scholarly journals Diversity minimization through part combination – a Portuguese railway infrastructure case study

2020 ◽  
Vol 7 (1) ◽  
pp. 86-94
Author(s):  
Diogo Rechena ◽  
Luís Sousa ◽  
Virgínia Infante ◽  
Elsa Henriques

Abstract With increasing market needs for product and service variety, companies struggle to provide diversity in cost-effective ways. Through standardization of components with a low perceived added value, companies can take advantage of economies of scale while maintaining product diversity. Railway infrastructure managers face similar challenges of providing economically sustainable services while dealing with the costs of maintaining the system diversity. Typically, unintended design diversity stems from design practices in which existing solutions are not reused for new problems and new solutions are rarely planned considering the dynamics of requirement changes. In this paper we provide a methodology to assess how to standardize different designs to minimize design diversity and to assess design divergence in a product family. The developed methodology is able to take into account any set of standardization compatibility constraints that the user can define. The methodology was applied in the context of a small-scale railway infrastructure manager using a dataset of 223 unique designs of functionally similar components from its electrification system. Depending on the activated compatibility constraints, results indicate that over 60% of components can be reduced to a set of 86 unique designs.

2019 ◽  
Vol 2 (2) ◽  
pp. 21
Author(s):  
Lindawati Lindawati

Reduction of food rations and shortages is one of the impacts of the increasing human population. Food sector industries then try to cope with the fast growing number of customers. Agribusiness sector gains its popularity in these recent years, including pig farm. The increase trend of animal farming industry is likely to bring increasing pollution problem unless effective treatment methods are used. The main problems related to the pig farm include odor nuisance and pig manure disposal. The existing land application of piggery wastewater is the traditional way to discharge the wastewater. This may yield in land and water contamination, due to the accumulation of unused nutrients by crop plant. A case study of a large commercial pig farm from Australia is proposed to apply in smaller scale in Indonesia. Operational strategies for the small-scale SBR (Sequencing Batch Reactor) treating piggery effluent were developed based on lab-scale experiments. Due to SBR characteristics, which are money-saving and space-saving, it is very suitable to be applied in urban area. An economic evaluation was made of various process options. The cost estimation showed that SBR is a cost effective process, allowing operational batches to be adjusted to reduce unnecessary aeration cost. A reduction in the aeration cost was achieved by shortening the batch time from 24-h to 8-h. A comparison of three different SBR options showed that smaller size reactors could be more flexible and cost effective when compared with the larger ones.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.


2012 ◽  
Vol 27 (4) ◽  
pp. 972-987 ◽  
Author(s):  
Yong Wang ◽  
Simona Tascu ◽  
Florian Weidle ◽  
Karin Schmeisser

Abstract The regional single-model-based Aire Limitée Adaptation Dynamique Développement International–Limited Area Ensemble Forecasting (ALADIN-LAEF) ensemble prediction system (EPS) is evaluated and compared with the global ECMWF-EPS to investigate the added value of regional to global EPS models. ALADIN-LAEF consists of 16 perturbed members at 18-km horizontal resolution, while ECMWF-EPS includes 50 perturbed members at 50-km horizontal resolution. In ALADIN-LAEF, the atmospheric initial condition uncertainty is quantified by using blending, which combines large-scale uncertainty generated by the ECMWF-EPS singular-vector approach with small-scale perturbations resolved by the ALADIN breeding technique. The surface initial condition perturbations are generated by use of the noncycling surface breeding (NCSB) technique, and different physics schemes are employed for different forecast members to account for model uncertainties. The verification and comparison have been carried out for a 2-month period during summer 2007 over central Europe. The results show a quite favorable level of performance for ALADIN-LAEF compared to ECMWF-EPS for surface weather variables. ALADIN-LAEF adds more value to precipitation forecasts and has greater skill for 10-m wind and mean sea level pressure results than does ECMWF-EPS. For 2-m temperature, ALADIN-LAEF forecasts have larger spread, are statistically more consistent, but also have less skill than ECMWF-EPS due to the strong cold bias in the ALADIN forecasts. For the upper-air weather parameters, the forecast of ALADIN-LAEF has a larger spread, but the forecast skill of ALADIN-LAEF is from neutral to slightly inferior compared to ECMWF-EPS. It may be concluded that a regional single-model-based EPS with fewer ensemble members could provide more added value in terms of greater skill for near-surface weather variables than the global EPS with larger ensemble size, whereas it may have limitations when applied to upper-air weather variables.


