• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.173-187
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• 2022

Recent studies have focused on self-management of hypertension using smart devices (cellular phones, tablets, watches). It has proven to be an effective tool for early detection and control of high Blood Pressure (BP) without affecting patients' daily routines. This systematic review surveys the existing self-monitoring systems, evaluate their effectiveness and compares the different approaches. We investigated the current systems in terms of various attributes, including methods used, sample size, type of investigation, inputs/ outputs, rate of success in controlling BP, group of users with higher response rate and beneficiaries, acceptability, and adherence to the system. We identified some limitations, shortcomings, and gaps in the research conducted recently studying the impact of mobile technology on managing hypertension. These shortcomings can generate future research opportunities and enable it to become more realistic and adaptive. We recommended including more observable factors and human behaviors that affect BP. Furthermore, we suggested that vital monitoring/logging and medication tuning are insufficient to improve hypertension control. There is also a need to observe and alter patient behavior and lifestyles.

• KDI Journal of Economic Policy
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• v.28 no.1
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• pp.193-218
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• 2006

This paper examines the macroeconomic structural differences of the free floating exchange rate regime and the managed float exchange rate regime focusing on the Korean economy, and compares it to the two benchmark economies, Japan and Australia. Korea's shift to the free floating exchange rate regime from the managed float exchange rate regime came after the 1997 economic crisis. Korea's exchange rate policy provides a unique opportunity to study the different behaviors or roles, if any, of managed float and free floating exchange rate regimes. Based on a simple monetary model, we find that the exchange rates of Korea are more sensitive to the economic fundamentals under the free floating regime than under the managed float regime. Impulse response analysis shows that exchange rate pass-through into domestic variables, especially inflation rate, has a bigger short-term impact under the floating regime than under the managed regime. This finding is consistent with the view that the managed (or fixed) regime provides the domestic price stability necessary for the economic growth for the developing countries.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.422-430
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• 2012

Previous studies have demonstrated that repeated restraint stress in rodents produces increases in depression and anxiety-like behaviors and alters the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. The current study focused on the impact of Bupleurum falcatum (BF) extract administration on repeated restraint stress-induced behavioral responses using the forced swimming test (FST) and elevated plus maze (EPM) test. Immunohistochemical examinations of tyrosine hydroxylase (TH) expression in rat brain were also conducted. Male rats received daily doses of 20, 50, or 100 mg/kg (i.p.) BF extract for 15 days, 30 min prior to restraint stress (4 h/day). Hypothalamic-pituitary-adrenal axis activation in response to repeated restraint stress was confirmed base on serum corticosterone levels and CRF expression in the hypothalamus. Animals that were pre-treated with BF extract displayed significantly reduced immobility in the FST and increased open-arm exploration in the EPM test in comparison with controls. BF also blocked the increase in TH expression in the locus coeruleus of treated rats that experienced restraint stress. Together, these results demonstrate that BF extract administration prior to restraint stress significantly reduces depression and anxiety-like behaviors, possibly through central adrenergic mechanisms, and they suggest a role for BF extract in the treatment of depression and anxiety disorders.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.47-54
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• 2021

This study shows that consumers' attitudes and behaviors are rapidly changing due to the COVID-19 outbreak in a situation where consumption patterns are already changing due to demographic changes such as an increase in the number of single-person households and dual-income couples. To this end, the results of an online survey conducted on 500 panels of Nielsen Korea were used in this study. In particular, consumers were divided into two generation groups (Generation Z vs. Millennial) and analyzed and presented changes in consumption activities and food purchasing behaviors changed by COVID-19. As a result, the existing online distribution trend has been strengthened, and its impact has been amplified by COVID-19. These changes also resulted in different consumption behaviors depending on the degree of concern for COVID-19 by generation. Based on the results of this study, it turns consumers' behavioral changes into new opportunities, focusing on the accelerating a new 'contactless' lifestyle, which will provide managerial implications for the food industry's response strategies in relation to the theoretical significance and in practice.

• Geomechanics and Engineering
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• v.7 no.4
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• pp.375-401
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• 2014

It is generally accepted that material heterogeneity has a great influence on the deformation, strength, damage and failure modes of rock. This paper presents numerical simulation on rock failure process based on the characterization of rock heterogeneity by using a digital image processing (DIP) technique. The actual heterogeneity of rock at mesoscopic scale (characterized as minerals) is retrieved by using a vectorization transformation method based on the digital image of rock surface, and it is imported into a well-established numerical code Rock Failure Process Analysis (RFPA), in order to examine the effect of rock heterogeneity on the rock failure process. In this regard, the numerical model of rock could be built based on the actual characterization of the heterogeneity of rock at the meso-scale. Then, the images of granite are taken as an example to illustrate the implementation of DIP technique in simulating the rock failure process. Three numerical examples are presented to demonstrate the impact of actual rock heterogeneity due to spatial distribution of constituent mineral grains (e.g., feldspar, quartz and mica) on the macro-scale mechanical response, and the associated rock failure mechanism at the meso-scale level is clarified. The numerical results indicate that the shape and distribution of constituent mineral grains have a pronounced impact on stress distribution and concentration, which may further control the failure process of granite. The proposed method provides an efficient tool for studying the mechanical behaviors of heterogeneous rock and rock-like materials whose failure processes are strongly influenced by material heterogeneity.

