• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.81-89
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• 2014

The present study aims to design an optimized hull shape of a floating pendulum-type wave energy converter(WEC). The purpose of these structure is to improve the performance and stability of the WEC by reducing its motion under operating and survival wave conditions. In this study, motion reduction structures, like restoring and dampling plates were installed on a floating pendulum WEC that has been the subject of previous studies. Restoring plates were installed to increase the restoring force and shift the natural period to a shorter period. Damping plates were installed to shift the natural period to a longer period by increasing the added mass. The effects of the structures were then analyzed under different incident wave conditions. The design parameters for the motion reduction structures were size, shape, and installed position. The wave-induced motion characteristics and performance of the floating pendulum WEC were also investigated numerically. Based on the simulation results, we are able to optimize the motion reduction structure of the WEC, thus improving its efficiency and durability.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.17-27
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• 2009

Purpose: This review article was written to determine the effects of parameters characterizing a hard contact lens (RGP included), such as BCs, diameters, edge angles, on the time interval for tight fitted lens to return to the equilibrium when it was decentered from blinking. Methods: A mathematical formulation was established to relate or calculate the restoring forces and thickness of lacrimal layer beneath the cornea with the various lens parameters when the tight fitted lens was decentered from blinking. Based on this formulation the differential equations and their numerical solution program were set up to describe the time dependence of the lens on the position and to estimate the time for the lens's return to the equilibrium after blink. Results: It is found that the time interval for the tight fitted lens to return to the equilibrium decreases as either the BC decreases or the diameter increases because both the reduction in BC and increase in diameter result in the increase in the lacrimal layer thickness between the lens and cornea increase which yielded the lowering of the viscous friction in the lens motion. As the edge angle of tight fitted lens increases the time for recentering decreases due to the increase in restoring force without change in lacrimal thickness beneath the lens. In the case of flat fitted hard lens (RGP included), the lacrimal layer thickness under the lens increases as either BC or diameter increases which results in reduction in viscous friction so that the time for the lens's return to the equilibrium were to decrease. The edge angle of flat fitted lens does not affect the lens motion. Conclusions: The effect of BCs on the lens motion (time to approach the equilibrium) was concluded to be significant with both tight and flat fitted lens where its results are contrary with each other. The edge angle of lens only affects the motion in tight fitted lenses.

• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.61-74
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• 2021

The objective of this study was to evaluate the community's capacity and hindrance factors affecting the community's activities by exploring the process of restoring the community's environmental pollution. This study examined the community activities related to the restoration of pollution that occurred at the former Janghang smelter in Seocheon-gun. The results of this study showed that leaders, cooperative resources, and the media were elements positively influencing the recovery of the community. The starting point that became the driving force for community activities was the presence of a leader who had a small stake in it. Moreover, it required cooperation such as the continuous interest of local active groups and residents to continue this effort. Above all, the media publicized the incident and amplified the activities of members. Meanwhile, there were various conflicts hindering the activities of local communities in the process of restoring the pollution such as the internal conflicts of community groups, conflicts between residents and active groups, and conflicts with the government. The behaviors that appeared in the process of restoring the pollution revealed a form of united governance. Moreover, they changed from an initial "supportive" character to "resistant" and "defensive" activities. Later, it was transformed into "subjective" and "creative" activities.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.679-682
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• 2000

In this paper, a MMSE filter in homomorphic wavelet transform domain is proposed for restoring an ultrasonic images corrupted by speckle noise. In order to remove effectively the speckle noise which is a kind of multiplicative noise, speckle noise is transformed into a form of additive noise and then the additive noise is denoised through the MMSE filter in homomorphic wavelet transform domain. The proposed method shows much higher quality in terms of ISNR and subject quality.

• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.613-625
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• 2001

In this paper, we investigate a simplified model of a particle suspended elastically from two towers by two nonlinear elastic springs, with a restoring force similar to Hooke’s law under extension and with no resistance to compression. Numerical results are presented, showing the solutions can be either of the same period oscillation the forcing term, can be a subharmonic response of multiple period, or can be noisy periodic which is apparently chaotic. Multiplicity of periodic solutions for certain physical parameters are demonstrated.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.835-840
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• 2001

The new approach is a kind method of restoring temporary defect. Here, it is important for the defect not to occur problems of both local effect and global system. A basic concept is that it measures remaining prestress of PSC structures during the defect is restored. This study suggested new approach for measurement of remaining prestress. Two important results are obtained. First, safety problems, local stress concentration and global system, are very satisfied. Second, measurement value exists within error bound $\pm$ 1% in comparison with known value.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.210-210
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• 2006

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.160.2-161
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• 2003

Hwang Chil (Dendropanax morbifera Lev.) belongs to Aralia elata group. This plant is only found in Korea and is considered to be along with ginseng. The physiological activities of it have been reported as having scavenging effect on oxygen free radicals and anti-carcinogenic effect. As most of the anti-oxidants were effective on protecting hepatotoxicity from alcohol, hard tissues restoring and skin whitening, the effectiveness of Hwang Chil extracts was screened. (omitted)

• Journal of the Korean Academy of Esthetic Dentistry
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• v.1 no.1
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• pp.50-57
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• 1992

Intrinsic discoloration of permanent anterior teeth is a continuing esthetic problem. Tetracycline ingested during amelogenesis has long been recognized as predisposing factor in intrinsic staining. Methods for restoring original tooth color have included (1) complete PFM crown coverage (2) porcelain laminate veneers (3) direct bonding of composite resin, and (4) bleaching. In the case of tetracycline-stained upper anterior teeth, We authors, obtained the satisfactory results by means of gingivectomy, preliminary bleaching and porcelain laminate veneer restoration.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.230-233
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• 2006

Conventionally, it used to be focused on simply prevention of further settlement of structures, where, much of problems were raised and sometimes the construction itself was not possible. Further, rough estimation of the ground, which is unseen, often incurred many troubles in the maintenance. D-ROG method is a high-tech technology that changes almost all of the concepts on the conventional grouting, is expanding its application scope spanning from the restoration of settled structures to ground strengthening works necessary for building enlargement and remodeling.