@article{63053, author = {{Hernández, Carlos and Rodriguez-Fernandez, Angel E. and Schäpermeier, Lennart and Cuate, Oliver and Trautmann, Heike and Schütze, Oliver}}, journal = {{IEEE Transactions on Evolutionary Computation}}, keywords = {{Optimization, Evolutionary computation, Hands, Proposals, Convergence, Computational efficiency, Artificial intelligence, Accuracy, Approximation algorithms, Aerospace electronics, Multi-objective optimization, evolutionary algorithms, nearly optimal solutions, multimodal optimization, archiving, continuation}}, pages = {{1--1}}, title = {{{An Evolutionary Approach for the Computation of ∈-Locally Optimal Solutions for Multi-Objective Multimodal Optimization}}}, doi = {{10.1109/TEVC.2025.3637276}}, year = {{2025}}, } @techreport{56494, abstract = {{Many industrialized countries have recognized the need to mitigate energy cost increases faced by low-income households by fostering the adoption of energy-efficient technologies. How to meet this need is an open question, but “behavioral insights” are likely components of future policy designs. Applying well-established behavioral insights to low-income house- holds raises questions of transportability as they are typically underrepresented in the existing evidence base. We illustrate this problem by conducting a randomized field experiment on scalable, low-cost design elements to improve program take-up in one of the world’s largest en- ergy efficiency assistance programs. Observing investment decisions of over 1,800 low-income households in Germany’s “Refrigerator Replacement Program”, we find that the transportabil- ity problem is real and consequential: First, the most effective policy design would not have been chosen based on existing behavioral insights. Second, design elements favored by these insights either prove ineffective or even backfire, violating ‘do no harm’ principles of policy advice. Systematic testing remains crucial for addressing the transportability problem, partic- ularly for policies targeting vulnerable groups. }}, author = {{Kesternich, Martin and Chlond , Bettina and Goeschl, Timo and Werthschulte, Madeline}}, keywords = {{Transportability, low-income households, field experiment, randomized controlled trial, governmental welfare programs, energy efficiency, technology adoption}}, publisher = {{ AWI Discussion Paper Series No. 755}}, title = {{{Transporting behavioral insights to low-income households: A field experiment on energy efficiency investments}}}, year = {{2024}}, } @article{56420, abstract = {{There are a number of school choice problems in which students are heterogeneous according to the number of seats they occupy at the school they are assigned to. We propose a weighted school choice problem by assigning each student a so-called weight and formulate the weighted top trading cycles algorithm (WTTC) to find a matching. The WTTC is strategy-proof and results in a Pareto efficient matching. While the WTTC is a robust extension of the TTC when weights are introduced, it is no longer guaranteed that each student gets a seat at a school even if the overall capacity exceeds the sum of weights. Additionally, the WTTC introduces a trade-off between weights and priorities as a student with a higher weight has a disadvantage to be matched to a particular school compared to a student with the same schools’ priorities but a smaller weight.}}, author = {{Stroh-Maraun, Nadja}}, issn = {{0165-4896}}, journal = {{Mathematical Social Sciences}}, keywords = {{Matching, School choice, College admission problems, Top trading cycles, Pareto efficiency, Strategy-proofness}}, pages = {{49--56}}, publisher = {{Elsevier BV}}, title = {{{Weighted school choice problems and the weighted top trading cycles mechanism}}}, doi = {{10.1016/j.mathsocsci.2024.09.001}}, volume = {{132}}, year = {{2024}}, } @inproceedings{44036, abstract = {{Abstract. In order to reduce global energy consumption in production and industry along with the associated CO2 emissions, existing resources must be used more efficiently. This includes the energy-efficient and comprehensive recycling of a wide range of metals. Especially for the production of aluminium, there is a large potential for saving energy using efficient recycling processes. With regard to the recycling of aluminium studies have shown that solid-state recycling processes are significantly more efficient considering the used energy and resources compared to the conventional, smelting-metallurgical recycling process. In this paper, the direct and energy-efficient friction-induced recycling process (FIRP) based on the conform process is further described and analysed in terms of the temperature-property relationships. For this purpose, the influence of the processing temperature on the microstructure and properties of the recycled semi-finished products is investigated using the toll system that enables an ECAP forming. Specific sections of the (in theory) infinite, recycled semi-finished product are taken and analysed at different process temperatures of the solid state recycling