Unique Artifacts Research Articles

On-line, collision-free positioning of a scanner during fully automated three-dimensional measurement of cultural heritage objects

Fully automated three-dimensional (3D) measurement (either with contact or non-contact measurement heads) cannot be easily completed without detailed a priori knowledge of the measured object. This requirement may be easily fulfilled for objects whose CAD models are available (for example, mechanical parts); however, for unique artifacts (such as sculptures), such models are usually unavailable. A description of the object’s shape is required to create a list of positions at which the scanning head should be placed to completely measure the whole object (so-called next best views list). For unique objects, this analysis has to be performed on-line during measurements, using obtained data to update the list. For a fully automated measurement, the scanning system must be positioned mechanically, and the transition between subsequent head positions has to be collision free.This paper presents a novel system for 3D digitization of cultural heritage objects which allows one to perform completely automated shape measurements in a given volume with sampling resolutions up to 10000 points/ mm2. Its main novelties are the next best view module for identifying the best position and orientation of the measurement head in subsequent directional scans (optimized for artifacts of size much bigger than the measurement volume) and flexible software modules for inverse kinematics and collision detection, which allow one to build a positioning system tailored to specific measurement objects. The system is used for digitization of a collection from the Wilanow Palace Museum, Warsaw.

Colorectal Stents Orient Specimens and Induce Artifacts That Mimic Crohn Disease

Colorectal malignancies may be stented to alleviate obstruction. The stent is a polarized and braided network of metallic wires. Pathology associated with colorectal stents is yet to be described. The authors reviewed 7 cases involving stented colorectal segments from patients lacking clinical suspicion of Crohn disease. In 4 cases, orientation of the specimens and stents matched the corresponding anatomic landmarks. In 3 cases, the specimens lacked helpful anatomic landmarks, and orientation was possible only after correlating with the intrinsic polarity of the stents. Stented areas showed artifacts resembling Crohn disease, including rounded cobblestones, pseudopolyps, and simple fissures, as well as unique artifacts including rhomboid cobblestones, complex fissures, oblique fissures with remarkably straight edges, and conical fragments of tissue that appeared to float. Crohn disease was misdiagnosed in 1 case in which the stent was removed intraoperatively and was never received. Colorectal stents help orient ambiguous specimens and induce patterned injury that can be confused with Crohn disease.

Art Education and Disability Studies

This article explores the field of Art Education as a valuable contributor to Disability Studies. Art Education has longstanding ties to disability research and pedagogy, and recent advancements in Art Education as well as Disability Studies closely align the two fields. Their mutual investment in visual culture studies engenders the possibility for a transdisciplinary space in which disability can be explored in new pedagogical ways to yield unique artifacts. Through several Art Education perspectives, I propose strategies for interjecting meaningful art activities into post-secondary, humanities-based Disability Studies curricula.Keywordsart, Art Education, visual culture, disability, Disability Studies, transdisciplinary

Digital Radiographic Artifacts

Artifacts in radiography can be detrimental to interpretation by decreasing visualization or altering the appearance of an area of interest. Digital radiographs (DRs) have their own unique artifacts, and recognition of these artifacts is important to prevent misinterpretation and help identify the cause. A DR artifact can be categorized according to the step during which it was created. The major categories are preexposure, exposure, postexposure, reading, and workstation artifacts. Understanding the cause of artifacts and method of resolution is paramount in acquiring high-quality digital images.

Industrial Urbanism as an Archival Project: The Work of the Building Arts Foundation

St. Louis-based salvage contractor and self-taught curator Larry Giles has spent the last thirty-seven years assembling one of the largest collections of architectural artifacts in the United States. Under the auspices of the non-profit Building Arts Foundation, he has gathered together tens of thousands of unique artifacts in material and print form. In this interview conducted in the fall of 2006, Mr. Giles talks about the origins of his collection, its unparalleled scope, and his vision for its future home in a new national museum devoted to architecture and the allied arts. The authors provide an update on the work of the Building Arts Foundation as of January 2009.

