• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1325-1344
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• 2019

Recently, to satisfy mobile users' increasing data transmission requirement, energy efficiency (EE) resource allocation in distributed antenna systems (DASs) has become a hot topic. In this paper, we aim to maximize EE in DASs subject to constraints of the minimum data rate requirement and the maximum transmission power of distributed antenna units (DAUs) with different density distributions. Virtual cell is defined as DAUs selected by the same user equipment (UE) and the size of virtual cells is dependent on the number of subcarriers and the transmission power. Specifically, the selection rule of DAUs is depended on different scenarios. We develop two scenarios based on the density of DAUs, namely, the sparse scenario and the dense scenario. In the sparse scenario, each DAU can only be selected by one UE to avoid co-channel interference. In order to make the original non-convex optimization problem tractable, we transform it into an equivalent fractional programming and solve by the following two sub-problems: optimal subcarrier allocation to find suitable DAUs; optimal power allocation for each subcarrier. Moreover, in the dense scenario, we consider UEs could access the same channel and generate co-channel interference. The optimization problem could be transformed into a convex form based on interference upper bound and fractional programming. In addition, an energy-efficient DAU selection scheme based on the large scale fading is developed to maximize EE. Finally, simulation results demonstrate the effectiveness of the proposed algorithm for both sparse and dense scenarios.

• Journal of Korean Society of Rural Planning
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• v.27 no.3
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• pp.103-116
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• 2021

In this study, the characteristics of rural tourism image perceived by urban residents were analyzed through text analysis of blog data. In order to examine the images related to rural tourism, blog data written with the keyword "Gochang-gun travel" was used. LDA topic analysis, one of the text mining techniques, was used for the analysis. In the tourism image of Gochang-gun, 9 topics were derived, and 112 major places appeared. This was divided into 3 main activities and 5 object spaces through the review of keywords and the original text of blog data. As a result of the analysis, the traditional main resources of the region, Seonun mountain, Seonun temple, and Gochang-eup fortress, formed topic. On the other hand, world heritage such as dolmen and Ungok wetland did not appear as topic. In particular, the farms operated by the private sector form individual topics, and the theme farm can be seen as an important resource for tourism in Gochang-gun. Also, through the distribution of place keywords, it was possible to understand the characteristics of travel by region and the usage behavior of visitors. In the case of Gochang-gun, there was a phenomenon in which visitors were biased by region. This seems to be the result of Gochang-gun seeking to vitalize local tourism focusing on natural, ecological, and scenic resources. It is necessary to establish a plan for balanced regional development and develop other types of tourism resources. This study is different in that it identified the types and characteristics of rural tourism images in the region perceived by visitors, and the status of tourism at the regional level.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.439-445
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• 2021

In view of the complex geometric structure of the rod bundle channel and the limitation of the current CHF visualization experiment technology, it is very difficult to obtain the rod bundle CHF mechanism directly through the phenomenon of the rod bundle CHF visualization experiment. In order to obtain the applicable CHF mechanism assumption for rod bundle channel, firstly, five most representative DNB type round tube CHF mechanistic models are obtained with evaluation and screening. Then these original round tube CHF mechanistic models based on inlet conditions are converted to local conditions and coupled with subchannel analysis code ATHAS. Based on 5 × 5 full-length rod bundle CHF experimental data independently developed by Nuclear Power Institute of China (NPIC), the applicability research of each model for CHF prediction performance in rod bundle channel is carried out, and the commonness and difference of each model are comparatively studied. The CHF mechanism assumption of superheated liquid layer depletion that is most likely to be applicable for the rod bundle channel is selected and two directions that need to be improved are given. This study provides a reference for the development of CHF mechanistic model in rod bundle channel.

