Statistical Characteristics of Optical Signals and Images in Machine Vision Systems

The chapter is devoted to the creation of a comprehensive approach to the physical and mathematical description of signals in optoelectronics in machine vision, taking into account the phenomena of interaction of optical radiation with system elements. A new methodology for the study of the statistical properties of input and output signals in optoelectronic systems is proposed, taking into account the availability of grouped statistical properties that do not obey the Poisson statistics. The basis is the joint use of wave and corpuscular description of signals in systems, stochastic flow theories, and elements of statistical detection theory. Information and energetic technology have been developed that integrates the theoretical justification of signal description under various observation conditions and decision-making methods.

A Critical Appraisal of Theory and Methodology of Irrigation Systems in the Chemical Debridement of the Root Canal System

Irrigation of the endodontic space is one of the most important steps in the chemical-mechanical treatment of the root canal. Since endodontic infections have been shown to be a result of the microbial factor, debris, bacterial biofilm, planktonic bacteria and pulp tissue removal by means of irrigation has gained significant emphasis over the past half century. No sector of endodontics has undergone so much change and raised so much interest, resulting in thousands of studies, as the irrigation of the endodontic space. Studies do not continue to flow, theories do not cease to be formulated, hypotheses do not cease to be launched, new and new techniques and devices are launched on the market in order to optimize this process both in time and effect. The present study aimed to review the most popular methods, not all, along with the most used irrigants, not all of them.

Investigating the Relationship of Corporate Cash Holdings, Corporate Governance, and Firm Performance in Malaysia

Current practice shows that firms throughout the world are in favor of high cash holdings; yet, they are still performing well. This situation contradicts the agency and free cash flow theories, which suggest that excessive cash may increase agency costs and lower firm performance. The purpose of this study is to examine the relationship between corporate governance, cash holdings, and firm performance. Five thousand four hundred twenty observations were conducted, and a balanced panel data analysis was performed. The results indicate that corporate governance has a significant impact on cash holdings, corporate governance has a significant impact on firm performance, and cash holding has a significant impact on a firm's performance. The findings of this study do not show any evidence to support the agency and free cash flow theories among non-financial Malaysian firms listed on Bursa Malaysia. Thus, this study contributes to the finance and accounting literature by gaining a better understanding of firm performance indicators in Malaysia, specifically.

High-enthalpy hypersonic flows

Nearly all illuminating classic hypersonic flow theories address aerodynamic phenomena as a perfect gas in the high-speed range and at the upper limit of continuum gas domain. The hypersonic flow is quantitatively defined by the Mach number independent principle, which is derived from the asymptotes of the Rankine-Hugoniot relationship. However, most hypersonic flows encounter strong shock-wave compressions resulting in a high enthalpy gas environment that always associates with nonequilibrium thermodynamic and quantum chemical-physics phenomena. Under this circumstance, the theoretic linkage between the microscopic particle dynamics and macroscopic thermodynamics properties of gas is lost. When the air mixture is ionized to become an electrically conducting medium, the governing physics now ventures into the regimes of quantum physics and electromagnetics. Therefore, the hypersonic flows are no longer a pure aerodynamics subject but a multidisciplinary science. In order to better understand the realistic hypersonic flows, all pertaining disciplines such as the nonequilibrium chemical kinetics, quantum physics, radiative heat transfer, and electromagnetics need to bring forth.

Influence of Viscosity and Non-Linearities in Predicting Motions of a Wind Energy Offshore Platform in Regular Waves

Motion predictions of floating bodies in extreme waves represent a challenging problem in naval hydrodynamics. The solution of the seakeeping problem involves the study of complex non-linear wave-body interactions that require large computational costs. For this reason, over the years, many seakeeping models have been formulated in order to predict ship motions using simplified flow theories, usually based on potential flow theories. Neglecting viscous effects in the wave-induced forces might largely underestimate the energy dissipated by the system. This problem is particularly relevant for unconventional floating bodies at resonance. In these operating conditions, the linear assumption is no longer valid, and conventional boundary element methods, based on potential flow, might predict unrealistic large responses if not corrected with empirical viscous damping coefficients. The application considered in this study is an offshore platform to be operated in a wind farm requiring operability even in extreme meteorological conditions. In this paper, we compare heave and pitch response amplitude operators predicted for an offshore platform using three different seakeeping models of increasing complexity, namely, a frequency-domain boundary element method (BEM), a partly nonlinear time domain BEM, and a non-linear viscous model based on the solution of the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. Results are critically compared in terms of accuracy, applicability, and computational costs.

