Miracle-dz/UniFAR-FTUs huggingface dataset:
Graphene Sensor Based on Surface Plasmon Resonance for Optical Scanning

The experimental and theoretical evaluation of a simple, low cost, and compact footprint, as well as a high resolution graphene plasmonics sensor are presented here for optical scanning. The strong coupling condition between incident light and excited surface plasmon resonance (SPR) of the graphene-SiO2/Si structure is thoroughly utilized to assay the proposed model. The substrate thickness, incident angle, and coupling conditions are considered to obtin optimal results including the highest resolution, and physical and optical properties including graphene thickness. The results show that high-resolution condition can be provided when the chemical vapor deposition monolayer graphene thickness is 0.335 nm, SiO2/Si thickness is 300 nm, and incident angle is $\theta $ = 62.5 °. Moreover, atomic force microscopy (AFM) and scanning electron microscopy (SEM) are employed to obtain and investigate the physical structures. Finally, it is shown that the highest sensitivity can be achieved by a strong coupling condition.
Low-Complexity Coordinated Relay Beamforming Design for Multi-Cluster Relay Interference Networks

Consider a multi-user multi-cluster relay interference network where each cluster contains a source–destination pair communicating through their own dedicated multi-antenna relays. We propose a coordinated relay beamforming design for interference management among relaying clusters, aiming to maximize the minimum signal-to-interference-and-noise ratio (SINR) at destinations, subject to per relay power budgets. We propose a structured relay beam matrix solution based on a weighted sum of two types of beam matrices: zero-forcing (ZF) beamforming and maximum ratio combining (MRC) beamforming, of which we obtain the optimal ZF and MRC beam matrices in closed form. Our proposed beamforming structure allows us to transform the original max–min SINR problem into a low-complexity weight optimization problem, which we solve via the semi-definite relaxation approach. Our solution is highly computationally efficient with the complexity not growing with the number of antennas at each relay. Comparing with the direct approach to obtain relay beam matrices for the original problem, our solution provides a very similar performance but with a significantly lower complexity and thus is scalable and suitable for large-antenna systems. The weights in our relay beamforming solution clearly reveal how the relay power splits and shifts between suppressing inter-cluster interference and maximizing signal beamforming gain as the channel strength or cluster distance changes. The simulation shows that our solution significantly outperforms the MRC-only or ZF-only solution under both the perfect channel-state information (CSI) and imperfect CSI over interference channels.
RFM Based Market Segmentation Approach Using Advanced K-means and Agglomerative Clustering: A Comparative Study

Customer segmentation based on RFM (Recency, Frequency & Monetary) variables is very popular nowadays to partition the customers pursuant to their characteristics and behaviour. Several clustering algorithms have been implemented to segment customers into groups to achieve better clustering results. In this paper a comparative analysis among agglomerative, k-means and advanced version of k-means are carried out for RFM based market segmentation approach. The experimental outputs show that the agglomerative clustering needs a long processing time for large dataset in comparison with k-means and advanced version of k-means clustering. However one crucial advantage of agglomerative clustering is, it does not require to appoint the total number of clusters initially. The segmentation outcomes also exhibit that the advanced version of k-means can effectively reduce the total running time by 27.8% and 97.8% compared to standard k-means and agglomerative clustering respectively and so effectively increases the speed of clustering. It can also produce better clustering results than standard k-means in respect of intra cluster distance and inter cluster distance. Our proposed method of clustering based customer segmentation uses advanced version of k- means which reduces the overall time complexity and performs quite well for large dataset.
Numerical Prediction of Levitation Properties of HTS Bulk in High Magnetic Fields

