• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.521-534
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• 2019

From the day of luxurious inland river cruise ship started in Chongqing, China, the controversy is continuous; some people think those luxurious cruise ships on inland river might reduce the experience to enjoy the scenery of the Three Gorges, while some people think, which could improve the experience. In the study, the service facilities provided by luxurious inland river cruise ship will be evaluated by Pre-Post comparison based on IPA methods. After a review of the service facilities provided by luxurious inland river cruise ship running on Three Gorges areas. The tourists who would take the trip were asked to fill an questionnaire to examine the desired service facilities performance, which represents the highest level of the service facilities of the cruise ship that is expected by customers. After the trip, they were asked again to fill another questionnaire to examine the importance of service facilities and the performance of service. Pre-Post comparison would be examined to tell whether there is any change between pre and post experience. IPA would be used to evaluate the service facilities provided by inland river cruise ship. At last, some strategic suggestions to the development of inland river cruise ship are made.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1494-1503
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• 2016

Power quality promotion has received increasing attention because of the wide use of semiconductor devices in recent decades. Reactive power regulation is crucial to ensuring the stable operation of power systems. In this study, a continuous reactive power controller, which is referred to as a parallel-connected magnetic energy recovery switch (MERS), is developed to regulate voltage or power factor in power grids. First, the operating principle is introduced, and a mathematical model is built. Second, a new control method for restraining current harmonics and the peak voltages of capacitors is presented. Using the proposed method, the MERS shows a wide range in terms of reactive power compensation. Finally, the performance of the proposed controller is demonstrated through computer simulations and experiments. Unlike STATCOMs, the proposed controller entails low losses, adopts a small dc capacitor, and offers ease of use.

• Environmental Engineering Research
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• v.25 no.1
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• pp.71-79
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• 2020

This paper uses super-efficiency DEA model and Malmquist index to evaluate the carbon emission efficiency (CEE) values of the nine western provinces along the "Silk Road Economic Belt" for the period from 2000 to 2015, and analyses the influencing factors of the CEE. The major findings of this study are the following: (1) the overall CEE of the nine western provinces is not high, and there are significant inter-provincial differences in the CEE. Meanwhile, the provinces with higher levels of economic development generally have higher CEE. (2) The annual total factor productivity (TFP) of the nine western provinces, which is mainly determined by technological change, is greater than 1. Moreover, the total average growth rate of the TFP is 15.5%. (3) The CEE of the nine western provinces is not spatially dependent. In addition, the urbanization, openness, use of energy-saving technologies and research and development (R&D) investment have a significant positive impact on the CEE values, while the industrial structure, foreign direct investment, fixed asset investment, government expenditure levels and energy structure have a significant negative impact on the CEE. Among them, R&D investment is the primary factor in promoting the development of CEE, and the government expenditure has the greatest negative impact on the CEE.

• Wind and Structures
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• v.29 no.6
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• pp.389-403
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• 2019

In this study, two original spectral representations of stationary stochastic fields, say the continuous proper orthogonal decomposition (CPOD) and the frequency-wavenumber spectral representation (FWSR), are derived from the Fourier-Stieltjes integral at first. Meanwhile, the relations between the above two representations are discussed detailedly. However, the most widely used conventional Monte Carlo schemes associated with the two representations still leave two difficulties unsolved, say the high dimension of random variables and the incompleteness of probability with respect to the generated sample functions of the stochastic fields. In view of this, a dimension-reduction model involving merely one elementary random variable with the representative points set owing assigned probabilities is proposed, realizing the refined description of probability characteristics for the stochastic fields by generating just several hundred representative samples with assigned probabilities. In addition, for the purpose of overcoming the defects of simulation efficiency and accuracy in the FWSR, an improved scheme of non-uniform wavenumber intervals is suggested. Finally, the Fast Fourier Transform (FFT) algorithm is adopted to further enhance the simulation efficiency of the horizontal stochastic wind velocity fields. Numerical examplesfully reveal the validity and superiorityof the proposed methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.924-944
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• 2017

Telecare Medical Information System (TMIS) helps the patients to gain the health monitoring information at home and access medical services over the mobile Internet. In 2015, Das et al proposed a secure and robust user AKA scheme for hierarchical multi-medical server environment in TMIS, referred to as DAKA protocol, and claimed that their protocol is against all possible attacks. In this paper, we first analyze and show DAKA protocol is vulnerable to internal attacks, impersonation attacks and stolen smart card attack. Furthermore, DAKA protocol also cannot provide confidentiality. We then propose a lightweight pseudonym AKA protocol for multi-medical server architecture in TMIS (short for PAKA). Our PAKA protocol not only keeps good security features declared by DAKA protocol, but also truly provides patient's anonymity by using pseudonym to protect sensitive information from illegal interception. Besides, our PAKA protocol can realize authentication and key agreement with energy-saving, extremely low computation cost, communication cost and fewer storage resources in smart card, medical servers and physical servers. What's more, the PAKA protocol is proved secure against known possible attacks by using Burrows-Abadi-Needham (BAN) logic. As a result, these features make PAKA protocol is very suitable for computation-limited mobile device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5888-5903
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• 2019