process. Based on these sections, the properties in terms of mechanical hardness, strength, ductility and grain size are analysed and a degressive relationship between process temperature and mechanical hardness up to a temperature of 270 °C can be shown. Applying the Hall-Petch relationship, it is analysed whether there is a correlation between the strength and the microstructure in the form of the grain size. }}, author = {{Borgert, Thomas and Homberg, Werner}}, booktitle = {{Materials Research Proceedings}}, issn = {{2474-395X}}, keywords = {{Recycling, Aluminium, Friction-Induced, Energy Efficiency}}, location = {{Kraków}}, publisher = {{Materials Research Forum LLC}}, title = {{{Analysis of temperature effect on strength and microstructure in friction induced recycling process (FIRP)}}}, doi = {{10.21741/9781644902479-211}}, year = {{2023}}, } @inproceedings{24550, abstract = {{Efficiencies and energy yields of microinverters available on the market during 2014‒2021 have been measured, compared, and ranked. Conversion efficiencies as a function of load have been measured indoors with high accuracy and ranked according to Euro- and CEC weightings. Energy yields have been measured outdoors via identical and calibrated crystalline silicon PV modules of 215 Wp (until 2020) and 360 Wp (starting 2021). Inverters with two inputs have been fed by two of those modules. DC input, AC power output and energy yield of each microinverter have been recorded by individual calibrated electricity meters. CEC and EU efficiency rankings have been computed and compared. To assess the influence of PV module size, two extremes have been investigated: A rather small module with 215 Wp - as it has been used 10 years ago, and a brand-new module (2021) offering 360 Wp. Both types of modules contain 60 solar cells in series connection. Appling the low-power modules, the challenge for the different micro-inverters has been during weak-light conditions, using the high-power modules, some inverters temporarily reach their power limits and yield is reduced. A method using a reference configuration of inverter & module and a linear equation y = ax + b resulting in the actual yield, any module & inverter configuration can be characterized by just the coefficients a and b.}}, author = {{Krauter, Stefan and Bendfeld, Jörg}}, booktitle = {{Proceedings of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC 2021)}}, isbn = {{3-936338-78-7}}, keywords = {{AC-modules, Microinverter, Power Conditioning, Efficiency, Yield, PV module size, saturation, performance}}, pages = {{659 -- 663}}, title = {{{Module-Inverters (Microinverters): Influence of Module Size on Conversion Efficiencies and Energy Yields}}}, doi = {{10.4229/EUPVSEC20212021-4CO.3.4}}, year = {{2021}}, } @inproceedings{18387, abstract = {{ During comparative measurements of different PV microinverters, two yield issues came up that could not be explored via conventional efficiency measurements, but do have a significant impact on electrical energy yield: First category of issues are either sluggish or nervously acting maximum–power–point–tracking devices, which lead to reduced energy yields. The other category of issues is thermal: As a first explanation for observed reduced energy yields, it has been assumed that the conversion efficiency degrades at higher operating temperatures. This matter has been investigated in this article: A change in conversion efficiency could not be observed for elevated operation temperatures up to 50°C, despite high-precision and repeated measurements. But it was found that some inverters temporarily interrupted (or entirely stopped) operation after long periods of running at high temperatures. Also, a reduction in potential maximum power output has been detected for those inverters. Summarizing: With a high degree of certainty it can be stated that those reported yield losses have been caused by the temporary shutdowns and power limitations of the inverters.}}, author = {{Krauter, Stefan and Bendfeld, Jörg}}, booktitle = {{Proceedings of the EU PVSEC 2020 }}, issn = {{3-936338-73-6}}, keywords = {{AC-modules, Microinverter, Power Conditioning, Thermal Performance, Ventilation, Stability, Efficiency, Yield}}, location = {{online}}, pages = {{1179 -- 1180}}, title = {{{Elevated Temperatures Affecting Efficiency, Overall Performance and Energy Yield of PV Microinverters}}}, doi = {{10.4229/EUPVSEC20202020-4AV.3.6}}, year = {{2020}}, } @inproceedings{16899, abstract = {{To compare efficiency and yield of many micro-inverters available on the world market in 2014-2020, an in- and outdoor test laboratory at the University of Paderborn has been set up. The inverters have been fed by identical and calibrated crystalline silicon PV modules of 215 Wp. To monitor accurately DC input, AC power output and energy yield, each of the micro-inverters has been equipped with a calibrated electricity meter. For micro-inverters requiring control units for grid-feeding that has been acquired also. The comparison covers efficiency-load characteristics as well as electrical energy