• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.1-7
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• 2009

The purpose of this study was to evaluate the legibility of one-syllable Korean characters with the participation of sixteen subjects. The experiment considered nine factors including age (young and old), gender (male and female), illuminance (150lx and 600lx), viewing distance (50cm and 200cm), material type (paper and LCD), typeface (Ming and Gothic), thickness (plain and bold), color contrast (black letter/white background and white letter/black background), and complexity (simple, complex, and number) to examine main effects with a $2^{6-3}\times3$ fractional factorial design. The dependent variables were minimum character size of 100% correctness, maximum character size of 0% correctness, and minimum character size of comfortable reading preference. The results of analysis of variance (ANOVA) revealed that age, illuminance, viewing distance and complexity were significant for all dependent variables, except gender which was significant only for the minimum character size of comfortable reading preference. In general, the young could see twofold smaller size letters than the elderly. The subjects could see smaller sized letters with the illuminance of 600lx and viewing distance of 50cm than 150lx and 200cm, respectively and also with numbers, simple characters, and complex characters in that order. The findings of this study could be characterized about the legibility of Korean characters and be good resources for developing its standard.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.92-100
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• 2009

This study evaluated the effects of the syllable number(one, two), font type(gothic, myung), color contrast (black on white, white on black), display type(paper, LCD), age(20s, 60s) and character size(2~80pt) on the Korean characters' legibility. Total twenty subjects from two age groups (20s: n=10, 60s: n=10, five male and five female in each group) participated in the legibility test. A target panel was presented in the distance of 50 cm, and subjects conducted a reading tests for, in total, 16 treatment conditions (full combination of syllable number, font type, color contrast and display type). Results showed that two-syllable words revealed better legibility than one-syllable character. The main effects of the age, display type, font type, color contrast, and character size were statistically significant(p<0.01). Paper showed better legibility than LCD, particularly in the 20s and in the character sizes of less than 9pt. Gothic revealed more correct answers than Myung, particularly in the 60s, paper, and white on black conditions. It is expected that these results can provide basic data for the determination of the Korean characters' minimum legible size standards. For example, the minimum legible size for the Gothic and black on white characters presented in the paper should be 5pt for 20s and 1lpt for 60s if the 75% correct reading(3 correct answers in this study) was applied for the legibility criterion.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.1
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• pp.27-33
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• 1975

The required minimum size of character diode matrix of Korean letters is estimated from the topological complexity of letter structure. The OR aombination of three letter boards (diode matrice) gives all possible Hangout whole letters in proper traditional combined form with minimum required discernibility. Two forms of first consonants (centre located ones for horizontal vowels and leftward displaced ones for vertical and composed vowels) are switched by only 1 bit of the vowel code. The vowel pattern length is modified by again the last four bits of the code. A new 15bit sized inner code is proposed which permits considerably small sized decoding mechanism.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.153-160
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• 2015

This study tried to investigate the difference of the legibility in different age groups (young and old) with same near visual acuity and to provide preliminary guidelines for the text sizes in the pesticides products based on the legibility experiments. To achieve the objective, legibility evaluation experiments were conducted to test the effects of different age(20s, 50-60s), gender, font type(thick gothic-type and fine gothic-type), thickness (plain and bold), and number of syllables(2 and 3 syllables) in the same near visual acuity(0.6). The results showed that legibility 50s was higher than 20s. And 20s are appealed higher discomfort than 50s. Considering these experimental results, it was recommended that the 14 pt or larger characters (100% readable size) should be used the important information such as toxicity, and the minimum character size was 7 pt (50% readable size) for other information.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.521-526
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• 2005

In this Paper, we propose a keyword spotting system as an alternative to searching system for poor quality Korean document images and compare the Proposed system with an OCR-based document retrieval system. The system is composed of character segmentation, feature extraction for the query keyword, and word-to-word matching. In the character segmentation step, we propose an effective method to remove the connectivity between adjacent characters and a character segmentation method by making the variance of character widths minimum. In the query creation step, feature vector for the query is constructed by a combination of a character model by typeface. In the matching step, word-to-word matching is applied base on a character-to-character matching. We demonstrated that the proposed keyword spotting system is more efficient than the OCR-based one to search a keyword on the Korean document images, especially when the quality of documents is quite poor and point size is small.

• Journal of the Korea Safety Management & Science
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• v.13 no.3
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• pp.29-35
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• 2011

Safety and health related information for the proper use and handling of pesticides is usually printed on the surface of the pesticide products (bottle type or bag type) in the form of texts. But, the guidelines or standards for the appropriate presentation of the texts for the pesticide products are most vague or not practical. Thus, this study aimed to provide the preliminary guidelines for the text sizes based on the legibility experiments. Total twenty subjects from two age groups (young: n=10, old: n=10, five males and five females in each group) participated in the experiment. First, subjects read the text cards presented in the distance of 50cm from the eyes of the subjects. Eight different text card sets were prepared for different font type(thick gothic-type and fine gothic-type), thickness of font(plain and bold), and number of syllables (2 and 3 syllables). When subjects read the cards, the correctness of reading (correct or wrong) was recorded and the degree of discomfort (from 1: no discomfort at all to 4: can't read at all) was also evaluated for all the text sizes. Results showed that the character size should be 4 pt or larger for the young subjects to read at least one word correctly in all the text conditions. For the old subjects to read at least one word correctly, the character size should be five pt or larder. The average of the minimum character sizes for 100% correct answer is 6.1 pt for young subjects and 10.5 pt for old subjects, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3444-3451
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• 2012

