Impact of inventory inaccuracy on service-level quality: A simulation analysis

This article discusses the impact of inventory inaccuracy on service-level quality in (Q,R) continuous review, lost-sales inventory models. A simulation model is built to study the behaviour of this kind of model exposed to an inaccuracy in inventory records as well as demand variability. We have observed an unusual result which goes against certain empirical practices in the SMEs that consist in hiking the inventory level proportionally to the data inaccuracy rate. A nonmonotone function shows that at the outset, the service-level quality is lowered as the inaccuracy rate increases but when the inaccuracy rate becomes much higher this quality is conversely enhanced. This relation can equally be observed given that stocktaking commences as soon as the threshold of decline in the service-level rate has been reached and when demand consequently dwindles. Finally, another noteworthy result also shows the same phenomenon between the function involving a level of safety stock defined by the simulation and the function between the service-level quality and the inventory inaccuracy. These different observed results are discussed in terms of both contribution to the (Q,R) inventory management policies in SMEs and of the limitations to this study.Continuous review inventory system, inventory inaccuracy, continuous model, discrete-time simulation

A CRISPR View of Human Genome Editing in the 21st Century

Scientists, policymakers, and bioethicists agree that the public should weigh in on the ethical issues raised by genomics and biotechnology. But it’s not always clear what role non-experts can play in these debates, or how scholars should measure public opinion about complex scientific issues. The gene-editing technology CRISPR-cas9 offers an excellent case to consider how the public is invited into and excluded from debates about promising and controversial new technologies. This dissertation advances our understanding of social and ethical dimensions of gene-editing by asking how the news media present CRISPR to the public, analyzing the role laid out for the public in media discourse about CRISPR, and investigating U.S. public attitudes about gene-editing using data from a national survey. Chapter 1 analyzes 304 articles from 8 ideologically diverse U.S. news sources to learn how CRISPR was framed in the news media in its early years (2012-2018). Most CRISPR coverage adopted a master frame I call “cautious optimism” consistently weighing both risks and benefits, but some veered into “boosterism,” framing that hypes possible benefits but ignores risks. Critical coverage of CRISPR was discernible though it was marginalized and under-represented. In general, coverage of CRISPR emphasized progress, profits and promises of cures, but generally steered clear of earlier decades’ worst tendencies (naïve genetic determinism, discrimination and perfectionism). Chapter 2 uses the news corpus to investigate the role of the public in the media narratives of CRISPR. Drawing on theories of expertise and lay publics developed by scholars in Science and Technology Studies (STS) and the Sociology of Scientific Knowledge, I argue that in the case of CRISPR, the hope for meaningful, policy-informing public engagement may be trapped in a temporal paradox wherein the time for the public to participate is always too soon, until it turns out to be too late. What appears as an earnest desire on the part of expert communities for the public to join in dialogue, discussion, or even consensus building about the future of CRISPR turns out to be illusory. A push and pull of inclusion and exclusion leaves the public no clear entry point to the discussion. Further, while some experts used public relations tactics to manage public opinion, others engaged in protective boundary work that had the effect of crowding publics out. The net effect of these dynamics is a public largely absent from the discourse and debates over gene-editing. Chapter 3 draws on nationally representative survey data to understand U.S. lay public perspectives on the development of gene-editing. Prior survey research about gene-editing asks how the technology may impact the respondent individually. To expand on this framing, we ask about respondents’ hopes and fears about the future of gene-editing for themselves, their families and society. We also go beyond asking simply whether respondents favor gene-editing by inquiring about their willingness to spend public money and contribute their own biospecimens to support gene-editing research. We find that public opinion is still somewhat underdeveloped, with most respondents neither strongly optimistic nor fearful and that trust in the healthcare system is an important predictor of attitudes about gene-editing. With the gene-editing revolution underway, the future of media framing and public inclusion in shaping the direction of this technology is uncertain, but this research identifies pitfalls to avoid and insights to build on to improve engagement moving forward.PHDHlth Svc Org & Plcy & Soc PhDUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169935/1/dbthiel_1.pd

Justification et validation d\u27un outil d\u27apprentissage actif de la dynamique des systèmes industriels en univers incertain

This paper formulates the apprenticeship problematic of the complex relationships (1) between the companies internal and external agents. Within the framework of a rational view of these complex phenomena based on the Forrester\u27s System Dynamics paradigm, we try to justify the significance of this method in relation to the traditional educational techniques. Finally, we present an active learning tool by using a generic simulation model of production system behavior based on a management flight simulator approach (2).(1) Il s\u27agit ici d\u27interrelations de type réciproque au sens de Thomson (1967), donc de type cybernétique(2) Voir Bakken et al. in Modeling for learning Organizations (1994) ; Forrester (1990) ; Sterman (1988) ; Meadows (1989)

