• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.30-34
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• 2009

Recently, systems providing the interaction different according to an interval between a user and the display were developed in order to construct the ambient or the ubiquitous computing environment. Therefore, we propose a new type of spatial interaction system; our main goal is to provide the interactive domain in the large-scale ambient display environment. So, we divide into two zones of interaction dependent on the distance from the interaction surface interactive zone and ambient zone. In interactive zone, the users can approach the interaction surface and interact with natural hand-touch. When the users are outside the range of the interactive zone, the display shows only general information. Therefore, this system offers the various interactions and information to users in the ubiquitous ambient environment.

• Journal of Family Resource Management and Policy Review
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• v.17 no.1
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• pp.159-178
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• 2013

This study aims to evaluate the retirement income readiness of Korea, a country that-considering its high property asset ratio-is seeing an unprecedented rapid progression of graying. The result of analyzing 6,589 non-retired households in Statistics Korea's Survey of Household Finances (2011) is as follows. First, the Retirement Readiness Index, considering annual income and asset utilization income before including longevity risk, was 70.6. The index increased to 89.5 when utilizing real assets excluding houses and exceeded 100 when utilizing houses. Second, when designating 100 to be the life expectancy and taking into consideration longevity risk, there results were 52.5, 63.7, and 81.1, respectively. Third, since it is less likely for one to use all current financial assets as post-retirement income, the study reviewed the changes in the Retirement Readiness Index by applying three different levels of asset utilization ratios (50%, 75%, and 100%), which refer to the conversion ratios of current assets to retirement assets. This study is significant in that it considers longevity risk and applies asset utilization ratios in various ways, outside of the assumption that all current financial assets will be used as post-retirement income, to take a more realistic approach to retirement readiness.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.301-306
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• 2016

During the initial stage of propulsion shaft design, the shaft alignment process includes a thorough consideration of lateral vibration to verify the operational safety of the shaft. However, a theoretical method for analyzing forced lateral vibrations has not been clearly established. The methods currently used in classification societies and international standards can only ensure a sufficient margin to avoid the blade-passing frequency resonance speed outside the range of ${\pm}20%$ of the maximum continuous rating (MCR) for the engine. Typically, in shaft alignment analyses, longer center distances between the support bearings promote affirmative results, but the blade order resonance speed can approach the lower limit for lateral vibration. Therefore, this matter requires careful attention by engineers, and a verification of the theoretical analysis by experimental measurements is highly desirable. In this study, both theoretical and experimental analyses were conducted using strain gauges under two draught conditions of vessels used as 50,000-DWT oil/chemical tankers, introduced recently as eco-friendly ships. Based on the analyses, the influence of the lateral vibration on the shafting system and the system's reliability was reviewed.

• Archives of design research
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• v.13 no.2
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• pp.15-24
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• 2000

The demands of golf car is being increased with increment in golf population, gradually proceeding to the trend of popularization, but domestic golf car industry is not so mature as it cope with the need of this market appropriately. Most import golf cars of high price have occupied the domestic market from the viewpoint of the its demands. Although the import golf car provided bad after-sales services and very expensive components, those demand's breadth continue to rise steadily. We decide to have to approach an appropriate time to develop the competitive model native to korean style in the field of golf car, since we have established our foundation in auto industry. At this point we try to analyze the golf car expected from a competition and the present state of golf car industry inside and outside of the country through this study. We attempt to derive the precondition for design development of a proper model to possess competitive power in foreign market from now on.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.39.4-40
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• 2016

We aim to investigate formation of satellite sub-galactic structures around isolated dwarf galaxies using cosmological hydrodynamic zoom simulations. For this, we modify a cosmological hydrodynamic code, GADGET-3, in a way that includes gas cooling down to T~10K, gas heating by universal reionization when z < 8.9, UV shielding for high density regions of $n_{shield}$ > $0.014cm^{-3}$, star formation in the dense regions ($n_H$ > $100cm^{-3}$), and supernova feedback. To get good statistics, we perform three different simulations for different target galaxies of the same mass of ${\sim}10^{10}M_{sun}$. Each simulation starts in a cubic box of a side length of 1Mpc/h with 17 million particles from z = 49. The mass of dark matter (DM) and gas particle is $M_{DM}=4.1{\times}10^3M_{sun}$ and $M_{gas}=7.9{\times}10^2M_{sun}$, respectively, thus each satellite sub-galactic structure can be resolved with more than hundreds or thousands particles. We analyze total 90 sub-galactic structures that have formed outside of the main halos but infall the main halos. We found that 1) mini halos that interact more with the other mini halos tend to accrete the more mass, 2) mini halos that interact more before the reionization tend to form more stars, 3) mini halos with the more interaction tend to approach closer to the galactic center and have the lower orbital circularity, 4) survivals even in the strong tidal fields evolve baryon dominated system, such as globular clusters.

