scholarly journals Optimising the Performance of Complex Sociotechnical Systems in High-Stress, High-Speed Environments: The Formula 1 Pit Stop Test Case

2021 ◽  
Vol 11 (24) ◽  
pp. 11873
Author(s):  
David Slater ◽  
Rees Hill ◽  
Maneesh Kumar ◽  
Ben Ale
Keyword(s):  
High Speed ◽  
High Stress ◽  
Sociotechnical Systems ◽  
Test Case ◽  
Sociotechnical System ◽  
Resonance Analysis ◽  
Alternative Approach ◽  
New Development ◽  
Stop Test ◽  
Flow Diagrams

In analysing the performance of complex sociotechnical systems, of particular interest is the inevitable and inherent variability that these systems exhibit, but can normally tolerate, in successfully operating in the real world. Knowing how that variability propagates and impacts the total function mix then allows an understanding of emergent behaviours. This interdependence, however, is not readily apparent from normal linear business process flow diagrams. An alternative approach to exploring the operability of complex systems, that addresses these limitations, is the functional resonance analysis method (FRAM). This is a way of visualising a system’s behaviour, by defining it as an array of functions, with all the interactions and interdependencies that are needed for it to work successfully. Until now this methodology has mainly been employed as a qualitative mind map. This paper describes a new development of the FRAM visualisation software that allows the quantification of the extent and effects of this functional variability. It then sets out to demonstrate its application in a practical, familiar test case. The example chosen is the complex sociotechnical system involved in a Formula 1 pit stop. This has shown the potential of the application and provided some interesting insights into the observed performances.

Can Cultural Differences Lead to Accidents? Team Cultural Differences and Sociotechnical System Operations

2010 ◽  
Vol 52 (2) ◽  
pp. 246-263 ◽  
Author(s):  
Barry Strauch
Keyword(s):  
Cultural Differences ◽  
Team Performance ◽  
High Stress ◽  
Cultural Factors ◽  
Review Literature ◽  
Sociotechnical Systems ◽  
Future Research ◽  
Sociotechnical System ◽  
Considerable Work ◽  
Perceptual Styles

Objective: I discuss cultural factors and how they may influence sociotechnical system operations. Background: Investigations of several major transportation accidents suggest that cultural factors may have played a role in the causes of the accidents. However, research has not fully addressed how cultural factors can influence sociotechnical systems. Method: I review literature on cultural differences in general and cultural factors in sociotechnical systems and discuss how these differences can affect team performance in sociotechnical systems. Results: Cultural differences have been observed in social and interpersonal dimensions and in cognitive and perceptual styles; these differences can affect multioperator team performance. Conclusion: Cultural factors may account for team errors in sociotechnical systems, most likely during high-workload, high-stress operational phases. However, much of the research on cultural factors has methodological and interpretive shortcomings that limit their applicability to sociotechnical systems. Application: Although some research has been conducted on the role of cultural differences on team performance in sociotechnical system operations, considerable work remains to be done before the effects of these differences can be fully understood. I propose a model that illustrates how culture can interact with sociotechnical system operations and suggest avenues of future research. Given methodological challenges in measuring cultural differences and team performance in sociotechnical system operations, research in these systems should use a variety of methodologies to better understand how culture can affect multioperator team performance in these systems.

Endoscopy-assisted removal of periorbital inclusion cysts in children

2011 ◽  
Vol 7 (2) ◽  
pp. 161-164 ◽  
Author(s):  
George Chater-Cure ◽  
Caitlin Hoffman ◽  
Jared Knopman ◽  
Samuel Rhee ◽  
Mark M. Souweidane
Keyword(s):  
High Speed ◽  
Complete Removal ◽  
Skin Incision ◽  
Clinical Findings ◽  
Complete Excision ◽  
Alternative Approach ◽  
Cyst Recurrence ◽  
Scalp Incision ◽  
Access Technique

Object Surgical treatment for periorbital inclusion cysts typically involves a brow, pterional, or partial bicoronal scalp incision for sufficient exposure. The authors have recently employed an endoscopy-assisted technique as an alternative approach intended to minimize the length of the skin incision and avoid scarring in the brow. Methods Children having typical clinical findings of a dermoid cyst located on the hairless forehead were selected to undergo endoscopy-assisted cyst removal. For suspected intradiploic lesions, MR imaging was used to assess osseous involvement. After induction of general anesthesia, a 1–2-cm curvilinear incision was made posterior to the hairline. A 30°-angled endoscope (4 mm) was then used for dissection in the subgaleal compartment. Subgaleal dissection was followed by a circumferential periosteal incision in which the authors used an angled needle-tip unipolar cautery. For lesions within the diploe, a high-speed air drill was used to expose the lesion. Complete removal was accomplished with curettage of either the skull or dural surface. Results Eight patients (5–33 months of age) underwent outpatient endoscopic resection. Seven cysts were extracranial, and 1 cyst extended through the inner table. In all patients complete excision of the cyst was achieved. There was negligible blood loss, no dural violation, and no postoperative infection. There have been no recurrences at a mean follow-up of 15 months. Conclusions Endoscopy-assisted resection of inclusion cysts of the scalp and calvaria is a safe and effective surgical approach. The technique results in negligible incisions with less apparent scarring compared with previously described incisions. This limited-access technique does not appear to be associated with a higher incidence of cyst recurrence.

