Documentation: Motivation and training or automation

The road blocks and mental blocks in areas where automation is not taking care of basic documentation problems are discussed. Original project documentation, documentation for project maintenance, and comparison of preliminary and final documentation are described. The use of flow charts is also mentioned

Nerve Injury and Small Saphenous Vein Surgery

AbstractObjectiveTo assess nerve injuries in small (short) saphenous vein surgery.DesignProspective study.MethodsDuring a five and a half year period, 272 small saphenous vein operations were studied in 217 consecutive unselected patients, to assess postoperative nerve injuries. Patients with nerve injuries were treated and followed-up by an independent peripheral nerve surgeon.ResultsA peripheral nerve injury occurred three times in 272 procedures: two sural nerve injuries and one common peroneal nerve injury. There was a full recovery of all three nerve injuries, the latest after 18 months.ConclusionsNerve injuries following small saphenous vein surgery are rare and may have a good recovery

Ripple compensation for a class-D amplifier

This paper presents the first detailed mathematical analysis of the ripple compensation technique for reducing audio distortion in a class-D amplifier with negative feedback. The amplifier converts a relatively low-frequency audio signal to a high-frequency train of rectangular pulses whose widths are slowly modulated according to the audio signal (pulse-width modulation, PWM). Distortion manifests itself through unwanted audio-frequency harmonics that arise in the output due to nonlinearities inherent in the design. In this paper, we first develop a small-signal model, which describes the fate of small-amplitude perturbations to a constant input, and demonstrate how this traditional engineering tool may be extended to allow one to infer the most significant contributions to the full output in response to a general audio input. We then compute the audio output of the amplifier through a perturbation expansion based on the ratio between audio and switching frequencies. Our results explicitly demonstrate how the ripple compensation technique significantly linearizes the output, thereby reducing the distortion

Community structure and intertidal zonation of the macrobenthos on a macrotidal, ultra-dissipative sandy beach: summer-winter comparison

Community structure and intertidal zonation of the macrobenthos on a macrotidal, ultra-dissipative beach were studied. On the beach of De Panne, Belgium, six transects perpendicular to the waterline (each with five stations) were sampled in September 1995 (summer) and March 1996 (winter). The 30 stations were distributed across the continuum from mean high water spring to mean low water spring in order to sample the macrobenthos at different levels of elevation. The 39 species found had total densities up to 5,500 ind m-2 in summer and 1,400 ind m-2 in winter. The highest densities were found in the spionid polychaetes Scolelepis squamata and Spio filicornis, the nephtyid polychaete Nephtys cirrosa, the cirolanid isopod Eurydice pulchra, and the haustorid amphipods Bathyporeia spp. Based on species composition, specific densities, and biomass, two species associations were defined: a relatively species-poor, high intertidal species association, dominated by S. squamata and with an average density of 1,413 ind m-2 and biomass of 808 mg AFDW m-2 (summer); and a relatively species-rich, low intertidal species association, dominated by N. cirrosa, and with an average density of 104 ind m-2 and biomass of 162 mg AFDW m-2 in summer. For both seasons, the high intertidal species association was restricted in its intertidal distribution between the mean tidal and the mean high-water spring level, whereas the low intertidal species association was found from the mean tidal level to the subtidal. The latter showed good affinities with the subtidal N. cirrosa species association, occurring just offshore of De Panne beach, confirming the existence of a relationship between the low intertidal and subtidal macrobenthic species associations. Summer-winter comparison revealed a strong decrease in densities and biomass in the high intertidal zone during winter. Habitat continuity of the low intertidal zone with the subtidal allows subtidal organisms to repopulate the low intertidal zone

Joint-Angle Coordination Patterns Ensure Stabilization of a Body-Plus-Tool System in Point-to-Point Movements with a Rod

