Fundamental Definitions Research Articles

Layer-to-Layer Stability of Linear Layerwise Spatially Varying Systems: Applications in Fused Deposition Modeling

Closed-loop control applications for additive manufacturing (AM) technologies introduce unique challenges in control-oriented modeling and controller development. There have been developments in current literature to model the temporal and spatial dynamics of AM processes. The temporal dynamics of AM processes are often modeled using tools from fluid dynamics and mechanics to represent the material deposition and the motion of the deposition system. Spatial dynamics are often modeled by representing the spreading dynamics of the deposited material in the layerwise spatial domain. An important challenge with the spatial dynamics of AM processes is to understand the performance of the layer-to-layer (L2L) spatial dynamics under spatial disturbances in the system. To this end, this article presents a linear layerwise spatially varying (LLSV) systems modeling framework to represent the L2L spatial height evolution of a generic AM process. The proposed unifying modeling framework can easily represent various AM processes. An L2L stability measure is provided as a performance measure for the spatial dynamic state of an AM process. L2L stability is a novel analysis tool to understand and analyze the spatial characteristics of AM processes. Fundamental L2L stability definitions for a nominal system model and a system model with known Gaussian spatial noise are presented. Theoretical robustness bounds for L2L stability are experimentally compared to a fused deposition modeling (FDM) process. The results show that the theoretical robustness bounds given in this work provide an important foundation for developing novel closed-loop L2L spatial control applications.

Solutions of multiplicative ordinary differential equations via the multiplicative differential transform method

In this study, fundamental definitions and theorems of the Multiplicative Differential Transform Method (MDTM) are given. First and second order multiplicative initial value problems are numerically solved with the help of MDTM.

Safety and Health for the Stage: Collaboration with the Production Process by Willaim J. Reynolds

Reviewed by: Safety and Health for the Stage: Collaboration with the Production Process by Willaim J. Reynolds Ted Kraus Safety and Health for the Stage: Collaboration with the Production Process. By Willaim J. Reynolds. Routledge, 2020, pp. 266. For those of us responsible for designing, implementing, and maintaining safety and health programs for our institutions, it can be daunting (possibly even overwhelming) to know where to begin. The OSHA codebook is intimidating, written in language that is so specific it can be challenging to understand, let alone know how to apply. William Reynolds’s book, Safety and Health for the Stage, advocates for an industry-wide adoption of safety and health programs that represent “a systematic approach to achieving the goal of a positive safety culture” (38). Throughout, he provides the context and vocabulary required to help everyone involved in the artistic endeavor identify what questions to ask in pursuit of this call to arms. Drawing on over thirty years of experience teaching safety classes at the Yale School of Drama as well as his work as the Vice-Chair of the Education and Student Alliance Program in the USITT safety and health commission, Reynolds demystifies the code’s terminology, nomenclature, and structure so that we can focus on what is essential: making our organizations, programs, and facilities safer. Reynolds uses the first two chapters to outline why organizations need these comprehensive safety programs and to give a historical context for OSHA’s relationship with the theatre industry. He stresses the need for developing an integrated and holistic safety culture, beginning at the highest levels of the organization and considered in the earliest stages of the planning process for every production. Organizations must value safety as strongly and intensely as our productions’ budget, schedule, and artistic vision. Safety cannot be an afterthought; it must be a core principle, because safety affects everyone who works in the theatre. Accidents (even seemingly small ones or near misses) have a cost to the organization. We lose time and productivity, which can lead to a drop in the organization’s morale. Reynolds divides hazards into two broad categories: fixed and fluid. The fixed hazards are those associated with routine production activities and typical fabrication processes; fluid hazards are those related and unique to the specific production. Adopting this framework can help the organization clarify its safety needs as it works to design and implement new protocols. In chapters 3 through 6, Reynolds gets deeper into explaining the complexities of safety and health programs. He begins by offering fundamental definitions of terms and concepts used by agencies like OSHA, NIOSH, and NFPA that regulate the codes and standards that inform our practices. Rather than identifying a list of rules that organizations must follow, Reynolds instead gives the reader the information needed to understand and gain agency in developing the required programs. At the core of this approach is the concept that safety programs must be focused on proactive behavior and designed to reduce or eliminate the uncertainty associated with any risk. In addition, these programs must be created collaboratively and embraced by the organization’s leadership and those directly responsible for implementation. Finally, the programs must have the same weight within the organization as the other production-related procedures; we must consider safety at the earliest stages of the production process. In these four chapters, Reynolds defines the recommended components of a thorough program, and shows how these components fit together within an institution’s operating culture. He provides a straightforward path through the complexities of what to do once risks have been identified and quantified. After articulating this systematic approach to planning, Reynolds explains how to work within OSHA’s [End Page 272] Hierarchy of Controls, highlights the difference between codes and standards, and explains what it means to comply with the codes used in the governance of work environments. He recommends specific training and certifications that will help educate the organization’s members, and then summarizes the information into a clear guide for compliance. He neither castigates nor implies that this work is simple; instead, he explains the subject matter in a manner that allows the reader to imagine a better way to...

