High Power Characterization of Piezoelectric Materials

Three techniques for measuring high voltage/power piezoelectric properties, which have been developed recently, are compared: a voltage-constant piezoelectric resonance method, a current-constant piezoelectric resonance method, and a pulse drive method. The conventional resonance method with a constant voltage circuit exhibits significant distortion (or a hysteresis) in the resonance frequency spectrum under a high vibration level due to large elastic non-linearity, which limits precise determination of the electromechanical coupling parameters. To the contrary, the resonance method with a constant current circuit (i.e., constant velocity) can determine the coupling parameters more precisely from a perfectly-symmetrical resonance spectrum. The general problem in both resonance methods is heat generation in the sample during the measurement. In order to separate the temperature characteristic from the non-linearity, it is recommended that the pulse method be used in parallel, even though the accuracy is not very high.     

Discrimination between Butylammonium Isomers by Calix[5]arene-Based ISEs

Penta-O-alkylated p-tert-butylcalix[5]arenes 1-5 (R = benzyl, isohexyl, isopropoxyethyl, isopropoxycarbonylmethyl, and tert-butoxycarbonylmethyl, respectively) in a fixed C(5)(v) cone conformation have been studied as ionophores in liquid membrane ion-selective electrodes (ISEs) for n-butylammonium against the other branched butylammonium isomers, alkali metals, and ammonium ions, in terms of detection limits, sensitivity, and selectivity. The highest levels of potentiometric selectivity and detection limits up to 3 × 10(-)(6) M are observed with ISEs based on ionophore 2, where selectivity follows the order n-BuNH(3)(+) ? i-BuNH(3)(+) > s-BuNH(3)(+) > t-BuNH(3)(+). The lower potentiometric selectivity displayed by ISEs based on ionophores 3-5 is ascribed to their affinity for the Na(+) ion of the lipophilic salt present in the membrane, as evidenced by appropriate (1)H NMR competition experiments with Na(+) and n-BuNH(3)(+) ions. Further investigation on the selectivity mechanism of ionophore 2 by means of frequency response analysis shows that the interaction of the linear butylammonium ion with membranes containing 2 involves a lower resistance process than that occurring with the other branched isomers, thus suggesting the presence of a favorable kinetic-controlled mechanism.     

Computer numerically controlled plasma chemical vaporization machining with a pipe electrode for optical fabrication

We have developed a chemical vaporization machining device that has computer numerically controlled plasma, by using a pipe electrode for optical fabrications. In this device, less than approximately 1 atm of pressure, plasma is generated around the tip of a pipe electrode. During the process, a workpiece is scanned against the electrode under computer control to achieve the desired shape to be removed. A workpiece of silica glass plate is shaped by use of this device, and the removal characteristics of the device are examined. The equations to characterize numerically the shape resulting from scanning of a workpiece have been derived. The new device allows the high precision of optics from the micrometer to the nanometer level with high-speed removal. The shaped surface is sufficiently smooth to be suitable for optical use.     

BearCam: automated wildlife monitoring at the arctic circle

In this paper we describe the development of the BearCam, a camera system which was deployed in Fall 2005 to monitor the behaviour of grizzly bears at a remote location near the arctic circle. The system aided biologists in collecting the data for their study on bears’ behavioural responses to ecotourists. We developed a camera system for operating in the challenging arctic conditions. We describe a novel “motion shapelet” algorithm for automatically detecting bears in the video captured by this camera system. This algorithm is an extension of the shapelet features (Sabzmeydani and Mori in CVPR 2007), which are mid-level features capturing pieces of shape. Our extension of this technique incorporates motion information and proves effective at automatically detecting the occurrence of bears. We present quantitative results demonstrating that our algorithm can reliably detect bears in the vast amounts of video footage collected by our system.

