• Journal of Biomedical Engineering Research
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• v.41 no.5
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• pp.195-202
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• 2020

Needle detection in ultrasound images is sometimes difficult due to obstruction of fat tissues. Accurate needle detection using continuous ultrasound (CUS) images is a vital stage of treatment planning for tissue biopsy and brachytherapy. The main goal of the study is classified into two categories. First, new detection model, i.e. D-Attention Unet, is developed by combining the context information of 3D medical data and CUS images. Second, the D-Attention Unet model was compared with other models to verify its usefulness for needle detection in continuous ultrasound images. The continuous needle images taken with ultrasonic waves were converted into still images for dataset to evaluate the performance of the D-Attention Unet. The dataset was used for training and testing. Based on the results, the proposed D-Attention Unet model showed the better performance than other 3 models (Unet, D-Unet and Attention Unet), with Dice Similarity Coefficient (DSC), Recall and Precision at 71.9%, 70.6% and 73.7%, respectively. In conclusion, the D-Attention Unet model provides accurate needle detection for US-guided biopsy or brachytherapy, facilitating the clinical workflow. Especially, this kind of research is enthusiastically being performed on how to add image processing techniques to learning techniques. Thus, the proposed method is applied in this manner, it will be more effective technique than before.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.79-86
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• 2007

The corrosion durability of steel bridge coatings, such as organic and metallic coatings, is often evaluated by field exposure tests, but such tests take from several years to decades to complete. As a potential method for fast corrosion testing, accelerated exposure tests were considered in this study. The S6-cycle accelerated exposure test, specified in the Japanese Industrial Standards (JIS K5621), was carried out on uncoated structural steels for 30, 60, 90, 120 and 150 days, and the resultant weight loss was determined. The weight loss was compared with that obtained from previous field exposure tests, and acceleration factors of the S6-cycle test to field exposure test sites were determined. The application of the S6-cycle accelerated exposure tests to field environments was presented based on the acceleration factor and the amount of flying salt.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.537-540
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• 2009

Bactericidal efficacies of various sanitizers and disinfectants against 10 Bacillus cereus strains isolated from Korean foods and 8 standard B. cereus strains were investigated. The sanitizing capabilities of ethanol, iodine, chloride, quaternary ammonium, hydrogen peroxide, and peroxide acetic acid were investigated using the EN 1276 method based on quantitative suspension testing. The resistance against sanitizers and disinfectants was higher for wild-type than standard strains, and the bactericidal activities decreased in dirty conditions. Ethanol, chlorine, and iodine at the maximum level allowed under Korean food sanitation laws showed a great effectiveness against B. cereus. Hydrogen peroxide at 1,100 ppm showed the lowest bactericidal activity against B. cereus. These results indicate that the legally allowed maximum concentrations of sanitizers and disinfectants in Korea do not reduce all B. cereus strains by at least $5\;{\log}_{10}\;CFU/mL$.

• Safety and Health at Work
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• v.11 no.1
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• pp.61-70
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• 2020

Background: This study aims to assess whether the TSI PortaCount (Model 8020) is a measuring instrument comparable with the flame photometer. This would provide an indication for the suitability of the PortaCount for determining the workplace protection factor for particulate filtering facepiece respirators. Methods: The PortaCount (with and without the N95-Companion^TM) was compared with a stationary flame photometer from Moores (Wallisdown) Ltd (Type 1100), which is a measuring instrument used in the procedure for determining the total inward leakage of the particulate filtering facepiece respirator in the European Standard. Penetration levels of sodium chloride aerosol through sample respirators of two brands (A and B) were determined by the two measuring systems under laboratory conditions. For each brand, thirty-six measurements were conducted. The samples were split into groups according to their protection level, conditioning before testing, and aerosol concentration. The relationship between the gauged data from two measuring systems was determined. In addition, the particle size distribution inside the respirator and outside the respirator was documented. Linear regression analysis was used to calculate the association between the PortaCount (with and without the N95-Companion^TM) and the flame photometer. Results: A linear relationship was found between the raw data scaled with the PortaCount (without N95-Companion^TM) and the data detected by the flame photometer (R² = 0.9704) under all test conditions. The distribution of particle size was found to be the same inside and outside the respirator in almost all cases. Conclusion: Based on the obtained data, the PortaCount may be applicable for the determination of workplace protection factor.

• Nuclear Engineering and Technology
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• v.44 no.4
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• pp.421-428
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• 2012

Analog instrument and control systems in nuclear power plants have recently been replaced with digital systems for safer and more efficient operation. Digital instrument and control systems have adopted various fault-tolerant techniques that help the system correctly and safely perform the specific required functions regardless of the presence of faults. Each fault-tolerant technique has a different inspection period, from real-time monitoring to monthly testing. The range covered by each faulttolerant technique is also different. The digital instrument and control system, therefore, adopts multiple barriers consisting of various fault-tolerant techniques to increase the total fault detection coverage. Even though these fault-tolerant techniques are adopted to ensure and improve the safety of a system, their effects on the system safety have not yet been properly considered in most probabilistic safety analysis models. Therefore, it is necessary to develop an evaluation method that can describe these features of digital instrument and control systems. Several issues must be considered in the fault coverage estimation of a digital instrument and control system, and two of these are addressed in this work. The first is to quantify the fault coverage of each fault-tolerant technique implemented in the system, and the second is to exclude the duplicated effect of fault-tolerant techniques implemented simultaneously at each level of the system's hierarchy, as a fault occurring in a system might be detected by one or more fault-tolerant techniques. For this work, a fault injection experiment was used to obtain the exact relations between faults and multiple barriers of faulttolerant techniques. This experiment was applied to a bistable processor of a reactor protection system.