scholarly journals Analysis of ATO System Operation Scenarios Based on UPPAAL and the Operational Design Domain

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 503
Author(s):  
Zicong Meng ◽  
Tao Tang ◽  
Guodong Wei ◽  
Lei Yuan
Keyword(s):  
High Speed ◽  
Test Case ◽  
Design Domain ◽  
System Operation ◽  
High Speed Railway ◽  
Functional Specification ◽  
Operational Design ◽  
Train Operation ◽  
System Requirements ◽  
Automatic Train Operation

With the gradual maturity of the automatic train operation (ATO) system in subways, its application scope has also expanded to the high-speed railway field. Considering that the ATO system is still in the early stages of operation, it will take time to fully mature, and definite specifications of the requirements for system operation have not yet been formed. This paper presents the operational design domain (ODD) of the high-speed railway ATO system and proposes a scenario analysis method based on the operational design domain to obtain the input conditions of the system requirements. The article models and verifies the scenario of the linkage control of the door and platform door based on the UPPAAL tools and extracts the input and expected output of the system requirements of the vehicle ATO system. Combined with the input conditions of the system requirements, the system requirements of the vehicle ATO in this scenario are finally obtained, which provides a reference for future functional specification generation and test case generation.

A New Shaft Coupling Design for a High-Speed Rotor Wheel

1995 ◽  
Author(s):  
Tibor Kiss ◽  
Wing-Fai Ng ◽  
Larry D. Mitchell
Keyword(s):  
High Speed ◽  
High Stress ◽  
Critical Issue ◽  
Working Environment ◽  
Outer Diameter ◽  
Stress Concentrations ◽  
Coupling Region ◽  
Rotor Wheel ◽  
High Stress Concentration ◽  
Safety Margins

Abstract A high-speed rotor wheel for a wind-tunnel experiment has been designed. The rotor wheel was similar to one in an axial turbine, except that slender bars replaced the blades. The main parameters of the rotor wheel were an outer diameter of 10“, a maximum rotational speed of 24,000 RPM and a maximum transferred torque of 64 lb-ft. Due to the working environment, the rotor had to be designed with high safety margins. The coupling of the rotor wheel with the shaft was found to be the most critical issue, because of the high stress concentration factors associated with the conventional coupling methods. The efforts to reduce the stress concentrations resulted in an advanced coupling design which is the main subject of the present paper. This new design was a special key coupling in which six dowel pins were used for keys. The key slots, now pin-grooves, were placed in bosses on the inner surface of the hub. The hub of the rotor wheel was relatively long, which allowed for applying the coupling near the end faces of the hub, that is, away from the highly loaded centerplane. The long hub resulted in low radial expansion in the coupling region. Therefore, solid contact between the shaft and the hub could be maintained for all working conditions. To develop and verify the design ideas, stress and deformation analyses were carried out using quasi-two-dimensional finite element models. An overall safety factor of 3.7 resulted. The rotor has been built and successfully accelerated over the design speed in a spin test pit.

Turbine Nozzle Endwall Phantom Cooling With Compound Angled Pressure Side Injection

2018 ◽  
Author(s):  
Kevin Liu ◽  
Hongzhou Xu ◽  
Michael Fox
Keyword(s):  
Film Cooling ◽  
High Speed ◽  
Axial Direction ◽  
Secondary Flows ◽  
Test Case ◽  
Pressure Side ◽  
Complex Flow ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Extended Area

Cooling of the turbine nozzle endwall is challenging due to its complex flow field involving strong secondary flows. Increasingly-effective cooling schemes are required to meet the higher turbine inlet temperatures required by today’s gas turbine applications. Therefore, in order to cool the endwall surface near the pressure side of the airfoil and the trailing edge extended area, the spent cooling air from the airfoil film cooling and pressure side discharge slots, referred to as “phantom cooling” is utilized. This paper studies the effect of compound angled pressure side injection on nozzle endwall surface. The measurements were conducted in a high speed linear cascade, which consists of three nozzle vanes and four flow passages. Two nozzle test models with a similar film cooling design were investigated, one with an axial pressure side film cooling row and trailing edge slots; the other with the same cooling features but with compound angled injection, aiming at the test endwall. Phantom cooling effectiveness on the endwall was measured using a Pressure Sensitive Paint (PSP) technique through the mass transfer analogy. Two-dimensional phantom cooling effectiveness distributions on the endwall surface are presented for four MFR (Mass Flow Ratio) values in each test case. Then the phantom cooling effectiveness distributions are pitchwise-averaged along the axial direction and comparisons were made to show the effect of the compound angled injection. The results indicated that the endwall phantom cooling effectiveness increases with the MFR significantly. A compound angle of the pressure side slots also enhanced the endwall phantom cooling significantly. For combined injections, the phantom cooling effectiveness is much higher than the pressure side slots injection only in the endwall downstream extended area.

