• Journal of Information Technology Applications and Management
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• 제26권2호
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• pp.27-40
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• 2019

As reliance on information and communication becomes widespread, a variety of information dysfunctions such as hacking, viruses, and the infringement of personal information are also occurring. Korean adolescents are especially exposed to an environment in which they are experiencing information dysfunction. In addition, youth cybercrimes are steadily occurring. To prevent cybercrime and the damage caused by information dysfunction, information security practices are essential. Accordingly, the purpose of this study is to discuss the factors affecting the information security practices of Korean youths, considering information security education, perceived severity, and perceived vulnerability as leading factors of the theory of planned behavior. A questionnaire survey was administered to 118 middle and high school students. Results of the hypothesis test show that information security education affects perceived behavior control, and perceived severity affects attitude. Subjective norms, information security attitudes, and perceived behavioral control were found to influence adolescents' practices of information security. However, perceived vulnerabilities did not affect youths' information security attitudes. This study confirms that information security education can help youths to practice information security. In other words, information security education is important, and it is a necessary element in the information curriculum of contemporary youth. However, perceived vulnerability to youth information security threats did not affect information security attitudes. Consequently, we suggest that it is necessary to strengthen the contents of the information security education for Korean youths.

• 대한금속재료학회지
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• 제49권1호
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• pp.32-39
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• 2011

The present investigation was performed on the die compaction and sintering behavior of Fe micro-nano mixed powder with a mixed binder for powder injection molding. Warm die compaction of the feedstock for simulation of the static injection molding process was conducted using a cylindrical mold of 10 mm diameter at $100^{\circ}C$ under 4MPa. The die compaction of the micro-nanopowder feedstock underwent a uniform molding behavior showing a homogeneous distribution of nanopowders among the micropowders without porosity and distortion. After debinding, the powder compact maintained a uniform structure without crack and distortion, leading to a high green density of 64.2% corresponding to the initial powder loading of 65%. The sintering experiment showed that the micro-nanopowder compact underwent a near full and isotropic densification process during sintering. It was observed that the nanopowders effectively suppressed the growth of micropowder grains during densification process. Conclusively, the use of nanopowder for PIM feedstock might provide a new concept for processing a full density PIM parts with fine microstructure.

• 대한금속재료학회지
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• 제46권3호
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• pp.144-149
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• 2008

Equal channel angular pressing (ECAP) has been studied intensively over the decade as a typical top-down process to produce ultrafine/nano structured materials. ECAP has successfully been applied for a processing method of severe plastic deformation to achieve grain refinement of magnesium and to enhance its low ductility. However, difficult-to-work materials such as magnesium and titanium alloys were susceptible to shear localization during ECAP, leading to surface cracking. The front pressure, developed by Australian researchers, can impose hydrostatic pressure and increase the strain level in the material, preventing the surface defect on workpiece. In the present study, we investigated the deformation and fracture behavior of pure magnesium using experimental and numerical methods. The finite element method with different ductile fracture models was employed to simulate plastic deformation and fracture behavior of the workpiece.

• 한국지반환경공학회 논문집
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• 제23권12호
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• pp.33-39
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• 2022

본 논문은 터널을 구성하고 있는 구성요소(지보재, 주변지반)들의 열화로 인한 터널의 장기거동을 수치해석을 이용하여 예측/분석하였다. 터널의 구성요소들은 시간이 지남에 따라 열화를 겪게 된다. 이러한 열화로 인해 터널의 장기적인 안정성을 예측하는 것은 매우 중요한 이슈이다. 따라서 본 연구에서는 열화를 예측하는 모델을 제시하였으며, 이 모델은 두 개의 파라미터로 구성되어 있다. 그 중 하나는 부재 및 주변지반의 열화로 인해 남아있는 잔류강도를 나타내며, 나머지 하나는 열화되는 모양을 표시한다. 제안한 열화 모델을 이용하여 수치해석을 수행하여 터널의 장기거동을 예측하였다. 그 결과 열화로 인해 터널 주변 지반의 이완응력이 증가하여 터널의 장기적인 안정성에 영향을 미치고 있음을 알 수 있었다.