Philosophical and legal comprehension of constitutional legal consciousness in the works of domestic political and legal thought of the 19th-20th centuries

The article provides a philosophical and legal understanding of the category of constitutional (state) legal consciousness, through the analysis of the works of representatives of domestic political and legal thought of the 19th-20th centuries. The author substantiates the need for a philosophical and legal analysis of constitutional legal consciousness by the importance of such a study in the process of constructing a fundamental definition and concretization of the essential features of this category, which is for the science of constitutional law, where theorists have never come to a consensus on the advisability of constitutional variation of legal consciousness, and therefore never worked out its traditional definition is of absolute importance.

Toward inclusive theories of the evolution of musicality.

We compare and contrast the 60 commentaries by 109 authors on the pair of target articles by Mehr et al. and ourselves. The commentators largely reject Mehr et al.'s fundamental definition of music and their attempts to refute (1) our social bonding hypothesis, (2) byproduct hypotheses, and (3) sexual selection hypotheses for the evolution of musicality. Instead, the commentators generally support our more inclusive proposal that social bonding and credible signaling mechanisms complement one another in explaining cooperation within and competition between groups in a coevolutionary framework (albeit with some confusion regarding terminologies such as "byproduct" and "exaptation"). We discuss the proposed criticisms and extensions, with a focus on moving beyond adaptation/byproduct dichotomies and toward testing of cross-species, cross-cultural, and other empirical predictions.

Surveying the Methodological and Analytical Foundations of the New Institutional Economics: A Critical Comparison with Neoclassical and (Old) Institutional Economics

The purpose of this article is to review the methodological and analytical foundations of the New Institutional Economics by implying a critical comparison with the Neoclassical and (old) Institutional Economics. After a discussion of the fundamental definitions and concepts of the New Institutional Economics, I turn to the critical comparison with other schools of thought. It is shown that the New Institutional Economics does not break fundamentally from the neoclassical economics. To the contrary, it can be fairly argued that the New Institutional Economics is a research program which is developed within and around the dominant neoclassical paradigm. On the other hand, it is argued that the Old and New Institutional Economics constitute two distinct approaches to the analysis of institutions, stemming from different paradigmatic viewpoints that produce and nurture contrasting perspectives on how to theoretically tackle institutions.

Fundamental Definitions for Axially-Strained Piezo-Semiconductive Nanostructures.

Piezoelectric nanotransducers may offer key advantages in comparison with conventional piezoelectrics, including more choices for types of mechanical input, positions of the contacts, dimensionalities and shapes. However, since most piezoelectric nanostructures are also semiconductive, modeling becomes significantly more intricate and, therefore, the effects of free charges have been considered only in a few studies. Moreover, the available reports are complicated by the absence of proper nomenclature and figures of merit. Besides, some of the previous analyses are incomplete. For instance, the local piezopotential and free charges within axially strained conical piezo-semiconductive nanowires have only been systematically investigated for very low doping (1016 cm−3) and under compression. Here we give the definitions for the enhancement, depletion, base and tip piezopotentials, their characteristic lengths and both the tip-to-base and the depletion-to-enhancement piezopotential-ratios. As an example, we use these definitions for analyzing the local piezopotential and free charges in n-type ZnO truncated conical nanostructures with different doping levels (intrinsic, 1016 cm−3, 1017 cm−3) for both axial compression and traction. The definitions and concepts presented here may offer insight for designing high performance piezosemiconductive nanotransducers.

Numerical simulation of lower ionospheric reflection parameters by using International Reference Ionosphere (IRI) model and validation with Very Low Frequency (VLF) radio signal characteristics

