• Journal of Chest Surgery
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• v.23 no.3
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• pp.550-555
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• 1990

Since Steichen and Ravich`s pioneer work in 1972 proved that staples reduced anastomotic leaks and operative time, the use of EEA stapler`s in esophagogastrostomy have gained acceptance and popularity. But overriding these benefits are the high stricture rate, which leads to the reappearance of dysphagia. The mechanism for the development of stricture in stapled anastomosis is likely to be due to the lack of mucosa to mucosa apposition and presence of necrotic tissue between the luminal edge and the rows of the stapler. All strictures were easily dilated. Recently, we encountered a patient who suffered from an esophageal stricture that slowly developed 10 months after an esophagogastric anastomosis with a EEA 425 was performed due to severe muscular hypertrophy of esophagus. Because the stricture failed to respond to the Bougienage, we reoperated using a EEA 28 this time. We feel that this case review helps to show that despite the very low leakage rate in small size EEA stapler, there is also a very high risk of stricture.

• Journal of Korean Neurosurgical Society
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• v.55 no.4
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• pp.218-221
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• 2014

Chronic subdural hematoma (CSDH), which rarely happens in the young, is thought to be a disease of the elderly. Whereas unspecific symptoms and insidious onset in juveniles and young adults, as a result of its relative low morbidity, CSDH is usually neglected even undertreated in the young. Through the three cases and review of the current literature on this subject, we tried to illustrate the clinical and etiopathological characteristics of this entity and find out the most appropriate treatment strategy. We report three young CSDH patients with different but similar symptoms. The present histories, tests and examinations revealed different predisposing factors accounting for the genesis of CSDH. Their preoperative symptoms were all resolved with burr hole and drainage operation. Juveniles and young adults suffering from CSDH differ from that of their elderly counterparts in their clinical and etiopathological characteristics. Although trauma is the most important risk factor in young and old CSDH patients, some other predisposing factors may exist. Burr hole and drainage surgery could resolve the problem most of the time. But further tests and examinations even specific management should be made in some cases.

• Journal of Yeungnam Medical Science
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• v.35 no.1
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• pp.135-139
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• 2018

There has been a significant increase in the number of multiple pregnancies that are associated with a high risk of preterm delivery among Korean women. However, to date, delayed-interval delivery in women with multiple pregnancy is rare. We report a case of delayed-interval delivery performed 128 days after the vaginal delivery of the first fetus in a dichorionic diamniotic twin pregnancy. The patient presented with vaginal leakage of amniotic fluid at 16 weeks of gestation and was diagnosed with a preterm premature rupture of membranes. Three days later, the first twin was delivered, but the neonate died soon after. The second twin remained in utero, and we decided to retain the fetus in utero to reduce the morbidity and mortality associated with a preterm birth. The patient was managed with antibiotics and tocolytics. Cervical cerclage was not performed. The second twin was delivered vaginally at 34 weeks and 5 days of gestation, 128 days after the delivery of the first-born fetus. This neonate was healthy and showed normal development during the 1-year follow-up period. Based on our experience with this case, we propose that delayed-interval delivery may improve perinatal survival and decrease morbidity in the second neonate in highly selected cases.

• Safety and Health at Work
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• v.12 no.3
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• pp.416-420
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• 2021

Hazardous area classification design is required to reduce the explosion risk in process plants. Among the international design guidelines, only IEC 60079-10-1 proposes a new type of zone, namely zone 2 NE, to prevent explosion hazards. We studied how to meet the zone 2 NE grade for a facility handling hydrogen gas, which is considered as most dangerous among explosive gases. Zone 2 NE can be achieved considering the grade of release, as well as the availability and effectiveness of ventilation, which are factors indicative of the facility condition and its surroundings. In the present study, we demonstrate that zone 2 NE can be achieved when the degree of ventilation is high by accessing temperature, pressure, and size of leak hole. The release characteristic can be derived by substituting the process condition of the hydrogen gas facility. The equations are summarized considering relation of the operating temperature, operating pressure, and size of leak hole. Through this relationship, the non-hazardous condition can be realized from the perspective of inherent safety by the combination of each parameter before the initial design of the hydrogen gas facility.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.43-48
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• 2021

