Position control for haptic device based on discrete-time proportional integral derivative controller

Haptic devices had known as advanced technology with the goal is creating the experiences of touch by applying forces and motions to the operator based on force feedback. Especially in unmanned aerial vehicle (UAV) applications, the position of the end-effector Falcon haptic sets the velocity command for the UAV. And the operator can feel the experience vibration of the vehicle as to the acceleration or collision with other objects through a forces feedback to the haptic device. In some emergency cases, the haptic can report to the user the dangerous situation of the UAV by changing the position of the end-effector which is be obtained by changing the angle of the motor using the inverse kinematic equation. But this solution may not accurate due to the disturbance of the system. Therefore, we proposed a position controller for the haptic based on a discrete-time proportional integral derivative (PID) controller. A Novint Falcon haptic is used to demonstrate our proposal. From hardware parameters, a Jacobian matrix is calculated, which combines with the force output from the PID controller to make the torque for the motors of the haptic. The experiment was shown that the PID has high accuracy and a small error position.

Neuroimaging Prediction of Hemorrhagic Transformation for Acute Ischemic Stroke

<b><i>Background:</i></b> Hemorrhagic transformation (HT) is a common complication of acute ischemic stroke, often resulting from reperfusion therapy. Early prediction of HT can enable stroke neurologists to undertake measures to avoid clinical deterioration and make optimal treatment strategies. Moreover, the trend of extending the time window for reperfusion therapy (both for intravenous thrombolysis and endovascular treatment) further requires more precise detection of HT tendency. <b><i>Summary:</i></b> In this review, we summarized and discussed the neuroimaging markers of HT prediction of acute ischemic stroke patients, mainly focusing on neuroimaging markers of ischemic degree and neuroimaging markers of blood-brain barrier permeability. This review is aimed to provide a concise introduction of HT prediction and to elicit possibilities of future research combining advanced technology to improve the accessibility and accuracy of HT prediction under emergent clinical settings. <b><i>Key Messages:</i></b> Substantial studies have utilized neuroimaging, blood biomarkers, and clinical variables to predict HT occurrence. Although huge progress has been made, more individualized and precise HT prediction using simple and robust imaging predictors combining stroke onset time should be the future goal of development.

Kinematics analysis and gait planning for a hemiplegic exoskeleton robot

Background: As the world's aging population increases, the number of hemiplegic patients is increasing year by year. At present, in many countries with low medical level, there are not enough rehabilitation specialists. Due to the different condition of patients, the current rehabilitation training system cannot be applied to all patients. so that patients with hemiplegia cannot get effective rehabilitation training. Methods: Through a motion capture experiment, the mechanical design of the hip joint, knee joint and ankle joint was rationally optimized based on the movement data. Through the kinematic analysis of each joint of the hemiplegic exoskeleton robot, the kinematic relationship of each joint mechanism was obtained, and the kinematics analysis of the exoskeleton robot was performed using the Denavit-Hartenberg (D-H) method. The kinematics simulation of the robot was carried out in automatic dynamic analysis of mechanical systems (ADAMS), and the theoretical calculation results were compared with the simulation results to verify the correctness of the kinematics relationship. According to the exoskeleton kinematics model, a mirror teaching method of gait planning was proposed, allowing the affected leg to imitate the movement of the healthy leg with the help of an exoskeleton robot. Conclusions: A new hemiplegic exoskeleton robot designed by Shenzhen Institute of Advanced Technology (SIAT-H) is proposed, which is lightweight, modular and anthropomorphic. The kinematics of the robot have been analyzed, and a mirror training gait is proposed to enable the patient to form a natural walking posture. Finally, the wearable walking experiment further proves the feasibility of the structure and gait planning of the hemiplegic exoskeleton robot.

The Extension of Vegetable Production to High Altitudes Increases the Environmental Cost and Decreases Economic Benefits in Subtropical Regions

Global warming has driven the expansion of cultivated land to high-altitude areas. Intensive vegetable production, which is generally considered to be a high economic value and high environmental risk system, has expanded greatly in high-altitude mountainous areas of China. However, the environmental cost of vegetable production in these areas is poorly understood. In this study, we investigated pepper production at low (traditional pepper production area) and high (newly expanded area) altitudes in Shizhu, a typical pepper crop area. The output and environmental cost at the two altitudes were identified. We evaluated the influence of resource inputs, climate, and soil properties on pepper production. There were obvious differences in output and environmental cost between the two altitudes. High-altitude pepper production achieved a 16.2% lower yield, and had a higher fertilizer input, resulting in a 22.3% lower net ecosystem economic benefit (NEEB), 23.0% higher nitrogen (N) footprint and 24.0% higher carbon (C) footprint compared to low-altitude farming. There is potential for environmental mitigation with both high- and low-altitude pepper production; Compared to average farmers, high yield farmers groups reduced their N and C footprints by 16.9–24.8% and 18.3–25.2%, respectively, with 30.6–34.1% higher yield. A large increase in yield could also be achieved by increasing the top-dress fertilizer rate and decreasing the plant density. Importantly, high-altitude pepper production was achieved despite less advanced technology and inferior conditions (e.g., a poor road system and uneven fields). It provides a reference for the study on environmental cost of other high-altitude regions or other crop systems at high altitude area.

