An Integrated Vision-Force System for Peg-in-hole Assembly Operations

In this article the integration of an artificial vision system and a 6-component force-torque sensor for high accuracy insertions is proposed. The former has the advantage of intervening before the contact of the two parts and providing an initial correction to allow the force sensor action; the latter is charged of completing the operation through the control of a neural network. An experimental facility has been developed for performance assessment. Two monochromatic CCD cameras are positioned with the optical axes perpendicular to each other, outside the working area in order not to interfere with the assembly operations. During tests it has been shown that the artificial vision system yields a fast, reliable and accurate measurement, by direct comparison with a co-ordinate-measuring machine. Results show that the use of an integrated vision-force sensor represents a complete solution to the peg-in-hole problem. Furthermore the 3-D localisation algorithm implemented on the vision system and the problems concerned with the system engineering are dealt with

Validation of behaviour measurement instrument of patients with diabetes mellitus and hypertension

Non-adherence to the treatment of chronic diseases such as hypertension and Diabetes Mellitus (DM) is a major obstacle in achieving patient therapy targets and quality of life of patients. A comprehensive approach involving pharmacists counselling has shown influences on changes in health behaviour and patient compliance. Behaviour changes in patients are one of the parameters to assess the effectiveness of counselling and education by pharmacists. Therefore, it is necessary to develop questionnaires of behaviour change measurement in DM-hypertension patients. This study aims to develop a measurement instrument in the form of questionnaires in assessing the behaviour change of DMhypertension patients. Preparation of question items from the questionnaire research instrument refers to some guidelines and previous research references. Test of questionnaire instrument valid was done with expert validation, followed by pilot testing on 10 healthy respondents, and 10 DM-hypertension patients included in the inclusion criteria. Furthermore, field validation test was conducted on 37 patients who had undergone outpatient care at the PKU Muhammadiyah Yogyakarta City Hospital and The Gading Clinic in Yogyakarta. The inclusion criteria were male and female patients, aged 18-65, diagnosed with type 2 diabetes with hypertension who received oral antidiabetic drugs and antihypertensives, and who were not illiterate and co-operative. The data were collected by questionnaire interviews by a standardized pharmacist. The result of validation test using Person correlation shows the value of 0.33. The results of the questionnaire validation test on 37 patients showed 5 items of invalid questions with the value of r <0.33, e: questions 2, 3, 6, 10 and 11, while the other 10 questions show the value of Pearson correlation > 0.33. The reliability value is shown from the Cronbach’s alpha value of 0.722 (> 0.6), implying that the questionnaire is reliable for DMhypertension patients. This Behavioural change questionnaire can be used on DM-hypertension patients, and an FGD approach is required for the development of factors affecting this questionnaire. Keywords: DM-hypertension, behaviour, compliance, validation, reliabilit

Contact glow discharge electrolysis: Effect of electrolyte conductivity on discharge voltage

Contact glow discharge electrolysis (CGDE) can be exploited in environmental chemistry for the degradation of pollutants in wastewater. This study focuses on the employment of cheap materials (e.g., steel and tungsten) as electrodes for experiments of CGDE conducted in electrochemical cells with variable electrolytic composition. A clear correlation between breakdown voltage (VB)/discharge (or midpoint) voltage (VD) and the conductivity of the electrolyte is shown. Regardless of the chemical nature of the ionogenic species (acid, base or salt), the higher the conductivity of the solution, the lower the applied potential required for the onset of the glow discharge. Concerning practical application, these salts could be added to poorly conductive wastewaters to increase their conductivity and thus reduce the ignition potential necessary for the development of the CGDE. Such an effect could render the process of chemical waste disposal from wastewaters more economical. Moreover, it is evidenced that both VB and VD are practically independent on the ratio anode area to cathode area if highly conductive solutions are employed. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

EMOGA: a hybrid genetic algorithm with extremal optimization core for multiobjective disassembly line balancing

