• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.183-192
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• 2023

Radiofrequency ablation (RFA) is an alternative treatment for liver cancer to the surgical intervention preferred by surgeons. However, the main challenge remains the use of RF for the ablation of large tumours (i.e., tumours with a diameter of >3 cm). For large tumours, RFA takes a large duration in the ablation process compared with surgery, which increases patient pain. Therefore, RFA for large tumours is not preferred by surgeons. The currently materials used in RF electrodes, such as the nickeltitanium alloy (nitinol), are characterized by low thermal and electrical conductivities. On the other hand, the use of materials that have high thermal and electrical conductivities, such as titanium aluminide alloy (gamma titanium), produces more thermal energy for tumours. In this paper, we developed a cool-tip RF electrode model that uses nickel-titanium alloy and replaced it with titanium aluminide alloy by using the finite element model (FEM). The aim of this paper is to study the effect of the thermal and electrical conductivities of gamma titanium on the ablation volume. Results showed that the proposed design of the electrode increased the ablation rate by 1 cm³ /minute and 6.3 cm³/10 minutes, with a decrease in the required time ablation. Finally, the proposed model reduces the ablation time and damages healthy tissue while increasing the ablation volume from 22.5% cm³ to 62.5% cm³ in ten minutes compared to recent studies.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.256-263
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• 2022

Skin cancer is one of the most common diseases in the world, and the incidence rate in Korea has increased by about 100% over the past five years. In the United States, more than 5 million people are diagnosed with skin cancer every year. Skin cancer mainly occurs when skin tissue is damaged for a long time due to exposure to ultraviolet rays. Melanoma, a malignant tumor of skin cancer, is similar in appearance to Atypical melanocytic nevus occurring on the skin, making it difficult for the general public to be aware of it unless secondary signs occur. In this paper, we propose a skin cancer lesion edge detection algorithm and a deep learning model, CRNN, which performs skin cancer lesion classification for early detection and classification of these skin cancers. As a result of the experiment, when using the contour detection algorithm proposed in this paper, the classification accuracy was the highest at 97%. For the Canny algorithm, 78% was shown, 55% for Sobel, and 46% for Laplacian.

• Structural Engineering and Mechanics
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• v.86 no.4
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• pp.487-501
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• 2023

Nanoparticles have lower size and larger specific surface area, good stability and less toxic and side effects. In recent years, with the development of nanotechnology, its application range has become wider and wider, especially in the field of biomedicine, which has received more and more attention. Bone defect repair materials with high strength, high elasticity and high tissue affinity can be prepared by nanotechnology. The purpose of this paper was to study how to analyze and study the composite materials for sports bone injury based on multifunctional nanomaterials, and described the electrospinning method. In this paper, nano-sized zirconia (ZrO₂) filled micro-sized hydroxyapatite (HAP) composites were prepared according to the mechanical properties of bone substitute materials in the process of human rehabilitation. Through material tensile and compression experiments, the performance parameters of ZrO₂/HAP composites with different mass fraction ratios were analyzed, the influence of filling ZrO₂ particles on the mechanical properties of HAP matrix materials was clarified, and the effect of ZrO₂ mass fraction on the mechanical properties of matrix materials was analyzed. From the analysis of the compressive elastic modulus, when the mass fraction of ZrO₂ was 15%, the compressive elastic modulus of the material was 1222 MPa, and when 45% was 1672 MPa. From the analysis of compression ratio stiffness, when the mass fraction of ZrO₂ was 15%, the compression ratio stiffness was 658.07 MPa·cm³/g, and when it was 45%, the compression ratio stiffness is 943.51MPa·cm³/g. It can be seen that by increasing the mass fraction of ZrO₂, the stiffness of the composite material can be effectively increased, and the ability of the material to resist deformation would be increased. Typically, the more stressed the bone substitute material, the greater the stiffness of the compression ratio. Different mass fractions of ZrO₂/HAP filling materials can be selected to meet the mechanical performance requirements of sports bone injury, and it can also provide a reference for the selection of bone substitute materials for different patients.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.20-50
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• 2000

