• 한국표면공학회지
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• 제49권4호
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• pp.389-394
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• 2016

The operation method of nuclear power plants is currently changing to high burn-up and long period that can enhance economics and efficiency of the plant. Since nuclear plant operation environment has been becoming severe, the amount of absorbed hydrogen also has increased. Absorbed hydrogen can be fatal securing safety of nuclear fuel cladding in case of Loss of Coolant Accidents(LOCA). In order to examine the impact of hydride on high-temperature oxidation, high-temperature oxidation experiment was performed on normal Zry-4 cladding and on Zry-4 cladding where hydrogen is charged in air pressure steam atmosphere under the $950^{\circ}C$ and $1000^{\circ}C$. According to the results, while oxidation acceleration due to charged hydrogen was not observed prior to breakaway oxidation creation, oxidation began to accelerate in cladding where hydrogens charged as soon as the breakaway oxidation started. If so much hydrogen are charged in the cladding, equiaxial monoclinic phase to unstable of stress is formed and it is presumed that oxidation is accelerated because nearby stress caused a crack in equiaxial phase, and that makes corrosion resistance decline sharply.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권3호
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• pp.165-173
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• 2016

Dentists often sedate patients in order to reduce their dental phobia and stress during dental treatment. Sedatives are administered through various routes such as oral, inhalation, and intravenous routes. Intravenous administration has the advantage of rapid onset of action, predictable duration of action, and easy titration. Typically, midazolam, propofol or dexmedetomidine are used as intravenous sedatives. Administration of these sedatives via infusion by using a syringe pump is more effective and successful than infusing them as a bolus. However, during intravenous infusion of sedatives or opioids using a syringe pump, fatal accidents may occur due to the clinician's carelessness. To prevent such risks, smart syringe pumps have been introduced clinically. They allow clinicians to perform effective sedation by using a computer to control the dose of the drug being infused. To ensure patient safety, various alarm features along with a drug library, which provides drug information and prevents excessive infusion by limiting the dose, have been added to smart pumps. In addition, programmed infusion systems and target-controlled infusion systems have also been developed to enable effective administration of sedatives. Patient-controlled infusion, which allows a patient to control his/her level of sedation through self-infusion, has also been developed. Safer and more successful sedation may be achieved by fully utilizing these new features of the smart pump.

• 대한교통학회지
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• 제16권4호
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• pp.89-98
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• 1998

교통사고의 원인은 인적 요인, 차량적 요인, 도로 환경적 요인으로 분류된다. 주어진 도로 환경과 차량 조건하에서는 운전자가 마지막으로 안전을 제어할 책임을 지고 있다. 따라서, 교통사고를 사전에 예방하기 위하여 운전자의 교통법규 위반 행위에 대하여는 도로교통법에 근거하여 징역, 벌금, 구류, 과료, 과태료, 범칙금에 처하고 있다. 교통법규 위반 행위 단속 시에는 교통사고 유발 가능성과 위험도에 따라 단속의 강약을 포함하여 차등화된 처벌이 이루어져야 한다. 교통 범칙금 기준 제시를 위하여 1991~1995년의 5년간 교통사고 및 교통법규 위반을 분석한 결과 전체 교통법규 위반 단속 중 교통사고를 야기하는 동적 위반 행위인 사고관련 위반 행위 단속의 비율이 44%로 일본의 61%에 비해 매우 낮은 수준이다. 따라서 사고유발 가능성에 근거한 교통법규 위반 행위 단속의 강화가 필요하다. 한편 범칙금 부과방안으로 피해도 모형과 빈도 모형을 비교한 결과 교통법규 위반 행위로 인해 발생된 교통사고 비용을 고려한 피해도 모형은 범칙금의 차등화가 분명하지 않고 변별력이 뚜렷이 나타나지 않아 적합하지 않은 것으로 분석되었다. 교통법규 위반 행위에 따른 빈도 모형은 교통사고 건수와 사망사고 건수의 가중치(w)설정을 위해 동적 위반행위가 우리나라와 유사한 일본 자료와 비교한 결과 가중치가 한국=0.7, 일본=0.8일 때 상대적으로 $x^2$가 31.71로 가장 낮게 나타났다. 따라서, 사고건수에 대한 가중치는 0.7로 사망사고에 대한 가중치는 0.3을 적용하였다. 마지막으로 현행 범칙금과 제안된 범칙금을 비교분석하였다.

• 대한안전경영과학회지
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• 제23권3호
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• pp.1-9
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• 2021

Crane is an important equipment for the transport of heavy goods in industrial sites, but it is also known as one of the most fatal machines. In order to reduce crane accidents, it is necessary to minimize human errors during crane operations. To achieve this, ergonomic design principles are recommended to be reflected from the crane design stage. The study analyzed the safety certification standards for crane that should be fulfilled at the crane design and manufacturing stage. This study selected five representative ergonomic design principles (feedback, compatibility, consistency, full-proof, and fail-safe) by surveying heuristic evaluation principles that are widely used for usability evaluation in early design stage. Next, the principles were applied to the safety certification standards to identify insufficient clauses. This study identified 12 insufficient clauses out of 119 in the current safety certification standards for crane and discussed their improvement directions to comply the ergonomic principles. The analysis results of this study can help of improving the safety certification standards and the method used in this study can also be applied to identify insufficient clauses in the safety certification standards for other industrial machines such as press machine and lift.

