• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.21-25
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• 2009

Generally, fully implantable middle ear hearing device (F-IMEHD) is implanted under the skin nearby human temporal bone with all components including implantable microphone and vibration transducer. The microphone and transducer have different characteristic before and after implant. Fitting process is performed for this characteristic change of them and proper performance of hearing aids for each patient. Conventional hearing aids and partially implantable hearing aids, they have wired connector for fitting process. However in case of F-IMEHD, it is difficult this wired connection, because all components of F-IMEHD is implanted. In this paper, fitting software that can be apply wireless fitting hardware for F-IMEHD has been designed and implemented. It can find out proper fitting parameter reflecting characteristics of the microphone and transducer for patients who has difficulty in hearing.

• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.357-365
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• 2005

We present a B-spline fitting method based on genetic algorithm for the extraction of object contours from the complex image sequence, where objects with similar shape and intensity are adjacent each other. The proposed algorithm solves common malfitting problem of the existing B-spline fitting methods including snakes. Classical snake algorithms have not been successful in such an image sequence due to the difficulty in initialization and existence of multiple extrema. We propose a B-spline fitting method using a genetic algorithm with a new initial population generation and fitting function, that are designed to take advantage of the contour of the previous slice. The test results show that the proposed method extracts contour of individual object successfully from the complex image sequence. We validate the algorithm by false-positive/negative errors and relative amounts of agreements.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.5 s.153
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• pp.722-732
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• 2006

The pattern making of the tight-fitting collars which often used in diving suits, dance wear, or cycle wear has not been fully established. To develop tight-fitting collar pattern directly from 3D images from the representative somatotypes, dressforms developed by Jaeun Jung were used. The 3D scan data of the four male dressforms were obtained using Exyma-1200. Triangle Simplification and the Runge-Kutta method were applied to reduce the 3D scan data points and to make the segmented triangular patches in a plane from 3D data. As results, apparent differences between the tight-fitting collar patterns obtained from the 3D scan data and the ordinary 2D collar patterns were found around the center back line. The curvatures of the center back line were higher in all types of the tight-fitting collar than in the ordinary collar pattern. Relative differences in the shape of collar lines among four representative Korean men were reported. To fit the curved shape of the back neckline, 1.8 cm should be reduced from the upper neckline in average. We suggested the direct pattern making method for the 2D tight-fitting collar patterns considering the 3D shape of various types of men's dressform.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.319-324
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• 2003

In general industrial rotating machinery is operated under 3,600 rpm as rotating speed and designed to have critical speed that is above operating speed. So, there was no problem to operate rotating machine under critical speed. But nowadays, they should be operated more than the frist critical speed as usual with the trend of high speed, large scale and hish precision in industries. In case of the large rotor assembly as the trend of large scale, using fitting method of disk or cylinder on shaft is rising for the convenience of assembly and cutting down of manufacturing cost. The shrink fitting is used to assemble lamination part on shaft for manufacturing of rotor of motor or generator in many cases and also is widely used for other machinery. In rotating system, which is compose of rotor and bearing, the critical speed is determined from inertia and stiffness for the rotor and bearings. In case of fitting assembly, analysis and design of the rotor is not easy because the rotor stiffness is determined depend on a lot of factors such as shaft material/dimension, disk material/dimension and assembled interference etc. Therefore designer who makes a plan for hish-speed rotating machine should design that the critical speed is located out of operating range, as dangerous factors exist in it. In order to appropriate design, an accurate estimation of stiffness and damping is very important. The stiffness variation depend on fitting interference is a factor that changes critical speed and if it's possible to estimate it, that Is very useful to design rotor-bearing system. In this paper, the natural frequency variation of the rotor depends on fitting interference between basic shaft and cylinder is examined by experimentation. From the result, their correlation is evaluated quantitatively using numerical analysis that is introduced equivalent diameter end the calculation criteria is presented for designer who design fitting assembly to apply with ease for determination of appropriate interference.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.25-29
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• 2004

Corona on polymer materials causes deterioration by the combined action of the discharge striking the surface and the action of certain chemical compounds that are formed by the discharges. In the design and manufacture of polymer insulators must be sufficiently large to avoid corona discharges, otherwise a shielding or corona ring (grading ring) needs to be installed on the insulator. To conduct this purpose, many researchers have investigated end-fitting of polymer insulator by voltage distribution simulation and electrical test. Grading rings are used to improve the performance of the insulator in multiple ways. They can reduce corona and associated audible noise and radio influence and television interference. The factors determining the uses of a grading ring are line voltage, geometry and dimensions of end fittings, geometry and dimensions of line hardware, and environmental conditions. In this paper, electrical property of polymer insulator with end-fitting design have been investigated by electrical field analysis, various end-fitting design, tracking wheel test, corona inception voltage and extinction voltage. Electrical field analysis is conducted by FEM program and various end-fitting is designed through this result. Designed end-fittings are manufactured and their performance is conducted by electrical performance test.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.85-99
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• 1998

This paper describes an experimental study to examine collapse causes of the lifting cable due to brittle failure of an fitting anchor under the lifting works. Also, in this study an collapse mechanism that was obtained from stress analysis was compared with an actual collapse procedure. Fractographical analysis as well as chemical component test, tension test and Charpy V-Notch impact test for the fractured steel members were carried out. And then, its results were compared with that of normal steel members. Circumferential surface flaws were developed at internal facets of the fitting anchor before tensile stress occurred. Hence, a higher stress than nominal stress was occurred at flaws by stress concentration at the crack tip. Also, stress intensity factor of members increased by crack size of the potential flaws. Because the stress intensity factor at the crack tip was greater than critical values(fracture toughness), brittle fracture occurred under the lifting works. It is judged that the main collapse of the lifting cable is due to brittle fracture of the fitting anchor.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.283-291
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• 2011

