• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.6
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• pp.1599-1618
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• 2024

Access control has always been one of the effective methods to protect data security. However, in new computing environments such as big data, data resources have the characteristics of distributed cross-domain sharing, massive and dynamic. Traditional access control mechanisms are difficult to meet the security needs. This paper proposes CACM-MMSR to solve distributed cross-domain access control problem for massive resources. The method uses blockchain and smart contracts as a link between different security domains. A permission decision model migration method based on access control logs is designed. It can realize the migration of historical policy to solve the problems of access control heterogeneity among different security domains and the updating of the old and new policies in the same security domain. Meanwhile, a semantic reasoning-based permission decision method for unstructured text data is designed. It can achieve a flexible permission decision by similarity thresholding. Experimental results show that the proposed method can reduce the decision time cost of distributed access control to less than 28.7% of a single node. The permission decision model migration method has a high decision accuracy of 97.4%. The semantic reasoning-based permission decision method is optimal to other reference methods in vectorization and index time cost.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.302-308
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• 2012

Self-configuration network model is to overcome the limits of data communications at sea. As a research for enhancing the connectivity and scalability of data networks at sea using the diversity and heterogeneity of the data networks on land, in this paper, a routing scheme (NLTCR) based on not conventional hop counts but distances to destination ships is introduced. The NLTCR seeks an optimal route by normalized distances to a destination, and transmission characteristics of applications and carriers. Performance is evaluated and compared with those of the max-win (MWR) and the normalized transmission characteristics (NTCR) based schemes.

• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.677-688
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• 2016

Purpose: In this study, we examine the effects of circulatory diseases mortality in South Korea 2005-2013 using the air pollution index, Methods: We cluster the region of high risk mortality by SaTScan$^{TM}$9.3.1 and compare this result with the regional distribution of air pollution. We use the Geographically Weighted Regression (GWR) to consider the spatial heterogeneity of data collected by administrative district in order to estimate the model. As GWR is spatial analysis techniques utilizing the spatial information, regression model estimated for each region on the assumption that regression coefficients are different by region. Results: As a result of estimating model of the collected air pollution index, circulatory diseases mortality data combined with the spatial information, GWR was found to solve the problem of spatial autocorrelation and increase the fit of the model than OLS regression model. Conclusion: GWR is used to select the air pollution affecting the disease each year, the K-means cluster analysis discover the characteristics of the distribution of air pollution by region.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.145-153
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• 2015

Development of IT technology, in combination with the medical area, a number of developments have been made of the digital advanced medical devices, also increased interest in health, sharing of medical information has become increasingly necessary. Standardization for medical information sharing to satisfy these requirements have been studied. However, the medical information system is to build a system independent hospital itself, is difficult to share and exchange medical data with other medical institutions. In this paper, we provide a medical cloud system that can share medical information. Use DBaaS of cloud services. And is an international standard to have a HL7 share information by forming a meta-schema, each of the data transfer, the format of the document oriented data solves the heterogeneity between hospitals. Extracts the required field name of examination information, to exchange information with each of the local information and mapping. Health diagnostic information in the present study and diagnosis through accurate information sharing and exchange is possible ongoing management.

• East Asian Economic Review
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• v.18 no.4
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• pp.395-423
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• 2014

This study examines the role of trade finance in the trade collapse of 2008-09 from the perspective of the Korean economy. We use two approaches. Firstly, as background to a more formal analysis, we make a casual observation on the behavior of aggregate data on trade finance, on which Korea has relatively abundant data. Aggregate data do not convincingly support the view that trade finance played an active role in causing the trade collapse. The measures of trade finance and the value of trade both dropped sharply, but the ratio of trade finance over trade was stable and in some cases increased during the crisis period. Secondly, using quarterly data on listed firms in Korea, we conduct panel estimations to test whether firms that are more dependent on external finance experienced greater export contraction during the crisis. Our regression analysis suggests that the financial vulnerability of firms, measured by various financial ratios, did not contribute to export contraction during the financial crisis. This observation largely applies even to smaller firms, who are usually thought of as being more vulnerable financially. However, we find that small exporters that relied heavily on cross-border trade payables or receivables suffered larger drops in export growth during the crisis.

