bluuebunny/crossref_metadata_2025 huggingface dataset:
Multidisciplinary assessment of patients with ischemic stroke, the structure of a stroke team, and first Egyptian experience in adults undergoing transcatheter PFO closure for PFO-related stroke
Authors: Mansour Amr , Gamal Noha M. , Elfiky Azza A. , Saleh Mohamed Ayman , Mohamed Samia Ashour , ElKhawas Hala Mahmoud , ElSadek Ahmed , Dawood Noha L. , Elsayed Maiy H.
Published: March 2021

Background

Patent foramen ovale closure in the setting of stroke was debatable until the recent data from the long-term follow-up of multiple randomized control trials. These recent data have led to increase the number of the procedure worldwide.

To our knowledge, there was no previous formal structured program in Egypt between cardiologists and neurologists for investigation and management of patients with cryptogenic stroke.

The first Egyptian-dedicated stroke team was created in two large tertiary centers with collaboration between cardiologists, dedicated cardiac imagers, and neurologists for investigation and management of patients with cryptogenic stroke.

Results

Sixty-three patients with cryptogenic stroke were identified from a total of 520 patients admitted to the stroke units between 2016 and 2019. Twenty-five patients had a proven PFO-related stroke. Three patients were referred for surgical closure, 19 patients underwent transcatheter PFO closure, and procedural success was met in 18 patients (94.7%). We did not experience any major procedure-related complication. Complete closure was achieved in 83.3% of patients at 6 months. One patient had a single attack TIA within the first 3 months after device closure; one patient had a device-related thrombosis; both were managed successfully.

Conclusion

Our initial experience in collaboration between cardiologist and neurologist with the establishment of a dedicated cryptogenic stroke team added significantly to the management of patients with stroke.

The results of the first Egyptian cohort who underwent transcatheter PFO closure demonstrated procedural feasibility, safety, and efficacy with very low incidence of major complications.

A nationwide program is needed to reduce the ischemic stroke disease burden and the risk of recurrence.
Optical waveguides based on one-dimensional organic crystals
Authors: Chen Song , Zhuo Ming-Peng , Wang Xue-Dong , Wei Guo-Qing , Liao Liang-Sheng
Published: March 2021

Optical waveguide of organic micro/nanocrystals is one of crucial elements in miniaturized integrated photonics. One-dimensional (1D) organic crystals with various optical features have attracted increasing interests towards promising photonic devices, such as multichannel signal converter, organic field-effect optical waveguide, sensitive detector, and optical logic gate. Therefore, a summary about the 1D organic micro/nanocrystals based optical waveguide is important for the rational design and fabrication of novel optical devices towards optoelectronics applications. Herein, recent advances of optical waveguide based on 1D organic micro/nanocrystals with solid, flexible, hollow, uniformly doped, core-shell, multiblock and branched structures are summarized from the aspects of the waveguide properties and applications in photonic devices. Furthermore, we presented our personal view about the expectation of future development in 1D organic optical waveguide for the photonic applications.

Graphical abstract
Record of tritrophic relationship between Syagrus coronata (Martius) Beccari (Arecaceae), Pachymerus nucleorum Fabricius (Coleoptera: Chrysomelidae: Bruchinae) and Heterospilus sp. (Hymenoptera: Braconidae) in the State of Alagoas, northeastern Brazil
Authors: Duarte de Melo Jefferson , Cajé Suianne Oliveira dos Santos , Lima Iracilda Maria de Moura
Published: March 2021

Some conservation units in Brazil border urban areas, like the Catolé and Fernão Velho Environmental Protection Area (EPA) in the State of Alagoas. In urban areas, there is the habit of cultivating plants for landscape purposes, and Syagrus coronata (Martius) Beccari (Arecaceae), “Licuri” or “Ouricuri”, is a palm tree commonly used in ornamentation; a native species from Caatinga and Atlantic Forest biomes widely explored through time. Some insects have part of their development associated with plants, and Pachymerus nucleorum Fabricius (Coleoptera: Chrysomelidae: Bruchinae) has a close connection with some Arecaceae. Females usually lay eggs on the surface of fallen fruits and the immatures feed on the seed under the drupe endocarp; the larvae, even protected by the hard surface could be preyed by skilled parasitoid wasps. Here, the record of a tritrophic relationship between S. coronata, P. nucleorum, and a wasp of the genus Heterospilus (Hymenoptera: Braconidae) in an urbanized region of Alagoas, close to a remnant of Atlantic Forest of the Catolé and Fernão Velho EPA is communicated. Fruits were collected from the soil surface under the canopy of Licuri palms in the “Universidade Federal de Alagoas” A. C. Simões Campus and transported for laboratory monitoring. Either adults of Heterospilus parasitoid wasps and P. nucleorum beetles from some fruits were recorded. The specimens of S. coronata had seeds preyed upon by P. nucleorum close to a remnant of the Atlantic Forest. The record of a tritrophic relationship involving Heterospilus seems to indicate the tenacity of natural biological control.
Nullities for a class of 0-1 symmetric Toeplitz band matrices
Authors: Evans Ron , Greene John , Van Veen Mark
Published: March 2021

