• Journal of Digital Convergence
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• v.16 no.12
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• pp.327-334
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• 2018

This study proposes a CMS platform for AR-based remote collaboration in a smart factory. The Smart Factory site utilizes various forms of AR technology to save time and money. As the level of smart factory increases, system-oriented tasks such as machinery and equipment are performed in people-oriented work. Therefore, there is a need for a system that allows the operator to immediately repair the machine or equipment in case of a failure, or to get help if necessary. Remote collaborative CMS platform is designed to work in conjunction with DATABASE of ERP, MES / POP, and PLM system built through text, 2D 3D contents and smart factory business, This study is meaningful in that it saves time and cost by sharing information such as management, repair method, manual, etc., and repairing it quickly.

• Journal of Radiation Protection and Research
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• v.44 no.3
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• pp.97-102
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• 2019

Background: Dose rate meters are the most widely used, and perhaps one of the most important tools for the measurement of ionising radiation. They are often the first, or only, device available to a user for an instant check of radiation dose at a certain location. Throughout the world, radiation safety practices rely strongly on the output of these dose rate meters. But how well do we know the quality of their output? Materials and Methods: This review is based on the measurements 1,158 commercially available dose rate meters of 116 different makes and models. Expected versus the displayed dose patterns and consistency was checked at various dose rates between $5{\mu}Gy{\cdot}h^{-1}$ and $2mGy{\cdot}h^{-1}$. Samples of these meters were then selected for further investigation and were exposed to radiation sources covering photon energies from 50 keV to 1.5 MeV. The effect of detector orientation on its reading was also investigated. Rather than focusing on the angular response distribution that is often reported by the manufacturer of the device, this study focussed on the design ergonomics i.e. the angles that the operator will realistically use to measure a dose rate. Results and Discussion: This review shows the scope and boundaries of the ionising radiation dose rate estimations that are made using commonly available meters. Observations showed both inter and intra make and model variations, occasional cases of instrument failure, instrument walk away, and erroneous response. Conclusion: The results indicate the significance of selecting and maintaining suitable monitors for specific applications in radiation safety.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.657-665
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• 2021

Nondestructive evaluation methods play an important role in ensuring component integrity and safety in many industries. Operator fatigue can play a critical role in the reliability of such methods. This is important for inspecting high value assets or assets with a high consequence of failure, such as aerospace and nuclear components. Recent advances in convolution neural networks can support and automate these inspection efforts. This paper proposes using residual neural networks (ResNets) for real-time detection of corrosion, including iron oxide discoloration, pitting and stress corrosion cracking, in dry storage stainless steel canisters housing used nuclear fuel. The proposed approach crops nuclear canister images into smaller tiles, trains a ResNet on these tiles, and classifies images as corroded or intact using the per-image count of tiles predicted as corroded by the ResNet. The results demonstrate that such a deep learning approach allows to detect the locus of corrosion via smaller tiles, and at the same time to infer with high accuracy whether an image comes from a corroded canister. Thereby, the proposed approach holds promise to automate and speed up nuclear fuel canister inspections, to minimize inspection costs, and to partially replace human-conducted onsite inspections, thus reducing radiation doses to personnel.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.171-178
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• 2022

In this paper, we propose a classification method according to the type and characteristics of stablecoins for risk analysis, and analyze the risk factors of each stablecoin based on this classification. First, this paper explains the technologies and ecosystem of blockchain and decentralized finance(DeFi) to understand stablecoins. In addition, the operation principle of the major stablecoins currently released and used is explained for each proposed classification type. Based on this, the risk type and risk factors of each stablecoin are derived. The risk types proposed in this paper are classified as defegging, liquidation, and exploit, and the risk factors are classified as depegging due to reliability of operator, depegging due to reliability of algorithm, depegging due to failure of algorithm, liquidation due to high volatilty and oracle attack. Based on the proposed classification, we analyze the risk factors of major stablecoins currently circulating in the crypto market.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.5
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• pp.281-285
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• 2023

Background: Dentists bend needles prior to certain injections; however, there are concerns regarding needle fracture, lumen occlusion, and sharps handling. A previous study found that a 30-gauge needle fractures after four to nine 90° bends. This fatigue life study evaluated how many 90° bends a 30-gauge dental needle will sustain before fracture when bent using a needle guide. Methods: Two operators at Element Materials Technology, an independent testing, inspection, and certification company tested 48 30-gauge needles. After applying the needle guide, the operators bent the needle to a 90° angle and expressed the anesthetic from the tip. The needle was then bent back to a 0° angle, and the functionality was tested again. This process was repeated until the anesthetic failed to pass through the end of the needle due to fracture or obstruction. Each operator tested 24 needles (12 needles from each lot), and the number of sustained bends before the needle fracture was recorded. Results: The average number of sustained bends before needle failure was 40.33 (95% confidence interval = 37.41-43.26), with a minimum of 20, median of 40, and a maximum of 54. In each trial, the lumen remained patent until the needle fractured. The difference between the operators was statistically significant (P < 0.001). No significant differences in performance between needle lots were observed (P = 0.504). Conclusion: Our results suggest that using a needle guide increases the number of sustained bends before needle fracture (P < 0.000001) than those reported in previous studies. Future studies should further evaluate the use of needle guides with other needle types across a variety of operators. Furthermore, additional opportunities lie in exploring workplace safety considerations and clinical applications of anesthetic delivery using a bent needle.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.87-96
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• 2020

