scholarly journals Developing and Deploying Electronics Assembly Line Optimization Tools: A Motorola Case Study

2008 ◽  
Vol 2 (2) ◽  
pp. 63-78 ◽  
Author(s):  
Thomas M. Tirpak
Keyword(s):  
Optimization Problem ◽  
Integer Program ◽  
Production Equipment ◽  
Electronics Assembly ◽  
Cycle Times ◽  
Linear Integer Program ◽  
Planning Decision ◽  
Placement Accuracy ◽  
High Degree

The assignment of workloads to production equipment is one category of planning decision for an electronics assembly factory. In practice, line balancing requires not only selecting machines with sufficient placement accuracy and feeder capacity, but also address- ing a host of other operational objectives and constraints. Motorola Labs led a multi-year effort to apply mathematical programming to balance a variety of production mix and vol- ume scenarios. By representing the optimization problem as a specially structured, mixed linear-integer program, we were able to incorporate a high degree of reality in the model, simultaneously optimizing fixed setups, handling custom parts, maximizing machine uptime, and mitigating secondary bottlenecks. This paper presents the story of how we developed and deployed a software solution that significantly improved assembly cycle times, setup changeovers, and overall factory productivity, saving the company tens of millions of dollars.

CSim 2

2021 ◽  
Vol 43 (1) ◽  
pp. 1-46
Author(s):  
David Sanan ◽  
Yongwang Zhao ◽  
Shang-Wei Lin ◽  
Liu Yang
Keyword(s):  
Programming Languages ◽  
Concurrent Systems ◽  
Theorem Prover ◽  
Compositional Techniques ◽  
Machine Code ◽  
Top Down ◽  
Hol Theorem Prover ◽  
High Level ◽  
High Degree

To make feasible and scalable the verification of large and complex concurrent systems, it is necessary the use of compositional techniques even at the highest abstraction layers. When focusing on the lowest software abstraction layers, such as the implementation or the machine code, the high level of detail of those layers makes the direct verification of properties very difficult and expensive. It is therefore essential to use techniques allowing to simplify the verification on these layers. One technique to tackle this challenge is top-down verification where by means of simulation properties verified on top layers (representing abstract specifications of a system) are propagated down to the lowest layers (that are an implementation of the top layers). There is no need to say that simulation of concurrent systems implies a greater level of complexity, and having compositional techniques to check simulation between layers is also desirable when seeking for both feasibility and scalability of the refinement verification. In this article, we present CSim 2 a (compositional) rely-guarantee-based framework for the top-down verification of complex concurrent systems in the Isabelle/HOL theorem prover. CSim 2 uses CSimpl, a language with a high degree of expressiveness designed for the specification of concurrent programs. Thanks to its expressibility, CSimpl is able to model many of the features found in real world programming languages like exceptions, assertions, and procedures. CSim 2 provides a framework for the verification of rely-guarantee properties to compositionally reason on CSimpl specifications. Focusing on top-down verification, CSim 2 provides a simulation-based framework for the preservation of CSimpl rely-guarantee properties from specifications to implementations. By using the simulation framework, properties proven on the top layers (abstract specifications) are compositionally propagated down to the lowest layers (source or machine code) in each concurrent component of the system. Finally, we show the usability of CSim 2 by running a case study over two CSimpl specifications of an Arinc-653 communication service. In this case study, we prove a complex property on a specification, and we use CSim 2 to preserve the property on lower abstraction layers.

scholarly journals Urban Rivers Corridors in the Don Catchment, UK: From Ignored, Ignoble and Industrial to Green, Seen and Celebrated

2021 ◽  
Vol 13 (14) ◽  
pp. 7646
Author(s):  
Ed Shaw ◽  
Debbie Coldwell ◽  
Anthony Cox ◽  
Matt Duffy ◽  
Chris Firth ◽  
...  
Keyword(s):  
Industrial Revolution ◽  
Urban River ◽  
Urban Rivers ◽  
River Habitat ◽  
Negative Perceptions ◽  
High Degree ◽  
River Corridors ◽  
Advance Knowledge ◽  
Ecological Recovery