• Ocean Systems Engineering
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• v.5 no.3
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• pp.139-160
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• 2015

The global performance of the 5MW OC4 semisubmersible floating wind turbine in random waves was numerically simulated by using the turbine-floater-mooring fully coupled and time-domain dynamic analysis program FAST-CHARM3D. There have been many papers regarding floating offshore wind turbines but the effects of second-order wave-body interactions on their global performance have rarely been studied. The second-order wave forces are actually small compared to the first-order wave forces, but its effect cannot be ignored when the natural frequencies of a floating system are outside the wave-frequency range. In the case of semi-submersible platform, second-order difference-frequency wave-diffraction forces and moments become important since surge/sway and pitch/roll natural frequencies are lower than those of typical incident waves. The computational effort related to the full second-order diffraction calculation is typically very heavy, so in many cases, the simplified approach called Newman's approximation or first-order-wave-force-only are used. However, it needs to be justified against more complete solutions with full QTF (quadratic transfer function), which is a main subject of the present study. The numerically simulated results for the 5MW OC4 semisubmersible floating wind turbine by FAST-CHARM3D are also extensively compared with the DeepCWind model test results by Technip/NREL/UMaine. The predicted motions and mooring tensions for two white-noise input-wave spectra agree well against the measure values. In this paper, the numerical static-offset and free-decay tests are also conducted to verify the system stiffness, damping, and natural frequencies against the experimental results. They also agree well to verify that the dynamic system modeling is correct to the details. The performance of the simplified approaches instead of using the full QTF are also tested.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.161-169
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• 2022

With the development of mobile devices and global positioning systems, various location-based services can be utilized, which collects user's location information and provides services based on it. In this process, there is a risk of personal sensitive information being exposed to the outside, and thus Geo-indistinguishability (Geo-Ind), which protect location privacy of LBS users by perturbing their true location, is widely used. However, owing to the data perturbation mechanism of Geo-Ind, it is hard to accurately obtain the density distribution of LBS users from the collection of perturbed location data. Thus, in this paper, we aim to develop a novel method which enables to effectively compute the user density distribution from perturbed location dataset collected under Geo-Ind. In particular, the proposed method leverages Expectation-Maximization(EM) algorithm to precisely estimate the density disribution of LBS users from perturbed location dataset. Experimental results on real world datasets show that our proposed method achieves significantly better performance than a baseline approach.

• Korea journal of population studies
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• v.31 no.3
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• pp.107-130
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• 2008

The study of Korean diaspora has focused on migration, adaptation, and identity of overseas Koreans in China, the CIS, Japan, and the United States. However, the contemporary concept of a diaspora is a way of understanding migration, cultural difference, identity politics, and so on. Thus, this more broadly defined diaspora is used to mean a dispersion of people of a common national origin or of common beliefs living in exile. As of 2007, it is estimated that there are about 7 million Koreans living in 170 countries outside the Korean peninsula. Some have left Korea involuntarily and some others voluntarily. But most of them actively try to maintain their identity and culture as Koreans. With the large number of overseas Koreans, there has recently been the recognition of the importance of networking among overseas Koreans in the 21st century. The purpose of this paper is to emphasize the necessity of Korean Global Network of overseas Koreans. In doing so, this paper reviewed the case of Jewish and Chinese network. Then, this paper indicates the problems in the networking of overseas Koreans and suggests the policy implications for Korean Global Network. Above all, there should be changes in the government's policy towards overseas Koreans in the direction of organizing networks of overseas Koreans to coexist with the mother country. The government should adopt a policy to restore trust in overseas Koreans. It should take a pragmatic approach to the mutual interests in the socioeconomic relations instead of taking a political approach to overseas Koreans.

• Cartoon and Animation Studies
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• s.37
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• pp.509-537
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• 2014

This paper proposes 'postfilimc metamorphosis' and 'reanimation' as two concepts that aim at giving account to the aesthtetic tendencies and genealogies of what Suzanne Buchan calls 'pervasive animation', a category that refers to the unprecedented expansion of animation's formal, technological and experiential boundaries. Buchan's term calls for an interdisciplinary approach to animation by highlighting a range of phenomena that signal the growing embracement of the images and media that transcend the traditional definition of animation, including the lens-based live-action image as the longstanding counterpart of the animation image, and the increasing uses of computer-generated imagery, and the ubiquity of various animated images dispersed across other media and platforms outside the movie theatre. While Buchan's view suggests the impacts of digital technology as a determining factor for opening this interdisciplinary, hybrid fields of 'pervasive animation', I elaborate upon the two concepts in order to argue that the various forms of metamorphorsis and motion found in these fields have their historical roots. That is, 'postfilmic metamorphosis' means that the transformative image in postfimic media such as video and the computer differs from that in traditional celluloid-based animation materially and technically, which demands a refashioned investigation into the history of the 'image-processing' video art which was categorized as experimental animation but largely marginalized. Likewise, 'reanimation' cne be defined as animating the still images (the photographic and the painterly images) or suspending the originally inscribed movement in the moving image and endowing it with a neewly created movement, and both technical procedues, developed in experimental filmmaking and now enabled by a variety of moving image installations in contemporary art, aim at reconsidering the borders between stillness and movement, and between film and photography. By discussing a group of contemporary moving image artworks (including those by Takeshi Murata, David Claerbout, and Ken Jacobs) that present the aesthetic features of 'postfilmic metamorphosis' and 'reanimation' in relation to their precursors, this paper argues that the aesthetic implications of the works that pertain to 'pervasive animation' lie in their challenging the tradition dichotomies of the graphic/the live-action images and stillness/movement. The two concepts, then, respond to a revisionist approach to reconfigure the history and ontology of other media images outside the traditional boundaries of animation as a way of offering a refasioned understanding of 'pervasive animation'.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.842-848
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• 2012

In this paper, as a proper authentication method, we made it authenticate a user who has unauthorized device with using authorized device received from telecommunication company using QR code. We designed a better performance protocol which can authenticate mutually using safer and uncomplicated operations than existing user authentication system. Proposed user authentication system authenticates previously authorized mobile device without any information of client who is requesting to get access from outside, so we can basically prevent attack from hackers. In the future, we can possibly use it as user authentication method in common internet environment or we could study on user unique information instead of mobile device information.