yields. Purchase costs vary considerably between the models in comparison, sometimes inverter costs are higher than module costs, particularly if an additional grid-connection or interface device is needed for operation. The weighted conversion efficiency according to EU and CEC standards has been measured and calculated. While some inverters have been optimized for high irradiance levels, they ranked better at the CEC efficiency, others performed very well also for low irradiance levels, thus ranking higher at in the EU-efficiency tables. These results are deviating from the actual energy yield measurements, which show a slightly different ranking. At one inverter, an accurate, but very slow MPPT algorithm that barely could follow quickly changing irradiance levels could be the reason for this effect. Another inverter switched off after operation at high power output for a while. Apparently, some inverters are been optimized to show excellent EU and CEC efficiency ratings. Two of the inverters featuring two inputs did not show an exceptional performance at the EU- and CEC-ratings, but they achieved top ranks at the AC energy yield for the first years. For the customer, the AC yield is a major performance indicator of any microinverter and should be included in the datasheet.}}, author = {{Krauter, Stefan and Bendfeld, Jörg}}, booktitle = {{Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING}}, issn = {{ 0160-8371}}, keywords = {{yield, AC, micro-inverter, MPPT, CEC rating, EU efficiency, Photovoltaic, Solar}}, location = {{VIRTUAL MEETING}}, pages = {{1429--1432}}, publisher = {{IEEE}}, title = {{{Comparison of Microinverters: Update on Rankings of Conversion Efficiencies and Energy Yields}}}, doi = {{10.1109/PVSC45281.2020.9300953}}, year = {{2020}}, } @inproceedings{17667, abstract = {{Resolving distributed attacks benefits from collaboration between networks. We present three approaches for the same multi-domain defensive action that can be applied in such an alliance: 1) Counteract Everywhere, 2) Minimize Countermeasures, and 3) Minimize Propagation. First, we provide a formula to compute efficiency of a defense; then we use this formula to compute the efficiency of the approaches under various circumstances. Finally, we discuss how task execution order and timing influence defense efficiency. Our results show that the Minimize Propagation approach is the most efficient method when defending against the chosen attack.}}, author = {{Koning, Ralph and Polevoy, Gleb and Meijer, Lydia and de Laat, Cees and Grosso, Paola}}, booktitle = {{2019 6th IEEE International Conference on Cyber Security and Cloud Computing (CSCloud)/ 2019 5th IEEE International Conference on Edge Computing and Scalable Cloud (EdgeCom)}}, issn = {{null}}, keywords = {{computer network security, multinetwork environments, multidomain defensive action, task execution order, timing influence defense efficiency, distributed attacks, collaborative security defence approach, minimize propagation approach, minimize countermeasure approach, counteract everywhere approach, Conferences, Cloud computing, Computer crime, Edge computing, Security, Defense Approaches, Multi-Domain Defense, Collaborative Defense, Defense Algorithms, Computer Networks}}, pages = {{113--123}}, title = {{{Approaches for Collaborative Security Defences in Multi Network Environments}}}, doi = {{10.1109/CSCloud/EdgeCom.2019.000-9}}, year = {{2019}}, } @techreport{7630, abstract = {{In this paper, we analyze a credence goods model adjusted to the health care market with regulated prices and heterogeneous experts. Experts are physicians and are assumed to differ in their cost of treating a small problem. We investigate the effects of this heterogeneity on the physicians’ level of fraud and on the patients’ search for second opinions. We find that introducing a fraction of more efficient low-cost physicians always increases social welfare, but in some cases only because of the raised physicians’ surplus. When the low-cost physicians’ cost advantage is small, imposing a share of low-cost physicians does not change the equilibrium fraud level. When the cost advantage is large, however, different changes in the fraud level occur depending on the share of generated low-cost physicians, the search rate and the initial level of fraud.}}, author = {{Heinzel, Joachim Maria Josef}}, keywords = {{credence goods, treatment efficiency, heterogeneous experts, overcharging}}, publisher = {{CIE Working Paper Series}}, title = {{{Credence Goods Markets with Heterogeneous Experts}}}, volume = {{118}}, year = {{2019}}, } @techreport{15204, abstract = {{We criticize some conceptual weaknesses in the recent literature on coalitional TUgames and propose, based on our critics, a new definition of dual TU-games that coincides with the one in the literature on the class of super-additive games. We justify our new definition in four alternative ways: 1. Via an adequate definition of ecient payo vectors. 2. Via a modification of the Bondareva-Shapley duality. 3. Via an explicit consideration of \coalition building". 