In a world where products get obsolescent ever more quickly, discarded devices produce million tons of electronic waste. Improving how end-of-life products are dismantled helps reduce this waste, as resources are conserved and fed back into the supply chain, thereby promoting reuse and recycling. This paper presents the Extremal MultiObjective Genetic Algorithm (EMOGA), a hybrid nature-inspired optimization technique for a multiobjective version of the Disassembly Line Balancing Problem (DLBP). The aim is to minimize the number of workstations, and to maximize profit and disassembly depth, when dismounting products in disassembly lines. EMOGA is a Pareto-based genetic algorithm (GA) hybridized with a module based on extremal optimization (EO), which uses a tailored mutation operator and a continuous relaxation-based seeding technique. The experiments involved the disassembly of a hammer drill and a microwave oven. Performance evaluation was carried out by comparing EMOGA to various efficient algorithms. The results showed that EMOGA is faster or gets closer to the Pareto front, or both, in all comparisons

Kompetensi Mahasiswa Program Studi Pendidikan Biologi Kelas Unggulan Dan Kelas Reguler Pada Pelaksanaan PPL Di Sekolah Tahun 2014/2015

: The purpose of this research is to know the competency students of Biology Education Study Program on excellent and regular classes in conducting Field Experience Program in 2014/2015. There are 46 students conducted Field Experience Program in 23 schools. Eighteen of them are excellent class and the rest twenty eight students are regular class. Data of this research were collected by observation of theacher tutor, where it is using the instrument of Field Experience Program Implementation Unit Faculty of Teacher Training and Education University Mataram. Data were analyzed qualitatively and quantitatively. The data of students competency in conducting Field Experience Program were analyzed using ANOVA with software SPSS version 16. The results show that the average score of the Field Experience Program students competency in all aspects of planning 4.19 for excellent class and 4.30 for regular class. the competency of Field Experience Program students in implementation aspect has the average score of 3.77 for excellent class and 4.11 for regular class. Competency of students in the aspect of attitude and personality has average score of 4.38 for excellent class and 4.28 for regular class. these average all aspect have good categories. The result of ANOVA analysis has show there is no different in competency of students of Biology Education Study Program classes between excellent and regular classes in carry out Field Experience Program in school the year of 2014/2015

Defects drive the tribocharging strength of PTFE: An ab-initio study

If polytetrafluoroethylene (PTFE), commonly known as Teflon, is put into contact and rubbed against another material, almost surely it will be more effective than its counterpart in collecting negative charges. This simple, basic property is captured by the so called triboelectric series, where PTFE ranks extremely high, and that qualitatively orders materials in terms of their ability to electrostatically charge upon contact and rubbing. However, while classifying materials, the series does not provide an explanation of their triboelectric strength, besides a loose correlation with the workfunction. Indeed, despite being an extremely familiar process, known from centuries, tribocharging is still elusive and not fully understood. In this work we employ density functional theory to look for the origin of PTFE tribocharging strength. We study how charge transfers when pristine or defective PTFE is put in contact with different clean and oxidized metals. Our results show the important role played by defects in enhancing charge transfer. Interestingly and unexpectedly our results show that negatively charged chains are more stable than neutral ones, if slightly bent. Indeed deformations can be easily promoted in polymers as PTFE, especially in tribological contacts. These results suggest that, in designing materials in view of their triboelectric properties, the characteristics of their defects could be a performance determining factor