Let $S(n,k)$ denote the $n \times n$ symmetric Toeplitz band matrix whose first $k$ superdiagonals and first $k$ subdiagonals have all entries $1$, and whose remaining entries are all $0$. For all $n > k >0$ with $k$ even, we give formulas for the nullity of $S(n,k)$. As an application, it is shown that over half of these matrices $S(n,k)$ are nonsingular. For the purpose of rapid computation, we devise an algorithm that quickly computes the nullity of $S(n,k)$ even for extremely large values of $n$ and $k$, when $k$ is even. The algorithm is based on a connection between the nullspace vectors of $S(n,k)$ and the cycles in a certain directed graph.
Risk Management and Organizational Considerations for Enhancing Safety State Given the Continuous Technological Development Processes
Authors: IORDACHE Valentin Marian , ZAHARIA Sorin Eugen , PIETREANU Casandra Venera
Published: March 2021

Decision-making processes within aeronautical organizations are becoming increasingly challenging not only because of social, economic or flight planning threats, but also because of the need to properly implement new technologies that may require different approaches to allow a high performance operational state in air transport. The paper outlines the organizational management improvements in the complex and dynamic operational environment and analyzes the decision-making processes related to different risk levels which require a strong commitment from organizational management in the context of operational objectives. The authors also analyze the implementation of new technologies that affect the processes carried out within the organization and propose ways to adapt organizational management in order to control safety processes. The authors also analyze the implementation of new technologies that the processes carried out within the organization and propose ways organizational management security processes.
Observation of split evanescent field distributions in tapered multicore fibers for multiline nanoparticle trapping and microsensing
Authors: Yan Dong , Tian Zhen , Chen Nan-Kuang , Zhang Liqiang , Yao Yicun , Xie Yanru , Shum Perry Ping , Grattan Kenneth T. V. , Wang Daqin
Published: March 2021

The optical attractive force in tapered single-mode fibers (SMFs) is usually uniformly distributed around the tapered section and has been found to be important for trapping and manipulating targeted atoms and nanoparticles. In contrast, a peculiar phenomenon of the evanescent field splitting along the azimuth axis can be experimentally observed by tapering a weakly-coupled MCF into a strongly-coupled MCF to generate supermode interference. Moreover, the supermode interference produces a hexagonally distributed evanescent field and its six vertices give rise to the multiline optical attractive force. For such spectral resonances, the optimum extinction ratio for the transmission dips is given by 47.4 dB, this being determined using an index liquid to cover the tapered MCF. The resonant dips move to a greater extent at longer wavelengths, with the optimum tuning efficiency of 392 nm/RIU for index sensing. The split evanescent fields respectively attract the excited upconversion nanoparticles in the liquid to be linearly aligned and running down the tapered region over the fiber surface, emitting green light with 60° symmetry. The charged nanoparticles were periodically self-organized, with a period of around 1.53 µm. The parallel lines, with 60° rotational symmetry, can be useful for (1) indicating the exact locations of the side-cores or orientations of the tapered MCF; (2) as precision alignment keys for micro-optical manipulation; and (3) enhancing the upconversion light, or for use in lasers, coupling back to the MCF. The split evanescent fields can be promising for developing new evanescent field-based active and passive fiber components with nano-structures.
Measuring the BRDF and radius of curvature with patterned illumination
Authors: Inoue Shinichi , Tsumura Norimichi
Published: March 2021

In this study, we propose a method to measure simultaneously the bidirectional reflectance distribution function (BRDF) and the radius of curvature of a curved surface. The surfaces of pre-molded products or artworks are not always flat. The measurement targets were a planar surface and convex surfaces with constant radiuses of curvature. We developed and experimented with an apparatus that uses patterned illumination and a collimator optical system. The results show that BRDF and radius of curvature can be measured on a curved surface. In future work, we are developing a method to accurately estimate the BRDF of a planar surface from the measured BRDF and radius of curvature.
Attribute-based multiuser authentication scheme between IoT devices for 5G environment
Authors: Su Jeong Yoon , Tae Kim Yong , Cheol Park Gil
Published: March 2021

Background/Objectives: Due to the development of mobile communication technology, infrastructure construction from 4G to 5G service, which is currently being serviced, is actively under way. In particular, as the types and functions of mobile phones and IoT devices using 5G services are diversified, mutual authentication technology among multiple users is required.Methods/Statistical analysis: In this paper, we propose a multi - user authentication scheme which can efficiently mutually authenticate different types of mobile phones and IoT devices that are provided with 5G service. The proposed method minimizes the authentication delay time because it identifies the authentication security parameter δ of multiple users requesting authentication to the server as a polynomial coefficient. As a result of the performance evaluation, the proposed method showed an average improvement of 9.3% in authentication processing time and 5.5% lower overhead than the existing method. In addition, the multiuser authentication latency was improved by 6.1% on average compared with the existing scheme.Findings: The proposed scheme minimizes the user 's authentication delay time by constructing the users who simultaneously request the 5G service into a subnet and then applying the authentication security parameter δ constituting each subnet to n - bit and applying it to the polynomial coefficients. Especially, for multi - user authentication, the proposed scheme divides the authentication path into two paths (main path and secondary path) to guarantee user authentication and integrity. The proposed scheme is suitable for mobile phones and IoT devices that use low power because it generates keys without performing additional cryptographic algorithms like conventional techniques when performing multi - user authentication.Improvements/Applications: In future research, we plan to apply the proposed method to the actual environment based on the results of this study.
Facial region detection robust to changing backgrounds
Authors: WooJang Seok , Byun Siwoo
Published: March 2021

