A Kosloff/Basal method, 3D migration program implemented on the CYBER 205 supercomputer

Conventional finite difference migration has relied on approximations to the acoustic wave equation which allow energy to propagate only downwards. Although generally reliable, such approaches usually do not yield an accurate migration for geological structures with strong lateral velocity variations or with steeply dipping reflectors. An earlier study by D. Kosloff and E. Baysal (Migration with the Full Acoustic Wave Equation) examined an alternative approach based on the full acoustic wave equation. The 2D, Fourier type algorithm which was developed was tested by Kosloff and Baysal against synthetic data and against physical model data. The results indicated that such a scheme gives accurate migration for complicated structures. This paper describes the development and testing of a vectorized, 3D migration program for the CYBER 205 using the Kosloff/Baysal method. The program can accept as many as 65,536 zero offset (stacked) traces

Surgical Repair of Umbilical and Inguinal Hernias in the Bovine

Many different techniques have been described for hernia repair and all are aimed at securing the same result, a firm union of the opposing edges of the hernial ring

El temprano comercio de esclavos desde Angola hacia Hispanoamérica y Brasil, 1575-1595

In this essay we use new and overlooked sources to provide a chronology for the early slave trade from Angola to Spanish America, beginning with two voyages that sailed from Luanda Island soon after the arrival of the first governor of Portuguese Angola. Similar voyages to the Caribbean and Río de la Plata were common after 1595, but during the preceding decade, the traffic of enslaved Africans from Angola to Spanish America was largely an extension of an older, more intensive trade from Angola to Brazil.En este ensayo empleamos fuentes nuevas y subutilizadas para ofrecer una cronología del temprano comercio de esclavos desde Angola hacia Hispanoamérica, lo cual comenzó con dos navíos que zarparon de la Isla de Luanda justo después de la llegada del primer gobernador de la Angola portuguesa. Semejantes viajes al Caribe y al Río de la Plata eran comunes a partir de 1595, pero en la década anterior la trata de africanos esclavizados desde Angola hacia Hispanoamérica fue en gran medida una extensión de un tráfico más viejo y más intensivo desde Angola hacia Brasil

A depth camera-based system for estimating cyclist-bike projected frontal area

A major component of total resistive force in cycling is aerodynamic drag. For speeds greater than ~14 m/s aerodynamic drag accounts for approximately 90% of total resistive force (Debraux et al., 2009: International Journal of Sports Medicine, 30, 266-272). Together with the air density, the coefficient of drag and the velocity of the cyclist-bike, an important determinant of aerodynamic drag is projected frontal area. Several techniques have been used to estimate the projected frontal area of a cyclist-bike, including the weighing of photographs and image digitising (Debraux et al., 2009). These techniques are similar as they involve extracting the cyclist-bike from a two-dimensional (2D) image and using scaling information from a plane of known dimensions. With the weighing photographs method this is done physically using sensitive weighing scales whereas image processing software is used for the image digitising technique. Both techniques require the collection of a calibration plane, involve considerable post-processing and cannot be performed in real time. We have developed a depth camera-based system for estimating cyclist-bike projected frontal area which addresses these issues. The depth camera algorithm works by creating a metrically scaled, three-dimensional point cloud of the cyclist-bike. The point cloud is projected on to a 2D representation of the scene and the area of the point cloud is calculated using a technique similar to ‘voxelization’; points in the cloud occupy spaces in a fine grid – the sum of the occupied grid spaces gives total area. The aim of this study was to investigate the agreement between our new method and the image digitising technique.After institutional ethics approval, eight regular cyclists volunteered to participate and provided written informed consent. Participants wore their normal cycling clothing and their bicycle was mounted on a stationary indoor trainer. The bicycle was positioned against a white background to help with the image digitising method. Participants placed their feet on the pedals and held the cranks parallel to the floor. A digital camera (Canon EOS 400D, 10.1 megapixel) and Kinect depth camera (Microsoft, Redmond, WA, USA) were mounted on tripods at a height of 1.1 m and positioned 5 m and 2.2 m in front of the participant, respectively. Similar to Debraux et al. (2009), participants adopted two positions on the bike: 1. Upright – upright torso with hands close to the stem and 2. Drops Position – hands on the drops. Three repeat captures were performed in each position, with the participant relaxing between each capture. The digitising method was performed as described by Debraux et al. (2009). Agreement between methods was assessed using limits of agreement (LOA - Bland and Altman, 1986: Lancet, 1, 307-310). A two-way repeated measures analysis of variance (method by position) was used to assess the effect of cyclist position on the systematic difference between measurement methods.There was no interaction between cyclist position and measurement method (p = 0.201) indicating that the same effect of cyclist position was observed using both measurement techniques. A significant main effect for cyclist position (p = 0.017) indicated that projected frontal area was smaller with hands on the drops (upright: 0.485 m2, drops: 0.434 m2). There was also a significant main effect for measurement method (p < 0.001) indicating a significantly smaller estimation of projected frontal area using the Kinect (Kinect: 0.416 m2, Image: 0.503 m2). A predominantly systematic difference between methods was also suggested by the LOA analysis (upright: 0.086 ± 0.029 m2, drops: 0.090 ± 0.033 m2).The aim of this study was to assess the agreement between a common method of estimating cyclist-bike frontal area and a new depth camera-based technique. The new technique estimated systematically smaller projected frontal area than the image digitisation method but there was relatively little random variation and the same effect of cyclist position was observed with both techniques. Which technique gives the most accurate estimate of projected frontal area is not clear as the image digitisation technique - to which the new technique was compared - has associated errors e.g. identification of the cyclist-bike outline and out-of-plane errors. However, it was apparent during testing that the depth camera-based system often failed to identify parts of the bike and this is most likely the cause of the difference between techniques. Regardless, the results of this study suggest that the new technique can be used to assess changes in projected frontal area – as the cyclist changes position, for example. Further, the new technique offers the possibility of analysing changes in projected frontal area in real time – there is no requirement for calibration or post-processing

Muscling selection in swine and its effect on carcass traits

We are attempting to develop a well-muscled line of Durocs by selecting for minimum back fat and maximum loin eye area as estimated by the Anscan and to form a control line by randomly selecting from the same base population. The lines will be compared for performance and carcass traits, including incidence of pale soft exudative carcasses. Expected and realized heritability estimates for carcass traits will be calculated.; Swine Day, Manhattan, KS, November 2, 197

Selection for muscling in swine and its effect on carcass traits

Line differences in weight, litter size at different ages, and in age, loin eye area, and backfat thickness of pigs (adjusted to 200 pounds live weight) were not significant. Sex differences in weight and backfat thickness were significant. Dam groups of progeny differed significantly (P\u3c.0l) in-weights at birth and at 14 and 28 days old and in age, loin eye area, and backfat thickness adjusted to 220 pounds live weight. Hams produced by barrows in the select line were significantly (P\u3c.0l) darker and firmer than those from barrows in the control line.; Swine Day, Manhattan, KS, November 14, 197

Muscling selection in swine and its effect on carcass traits

Pigs farrowed in May, 1972, were the first born in the select and control lines. Performances of animals in the two lines were essentially the same. However, ham firmness and color differed significantly (P\u3c0.0l) between lines, with those in the select line firmer and darker than those from the control line.; Swine Day, Manhattan, KS, November, 197