2021 ◽  
pp. 1-17
Author(s):  
Emma Davidson ◽  
Briege Nugent ◽  
Sarah Johnsen

This article reflects on the contribution of qualitative longitudinal research (QLR) to understandings of homeless peoples’ experiences of support service interventions in an era of austerity in the UK. It brings into ‘analytic conversation’ data from qualitative longitudinal evaluations of homeless support projects operated by voluntary sector organisations in Scotland. With fieldwork spanning 2014-2019, the analysis expands the analytical potential of pooling small-scale studies through an interrogation of individuals’ ‘journeys’ through homelessness services and their rough path to ‘home’. By reflecting on our substantive findings, the article explores the added value and challenges of a longitudinal approach. It concludes that while QLR can deliver deep insight into lives lived by vulnerable populations and potentially reduce the distance between policy makers and those affected, its benefits must be balanced against pragmatism and the ethical responsibilities associated with the method.


2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Seung Ki Moon ◽  
Daniel A. McAdams

Companies that generate a variety of products and services are creating, and increasing research on, mass-customized products in order to satisfy customers’ specific needs. Currently, the majority of effort is focused on consumers who are without disabilities. The research presented here is motivated by the need to provide a basis of product design methods for users with some disability—often called universal design (UD). Product family design is a way to achieve cost-effective mass customization by allowing highly differentiated products serving distinct market segments to be developed from a common platform. By extending concepts from product family design and mass customization to universal design, we propose a method for developing and evaluating a universal product family within uncertain market environments. We will model design strategies for a universal product family as a market economy where product family platform configurations are generated through market segments based on a product platform and customers’ preferences. A coalitional game is employed to evaluate which design strategies provide more benefit when included in the platform based on the marginal profit contribution of each strategy. To demonstrate an implementation of the proposed method, we use a case study involving a family of light-duty trucks.


Author(s):  
X. C. Nguyen ◽  
Komla Miheaye ◽  
Mun-gyu Kim ◽  
Howard Newman ◽  
Dong-hoon Yoo ◽  
...  

This study describes a FLNG specifically designed to monetize Associated Gas (AG) of producing oil fields located within convenient distance of an existing LNG Plant or Port with LNG storage facility. Limited production capacity combined with short range small capacity shuttles and limited LNG storage capacity, provide a cost effective means for LNG production. This FLNG is designed to service an existing industry and does not require development of stranded gas discoveries.


PLoS ONE ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. e0170706 ◽  
Author(s):  
Marta Ramírez-Pérez ◽  
Rafael Gonçalves-Araujo ◽  
Sonja Wiegmann ◽  
Elena Torrecilla ◽  
Raul Bardaji ◽  
...  

Author(s):  
Kala Meah ◽  
Steven Fletcher ◽  
Yu Wan ◽  
Sadrul Ula

Many parts of the western US is rural in nature and consequently do not have electrical distribution lines in many parts of farms and ranches. Distribution line extension costs can run from $15,000 to $25,000 per mile, thereby making availability of electricity to small water pumping projects economically unattractive. Solar photo-voltaic (PV) powered water pumping is more cost effective in these small scale applications. Many western states including Wyoming are passing through fifth year of drought with the consequent shortages of water for many applications. Wyoming State Climatologist is predicting a possible 5–10 years of drought. Drought impacts the surface water right away, while it takes much longer to impact the underground aquifers. To mitigate the effect on the livestock and wildlife, Wyoming Governor Dave Freudenthal initiated a solar water pumping initiative in cooperation with the University of Wyoming, County Conservation Districts, Rural Electric Cooperatives, and ranching organizations. Solar water pumping has several advantages over traditional systems; for example, diesel or propane engines require not only expensive fuels, they also create noise and air pollution in many remote pristine areas. Solar systems are environment friendly, low maintenance and have no fuel cost. In this paper the design, installation and performance monitoring of the solar system for small scale remote water pumping will be presented.


Author(s):  
Bilim Atli-Veltin

In the small scale LNG infrastructure, composite materials are scarcely employed. Potentially, cost effective solutions for LNG applications could be developed thanks to the advantages of composite materials over metals such as weight savings, design flexibility and recyclability. The research presented in this paper focuses on the mechanical performance of fully recyclable, thermoplastic Polypropylene (PP) composite tapes at cryogenic LNG temperatures. Quasi-static tensile tests performed on [±45] laminates made of plain woven plies of PURE® show that at −196°C the behavior is bilinear with the failure strain of 6.5% and failure stress of 37 MPa. Such non-brittle failure behavior of PP is desirable for cryogenic applications. The other results presented in the paper contains [0/90] laminate results and the interlaminar shear strength characteristics at room and cryogenic temperatures.


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