Improvement of the Best and the Worst Case Method on the Automobile Cable Bundles Dynamic Crosstalk Based on the Statistical Model

2013 ◽  
Vol 13 (16) ◽  
pp. 3330-3334
Author(s):  
Gao Yin-Han ◽  
Wang Tian-Hao ◽  
Yang Kai-Yu ◽  
Zhang Jun-Dong ◽  
Song Yu-He ◽  
...  
Keyword(s):  
Statistical Model ◽  
Case Method ◽  
Worst Case

Process Capability Based Tolerance Allocation in Pneumatic Percussive Riveting

2020 ◽  
Author(s):  
Hua Wang ◽  
Jialei Zhang ◽  
Junyang Yu
Keyword(s):  
High Efficiency ◽  
Load Transfer ◽  
Process Capability ◽  
Tolerance Analysis ◽  
Tolerance Allocation ◽  
Hole Drilling ◽  
Case Method ◽  
Pneumatic Hammer ◽  
Worst Case ◽  
Mating Conditions

Abstract Pneumatic percussive riveting is an important way to join the sheet metals. In order to ensure the load transfer and the fatigue performance of riveted joint, the interference of the rivet/hole is strictly specified. The interference of the rivet/hole is highly correlated with the process capability of the pneumatic hammer and the diameter of the pre-hole. It is a critical step to choose the appropriate pneumatic hammer to ensure the interference requirements. Energy per blow of the pneumatic hammer is a proclaimed parameter from the riveting hammer manufacturer. It is difficult for the designer to choose the riveting hammer in practical riveting scheme based on energy per blow. Tolerance analysis is an efficient way to model the manufacturing variation and implement process control. This paper presents the tolerance allocation of the pneumatic percussive riveting based on the process capability of the pneumatic hammer. In order to obtain the designed interferences of the rivet/hole, a tolerance chain is built with the process capability of the pneumatic hammer, the diameter of the pre-hole and the diameter of the rivet shank. The process capability of the pneumatic hammer is represented with the interferences of the rivet/hole after riveting. It is an intuitive parameter for the designer to choose the riveting hammer in practical riveting scheme. The process capability of the pneumatic hammer is obtained from the designed riveting experiments with the pneumatic percussive riveting platform. The diameter of the pre-hole affects the interference of the rivet/hole also. The tolerance for manual hole-drilling should be determined to assure the interference requirements and high drilling operation efficiency simultaneously. The variation of the pre-hole is obtained from the manual drilling experiments and diameter measurements. Different hole-drilling results in different mating conditions between the pre-hole and the rivet. The fit conditions of different pre-holes are modeled and the final interferences after riveting are analyzed. Worst case method and statistical analysis method are two common methods for tolerance analysis. For the manual hole-drilling and the pneumatic percussive riveting, worst case method is employed to analyze the constructed tolerance chain in order to accomplish the interferences of the rivet/hole. The different analyzed dimensions, rivet-hole clearances and pre-hole drilling variation, are investigated respectively. The reported work enhances the understanding of the tolerance allocation for the pneumatic percussive riveting. The interference based process capability of the pneumatic hammer provides good reference for pneumatic hammer choosing in riveting scheme. The reported tolerance chain of the interference could be used for the tolerance determination of manual hole-drilling with good quality and high efficiency.

Sensory evaluation of the odors produced during bromophenol formation using a multi-level statistical model

2004 ◽  
Vol 49 (9) ◽  
pp. 241-248
Author(s):  
H. Al-Samarrai ◽  
J. Matud ◽  
K. Wiesenthal ◽  
P. Atiyah ◽  
A. Bruchet ◽  
...  
Keyword(s):  
Water Quality ◽  
Statistical Model ◽  
Profile Analysis ◽  
Quality Parameters ◽  
High Concentration ◽  
Worst Case ◽  
Taste And Odor ◽  
Products Of Reaction ◽  
Flavor Profile Analysis ◽  
Flavor Profile

In response to reports of medicinal taste and odor problems in suburban Paris, a lab scale study was conducted to investigate the contribution of different water quality parameters - pH, phenol, bromide, chlorine, temperature and dissolved oxygen levels - on bromophenol medicinal odor formation using the Flavor Profile Analysis (FPA) method. A study of six parameters at 2 levels (64 experiments) analyzed by the FPA method suggests that chlorine at high concentration is more important as a controlling agent than phenol under similar conditions and the ratio of HOBr:Phenol and the time for reaction will control subsequent brominated products of reaction. Results from a three-level statistical model indicate that high pH was associated with lower odor intensities, whereas high levels of chlorine, phenol and temperature were associated with high odor intensities. Potential worst case scenarios of water quality conditions were determined for evaluation by chemical identification and kinetics.

