• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.10-20
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• 2010

Purpose : Recently, the Recon Challenge at the 2009 ISMRM workshop on Data Sampling and Image Reconstruction at Sedona, Arizona was held to evaluate feasibility of highly accelerated acquisition of time resolved contrast enhanced MR angiography. This paper provides the step-by-step description of the winning results of k-t FOCUSS in this competition. Materials and Methods : In previous works, we proved that k-t FOCUSS algorithm successfully solves the compressed sensing problem even for less sparse cardiac cine applications. Therefore, using k-t FOCUSS, very accurate time resolved contrast enhanced MR angiography can be reconstructed. Accelerated radial trajectory data were synthetized from X-ray cerebral angiography images and provided by the organizing committee, and radiologists double blindly evaluated each reconstruction result with respect to the ground-truth data. Results : The reconstructed results at various acceleration factors demonstrate that each components of compressed sensing, such as sparsifying transform and incoherent sampling patterns, etc can have profound effects on the final reconstruction results. Conclusion : From reconstructed results, we see that the compressed sensing dynamic MR imaging algorithm, k-t FOCUSS enables high resolution time resolved contrast enhanced MR angiography.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.195-206
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• 1993

As the first step in developing the urban information system it is very important to identify the location of the street, and the feature of objects on it Also it is necessary to understand the relationship between objects concerned. In order to manage these information efficiently, the road information should be well organized and standardized for digital data. Because the road is the base place under which most urban utilities are buried. However, the present real situation is that even if we have unique numbers authorized by law for some parts of the road it is too ambiguous to figure out the spatial location of the specific area because the assigned area is so large and incoherent. Therefore, the purpose of this study is to propose a road location identication scheme, to apply this scheme at Kangnam-ku Seoul, and finally to propose the guideline in developing the road management information system in Korea. The road identification scheme developed in this study are as follows: (1) The road is defined as a fixed factor, and was given the identification number which repressents the funtion, relationship, and direction of the road without the road section and absolute coordinates. (2) The parcel identification nutter was given to each route to understand it possible to understand the location of the road itself and surroundings. (3) To update the md information using the scheme developed in this study relative coordinate method(Dynamic Segmentation) based on the road centerline was applied.

• Journal of Korean Philosophical Society
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• v.141
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• pp.63-84
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• 2017

In the twentieth century Anscombe's 1958 article "Modern Moral Philosophy" argued that duty-based conceptions of morality are conceptually incoherent for they are based on the idea of a "law without a lawgiver". Concepts such as "morally ought", "morally obligated", and "morally right" require a legislator as the source of moral authority. In the past God occupied the role, but systems that dispense with God are lacking the proper foundation for meaningful employment of those concepts. Aristotle's virtue ethics can do so without appealing to any such lawgiver, and ground morality in the well being of human moral agents. Therefore Anscombe recommends a return to the eudaimonistic ethical theories of the ancients as secular approaches. Eudaimonia is a central concept in Aristotelian ethics, along with the terms "aret?"(translated as virtue or excellence) and "phronesis"(translated as practical wisdom). In Aristotle's works, eudaimonia was used as the term for the highest human good, and so it is the aim of practical philosophy to consider what it really is and how it can be achieved. Eudaimonia is a Greek word commonly translated as well-being, happiness, welfare or "human flourishing". As Aristotle points out, saying that eudaimon life is a life which is objectively desirable, and means living well. Everyone wants to be eudaimon. And everyone agrees that being eudaimon is related to faring well and to an individual's well being. But the really difficult question is to specify just what sort of activities enable one to live well. Aristotle says that the eudaimon life is one of "virtuous activity in accordance with reason," this is a necessary condition of eudaimonia, the pleasure accompanied by virtuous activities is a sufficient condition. Hence we have a more accurate translation of eudaimonia with a review the practical meaning of eudaimonia, and the correlation between eudaimonia and arete, pleasure.

• The Southeast Asian review
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• v.28 no.4
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• pp.31-76
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• 2018

This article explores why the two Southeast Asian countries, Vietnam and the Philippines, choose different strategies to cope with the Chinese threat. Despite the evident Chinese threat in the South China Sea, Vietnam has not meaningfully expanded the military cooperation with the United States, whereas the Philippines, ironically, has distanced itself with its ally, the United States. Existing studies on the topic does not offer a satisfactory explanation. We assign that two cases are examples of "underbalancing" - the failure of balancing even though there is an evident threat. Furthermore, we demonstrate the difference between cases of the Philippines and Vietnam by arguing that the number of veto players affects the outcome of foreign policy, underbalancing of two countries. The Philippines has only one veto player, the president, hence its response to external threats is incoherent. On the other hand, the number of veto players in Vietnam is more than one and those players demand negotiation among them on the matter of foreign policy. Upon analyses on two cases we argue that the former is the case of underbalancing caused by a lack of policy stability, while the latter is the case of underbalancing caused by a lack of policy responsiveness.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.274-280
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• 2020

In this paper, the effect of atmospheric turbulence is numerically modeled and analyzed via a phase-screen model, in regard to long-range optical energy transfer using coherent beam combination. The coherent-beam-combination system consists of three channel beams pointing at a target at a distance of 1-2 km. The phase and propagation direction of each channel beam are assumed to be corrected in an appropriate manner, and the atmospheric turbulence that occurs while the beam propagates through free space is quantified with a phase-screen model. The phase screen is statistically generated and constructed within the range of fluctuations of the structure constant Cn2 from 10-15 to 10-13 [m-2/3]. Particularly, in this discussion the shape, distortion, and combining efficiency of the 3-channel combined beam are calculated at the target plane by varying the structure constant used in the phase-screen model, and the effect of atmospheric turbulence on beam-combination efficiency is analyzed. Analysis with this numerical model verifies that when coherent beam combination is used for long-range optical energy transfer, the received power at the target can be at least three times the power obtainable by incoherent beam combination, even for maximal atmospheric fluctuation within the given range. This numerical model is expected to be effective for analyzing the effects of various types of atmospheric-turbulence conditions and beam-combination methods when simulating long-range optical energy transfer.

• The Journal of the Acoustical Society of Korea
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• v.25 no.7
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• pp.346-355
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• 2006

Acoustic data from a shallow water experiment in the East Sea of Korea (MAPLE IV) is Processed to investigate the Performance of matched-field geo-acoustic inversion and source localization. The receiver array consists of two legs as in an L-shape. one vertical and the other horizontal lying on the seabed. Narrowband multi-tone CW source was towed along a slightly inclined bathymetry track. The matched-field geo-acoustic inversion includes comparisons between three processing techniques. all based on the Bartlett processor as; (1) the coherent processing of the data from the full array, (2) the incoherent Product of each output from both the horizontal and vertical arrays, and (3) the cross correlation between the horizontal and vertical arrays. as well as processing each array leg separately. To verify the inversion results. matched-field source localization for low level source signal components were performed using the same Processors used at the inversion stage.