Research on urban rivers often seeks to find commonalities to advance knowledge of the effect of urbanisation on rivers, and rightly so. But it is important, also, to develop a complementary understanding of how urban rivers can be distinct, to facilitate a more nuanced view of concepts such as the ‘urban river syndrome’ and of the challenges facing those who wish to create more sustainable urban river corridors. To this end we use the Don Catchment as a case study to illustrate how historic patterns of urbanisation have been fundamental in shaping the catchment’s rivers. Following the Industrial Revolution, the catchment became an industrial centre, resulting in the ecological death of river ecosystems, and the disconnection of communities from stark urban river corridors. Widescale deindustrialisation in the 1970s and 1980s then resulted in a partial ecological recovery of the rivers, and ignited public interest. This history has imbued the catchment’s urban river corridors with a distinctive industrial character that can vary greatly between and within settlements. It has also left a legacy of particular issues, including a high degree of river habitat fragmentation and physical modification, and of negative perceptions of the rivers, which need improving to realise their potential as assets to local communities.

Probabilistic nature of storage delay parameter of the hydrologic model RORB: a case study for the Cooper's Creek catchment in Australia

2014 ◽  
Vol 46 (3) ◽  
pp. 400-410 ◽  
Author(s):  
Hitesh Patel ◽  
Ataur Rahman
Keyword(s):  
Hydrologic Model ◽  
Exceedance Probability ◽  
Design Flood ◽  
Flood Peak ◽  
Monte Carlo Simulation Technique ◽  
South Wales ◽  
Accurate Design ◽  
High Degree ◽  
Probabilistic Nature

In rainfall–runoff modeling, Design Event Approach is widely adopted in practice, which assumes that the rainfall depth of a given annual exceedance probability (AEP), can be converted to a flood peak of the same AEP by assuming a representative fixed value for the other model inputs/parameters such as temporal pattern, losses and storage-delay parameter of the runoff routing model. This paper presents a case study which applies Monte Carlo simulation technique (MCST) to assess the probabilistic nature of the storage delay parameter (kc) of the RORB model for the Cooper's Creek catchment in New South Wales, Australia. It has been found that the values of kc exhibit a high degree of variability, and different sets of plausible values of kc result in quite different flood peak estimates. It has been shown that a stochastic kc in the MCST provides more accurate design flood estimates than a fixed representative value of kc. The method presented in this study can be adapted to other catchments/countries to derive more accurate design flood estimates, in particular for important flood study projects, which require a sensitivity analysis to investigate the impacts of parameter uncertainty on design flood estimates.

The Use of Photogrammetry in Piping Design

1983 ◽  
Vol 197 (2) ◽  
pp. 125-138 ◽  
Author(s):  
P A Bracewell ◽  
U R Klement
Keyword(s):  
Information Retrieval ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Cost Effective ◽  
Process Industry ◽  
Process Plant ◽  
Definition Of ◽  
High Degree ◽  
Positional Data

Piping design for ‘revamp’ projects in the process industry requires the retrieval of large amounts of ‘as-built’ data from existing process plant installations. Positional data with a high degree of accuracy are required. Photogrammetry, the science of measurement from photographs, was identified in Imperial Chemical Industries plc (ICI) as a suitable tool for information retrieval. The mathematical formulation enabling the definition of three-dimensional positions from photographic information is described. The process of using ICI's photogrammetric system for the definition of complete objects such as structures and pipes is illustrated. The need for specialized photogrammetric software for design purposes is explained. A case study describing how the photogrammetric system has been applied is described and graphical outputs from this exercise are shown. It is concluded that this particular photogrammetric system has proved to be a cost effective and accurate tool for the retrieval of ‘as-built’ information.

scholarly journals FEATURE FILTERING AND SELECTION FOR DRY MATTER ESTIMATION ON PERENNIAL RYEGRASS: A CASE STUDY OF VEGETATION INDICES

