Two-Stage Algorithm for Determination of the Bending Sequence in Sheet Metal Products

1997 ◽  
Vol 119 (2) ◽  
pp. 259-266 ◽  
Author(s):  
B. Radin ◽  
M. Shpitalni ◽  
I. Hartman
Keyword(s):  
Sheet Metal ◽  
Low Cost ◽  
Combinatorial Problem ◽  
Two Stage ◽  
Practical Applications ◽  
Second Stage ◽  
Metal Products ◽  
Bending Sequence ◽  
Time Limitations

This paper presents an algorithm for solving the complex and critical problem of bending sequence in sheet metal manufacturing. Finding the bending sequence and required tool assignment presents a large combinatorial problem which is impossible to solve optimally for practical applications within a reasonable period of time. The paper presents a two-stage algorithm. The first stage finds a feasible solution based upon collision avoidance heuristics. The second stage rapidly seeks an alternative feasible sequence with a lower cost without exceeding time limitations. The algorithm is very practical because it reaches a low-cost solution quickly within computer memory limitations. In this paper, the problem is defined, the approach is presented formally, and finally, the power of the algorithm is demonstrated by solving bending sequences for real products.

Two-Stage Algorithm for Rapid Determination of the Bending Sequence in Sheet Metal Products

1996 ◽  
Author(s):  
B. Radin ◽  
M. Shpitalni ◽  
I. Hartman
Keyword(s):  
Sheet Metal ◽  
Rapid Determination ◽  
Low Cost ◽  
Combinatorial Problem ◽  
Two Stage ◽  
Practical Applications ◽  
Second Stage ◽  
Bending Sequence ◽  
Time Limitations

Abstract This paper presents an algorithm for solving the complex and critical problem of bending sequence in sheet metal manufacturing. Finding the bending sequence and required tool assignment presents a large combinatorial problem which is impossible to solve optimally for practical applications within a reasonable period of time. The paper presents a two-stage algorithm. The first stage finds a feasible solution based upon collision avoidance heuristics. The second stage rapidly seeks an alternative feasible sequence with a lower cost without exceeding time limitations. The algorithm is very practical because it reaches a low-cost solution quickly within computer memory limitations. In this paper, the problem is defined, the approach is presented formally, and finally, the power of the algorithm is demonstrated by solving bending sequences for real products.

Critical Tolerance Oriented Process Planning in Sheet Metal Bending

1999 ◽  
Vol 121 (1) ◽  
pp. 136-144 ◽  
Author(s):  
M. Shpitalni ◽  
B. Radin
Keyword(s):  
Sheet Metal ◽  
Process Planning ◽  
Tolerance Analysis ◽  
Automatic Determination ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Precedence Graph ◽  
Metal Products ◽  
Bending Sequence

Although bending is one of the final processes in sheet metal part manufacture, it is relatively inaccurate compared to the other components of sheet metal processing. Critical tolerances at several locations on the sheet metal part impose limitations on bending operations and sequences. The lack of success up to now in embedding accuracy in process planning for sheet metal products has resulted mainly from the fact that tolerance analysis usually requires simulating the manufacturing process. This paper discusses the issue of automatic determination of the bending sequence in sheet metal products subject to critical tolerance constraints. It proposes conditions for identifying cases where the problem of determining the bending order which results in the best accuracy at specific locations is, in fact, a topological problem. Two explicit rules for achieving the best accuracy in such cases are formulated and then demonstrated by using these rules to construct a precedence graph.

A Novel Initial Alignment Scheme for Low-Cost INS Aided by GPS for Land Vehicle Applications

2010 ◽  
Vol 63 (4) ◽  
pp. 663-680 ◽  
Author(s):  
Songlai Han ◽  
Jinling Wang
Keyword(s):  
Kalman Filtering ◽  
Inertial Sensors ◽  
Low Cost ◽  
Experimental Results ◽  
Initial Alignment ◽  
Two Stage ◽  
Second Stage ◽  
Attitude Error ◽  
Error Dynamic ◽  
Error Dynamics

This paper proposes a novel mechanism for the initial alignment of low-cost INS aided by GPS. For low-cost INS, the initial alignment is still a challenging issue because of the high noises from low-cost inertial sensors. In this paper, a two-stage Kalman Filtering mechanism is proposed for the initial alignment of low-cost INS. The first stage is designed for the coarse alignment. To solve the problems encountered by the general coarse alignment approach, an INS error dynamic accounting for unknown initial heading error is developed, and the corresponding observation equation, taking into account the unknown heading error, is also developed. The second stage is designed for the fine alignment, where the classical INS error dynamics based on small attitude error is used. Experimental results indicate that the proposed alignment approach can complete the initial alignment more quickly and more accurately compared with the conventional approach.

scholarly journals How contractual terms determine fiduciary duties: a two-stage process

2019 ◽  
Vol 70 (2) ◽  
pp. 242-262
Author(s):  
David Gibbs-Kneller ◽  
Derek Whayman
Keyword(s):  
Fiduciary Duty ◽  
Single Factor ◽  
Two Stage ◽  
Fiduciary Duties ◽  
Second Stage ◽  
Stage Process ◽  
Duty Of Loyalty ◽  
Two Stages

The determination of the scope of the fiduciary duty of loyalty, when created by contract, is not a unitary process. It is raised following a multi-factorial enquiry, which considers the nature of the engagement, in a first stage. Here, no single factor is conclusive. It is then, in a separate, second stage, reduced by qualifying contractual terms, which are applied almost strictly logically. This second stage uses the contractual doctrines of interpretation and implication. However, since it is a form of the fiduciary doctrine of authorisation, those contractual doctrines are modified according to fiduciary principles. We argue this follows from the underlying nature of the fiduciary obligation as a way of resolving its internal tensions. While this division has not yet been fully recognised in the cases, the courts have been inching towards it. However, not fully recognising this inevitable division and eliding the two stages has led to defective reasoning and outcomes.

