Integrated circuit design for physical unclonable function using differential amplifiers

A physical unclonable function (PUF) based on process variations on silicon wafers is a very promising technology which finds various applications in identification and authentication, but only a few integrated circuits have been reported so far. As those circuits are vulnerable to power supply noises, switching noises and environmental variations, they lead to a reliability issue such as time-varying or metastable responses. To resolve this issue, this letter proposes a new integrated circuit design for PUFs using differential amplifiers. The feasibility of the proposed circuit has been theoretically analyzed and validated through HSPICE simulations for the previous and proposed circuits.     

Spectrum‐Based Color Reproduction Algorithm for Makeup Simulation of 3D Facial Avatar

Various simulation applications for hair, clothing, and makeup of a 3D avatar can provide more useful information to users before they select a hairstyle, clothes, or cosmetics. To enhance their reality, the shapes, textures, and colors of the avatars should be similar to those found in the real world. For a more realistic 3D avatar color reproduction, this paper proposes a spectrum‐based color reproduction algorithm and color management process with respect to the implementation of the algorithm. First, a makeup color reproduction model is estimated by analyzing the measured spectral reflectance of the skin samples before and after applying the makeup. To implement the model for a makeup simulation system, the color management process controls all color information of the 3D facial avatar during the 3D scanning, modeling, and rendering stages. During 3D scanning with a multicamera system, spectrum‐based camera calibration and characterization are performed to estimate the spectrum data. During the virtual makeup process, the spectrum data of the 3D facial avatar is modified based on the makeup color reproduction model. Finally, during 3D rendering, the estimated spectrum is converted into RGB data through gamut mapping and display characterization.     

A dead-time minimization algorithm for improving the output characteristics of the PWM inverter

The dead time in an inverter is necessary to prevent the short circuit of the DC source. However, the dead time may cause serious problems such as waveform distortion, voltage drop, increased torque ripple and heating of the motors. In this paper, a dead-time minimization algorithm is proposed for improving the inverter output performance. The adverse effects of the dead time are investigated, focusing on the voltage drop and the distortion factor of inverter output current. The proposed algorithm consists of forbidding unnecessary triggers for the inverter switches that are not turned on although the gate drive signal is impressed. The proposed algorithm is explained in terms of the conduction modes of the output currents. The validity of the proposed method is verified by comparing the simulated and experimental results with those of the conventional methods. It is concluded from the results that the proposed algorithm can reduce the output current harmonics. Further, the output voltage can be equal to the reference value and the number of inverter switchings can also be reduced to 50% compared with those of conventional methods.     

New single-stage low dc bus voltage stress converter for universal line applications

A new single-stage power factor corrected ac–dc converter for universal line applications is proposed in this paper. This converter has a buck topology as a power factor corrector. The dc bus voltage of the proposed converter is always lower than the peak input voltage at any load condition. Therefore, the problem of high dc bus voltage under the light load condition for the single-stage converter is solved, especially in the case of universal line applications. The design equations are presented for the proposed converter and a design example for a 5V 12A application is presented. The theoretical analysis and experimental results show that the dc bus voltage can be limited within 260V and the line input current harmonics can meet IEC 61000-3-2 Class D requirements at any load conditions for the line input voltages from 90 to 260V_ac.     

Potential interference and rain attenuation at 21.4–22 GHz downlink broadcasting satellite signals

World Radio Conference WRC-1992 has allocated the frequency band 21.4–22.0?GHz to regions 1 and 3 to be utilised to carry direct broadcasting satellite (DBS) services. This high-frequency band is more susceptible to rain attenuation, leading to degradation of the signal quality. Moreover, this frequency band is assigned to two different services, i.e. satellite broadcasting and fixed mobile services at the same regions; hence, the impact of intersystem interference in a depredated signal is a critical issue in the DBS receiver. In this study, the effects of rain attenuation on the DBS downlink signals as well as the impact of the potential interference on the reception quality will be estimated. An interference scenario will be introduced to investigate the system performance in both propagation mechanisms of clear-sky and rain conditions.     

Advanced Functional Structure‐Based Sensing and Imaging Strategies for Cancer Detection: Possibilities,Opportunities, Challenges,and Prospects

Cancer is the second most common cause of death in the world. The principal limitations thus far encountered in the clinical practice of probing cancer are diverse and include low sensitivity, time consumption, bulkiness, and cost. In this respect, nanomaterial (NM)‐based sensing techniques are recognized as a superior alternative to efficiently resolve such limitations. A better understanding of NM‐based sensing platforms is thus important so that these novel avenues can easily be explored for clinical applications. These platforms have the merits of high sensitivity, high specificity, rapid response, and easy‐to‐read signals. This review offers a comprehensive survey of NM‐based advanced cancer‐sensing techniques and will help the scientific community establish optimum sensing strategies based on an accurate assessment of the interactions between cancer biomarkers and NM‐based platforms.     