• 한국인터넷방송통신학회논문지
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• 제19권2호
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• pp.237-242
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• 2019

최근, 자율주행 이동체에 대한 대중의 관심도가 높아짐에 따라 자율주행 이동체의 상용화 확대를 위한 유관 기관들의 연구 활동이 꾸준하게 진행되고 있다. 이로 인해, 부분적이지만 실제 사용이 가능한 단계로 발전이 이루어졌다. 하지만, 2018년 3월 우버와 테슬라 자동차로 인해 최초로 두 차례의 사망사고가 발생하였고, 새로운 시스템 보완에 대한 필요성이 대두되고 있다. 이에 본 논문은 자율주행자동차의 사망 사고를 중점적으로 사고 원인을 분석하여 원인이 되었던 사물 인지오류를 확인하고, 이를 보완할 수 있는 시스템의 구현을 위한 새로운 자율주행 이동체의 정보처리 모델을 제안한다.

• The Korean Journal of Legal Medicine
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• 제42권4호
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• pp.168-171
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• 2018

In Korea, small octopus (Octopus minor) and webfoot octopus (Octopus ocellatus) are food items and fatal laryngeal choking due to ingestion of live octopus is not uncommon. We recently encountered two autopsy cases of accidental choking on small octopus and webfoot octopus. Case 1 involved a 58-year-old fisherman who ingested two live webfoot octopuses in his fishing boat and collapsed. He was immediately taken to the hospital but died. During autopsy, one of the webfoot octopuses was found between his pharynx and esophagus; it was obstructing the epiglottis and upper esophagus. His blood alcohol concentration was 0.140%. Case 2 involved a 55-year-old man who ingested an intact body part of a small octopus and was found dead in his house. He had a history of cerebral infarction and angina pectoris. During autopsy, an intact body part of the small octopus was found to be lodged in the laryngeal inlet.

• 자동차안전학회지
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• 제13권1호
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• pp.14-25
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• 2021

This paper presents a RLS based adaptive sliding mode observer (A-SMO) for unknown fault reconstruction in longitudinal autonomous driving. Securing the functional safety of autonomous vehicles from unexpected faults of sensors is essential for avoidance of fatal accidents. Because the magnitude and type of the faults cannot be known exactly, the RLS based A-SMO for unknown acceleration fault reconstruction has been designed with relationship function in this study. It is assumed that longitudinal acceleration of preceding vehicle can be obtained by using the V2V (Vehicle to Vehicle) communication. The kinematic model that represents relative relation between subject and preceding vehicles has been used for fault reconstruction. In order to reconstruct fault signal in acceleration, the magnitude of the injection term has been adjusted by adaptation rule designed based on MIT rule. The proposed A-SMO in this study was developed in Matlab/Simulink environment. Performance evaluation has been conducted using the commercial software (CarMaker) with car-following scenario and evaluation results show that maximum reconstruction error ratios exist within range of ±10%.

• 센서학회지
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• 제31권2호
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• pp.96-101
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• 2022

As the elderly population gradually increases, the risk of fatal fall accidents among the elderly is increasing. One way to cope with a fall accident is to determine the fall direction before impact using a wearable inertial measurement unit (IMU). In this context, a previous study proposed a method of classifying fall directions using a support vector machine with sensor velocity, acceleration, and tilt angle as input parameters. However, in this method, the IMU signals are processed through several processes, including a Kalman filter and the integration of acceleration, which involves a large amount of computation and error factors. Therefore, this paper proposes a machine learning-based method that classifies the fall direction before impact using IMU raw signals rather than processed data. In this study, we investigated the effects of the following two factors on the classification performance: (1) the usage of processed/raw signals and (2) the selection of machine learning techniques. First, as a result of comparing the processed/raw signals, the difference in sensitivities between the two methods was within 5%, indicating an equivalent level of classification performance. Second, as a result of comparing six machine learning techniques, K-nearest neighbor and naive Bayes exhibited excellent performance with a sensitivity of 86.0% and 84.1%, respectively.

• 한국수소및신에너지학회논문집
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• 제34권3호
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• pp.297-306
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• 2023

The frequency of fatal accidents that can occur at hydrogen refueling station was compared with the risk criterion for the general public suggested by the health and safety executive. If hydrogen refueling station meets the accident prevention facility standards presented in KGS Code FP216/217, it was confirmed that the risk of hydrogen refueling station was not at an unacceptable (intolerable) risk level. However, the risk of hydrogen refueling station due to small leak was analyzed as low as reasonably practicable. Therefore, methods for improving the safety instrumented function of hydrogen refueling station were reviewed. It was confirmed that the risk of hydrogen refueling station can be affected by the number of installed safety instrumentation system components, redundant architecture, mission time, proof test interval, etc. And methods for maintaining the risk of hydrogen refueling station at an acceptable risk level have been proposed.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.313-316
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• 2015

Construction is one of the most dangerous job sectors, which reports tens of thousands of time-loss injuries and deaths every year. These disasters incur delays and additional costs to the projects. The safety management needs to be on the top primary tasks throughout the construction to avoid fatal accidents and to foster safe working environments. One of the safety regulations that are frequently violated is the wearing of personal protection equipment (PPE). In order to facilitate monitoring of the compliance of the PPE wearing regulations, this paper proposes a vision based method that automatically identifies whether workers wear hard hats and safety vests. The method involves three modules - human body detection, identification of safety vest wearing, and hard hat detection. First, human bodies are detected in the video frames captured by real-time on-site construction cameras. The detected human bodies are classified into with/without wearing safety vests based on the color features of their upper parts. Finally, hard hats are detected on the nearby regions of the detected human bodies and the locations of the detected hard hats and human bodies are correlated to reveal their corresponding matches. In this way, the proposed method provides any appearance of the workers without wearing hard hats or safety vests. The method has been tested on onsite videos and the results signify its potential to facilitate site safety monitoring.