scholarly journals Tolerance Analysis of Mechanical Parts

2020 ◽  
Vol 14 (3) ◽  
pp. 265-272
Author(s):  
Živko Kondić ◽  
Đuro Tunjić ◽  
Leon Maglić ◽  
Amalija Horvatić Novak
Keyword(s):  
Tolerance Analysis ◽  
Case Method ◽  
Worst Case ◽  
Mechanical Parts ◽  
Assembly Tolerance ◽  
Huge Impact ◽  
Quality Of Products ◽  
The One

The determination of tolerances has a huge impact on the price and quality of products. The objective of tolerance analysis is to provide the widest possible tolerance range of parts, without disturbing the functionality of the assembly. Tolerance analysis should be performed during the design process because then there is still the possibility for change. For the purpose of carrying out the analysis, three methods will be used: Worst Case method, Root Sum Square method and Monte Carlo Simulation. Methods are explained through simple examples and applied on the one-way clutch.

Uncertainty analysis by the "worst case" method

1984 ◽  
Vol 61 (9) ◽  
pp. 780 ◽  
Author(s):  
Roy Gordon ◽  
Miles Pickering ◽  
Denise Bisson
Keyword(s):  
Uncertainty Analysis ◽  
Case Method ◽  
Worst Case

scholarly journals Robustness assessment of a novel 4D optimization approach for lung cancer radiotherapy

2021 ◽  
Author(s):  
Shahad M. Al-Ward
Keyword(s):  
Lung Cancer ◽  
Image Data ◽  
Maximum Intensity ◽  
Planning Method ◽  
Case Method ◽  
Worst Case ◽  
Case Methods ◽  
Patient Motion ◽  
Wide Range ◽  
Case Planning

One of the main challenges to treatment of lung cancer with radiation therapy is the tumor motion due to respiration. Previously, a novel approach was developed to generate treatment plans which compensate for respiratory motion and its variations. The worst case method is based on combining two intensity maps from two 4D plans optimized on the two worst cases of motion variations. The worst case planning method was previously tested on simulated motion variations. The goal of this project was to further test the worst case approach on realistic patient motion variations and treatment planning data. Two approaches to combining worst case plans were investigated: the first method takes the average of the two intensity maps, and the second method takes the maximum intensity of the two intensity maps. The robustness of worst case plans was compared with ITV plans and nominal 4D plans on three different motion variation scenarios. Study 1 and 2 investigated the robustness of the worst case methods on amplitude variations and patient motion variations on simulated image data. Study 3 investigated the robustness of the worst case methods on patient motion variations using real patient image data. The average intensity worst case method was only robust to Study 3 motion variations. The maximum intensity worst case method, the margin based, and the nominal approaches were not robust to any of the motion variations. Further evaluation over a wide range of tumour sizes, motion amplitudes and variability is required to determine the clinical applicability of the worst case planning method.

scholarly journals Robustness assessment of a novel 4D optimization approach for lung cancer radiotherapy

2021 ◽  
Author(s):  
Shahad M. Al-Ward
Keyword(s):  
Lung Cancer ◽  
Image Data ◽  
Maximum Intensity ◽  
Planning Method ◽  
Case Method ◽  
Worst Case ◽  
Case Methods ◽  
Patient Motion ◽  
Wide Range ◽  
Case Planning

One of the main challenges to treatment of lung cancer with radiation therapy is the tumor motion due to respiration. Previously, a novel approach was developed to generate treatment plans which compensate for respiratory motion and its variations. The worst case method is based on combining two intensity maps from two 4D plans optimized on the two worst cases of motion variations. The worst case planning method was previously tested on simulated motion variations. The goal of this project was to further test the worst case approach on realistic patient motion variations and treatment planning data. Two approaches to combining worst case plans were investigated: the first method takes the average of the two intensity maps, and the second method takes the maximum intensity of the two intensity maps. The robustness of worst case plans was compared with ITV plans and nominal 4D plans on three different motion variation scenarios. Study 1 and 2 investigated the robustness of the worst case methods on amplitude variations and patient motion variations on simulated image data. Study 3 investigated the robustness of the worst case methods on patient motion variations using real patient image data. The average intensity worst case method was only robust to Study 3 motion variations. The maximum intensity worst case method, the margin based, and the nominal approaches were not robust to any of the motion variations. Further evaluation over a wide range of tumour sizes, motion amplitudes and variability is required to determine the clinical applicability of the worst case planning method.

scholarly journals Investigation of the fake reject cases with unqualified operational dimension based on the error compensation and tolerance compression