scholarly journals Reverse Thrust Aerodynamics of Variable Pitch Fans

2018 ◽  
Author(s):  
Tim S. Williams ◽  
Cesare A. Hall
Keyword(s):  
High Speed ◽  
Pressure Ratio ◽  
Test Case ◽  
Suction Surface ◽  
Flow Angle ◽  
Variable Pitch ◽  
Open Rotor ◽  
Weight Penalty ◽  
Reverse Thrust ◽  
Rotor Loss

Variable pitch fans are of interest for future low pressure ratio fan systems since they provide improved operability relative to fixed pitch fans. If they can also be re-pitched such that they generate sufficient reverse thrust they could eliminate the engine drag and weight penalty associated with bypass duct thrust reversers. This paper sets out to understand the details of the 3D fan stage flow field in reverse thrust operation. The study uses the Advanced Ducted Propulsor variable pitch fan test case, which has a design fan pressure ratio of 1.29. Comparison with spanwise probe measurements show that the computational approach is valid for examining the variation of loss and work in the rotor in forward thrust. The method is then extended to a reverse thrust configuration using an extended domain and appropriate boundary conditions. Computations, run at two rotor stagger settings, show that the spanwise variation in relative flow angle onto the rotor aligns poorly to the rotor inlet metal angle. This leads to two dominant rotor loss sources: one at the tip associated with positive incidence, and the second caused by negative incidence at lower span fractions. The second loss is reduced by opening the rotor stagger setting, and the first increases with rotor suction surface Mach number. The higher mass flow at more open rotor settings provide higher gross thrust, up to 49% of the forward take-off value, but is limited by the increased loss at high speed.

scholarly journals Deriving Design Knowledge Graph for Complex Sociotechnical Systems Using the AIA Design Thinking

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tao Shen ◽  
Chan Gao ◽  
Yukari Nagai ◽  
Wei Ou
Keyword(s):  
Design Thinking ◽  
Integrated Approach ◽  
Structure Design ◽  
Sociotechnical Systems ◽  
Design Knowledge ◽  
Knowledge Graph ◽  
Sociotechnical System ◽  
Complex Design ◽  
Validation Experiment ◽  
Concept Framework

The AIA design thinking has been validated in complex design tasks, which includes three overlapping design thinking fields and uses the knowledge field theory as a theoretical mechanism of knowledge flow among design thinking fields. Meanwhile, the design of complex sociotechnical systems highly relies on multidisciplinary knowledge and design methods. Despite the emergence of knowledge management techniques (ontology, expert system, text mining, etc.), designers continue to store knowledge in unstructured ways. To facilitate the integration of knowledge graph and design thinking, we introduce an integrated approach to structure design knowledge graph with the AIA design thinking, which organizes existing design knowledge through Agent (concept)-Interaction (relation)-Adaptation (concept) framework. The approach uses an optimized convolutional neural network to accomplish two tasks: building concept graph from text and stimulating design thinking information processing for complex sociotechnical system tasks. Based on our knowledge graph, the validation experiment demonstrates the advantages of promoting the designer’s extension of idea space and idea quality.

scholarly journals Development of gear dynamic performance testing machine

2021 ◽  
Vol 12 ◽  
pp. 20
Author(s):  
Ke Li ◽  
Bo Yu ◽  
Zhaoyao Shi ◽  
Zanhui Shu ◽  
Rui Li
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Dynamic Testing ◽  
Mechanical Design ◽  
Dynamic Performance ◽  
External Disturbance ◽  
Testing Machine ◽  
High Stress ◽  
Performance Testing ◽  
Current Application

With the development of gears towards high temperature, high pressure, high speed and high stress, gear measurement, in which only the static geometric accuracy is considered, is unable to meet the current application requirements. While, the low precision and single function gear tester constrains the measurement of gear dynamic performance. For the resolution of this problem, based on the principle of gear system dynamics and several precision mechanical design techniques, a gear dynamic testing machine has been developed, providing new instruments for gear testing. On the basis of research of the principle of dynamic performance test, the primary measurement items of the testing machine have been determined. The measuring principles of each item and the driving and loading form of the testing machine have been examined. The measurement and control system of the testing machine and its corresponding software have been developed. The instrument can not only obtain the static precision index of the gear, but also obtain the dynamic performance index of the gear in variable working conditions. According to the actual test, the uncertainty of instrument is 3.8 μm and the external disturbance caused by the shaft vibration is less than 0.6 μm, which can meet the 5–6 grade precision gear testing requirement.

Fiber formation by high speed spinning under high stress

1991 ◽  
Vol 47 (0) ◽  
pp. 161-169 ◽  
Author(s):  
S. Murase ◽  
K. Kudo ◽  
M. Hirami
Keyword(s):  
High Speed ◽  
High Stress ◽  
Fiber Formation
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