• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.377-384
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• 2015

Purpose: On this study, we measured and compared the dynamic stereoacuity by two-rods test (Howard-Dolman Test) and three-rods test. And we analyzed the correlation between PD and refractive error with dynamic stereoacuity. Methods: Dynamic stereoacuity of two-rods test and three-rods test at 2.5 m distance for 93 adults 93 (50 males, 43 females), mean age of $21.27{\pm}2.32$ (19~32) years old, were measured 5 times for two tests. Results: The mean of dynamic stereoacuity measured by two-rods test and three-rods test were $29.91{\pm}23.03sec$ of arc and $23.75{\pm}21.65sec$ of arc for total subjects, respectively. The mean of male and female were $36{\pm}22.38sec$ of arc and $22.28{\pm}23.79$, respectively. Three-rods test showed better dynamic stereoacuity than two-rods test, but there was no statistically significant difference (p>0.05). For the average standard deviation of PD between 60.63 mm~66.19 mm, dynamic stereoacuity fo two-rod test and three-rod test were $31.48{\pm}24.87sec$ of arc and $31.48{\pm}24.87sec$ of arc, respectively. The results showed statistically significant difference (p<0.05), but the relationship between dynamic stereoacuity and PD was not great. Comparison between two tests on the basis of refractive error, dynamic stereoacuity by three-rods test was better than by two-rods test with no significant difference between both tests (p>0.05) and there was little correlation between refractive error and two dynamic stereoacuity. Conclusions: Three-rods test showing lower stereoacuity than two-rods tests could measure the lower minimum threshold of dynamic stereoacuity. It was found that both tests can be applied to dynamic stereoacuity test as a standard test, and PD and refractive error was found that little effect upon the dynamic stereoacuity. PD and refractive error was found that little effect upon the dynamic stereoacuity.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.471-475
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• 2008

Background: In order to achieve a maintenance level and to prevent hemorrhagic complications, regular monitoring of the INR is mandatory for patients on oral anticoagulation therapy (OAT). A point-of-care instrument for INR monitoring is convenient for users, but the accuracy of the results has been controversial, and so this calls for exact evaluation of the point-of-care instrument that is used for INR monitoring. Methods: From Aug 2007 through Feb 2008, 85 patients on OAT among the all the patients who were admitted to Soonchunhyang University Bucheon Hospital were involved in this study. Parallel measurements of the PT INR were performed using a CoaguChek-XS and, a CA-7000 laboratory reference instrument and the results were analyzed. In addition, the patients' clinical data, including the diagnosis and the frequency and interval of the INR measurements, were also analyzed. Results: Of the 85 patients, 25 were admitted more than once to undergo INR testing and the mean interval between testing was 8.6 weeks with 39% and 38% of the tests being less than INR 2 units with using the CoaguChek-XS and the reference method, respectively. The coefficients of variation of CoaguChek-XS were 4.50 and 2.45 for the high and low INR patients, respectively. An excellent correlation was found between the two methods with a $R^2$ of 0.966 (p<0.001). Through Bland-Altman analysis, the mean INR difference between the two methods was 0.13 with the limit of agreement being -0.47~+0.72 with a 95% confidence interval. CoaguChek-XS was shown to overestimate the INR value for patients with an increasing INR, as compared to the reference method. Conclusion: CoaguChek-XS demonstrated great precision and accuracy for patients on OAT when compared to the laboratory INR results. Accordingly, the instrument should help to monitor the INR in the patients on OAT.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.955-961
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• 2014

This study was carried out to investigate the amounts of vitamin C in 22 sweet potato cultivars cultivated in Korea as well as evaluate the effects of cooking methods on vitamin C contents. Methods for determining vitamin C was validated by determining linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using HPLC. Results showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The LOD and LOQ values for ascorbic acid (AA) were 0.03 and $0.10{\mu}g/mL$, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of AA were less than 5%. The recovery rates of AA and dehydroascorbic acid (DHA) were in the range from 98.21~98.64 and 98.28~100.68%, respectively. Depending on cultivar, contents of AA, DHA, and total ascorbic acid (TA) in sweet potatoes varied in the range from 37.76 (Sinyulmi)~89.25 (Juhwangmin), 23.37 (Sinjami)~63.94 (Sinyulmi), and 68.52 (Sinjami)~115.95 (Juhwangmin) mg/100 g, respectively, and their average levels were $56.98{\pm}12.53$, $36.46{\pm}9.03$, and $93.44{\pm}12.00mg/100g$, respectively. The average TA levels were also dependent on flesh color, whish was significantly higher in general sweet potato and orange sweet potato than in purple sweet potato. Steaming, baking, and frying processes significantly reduced AA (10.61~58.41%), DHA (2.57~52.81%), and TA (14.54~49.92%) contents in sweet potatoes. The highest reduction of AA, DHA, and TA contents was observed after baking, followed by steaming and frying. We expect that the basic information provided by this study will be useful to plant breeders and food scientists.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.739-746
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• 2010

