Reentry Design Solution for a Hypersonic Small Capsule

2013 ◽  
Vol 332 ◽  
pp. 33-43
Author(s):  
Radu Dan Rugescu
Keyword(s):  
Attitude Control ◽  
Cost Reduction ◽  
Selection Criteria ◽  
Research Team ◽  
High Mass ◽  
Design Solution ◽  
Specific Research ◽  
Optimal Balance ◽  
Simplified Method ◽  
The Given

Restriction and selection criteria of inertial guidance sensors and system for a small recoverable capsule from onboard a hypersonic, atmospheric reentering rocket vehicle have attracted a specific research on the reentry design and challenges, with emphasize on the overall cost reduction and an optimal balance between the performances and costs under the given exploitation constraints. A simplified method for attitude control is derived that shows an easy accommodation in the capsule, given its high mass constraints, and convenient applicability for the class of small payloads under investigation. The palled experiments and investigating methodology is shown, as the result of the ORVEAL contract research team of ADDA-Association Dedicated to Development in Astronautics research organization, under the sponsorship of Romanian UEFISCDI authority for scientific research.

scholarly journals Breaking the problem into pieces: pre-clustering on-the-fly with the NGLMS

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
James Farrow
Keyword(s):  
Cost Reduction ◽  
Linked Data ◽  
Selection Criteria ◽  
Transitive Closure ◽  
Computational Cost ◽  
Quality Analysis ◽  
Clustering Techniques ◽  
Computationally Intensive ◽  
The Cost ◽  
Manual Review

ABSTRACT ObjectivesThe SA.NT DataLink Next Generation Linkage Management System (NGLMS) stores linked data in the form of a graph (in the computer science sense) comprised of nodes (records) and edges (record relationships or similarities). This permits efficient pre-clustering techniques based on transitive closure to form groups of records which relate to the same individual (or other selection criteria). ApproachOnly information known (or at least highly likely) to be relevant is extracted from the graph as superclusters. This operation is computationally inexpensive when the underlying information is stored as a graph and may be able to be done on-the-fly for typical clusters. More computationally intensive analysis and/or further clustering may then be performed on this smaller subgraph. Canopy clustering and using blocking used to reduce pairwise comparisons are expressions of the same type of approach. ResultsSubclusters for manual review based on transitive closure are typically computationally inexpensive enough to extract from the NGLMS that they are extracted on-demand during manual clerical review activities. There is no necessity to pre-calculate these clusters. Once extracted further analysis is undertaken on these smaller data groupings for visualisation and presentation for review and quality analysis. More computationally expensive techniques can be used at this point to prepare data for visualisation or provide hints to manual reviewers. 
Extracting high-recall groups of data records for review but providing them to reviews grouped further into high precision groups as the result of a second pass has resulted in a reduction of the time taken for clerical reviewers at SANT DataLink to manual review a group by 30–40%. The reviewers are able to manipulate whole groups of related records at once rather than individual records. ConclusionPre-clustering reduces the computational cost associated with higher order clustering and analysis algorithms. Algorithms which scale by n^2 (or more) are typical in comparison scenarios. By breaking the problem into pieces the computational cost can be reduced. Typically breaking a problem into many pieces reduces the cost in proportion to the number of pieces the problem can be broken into. This cost reduction can make techniques possible which would otherwise be computationally prohibitive.

3PL selection criteria in integrated circuit manufacturing industry in Taiwan

2016 ◽  
Vol 21 (1) ◽  
pp. 103-124 ◽  
Author(s):  
Bang-Ning Hwang ◽  
Tsai-Ti Chen ◽  
James T. Lin
Keyword(s):  
Integrated Circuit ◽  
Cost Reduction ◽  
Selection Criteria ◽  
Manufacturing Industry ◽  
Market Competition ◽  
Value Added ◽  
The Body ◽  
High Tech ◽  
Content Type ◽  
Ic Manufacturing

