Improving the benefits of sewer condition deterioration modelling through information content analysis

2016 ◽  
Vol 74 (10) ◽  
pp. 2270-2279 ◽  
Author(s):  
M. M. Rokstad ◽  
R. M. Ugarelli
Keyword(s):  
Information Content ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Structural Condition ◽  
Decision Making Process ◽  
Structural Deterioration ◽  
Functional Defect ◽  
Data Heterogeneity ◽  
Prediction Reliability

As urban sewer infrastructures age, it becomes increasingly important to make effective decisions to maintain the structural condition of the sewers at an acceptable level. To support the decision-making process, the utility manager can apply sewer deterioration models. However, the quality of the decision support from such models is dependent on the accuracy and reliability of the predictions, and previous research has shown that sewer deterioration predictions can be unreliable. In this paper it is shown, by numerical experiment and analysis of information content, how the accuracy of sewer deterioration models is inhibited by data heterogeneity. The data heterogeneity arises when the condition class is used as a response variable, because the condition class is an aggregation of different failure modes, and contains information that does not describe structural deterioration. Based on these findings, the paper suggests changes to be implemented in the condition classification standard, which can mitigate heterogeneity and improve prediction reliability. The suggestions for improvement include distinguishing between structural and functional defect codes, defining new condition metrics better suited for deterioration modelling, and registration of detailed defect codes to allow distinction of different failure mechanisms.

The Footprint of Factorization Models and Their Applications in Collaborative Filtering

2022 ◽  
Vol 40 (4) ◽  
pp. 1-32
Author(s):  
Jinze Wang ◽  
Yongli Ren ◽  
Jie Li ◽  
Ke Deng
Keyword(s):  
Collaborative Filtering ◽  
Gradient Descent ◽  
High Reliability ◽  
Stochastic Gradient Descent ◽  
Decision Making Process ◽  
Intermediate Data ◽  
Benchmark Datasets ◽  
Rich Information ◽  
Prediction Reliability

Factorization models have been successfully applied to the recommendation problems and have significant impact to both academia and industries in the field of Collaborative Filtering ( CF ). However, the intermediate data generated in factorization models’ decision making process (or training process , footprint ) have been overlooked even though they may provide rich information to further improve recommendations. In this article, we introduce the concept of Convergence Pattern, which records how ratings are learned step-by-step in factorization models in the field of CF. We show that the concept of Convergence Patternexists in both the model perspective (e.g., classical Matrix Factorization ( MF ) and deep-learning factorization) and the training (learning) perspective (e.g., stochastic gradient descent ( SGD ), alternating least squares ( ALS ), and Markov Chain Monte Carlo ( MCMC )). By utilizing the Convergence Pattern, we propose a prediction model to estimate the prediction reliability of missing ratings and then improve the quality of recommendations. Two applications have been investigated: (1) how to evaluate the reliability of predicted missing ratings and thus recommend those ratings with high reliability. (2) How to explore the estimated reliability to adjust the predicted ratings to further improve the predication accuracy. Extensive experiments have been conducted on several benchmark datasets on three recommendation tasks: decision-aware recommendation, rating predicted, and Top- N recommendation. The experiment results have verified the effectiveness of the proposed methods in various aspects.

Scanning Electron Microscopy in Hybrid Microelectronics

1976 ◽  
Vol 34 ◽  
pp. 456-457
Author(s):  
S. Khadpe ◽  
R. Faryniak
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Integrated Circuit ◽  
Failure Modes ◽  
Three Dimensional ◽  
Circuit Components ◽  
Hybrid Microcircuit ◽  
Electrical Connections ◽  
Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

scholarly journals Children’s Understanding of Informed Assents in Research Studies

Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 871
Author(s):  
Hortense Cotrim ◽  
Cristina Granja ◽  
Ana Sofia Carvalho ◽  
Carlos Cotrim ◽  
Rui Martins
Keyword(s):  
Health Care ◽  
Positive Relationship ◽  
Age Groups ◽  
High Capacity ◽  
Decision Making Process ◽  
Objective Understanding ◽  
Level Of Understanding ◽  
Age And Sex ◽  
Acceptance Of Health Care

The assent procedure reflects an effort to enable the minor to understand, to the degree they are capable of, what their participation in the decision making process would involve. Aims: To evaluate the minors’ ability to understand the information provided to them when obtaining assent and to evaluate the opinion of the parents regarding the importance of asking the child’s assent. Methods: The sample included a total of 52 minors aged between 10 and 17 years who underwent exercise echocardiogram. The Quality of Informed Consent is divided into two parts: Part A was used to measure objective understanding and part B to measure subjective understanding. Results: The results show that the minors have a high capacity to understand the information given to them when asking for assent. A positive relationship was found between the two parts of the questionnaire. No statistically significant relationship was found between age and sex and part A and part B or between both age groups (<14 years old and ≥14 years old) and the measure. In the case of the parents, 96.6% of parents consider assent as an advantage for the child’s acceptance of health care. The opinion of the parents is not related to the age, sex or level of schooling. Conclusion: Minors showed a substantial level of understanding regarding the information provided to them. The parents considered the implementation of assent fundamental to the child’s acceptance of health care.