Background/Objectives: These days, many studies have actively been conducted on intelligent robots capable of providing human friendly service. To make natural interaction between humans and robots, it is required to develop the mobile robot-based technology of detecting human facial regions robustly in dynamically changing real backgrounds.Methods/Statistical analysis: This paper proposes a method for detecting facial regions adaptively through the mobile robot-based monitoring of backgrounds in a dynamic real environment. In the proposed method, a camera-object distance and a color change in object background are monitored, and thereby the skin color extraction algorithm most suitable for the measured distance and color is applied. In the face detection step, if the searched range is valid, the most suitable skin color detection method is selected so as to detect facial regions.Findings: To sum up the experimental results, algorithms have a difference in performance depending on a distance and a background color. Overall, the algorithms using neural network showed stable results. The algorithm using Kismet had a good perception rate for the ground truth part of an original image, and a skin color detection rate was greatly influenced by pink and yellow background colors similar to a skin tone, and consequently an incorrect perception rate of background was considerably high. With regard to each algorithm performance depending on a distance, the closer a distance with an object was to 320cm, the more an incorrect perception rate of a background sharply increased. To analyze the performance of each skin color detection algorithm applied to face detection, we examined how much a skin color of an original image was detected by each algorithm. For a skin color detection rate, after the ground truth for the skin of an original image, the number of pixels of the skin color detected by each algorithm was calculated. In this case, the ground truth means a range of the skin color of an original image to detect.Improvements/Applications: We expect that the proposed approach of detecting facial regionsin a dynamic real environment will be used in a variety of application areas related to computer vision and image processing.
Construction of remote control for web based street light pole
Authors: Mo Kim Yong
Published: March 2021

Background/Objectives: It is not easy to ascertain a maximum electricity production in case of solar energy generation and there is problem not to recognize failures for a long time even iffailures occurred in facility. Measures need to be taken not only to check irregularities and replacement time but to maximize overall efficiency of solar energy generation system.Methods/Statistical analysis: It is necessary to build a control system based on web to analysis of various statistics information and real time index visibility. It is also necessary to verify SMS notification in the number of lightning in case of the falling of a thunderbolt, date and time of the occurrence, and correct operation of circuit breaker in the connection board.Findings: It is needed to be introduced the system which not only considers excessive communication cost as well as failure treatment of communication device and replacement cost but also makes full use of a dispersed generating system. Control system which is able to do scientific action of making up for fault and proper monitoring as well as maintenance in a solar power plant is constructed in this study.Improvements/Applications: Smart control system that electricity generation is stopped or reactivated in case of emergency through making an autonomous judgment of difficulties or faulted conditions will be extended. Technology of new renewable energy such as wind power and geothermal power will be applied through enhanced design technology of communication interface.
Methods of ship trajectory data processing for applying artificial neural network in port area
Authors: II Kim Kwang , Myung Lee Keon , Young Ahn Jang
Published: March 2021

Background/Objectives: In Vessel Traffic Service (VTS), prediction of the flow of vessel traffic is essential to serve safety information and control ship traffic. However, it is difficult to predict a ship’s speed due to many external forces and environmental conditions. This study proposes a data processing method to convert ship speed data to categorical data by dividing ship navigating routes into several gate lines.Methods/Statistical analysis: A ship’s trajectory is converted to each route’s gate line speed. To determine the gate line speed, we convertedthe previous and subsequent gate line speeds into category data. The input and output category data were applied to a multilayer perceptron network using as input variablesthe previous speed variance category, ship type, and ship length, and as output variable the subsequent speed variance.Findings: These results are useful because categorical data can be applied to various neural network models. As a result of the conducted experiments, the accuracy of the model improved when many gate lines are included.Improvements/Applications: The study results can be applied topredict ship traffic flow for VTS operators.
Study on non - audible acoustic communication uplink for bidirectional visible light communication
Authors: Han Doohee , Lee Kyujin
Published: March 2021