Simulation verification for the robustness of passive compass gait with a joint stiffness adjustment

A passive walking robot can achieve a smooth gait without any sensory feedback while walking down a slope. This phenomenon is based on the transformation of potential energy into kinetic energy in the legs. Although the entrainment is observed in a passive gait motion, there is a possibility that the passive gait cannot be achieved in the case of variations in physical parameters, initial conditions, and disturbances. To realize a robust passive gait against variations in physical parameters, this paper proposes a passive gait system that possesses a joint stiffness adjustment. Targeting a compass model, this paper investigates the effectiveness of the proposed method for a passive gait against variations in slope angle and hip joint mass through simulation. As a result, the simulation results show that this method especially has strong robustness against the slope angle variation.     

Action-based multifield video visualization

One challenge in video processing is to detect actions and events, known or unknown, in video streams dynamically. This paper proposes a visualization solution, where a video stream is depicted as a series of snapshots at a relatively sparse interval, and detected actions are highlighted with continuous abstract illustrations. The combined imagery and illustrative visualization conveys multi-field information in a manner similar to electrocardiograms (ECG) and seismographs. We thus name this type of video visualization as VideoPerpetuoGram (VPG). In this paper, we describe a system that handles the aw and processed information of the video stream in a multi-field visualization pipeline. As examples, we consider the needs for highlighting several types of processed information, including detected actions in video streams, and estimated relationship between recognized objects. We examine the effective means for depicting multi-field information in VPG, and support our choice of visual mappings through a survey. Our GPU implementation facilitates the VPG-specific viewing specification through a sheared object space, as well as volume bricking and combinational rendering of volume data and glyphs.     

Extracting mobile objects by sequential background detection on a video

This paper describes a technique for extracting moving objects from a video image sequence taken by a slowly moving camera as well as a fixed camera. The background subtraction method is effective for extracting moving objects from a video. But the latest background image should be employed for the subtraction in the mobile camera case and in order not to be influenced by the light intensity change. A temporal median technique is proposed in this paper which detects the background at every moment. The camera motion is estimated using a local correlation map and the temporal median filter is applied to the common image area among a set of successive image frames to extract the background. The technique was applied to the video images obtained at a junction from a hand-held camera and those taken at a pedestrians crossing by a camera fixed in a car and successfully detected pedestrians. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Recovering 3D human body configurations using shape contexts

The problem we consider in this paper is to take a single two-dimensional image containing a human figure, locate the joint positions, and use these to estimate the body configuration and pose in three-dimensional space. The basic approach is to store a number of exemplar 2D views of the human body in a variety of different configurations and viewpoints with respect to the camera. On each of these stored views, the locations of the body joints (left elbow, right knee, etc.) are manually marked and labeled for future use. The input image is then matched to each stored view, using the technique of shape context matching in conjunction with a kinematic chain-based deformation model. Assuming that there is a stored view sufficiently similar in configuration and pose, the correspondence process would succeed. The locations of the body joints are then transferred from the exemplar view to the test shape. Given the 2D joint locations, the 3D body configuration and pose are then estimated using an existing algorithm. We can apply this technique to video by treating each frame independently - tracking just becomes repeated recognition. We present results on a variety of data sets.     

Enhancing grid security by fine-grained behavioral control and negotiation-based authorization

Nowadays, Grid has become a leading technology in distributed computing. Grid poses a seamless sharing of heterogeneous computational resources belonging to different domains and conducts efficient collaborations between Grid users. The core Grid functionality defines computational services which allocate computational resources and execute applications submitted by Grid users. The vast models of collaborations and openness of Grid system require a secure, scalable, flexible and expressive authorization model to protect these computational services and Grid resources. Most of the existing authorization models for Grid have granularity to manage access to service invocations while behavioral monitoring of applications executed by these services remains a responsibility of a resource provider. The resource provider executes an application under a local account, and acknowledges all permissions granted to this account to the application. Such approach poses serious security threats to breach system functionality since applications submitted by users could be malicious. We propose a flexible and expressive policy-driven credential-based authorization system to protect Grid computational services against a malicious behavior of applications submitted for the execution. We split an authorization process into two levels: a coarse-grained level that manages access to a computational service; and a fine-grained level that monitors the behavior of applications executed by the computational service. Our framework guarantees that users authorized on a coarse-grained level behave as expected on the fine-grained level. Credentials obtained on the coarse-grained level reflect on fine-grained access decisions. The framework defines trust negotiations on coarse-grained level to overcome scalability problem, and preserves privacy of credentials and security policies of, both, Grid users and providers. Our authorization system was implemented to control access to the Globus Computational GRAM service. A comprehensive performance evaluation shows the practical scope of the proposed system.

