Collision Detection and Safe Reaction Algorithm for Non-backdrivable Manipulator with Single Force/Torque Sensor

The paper presents a robust control law for homing of an autonomous robot. The proposed work aims to solve this problem for practical conditions such as random errors in commanded velocities and unknown distance sensor characteristics. The proposed steering control aligns the robot’s orientation with homing vector using arbitrary real valued distance function providing the capability to work in changing environment conditions. Finite time convergence to the equilibrium using proposed control law is achieved in the presence of bounded random velocity errors regardless of the initial position and orientation. Just the sign information as feedback supports applicability of proposed control law with any distance function. A matching parameter between panoramic images obtained at home and current positions is a function of distance between home and current positions. However, explicit relation between distance and image matching parameter is unknown. This work demonstrates the application of proposed method for visual homing based on image distance function rendering the benefit of minimal image processing. Various simulation and experimental results are presented for visual homing to support the theory presented in this paper. Advantage of proposed visual homing is also explored in changing environment conditions.     

Major findings from LBLOCA reflood tests using the ATLAS facility

A set of LBLOCA (large-break loss of coolant accident) reflood tests was performed in the first phase of the ATLAS (advanced thermal-hydraulic test loop for accident simulation) program. Their main objectives were to identify the major thermal-hydraulic characteristics during the reflood phase of a LBLOCA for APR1400 and to provide qualified data for APR1400 licensing. The ATLAS reflood test program could be divided into two phases (Phase-1 and Phase-2) according to the target period to be simulated. The Phase-1 tests were parametric effect tests for downcomer boiling in the late reflood phase of LBLOCA and the Phase-2 tests were integral effect tests for the entire reflood phase of LBLOCA. The experimental results from both Phase-1 and Phase-2 tests reproduced typical thermal-hydraulic trends expected to occur during the APR1400 LBLOCA scenario. A separate effect test was also performed under a low reflooding rate condition to provide data to validate the RELAP5 reflood models, and its experimental results showed a gradual reflooding in the core, a subsequent quenching of the core heater rods and the cooling of the reactor pressure vessel downcomer.     

Effect of loading rate upon fracture behavior of ferritic steel under large scaled yielding

Dynamic loading to ferromagnetic materials and large scaled yielding result in peak or valley and non-linear curve, respectively, on the Direct Current Potential Drop (DCPD) versus Crack Opening Displacement (COD) plots, which make it difficult to determine the crack initiation point. In this work high intensity of current up to 100 A was applied to the specimens of SA106Gr.C ferritic steel and the crack growth behavior was directly monitored by a high speed camera to obtain the crack initiation point. The effects of loading rate up to 1200 mm min⁻¹ upon the fracture resistance were explored. As the results, it has been shown that, although no substantial difference was seen in the load–COD plots, the crack initiation and then J_i and J–R curve were quite sensitive to the loading rate. That is, under the loading rate of 300 mm min⁻¹ the material showed the worst fracture resistance than under static loading and even under the higher loading rates of 600 and 1200 mm min⁻¹. Also applying the high speed camera and high current source have been proved to be an effective way to find out the accurate crack initiation point and to compensate the pulse of DCPD due to the ferromagnetic effect.     

Effect of γ-ray irradiation on Nd–Fe–B alloys

We report on how γ-ray irradiation affects the magnetic properties of a powder sample of Nd–Fe–B, which was irradiated at room temperature with doses up to 700 kGy. Both the magnetic properties and surface morphology were changed by the effects of the γ-ray irradiation. The unirradiated and irradiated samples were then characterized using the VSM, XRD and SEM techniques.     

Resource and Power Allocation for OFDM-Based Device-to-Device Communications in a Multicell Environment

Journal of Communications Technology and Electronics - We investigate the optimal resource and power allocation for device-to-device (D2D) communications in a multicell environment. When D2D links...     

Cooperative communication system for high performance using ambient signals

This paper proposes the Internet connectivity of RF-powered devices in the backscatter system. The RF-powered devices do not use a battery and charge energy by harvesting from ambient RF signals of TV, a cellular phone and Wi-Fi devices. The Internet connectivity of the RF-powered devices in the backscatter system is very useful in Internet of things technology because the RF-powered devices which are called to a tag have a small size by the harvesting from ambient RF signals without a battery. This paper proposes a method improving the communication performance of the Wi-Fi backscatter system by applying the cooperative communication scheme.

     

A collaborative contour detector by gradient and active contours for ultrasound kidney images

In the process of urinary system disease diagnosis, a complete kidney contour is crucial to estimate its size, area, volume and other properties. These properties can effectively help doctors diagnosis and prepare treatment plans. However, ultrasound images suffer from low signal-to-noise ratio, speckle, missing boundaries and other artefacts. Traditional contour detection algorithms can hardly extract a continuous and accurate kidney contour. To solve the problem, we propose a collaborative contour detector by gradient and active contour. It not only can make sure that the extracted contour is continuous and accurate but also is simple and suitable to use in practice. Both the simulated experiments and clinical experiments show that the proposed algorithm achieves a good performance in ultrasound kidney images and can effectively assist doctors in diagnosis.     

A simple regression method for determining the quantity of translated protein in a cell-free protein synthesis system

A simple regression method for quantifying endogenous leucine in S30 extract was developed. This method enabled the quantity of translated protein in a cell-free protein synthesis system to be exactly determined.     

Effects of moisture content and drying temperature on the physicochemical properties of ostrich jerky

The objective of this study was to investigate the influence of temperature (50, 60, and 70 degrees C) and moisture content (18, 21, and 24%) on the quality ofjerky products from ostrich meat. The jerky products were evaluated by physicochemical and sensory methods. The tensile strength of the samples prepared to 24% w.b. moisture content at 50 degrees C was lowest (p < 0.05; 124 N) while those prepared under other conditions were in the range of 208-268 N (p > 0.05). The water activity of the jerky products was 0.51-0.72, and significant influence of drying temperature on protein solubility was also observed, but the samples dried at the same temperature had similar levels of soluble protein (p > 0.05) regardless of moisture content of samples. The pH of the samples dried at 50 degrees C and 60 degrees C showed little change in different moisture content, but samples dried at 70 degrees C tended to affect the pH by moisture content. Hunter a-values showed a predominantly increasing trend in all moisture levels as the heating temperature increased. The jerky product prepared to 24% w.b. moisture content at 60 degrees C showed the best sensory overall acceptability.     

芦苇纤维的细胞腔加填技术的研究 第一部分 超细粒度填料的高速搅拌细胞腔加填技术

利用高速搅拌的方法通过纹孔将填料加入芦苇纤维细胞腔，研究了影响加填的一些主要因素及加填后纸页的物理性质和光学性质。