• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.2
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• pp.71-77
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• 1994

A serious of study is carried out to practical use of the three-slot cambered otter board improved by the authors. As the first step, we designed main plates, slots and accessories, such as holding plate, fan-shaped towing plate, normans, center ring, etc. Standing on this design, we made the simple cambered and three-slot cambered model otter board with accessories in a linear scale 6:1. and carried out model test to examine the efficiency of these boards. The obtained results can be summarized as follows: 1. On the simple cambered board with accessories, the values of the maximum shear coefficient($C _{LX}$ ). drag coefficient(($C _{D}$) and hydrodynamic efficiency($C _{L}$/$C _{D}$ ) are 1.39, 0.56, 2.48 at $22^{\circ}$ of the angle of stall respectively. 2. On the three-slot cambered board with accessories, $C _{LX}$/$C _{D}$ and $C _{I}$/$C _{D}$ are 1.67, 0.92, 1.82 at $32^{\circ}$ of the angle of stall respectively. 3.$C _{LX}$ of board with accessories is smaller 10~12% than that of only the main plate, and the angle of stall is almost same. 4. $C _{LX}$ and the angle of stall of the three-slot cambered board with accessories are greater 20% and $10^{\circ}$ than that of the simple cambered board respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.16-23
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• 2007

For a fully depleted SOI type symmetric double gate MOSFET, a simple expression for the threshold voltage has been derived in a closed-form To solve analytically the 2D Poisson's equation in a silicon body, the two-dimensional potential distribution is assumed approximately as a polynomial of fourth-order of x, vertical coordinate perpendicular to the silicon channel. From the derived expression for the surface potential, the threshold voltage can be obtained as a simple closed-form. Simulation result shows that the threshold voltage is exponentially dependent on channel length for the range of channel length up to $0.01\;[{\mu}m]$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1485-1492
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• 1992

While the vibration of circular plates were considered by many researchers, rather less attention is given to elliptical plates. In the present paper, the Rayleigh-Ritz mothod is used to obtain an eigenvalue equation for the free flexural vibration of thin elliptical plates having the classical free, simply suported or clmped boundary condition. Circular plates are included as a special case of the elliptical plates. Products of simple polynomials are used as the admissible functions and a recurrence relationship facilitates the evaluation of the necessary integrals. The analysis is developed for rectilinear orthotropic plates but the numerical results are given for isotropic plates with various aspect ratios.

• International Journal of Industrial Entomology and Biomaterials
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• v.41 no.2
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• pp.56-62
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• 2020

Mulberry (Morus spp. family: Moraceae) has prime importance in the sericulture industry, and its foliage is the only natural feed of the silkworm Bombyx mori L. Traditional classification methods using morphological traits were largely unsuccessful in assessing the diversity and relationships among different mulberry species because of environmental influences on the traits of interest. For these reasons, it is difficult to differentiate between the varieties and cultivars of Morus spp. In the present study, inter-simple sequence repeat (ISSR) markers were used to investigate the genetic diversity of 48 mulberry samples genotyped using nine ISSR primers. The ISSR markers exhibited polymorphisms (53.2%) among mulberry genotypes. Furthermore, similarity coefficient estimated for these ISSR markers was found to vary between 0.67 and 0.99 for the combined pooled data. The phenogram drawn using the UPGMA cluster method based on combined pooled data of the ISSR markers divided the 48 mulberry genotypes into seven major groups. No genetic association was found in the collection area, and there was a mixed pattern between the mulberry lines. The hybridization between different mulberry species is highly likely to be homogenized due to natural hybridization.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.21-25
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• 2000

The old age may experienced the visual acuity decrease according to refraction abnormality and they have a inconvenient real life style on viewing condition. So that, This study can provide the accurate information on the treatment of visual acuity of a male old ages by test of eye refraction state. The test was performed the visual acuity test by the object and subject methods.and the subjects was the Korean male over 55 old age. The eye types were 0.8 % positive for emmetropia, 15.2 % for myopia, and 84 % for hyperopia, respectively. The abnormal refraction eyes were 1.3 % positive for simple myopic astigmatism, 13.9 % for compound myopic astigmatism. 3.4 % for simple hyperopia and 3.1 % for simple hyperopic astigmatism, 77.5 % for mixed astigmatism, respectively. The asix of astigmatisms were 62% positive for against-the-rule astigmatism, 6% for with-the rule astigmatism, and 32 % for oblique astigmatism, respectively. On the total myopic spherical power, the $-0.50{\leq}$spheric equivalent <-2.00 diopter was 84.3%, the $-2.00{\leq}$spherical equivalent <-6.00.diopter was 15.7%. On the total hyperopic spherical power, the $+0.50{\leq}$spheric equivalent <+2.00 diopter was 74.2%, the $+2.00{\leq}$spherical equivalent <+6.00 diopter was 24.8%, and anything over the +6.00 diopter was 1%. On the astigmatic power, the $0.5{\leq}$cylinder <1.00 diopter was 54.1%, the $1.00{\leq}$cylinder <2.00 diopter was 32.4%, and anything over the 2.00 cylinder diopter was 13.5%.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.235-240
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• 2001

