• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.919-928
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• 2012

The applications of computers and communication system and network technologies in nuclear power plants have expanded recently. This application of digital technologies to the instrumentation and control systems of nuclear power plants brings with it the cyber security concerns similar to other critical infrastructures. Cyber security risk assessments for digital instrumentation and control systems have become more crucial in the development of new systems and in the operation of existing systems. Although the instrumentation and control systems of nuclear power plants are similar to industrial control systems, the former have specifications that differ from the latter in terms of architecture and function, in order to satisfy nuclear safety requirements, which need different methods for the application of cyber security risk assessment. In this paper, the characteristics of nuclear power plant instrumentation and control systems are described, and the considerations needed when conducting cyber security risk assessments in accordance with the lifecycle process of instrumentation and control systems are discussed. For cyber security risk assessments of instrumentation and control systems, the activities and considerations necessary for assessments during the system design phase or component design and equipment supply phase are presented in the following 6 steps: 1) System Identification and Cyber Security Modeling, 2) Asset and Impact Analysis, 3) Threat Analysis, 4) Vulnerability Analysis, 5) Security Control Design, and 6) Penetration test. The results from an application of the method to a digital reactor protection system are described.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.55-64
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• 2014

In a Web application, you can pass without restrictions special network security devices such as IPS and F/W, URL parameter, which is an important element of communication between the client and the server, is forwarded to the Web server. Parameters are modulated by an attacker requests a URL, disclose confidential information or through e-commerce, can take financial gain. Vulnerability parameter manipulation thereof cannot be able to determine whether to operate in only determined logical application, blocked with Web Application Firewall. In this paper, I will present a technique OTACUS(One-Time Access Control URL System) to complement the shortcomings of the measures existing approaches. OTACUS can be effectively blocked the modulation of the POST or GET method parameters passed to the server by preventing the exposure of the URL to the attacker by using clean URL technique simplifies complex URL that contains the parameter. Performance test results of the actual implementation OTACUS proves that it is possible to show a stable operation of less than 3% increase in the load.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.1
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• pp.77-86
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• 2020

Purpose : This study is a descriptive survey research that examines the effect of nursing students' satisfaction in major and consciousness of biomedical ethics on nursing professionalism. Methods : The research subjects consisted of junior and senior nursing students enrolled in four colleges located in City B, South Korea Structured questionnaires were distributed to the subject and a total of 262 copies of survey responses were analyzed. The collected data were analyzed by frequency, percentage, mean and standard deviation, t-test, and analysis of variance (ANOVA) using SPSS/WIN 22.0 program. The correlation relationship was investigated based on the Pearson correlation coefficient. Multiple regression was used to capture the effect on the nursing professionalism. Results : A positive correlation was observed between the nursing students satisfaction in major and consciousness of biomedical ethics (r=.280, p<.001), between satisfaction in major and nursing professionalism (r=.581, p<.001), and between consciousness of biomedical ethics and nursing professionalism (r=.290, p<.001). General satisfaction (β=.227, p=.001), and relationship satisfaction (β=.248, p=.000) among major satisfaction had the strongest prediction power for the nursing professionalism of nursing students, followed by right to life of fetus (β=.190, p=.000) among consciousness of biomedical ethics and motivation for admission (β=.137, p=.006). These predictors explained 36.9 % of the variable of nursing professionalism. Conclusion : Based on this study result, repeated studies are required that can confirm diverse influential factors on the nursing professionalism of nursing students. Operation of curriculums and development of programs that increase the nursing students' satisfaction in major and foster their nursing professionalism are required in the future.

• Journal of Korea Spatial Information System Society
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• v.4 no.1 s.7
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• pp.39-46
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• 2002

In distributed spatial database systems, users nay issue a query that joins two relations stored at different sites. The sheer volume and complexity of spatial data bring out expensive CPU and I/O costs during the spatial join processing. This paper shows a new spatial join method which joins two spatial relation in a parallel way. Firstly, the initial join operation is divided into two distinct ones by partitioning one of two participating relations based on the region. This two join operations are assigned to each sites and executed simultaneously. Finally, each intermediate result sets from the two join operations are merged to an ultimate result set. This method reduces the number of spatial objects participating in the spatial operations. It also reduces the scope and the number of scanning spatial indices. And it does not materialize the temporary results by implementing the join algebra operators using the iterator. The performance test shows that this join method can lead to efficient use in terms of buffer and disk by narrowing down the joining region and decreasing the number of spatial objects.

• Archives of Plastic Surgery
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• v.45 no.4
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• pp.357-362
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• 2018

Background The most common complication after tendon repair is the development of adhesion, with subsequent rupture. Methods In this study, we present a new method in which the tendon healing contact surface is increased to reduce these complications. The tendons of chickens in groups 1, 3, and 5 were transversely cut and repaired with in the traditional fashion with double-modified Kessler method and 5/0 polypropylene. In the other groups, 3 mm of the tendon was removed from the proximal half of the upper end and from the distal half of the lower end of the tendon, and they were repaired with the modified Kessler method. The tendons of the chickens in groups 1 and 2 were evaluated immediatelly after surgery. Groups 3 and 4 were evaluated at 4 weeks after surgery. Groups 5 and 6 were evaluated at 6 weeks. Results Increases in transient inflammation and connective tissue formation were observed more clearly in the group treated with the new method in histopathological investigations at weeks 4 and 6. The stretching test showed statistically significant differences between groups 3 and 4 (P<0.05) and groups 5 and 6 (P<0.05). Conclusions When repairing tendons with the new method, the healing surface increases and the direction of collagen fibers at the surface changes. Because of these effects, the strength of the tendon healing line increases; we therefore expect that this technique will enable patients to safely engage in early active exercise after the operation, with less risk of tendon rupture.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.184-187
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• 2007

