Flexural Joints in Mechanisms

2000 ◽  
Author(s):  
M. P. Koster
Keyword(s):  
Consumer Goods ◽  
Design Methodology ◽  
Low Cost ◽  
Point Of View ◽  
Industrial Technology ◽  
Scientific Instruments ◽  
Manufacturing Equipment ◽  
Flexural Fatigue ◽  
Elastic Deflection ◽  
Flexural Joints

Abstract The application of flexural joints in mechanisms has a number of advantages. Extreme repeatability of position is obtained because of the absence of backlash and friction. From a tribological point of view, no lubrication is needed and no wear exists. In many cases their application gives rise to a low cost assembly. Flexural elements have their particular drawbacks as well. Deflections are limited; only oscillating motions can be performed and work has to be done as a consequence of the elastic deflection. Flexural fatigue sets another limit to their application. The paper gives an overview of a design methodology that has been developed at the Philips Center for Industrial Technology by the author and his colleagues over the last several decades. Some aspects of this methodology are well known; other aspects are unique. The methodology is described in detail in a book by the author about design principles (Koster 1998). The methodology has been used to design hundreds of practical mechanisms incorporated in scientific instruments, manufacturing equipment and consumer goods. Many examples are given in (Koster 1998). Several interesting examples are given in this paper.

scholarly journals A Feasibility Study of the Use of Smartwatches in Wearable Fall Detection Systems

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2254
Author(s):  
Francisco Javier González-Cañete ◽  
Eduardo Casilari
Keyword(s):  
Low Cost ◽  
Fall Detection ◽  
The Elderly ◽  
Point Of View ◽  
False Alarms ◽  
Battery Life ◽  
Area Network ◽  
Battery Lifetime ◽  
Detection Systems ◽  
Operational Aspects

Over the last few years, the use of smartwatches in automatic Fall Detection Systems (FDSs) has aroused great interest in the research of new wearable telemonitoring systems for the elderly. In contrast with other approaches to the problem of fall detection, smartwatch-based FDSs can benefit from the widespread acceptance, ergonomics, low cost, networking interfaces, and sensors that these devices provide. However, the scientific literature has shown that, due to the freedom of movement of the arms, the wrist is usually not the most appropriate position to unambiguously characterize the dynamics of the human body during falls, as many conventional activities of daily living that involve a vigorous motion of the hands may be easily misinterpreted as falls. As also stated by the literature, sensor-fusion and multi-point measurements are required to define a robust and reliable method for a wearable FDS. Thus, to avoid false alarms, it may be necessary to combine the analysis of the signals captured by the smartwatch with those collected by some other low-power sensor placed at a point closer to the body’s center of gravity (e.g., on the waist). Under this architecture of Body Area Network (BAN), these external sensing nodes must be wirelessly connected to the smartwatch to transmit their measurements. Nonetheless, the deployment of this networking solution, in which the smartwatch is in charge of processing the sensed data and generating the alarm in case of detecting a fall, may severely impact on the performance of the wearable. Unlike many other works (which often neglect the operational aspects of real fall detectors), this paper analyzes the actual feasibility of putting into effect a BAN intended for fall detection on present commercial smartwatches. In particular, the study is focused on evaluating the reduction of the battery life may cause in the watch that works as the core of the BAN. To this end, we thoroughly assess the energy drain in a prototype of an FDS consisting of a smartwatch and several external Bluetooth-enabled sensing units. In order to identify those scenarios in which the use of the smartwatch could be viable from a practical point of view, the testbed is studied with diverse commercial devices and under different configurations of those elements that may significantly hamper the battery lifetime.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

Natural Locomotion Based on Foot-Mounted Inertial Sensors in a Wireless Virtual Reality System

2015 ◽  
Vol 24 (4) ◽  
pp. 298-321 ◽  
Author(s):  
Ernesto de la Rubia ◽  
Antonio Diaz-Estrella
Keyword(s):  
Virtual Reality ◽  
Gait Cycle ◽  
Inertial Sensors ◽  
Low Cost ◽  
Point Of View ◽  
Handheld Devices ◽  
Preliminary Evaluation ◽  
Virtual Reality System ◽  
Object Searching