Purpose – The purpose of this study was to identify the key third-party logistics (3PL) selection criteria for the integrated circuit (IC) manufacturing industry in Taiwan. The IC manufacturing industry seeks global sourcing, and is facing increasing pressure due to fierce market competition. More than a cost reduction strategy, 3PL is a strategic tool for IC manufacturers to gain a competitive advantage in a global supply chain complex. Design/methodology/approach – The triangulation method that combines qualitative and quantitative approaches was used in the study. The qualitative approach of focus group discussions was adopted to establish the decision framework, and the quantitative approach of the analytic hierarchy process was used to explore the relative importance of the 3PL selection criteria. Finally, an in-depth proof-by-example interview was undertaken to provide an insightful interpretation of the research results. Findings – The research shows that performance is the most important criterion group, followed by cost, service, quality assurance, intangible and information technology. At the detailed sub-criteria level, document accuracy, problem-solving capability, continuous cost reduction, value-added services and associated cost control capability are the top five criteria. Research limitations/implications – This study focused on the IC manufacturing sector in Taiwan. Multi-country and multi-industry studies are recommended to help further validate and generalise the research findings. Originality/value – Due to its application of triangulation, this study is a pioneering work on the 3PL selection criteria in a high-tech manufacturing industry. Furthermore, the value of this research is that it enhances the body of knowledge of 3PL selection by identifying certain emerging selection criteria, it could serve as a guideline for IC manufacturers in planning logistics outsourcing actions and it could significantly contribute to the efforts of 3PL providers in evaluating whether they comply with customer needs and adhere to core competency development.

scholarly journals Methodology of technological and operational factors accounting in the process of complex optimal design of microand nanodevices manufactured using group technologies

2018 ◽  
Vol 224 ◽  
pp. 02094
Author(s):  
Sergey Meshkov
Keyword(s):  
Optimal Design ◽  
Group Technology ◽  
Design Stage ◽  
Time To Failure ◽  
Serial Production ◽  
Operation Conditions ◽  
Optimal Balance ◽  
Operational Factors ◽  
The Given ◽  
Production Conditions

The problem of providing key quality indicators (indicators of purpose, manufacturability, reliability) of micro-and nanodevices at the design stage is considered. The limitations imposed by a group technology production on methods ensuring serial production availability and reliability of micro- and nanodevices are described. The design of micro-and nanodevices methodology that allows to ensure the optimal balance between serial production availability in the given production conditions and time to failure in the specified operation conditions under given restrictions on the device purpose indicators by taking into account the technological and operational factors is described.

scholarly journals Sub-Saharan Africa’s rail freight transport system: Potential impact of densification on cost

2010 ◽  
Vol 4 (1) ◽  
Author(s):  
Anneke De Bod ◽  
Jan Havenga
Keyword(s):  
Foreign Aid ◽  
Cost Reduction ◽  
Critical Role ◽  
Transport Sector ◽  
Rail Freight ◽  
Optimal Balance ◽  
Potential Impact ◽  
Sub Saharan ◽  
Significant Cost Reduction ◽  
Ssa Countries

The main response to sub-Saharan Africa’s (SSA) challenges has been foreign aid. Yet, despite the large amounts received, the challenges remain. There is an opportunity to consider a different model with less focus on aid and more on investment. In the transport sector specifically, investment decisions should be informed by a longterm optimal balance between different transport modes. The research presented in this paper highlights the significant cost reduction opportunities possible through the densification of rail freight, especially over longer distances, with concomitant implications for increased profitability for rail operators. The densification opportunity should also place a core focus on transport corridors being developed throughout the region. SSA countries themselves can play a critical role in unlocking this potential through, inter alia, simplifying regional economic communities and taking the lead in structuring agreements with the international community.

Simplified Hydrodynamic Design Procedure of a Submerged Floating Tube Bridge Across the Digernessund of Norway

2017 ◽  
Author(s):  
Xu Xiang ◽  
Arianna Minoretti ◽  
Mathias Egeland Eidem ◽  
Kjell Håvard Belsvik ◽  
Tale Egeberg Aasland ◽  
...  
Keyword(s):  
Cross Sections ◽  
Present Model ◽  
Design Procedure ◽  
Analysis Procedure ◽  
Hydrodynamic Coefficients ◽  
Bending Moments ◽  
Vortex Induced Vibrations ◽  
Simplified Method ◽  
Hydrodynamics Coefficients ◽  
The Given