Background/Objectives: In this paper, we present a problem of conventional unidirectional visible light communication and limited bidirectional visible light communication, and propose a suitable uplink feedback communication structure.Methods/Statistical analysis: In the visible light communication environment using only the conventional LED, bidirectional communication for feedback of user data information between the transmitter and receiver is limited. When all the receiving devices transmit the feedback information through the LED light source, it is inconvenient for the users due to the unnecessary light source generation in the indoor lighting environment due to the characteristics of the visible light communication system performing both the communication and the illumination. In addition, interference due to a plurality of light sources occurs, and the performance of the system is deteriorated.To solve this problem, we propose the uplink system configuration using the non - audible band acoustic wave communication in the visible light communication system.Findings: The uplink transmission is a necessary function for transmitting the feedback information of the terminal, and a transmission scheme capable of ensuring sufficient transmission distance, interference elimination of LED illumination, and power efficiency should be used. In this paper, we have solved the problem of optical interference between downlink transmission and uplink transmission by securing transmission distance using non - audible band acoustic communication.In addition, the problem of the conventional unidirectional visible light communication can be solved by actively transmitting a signal to a channel state change due to communication distance or communication environment change through state information and position information feedback of devices using non-audible sound wave communication.Improvements/Applications: The non-audible sound wave communication uplink system can be applied as fusion technology to various environments such as an IoT network environment requiring a bidirectional network or an indoor small-scale network configuration and a home network configuration.
Application of artificial neural network analysis and decision tree analysis to develop a model for predicting life satisfaction of the elderly in south korea
Authors: Byeon Haewon
Published: March 2021

Background/Objectives: This study developed a prediction model with taking into account various factors that could affect the life satisfaction of the elderly in South Korea by using data mining techniques.Methods/Statistical analysis: This study analyzed the data of 2,111 elderly (879 males and 1, 232 females) who were equal to or older than 60 among 7,761 people completed the Seoul Welfare Pane Study 2010. The life satisfaction, a result variable, was classified as ‘satisfactory’, ‘normal’, and ‘dissatisfactory’ based on the question of ‘how are you satisfied with your current life?’The latent factors of the life satisfaction of the elderly were explored by using the neural network. The decision tree model was constructed by using the classification and regression tree (CART) algorithm.Findings: Subjective friendship, subjective health status, subjective family relationship, and the highest level of education were significant classification variables. The most predominant predictive variable was subjective friendship. Moreover, it was predicted that ‘the elderly with good subjective friendship and subjective health’ and ‘the elderly with good subjective friendship, subjective health, and family relationship and whose highest level of education was higher than middle school graduate’ would be groups with high life satisfaction.Improvements/Applications: It is necessary to expand the perceived social network support for promoting the family relationship and friendship as well as the health enhancement in order to improve the life satisfaction of the elderly
Development of mobile control system for lighting tower in golf courses
Authors: Ho Kim Yong , IL Chang Hui
Published: March 2021

Background/Objectives: It is a common for existing golf courses to manage all lighting facilities in batches because it is hard to controllighting individually. That is very much part of the golf courses and forces the whole golf course to light on even though play was finished due to the difficulty of real time checking situationMethods/Statistical analysis: Lighting control device and method in this study are provided not only to control remotely individual lighting installed each hole in golf course but to inspect failure of lighting. There is no longer to stay golf course in person to control lighting system.Findings:Lighting control device and method to be able to control individual lighting installed each hole in golf course is provided to response for the problem in a waste of electricity after playing. User device makes it possible to remotely control lighting and inspect failure of itImprovements/Applications: It can expect to reduce golf course operation management cost by building a smart tower remote control system
Zadoff-chu sequence based preamble design of fbmc/oqam for 5g
Authors: Krishna Namani Vamshi , Arthi R
Published: March 2021

The Spectrum effectiveness for 5G networks can be accomplished by Filter Bank Multi Carrier / Orthogonal Quadrature Amplitude Modulation (FBMC / OQAM) that avoids the benefit of guard band. FBMC is very considerate to Carrier Frequency Offset (CFO) and Timing Offset (TO). This paper suggests Zadoff-chu (ZC) sequence based preamble or pilot is accustomed to design the FBMC frame for synchronize more with receiver to achieve sufficient channel inference and phase tracking which reduces the carrier frequency and timing synchronization. This method helps to influence the out of band emissions and conceive non-orthogonal waveforms to investigate the overall system performance such as Bit Error Rate (BER) over AWGN channels. The performance measuresbeing Complementary Cumulative Distribution Curve (CCDF) for FBMC signal with different multicarrier to evaluate the Peak to Average Power Ratio (PAPR) has been achieved by simulation. The simulation outcomeshows that FBMC outperforms well when analyzed with other multicarrier systems.
Design of high performance, low power sub thresholds ram using source coupled logic for implantable applications.
Authors: Vasudeva Reddy T , B.K. Madhavi Dr
Published: March 2021