Virtual reality has become a promising field in recent decades, and its potential now seems clearer than ever. With the development of handheld devices and wireless technologies, interest in virtual reality is also increasing. Therefore, there is an accompanying interest in inertial sensors, which can provide such advantages as small size and low cost. Such sensors can also operate wirelessly and be used in an increasing number of interactive applications. An example related to virtual reality is the ability to move naturally through virtual environments. This is the objective of the real-walking navigation technique, for which a number of advantages have previously been reported in terms of presence, object searching, and collision, among other concerns. In this article, we address the use of foot-mounted inertial sensors to achieve real-walking navigation in a wireless virtual reality system. First, an overall description of the problem is presented. Then, specific difficulties are identified, and a corresponding technique is proposed to overcome each: tracking of foot movements; determination of the user’s position; percentage estimation of the gait cycle, including oscillating movements of the head; stabilization of the velocity of the point of view; and synchronization of head and body yaw angles. Finally, a preliminary evaluation of the system is conducted in which data and comments from participants were collected.

Overheated stomachs: notes on urban life and toxicity in Nakuru, Kenya

Africa ◽  
2021 ◽  
Vol 91 (3) ◽  
pp. 453-472
Author(s):  
Nick Rahier
Keyword(s):  
Consumer Goods ◽  
Point Of View ◽  
Urban Life ◽  
Processed Foods ◽  
Secondary City ◽  
National Borders

AbstractIn Nakuru, a secondary city in Kenya, herbal doctors argue that African bodies are infested by ‘dirt’. Gathering at crossroads, they teach about the dangerous effects of processed foods on African bodies. During public product demonstrations, they patch together urban gossip, kemikali (chemicals in Kiswahili) and consumer goods from abroad to demonstrate their overheating effects on stomachs. In this article, I think through metabolism and digestion to demonstrate how ‘navigating’ urban toxicity in Nakuru implies a bodily praxis that hinges on debates about the porosity of the nation's borders responding to the afflictions of globalization. I show how the occult character of kemikali pivots on the collapse between insides and outsides, leading to overheating stomachs, and consequently argue that herbal interventions coating the lining of the stomach and the gut do what national borders are unable to achieve: keeping out toxic intrusions. From this point of view, herbal practices in Nakuru demonstrate agency and resistance to worlds perceived as increasingly toxic and polluted.

Evaluating and Exploring Successful Disruptive Innovation in the Aviation Industry From the Perspective of Consumers

2021 ◽  
Vol 13 (4) ◽  
pp. 105-119
Author(s):  
Gang-Hoon Seo
Keyword(s):  
Word Of Mouth ◽  
Low Cost ◽  
Disruptive Innovation ◽  
Point Of View ◽  
Aviation Industry ◽  
Basic Service ◽  
Low Cost Carriers ◽  
Content Analyses ◽  
Southwest Airlines

Since Southwest Airlines' disruptive innovation was introduced, low-cost carriers (LCCs) have had a prominent impact on the aviation industry. Therefore, considerable attention has been paid to the LCC model. However, it is still not clear whether it is a successful disruptive innovation, or what factors and differentiation points for successful LCC service exist from the passengers' perspective. As this study's methodology, quantitative and qualitative content analyses are conducted using the word-of-mouth data of 1,854 passengers of 20 airlines. This study found that the LCC model is perceived as a successful disruptive innovation from the passengers' point of view. For successful LCC service, LC airlines should offer higher quality services than passengers' expectations using basic service elements. Also, good staff characteristics, leaving a professional impression, and providing good optional services could play a role as differentiation tools.

Web-based tools for collaborative research

2017 ◽  
Vol 34 (8) ◽  
pp. 8-19
Author(s):  
Stacy Brody
Keyword(s):  
Collaborative Research ◽  
Design Methodology ◽  
Research Collaboration ◽  
Low Cost ◽  
Research Process ◽  
Web Based ◽  
Content Type ◽  
Collaborative Tools ◽  
Start Ups ◽  
Practical Implications

Purpose The purpose of this paper is to profile various types of Web-based tools to facilitate research collaboration within and across institutions. Design/methodology/approach Various Web-based tools were tested by the author. Additionally, tutorial videos and guides were reviewed. Findings There are various free and low-cost tools available to assist in the collaborative research process, and librarians are well-positioned to facilitate their usage. Practical implications Librarians and researchers will learn about various types of tools available at free or at low cost to fulfill needs of the collaborative research process. Social implications As the tools highlighted are either free or of low cost, they are also valuable to start-ups and can be recommended for entrepreneurs. Originality/value As the realm of Web-based collaborative tools continues to evolve, the options must be continually revisited and reviewed for currency.

scholarly journals PHOTOGRAMMETRY AS A PARTICIPATORY RECOVERY TOOL AFTER DISASTERS: A GROUNDED FRAMEWORK FOR FUTURE GUIDELINES