Hydrogen could be produced from any substance containing hydrogen atoms, such as water, hydrocarbon (HC) fuels, acids or bases. Hydrocarbon fuels couold be converted to hydrogen-rich gas through reforming process for hydrogen production. Even though fuel cell have high efficiency with pure hydrogen from gas tank, it is more beneficial to generate hydrogen from city gas (mainly methane) in residential application such as domestic or office environments. Thus hydrogen is generated by reforming process using hydrocarbon. Unfortunately, the reforming process for hydrogen production is accompanied with unavoidable impurities. Impurities such as CO, $CO_2$, $H_2S$, $NH_3$, and $CH_4$ in hydrogen could cause negative effects on fuel cell performance. Those effects are kinetic losses due to poisoning of electrode catalysts, ohmic losses due to proton conductivity reduction including membrane and catalyst ionomer layers, and mass transport losses due to degrading catalyst layer structure and hydrophobic property. Hydrogen produced from reformer eventually contains around 73% of $H_2$, 20% or less of $CO_2$, 5.8% of less of $N_2$, or 2% less of $CH_4$, and 10ppm or less of CO. Most impurities are removed using pressure swing adsorption (PSA) process to get high purity hydrogen. However, high purity hydrogen production requires high operation cost of reforming process. The effect of carbon dioxide on fuel cell performance was investigated in this experiment. The performance of PEM fuel cell was investigated using current vs. potential experiment, long run (10 hr) test, and electrochemical impedance measurement when the concentrations of carbon dioxide were 10%, 20% and 30%. Also, the concentration of impurity supplied to the fuel cell was verified by gas chromatography (GC).

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.565-568
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• 2006

A 46-year-old man who had been diagnosed with esophageal tumor by PET-CT was admitted to our hospital for operation. Preoperative examination and intraoperative findings showed leiomyoma-like lesion and enucleation was done, but an immunohistochemical test on the case found gastrointestinal stromal tumor (GISTs). GISTs are very rarely found in the esophagus. As GISTs differ from leiomyoma pathogenetically and clinically, different treatments and follow-up strategies are required. The patient is under continuous observation to check recurrence and metastasis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.108-115
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• 2011

Virtual Robot Education System (VRES), which is for programming education with a Lego Mindstorm NXT robot, is designed and implemented. Through this system, program learners can edit source code, compile, download it into the robot, and run their executive program. In order to observe it, the system includes web cameras and provide monitoring services. Thus, students are able to verify the operation of robot into which they download their program in detail and to debug if necessary. In addition, we design a new simple user-friendly programming language and a corresponding compiler for it. With those tools, learner can more easily create programs for NXT robot and test them than Java language. A educator can control and manage the robot for the subject of a class with direct control mode of our system. Therefore, the proposed system is able to support students to learn robot programming during or after regular classes with web browsers through Internet.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.940-946
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• 2010

In this paper, we proposed the internal antenna on PCB(Planar Circuit Board) for achieving WWAN(Wireless Wide Area Network) operation in the laptop computer. The proposed antenna has a metal structure instead of printed pattern on PCB to improve the antenna characteristics for GSM850/900 bands. Compared to PCB embedded antenna without metal structure, the proposed antenna occupies similar area of $74{\times}11{\times}0.5\;mm^3$ with before and the bandwidth of the proposed one for GSM850/900 bands is increased 13 MHz than before. Further we confirmed that the proposed antenna has higher radiation gain of -4.45~-2.29 dBi for GSM850/900 bands than PCB embedded antenna without metal structure.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.122-129
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• 2017

Objectives: Most of the $PM_{10}$ in subway stations is spread by the train-induced wind from the tunnels. Therefore, in order to improve air quality in subway stations, it is important to remove the $PM_{10}$ from the tunnels. After the installation of PSD (platform screen doors), the influence of train-induced wind and $PM_{10}$ at the platform has decreased, but is estimated to have increased in subway tunnels. This study was conducted to investigate the control of $PM_{10}$ in subway tunnels by applying a 500-fold diluted solution mixed with a humectant using a natural polymer. Methods: For this purpose, we tested the dust reduction effect in a laboratory and corrosion test and water pollution using fish and aquatic plants for the natural dust collecting agent. In the tunnel of a subway station, we used the natural dust collecting agent over 15 days. The study was carried out on $PM_{10}$ control during operation, which accounts for more than 70% of subway dust. Results: As results, the natural dust collecting agent exhibited an excellent dust control effect, and it was safe for water quality and soil. It showed the effect of controlling $PM_{10}$ in the subway tunnel by 49.5- 64.7% over 15 days. The use of the dust collecting agent for the control of $PM_{10}$ could be confirmed in the subway. Conclusion: It is necessary to clearly explain the major portions of chemical components contained in $PM_{10}$ to figure out the characteristics of $PM_{10}$ and to develop effective reduction measures to decrease the adverse effects of $PM_{10}$ in the subway.