An optimal auction with moral hazard

Abstract We consider a single-item, independent private value auction environment with two bidders: the leader, who knows his valuation, and the follower, who exerts an effort that affects the probability distribution of his valuation, which he then learns. We provide sufficient conditions under which an ex-post efficient revenue-maximizing auction solicits bids sequentially and partially discloses the leader’s bid to the follower, thereby influencing the follower’s effort. This disclosure rule, which is novel, is non-monotone and prescribes sometimes revealing only a pair to which the leader’s bid belongs and sometimes revealing the bid itself. The induced effort distortion relative to the first-best is discussed

Dynamic project selection

We study a normative model of an internal capital market, used by a company to choose between its two divisions’ pet projects. Each project’s value is initially unknown to all but can be dynamically learned by the corresponding division. Learning can be suspended or resumed at any time and is costly. We characterize an internal capital market that maximizes the company’s expected cash flow. This market has indicative bidding by the two divisions, followed by a spell of learning and then firm bidding, which occurs at an endogenous deadline or as soon as either division requests it

Persecution Act as Filter Bubble Effect: Digital Society and the Shift of Public Sphere

This article discusses persecution acts associated with the filter bubble effect, the condition of digital society, the concept of the public sphere and the rational action theory of Jurgen Habermas. The results, obtained through the literature research method, show that acts of persecution in social media can be caused by the personalization of the web. Social media allows the occurrence of large bubbles (filter bubbles) that make users reject ideologies or other truths. This becomes a revolution of mindset due to the freedom of information. Meanwhile, in the Habermas public sphere concept, which emphasizes the existence of a critical and rational discussion, this phenomenon indicates a shift. The shift that occurs brings about the lifeworld realm as the basis for the formation of the public sphere with its communicative action, again dominated by the system realm that is dominated by capitalist forces through strategic action. Thus, Habermas\u27s initial goal of strengthening civil society\u27s position against the dominance of the system is now changing

Data-Driven Aeroacoustic Modelling: Trailing-Edge Noise

Broadband noise emitted at the trailing edge of an airfoil represents a significant contribu- tion to the noise emission in rotors, wind turbine and fan blades, in low Mach number flows. High-fidelity calculations are out of the scope when fast parametric calculations are needed. In these cases it is necessary to resort to analytical models and the most popular one is the model proposed by Amiet. In the model, the knowledge of the wall pressure spectrum allows to define an equivalent point source located at the trailing edge. The description of the turbulent wall pressure spectrum is of major importance for the correct noise prediction. Proposed empirical laws of wall pressure spectra in presence of adverse pressure gradients are limited to cases which are not too far from the test cases employed for their calibration. Recently, the development of machine learning techniques make it possible to analyze large amounts of experimental data in order to automatically extract modeling knowledge. However measurements of pressure fluctuations near a trailing edge are difficult. An alternative solution is to measure the far-field trailing-edge noise at each condition. The measures are comparatively simpler and contain all the information about the source. In this work a deep learning algorithm, based on a standard feed-forward Artificial Neural Network (ANN) and a Random Forest (RF) algorithm are applied to far-field directivity data sets. The motivation of the present work is to evaluate the prediction ability of the ANN and RF models. The proposed approach allows to build a general model which can potentially be trained on experimental data and so it is not limited by the simplifying assumptions required by analytical models or empirical wall pressure spectrum. The prediction capabilities of ANN and RF are investigated by considering data not included in the training database. The potential of RF regression for the evaluation of the prediction uncertainty is also addressed. The proposed models are based on a splitting in sub models: the ANN or the RF algorithm is used to describe the noise directivity while a polynomial model is introduced for the prediction of the emitted acoustic power. This splitting, which improves significantly the training performance, can be seen as a possible way to introduce a physical constraint to the machine learning model which is forced to satisfy a constraint on the emitted power. The proposed procedure is tested on an artificial database generated by the Amiet model. However, it can be directly applied to experimental data or high-fidelity calculations

A Tight Connection Between Direct and Indirect Detection of Dark Matter through Higgs Portal Couplings to a Hidden Sector

We present a hidden Abelian extension of the Standard Model including a complex scalar as a dark matter candidate and a light scalar acting as a long range force carrier between dark matter particles. The Sommerfeld enhanced annihilation cross-section of the dark matter explains the observed cosmic ray excesses. The light scalar field also gives rise to potentially large cross-sections of dark matter on nucleon, therefore providing an interesting way to probe this model simultaneously at direct and indirect dark matter search experiments. We constrain the parameter-space of the model by taking into account CDMS-II exclusion limit as well as PAMELA and FermiLAT data.Comment: 15 pages, 7 figures. Added discussions on tuning and inverse Compton scattering constraints. References added and updated. Matches the published versio