2021 ◽  
Author(s):  
Xiaosan Ma ◽  
Feng Jiao ◽  
Wenhui Feng ◽  
Wenbo Bie ◽  
Fan Chen
Keyword(s):  
Error Compensation ◽  
Case Method ◽  
Remedial Measures ◽  
Remedial Measure ◽  
Worst Case ◽  
Qualification Rate ◽  
Process Dimension ◽  
Operational Data ◽  
Compensation Relationship ◽  
Operational Dimension

A fake reject (FR) with unqualified operational dimension often occurs during part machining when the operational data do not coincide with the design ones. This may lead to unnecessary waste. A novel judgment and remedial measures for FR are investigated in this paper to enhance products' qualification rate. Firstly, the reasons for the FR occurrence are discussed based on the fact that the operational dimension tolerance calculated using the worst-case method of the process dimension chain calculation is too tight. Secondly, a novel judgment method of FR is proposed by calculating a new dimension chain. The operational dimension is treated as the concluding link. The actual deviations of the dimensions generated before the operational dimension generation are used to replace their upper and lower deviations. Finally, based on the error compensation relationship among the component links in the process dimension chain, a novel remedial measure of FR by compressing dimension tolerance in subsequent processing is proposed. The calculation flow of the dimension tolerance after tolerance compression is worked out. This study's results of this study are considered for instrumental in judging and processing FR in part machining.

scholarly journals Multi-Year High-Voltage Power System Planning Considering Active Power Curtailment

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4920
Author(s):  
Florian Schäfer ◽  
Martin Braun
Keyword(s):  
Time Series ◽  
Power System ◽  
High Voltage ◽  
Renewable Energy Sources ◽  
Active Power ◽  
Case Method ◽  
Power System Planning ◽  
System Planning ◽  
Worst Case ◽  
Planning Methods

Integrating active power curtailment (APC) of renewable energy sources (RES) in power system planning reduces necessary investments in the power system infrastructure. In current target grid planning methods, APC is considered by fixed curtailment factors without considering the provided flexibility to its full extent. Time-series-based planning methods allow the integration of the time dependency of RES and loads in power system planning, leading to substantial cost savings compared to the worst-case method. In this paper, we present a multi-year planning strategy for high-voltage power system planning, considering APC as an alternative investment option to conventional planning measures. A decomposed approach is chosen to consider APC and conventional measures in a long-term planning horizon of several years. The optimal investment path is obtained with the discounted cash flow method. A case study is conducted for the SimBench high-voltage urban benchmark system. Results show that the time-series-based method allows for reducing investments by up to 84% in comparison to the worst-case method. Furthermore, a sensitivity analysis shows the variation in total expenditures with changing cost assumptions.

scholarly journals ANALYSIS OF GEOMETRICAL SPECIFICATION IN DECANTER CENTRIFUGE MACHINE

2018 ◽  
Vol 8 (2) ◽  
pp. 29-47
Author(s):  
Bagus Budiwantoro ◽  
Indra Djodikusumo ◽  
Ade Ramdan
Keyword(s):  
Statistical Method ◽  
Manufacturing Process ◽  
Tolerance Analysis ◽  
Mean Value ◽  
Case Method ◽  
3D Design ◽  
Worst Case ◽  
Production Phase ◽  
Performance Requirements ◽  
Decanter Centrifuge

A decanter centrifuge machine has been developed and currently at a complete stage of a preliminary 3D design layout. The next phase is a production phase. In the production phase, an ideal component that is identical with the 3D model will never be realized. Every manufacturing process has unavoidable variations. If they are accumulated, they can be immense and may cause serious problems. The machine may fail. Thus, the analysis of geometry specification is necessary to be conducted. The main objective of this study is to design the geometry specification which includes their tolerance to assure that the machine will work and achieve its performance, considering variation in manufacturing process. The study consists of four stages, they are: (1) reviewing the 3D design layout, (2) identifying functional key characteristics, (3) analyzing each requirement to determine the geometric dimensioning and tolerancing schemes and (4) allocating tolerances. Every scheme was built through six steps, establish the performance requirements, draw a loop diagram, converting dimension to mean dimension, calculate mean value with stack tolerance, determine the method of tolerance analysis and calculate the variation of performance requirements. The tolerance analysis uses the worst case and statistical methods. They involve 45 fixed tolerances and 38 variable tolerances. The calculated variation data output of every requirement is elaborated to finalize tolerance value that will meet all requirements. Finally, the final tolerance values are allocated and set to component geometry. This analysis concludes that every final tolerance of variable tolerance values must be tighter for the worst case method, and only 42% for statistical method. Probability of machine will work and achieve its performance is 100% for the worst case method and 99.73% for the statistical method.

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