scholarly journals AN efficient algorithm for the bottleneck product rate variation problem with precedence constraints

1970 ◽  
Vol 7 (1) ◽  
pp. 63-73
Author(s):  
TN Dhamala
Keyword(s):  
Mixed Model ◽  
Optimal Solution ◽  
Industrial Applications ◽  
Precedence Constraints ◽  
Model Systems ◽  
Time Variability ◽  
Just In Time ◽  
Rate Variation ◽  
Variation Problem ◽  
Single Level

We consider the problem of obtaining an optimal mixed-model sequence under the just-in-time environment. Industrial applications include the production planning, real-time scheduling, response time variability and networking. The single-level problems are already solved, but they are strongly NP-hard in the multi-levels. Here, we study a bottleneck product rate variation problem with a general objective where a given set of sequences serves as chain constraints. We extend the previous result of a similar problem with min-max deviation objective in single- level. We present a pseudo-polynomial algorithm that obtains an optimal solution for the considered objective. The results are valid for precedence constraints. Keywords: integer programming; just-in-time sequencing; mixed-model systems; bottleneck product rate variation; precedence constraints. DOI: http://dx.doi.org/ 10.3126/kuset.v7i1.5423 KUSET 2011; 7(1): 63-73

scholarly journals Estimation of the Largest and the Smallest Function Values of a Feasible Solution for the Total Product Rate Variation Problem

2015 ◽  
Vol 19 (1) ◽  
pp. 35-38
Author(s):  
Shree Ram Khadka
Keyword(s):  
Mixed Model ◽  
Feasible Solution ◽  
Production Systems ◽  
Exact Algorithms ◽  
Just In Time ◽  
Rate Variation ◽  
Variation Problem ◽  
Total Product ◽  
Cumulative Production ◽  
The Ideal

The problem of minimizing the total deviations between the actual and the ideal cumulative production of a variety of models of a common base product arises as a sequencing problem in mixed-model just-in-time production systems. This is called the total product rate variation problem. Several pseudo-polynomial exact algorithms and heuristics have been derived for this problem. In this paper, we estimate the largest and the smallest function values of a feasible solution for the problem when the m-th power of the total deviations between the actual and the ideal cumulative productions has to be minimizedJournal of Institute of Science and Technology, 2014, 19(1): 35-38

scholarly journals Bottlenecks to product rate variation problem with batching

BIBECHANA ◽  
2012 ◽  
Vol 8 ◽  
pp. 53-58
Author(s):  
Shree Ram Khadka
Keyword(s):  
Optimal Solution ◽  
Rate Variation ◽  
Assembly Lines ◽  
Sequencing Problem ◽  
Variation Problem ◽  
Processing Times ◽  
Common Base

The product rate variation problem with batching minimizes the variation in the rate at which different models of a common base product are produced on the assembly lines with the assumption of significant setup and arbitrary processing times for each copy of each model. Establishment of bottlenecks to the problem is important for the feasible and the optimal solution to the problem. In this paper, the lower and the upper bottlenecks to the problem are established. Moreover, small bottlenecks that lead to optimality to some instances are investigated.Keywords: Product rate variation problem; batching; sequencing problem; nonlinear integer programmingDOI: http://dx.doi.org/10.3126/bibechana.v8i0.4876BIBECHANA 8 (2012) 53-58

A fast and accurate solution to optimal design of eddy-current PMCs with standard disc type

2021 ◽  
pp. 1-19
Author(s):  
Zheng rong Xia ◽  
Yong chen Pei ◽  
Dong xu Wang ◽  
Shun Wang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Optimal Solution ◽  
Industrial Applications ◽  
Accurate Solution ◽  
Parameter Determination ◽  
Experimental Investigations ◽  
Fe Model ◽  
Contribution Rate ◽  
Standard Disc

Although permanent magnet couplings (PMCs) have been under research for many years and have found successful industrial applications, this is still a technology under development. Accurate parameter determination is of significance for performance analysis and critical decisions on PMC design. However, the determination can often lead to an unacceptable increase in computation, especially when finite elements (FE) are used. The study aims to develop an FE model that is used for the structural design of a standard-disc type PMC for optimal torque. For the quick and accurate design, an integration optimal solution of the response surface methodology (RSM) and the Taguchi’s method was proposed. To verify the simulation, a series of experimental investigations were conducted on a self-developed testing platform. Furthermore, for a minimum set of FE analyses (FEA), a quantitative indicator called contribution rate, which can reflect effect level of structure parameters on the torque, was given based on the Taguchi method. Apart from this, the orthogonal matrix was used for the reduction of the FE calculation. Based on the contribution rate, the response surface methodology was adopted for the optimal torque determination with no increase in the PM volume. According to the optimization results, a fitting formula, which considers the contribution rates of the optimization variables, was presented. The results suggest that the FE simulations agree very well with the experiments, and the fitting formula can be used in the PMC design.

scholarly journals Exome-wide association studies in general and long-lived populations identify genetic variants related to human age