scholarly journals Ratiometric Colorimetric Detection of Nitrite Realized by Stringing Nanozyme Catalysis and Diazotization Together

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 280
Author(s):  
Mengzhu Wang ◽  
Peng Liu ◽  
Hengjia Zhu ◽  
Bangxiang Liu ◽  
Xiangheng Niu
Keyword(s):  
Detection Limit ◽  
Signal Analysis ◽  
High Efficiency ◽  
Colorimetric Assay ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Health It ◽  
Practical Applications ◽  
Higher Sensitivity

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3–133.3 μM with good specificity was realized, providing a detection limit down to 0.2 μM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.

scholarly journals Determination of optimum gear ratios of a two-stage helical gearbox with second stage double gear sets

2019 ◽  
Vol 635 ◽  
pp. 012012
Author(s):  
Vu Ngoc Pi ◽  
Nguyen Thi Hong Cam ◽  
Tran Thi Hong ◽  
Le Xuan Hung ◽  
Luu Anh Tung ◽  
...  
Keyword(s):  
Two Stage ◽  
Second Stage

scholarly journals Real-Time Multifault Rush Repairing Strategy Based on Utility Theory and Multiagent System in Distribution Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Zhao Hao ◽  
Zhang Jing ◽  
Lu Zhi-gang ◽  
Yang Li-jun ◽  
Cheng Hui-lin
Keyword(s):  
Real Time ◽  
Utility Theory ◽  
Multiagent System ◽  
Mathematical Optimization ◽  
Combinatorial Problem ◽  
Distribution Networks ◽  
Two Stage ◽  
Optimal Sequence ◽  
Bacterial Colony ◽  
Second Stage

The problem of multifault rush repair in distribution networks (DNs) is a multiobjective dynamic combinatorial problem with topology constraints. The problem consists of archiving an optimal faults’ allocation strategy to squads and an admissible multifault rush repairing strategy with coordinating switch operations. In this article, the utility theory is introduced to solve the first problem and a new discrete bacterial colony chemotaxis (DBCC) algorithm is proposed for the second problem to determine the optimal sequence for each squad to repair faults and the corresponding switch operations. The above solution is called the two-stage approach. Additionally, a double mathematical optimization model based on the fault level is proposed in the second stage to minimize the outage loss and total repairing time. The real-time adjustment multiagent system (RA-MAS) is proposed to provide facility to achieve online multifault rush repairing strategy in DNs when there are emergencies after natural disasters. The two-stage approach is illustrated with an example from a real urban distribution network and the simulation results show the effectiveness of the two-stage approach.

Structure and Properties of Concrete for Injection with Two-Stage Expansion

2017 ◽  
Vol 265 ◽  
pp. 103-108 ◽  
Author(s):  
Y.I. Koryanova
Keyword(s):  
Cement Stone ◽  
Structure And Properties ◽  
Operational Control ◽  
Two Stage ◽  
Second Stage ◽  
Mix Proportion ◽  
Kinetics Of ◽  
Technology Structure ◽  
Structure Properties

Often, when it is necessary to fill formwork space in confined working conditions with limited operational control in some engineering solutions the special materials for injection are used. In this case, it is advisable to use high-fluidity concrete mixes made with К-cement, regulator of the kinetics of structure formation, superplasticizer and gas-forming admixture. The gas-forming admixture obtains of expansion of fresh-concrete during first stage. The special sulfo-alumina additive in K-cement obtains of expansion of hardening concrete during second stage. The main regularities in the formation of the structure and properties of cement stone are considered. The dependences "composition-technology-structure-properties" for concretes with two-stage expansion are clarified. The main provisions for determination of mix proportion for concrete are proposed. The quantitative relationships between the construction properties of concretes and prescription and technological factors are obtained.

Quantification of analyte and interferent by multipoint analysis.

1986 ◽  
Vol 32 (9) ◽  
pp. 1648-1654 ◽  
Author(s):  
R L Czervionke ◽  
G F Johnson ◽  
N F Nuwayhid ◽  
R D Feld
Keyword(s):  
Linear Regression ◽  
Kinetic Curve ◽  
Model System ◽  
Simultaneous Equations ◽  
Multipoint Analysis ◽  
Two Stage ◽  
Second Stage ◽  
Regression Approach ◽  
Multivariable Nonlinear Regression

Abstract We have investigated the application of multipoint kinetic curve-fitting methods to the determination of an analyte in the presence of a single interferent. Our model system for the analyte-interferent was creatinine-acetoacetate as determined with the kinetic Jaffé method. We examined the utility of the following multipoint approaches: simultaneous equations, multivariable linear regression, and iterative multivariable nonlinear regression. With appropriate restrictions, all approaches could detect acetoacetate interference and quantify both creatinine and acetoacetate. A two-stage linear regression approach was both versatile and computationally simple. Interferent was detected in the first stage, and both analyte and interferent were quantified in the second stage if the interferent was assumed known and an adequate fit of the model to the data was obtained. Using the two-stage linear regression model, we obtained results for 10 ketotic patients that correlated well with results by enzymatic methods for creatinine (r = 0.976) and acetoacetate (r = 0.995); we also demonstrated that creatinine could be quantified in the presence of the antibiotic cefoxitin.

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