• Journal of Korean Ophthalmic Optics Society
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• v.2 no.1
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• pp.61-76
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• 1997

In this paper, we found out the objective refractive errors, the full corrective refractive powers, and the prescriptions for 64 males and 36 females aged 18 to 26 years. To increase the unaided visual acuity 0.1 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -3.00D for male and -2.91D for female respectively. To increase the unaided visual acuity 0.5 to the aided visual acuity 1.0 with the glasses, we needed the spherical equivalent refractive power of -0.5D for male and -1.38D for female respectively. Comparing unaided visual acuity and corrective refractive power, the more one has refractive error the less one has unaided visual acuity but these are not linear relationships. Comparing objective refractive error figures, full corrective refractive power figures and prescriptions, objective refractive error figures are the hightest, followed by full corrective refractive power figures. Prescriptions compared with the other two are lower. The cylindrical refractive powers are less than -2.50D. In this study, with the rule astigmatism is dominant over against the rule astigmatism and oblique astigmatism. The accommodation measured by push up method is 6.75D~10.04D for male and 7.50D~9.60D for female respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.383-387
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• 2014

Purpose: To investigate the effect of corneal unique shape to changes of refractive full corrections when pupil size changes. Methods: Subjective refraction for monocular full correction was performed to 30 subjects ($23.33{\pm}1.78$ of age, 60 eyes) in two room conditions, 760 lx and 2 lx, respectively. Pupillary diameter was measured in two conditions and the change pattern was analyzed using a peak data of corneal topography. Results: Pupillary diameter was 3.74~4.00 mm in 760 lx and 5.52~5.90 mm in 2 lx. By comparison with refractive data in 760 lx, those data in 2 lx was changed as follows: more (-) spherical power of 17 eyes (28.3%), more (+) spherical power of 10 eyes (17.7%), more (-) cylinderical power of 17 eyes (28.8%), less (-) cylinderical power of 9 eyes (15.3%), and astigmatic axis rotation of 36 eyes (62.1%). From peak data of corneal topography, the changing pattern of two principal meridians was classified into 4 types. Conclusions: Expansion of the corneal refractive surface accompanied with pupillary dilation may be a main factor that effects the changing a values of subjective refraction because of unique corneal shape. Therefore, subjective refraction should be performed under the nearest lighting condition to a main living environment.

• Journal of Korean Clinical Health Science
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• v.3 no.3
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• pp.378-389
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• 2015

Purpose. The actual status of wearing toric soft contact lenses was investigated to learn why it is not used although it is required. Materials and Methods. This study has studied 64 contact lens wearing the local college students, Gyeongsangnam-do who are 20.17(${\pm}0.70$)years old, by measuring their refractive power and over-refractive power with auto refractometer(HRK-8000A, Huvitz, Korea). In addition to that, a survey was done to figure out why they do not wear toric soft contact lenses, the purpose of using toric soft contact lenses, whether they have astigmatism or any knowledge about it, the kinds of contact lens, whether they are willing to buy corrective lenses, and how they are satisfied after purchasing them. Results. 17 students (21.9%) said they experienced light-spread; 9 students (14.1%)said that they have dizziness when they wear contact lens all day long. In the survey to see whether they had astigmatism or not, 37 students (57.8%) said they had it. For the reason they do not wear toric soft contact lenses, 33 students (51.6%) said that "they were prescribed regardless of astigmatism in the optometrist." To the question asking if they are willing to buy toric soft contact lenses according to the existence of astigmatism, 51 students (79.6%) answered they are. 31 students (48.4%) said they heard a description about astigmatism at the time of purchase for contact lens. Conclusion. As the ways for any people who need to correct astigmatism to wear corrective lens, enough education about astigmatism and consistent follow-up management are needed, where the role of optometrist is considered important.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.323-328
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• 1982