Low power circuits functioning in sub threshold were proposed in earlier seventies. Recently, growing with the need of low power consumption, the low power circuits have became more attractive. However, the act of sub threshold design logics has become sensitive to the supply voltage & process variations like temperature and so on. In sub threshold region of operations the supply voltage (Vgs) is less than the threshold (Vth).This leads to less power dissipation in over all circuit, but drastically increment in propagation delay. The major intention of the paper is to offer new low power & less delay digital circuits. SRAM is the major power drawing element and dissipation is about 40% in total power. The primary objective is to design of sub threshold SRAM design, Functionality and performance is estimated from the power and delay.The second objective is to offer novel Source coupled logic based SRAM (ST-SC SRA) M & Operating these design under sub threshold operating region. Performance is analyzed through power and delay. Finally comparing the traditional sub threshold SRAM with source coupled based SRAM in power and delay on par with the performance. Discussing some of the applications, where there is a requirement of less power and delay.
Design and analysis of key shaped wearable textile antenna
Authors: Bano Nausheen , Kumar Singh Vinod , Kumar Bhoi Akash , Sharma Sanjeev
Published: March 2021

The proposed antenna is designed to achieve high gain and wide band with partial ground. In this paper, textile wearable antennas work-ing in the craved range of frequency are fabricated and demonstrated. Simulated and measured reflection coefficient, directivity and radi-ation characteristics have been studied. CST is used for design & simulation of existing antenna with design frequency 3GHz.
Power factor correction using capacitors & filters
Authors: Subramanian Karthik , Tandon Shantam
Published: March 2021

Power factor is the ratio of the real current or voltage received by a load to the root mean square (rms) value of the current or voltage that was supposed to be acquired by the same load. The fact that the two become different is due to the presence of reactive power in the circuit which gets dissipated.Improving the power factor means reducing the phase difference between voltage and current. Since majority of the loads are of inductive nature, they require some amount of reactive power for them to function. Therefore, for the better use of electrical appliances with minimum amount of electrical consumption, the power factor should necessarily be increased and should be brought near to 1. This can be easily done by the help of Automatic Power Factor Correction Capacitors and Active filters.
A Comparative study of durability property on compact tension specimen with unique CFRP and inhomogeneous iron through analysis
Authors: Ho Lee Jung , Ung Cho Jae
Published: March 2021

Most damage of mechanical structures is due to cracks within the structure. This study is to develop the design of safer structures with strength characteristics by material. We have performed 3D modeling for compact tension specimen such as CFRP material, stainless steel and aluminum alloy, and stainless steel and copper alloy as inhomogeneous material. The boundary conditions are applied to each CFRP and compact tension specimen model with inhomogeneous material and the identical conditions are also applied to each specimen model. The simulation tension analysis has been carried for this study to investigate the strength characteristic. The inhomogeneous material in mechanical structure can be maximized with durability and material strength combined with the advantages of each metal. The material used for these mechanical structures is an essential factor. CFRP made of carbon fiber has been received the attention for a high level of durability and lightweight characteristics. If we apply CFRP material to mechanical structures, we may reduce deformation and stress that occurs, maximize durability of mechanical structures, and prevent deformation and damage. Comparing each specimen model, we can consider the CFRP compact tension specimen model to be the most suitable material for real application as its maximum deformation and maximum equivalent stress turned out to be lower than the other inhomogeneous material specimen models. We could find out that although it is a single material, it possesses a stronger durability and strength characteristic compared to inhomogeneous material combined with the advantages of each material. In this study, the durability and strength characteristics of specimen models are thought to be improved by applying simulation analysis after designing compact tension models for each material.
A Study on improving the durability of drone according to the area of impact applied with finite element analysis method
Authors: Kwang Choi Kye , Ung Cho Jae
Published: March 2021

The objective of this paper is to identify the dangers of damage on drones according to the area of impact and obtain the basic data for improving the durability. The durability by impact according to the weight and speed of the large-size drone is calculated and analyzed using a finite element analysis method with 3D model according to the area of impact. For the analytical results, the possibility of fracture is identified and weak areas are improved through the distribution of equivalent stress and deformation analysis using polyester resin, which is a material used for the drone. The equivalent stresses applied to drones in head-on impact and broadside impact were 296.22MPa and 349.36MPa respectively. The broadside impact producing the highest fracture stress of over 300MPa and the bottom part of the battery pack is limited to a fairly narrow area, so the improvements can be made by reinforcing this area. The great damage may occur from rear impact as the results show 828.28MPa, which is much higher than the fracture stress at rear impact to be the greatest drawback. Also for the deformation results, the values of head-on impact and broadside impact were in the safety range according to the elongation rate, while the drone greatly suffered from deformation and damage in rear impact. At the simulation analysis, the change of material must also be considered along with the change in design for rear collision. It is thought to obtain the basic data for future designing of large-sized drones by referring the results of this research, and it may contribute to the improvement of drone durability. By applying this study result to the drone, it is thought to contribute to the improvement on the durability of drone design due to the area of impact.
Optimal design for improving torque performance of permanent magnet motor
Authors: Kyoung Bang Tae , Hun Shin Kyung , In Lee Jeong , Han Cheol , Kook Cho Sung , Wook Cho Han , Young Choi Jang
Published: March 2021

