• Journal of Information Technology Services
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• v.22 no.3
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• pp.141-165
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• 2023

With the advent of the fourth industrial revolution, technologies such as the Internet of Things, artificial intelligence and cloud computing are developing rapidly, and smart homes enabled by these technologies are rapidly gaining popularity. To gain a competitive advantage in the global market, companies must understand the differences in consumer needs in different countries and cultures and develop corresponding business strategies. Therefore, this study conducts a comparative analysis of consumer reviews of smart homes in South Korea and China. This study collected online reviews of SmartThings, ThinQ, Msmarthom, and MiHome, the four most commonly used smart home apps in Korea and China. The collected review data is divided into satisfied reviews and dissatisfied reviews according to the ratings, and topics are extracted for each review dataset using LDA topic modeling. Next, the extracted topics are classified according to five evaluation factors of Perceived Usefulness, Reachability, Interoperability,Trustness, and Product Brand proposed by previous studies. Then, by comparing the importance of each evaluation factor in the two datasets of satisfaction and dissatisfaction, we find out the factors that affect consumer satisfaction and dissatisfaction, and compare the differences between users in Korea and China. We found Trustness and Reachability are very important factors. Finally, through language network analysis, the relationship between dissatisfied factors is analyzed from a more microscopic level, and improvement plans are proposed to the companies according to the analysis results.

• Convergence Security Journal
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• v.22 no.4
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• pp.11-16
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• 2022

Development of science technology make integrated CPS(Cyber-Physical System) appear. In CPS era, cyberspace and physical-space are hard to separate anymore, that is developing toward integrated CPS. The reality is not stopping, that is consistently changing and the concept of space is developing too. But several articles are considering for cyberspace and physical-space separately, and they are developing tailed alternative each case. The theorical approaching that is not considering reality is dwelled on past, and is dangerous from dropping down to floating cloud that is not considering progressed reality. This article is suggested to consider rimland theory to control measures in cyberspace. That is dedicated to integrated approaching from physical-space to cyberspace. And that is developing concreted controling measures in cyberspace. Especially, this article is suggested to policy alternative by analyzing north korea cyber warfare from rimland theory including human sources. Simplicity is the ultimate sophistication. This article make integrated approaching effects about cyberspace and physical-space to preparing in the CPS era.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2001.10a
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• pp.177-186
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• 2001

Based upon the previous experiences and typical oases of typhoon evasion fur ships as well as tile achievement in scientific research in this detrain, we developed the Intelligent Typhoon Evasion System for Ships. It consists of five subsystems, including electronic charts, ship movement management, typhoon information query and automatic plotting, real-time calculation of ship-typhoon situation, intelligent typhoon evasion decision making. With the synthetical application of analogy theory, synoptic chart, satellite cloud picture analysis, typhoon digital forecast and other relevant technologies, we leave established the typhoon evasion data bases. model bases and knowledge bases, which make it possible to automatically track the ships and typhoon paths. The system can realize ship-typhoon situation analysis, risk levee assessment, typhoon paths correction and course synoptic forecast, and intelligent typhoon evasion decision making.

• The Journal of Information Systems
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• v.26 no.2
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• pp.123-142
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• 2017

Purpose The development of the Fintech industry can be on the basis of the development in IT technologies such as Big data, IoT, cloud computing, it can be considered that the financial industry is repeating the evolution into Fintech. But the awareness of the consumers is still very low. Therefore the current dissertation, tries to deduce the suggestions for invigoration measures for Fintech by conducting an empirical study on the factors that influence the intention of reuse of Fintech on the consumer's point of view. Design/methodology/approach This study made a design of the research model by integrating the factors deducted from the Expectation Confirmation Theory. This paper empirically analyzes the impact of Continuous Usage Intention for Improvement of Fintech. The 302 survey responses were used to verify research hypotheses through covariate structural equation model. Findings According to the empirical analysis result, this study confirmed that the ultimate purpose of the Fintech service is to eliminate the social cost's waste element occurring from issue of money by not using or reducing the usage of cash. Since many Fintech users have pointed out security as the priority task, a direction for the related institutions has been proposed. Second, the content of the current dissertation will be the opportunity of broadening the perception of the current consumers that perceive Fintech as only a NFC simple payment service.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.4
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• pp.233-244
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• 1994

The phenomenon of yellow sand (dust clouds) occurred in Korea during the spring of 1993 and 1994 is studied in detail. In total 6 cases including 15 days of yellow sand were observed in 1993 and the annual number of these events was found to increased. Examinations in this study include meteorological charts satellite imagery, pilot reports (PIREP) of Korea Air Force, and air concentrations of total suspended particulates(TSP). We present on estimation of total atmospheric loadings based on the observation and theory. According to the PIREP, in general the dust clouds travelled in the lower troposphere up to the level 5km. The visibility within the clouds was in the range of 3-8km The area covered by yellow sand in an event exceeded 0.4 M $\textrm{km}^2$ . According to trajectory analyses, dust clouds invaded Korea in April and May 1993 were landed in the sink area after 2~4 days travelling for 2,000~3,000km from a source region. Estimates of total atmospheric loadings of a dust cloud for April 23~24 in 1993 were 1.5 M ton. In addition, 7 dust storms were also reported in synoptic observations in NW China and Mongolia during the spring in 1994. The yellow sand was not reported with meteorological observations in Korea, however pilots reported significant dust clouds over the Yellow Sea on 8 and 13 April and 20 May 1994.