This paper was written into condsideration records about the definition of "Ong-Jeo", the difference between "Ong" and "Jeo", the Western medical approach to "Ong-Jeo", and the etiology and pathologic mechanism of "Ong-Jeo". After this study, I report the following results from it. 1. "Ong" is an acute diapyesis disease which is found is in our skin and muscle and flesh. The chrateristics of this disease is that the affacted site is shine, no head, and the size is 3-4 chon. The prossess of the diesease shows that it is very quick, and very easily swell, and becomes pus easily, easily become to ulcer, easily converge. But this don't damage to the muscle and bone. 2. "Jeo" is the disease which damages bone-skeleton, muscle and flesh, and even destroy the stationary tissue. Jeo can be divided into two. One is called "Yudujeo" and it is acute diapydesis disease. The characteriscs of this disease is the miliary abscess, swell, has fever, and has an ache which is feeled spaned. And this is diffused into periphrey tissue and is diffused into deep site. After the ulcer, this becomes to shape the cellula. The size is more than 3-4 chon and this disease goes into chuk if this is serious. The other one is called "Mudujeo" and this disease is the ulcerative one in our joint and skeleton. The characteristic of this disease shows that the color of skin be not changed, and swell diffusely, and is not easily vanished, not easily becomes ulcerative, and not easily becomes converged. 3. "Ong-Jeo" is caused by the bacteriunm named by the "Golden and Yeollw Staphylococcus" in the Western medicine. "Ong" can be applicable to the carbuncle, acute diapyesis lymphadenitis, and some of cellulitis. "Jeo" can belong to cellulitis, and Mudujeo can belong to suppurative arthritis, suppurative osteomyelitis, tuberculous arthritis and osteomyelitis, and tuberculous lymphadenitis. 4. The etiologies of "Ong-Jeo" can be divided three, which are internal, external and other etiology which can not be clasiffied by two etiologies above. The internal etiology is seven emotion, and the external etiology is the six eumsa, unki, chunhang and so on. Other etiology is inadequate absorption of food, and excessive bang-sa. 5. The etiology of "Ong" is suppurative one which is choked between our skin and muscle and flesh, and is congested, become to hot, and finally erodes the muscle and flesh because of the inbalance of cirrculation in the enegy and blood. "Jeo" is the same as the Ong, but this is the suppurative disease which damages the muscle, flesh, and skeleton, and even damages into five Zang, the internal intestine.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.180-187
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• 2011

Introduction: Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review: The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion: Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.81-86
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• 2020

Purpose: Ankle fractures with dislocations and pilon fractures at the distal tibia are usually associated with soft tissue damage caused by high-energy damage. Recently, a two-stage operation to perform internal fixation after the application of external fixation devices for stabilizing soft tissues has been accepted as the treatment of choice. This paper reports the clinical result of these injuries treated with threaded trans-calcaneal pin external fixation devices. Materials and Methods: Thirty-three patients diagnosed with ankle fractures with dislocations or tibial pilon fractures without open wounds. They underwent surgical treatment with threaded trans-calcaneal pin external fixation from January 2008 to February were enrolled in this study. This study evaluated the visual analogue scale (VAS), foot function index (FFI), and Olerud & Molander score as well as whether complications occurred. Results: The average VAS showed a meaningful decrease (p<0.001) from 7.4 before surgery to 2.6 after application of the external fixation device, and 1.4 at 12 months after surgery. The FFI also decreased significantly from 84.3 preoperatively to 20.3 at 12 months postoperatively (p<0.001). The Olerud & Molander score averaged 71.4 points, showing good clinical results. Complete bone union was observed in all patients. One patient each underwent debridement due to wound necrosis and infection in the pin insertion site. At the final follow-up, seven patients had posttraumatic ankle joint arthritis, according to a radiological examination. Conclusion: Manual reduction and external fixation using a threaded trans-calcaneal pin is a suitable surgical technique that is easy to perform and shows good clinical outcomes in stabilizing soft tissue damage in fractures and dislocations of ankle fracture or tibia pilon fractures in foot and ankle injury.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.503-527
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• 1993

This paper describes a new method to create an animal model for TMJ internal derangement in the New Zealand white rabbits and the light and electron microscopical changes of posterior attachment of them. Twenty six rabbits(2.5-3.0kg), four normal and twenty two experimental, were used. The right disc of experimental animal was displaced anteriorly without sectioning the posterior attachment and tied to the zygomatic arch with nylon not to be reduced to the original position. The left TMJ was sham-operated to be compared with its right experimental one. Normal animals were sacrificed one day and eight weeks after experiment. Experimental animals were sacrificed one day, ten days, three weeks, five weeks and eight weeks after surgery respectively. They were fixed intravenously with $2\%$ glutaldehyde under general anesthesia and the samples of them were processed for light and electron microscopic examination. The purpose of this experiment is to make a suitable animal model of disc displacement without reduction for studying and understanding the cellular and morphologic events in posterior attachment of TMJ including early changes which were difficult to be observed in human TMJs. The results of this investigation suggest the following conclusions : 1. Authors induced anterior disc displacement surgically in rabbits with new method to examine histologic changes of posterior attachment. Tissue reactions of this model seem to be similar to those observed in human disc displacement. We think this animal model for anterior disc displacement may be used to explore and evaluate objectively the effects of many treatment modalities in disc displacements. 2. The animal disease model showed inflammation at early stage(one and ten days). At this stage there were mild-to-severe mononuclear inflammatory cell infiltration, numerous newly formed vessels, vessel dilatation and engormement and many fibroblasts. 3. At middle stage(three weeks), fibrosis occurred, where fibroblasts decreased in number, but their cytoplasm was profuse indicating high activity. Collagen fibers increased in number and the tissue looked more dense. 4. At late stage(five weeks and eight weeks) showed degenerative changes including perforation of posterior attachment, disintegration of collagen fiber bundles, degeneration of fibroblasts, metastatic ossification, and dystrophic calcification.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.5
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• pp.43-51
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• 2010