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1827-1831 ◽  
Author(s):  
G. T. Alckmin ◽  
L. Kooistra ◽  
A. Lucieer ◽  
R. Rawnsley
Keyword(s):  
Feature Selection ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Selection Process ◽  
Vegetation Indices ◽  
Robust Model ◽  
Trade Offs ◽  
Initial Dataset ◽  
High Degree

<p><strong>Abstract.</strong> Vegetation indices (VIs) have been extensively employed as a feature for dry matter (DM) estimation. During the past five decades more than a hundred vegetation indices have been proposed. Inevitably, the selection of the optimal index or subset of indices is not trivial nor obvious. This study, performed on a year-round observation of perennial ryegrass (n&amp;thinsp;=&amp;thinsp;900), indicates that for this response variable (i.e. kg.DM.ha<sup>&amp;minus;1</sup>), more than 80% of indices present a high degree of collinearity (correlation&amp;thinsp;&amp;gt;&amp;thinsp;|0.8|.) Additionally, the absence of an established workflow for feature selection and modelling is a handicap when trying to establish meaningful relations between spectral data and biophysical/biochemical features. Within this case study, an unsupervised and supervised filtering process is proposed to an initial dataset of 97 VIs. This research analyses the effects of the proposed filtering and feature selection process to the overall stability of final models. Consequently, this analysis provides a straightforward framework to filter and select VIs. This approach was able to provide a reduced feature set for a robust model and to quantify trade-offs between optimal models (i.e. lowest root mean square error &amp;ndash; RMSE&amp;thinsp;=&amp;thinsp;412.27&amp;thinsp;kg.DM.ha<sup>&amp;minus;1</sup>) and tolerable models (with a smaller number of features &amp;ndash; 4 VIs and within 10% of the lowest RMSE.)</p>

scholarly journals Employment Opportunities And Human Resources Development In Digital Era: A Case Study In Industrial Sector

2018 ◽  
Vol 8 (2) ◽  
pp. 159-168
Author(s):  
Devi Asiati ◽  
Gutomo Bayu Aji ◽  
Vanda Ningrum ◽  
Ngadi Ngadi ◽  
Triyono Triyono ◽  
...  
Keyword(s):  
Industrial Sector ◽  
Production Equipment ◽  
Improvement Program ◽  
Digital Era ◽  
Local Resources ◽  
The World ◽  
The Government ◽  
Machine Replacement ◽  
The Impact

Transformation of digitalization in large industries has an impact on the automation of production equipment, including the replacement of production machines from conventional machines (manual) to digital machines. Meanwhile, automation of production equipment requires workers with higher skills, in fact the existing workforce does not have expertise in carrying out all-digital equipment. The impact is a reduction in labor (layoffs). Machine replacement is done in stages so that the reduction of workforce (PHK) in bulk is not visible. However, the inconsistency between the preparation in the world of education and the needs in the world of work continues to occur today. Until now, vocational development based on local resources has not been operating optimally and needs serious attention from the local government. The government on various occasions mentioned four leading sectors that will be strengthened in the development of vocational institutions, namely maritime, tourism, agriculture (food security), and the creative industry. In addition, the government is also developing a policy scheme for Skill Development Funds (SDF), which is a skills improvement program for workers affected by automation (PHK), including through Vocational Training Center (BLK).

scholarly journals STEADY-STATE MODELLING OF PEM FUEL CELLS USING GRADIENT-BASED OPTIMIZER

10.6036/10099 ◽  
2021 ◽  
Vol DYNA-ACELERADO (0) ◽  
pp. [ 8 pp.]-[ 8 pp.]
Author(s):  
SALAH KAMAL ◽  
ATTIA EL-FERGANY ◽  
EHAB EHAB ELSAYED ELATTAR ◽  
AHMED AGWA
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Fuel Cell ◽  
Optimization Problem ◽  
Pem Fuel Cells ◽  
Test Cases ◽  
Uncertain Parameters ◽  
Gradient Based ◽  
High Degree ◽  
Exchange Membrane