4. Via associating general TU-games to coalition-production economies. Rather than imputations, we base our analysis on a modification of aspirations.}}, author = {{Aslan, Fatma and Duman, Papatya and Trockel, Walter}}, keywords = {{TU-games, duality, core, c-Core, cohesive games, complete game efficiency}}, publisher = {{CIE Working Paper Series, Paderborn University}}, title = {{{Duality for General TU-games Redefined}}}, volume = {{121}}, year = {{2019}}, } @article{17666, abstract = {{Software Defined Networks (SDN) and Network Function Virtualisation (NFV) provide the basis for autonomous response and mitigation against attacks on networked computer infrastructures. We propose a new framework that uses SDNs and NFV to achieve this goal: Secure Autonomous Response Network (SARNET). In a SARNET, an agent running a control loop constantly assesses the security state of the network by means of observables. The agent reacts to and resolves security problems, while learning from its previous decisions. Two main metrics govern the decision process in a SARNET: impact and efficiency; these metrics can be used to compare and evaluate countermeasures and are the building blocks for self-learning SARNETs that exhibit autonomous response. In this paper we present the software implementation of the SARNET framework, evaluate it in a real-life network and discuss the tradeoffs between parameters used by the SARNET agent and the efficiency of its actions.}}, author = {{Koning, R. and de Graaff, B. and Polevoy, Gleb and Meijer, R. and de Laat, C. and Grosso, P.}}, issn = {{0167-739X}}, journal = {{Future Generation Computer Systems}}, keywords = {{Software defined networks, Network function virtualization, Cyber attacks, Cyber security, Defense efficiency, Overlay networks}}, title = {{{Measuring the efficiency of SDN mitigations against attacks on computer infrastructures}}}, doi = {{https://doi.org/10.1016/j.future.2018.08.011}}, year = {{2018}}, } @inproceedings{17653, author = {{Polevoy, Gleb and de Weerdt, M.M.}}, booktitle = {{Proceedings of the 29th Benelux Conference on Artificial Intelligence}}, keywords = {{interaction, reciprocation, contribute, shared effort, curbing, convergence, threshold, Nash equilibrium, social welfare, efficiency, price of anarchy, price of stability}}, publisher = {{Springer}}, title = {{{Reciprocation Effort Games}}}, year = {{2017}}, } @inproceedings{17654, author = {{Polevoy, Gleb and de Weerdt, M.M.}}, booktitle = {{Proceedings of the 29th Benelux Conference on Artificial Intelligence}}, keywords = {{agents, projects, contribute, shared effort game, competition, quota, threshold, Nash equilibrium, social welfare, efficiency, price of anarchy, price of stability}}, publisher = {{Springer}}, title = {{{Competition between Cooperative Projects}}}, year = {{2017}}, } @article{4586, abstract = {{This study examines the loan-pricing behavior of German banks for a large variety of retail and corporate loan products. We find that a bank’s operational efficiency is priced in bank loan rates and alters interest-setting behavior. Specifically, we establish that a higher degree of operational efficiency leads to lower loan markups, which makes prices more competitive and smoothes the setting of interest rates. By employing state-of-the-art stochastic frontier efficiency measures to capture a bank’s operational efficiency, we take a look at the bank customers’ perspective and demonstrate the extent to which bor-rowers benefit from cost-efficient banking. }}, author = {{Schlueter, Tobias and Busch, Ramona and Sievers, Soenke and Hartmann-Wendels, Thomas}}, journal = {{Credit and Capital Markets--Kredit und Kapital}}, keywords = {{interest rate pass-through models, error correction models, bank efficiency, cost efficiency, stochastic frontier analysis}}, number = {{1}}, pages = {{93--125}}, title = {{{Loan Pricing: Do Borrowers Benefit from Cost-Efficient Banking?}}}, doi = {{10.3790/ccm.49.1.93}}, volume = {{49}}, year = {{2016}}, } @article{52208, author = {{Khripko, Diana and Schlüter, Alexander and Rommel, Benjamin and Rosano, Michele and Hesselbach, Jens}}, issn = {{2008-9163}}, journal = {{International Journal of Energy and Environmental Engineering}}, keywords = {{Primary energy demand, Energy efficiency within industry, Polymer processing}}, number = {{2}}, pages = {{225--233}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Energy demand and efficiency measures in polymer processing: comparison between temperate and Mediterranean operating plants}}}, doi = {{10.1007/s40095-015-0200-2}}, volume = {{7}}, year = {{2016}}, } @article{17662, author = {{Polevoy, Gleb and Smorodinsky, Rann and Tennenholtz, Moshe}}, issn = {{2167-8375}}, journal = {{ACM Trans. Econ. Comput.