In this paper, high magnetic fields generated by HTS magnet, instead of permanent magnet, was adopted to enhance the levitation property of HTS bulk on the fact that levitation force is positively related to the magnetic field strength. Based on the generally-accepted H-formulation, a validated 2-D axisymmetric finite element model was established to study and predict the levitation performances of HTS bulk in high magnetic fields. The fishtail effect <italic>J<sub>c</sub></italic>(<italic>|B|,T</italic>) dependence, which is closer to reality demonstrating unique magnetic dependence of HTS critical current in high magnetic fields, was employed to improve the effectiveness of numerical model. The results indicate that the levitation force could be greatly improved by taking magnetic field close to the peak field of fishtail effect <italic>J<sub>c</sub></italic>(<italic>|B|,T</italic>) curve. This work could serve as a vital method to predict the levitation performance of HTS bulk in high magnetic fields and a guide concerning how to choose external field in balance of performance and cost in future applications.
Numerical Simulation Analysis of Microstructure of Dielectric Layers in Capacitive Pressure Sensors

Sensitivity and linearity are important performance metrics of flexible sensors in the application. An effective approach toward improving the performance of capacitive pressure sensors (CPSs) is the appropriate design of the microstructure of the dielectric layer. Using the finite-element modeling in an integration of Abaqus and COMSOL Multiphysics, we propose a methodology to simulate the deformation and capacitance responses of CPS upon external pressure; the numerical results agree well with the experimental data. With the attempt to improve the performance of widely used pyramidal and cylindrical microstructure-based CPS, the effects of microstructure geometric parameters and mechanical property of materials, such as the elastic modulus, length of hemline, sidewall angle, height, and size on the pressure response, were investigated, and the sensitivity and nonlinear error were also analyzed. It has been found that the sensitivity and linearity are more sensitive to elastic modulus and are less sensitive to height. With the same sensitivity, the cylinders-based CPSs have higher linearity, while the pyramids-based CPSs have larger pressure measuring range. The obtained results could provide reference information for the design of CPS with improved application characteristics.
Performance Analysis of Perovskite Solar Cells with Different Structures

Perovskite solar cells (PSCs) have recently emerged as a promising candidate for photovoltaic technology because of their potential low cost with considerable power conversion efficiency. In this paper, the performance of PCSs is investigated using a physics based analytical model considering important parameters. Two basic structures (i.e., p-i-n and n-i-p) of PSC are considered for this work to find out the optimal design parameters. The changes of the short circuit current density, open circuit voltage, efficiency along with the J-V characteristics curves for both structures of PSCs are shown here as performance indicating parameters. This analysis would help to understand the basic physical parameters responsible for increasing the efficiency of PSCs and find out their optimal design parameters.
Development of Swallowing-Movement-Sensing Device and Swallowing-State-Estimation System

In elderly nursing care, various food-related problems, such as low nutrition, dehydration, binge eating, aspiration, and suffocation, arise. To prevent such problems, caregivers must continuously monitor elderly patients’ swallowing of food/water, which is burdensome. Hence, a monitoring system that can automatically estimate whether an elderly patient has swallowed food, water, or a highly viscous bolus is required. In this paper, we propose a sensing device based on the bi-directional electret condenser microphone that measures vibrations due to swallowing, along with an estimation system that estimates elderly swallowing behavior utilizing the developed sensing device. To verify the validity of the proposed method, we perform verification experiments with four swallowing states <inline-formula> <tex-math notation="LaTeX">$\text{f}_{1}$ </tex-math></inline-formula>–<inline-formula> <tex-math notation="LaTeX">$\text{f}_{4}$ </tex-math></inline-formula> corresponding to swallowing of nothing, tea, tea with thickener, and rice cake, respectively. The proposed method is validated based on the estimation of <inline-formula> <tex-math notation="LaTeX">$\text{f}_{1}$ </tex-math></inline-formula>–<inline-formula> <tex-math notation="LaTeX">$\text{f}_{4}$ </tex-math></inline-formula>, and the accuracies of 0.99, 0.81, 0.84, and 0.91, respectively, are achieved. Therefore, this technique can be feasibly applied in elderly nursing care.
A Hybrid Infrastructure of Enterprise Architecture and Business Intelligence & Analytics for Knowledge Management in Education