Sub-Ionospheric Very Low Frequency (VLF) radio wave propagation characteristics are the major tool to study the lower ionospheric heights mainly D-region. Wait’s 2-component exponential model is a well-known mechanism to understand the basic characteristics of this layer based on VLF remote sensing. This model deals with two major ionospheric parameters, namely, ‘steepness parameter’ (β) and ‘effective reflection height’ (h′). ‘International Reference Ionospheric (IRI)’ is a famous model for the terrestrial ionosphere that provides mostly the altitude profile temperature of the electron and ions globally. In this manuscript, we use such electron density profiles based on IRI outcomes during a quiet ionospheric condition. We choose our VLF reception location ‘Ionospheric and Earthquake Research Center & Optical Observatory’ (IERCOO), Sitapur (Lat 22.5° N, Lon 87.48° E) to compute the electron density from IRI model. By using the Wait’s exponential model with a log-linear fitting of electron density, we compute the β and h′ from their fundamental definition. With an automation technique, we repeat this process several times and generate a complete data set of such parameters for different time of the day during the summer and winter seasons of the year 2016. To get a qualitative comparison with the VLF signal amplitude variation with β and h′, we choose the Indian VLF transmitter VTX of frequency 18.2 kHz (Lat 8.26°N and 77.44°E). By computing similar data sets for other four receiving locations in India, we replicate the VLF signal amplitude profiles using Long Wavelength Propagation Capability (LWPC) model which matches with the observed signal profile satisfactorily.

A conceptual framework for resilience: fundamental definitions, strategies and metrics

The resilience system property has become more and more relevant, mainly because of the increasing dependance on a rapidly growing number of software-intensive, complex, socio-technical systems, which are facing uncertainty about changes they are expected to experience during their life-cycle and ways to deal with them. Methodologies for the systematic design and validation of resilience for such systems are thus highly necessary, and require contributions from several different fields. This paper contributes to current resilience research by providing a conceptual framework intended to serve as a common ground for the development of such methodologies. Its main points are: the identification of the main categories of changes a system should face; a clear definition of the different facets of resilience one could want to achieve, expressed in terms of the system dynamics; a mapping of each of these facets to design strategies that are better suited to achieve it; and the corresponding identification of possible metrics that can be used to assess its achievement.

Cardiovascular management following hypoxic-ischemic encephalopathy in North America: need for physiologic consideration.

BackgroundHypotension and hypoxemic respiratory failure are common among neonates with hypoxic–ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). Right ventricular (RV) dysfunction is associated with adverse neurodevelopment. Individualized management utilizing targeted neonatal echocardiography (TnECHO) may enhance care.MethodsWe evaluated the influence of TnECHO programs on cardiovascular practices in HIE/TH patients utilizing a 77-item REDCap survey. Nominated representatives of TnECHO (n = 19) or non-TnECHO (n = 96) sites were approached.ResultsSeventy-one (62%) sites responded. Baseline neonatal intensive care unit characteristics and HIE volume were comparable between groups. Most centers monitor invasive blood pressure; however, we identified 17 unique definitions of hypotension. TnECHO centers were likelier to trend systolic/diastolic blood pressure and request earlier echocardiography. TnECHO responders were less likely to use fluid boluses; TnECHO responders more commonly chose an inotrope first-line, while non-TnECHO centers used a vasopressor. For HRF, TnECHO centers chose vasopressors with a favorable pulmonary vascular profile. Non-TnECHO centers used more dopamine and more extracorporeal membrane oxygen for patients with HRF.ConclusionsCardiovascular practices in neonates with HIE differ between centers with and without TnECHO. Consensus regarding the definition of hypotension is lacking and dopamine use is common. The merits of these practices among these patients, who frequently have comorbid pulmonary hypertension and RV dysfunction, need prospective evaluation.Impact Cardiovascular care following HIE while undergoing therapeutic hypothermia varies between centers with access to trained hemodynamics specialists and those without.Because cardiovascular dysfunction is associated with brain injury, precision medicine-based care may be an avenue to improving outcomes.Therapeutic hypothermia has introduced new physiological considerations and enhanced survival. It is essential that hemodynamic strategies evolve to keep pace; however, little literature exists.Lack of consensus regarding fundamental definitions (e.g., hypotension) highlights the importance of collaboration among the scientific community to advance the field.The value of enhanced cardiovascular care guided by hemodynamic specialists requires prospective evaluation.

Delayed Treatment and Missed Opportunities for Limb Salvage in Patients with Peripheral Arterial Embolism

