• 한국안광학회지
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• 제15권1호
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• pp.67-71
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• 2010

Purpose: The effect of two different levels of illumination and the effect of three letter chart types on subjective refraction findings were investigated. Methods: This study involved thirty Malay university students aged between 19 to 23 years old (7 males, 23 females), with their spherical refractive error ranged between plano to -7.75D astigmatism ranged from plano to -1.75D, anisometropia less than 1D and with no history of ocular injury and pathology. Monocular subjective refraction was measured under two levels of illumination (with and without room light) and with three different letter charts (Snellen letter chart, wall mounted letter chart and projected letter chart). Subjective refraction finding was calculated in spherical equivalent in unit diopter (D). Results: There was no significant effect in the subjective refraction findings with Snellen letter chart (t-test=0.15, p-value=0.88), projected letter chart (t-test=-0.19, p-value=0.85) as well as wall mounted letter chart (t-test=0.12, p-value=0.94). One Way ANOVA also revealed when the subjective refractive measures were compared under two different level of room illumination (with and without room light), no significant effect of letter chart types on subjective refraction readings with room light ($F_{2.185}$=0.11, p-value=0.89) and without room light ($F_{2.185}$=0.02, p-value=0.98). Conclusions: Subjective refraction findings were not affected whether the room light was on or off. They were also not affected by the types of letter chart used.

• 품질경영학회지
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• 제23권1호
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• pp.1-14
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• 1995

ISO 3951 (1989) Sampling Procedures and Charts for Inspection by Variables for Percent Nonconforming is an acceptable quality level (AQL) type sampling scheme. Sample size code letters and inspection levels in this International Standard correspond to those given in the ISO 2859 (1989), a standard for sampling plans by attributes. Two acceptance sampling procedures can be used ; tabular and graphical methods. The graphs could be used in less critical applications while the tabular method would be available for those familiar with MIL-STD-414 tables and to confirm the results of the graphs when needed. The sampling procedures of the ISO 3951 are matched to the ISO 2859 to enable us to move between them. Composite OC and ASN curves are given for AQL 2.5% and code letter F.

• 한국안광학회지
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• 제3권1호
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• pp.181-188
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• 1998

한글 자의 가독도를 조사하기 위해, ㄱ, ㄴ, ㄷ, ㄹ, ㅁ, ㅂ, ㅅ, ㅇ, ㅈ, ㅋ, ㅌ, ㅍ, ㅎ의 14 자음과 ㅏ, ㅓ, ㅗ, ㅜ, ㅡ, ㅣ의 6 모음 자들로 조합된 총 98개의 ($14{\times}7$) 고딕체 글자들로 3가지 형태의 시표를 레이저 프린터로 제작했다. 시력이 1.5인 사람들로 하여금 인쇄된 글자들을 판독하게 하는 방법과, 레이저 프린터의 해상력을 이용하는 방법을 사용했다. 이들 방법으로 구해진 데이터는 글자가 판독될 수 있는 최대거리 값들과 글자의 최소크기 값들이다. 값들로부터 ㄱ자의 가독도를 1로 하는 상대적 가독도를 구하였다. 이 상대적 가독도 값들을 분석한 결과 ㄱ, ㄴ, ㅅ, ㄷ, ㅈ, ㅇ, ㅁ, ㅋ, ㅌ, ㅍ, ㅎ의 순서에 따라 이들 자음이 사용된 글자의 가독도가 점점 낮아 졌다. 또한, ㅣ, ㅡ, ㅏ, ㅗ, ㅓ, ㅜ의 순서에 따라 이들 모음이 사용된 글자의 가독도가 작아졌다. 그리고 글자의 가독도는 자음이 바뀜에 따른 변화가 모음자가 바뀜에 따른 변화 보다 더 컸다.

• 천문학논총
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• 제31권3호
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• pp.65-76
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• 2016

We study a manuscript that includes 28 oriental constellations in the flags of barracks in Gangjin. According to the Joseon Chronicles, the constellation flags in the manuscript are thought to have originated from Seon-Pil Kim (金善弼) who first made 28 constellation flags for the barracks in 1878 during the Joseon Dynasty. Seon-Pil Kim was a commander and he used the 28 constellation flags for communications in a military camp. The flags also contain 28 animals and letter-like symbols with constellation maps. We examine the constellation maps in flags in terms of shapes and number of stars, and compare them with those of constellations in the Korean and Chinese star charts such as CheonSangYeolChaBunYaJiDo (天象列次分野之圖), Joseon-Butienge (朝鮮步天歌), Suzhou (蘇州) Star Chart, and Tang-Butiange (唐步天歌). Finally, we found that the shape of constellations in the flags might be similar to those in the Chinese Tang-Butienge. We also found several errors such as the shape, connecting pattern, and number of constellations drawn in the flags. It seems that the constellation flags were unofficially used in military camps in the late Joseon dynasty. Meanwhile, the 28 constellations are divided into four groups and each group has its own color and direction. We suppose that the constellation flags might represent the positions of military camps and each group of flags has their own color based on their cardinal points.