Asymmetric Collusion and Merger Policy

In their merger control, EU and the US have considered symmetric size distribution (cost structure) of firms to be a factor potentially leading to collusion. We show that forbidding mergers leading to symmetric market structures can induce mergers leading to asymmetric market structures with higher risk of collusion, when firms face indivisible costs of collusion. In particular, we show that if the rule determining the collusive outcome has the property that the large (efficient) firm benefits sufficiently more from collusion when industry asymmetries increase, collusion can become more likely when firms are moderately asymmetric.Collusion; Cost Asymmetries; Merger Policy

Asymmetric Collusion and Merger Policy

In their merger control, EU and the US have considered symmetric size distribution (cost structure) of firms to be a factor potentially leading to collusion. We show that forbidding mergers leading to symmetric market structures can induce mergers leading to asymmetric market structures with higher risk of collusion, when firms face indivisible costs of collusion. In particular, we show that if the rule determining the collusive outcome has the property that the large (efficient) firm benefits sufficiently more from collusion when industry asymmetries increase, collusion can become more likely when firms are moderately asymmetric.Collusion; Cost Asymmetries; Merger Policy

Inertia Support During Variable Wind Conditions

Wind variations are important to consider while designing inertia support strategies. A model has been evaluated but the findings should reflect issues with several control strategies utilizing a fixed inertia support pattern. Wind variability of 0.5 m/s from second to second is observed in real wind data. However, drastic changes in wind speed can occur within the duration of inertia support. An improved inertia control algorithm has been presented allowing a stable delivery of inertia support from variable speed wind turbines (VSWT) subjected to realistic wind conditions. The controller improves the previously presented inertia algorithm and smoothly transitions from a locked operation window to MPPT-operation. The impact of the utilized wind speed filter is described and its impact on the simulation found to be of great importance

Asymmetric Collusion and Merger Policy

In their merger control, EU and the US have considered symmetric size distribution (cost structure) of rms to be a factor potentially leading to collusion. We show that forbidding mergers leading to symmetric market structures can induce mergers leading to asymmetric market structures with higher risk of collusion, when rms face indivisible costs of collusion. In particular, we show that if the rule determining the collusive outcome has the property that the large (eficient) rm bene ts su¢ ciently more from collusion when industry asymmetries increase, collusion can become more likely when are moderately asymmetric.info:eu-repo/semantics/publishedVersio

Measurements and modelling of three- and five-limb transformer behaviour during large voltage and frequency disturbances

This study presents the modelling of transformers for voltage disturbances. The focus in this study is on the security of the power supply for sensitive loads, for instance, the auxiliary systems for a nuclear power station feeding, for instance, pumps for emergency systems. Both steady-state operation as well as transient conditions have been analysed. A five-limb as well as a three-limb 4 kVA transformer was designed in order to verify theoretical assumptions with experimental results. The results show that the theoretical models provided results in conformity to the actual experiments with an average discrepancy of 3%. Moreover, it is shown that a five-limb transformer gives lower inrush currents, especially in the highly saturated region. In addition, it was demonstrated that an inductive load gives much higher inrush currents compared with a resistive load. A final observation was that the current drawn by the two transformers in their saturated state differ severely depending on the topology of the core

Effekt av torkstress på tillväxt hos annuella ogräs

En minskad herbicidanvändning är önskvärt ur flera aspekter. Bäst effekt på plantan ska fås från appliceringen om denna är i aktiv tillväxt. För att herbicider ska kunna användas framgångsrikt så är en avstannad tillväxt en förutsättning för en lyckad bekämpning. I arbetet har en frågeställning varit om det går att avgöra om växter avstannat i tillväxt, genom att utvärdera en växtfysiologisk metod. I experimentet har mätning av växtens fotosynteskapacitet, som kan mätas med klorofyllfluorescens valts som metod. För att mäta skillnader i tillväxtstatus, så ämnade vi skapa en mätbar förändring genom att ge plantorna olika tillväxtförhållanden. För att begränsa tillväxten och skapa en stress i plantorna valdes vattenstress som miljöfaktor. Plantorna skulle då få optimal-, reducerad- och helt avstannad tillväxt, genom olika tillgång på vatten, mätt från vattenmättnad. En metod har prövats för att undersöka om det går att finna ett samband mellan stress och en minskad fotosynteskapacitet. Till hjälp har en fluorescensmätare av modellen MINI-PAM använts. För att kunna mäta denna kapacitet var växterna först tvungna att utsättas för stress. I arbetet har en litteraturstudie gjorts för att se vilka metoder, som använts för att i försök framkalla torkstress hos växter. Till experimenten valdes sedan att undanhålla plantorna olika mycket vatten för att framkalla stress. Det visade sig dock svårt att få en säkert avstannad tillväxt hos plantorna, då dessa aldrig helt slutade att växa. Mätningarna med fluorescensmätaren kunde endast i ett fall påvisa ett samband mellan god vattentillgång och en högre fotosynteskapacitet och då utan med statistisk signifikans. Samband gick att finna genom att torkstressade plantor visade på lägre biomassa vid slutskörd jämfört med dem som haft full tillgång till näring.A reduced use of herbicides is desirable from several aspects. The best effect on the plant should be obtained from the application if the plant is actively growing. If herbicides are to be used successfully, it is a stunted growth is a prerequisite for successful control. In this work, an issue has been whether it is possible to determine whether plants stalled in growth, by evaluating a plant physiological method. In the experiment, the measurement of the plant's photosynthetic capacity, which can be measured with chlorophyll fluorescence selected as the method. To measure differences in growth status, we wanted to create a measurable change by giving the plants of different growth conditions. To limit growth and create stress in the plants were water-stressed by environmental factors. The plants would then be optimal, reduced or completely stunted growth, through different water availability, as measured by water saturation. A method has been tested to determine if it is possible to find a link between stress and a reduced photosynthetic capacity. To help with a fluorescence meter, MINI-PAM is used. In order to measure this capacity, the plants were first forced to be exposed to stress. A literature study has been done to see which methods used in attempts to induce drought stress in plants. For further experiments were then chosen to withhold the plants different amounts of water to induce stress. It proved difficult to get a safe stunted growth of the plants. The plants never stopped completely to grow. The measurements of fluorescence meter, only in one case showing a correlation between high water and a higher photosynthetic capacity. Without having statistical significance. Correlation could be found by drought stressed plants showed lower biomass at final harvest compared to those who had full access to nutrition