Attenuation coefficients of medical ultrasound not only reflect the pathological information of tissues scanned but also provide the quantitative information to compensate the decay of backscattered signals for other medical ultrasound parameters. Based on the frequency-selective attenuation property of human tissues, attenuation estimation methods in spectral domain have difficulties for real-time implementation due to the complexicity while estimation methods in time domain do not achieve the compensation for the diffraction effect effectively. In this paper, we propose the modified VSA method, which compensates the diffraction with reference phantom in time domain, using adaptive bandpass filters with decreasing center frequencies along depths. The adaptive bandpass filtering technique minimizes the distortion of relative echogenicity of wideband transmit pulses and maximizes the signal-to-noise ratio due to the random scattering, especially at deeper depths. Since the filtering center frequencies change according to the accumulated attenuation, the proposed algorithm improves estimation accuracy and precision comparing to the fixed filtering method. Computer simulation and experimental results using tissue-mimicking phantoms demonstrate that the distortion of relative echogenicity is decreased at deeper depths, and the accuracy of attenuation estimation is improved by 5.1% and the standard deviation is decreased by 46.9% for the entire scan depth.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.123-132
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• 2005

중등도 이상의 치주염 환자에서 치은 열구액내의 MMPs 및 TIMP-1 과 치주염과의 연관성을 규명하고, 치주 수술이 MMPs 및 TIMP-1의 정량에 미치는 영향을 연구하고자 하였다. 총 14명의 치주낭 깊이 6mm 이상의 중등도 이상의 치주 질환 이환자에서 치아를 선정하여, 치주낭 심도, 치은 지수(gingival index)를 측정하고, 치은의 조직학적 염증의 정도를 측정하기 위해, 해당 치아의 치주낭 연조직을 절취하여 H-E염색을 하고, 치은 절편에서 염증세포 침윤의 정도 및 분포를 비교하였다. Perio-paper를 이용하여 치은열구액을 얻고, pyrogen-free water에서 추출하였다. 채취한 치은 열구액에서 ELISA-kit를 이용하여 MMP-1, 8, 9, 13과 TIMP-1을 측정하여 수술 전과, 수술 후, 그리고 건강한 조직인 대조군을 비교하였으며, 통계처리는 Wilcoxon 검정을 사용하였다. 또한 MMPs 혹은 TIMP-1이 치주낭 심도나 치은지수등의 임상적 지표와 가지는 연관성을 Spearman's correlation coefficient를 이용하여 알아보았다. TIMP-1을 제외한 MMP-1, 8 ,9, 13 에서 수술 전보다 수술 후에 치은 열구액 내의 양이 현저하게 줄어든 것을 관찰할 수 있었으나, MMP-1(p=0.025), MMP-9(p=0.016) 와 MMP-13(p=0.009) 에서만 통계적으로 유의성있는 차이를 보였다. 한편 MMP-9 (p=0.011) 나 MMP-13(p=0.026) 은 건강한 대조군과 수술 전 사이에도 유의성있는 차이를 보였다. 연조직의 조직학적 관찰을 통하여 치은지수의 임상적 신뢰도를 평가한 결과 통계학적으로 유의한 결과를 얻을 수 있었으며, 치주 치료 전의 치주낭 심도와 치은지수와의 관계나, 수술 전과 수술 후의 치주낭 심도등의 변화도 통계적으로 유의성있는 결과를 보였다. 하지만 치주낭 심도나 치은지수등의 임상적 지표는 MMPs나 TIMP의 정량과는 별다른 연관성을 보이지 않았다. 이 실험의 결과로 보아 MMP-1, MMP-9나 MMP-13을 치주 수술 전과 수술 후의 치주염의 심도 변화를 반영할 수 있는 지표로 생각할 수 있으며, 특히 MMP-9와 MMP-13가 치주염과 가지는 연관성은 크다고 할 수 있겠다.

• Quality Improvement in Health Care
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• v.22 no.2
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• pp.95-108
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• 2016

Purpose: Ancillary tests such as immunohistochemistry or molecular testing for pathologic diagnosis are performed using ready-made tissue blocks for a histological examination. Various methods and processes during ancillary testing cause some of issues, particularly in the time required and the results reporting scheme. Methods: To solve these issues, we constructed real-time management software. When a pathologist or a clinician had ancillary tests examined using this software by selecting the codes of the needed ancillary tests on site and the system assigned the tests to each laboratory. Then, pathology technologists checked the referred tests and performed the examination. In clinical departments, serial number of each ancillary test can be matched the original pathologic ID. In the department of pathology, numbers of tissue blocks that needed additional tests could be indicated and detected using one-click detection system when a clinician referred the test. Results: Using this system resulted in simplifying the referral procedures from nine-steps to three-steps in each clinical department and from seven-steps to two-steps in department of pathology. Errors that happened on the paper-based request system were also reduced. Furthermore, the time required was saved by seven hours in pathologic laboratory on average. Mean durations from requesting to reporting of the ancillary test was reduced by three days for specimens of health promotion center. Conclusion: Construction of an effective information transfer system may be helpful for shortening the time required, reducing errors, and checking processing information of the tests in real time.