Safety and health related information for the proper use and handing of pesticides is usually printed on the surface of the pesticide products in the form of texts. But, the guidelines or standards for the appropriate presentation of the texts for the pesticide products are most vague or not practical. Thus, this study aimed to provide the preliminary guidelines for the text sizes based on the legibility experiments. To achieve the objective legibility evaluation experiments were conducted to test the effects of different near vision (0.6, ${\geq}0.8$), gender, font type(thick gothic-type and fine gothic-type), thickness of font(plain and bold), and number of syllables(2 and 3 syllables) in the same age group of 20s. The results showed that legibility was different according to the visual acuity (p<0.05), and no other main effects showed statistically significant effects. The 'maximum illegible size' to read at least one word correctly in all the text conditions was 2 pt when the near vision was ${\geq}0.8$, and 2 pt or 3 pt when the near vision was 0.6. The 'minimum legible size' for 100% correct answer was 9 pt for the near vision of 0.6, and 5.3 pt for ${\geq}0.8$, respectively. Mean character size does not read any discomfort in 0.6 was 15.5 pt in both male and female but male was mean 8.5 pt, female was 10 pt in ${\geq}0.8$. Considering these experimental results, it was recommended that the 16 pt or larger characters should be used the important information such as 'Pesticides' or toxicity, and the minimum character size was 9 pt for the less important information.

• Genomics & Informatics
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• v.9 no.2
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• pp.74-78
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• 2011

Numerous restraints and simplifications have been developed for methods that anticipate protein structure to reduce the colossal magnitude of possible conformational states. In this study, we investigated if globularity is a general characteristic of proteins and whether they can be applied as a valid constraint in protein structure simulations with approximated measurements (Gb-index). Unexpectedly, most of the proteins showed strong structural globularity (i.e., mode of approximately 76% similarity to the perfect globe) with only a few percent of proteins being outliers. Small proteins tended to be significantly non-globular ($R^2$=0.79) and the minimum Gb-index showed a logarithmic increase with the increase in protein size ($R^2$=0.62), strongly implying that the non-globular characteristics might be more acceptable for smaller proteins than larger ones. The strong perfect globe-like character and the relationship between small size and the loss of globular structure of a protein may imply that living organisms have mechanisms to aid folding into the globular structure to reduce irreversible aggregation. This also implies the possible mechanisms of diseases caused by protein aggregation, including some forms of trinucleotide repeat expansion-mediated diseases.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.4
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• pp.133-140
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• 2006

The growth characteristics and properties of large size $SrAlF_5$ single crystals are described and compared with those of $BaMgF_4$. Transmission spectra in the vacuum ultraviolet wavelength region indicate a high transparency of $SrAlF_5$ (about 90% without considering surface reflection loses) down to 150 nm, on contrast to the optical loses observed for $BaMgF_4$. The ferroelectric character of $SrAlF_5$ is evidenced by the reversal of the spontaneous polarization in a hysteresis loop. The higher potential of $SrAlF_5$ in comparison with $BaMgF_4$ for the realization of all-solid-state lasers in the ultraviolet wavelength region by the quasi-phase matching (QPM) technique is pointed out. $SrAlF_5$, besides a higher grade of transparency, shows a nonlinear effective coefficient similar to that of quartz and uniaxial nature, on contrast to the one order smaller nonlinear coefficient and biaxial character of $BaMgF_4$. The refractive index of $SrAlF_5$ from the ultraviolet to the near-infrared wavelength region is measured by the minimum deviation method. The Sellmeier and Cauchy coefficients are obtained from the fits to the curves of the ordinary and extraordinary refractive indices, and the grating period for the first order QPM is estimated as a function of the wavelength. The poling periodicity for 193 nm SHG from 386 nm is $4{\mu}m$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.1
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• pp.170-191
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• 2024

The transmission of confidential data using cover media is called steganography. The three requirements of any effective steganography system are high embedding capacity, security, and imperceptibility. The text file's structure, which makes syntax and grammar more visually obvious than in other media, contributes to its poor imperceptibility. Text steganography is regarded as the most challenging carrier to hide secret data because of its insufficient redundant data compared to other digital objects. Unicode characters, especially non-printing or invisible, are employed for hiding data by mapping a specific amount of secret data bits in each character and inserting the character into cover text spaces. These characters are known with limited spaces to embed secret data. Current studies that used Unicode characters in text steganography focused on increasing the data hiding capacity with insufficient redundant data in a text file. A sequential embedding pattern is often selected and included in all available positions in the cover text. This embedding pattern negatively affects the text steganography system's imperceptibility and security. Thus, this study attempts to solve these limitations using the Part-of-speech (POS) tagging technique combined with the randomization concept in data hiding. Combining these two techniques allows inserting the Unicode characters in randomized patterns with specific positions in the cover text to increase data hiding capacity with minimum effects on imperceptibility and security. Format-preserving encryption (FPE) is also used to encrypt a secret message without changing its size before the embedding processes. By comparing the proposed technique to already existing ones, the results demonstrate that it fulfils the cover file's capacity, imperceptibility, and security requirements.