The paper will look into the hydrodynamic loads and responses on the proposed Submerged Floating Tube Bridge (SFTB) through the Digernessund by the Norwegian Public Roads Administration (Statens vegvesen, NPRA). The aim is to show how different hydrodynamics aspects during the prelimiary design can be simply addressed under the given environmental conditions. Different SFTB systems are introduced as the first step. A simplified method based on modal analysis is introduced and implemented for evaluation of the motions and stress, bending moments along the bridge. Firstly, a 2D Boundary Element Method (BEM) solver is developed and verified, which is further used for solving the hydrodynamics coefficients of different bridge cross sections. The 3D hydrodynamic coefficients of pontoons are solved by the commercial software AQWA. The analysis procedure of the simplified method for the global SFTB responses is presented. The Eigen periods of the Bjørnefjord SFTB is re-calculated by the present model as a first validation of the implementation. The loads and responses of the bridge under given wave conditions are then estimated. The evaluation of the possibility of vortex induced vibrations of the current SFTB design is given.

Path Guidance and Attitude Control of a Vectored Thruster AUV

Volume 2 ◽  
2004 ◽  
Author(s):  
Emanuele Cavallo ◽  
Rinaldo C. Michelini ◽  
Vladimir F. Filaretov ◽  
Dimitri A. Ukymets
Keyword(s):  
Attitude Control ◽  
Degrees Of Freedom ◽  
Autonomous Underwater Vehicles ◽  
The Body ◽  
Sensors And Actuators ◽  
Counter Rotation ◽  
Continuous Rotation ◽  
Robotic Wrist ◽  
The Given ◽  
Reactive Mode

The study deals with developing small and cheap autonomous underwater vehicles, AUV, entrusted of extended manoeuvrability for surveying and docking missions, with accurate of path tracking and attitude keeping, capable of travelling at low speed, down to proper depth, to carry out the given tasks with proper autonomy and without relevant impact on the surroundings. The to day available AUVs, generally, make use of several propellers, distributed around the body, to achieve the desired mobility with full attitude control. The solution requires the closure of multiple loops between sensors and actuators, highly cross-coupled and dependent on dynamics non-linearity and marine surroundings disturbances. The prospected solution considers a properly shaped vehicle, to grant minimal drag for lowering power consumption. A single rear propeller has in charge propulsion and manoeuvring. The propeller can be oriented around two axes, say, pitch (for heaving) and yaw (for veering); the screw (hydrodynamic) torque is balanced by variable tilt fins, either, by counter-rotating vanes. A three degrees of freedom parallel kinematics robotic wrist provides joint path-and-attitude selection and twist compensation, by driving the propeller assembly through three independent actuations. The build-up makes use of a duct-restricted propeller, with externally driven pitch-and-yaw bending and twist to counteract the screw torque by reactive fins, either, continuous rotation. The balancing wile assures best performance, in the reactive mode, during steady surveying missions, while the local hover or docking is better accomplished by active counter-rotation. The paper discusses the basic design steps by example manoeuvres carried with virtual checks on a digital mock-up.

scholarly journals Projects selection method based on the theory of possibility

2018 ◽  
pp. 12-25
Author(s):  
S. Rudenko ◽  
V. Andrievska
Keyword(s):  
Selection Criteria ◽  
Fuzzy Numbers ◽  
Selection Procedure ◽  
Selection Method ◽  
Dynamic Nature ◽  
Project Environment ◽  
Block Form ◽  
The Given

A method for selecting projects based on the theory of possibilities is developed. The proposed approach reflects the situation when the dynamic nature of the project environment determines the impossibility of applying a deterministic or probabilistic approach.The method is based on the «project card», which, in the block form separated by content, unites the characteristics of the project, from which constraints and selection criteria of projects can be formed. This ensures the universality of the proposed approach.The type of fuzzy numbers used is trapezoidal to match the pessimistic, optimistic and most probable estimates.The developed selection procedure presupposes the «filtration» of projects by the given levels of reliability for the conditions under consideration. This reduces the volume of the information operated at subsequent stages. Also, within the framework of a scheme, the options for selecting projects according to one or more criteria are linked.

scholarly journals Systematic Review of Methods Used for Food Pairing with Coffee, Tea, Wine, and Beer