• Corrosion Science and Technology
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• 제22권6호
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• pp.478-483
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• 2023

This study examined the corrosion behavior of bimetal materials composed of Fe-Ni alloy and Fe-Ni-Mo alloy, both suitable for use in electromagnetic switches. Electrochemical polarization and weight loss measurements revealed that, in contrast to Fe-Ni alloy, which exhibited pseudo-passivity behavior, Fe-Ni-Mo alloy had higher anodic current density, displaying only active dissolution and greater weight loss. This indicated a lower corrosion resistance in the Fe-Ni-Mo alloy. Equilibrium calculations for the phase fraction of precipitates suggested that the addition of 1 wt% Mo may lead to the formation of second-phase precipitates, such as Laves and M₆C, in the γ matrix. These precipitates might degrade the homogeneity of the passive film formed on the surface, leading to localized attacks during the corrosion process. Therefore, considering the differences in corrosion kinetics between these bimetal materials, the early degradation caused by galvanic corrosion should be prevented by designing a new alloy, optimizing heat treatment, or implementing periodic in-service maintenance.

• 대한지역사회영양학회지
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• 제10권2호
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• pp.163-173
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• 2005

School Lunch Program (SLP) should provide adequate and qualitative nutritional food for student's growth and proper food habit. With this fact, this study divided 524 middle school students who resided in Jeonju, Jellabukdo into two groups, SLP or non SLP according to whether they were provided SLP or not. Then this research estimate each group's nutritional knowledge, nutritional attitude, dietary behavior, balance of three meals, and health checking their clinical symptom to investigate the effects of the SLP. This research applied anthropometric data, questionnaires and food intake data using 24 hours recall method. Each group's age average was same as 14.0 years old respectively. The average score of nutritional knowledge and condition of balance of lunch were significantly higher in SLP group than those of non-SLP group, although, there were no significant differences in the scores of nutritional attitude, dietary behavior, and balance of breakfast and dinner within both groups. This research showed that SLP had positive role on nutritional knowledge and balanced lunch. However, current SLP is not sufficient to cause change the nutritional attitude and dietary behavior. To make more applicable and effective result of SLP leading nutritional attitude changes and development of appropriate dietary behavior, certain level of nutritional education to the student may be important.

• 성인간호학회지
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• 제28권2호
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• pp.202-212
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• 2016

Purpose: The purpose of this study was to assess the relationship between cognitive function impairment and quality of life (QoL) among patients with breast cancer. Specifically, the intention was to verify the mediating effects for promoting behaviors leading to better health and QoL. Methods: A purposive sample of 152 patients undergoing chemotherapy was recruited. A cross-sectional survey design was used. Data were collected using four instruments: Everyday Cognition Scale, Korean Mini-Mental State Examination, Functional Assessment of Cancer Therapy-Breast Cancer Version 4, and Health Promoting Lifestyle Profile. Results: The mean score for subjective cognitive decline was 65.84; the health promotion behavior was 95.89, and 83.34 for QoL. Health promotion behavior was directly affected by cognitive decline ($R^2=6.0%$) as was QoL ($R^2=43%$). Subjective cognitive decline (${\beta}=-.57$ p<.001) and health promotion behavior (${\beta}=.37$, p<.001) were seen as predicting factors in QoL and explained 56% ($R^2=56%$). Health promotion behavior had a partial mediating effect in the relationship between self-reported cognitive decline and QoL (Sobel test: Z=-3.37, p<.001). Conclusion: Based on the findings of this study, nursing intervention programs focusing on managing cognitive decline and promoting health promotion behavior are highly recommended to improve QoL in cancer patients.