Purpose: To find an empirical fitting curve to represent the relationship between the luminous transmittance and tinted time in tinted lenses using exponential decay curves. Methods: Total ninety tinted lenses were prepared with CR-39 lenses and six different colored dyes. Single, double and triple exponential decay curves were used as trial curves in order to find the empirical fitting curve. Result: The results showed that the best empirical fitting curve was triple exponential decay curves. Conclusions: We propose triple exponential decay curves as proper empirical fitting curves to represent the tinted-time dependence of the luminous transmittance in tinted lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.163-169
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• 2014

Purpose: This study is for compared the change of corneal refractive power before and after wearing of rigid gas permeable contact lense with diagnostic method which is 1 D flatter than alignment fitting on right eye and alignment fitting on left eye for 2 months and investigate the preference. Methods: Twenty middle school and high school students (40 eyes) who had never worn a contact lense before for no corneal topographical change, no ocular disease, no experience of ophthalmic surgery and have normal tear amount were selected for this study and corneal refractive power were examined before wearing rigid gas permeable contact lense and adaptation status and corneal examination were performed after 10 days of wearing and after cheking up the continuation of wearing, all candidate wear contact lens 8 hours per day for 2 month and corneal refractive power were compared. Results: After 2 months of wearing with 1 D flatter than the alignment fitting on right eyes, there was significant difference in the central corneal refractive power was $43.84{\pm}1.33D$, flat K power was $43.05{\pm}1.29D$, and steep K power was $44.61{\pm}1.42D$ decreased than before wearing (p<0.001, 0.001, 0.047). The e-value of the principal meridians also shows statistically significant difference (p=0.037, 0.015). After 2 months of wearing with alignment fitting on left eyes, the central corneal refractive power was $44.40{\pm}1.26D$, flat K power was $43.57{\pm}1.23D$. and flat K e-value was $0.58{\pm}0.05$ which showed no statistically significant difference (p = 0.769, 0.614, 0.181). But steep K power was $45.25{\pm}1.36$, and steep K e-value was $0.45{\pm}0.18$ which shows statistically significant difference (p=0.018, 0.027). Conclusions: Consider the comfort, clear vision, dryness for preference fitting investment, 6 students (30%) prefer right eye which is 1 D flatter fitting, 14 students (70%) prefer left eye which is alignment fitting. For rigid gas permeable fitting needed for accurate examination and should prescribe the alignment fitting which is suitable for each cornea.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.21-30
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• 2011

Purpose: The study was performed to compare the differences in lens rotation, lens movement by blinking and lens centration with alignment or steep fitting of soft contact lens in normal and dry eyes. Methods: Total 40 eyes (aged 20~30 years) were classified into the normal (n=20) or dry eye group (n=20) by the diagnosis methods for dry eyes and worn soft contact lens (polymacon material) with alignment fitting or steep fitting. Lens rotation, lens movement by blinking and lens centration were separately measured immediately after lens wearing and after stabilization of tear film and compared by fitting states of soft contact lenses. Results: With steep fitting of soft contact lens in dry eyes, averaged lens rotation immediately after lens wearing was not significantly different from that of the normal eye group with alignment fitting however, lens rotation after stabilization in dry eyes was significantly larger than that in normal eyes. Any significant difference in lens movement by blinking was not shown in normal eyes. However, lens movement by blinking in dry eyes was increased with steep fitting. The range of lens centration on cornea in normal eyes with alignment fitting was more vertically distributed. On the other hand, the range of lens centration on cornea in dry eyes with alignment fitting was more horizontally distributed. Lens centration was shown to be changed by stabilization of tear film. That is, lens centrations were somewhat vertically widespread immediately after lens wearing and restrictively distributed in horizontal direction, respectively, with steep fitting in dry eyes. Conclusions: These results suggested that lens movements and centration in dry eyes were different from those of normal eyes. Especially, those differences between normal and dry eyes were much bigger with steep fitting of soft contact lenses. Thus, those differences should be considered for the comfortable and safe fitting of soft contact lens in dry eyes.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.9-16
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• 2008

To assess the preference and efficacy of empirical fitting methods with spheric and aspheric RGP lenses. Methods: Healthy 37 subjects were fitted with spheric design (diameter 9.3 mm) on right eye and aspheric design (dia 9.6 mm) on the left eye. Base curves which were fitted empirically (using on-K, Kavg-0.50D (or 1.00D) and manufacturer's recommended fitting guide) were compared with another base curve which obtained the best diagnostic fit with spheric and aspheric RGP lenses. The preference and fitting type (lid attachment or interpalpebral) for two design lenses were investigated 2 weeks after fitting RGP lenses. Results: Of 33 successful RGP lens-wearing subjects, 76% preferred spheric design compared with 24% of aspheric RGP lens wearers. Sixty seven percent were fitted with lid-attachment in spheric lenses, whereas 64% were fitted with lid-attachment in aspheric lenses. The acceptable fit success rates within ${\pm}$0.50D of base curves were 97% for the on-K fit, 100% for the Kavg-0.50D fit and 100% of the manufacturer's guide fit compared with the diagnostic fit in spheric design, whereas 91%, 79% and 94% reported on-K, Kavg-1.00D and manufacturer's guide, respectively, in aspheric design. Conclusions: Although aspheric RGP lenses are more popular in the Korean market, it is still preferable to fit subjects with spheric RGP lenses. Empirical fitting may be best accomplished with the spheric lenses using Kavg-0.50D fit and the manufacturer's fitting guide, whereas aspheric RGP lens designs are unacceptable lens fit based on empirical fitting.