This study was conducted using FLACS, a specialized gas accident analysis program. Hydrogen refueling stations subject of safety analysis, consist of compression facilities, storage tanks, and hydrogen piping. The safety analysis of potential risk factors was conducted after reflecting the design specifications of major facilities and components, environmental conditions around hydrogen refueling stations, etc. As of 2021, about 70 refueling stations in Korea are available, and 1,200 are scheduled to be introduced in the next 2040. To prepare for possible accidents caused by potential hazards for the safe distribution of hydrogen refueling stations, we intend to derive hydrogen leakage diffusion scenarios and review their safety.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.21-26
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• 2019

Various pipes are buried in the city as needed, such as water pipes, gas pipes and hydrogen pipes. As the time passes, buried pipes becomes aged due to crack, etc. these pipes has the risk of accidents such as explosion and leakage. To prevent the risks, many pipes are repaired or replaced, but the location of the pipes can also be changed. Failure to identify the location of the altered pipe may cause an accident by touching the pipe. In this paper, we propose a method to detect buried pipes by gathering the GPR images by using GPR and Learning with Faster R-CNN. Then experiments was carried out by raw data sets and data sets augmentation applied to increase the amount of images.

• International journal of steel structures
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• v.18 no.4
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• pp.1200-1209
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• 2018

In this study, a probabilistic framework of the damage assessment of pipelines subjected to extreme hazard scenario was developed to mitigate the risk and enhance design reliability. Nonlinear 3D finite element models of T-joint systems were developed based on experimental tests with respect to leakage detection of black iron piping systems, and a damage assessment analysis of the vulnerability of their components according to nominal pipe size, coupling type, and wall thickness under seismic wave propagations was performed. The analysis results showed the 2-inch schedule 40 threaded T-joint system to be more fragile than the others with respect to the nominal pipe sizes. As for the coupling types, the data indicated that the probability of failure of the threaded T-joint coupling was significantly higher than that of the grooved type. Finally, the seismic capacity of the schedule 40 wall thickness was weaker than that of schedule 10 in the 4-inch grooved coupling, due to the difference in the prohibition of energy dissipation. Therefore, this assessment can contribute to the damage detection and financial losses due to failure of the joint piping system in a liquid pipeline, prior to the decision-making.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.243-249
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• 2019

In this paper, we have developed a device to reduce the standby power consumption that is unnecessarily consumed in unused electrical appliances. The Doppler sensor is used to automatically power off and power off the outlet depending on whether or not a person is present near the outlet. The Doppler sensor uses a coaxial cable trap to design a transmitting antenna and emits a 10 GHz band RF signal and receives a reflected wave signal whose wavelength is reflected from the target object to the receiver to detect an object and recognize human approach. It automatically cuts off and restores standby power to prevent unnecessary power consumption, saving energy and developing a standby power automatic shutdown and recovery device that can prevent the risk of large fires caused by leakage current.

• Journal of Auto-vehicle Safety Association
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• v.13 no.1
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• pp.51-56
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• 2021

As hydrogen is classified as an eco-friendly fuel, vehicles using hydrogen fuel are being developed worldwide. Vehicle fuel hydrogen is stored in cylinders at 70 MPa, so there is a high risk of explosion. Therefore, it is important to inspect hydrogen cylinders in used-vehicles. This study was conducted to improve the inspection method of the cylinders currently mounted on used-hydrogen buses. The inspection method is an image analysis method using a camera. Calcaulation algorithm was developed to quantitatively chech the amount of hydrogen leakage by the image method. As a result of adding a contact angle element to the calculation algorithm suggested by the GTR regulation and comparing it with the experimental data of the GTR regulation, the algorithm reliability was 94%, which secured similarity.

• Convergence Security Journal
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• v.20 no.4
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• pp.209-215
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• 2020

The environment of the Internet provides an efficient communication of the things which are connected. While internet and online service provide us many valuable benefits, online services offered and accessed remotely through internet also exposes us to many different types of security threats. Most security threats were just related to information leakage and the loss of authentication on client-server environment. In 2016, Ahmed et al. proposed an efficient lightweight remote user authentication protocol. However, Kang et al. show that it's scheme still unstable and inefficient. It cannot resist offline identity guessing attack and cannot provide session key confirmation property. Moreover, there is some risk of biometric information's recognition error. In this paper, we propose an improved scheme to overcome these security weaknesses by storing secret data in device. In addition, our proposed scheme should provide not only security, but also efficiency since we only use hash function and XOR operation.