• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.179-188
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• 2019

In ultrasound telemedicine, it is important to reduce the size of the data by compressing the ultrasound image when sending it. Ultrasound images can be divided into image context and other information consisting of patient ID, date, and several letters. Between them, ultrasound context is very important information for diagnosis and should be securely preserved as much as possible. In several previous papers, ultrasound compression methods were proposed to compress ultrasound context and other information into different compression parameters. This ultrasound compression method minimized the loss of ultrasound context while greatly compressing other information. This paper proposed the method of automatic segmentation of ultrasound context to overcome the limitation of the previously described ultrasound compression method. This algorithm was designed to robust for various ultrasound device and to enable real-time operation to maintain the benefits of ultrasound imaging machine. The operation time of extracting ultrasound context through the proposed segmentation method was measured, and it took 311.11 ms. In order to optimize the algorithm, the ultrasound context was segmented with down sampled input image. When the resolution of the input image was reduced by half, the computational time was 126.84 ms. When the resolution was reduced by one-third, it took 45.83 ms to segment the ultrasound context. As a result, we verified through experiments that the proposed method works in real time.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.294-299
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• 2007

For efficient and accurate diagnosis of ultrasound images, appropriate time gain compensation(TGC) and dynamic range(DR) control of ultrasound echo signals are important. TGC is used for compensating the attenuation of ultrasound echo signals along the depth, and DR controls the image contrast. In recent ultrasound systems, these two factors are automatically set by a system and/or manually adjusted by an operator to obtain the desired image quality on the screen. In this paper, we propose an algorithm to find the optimized parameter values far TGC and DR automatically. In TGC optimization, we determine the degree of attenuation compensation along the depth by dividing an image into vertical strips and reliably estimating the attenuation characteristic of ultrasound signals. For DR optimization, we define a novel cost function by properly using the characteristics of ultrasound images. We obtain experimental results by applying the proposed algorithm to a real ultrasound(US) imaging system. The results verify that the proposed algorithm automatically sets values of TGC and DR in real-time such that the subjective quality of the enhanced ultrasound images may be sufficiently high for efficient and accurate diagnosis.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.20 no.3
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• pp.175-202
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• 2016

Ultrasound imaging is a widely used tool for visualizing human body's internal organs and quantifying clinical parameters. Due to its advantages such as safety, non-invasiveness, portability, low cost and real-time 2D/3D imaging, diagnostic ultrasound industry has steadily grown. Since the technology advancements such as digital beam-forming, Doppler ultrasound, real-time 3D imaging and automated diagnosis techniques, there are still a lot of demands for image quality improvement, faster and accurate imaging, 3D color Doppler imaging and advanced functional imaging modes. In order to satisfy those demands, mathematics should be used properly and effectively in ultrasound imaging. Mathematics has been used commonly as mathematical modelling, numerical solutions and visualization, combined with science and engineering. In this article, we describe a brief history of ultrasound imaging, its basic principle, its applications in obstetrics/gynecology, cardiology and radiology, domestic-industrial products, contributions of mathematics and challenging issues in ultrasound imaging.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.248-251
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• 1995

Nowadays, the internal images of a human body can be easily provided by the ultrasound imaging, the X-ray CT, or the MRI device, among which the ultrasound imaging device has good resolution for soft tissues of a human body compared with the other devices. Furthermore, the use of ultrasound imaging devices will increase in future especially in the obstetrics, territory, since it does not give harm to the human body. Although several techniques have been investigated until now in order to extract organs from ultrasound images, very few of them have achieved satisfactory results because of low contrast and high noise nature of images. This paper proposes a technique for automatic extraction of the gall bladder area from ultrasound images. The proposed technique first extracts a small reliable area of a gall bladder from an ultrasound image employing smoothing, binarization, expanding and shrinking, and labeling, and then expands the area referring to the binarized version of the original image. The technique is examined its performance by real ultrasound images of a gall bladder and satisfactory results are obtained. Some problems to be solved are discussed finally.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.154-158
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• 2013

Development of dual functional liposome has been studied for cancer theragnostics. Therefore, we focused on ultrasound-sensitive liposomes with doxorubicin (DOX) and gadolinium (Gd) as a theragnostic carrier having a potential for cancer therapy and diagnosis. In this study, Gd(III)-DOTA-modified sonosensitive liposomes (GL) was developed using chemically synthesized Gd(III)-DOTA-DPPE lipid. Sonosensitivity of GL to 1 MHz ultrasound induced 25% of DOX release. The relaxivities ($r_1$) of GL were $7.33-10.34\;mM^{-1}s^{-1}$, which was higher than that of MR-bester$^{(R)}$. Intracellular delivery of DOX from GL by ultrasound irradiation was evaluated according to ultrasound intensity, resulting in increase of uptake of DOX released from ultrasound-triggered GLs compared to GL3 or Doxil$^{(R)}$ without ultrasound. Taken together, this study shows that the paramagnetic and sonosensitive liposomes, GL, is a novel and highly effective delivery system for drug with the potential for broad applications in human disease.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.3
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• pp.200-206
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• 2010

