scholarly journals Using Multiple Criteria Optimization and Two-Stage Genetic Algorithms to Select a Population Management Strategy with Optimized Reliability

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Jessica L. Chapman ◽  
Lu Lu ◽  
Christine M. Anderson-Cook
Keyword(s):  
Multiple Objectives ◽  
Second Phase ◽  
Two Phase ◽  
Phase Approach ◽  
Reliability Estimates ◽  
Starting Point ◽  
Single Use ◽  
Management Optimization ◽  
Reliability Performance ◽  
The Impact

An important aspect of good management of inventory for many single-use populations or stockpiles is to develop an informed consumption strategy to use a collection of single-use units, with varied reliability as a function of age, during scheduled operations. We present a two-phase approach to balance multiple objectives for a consumption strategy to ensure good performance on the average reliability, consistency of unit reliability over time, and least uncertainty of the reliability estimates. In the first phase, a representative subset of units is selected to explore the impact of using units at different time points on reliability performance and to identify beneficial consumption patterns using a nondominated sorting genetic algorithm based on multiple objectives. In the second phase, the results from the first phase are projected back to the full stockpile as a starting point for determining best consumption strategies that emphasize the priorities of the manager. The method can be generalized to other criteria of interest and management optimization strategies. The method is illustrated with an example that shares characteristics with some munition stockpiles and demonstrates the substantial advantages of the two-phase approach on the quality of solutions and efficiency of finding them.

scholarly journals Multi-Objective Service Selection and Scheduling with Linguistic Preference in Cloud Manufacturing

2019 ◽  
Vol 11 (9) ◽  
pp. 2619 ◽  
Author(s):  
Wei He ◽  
Guozhu Jia ◽  
Hengshan Zong ◽  
Jili Kong
Keyword(s):  
Service Management ◽  
Service Selection ◽  
Cloud Manufacturing ◽  
Multiple Objectives ◽  
Second Phase ◽  
Time Cost ◽  
Two Phase ◽  
Preference Information ◽  
Multi Objective ◽  
Service Selection And Scheduling

Service management in cloud manufacturing (CMfg), especially the service selection and scheduling (SSS) problem has aroused general attention due to its broad industrial application prospects. Due to the diversity of CMfg services, SSS usually need to take into account multiple objectives in terms of time, cost, quality, and environment. As one of the keys to solving multi-objective problems, the preference information of decision maker (DM) is less considered in current research. In this paper, linguistic preference is considered, and a novel two-phase model based on a desirable satisfying degree is proposed for solving the multi-objective SSS problem with linguistic preference. In the first phase, the maximum comprehensive satisfying degree is calculated. In the second phase, the satisfying solution is obtained by repeatedly solving the model and interaction with DM. Compared with the traditional model, the two-phase is more effective, which is verified in the calculation experiment. The proposed method could offer useful insights which help DM balance multiple objectives with linguistic preference and promote sustainable development of CMfg.

scholarly journals Evaluating and comparing biomarkers with respect to the area under the receiver operating characteristics curve in two-phase case–control studies

Biostatistics ◽  
2016 ◽  
Vol 17 (3) ◽  
pp. 499-522 ◽  
Author(s):  
Ying Huang
Keyword(s):  
Case Control ◽  
Receiver Operating Characteristics ◽  
Biased Sampling ◽  
Second Phase ◽  
Operating Characteristics ◽  
Case Control Studies ◽  
Two Phase ◽  
Receiver Operating Characteristics Curve ◽  
The Impact ◽  
Receiver Operating

Abstract Two-phase sampling design, where biomarkers are subsampled from a phase-one cohort sample representative of the target population, has become the gold standard in biomarker evaluation. Many two-phase case–control studies involve biased sampling of cases and/or controls in the second phase. For example, controls are often frequency-matched to cases with respect to other covariates. Ignoring biased sampling of cases and/or controls can lead to biased inference regarding biomarkers' classification accuracy. Considering the problems of estimating and comparing the area under the receiver operating characteristics curve (AUC) for a binary disease outcome, the impact of biased sampling of cases and/or controls on inference and the strategy to efficiently account for the sampling scheme have not been well studied. In this project, we investigate the inverse-probability-weighted method to adjust for biased sampling in estimating and comparing AUC. Asymptotic properties of the estimator and its inference procedure are developed for both Bernoulli sampling and finite-population stratified sampling. In simulation studies, the weighted estimators provide valid inference for estimation and hypothesis testing, while the standard empirical estimators can generate invalid inference. We demonstrate the use of the analytical variance formula for optimizing sampling schemes in biomarker study design and the application of the proposed AUC estimators to examples in HIV vaccine research and prostate cancer research.

