• Current Optics and Photonics
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• v.6 no.1
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• pp.104-113
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• 2022

We present a method to count the overall length of the zoom system in an initial design stage. In a zoom-lens design using the concept of the group, it has been very hard to precisely estimate the overall length at all zoom positions through the previous paraxial studies. To solve this difficulty, we introduce T_eq as a measure of the total track length in an equivalent zoom system, which can be found from the first order parameters obtained by solving the zoom equations. Among many solutions, the parameters that provide the smallest T_eq are selected to construct a compact initial zoom system. Also, to obtain an 8× four-group zoom system without moving groups, tunable polymer lenses (TPLs) have been introduced as a variator and a compensator. The final designed zoom lens has a short overall length of 29.99 mm, even over a wide focal-length range of 4-31 mm, and an f-number of F/3.5 at wide to F/4.5 at tele position, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.441-448
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• 1994

Postweaning performance data were obtained on 187 group fed purebred Angus calves from 12 selected sires (six high and six low feed conversion sires) in 1985 and 1986. The objective of this portion of the study was to develop prediction equations for feed conversion from a stepwise regression analysis. Variables measured were on-test weight (ONTSTWT), on-test age (ONTSTAG), five weights by 28-d periods, seven linear body measurements: heart girth (HG), hip height (HH), head width (HDW), head length (HDL), muzzle circumference (MC), length between hooks and pins (HOPIN) and length between shoulder and hooks (SHHO), and backfat thickness (BF). Stepwise regressions for maintenance adjusted feed conversion (ADJFC) and unadjusted feed conversion (UNADFC) over the first 140 d of the test, and total feed conversion (FC) until progeny reached 8.89 mm of back fat were obtained separately by conversion groups and sexes and for combined feed conversion groups and sexes. In general, weights were more important than linear body measurements in prediction of feed utilization. To some extent this was expected as weight is related directly to gain which is a component of feed conversion. Weight at 112 d was the most important variable in prediction of feed conversion when data from both feed conversion groups and sexes were combined. Weights at 84 and 140 d were important variables in prediction of UNADFC and FC, respectively, of bulls. ONTSTWT and weight at 140 d had the highest standardized partial regression coefficients for UNADFC and ADJFC, respectively, of heifers. Results indicated that linear measurements, such as MC, HDL and HOPIN, are useful in prediction of feed conversion when feed in takes are unavailable.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.93-105
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• 1993

In this paper, the maximum scour depths at piers located in the Bo Cheong Stream, which is a tributary in the Geum River System, were calculated and compared using 24 local pier scour equations. The equations were classified as six groups by non-dimensional types of equations. The geometric data in the stream bed and pier data at San Seong, Yi Pyung and San Gye, which are IHP data collection stations, were utilized for applying the scour equations. The geometric data in the stream bed were obtained by analyzing the bed material sampled in three stations which are in the left side, middle and right side for stream direction. The maximum flow velocities at maximum flow depths which were measured from 1982 to 1991, were used as the hydraulic flow data. The pier data for predicting pier scour depths were measured in the fields. The maximum pier scour depths calculated using the equations were compared with the held scour depths measured in the streams or rivers in the world. Arunachalam, Shen-Karaki III, Jain-Fischer equations are selected as the proper local scour equations for predicting the maximum local scour depths at piers in the Bo Cheong Stream. Inglis-Lacey and Shen-Karaki II equations are applicable in case of rapid flows conditions in which Froude number is over 0.3. Froehlich, Laursen I, Laursen II, Neill, Melville equations are applicable in the slow flow conditions in which Froude number is less than 0.3. Blench equation or Inglis-Poona equation varies rapidly by changing Froude numbers. Therefore the equations should not be used without careful considerations in selecting the applicable ranges. The maximum local scour depths calculated using Sarma-Krishnamurthy, Ahmad, Coleman, Varzeliotis, Larras, Bata, Chitale, Venkatadri, Basik-Basamily-Ergun, U.S.G.S., Shen I equations are usually less than the scour depths measured in the fields.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.4
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• pp.45-56
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• 2012

