• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.145-159
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• 2004

A mathematical model and its computer solution program were proposed to analyze the motion of contact lenses which are being subject to lid-blinking. The equation was derived by incorporating an acceleration induced lid's force exerting on the contact lens, the viscous damping resistance in the tear layer beneath the lens and the sliding frictional force between the lid and the contact lens surface into the formulation of differential equation describing the vibration. The model predicts the time-dependent displacement from the equilibrium postion during/after the blinking. During the blinking, as the time for the completion of one cycle of blinking decreases the off-the-equilibrium displacement of contact lens increases while the decrease of diameter in the contact cause the opposite effect. It is found that lid pressure exerting on the lens cause an insignificant lens displacement from the equilibrium position. After blinking the frequency of damped oscillation of contact lens decreases as the diameter of lens increases, due to the incresed surface while the reduced blinking time does not cause a significant frequency change. This is because that driving force for the contact lens movement posterior to blinking is the capillary-induced force not the lid force.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.273-281
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• 2005

The weight of spectacles fined on is resolved into its components along the nose's slide plane and the normal to the nose plane where the nosepad is located. The equation and its numerical solution to determine the component force was derived as a function of splay angle ${\Psi}$, $sin{\Psi}$, $cos{\Psi}$, and $cot{\Psi}$, incorporated with ${\theta}$ and ${\Phi}$, the angles viewed from side and front of the face, respectively. Values of inclination angle ${\theta}$ and ${\Phi}$ could be obtained to fulfill the condition where the frictional force between the nose and pad is either greater than the normal pressure exerted by the spectacles on the nose. With the value of ${\theta}$ fixed the normal pressure increases as ${\Phi}$ increases. With ${\Phi}$ fixed, the effect of ${\theta}$ is the same.

• The Journal of the Korean dental association
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• v.54 no.1
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• pp.57-66
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• 2016

This study was to evaluate the effects of oral health education conducted on air force personnel according to the use of disclosing solution. They were divided into 3 groups: Group A: oral health education was not conducted, Group B: oral health education was conducted without using disclosing solution, and Group C: oral health education was conducted using disclosing solution. The subjects who had not participated in the education at least once were excluded, and the remaining 83 subjects received oral health education four times and one time each week. The probing depth, plaque index, gingival index, and bleeding on probing were measured one week before the implementation of the first oral health education and one week after the implementation of the fourth oral health education. The results of verifying the homogeneity of the clinical indices before the oral health education showed statistically significant differences in bleeding on probing among the three groups. The results of comparing the clinical indices among the three groups after the oral health education exhibited statistically significant differences in the plaque and gingival indices among the three groups. Groups B and C showed lower values than Group A. The comparison of the clinical indices before and after the oral health education showed statistically significant improvements in all clinical indices after the education in Group C. The results suggested that the oral health education using disclosing solution could maximize that visual effects and encourage self-motivation, consequently improve the oral hygiene of the patients.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.51-56
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• 2003

The main goal of existing mobile robot system was a complete autonomous navigation and the vision information was just used as an assistant way such as monitoring For this reason, the researches have been going towards sophistication of autonomousness gradually and the production costs also has been risen. However, it is also important to control remotely an inexpensive mobile robot system which has no intelligence at all. Such systems may be much more effective than fully autonomous systems in practice. Visual information from a simple camera and distance information from ultrasonic sensors are used for this system. Collision avoidance becomes the most important problem for this system. In this paper, we developed a force feedback joystick to control the robot system remotely with collision avoiding capability. Fuzzy logic is used for the algorithm in order to implement the expert s knowledge intelligently. Some experimental results show the force feedback joystick werks very well.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.97-106
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• 2011

Purpose: This review article was written to theoretically compare the depressing force (pressure, adhesion) to the cornea between when the spherical lenses were being tightly and flat fitted. Methods: Mathematical equations and their numerical solution programs (model) were formulated to calculate the depressing (adhesion) force to the cornea by both the tightly and flat fitted contact lenses. Based on this proposed model the effects of parameters characterizing a contact lens such as BCs, diameters, edge shape and corneal shape (ratio of long and short corneal axis, p) on the depressing force to the cornea were predicted/analyzed in both tightly and flat fitting regimes. Results: Corneal adhesion increased as the corneal p-value increased. Adhesion increase caused by the increased p-value was much larger in flat fitted case than in tight fitted one. Corneal adhesion reduced abruptly as the BC increased in flat fitting regimes while the adhesion rise was insignificant in tight fitting ones. Reduction in corneal adhesion due to lens-size increase was predicted to be insignificant in both tight and flat fitting regimes. Both the lens edge shape (edge angle) and thickness were relevant only in tight fitting regime. Corneal adhesion increased as the increased with tight-fitted lenses. As the thickness of tight fitted lenses increased, corneal adhesion inversely decreased. Conclusions: The two most significantly affecting the depressing force to cornea were found to be the degree of corneal bending toward the periphery and the BCs of lenses.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.744-750
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• 2015