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 921-928
Author(s):  
C. Pezzica ◽  
A. Piemonte ◽  
C. Bleil de Souza ◽  
V. Cutini
Keyword(s):  
Low Cost ◽  
Central Italy ◽  
Semantic Content ◽  
Ethnographic Study ◽  
Point Of View ◽  
Humanitarian Response ◽  
Central Italy Earthquake ◽  
Depth Analysis ◽  
Crowdsourced Data ◽  
Fit For Purpose

<p><strong>Abstract.</strong> This paper identifies the application domain, context of use, processes and goals of low-cost street-level photogrammetry after urban disasters. The proposal seeks a synergy between top-down and bottom-up initiatives carried out by different actors during the humanitarian response phase in data scarce contexts. By focusing on the self-organisation capacities of local people, this paper suggests using collaborative photogrammetry to empower communities hit by disasters and foster their active participation in recovery and reconstruction planning. It shows that this task may prove technically challenging depending on the specifics of the collected imagery and develops a grounded framework to produce user-centred image acquisition guidelines and fit-for-purpose photogrammetric reconstruction workflows, useful in future post-disaster scenarios. To this end, it presents an in-depth analysis of a collaborative photographic mapping initiative undergone by a group of citizen-scientists after the 2016 Central Italy earthquake, followed by the explorative processing of some sample datasets. Specifically, the paper firstly presents a visual ethnographic study of the photographic material uploaded by participants from September 2016 to November 2018 in the two Italian municipalities of Arquata del Tronto and Norcia. Secondly, it illustrates from a technical point of view issues concerning the processing of crowdsourced data (e.g. image filtering, selection, quality, semantic content and 3D model scaling) and discusses the viability of using it to enrich the pool of geo-information available to stakeholders and decision-makers. Final considerations are discussed as part of a grounded framework for future guidelines tailored to multiple goals and data processing scenarios.</p>

scholarly journals Interface Engineering for Perovskite Solar Cells Based on 2D-Materials: A Physics Point of View

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5843
Author(s):  
Rosaria Verduci ◽  
Antonio Agresti ◽  
Valentino Romano ◽  
Giovanna D’Angelo
Keyword(s):  
Solar Cells ◽  
Transition Metal ◽  
2D Materials ◽  
Low Cost ◽  
Transition Metal Dichalcogenides ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Point Of View ◽  
Physical Mechanisms ◽  
Metal Dichalcogenides

The last decade has witnessed the advance of metal halide perovskites as a promising low-cost and efficient class of light harvesters used in solar cells (SCs). Remarkably, the efficiency of lab-scale perovskite solar cells (PSCs) reached a power conversion efficiency of 25.5% in just ~10 years of research, rivalling the current record of 26.1% for Si-based PVs. To further boost the performances of PSCs, the use of 2D materials (such as graphene, transition metal dichalcogenides and transition metal carbides, nitrides and carbonitrides) has been proposed, thanks to their remarkable optoelectronic properties (that can be tuned with proper chemical composition engineering) and chemical stability. In particular, 2D materials have been demonstrated as promising candidates for (i) accelerating hot carrier transfer across the interfaces between the perovskite and the charge extraction layers; (ii) improving the crystallization of the perovskite layers (when used as additives in the precursor solution); (iii) favoring electronic bands alignment through tuning of the work function. In this mini-review, we discuss the physical mechanisms underlying the increased efficiency of 2D material-based PSCs, focusing on the three aforementioned effects.

Data mining in anti-money laundering field

2017 ◽  
Vol 20 (3) ◽  
pp. 301-310 ◽  
Author(s):  
Noriaki Yasaka
Keyword(s):  
Data Mining ◽  
Knowledge Management ◽  
Money Laundering ◽  
Design Methodology ◽  
Point Of View ◽  
Important Task ◽  
Content Type ◽  
Suspicious Transaction ◽  
Mining Methods ◽  
The Creation

Purpose This report aims to focus on how suspicious transaction report is created with data mining methods and used from the point of view of knowledge management. Design/methodology/approach This paper considers data mining versus knowledge management in the anti-money laundering (AML) field. Findings In the AML field, the information and knowledge gained are not necessarily used for or shared with the related shareholders. Creating and co-evolving the network of “knowledge professionals” is the impending assignment in this industry. The first and most important task is knowledge management in the global AML field. Originality/value The report considers the creation with data mining methods and utilization from the point of view of knowledge management.

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