scholarly journals The Reduction of Modal Sensor Channels through a Pareto Chart Methodology

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Kaci J. Lemler ◽  
William H. Semke
Keyword(s):  
Test Procedure ◽  
Modal Testing ◽  
Laser Vibrometer ◽  
Pareto Chart ◽  
Complicated Model ◽  
Placement Procedure ◽  
Candidate Set ◽  
Significant Data ◽  
Sensor Locations

Presented herein is a new experimental sensor placement procedure developed to assist in placing sensors in key locations in an efficient method to reduce the number of channels for a full modal analysis. It is a fast, noncontact method that uses a laser vibrometer to gather a candidate set of sensor locations. These locations are then evaluated using a Pareto chart to obtain a reduced set of sensor locations that still captures the motion of the structure. The Pareto chart is employed to identify the points on a structure that have the largest reaction to an input excitation and thus reduce the number of channels while capturing the most significant data. This method enhances the correct and efficient placement of sensors which is crucial in modal testing. Previously this required the development and/or use of a complicated model or set of equations. This new technique is applied in a case study on a small unmanned aerial system. The test procedure is presented and the results are discussed.

Case Study on Determination of Tensile Properties of Construction Sealants at Variable Temperatures

2016 ◽  
Vol 824 ◽  
pp. 18-26 ◽  
Author(s):  
Barbora Nečasová ◽  
Pavel Liška ◽  
Jiří Šlanhof ◽  
Martina Šimáčková
Keyword(s):  
High Temperature ◽  
Porous Materials ◽  
Tensile Properties ◽  
Test Procedure ◽  
European Standard ◽  
Specific Material ◽  
Modified Test

The authors of presented research case focused on possibilities of sealing porous as well as non – porous materials and analysed the measured results. It is the second article of the above mentioned authors dealing with sealed joints, however, in this case study the focus was placed on a group of industrially manufactured modified silyl polymer and polyurethane sealants. The research is based on the modified test procedure for the determination of adhesion and cohesion properties during maintained extension at variable temperatures, i.e. a high temperature of (70 + 2) °C and a temperature simulating freezing, i.e. (-20 + 2) °C, according to the European standard EN ISO 9047. The degree of specimen extension was set to amplitude of 20.0 % and the aim of the research case was to discover any differences that might appear in the resistance. The measured results demonstrate that there are significant differences between individual sealants in the results they provide in combination with specific material, e.g. wood appears to be a problematic substrate as well as glass cement or aluminium.

scholarly journals A Factory Analysis on the Proportion of Defects Reduction in The Animal Feed Pellet Production Process using Design of Experiment Analysis

2019 ◽  
Vol 3 (2) ◽  
pp. 26-33
Author(s):  
Keyword(s):  
Production Process ◽  
Failure Modes ◽  
Animal Feed ◽  
Fractional Factorial ◽  
Pareto Chart ◽  
Manufacturing Defects ◽  
Root Cause ◽  
Pellet Production ◽  
Feed Pellet

The aim of this research is to reduce a number of defects during a feed pellet production process to improve customer satisfaction. A factory case study produces the feed pellets for several species such as food for pigs, chickens, and ducks. Production data from January to June 2017 manufacturing found that the manufacturing defects rate were about 3.32%. The data showed that the overall defects originated from different problems; 1) cracked or broken food; 2) high humidity; 3) distorted of product color; and 4) an ingredient error, respectively. Statistical methods, design analysis, and cause analysis techniques e.g. the Ishikawa diagram, Pareto chart, and FMEA (Failure Mode and Effects Analysis) were applied to help the factory to identify the main root cause of the defects and the potential failure modes of the factory case study. Due to an increasing number of complaints, this study only concentrated on the duck feed pellet production process. The study was divided into two parts: finding the root cause of the defects, which are the most critical factors for further analysis, and applying an experimental statistical design to decrease the number of defects during the duck pellet production process. The problem with cracked or broken pellets (dust) was found as the main factor affecting the production defects. Results showed that the main factors contributing to the amount of dusk in the duck feed productions came from three factors as follow: the thickness of die, distance between compression rollers and die, and time and temperature of mill machine needed during compressing the duck feed pellet production. Both the fractional factorial experimental design, 2k and 3k, were used to evaluate the influence of each factor on the duck feed production defects. The results by using the factorial 2K experimental show that the most important variable in duck pellets production were thickness of the die, distance between compression rollers and die, and temperature of mill machine needed during compressing the duck feed pellet production while time was not an interaction effect in this problem. The 3k factorial design was used to determine the interaction effects for the duck pellets production process. The experiment was ran and tested for 3 months. The final outcomes showed a significant reduction of defects from 2.51% to 1.09% (P<0.01). The results indicated that thickness -20 mm. of the die, 0.05 mm of distance between compression rollers and die, and 95 degree Celsius of temperature of mill machine needed during compressing the duck feed pellet production would be the most appropriate set of pelleting machine for the duck production process case study.