• Journal of Technologic Dentistry
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• v.36 no.4
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• pp.239-246
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• 2014

Purpose: The purpose of this study was to compare the tensile strength and mechanical properties of orthodontic wire joints made by gas soldering and laser welding, with and without filling material, to identify the effectiveness and potential clinical application of laser welded orthodontic wires. Methods: Three joint configurations of orthodontic wire were used: diameter 0.9 to 0.9 mm wire, diameter 0.9 to 0.5 wire and diameter 0.9 mm wire to band. The joints were made using three different methods: gas soldering, laser welding with and without filling material. For each kind of joint configuration or connecting method 7 specimens were carefully produced. The tensile strengths were measured with a universal testing machine (Zwick/Roell, Instron, USA). The hardness measurements were carried out with a hardness tester(Future-Tech Co. Tokyo, Japan). Data were analyzed by AVOVA(p= .05) and Turkey HD test(p= .05). Results: In all cases, gas soldering joints were ruptured on a low level on tensile bonding strength. Significant differences between laser welding and gas soldering(p< .05) were found in each joint configuration. The highest tensile strength means were observed for laser welding, with filling material, of 0.9 to 0.9 mm wire joint. Conclusion: In conclusion, the elastic modulus and tensile strength means of laser soldering with filling material were the highest, and the tensile strength means of laser soldering were higher than those of gas soldering.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.9-16
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• 2017

Purpose: The purpose of this study was to evaluate flexural strength, composite surface and fractured surface of three different indirect composite resins. Methods: Fifteen bar-shaped specimens ($25mm{\times}2mm{\times}2mm$) were fabricated for each FL group (Flow type and Light curing) and PLP group (Putty type and Light, Pressure curing) and PL group (Putty type and Light curing) according to manufacturer's instructions and ISO 10477. Fabricated specimens were stored in the distilled water for 24 hours at the temperature of $37^{\circ}C$. Three-point bending strength test was performed to measure flexural strength using universal testing machine at a crosshead speed of 1mm/min (ISO 10477). Surface and fractured surface of specimens were observed by digital microscope. Results were analyzed with Kruskal-wallis tests (${\alpha}=0.05$). Results: Mean (SD) of three different indirect composite resins were 83.38 (6.67) MPa for FL group, 139.90(16.53) MPa for PLP group and 171.72(16.74) MPa for PL group. Flexural strength were statistically significant (p<0.05). Differences were not observed at fractured surface among three groups. However, many pores over $100{\mu}m$ were observed at PL group in observing surface of specimen. Conclusion: Flexural strength of composite resins was affected by second polymerization method and content of inorganic filler.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.993-1000
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• 2009

In general, a drilled shaft embedded in weathered rock has a large load bearing capacity. Therefore, most of the load tests are performed only up to the load level that confirms the pile design load capacity, and stopped much before the failure load of the pile is attained. If a reliable failure load value can be extracted from the premature load test data, it will be possible to greatly improve economic efficiency as well as pile design quality. The main purpose of this study is to propose a standard for judging the reliability of the failure load of piles that is obtained from extrapolated load test data. To this aim, eleven static load test data of load-displacement curves were obtained from testing of piles to their failures from 3 different field sites. For each load-displacement curve, loading was assumed as 25%, 50%, 60%, 70%, 80%, and 90% of the actual pile bearing capacity. The limited known data were then extrapolated using the hyperbolic function, and the failure load was re-determined for each extrapolated data by the ASCE 20-96 method (1997). Statistical analysis was performed on the reliability of the re-evaluated failure loads. The results showed that if the ratio of the maximum-available displacement to the failure-load displacement exceeds 0.6, the extrapolated failure load may be regarded as reliable, having less than a conservative 20% error on average. The applicability of the proposed standard of judgment was also verified with static load test data of driven piles.

• Convergence Security Journal
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• v.13 no.6
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• pp.35-41
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• 2013

What is an alternative to medical information security of medical information more secure preservation and safety of various types of security threats should be taken, starting from the software design. Interspersed with medical information systems medical information to be able to integrate the real-time exchange of medical information must be reliable data communication. The software architecture design of medical information systems and sharing of medical information security issues and communication phase allows the user to identify the requirements reflected in the software design. Software framework design, message standard design, design a web-based inter-process communication procedures, access control algorithm design, architecture, writing descriptions, evaluation of various will procedure the establishing architecture. The initial decision is a software architecture design, development, testing, maintenance, ongoing impact. In addition, the project will be based on the decision in detail. Medical information security method based on the design software architecture of today's medical information security has become an important task of the framework will be able to provide.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.2
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• pp.190-198
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• 2012

This research evaluated and analyzed the level of acceptability of spinach according to blanching time by testing consumer taste of corresponding countries for the purpose of globalizing Korean food. General taste, appearance, flavor, and texture of spinach blanched for 20 seconds were highly evaluated by Koreans and Japanese ($p$<0.05), who are used to the method of slightly blanching, mixing, and eating spinach. On the other hand, general taste, appearance, flavor, and texture of spinach blanched for 5 minutes was highly evaluated by the French ($p$<0.05), who are used to eating boiled spinach. Concerning the result of JAR, there were clear differences in hardness and boiling level according to country among spinach samples, even though they were blanched for the same time and mixed with the same spices. Koreans and Japanese evaluated that hardness and boiling level of spinach blanched for 20 seconds were proper, whereas the French evaluated that spinach scalded for 20 seconds was too raw and crispy. Under the same context, French consumers evaluated that hardness and boiling level of spinach blanched for 5 minutes was proper, whereas Koreans and Japanese evaluated that spinach blanched for 5 minutes was boiled too much. These results show that familiarity level is an important driver of affecting the preference levels for three kinds of spinach according to country.