BackgroundA variety of forces are now shaping a passionate debate regarding the optimal approaches to improving the quality of substance abuse services for American Indian and Alaska Native communities. While there have been some highly successful efforts to meld the traditions of American Indian and Alaska Native tribes with that of 12-step approaches, some American Indian and Alaska Natives remain profoundly uncomfortable with the dominance of this Euro-American approach to substance abuse treatment in their communities. This longstanding tension has now been complicated by the emergence of a number of evidence-based treatments that, while holding promise for improving treatment for American Indian and Alaska Natives with substance use problems, may conflict with both American Indian and Alaska Native and 12-step healing traditions.DiscussionWe convened a panel of experts from American Indian and Alaska Native communities, substance abuse treatment programs serving these communities, and researchers to discuss and analyze these controversies in preparation for a national study of American Indian and Alaska Native substance abuse services. While the panel identified programs that are using evidence-based treatments, members still voiced concerns about the cultural appropriateness of many evidence-based treatments as well as the lack of guidance on how to adapt them for use with American Indians and Alaska Natives. The panel concluded that the efforts of federal and state policymakers to promote the use of evidence-based treatments are further complicating an already-contentious debate within American Indian and Alaska Native communities on how to provide effective substance abuse services. This external pressure to utilize evidence-based treatments is particularly problematic given American Indian and Alaska Native communities' concerns about protecting their sovereign status.SummaryBroadening this conversation beyond its primary focus on the use of evidence-based treatments to other salient issues such as building the necessary research evidence (including incorporating American Indian and Alaska Native cultural values into clinical practice) and developing the human and infrastructural resources to support the use of this evidence may be far more effective for advancing efforts to improve substance abuse services for American Indian and Alaska Native communities.

ABSTRACT:This paper proposes a method for the reconstruction of city buildings with automatically derived textures that can be directly used for façade element classification. Oblique and nadir aerial imagery recorded by a multi-head camera system is transformed into dense 3D point clouds and evaluated statistically in order to extract the hull of the structures. For the resulting wall, roof and ground surfaces high-resolution polygonal texture patches are calculated and compactly arranged in a texture atlas without resampling. The façade textures subsequently get analyzed by a commercial software package to detect possible windows whose contours are projected into the original oriented source images and sparsely ray-casted to obtain their 3D world coordinates. With the windows being reintegrated into the previously extracted hull the final building models are stored as semantically annotated CityGML "LOD-2.5" objects.

<p><strong>Abstract.</strong> Geometric camera calibration is a mandatory prerequisite for many applications in computer vision and photogrammetry. Especially when requiring an accurate camera model the effort for calibration can increase dramatically. For the calibration of the stereo-camera used for optical navigation a new chessboard based approach is presented. It is derived from different parts of existing approaches which, taken separately, are not able to meet the requirements. Moreover, the approach adds one novel main feature: It is able to detect all visible chessboard fields with the help of one or more fiducial markers simply sticked on a chessboard (AprilTags). This allows a robust detection of one or more chessboards in a scene, even from extreme perspectives. Except for the acquisition of the calibration images the presented approach enables a fully automatic calibration. Together with the parameters of the interior and relative orientation the full covariance matrix of all model parameters is calculated and provided, allowing a consistent error propagation in the whole processing chain of the imaging system. Even though the main use case for the approach is a stereo camera system it can be used for a multi-camera system with any number of cameras mounted on a rigid frame.</p>

Aerial imaging systems increasingly gain oblique viewing capabilities. Through these passive systems, photogrammetric 3D point clouds of a scene become available in addition to traditional vertical 2.5D information. In the field of urban reconstruction, this complementary information seeks for robust and automated fusion methods in order to derive 3D building geometry as well as topology in larger scales. It is sequentially shown how to get from façade planes over building footprints to roof reconstruction including overhangs. Façade planes are extracted from a photogrammetric high-resolution 3D point cloud. Local regression methods in 2D space are used to determine the local direction and a criterion for the local linearity of the point cloud. Based on these two parameters, the 3D point cloud is segmented according to which façade it belongs to. From the segmented point cloud, building footprints are extracted as polygons. Similar to cadaster information, those polygons, along with a traditional digital surface model (DSM), serve for one thing as the basis for overhang determination which is performed by fitting polynoms on the outside of façades and using their inflection points as overhang boundary. For another thing, they serve as roof areas which are segmented, topologically described and geometrically modelled. Again local regression methods are used but this time in 3D space in order to segment roof parts. Subsequently, the roof topology is derived using region growing methods. The final building models hold both, geometrical and topological properties.

<p><strong>Abstract.</strong> This paper presents a system calibration method for a trifocal sensor, which is sensitive to different spectral bands. The trifocal camera system consists of a stereo camera, operating in the visual (VIS) spectrum and a thermal imaging camera, operating in the Long-Wave- Infrared (LWIR) spectrum. Intrinsic parameters and spatial alignment are determined simultaneously. As calibration target a passive aluminium chessboard is used. Corner detection and subsequent bundle adjustment is done on all synchronized image triplets. The remaining reprojection errors are in the sub-pixel range and enable the system to generate metric point clouds, colored with thermal intensities in real-time.</p>