BACKGROUND: The peripheral arterial embolism (PAE) is a sudden decrease in limb perfusion due to acute occlusion of peripheral artery which leads to ischemic tissue damage, that can threaten the limb of a patient and requires immediate revascularization. It is estimated that the incidence of acute limb emoblism in the general population is around 14/100,000 inhabitants per year. Accurate and timely diagnosis is crucial to salvage the patient’s limb and sometimes the patient’s life. In cases of complete arterial occlusion and absence of collateral perfusion, irreversible damage can occur within 4 to 6 hours. The fundamental definition for treatment of acute peripheral arterial embolism is revascularisation. Revascularisation is either performed endovascularly or by an open surgical approach. A suspicion of acute ischemia based on history and physical examination warrants heparin administration and vascular surgery consultation. Delays in the management of acute peripheral arterial ischemia due to an embolism are common and associated with poor limb - salvage outcomes.
 AIM: Our study aims to identify medical consultations and cardiovascular assessments undergone by patients in the period prior to being hospitalised, in order to evaluate for missed or delayed opportunities for diagnosis.
 METHODS: Retrospective cohort study, utilising the medical documentation and previous outpatiently or inhospital consultations. Adult patients undergone treatment due to peripheral arterial embolism were identified and analyzed. Patients were identified through the administrative hospital database using the International Classification of Diseases. Hospitalised patients with those medcodes between 1st January 2010 - 1st March 2020 were recorded.
 RESULTS: Following exclusion, 424 patients (mean age 68.5 ± 5.85 years) were included. 159 patients (66.8%) had visited their family doctors or other medical specialist before admission and in all of the cases was initiated therapeutic approach. The rest of the cohort 79 patients (33.2%) presented lately due to other social reasons. The group of 159 patients that admitted lately due to medical indications - diagnostic, healthcare - administrative or treatment related problems are subject of our study. The largest group including 113 (71%) patients were treated outpatientley by vascular surgeons with preventative medications.17 patients (10.6%) were directed outpatientley to orthopaedic surgeon due to suspicion of trauma.15 patients (9.4%) were treated by their family doctors with pain relief medications. The rest of the 14 patients (8.8%) were treated by neurosurgeons or neurologists due to a suspicion of cauda eniqua and other neuropathies. The majority of the patients 108 (67.9%) were free of complains at the discharge, 11.3% of the studied cohort were with minimal post-treatment complains (numbness, coldness, absent peripheral pulsations, insignificant claudicatio). Amputation rate was 14.4%, incidence of rethrombosis 8.8% and recurrent embolism frequency around 3.7%. Death was registered in 21 cases (13.2%).
 CONCLUSION: The consequences of acute limb embolism such as prolonged hospitalization, major limb amputation, and/or death have a profound socioeconomic impact. Unrecognition of this vascular pathology and differential diagnosis difficulties are possibly leading factors for delayed or missed treatment.

Tocilizumab versus the Covid19 tempest: All’s well that ends well or much ado about nothing?

Tocilizumab versus the Covid19 tempest: All’s well that ends well or much ado about nothing?

Cyclostationary Analysis towards Fault Diagnosis of Rotating Machinery

In the light of the significance of the rotating machinery and the possible severe losses resulted from its unexpected defects, it is vital and meaningful to exploit the effective and feasible diagnostic methods of its faults. Among them, the emphasis of the analysis approaches for fault type and severity is on the extraction of useful components in the fault features. On account of the common cyclostationarity of vibration signal under faulty states, fault diagnosis methods based on cyclostationary analysis play an essential role in the rotatory machine. Based on it, the fundamental definition and classification of cyclostationarity are introduced briefly. The mathematical principles of the essential cyclic spectral analysis are outlined. The significant applications of cyclostationary theory are highlighted in the fault diagnosis of the main rotating machinery, involving bearing, gear, and pump. Finally, the widely-used methods on the basis of cyclostationary theory are concluded, and the potential research directions are prospected.

New paradigm in the metrology of concrete surface morphology: Methods, parameters and applications

This article provides a new paradigm of concrete surface morphology and discusses the fundamental definitions of concrete surface metrology. The basic phenomena of the morphology of concrete are discussed. It also presents a synthetic description of widespread metrological methods used for characterizing the morphology of concrete surfaces. The critical analysis lists the advantages and weaknesses of the described methods. The classification and definitions of parameters useful for describing the morphology of surfaces is also presented. This classification particularly includes three-dimensional parameters (height, spatial, hybrid parameters, functions and related parameters, as well as miscellaneous parameters), which are also discussed in the context of concrete surfaces. The application of surface morphology methods in concrete has been widely investigated over the past decades. For this purpose, the selected examples of applications of the discussed methods and parameters for the measurement of the morphology of concrete surfaces are also specified.

Power System Mode Metering in the Presence of Non-Gaussian Noise

This letter presents a robust generalized correlation approach for monitoring of power system oscillatory modes. Due to the non-Gaussian nature of measurement noise, and presence of impulsive outliers, the wide-sense stationarity assumption of power system measurement data is violated even under ambient conditions thus limiting the effectiveness of conventional autocorrelation based approaches in mode metering. The fundamental definition of correlation function for power system measurements is extended to a generalized correlation function in order to incorporate higher order statistics into existing modal estimation technique. Simulations on synthetic and real-life test signals have been conducted to demonstrate the robustness of the proposed method.

