The United States after unipolarity: repairing the American image, one tweet at a time

For nearly all of the Bush administration, America’s standing in most parts of the world remained dismally low. The reputation it left behind after 2008 stood ready for a dramatic overhaul with the arrival of the popular Barack Obama. Beginning almost immediately with a positive new message offered to the Muslim world, Obama’s public diplomacy is decidedly less notable for its substantive achievements than the strides he and Secretary Hillary Clinton have made in modernising the means of public diplomatic discourse. During its time in office the Obama administration has worked to broaden and accelerate communications with audiences abroad by inserting social media and technology exchanges into the toolkit of the public diplomat. Yet the administration’s tendency toward strategic incoherence means public diplomacy strategy remains a mystery. As the content of public diplomacy falls behind innovations in methods to deliver it, one has to wonder: what is the world hearing

Planning 3-D collision-free paths using spheres

A scheme for the representation of objects, the Successive Spherical Approximation (SSA), facilitates the rapid planning of collision-free paths in a 3-D, dynamic environment. The hierarchical nature of the SSA allows collision-free paths to be determined efficiently while still providing for the exact representation of dynamic objects. The concept of a freespace cell is introduced to allow human 3-D conceptual knowledge to be used in facilitating satisfying choices for paths. Collisions can be detected at a rate better than 1 second per environment object per path. This speed enables the path planning process to apply a hierarchy of rules to create a heuristically satisfying collision-free path

Vision-guided gripping of a cylinder

The motivation for vision-guided servoing is taken from tasks in automated or telerobotic space assembly and construction. Vision-guided servoing requires the ability to perform rapid pose estimates and provide predictive feature tracking. Monocular information from a gripper-mounted camera is used to servo the gripper to grasp a cylinder. The procedure is divided into recognition and servo phases. The recognition stage verifies the presence of a cylinder in the camera field of view. Then an initial pose estimate is computed and uncluttered scan regions are selected. The servo phase processes only the selected scan regions of the image. Given the knowledge, from the recognition phase, that there is a cylinder in the image and knowing the radius of the cylinder, 4 of the 6 pose parameters can be estimated with minimal computation. The relative motion of the cylinder is obtained by using the current pose and prior pose estimates. The motion information is then used to generate a predictive feature-based trajectory for the path of the gripper

Efficient visual grasping alignment for cylinders

Monocular information from a gripper-mounted camera is used to servo the robot gripper to grasp a cylinder. The fundamental concept for rapid pose estimation is to reduce the amount of information that needs to be processed during each vision update interval. The grasping procedure is divided into four phases: learn, recognition, alignment, and approach. In the learn phase, a cylinder is placed in the gripper and the pose estimate is stored and later used as the servo target. This is performed once as a calibration step. The recognition phase verifies the presence of a cylinder in the camera field of view. An initial pose estimate is computed and uncluttered scan regions are selected. The radius of the cylinder is estimated by moving the robot a fixed distance toward the cylinder and observing the change in the image. The alignment phase processes only the scan regions obtained previously. Rapid pose estimates are used to align the robot with the cylinder at a fixed distance from it. The relative motion of the cylinder is used to generate an extrapolated pose-based trajectory for the robot controller. The approach phase guides the robot gripper to a grasping position. The cylinder can be grasped with a minimal reaction force and torque when only rough global pose information is initially available

Reliable vision-guided grasping

Automated assembly of truss structures in space requires vision-guided servoing for grasping a strut when its position and orientation are uncertain. This paper presents a methodology for efficient and robust vision-guided robot grasping alignment. The vision-guided grasping problem is related to vision-guided 'docking' problems. It differs from other hand-in-eye visual servoing problems, such as tracking, in that the distance from the target is a relevant servo parameter. The methodology described in this paper is hierarchy of levels in which the vision/robot interface is decreasingly 'intelligent,' and increasingly fast. Speed is achieved primarily by information reduction. This reduction exploits the use of region-of-interest windows in the image plane and feature motion prediction. These reductions invariably require stringent assumptions about the image. Therefore, at a higher level, these assumptions are verified using slower, more reliable methods. This hierarchy provides for robust error recovery in that when a lower-level routine fails, the next-higher routine will be called and so on. A working system is described which visually aligns a robot to grasp a cylindrical strut. The system uses a single camera mounted on the end effector of a robot and requires only crude calibration parameters. The grasping procedure is fast and reliable, with a multi-level error recovery system

Utilizing semantic networks to database and retrieve generalized stochastic colored Petri nets

Previous work has introduced the Planning Coordinator (PCOORD), a coordinator functioning within the hierarchy of the Intelligent Machine Mode. Within the structure of the Planning Coordinator resides the Primitive Structure Database (PSDB) functioning to provide the primitive structures utilized by the Planning Coordinator in the establishing of error recovery or on-line path plans. This report further explores the Primitive Structure Database and establishes the potential of utilizing semantic networks as a means of efficiently storing and retrieving the Generalized Stochastic Colored Petri Nets from which the error recovery plans are derived

Beyond Financial Aid: How Colleges Can Strengthen the Financial Stability of Low-income Students and Improve Student Outcomes

Completing education beyond high school is essential to Americans' well-being and economic success. But rising costs and inadequate financial resources hinder too many students from earning postsecondary credentials. This guidebook identifies six key strategies for improving services for low-income students. The report showcases promising approaches that colleges and universities are already employing, and offers these ideas as guides for all institutions. It also features an institutional self-assessment designed to help postsecondary institutions determine their effectiveness in serving low-income students and take steps toward improving their practices

Snapshots of Obama’s first 100 Days: A French Spring in Washington?

When Barack Obama fielded questions from an adoring French audience in Strasbourg earlier this month, he pleased his hosts by singling out a shining example of European ingenuity in public transportation – the high-speed rail system. The president disclosed his envy for high-speed trains to the audience, and it should not be taken lightly when American presidents get envious. Just two weeks later in Washington Obama actively campaigned for a similar network in the United States and committed $8 billion for good measure

Obama abroad and in the minds of American voters

The word is out: US presidential candidate Barack Obama scored a resounding victory with his recent eight-nation swing through the Middle East and Europe. With every stop, a remarkable media buzz and scores of well-timed, dignified images poured into the global political consciousness. It even seemed that for a short time, the world could regale in a US presidential campaign appearing to court a riveted (albeit non-voting) foreign public. In Afghanistan and the Middle East embattled leaders embraced Obama, understanding he may one day hold their respective fates in his hands. Obama struck the rights chords by promising more help in Afghanistan, more sovereignty to Iraq, and undiminished support for Israel. In Europe, Obamamania soared as he skipped across the continent, one day a public blitz in Berlin, another in Paris for a coup of statecraft, and concluding in London with grand day out

DAS Reentry Survivability Analysis

No abstract availabl