Artistic Robotic Arm: Drawing Portraits on Physical Canvas under 80 Seconds.

In recent years, the field of robotic portrait drawing has garnered considerable interest, as evidenced by the growing number of researchers focusing on either the speed or quality of the output drawing. However, the pursuit of either speed or quality alone has resulted in a trade-off between the two objectives. Therefore, in this paper, we propose a new approach that combines both objectives by leveraging advanced machine learning techniques and a variable line width Chinese calligraphy pen. Our proposed system emulates the human drawing process, which entails planning the sketch and creating it on the canvas, thus providing a realistic and high-quality output. One of the main challenges in portrait drawing is preserving the facial features, such as the eyes, mouth, nose, and hair, which are crucial for capturing the essence of a person. To overcome this challenge, we employ CycleGAN, a powerful technique that retains important facial details while transferring the visualized sketch onto the canvas. Moreover, we introduce the Drawing Motion Generation and Robot Motion Control Modules to transfer the visualized sketch onto a physical canvas. These modules enable our system to create high-quality portraits within seconds, surpassing existing methods in terms of both time efficiency and detail quality. Our proposed system was evaluated through extensive real-life experiments and showcased at the RoboWorld 2022 exhibition. During the exhibition, our system drew portraits of more than 40 visitors, yielding a survey outcome with a satisfaction rate of 95%. This result indicates the effectiveness of our approach in creating high-quality portraits that are not only visually pleasing but also accurate.

Evaluation of Silk Fibroin/Gellan Gum Hydrogels with Controlled Molecular Weight through Silk Fibroin Hydrolysis for Tissue Engineering Application.

Hydrogel is a versatile material that can be manipulated to achieve the desired physicochemical properties, such as stiffness, pore size, and viscoelasticity. Traditionally, these properties have been controlled through parameters such as concentration and pH adjustments. In this study, we focused on exploring the potential of hydrolyzed silk fibroin (HSF) as a molecular weight-modulating agent to control the physicochemical properties of double-composite hydrogels. We developed a synergistic dual-crosslinked hydrogel by combining ionically crosslinked silk fibroin with gellan gum (GG). The hydrolysis of silk fibroin not only enhanced its hydrophilicity but also enabled adjustments in its mechanical properties, including the pore size, initial modulus elasticity, and relaxation time. Moreover, biocompatibility assessments based on cell viability tests confirmed the potential of these hydrogels as biocompatible materials. By highlighting the significance of developing an HSF/GG dual-crosslinked hydrogel, this study contributes to the advancement of novel double-composite hydrogels with remarkable biocompatibility. Overall, our findings demonstrate the capability of controlling the mechanical properties of hydrogels through molecular weight modulation via hydrolysis and highlight the development of a biocompatible HSF/GG dual-crosslinked hydrogel with potential biomedical applications.

Chirp-Based FHSS Receiver with Recursive Symbol Synchronization for Underwater Acoustic Communication.

In this paper, we propose a covert underwater acoustic communication method that is robust to fading using a chirp signal combined with a frequency-hopping spread spectrum scheme. A fractional Fourier transform, which estimates the slope of the signal frequency variation, is applied to the receiver to enable a robust and reliable symbol estimation with respect to the frequency and irregular phase variations. In addition, since the recursive symbol synchronization can be implemented using a chirp signal, compression and expansion effects due to the Doppler shift can be mitigated. Simulation and lake trials were performed to verify the performance of the proposed method. The simulation was performed by two different methods.

Psychopathological, temperamental, and characteristic factors in adults with remaining childhood attention-deficit hyperactivity symptoms.

OBJECTIVES: To investigate differences in psychopathological, temperamental and characteristic factors between young adults with and without persistent Attention-Deficit Hyperactivity disorder (ADHD) symptoms. METHODS: A total of 429 university students were divided into three groups: persistent adult ADHD (n = 53), only childhood ADHD (n = 56) and healthy controls (n = 320). The Korean Adult ADHD Scale, Korean Wender-Utah Rating Scale, Beck Depression Inventory-II, Beck Anxiety Inventory, Barratt Impulsiveness Scale, Korean Young Internet Addiction Scale, and Temperament Character Inventory-Revised (TCI-R; based on Cloninger's seven factor model of temperament and character) were used to evaluate psychopathological factors. RESULTS: Participants with persistent adult ADHD symptoms had significantly higher levels of childhood ADHD, depression, anxiety and the Internet addiction symptoms than did the only-childhood ADHD and control groups. The adult ADHD group also had significantly higher tendencies toward novelty seeking, harm avoidance, and self-transcendence, as well as low self-directedness and cooperativeness. CONCLUSIONS: Results suggest that persistent ADHD is associated with several unfavourable psychopathological, temperamental and characteristic factors. Therefore, thorough evaluation of these factors for childhood ADHD could help predict prognoses and provide treatment plans for preventing persistent ADHD into adulthood.

Theta-phase gamma-amplitude coupling as a neurophysiological marker of attention deficit/hyperactivity disorder in children.

Theta-phase gamma-amplitude coupling (TGC) between slow and fast oscillations is considered to represent cortico-subcortical interactions. The purpose of this electroencephalographic (EEG) study was to evaluate the diagnostic utility of TGC by comparing the power spectra and TGC at rest between ADHD and control children. Nineteen-channel EEGs were recorded from 97 volunteers (including 53 subjects with ADHD attending a camp for hyperactive children). The EEG power spectra and TGC data were analyzed. Analysis of covariance (ANCOVA) was conducted on the quantitative EEG results between the groups to adjust for sex. Receiver operator characteristic (ROC) analysis was conducted to examine the discriminating ability of each parameter for ADHD diagnosis. The ADHD group exhibited significantly decreased TGC in multiple areas, including frontal (Fp1, F3, F7, F6), temporal (T3), and occipital (O2) areas, compared with the control group. The ROC analysis performed on the TGC data generated the most accurate result among the EEG measures, with an overall classification accuracy of 71.7%. TGC, which reflects the degree of neuronal interactions between functional systems, provides information about an individual's attentional network. Therefore, resting-state TGC is a promising neurophysiological marker of ADHD in children.