• Coupled systems mechanics
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• v.8 no.4
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• pp.299-313
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• 2019

The paper represents computer modeling of the deformed state of physically nonlinear transversally isotropic bodies with hole. In order to describe the anisotropy of the mechanical properties of transversally-isotropic materials a structurally phenomenological model has been used. This model allows representing the initial material in the form of the coupled isotropic materials: the basic material (binder) considered from the positions of continuum mechanics and the fiber material oriented along the anisotropy direction of the original material. It is assumed that the fibers perceive only the axial tensile-compression forces and are deformed together with the base material. To solve the problems of the theory of plasticity, simplified theories of small elastoplastic deformation have been used for a transversely-isotropic body, developed by B.E. Pobedrya. A simplified theory allows applying the theory of small elastoplastic deformations to solve specific applied problems, since in this case the fibrous medium is replaced by an equivalent transversely isotropic medium with effective mechanical parameters. The essence of simplification is that with simple stretching of composite in direction of the transversal isotropy axis and in direction perpendicular to it, plastic deformations do not arise. As a result, the intensity of stresses and deformations both along the principal axis of the transversal isotropy and along the perpendicular plane of isotropy is determined separately. The representation of the fibrous composite in the form of a homogeneous anisotropic material with effective mechanical parameters allows for a sufficiently accurate calculation of stresses and strains. The calculation is carried out under different loading conditions, keeping in mind that both sizes characterizing the fibrous material fiber thickness and the gap between the fibers-are several orders smaller than the radius of the hole. Based on the simplified theory and the finite element method, a computer model of nonlinear deformation of fibrous composites is constructed. For carrying out computational experiments, a specialized software package was developed. The effect of hole configuration on the distribution of deformation and stress fields in the vicinity of concentrators was investigated.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.57-65
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• 2019

Creative works such as webtoon and web novel are part of property rights. However, illegal copies of them are distributed on the internet easily, which raises social issues in today's society. In order to tackle these problems, this paper proposes and presents a blockchain based copyright management system that ensures forgery prevention, robust security features, improving trading performance, cost-effective, and enhanced visibility. The system allows a user to register creative works formally just the same as before registration and also to register simple creative ideas just anytime. In the latter case, if an idea or a thought flashes across through somebody's mind, he or she can register it to the system immediately without formal registration process and afterward, can utilize a way to prove its originality through the system. Regarding large size images and video files of creative works, the system reduces data size and storage volume sharply to be processed by network entities by storing original creative works separately and including only the hash result of creative works to the transactions.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.33 no.12
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• pp.53-63
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• 2017

The purpose of this study is to present an integrated analysis for energy use and its patterns as vertical locations of the dwelling units in apartment buildings which are located in an urban area and constructed by a renowned contractor. In order to enhance the effectiveness of the method, the original data of electricity, water, and gas bills which directly reflect the energy use are sorted and analyzed into several groups as vertical locations in each building. And also, by use of comparing and contrasting the data on a monthly and yearly basis, the accuracy of analyses for seasonal energy use and its patterns is strengthened. Comparative analyses used in this study describe the results that vertical locations of dwelling units do not have much influence on electricity and water usage, but are closely related with gas usage for a heating season. According to the analysis of gas usage, the units on the ground and right above pilotis need enhancement in the insulations for heating to mitigate energy loss. Also, the analysis for the middle floor units in each group describe the fact that the gas usage of the units on the ground is consumes 1.5 times greater than that of the typical floors. Therefore, enhanced insulation strategies need to be considered against the adverse condition that the heat loss increases as the wall facing the outside air increases or as the wind velocity increases through the pilotis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1682-1687
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• 2020

We study the problem of sampling a subset of nodes of graphs for bandlimited graph signals such that the signal values on the sampled nodes provide the most information in order to reconstruct the original graph signal. Instead of directly minimizing the reconstruction error, we focus on minimizing the upper bound of the reconstruction error to reduce the complexity of the selection process. We further simplify the upper bound by applying useful approximations to propose a low-weight greedy selection process that is iteratively conducted to find a suboptimal sampling set. Through the extensive experiments for various graphs, we inspect the performance of the proposed algorithm by comparing with different sampling set selection methods and show that the proposed technique runs fast while preserving a competitive reconstruction performance, yielding a practical solution to real-time applications.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.35-44
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• 2021

Previous studies have studied short videos, short form content, snack culture and so on, but few studies have been conducted on the form of summary content that compressing and summarizing the original content. This study aims to contribute to the revitalization of the summary content market by exploring ways to enhance user satisfaction through analysis of the YouTube summary content features and the credibility of content providers that bring about flow and satisfaction of YouTube summary content users. The survey was conducted on 202 people who have watched YouTube summary contents for finding out the effects of YouTube summary contents features and content provider credibility on the details of flow. As a result, only entertainment had a significant impact on all flow details. This study is of academic significance in that it defines the features of YouTube summary contents, and has practical significance in that it suggests what direction the summary content should have in order to arouse user satisfaction in future.

