• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.95-102
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• 2014

There are a variety of structures below the surface are buried. In particular, if It is experiencing problems in the city gas pipe or electrical wire, our safety would be greatly jeopardized. Therefore, the underground structures which encounter a variety of pollutants are highly sensitive to corrosion. So if you are not identify the degree of corrosion, it can lead to large accidents such as gas leakage. Until now, person visit directly every underground structure to measure and record manually, but This approach requires a lot of human and material resources and the continuity of management. Therefore, the research to find out the risk factors quickly via the continuous management is needed, and in this paper the structures management systems in the vehicle being moved by combining ICT underground structures for state information wirelessly collects and analyzes system is proposed.

• Journal of Radiation Protection and Research
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• v.44 no.4
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• pp.156-160
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• 2019

Background: To compare the dose of radiation received by the fetus in a pregnant patient irradiated for head and neck cancer using helical tomotherapy and three-dimensional conformal radiation therapy (3DCRT). Materials and Methods: The patient was modeled with a humanoid phantom to mimic a gestation of 26 weeks. Radiotherapy with a total dose of 2 Gy was delivered with both tomotherapy (2.5 and 5.0 cm jaw size) and 3DCRT. The position of the fetus was predicted to be 45 cm from the field edge at the time of treatment. The delivered dose was measured according to the distance from the field edge and the fetus. Results and Discussion: The accumulated dose to the fetus was 1.6 cGy by 3DCRT and 2 and 2.3 cGy by the 2.5 and 5 cm jaw tomotherapy plans. For tomotherapy, the fetal dose with the 2.5 cm jaw was lower than that with the 5 cm jaw, although the radiation leakage was greater for 2.5 cm jaw plan due to the 1.5 fold longer beam-on time. At the uterine fundus, tomotherapy with a 5 cm jaw delivered the highest dose of 2.4 cGy. When the fetus moves up to 35 cm at the 29th week of gestation, the resultant fetal doses for 3DCRT and tomotherapy with 2.5 and 5 cm jaws were estimated as 2.1, 2.7, and 3.9 cGy, respectively. Conclusion: For tomotherapy, scattering radiation was more important due to the high monitor unit values. Therefore, selecting a smaller jaw size for tomotherapy may reduce the fetal dose. however, evaluation of risk should be individually performed for each patient.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.114-119
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• 2015

Nowdays, fossil fuels have been used as an important resource in development of industry. But it is limited and caused climate change such as pollution and global warming. So nuclear fusion research is being issued with tritium to develop eco-friendly and sustainable energy. Republic of Korea is in charge of Storage and Delivery System (SDS) in the International Thermonuclear Experimental Reactor (ITER), weld present in the SDS bottles are easily exposed to the hydrogen embrittlement of special characteristics of the hydrogen in hydrogen atmosphere, When the hydrogen embrittlement is rapidly progresses, the cracking is generated in the weld zone. Due to this cracking, the risk of leakage of tritium into the atmosphere occurs. In this study, hydrogen heat treatment was processed through the Pressure-Composition-Temperature (PCT) device according to the time variation. Also mechanical properties such as rupture strength test, three point bend test and hardness test in accordance with the respective time have been conducted and the fracture was observed by scanning electron microscopy(SEM) after the mechanical properties evaluation.

• Journal of Hydrogen and New Energy
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• v.29 no.4
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• pp.307-316
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• 2018

In this study, the failure mode and effect analysis (FMEA) of hydrogen production process by using the Thermococcus onnurineus NA1 was conducted and advanced methodology to compensate the weakness of previous FMEA methodology was applied. To bring out more quantitative and precise FMEA result for bio-hydrogen production process, fuzzy logic and potential loss cost estimated from ASPEN Capital Cost Estimator (ACCE) was introduced. Consequently, risk for releasing the flammable gases via internal leakage of steam tube which to control the operating temperature of main reactor was caution status in FMEA result without applying the fuzzification and ACCE. Moreover, probability of the steam tube plugging caused by solid property like medium was still caution status. As to apply the fuzzy logic and potential loss cost estimated from ACCE, a couple of caution status was unexpectedly upgraded to high dangerous status since the potential loss cost of steam tube for main reactor and decrease in product gases are higher than expected.

• Convergence Security Journal
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• v.16 no.5
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• pp.33-40
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• 2016

Credit card is means of payment used like cash in terms of function and its users have increased consistently. With development of Internet and electronic commerce a role as payment method of credit card has been growing. But as the risk which results from centralized information and online increases, credit card fraud is also growing. Card theft and loss are decreasing due to countermeasure of card companies and financial supervisory authorities, while card forge and identity theft are increasing. Recently because of frequent personal information leakage and deregulation of financial security following easy-to-use payment enforcement, customer's anxiety about card fraud is growing. And the increase of card fraud lowers trust on credit system as well as causes social costs. In this paper, the security problems of card operating system are addressed in depth and the measures such as immediate switch to IC card terminals, introduction of new security technology, supervision reinforcement of the authorities are proposed.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.291-301
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• 2018

The purpose of this study is to investigate the factors that affect the perceived awareness and the intention of continuous use by FinTech users and system characteristics. Data collection was carried out by targeting and surveying 600 people living in Gwangju, and office workers using smartphones. As a result, first, self-efficacy, innovation, and fitness for Fin-Tech services were found to influence the degree of perceptual awareness and intent to use of Fin-tech service users. Second, the system characteristics have a positive effect on perceived awareness and intention of using FinTech service. Third, the hypothesis about the dangers in the user attributes and system properties were dismissed. It seems that the priority concern was regarding the leakage of personal information and security as privacy and the increasing damage cases of financial fraud by electronic financial transactions spill. Therefore, in order to spread FinTech services, it would be effective if a Fin-Tech service strategy could eliminate inconveniences such as the risk of hindering convenience and intention to use by the marketing strategy established by the company.