Experimental analysis of the modal characteristics of rail fastening clips

2019 ◽  
Vol 234 (2) ◽  
pp. 134-141
Author(s):  
Linlin Sun ◽  
Ziquan Yan ◽  
Junheng Xiao ◽  
Hangwei Fang ◽  
Shukun Cui
Keyword(s):  
Pressure Sensor ◽  
Sound Pressure ◽  
Low Noise ◽  
Modal Testing ◽  
Laser Vibrometer ◽  
Test Results ◽  
Noisy Environment ◽  
Additional Mass ◽  
Modal Characteristics ◽  
Operating Environments

It is usually difficult to obtain the modal characteristics of the rail fastening clip analytically owing to its complex spatial structure and operating environments. Therefore, experimental modal testing is frequently adopted to identify the modal characteristics of rail fastening clips. This study takes the SKL 15 clip of the Vossloh 300-1 fastening system as the research object to analyse the following three aspects in great detail: (1) Locations of the measurement points are reasonably designed to capture all modes of the clip in the frequency range 0–1000 Hz. (2) The appropriate sensors are selected for the clip in different operating situations by comparing the measured results of three kinds of sensors, namely the accelerometer, laser vibrometer and sound pressure sensor. In addition, the test results suggest that the accelerometer which has a strong anti-disturbance ability in an ambient environment is recommended to be chosen in a noisy environment while the laser vibrometer and sound pressure sensor which have no added mass to the tested structures may be used in an indoor environment with suitable temperature and low noise. (3) In order to eliminate the effect of the additional mass on the modal characteristics of the clip, the accelerometer is recommended to be installed at the rear end of the side leg of the clips in the experimental modal test.

Case Study: Vibration analysis for the design of a high-speed generator for a turbo-electric hybrid vehicle

1998 ◽  
Vol 212 (4) ◽  
pp. 271-283 ◽  
Author(s):  
C Leontopoulos ◽  
D. A. Robb ◽  
C. B. Besant
Keyword(s):  
Power Output ◽  
High Speed ◽  
Test Procedure ◽  
Volume Ratio ◽  
Hybrid Vehicle ◽  
Modal Testing ◽  
Diesel Generator ◽  
Element Analysis ◽  
Turbo Generator ◽  
Adequate Understanding

The project relates to the design and development of a prototype high-speed turbo-generator as the thermal engine in a series hybrid vehicle. The substantial benefit of the turbo-generator against a diesel generator lies in the very high power-weight, power-volume ratio and renders itself particularly attractive for use in hybrid vehicle applications. However, to achieve a 50 kW power output, the turbo-generator has to have an operating speed of 60 000 r/min and thus important mechanical problems have to be solved. The core of this study addresses the requirement for an adequate understanding of rotor-dynamic behaviour by combining the results from both analytical and practical techniques. The assessment of modal testing, finite element analysis and vibration-condition monitoring, their feedback within the design-make-and-test procedure and the practical compromises and design constraints are presented and a design methodology is formulated. It is concluded that, under certain conditions, the prototype generator can be directly coupled to a small gas turbine, can operate safely and can produce the required power output.

Calibration and Validation of Microscopic Traffic Simulation Tools: Stockholm Case Study

2003 ◽  
Vol 1831 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Tomer Toledo ◽  
Haris N. Koutsopoulos ◽  
Angus Davol ◽  
Moshe E. Ben-Akiva ◽  
Wilco Burghout ◽  
...  
Keyword(s):  
Travel Behavior ◽  
Traffic Simulation ◽  
Choice Model ◽  
Aggregate Data ◽  
Flow Measurements ◽  
Microscopic Traffic Simulation ◽  
Calibration And Validation ◽  
The North ◽  
Sensor Locations

The calibration and validation approach and results from a case study applying the microscopic traffic simulation tool MITSIMLab to a mixed urban-freeway network in the Brunnsviken area in the north of Stockholm, Sweden, under congested traffic conditions are described. Two important components of the simulator were calibrated: driving behavior models and travel behavior components, including origin–destination flows and the route choice model. In the absence of detailed data, only aggregate data (i.e., speed and flow measurements at sensor locations) were available for calibration. Aggregate calibration uses simulation output, which is a result of the interaction among all components of the simulator. Therefore, it is, in general, impossible to identify the effect of individual models on traffic flow when using aggregate data. The calibration approach used takes these interactions into account by iteratively calibrating the different components to minimize the deviation between observed and simulated measurements. The calibrated MITSIMLab model was validated by comparing observed and simulated measurements: traffic flows at sensor locations, point-to-point travel times, and queue lengths. A second set of measurements, taken a year after the ones used for calibration, was used at this stage. Results of the validation are presented. Practical difficulties and limitations that may arise with application of the calibration and validation approach are discussed.