scholarly journals TPA: A Two-Phase Approach Using Simulated Annealing for the Optimization of Census Taker Routes in Mexico

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Silvia Gaona ◽  
David Romero
Keyword(s):  
Simulated Annealing ◽  
Shortest Path ◽  
Travel Distance ◽  
Visibility Graph ◽  
Second Phase ◽  
Two Phase ◽  
Phase Approach ◽  
Dijkstra's Algorithm ◽  
Average Improvement ◽  
Parameter Values

Censuses in Mexico are taken by the National Institute of Statistics and Geography (INEGI). In this paper a Two-Phase Approach (TPA) to optimize the routes of INEGI’s census takers is presented. For each pollster, in the first phase, a route is produced by means of the Simulated Annealing (SA) heuristic, which attempts to minimize the travel distance subject to particular constraints. Whenever the route is unrealizable, it is made realizable in the second phase by constructing a visibility graph for each obstacle and applying Dijkstra’s algorithm to determine the shortest path in this graph. A tuning methodology based on theiracepackage was used to determine the parameter values for TPA on a subset of 150 instances provided by INEGI. The practical effectiveness of TPA was assessed on another subset of 1962 instances, comparing its performance with that of the in-use heuristic (INEGIH). The results show that TPA clearly outperformsINEGIH. The average improvement is of 47.11%.

scholarly journals Accountability legislation: Implications for financial and performance reporting

2012 ◽  
Vol 1 (1) ◽  
pp. 25-35
Author(s):  
Daphne Rixon
Keyword(s):  
Public Sector ◽  
Stakeholder Management ◽  
The Body ◽  
Second Phase ◽  
Theoretical Frameworks ◽  
Two Phase ◽  
Performance Reporting ◽  
Accountability Legislation ◽  
And Performance ◽  
The Impact

The purpose of this case study is to first examine the implications of accountability legislation on the financial and performance reporting of a public sector agency in the Canadian province of Newfoundland and Labrador and secondly, to compare the level of accountability with Stewart’s (1984) ladder of accountability. This paper is based on the first phase of a two-phase study. The first phase focuses on the initial impacts of accountability legislation on agencies and the challenges created by the legislation’s ‘one size fits all’ approach. The second phase of this study will examine the impact of the legislation on stakeholders after it has been in operation for five years. The second phase will include interviews with stakeholders to ascertain the level of satisfaction with the new legislation. The first phase of the study is significant since it highlights how governments could consider stakeholder needs when drafting such legislation. This research contributes to the body of literature on stakeholder accountability since there is a paucity of research focused specifically on the impact of accountability legislation on public sector agencies. An important contribution of this paper is the introduction of a framework for legislated accountability reporting. The main theoretical frameworks used to analyse the findings are Stewart’s (1984) ladder of accountability in conjunction with Friedman and Miles (2006) ladder of stakeholder management and engagement.

scholarly journals Trust Dynamics and Verbal Assurances in Human Robot Physical Collaboration

2021 ◽  
Vol 4 ◽  
Author(s):  
Basel Alhaji ◽  
Michael Prilla ◽  
Andreas Rausch
Keyword(s):  
Mixed Reality ◽  
Second Phase ◽  
Two Phase ◽  
Reliability Level ◽  
Trust Level ◽  
Interesting Conclusion ◽  
Conditional Effect ◽  
The Impact ◽  
Human Robot Collaboration ◽  
Relevant Factors