• Journal of English Language & Literature
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• v.55 no.6
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• pp.1163-1191
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• 2009

As many critics do, this article starts from the premise that Charles Waddell Chesnutt wrote The Conjure Woman with a distinct socio-ethical view to ameliorating white readers' racism. For this purpose of social activism, first, the author uses a racially submissive genre and narrator- antebellum plantation-dialect fiction and an old ex-slave Julius-in order to win the attention of white racists, who constituted the majority of the reading public of postbellum America. Chesnutt then allows this seemingly submissive ex-slave consecutively to wage narrative battles against a Northern white capitalist, John. This fiction's structure is thus based on interracial narrative conflict. Granted, the result of these narrative battles is Julius's defeat. Even though he sometimes has narrative success through his manipulation of either his white female auditor's sentimentalism or the white capitalist's racial prejudice, it does not lead to any fundamental change in the white audience members' awareness: John still regards Julius's tacitly reformoriented tales merely as nonsensical ghost stories invented by the absurd imagination of a subservient, entertaining, and exploitable black coachman. Admitting his defeat, Julius relinquishes his original goal of deterring John's capitalist exploitation of both racial Others and the natural environment of the South and finally decides to serve the economic power of white capitalism. This self-defeating conclusion, however, should not be identified with Chesnutt's failure as an author. Rather, it should be understood as an interim result of the black author's earnest experiment with literary media best suited to his reform project. In fact, this narrative failure reveals Chesnutt's accurate diagnosis of the postbellum literary world: a black voice is still feebly heard and even easily buried by the whites' capitalist ambition and consequently intensifying racism. Conclusively, Julius's narrative failure should be positively evaluated as Chesnutt's one step further in his gradual and lifelong progress to a narrative goopher effectively to engage whites' imagination and sympathy for a vision of equal interracial coexistence.

• Journal of English Language & Literature
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• v.55 no.2
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• pp.241-257
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• 2009

The essay discusses the way in which the aesthetic of Pre-Raphaelites reformulates the habitual system of knowledge in the Victorian age by adapting $Ranci{\acute{e}}re^{\prime}s$ concept of aesthetics. $Ranci{\acute{e}}re$ develops an original theory of aesthetics, a regime of knowledge which enables to perceive and reflect art as such. In this way, aesthetics turns to be the logical system by which the consensus idea of the beautiful comes to exist. For $Ranci{\acute{e}}re$, aesthetics is an agreed system of the sensible and reproduces the habitual knowledge of the world. Therefore, a new aesthetic movement means an attempt to break the given aesthetics and reorients the new distribution of the sensible. The important point of $Ranci{\acute{e}}re^{\prime}s$ argument is that he does not presuppose the dimension beyond the present unlike Frankfurt School. What $Ranci{\acute{e}}re$ claims is that there is no such the aesthetic which can correct the instrumental reason, but rather an indifferent moment in which a worker finds out himself as a creator who can give rise to the new regime of the sensible and feels free from what he must work for. From this perspective, the essay explores the aesthetic of Pre-Raphaelites and its meaning in nineteenth century Britain. Pre-Raphaelites was an artist group who railed against a so-called academic style of paintings and created a new aesthetic criterion to describe the truth of the natural world. The essay examines the interrelationship between Pre-Raphaelites and photography that would enable them to re-distribute the sensible and produce a new way of seeing the order of things. This is related to the birth of a modern gaze as in the case of landscape paintings. What is crucial is that the distribution of the sensible is always-already doubled with the political. In short, Pre-Raphaeltes is not only an aesthetic movement but also a political pursuit to achieve a disenchanted perception of nineteenth century industrial capitalism.