• Nuclear Engineering and Technology
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• 제34권1호
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• pp.42-59
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• 2002

In order to transmute long-lived radioactive nuclides such as transuranics(TRU), Tc-99, and I- l29 in LWR spent fuel, a preliminary conceptual design study has been performed for the accelerator driven subcritical reactor system, called HYPER(Hybrid Power Extraction Reactor) The core has a hybrid neutron energy spectrum: fast and thermal neutrons for the transmutation of TRU and fission products, respectively. TRU is loaded into the HYPER core as a TRU-Zr metal form because a metal type fuel has very good compatibility with the pyre- chemical process which retains the self-protection of transuranics at all times. On the other hand, Tc-99 and I-129 are loaded as pure technetium metal and sodium iodide, respectively. Pb-Bi is chosen as a primary coolant because Pb-Bi can be a good spallation target and produce a very hard neutron energy spectrum. As a result, the HYPER system does not have any independent spallation target system. 9Cr-2WVTa is used as a window material because an advanced ferritic/martensitic steel is known to have a good performance under a highly corrosive and radiation environment. The support ratios of the HYPER system are about 4∼5 for TRU, Tc-99, and I-129. Therefore, a radiologically clean nuclear power, i.e. zero net production of TRU, Tc-99 and I-129 can be achieved by combining 4 ∼5 LWRs with one HYPER system. In addition, the HYPER system, having good proliferation resistance and high nuclear waste transmutation capability, is believed to provide a breakthrough to the spent fuel problems the nuclear industry is faced with.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.838-848
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• 2015

One of the most important operations in nuclear power plants is load following, in which an imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation is considered to be a constraint for the load following operation. In this paper, the design of a sliding mode control (SMC), which is a robust nonlinear controller, is presented.SMCis ameansto control pressurized water nuclear reactor (PWR) power for the load following operation problem in a way that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to ensure xenon oscillations remain bounded. The constant AO is a robust state constraint for the load following problem. The reactor core is simulated based on the two-point nuclear reactor model with a three delayed neutron groups. The stability analysis is given by means of the Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the SMC exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness, and stability. Results show that the proposed controller for the load following operation is so effective that the xenon oscillations are kept bounded in the given region.

• 동의신경정신과학회지
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• 제30권3호
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• pp.153-164
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• 2019

Objectives: The purpose of this study was to examine the correlation between CSEI (The Core Seven-Emotions Inventory) and MMPI-2 (Minnesota Multiphasic Personality Inventory-2). Methods: We analyzed the correlation between students' demographic characteristics, blood type, MMPI-2, and CSEI using the SPSS (Statistical Package for the Social Science) 24.0. Descriptive Statistical Analysis, independent t-test, analysis of variance (ANOVA), subsequent analysis duncan (post hoc multiple comparison), and correlation analysis were conducted. Results: 1. According to the demographic characteristics of 91 participants in this study: 60 males (65.9%), 88 unmarried (96.7%), 58 without religion (63.7%), 54 who have experienced stress in the last three months (59.4%), and 82 in their 20s (90.1%) comprised the majority. 2. As a result of verifying correlation by subfactors of CSEI, Hui (喜) showed statistically significant negative correlation with U (憂), Bi (悲), and Gong (恐). Six emotions except Hui (喜) showed statistically significant positive correlation, except for the relationship between U (憂) and Kyeong (驚). 3. Hui (喜) of CSEI had negative correlation with eight factors of MMPI-2 Clinical Scales except Pa (Paranoia) and Ma (Hypomania), whereas Bi (悲) had positive correlation with nine factors of MMPI-2 clinical scales except Mf (Masculinity-Femininity). Sa (思), Bi (悲), and Gong (恐) had similar tendency of positive correlation with six factors of MMPI-2 Restructured Clinical Scales. Conclusions: Based on the above results, we concluded that CSEI's sub factors had consistent correlations with MMPI-2. Thus, CSEI could contribute to psychiatry clinical use.

• 대한간호학회지
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• 제51권3호
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• pp.320-333
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• 2021

Purpose: The study was conducted to explore the experiences of job retention among working people with mental illness. Methods: The participants were members with mental illness at the S Community Mental Health Center in Gyeonggi Province and who had been working for more than six months. The data were collected through in-depth interviews with 11 participants between June 27 and August 20, 2018. The data were analyzed through Corbin and Strauss's grounded theory method. Results: The core category was struggling to take root in the community as a productive member. The core phenomenon was the desire to be a productive person, and the causal condition was the willingness to change for a purposeful life. The action and interaction strategies included maintaining regular living patterns, maintaining medication, developing one's tips for self-management, and self-approval. The intervening conditions were difficulties in forming social relationships, presence of symptoms, social resources, and acceptance of one's mental illness. The consequences were restoration of family relationships, healthy pleasure through work, social inclusion, development of self-worth, and transition to an independent person. Conclusion: Working people with mental illness are struggling to take root in the community as a productive member. This study suggests that a holistic understanding of the job retention experience among people with mental illness is required. The findings will provide the basis for developing interventions that can improve job retention among working people with mental illness.

