• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.27-35
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• 2024

Fuel gases such as methane and propane are used in explosion hazardous area of domestic plants and can form non-uniform mixtures with the influence of process conditions due to leakage. The fire-explosion risk assessment using literature data measured under uniform mixtures, damage prediction can be obtained the different results from actual explosion accidents by gas leaks. An explosion characteristics such as explosion pressure and flame velocity of non-uniform gas mixtures with concentration change similar to that of facility leak were examined. The experiments were conducted in a closed 0.82 m long stainless steel duct with observation recorded by color high speed camera and piezo pressure sensor. Also we proposed the quantification method of non-uniform mixtures from a regression analysis model on the change of concentration difference with time in explosion duct. For the non-uniform condition of this study, the area of flame surface enlarged with increasing the concentration non-uniform in the flame propagation of methane and was similar to the wrinkled flame structure existing in a turbulent flame. The time to peak pressure of methane decreased as the non-uniform increased and the explosion pressure increased with increasing the non-uniform. The ranges of K_G (Deflagration index) of methane with the concentration non-uniform were 1.30 to 1.58 [MPa·m/s] and the increase rate of K_G was 17.7% in methane with changing from uniform to non-uniform.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.7-11
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• 2024

Pump car is an equipment that transports concrete products as needed to the place where they are poured. In order to pour a large amount of concrete in a short period of time, using a pump car is the most efficient in terms of economic efficiency and quality control. However, recently, many casualties have occurred due to boom damage during concrete pouring, so this study suggests that improvements are needed in the equipment manufacturing stage, inspection standards for old equipment, and equipment rental system. The reason is that, as a result of the finite element analysis of the pump car, the significant stress acting at the second stage of the boom and the maximum stress at the top of the boom were found to be 895.39 MPa, and M.S. Since it was evaluated the lowest at 0.04, the need for reinforcement was recognized. And it was confirmed that the 2nd stage boom was the most stressful and vulnerable part of the 1st to 5th stage booms. Therefore, it is necessary to increase the thickness and rigidity of members at the design and manufacturing stage, and to reinforce the steel plates of currently used equipment. In addition, it is urgent to establish a system that makes non-destructive testing mandatory for all general construction machinery and holds inspection agencies responsible for missing boom defects during non-destructive testing and regular inspections.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.4
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• pp.291-297
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• 2023

Gastritis is an inflammation of the gastric mucosa and gastric ulcers are a break in the mucosa of the stomach lining. Past research on gastritis and gastric ulcers has been mainly conducted from the perspective that environmental factors are the primary cause of these gastric diseases. However, recently the importance of genetic factors has been emphasized due to current developments in genetic research. The SLC25A26 gene is believed to be associated with the accumulation of reactive oxygen species. Oxidative stress promotes an inflammatory response, which increases the production of free radicals and causes cellular damage, and these lead to the development of gastric diseases. In this study, the correlation between SLC25A26 and gastric diseases was analyzed. Polymorphisms in SLC25A26 were analyzed in 1,369 domestic gastric disease patients and 7,471 healthy controls. As a result, 11 single nucleotide polymorphisms (SNPs) (in the genotype) and 13 SNPs (in the imputation) showed statistical significance (P<0.05), and high relative risk of gastric diseases. Among them, the rs13874 allele of SLC25A26 showed a highly significant association with gastric diseases. In the genotype-based mRNA expression analysis, the minor allele (C) group showed increased mRNA expression and this could increase oxidative stress. In conclusion, SLC25A26 polymorphisms are associated with gastric diseases. These results may provide a basis for new guidelines for gastric disease management in the Korean population.