In ultrasound-excited thermography, the injected ultrasound to an object is transformed to heat and the appearance of defects can be visualized by thermography camera. The advantage of this technology is selectively sensitive to thermally active defects. Despite the apparent simplicity of the scheme, there are a number of experimental considerations that can complicate the implementation of ultrasound excitation thermography inspection. Factors including acoustic horn location, horn-crack proximity, horn-sample coupling, and effective detection range all significantly affect the detect ability of this technology. As conclusions, the influence of coupling pressures between ultrasound exciter and specimen was analyzed, which was dominant factor in frictional heating model.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.63-70
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• 2023

Ultrasound-assisted dissolution of U₃O₈ powder in carbonate solution was explored to determine if and how ultrasound act during the dissolution. The variation of U₃O₈ solid particles and uranyl complexes under ultrasound treatment and magnetic stirring was observed in carbonate media. The results show that the use of ultrasound can increase the solubility and dissolution rate of U₃O₈ powder than that under magnetic stirring. The crush of U₃O₈ particles and the reduction of the activation energy (Ea, kJ/mol) of U₃O₈ dissolution reaction were observed, which both play an important role in the ultrasonic-assisted dissolution of U₃O₈ in carbonate-peroxide solution. Meanwhile, there is no observation of the ultrasound effect on the distribution of uranyl species and hydrolysis of uranyl complexes during the ultrasound treatment in carbonate-peroxide solution. Although the generation of ·OH radicals under ultrasound (22 ± 2 kHz) was observed, the oxidation of ·OH had little effect on the dissolution of U₃O₈ in the carbonate-peroxide solution system.

• Journal of Sensor Science and Technology
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• v.31 no.5
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• pp.286-292
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• 2022

As mobile electronics become smarter, higher-level security systems are necessary to protect private information and property from hackers. For this, biometric authentication systems have been widely studied, where the recognition of unique biological traits of an individual, such as the face, iris, fingerprint, and voice, is required to operate the device. Among them, ultrasound fingerprint imaging technology using piezoelectric materials is one of the most promising approaches adopted by Samsung Galaxy smartphones. In this review, we summarize the recent progress on piezoelectric ultrasound micro-electro-mechanical systems (MEMS) transducers with various piezoelectric materials and provide insights to achieve the highest-level biometric authentication system for mobile electronics.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.149-154
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• 1999

Response Surface Methodology was applied for optimizing the processing parameters of ultrasound treatment in order to produce low-molecular alginate. The use of ultrasound significantly reduced viscosity of alginate solutions. Suggested parameters of ultrasound treatment for maximum reduction of alginate molecular weight were: specific intensity, 115.81 $W/cm^2$ at 20kHz frequency; treatment time, 35.55 min; temperature, $20.08^{\circ}C$; alginate concentration, $2.5\%$. Low-molecular alginate obtained by ultrasound had two peaks on Sepharose CL-6B gel filtration. The viscosities of control, fraction I, and fraction II at $0.1\%$ concentration and $25^{\circ}C$ were 3.07, 1.23, and 0.82cps, respectively. Molecular weights of control, fraction I, and fraction II alginates were 336,500, 70,400, and 52,800 daltons, and their solubilities were 3, 6, and $14\%$, respectively. The lower molecular weight of alginate, the lower the alcohol precipitation and the higher $Ca^{2+}$ ion binding capacities. Heavy metal ion binding capacities of alginates were high in the following order of Pb, Cd, Zn, and Co.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.470-473
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• 2021

In this study, we developed the biometric ultrasound transducer, residual thickness measurement algorithm and optimized ultrasound operation methods to diagnose precise conditions of implanted medical prosthetic material inserted during total hip artificial joint replacement. In detail, ultrasound transducers having 8 MHz and 20 MHz center frequencies with similar sensitivity and bandwidth were fabricated to measure various thicknesses of commercial polyethylene-based artificial hip liners, resulting in a comparative analysis of signal-to-noise ratio and axial resolution to conduct an optimization study of ultrasound operations in vivo.