scholarly journals Renal Manifestations of Fabry Disease: A Narrative Review

2021 ◽  
Vol 8 ◽  
pp. 205435812098562
Author(s):  
Cassiano Augusto Braga Silva ◽  
José A. Moura-Neto ◽  
Marlene Antônia dos Reis ◽  
Osvaldo Merege Vieira Neto ◽  
Fellype Carvalho Barreto
Keyword(s):  
Fabry Disease ◽  
Specific Treatment ◽  
Narrative Review ◽  
Decision Making Process ◽  
Formal Tool ◽  
General Aspects ◽  
Progressive Accumulation ◽  
Source Of Information ◽  
Worse Prognosis

Purpose of review: In this narrative review, we describe general aspects, histological alterations, treatment, and implications of Fabry disease (FD) nephropathy. This information should be used to guide physicians and patients in a shared decision-making process. Source of information: Original peer-reviewed articles, review articles, and opinion pieces were identified from PubMed and Google Scholar databases. Only sources in English were accessed. Methods: We performed a focused narrative review assessing the main aspects of FD nephropathy. The literature was critically analyzed from a theoretical and contextual perspective, and thematic analysis was performed. Key findings: FD nephropathy is related to the progressive accumulation of GL3, which occurs in all types of renal cells. It is more prominent in podocytes, which seem to play an important role in the pathogenesis of this nephropathy. A precise detection of renal disorders is of fundamental importance because the specific treatment of FD is usually delayed, making reversibility unlikely and leading to a worse prognosis. Limitations: As no formal tool was applied to assess the quality of the included studies, selection bias may have occurred. Nonetheless, we have attempted to provide a comprehensive review on the topic using current studies from experts in FD and extensive review of the literature.

scholarly journals Failure Modes in Electricity and Telecommunication Facilities in Dwellings in Spain

2021 ◽  
Vol 11 (11) ◽  
pp. 5274
Author(s):  
Manuel J. Carretero-Ayuso ◽  
Gonzalo Sánchez-Barroso ◽  
Jaime González-Domínguez ◽  
Justo García-Sanz-Calcedo
Keyword(s):  
Failure Modes ◽  
Functional Deterioration ◽  
The Way

The value of a house depends not only on the quality of the construction elements but also on the functionality of its installations. Making mistakes during the design and even execution phases of installations in newly built homes is common. This paper determines, catalogues, and quantifies faults in electrical and telecommunications installations in dwellings based on owners’ complaints and using the ‘learning from faults’ philosophy. To this end, 154 complaints concerning these installations in all of Spain were analyzed and protocolized. The results show that, in all types of dwellings, the most common fault was ‘alterations and malfunctions’ (81%), followed by ‘incorrect or lack of placement of elements’ (14%). The pathological origin with the greatest presence in the research was ‘shortcomings and omissions in the installation’ (40%) and ‘anomalies in the installation’ (36%). Moreover, all functional deterioration processes as well as the type of dwelling where each of these parameters occurred most were defined and quantified (association between each fault and its cause). Finally, the ‘probability factor’ (PF) was determined, which numerically quantifies the probable existence of complaints according to four ranges. The results will pave the way for more precise inspections during the construction phase.

Analysis of the Relationship Between Rail Seat Load Distribution and Rail Seat Deterioration in Concrete Crossties

2014 ◽  
Author(s):  
Matthew Greve ◽  
Marcus S. Dersch ◽  
J. Riley Edwards ◽  
Christopher P. L. Barkan ◽  
Jose Mediavilla ◽  
...  
Keyword(s):  
Load Distribution ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Past Research ◽  
Concrete Surface ◽  
Hydraulic Pressure ◽  
Valuable Insight ◽  
Increased Risk ◽  
Abrasive Erosion ◽  
Field Experimentation

One of the most common failure modes of concrete crossties in North America is the degradation of the concrete surface at the crosstie rail seat, also known as rail seat deterioration (RSD). Loss of material beneath the rail can lead to wide gauge, rail cant deficiency, and an increased risk of rail rollover. Previous research conducted at the University of Illinois at Urbana-Champaign (UIUC) has identified five primary failure mechanisms: abrasion, crushing, freeze-thaw damage, hydro-abrasive erosion, and hydraulic pressure cracking. The magnitude and distribution of load applied to the rail seat affects four of these five mechanisms; therefore, it is important to understand the characteristics of the rail seat load distribution to effectively address RSD. As part of a larger study funded by the Federal Railroad Administration (FRA) aimed at improving concrete crossties and fastening systems, researchers at UIUC are attempting to characterize the loading environment at the rail seat using matrix-based tactile surface sensors (MBTSS). This instrumentation technology has been implemented in both laboratory and field experimentation, and has provided valuable insight into the distribution of a single load over consecutive crossties. A review of past research into RSD characteristics and failure mechanisms has been conducted to integrate data from field experimentation with existing knowledge, to further explore the role of the rail seat load distribution on RSD. The knowledge gained from this experimentation will be integrated with associated research conducted at UIUC to form the framework for a mechanistic design approach for concrete crossties and fastening systems.