• 대한지역사회영양학회지
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• 제13권2호
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• pp.189-198
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• 2008

This study investigated the influences of the beverage intake on food behavior and personality for 1295 adolescents. The results were as follows. The favorite beverage was 'fruit juice', and preference of 'coffee' was the lowest. 'Milk and dairy product' was highest and 'milkshake' was lowest in intake frequency of beverage. The preference correlated positively(r = 0.391) with the intake frequency of beverage, especially high in 'green tea and black tea'(r = 0.622), 'coffee'(r = 0.581), 'carbonated drink'(r = 0.538), and 'milk and dairy product'(r = 0.501). The explanation power(R2) of beverage preference on beverage intake was 0.153. The explanation power($R^2$) of beverage intake on food behavior was 0.127, and 'carbonated drink' and 'coffee' as well as 'milkshake' had a negative influence on food behavior: however, 'milk and dairy product', 'green tea and black tea', and 'fruit juice' had a positive influence on food behavior. The relationship of beverage intake and sociality was very low($R^2$= 0.013), and 'isotonic drink' and 'green tea and black tea' had a positive influence on sociality. The relationship between beverage intake and anger expression was also very low. 'Coffee' showed a positive relationship with anger-in. 'Carbonated drink' and 'milkshake' showed a positive result with anger-out. 'Milkshake' showed a negative relation with anger-control, but 'green tea and black tea' and 'milk and dairy product' showed a positive relation. From these results, it was necessary to develop the practical nutritioneducation program on proper beverage choice for adolescents leading to better metal and physical status.

• Journal of Information Science Theory and Practice
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• 제8권3호
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• pp.30-46
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• 2020

This research aimed (1) to study and analyze the ability of current information retrieval (IR) systems based on views of information behavior (IB), and (2) to propose a conceptual framework for an IB model based on the collaboration between the system and user, with the intent of developing an IR system that can apply intelligent techniques to enhance system efficiency. The methods in this study consisted of (1) document analysis which included studying the characteristics and efficiencies of the current IR systems and studying the IB models in the digital environment, and (2) implementation of the Delphi technique through an indepth interview method with experts. The research results were presented in three main parts. First, the IB model was categorized into eight stages, different from traditional IB, in the digital environment, which can correspond to all behaviors and be applied to with an IR system. Second, insufficient functions and log file storage hinder the system from effectively understanding and accommodating user behavior in the digital environment. Last, the proposed conceptual framework illustrated that there are stages that can add intelligent techniques to the IR system based on the collaboration perspective between the user and system to boost the users' cognitive ability and make the IR system more user-friendly. Importantly, the conceptual framework for the IB model based on the collaboration perspective between the user and system for IR assisted the ability of information systems to learn, recognize, and comprehend human IB according to individual characteristics, leading to enhancement of interaction between the system and users.

• Journal of Information Science Theory and Practice
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• 제7권2호
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• pp.40-53
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• 2019

Although fake news has been present in human history at any time, nowadays, with social media, deceptive information has a stronger effect on society than before. This article answers two research questions, namely (1) Is the dissemination of fake news supported by machines through the automatic construction of filter bubbles, and (2) Are echo chambers of fake news manmade, and if yes, what are the information behavior patterns of those individuals reacting to fake news? We discuss the role of filter bubbles by analyzing social media's ranking and results' presentation algorithms. To understand the roles of individuals in the process of making and cultivating echo chambers, we empirically study the effects of fake news on the information behavior of the audience, while working with a case study, applying quantitative and qualitative content analysis of online comments and replies (on a blog and on Reddit). Indeed, we found hints on filter bubbles; however, they are fed by the users' information behavior and only amplify users' behavioral patterns. Reading fake news and eventually drafting a comment or a reply may be the result of users' selective exposure to information leading to a confirmation bias; i.e. users prefer news (including fake news) fitting their pre-existing opinions. However, it is not possible to explain all information behavior patterns following fake news with the theory of selective exposure, but with a variety of further individual cognitive structures, such as non-argumentative or off-topic behavior, denial, moral outrage, meta-comments, insults, satire, and creation of a new rumor.