2020 ◽  
Author(s):  
Patrick Sin-Chan ◽  
Nehal Gosalia ◽  
Chuan Gao ◽  
Cristopher V. Van Hout ◽  
Bin Ye ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Large Scale ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Association Studies ◽  
Model Systems ◽  
P Value ◽  
Ashkenazi Jews ◽  
Association Analyses ◽  
Age Related

SUMMARYAging is characterized by degeneration in cellular and organismal functions leading to increased disease susceptibility and death. Although our understanding of aging biology in model systems has increased dramatically, large-scale sequencing studies to understand human aging are now just beginning. We applied exome sequencing and association analyses (ExWAS) to identify age-related variants on 58,470 participants of the DiscovEHR cohort. Linear Mixed Model regression analyses of age at last encounter revealed variants in genes known to be linked with clonal hematopoiesis of indeterminate potential, which are associated with myelodysplastic syndromes, as top signals in our analysis, suggestive of age-related somatic mutation accumulation in hematopoietic cells despite patients lacking clinical diagnoses. In addition to APOE, we identified rare DISP2 rs183775254 (p = 7.40×10−10) and ZYG11A rs74227999 (p = 2.50×10−08) variants that were negatively associated with age in either both sexes combined and females, respectively, which were replicated with directional consistency in two independent cohorts. Epigenetic mapping showed these variants are located within cell-type-specific enhancers, suggestive of important transcriptional regulatory functions. To discover variants associated with extreme age, we performed exome-sequencing on persons of Ashkenazi Jewish descent ascertained for extensive lifespans. Case-Control analyses in 525 Ashkenazi Jews cases (Males ≥ 92 years, Females ≥ 95years) were compared to 482 controls. Our results showed variants in APOE (rs429358, rs6857), and TMTC2 (rs7976168) passed Bonferroni-adjusted p-value, as well as several nominally-associated population-specific variants. Collectively, our Age-ExWAS, the largest performed to date, confirmed and identified previously unreported candidate variants associated with human age.

Level Schedules for Mixed-Model, Just-in-Time Processes

1993 ◽  
Vol 39 (6) ◽  
pp. 728-735 ◽  
Author(s):  
George Steiner ◽  
Scott Yeomans
Keyword(s):  
Mixed Model ◽  
Just In Time

Lightweight Design of a Brake Caliper

2013 ◽  
Author(s):  
Federico Maria Ballo ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Amir Pishdad
Keyword(s):  
Cross Sections ◽  
Lightweight Design ◽  
Optimal Solution ◽  
Element Model ◽  
Industrial Applications ◽  
Structural Topology ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Beam Elements ◽  
Starting Point

As lightweight design assumes greater importance in road vehicles development, the present paper is mainly devoted to the structural optimization of a brake caliper. In the first part of the study a simplified finite element model based on beam elements of a brake caliper has been developed and validated. By using the developed model, a multi-objective optimization has been completed. The total mass of the caliper and the deformations at some critical locations have been minimised. The considered design variables are related to the shape of the caliper and the cross sections of the beam elements. The obtained optimal solutions are characterized by an asymmetric shape of the caliper. Optimised symmetric shapes currently used have been compared with the asymmetric ones in terms of performance. In the second part of the study, a detailed analysis on the optimal caliper shape has been carried out by performing a structural topology optimization. The minimum compliance problem has been solved using the SIMP (solid isotropic material with penalization) approach and the optimal solution has been compared with the ones obtained by applying the multi-objective optimization on the simplified model (beam elements). The obtained design solutions represent a good starting point for future developments in actual industrial applications.

scholarly journals Scheduling Just-in-Time Transport Vehicles to Feed Parts for Mixed Model Assembly Lines

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Yunfang Peng ◽  
Tian Zeng ◽  
Yajuan Han ◽  
Beixin Xia
Keyword(s):  
Large Scale ◽  
Assembly Line ◽  
Mixed Model ◽  
Programming Model ◽  
Primary Objective ◽  
Mixed Integer ◽  
Inventory Level ◽  
Just In Time ◽  
Time Model ◽  
Delivery Strategy

In order to solve the problem of vehicle scheduling to feed parts at automobile assembly line, this study proposes a just-in-time delivery method combined with the mode of material supermarket. A mixed integer linear programming model with the primary objective of using the least number of tow trains is constructed by considering capacity of vehicle and inventory levels of line. On the basis of the minimum number of tow trains, the schedule of each tour is reasonably planned to minimize inventory of assembly line, which is the secondary objective of the part supply problem. Additionally, a heuristic algorithm which can obtain a satisfactory solution in a short time is designed to solve large-scale problems after considering continuity and complexity of modern automobile production. Furthermore, some cases are analyzed and compared with the widely used periodic delivery strategy, and the feasibility of just-in-time model and algorithm is verified. The results reveal that just-in-time delivery strategy has more advantages in reducing inventory level than periodic delivery strategy.

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