This study was performed to compare the lead levels of 20 quality control standard samples(KOSHA:18-2000) and 72 field samples in lead-acid battery manufacturing plant between ICP and portable-XRF methods. 1. While the proficiencies of 20 quality control standard samples by ICP were 100%, those of analytic result values by XRF were 75%. 2. The correlation coefficient(r) between the reference values for quality control (REF) and the analytic result values by ICP (ICP) was 1.0(p<0.05), and simple linear regression equation and the coefficient(R2) were REF = -0.0009 + 1.016 ICP and 0.9997, respectively. 3. The correlation coefficient(r) between the analytic result values of quality control standard samples by ICP (ICP) and by XRF (XRF) was 0.975(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -0.0003 + 1.002 XRF and 0.950, respectively. 4. The correlation coefficient(r) between the analytic result values for lead samples of a lead-acid battery manufacturing plant by ICP (ICP) and by XRF (XRF) was 0.993(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -2.058 + 0.996 XRF and 0.987, respectively. 5. While the frequency distributions of XRF /ICP(Ratio) for each ICP concentration levels in a lead-acid battery manufacturing plant revealed high proportion in ratio range of 0.876-1.125 than in ration range of 1.126-1.375. Also, ICP concentration level in ration range of 0.786-1.125 was increased with increase of frequency distribution of XRF/ICP. 6. The limit of detection of XRF on lead was determined to be $6.11{\mu}g$/filter The data presented in this study indicated that relationship for lead level of quality control samples and field samples in a lead -acid battery manufacturing plant by ICP and portable-XRF methods was proved. The practicing industrial hygienist can use portable-XRF to produce a rapid on-site determination of lead exposure that can immediately becommunicated to workers and help identify appropriate levels of personal protection.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.184-193
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• 2021

This paper investigates the performance of technology innovation activities performed by firms in 16 major regions in Korea using 2002-2010 survey data by STEPI. The theoretical and empirical analysis is carried out via the 2 models which are the simple R&D - total revenue model and Cobb-Douglas model based on the simple model adding labor variable. The main results shows that for simple model, the R&D elasticity for total revenue is 0.42 for all areas and Ul-San shows the highest elasticity level, 0.66 and Bu-San the lowest level, 0.2. In case of Cobb Douglas model the R&D elasticities are not statistically significant for many regions. To overcome the low statistical significance, we grouped the 15 regions for 3 wider regions using ANOVA based on the R&D intensity for the homogeneity of R&D activities. By grouping, each region has more observations to analyze and the results from the empirical analysis shows higher statistical significance level and data explanation capability. In this case, Group 3 which shows larger firm size and slightly higher export share shows the highest level of R&D elasticity, 0.088 and Group 1 which has the smallest firm size and the lowest revenue growth rate shows the lowest level, 0.31. For the labor elasticity, Group 1 shows the higest level, 1.16 and Group2 the lowest level, 1.096. These results show that the regions which have many middle and small firms reveal low R&D-revenue elasticity and high labor-revenue elasticity.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.147-153
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• 2007

A simple, selective and highly sensitive flow injection catalytic method was presented for determination of ruthenium based on its catalytic effect on the oxidation of pyronin B by periodate in pH=1.0. The reaction rate is controlled specrophotometricaly by monitoring the dye absorbance at 555 nm. The optimized conditions make it possible to determine ruthenium in the ranges of 0.1-10.0 ng/mL (r2=0.9982) and 10.0-50.0 ng/mL (r2=0.9934) with a detection limit of 0.04 ng/mL and a sample rate of 30±5 samples/h. Relative standard deviation for the results of five replicate measurements does not exceed 1.44%. The proposed method has been successfully applied for quantitation of ultra trace amounts of ruthenium in some environmental and biological samples.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.431-437
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• 2004

This research reviewed the objects of 384 persons (male:86, female:298) from 6 to 50 years old visited the S. Optical shop at Mokpo over two times from Mar. 2002 to Feb. 2004. We obtained the following results by analyzing the visual acuity prescription to keeping at S. Optical shop. 1. The abnormal refraction eyes were 191 persons(49.74%) for simple myopia, 2 persons(0.52%) for myopic simple astigmatism, 180 persons(46.88%) for myopic compound astigmatism, and 1 person(0.26%) for simple hyperopia, 2 persons(0.52%) for hyperopic simple astigmatism, 8 persons(2.08%) for hyperopic compound astigmatism, respectively. 2. Classifying of correction power for 373 persons (male:84, female:289) myopia, so that showed 166 persons(male:36, female) between $$0.25D{\leq_-}2.00D$$, 194 persons(male:46, female:148) between $$2.25D{\leq_-}6.00D$$, 13 persons(male:2, female:11) for over 6.250 respectively. 3. According to the kinds of 192 persons astigmatism subjects(male:53, female:148), direct astigmatism was 145 persons(male:32, female:113), oblique astigmatism 33 persons (male:12, female:21), reverse astigmatism 14 persons(male:5, female:9). 4. The variation of spherical power for myopia showed 299 persons(male:71, female:228) between $$0.00D{\leq_-}0.50D$$, 64 persons(male:11, female:53) between $$0.51D{\leq_-}1.00D$$, 9 persons(male:2, female:7) between $$1.01D{\leq_-}1.50D$$, 1 person(male:0, female:1) between $$1.51D{\leq_-}2.00D$$ variation respectively. Hyperopia showed 8 persons(male:1, female:7) between $$0.00D{\leq_-}0.50D$$, 3 persons(male:1, female:2) between $$0.51D{\leq_-}1.00D$$ variation respectively. 5. The variation of astigmatism power showed 181 persons(male:48 female:113) between $$0.00D{\leq_-}0.25D$$, 25 persons(male:9, female:16) between $$0.26D{\leq_-}0.50D$$, 6 persons(male:0, female:6) between $$0.51D{\leq_-}0.75D$$ astigmatism variation respectively.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.261-264
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• 2001

In this paper, we introduce a simple design method f9r mot-squared type raised cosine filter with equiripple characteristics. Through some design examples, we show that the proposed filter has much better performance in ripple than the conventional SRCF at the expense of small increasing of ISI. In addition, the proposed Inter is compatible with conventional SRCF. Finally, we designs the filter for W-CDMPI which uses RRC (Root Raised Cosine) with a=0.22, in 12bit finite precision.