Improved image reconstruction for partial fourier gradient‐echo echo‐planar imaging (EPI)

The partial Fourier gradient-echo echo planar imaging (EPI) technique makes it possible to acquire high-resolution functional MRI (fMRI) data at an optimal echo time. This technique is especially important for fMRI studies at high magnetic fields, where the optimal echo time is short and may not be achieved with a full Fourier acquisition scheme. In addition, it has been shown that partial Fourier EPI provides better anatomic resolvability than full Fourier EPI. However, the partial Fourier gradient-echo EPI may be degraded by artifacts that are not usually seen in other types of imaging. Those unique artifacts in partial Fourier gradient-echo EPI, to our knowledge, have not yet been systematically evaluated. Here we use the k-space energy spectrum analysis method to understand and characterize two types of partial Fourier EPI artifacts. Our studies show that Type 1 artifact, originating from k-space energy loss, cannot be corrected with pure postprocessing, and Type 2 artifact can be eliminated with an improved reconstruction method. We propose a novel algorithm, that combines images obtained from two or more reconstruction schemes guided by k-space energy spectrum analysis, to generate partial Fourier EPI with greatly reduced Type 2 artifact. Quality control procedures for avoiding Type 1 artifact in partial Fourier EPI are also discussed.

Godard Counts

Godard Counts

Digital EEG: Trouble in Paradise?

Digital EEG embodies enormous technological advances, but also presents new problems that users have not previously encountered and are still learning to deal with. Digital recording and display can produce unique artifacts, data distortion, and risks to data integrity. If used incautiously, digital displays may obscure important activity.

Toywars

Toywars

Paper Profiles: American Portrait Silhouettes

American portrait silhouettes were made by a range of people, from highly trained portrait artists to itinerant peddlers to family members snipping away in the drawing room. Some silhouettes are fine examples on watermarked paper deftly tipped into albums, and others are constructed from homemade materials cobbled together. This article discusses the history, materials, and techniques of silhouettes in the United States and their historical precedents abroad. The range of silhouette formats and the wide array of tracing machines that were employed to capture profiles straight from the face are also considered. A final section surveys conservation problems presented by these unique artifacts.

Dinosaurs and white elephants: the science center in the twenty-first century

This paper argues that science centers are expensive to create as capital projects, expensive to maintain with professional staff, and, given the high costs of exhibit development, expensive to change. Lacking a fixed collection of unique artifacts with which to attract visitors, the science center is at risk when it cannot change quickly enough to meet the demands of its users. In the past, temporary exhibitions have been used as a means of creating more frequent change. Now, however, given the exponential increase of the availability of new electronic media, coupled with their massive interconnection via the Internet, informal learning can be had at home and in other sites, rendering the science center unwieldy, expensive, irrelevant, and obsolete. Threats to the science center cannot be lightly shrugged off, and a real transformation of the institution is required. The paper concludes that the science center, as an institution and as a building project, is doomed to extinction as a consequence of two factors—ecology and economy. It argues for the need to develop a new kind of institution of informal learning in its place.

Magnetic Resonance Imaging of the Female Pelvis

To perform magnetic resonance imaging of the female pelvis, one must be familiar with the imaging appearance of normal structures as well as the disease entities that may be encountered. However, it is also important to be familiar with and understand the basic physical principles of the available imaging techniques to be able to optimize image quality and the detection of abnormalities. This discussion is intended to describe the available imaging techniques used in evaluation of the female pelvis. Following a discussion of conventional spin echo (CSE) techniques, the fast spin echo (FSE) technique will be described in detail. This will include how the FSE sequence generates images, the choice of imaging parameters, and the unique contrast characteristics and artifacts associated with the FSE technique. Pelvic multicoils will also be described in detail, including the choice of imaging parameters when using these coils and the unique artifacts that can be encountered. Chemical-selective imaging and motion artifact reduction techniques will additionally be described. At the end of the discussion, suggested imaging parameters are given for CSE and FSE sequences and for body coil and multicoil imaging.

Prehistoric hunters of the High Plains

The Northwestern Plains and the Adjacent Mountain Ranges: An Ecological Area for Prehistoric Hunters and Gatherers. The Archaeological Record for the Northwestern Plains and Mountains. The Prehistoric Plains Indian Hunter. Prehistoric Hunting of the Lesser Game Animals. Studies of Animal Populations in Archaeological Sites and Their Use in Biological and Cultural Interpretations. Experimental Archaeology and the Use of Weaponry and Tools. Hunting and Gathering Subsistence Strategies. Miscellaneous and Unique Artifacts and Features. Lithic Technology. An Overview of Wyoming Rock Art. Human Skeletal Remains on the Northwestern Plains. Lithic Resources. Final Thoughts and Remarks. Index.