A review on issues, challenges and various optimization techniques in microgrid

A drastic change in the increase of carbon emission and green-houses gases has increased the demand of the use of Renewable Energy Sources (RESs). The integration of renewable energy in a power system network is due to the fact that the available natural resources are depleting at a faster rate. Microgrid with different configurations along with the development of smart grids ensures a paradigm shift from centralised to decentralized control. The installations done at the demand side of distributed generation marks change in the forthcoming years in the electricity markets both at the generating and distribution end. With the introduction of Microgrid the hedging of investment is done in different sectors of the electric industry such as generation operations, etc., easily. This review paper gives an idea about fundamental definition of a Microgrid (MGs); classification of Microgrid, issues, and challenges associated and optimization techniques for the overall stability and security of the grid.

Detection of Outlying Cells in Contingency Tables Using Model Based Diagnostics

Detecting outliers in contingency table is an interesting statistical problem and it poses additional difficulties due to the polarization of cell counts. The fundamental definition of 'markedly deviant' cell as an outlier is clearly exploited in this study by introducing a pivot element to capture the deviations. The present study considers a two-step confirmatory procedure to detect outliers in I x J contingency table. The procedure deals with (i) identifying the reliable set of candidate outliers using the deviation from the pivot element and then (ii) detect those set of outlying cells by examining different type of residuals of the suitable fitted model. The robustness of the procedure is investigated through a simulation study along with applications to real datasets.

Irritable Bowel Syndrome: Straightening the road from the Rome criteria.

A sequence of consensus-based Rome criteria for irritable bowel syndrome (IBS) has been published since 1989. The fundamental definition based on abdominal pain in association with bowel dysfunction has been consistent. However, two major changes occurred in the Rome II and IV criteria. The former change involved "splitting off" of symptoms that were not consistently associated with pain, such as functional, constipation, diarrhea, and bloating. In Rome IV, the main changes were the exclusion of discomfort (in contrast to pain) and the more stringent frequency criteria for the pain to be eligible for diagnosis of IBS (specifically, on average, at least 1day per week in the last 3months). Validation studies of the consensus, symptom-based criteria have identified multiple deficiencies that question the rationale for "splitting" the different syndromes, and favor a simpler identification of the classical symptoms of abdominal pain, bowel dysfunction, and bloating, and exclusion of alarm symptoms. Advances in the identification of actionable biomarkers related to the symptoms suggestive of functional gastrointestinal disorders have the potential to usher a change in practice from positive diagnosis of symptom complexes followed by empirical treatment to identification of the mechanisms causing the symptoms and targeted therapy.

Understanding and managing identification uncertainty of close modes in operational modal analysis

Close modes are much more difficult to identify than well-separated modes and their identification (ID) results often have significantly larger uncertainty or variability. The situation becomes even more challenging in operational modal analysis (OMA), which is currently the most economically viable means for obtaining in-situ dynamic properties of large civil structures and where ID uncertainty management is most needed. To understand ID uncertainty and manage it in field test planning, this work develops the ‘uncertainty law’ for close modes, i.e., closed form analytical expressions for the remaining uncertainty of modal parameters identified using output-only ambient vibration data. The expressions reveal a fundamental definition that quantifies ‘how close is close’ and demystify the roles of various governing factors. The results are verified with synthetic, laboratory and field data. Statistics of governing factors from field data reveal OMA challenges in different situations, now accountable within a coherent probabilistic framework. Recommendations are made for planning ambient vibration tests taking close modes into account. Up to modelling assumptions and the use of probability, the uncertainty law dictates the achievable precision of modal properties regardless of the ID algorithm used. The mathematical theory behind the results in this paper is presented in a companion paper.

Estimation of dispersion coefficient in a solid-liquid fluidised bed system

Particle dispersion behaviour in a solid liquid fluidised system leads to interesting outcomes such as mixing and segregation which are often quantified by an empirical dispersion coefficient. The present study aims at providing a better estimation of particle dispersion behaviour from a fundamental definition analogous to diffusion coefficient. By tracking a tracer particle using high speed image analysis, fluctuating velocity components (Vi/) were determined in a solid-liquid fluidised bed comprising glass particles (dS = 8 mm, ρS = 2230 kg m−3) and water as a fluidising medium. Both inter-particle and particle-wall collisions were determined from the time varying jerk data. The particle mean-free path (λ) was then estimated as a distance between two successive peaks in the jerk profile. Finally, dispersion efficient D was computed based on the product of λ and V. Estimated dispersion coefficients were compared with the available correlations and reasonable agreement was obtained.