Trust is the foundation of successful human collaboration. This has also been found to be true for human-robot collaboration, where trust has also influence on over- and under-reliance issues. Correspondingly, the study of trust in robots is usually concerned with the detection of the current level of the human collaborator trust, aiming at keeping it within certain limits to avoid undesired consequences, which is known as trust calibration. However, while there is intensive research on human-robot trust, there is a lack of knowledge about the factors that affect it in synchronous and co-located teamwork. Particularly, there is hardly any knowledge about how these factors impact the dynamics of trust during the collaboration. These factors along with trust evolvement characteristics are prerequisites for a computational model that allows robots to adapt their behavior dynamically based on the current human trust level, which in turn is needed to enable a dynamic and spontaneous cooperation. To address this, we conducted a two-phase lab experiment in a mixed-reality environment, in which thirty-two participants collaborated with a virtual CoBot on disassembling traction batteries in a recycling context. In the first phase, we explored the (dynamics of) relevant trust factors during physical human-robot collaboration. In the second phase, we investigated the impact of robot’s reliability and feedback on human trust in robots. Results manifest stronger trust dynamics while dissipating than while accumulating and highlight different relevant factors as more interactions occur. Besides, the factors that show relevance as trust accumulates differ from those appear as trust dissipates. We detected four factors while trust accumulates (perceived reliability, perceived dependability, perceived predictability, and faith) which do not appear while it dissipates. This points to an interesting conclusion that depending on the stage of the collaboration and the direction of trust evolvement, different factors might shape trust. Further, the robot’s feedback accuracy has a conditional effect on trust depending on the robot’s reliability level. It preserves human trust when a failure is expected but does not affect it when the robot works reliably. This provides a hint to designers on when assurances are necessary and when they are redundant.

scholarly journals Online Word-of-Mouth Communication in a Collectivist Society

2021 ◽  
Author(s):  
◽  
Lin Yang
Keyword(s):  
Structural Equation ◽  
Online Survey ◽  
Word Of Mouth ◽  
Social Acceptance ◽  
Second Phase ◽  
Measurement Instruments ◽  
Two Phase ◽  
Holistic View ◽  
Online Word Of Mouth ◽  
The Impact

<p>Word-of-mouth (WOM) is perceived by consumers as a highly credible source of information, and online channels for WOM have become increasingly popular among consumers. Although the impact of online word-of-mouth (OWOM) on consumers‘ purchase decisions has been researched, it remains unclear why information about products, brands or organisations is generated online and what influences its initiation from the sender‘s perspective. This research explores the antecedents of customer OWOM and examines the relationships between key antecedent variables and customer OWOM engagement in a Chinese context.  A conceptual model was developed based on the literature and information obtained through one-to-one in-depth interviews. Customer perceived value, satisfaction, loyalty and affective commitment were incorporated as key antecedent constructs of customer OWOM.  The research used a two-phase research design. The first phase was a qualitative exploration of the customer‘s OWOM experience. These findings were used to gain an understanding of customers‘ OWOM initiation, provide confirmation of the model, and refine the measurement thereof. The second phase used a quantitative online survey to validate the measurement instruments and test the model. The data for the study were collected from OWOM initiators in China over a period of one and a half months. A sample of 574 respondents was obtained. Hypotheses were tested using structural equation modelling and multiple regression analysis.  Findings from the research suggest that an emphasis on creating an affective bond with the brand and organisation is the key to customers‘ engagement of WOM on the Internet. The study also indicates that customer perceived QEP (quality, emotional and price) value is a less immediate but critical antecedent. In addition, the customer perceived social value of a product or service is found to significantly impact OWOM. In China, where the collectivist view predominates, customers conform to social standards and withhold negative comments in their OWOM activities in order to maintain social acceptance and inclusion, and to make favourable impressions. They also engage in OWOM to gain and enhance face, which is a social need in China‘s status driven society.  This research contributes to a growing body of research on customers‘ OWOM behaviour by developing and empirically testing the customer OWOM model. It provides a more holistic view of post-purchase OWOM by simultaneously investigating a set of key antecedents for OWOM in a single framework. The research also widens the geographic and culture scope of OWOM research by undertaking the study in China. By using a mixed method, incorporating both qualitative and quantitative approaches, the research offers a balance among objectivity, detailed description and the predictability of the study. Furthermore, the research provides marketing practitioners with a better understanding of the behaviour of Chinese OWOM initiators, and offers directions to improve their marketing communication strategies.</p>

scholarly journals A methodological framework to allocate storage space for outbound containers