• Land and Housing Review
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• v.15 no.2
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• pp.57-71
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• 2024

This study aims to develop an evaluation method for solar power facilities considering disaster impacts and to analyse the vulnerabilities of existing facilities. Haenam-gun in Jeollanam-do, where the reassessment of existing facilities is urgent, was selected as the study area. To evaluate the vulnerability from a more objective perspective, principal component analysis and entropy methods were utilised. Seven vulnerability assessment indicators were selected: maximum hourly rainfall, maximum wind speed, number of typhoon occurrence days, number of rainfall days lasting more than five days, maximum daily rainfall, impermeable area ratio, and population density. Among these, maximum hourly rainfall, maximum wind speed, maximum daily rainfall, and number of rainfall days lasting more than five days were found to have the highest weights. The overlay of the derived weights showed that the southeastern regions of Haenam-eup and Bukil-myeon were classified as Grade 1 and 2, whereas the northern regions of Hwawon-myeon, Sani-myeon, and Munnae-myeon were classified as Grade 4 and 5, indicating differences in vulnerability. Of the 2,133 facilities evaluated, 91.1% were classified as Grade 3 or higher, indicating a generally favourable condition. However, there were more Grade 1 facilities than Grade 2, highlighting the need for countermeasures. This study is significant in that it evaluates solar power facilities considering urban disaster resilience and is expected to be used as a basic resource for the installation of new facilities or the management and operation of existing ones.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.83-89
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• 2024

After the end of the service of Internet Explorer, the use of ActiveX ended, and the Non-ActiveX policy spread. HTML5 is used as a standard protocol for web pages established based on the Non-ActiveX policy. HTML5, developed in the W3C(World Wide Web Consortium), provides a better web application experience through API, with various elements and properties added to the browser without plug-in. However, new security vulnerabilities have been discovered from newly added technologies, and these vulnerabilities have widened the scope of attacks. There is a lack of research to find possible security vulnerabilities in HTML5-applied websites. This paper proposes a model for detecting tags and attributes with web vulnerabilities by detecting and analyzing security vulnerabilities in web pages of public institutions where plug-ins have been removed within the last five years. If the proposed model is applied to the web page, it can analyze the compliance and vulnerabilities of the web page to date even after the plug-in is removed, providing reliable web services. And it is expected to help prevent financial and physical problems caused by hacking damage.

• Information Systems Review
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• v.21 no.3
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• pp.1-26
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• 2019

Now we are facing with a possibility of having crimes, which have been only possible offline, in cyber spaces as well.Especially, a recent growth in the use of SNS, promoted by popularization of smart phones, also has led an abrupt increase in cyber crime. It would be important to have a understanding of cyber crime and its characteristics by type as well as factors associated with each type of cyber crime in order to devise appropriate preventive measures against cyber crime. However, most of the previous studies on cyber crimesolely made through literature review or indirect approaches. Therefore, this study has been designed to conduct the interview with actual suspects(criminals) of cyber crime to address factors of cyber crime and to devise specific preventive measures and countermeasures against cyber crime. Especially, among various types of cyber crime, this study aims at addressing the 'trades' and 'financial transaction' of crimes committed using the information and communication network and the 'cyber libel/insult'of crimes committed using unlicensed contents, which have been soared recently and become significant issues. The findings of this study could be beneficial for the society since it has managed to conduct the interview and reveal relationships among major factors of cyber crime. The findings of this study could be used for devising and developing proper preventive and countermeasures against cyber crime, in turn reducing and preventing its damage.

• Information Systems Review
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• v.20 no.1
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• pp.159-177
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• 2018

With an extensive proliferation of information and communication technology, the volume and amount of digital information collected and utilized on the Internet have been increasing rapidly. Also on the rapid rise are side effects such as unintended breach of accumulated personal information and consequent invasion of personal privacy. Informational self-determination is rarely practiced, despite various states' legal efforts to redress data subjects' damage. Personal health information, in particular, is a subcategory of personal information where informational self-determination is hardly practiced enough. The observation is contrasted with the socio-economic inconvenience that may follow due to its sensitive nature containing individuals' physical and health conditions. This research, therefore, reviews factors of self-determination on personal health information while referring to the protection motivation theory (PMT), the long-time framework to understand personal information protection. Empirical analysis of 200 data surveyed reveals threat-appraisal (perceived vulnerability and perceived severity of threats) and coping-appraisal (perceived response effectiveness), in addition to individual levels of concern regarding provided personal health information, influence self-determination to protect personal health information. The research proposes theoretical findings and practical suggestions along with reference for future research topics.

