scholarly journals CLASSIFICATION CHARACTERISTICS OF UNMANNED TETHERED UNDERWATER SYSTEMS AS A COMPONENT OF IMPROVING THE EFFICIENCY OF THEIR DESIGN

Author(s):  
V. S. Blintsov ◽  
◽  
O. P. Klochkov ◽  
P. S. Kucenko ◽  
◽  
...  

The design stage is considered to be rather resource-intensive in the entire process of creating marine robotic technology. Therefore, the applied scientific task of reducing the resource costs for those processes is of high interest. Among other things, the time consumed for design stage has to be reduced by determining the design characteristics at an early stage of design. The approach considered to reduce such costs involves structuring the classification features of tethered underwater systems in such a way as to simplify the selection and justification of design solutions at the stage of preliminary system design. For design engineers of underwater equipment, the list of classification features of tethered self-propelled and those towed underwater systems has been suggested. The list is based on a system approach and is structured according to material, energy, information and operational (functional) criteria. All of that enables performing the comparative assessment of existing systems upon key indicators and formalizing the processes of their synthesis at early stages of design. To demonstrate the capabilities of the system approach, the generalized algorithm for the organization of design works using the system of classification features of tethered self-propelled and towed underwater systems at the early stages of their design. The algorithm involves the formation and structuring of many classification features of such systems as the initial stage of the process of making effective design decisions in the early stages of design of underwater robotics. It has been revealed that putting in use the classification features system in question, enables deploying minimal project resources to make reference to the relevant databases and decide on already-existing artifact projects and select out of those available in the underwater equipment market key components and parts of underwater systems which would satisfy the requirements of the technical task of implementing the tethered underwater systems. That would significantly reduce the prime cost of design works and enhance the competitiveness of domestic science-based achievements in the markets of marine robotics.

Author(s):  
Malgorzata M. Sturgill ◽  
Elaine Cohen ◽  
Richard F. Riesenfeld

Abstract During early stages of design, the mere presence of items, their relative positioning, and their interrelationships can be more significant than fine details, like exact dimensions, whether a hole is counterbored, or the exact cross-sectional shape of a groove. Most CAD systems have little, if any, support for this critical, incipient design stage, In addressing this economically compelling and highly leveraged area, we present an intuitive, feature-based approach to 3-D design which permits a complete first pass through the design-manufacturing cycle even before a detailed specification is complete. We report a functioning 3-D design front-end for a solid modeling system that has been used for fast intra-part and inter-part, visual, generalized feature specification, a frontend that is intimately connected to the system so that both visual and detailed design can be carried out concurrently on the same model to meet designer needs. Hence, the design that is “captured” during the sketch and modify phase using this approach is fully usable for activities that traditionally require a fully detailed solid model, such as rendering, finite element and other analysis, assembly analysis, process planning, and manufacturing at this initial stage instead of the traditionally late stages.


Author(s):  
C. Vannuffel ◽  
C. Schiller ◽  
J. P. Chevalier

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.


2006 ◽  
Vol 34 (3) ◽  
pp. 170-194 ◽  
Author(s):  
M. Koishi ◽  
Z. Shida

Abstract Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good design of tires is to solve the multi-objective design problems, i.e., inverse problems. However, due to the lack of suitable solution techniques, such problems are converted into a single-objective optimization problem before being solved. Therefore, it is difficult to find the Pareto solutions of multi-objective design problems of tires. Recently, multi-objective evolutionary algorithms have become popular in many fields to find the Pareto solutions. In this paper, we propose a design procedure to solve multi-objective design problems as the comprehensive solver of inverse problems. At first, a multi-objective genetic algorithm (MOGA) is employed to find the Pareto solutions of tire performance, which are in multi-dimensional space of objective functions. Response surface method is also used to evaluate objective functions in the optimization process and can reduce CPU time dramatically. In addition, a self-organizing map (SOM) proposed by Kohonen is used to map Pareto solutions from high-dimensional objective space onto two-dimensional space. Using SOM, design engineers see easily the Pareto solutions of tire performance and can find suitable design plans. The SOM can be considered as an inverse function that defines the relation between Pareto solutions and design variables. To demonstrate the procedure, tire tread design is conducted. The objective of design is to improve uneven wear and wear life for both the front tire and the rear tire of a passenger car. Wear performance is evaluated by finite element analysis (FEA). Response surface is obtained by the design of experiments and FEA. Using both MOGA and SOM, we obtain a map of Pareto solutions. We can find suitable design plans that satisfy well-balanced performance on the map called “multi-performance map.” It helps tire design engineers to make their decision in conceptual design stage.