Objective : This study was done to investigate the correlation between general quality of life(QOL) and disease specific QOL of tinnitus patients. Methods : 2009 National health and nutrition survey(NHNS) data were employed for analyzing the mean estimates of total population and tinnitus sub-group patients, and predicting the regression equation of mapping between EQ-5D and disease severity. Baseline statistical analyses and normality tests were done by using Student t-test, Chi-square test, Shapiro-Wilk test and ladder test. Hierarchial regression analyses were performed using related variables and predicted the optimal regression equations. Statistical significance was achieved if the probability was less than 5%. Results : Firstly, the standardized prevalence of tinnitus patient in South Korea was 18.69% and over 90th age-group was relatively higher than other groups. Mean value of domestic QOL measured by EQ-5D was estimated as 0.9486 and QOL of tinnitus subgroup(0.9169) was lower than the non-tinnitus subgroup(0.9559), significantly. Stratified by age and sex, QOLs of all sub-groups with tinnitus were lower than without tinnitus sub-groups significantly. Regression equations from 2009 NHNS data were developed using hierarchial regression analysis which is as follows. $$Y_{EQ-5D}=0.9224-0.0079{\times}T1-0.0261{\times}T2-0.0951{\times}T3+\sum_{i=1}^{n}{\beta}_i{\times}X_i\\{\hspace{95}}(0.0106){\hspace{3}}(0.0037){\hspace{30}}(0.0072){\hspace{30}}(0.0038)$$ ($X_i$=Other explanatory variables except Tinnitus QOL1, 2, 3, ${\beta}$= Regression Coefficient of Model 4) Conclusion : We confirmed the correlation among THI and EQ-5D and HUI-III, and developed the inference for regression equation of EQ-5D.

• Journal of Korean Biological Nursing Science
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• v.23 no.3
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• pp.180-187
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• 2021

Purpose: This study aimed to compare breast milk minerals between mothers with gestational diabetes mellitus (GDM) and healthy mothers. Methods: This study was a short-term prospective study to determine the difference in milk minerals of 30 GDM mothers and 30 healthy mothers. Mineral concentrations in breast milk were measured for Na, K, Ca, Mg, and P. The first breast milk was collected on the 5th day after childbirth, while the second one was collected on the 14th day. For the variation of mineral content of breast milk over time between groups, generalized estimation equations were used. Results: The mean age of the GDM group and healthy mother group was 32.56 and 31.17 years old, respectively. Na was significantly higher in GDM mother group (Wild 𝛘²=4.35, p=.037) over time (Wild 𝛘²=21.59, p<.001), and Ca was significantly higher in healthy mother group (Wild 𝛘²=1.77, p=.018) over time (Wild 𝛘²=19.09, p<.001). Mg, P, and K showed a significant difference in time (Wild 𝛘²=18.12, p<.001; Wild 𝛘²=7.73, p=.005; Wild 𝛘²=7.10, p=.008). P was significantly higher in GDM mother group on 5th day of delivery (t=2.08, p=.042). Conclusion: There was a difference in the mineral composition of breast milk between GDM mothers and healthy mothers. Therefore, it is necessary to develop and apply intervention programs such as effective prenatal blood sugar management and postpartum breast massage considering the characteristics of GDM mothers.

• Carbon letters
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• v.11 no.3
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• pp.224-234
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• 2010

Four activated carbons were produced by two-stage process as followings; semi-carbonization of indigenous biomass waste, i.e. cotton stalks, followed by chemical activation with KOH under various activation temperatures and chemical ratios of KOH to semi-carbonized cotton stalks (CCS). The surface area, total pore volume and average pore diameter were evaluated by $N_2$-adsorption at 77 K. The surface morphology and oxygen functional groups were determined by SEM and FTIR, respectively. Batch equilibrium and kinetic studies were carried out by using a basic dye, methylene blue as a probe molecule to evaluate the adsorption capacity and mechanism over the produced carbons. The obtained activated carbon (CCS-1K800) exhibited highly microporous structure with high surface area of 950 $m^2/g$, total pore volume of 0.423 $cm^3/g$ and average pore diameter of 17.8 ${\AA}$. The isotherm data fitted well to the Langmuir isotherm with monolayer adsorption capacity of 222 mg/g for CCS-1K800. The kinetic data obtained at different concentrations were analyzed using a pseudo-first-order, pseudo-second-order and intraparticle diffusion equations. The pseudo-second-order model fitted better for kinetic removal of MB dye. The results indicate that such laboratory carbons could be employed as low cost alternative to commercial carbons in wastewater treatment.