Parallel active link suspension: a quarter car experimental study

In this paper, a novel electro-mechanical active suspension for cars, the Parallel Active Link Suspension (PALS), is proposed and then experimentally studied. PALS involves the introduction of a rotary-actuator-driven rocker-pushrod mechanism in parallel with the conventional passive suspension assembly, to exert an additional controlled force between the chassis and the wheel. The PALS geometric arrangement is designed and optimized to maximize the rocker torque propagation onto the tire load increment. A quarter car test rig with double wishbone suspension is utilized for the PALS physical implementation. Based on a linear equivalent model of the PALS quarter car, a conservative and an aggressive robust H∞ control schemes are synthesized separately to improve the ride comfort and the road holding, with different levels of control effort allowed in each of the control schemes. Simulations with a theoretical nonlinear model of the PALS quarter car are performed to evaluate the potential in suspension performance enhancement and power demand in the rocker actuator. Experiments with a harmonic road, a smoothed bump and hole, and swept frequency are conducted with the quarter car test rig to validate the practical feasibility of the novel PALS, the ride comfort enhancement, as well as the accuracy of the theoretical model and of a further nonlinear model in which practical features existing in the test rig are identified and included

Bound by Debt: Nutmeg Trees and Changing Relations Between Farmers and Agents in a Moluccan Agroforestry Systems

Agroforestry is a land management system long practiced by communities in the Moluccas. The practice is commonly known as "Dusung", where one cash crop in particular, nutmeg, is interspersed throughout farmer groves. Farmers have faced a number of challenges in recent years, especially concerning a system of debt bondage inflicting undue losses upon them. This study aims to explain the involvement of farmers within the debt bondage system, otherwise known as the tree mortgage system. We utilize a case study methodology, whereby data were collected through interviews and participant observation and results analyzed using principal agent theory. Findings highlight that nutmeg farmers, what we call the Principal, incur high risks when debt bondage is applied by an Agent that has the increasing ability to deny and change the terms of an agreement. This occurs when Agents exploit information unavailable to farmers about nutmeg marketing prospects, which weakens farmer negotiating positions. Improving institutional support for contracts in the tree mortgage system could help to ensure a more equitable arrangement, improving the terms for nutmeg farmers, meanwhile also encouraging the continued preservation of the dusung system, which has long helped to manage forest resources sustainably

Time-space focused intrusion of genetically unrelated arc magmas in the early Paleozoic Ross-Delamerian Orogen (Morozumi Range, Antarctica)

The growth of continental crust in accretionary orogenic belts takes place through repeated cycles of subduction– accretion of rock units fromcontinental and oceanic magmatic arcs, supra-subduction zone backarcs and forearcs loaded with continent-derived materials. An ancient example relevant to magmatic arc accretion models is represented by the remnants of the Cambrian–Ordovician Ross Orogen in the Morozumi Range, Victoria Land (Antarctica). There, late Neoproterozoic phyllites host an intrusive complex which preserves a remarkably uncommon record of genetically unrelated magma pulses emplaced under a variable stress regime in a short time span: (1) a dominant K-feldspar–phyric granite, (2) fine-grained dioritic stocks and dykes, (3) a peraluminous granite; and (4) a tonalitic–granodioritic dyke swarm. Laserprobe U–Pb zircon dates cluster at late Cambrian times for all these units, yet they carry differential cargoes of relict cores. Unique geochemical– isotopic signatures for both the less evolved magmas (diorite and dyke tonalite) and the most acidic ones (granite and peraluminous granite) indicate that each one of them originated from distinct sources at depth. Additionally, field relationships and chemical evolutionary trends testify for a variety of shallow level open-system processes, such as magma mingling/mixing between diorite and main granite magmas, as well as progressive incorporation of the host schists by the dyke tonalite magma. In summary, crustal growth in the Morozumi intrusive complex was contributed by fresh mantle magma issuing from the metasomatised mantle wedge, while the production of othermelts did recycle different crustal portions/layers: the main granite derived fromGrenville-age granulitic lower crust; the peraluminous granite from late Proterozoic upper crust, and the tonalite magmas derived from subduction erosion-enriched subarc mantle and evolved by ingestion of local metasedimentary rocks. Overall, the Morozumi intrusive complex yields evidence for emplacement in the same site at the same time of magmas issuing fromdifferent sources that are usually found at a different depth in the arc lithospheric section. A likely scenario to activate this specific mechanism of melt production is a subduction zone affected by subduction erosion