When performing a goal-directed action with a tool, it is generally assumed that the point of control of the action system is displaced from the hand to the tool, implying that body and tool function as one system. Studies of how actions with tools are performed have been limited to studying either end-effector kinematics or joint-angle coordination patterns. Because joint-angle coordination patterns affect end-effector kinematics, the current study examined them together, with the aim of revealing how body and tool function as one system. Seated participants made point-to-point movements with their index finger, and with rods of 10, 20, and 30 cm attached to their index finger. Start point and target were presented on a table in front of them, and in half of the conditions a participant displacement compensated for rod length. Results revealed that the kinematics of the rod’s tip showed higher peak velocity, longer deceleration time, and more curvature with longer rods. End-effector movements were more curved in the horizontal plane when participants were not displaced. Joint-angle trajectories were similar across rod lengths when participants were displaced, whereas more extreme joint-angles were used with longer rods when participants were not displaced. Furthermore, in every condition the end-effector was stabilized to a similar extent; both variability in joint-angle coordination patterns that affected end-effector position and variability that did not affect end-effector position increased in a similar way vis-à-vis rod length. Moreover, the increase was higher in those conditions, in which participants were not displaced. This suggests that during tool use, body and tool are united in a single system so as to stabilize the end-effector kinematics in a similar way that is independent of tool length. In addition, the properties of the actual trajectory of the end-effector, as well as the actual joint-angles used, depend on the length of the tool and the specifics of the task

Life After Death: How Olivewood's Cemetery Records Resurrect the History of Houston's Black Community

Cemeteries contribute to the tapestry of a community’s social history. Olivewood, the oldest incorporated African American cemetery in Houston, tells the stories of courage, struggle, joys, and the sorrows that contribute to the community’s collective memory. The memorial itself, as well as the lives of those interred in Olivewood also offer insight into the quality of their lives. The records collected by Descendants of Olivewood, Inc., the official guardians of Olivewood Cemetery, offer valuable information that can begin to answer questions about not only death, but also life. These records, many of which remain unpublished, help paint a picture of the community that founded and maintained this historic cemetery, as well as provide insight into the lives that these men, women, and children led. This study uses the information gleaned from the cemetery’s records to add to the existing historiography regarding the quality of life of the African American community in Houston during the Great Depression. A time of struggle for many, due to the socioeconomic, sociocultural, and political dynamics of the era, the Great Depression particularly burdened black Americans. This thesis takes an in-depth look at the records available through the cemetery as well as other primary sources to look at a microcosm of Houston’s Black community and the quality of the lives they led. Moreover, by looking at the cemetery itself—the markers, headstones, and even its layout—one can see the impact of religious belief on their society. This thesis merges statistics with the broader human aspect to draw conclusions regarding longevity, disease, healthcare, labor, education, business development, family, and the building of the African American community in Houston. The Great Depression was a time of enormous tragedy and socioeconomic instability that impacted impoverished Blacks to a greater degree than their counterparts of the racial majority, due to the special challenges they faced during this time of Jim Crow segregation and racial exclusion. However, this thesis shows that despite the crisis, Blacks in Houston enjoyed a greater quality of life than might be expected under the circumstances. Those interred in Olivewood fought to the end, and they can still tell their tale, long after their deaths

On using Feature Descriptors as Visual Words for Object Detection within X-ray Baggage Security Screening

Here we explore the use of various feature point descriptors as visual word variants within a Bag-of-Visual-Words (BoVW) representation scheme for image classification based threat detection within baggage security X-ray imagery. Using a classical BoVW model with a range of feature point detectors and descriptors, supported by both Support Vector Machine (SVM) and Random Forest classification, we illustrate the current performance capability of approaches following this image classification paradigm over a large X-ray baggage imagery data set. An optimal statistical accuracy of 0.94 (true positive: 83%; false positive: 3.3%) is achieved using a FAST-SURF feature detector and descriptor combination for a firearms detection task. Our results indicate comparative levels of performance for BoVW based approaches for this task over extensive variations in feature detector, feature descriptor, vocabulary size and final classification approach. We further demonstrate a by-product of such approaches in using feature point density as a simple measure of image complexity available as an integral part of the overall classification pipeline. The performance achieved characterises the potential for BoVW based approaches for threat object detection within the future automation of X-ray security screening against other contemporary approaches in the field