• Journal of the Korean Applied Science and Technology
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• v.10 no.1
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• pp.75-81
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• 1993

The hydrolysis kinetics of 2-furyl chalcone derivatives $[I]{\sim}[V]$ was investigated by ultraviolet spectrophotometery in 30% dioxane-$H_{2}O$ at $25^{\circ}C$ and the structure of these compounds were ascertained by means of ultraviolet, infrared and NMR spectra. The rate equations which were applied over a wide pH range(pH $1.0{\sim}12.0$) were obtained. The substituent effects on 2-furyl chalcone derivatives $[I]{\sim}[V]$ were studied, and the hydrolysis were facilitated by the electron attrecting groups. On the basis of the rate equation, substituent effect, general base effect and final product. the plausible hydrolysis mechaism was proposed: Below pH 4.0, it was only proportional to concentration of hydronium ion, at pH $4.0{\sim}9.0$, neutral $H_{2}O$ molecule competitively attacked on the double bond. By contrast, above pH 9.0, it was proportional to concentration of hydroxide ion.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.73-80
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• 1993

The hydrolysis reaction kinetics of 2-thienyl chalcone derivatives $[II]{\sim}[V]$ was investigated by ultraviolet spectrophotometery in 20% dioxane-$H_2O$ at $25^{\circ}C$ and the structure of these compounds were ascertained by means of ultraviolet, infrared and NMR spectra. The rate equations which were applied over a wide pH range(pH $1.0{\sim}13.0$) were obtained. The substituent effects on 2-thienyl chalcone derivatives$[II]{\sim}[V]$ were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation, substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed : At pH $1.0{\sim}9.0$, not relevant to the hydrogen ion concentration, neutral $H_2O$ molecule competitvely attacked on the double bond. By contraries, above pH 9.0, it was proportional to concentration of hydroxide ion.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.35-41
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• 1995

The Hydrolysis kinetics of Benzoyl Styrene Derivatives[I]${\sim}$[IV] was investigated by ultraviolet spectrophotometery in 5% dioxane-$H_2O$ at $40^{\circ}C$. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and NMR spectra. The rate equations which were applied over a wide pH range (pH $1.0{\sim}13.0$) were obtained. The substituent effects on Benzoyl styrene derivatives[I]${\sim}$[IV] were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed: At pH 1.0${\sim}$pH 9.0, not relevant to the hydrogenl ion concentration, neutral $H_2O$ molecule competitively attacked on the double bond. By contrary. Above pH 9.0, It was proportional to concentration of hydroxidel ion.

• Electrical & Electronic Materials
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• v.7 no.3
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• pp.187-199
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• 1994

In order to find an effect of structural changes due to variation of addition ratio of anhydride hardener and postcuring herat-treatments upon electrical properties of epoxy composites, the dielectric properties over a frequency range from 30[Hz] to l[MHz] were investigated in the temperature range of 20-180[.deg. C]. From the dielectric properties, the a peaks related with glass-transition phenomena of epoxy network appeared near 130[.deg. C], the conduction loss in high temperature region above 150[.deg. C] due to thermal dissociation of hardener started off with the low frequency side and the .betha. peak concerned with contribution of movable unreacted terminal epoxy groups and curing agents in the glass states concurred with the high-frequency side below 20[.deg. C]. And an effect of an hydride hardener upon structural changes and of postcuring heat treatments upon structural stability in epoxy composites would be explained through the estimation of the distribution of relaxation times and the activation energy for a .alpha. peak according to the WLF equations.