A hybrid Wi-Fi P2P with bluetooth low energy for optimizing smart device’s communication property

Peer-to-Peer Networking and Applications - Recently, due to the popularity of smart devices, a need for various types of wireless communication has been tremendously increasing and several types of...     

A Smart Wellness Service Platform and Its Practical Implementation

Advances in the field of medical sciences and medical technology, and present-day challenges, such as an aging population, rising medical expenses, and lifestyle-related diseases, have collectively catalyzed a research ecosystem termed “smart wellness.” This article describes the establishment of a smart wellness service platform designed to empower individuals to create a sense of balance in their lives. Step-by-step details include service model, design, and architectural considerations. As a proof of concept, implementation details of a Health Improvement and Management Systems (HIMS) Hub, a Smart Wellness Service Platform deployed in six cities in South Korea, are presented. An on-site survey conducted in Busan Metropolitan City reveals the percentage of satisfied users to be 91.3%. Furthermore, data gathered from 27,236 physical evaluations of users from a Busan city center over the period of April 2013 to May 2018 reveal that males and females in their 50s and 60s account for the highest number of participants, while males in their 70s have a higher rate of participation than females in the same age group.     

The internet of everything based on energy efficient P2P transmission technology with Bluetooth low energy

This paper introduces a fundamental energy efficient hybrid P2P transmission technology for P2P networking environment as well as Internet of Everything (IoE) infrastructure. Based on the transmission characteristics of wireless communication technologies of Bluetooth and Wi-Fi, the proposed P2P transmission technique integrates them into an energy efficient hybrid transmission technology and provides the IPification for specific group, society, and the entire world. We have shown that the proposed hybrid transmission technology outperforms the existing transmission technologies in the aspects of initial connection establishment time and overall data transmission capability.     

Decomposition-based design optimization method using genetic co-evolution

The paper examines new strategies for the implementation of genetic algorithms in a decomposition-based approach for design. In this approach, the design problem is decomposed into smaller-sized sub-problems, the solutions for which are obtained through co-evolution. The emphasis resides in evaluating methods for exchanging design information relevant to coordinating solutions of temporarily decoupled sub-problems. Methods based on modification of genetic makeup through experiential inheritance (exposure to another species), and through inter-species migration are investigated in this work. Different forms of design problem coupling are investigated, ranging from coupling through constraints only, to coupled objective and constraint functions. The proposed strategies are validated through implementation in representative algebraic and structural design problems.     

Linear and non-linear analyses on the onset of miscible viscous fingering in a porous medium

The onset of miscible viscous fingering in porous media was analyzed theoretically. The linear stability equations were derived in the self-similar domain, and solved through the modal and non-modal analyses. In the non-modal analysis, adjoint equations were derived using the Lagrangian multiplier technique. Through the non-modal analysis, we show that initially the system is unconditionally stable even in the unfavorable viscosity distribution, and there exists the most unstable initial disturbance. To relate the theoretical predictions with the experimental work, nonlinear direct numerical simulations were also conducted. The present stability condition explains the system more reasonably than the previous results based on the conventional quasi-steady state approximation.     

Study of hydrogen physisorption on nanoporous carbon materials of different origin

Hydrogen adsorption capabilities of different nanoporous carbon, i.e. amorphous carbons obtained by chemical activation (with KOH) of a sucrose-derived char previously ground by ball milling and carbon replicas of NH₄-Y and mesocellular silica foam (MSU-F) inorganic templates, were measured and correlated to their porous properties. The porous texture of the prepared carbon materials was studied by means of N₂ and CO₂ adsorption isotherms measured at −196 °C and 0 °C, respectively. Comparison with nanoporous carbons obtained without pre-grinding the sucrose-derived char [12] shows that the ball milling procedure favours the formation of highly microporous carbon materials even at low KOH loadings, having a beneficial effect of the interaction between the char particles and the activating agent. Hydrogen adsorption isotherms at −196 °C were measured in the 0.0-1.1 MPa pressure range, and a maximum hydrogen adsorption capacity of 3.4 wt.% was obtained for the amorphous carbon prepared by activation at 900 °C with a KOH/char weight ratio of 2. Finally, a linear dependence was found between the maximum hydrogen uptake at 1.1 MPa and the samples microporous volume, confirming previous results obtained at −196 °C and sub-atmospheric pressure [12].     

Preparation of nanosize Pt clusters using ion exchange of Pt(NH3) 4 2+ inside mesoporous channel of MCM-41

Mesoporous molecular sieve MCM-41 with a Si/Al ratio of 35 was obtained by hydrothermal synthesis using a gel mixture with a molar composition of 6 SiO₂0.1 Al₂O₃1 hexadecyltrimethylammonium chloride 0.25 dodecyltrimethylammonium bromide 0.25 tetrapropylammonium bromide0.15 (NH₄)₂O1.5 Na₂O300 H₂O. The MCM-41 sample was calcined in O₂ flow at 813 K and subsequently ion exchanged with Ca²⁺. A small Pt cluster has been supported on the MCM-41 sample following a procedure using ion exchange of Pt(NH₃) ₄ ²⁺ . The Pt(NH₃) ₄ ²⁺ ion supported on MCM-41 has been activated in O₂ flow at 593 K and subsequently reduced with Fh flow at 573 K, in the same way used for the preparation of a Pt cluster entrapped inside the supercage of zeolite NaY. The resulting Pt cluster supported on the MCM-41 shows hydrogen chemisorption oftotal two H atoms per Pt at 296 K (based on the total amount of Pt) and high catalytic activity for hydrogenolysis of ethane. The chemical shift in¹²⁹Xe NMR spectroscopy of adsorbed xenon indicates that the Pt cluster is located inside the mesoporous molecular sieve.     

Characterization of bimetallic NaY-supported Pt-Pd catalyst by EXAFS,TEM and TPR

NaY-supported bimetallic Pt-Pd catalysts have been studied by TEM, TPR and EXAFS. Small, randomly mixed particles are formed in the zeolite cages. When the Pt content is increased, a Pt core structure appears and the dispersion increases. Particle diameters are about 1–2 nm for bimetallic samples.     

Assignment of individual orientations by gaussian distribution and monte-carlo grain growth simulation by grain boundary character distribution (GBCD) in Fe-3%Si alloy

In order to investigate the effect of GBCD on microstructural evolution, a Monte-Carlo computer simulation method was developed in which the texture of real material was closely reconstructed in the simulated microstructure. This method consists of extracting a volume fraction and a Gaussian half-width from an experimental ODF of a Fe-3%Si alloy and planting them into the simulated microstructure. Using the reconstructed microstructure, the recrystallization texture formation characteristic of this alloy was studied with a particular focus on the anisotropic mobility of grain boundaries. By deliberately assigning a high anisotropic mobility (1000 times) to the grain boundaries with a misorientation angle in the range of 20 to 45 degrees, the abnormal grain growth phenomenon was analyzed. It was found that a selective growth of grains occurred when they were subjected to such pertinent conditions as their own high mobility accompanied by the presence of the neighboring low-mobility grains. Grains with a Goss orientation conformed to this general pattern of selective coarsening. Therefore, the present result strongly suggests that the theory of Hayakawaet al. - based on the selective growth of the Goss grains with particular boundary misorientation angles - needs to be modified so as to incorporate more general cases.