Applying Lean Manufacturing Principles at VIP Cinema: Standardizing Hardware Assembly Workstations

This paper will explore the benefits of standardization and consistency in a manufacturing setting by demonstrating the value of improved tooling and organization. “Lean Manufacturing” is the broad term used to describe key principles that can be applied to most businesses to reduce waste and increase efficiency. This ideology’s theme is to maximize customer value while minimizing waste. The purpose of its adoption is to transform managers and operators into experts of identifying the deficiencies in many manufacturing and assembly processes and implementing changes that can lead to enormous improvements in takt time, production output, and ultimately, profitability. At VIP Cinema Seating in New Albany, MS, these lean manufacturing principles are set to be implemented without disturbing current work or output. In this paper I will focus on how the standardization of a hardware assembly station can impact the output, efficiency, and operator well-being at VIP Cinema Plant #6. Our project had a narrow focus on redesigning the hardware assembly process, so that it can be used as an example of the benefits of lean manufacturing principles which shall be revered throughout the VIP campus in the near future

Neuron dynamics in the presence of 1/f noise

Interest in understanding the interplay between noise and the response of a non-linear device cuts across disciplinary boundaries. It is as relevant for unmasking the dynamics of neurons in noisy environments as it is for designing reliable nanoscale logic circuit elements and sensors. Most studies of noise in non-linear devices are limited to either time-correlated noise with a Lorentzian spectrum (of which the white noise is a limiting case) or just white noise. We use analytical theory and numerical simulations to study the impact of the more ubiquitous "natural" noise with a 1/f frequency spectrum. Specifically, we study the impact of the 1/f noise on a leaky integrate and fire model of a neuron. The impact of noise is considered on two quantities of interest to neuron function: The spike count Fano factor and the speed of neuron response to a small step-like stimulus. For the perfect (non-leaky) integrate and fire model, we show that the Fano factor can be expressed as an integral over noise spectrum weighted by a (low pass) filter function. This result elucidates the connection between low frequency noise and disorder in neuron dynamics. We compare our results to experimental data of single neurons in vivo, and show how the 1/f noise model provides much better agreement than the usual approximations based on Lorentzian noise. The low frequency noise, however, complicates the case for information coding scheme based on interspike intervals by introducing variability in the neuron response time. On a positive note, the neuron response time to a step stimulus is, remarkably, nearly optimal in the presence of 1/f noise. An explanation of this effect elucidates how the brain can take advantage of noise to prime a subset of the neurons to respond almost instantly to sudden stimuli.Comment: Phys. Rev. E in pres

Strings from Feynman Graph counting : without large N

A well-known connection between n strings winding around a circle and permutations of n objects plays a fundamental role in the string theory of large N two dimensional Yang Mills theory and elsewhere in topological and physical string theories. Basic questions in the enumeration of Feynman graphs can be expressed elegantly in terms of permutation groups. We show that these permutation techniques for Feynman graph enumeration, along with the Burnside counting lemma, lead to equalities between counting problems of Feynman graphs in scalar field theories and Quantum Electrodynamics with the counting of amplitudes in a string theory with torus or cylinder target space. This string theory arises in the large N expansion of two dimensional Yang Mills and is closely related to lattice gauge theory with S_n gauge group. We collect and extend results on generating functions for Feynman graph counting, which connect directly with the string picture. We propose that the connection between string combinatorics and permutations has implications for QFT-string dualities, beyond the framework of large N gauge theory.Comment: 55 pages + 10 pages Appendices, 23 figures ; version 2 - typos correcte

On the refined counting of graphs on surfaces

Ribbon graphs embedded on a Riemann surface provide a useful way to describe the double line Feynman diagrams of large N computations and a variety of other QFT correlator and scattering amplitude calculations, e.g in MHV rules for scattering amplitudes, as well as in ordinary QED. Their counting is a special case of the counting of bi-partite embedded graphs. We review and extend relevant mathematical literature and present results on the counting of some infinite classes of bi-partite graphs. Permutation groups and representations as well as double cosets and quotients of graphs are useful mathematical tools. The counting results are refined according to data of physical relevance, such as the structure of the vertices, faces and genus of the embedded graph. These counting problems can be expressed in terms of observables in three-dimensional topological field theory with S_d gauge group which gives them a topological membrane interpretation.Comment: 57 pages, 12 figures; v2: Typos corrected; references adde

Tumor Response to Radiotherapy is Dependent on Genotype-Associated Mechanisms in vitro and in vivo

