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Market structure analysis is a basic pillar of marketing research. Classic challenges in marketing such as pricing, campaign management, brand positioning, and new product development are rooted in an analysis of product substitutes and complements inferred from market structure. In this article, the authors present a method to support the analysis and visualization of market structure by automatically eliciting product attributes and brand's relative positions from online customer reviews. First, the method uncovers attributes and attribute dimensions using the \"voice of the consumer,\" as reflected in customer reviews, rather than that of manufacturers. Second, the approach runs automatically. Third, the process supports rather than supplants managerial judgment by reinforcing or augmenting attributes and dimensions found through traditional surveys and focus groups. The authors test the approach on six years of customer reviews for digital cameras during a period of rapid market evolution. They analyze and visualize results in several ways, including comparisons with expert buying guides, a laboratory survey, and correspondence analysis of automatically discovered product attributes. The authors evaluate managerial insights drawn from the analysis with respect to proprietary market research reports from the same period analyzing digital imaging products.

This paper studies a serial production line that is uncertain. We introduce a linear model of the uncertainty that can exist in the demand for the product and in each stage's processing time, yield, rework probability, and reliability. We construct a linear discrete-time rule for controlling production, and we show that repeated application of this rule leads the system to steady-state conditions, which include closed-form formulas for the mean and variance of each buffer's stock and the mean and variance of the workload in each stage. We optimize these operating characteristics by a convex nonlinear program. For the case of identical stages with no scrap, we show that this optimal solution tends to place larger buffer stocks toward the end of the line. We adapt these discrete-time results to the short-period surrogate of the analogous continuous-time control problem.

Perceptual systems can improve their performance by integrating relevant perceptual information and segregating away irrelevant information. Three studies exploring perceptual integration and segregation in audition and vision are reported in this thesis. In Chapter 1, we explore the role of similarity in informational masking. In informational masking tasks, listeners detect the presence of a signal tone presented simultaneously with a random-frequency multitone masker. Detection thresholds are high in the presence of an informational masker, even though listeners should be able to ignore the masker frequencies. The informational masker's effect may be due to the similarity between signal and masker components. We used a behavioral measure to demonstrate that the amount of frequency change over time could be the stimulus dimension underlying the similarity effect. In Chapter 2, we report a set of experiments on the visual system's ability to discriminate distributions of luminances. The distribution of luminances can serve as a cue to the presence of multiple illuminants in a scene. We presented observers with simple achromatic scenes with patches drawn from one or two luminance distributions. Performance depended on the number of patches from the second luminance distribution, as well as knowledge of the location of these patches. Irrelevant geometric cues, which we expected to negatively affect performance, did not have an effect. An ideal observer model and a classification analysis showed that observers successfully integrated information provided by the image photometric cues. In Chapter 3, we investigated the role of photometric and geometric cues in lightness perception. We rendered achromatic scenes that were consistent with two oriented background context surfaces illuminated by a light source with a directional component. Observers made lightness matches to tabs rendered at different orientations in the scene. We manipulated the photometric cues by changing the intensity of the illumination, and the geometric cues by changing the orientation of the context surfaces. Observers' matches varied with both manipulations, demonstrating that observers used both types of cues to account for the illumination in the scene. The two types of cues were found to have independent effects on the lightness matches.

Ahora, casi cuatro meses más tarde, las firmas de corretaje están rebajando los pronósticos del valor de la acción de la empresa y sus previsiones de envíos y ganancias, al señalar que se prevé que las ventas de teléfonos inteligentes de alta gama de Samsung serán decepcionantes, según los pedidos de componentes realizados para el tercer trimestre.

Measurement of intratesticular sex steroid concentrations in men informs both the development of male hormonal contraceptives and the understanding of male infertility. Given the challenges of using invasive techniques to measure testicular hormone physiology, our group has used a minimally-invasive fine-needle aspiration technique to measure intratesticular hormones in normal healthy men. Herein, we present a post-hoc analysis of the safety and efficacy of testicular fine-needle aspiration （FNA） completed as part of six clinical trials. From 2001 through 2011, a total of 404 procedures were conducted among 163 research volunteers, 85.9% of which were successful in obtaining sufficient fluid for the measurement of intratesticular steroid concentrations. Pain was the most common side effect, with 36.8% of procedures associated with moderate procedural pain and 4.7% with severe procedural pain. Postprocedural pain was uncommon and abated within a few days. Mild local bruising occurred with 14.9% of procedures. Two serious adverse events （0.5%） required surgical intervention. The risk of an adverse event was not associated with age, body mass index, testicular size, or the volume of fluid aspirated. Testicular FNA to obtain fluid for measurement of intratesticular steroid concentrations frequently causes mild to moderate procedural pain, but serious adverse events occur rarely. Testicular FNA has been instrumental for defining human intratesticular hormone physiology and is a minimally-invasive, safe, effective method for obtaining fluid for research on testicular physiology and pathology.

TAKING pictures of show business people during their performances can be one of the most rewarding -- and frustrating -- parts of photography. The biggest problem in this type of work is the lights.