• Progress in Superconductivity
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• v.1 no.1
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• pp.36-41
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• 1999

Methods for mode identification and accurate measurements of the unloaded Q ($Q_0$) of a dielectric-loaded $TE_{01{\delta}}$ mode cavity resonator with HTS endplates are proposed. A resonator with a sapphire rod and $YBa_2Cu_3O_{7-x}$(YBCO) endplates was prepared and its microwave properties were studied at temperatures above 30 K. The $TE_{01{\delta}}$ mode $Q_0$ of the resonator, designed to work as a tunable resonator with variations in the gap distance (s) between the sapphire rod and the top YBCO, was more than 1000000 at s = 0 mm and at 30 K with the resonant frequency of 19.56 GHz. The $TE_{01{\delta}}$ mode $Q_0$ decreases as s increases for s < 2 mm until mode couplings between the $TE_{01{\delta}}$ mode and other modes appeared at s = 2 mm. Significant dependence of the $TE_{01{\delta}}$ mode $Q_0$ on the input and output coupling constants was also observed. Applications of the open-ended $TE_{01{\delta}}$ mode cavity resonator for a tunable resonator with a very high Q as well as a characterization tool for the surface resistance measurements of HTS films are described.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.150-155
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• 2021

Objective: Oxidative stress (OS) plays a key role in the etiology of unexplained male infertility. Coenzyme Q10 (CoQ10) is a potent antioxidant that may improve semen quality and OS in infertile men with idiopathic oligoasthenoteratospermia (OAT), but the underlying mechanism is unknown. Therefore, the present study was undertaken to investigate the effect of CoQ10 on OS markers and sperm DNA damage in infertile patients with idiopathic OAT. Methods: This prospective controlled study included 50 patients with idiopathic OAT and 50 fertile men who served as controls. All patients underwent a comprehensive medical assessment. Patients and controls received 200 mg of oral CoQ10 once daily for 3 months. Semen and blood were collected and analyzed for sperm parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity, catalase, sperm DNA fragmentation (SDF), and serum hormonal profile. Results: The administration of CoQ10 to patients with idiopathic OAT significantly improved sperm quality and seminal antioxidant status and significantly reduced total ROS and SDF levels compared to pretreatment values. Conclusion: CoQ10, at a dose of 200 mg/day for 3 months, may be a potential therapy for infertile patients with idiopathic OAT, as it improved sperm parameters and reduced OS and SDF in these patients.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.112-118
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• 2023

As technology advances, the need for enhanced preparedness against cyber-attacks becomes an increasingly critical problem. Therefore, it is imperative to consider various circumstances and to prepare for cyber-attack strategic technology. This paper proposes a method to solve network security problems by applying reinforcement learning to cyber-security. In general, traditional static cyber-security methods have difficulty effectively responding to modern dynamic attack patterns. To address this, we implement cyber-attack scenarios such as 'Tiny Alpha' and 'Small Alpha' and evaluate the performance of various reinforcement learning methods using Network Attack Simulator, which is a cyber-attack simulation environment based on the gymnasium (formerly Open AI gym) interface. In addition, we experimented with different RL algorithms such as value-based methods (Q-Learning, Deep-Q-Network, and Double Deep-Q-Network) and policy-based methods (Actor-Critic). As a result, we observed that value-based methods with discrete action spaces consistently outperformed policy-based methods with continuous action spaces, demonstrating a performance difference ranging from a minimum of 20.9% to a maximum of 53.2%. This result shows that the scheme not only suggests opportunities for enhancing cybersecurity strategies, but also indicates potential applications in cyber-security education and system validation across a large number of domains such as military, government, and corporate sectors.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.2
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• pp.119-125
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• 2008

This paper presents the polygon-based Q-leaning and Cascade Support Vector Machine algorithm for object search with multiple robots. We organized an experimental environment with ten mobile robots, twenty five obstacles, and an object, and then we sent the robots to a hallway, where some obstacles were lying about, to search for a hidden object. In experiment, we used four different control methods: a random search, a fusion model with Distance-based action making (DBAM) and Area-based action making (ABAM) process to determine the next action of the robots, and hexagon-based Q-learning and dodecagon-based Q-learning and Cascade SVM to enhance the fusion model with DBAM and ABAM process.