A COMP ARAT IV E STU DY B ETWEE N THE USE OF DICTOGLOSS AND DICTOCOMP TECHNIQUE IN INCREASING STUDENTS’ NARRATIVE TEXT WRITING ABILITY OF THE TENTH GRADE OF MA MATHLA’UL ANWAR IN ACADEMIC YEAR OF 2020/2021

ABSTRACT In every activity of learning and teaching, especially in language acquisition, a lot of problems could be found. Thus, a preliminary research was done to find the problem which was done in MA Mathla‟ul Anwar Gisting. From the data that were obtained from both teacher and students, the technique that was used to utilize are less effective and interactive. Other techniques were offered, namely Dictogloss and Dicto-comp techniques. The objective of this research was to investigate whether there was any significant difference of the achievements in writing narrative text and which technique was better between Dictogloss Technique and Dictocomp Technique to teach writing. Static Group Comparison was used in this research. Cluster Random Sampling was used as its sampling technique. There were two groups that were given different treatment. The first group was X MIA D as experimental class 1 that was taught by using Dictogloss Technique, and the second group was X MIA B as experimental class 2 that was taught by using Dictocomp Technique. Based on the data analysis, it was obtained that. It could be concluded that Sig. (PValue) for was 0,006 and α = 0,05. Here, it could be seen that 0.006 α = 0,05. But Ha was accepted because 0.006 < 0,05 . Then, there was significant difference between the use of Dictogloss Technique and Dictocomp Technique in Increasing Students‟ Narrative Text Writing Ability. Keywords : Dictogloss technique, Dictocomp technique, Narrative tex

Analisis Dan Simulasi Video Watermarking Menggunakan Metode Dual Tree Complex Wavelet Transform (DT-CWT) Dan Singular Value Decomposition (SVD)

Video piracy is the act of obtaining, copying, and selling or distributing videos that already had the copyright without the consent of the copyright owner. Watermarking is a process which embeds an additional information in the host video signal so that the embedded watermark cannot be seen and difficult to be erased or altered. Video watermarking in this journal used a mp4 format video and two different watermark images. Host video frames are divided into two equal lots, some of the frames are embedded by watermark image 1, and the others are embedded by watermark images 2. The methods used are Dual-Tree Complex Wavelet Transform (DTCWT) and Singular Value Decomposition (SVD). The two watermarks are embedded and extracted in each subband at a depth level 1 to level 4 DTCWT - SVD with the aim of seeking the best subband and the best level for embedding and extracting. In the extraction testing, watermarked video is given several attacks before extraction process. Based on the MOS and PSNR value the DTCWT-SVD level for embedding process is level 4, and based on the MOS and MSE value, the best extraction images are produced from the level 3. The best subband for embedding watermark are the subbands with three parts such as {1,5}{1,1}{1,2} and {1,5}{1,2}{1,2}

An experimental study on the evolution of modal damping with damage in carbon fiber laminates

Many of the techniques developed to assess structural damage are based on experimental modal analysis. This paper presents a study to extend the current understanding of how increasing damage in a carbon fiber reinforced plastic affects the modal damping factor of a laminated structure. Damage is introduced and quantified in terms of the dissipated energy. It is shown that there is a tendency for the overall damping to increase whereas there is a tendency for the overall stiffness to decrease. While these results are not novel, the former is quite relevant, since the authors are not aware of many other experimental studies on the evolution of the modal damping factor with damage in carbon fiber reinforced plastic. At the same time, a modal-based damage location technique that combines both the natural frequencies and the modal damping factors as damage sensitive features is discussed. The hypothesis that different damage morphologies on composite materials have different contributions to the damage features is drawn. The methods are illustrated with both numerical and experimental examples. One of the problems observed is that, although damping is consistently found to increase globally with damage, the determination of the individual changes of the modal damping factors is still very uncertain. This may be due to concurrent damage types being present at the same time, but most certainly due to uncertainties involved in the identification of the modal damping factors

Analisis Faktor-faktor Yang Mempengaruhi Ocb Pegawai Kontrak (Studi Pada Pegawai Kontrak Di Lingkungan Universitas Diponegoro Semarang)

Human resource is the spear from organizations. Without Human Resource, all of the organization resources can't process and developed to get profit, and it is happened on government organization too. The government organization has Organizational Citizenship Behavior, who helped the employee included the contract workers on their social working scope. Some factors that needed to determine higher or lower the OCB's level even contract or permanent workers it is loyalty, obesity and their participation to the organization who covered them. Loyalty, obesity and participation levels of contract workers on government sector is an interesting case to research. This research want to analyze and examine influence factors to the OCB's contract workers in government organization, with working satisfaction and Organization behavior as an independent variable and use Working Motivation as an intervening variable. Sample of this research is a contract workers who working at Diponegoro University, Semarang. Whereas, analysis technique on this research using SEM. Based on the research results, that working satisfaction and organization behavior is positively influential to the contract workers working motivation, whereas working motivation factor with a significant too, that positively influential to the OCB's contract working