Background: We have previously shown that in vitro radiosensitivity of human tumor cells segregate non-randomly into a limited number of groups. Each group associates with a specific genotype. However we have also shown that abrogation of a single gene (p21) in a human tumor cell unexpectedly sensitized xenograft tumors comprised of these cells to radiotherapy while not affecting in vitro cellular radiosensitivity. Therefore in vitro assays alone cannot predict tumor response to radiotherapy. In the current work, we measure in vitro radiosensitivity and in vivo response of their xenograft tumors in a series of human tumor lines that represent the range of radiosensitivity observed in human tumor cells. We also measure response of their xenograft tumors to different radiotherapy protocols. We reduce these data into a simple analytical structure that defines the relationship between tumor response and total dose based on two coefficients that are specific to tumor cell genotype, fraction size and total dose. Methods: We assayed in vitro survival patterns in eight tumor cell lines that vary in cellular radiosensitivity and genotype. We also measured response of their xenograft tumors to four radiotherapy protocols: 8 × 2 Gy; 2 × 5Gy, 1 × 7.5 Gy and 1 × 15 Gy. We analyze these data to derive coefficients that describe both in vitro and in vivo responses. Results: Response of xenografts comprised of human tumor cells to different radiotherapy protocols can be reduced to only two coefficients that represent 1) total cells killed as measured in vitro 2) additional response in vivo not predicted by cell killing. These coefficients segregate with specific genotypes including those most frequently observed in human tumors in the clinic. Coefficients that describe in vitro and in vivo mechanisms can predict tumor response to any radiation protocol based on tumor cell genotype, fraction-size and total dose. Conclusions: We establish an analytical structure that predicts tumor response to radiotherapy based on coefficients that represent in vitro and in vivo responses. Both coefficients are dependent on tumor cell genotype and fraction-size. We identify a novel previously unreported mechanism that sensitizes tumors in vivo; this sensitization varies with tumor cell genotype and fraction size

Rearing and foraging affects bumblebee (Bombus terrestris) gut microbiota

Bumblebees are ecologically and economically important as pollinators of crop and wild plants, especially in temperate systems. Species, such as the buff-tailed bumblebee (Bombus terrestris), are reared commercially to pollinate high value crops. Their highly specific gut microbiota, characterised by low diversity, may affect nutrition and immunity and are likely to be important for fitness and colony health. However, little is known about how environmental factors affect bacterial community structure. We analyzed the gut microbiota from three groups of worker bumblebees (B. terrestris) from distinct colonies that varied in rearing and foraging characteristics: commercially reared with restricted foraging (RR); commercially reared with outside foraging (RF); and wild-caught workers (W). Contrary to previous studies, which indicate that bacterial communities are highly conserved across workers, we found that RF individuals had an intermediate community structure compared to RR and W types. Further, this was shaped by differences in the abundances of common OTUs and the diversity of rare OTUs present which we propose results from an increase in the variety of carbohydrates obtained through foraging

Models for the lithium abundances of multiple populations in globular clusters and the possible role of the Big Bang lithium

Globular cluster stars show chemical abundance patterns typical of hot-CNO processing. Lithium is easily destroyed by proton capture in stellar environments, so its abundance may be crucial to discriminate among different models proposed to account for multiple populations. In order to reproduce the observed O-Na anticorrelation and other patterns typical of multiple populations, the formation of second generation stars must occur from the nuclearly processed stellar ejecta, responsible of the chemical anomalies, diluted with pristine gas having the composition of first generation stars. The lithium abundance in the unprocessed gas -which is very likely to be equal to the lithium abundance emerging from the Big Bang- affects the lithium chemical patterns among the cluster stars. This paper focuses on a scenario in which processed gas is provided by asymptotic giant branch (AGB) stars. We examine the predictions of this scenario for the lithium abundances of multiple populations. We study the role of the non-negligible lithium abundance in the ejecta of massive AGB (A(Li)~2), and, at the same time, we explore how our models can constrain the extremely large ---and very model dependent--- lithium yields predicted by recent super--AGB models. We show that the super--AGB yields may be tested by examining the lithium abundances in a large set of blue main sequence stars in wCen and/or NGC2808. In addition, we examine the different model results obtained by assuming for the pristine gas either the Big Bang abundance predicted by the standard models (A(Li)=2.6-2.7), or the abundance detected at the surface of population II stars (A(Li)=2.2-2.3). Once a chemical model is well constrained, the O--Li distribution could perhaps be used to shed light on the primordial lithium abundance

Perception of the visual environment

The eyes are the front end to the vast majority of the human behavioural repertoire. The manner in which our eyes sample the environment places fundamental constraints upon the information that is available for subsequent processing in the brain: the small window of clear vision at the centre of gaze can only be directed at an average of about three locations in the environment in every second. We are largely unaware of these continual movements, making eye movements a valuable objective measure that can provide a window into the cognitive processes underlying many of our behaviours. The valuable resource of high quality vision must be allocated with care in order to provide the right information at the right time for the behaviours we engage in. However, the mechanisms that underlie the decisions about where and when to move the eyes remain to be fully understood. In this chapter I consider what has been learnt about targeting the eyes in a range of different experimental paradigms, from simple stimuli arrays of only a few isolated targets, to complex arrays and photographs of real environments, and finally to natural task settings. Much has been learnt about how we view photographs, and current models incorporate low-level image salience, motor biases to favour certain ways of moving the eyes, higher-level expectations of what objects look like and expectations about where we will find objects in a scene. Finally in this chapter I will consider the fate of information that has received overt visual attention. While much of the detailed information from what we look at is lost, some remains, yet our understanding of what we retain and the factors that govern what is remembered and what is forgotten are not well understood. It appears that our expectations about what we will need to know later in the task are important in determining what we represent and retain in visual memory, and that our representations are shaped by the interactions that we engage in with objects