Frequency Response by Wind Farms in Islanded Power Systems with High Wind Power Penetration

The integration of variable speed wind turbines (VSWT) in power systems keep increasing in order to reduce the emission of green house gases. This increase of power electronic converter interfaced generation causes a decrease of power system inertia and issues previously existing in power systems tend to become more complicated and new solutions should be evaluated. This thesis investigates the impacts on frequency stability that can be caused by a decreased inertia in weak power systems. This by firstly investigating the frequency behavior and the roots and causes of the decreasing frequency quality in the Nordic power system (NPS). This by means of phasor measurement units (PMU) from different locations in the NPS. In particular the focus has been on large power imbalances, the rate of change of frequency (ROCOF) and the impact of location of disconnected generation, frequency quality and the evaluation of a new automatic frequency restoration reserve (FRR-A) service that was introduced in the NPS in 2013. Furthermore, the concept of inertia emulation to handle large power imbalances is developed further with the adaptation to handle variable wind. Two strategies of utilize the rotating mass of the VSWT in order to balance 20 and 50 % VSWT instantaneous wind penetration ratios (WPR) in a islanded power system based on a hydro unit. The temporary frequency drop for a wind penetration of 50 % was improved from 47.33 Hz, for the uncontrolled case, to 49.10 Hz utilizing the suggested adaption of inertia support responindg to a disturbance of 0.1 pu. Lastly, the capability of a VSWT to provide temporary primary frequency support in islanded power systems with 50 % through an alternating generation mix based on hydro, reheat or thermal units in charge of automatic generation control (AGC) considering delays, dead band settings and a combined pitch and droop controlled control strategy. The combined strategy showed clear improvements to the span of 49.9 Hz ≤ f < 50.1 Hz of 28 percentage points for a hydro based power system, this while only reducing the energy produced by 6 %

Economic Evaluation of Supported-Employment Inspired Program for Pupils With Intellectual Disabilities

In this study, we investigate whether, or to what degree, a ‘business case’ could be made for implementation of a Supported-Employment (SE) inspired program for pupils with intellectual disabilities (IDs), starting during the final school years. For this aim, we do a quasi-experimental before-after intervention impact evaluation of such a project funded by the European Social Fund in the Swedish city of Örebro (135,000 inhabitants) during 2010–2013. From an estimate of the average treatment effect, we calculate the internal net present value and the payback period that would make this program break even from avoided expenditure for day-activity services, assuming that it had been funded entirely by the municipality

Investigating goal conflicts in menu planning in Swedish school catering on the pathway to sustainable development

The 260 million publicly funded school meals served annually in Sweden generate 21.000 tons of food waste. At national level, school meals should meet the goal of food waste reduction, together with various other goals such as meeting nutritional requirements, being environmentally friendly and, most importantly, achieving high acceptance among schoolchildren. There is a preconception among kitchen staff that the most popular school meals drive food waste in Swedish school catering and that vegetarian dishes increase food waste, despite being less popular than meat options. By applying mixed methods, this study investigated possible goal conflicts between reduced food waste, high acceptance, and vegetarian options on the lunch menu. An overall aim was to gain knowledge on how lunch menus could be adapted for increased sustainability. Kitchen staff from 10 Swedish primary and secondary schools were interviewed to identify the most popular and unpopular meals, and food waste quantification data and lunch menus from 61 school canteens were analyzed. The results showed that, while the common perception of popular and vegetarian meals creating most waste was held by kitchen staff, it proved to be untrue. In fact, popular school meals and vegetarian options generated less waste than unpopular meals. A vegetarian paradox was detected in interviews, with vegetarian options considered unpopular but with several vegetarian options among the most popular dishes. Thus, school-catering units should stop serving unpopular meals and shift their focus to serving popular nutritious meals, including popular plant-based options, as part of efforts to make school meal schemes more sustainable