2021 ◽  
Vol 22 (3) ◽  
pp. 1-12
Author(s):  
María D. Gracia
Keyword(s):  
Performance Metrics ◽  
Container Terminals ◽  
Second Phase ◽  
Storage Space ◽  
Methodological Framework ◽  
Two Phase ◽  
The Impact ◽  
Alternative Solutions ◽  
Outbound Containers

The staking of containers on ideal locations within the yard is a tactical decision that affects the productivity of container terminals. The goal is to improve posterior loading and retrieval operations, to get better use of terminal resources. In this paper, we study how to allocate storage space for outbound containers in container terminals. A two-phase methodological framework is proposed. The first phase groups outbound containers into clusters of similar operational loading conditions. Then in a second phase, a bi-objective storage space assignment model is solved to determine the set of block-bays where groups of similar containers will be stored during the planning horizon. This study presents a double contribution. On one hand, it proposes a new methodological framework that combines operations research and data mining techniques to solve a storage space assignment problem for outbound containers. On the other hand, it analyzes the impact of three factors on four performance metrics used to evaluate the quality and quantity of alternative solutions to the problem of allocation of storage space for outbound containers. The experimental framework is composed of an experimental design study to assess the impact of three factors on four performance metrics used to assess the quality of the storage space assignment solutions, and a case study to validate the proposed approach. The experimental results reveal that the storage yard's capacity and the number of clusters used to group the containers destined to a vessel are the main factors that affect the number and quality of alternative solutions.

A Case Study for Infrastructure Scour Management

2020 ◽  
Author(s):  
Eftychia Koursari ◽  
Stuart Wallace ◽  
Panagiotis Michalis ◽  
Yi Xu ◽  
Manousos Valyrakis
Keyword(s):  
At Risk ◽  
Water Levels ◽  
Bridge Engineering ◽  
Second Phase ◽  
Two Phase ◽  
Phase Approach ◽  
Remediation Measures ◽  
Stability Of Structures ◽  
Safety Inspections

&lt;p&gt;Scour is the leading cause of bridge collapse worldwide, being responsible for compromising the stability of structures&amp;#8217; foundations. Scour and erosion can take place without prior warning and cause sudden failure. This study describes engineering measures and complications encountered during construction for a case study in the Scottish Borders (A68 Galadean Bridge). The bridge studied carries the A68 road across the Leader Water.&lt;/p&gt;&lt;p&gt;Transport Scotland&amp;#8217;s structures crossing or near a watercourse are subject to a two-stage scour assessment following the Design Manual for Roads and Bridges (DMRB) BD97/12 Standard, &amp;#8216;The Assessment of Scour and Other Hydraulic Actions at Highway Structures&amp;#8217;. Structures identified at risk are monitored through Reactive Structures Safety Inspections following events likely to increase water levels. The most common form of monitoring includes visual inspections, however, monitoring sensors are being currently implemented and trialled at locations at high risk of scour.&lt;/p&gt;&lt;p&gt;Scour in the area was identified during a Reactive Structures Safety Inspection, following which a weekly scour monitoring regime was established, alongside further Reactive Structures Safety Inspections, until remediation measures were put in place.&lt;/p&gt;&lt;p&gt;Despite the bridge being constructed perpendicular to the Leader Water, meandering of the watercourse was detected upstream. Sediment transport was the cause of an island formation immediately upstream of the structure. Non-uniform flow and secondary, spiral currents, resulting from the formation of the bend were exacerbating scour and erosion in the area. The design of the remediation measures included the implementation of rock rolls alongside the affected riverbank. However, during construction, increased water levels resulting from thawing snow resulted in the collapse of a significant portion of the embankment supporting the structure&amp;#8217;s abutment and the A68 road, prior to the realisation of the remediation measures. An emergency design revision was required and emergency measures had to be enforced.&lt;/p&gt;&lt;p&gt;The urgency of the works led to a two-phase approach being followed for the design and construction of the scour measures in the affected area. The first phase included the construction of a platform in front of the affected road embankment and the implementation of rock rolls to provide scour protection. The two-phase approach ensured the infrastructure at risk was protected from further deterioration while the reconstruction of the embankment was being designed.&lt;/p&gt;&lt;p&gt;The second phase of works included the reconstruction of the affected road embankment, for which the anticipated total scour depth was taken into account.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;Koursari E and Wallace S. 2019. Infrastructure scour management: a case study for A68 Galadean Bridge, UK. Proceedings of the Institution of Civil Engineers &amp;#8211; Bridge Engineering, https://doi.org/10.1680/jbren.18.00062&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Acknowledgements:&lt;/p&gt;&lt;p&gt;The authors would like to acknowledge Transport Scotland for funding this project.&lt;/p&gt;

scholarly journals Evolving Trends in Teaching: Narration and Imagination vs Video Footages