Background/Objectives: This paper deals with the optimal design of the BLDC motor considering a rotor structure that is used to electrically drive tools. Generally, electrically driven tools employ the BLDC motor, which should be able to operate in high-speed and high-vibration environments. However, it has the disadvantages of a high torque ripple and significant waveform fluctuation. Therefore, it is necessary to optimize it according to the usage condition.Methods/Statistical analysis: In improving the torque performance, this study performed the optimization process by employing the Taguchi method, which can achieve a robust design based on the design variables. In the optimization process, the objective functions are set using a weighting ratio depending on the importance of the objective function as back EMF, torque performance, and loss. Through the optimization process, the optimal design point that improved the performance of the objective function is derived. The improved design that applied the optimal design point is compared with the original design by using the finite element method (FEM) analysis results.Findings: In this study, the optimum design of the motor according to the design variables and the objective function is derived through the optimum design method using the Taguchi method by adopting the motor for the electrically driven tool as the interior permanent magnet type BLDC motor and the FEM results. Moreover, by comparing the analysis results with the optimized model and the initial model, the optimum design point that satisfies the restriction specification and the rated specification was found.Improvements/Applications: The optimum design point was found by using the Taguchi method and the loss and torque characteristics were improved.
A Study on characteristics improvement of concentrated flux IPM BLDC motor using the flared-shape rotor Structure with Ferrite Magnets
Authors: Young Yoon Keun
Published: March 2021

Background/Objectives: This paper proposes the alternative possibilities that the flared-shape rotor structure of IPM BLDC motor has the similar high performances as the basic IPM BLDC motor that has the spoke structure with ferrite magnet.Methods/Statistical analysis: The proposed rotor structure has the structural feature of ferrite magnets which has inserted as the flared shape in the rotor core. Through the finite element analysis, the performances of the proposed flared-shape IPM BLDC motor has compared with the basic spoke type IPM BLDC motor.Findings: This paper show the comparison with the analysis results of 2D FEM and it has shown that the proposed IPM motor has a substitute for the spoke type IPM motor which requires low cost and high output power. Especially the proposed flared IPM motor has a low pulsation of torque than the basic type IPM motor. So the proposed flared IPM motor has the advantage for acoustic noise and vibration the spoke type IPM motor.Improvements/Applications: The proposed flared-shape IPM BLDC motor is suitable for as electric vehicle and home appliances motor.
Potential Feedstock of Rubber Seed Oil for Biodiesel Production
Authors: Hamzah N. , Mohd Isa S. , Ahmad Tajuddin N.
Published: March 2021

Biodiesel can help to reduce the world‘s dependence on fossil fuels and which also has significant environmental benefits. Biodiesel is a mixture of fatty acid methyl esters (FAME) obtained via transesterification of vegetable oils or animal fats with an alcohol. The rubber seed oil (RSO) is chosen as a potential non-edible vegetable oil for the production of biodiesel. The oil was extracted from the seed by using pressurized liquid extraction (ASE). The percentage rubber seed oil extracted from 2.6 kilograms rubber seed was obtained 35%. The acid value of RSO has reduced from 52.3 mg KOH/g to 0.8 mg KOH/g while FFA% value has reduced from 35% to 1.18% after acid esterification was applied to RSO. The oil was proceed with base transesterification where the triglycerides from the oil were converted into FAME. The optimization of transesterification process was performed in order to determine the optimum conditions that give the highest FAME yield. Result shows that optimum conditions of the transesterification of rubber seed oil were 1:6 of oil to methanol mass ratio ,30 wt% KOH catalyst, 60 oC reaction temperature and 60 minutes reaction time, that offering the highest biodiesel yield of 96%.
Effect of Swirl Number on the Combustion Characteristic of Syngas using FGM Model Simulation
Authors: Samiran N. , N. M. Jaafar M. , T. Chong C. , N. M. Hassan N. , L. M. Tobi A.
Published: March 2021

Synthesis gas (syngas) is one of the potential alternative clean fuel energy in gas-fired boilers swirl burners system. Computational Fluid Dynamic (CFD) simulations were conducted to study the effect of different swirl number on the combustion characteristics of CO-rich syngas in premixed swirl mode using a model boiler swirl burner. The composition of CO-rich syngas is 67.5 % CO, 22.5 % H2, 5 % CO2 and 5 % CH4. Two types of combustion model for simulation analysis were used in this study namely flamelet generated manifold (FGM) and chemical equilibrium (CE) approaches. The CFD results were validated with actual experimental data with the same swirl number. The FGM method shows better agreement with experimental result, hence adopted to model and predict the CO-rich syngas flame characteristic in the reaction zones. The CO-rich syngas was then numerically tested on different type of swirl number including 0.39, 0.59, 0.84, 1.20 and 1.80. Result shows that the angle of flame distribution was apparently equivalence with the vane angle swirler. Swirler with a higher swirl number (1.20 and 1.80) showed lower NO (57%) and lower CO (98%) species compared to the one with a lower swirler number (0.39 – 0.84). Flame with lower swirl number (0.39) exhibited higher temperature, OH and O radical content. Thus, it contribute to the high production of NO and CO species.
Isolation of Four Flavanones from the Leaves of Macaranga Hypoleuca (Rchb.f. & Zoll.) Müll.Arg
Authors: Muhamad Nazeri H. , Ahmat N. , Abdul Khalil K.
Published: March 2021