• Steel and Composite Structures
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• 제43권5호
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• pp.581-601
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• 2022

The main objective of this research work is to investigate the free vibration behavior of annular sandwich plates resting on the Kerr foundation at thermal conditions. This sandwich configuration is composed of two FGM face sheets as coating layer and a porous GPLRC (GPL reinforced composite) core. It is supposed that the GPL nanofillers and the porosity coefficient vary continuously along the core thickness direction. To model closed-cell FG porous material reinforced with GPLs, Halpin-Tsai micromechanical modeling in conjunction with Gaussian-Random field scheme is used, while the Poisson's ratio and density are computed by the rule of mixtures. Besides, the material properties of two FGM face sheets change continuously through the thickness according to the power-law distribution. To capture fundamental frequencies of the annular sandwich plate resting on the Kerr foundation in a thermal environment, the analysis procedure is with the aid of Reddy's shear-deformation plate theory based high-order shear deformation plate theory (HSDT) to derive and solve the equations of motion and boundary conditions. The governing equations together with related boundary conditions are discretized using the generalized differential quadrature (GDQ) method in the spatial domain. Numerical results are compared with those published in the literature to examine the accuracy and validity of the present approach. A parametric solution for temperature variation across the thickness of the sandwich plate is employed taking into account the thermal conductivity, the inhomogeneity parameter, and the sandwich schemes. The numerical results indicate the influence of volume fraction index, GPLs volume fraction, porosity coefficient, three independent coefficients of Kerr elastic foundation, and temperature difference on the free vibration behavior of annular sandwich plate. This study provides essential information to engineers seeking innovative ways to promote composite structures in a practical way.

• 대한약침학회지
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• 제26권3호
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• pp.227-237
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• 2023

Objectives: Pharmacopuncture is considered a unique new type of acupuncture in Korean medicine (KM). This study was performed to investigate the research trends regarding pharmacopuncture through a bibliometric analysis using VOSviewer. Methods: The Web of Science Core Collection was searched for this study. The search terms were pharmacopuncture and pharmaco-puncture. The search was conducted on May 23, 2023, and 185 studies retrieved up to this date were included. Software VOSviewer version 1.6.19 was used to perform the bibliometric analysis. After data clearing, keyword co-occurrence and cooperation pattern analyses were performed. Results: The number of studies on pharmacopuncture have gradually increased since the mid-2000s, with the most published in 2020 (46 studies). The quality of the studies has also steadily increased, and recently, several randomized controlled trials of pharmacopuncture have been conducted. Moreover, this treatment has been investigated in the context of KM clinical practice guideline development in Korea. The scope of pharmacopuncture studies to date seems to be limited to musculoskeletal pain and bee venom pharmacopuncture. The researchers from Jaseng Medical Foundation have been the core researchers in the field of pharmacopuncture in Korea. They collaborated with researchers from universities or government-funded research institutes. However, small-scale research teams from KM clinics and university researchers were also identified as independent clusters. Conclusion: Pharmacopuncture research has grown both quantitatively and qualitatively, but the scope needs to be further expanded. There is also a gap between the use of pharmacopuncture by KM doctors in clinical settings and pharmacopuncture research. Based on these findings, some suggestions for future studies in this field are discussed. Furthermore, these findings may be used as data to expand and globalize pharmacopuncture research in the future.

• Asia Marketing Journal
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• 제20권1호
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• pp.23-48
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• 2018

SK group has been a pioneer in overall brand management and, more recently, in CSR-imbedded brand management. SK vision of "improving itself to give greater happiness to all of its customers" and the symbol mark of "Wings of Happiness" are some good examples of integrating distinct brand identities of various member companies. After impressive growth and expansions into diverse business areas, SK group is ranked as the third largest company based on asset amounts according to the Fair Trade Commission of Korea, only after Samsung and Hyundai Motor groups. SK brand management can be analyzed, using the framework of 4 stages - 'infrastructure', 'planning', 'doing', and 'seeing' stages. In order to secure 'infrastructure' of brand management system, SK has invested huge resources to the 'SK BMS' (SK Brand Management System). At the 'planning' stage, the most important task of SK like other Korean business groups is perhaps to adopt a well-organized 'brand identity (BI) system' which may consolidate brand values of individual member companies. In actuality, SK BI consists of Customer Happiness located at the center and 3 other elements of Pride, Professionalism, and Customer-orientation. At the 'doing' stage, the slogan of 'OK! SK' and the logo of 'Wings of Happiness' have been placed at the core of the SK group brand building programs. SK adopts the principle of 'independent yet united', pinpointing that each member company independently works for its business performance but it is, at the same time, encouraged to integrate its capabilities for the SK group brand. In addition, SK has sought 'shared growth' with business partners for happiness for all the members in the society. 'Social Contribution Philosophy' based on SK value of 'creation of greater happiness' is again one of the most important guidelines for CSR (corporate social responsibility) at the doing stage. At the seeing stage, SK regularly evaluates its branding programs. SK has shown some very impressive achievements in brand management: (1) a core identity of 'Customer Happiness' participating member companies may share, (2) harmonious relationships between the group brand management office and brand management divisions of member companies, and (3) consistency-keeping in brand management over time. However, there remain two major challenges: (1) globalization of SK and (2) reinforcing sustainable superiority over not only Korean rivals but also global ones.