• Research in Community and Public Health Nursing
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• v.31 no.1
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• pp.107-118
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• 2020

Purpose: Nursing students are key personnel to take care of people with dementia in the nursing field in future. The purpose of this study was to identify subjective attitudes toward dementia in nursing students. Methods: Q methodology, which is a research method to study people's subjective points of views, was used. Thirty seven Q-statements (Q-sample) were derived from the Q population (Concourse) and were arranged in rank order by each of 42 participants into a normal distribution grid (from -4 to +4). A QUANL program was used to analyze the collected data. Results: Three types of attitudes toward dementia were identified: 'self-guided dementia management', 'national-guided dementia management' and 'facility-guided dementia management.' Conclusion: The results of this study suggest that nursing strategies to improve understanding of dementia and actively cope with dementia should be considered.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.277-285
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• 2010

For regional earthquakes in the Korean Peninsula, the seismic Lg waves have the largest amplitude. Our researches in South Korea found that more reasonable low ${Q_{Lg}}^{-1}$ was obtained as the inter-station distances increase. The other methods such as coda normalization method and multiple lapse time window method also produced that the low ${Q_{Lg}}^{-1}$ is related to the values of seismically inactive region.

• Korean Institute of Interior Design Journal
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• v.13 no.3
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• pp.120-128
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• 2004

The worthness of life of an elderly person is a subjective thing that is based on the individual's sense of values, and it depends on what he or she pursues in life. Therefore, the quality of life is a relative concept and it varies according to individual tastes and changes of values resulted from changes of social framework. The purpose of this study is to furnish information about the basic plan for the increase of Q.O.L. There are three methods used in this study. First is to understand the structure and the factors related to Q.O.L by research and documents. Second, site survey and analysis of urban and rural areas, for example Seoul and Jochiwon, and third, study the condition of the old using SPSS. The result of study to enrich the Q.O.L of the old can be categorized into two ways. First, the old themselves has to satisfy the image of the old who has a high Q.O.L. Second, the community has to support the proper environment for the old to get worth of life.

• Bulletin of the Korean Mathematical Society
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• v.51 no.3
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• pp.739-763
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• 2014

In this paper, the nonlinear matrix equation $$X+\sum_{i=1}^{m}A_i^*X^{-q}A_i=Q(0<q{\leq}1)$$ is investigated. Some necessary conditions and sufficient conditions for the existence of positive definite solutions for the matrix equation are derived. Two iterative methods for the maximal positive definite solution are proposed. A perturbation estimate and an explicit expression for the condition number of the maximal positive definite solution are obtained. The theoretical results are illustrated by numerical examples.

• Journal of Korean Academy of Nursing Administration
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• v.22 no.1
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• pp.57-66
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• 2016

Purpose: This exploratory study was done to categorize medical personnel's perceptions of burnout and analyzed the characteristics. Methods: Q methodology was applied using a 45 Q-sample categorized on an 11-point scale which was completed by nurses and doctors working at a university hospital in Seoul, Korea. Collected data were analyzed using the PC-QUANL program. Results: Medical personnel's perceptions of burnout were categorized into three types; 33.83% of the total variance was explained. The first type was 'functionally deteriorating pressure' the second type was 'daily powerlessness' and the third was 'achievement-oriented re-energization'. Conclusion: There is a need to establish and apply intervention strategies for each type to alleviate medical personnel burnout and increase work efficiency to qualitatively improve medical services.

• Women's Health Nursing
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• v.21 no.4
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• pp.272-283
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• 2015

Purpose: The purpose of this study was to identify the type of sexual assertiveness of female adolescents. Methods: A Q methodology which provided a method of analyzing the subjectivity of each type was used. Thirty-three female high school students classified 40 selected Q statements into 9 points standard. The collected data was analyzed by using the PC-QUNAL program. Results: Four types of sexual assertiveness manifested by female adolescents were identified: Type 1: Self-normative line-drawing type, Type 2: Pleasure-seeking negotiation type, Type 3: Passive relationship maintenance type, Type 4: future-oriented satisfaction-delay type. Conclusion: This study is meaningful because it provides empirical information necessary for the development of theories by verifying integrated attributes related to the female adolescents' sexual assertiveness. Results also induced the measuring tools and succeeding studies, and presented educational material for sex education that is tailored to the developmental level and characteristics of female adolescents.