The purpose of this paper is to develop a fire HRA (Human Reliability Analysis) procedure for full power operation of domestic NPPs (Nuclear Power Plants). For the development of fire HRA procedure, the recent research results of NUREG-1921 in an effort to meet the requirements of the ASME/ANS PRA Standard were reviewed. The K-HRA method, a standard method for HRA of a domestic level 1 PSA (Probabilistic Safety Assessment) and fire related procedures in domestic NPPs were reviewed. Based on the review, a procedure for the fire HRA required for a domestic fire PSA based on the K-HRA method was developed. To this end, HRA issues such as new operator actions required in the event of a fire and complexity of fire situations were considered. Based on the four kinds of HFE (Human Failure Event) developed for a fire HRA in this research, a qualitative analysis such as feasibility evaluation was suggested. And also a quantitative analysis process which consists of screening analysis and detailed analysis was proposed. For the qualitative analysis, a screening analysis by NUREG-1921 was used. In this research, the screening criteria for the screening analysis was modified to reduce vague description and to reflect recent experimental results. For a detailed analysis, the K-HRA method and scoping analysis by NUREG-1921 were adopted. To apply K-HRA to fire HRA for quantification, efforts to modify PSFs (Performance Shaping Factors) of K-HRA to reflect fire situation and effects were made. For example, an absence of STA (Shift Technical Advisor) to command a fire brigade at a fire area is considered and the absence time should be reflected for a HEP (Human Error Probability) quantification. Based on the fire HRA procedure developed in this paper, a case study for HEP quantification such as a screening analysis and detailed analysis with the modified K-HRA was performed. It is expected that the HRA procedure suggested in this paper will be utilized for fire PSA for domestic NPPs as it is the first attempt to establish an HRA process considering fire effects.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.591-597
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• 1998

Background: The aim of the current study was to analyze the early and intermediate-term performance of aortic valve replacement. Material and Method: Between January 1986 and January 1996, records of 61 consecutive patients who had received aortic valve replacement were reviewed. 38 were male and 23 were female patients, ranging from 10 to 71 years of age(mean: 40.5${\pm}$11.2). Results: The early death rate was 4.9%(3/61). A thorough follow-up rate of 93.1% was accomplished in these 58 patients who left the hospital(mean: 51.5${\pm}$32.0 patient-months) under the assistance of the same operator. Three of these patients who left the hospital died. The late death rate was 5.2%(3/58). Five patients experienced anticoagulant-related hemorrhage(all were minor). Three patients had thromboembolic episodes. There was no clinical evidence of hemolysis and structural failure of valves used. Of those patients who survived, the NYHA functional class improved significantly. Linearized rate were 1.58%/patient-year and 2.0%/patient-year respectively for thromboembolism and anticoagulant-related hemorrhage. The 10 year actuarial survival rate was 83.6%. Conclusion: This early and intermediate-term follow-up suggests that the mechanical valve is a reliable and durable prosthesis with good hemodynamic function and low rate of prosthesis-related complication.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.2
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• pp.67-76
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• 2017

In industrial site in various fields it will be generated in combination with large amounts of data have a correlation. It is able to collect a variety of data in types of industry process, but they are unable to integrate each other's association between each process. For the data of the existing industry, the set values of the molding condition table are input by the operator as an arbitrary value When a problem occurs in the work process. In this paper, design the fusion and analysis processing model of data collected for each industrial type, Prediction Case(Automobile Connect), a through for corporate earnings improvement and process manufacturing industries such as master data through standard molding condition table and the production history file comparison collected during the manufacturing process and reduced failure rate with a new molding condition table digitized by arbitrary value for worker, a new pattern analysis and reinterpreted for various malfunction factors and exceptions, increased productivity, process improvement, the cost savings. It can be designed in a variety of data analysis and model validation. In addition, to secure manufacturing process of objectivity, consistency and optimization by standard set values analyzed and verified and may be optimized to support the industry type, fits optimization(standard setting) techniques through various pattern types.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.804-810
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• 2017

Distress accidents occur annually by and failure of sea rescue and time delay lead to fatal accident. In the event of maritime distress, most of the equipments used for search and rescue are in responsible for the position of ships. An MOB equipment is a representative equipment for lifesaving and uses AIS communication method. However, the MOB equipment has problems of interference with existing vessel traffic process and it is difficult to apply because there is no proper certification standard. Therefore, this paper proposes a maritime search and rescue supporting system using smartphone. Utilizing the widely constructed IT infrastructure, it collects position information of the fishing boat and leisure ship using GPS embedded in the smartphone. Also the developed system supports to participate in the rescue by sending the information about the occurrence of the survivor in a certain area to the ship operator.

• Archives of Reconstructive Microsurgery
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• v.3 no.1
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• pp.72-80
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• 1994

There are several methods to reconstruct an amputated or lost thumb such as toe to thumb transfer, pollicization and other variety of free flaps. In 1980, Morrison and O'Brien advocated reconstruction of the thumb with a free wrap-around flap from the big toe to recreate a stable, sensate and functional digit, including the nail. From March, 1982 to December, 1992, thirty cases of thumb reconstructions were performed using the wrap-around procedure at Korea University Hospital. 1. 29 cases of total 30 cases were successful and can be obtained the excellent results in functional and cosmetic aspect. 2. In postoperative complications, one case is graft failure, six cases in partial skin necrosis, one case in malunion, 15 cases in resorption of grafted bone piece were come out. 3. Even if the 1st metacarpal neck amputation is occurred, thumb reconstruction with a free neurovascular wrap-around flap was also possible, however, the limitation of the mobility of the reconstructed thumb and resorption of grafted bone piece were come out. We concluded that cosmesis and fuctional results were quite satisfactory despite of some complications. The thumb reconstruction with a wrap around free flap from the big toe in thumb amputated patients is the excellent method in the cosmetic and functional aspect and can be considered as the most useful method because of less morbidity to the donor site and the operator should be trained to get the meticulous microsurgical technique and to detect the complications.