Search

Background: Anticancer agents induce a variety of adverse effects when administered to cancer patients. Busulfan is a known antileukemia agent. When administered for treatment of leukemia in young patients, busulfan could cause damage to the male reproductive system as one of its adverse effects, resulting in sterility. Methods: We investigated the effects of Korean Red Ginseng extract (KRGE) on busulfan-induced damage and/or dysfunction of the male reproductive system. Results: We found that administration of busulfan to mice: decreased testis weight; caused testicular histological damage; reduced the total number of sperm, sperm motility, serum testosterone concentration; and eventually, litter size. Preadministration of KRGE partially attenuated various busulfan-induced damages to the male reproductive system. These results indicate that KRGE has a protective effect against busulfan-induced damage to the male reproduction system. Conclusion: The present study shows a possibility that KRGE could be applied as a useful agent to prevent or protect the male reproductive system from the adverse side effects induced by administration of anticancer agents such as busulfan.

A trajectory reconstruction approach is proposed for accurate leader-following with a desired separation distance on the trajectory. The approach aims to reconstruct the relative trajectory of the leader within a sliding time window based on the on-board sensors. The needed trajectory information of the leader relative to the follower is acquired by combining the noisy and intermittently available visual measurement with the odometry information. The situation that the leader is out of filed of view (FOV) is also taken into consideration. Moreover, instead of following the current pose of the leader, the trajectory information of a historical point on the trajectory is used as the reference input for controller, thereby avoiding the cutting-corner issue. Simulation results demonstrate the effectiveness of the proposed trajectory reconstruction approach.

In this paper, we propose a discriminative and robust appearance model based on features extracted from a random partition image hashing algorithm to account for severe occlusion and disappearance. We divide the original image into multiple sub-blocks with random positions and scales. Hash functions are used to map blocks into compact binary codes, with which more effective target matching can be achieved. The tracking task is then formulated by producing a confidence map for the target and background, and obtaining the best samples using maximum a posteriori estimate. Experimental results demonstrate that our tracker can achieve more accurate tracking results in situations of occlusion, out-of-view, and violent motion blur when compared with most of state-of-the-art competing algorithms. Besides, the proposed tracking algorithm is able to run in real time. Accepted version

The paper is concerned with the multi-robot leader-following problem in the presence of frequent dropouts in vision detection. In many scenarios, for instance a structured environment, it is inevitable to experience outage of vision detection due to reasons such as the target moving out of view, vision occlusion, motion blurring, etc. The paper proposes a Bayesian trajectory estimation based leader-following approach that can offer accurate path following given intermittent vision observations. The follower robot estimates the trajectory of the leader robot based on the noise-corrupted odometry information of both robots, and inter-robot relative observations based on detection of fiducial markers using an RGBD camera. A linear trajectory-following control method is employed to track a historical pose of the leader robot on the estimated trajectory. Results are obtained based on evaluating the proposed leader-following approach in tests with a zig-zag shaped trajectory and with a trajectory that contains sharp turns. Accepted version

The surface modification of polyimide (PI) by the irradiation of 3 keV He+, Ne+ and Ar+ ions was studied using XPS and AFM at various ion dose ranging from 1􀂯1014 to 1􀂯1017 ions/cm2. The change of surface roughness of PI by 3 keV inert ions was closely connected to the change of surface composition. At low doses below 5􀂯1015 ions/cm2, the surface of polyimide was carbonized by ion irradiations, showing rough surfaces. At higher ion doses, the surface composition was saturated due to the accumulation of damages, and the surface morphology became smoother as compared with the low dose case.

A novel self-calibrating sensing technology using miniature linear encoders and inertial/magnetic measurement unit (IMU) provides the accuracy, fast response and robustness required by many body motion processing applications. Our sensor unit consists of an accelerometer, a 3-axis magnetic sensor, 2 gyroscopes and a miniature linear encoder. The fusion of data from the sensors is accomplished by extracting the gravity related term from the accelerometer and consistently calibrating the gyroscopes and linear encoder when the sensor unit is under static conditions. Using the fused sensors, we developed a complete motion processing system that consists of a gateway where the human kinematics modeling is embedded. A time divided multiple access wireless architecture is adopted to synchronize the sensor network at 100 Hz. Experimental results show that the combination of the IMU and linear encoder produces a low RMS error of 3.5deg and correlation coefficient of 99.01%. A video showing the capture a performer's upper body motion is also realized.

This paper develops a physical model of an inertial/magnetic measurement unit by effectively integrating an accelerometer, a magnetometer, and two gyroscopes for low-g motion tracking applications. The proposed model breaks down the errors contributed by individual components, then determines error elimination methods based on sensor behavior and characteristics, and finally constructs a feedback loop for continuous self-calibration. Measurement errors are reduced by adopting a systematic design methodology: 1) tilt errors are minimized through a careful selection of A/D convertor resolution and by making compensation on sensor bias and scale factor; 2) heading errors are reduced by cancelling out nearby ferrous distortions and making tilt-compensation on the magnetometer; 3) errors from gyroscope measurements are eliminated via the least squares algorithm and continuous corrections using orientation data at the steady-state position. Preliminary tests for low-g motion sensing show that the motion tracker can achieve less than plusmn0.5deg accuracy in tilt and less than plusmn1deg accuracy in yaw angle measurement with above-mentioned methods.

A 2.4 GHz low-power wireless platform based on the Texas Instrumentstrade CC2431 System-On-Chip (SOC) transceiver is used to conduct a preliminary investigation of the accuracy of a 3-axis accelerometer fused with a linear encoder for capturing high-speed motion. Calibration of the fused sensors is accomplished by extracting the gravity related term from the accelerometer when it is under static conditions. When moving at acceleration greater than 1.1 g, the wireless platform switches to the linear encoder for local joint angle data. To ascertain the concept of sensor calibration when the sensor is under static conditions, experiments that compare results from a high-speed motion analysis system (Silicon Coachtrade) and the combination of the accelerometer and linear encoder is carried out. Experimental results for pronation and supination of the forearm that has acceleration less than 1.1 g show that the accelerometer and linear encoder produces a low root mean square (RMS) error of 5.3deg and 6.6deg respectively. Correlation coefficient for the accelerometer and linear encoder for the above experiment are 98.7% and 98.9% respectively. A similar experiment where the maximum acceleration exceeds 1.1g produces a RMS error of 10.5deg and 6.9deg for the accelerometer and linear encoder respectively. Correlation coefficients for both sensors are approximately 98.2%. This study shows that linear encoder as a joint angle measurement device is preferred for both high and low acceleration motion while the errors associated with extracting gravity related tilt from the accelerometer increases with increasing acceleration.