The purposes of this study are 1) to develop an advanced chamber system within ${\pm}10%$ of air velocity at the particulate matter (PM) collection area, 2) to research theoretical characteristics of PM10 and PM2.5 samplers, 3) to assess the performance characteristics of PM10 and PM2.5 samplers through chamber experiments. The total six one-hour experiments were conducted using the cornstarch with an mass median aerodynamic diameter (MMAD) of $20\;{\mu}m$ and an geometric standard deviation of 2.0 at the two different air velocity conditions of 0.67 m/s and 2.15 m/s in the chamber. The aerosol samplers used in the present study are one APM PM10 and one PM2.5 samplers accordance with the US federal reference methods and specially designed three mini-volume aerosol samplers (two for PM10 and one for PM2.5). The overall results indicate that PM10 and PM2.5 mini-volume samplers need correction factors of 0.25 and 0.39 respectively when APM PM samplers considered as reference samplers and there is significant difference between two mini-volume aerosol samplers when a two-way analysis of variance is tested using the measured PM10 mass concentrations. The PM10 and PM2.5 samplers with the cutpoints and slopes (PM10: $10{\pm}0.5\;{\mu}m$ and $1.5{\pm}0.1$, PM2.5: $2.5{\pm}0.2\;{\mu}m$ and $1.3{\pm}0.03$) theoretically collect the ranges of 86~114% and 64~152% considering the cornstarch characteristics used in this research. Furthermore, the calculated mass concentrations of PM samplers are higher than the ideal mass concentrations when the airborne MMADs for the cornstarch used are smaller than the cutpoints of PM samplers and the PM samplers collected less PM in another case. The chamber experiment also showed that PM10 and PM2.5 samplers had the bigger collection ranges of 37~158% and 55~149% than the theocratical calculated mass concentration ranges and the relatively similar mass concentration ranges were measured at the air velocity of 2.15 m/s comparing with the 0.67 m/s.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.528-539
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• 2005

The H.264 has been adopted as the video codec for various multimedia services such as DMB and next-generation DVD because of its superior coding performance. However, the reference codec of the standard, the joint model (JM) contains quite a few algorithms which are too complex to be used for the resource-constraint embedded environment. This paper introduces very low-complexity H.264 encoding algorithm which is applicable for the embedded environment. The proposed algorithm was realized by restricting some coding tools on the basis that it should not cause too severe degradation of RD-performance and adding a few early termination and bypass conditions during the motion estimation and mode decision process. In case of encoding of 7.5fps QCIF sequence with 64kbpswith the proposed algorithm, the encoder yields worse PSNRs by 0.4 dB than the standard JM, but requires only $15\%$ of computational complexity and lowers the required memory and power consumption drastically. By porting the proposed H.264 codec into the PDA with Intel PXA255 Processor, we verified the feasibility of the H.264 based MMS(Multimedia Messaging Service) on PDA.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.141-146
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• 2016

HEVC/H.265 is the latest joint video coding standard proposed by ITU-T SG 16 WP and ISO/IEC JTC 1/SC29/WG 11. In H.265, pictures are divided into a sequence of coding tree units(CTUs), and the CTU further is partitioned into multiple CUs to adapt to various local characteristics. Its coding efficiency is approximately two times high compared to previous standard H.264/AVC. However according to the size of extended CU(coding unit) and transform block, the hardware size of PMR(prediction/mode decision/reconstruction) block within video encoder is about 4 times larger than previous standard. In this study, we propose a new less complex hardware architecture of PMR block which has the most high complexity within encoder without any noticeable PSNR loss. Using this simplified block, we can shrink the overall size the H.265 encoder. For FHD image, it operates at clocking frequency of 300 MHz and frame rate of 60 fps. And also for the test image, the Bjøntegaard Delta (BD) bit rate increase about average 30 % in PMR prediction block, and the total estimated gate count of PMR block is around 1.8 M.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.521-527
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• 1989