}}, keywords = {{Competition, efficiency, equilibrium, market, social welfare}}, number = {{1}}, pages = {{1:1--1:16}}, publisher = {{ACM}}, title = {{{Signaling Competition and Social Welfare}}}, doi = {{10.1145/2560766}}, volume = {{2}}, year = {{2014}}, } @article{4397, abstract = {{Employing four event dates of the U.S. “Troubled Asset Relief Program” (TARP) this paper empirically investigates the impact of the first announcement of TARP (September 19, 2008), the announcement of revised TARP (October 14, 2008), respective capital infusions under TARP-CPP and capital repayments on changes in shareholder value and risk exposure of 125 supported U.S. banks as perceived by the capital market through share price reactions for an entire sample period from September 19, 2008 to June 16, 2010. Our analysis reveals a light and a dark side of TARP. While announcements as well as capital repayments may restore market confidence and financial stability, equity capital injections to banks are observed to be a severe impediment to an increase in bank shareholder value and financial soundness. }}, author = {{Farruggio, Christian and Michalak, Tobias C. and Uhde, André}}, journal = {{Journal of Banking and Finance}}, keywords = {{Financial crisis, TARP, Market efficiency, Event study}}, number = {{5}}, pages = {{2586--2604}}, title = {{{The light and dark side of TARP}}}, doi = {{10.1016/j.jbankfin.2013.02.020}}, volume = {{32}}, year = {{2013}}, } @inproceedings{5690, abstract = {{In a world, where more and more businesses seem to trade in an online market, the supply of online services to supply the ever-growing demand could quickly reach its capacity limits. Online service providers may find themselves maxed out at peak operation levels during high-traffic timeslots but too little demand during low-traffic timeslots, although the latter is becoming less frequent. At this point not only deciding which user is allocated what level of service becomes essential, but also the magnitude of the service provided, can be controlled by pricing. Pricing is an important factor when efficient and acceptable allocation of resources between individuals must be reached. Without prices, transferring or sharing goods would be impossible. In sharing information, pricing a product however is not as simple as relatively pricing an apple or a pear. Often the costs, and hence the prices are simply unknown. Backed by this scenario, the online services market could be combined with the market design mechanism of diamonds. For this we propose an ultimatum pricing strategy which effectively allows for valuations to be accounted for, but no longer a necessity when pricing in grid, cloud or other online computing environments.}}, author = {{Bodenstein, Christian and Schryen, Guido and Neumann, Dirk}}, booktitle = {{18th European Conference on Information Systems (ECIS 2010)}}, keywords = {{Posted Price, Ultimatum Game, Energy Efficiency, Mechanism Design}}, title = {{{From "Take-it-or-leave-it" offers to "Take-it-or-be-left-out" Ultimatum - A trade mechanism for Online Services}}}, year = {{2010}}, } @inproceedings{38104, abstract = {{Location-aware services for private use such as GPS- based navigation systems and GSM-based offerings have become quite a success for outdoor applications, while indoor positioning systems are still mainly employed for professional use only. The main reasons are cost issues and the complexity of setup and maintenance of those systems. In this paper we present CaMPTrack (Camera-based Multiple Person Tracker), a prototype of a webcam-based positioning system and discuss its application and development challenges.}}, author = {{Schäfer, Robbie and Müller, Wolfgang and Deimann, Roman and Kleinjohann, Bernd}}, booktitle = {{Proceedings of the Workshop on Mobile Spatial Interaction at CHI 2007}}, keywords = {{Positioning Systems, Camera Based, Cost Efficiency, Smart Home Applications}}, title = {{{A Low-Cost Positioning System for Location-Aware Applications in Smart Homes}}}, year = {{2007}}, } @inproceedings{8926, abstract = {{Piezoelectric transformers are well known since the publication of some patent applications at the end of the 1950s. But until today their only business use lies in the field of backlighting systems for LCDs. Due to key features as light-weight, flatness, high step-up at low volume and high efficiency piezoelectric transformers should be usable in a much broader range of applications. This contribution returns to mind their operating principle, shows how to model and to develop such devices as well as give some aspects for development trends that will lead to further applications.}}, author = {{Hemsel, Tobias and Littmann, Walter and Wallaschek, Jörg}}, booktitle = {{Ultrasonics Symposium, 2002. Proceedings. 2002 IEEE}}, issn = {{1051-0117}}, keywords = {{piezoelectric devices, reviews, transformers, backlighting systems, flatness, high efficiency piezoelectric transformers, high step-up, light-weight, low volume, operating principle, piezoelectric transformers, Circuits, Costs, Electromagnetic devices, Electromagnetic fields, Mechanical energy, Piezoelectric materials, Power electronics, Switching frequency, Transformers, Vibrations}}, number = {{vol.1}}, pages = {{645--648}}, title = {{{Piezoelectric transformers - state of the art and development trends}}}, doi = {{10.1109/ULTSYM.2002.1193485}}, volume = {{1}}, year = {{2002}}, }