The accuracy of fuel cell (FC) models is important for the further numerical simulations and analysis at several conditions. The electrical (I-V) characteristic of the polymer exchange membrane fuel cells (PEMFCs) has high degree of nonlinearity comprising uncertain seven parameters as they aren’t given in fabricator's datasheets. These seven parameters need to be obtained to have the PEMFC model in order. This research addresses an up-to-date application of the gradient-based optimizer (GBO) to generate the best estimated values of such uncertain parameters. The estimation of these uncertain parameters is adapted as optimization problem having a cost function (CF) subjects to set of self-constrained limits. Three test cases of widely used PEMFCs units; namely, SR-12, 250-W module and NedStack PS6 to appraise the performance of the GBO are demonstrated and analyzed. The best values of the CF are 0.000142, 0.33598, and 2.10025 V2 for SR-12, 250-W module and NedStack PS6; respectively. Furthermore, the assessment of the GBO-based model is made by comparing its obtained results with the experiential results of these typical PEMFCs plus comparisons to other methods. At a due stage, many scenarios as a result of operating variations in regard to inlet regulation pressures and unit temperatures are performed. The copped reported results of the studied scenarios indicate the effectiveness of the GBO in establishing an accurate PEMFC model.

scholarly journals The Significance of Enabling Human Consideration in Policymaking: How to Get the E-Ferry That You Want

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexander Berntsen ◽  
Simen Sæther ◽  
Jens Røyrvik ◽  
Mehmet Efe Biresselioglu ◽  
Muhittin Hakan Demir
Keyword(s):  
Driving Force ◽  
Transport Sector ◽  
Work Package ◽  
Moral Issues ◽  
Moral Conviction ◽  
Broad Agreement ◽  
High Degree ◽  
Environmental Challenge ◽  
The Eu

There is broad agreement in literature and policy that the transport sector needs to maximise electric mobility, in order to lower both energy consumption and greenhouse gas emissions. This ongoing transformation continues to require a high degree of technological innovation. Consequently, policymakers are striving to reward innovation in procurement tender contracts, in order to achieve sustainable innovation. At the same time, such contracts are often designed with a principle of technology neutrality in mind, to prevent any distortion of the market logic. This article suggests that it is misguided to try to perfect the logic of the tender system and that articulating contract that rewards innovation is no guarantee of a sustainable solution. Rather than being technological, the problem should be seen as moral: the mounting environmental challenge. Policymakers thus have clear ideas about the action needed based on what they, through moral conviction, consider to be appropriate action. This case study—conducted as a part of the EU H2020-funded ECHOES Project under Work Package 6—on the electrification of the Flakk–Rørvik ferry connexion reveals how policymakers were able to achieve the intended results: in this case, an e-ferry rather than a biodiesel ferry, in spite of, rather than because of, the tender system logic. They achieved this by involving stakeholders in the process with a continuous and uninterrupted dialogue. The project stakeholders were able to intervene in the tender system logic in favour of human considerations. We argue that this project was a success because human judgement, not system logic, was the driving force. By extension, we argue that systems will only allow policymakers to pursue moral issues to the degree that they allow human intervention.

scholarly journals A case study examining the mediating impact of Coach Educators delivering a professional development programme.

2019 ◽  
Author(s):  
Alexander Sobolewski
Keyword(s):  
Professional Development ◽  
Qualitative Data ◽  
Research Strategy ◽  
Development Programme ◽  
Personal Agency ◽  
Structured Interviews ◽  
Coach Development ◽  
Professional Development Programme ◽  
High Degree

The important mediating influence of Coach Educators (CEs) delivering a programme of learning has been largely ignored in research seeking to find the key to effective CPD. This paper aims to bring CEs to the fore by reporting the experiences of 7 CEs and 2 Programme Managers delivering a sport National Governing Body coach development programme. Qualitative data were collected via semi-structured interviews and interpreted through the theoretical lens of relational interdependence (Billett, 2008) using a retroductive research strategy. The findings identified the subjective and idiosyncratic processes through which CEs developed their understanding of the programme resulting in individual differences in construal. The high degree of workplace affordance gave CEs autonomy to deploy their personal agency and intentionality to shape practice leading to wide variations in CPD delivery. The results suggest the subjectivity of CEs can have a potentially significant impact on the fidelity of the programme being delivered.

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