Design of a New Bilayer Multipole Electromagnetic Brake System for a Haptic Interface

This paper deals with the design, simulation and experimental verification of a new bilayer multipole electromagnetic brake. The design utilizes the superposition principle of magnetic flux across the inner and outer layers of axially-oriented electromagnetic poles to provide gradual braking about the single axis of rotation. The braking principle exploits the Coulomb friction between the two rigid contact surfaces. Compared with conventional, multi-pole, multi-layer type radial brakes in haptic applications, the proposed design provides high fidelity of free motion through an absolutely disconnected rotor. The design also provides a wide operating range by delaying the saturation limit of a magnetic circuit for a wide range of input power. In this paper, the analytical model of the brake is derived and compared with the FEM-based simulation results. The optimal design obtained from multi-objective optimization was experimentally verified for its capability in haptic applications.This work was supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program-Artificial intelligence bio-robot medical convergence project) (20001257, Artificial intelligence algorithm based vascular intervention robot system for reducing radiation exposure and achieving 0.5 mm accuracy)—funded by the Ministry of Trade, Industry and Energy(MOTIE, Korea), the Ministry of Health and Welfare(MOHW), the Ministry of Science and ICT (MSIT) and the Korean Evaluation Institute of Industrial Technology (KEIT); the Technology Innovation Program (10052980, Development of micro-robotic system for surgical treatment of chronic total occlusion)—funded by the Ministry of Trade, Industry and Energy (MI, Korea); and the WC300 R&D Program (S2482672)—funded by the Small and Medium Business Administration (SMBA, KOREA)

Reduction of wafer bow in free standing GaN grown by HVPE

In this study, GaN layers on sapphire were grown by hydride vapor phase epitaxy (HVPE). And free standing (FS) GaN layers were obtained after laser lift off (LLO) process. We controlled growth temperature to minimized bow of the FS-GaN after LLO process. Target thickness of GaN epilayers were over 300 mu m. GaN templates showed strong convex bowing at room temperature and the bow values showed any particular relation with growth temperature. But bows of FS-GaN substrates after LLO treatment showed mainly concave mode and those decreased according to reducing the growth temperature from 1010 degrees C to 1000 degrees C We show that reduction of bows in FS-GaN can be controlled by the growth condition of HVPE process.This work was supported by the Industrial Strategic Technology Development program funded by the Ministry of Trade Industry & Energy, KORE

Comprehensibility of Newly Introduced Water-sport Prohibitive Signs in Korea by Koreans and Westerners

Objective: The goal of this study is to evaluate the comprehensibility of the newly introduced water-sport prohibitive signs by the Ministry of Knowledge Economy (MKE, later merged into the Ministry of Trade, Industry and Energy) among Koreans and westerners, and to check whether the comprehensibility is affected by cultural differences. Background: The Ministry of Knowledge Economy had newly introduced fourteen water-sport prohibitive signs at the end of 2011 to alert people to potentially dangerous situations. However, no studies had been found so far to review or assess their comprehensibility. Method: Comprehensibility tests of fourteen water-sport prohibitive signs were conducted with forty Koreans and forty Westerners in two sequential sessions. In session I, participants were asked to guess the meaning of each sign verbally in an open-ended test. In session II, participants were encouraged to provide feedback for each sign after its intended meaning was given. Results: Only two out of fourteen signs satisfied the comprehension rate (67%) recommended by ISO standard for both groups (Koreans and Westerners). Cultural difference between Koreans and westerners significantly affect the comprehension rates of the investigated signs, and Westerners exhibit better overall comprehension than Koreans. Five poorly comprehended signs for both Korean and Western groups were identified. Conclusion: The recently introduced water-sport prohibitive warning signs by MKE still need a lot of improvements in order to be implemented nationally or internationally. There were significant differences in the signs' comprehensibility between Koreans and westerners. Application: The findings may serve as a useful input for researchers and watersport sign designers in creating easy-to-comprehend safety signs.clos

CO2 Plume Migration with Gravitational, Viscous, and Capillary Forces in Saline Aquifers

When injecting CO2 in saline aquifers, in order to investigate realistic flow, this study proposes a dimensionless group in the form of combination of Capillary number and Bond number to consider three forces of gravitational, viscous and capillary forces, simultaneously. Using of each dimensionless group individually is insufficient to obtain a satisfactory correlation with flow behavior of injected CO2. With the proposed dimensionless group, the universal profile of CO2 saturation was obtained in describing CO2 flow behaviors for CO2 injection rate, CO2-water interfacial tension, and density difference between CO2 and water. Thus, more realistic CO2 flow behavior was analyzed. © Copyright 2016 by the International Society of Offshore and Polar Engineers (ISOPE)This work was supported by the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grand funded by the Korea government Ministry of Trade, Industry & Energy (No. 20132010201760)

