• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.241-246
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• 2013

Purpose: The aim of this study was a comparative analysis of the effect of distance contrast sensitivity when wearing free-form progressive lens and conventional progressive lens. Methods: The 20 subjects who do not have any ocular diseases were participated in this study. Contrast sensitivities at 5 different levels of spatial frequency were conducted by using FACT (Stereo Optical, USA). Results: Contrast sensitivity was measured for free-form progressive lens and conventional progressive lens in the order of right eye, left eye and binocular. Right/left/binocular contrast sensitivity values of the free-form progressive lenses compared to the conventional progressive lenses were higher 16%/17%/11% at A(1.5 cpd) of spatial frequency, 11%/5%/5% at B(3 cpd) of spatial frequency, 6%/6%/9% at C(6 cpd) of spatial frequency, 19%/16%/13% at D(12 cpd) of spatial frequency, 4%/3%/18% at E(18 cpd) of spatial frequency. Conclusions: In all the area of spatial frequency, distance contrast sensitivity values were measured highly on free-form progressive lens than on conventional progressive lens.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.225-229
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• 2014

Purpose: The study was to analyze the correlation between kinetic visual acuity (KVA), visual acuity(static visual angle, SVA) and contrast sensitivity. Methods: Ninety-nine undergraduate students studying Ophthalmic Optics were fully corrected by the Topcon CV-3000 Phoropter. The contrast sensitivity was measured for the participants under the photopic condition ($100cd/m^2$) with Vector Vision CSV-1000E at 2.5 meter, while KVA was measured with KOWA AS-4A. The participants were classified into three groups L, M and H depending on the KVA (0.1~0.3, 0.31~0.6 and greater than 0.61, respectively) and were analyzed whether there was the correlation between the contrast sensitivity, visual acuity and refractive error. Results: The KVA was correlated with the contrast sensitivity for 3 cpd (r=0.26), for 6 cpd (r=0.48), for 12 cpd (r=0.38) and 18 cpd (r=0.47). Except for the low frequency of 3 cpd, they all were higher than the one of the SVA and the KVA (r = -0.37). The contrast sensitivity for 3, 6, 12 and 18 cpd was 59.41, 92.22, 38.41 and 14.39 in the group L, respectively. The contrast sensitivity in the group M was 66.03, 108.78, 53.51 and 19.20 and the one in the group H was 70.90, 146.10, 62.90 and 25.33 for 3, 6, 12 and 18 cpd, respectively. Conclusions: The correlation of the contrast sensitivity and the KVA was higher than the one of the contrast sensitivity and the SVA. It can be assumed that the contrast sensitivity will be high if the KVA is high, except for the case for low spatial frequency.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.505-511
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• 2014

Purpose: This study was to investigate the effect of breath alcohol concentration (BrAC) increase with drinking alcohol on contrast sensitivity in the conditions of restricted BrAC. Methods: 23 males in 20s (average age $21.17{\pm}2.19$ years, body mass index (BMI) $22.09{\pm}2.16$) were selected and administered the amount of alcohol to reach 0.05% and 0.08% BrAC calculated by BAC (blood alcohol concentration) Dosing Software program, which was developed as basis of Watson's formula. Then, the contrast sensitivity in various luminance conditions (photopic, mesopic, and mesopic with glare) was measured and compared between these conditions. Results: The contrast sensitivity in all spatial frequency was decreased with BrAC increase. Although BrAC was increased, the peak of contrast sensitivity didn't change as 6 cycle per degree (cpd) in the photopic condition and 3 cpd in the mesopic condition, respectively. But, in the mesopic condition with glare, the peak of contrast sensitivity was shifted from 6 cpd at 0% and 0.05% BrAC to 3 cpd at 0.08% BrAC with increase of alcohol concentration. Conclusions: The increase of BrAC by drinking alcohol induces the decrease of contrast sensitivity in all spatial frequency and the shift of peak of contrast sensitivity, which can cause safety accidents, and may have an effect on various visual tasks.

• 지반과기술
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• v.10 no.2
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• pp.35-45
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• 2013

• Journal of Life Science
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• v.20 no.7
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• pp.1086-1092
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• 2010

To estimate the genetic characteristics and cumulative power of discrimination (CPD) within Korean native commercial chicken, we used a total of 395 genomic DNAs from six breeds population (Korean Native Red chicken: R, Korean Native Yellow chicken: Y, Korean native Commercial Chicken: C, Ogal chicken: S, Hy-Line Brown: H, White Leghorn: W). Genetic diversity indices including mean allele number among loci, unbiased heterozygosity ($h_i$) within locus, effective number of alleles ($N_e$) and polymorphism information content (PIC) as well as the unbiased average heterozygosity (H) among loci in the populations were calculated using the generated allele frequencies by each marker. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The nearest distance (0.119) was observed between the C and Y strains. The generated unbiased average heterozygosity among loci in each population was integrated to the global formula of CPD and the result demonstrated that the CPD within the six chicken populations was 99.461%.