• Nuclear Engineering and Technology
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• v.42 no.1
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• pp.9-16
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• 2010

Experimental examinations for evaluating fracutres were conducted by using transparent replicas of a single fracture in order to obtain the fracture data to contribute to the methodlogy on how to improve the definitaion of representative parameter values used for a parallel plate fracture model. Quantitative aperture distribution and quantitative tracer concentration data at each point in time were obtained by measuring the attenuation of transmitted light through the fracture in high spatial resolution. the representative aperture values evaluated from the multiple different measurement methods, such as arithmetic mean of aperture distribution measured by the optical method, transport aperture evaluated from the tracer test, and average aperture evaluated from the fracture void volume measurement converged to a unique value that indicates the accuracy of this experimental study. The aperture data was employed for verifying the numerical simulation under the assuption of Local Cubic Law and showed that the calculated flow rate through the fracture is 10%-100% larger than hydraulic test results. The quantitative tracer concentration data is also very valuable for validating existing numerical code for advection dispersion transport in-plane heterogeneous fractures.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.295-305
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• 1988

It has been well known that the renal cortical blood flow rate was much higher than that of the medulla and the renal blood flow distribution was affected by hemorrhage, volume expansion or salt-loading. The existance of the heterogeneities of glomerular filtration rate and nephron has also been reported. In order to understand the regulations and physiological roles of the heterogeneities, studies on the intrarenal renin-angiotensin system have been focused. Although it is well known that the granularity of iuxtaglomerular cells and renal renin content are more marked in superficial than in the deep glomeruli, their physiological significance is not quite clear. This study was therefore undertaken to clarify changes in renin response and isoelectric ronin profile to TMB-8 in outer, mid and inner cotices of normotensive and hypertensive rats. The basal rate of renin release was highest in outer cortex of Sprague-Dawley rat (SDR), Wistar rat (WR) and spontaneously hypertensive rat (SHR). The basal renin release from outer and inner cortex of SHR was significantly lower than that from those of SDR. The reponse of renin release to TM8-8 was highest in mid cortex and the increase of renin release in response to TMB-8 from inner cortex of SDR was significantly higher than that in SHR. In dehydrated rats, the basal renin release from renal cortical slices of SDR was increased but that from WR and SHR was not. The response of renin release to TMB-8 from mid and inner cortex of dehydrated WR tended to increase. In dehyrated SHR, increase of renin release from inner cortex was significantly higher than that in euhydrated SHR. No significant differences in the isoelectric renin profile were found both in different cortical areas and strains. In dehydrated rats, the percentage of renin form 2 was decreased and those of renin form 5 and 6 were increased. These results suggest that the heterogeneity of renin release from cortical area of euhydrated and dehydrated rats in response to TMB-8 may be related to the changes of renal blood flow and/or calcium metabolism in cortical area. These data also suggest that the renin forms with different isoelectric points may have an physiological significance.

• Journal of Distribution Science
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• v.11 no.4
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• pp.61-72
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• 2013

