Automatic algorithm for determining bone and soft-tissue factors in dual-energy subtraction chest radiography

Lung cancer is currently the first leading cause of worldwide cancer deaths since the early stage of lung cancer detection is still a challenge. In lung diagnosis, nodules sometimes overlap with ribs and tissues on lung chest radiographic images, which are complex for doctors and radiologists. Dual-energy subtraction (DES) is a suitable solution to solve those issues. This article will develop an efficient iterative DES for lung chest radiographic images. Moreover, we propose an automatic algorithm for accurately determining bone and soft-tissue factors for subtraction. The proposed algorithm for determining the bone and soft-tissue factors is based on window/level ratio and radiographic histogram analysis. First, we take the image sampling from the original size 3072 × 3072 to 512 × 512 to reduce the processing time while achieving the bone and soft-tissue factors. Next, we compute the window/level ratio on the soft-tissue image. Finally, we determine the minimum value of the ratio to obtain the optimal soft-tissue and bone factors. Our experimental results show that our proposed algorithm achieves a minimized runtime of 200 ms, outperforming the GE algorithm’s time of 4 s. The runtime of our DES of 6.066 s is shorter than the Fujifilm algorithm of 10 s while visualizing nodules on soft-tissue images and obtaining a similar quality of the soft-tissue images compared with the other algorithms. The academic contributions include the proposed algorithm for determining bone and soft-tissue factors and the optimized iterative DES algorithm to minimize time and dose consumption

Re-derivation of Young’s Equation, Wenzel Equation, and Cassie-Baxter Equation Based on Energy Minimization

Recently, Young’s equation, the Wenzel equation, and the Cassie-Baxter equation have been widely used with active research on superhydrophobic surfaces. However, experiments showed that the Wenzel equation and the Cassie-Baxter equation were not derived correctly. They should be reviewed on a firm physical ground. In this study, these equations are re-derived from a thermodynamic point of view by employing energy minimization and variational approach. The derivations provide a deeper understanding of these equations and the behavior of a contact angle. Also, in applying these equations, the limitations and considerations are discussed. It is expected that this study will provide a theoretical basis for the careful use of these equations on rough or chemically heterogeneous surfaces

Synthetic Aperture Imaging of Contact Acoustic Nonlinearity at Closed Interfaces

Ultrasonic imaging has been widely used as an intuitive recognition method for the detection of defects [1]. To enhance the resolution in ultrasound imaging, various kinds of techniques have been developed. Synthetic aperture focusing technique (SAFT) is one of effective post-processing techniques for the resolution improvement. Many studies have shown that SAFT has high resolution as well as high signal to noise ratio for identifying the characteristics of defects accurately [2]. However, most of the imaging techniques based on linear characteristics of ultrasound could underestimate the size of flaws. In particular, the defects in initial state so called micro cracks or closed interfaces are very difficult to be visualized. In order to visualize these micro defects, it is necessary to adopt novel imaging technique using nonlinear ultrasonic characteristics such as contact acoustic nonlinearity (CAN) effect. This study proposed a nonlinear SAFT based on CAN effect and verified its effectiveness. The experiments with array probe for imaging closed interfaces were carried out. The pressure of the interfaces was increased by a hydraulic press, which resulted in the change of the contact state at the interfaces from open interfaces to closed interfaces. When a fundamental ultrasonic wave is incident at closed interfaces, the CAN effect leads the harmonic generation [3]. The proposed synthetic aperture imaging based on CAN effect was applied to visualize the closed interfaces with respect to the change of the contact interface condition. The results showed that SAFT based on CAN effect was effective for the detection of closed interface. This supports that synthetic aperture imaging techniques based on acoustic nonlinearity had advantages for the diagnosis of structural integrity

What sentiment attracts tourists? Analysis of tourist attractions based on consumer\u27s sentiment

This study tried to derive meaningful insights from consumers\u27 sentiments about tourist attractions. First, through descriptive statistics, seven sentiments representing tourist attractions were identified, and the unique sentiments about certain tourist attractions were identified. On the basis of the network analysis results, four interesting travel routes based on the sentiment theme were constructed, and four insights on the sentiment were presented. Finally, through the regression analysis, one negative word, two positive words, and three network centrality measures that significantly affect the number of visitors were identified. By applying social network analysis, more specific and differentiated conclusions have been drawn. It also provided useful implications for tourist attractions

A Study on ESD Protection Circuit Applying Silicon Controlled Rectifier-Based Stack Technology with High Holding Voltage

In this study, an improved Electrostatic Discharge (ESD) protection circuit with low trigger voltage and high holding voltage is proposed. ESD has become a serious problem in the semiconductor process because the semiconductor density has become very high these days. Therefore, much research has been done to prevent ESD. The proposed circuit is a stacked structure of the new unit structure combined by the Zener Triggering (SCR ZTSCR) and the High Holding Voltage SCR (HHVSCR). The simulation results show that the proposed circuit has low trigger voltage and high holding voltage. And the stack technology is applied to adjust the various operating voltage. As the results, the holding voltage is 7.7 V for 2-stack and 10.7 V for 3-stack

Both Basic and Acidic Amino Acid Residues of IpTxa Are Involved in Triggering Substate of RyR1

Imperatoxin A (IpTxa) is known to modify the gating of skeletal ryanodine receptor (RyR1). In this paper, the ability of charged aa residues of IpTxa to induce substate of native RyR1 in HSR was examined. Our results show that the basic residues (e.g., Lys19, Lys20, Lys22, Arg23, and Arg24) are important for producing substate of RyR1. In addition, other basic residues (e.g., Lys30, Arg31, and Arg33) near the C-terminus and some acidic residues (e.g., Glu29, Asp13, and Asp2) are also involved in the generation of substate. Residues such as Lys8 and Thr26 may be involved in the self-regulation of substate of RyR1, since alanine substitution of the aa residues led to a drastic conversion to the substate. The modifications of the channel gating by the wild-type and mutant toxins were similar in purified RyR1. Taken together, the specific charge distributions on the surface of IpTxa are essential for regulation of the channel gating of RyR1