• Advances in pediatric surgery
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• v.7 no.2
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• pp.112-117
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• 2001

With the advances in neonatal intensive care, pediatric surgeons experience very low birth weight infants, weighing <1,500 g, more frequently. We report our 14 cases of very low birth weight infants with intestinal perforations without congenital causes, at the Asan Medical Center during the 11-year period from 1989 to 2000. The average birth weight was 919 g(563-1,490), and average gestational age was 206 days(161-286). There were nine males and five females, Operation was performed at an average age of 14.0 days(3-38). Ten neonates with symptomatic PDA were given indomethacin in an attempt to close the ductus. Bowel perforation involved the jejunum in two and ileum in twelve. At laparotomy, there were seven focal intestinal perforations, five typical NEC, one intussusception, and an unknown cause, Four neonates underwent resection and anastomosis of the bowel, and nine underwent exteriorization. One underwent resection and anastomosis after peritoneal drainage. Four patients had postoperative complications; two leakage of anastomosis, one stoma necrosis, and one internal herniation. Seven of fourteen patients survived(50.0 %). Seven patients died of septic complication. There was a significant difference in the birth weight and gestational age in survivors compared with those who died(p<0.05). There was an increased risk of bowel perforation in indomethacin treatment for PDA. Careful clinical observation and keen judgment are essential for this particular group of infants.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.331-337
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• 2008

Polycyclic aromatic hydrocarbons (PAHs) derived from leakage of fossil fuels and incomplete combustion of organic materials have been considered as harmful contaminants in environments. This study evaluated the effect of benzo[k]fluoranthene (BkF), one of the PAHs, using the multiple biomarkers and applied the integration model with those biomarker responses. After 10 days of the exposure at the measured concentrations of BkF (6, 25, and 45 ${\mu}g\;L^{-1}$), the changes of the four biomarkers, that is, 7-ethoxyresorufin-O-deethylase (EROD), DNA single-strand breaks (Comet), acetylcholinesterase (AChE) and vitellogenin (VTG) in the common carp (Cyprinus carpio) were observed. The standardized values of four biomarker responses were computed and integrated as star plots, representing Integrated Biomarker Respnse (IBR) values. DNA damage was induced in a dose-dependent manner, and increased significantly compared with that in the control. EROD and VTG levels were significantly elevated at low concentrations of BkF. On the other hand, AChE activities were not altered by BkF. IBR values increased as the exposure concentrations increased. Thus, the metabolic, endocrine and genetic changes of the biomarker responses in the common carp exposed to BkF should be considered in the case of the ecological risk assessment of the BkF in fish and it can be used as a biomonitoring tool in aquatic ecosystems. In addition, star plots can be used as a useful analysis tool in multibiomarker integration approach.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.266-271
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• 1994

Between 1985 and 1993, 29 children from 1 to 15 years of age have undergone cardiac valve replacements at Buchon Sejong Hospital. The patients were composed of 20 males and 9 females and 17 patient had congenital heart disease and 12 patients had acquired heart disease. Two of these patients have had second valve replacements due to paravalvular leakage and valve thrombosis. Single valve replacements were 29 and double valve replacements were 2. All the patients had received prosthetic valves except one. Among the 25 patients who had definite post-operative records, the overall mortality was 12%[4% was early mortality and 8% was late mortality].25 patients were followed up with coumadin anticoagulation for total 633 patient-months[minimum 2 months to maximum 93 months, mean 25.3 months] and actuarial survival rate was 88.5 $\pm$ 6.3% at 7 years and event free rate was 70.3 $\pm$ 11.7% at 7 years. These results suggest that pediatric valve replacements can now be performed at a low operative risk although various problems are still remained and the choice of valve is prosthetic valve mainly due to its durability at the present time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.1027-1034
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• 2017

Recently, OTP (One-time-Password) log-in methods have been used in many areas to prevent leakage of personal information and enhance security. The OTP method is primarily used for security of bank personal account, this is one of the sophisticated security ways in which one time password is generated and checked to enhance security. Digital door locks frequently used in everyday life require convenience and safety simultaneously. Meanwhile, related technologies for digital door locks are evolving, but methods for enhancement of security are still unsatisfactory. Generally, the digital door lock using password input type has been most commonly used and especially it provides more convenience, but it has some problems such as password exposure and password oblivion. Therefore, in this study, we propose and implement the OTP-based digital door lock system with enhanced security and convenience features but without the risk of password exposure and oblivion.