A State-of-the-Art Approach to Unlock the Potential of Complex Sour Reservoirs in Southern Oman During Global Market Downturn

Recent years and especially the coronavirus pandemic have been very challenging for the oil industry, resulting in a significant reduction in investment, forcing companies to review budgets and search for more efficient and economical technologies to achieve the target level of hydrocarbon production and revenue generation. In PDO, one of the most challenging fields is "AS", where extreme downhole conditions require a very well-engineered approach to become economical. This field has already seen some of the most advanced technology trials in PDO that are also covered in multiple SPE papers. Based on the new approaches and techniques that were successfully implemented on recently drilled wells, it was decided to review the older, previously fractured wells in the area and assess them for a refracturing opportunity. The main challenge in this project was that these older wells were previously hydraulically fractured in multiple target intervals, therefore both zonal isolation and successful placement of the new fracs were becoming the major concerns. As the planned coverage by the new fractures was to ensure no bypassed pay, the only applicable technology on the market was a pinpoint fracturing process, whereby the targeted placement is achieved through limited entry perforations and focused energy of the injected fluid. The subject pinpoint technology anticipates that the limited entry sandblasting perforation is created and then proppant laden fluid is pumped through a sandblasting nozzle which is part of either a coiled tubing (CT) or a jointed pipe (JP) Bottom Hole Assembly (BHA), and the backside (or the annulus of the injection path) is used to maintain the positive backpressure from the top. This technology allows for choosing a desirable order of target interval selection inside the well, unlike conventional plug and perf or a simplified multistage completion, where the treatments must be placed only in order from bottom to top. Another advantage of this approach is a faster frac cycle through the elimination of wellbore cleanout requirement. Being a unique and first-ever application in the Middle East, using CT for placing frac treatments through a jetting nozzle demonstrates the full scale potential of this approach not only in conventional wells but also in complex, sour and High Pressure (HP) environments that are often found in the Sultanate of Oman and in the Middle East. This paper will cover the advantages and disadvantages, complexity and requirements, opportunities and lessons learnt in relation to this approach.

Using 3D Animation and Virtual Reality in Educations

This paper will look at the use of innovative and advanced technology teaching methods to support the goal of learning enhancement by using established teaching concepts. The primary aim is to explore the potential for using leading-edge virtual reality technology to help students learn and understand various concepts. The utility of the technology was examined by studying the latest 3D programming tools. Additionally, there were several styles of animation used. The results showed that Virtual Reality technologies can play a role in education and learning when supported by established learning and teaching concepts.

PENGGUNAAN APLIKASI PIXTON UNTUK MENINGKATKAN MINAT MENULIS PADA MATERI TEKS CERITA SEJARAH KELAS XII

Writing is not an easy thing. Especially for beginners or those who have never written. Writing activities become boring activities, not fun. Writing is a scary thing. It's very hard to do. Sometimes we don't know where to start. These problems can be solved with the development of increasingly advanced technology. Technology was created to be able to help and make it easier for humans to do things. In the field of education, various applications can be used to support teaching and learning activities, one of which is the Pixton application. Pixton is a website that allows students to create comics online without installing anything on their computer. The objectives to be achieved in this study are to (1) describe the increase in interest in writing stories through the Pixton application. (2) Describe the results of writing stories through the Pixton application. This study uses a qualitative approach with descriptive analysis. Data collection techniques in this study uses a questionnaire. The method of scaling the attitude statement uses a Likert scale with five alternative answers. The results of the study were 91.4% of respondents who answered strongly agree and agree that the Pixton application is interesting when used to write stories. 80% of respondents stated that the Pixton application did not make respondents bored in completing a story. 94.3% stated that writing stories using the Pixton application was more interesting than writing stories on a piece of paper. 94.3% of respondents stated that the Pixton application can increase creativity and interest in writing stories. The results of writing stories through the Pixton Application with an average value of compiling story texts are 83.8. ABSTRAKMenulis bukanlah hal yang mudah. Apalagi bagi pemula atau yang sama sekali belum pernah menulis. Kegiatan menulis menjadi kegiatan yang membosankan, tidak menyenangkan. Menulis menjadi hal yang menakutkan. Berat sekali untuk melakukannya. Tidak tahu harus mulai dari mana. Berbagai permasalahan ini dapat dipecahkan dengan perkembangan teknologi yang semakin maju. Teknologi diciptakan untuk dapat membantu dan mempermudah manusia dalam mengerjakan sesuatu. Dalam bidang pendidikan, beragam aplikasi bisa digunakan untuk menunjang kegiatan belajar mengajar, salah satunya adalah aplikasi Pixton. Pixton adalah situs web yang memungkinkan peserta didik membuat komik online tanpa memasang apa pun di komputer. Tujuan yang ingin dicapai dalam penelitian ini untuk (1) mendeskripsikan peningkatan minat menulis cerita melalui aplikasi Pixton. (2) Mendeskripsikan hasil menulis cerita melalui aplikasi Pixton. Penelitian ini menggunakan pendekatan kualitatif dengan analisis deskriptif. Teknik pengumpulan data dalam penelitian ini menggunakan quesioner. Metode penskalaan atas pernyataan sikap menggunakan skala likert dengan lima alternatif jawaban. Hasil penelitian 91,4% responden yang menjawab sangat setuju dan setuju bahwa aplikasi Pixton menarik bila digunakan untuk menulis cerita. Sebanyak 80% responden menyatakan aplikasi Pixton tidak membuat responden bosan dalam menyelesaikan sebuah cerita. Sebanyak 94,3% menyatakan menulis cerita dengan menggunakan aplikasi Pixton lebih menarik dari pada menulis cerita di selembar kertas. Sebanyak 94,3% responden menyatakan aplikasi Pixton dapat meningkatkan kreativitas dan minat menulis cerita. Hasil menulis cerita melalui Aplikasi Pixton dengan nilai rata-rata menyusun teks cerita 83,8.