• Journal of Integrative Natural Science
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• v.3 no.4
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• pp.231-236
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• 2010

Partial charge is an important and fundamental concept which can explain many aspects of chemistry. Since a molecule can be regarded as neclei surrounded by electron cloud, there is no way to define a partial charge accurately. Nevertheless, there have been many attempts to define these seemingly impossible parameters, since they would facilitate the understanding of molecular properties such as molecular dipole moment, solvation, hydrogen bonding, molecular spectroscopy, chemical reaction, etc. Common methods are based on the charge equalization, orbital occupancy, charge density, and electric multipole moments, and electrostatic potential fitting. Methods based on the charge equalization using electronegativity are very fast, and therefore they have been used to study many compounds. Methods to subdivide orbital occupancy using basis set conversion, relies on the notion that molecular orbitals are composed of atomic orbitals. The main idea is to reduce overlap integral between two nuclei using converted orthogonal basis sets. Using some quantum mechanical observables like electrostatic potential or charge multipole moments. Using potential grids obtained from wavefunction, partial charges can be fitted. these charges are most useful to describe intermolecular electrostatic interactions. Methods to using dipole moment and its derivatives, seems to be sensitive the level of theory, Dividing electron density using density gradient being the most rigorous theoretically among various schemes, bears best potential to describe the charge the most adequately in the future.

• Communications for Statistical Applications and Methods
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• v.25 no.1
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• pp.15-27
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• 2018

Parametric method of flood frequency analysis involves fitting of a probability distribution to observed flood data. When record length at a given site is relatively shorter and hard to apply the asymptotic theory, an alternative distribution to the generalized extreme value (GEV) distribution is often used. In this study, we consider the beta-P distribution (BPD) as an alternative to the GEV and other well-known distributions for modeling extreme events of small or moderate samples as well as highly skewed or heavy tailed data. The L-moments ratio diagram shows that special cases of the BPD include the generalized logistic, three-parameter log-normal, and GEV distributions. To estimate the parameters in the distribution, the method of moments, L-moments, and maximum likelihood estimation methods are considered. A Monte-Carlo study is then conducted to compare these three estimation methods. Our result suggests that the L-moments estimator works better than the other estimators for this model of small or moderate samples. Two applications to the annual maximum stream flow of Colorado and the rainfall data from cloud seeding experiments in Southern Florida are reported to show the usefulness of the BPD for modeling hydrologic events. In these examples, BPD turns out to work better than $beta-{\kappa}$, Gumbel, and GEV distributions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.4
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• pp.63-75
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• 2021

It is necessary to respond to rapid technological changes such as the 4th industrial revolution and digital transformation across industries. And, a change in the university education system is necessary in a crisis situation of universities due to the rapid decrease of the school-age population. This study is aimed at practical competency with the ability to apply intelligent information technology to their job fields based on a basic understanding of intelligent information technology rather than advanced competency centered on theory and research. Instead of presenting the curriculum system diagram so that it can be flexibly applied to the design and development of the curriculum for intelligent information technology, training modules according to job and level were presented. In relation to intelligent information technology, a questionnaire was conducted for college professors, and industry experts were conducted on the derived educational modules to reflect the opinions of the industry. Industry experts said that collaboration with PBL, Capstone, and industry is necessary to improve problem-solving and communication skills.

• Journal of Auto-vehicle Safety Association
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• v.11 no.2
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• pp.29-34
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• 2019

This paper presents a new method for construction of a static obstacle map. A static obstacle is important since it is utilized to path planning and decision. Several established approaches generate static obstacle map by grid method and counting algorithm. However, these approaches are occasionally ineffective since the density of LiDAR layer is low. Our approach solved this problem by applying probability theory. First, we converted all LiDAR point to Gaussian distribution to considers an uncertainty of LiDAR point. This Gaussian distribution represents likelihood of obstacle. Second, we modeled dynamic transition of a static obstacle map by adopting the Hidden Markov Model. Due to the dynamic characteristics of the vehicle in relation to the conditions of the next stage only, a more accurate map of the obstacles can be obtained using the Hidden Markov Model. Experimental data obtained from test driving demonstrates that our approach is suitable for mapping static obstacles. In addition, this result shows that our algorithm has an advantage in estimating not only static obstacles but also dynamic characteristics of moving target such as driving vehicles.

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.589-598
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• 2023

This article addresses the quasi-static analysis of time-dependent honeycomb sandwich plates with various geometrical properties based on the bending analysis of elastic honeycomb sandwich plates employing a time function with three unknown coefficients. The novel point of the developed method is that the responses of viscoelastic honeycomb sandwich plates under static transversal loads are clearly formulated in the space and time domains with very low computational costs. The mechanical properties of the sandwich plates are supposed to be elastic for the faces and viscoelastic honeycomb cells for the core. The Boltzmann superposition integral with the constant bulk modulus is used for modeling the viscoelastic material. The shear effect is expressed using the first-order shear deformation theory. The displacement field is predicted by the product of a determinate geometrical function and an indeterminate time function. The simple HP cloud mesh-free method is utilized for discretizing the equations in the space domain. Two coefficients of the time function are extracted by answering the equilibrium equation at two asymptotic times. And the last coefficient is easily determined by solving the first-order linear equation. Numerical results are presented to consider the effects of geometrical properties on the displacement history of viscoelastic honeycomb sandwich plates.