Advances in science and technology, the Internet of Things, and the proliferation of mobile apps are critical factors to the current increase in the amount, structure, and size of information that organizations have to store, process, and analyze. Traditional data storages present technical deficiencies when handling huge volumes of data and are not adequate for process modeling and business intelligence; to cope with these deficiencies, new methods and technologies have been developed under the umbrella of big data. However, there is still the need in higher education institutions (HEIs) of a technological tool that can be used for big data processing and knowledge management (KM). To overcome this issue, it is essential to develop an information infrastructure that allows the capturing of knowledge and facilitates experimentation by having cleaned and consistent data. Thus, this paper presents a hybrid information infrastructure for business intelligence and analytics (BI&A) and KM based on an educational data warehouse (EDW) and an enterprise architecture (EA) repository that allows the digitization of knowledge and empowers the visualization and the analysis of dissimilar organizational components as people, processes, and technology. The proposed infrastructure was created based on research and will serve to run different experiments to analyze educational data and academic processes and for the creation of explicit knowledge using different algorithms and methods of educational data mining, learning analytics, online analytical processing (OLAP), and EA analytics.
Design of Wideband In-Phase and Out-of-Phase Power Dividers Using Microstrip-to-Slotline Transitions and Slotline Resonators

A new class of in-phase and out-of-phase power dividers with constant equal-ripple frequency response and wide operating bandwidth is presented in this paper. The proposed design is based on microstrip-to-slotline transitions and slotline resonators. A slotted T-junction is adopted to split the power into two parts and obtain wideband isolation between the two output signals at the same time. The characteristic impedance of the transitions and resonators determines the operating bandwidth and in-band magnitude response. By reversing the placement direction of the slotline-to-microstrip transition, the electrical field is reversed, thus resulting in out-of-phase responses between output ports. A thorough analysis of the relations between the structure and the characteristic functions is provided to guide the selection of parameters of the structure in order to meet the design objectives. In the structure, simulation and measurement are conducted to verify the design method. For both in-phase and out-of-phase cases, more than 110% bandwidth has been achieved with excellent matching at all ports and isolation of output signals. Constant in-band ripple is obtained within the operating band of the power dividers, indicating that the proposed design can realise minimal power deviations, which is extremely desired in wireless systems.
Mammalian Oocyte Quality in Relation to Proteome at Different Stages of Development: An Update

In the course of growth and maturation of oocyte, numerous maternal mRNA gets accumulated which eventually contribute to its developmental competence to get fertilized. Most of the mRNA among these forms complex with protein, and remain silent as ribonucleoprotein. Message ribonucleoprotein gets selectively translated according to need during specific stages of growth phase (Hafidh et al., 2011). The exact amount of protein expression in oocyte varies according to species and stage of oocyte which is still poorly understood. Although it is evidenced that regulation of translational activity is vital for development and maturation of oocyte (MacNicol et al., 2010).
Dual-Voltage-Rectifier-Based Single-Phase AC–DC Converters With Dual DC Bus and Voltage-Sigma Architecture for Variable DC Output Applications

Novel single-phase ac–dc converters based on dual-voltage-rectifier (DV-rectifier) and voltage-sigma architecture is proposed in this paper. Dual dc-buses, i.e., a constant dc voltage bus and an adjustable dc voltage bus, are provided by the DV-rectifier. Voltages of the two dc-buses are stacked together on the output port through down-stream dc–dc transformers (DCXs). The dc output voltage is controlled by regulating the voltage of the adjustable dc-bus of the DV-rectifier. Therefore, voltage regulation is not required for the DCXs, which can always operate at their optimized operation point to ensure high efficiency. Since the voltage of the adjustable dc-bus is lower than the constant dc-bus, multi voltage-level characteristics can be obtained with the DV-rectifier, which is benefit for reduction of switching losses and improvement of conversion efficiency. In order to achieve current regulation of ac input port and voltage regulation of the two dc-buses simultaneously, multimode operation, and smooth mode transition strategies are proposed for the DV-rectifier. Operation principles, control strategies, and characteristics of the DV-rectifier and DCX-based ac–dc converter are analyzed in detail. Feasibility and effectiveness of the proposed solutions are verified with experimental results.
Recognizing Food Places in Egocentric Photo-Streams Using Multi-Scale Atrous Convolutional Networks and Self-Attention Mechanism