“Ngeli”: Flowing together in a Gamelan ensemble

The purpose of this study was to examine the collective flow experiences of participants while playing in a Gamelan ensemble. Participants were 15 members of a Gamelan ensemble in Singapore who were prompted to articulate their phenomenological experiences through extensive semi-structured interviews. Their responses were then transcribed and analyzed for emergent themes with initial codes guided by flow and collective flow theories. Three themes emerged from the data: community, chemistry, and collective peak. The Javanese term “ ngeli” surfaced from the interviews as a parallel notion to the Western concept of flow. Implications for theory and practice were proffered in light of the findings.

Influence of Mixed Flows on Ship Hydrodynamics in Dredged Channels

Although there is a significant body of research devoted to the shallow water hydrodynamic aspects of ships, several unexamined topics remain. Among these is that of critical outer flow in a dredged channel and its influence on parameters of interest. While empirical methods can be used with ease to resolve this, they can provide results with reliability sufficient only for an early design stage. On the other hand, more sophisticated potential flow theories are either inapplicable or do not perform well at the critical limit. However, RANS (Reynolds Averaged Navier-Stokes) – based tools can accurately capture all underlying phenomena without relying on limiting assumptions. This paper presents an attempt at comparing some results obtained via a CFD-based RANS solver and the slender body theory for critical outer flow in a dredged channel.

How do avatar attractiveness and customization impact online gamers’ flow and loyalty?

Purpose Avatars are known to be influential in gaming communication. However, little is known about how avatar attractiveness and customization impact online gamers’ flow, i.e., the experience of total concentration with intrinsic enjoyment and loyalty. Grounded in social identity and flow theories, the purpose of this paper is to construct a model to explain how avatar attractiveness and customization can impact online gamers’ flow and loyalty. Design/methodology/approach The responses of 1,944 online gamers are collected. Structural equation modeling is used for analyses. Findings The analytical results indicate that avatar attractiveness and customization are positively related to avatar identification, which is positively related to flow, and then to online gamer loyalty. In addition, avatar identification and flow are important process variables in the above relations. Originality/value This study is novel in being the first attempt to apply social identity and flow theories to explain how avatar attractiveness and customization contribute to online gamers’ flow and loyalty.

Interpretation of Four Unique Phenomena and the Mechanism in Unsteady Flow Separation Controls

Unsteady flow separation controls are effective in suppressing flow separations. However, the unique phenomena in unsteady separation control, including frequency-dependent, threshold, location-dependent, and lock-on effects, are not fully understood. Furthermore, the mechanism of the effectiveness that lies in unsteady flow controls remains unclear. Thus, this study aims to interpret further the unique phenomena and mechanism in unsteady flow separation controls. First, numerical simulation and some experimental results of a separated curved diffuser using pulsed jet flow control are discussed to show the four unique phenomena. Second, the bases of unsteady flow control, flow instability, and free shear flow theories are introduced to elucidate the unique phenomena and mechanism in unsteady flow separation controls. Subsequently, with the support of these theories, the unique phenomena of unsteady flow control are interpreted, and the mechanisms hidden in the phenomena are revealed.

The Implications of Investment–Cash Flow Sensitivities for Franchising Firms: Theory and Evidence From the Restaurant Industry

Expansion through franchising could help restaurant firms solve financial constraints, but it could also make overinvestment easier for misaligned CEOs. Whereas the former topic has been extensively examined, the latter has received scant attention from researchers. The purpose of this study is to investigate whether franchising alleviates financial constraints or leads to overinvestment problems in restaurant firms. For this purpose, we analyzed and compared investment–cash flow sensitivities between constrained and unconstrained; franchising and nonfranchising; constrained, franchising and unconstrained, franchising; and constrained, nonfranchising and unconstrained, nonfranchising restaurant firms. The results show that unlike other industries, unconstrained restaurant firms depend more on cash flows for investment than constrained restaurant firms do. Although investment–cash flow sensitivity in nonfranchising restaurant firms was similar to that of firms in other industries, unconstrained restaurant firms that expand through franchising rely more on cash flows. These findings suggest that restaurant firms’ expansion through franchising is likely to increase overinvestment problems. Franchising could serve as a long-term method of financing for financially constrained firms as well as a short-term financing tool. However, unconstrained, franchising firms should distribute their excess cash flows to shareholders. Theoretical implications are discussed within the realms of the franchising, pecking order, and free cash flow theories.