2014 ◽  
Vol 9 (1) ◽  
pp. 81-91
Author(s):  
Urooj Fatima
Keyword(s):  
Mode Of Delivery ◽  
Choice Test ◽  
Academic Learning ◽  
Second Phase ◽  
Two Phase ◽  
Mean Values ◽  
Video Footage ◽  
Group A ◽  
Group B ◽  
The Impact

The research discussed in this paper aims to study the impact of video footages on the academic performance of students. Video footages are usually inserted into video lectures — in addition to the verbal narration of any examples by the teachers — to explain and simplify concepts. Similarly, in conventional classrooms, teachers verbally narrate examples to clarify concepts — but, in this case, students have to rely on their imagination and previous exposure to similar situations to develop an understanding of the concepts. A two-phase experiment was designed to compare these two teaching methods. A sample of 70 participants was drawn from non-psychology students in the Virtual University of Pakistan; and two groups, Group A and Group B, each with 35 participants, were formed through random assignment of the students. In the first phase of the experiment, members of Group A were taught through a 24-minute video lecture on psychology, which had four chunks of video footage in it. After the lecture, the students' academic learning was measured through a multiple-choice test with 27 items, which was developed by incorporating an equal number of questions on three levels of Bloom's taxonomy (viz. understanding, comprehension and application). The item levels were decided after agreement by three examiners who had at least three years of experience of developing such questions. In the second phase, a lecture with similar content was taught to Group B. The only difference was in the mode of delivery: in this case, the content was conveyed verbally and no video footages were used. The same test of students' learning was employed to get the scores of Group B. In addition, a qualitative study, involving data gathered through participants' feedback on the performance of the learning facilitators and weaknesses in both teaching modes was collected in order to explore the participants' perceptions and experiences of the phenomenon being studied. The results indicated that the two groups were significantly different in terms of academic achievement. The mean values suggested that those who were taught through video footages showed a higher level of academic learning than those who received a traditional verbal narration lecture. In addition, the students reported that the video footages and examples facilitated their learning, and helped them to remain focused and motivated in class. The findings have broad implications for teachers, content developers, academic policy-makers and producers involved in the production of academic content.

scholarly journals The Impact of Age on Negative Emotional Reactions, Compliance With Health Guidelines, and Knowledge About the Virus During the COVID-19 Epidemic: A Longitudinal Study From Israel

2020 ◽  
Vol 11 ◽  
pp. 215013272098154
Author(s):  
Inbar Levkovich
Keyword(s):  
Longitudinal Study ◽  
Age Groups ◽  
Emotional Reactions ◽  
Second Phase ◽  
Age Group ◽  
Two Phase ◽  
Perceived Susceptibility ◽  
Phase Study ◽  
The Impact

In a longitudinal study we examined the impact of age on negative emotional reactions, compliance with health guidelines and knowledge about the virus during the COVID-19 epidemic. A total of 2509 people participated in a two-phase study: 1424 participants in the first phase (March 12-21) and 1085 participants in the second phase (April 23 to May 5). Age was categorized into 4 groups: age 18 to 30, age 31 to 40, age 41 to 50, and age 51 and over. In the first and second phase, compliance with health guidelines was highest among participants over the age of 50. Knowledge was significantly higher in the second phase than in the first among participants over age 50 and those between the ages of 40 and 50. In the second phase, knowledge did not differ by age group. Negative emotional reactions were significantly higher in the first phase than in the second. Moreover, negative emotional reactions were higher among participants up to age 30 than among all other participants. Perceived susceptibility did not differ by phase or by age group. The paper underscores the impact of age during the COVID-19 epidemic and points to the necessity of taking the needs of different age groups into consideration.

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