Wearable sensors (e.g., lifelogging cameras) represent very useful tools to monitor people’s daily habits and lifestyle. Wearable cameras are able to continuously capture different moments of the day of their wearers, their environment, and interactions with objects, people, and places reflecting their personal lifestyle. The food places where people eat, drink, and buy food, such as restaurants, bars, and supermarkets, can directly affect their daily dietary intake and behavior. Consequently, developing an automated monitoring system based on analyzing a person’s food habits from daily recorded egocentric photo-streams of the food places can provide valuable means for people to improve their eating habits. This can be done by generating a detailed report of the time spent in specific food places by classifying the captured food place images to different groups. In this paper, we propose a self-attention mechanism with multi-scale atrous convolutional networks to generate discriminative features from image streams to recognize a predetermined set of food place categories. We apply our model on an egocentric food place dataset called “EgoFoodPlaces” that comprises of 43 392 images captured by 16 individuals using a lifelogging camera. The proposed model achieved an overall classification accuracy of 80% on the “EgoFoodPlaces” dataset, respectively, outperforming the baseline methods, such as VGG16, ResNet50, and InceptionV3.
Fenomena Fashion Hijab dan Niqab Perspektif Tafsir Maqāsidi

Hijab fashion has become a growing trend in Indonesia, leading to the emergence of various new hijab styles. These new styles have influenced more women to wear a hijab; however, their motivation to wear one is not merely to cover their head, but also to immerse in the current hijab trend. It is, thus, important to investigate the real purposes of hijab by referring to the Quran, hadith, and the views of ulema (Muslim scholars). This research is library research employing a qualitative approach. It discusses the hijab fashion from the maqāṣidi interpretation. Through this interpretation, it was found that covering up the ‘ aurah’ (forbidden parts of body to be exposed) is part of hifẓ karāmah (maintaining honor). There are three purposes of wearing a hijab: 1) To cover oneself physically and mentally, 2) To protect humans from climate hazards and social harms (bilateral function), 3) To improve one’s appearance for positive intentions (additional function). Abstrak Fenomena fashion hijab semakin berkembang di Indonesia dan melahirkan trend baru dalam berhijab. Dengan banyaknya mode hijab yang ada memicu semangat para wanita untuk berhijab, akan tetapi pemakaian hijab di sini tidak semata-mata untuk menutup aurat, tetapi ada unsur mengikuti mode di dalamnya. Oleh sebab itu penting untuk dikaji mengenai konsep berhijab yang sebenarnya dengan merujuk pada al-Qur’an, hadis serta pendapat ‘ulama. Tulisan ini membahas mengenai fashion hijab ditinjau dari perspektif tafsir maqāṣidi . Jenis penelitian ini adalah penelitian kepustakaan yang menggunakan pendekatan kualitatif. Melalui tafsir maqāṣidi , dapat diketahui bahwasanya menutup aurat adalah bagian dari hifẓ karāmah (menjaga kehormatan). Ada tiga fungsi dari menutup aurat. Pertama, fungsi dasar, yakni menutup aurat secara zahir dan batin. Kedua, fungsi ganda (bilateral) yang melindungi manusia dari bahaya iklim dan kerugian sosial. Ketiga, fungsi tambahan, yakni menutup aurat salah satu sarana untuk menghias diri dan berpenampilan bagus dalam hal positif.
Improved Closed-Loop Flux Observer Based Sensorless Control Against System Oscillation for Synchronous Reluctance Machine Drives