UV‐Curable Silver Electrode for Screen‐Printed Thermoelectric Generator

Fabricating thermoelectric generators (TEGs) using the screen‐printing process has advantages, including mass production, device scalability, and system applicability. However, the thick film formed through the process typically has low film density, and reduced performance, because of the presence of pores in the film created by the vaporization of the resin during high‐temperature annealing. During the soldering process used for thermoelectric module fabrication, the printed solder infiltrates into the screen‐printed electrodes through the micropores in the electrodes, causing cracks of the electrode film and an increase in resistivity. In this paper, an ultraviolet radiation (UV)‐curable process for screen‐printed electrodes is reported. The paste for the electrodes is synthesized by mixing Ag flakes that can be cured at low temperature with a UV resin. Scanning electron microscope images show that the UV‐curing process significantly reduces pores and thereby results in a smooth‐surfaced electrode layer. The film density after crystallization is also enhanced. TEGs composed of 72 couples with UV‐curable Ag electrodes generate a high power density of ≈6.69 mW cm^?2 at a temperature difference of 25 °C; the device resistance is ≈0.75 Ω, and the figure of merit of the device is recorded to be 0.57, which is the highest among the printed TEGs.     

Determinants of the intention to use Buy-Online,Pickup In-Store (BOPS): The moderating effects of situational factors and product type

Despite the wider introduction of the buy online and pick up in-store (BOPS) service by retailers, research on BOPS is still sparse, especially those from the consumer perspective. This paper employs the scenario-based factorial survey method to investigate how the perceived characteristics of innovation and the perceived risk of online shopping influence the consumers’ intention to use BOPS while also considering the moderating effects of situational factors (location convenience) and product type (involvement). Our findings indicated that the consumer perceptions of relative advantage, complexity, compatibility, and risks involved in online shopping are important antecedents to intention to use BOPS, and that these relationships were significantly moderated by locational convenience and product involvement. The implications of the findings and suggestions for future research are discussed in detail.     

Virus‐Templated Self‐Mineralization of Ligand‐Free Colloidal Palladium Nanostructures for High Surface Activity and Stability

In solution‐based synthesis of colloidal nanostructures, additions of ligands, stabilizers, and redox reagents are generally required to obtain desirable structures, though ligands and stabilizers on the surface of nanostructures can substantially affect the surface‐related activity. Accordingly, an extensive rinsing process is usually required to remove residual reagents and stabilizers. This study reports a spontaneous self‐biomineralization of palladium (Pd) ions on a filamentous virus to form ligand‐free Pd nanowires under ambient conditions. No reducing reagents or additional surface stabilizers are used; the genetically modified virus alone supports the polycrystalline Pd nanowires within the nanostructure, maintaining the clean surface even without a rinsing process. The advantage of the ligand‐free Pd nanowires is found in the Suzuki‐coupling reaction, in which the nanowire catalytic activity is maintained after repeated reactions, while conventional Pd colloids undergo surface contamination by the stabilizer and lose their catalytic activity during repeated uses. The ligand‐free surface, high electronic connectivity, and structural stability of the Pd nanowires also allow high sensitivity and selectivity in hydrogen gas sensing analysis. This work emphasizes the importance of the ligand‐free surface of biotemplated nanostructures in maintaining functionalities without surface contamination.     

MIMO-HFM: A MIMO System with Hyperbolic Frequency Modulation for Underwater Acoustic Communication

Reliable transmission and high data rate over underwater acoustic channels are considerably challenging. In this paper, we propose Multiple-Input and Multiple-Output (MIMO) scheme using a Hyperbolic Frequency Modulation (HFM) waveform. Our proposed system combines the advantages of both systems-special multiplexing of MIMO and immunity against Doppler shift of HFM. To increase the spectral efficiency, we employ M-ray HFM and overlapped sub-channels by leveraging the high temporal resolution characteristic. To verify effectiveness of our system, we have designed a theoretically enhanced acoustic simulator, which especially focuses on the reflection phenomenon by utilizing approved reflection loss models. Based on our acoustic simulator, we could verify that our system is robust against for multipath fading and Doppler shifting while keeping the multiplexing benefit of MIMO, while maintaining a very low complexity and system overhead. In addition, the results provide a useful insight for physical layer design in acoustic communication systems.