Kareius bicoloratus (Basilewsky) is one of the commonly found right-eye flounders and widely distributed in the coastal waters of Korea and Japan. On December 11,1980, the ailthors carried out an experiment to obtain a large number of fertilized eggs from wild adult fish caught by a trawler. The fish were obtained from Maisaka fish market, Shizuoka Prefecture, Japan. The egg is pelagic, spherical in shape and measuring 1.014-1.04 mm in diameter. The yolk as well as the egg capsule is colorless and transparent, and contain no oil globules. The hatching took place in 73 hr 45 min after fertilization at the water temperature $8.0-9.5^{\circ}C$. Newly hatched larvae are 3.09-3.146 mm in total length, with the anus situated in the middle of the body. The marginal fin does not have Pigment cells and myotome number is 17+20=37. Within one day after hatching, the larvae attained 3.77 mm in total length, and there appeared three or four melanophore on yolk sac. When the larvae attained 3.96 mm in total length, melanophores began to appear on the eye ball. Two days after hatching, the larvae attained 4.05 mm in total length, most of yolk material was absorbed, and the caudal fin began to grow at the terminal part of the notochord. When the larvae attained 4.21 mm in total length, mouth and eyes began to move. After 3 days, the larvae attained 4.342-4.394 mm in total length, alimentary canal differentiated, melanophores appeared on the lower jaw and posterior part of the fin membrane. When the larvae attaind 4.576 mm in total length, marginal line of dorsal fin membrane became concave.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.137-144
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• 2010

Purpose: This study was to evaluate the clinical performance of 1-Day disposable toric soft contact lenses (TSCL) and to compare the visual performance with glasses and TSCL. Methods: In a two-week investigation of 'prism ballast' designed TSCL, occular refractions in 15 (30 eyes) healthy subjects were within the range of -2.75 D TO -8.00 D spherical power and -0.75 DC to -2.25 DC cylinderical power (with-the-rule). Subjects were assessed the clinical performance (orientation, centration, movement, tightness, rotation recovery, symptoms) of TSCL and compared binocular vision and contrast sensitivity with corrected glasses and TSCL at initial and two-week follow-up visits. Results: The prism-ballast design TSCL achieved better orientation, rotation recovery and symptoms over 2 week period. There was no statistically significant difference between spectacles and TSCL with respect to measuring binocular vision and contrast sensitivity. Conclusions: The clinical performance was good with prism-ballast design toric soft contact lenses. Evaluation of binocular vision and contrast sensitivity did not show the differences between spectacles and TSCL correction. This study suggests that TSCL wearers can be achieved similar visual performance for spectacles wearers.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.41-47
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• 1962

This work was carried out to investigate the phenotypic, genotypic, and environmental correlations between the number of the egg markings and other metric characters, and their heritability, with eight varieties in Bombyx mori L. Five European varieties, ten Chinese varieties and ten Japanese varieties were used to know the average number of the egg markings and their variabilities for each strains. The results may be summarized as follows: 1) there were highly negatively phenotypic and genotypic correlations between the number of the egg markings and total cocoon weight, weight of cocoon layer, or denier, but not an environmental correlation. 2) The average number of the egg markings in Chinese strain was more than that in other strains. 3) The correlation between the motality and the number of egg markings seemed not to be found. 4) The heritability of the weight of cocoon layer and the bave length was less than that of total cocoon weight, denier and number of egg markings. 5) The more the number of the polyhedral particles in an egg marking group became, the more the total number of egg markings increased. 6) The variation of the number of the egg markings in European strain was larger than that in any other strains. 7) It is expected that the selection for the number of the egg markings may have genetic advances of total cocoon weight, weight of cocoon layer, or denier. Especially the selection for the number of the egg markings before rearing will save the silkworm rearing cost.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.501-509
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• 2015

Purpose: To evaluate the reliability of refractive power by comparing the marked refractive power in an automatic phoropter and actually measured spherical/cylindrical refractive power. Methods: Actual refractive power of minus spherical lens and cylindrical lens in an automatic phoropter was measured by a manual lensmeter and compared with the accuracy of marked refractive power. Furthermore, combined refractive power and spherical equivalent refractive power of two overlapped lenses were compared and evaluated with the refractive power of trial lens. Results: An error of 0.125 D and more against the marked degree was observed in 70.6% of spherical refractive power of spherical lens which is built in phoropter, and the higher error was shown with increasing refractive power. Single cylindrical refractive power of cylindrical lens is almost equivalent to the marked degree. Combined spherical refractive power was equivalent to spherical refractive power of single lens when spherical lens and cylindrical lens were overlapped in a phoropter. Thus, there was no change in spherical refractive power by lens overlapping. However, there was a great difference, which suggest the effect induced by overlapping between cylindrical refractive power and the marked degree when spherical lens and cylindrical lens were overlapped. Spherical equivalent refractive power measured by using a phoropter was lower than that estimated by trial glasses frame and marked degree. The difference was bigger with higher refractive power. Conclusions: When assessment of visual acuity is made by using an automatic phoropter for high myopes or myopic astigmatism, some difference against the marked degree may be produced and they may be overcorrected which suggests that improvement is required.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.37-42
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• 2008