2017 ◽  
Vol 14 (1) ◽  
pp. 67
Author(s):  
Fadila Mohd Yusof ◽  
Azmir Mamat Nawi ◽  
Azhari Md Hashim ◽  
Ahmad Fazlan Ahmad Zamri ◽  
Abu Hanifa Ab Hamid ◽  
...  

Design development is one of the processes in the teaching and learning of industrial design. This process is important during the early stage of ideas before continuing to the next design stage. This study was conducted to investigate the comparison between  academic  syllabus  and  industry  practices  whether  these  processes  are  highly dependent on the idea generation and interaction related to the designer or to the student itself. The data were gathered through an observation of industry practice during conceptual design phase, teaching and learning process in academic through Video Protocol Analysis (VPA) method and interviews with industry practitioners via structured and unstructured questionnaires. The data were analysed by using NVivo software in order to formulate the results. The findings may possibly contribute to the teaching and learning processes especially in the improvement of industrial design syllabus in order to meet the industry demands. Keywords: design development, industrial design, industry demands


2019 ◽  
Author(s):  
Marcelino Jr Lunag ◽  
Jessie C. Elauria ◽  
Juanito D. Burguillos

This study confirms that lack of space due to high population density restricts household members and the barangay to comply with the existing law regarding composting. With these, community involvement in the design stage of compost bin as initial stage was done accordingly. The participants were voluntarily interviewed and were given questionnaires, which was endorsed and approved by barangay committee.


2021 ◽  
Vol 1 ◽  
pp. 3199-3208
Author(s):  
Emanuel Balzan ◽  
Pierre Vella ◽  
Philip Farrugia ◽  
Edward Abela ◽  
Glenn Cassar ◽  
...  

AbstractResearch funded projects are often concerned with the development of proof-of-concept products. Consequently, activities related to verification and validation testing (VVT) are often not considered in depth, even though various design iterations are carried out to refine an idea. Furthermore, the introduction of additive manufacturing (AM) has facilitated, in particular, the development of bespoke medical products. End bespoke products, which will be used by relevant stakeholders (e.g. patients and clinicians) are fabricated with the same manufacturing technologies used during prototyping. As a result, the detailed design stage of products fabricated by AM is much shorter. Therefore, to improve the market-readiness of bespoke medical devices, testing must be integrated within the development from an early stage, allowing better planning of resources. To address these issues, in this paper, a comprehensive VVT framework is proposed for research projects, which lack a VVT infrastructure. The framework builds up on previous studies and methods utilised in industry to enable project key experts to capture risks as early as the concept design stage.


Author(s):  
Siamack Sabrkhany ◽  
Marijke J. E. Kuijpers ◽  
Mirjam G. A. oude Egbrink ◽  
Arjan W. Griffioen

AbstractPlatelets have an important role in tumor angiogenesis, growth, and metastasis. The reciprocal interaction between cancer and platelets results in changes of several platelet characteristics. It is becoming clear that analysis of these platelet features could offer a new strategy in the search for biomarkers of cancer. Here, we review the human studies in which platelet characteristics (e.g., count, volume, protein, and mRNA content) are investigated in early-stage cancer. The main focus of this paper is to evaluate which platelet features are suitable for the development of a blood test that could detect cancer in its early stages.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reham A. Aboelwafa ◽  
Walid Ismail Ellakany ◽  
Marwa A. Gamaleldin ◽  
Marwa A. Saad

Abstract Background Hepatocellular carcinoma and hepatitis C are strongly associated. The current work aimed to study the expression levels of microRNA-331-3p and microRNA-23b-3p as propable biomarkers for detecting liver cancer (HCC) at its early stages in patients with HCV-related liver cirrhosis. The current prospective study included two hundred participants, divided into three groups: group I, 100 patients with HCV-related liver cirrhosis; group II, 50 HCC patients at early stages; and group III, 50 apparentlyhealthy controls. All patients had routine laboratory workup and ultrasound hepatic assessment. Values of microRNA-331-3p and microRNA-23b-3p were measured by real-time quantitative PCR. Results Levels of miR-331-3p were significantly higher in HCC patients than in cirrhotic patients and controls (p < 0.001), while levels of miR-23b-3p were significantly lower in HCC patients compared to cirrhotics and controls (p < 0.001). ROC curve revealed that miR-23b-3p had 80% sensitivity and 74% specificity, miR-331-3p had 66% sensitivity and 61% specificity, and AFP had 64% sensitivity and 61% specificity of 61% in discrimination between HCC patients from controls. Conclusion Serum miR-23b-3p is a more effective predictor than miR-331-3p and AFP for the development of hepatocellular carcinoma in hepatitis C (HCV)-related cirrhotic patients.


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