scholarly journals PENERJEMAHAN HARFIAH: DOMINASI DALAM TEKNIK PENERJEMAHAN SURAT INFORMAL

2020 ◽  
Vol 12 (1) ◽  
pp. 43-49
Author(s):  
Arif Hidayat
Keyword(s):  
Normal Distribution ◽  
Qualitative Approach ◽  
Case Study Method ◽  
Literal Translation ◽  
Translation Technique ◽  
Data Collecting ◽  
Translation Techniques ◽  
Significant Data

Translation techniques are expected to be solutions to cope with translation problems faced by translators. Due to this reason, translation learners are taught these techniques to be their provision in handling translation problems they will face as professional translators. This research is aimed at giving comprehension of the using translation techniques tendency in informal letter translation. Case study method is used in this research to analyze how English Letters students who have learnt translation through qualitative approach and document data collecting technique. This research uses Molina & Albir's (2002)Translation Techniques to identify the translation technniques used by the students.The result shows that the dominance of literal translation technique by a very significant data finding from the eleven techniques used with normal distribution ranging from 17 until 27 data per students.In the next research, it is hoped that there will be wider scope of study to analyze the trends of translation techniques in those students’ affiliation.Keywords: Literal Translation, Teknik Penerjemahan, Informal Letter

scholarly journals OPTIMIZATION OF PLATE RECOGNITION SENSOR LOCATIONS: A CASE STUDY IN TURKEY

2021 ◽  
Vol 32 (1) ◽  
pp. 147-163
Author(s):  
Buğra GÖR ◽  
Gülşah KARAKAYA
Keyword(s):  
Sensor Locations

scholarly journals Design and Testing of a Sensing System for Aero-Engine Smart Bearings

Proceedings ◽  
2019 ◽  
Vol 2 (13) ◽  
pp. 1005 ◽  
Author(s):  
Imran Bashir ◽  
Bahareh Zaghari ◽  
Terry J. Harvey ◽  
Alex S. Weddell ◽  
Neil M. White ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Test Procedure ◽  
Low Power Consumption ◽  
Wireless Data ◽  
Sensor Performance ◽  
Sensing System ◽  
Aero Engine ◽  
Self Powered ◽  
Design And Testing

Smart bearings incorporating self-powered sensors and wireless data communications with intelligence in monitoring bearing conditions can help to detect early faults in aero-engine bearings. This paper presents the challenges in design and development of a sensing system with compact and low-power consumption sensors and the procedures for sensor performance evaluation under the requirements of aerospace standard. Industrial standard DO160 testing is necessary for preliminary testing of the smart sensing system prior to being installed in aero-engine, thus a laboratory test procedure has been developed for sensor performance evaluation for the smart aero-engine bearings in this project. As a case study, this paper presents the details and results of the accelerometer evaluation following the requirements in DO160.

Application of Kaizen-Kata methodology to improve operational problem processes. A case study in a service organization

2021 ◽  
Vol 13 (1) ◽  
pp. 29-44
Author(s):  
Manuel F. Suárez-Barraza ◽  
José Angel Miguel-Dávila ◽  
Manuel Francisco Morales-Contreras
Keyword(s):  
Service Organization ◽  
Service Process ◽  
Successful Implementation ◽  
Manufacturing Companies ◽  
Pareto Chart ◽  
Content Type ◽  
Operational Problem ◽  
A Company ◽  
Operational Service

Purpose The purpose of this paper is to explore, study, analyze and implement Kaizen–Kata methodology in a service food organization (first-level restaurant), facing challenges in different operational processes that affect and influence the case company performance and customer satisfaction. Design/methodology/approach The service organization implemented Kaizen–Kata methodology to improve one operational problem process. A case-study approach was used in this research to understand the effects of the Kaizen–Kata methodology in solving problems in their operational service process. Different Kaizen–Kata techniques and tools (histograms, Pareto chart and Ishikawa diagram) using the Plan, Do, Check, Act improvement cycle framework were used. Findings Successful implementation of the proposed methodology reduced the main impact of the problem’s effects (customer’s complaints, process reworking, extra-cost, delays, among others). The effects of the problem were reduced on average by 70%. Some Kaizen–Kata routines were identified in a service process environment. Research limitations/implications The main limitation of the research is that this work is a just one-case study. A main generalization is not possible, because it involves a company within a company. Practical implications Some other service companies can use the Kaizen–Kata methodology to solve any kind of operational problem within their processes. Service managers can learn about the methodology to apply and improve their operational performance and handle customer’s complaints. Originality/value A continuous improvement manufacturing methodology was imported to apply in an operational service process. The Kaizen–Kata methodology contributed significantly to reduce delays, handle customer’s complaints, process reworking and deal with extra costs, among other operational problems’ effects. In addition to that, in the literature, most of the Kaizen applications are in manufacturing companies. To the best of authors’ knowledge, this was the first study of applied Kaizen–Kata in a service organization (a fast-food restaurant).

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