• Journal of Embryo Transfer
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• v.23 no.3
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• pp.203-209
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• 2008

To estimate the genetic characteristics and cumulative power of discrimination (CPD) existing among Hanwoo (Korean cattle) and exotic foreign population (Angus, Herford, Charolais, Holstein) we used a total of 414 genomic DNAs from five breeds population (Hanwoo, Angus, Hereford, Charolais, Holstein). Genetic characteristics indices including mean allele number among loci, unbiased heterozygosity ($h_i$) within locus and polymorphic information content (PIC) and unbiased average heterozygosity (H) among loci in four breeds were calculated using the generated allele frequencies by each marker. The mean allele numbers for all loci ranged between 5 and 7 while heterozygosity (H) ranged from 0.75 (HW) to 0.64 (HF) among loci and across breeds heterozygosity (H) was 0.69. The generated unbiased average heterozygosity among loci in each breed was integrated to the global formula of CPD resulting in 99.71 % within the populations. The genetic variation of HW (Hanwoo) showed highest estimates among the analyzed breeds.

• Journal of the Korean Society for Library and Information Science
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• v.51 no.2
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• pp.207-235
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• 2017

The purpose of this study was to develop a competency-based continuing professional development (CPD) model using the National Competency Standards (NCS)-Library & Information Management. This study specifically examined various competency standards for librarians developed in and out of the country, conducted a survey research and focused group interviews to obtain professional librarians' needs for continuing education and their opinions on the NCS for library professions. It analyzed the contents of the NCS elements and mapped with elements in the five other competency standards for library and information professions. It also scrutinized the current training programs at the National Library of Korea in order to identify their strengths and weaknesses. The results of the study informed the areas to enhance the current NCS by identifying underdeveloped competencies and identified the course contents that should be developed with priorities. The study also developed a modified National Competency Standards for Continuing Professional Development (NCS-CPD). Continuing education institutions can utilize this scheme as a useful guideline to develop balanced continuing professional development curriculums for the practitioners working in various library and information centers.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.110-115
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• 2010

The experiment was designed to compare pyrolysis kinetics of two different classes of imported coal. The pyrolysis behaviors of the coals were first observed with thermogravimetric analyzer(TGA). The kinetic analysis was further done based on a new distributed activation energy model(New DAEM). During the analysis, weight loss curves measured at three different heating rates were used to obtain the activation energy distribution function curve f(E) of a given coal sample where a mean activation energy is determined by its peak. The results show a significant difference in the mean activation energy between two coals for the pyrolytic reaction. The prediction of a chemical percolation devolatilization(CPD) model where the kinetics obtained from the New DAEM method were incorporated is in much closer agreement with an experimental data of TGA particularly for the bituminous coal.

• Journal of Korean Elementary Science Education
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• v.26 no.3
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• pp.295-308
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• 2007

The purpose of the study is to develop an effective model of a science teachers' professional development program. This study consists of two parts: (1) the theoretical review of science teachers' professional development and (2) a case study of a science teachers' professional development programme in the UK. After reviewing recent research on pedagogical content knowledge and new approaches to educational research, the following suggestions emerged: (1) Continuing Professional Development(CPD) should be embedded in teachers' real practice in the classroom and (2) embedded in the everyday life of learners' within the community. (3) CPD should support the development of teachers' communities of professional practice. The case study of 'CPD through Portfolios of Evidence' in the British programme indicated that collecting explicit evidence of good practice in the classroom and establishing agreement as to what constitutes good practice in a teachers' community helped teachers' professional development. Finally, what emerged from the case study of the CPD programme in the UK and the theoretical review of PCK was the following. An effective CPD model of science teachers should comprise these three stages: (1) providing opportunities of professional development, (2) changing practice in the classroom and research, and (3) spreading and sustaining change. The whole process is circular.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.505-511
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• 2018

Purpose : This study investigated the visual functions of drivers aged over 65 year olds and drivers aged 50~65 year olds. In addition, difference of visual functions between professional drivers and normal drivers were investigated. Methods : Forty Driver aged over 65 year olds and 67 drivers aged less than 67 year olds were participated. All participants had more than 5 years of driving experiences and had no ocular pathology. Demographic data(gender, job, age, body condition) and visual functions such as contrast sensitivity(CS), stereopsis, glare recovery time and discomfort glare index were measured. Results : Constrast sensivity under photopic condition was higher with bus driver group. In addition, difference of CS at 12cpd and 18cpd were signifcantly different between normal drivers(1.57) and bus drivers(1.70) (p<0.05). There was no significant difference for glare recovery time, despite of trend of longer recovery time with age. Discomfort glare index was significantly different that normal drivers with more than 65 year olds had 3, taxi and truck driver presented almost 5 index score (p<0.05). Conclusion : Analysis of visual function of elderly drivers, it was confirmed that their visual functions decreased with age. Therefore, visual function tests such as CS, discomfort glare index and stereopsis in addition to current available test may need to be considered for drivers aged over 65.