• Information Systems Review
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• v.19 no.4
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• pp.27-42
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• 2017

With the rapid development in network, graphic technology, and digital technology, content industry is emerging as an important industry for new cultural development and economic development. The development in digital content technology has remarkably expanded the generation and distribution of contents, thereby creating new value and extending into a large distribution market. However, the ease of distribution and duplication, which characterizes digital technology, has increased the circulation of illegal contents due to illegal copying, theft, and alteration. The damage caused by this illegal content is severe. Currently, a copyright protection system targeting online sites is available. By contrast, no system has been established for offline companies that sell offline genuine content, which compete with online companies. The demand for content of overseas tourists is increasing due to the Korean wave craze. Nevertheless, many offline content providers have lost competitiveness due to illegal content distribution with online companies. In this study, we analyzed the case and status of similar copyright certification systems in Korea and overseas through previous research and studied a system to certify the offline genuine contents business. In addition to the case analysis, we focused on interviews obtained through in-depth interviews with the copyright stakeholders. We also developed a certification framework by establishing the certification domain, certification direction, and incentive of the certification system for offline businesses with genuine content. Selected certification direction is ethical, open, inward, store, and rigid (post evaluation). This study aimed to increase awareness among consumers about the use of genuine content and establish a transparent trading order in a healthy content market.

• Journal of Korea Water Resources Association
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• v.57 no.5
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• pp.359-369
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• 2024

Korea prepares for potential floods by designating June 21st to September 20th as the flood season. However, many dams in Korea have suffered from extreme floods caused by different climate patterns, as in the case of the longest consecutive rain of 54 days in the 2020's flood season. In this context, various studies have tried to develop novel methodologies to reduce flood damage, but no study has ever dealt with the validity of the current statutory flood season thus far. This study first checked the validity of the current flood season through the observation data in the 21st century and proved that the current flood season does not consider the effects of increasing precipitation trends and the changing regional rainfall characteristics. In order to deal with these limitations, this study suggested seven new alternative flood seasons in the research area. The rigid reservoir operation method (ROM) was used for reservoir simulation, and the long short-term memory (LSTM) model was used to derive predicted inflow. Finally, all alternatives were evaluated based on whether if they exceeded the design discharge of the dam and the design flood of the river. As a result, the floods in the shifted period were reduced by 0.068% and 0.33% in terms of frequency and duration, and the magnitude also decreased by 24.6%, respectively. During this period, the second evaluation method also demonstrated that flood decreased from four to two occurrences. As the result of this study, the authors expect a formal reassessment of the flood season to take place, which will ultimately lead to the preemptive flood response to changing precipitation patterns.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.33-42
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• 2024

The green peach aphid, Myzus persicae is a representative agricultural insect pest that is polyphagous and causes serious damage to tobacco, potatoes, peppers, cabbage, and peaches. In this study, we analyzed the level of development of insecticide resistance to λ-cyhalothrin, imidacloprid, and flupyradifurone and the point mutations (R81T, L1014F, M918L) in 12 field populations of M. persicae. In addition, the expression level of CYP6CY3, a cytochrome P450 gene, was analyzed through qRT-PCR. As a result, λ-cyhalothrin showed high resistance ratio (RR) of > 200 in all 12 populations. Imidacloprid and flupyradifurone showed high RR of >200 in YS, UR, HY, and WJ populations. The R81T was detected in approximately 50%, L1014F in approximately 33.3%, and M918L in 100% of the 12 populations. Additionally, the expression level of subunit CYP6CY3 was highest in imidacloprid-resistant population (YS). These results suggest that M918L point mutation can be used as λ-cyhalothrin-resistance molecular diagnostic and R81T point mutation and the high expression of CYP6CY3 can be used as imidacloprid-resistance molecular diagnostic markers.