The Relational ranking method applies authority-based ranking in relational dataset that can be modeled as graphs considering also their tuples' values. Authority directions from tuples that contain the given keywords and transfer to their corresponding neighboring nodes in accordance with their values and semantic connections. From our previous work, ObjectRank extends to ValueRank that also takes into account the value of tuples in authority transfer flows. In a maked difference from ObjectRank, which only considers authority flows through relationships, it is only valid in the bibliographic databases e.g. DBLP dataset, ValueRank facilitates the estimation of importance for any databases, e.g. trading databases, etc. A relational keyword search paradigm Object Summary (denote as OS) is proposed recently, given a set of keywords, a group of Object Summaries as its query result. An OS is a multilevel-tree data structure, in which node (namely the tuple with keywords) is OS's root node, and the surrounding nodes are the summary of all data on the graph. But, some of these trees have a very large in total number of tuples, size-l OSs are the OS snippets, have also been investigated using ValueRank.We evaluated the real bibliographical dataset and Microsoft business databases to verify of our proposed approach.

• International Journal of CAD/CAM
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• v.8 no.1
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• pp.1-10
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• 2009

This paper presents a topology optimization approach using element-free Galerkin method (EFGM) for the optimal design of compliant mechanisms with geometrically non-linearity. Meshless method has an advantage over the finite element method(FEM) because it is more capable of handling large deformation resulted from geometrical nonlinearity. Therefore, in this paper, EFGM is employed to discretize the governing equations and the bulk density field. The sensitivity analysis of the optimization problem is performed by incorporating the adjoint approach with the meshless method. The Lagrange multipliers method adjusted for imposition of both the concentrated and continuous essential boundary conditions in the EFGM is proposed in details. The optimization mathematical formulation is developed to convert the multi-criteria problem to an equivalent single-objective problem. The popularly applied interpolation scheme, solid isotropic material with penalization (SIMP), is used to indicate the dependence of material property upon on pseudo densities discretized to the integration points. A well studied numerical example has been applied to demonstrate the proposed approach works very well and the non-linear EFGM can obtain the better topologies than the linear EFGM to design large-displacement compliant mechanisms.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.699-714
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• 2021

Supercritical CO₂ (S-CO₂) Brayton cycle has been applied to various heat sources in recent decades, owing to the characteristics of compact structure and high efficiency. Understanding the research development in this emerging research field is crucial for future study. Thus, a bibliometric approach is employed to analyze the scientific publications of S-CO₂ cycle field from 2000 to 2019. In Scopus database, there were totally 724 publications from 1378 authors and 543 institutes, which were distributed over 55 countries. Based on the software-BibExcel, these publications were analyzed from various aspects, such as major research areas, affiliations and keyword occurrence frequency. Furthermore, parameters such as citations, hot articles were also employed to evaluate the research output of productive countries, institutes and authors. The analysis showed that each paper has been cited 13.39 times averagely. United States was identified as the leading country in S-CO₂ research followed by China and South Korea. Based on the contents of publications, existing researches on S-CO₂ are briefly reviewed from the five aspects, namely application, cycle configurations and modeling, CO₂-based mixtures, system components, and experiments. Future development is suggested to accelerate the commercialization of S-CO₂ power system.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.135-142
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• 2021

This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.

• Journal of Korea Multimedia Society
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• v.25 no.4
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• pp.628-639
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• 2022

Starting from the content types of video advertisements produced by social media users, this paper conducts a comparative study on the information and entertainment video advertising effects of the same product, to help video producers achieve better advertising effects when facing different products. Experimental results show that. In Garment, the information is higher than that of entertainment in terms of advertising cognition. In terms of advertising attitude and purchase intention, the entertainment is higher than that of information; in food, the entertainment is higher than that of information in terms of advertising cognition, advertising attitude, and purchase intention; in household items, the entertainment is higher than that of information; in terms of advertising cognition and purchase intention, the information is higher than that of entertainment; in terms of advertising attitude, the entertainment is higher than that of information; in cosmetics, the information is higher than that of entertainment in terms of advertising cognition; in terms of advertising attitude and purchase intention, the entertainment is higher than that of the information; in digital accessories, the information is higher than that of the entertainment in terms of advertising cognition, advertising attitude and purchase intention.