Beverages ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Christina J. Birke Rune ◽  
Morten Münchow ◽  
Federico J. A. Perez-Cueto
Keyword(s):  
Selection Criteria ◽  
Web Of Science ◽  
Descriptive Analysis ◽  
Line Scale ◽  
Food And Beverage ◽  
Golden Standard ◽  
Current Article ◽  
The Given ◽  
Good Food

The current article is aimed at systematically reviewing the research methods used for food pairing with coffee, tea, wine, and beer. The primary aim of this review was to elucidate the state-of-the-art methods used for analysing food and beverage pairings with coffee, tea, wine, and beer; secondarily, to identify the basis of the selection criteria; and lastly, the method used to evaluate those pairings. The search was performed in three databases: Web of Science, ScienceDirect, and Scopus. Criteria for inclusion were studies with an experimental design, a descriptive analysis (DA), and/or hedonic consumer analysis of beverage and food pairing. The outcome had to be measured on a hedonic Likert scale, a line scale, a just about right (JAR), or a modified JAR scale or other relevant scale measurement method for the given attribute. A total of 24 studies were included in this review—the majority aimed at finding good food and beverage pairings. Most pairings were based on suggestions from experts on popular/common, similar origin, or quality of beverages and foods. The outcomes were measured in several different scales, precluding a direct comparison. The 24 articles used in this review did not provide a so-called “golden standard” of the pairing method. Only three articles provided a more scientifically based approach to investigate why a food and beverage pairing is perceived as a good match, using aromatic similarity, the primary taste, and the sensation of koku as their experimental factors.

scholarly journals TECHNOLOGY OF UNIQUE BUILDINGS’ CONSTRUCTION IN THE CONSTRAINED CONDITIONS OF OPERATING ENTERPRISE

2018 ◽  
Vol 15 (5) ◽  
pp. 726-741
Author(s):  
A. F. Andryushenkov ◽  
N. S. Volovnik ◽  
A. A. Andryushenkov
Keyword(s):  
Oil Refining ◽  
Design Solution ◽  
Construction Technology ◽  
Design Development ◽  
Economic Criterion ◽  
Detailed Consideration ◽  
Mixed Scheme ◽  
Rational Version ◽  
Constrained Conditions ◽  
The Given

Introduction.There is a need for detailed consideration of technological solutions of the constructed object while the process of the work projects’ development (WPD). The features of WPD development are considered on the basis of the flare tower as a part of the flare installation of the oil refining enterprise. The problems of organizational and technological design (development of WPD) for such facilities’ type should be solved many times due to the fact that there is a modernization of oil refining enterprises in the country. Moreover, the obtained results of calculations allow conducting more rational technological solutions for the construction of the flare tower and such solutions affect the period of the flare installation.Materials and methods.The technology of the flare tower construction as a part of the flare installation is quite complex due to the features of the unique structure and cramped construction site. Accordingly, the choice of technology for the flare tower construction is made by using the features of its design solution and by the detailed consideration of options for installation mechanization. The options are evaluated by using an economic criterion (reduced cost). The calculations are based on modern installation cranes recommended for usage on this type of unique structures.Results.As a result of technical and economic calculations of the flare tower construction technology, the method of its construction is chosen due to the rational version of installation mechanization. The paper presents the calculations’ results of the given costs and the technical characteristics of the cranes. In addition, the technology of the flare tower installation is organized with the method of the tower blocks assembly.Discussion and conclusions.As could be seen, the construction technology by the mixed scheme on the chosen option is developed by the authors.

scholarly journals Fuzzy improvement of the SQL

2011 ◽  
Vol 21 (2) ◽  
pp. 239-251 ◽  
Author(s):  
Miroslav Hudec
Keyword(s):  
Selection Criteria ◽  
Relational Databases ◽  
Query Language ◽  
Linguistic Terms ◽  
Proposed Model ◽  
Logical Condition ◽  
Structured Query Language ◽  
The Given

Structured Query Language (SQL) is used to obtain data from relational databases. Fuzzy improvement of SQL queries has advantages in cases when the user cannot unambiguously define selection criteria or when the user wants to examine data that almost meet the given criteria. In this paper we examine a realization of the fuzzy querying concept. For this purposes the fuzzy generalized logical condition for the WHERE part of the SQL is created. It allows users to create queries by linguistic terms. The proposed model is an extension of the SQL so that no modification inside databases has to be undertaken.

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