Dynamic Control of Soft Robotic Arm: An Experimental Study

In this paper, a reinforced soft robot prototype with a custom-designed actuator-space string encoder are created to investigate dynamic soft robotic trajectory tracking. The soft robot prototype embedded with the proposed adaptive passivity control and efficient dynamic model make the challenging trajectory tracking tasks possible. We focus on the exploration of tracking accuracy as well as the full potential of the proposed control strategy by performing experimental validations at different operation scenarios: various tracking speed and external disturbance. In all experimental scenarios, the proposed adaptive passivity control outperforms the conventional PD feedback linearization control. The experimental analysis details the advantage and shortcoming of the proposed approach, and points out the next steps for future soft robot dynamic control.Comment: 7 pages, 12 figure

The effects of myrtle (myrtus communis) and clindamycin topical solution in the treatment of mild to moderate acne vulgaris: A comparative split-face study

Objectives: Although Acne vulgaris is a chronic skin disease, which its standard treatment causes therapeutic limitations and some common adverse effects, medicinal plants can be effective in treatment with low adverse effects as combination therapy. Myrtle (Myrtus Communis) has some beneficial properties, which has been administered topically and orally for some skin diseases in Persian medicine. This study aimed to compare the efficacy and safety of Myrtle formula and 1 clindamycin topical solution. Methods: This was a split-face clinical trial that was done on 55 patients with mild to moderate acne vulgaris for 16 weeks. The patients received topical Myrtle solution to the right side of the face (group 1) and clindamycin solution to the left side (group 2) twice daily for 12 weeks. All participants were examined for the acne severity index (ASI) and total acne lesions counting (TLC) at certain times during the study. Then, they stopped using them for four weeks. They also did not take the drug in the final four weeks of the study. Results: Forty-eight patients completed the study for 16 weeks; 40 (83.2) patients were female and the rest of them were male. The mean age and standard deviation were 25.62 ± 7.62 years. After 12 weeks, the percentage changes of comedones, inflammatory lesions, ASI and TLC were significantly reduced in both groups (p < 0.001). The percentage change of inflammatory lesions and ASI decrease was significantly higher in the group 1 (p = 0.03). There was no significant difference in the incidence of side effects between the two groups. There was a more significant decrease in sebum percentage change in the group 1 (p = 0.003). Conclusion: Myrtle lotion was effective and safe for the treatment of mild to moderate acne vulgaris. Copyright © Korean Pharmacopuncture Institut

The value of Big 4 audits in Australia

Research suggests that equity markets value Big N audits over non-Big N audits. Explanations include the information quality hypothesis, whereby Big N auditors increase information quality, and the insurance hypothesis, whereby investors value the deeper pockets of Big N auditors. Using client firms'"ex ante" cost of capital as the dependent variable, we investigate whether capital market participants differentially value Big 4 versus non-Big 4 audits in Australia and whether the value of Big 4 audits in Australia changed as a result of the audit failures of 2001-2002. We find that Big 4 audits reduce the "ex ante" cost of equity capital until 2001, but not after 2001. We cannot dismiss the insurance hypothesis for the persistence of the loss beyond 2003 because of the establishment of liability caps, but the demise of the Big 4 audit value for 2001-2003 is consistent with the information quality hypothesis and does not support the insurance hypothesis. Copyright (c) 2010 The Authors. Accounting and Finance (c) 2010 AFAANZ.

A new robust multi-machine power system stabilizer design using quantitative feedback theory

Small-signal oscillations is one of the important problems in power system operation that caused by insufficient natural damping in the system. This paper uses the Quantitative Feedback Theory (QFT) to design a new robust PSS for multi-machine power systems able to provide acceptable damping over a wide range of operating points. In the design procedure the main purpose is to reject the load fluctuations and, therefore, a particular transfer function is used as the nominal plant. The parametric uncertainty in power system is readily handled using QFT. The decentralized design with a simple structure is easily applied to multi-machine power systems. The nonlinear time-domain simulations are carried out to validate the effectiveness of the proposed controller. Results clearly show the benefits of the proposed controller for stability enhancement of power systems

Evaluating validity of clinical criteria for requesting chest X-rays in trauma patients referred to emergency room

Background: Our goal was to identify the clinical criteria for requesting the chest X-ray in patients with blunt trauma and whether its findings such as clinical signs with a high sensitivity could be used to codify the final criteria. Materials and Methods: 386 patients with multiple trauma or blunt chest trauma examined by a physician and the injury mechanism, vital signs, O 2 saturation, auscultation findings, abrasions and ecchymosis, crepitation, tenderness on palpation, and pain on lateral compression were noted. The physician′s clinical judgment on the necessity of a chest X-ray was also noted in a questionnaire. After taking the X-ray, a digital photo was taken and showed to a radiologist to report any significant chest injury. Data were collected and the positive and negative predictive values, sensitivity and specificity were estimated. Results: 350 males (90.9%) and 35 females (9.1%) with the mean age of 47.1 ± 15.5 years old were evaluated. Falling down (37.7%) was the major mechanism of injury and chest pain (48%) the first complaint of patients. In 87.3% of the chest X-rays, there was no abnormal finding. Among several pathological findings in the chest X-rays, hemothorax, and rib fracture (each with 3.4% prevalence) had a higher prevalence. Tenderness on palpation with clinical judgment had a higher sensitivity about 95% and higher specificity about 100% in crepitation detected. Conclusion: Results showed the combination of positive chest pain and tachypnea in the patients could identify a significant chest injury with 100% sensitivity. More studies on this issue are warranted

New coordinated design of SVC and PSS for multi-machine power system using BF-PSO algorithm

Nowadays, flexible AC transmission system (FACTS) devices are increasingly used in power systems. They have remarkable effects on increasing the damping of the system. In this paper, a bacterial-foraging oriented by particle swarm optimization (BF- PSO) algorithm is employed to design the coordinated parameters of power system stabilizer (PSS) and static VAR compensator (SVC). With regard to nonlinearities of power system, linear methods can’t be used to design coordinated parameters of controllers. In this paper, nonlinear model of power system and SVC is used to design parameters of PSS and SVC. For this purpose, this design problem is firstly converted to an optimization problem and then the BF-PSO algorithm is used to solve it. Simulations are carried out on four machine 11 bus power system in MATLAB software. The results confirm the efficiency of the proposed method for stabilizing the power system oscillations. Comparing BF-PSO algorithm with other intelligent methods, (PSO, BFA) verifies better performance of the BF-PSO method