Electrochemical Pitting And Repassivation On Icosahedral AL-CU-FE, And A Comparison With Crystalline Phases

We report the electrochemical potentials at which localized pitting and repassivation occur on icosahedral Al-Cu-Fe, and on a series of related alloys and elemental metals. The electrochemistry occurs in a buffered NaCI solution, pH 8.4. Under these conditions, pitting and repassivation appear to be controlled mainly by the chemical composition of the alloy, although the quasicrystalline phase displays an anomalous resistance to repassivation. Corrosion of this phase proceeds by dissolution of Al and Fe, leaving behind pits which are Cu-enriched

An ancient FMRFamide-related peptide-receptor pair induces defense behavior in a brachiopod larva

Animals show different behaviors that can consist of various spatially or temporally separated sub-reactions. Even less complex organisms, like ciliated larvae that display important behaviors (e.g. metamorphosis, defense, feeding), need to coordinate coherent sub-reactions with their simple nervous system. These behaviors can be triggered by neuropeptides, which are short signaling peptides. Despite the high diversity of neuropeptides in animals, and although their immunoreactivity is widely used in morphological studies of animal nervous systems (e.g. FMRFamide), their function and role in trochozoan larval behavior has so far only been tested in a few cases. When mechanically disturbed, the planktonic larvae of the brachiopod Terebratalia transversa protrude their stiff and pointy chaetae in a defensive manner and sink down slowly: a startle reaction that is known from different chaetous trochozoan larvae. We found that both of these reactions can be induced simultaneously by the FMRFamide-related neuropeptide FLRFamide. We deorphanized the Terebratalia FLRFamide receptor and found its expression spatially separated in the apical lobe at the prototroch of the larvae and in the trunk musculature, which correlates with the tissues that are responsible to perform the two sub-reactions. A behavioral assay showed a decreasing efficiency of modified peptides in triggering this behavior, which correlates with the decreasing efficiency of activating the FLRFamide receptor in transfected CHO-K1 cells. Immunohistochemistry and in situ hybridization show FLRFamidergic neurons in the apical lobe as well as next to the trunk musculature. Our results show that the single neuropeptide FLRFamide can specifically induce the two coherent sub-reactions of the T. transversa startle behavior.draf

Room Temperature Oxidation of Al-Cu-Fe and Al-Cu-Fe-Cr Quasicrystals

We have investigated formation of oxides on quasicrystalline and crystalline alloy surfaces of similar composition, in different oxidizing environments. This includes a comparison between a quaternary orthorhombic approximate of Al-Cu-Fe-Cr quasicrystal and the ternary Al-Cu-Fe quasicrystalline and crystalline phases. We noted that each sample showed the following common trends: preferential oxidation of the Al, enrichment in the concentration of Al present at the surface upon oxidation, water concentration is directly related to oxide thickness, and the oxide thickness displays a strong correlation with the bulk concentration of Al in the sample

FINEX: A Fast Index for Exact & Flexible Density-Based Clustering (Extended Version with Proofs)*

Density-based clustering aims to find groups of similar objects (i.e., clusters) in a given dataset. Applications include, e.g., process mining and anomaly detection. It comes with two user parameters ({\epsilon}, MinPts) that determine the clustering result, but are typically unknown in advance. Thus, users need to interactively test various settings until satisfying clusterings are found. However, existing solutions suffer from the following limitations: (a) Ineffective pruning of expensive neighborhood computations. (b) Approximate clustering, where objects are falsely labeled noise. (c) Restricted parameter tuning that is limited to {\epsilon} whereas MinPts is constant, which reduces the explorable clusterings. (d) Inflexibility in terms of applicable data types and distance functions. We propose FINEX, a linear-space index that overcomes these limitations. Our index provides exact clusterings and can be queried with either of the two parameters. FINEX avoids neighborhood computations where possible and reduces the complexities of the remaining computations by leveraging fundamental properties of density-based clusters. Hence, our solution is effcient and flexible regarding data types and distance functions. Moreover, FINEX respects the original and straightforward notion of density-based clustering. In our experiments on 12 large real-world datasets from various domains, FINEX frequently outperforms state-of-the-art techniques for exact clustering by orders of magnitude

Signal processing for estimating energy expenditure of elite athletes using triaxial accelerometers

Fitness development of elite athletes requires an understanding of physiological factors such as athlete energy expenditure (EE). For athletes involved in football at the elite level, it is necessary to understand the energy demands during competition to develop training regimes. By identifying an appropriate EE estimator in triaxial accelerometer data, in conjunction with identifying sources of inter-athlete variance in that estimator, signal processing was developed to extract the estimator. In this system, low-power signal processing was implemented to extract both the EE estimator and other information of physiological and statistical interestGriffith Sciences, Griffith School of EngineeringFull Tex