Reward Crowdfunding: Who to Attract at the Beginning of the Campaign? An Analysis in Terms of Revealed Networks of Preferences

This research study combines the theoretical teachings of revealed preferences, signal theory and weak tie theory to better understand the dynamics at work at the beginning of a campaign and to explain its success. By identifying the revealed preferences of early backers through their common past contributions, we characterize as strong or weak the nature of the complex preference ties between them. We build networks of the contributions made by the individuals identified as early backers to 9,425 campaigns run on the Ulule platform between July 2010 and September 2014. The results of this study underline the importance of the presence of strong preference ties between early backers and other platform users for the success of campaigns. They also corroborate the theory of the strength of weak ties. Later in the campaign, the intervention of backers with less specific preferences, in the position of intermediaries, positively influences the future outcome by accelerating the fundraising speed at the beginning of the campaign.

On the perturbations of maps obeying Shannon–Whittaker–Kotel’nikov’s theorem generalization

Let $f: \mathbb{R}\rightarrow \mathbb{R}$ f : R → R be a map and $\tau \in \mathbb{R}^{+}$ τ ∈ R + . The map f obeys the Shannon–Whittaker–Kotel’nikov theorem generalization (SWKTG) if $f(t)=\lim_{n\to \infty } ( \sum_{k\in \mathbb{Z}} f^{ \frac{1}{n}} (\frac{k}{\tau } ) \operatorname{sinc} (\tau t-k) )^{n}$ f ( t ) = lim n → ∞ ( ∑ k ∈ Z f 1 n ( k τ ) sinc ( τ t − k ) ) n for every $t\in \mathbb{R}$ t ∈ R . The aim of the present paper is to characterize the perturbations of the map f that obeys SWKTG. Our results enlarge the catalog of maps that can be recomposed using SWKTG. We underline that maps obeying SWKTG play a central role in applications to chemistry and signal theory between other fields.

Faktor - Faktor yang Memengaruhi Profitabilitas pada Perusahaan Subsektor Investment Company di BEI Periode 2015 – 2019

<p><em>The aim of this study is to determine and analyse the effect of </em><em>ESOP, leverage, and the size of the company partially and simultaneously to the profitability of the Investment Company Subsector Company in IDX Period 2015-2019. The data used in this study is library studies and documentation. Sample selection in this study using nonprobability purposive sampling technique. The data analysis method used is multiple linear regression analysis. The results prove that ESOP and company size partially have no significant effect on profitabilitas, but leverage has a significant effect on profitability. Then simultaneously ESOP, Leverage, and Company Size have no effect on profitability. The results of research with Agency theory and signal theory, ESOP is expected to increase the loyalty of the company manager to the owner of the company in improving profitability, and ESOP does not affect the contribution of profitability information of a company in assessing the condition of a company, between the relationship of the manager and the owner of the company. Leverage, in the explanation of signal theory is one of the factors that influence in providing information to investors on the profitability of acompany. Size of the company is determined by the management steps to manage the company's profit as best as possible, which we know companies with large scale does not necessarily have a good company performance also in improving its profitability. This research is expected to help companies to improve the profitability of thecompany.</em></p><p><strong><em>Keywords:</em></strong><em> ESOP, leverage, company size, profitabilitas</em></p>

The Role of Fourier Series in Mathematics and in Signal Theory

This paper presents a praxeological analysis, based on ATD (Anthropological Theory of the Didactic), of the topic of Fourier series, as this topic is introduced and used in mathematics and in electrical engineering, more precisely in signal theory. The analysis is based mainly on one widely used textbook in mathematics for engineers, and a textbook and video lectures in signal theory. The aim of the analysis is to investigate possible differences in the motivation for introducing Fourier series in mathematics and in signal theory, as well as differences in the techniques used, and the justifications behind the techniques. This research is inspired by previous research showing lack of connection between mathematics courses and engineering courses applying mathematics. To get a wider perspective, the exposition in the textbook in mathematics for engineers is also compared to the exposition in more advanced books in mathematics. To add to the perspective, the historical origin of Fourier series is also discussed. The findings show that there are differences in the motivation for the topic both between mathematics and signal theory, but also between basic and more advanced mathematics. Within mathematics there are also differences in the underlying theories.

Financial Reporting Material Misstatements, Earnings Conservatism and Managerial Replacement Decisions

Purpose: Based on signal theory and legitimacy theory, this paper examines whether firms with financial reporting misstatements (restatements) would prefer conservative financial reporting to send signals regarding their determinants of improving financial reporting credibility and legitimate organizational image in Taiwan. This paper further examines whether these firms reduce the demand for conservative financial reporting after replacing managers in the reveal of restatements.

A Large Signal Theory of Multiple Cascaded Bunching Cavities for High-Efficiency Triaxial Klystron Amplifier

This paper presents a large signal theory of multiple cascaded bunching cavities for the design of high-efficiency triaxial klystron amplifiers (TKAs). The theoretical analysis of multiple cascaded bunching cavities is presented, focusing on the relationship between gap voltage and first harmonic current and velocity dispersion, which can exactly describe the clustering state of intense relativistic electron beams. The theoretical results of the first harmonic current and velocity dispersion are basically consistent with its simulation results, which can justify a high degree of confidence in the validity of that theory. This theory can predict the possibility of deep modulation of intense relativistic electron beams when the depth of the first harmonic current is about 150% by multiple cascaded bunching cavities. By properly accounting for this theory, we can design a Ku-band TKA with nearly 60% microwave conversion efficiency, which can provide theoretical and simulation guidance for the design of high-efficiency TKAs. More importantly, when we increase the electron beam voltage from 300 kV to 600 kV and keep the relativistic perveance constant, this device also can obtain more than 50% efficiency and 40 dB gain. As a result, we can design a Ku-band TKA with high average output power of about 1.5 GW, 52% efficiency and 46 dB gain.

Superoscillations and Analytic Extension in Schur Analysis

We give applications of the theory of superoscillations to various questions, namely extension of positive definite functions, interpolation of polynomials and also of R-functions; we also discuss possible applications to signal theory and prediction theory of stationary stochastic processes. In all cases, we give a constructive procedure, by way of a limiting process, to get the required results.