Flux-linkage based sensorless control method is well-known and has been widely used in the control of electrical machines. The closed-loop flux observer (CLFO), which is the adaptive combination of the machine voltage and current models, is commonly adopted. It can cover a wide speed operation range and was considered to be able to solve the dc drift and initial value problem associated to the pure integrator used in the observer. However, it is reported in this paper that this popular CLFO cannot always work as expected. In some situations, dc-offsets cannot be removed by this flux observer, causing large system oscillation at fundamental frequency and is very harmful to the drive system. This important issue has not been reported and discussed in the existing literatures of the CLFO. In this paper, this phenomenon is experimentally illustrated and solution to damp this harmful oscillation is proposed and verified experimentally on a synchronous reluctance machine drive system.
Analysis of Antenna Radiation Characteristics Using a Hybrid Ray Tracing Algorithm for Indoor WiFi Energy-Harvesting Rectennas

In this paper, the radiation features of indoor WiFi energy-harvesting antennas are analyzed, and the design guidelines that enhance receiving power are proposed. It is acknowledged that an RF energy-harvesting antenna is desired to depict circular polarization (CP) and omnidirectional patterns, as ambient sources are omnipresent; however, the polarization and half-power beamwidth (HPBW) of the antenna are inconclusive in earlier studies. To clarify the requirement of the radiation characteristics for indoor environments, the receiving performance of six antennas with different HPBWs and polarizations is analyzed. The research methodology is a hybrid ray tracing algorithm that integrates image and shooting-and-bouncing-ray methods. These antennas are placed at different locations in a room, and the orientations are evenly and uniformly sampled. The receiving performance of each antenna is cast into cumulative density functions, which clarify the antenna that provides the maximum amount of successful receptions at specified energy-harvesting sensitivity. The simulated results are verified by performing the measurement. Surprisingly, the results indicate that CP and omnidirectional patterns cannot offer the most favorable receiving performance. In contrast, linear polarization and narrow HPBWs with high gain are desired in most of the scenarios, even though the directions of signal arrival have been uniformly sampled.
Ge/Oxide Structured Programmable Phototransistors

A programmable phototransistor built with two Ge/GeOx/AlOx:HfOx/Pd structured RRAM devices is developed. The photon-induced current increase through the Ge/Oxide structured RRAM is explained by the photon-assisted tunneling mechanism when the RRAM is at the low-resistance state. Furthermore, the good output and transfer characteristics, which could be controlled by the light, of the phototransistor are also demonstrated. Since, when both RRAM devices are at the high-resistance state, the structure does not show any optical sensitivity, the phototransistor realized in this letter is programmable. This programmable phototransistor may significantly enhance the performance of photon-electric integrated circuits and reduce the circuit design and fabrication cost.
A Novel 3-dB Waveguide Hybrid Coupler for Terahertz Operation

This letter presents our investigation into a 3-dB waveguide hybrid coupler of a novel structure in the submillimeter frequency band. The proposed coupler has only three coupling branches with a circular cutout at the top and the bottom on both sides of the main branch and is of compact size. The simulation shows that the proposed design has eased the machining difficulty by providing more tolerance to fabrication errors. The simulation also shows that the amplitude imbalance of the proposed hybrid branch is 25% less than that of the traditional three-branch hybrid structure. The proposed coupler structure is verified in experiment through measuring a fabricated 90° waveguide coupler at a center frequency of 195 GHz with approximately 13% bandwidth where the amplitude imbalance is less than 0.3 dB. The simulated and measured S-parameters have shown that the amplitude and phase imbalances are within 0.3 dB and 4°, respectively, with an isolation and return loss of 17 dB.
Linearity Improved Doherty Power Amplifier Using Non-Foster Circuits

In this paper, linearity improved Doherty power amplifier (DPA) is proposed for linearity improvement by modifying the input capacitor value of peaking amplifier. The non-foster circuits are substituted for the conventional $\lambda /4$ transmission line in front of peaking amplifier, which the 90° phase shifter and impedance matching can be performed by the proposed structure. Furthermore, the input capacitor value of peaking amplifier FET can be modified through modifying bias voltage and match resistance of non-foster circuits. Therefore, the AM–PM distortion of peak amplifier is suppressed, and the linearity of total DPA is improved. Compared to a conventional DPA, the third-order inter-modulation distortion of proposed DPA is reduced by 12 dB without cutting efficiency.