scholarly journals Physical modelling of failure in composites

2016 ◽  
Vol 374 (2071) ◽  
pp. 20150280 ◽  
Author(s):  
Ramesh Talreja
Keyword(s):  
Composite Materials ◽  
Failure Modes ◽  
Structural Integrity ◽  
Failure Mechanisms ◽  
Local Stress ◽  
Physical Modelling ◽  
Stress Fields ◽  
Systematic Analysis ◽  
Composite Failure ◽  
Failure Theories

Structural integrity of composite materials is governed by failure mechanisms that initiate at the scale of the microstructure. The local stress fields evolve with the progression of the failure mechanisms. Within the full span from initiation to criticality of the failure mechanisms, the governing length scales in a fibre-reinforced composite change from the fibre size to the characteristic fibre-architecture sizes, and eventually to a structural size, depending on the composite configuration and structural geometry as well as the imposed loading environment. Thus, a physical modelling of failure in composites must necessarily be of multi-scale nature, although not always with the same hierarchy for each failure mode. With this background, the paper examines the currently available main composite failure theories to assess their ability to capture the essential features of failure. A case is made for an alternative in the form of physical modelling and its skeleton is constructed based on physical observations and systematic analysis of the basic failure modes and associated stress fields and energy balances. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

Research on user needs for mobile information services in Chinese university libraries

2016 ◽  
Vol 34 (4) ◽  
pp. 617-635 ◽  
Author(s):  
Yang Zhao ◽  
Shengli Deng ◽  
Ting Gao ◽  
Ruoxin Zhou
Keyword(s):  
Information Content ◽  
Mobile Services ◽  
Information Services ◽  
User Needs ◽  
University Libraries ◽  
Content Type ◽  
Mobile Information ◽  
User Groups ◽  
Mobile Information Services

Purpose This paper aims to investigate the service demand of existing users and potential users for mobile information services provided by university libraries in China. The primary objective is to explore the impact of user experience on user needs, which is conducted by a comparison between two user groups over their needs from three aspects – service function, service mode and information content. Design/methodology/approach Data were collected from 353 library users from ten Chinese universities via questionnaires. Based on the user needs model, three dimensions of user needs were established for mobile information services and 26 measurement items were generated through a review of the literature. Furthermore, based on frequency analysis, independent samples t-test and the calculation of need rate, the demand differences in mobile information services between existing and potential users were explored. Findings Significant differences existed in the needs for service functions and service modes of mobile information services between existing users and potential users. Existing users cared more about such characteristics as intelligence, personalization and the variety of mobile services. Potential users, in contrast, concerned themselves more with the usability of mobile services and similarity to traditional information services. These two user groups showed little difference in the needs for information content, as they both have strict requirements for specialty, richness in and quality of information resources in mobile network environments. Originality/value Previous research on user needs for mobile libraries services has been primarily conducted from the perspectives of existing users. This study, however, compared the needs of existing and potential users based on their previous experiences, which can help libraries to know better what their users need and improve the quality of mobile information services to meet those needs. This can also make existing users more willing to use the services and cultivate the usage habits of potential users at the same time.

Stiction Failure Mechanisms of the Micromachined Electrostatic Comb-Drive Structures

2011 ◽  
Vol 80-81 ◽  
pp. 850-854
Author(s):  
Yi Shen Xu ◽  
Ji Hua Gu ◽  
Zhi Tao
Keyword(s):  
Failure Modes ◽  
Failure Mechanisms ◽  
Mems Devices ◽  
Comb Drive ◽  
Interfacial Forces ◽  
Restoring Forces ◽  
Critical Investigation

Stiction is one of the most important and almost unavoidable problems in MEMS, which usually occurs when the restoring forces of the microstructures are unable to overcome the interfacial forces. Stiction could compromise the performance and reliability of the MEMS devices or may even make them malfunction. One of the pivotal process of advancing the performance and reliability of MEMS is to comprehend the failure modes and failure mechanisms of these microdevices. This article provides a critical investigation on the stiction failure mechanisms of the micromachined electrostatic comb-drive structures, which is significant to improve the reliability of microdevices, especially for microfilters, microgrippers, microaccelerometers, microgyroscopes, microrelays, and so on.

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