• Biomolecules & Therapeutics
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• v.21 no.4
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• pp.313-322
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• 2013

Previous studies have demonstrated that repeated administration of the exogenous stress hormone corticosterone (CORT) induces dysregulation in the hypothalamic-pituitary-adrenal (HPA) axis and results in depression and anxiety. The current study sought to verify the impact of catechin (CTN) administration on chronic CORT-induced behavioral alterations using the forced swimming test (FST) and the elevated plus maze (EPM) test. Additionally, the effects of CTN on central noradrenergic systems were examined by observing changes in neuronal tyrosine hydroxylase (TH) immunoreactivity in rat brains. Male rats received 10, 20, or 40 mg/kg CTN (i.p.) 1 h prior to a daily injection of CORT for 21 consecutive days. The activation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily CTN administration significantly decreased immobility in the FST, increased open-arm exploration in the EPM test, and significantly blocked increases of TH expression in the locus coeruleus (LC). It also significantly enhanced the total number of line crossing in the open-field test (OFT), while individual differences in locomotor activities between experimental groups were not observed in the OFT. Taken together, these findings indicate that the administration of CTN prior to high-dose exogenous CORT significantly improves helpless behaviors, possibly by modulating the central noradrenergic system in rats. Therefore, CTN may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression and anxiety disorders.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.375-401
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• 2023

A school library is where students develop their skills to cope with future uncertainty and can utilize various information materials to build their capability and response abilities to changes. Teachers' perception is crucial as their guidance is essential for the student to use the school library. Most studies, however, focused on quantitative measurement of the importance of the teachers' perception as an external environment, and there is a lack of specific categorization of different types of perceptions on the role of the school library. This study aims to examine types of perceptions about the school library among elementary school teachers. To do so, this study used Latent Profile Analysis (LPA), a person-centered approach, to identify teachers' complex perceptions about the role and importance of the school library, which were difficult to review in previous studies, and the teachers' most representative types of perceptions. Based on the findings from the above, this study is meaningful in proposing customized measures to operate and promote the school library depending on teachers' perceptions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.120-129
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• 2023

To evaluate the vertical loads on railway bridges, conventional load tests are typically conducted. However, these tests often entail significant costs and procedural challenges. Railway conditions involve nearly identical load profiles due to standardized rail systems, which may appear straightforward in terms of load conditions. Nevertheless, this study aims to validate load tests conducted under operational train conditions by comparing the results with those obtained from conventional load tests. Additionally, static and dynamic structural behaviors are extracted from the measurement data for evaluation. To ensure the reliability of load testing, this research demonstrates feasibility through comparisons of existing measurement data with sensor attachment locations, train speeds, responses between different rail lines, tendency analysis, selection of impact coefficients, and analysis of natural frequencies. This study applies to the Dongho Railway Bridge and verifies the applicability of the proposed method. Ten operational trains and 44 sensors were deployed on the bridge to measure deformations and deflections during load test intervals, which were then compared with theoretical values. The analysis results indicate good symmetry and overlap of loads, as well as a favorable comparison between static and dynamic load test results. The maximum measured impact coefficient (0.092) was found to be lower than the theoretical impact coefficient (0.327), and the impact influence from live loads was deemed acceptable. The measured natural frequencies approximated the theoretical values, with an average of 2.393Hz compared to the calculated value of 2.415Hz. Based on these results, this paper demonstrates that for evaluating vertical loads, it is possible to measure deformations and deflections of truss railway bridges through load tests under operational train conditions without traffic control, enabling the calculation of response factors for stress adjustments.

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.1027-1041
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• 2006

The purpose of this study was to identify the differences of internet shopping attitude, shopping behavior, and shopping satisfaction according to purchasing frequency of internet shoppers for children's clothing. Data were collected from 170 female internet users who had purchasing experiences of children's clothing. For data analysis, factor analysis, one-way ANOVA, Duncan test, cross tabulation, regression analysis, t-test, frequency and multi- response analysis were conducted. The results are as follows: The internet shoppers for children's clothing were classified by purchasing frequency. Factors of internet shopping attitude were convenience, reliability, and safety. Significant differences were found on internet usages, internet attitudes, and shopping behaviors between two groups. Heavy purchasers used internet longer, had more positive attitude toward convenience and safety, and paid more money than light purchasers. Significant differences were found on internet attitudes according to age and internet usage. Convenience and safety factors had impact on internet shopping satisfaction.

• Steel and Composite Structures
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• v.43 no.1
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• pp.1-17
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• 2022

The free and forced nonlinear dynamic behaviors of Porous Functionally Graded Material (PFGM) plates are examined by means of a High-Order Implicit Algorithm (HOIA). The formulation is developed using the Third-order Shear Deformation Theory (TSDT). Unlike previous works, the formulation is written without resorting to any homogenization technique neither rule of mixture nor considering FGM as a laminated composite, and the distribution of the porosity is assumed to be gradually variable through the thickness of the PFGM plates. Using the Hamilton principle, we establish the governing equations of motion. The Finite Element Method (FEM) is used to compute approximations of the resulting equations; FEM is adopted using a four-node quadrilateral finite element with seven Degrees Of Freedom (DOF) per node. Nonlinear equations are solved by a HOIA. The accuracy and the performance of the proposed approach are verified by presenting comparisons with literature results for vibration natural frequencies and dynamic response of PFGM plates under external loading. The influences of porosity volume fraction, porosity distribution, slenderness ratio and other parameters on the vibrations of PFGM plate are explored. The results demonstrate the significant impact of different physical and geometrical parameters on the vibration behavior of the PFGM plate.