Purpose - It is widely accepted that the process of developing marketing strategy is composed of three steps: market segmentation, target market selection and positioning. However, mass marketing strategy based on cost reduction through economies of scale and standardized products, can be also an effective strategic option. Many marketing scholars including Theodore Levitt emphasize the importance of applying the mass production concept to various industries including service industries. Especially, in times of economic downturn, the capability of providing consumers with low-priced, value products can be an important source of competitive advantage, as well as the ability of providing high-priced premium products. Marketers should decide whether they will implement mass marketing strategy or target marketing strategy. The present study theoretically shows that firms should understand the target customers' price elasticity as well as the firm's cost structure in order to make such a strategic decision. Research design, data, and methodology - Instead of implementing an empirical study, this study provides a theoretical(mathematical) investigation on the effect of consumers' price elasticity on a firm's optimal price level, profit, sales volume, revenue, and cost. The results are mostly deduced from derivative calculations and several graphs are utilized to represent the results on the relationships between the variables under study. Results - The analytical results suggest that it is more profitable for a firm to adopt the segment/target marketing strategy (more specifically the differentiation strategy) when the degree of consumers' heterogeneity is high and the proportion of the fixed cost in the total cost is low. On the other hand, if the degree of consumers' heterogeneity is low and the fixed cost is high, it is better to adopt the mass marketing strategy or the cost leadership strategy. The strategy of concentrating on a single target market will be effective when consumers' needs are highly heterogeneous but the fixed cost is high. Any of the three types of generic strategies proposed my Porter(1980, 1985) can be applied when both the consumers' heterogeneity and the fixed cost are low. This study also proposes the contribution-margin-based method for developing the optimal pricing strategy. Conclusions - One of the primary roles of marketers is to find a proper compromise between the two conflicting goals of maximizing customer satisfaction and minimizing cost. In order to do so, he or she should understand the characteristics of the target customers as well as the cost structure of the firm. In addition to the theoretical analyses, this study discusses several business cases and explains how superior companies find the optimal compromise position between these two goals and dominate the market. One of the radical changes recently taking place in business arena is the reduction of production and distribution costs of both physical goods and information due to the advancement and the wide diffusion of information technology. The cost reduction combined with lowered priced elasticity incurred by customized products and services, will enable many firms to adopt the mass customization strategy.

• Journal of the Korean GEO-environmental Society
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• v.23 no.8
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• pp.29-36
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• 2022

The importance of subsurface information is becoming crucial in urban area due to increase of underground construction. The position of underground facilities should be identified precisely before excavation work. Geophyiscal exporation method such as ground penetration radar (GPR) can be useful to investigate the subsurface facilities. GPR transmits electromagnetic waves to the ground and analyzes the reflected signals to determine the location and depth of subsurface facilities. Unfortunately, the readability of GPR signal is not favorable. To overcome this deficiency and automate the GPR signal processing, deep learning technique has been introduced recently. The accuracy of deep learning model can be improved with abundant training data. The ground is inherently heteorogeneous and the spacially variable ground properties can affact on the GPR signal. However, the effect of ground heterogeneity on the GPR signal has yet to be fully investigated. In this study, ground heterogeneity is simulated based on the fractal theory and GPR simulation is carried out by using gprMax. It is found that as the fractal dimension increases exceed 2.0, the error of fitting parameter reduces significantly. And the range of water content should be less than 0.14 to secure the validity of analysis.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.4
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• pp.283-309
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• 2021

Achieving profound anesthesia in mandibular molars with irreversible pulpitis is a tedious task. This review aimed at evaluating the success of buccal/lingual infiltrations administered with a primary inferior alveolar nerve block (IANB) injection or as a supplemental injection after the failure of the primary injection in symptomatic and asymptomatic patients with irreversible pulpitis in human mandibular molars. The review question was "What will be the success of primary and supplemental infiltration injection in the endodontic treatment of patients with irreversible pulpitis in human mandibular molars?" We searched electronic databases, including Pubmed, Scopus, and Ebsco host and we did a comprehensive manual search. The review protocol was framed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. We included clinical studies that evaluated and compared the anesthetic outcomes of primary IANB with primary and/or supplementary infiltration injections. Standard evaluation of the included studies was performed and suitable data and inferences were assessed. Twenty-six studies were included, of which 13 were selected for the meta-analysis. In the forest plot representation of the studies evaluating infiltrations, the combined risk ratio (RR) was 1.88 (95% CI: 1.49, 2.37), in favor of the secondary infiltrations with a statistical heterogeneity of 77%. The forest plot analysis for studies comparing primary IANB + infiltration versus primary IANB alone showed a low heterogeneity (0%). The included studies had similar RRs and the combined RR was 1.84 (95% CI: 1.44, 2.34). These findings suggest that supplemental infiltrations given along with a primary IANB provide a better success rate. L'Abbe plots were generated to measure the statistical heterogeneity among the studies. Trial sequential analysis suggested that the number of patients included in the analysis was adequate. Based on the qualitative and quantitative analyses, we concluded that the infiltration technique, either as a primary injection or as a supplementary injection, given after the failure of primary IANB, increases the overall anesthetic efficacy.