• 문화기술의 융합
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• 제9권1호
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• pp.501-511
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• 2023

본 연구는 G시에 소재하는 간호대학생 178명을 대상으로 자기주도학습, 핵심간호술 수행자신감, 임상실습 교육환경 및 임상수행능력 간의 상관관계를 살펴보기 위한 서술적 조사연구이다. 자료수집은 2019년 9월 24일부터 10월 19일까지 이루어졌으며, 자료분석은 IBM SPSS Statistics 21.0 프로그램을 사용하여 변수의 평균과 표준편차, 실수와 백분율로 분석하였고, 일반적 특성에 따른 변수의 차이는 independent t-test, ANOVA로 분석하였고, 변수 간의 상관관계는 Pearson's correlation coefficients로 분석하였다. 연구결과, 자기주도학습 3.36점, 핵심간호술 수행자신감 3.42점, 임상실습 교육환경 3.20점, 임상수행능력 3.66이었다. 자기주도학습, 핵심간호술 수행자신감, 임상실습 교육환경과 임상수행능력 간에는 유의한 정적 상관관계가 있었다. 이에 간호대학생의 임상수행능력을 향상사키기 위하여 핵심간호술 교육을 체계화하고, 유기적인 산학협력을 통하여 임상실습 교육환경을 지속적으로 개선시켜 나가야 할 것이다.

• Korean Journal of Radiology
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• 제21권1호
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• pp.42-57
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• 2020

Appropriate use and analysis of neuroimaging techniques is an inevitable aspect of clinical trials for patients with acute ischemic stroke. Neuroimaging examinations were recently used to define the core eligibility criteria and outcomes in acute ischemic stroke research. Recent clinical trials for endovascular treatment in acute ischemic stroke have also demonstrated the efficacy or safety of endovascular treatment using various imaging modalities as well as clinical indices. Furthermore, independent imaging reviews and imaging core laboratory assessments are essential to manage and analyze imaging data in order to enhance the reliability of the outcomes. Therefore, we systematically reviewed the use of neuroimaging in recent randomized clinical trials for endovascular treatment of acute ischemic stroke in order to provide a thorough summary, which would serve as a resource guiding the use of appropriate imaging protocols and analyses in future clinical trials for acute ischemic stroke. This review will help researchers select appropriate imaging biomarkers among the various imaging protocols available and apply the selected type of imaging examination for each study in accordance with the academic purpose.

• 한국산림과학회지
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• 제96권5호
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• pp.591-601
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• 2007

Spatial information on forest biomass is an important factor to evaluate the capability of forest as a carbon sequestrator and is a core independent variable required to drive models which describe ecological processes such as carbon budget, hydrological budget, and energy flow. The objective of this study is to understand the relationship between satellite image and field data, and to quantitatively estimate and map the spatial distribution of forest biomass. Landsat Enhanced Thematic Mapper (ETM+) derived vegetation indices and field survey data were applied to estimate the biomass distribution of mountainous forest located in Gwangneung Experimental Forest (230 ha). Field survey data collected from the ground plots were used as the dependent variable, forest biomass, while satellite image reflectance data (Band 1~5 and Band 7), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and RVI (Ratio Vegetation Index) were used as the independent variables. The mean and total biomass of Gwangneung catchment area were estimated to be about 229.5 ton/ha and $52.8{\times}10^3$ tons respectively. Regression analysis revealed significant relationships between the measured biomass and Landsat derived variables in both of deciduous forest ($R^2=0.76$, P < 0.05) and coniferous forest ($R^2=0.75$, P < 0.05). However, there still exist many uncertainties in the estimation of forest ecosystem parameters based on vegetation remote sensing. Developing remote sensing techniques with adequate filed survey data over a long period are expected to increase the estimation accuracy of spatial information of the forest ecosystem.