Seafood from Norway : food safety

Since Norway is a major supplier of seafood worldwide, monitoring the food safety of Norwegian fish products is a priority. This commentary gives a brief overview of the food safety of seafood from Norwegian waters. Several preventative measures during harvest/catch, processing and distribution have been established and are implemented regularly. Furthermore, comprehensive monitoring programmes to detect and quantify undesirable substances, such as heavy metals and polychlorinated biphenyls (PCBs), in Norwegian seafood are carried out. Substances with health benefits, such as omega-3 fatty acids, are also analysed. In general, evidence shows the level of undesirable substances in seafood from Norway to be low. In fact, in the majority of samples analysed, levels of undesirable substances were reported to be below the maximum limit set by the European Union (EU). This leads to the conclusion that consumption of seafood originating from Norway involves a low risk of negative health effects and that consumers can have confidence in the products they purchase.peer-reviewe

GENDER EMPOWERMENT IN AFRICA: AN ANALYSIS OF WOMEN PARTICIPATION IN ERITREAN ECONOMY

The role of women in African economies is more emphasised in recent years by ensuring gender equality and women empowerment. But the fact remains as women have less access to resources, education and health facilities in most of the developing countries. Greater participation of women in economic activities is the major concern of most of the countries in Africa. The picture is same in Eritrea, which became independence recently, with low levels of women education and their participation in the economy. An attempt is made in this paper to analyse women participation in economic activities in Africa in general and Eritrea in particular. The paper also provides some policy measures seeking higher participation of women in Eritrean economy.Women participation, gender gap, women empowerment, formal sector, informal sector, compensation to workers

A study on the failure prediction of composite laminates in bending

Failure prediction for composite materials under given loading conditions is important for efficient design in structural applications. Over the past several decades, there are numerous failure criteria proposed to more accurately predict the failure composite laminates. A lot of research was conducted to evaluate and validate the failure prediction capability for failure criteria. The most failure criteria are studied for in-plane loading conditions. Mechanical behavior of composite laminates varies depending on the loading conditions. Even if failure criterion is accurate under the in-plane loads, it cannot be accurate for out-of-plane loads such as bending. In many industrial structures, composite laminates is under out-of-plane load as well as in-plane loads. For the structural stability of the composite structures, it is important to accurately predict failure of composite laminates under bending. In this study, the failure prediction of composite laminates under bending is investigated. The non-linear finite element analysis using Arc-length method is performed. 2D strain-based interactive failure theory [1] that is more accurately final failure of composite laminate under multi-axial loading is applied to predict the final failure of composite laminates under bending. In order to compare the accuracy of the failure predictions, a 3-point bending test are performed for un-symmetric cross-ply [0/90]8 and quasi-isotropic [0/±45/90]2s composite laminates. Also, it is compared with the other failure criteria such as maximum strain, maximum stress and Tsai-Wu theories. Finally, the predicted results using 2D strain-based interactive failure theory more agree well with the experiment than other failure theories. Acknowledgements This work was supported under the framework of Aerospace Technology Development Program (No. 10074270, Development of Manufacturing Core Technology for 3-Dimnesional Woven Integrated Composite Wing Structure of 5,000 Pound VLJ Aircraft) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea) This work was supported by the New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea. (No. 20143030021130) References [1] S. Y. Lee and J. H. Roh, “Two-dimensional strain-based interactive failure theory for multidirectional composite laminates,” Composite Part B: Engineering, vol. 69, pp.69-75, 2015

Composition variations in Cu2ZnSnSe4 thin films analyzed by X-ray diffraction, energy dispersive X-ray spectroscopy, particle induced X-ray emission, photoluminescence, and Raman spectroscopy

Compositional and structural studies of Cu2ZnSnSe4 (CZTSe) thin films were carried out by X-ray diffraction, energy dispersive X-ray spectroscopy (EDS), particle induced X-ray emission (PIXE), photoluminescence, and Raman spectroscopy. CZTSe thin films with different compositions were deposited on sodalime glass by coevaporation. The composition of the filmsmeasured by two differentmethods, EDS and PIXE, showed significant differences. Generally, the Zn/Sn ratio measured by EDS is larger than that measured by PIXE. Both the micro- PIXE and the micro-Raman imaging results indicated the compositional and structural inhomogeneity of the sample. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/37033This researchwas supported by the International Research&Development Program of the National Research Foundation of Korea funded by theMinistry of Science, ICT and Future Planning of Korea (Grant number: 2011-0019204) and by the New & Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning grant funded by the Korea government’s Ministry of Trade, Industry and Energy (No. 20123010010130)

The Effect of Engineering Education Accreditation on Materials Engineering Education in University of Seoul

[EN] Korea implemented the Engineering Education Accreditation system in 2001, and it was adopted by 85 engineering colleges (out of 165) in 2015. Focusing on the Department of Materials Engineering at the University of Seoul, this study performed a time-series analysis of GPA, employment rate, and credits earned in MSC/design/major courses to compare the differences in academic achievements between accredited and non-accredited graduates. The results showed that accredited graduates had a generally higher GPA and employment rate than non-accredited students, and this can be traced to the curricula provided under the accreditation system having a positive effect on improving communication, teamwork, and creativityThis work is financially supported by the Korean Ministry of Trade, Industry and Energy in Korea through the fostering project of the Innovation for Engineering EducationKim, H.; Song, O. (2017). The Effect of Engineering Education Accreditation on Materials Engineering Education in University of Seoul. En Proceedings of the 3rd International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 329-337. https://doi.org/10.4995/HEAD17.2017.519032933