In this paper, development of mobile robot for the inspection of hull surface was mentioned. In the sea, it is difficult to proceed with the visual inspection of hull side and thus mobile robot for checking the status could be run with strap-on its surface. To do this, permanent magnet module to generate magnetic force between hull surface and mobile robot, and structure to minimize variance of the force under curvature circumstance were considered on the design. Based on the design, mobile robot with four NdFeB, four driving wheels and image aquisition module was applied. Load experiment to check the adhesive force, slip test during stop state and driving test to measure driving speed were executed. From the experiments 13 Kgf adhesive force was obtained and slip was not happened until 8 Kgf load on the inclined plate. Driving speed of mobile robot was measured at 0.82 m/s corresponding to 6.5 ampere. We confirmed the effectiveness of developed mobile robot by experiments to check its characteristics.

• Korean Institute of Interior Design Journal
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• no.21
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• pp.94-100
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• 1999

After fifteenth century artists sought for a method on representation of nature through perspectiva artificialis. Perspectiva artificialis is become a tool for establishment of their theory and value. This study aim to study Orientation and mean of Anamorphosis in Architectural Perspective and transitional procedure of perspective in appealing the will of Architects. Initially, the concern of perspective is begun with optics in the Middle Ages. In Renaissance Ages perspective are presented a scientific and real world to a transformation of non-scientific world with visual cone, vanish oint and anamorphosis. In artists anamorphosis specially is a effective means to emphasize a affect of mannerism. Accordingly, perspective is discoursed to approached between art and technique. After renaissance perspective is become the driving force of the representation in spirit of scientific investigation ; while anamorphosis such a manneristic present in art is motived to prevent from obtaining its universe and implicity through their methodology.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.56-63
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• 2020

The Avengers film produced by Marvel Comics shows visual effects that were impossible to produce in the past. Companies that produce film special effects were initially equipped with large personnel and equipment, but technology is gradually evolving to be feasible for smaller companies that do not have high-priced equipment and a large workforce. The development of hardware and software is becoming increasingly available to the general public as well as to experts. Equipment and software which were difficult for individuals to purchase before quickly popularized high-performance computers as the game industry developed. The development of the cloud has been the driving force behind software costs. As augmented reality (AR) performance of mobile devices improves, advanced technologies such as motion tracking and face recognition technology are no longer implemented by expensive equipment. Under these circumstances, after implementing mobile-based facial capture technology in animation projects, we have identified the pros and the cons and suggest better solutions to improve the problem.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.192-198
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• 2006

The real-time simulator of a turning-type sluice gate actuated by the hydraulic cylinders is developed using a PC and a visual C++ program language. The real-time simulator receives the directional control valve signal selected by the operator using the mouse, updates the state variables of the turning-type sluice gate system responding to the control signal, and draws the moving figures of the sluice gate, cylinder, reserved water every drawing time on the PC monitor. Also, the operator can observe the sluice gate angle, cylinder force, cylinder pressures, and hydraulic power representing the operation of sluice gate system through the PC monitor every drawing time. The simulator can be a very useful tool to design and improve the turning-type sluice gate system.

• Physical Therapy Korea
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• v.11 no.4
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• pp.51-60
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• 2004

Falls are common, costly, and a leading cause of death among older adults. The major predisposing factors of a fall may include age-related deterioration in the dynamic system composed of auditory, somatosensory, vestibular, visual, musculoskeletal, and neuromuscular subsystems. Older adults with a history of frequent falls demonstrated significant reductions in gait velocity, muscle force production, and balance performance. These altered neuromechanical characteristics may be further exaggerated when faced with conflicting multisensory conditions. Despite the important contribution of multisensory function on the sensorimotor system during postural and locomotor tasks, it remains unclear whether multisensory intervention will produce dynamic balance improvement during locomotion in older adults with a history of frequent falls. Therefore, the purpose of this paper is to address important factors associated with falls in elderly adults and provide theoretical rationale for a multisensory intervention program model.