A 64-year-old woman with progressive gait disturbance and dementia for one year

We report a 64-year-old Japanese woman who died one year after the onset of progressive gait disturbance and dementia. She noted a difficulty in holding a glass and hand tremor in June of 1996 when she was 63 years old. In July of 1996, she tended to lean toward left when she walked. She also noted truncal titubation. In November of 1996, she started to have visual hallucination and delusion in which she said "I see something is flying on the wall.", "Somebody has come into my room", and things like that. She was admitted to our service on November 22, 1996. On admission, she was alert and general physical examination was unremarkable. Neurologic examination revealed disturbance in recent memory. Hasegawa's dementia rating scale was 22/30. She showed vivid visual hallucination with colors in which she saw faces of dwarfs and angels, a space ship, and others. Higher cerebral functions were normal. She showed left oculomotor palsy which was a sequel of an aneurysm and subarachnoid hemorrhage nine years before. Otherwise cranial nerves were unremarkable. She showed ataxic gait, limb ataxia, truncal titubation, and postural hand tremor. She had no weakness and no muscle atrophy. Deep tendon reflexes were within normal limits. Plantar response was flexor. Sensation was intact. Laboratory examination was also unremarkable. Complete survey for occult malignancy was negative. CSF was under a normal pressure and cell count was 1/microliter, total protein 27 mg/dl, and sugar 68 mg/dl. Cranial CT scan was unremarkable. MRI was not obtained because of the presence of an aneurysm clip in the left internal carotid-posterior communication artery junction. She showed progressive deterioration in her mental function. By January 1997, she became unable to stand or walk with marked dementia. Repeated CSF exams and cranial CT scans were unremarkable. She suffered from several episodes of aspiration pneumonia. A trial of three days methylprednisolone pulse therapy was given starting on March 7, 1997, which was of no effect on her neurologic status. On March 28, 1997, she was intubated because of acute respiratory distress syndrome. In April 2, her body temperature rose to 38 degrees C. On April 9, 1997, her blood pressure dropped and resuscitation was unsuccessful. She was pronounced dead on the same day. The patient was discussed in a neurologic CPC and the chief discussant arrived at the conclusion that the patient had primary leptomeningeal lymphoma. Other possibilities entertained among the audience included brain stem encephalitis of unknown type, carcinomatous cerebellar degeneration plus limbic encephalitis, Creutzfeldt-Jakob disease, thalamic degeneration, and progressive multifocal leukoencephalopathy. Post-mortem examination revealed thickening and clouding of the leptomeninges; Gram-positive diplococci were found in the leptomeninges. This meningitis appeared to have been an complication in the terminal stage of her illness. Microscopic examination revealed astrocytosis in the midbrain tegmentum. Cerebral cortices showed only mild astrtocytosis. No cerebellar atrophy was seen and Purkinje cells were retained which excluded paraneoplastic cerebellar degeneration. Neuropathologic diagnosis was bacterial meningitis, however, the presence of brain stem encephalitis prior to the onset of bacterial meningitis could not be excluded. It is interesting to note that the diagnosis of the primary neurologic disease of this patient was not easy even after autopsy. As autopsy permission was obtained only for the brain, it was not clear whether or not this patient had an occult malignancy somewhere in her body, however, there was no evidence to indicate paraneoplastic degeneration of the central nervous system. As the patient did not have meningeal signs until one month before her death, it is difficult to ascribe her entire neurologic problems to her meningitis. Finally, her visual hallucination was vivid and colorful; we thought this might have been