This study was conducted to investigate the differneces in milling, physicochemical, rheological and end-product properties between Korean and American wheat cultivars. Also, rheological and bread baking properties of Korean wheat flour in blends with U.S. standard flour were investigated. The milling yield of Korean wheat rated 71.1% similar to 71.6% of U.S. wheat. The average AWRC 61.8% of the three Korean wheats ranked higher than the conventional value of 60% for classifying hard and soft wheat. The cookies made from Korean wheat flour showed comparatively good spread with diameter of 8.5-8.9 cm, and marked recommendable top grain score. The volume ranges 975-1175 cc of sponge cake made from all cultivars tested were lower about 4-26% than that of standard cake flour. especially, Wonkwang was selected as one which has special characteristics good for cookie and sponge cake. The volumes of breads from Korean wheat 리ours ranged 924-1020 cc, and Yongkwang of 1020cc marked the most appropriate characteristics for bread-making among the tested wheats. The proper blending ratio of Korean wheat flour to U.S. bread standard flour was revealed 30% in bread-making.

• Analytical Science and Technology
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• v.16 no.1
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• pp.70-77
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• 2003

The optimum conditions for the residue analysis of hydroxyanilide fungicide fenhexamid on cucumber, strawberry and grape were investigated by gas chromatography equipped with electron capture detector (GC-ECD) and the residual amount was determined by sprayed days before harvest. Each samples were extracted with acetone, filtered and concentrated to 50 mL. The concentrated extracts were transferred to dichloromethane and then thoroughly concentrated. The concentrated phase was loaded on the filtration column stuffed with silica gel and purified with acetone:hexane (5:95, 15:85, v/v) mixed solvent. The regression equation and linearity of the standard calibration curves between 0.05~2.00 ng were as follows : cucumber; Y=312.40X+10.26, $R^2=0.9996$, strawberry; Y=313.33X+5.54, $R^2=0.9998$, grape; Y=253.27X-2.23, $R^2=0.9994$. From the standard additional experiments with 0.10 mg/L and 0.40 mg/L, the average recoveries of cucumber, strawberry and grape were 94.8%, 88.1% and 93.7%, respectively and the detection limits were all the same as 0.01 mg/L. Residual amounts in crops were ranged from 0.01 to 0.58 mg/L.

• Resources Recycling
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• v.25 no.6
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• pp.73-81
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• 2016

Geopolymers produced from aluminosilicate materials such as metakaolin and coal ash react with alkali activators and show higher fire resistance than portland cement, due to amorphous inorganic polymer. The percentage of thermal shrinkage of geopolymers ranges from less than 0.5 % to about 3 % until $600^{\circ}C$, and reaches about 5 ~ 7 % before melting. In this study, geopolymers paste having Si/Al = 1.5 and being mixed with carbon nanofibers, silicon carbide, pyrex glass, and vermiculite, and ISO sand were studied in order to understand the compressive strength and the effects of thermal shrinkage of geopolymers. The compressive strength of geopolymers mixed by carbon nanofibers, silicon carbide, pyrex glass, or vermiculite was similar in the range from 35 to 40 MPa. The average compressive strength of a geopolymers mixed with 30 wt.% of ISO sand was lowest of 28 MPa. Thermal shrinkage of geopolymers mixed with ISO sand decreased to about 25 % of paste. This is because the aggregate particles expanded on firing and to compensate the shrinkage of paste. The densification of the geopolymer matrix and the increase of porosity by sintering at $900^{\circ}C$ were observed regardless of fillers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.546-559
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• 2016

This study was conducted to analyze the relationship between sleep quality, stress response, physical activity and sleep hygiene in shift work nurses and identify factors influencing sleep quality. The participants were 168 shift nurses from university hospitals and general hospitals located in C city, Gyeongnam. Data were collected from March 25 to 31, 2016. The study instrument use to the Pittsburgh Sleep Quality Index, Stress Response Inventory, Korean version of the International Physical Activity Questionnaire Short Form and Sleep Hygiene Scale. Date were analyzed by frequency, t-test, ANOVA, Pearson's correlation and hierarchical multiple regression using SPSS/win18.0. The sleep quality index was 7.35 (range 0-21), stress response was 2.20 (range 1-5), physical activity was 3986MET-min/week, and sleep hygiene was 2.73 (range 1-6 points). There were significant differences in sleep quality according to shift work experience, health status and circadian rhythm type. Factors influencing sleep quality included shift work experience, sleep hygiene, stress response and physical activity, which together explained 40% of the total variance of sleep quality. Therefore, it is recommended that sleep hygiene education be implemented as a strategy to reduce stress response, and that shift work nurses engage in a moderate level of physical activity to improve their sleep quality.