(Post) Modern Polemics

In American cultural politics today there are at least two positions on postmodernism now in place: one aligned with a neoconservative politics, other derived from poststructuralist theory. Neoconservative postmodernism is more familiar of two: defined mostly in terms of style, it depends on modernism, which, reduced to its own worst formalist image, is countered with a return to narrative, ornament and figure. This position is often one of reaction, but in more ways than stylistic for also proclaimed is return of history (the humanist tradition) and return of subject (the artist/architect as master auteur). Poststructuralist postmodernism, on other hand, assumes the death of man not only as original creator of unique artifacts but also as centered subject of representation and of history. This postmodernism, opposed to neoconservative, is profoundly antihumanist: rather than a return to representation, it launches a critique in which representation is shown to be more constitutive of reality than transparent to it (thus poststructuralist connection). And yet, however opposed in sytle and politics, it is my contention that these two cepts of postmodernism disclose an historical identity.

Easter Island: The Scottish Connection

SCHOLARLY work on Easter Island has been concerned almost wholly with ethnological and archaeological problems.' In particular, much effort has been devoted to elucidating the provenance, age, meaning, and cultural significance of the famed statues, the rongo-rongo script, and other unique artifacts.2 Although some attempts have been made to ascertain the lineaments of Easter Island prehistory (before 1722) and protohistory (1722-1864, the period of European exploration), work on the historical modernization and development of the island is almost completely lacking.3 Yet Easter Island's historical geography demands attention, for its development since the I86o's, largely the work of European entrepreneurs, broadly reflects the development of Oceania as a whole. The island differs, however, from most of Oceania in that its precise mode of exploitation during the last hundred years was directed not by plantation owners, miners, or traders but by the enterprise of two successive Scottish sheep-rearing companies. From the late i86o's Easter Island was under the economic control of the Brander-

Meaning in Artifacts: Hall Furnishings in Victorian America

Meaning in Artifacts: Hall Furnishings in Victorian America Most people agree that Independence Hall, the statue of Liberty, and the Brooklyn Bridge are important. Unique and heroic artifacts known to millions, they can be viewed as material culture counterparts of great individuals like George Washington, Abraham Lincoln, and Thomas Edison. There is probably less agreement about the significance of Victorian hall stands, hall chairs, and card receivers. Yet the commonplace artifacts of everyday life mirror a society's values as accurately as its great monuments.1 This article extends our understanding of Victorian America by analyzing hall furnishings typical of that era. By examining artifacts such as these one can gain insights into the past not readily accessible by conventional verbal approaches. Hall furnishings have usually been outside the scope of historical inquiry. So have the majority of their users. Today, however, many historians are looking at ordinary people rather than traditional heroes and asking new sets of questions. By concentrating less on the unique and more on the typical they hope to compile an account of the past which is more responsive to contemporary needs. Reflecting both this changing orientation of history and the growing intellectual prestige of the social sciences, material culture studies are becoming more varied, rigorous, and suggestive.2 Once dominated by historians of art and technology, the field is being invaded by scholars from many different disci-

Arboreal Figures in the Golden Age Sonnet

The tree beset by natural forces, the embrace of elm and vine, and the antithesis of mulberry and almond are related figures which Spanish sonneteers of the sixteenth and seventeenth centuries frequently used when structuring agudezas por semejanza. The extent to which these stock figures are revitalized in unique poetic artifacts reveals each poet s ability to work within the limitations of an aesthetics of invention through imitation. Moreover, to follow the varying fortunes of these topoi is to assess the efficacy of the modes of correlation (simile, allegory, adequate symbol, or objective correlative); to witness the interplay of the Petrarchan and emblematic traditions; to note the variations on a theme exploited first by the erotic poets, later by the moralists; and to highlight the shift of emphasis from the discursive to the pictorial which marks the transition from the aesthetics of the Renaissance to that of the Baroque. Finally, the precise delineation of the specific context or whole, of which each sonnet is an integral part, permits a more comprehensive exegesis of that sonnet's alma de sutileza, for Gracian the essence of the craft and criticism of poetry.