Purpose: The objective of the study: At present, the spectacles, with its use as a medical aids or a fashion trimming, are recognized as one of the living necessities which can't be separated from human body. One of the features of spectacles is that it must be worn on any part of human body. Such a feature has to be satisfied under the condition an user keeps feeling comfortable with the rim of spectacles worn. In order to ensure meeting this condition, a criterion has to be arranged for the design of the rim of spectacles. In order to manufacture a rim of spectacles which allows an user to secure a comfortable range of vision as well as enhancing the feeling when to be worn, a manufacturing standard has to be established based on optical science. No precise rim of spectacles could be made from the manufacturing method depending on the manufacturer's sensibility. When the rim of spectacles was manufactured according to the incorrect standards, it may cause an user such a fatal result as myopia, hyperopia or astigmatism. Methods: This study focuses on providing a detailed explanation about the design of rim, which is the most important element during designing a rim of spectacles, making use of the optical elements of spectacles, and helping the manufacturers and the people who work in the spectacles-related business understand and recognize what is correct and exact and then leading them to establish a standard in respect to the manufacture and selection of spectacles. Results, Conclusions: Considering the fact there happen many errors in relation with the names of rim stipulated in the provisions of International Standards Organization (ISO), due to wrong interpretation by some of the rim manufacturers, the right interpretation should be given about the bridge which is directly connected to rim, so that the rims of spectacles manufactured in Korea could keep a favorable position in competing with the foreign products of same kinds.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.3
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• pp.293-298
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• 2012

Purpose: We compared static retinoscopy in eyes opened with cycloplegic refraction depending on the hyperopia for school-aged children. Methods: There were 59 eyes (30 patients) who were divided into 3 groups - the mild hyperopia (+0.25 D ~ +1.00 D), moderate hyperopia (+1.25 D ~ +2.00 D) and high hyperopia (+2.25 D or more). They all had 0.8 visual acuity or more. Autorefraction and retinoscopy were performed prior to cycloplegic refraction, and then copmared with manifest refraction and cycloplegic refraction. Results: Hyperopia measured with static retinoscopy tends to be measured higher than manifest refraction for school-aged children. Changes of spherical power was statistically significant (p < 0.001). Changes of astigmatism was not statistically significant (p > 0.05). Conclusions: The difference between cycloplegic refraction and static retinoscopy was not significant for hyperopic school-aged children. The use of retinoscopy was limited for opticians because of legal constraints. The usage of static retinoscopy in eyes opened for optician should be generalized under the conditions not using the cycloplegic.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.156-163
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• 2015

In this paper, we propose an active water level and distance measurement algorithm using a light beam pattern. On behalf of conventional water level gauge types of pressure, float-well, ultrasonic, radar, and others, recently, extensive research for video analysis based water level measurement methods is gradually increasing as an importance of accurate measurement, monitoring convenience, and much more has been emphasized. By turning a reference light beam pattern on bridge or embankment actively, we suggest a new approach that analyzes and processes the projected light beam pattern image obtained from camera device, measures automatically water level and distance between a camera and a bridge or a levee. As contrasted with conventional methods that passively have to analyze captured video information for recognition of a watermark attached on a bridge or specific marker, we actively use the reference light beam pattern suited to the installed bridge environment. So, our method offers a robust water level measurement. The reasons are as follows. At first, our algorithm is effective against unfavorable visual field, pollution or damage of watermark, and so on, and in the next, this is possible to monitor in real-time the portable-based local situation by day and night. Furthermore, our method is not need additional floodlight. Tests are simulated under indoor environment conditions from distance measurement over 0.4-1.4m and height measurement over 13.5-32.5cm.