Macaranga is a large genus belongs to Euphorbiaceae family which commonly distributed in the tropical region of Africa, South-East Asia, China, and India. The plant of this genus contain flavonoids and stilbenes bearing various terpenyl groups including prenyl, geranyl and farnesyl groups. The leaves of M. hypoleuca were collected from reserved forest UiTM Jengka Pahang, Malaysia, and the dried powdered leaves were macerated in methanol at room temperature. The crude methanol extract was subjected to liquid-liquid partition using n-hexane and ethyl acetate to obtain hexane, ethyl acetate and aqueous fractions. The ethyl acetate fraction was semi purified using vacuum liquid chromatography (VLC) to give nine major fractions (MHL1-MHL9). Fraction MHL3 was further purified by column chromatography (CC) and preparative thin layer chromatography (p-TLC) to give two pure compounds, 8-prenylnaringenin (1) and sakuranetin (5,4’-dihydroxy-7-methoxyflavanone) (3). Meanwhile, fraction MHL6 was purified using column chromatography (CC) and p-TLC to yield another two pure compounds, 6-(3-hydroxy-3-methyl)naringenin (2) and 7-O-methyleriodictyol (4). The chemical structure of these isolated compounds were determined based on their 1D and 2D NMR, UV, and IR data. From this study, four flavanones were isolated from the leaves of M. hypoleuca.
Effect of Post-Harvest Preservation and Extraction Methods on Antioxidant Properties of Alternanthera Sessilis Red
Authors: Shaharuddin Syafiqah , Othman Azizah , Nor I’zzah Wan Mohd Zain Wan
Published: March 2021

Herbs with antioxidant properties are usually preserved and extracted before being converted into commercial products. The main focus of this study was to determine the effect of preservation of A. sessilis red as well as extraction method on its antioxidant properties. A. sessilis red was preserved using two different methods; freeze drying and superheated steam drying, followed by extraction with 70% ethanol using conventional extraction and ultrasonic-assisted extraction. Drying in the superheated steam oven displayed shorter drying period of 1 hour compared to freeze drying (several days). Combination of superheated steam drying and ultrasonic-assisted extraction showed the highest extraction yields (12.99%). Results showed that superheated steam drying and ultrasonic-assisted extraction displayed an increase in the total phenolic content. In terms of antioxidant capacity, A. sessilis extracts obtained from superheated steam drying has higher radical scavenging activity (72.39% - 76.70%) than those freeze-dried (60.68% - 65.33%). Meanwhile, ultrasonic-assisted extraction had negatively impacted the radical scavenging activity of the extracts due to the formation of free radicals that are related to acoustic cavitation. As for ferric reducing antioxidant power, both superheated steam drying and ultrasonic assisted extraction yielded extracts with greater capacity. Present result shows that the combination of superheated steam drying and ultrasonic-assisted extraction enhanced total phenolic content by 60% and improved antioxidant activity based on ferric reducing antioxidant power assay
Development of Snack Bar from Black Soybean and Black Rice for Breastfeeding Mothers
Authors: Pramitasari Rianita , Ivana Ignatia , . Yanti
Published: March 2021

Breastfeeding mothers need more nutrients compared to mothers who are not breastfed to maintain quality and quantity of human milk they produce. Black soybean and black rice contain carbohydrate, protein, fat, and other nutrients that needed by breastfeeding mothers. The purpose of this study was to develop a snack bar for breastfeeding mothers. Snack bars were made from three ratio variations of black soybean flour: black rice flour (30:70, 50:50, and 70:30) with baking temperature 150 0C for 20 minutes. They were then subjected to sensory analysis (taste, flavor, color, texture, aftertaste, and overall); physical analysis (hardness, color); and chemical analysis (nutritional analysis, genistein, and daidzein). The results showed that snack bar with ratio 30:70 (black soybean: black rice) was preferred by panelists. Its level of hardness was 6.10±0.01 N. Its color was showed in color index L* = 25.04±1.71, a* = 6.05±0.70, b* = 3.89 ± 0.71, chroma = 6.66±0.25, and hue = 54.70±2.40. One serving (30 gram/serving) of this snack bar contained 16.28 grams of carbohydrate; 3.10 grams of protein; and 6.05 grams of fat. It could suffice 4.98 % of total energy based on Recommended Dietary Allowance of Indonesian breastfeeding mother per day. Meanwhile, the content of daidzein and genistein were 0.09 mg/serving and 1.35 mg/serving, respectively. In conclusion, snack bar from black soybean and black rice can be used as a complementary food for breastfeeding mothers due to its nutrient content and acceptability.
A Comparative Evaluation of Search Engines on Finding Specific Domain Information on the Web
Authors: Azizan Azilawati , Abu Bakar Zainab , Abd Rahman Nurazzah , Masrom Suraya , Khairuddin Nurkhairizan
Published: March 2021

