-tooth numbers are needed for pinion shaper cutters and gear skiving cutters to avoid this type of undercut. However, the minimum tooth number to achieve a smooth continuous tool-tooth profile is reduced by modifications to the fillet of the basic rack profile

On the Machining of Involute Helical Gears - Prediction models on tool geometry, cut gear tooth surface topography, chip geometry, and tool cutting forces

The modern requirements on power transmissions focus on energy efficiency, low noise and dynamic vibrations, and power density. In order to meet these requirements, the gear wheels must be manufactured to very high precision. Additionally, it should be economical to manufacture these gears within the tight requested tolerances. Gears manufactured within automotive, truck, and construction equipment are usually cut using milling tools. The profile accuracy and the surface roughness achieved after manufacturing, which determines the gear quality, are connected to the process parameters and possible manufacturing related errors. Prediction models to accurately determine gear quality, where tool and process related errors are taken into account, are needed in order to improve the manufacturing process. Tool life has also a strong economic impact in machining operations. Tool life prediction is an important part in optimization of the machining processes, where tool life is strongly connected the cutting forces and the geometry of the cut chips. In this work mathematical models are established in parametric form, based on analytical differential description. These models are developed in order to increase knowledge and understanding of the complex machining processes involved in gear manufacturing. Focus is on the cut gear tooth surface quality, and on milling related topics, such as cut chip geometry, tool cutting forces, and tool wear prediction. The mathematical models are used in a number of experimental studies presented in this thesis. The experimental studies were performed in industrial conditions, where tool and process related errors that are common in industrial applications have been considered. The correlation is very good, which shows the industrial applicability of the presented models

Avskaffandet av revisionsplikten - Hur stora blir förändringarna?

Syftet med uppsatsen är att undersöka vilken påverkan ett eventuellt avskaffande av revisionsplikten kommer att innebära för revisionsbyråer, redovisningsbyråer, banker, Skatteverket och även till viss del ur företagens synvinkel. För att uppnå vårt syfte har vi valt att göra personliga intervjuer av semistrukturerad karaktär med revisorer, redovisningskonsulter, banker, SME och Skatteverket. Vi har under studiens gång inspirerats av grounded theory och vi har även tagit del av både litteratur och debattartiklar inom området. I teoriavsnittet har vi presenterat revisorns uppgifter samt revisionens betydelse. Vi har även presenterat revisionsplikten och hur ett avskaffande skulle kunna påverka olika intressenter. Genom vår studie har vi kommit fram till att värdet av revisionen är enkelt att fastställa medan åsikterna kring revisionsplikten går isär. I framtiden kommer ett ökat antal specialister att ha rådgivande roller där kompetens och närhet till klienten blir den primära nyckeln till framgång

Towards a Positioning Model for Evaluating the Use and Design of Anti-Disinformation Tools

With the increasing amounts of mis- and disinformation circulating online, the demand for tools to combat and contain the phenomenon has also increased. The multifaceted nature of the phenomenon requires a set of tools that can respond effectively, and can deal with the different ways in which disinformation can present itself, In this paper, after consulting independent fact-checkers to create a list, we map the landscape of tools available to combat different typologies of mis and disinformation on the basis of three levels of analysis: the employment of policy-regulated strategies, the use of co-creation, and the preference for manual or automated processes of detection. We then create a model in which we position the different tools across three axes of analysis, and show how the tools distribute across different market positions

Tooth Deviations of an Involute Helical Gear Manufactured in a Simulated Hobbing Process with Introduced Errors

External involute helical gears are usually manufactured through hobbing, commonly with a subsequent grinding or skiving operation. One way towards the industrial pursuit of more competitive and sustainable manufacturing is to reduce the number of processes, while retaining functionality and quality. In the hobbing of gears, the manufacturing errors are most often connected to the tool and/or the fixture. These errors need to be kept within tight tolerances to achieve sufficient quality of a finished hobbed gear. It would therefore be of great interest to be able to predetermine the quality of a finished hobbed gear, based on tolerances of the manufacturing process. Thereby the motivation is to analyze the impact of these errors, on the tooth surface of a hobbed gear. In this paper the manufacturing process is simulated, using an analytical geometric mathematical model, to determine the geometry of the hobbed gear tooth flank in three dimensions. Various errors, linked to the manufacturing process, are introduced in the software implementation of the mathematical model. An experimental study was performed, with errors of same type and magnitude, to validate the simulation results. The simulation model allows determining the geometry and the quality of the gear tooth, prior to manufacturing, at any section over both profile and helix

The Influence of Tool Tolerances on the Gear Quality of a Gear Manufactured by an Indexable Insert Hob

Advances in gear hobbing are driven to give higher cutting speeds, longer tool life and higher feed rates. Recently, a new type of hob with carbide inserts has been introduced with benefits in all these conditions compared to regrindable high speed steel hobs. However, with this kind of hob, new challenges occur due to positional errors of the cutting edges when mounted on the tool. These errors introduce manufacturing errors on the gear teeth which have to be controlled. In this paper, the tooth quality of a gear manufactured by hobs with different quality classes is analysed using a simulation model in combination with Monte-Carlo methods. A statistical analysis of a commercial hob provides input to the Monte-Carlo model, where the axial and the radial deviations of these inserts are considered. Simulations are performed with different hob quality classes according to DIN 3968. The results from simulation are compared with experimental results of this actual hob at a gear manufacturer