Recently search engines have provided a truly amazing search service, especially in finding general information on the Web. However, the question arises, does search engine perform the same when seeking domain specific information such as medical, geographical or agriculture information? Along with that issue, an experiment has been conducted to test the effectiveness of today’s search engines from the aspect of information searching in a specific domain. There were four search engines have been selected namely Google, Bing, Yahoo and DuckDuckGo for the experiment. While for the domain specific, we chose to test information about the popular fruit in Southeast Asia that is durian. Precision metric has been used to evaluate the retrieval effectiveness. The findings show that Google has outperformed the other three search engines. Nevertheless, the mean average precision value 0.51 given by Google is still low to be satisfied neither by the researcher nor the information seekers.
Optimising Contribution Rate for SOCSO’s Invalidity Pension Scheme: Actuarial Present Value (APV)
Authors: Zaki Awang Chek Mohd , Liana Ismail Isma , Faezah Jamal Nur
Published: March 2021

This study proposes the optimization of the contribution rate for Social Security Organization (SOCSO)’s Invalidity Pension Scheme (IPS). This study aims to statistically analyses the current situation of the contribution fund collection and the claim benefits payment under SOCSO’s IPS. It seeks to develop an actuarial formulation based on the benefits coverage from SOCSO’s IPS. It attempts to determine an optimal contribution rate to support the benefits provided under SOCSO’s IPS using an actuarial approach. It proposes an appropriate contribution rate to be implemented by SOCSO. Currently, the contribution rate for SOCSO’s IPS is 1%, which is shared equally between employer and employee. This contribution rate is directly deducted from the employee’s monthly gross salary. This contribution rate needs to be adjusted upwards by SOCSO soon to ensure that all payments of claims are sufficiently covered. Based on the 9th Actuarial Valuation Report issued by the International Labour Organization (ILO), recent statistics show that immediate revision of contribution rate is necessary to achieve the minimum loss ratio (max 20%) in SOCSO’s IPS funding systems. In this study, the Actuarial Present Value Approach is applied to all benefits under SOCSO’s IPS. SOCSO data from 1985 until 2014 are used in this study. Seven assumptions are made in this study namely mortality rate, salary ceiling, interest rate, retirement age, increment salary rate, age entry, and salary entry. By optimizing the worst-case scenario (single simulation), this study has found that the optimal contribution rate is 2.2% rather than the current 1%. This can be attributed to the fact that since 1969, many changes have occurred in the workplace, working conditions are different and many new jobs have been created. Therefore, an Actuarial Present Value Approach with regards to actuarial modeling was conducted to optimize SOCSO’s IPS contribution rate. In conclusion, an optimal contribution rate of 2.2% should be introduced and implemented in the future as part of the efforts to reduce society’s burden whilst ensuring that adequate protection is provided to the nation’s workforce.
Implementation of IEC 61499 and Model Checking for Drill Simulator
Authors: Izza Ainaa M. Ridza Nur , Alwi Saifulza
Published: March 2021

Reusability of control codes is one of the basic angles in mechanical robotization, especially for the advancement of high dependable control frameworks. In this paper, we examine a general structure and usage of IEC 61499 standard that can be utilized to speak to conveyed control frameworks and rebuilding the control programs. This paper likewise expects to change the current IEC 61131 based model of computerization framework into the models that pursues IEC 61499 standard. We utilize a bore test system as precedent by mimicking the model utilizing Function Block Development Kit (FBDK) in light of IEC 61499. Accordingly, a piece of the control codes can be used for reusable reason to accomplish framework control objective.
Variation of Suction during Wetting of Unsaturated Collapsible Gypseous Soils
Authors: A. H. Al-Obaidi Ahmed , Y. Fattah Mohammed , Kh. Al-Dorry Mohammed
Published: March 2021

Gypseous soils represent as essential soils that exhibit unsaturated behavior that differs completely than their behavior during soaking. Their strength, stiffness, and compressibility are dependent on the degree of saturation.The soil used in this research is disturbed natural gypseous soil having three different percentages of gypsum; 55, 30 and 18%. Nine model tests were conducted to investigate the variation of suction, settlement and total vertical stress with time, also, to study the effect of wetting on the volume change of unsaturated gypseous soil. The soil container used with inner dimensions of (length 700Ã— width 700Ã— height 600 mm). A square footing with (100 mm) sides was used. Models in loose, medium and dense soils were prepared. Watermark monitor data logger model 900M was used, with automatic data collection device that measures soil suction in kPa. The saturation process involved the complete saturation until the suction sensors readings approach to zero. The saturation process was established by allowing the water to infiltrate through the soil in upward-direction with a steady flow and head of 2 m.For all soil models, the time needed to reach the zero suction (saturation state) increased with the increase of the initial dry density. The initial value of suction for all soils increased with decreasing of the initial water content. The drop in the readings of suction may be due to the effect of gypsum content on the adsorption of water that leads to the saturation of the sensors surrounding area.Â Â