• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.174-189
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• 2012

The objective of this study was to determine the weight-length relations and condition factor (K) of Zacco platypus, along the trophic gradients from oligotrophic to eutrophic state in six reservoir ecosystems ($B_aR$, $Y_yR$, $J_yR$, $G_pR$, $Y_dR$, and $M_sR$), during 2008~2010. The species was selected as a sentinel species for the study, due to its wide distribution and wide trophic gradient. The analysis of trophic state index (TSI), based on total phosphorus (TP) and chlorophyll-a (Chl-a), indicated that reservoirs of $Y_yR$ and $B_aR$ were classified as to be in an oligotrophic state (30~40), the $J_yR$ and $G_pR$ as mesotrophic (40~50), and the $Y_dR$ and $M_sR$ as eutrophic state (50~70). Total 47 species and 26,226 individuals were sampled from 6 reservoirs and sensitive species dominated in the oligotrophic reservoirs ($Y_yR$ and $B_aR$). In the mean time, the tolerant speciesdominated the community in the mesotrophic ($J_yR$ and $G_pR$) and eutrophic ($Y_dR$ and $M_sR$) reservoirs. Regression analysis of body weight, against the total length, indicated that the regression coefficient (b value) was lower in the oligotrophic reservoir (2.77~2.79) than the mesotrophic (3.07~3.17) and eutrophic reservoirs (3.15~ 3.21). This result suggests that the population growth rate Zacco platypus reflected the trophic gradients of the reservoirs. The analysis of condition factor (K) against the total length showed positive slopes (b>3.0) in mesotrophic and eutrophic reservoirs, and a negative slope (b<3.0) in oligotrophic reservoir. The variation of the regression slope of "b" in Z. platypus was accounted for 79.7% [$b=0.012{\times}TSI(TP)+2.395$, p=0.017] by the variation of TSI (TP) and 82.2% [$b=0.013{\times}TSI(Chl-a)+2.36$, p=0.013] by the variation of TSI (Chl-a). The proportion of DELT abnormality increased as the trophic state increases in the reservoirs. The overall data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic state of nutrient and phytoplankton biomass of the reservoir waters. Thus, in spite of the tolerant characteristics of Z. platypus, hypertrophic states might negatively affect the health of the population.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1705-1710
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• 2003

A small body size of Brown Tsaiya laying duck is desirable to reduce maintenance requirements, so the body weight at 40 weeks of age (BW40) has to be maintained at its current level. Egg weight has to be maintained at around 65 g to meet market requirements. Eggshell strength at 40 weeks of age (ES40) must to be increased in order to maintain a low incidence of broken eggs. Thus, number of eggs laid up to 52 weeks of age (EN52) has to be increased without negative correlated response on ES40. A new linear genetic selection index was used: $I_g=a_0{\times}GEW40\;(g)+a_1{\times}GBW40\;(g)+a_2{\times}GES40\;(kg/cm^2)+a_3{\times}GEN52\;(eggs)$ where GEW40, GBW40, GES40 and GEN52 were the multitrait best linear unbiased prediction (MT-BLUP) animal model predictors of the breeding values respectively of egg weight and body weight at 40 weeks of age (EW40, BW40), ES40 and EN52. The coefficients $a_0$, $a_1$, $a_2$ and $a_3$ were calculated with constraints of 0.0 g, 0.0 g and $0.013kg/cm^2$ for expected genetic gains in EW40, BW40 and ES40 respectively and maximum gain in EN52. Since 1997, the drakes and the ducks were selected according to their own indexes, with this new genetic selection index. From G0 to G4, the average per generation predicted genetic responses in female duck were +0.05 g for EW40, +0.92 g for BW40, $+0.035kg/cm^2$ for ES40 and +2.13 eggs for EN52. Which represented respectively 0.07%, 0.06%, 0.67% and 1.0% of the means of the EW40, BW40, ES40 and EN52. For ES40 and EN52, it represented also respectively 16.1% and 21.6% of the additive genetic standard deviation of these traits. Thevse results indicated that selection of laying Brown Tsaiya by a restricted genetic selection index and with MT-BLUP animal model could be an efficient tool for improving the efficiency of egg production, increasing egg shell strength and egg number while holding egg weight and body weight constants.

• East Asian mathematical journal
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• v.31 no.1
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• pp.33-40
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• 2015

We study the geometry of r-lightlike submanifolds M of a semi-Riemannian manifold $\bar{M}$ with a semi-symmetric non-metric connection subject to the conditions; (a) the screen distribution of M is totally geodesic in M, and (b) at least one among the r-th lightlike second fundamental forms is parallel with respect to the induced connection of M. The main result is a classification theorem for irrotational r-lightlike submanifold of a semi-Riemannian manifold of index r admitting a semi-symmetric non-metric connection.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.707-710
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• 2009

As the inner diameter of CCFL is increased in the range of outer diameters 3~5 mm, the luminance efficiency is increased by the low power consumption. For the outer diameter 5 mm, the efficiency is linearly increased even at the range of a high current.

• Journal of applied mathematics & informatics
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• v.40 no.3_4
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• pp.785-794
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• 2022

In this paper we show that if A ∈ L(X) and R ∈ L(X) is a quasinilpotent operator commuting with A then X_A(F) = X_A+R(F) for all subset F ⊆ ℂ and 𝜎_loc(A) = 𝜎_loc(A + R). Moreover, we show that A and A + R share many common local spectral properties such as SVEP, property (C), property (𝛿), property (𝛽) and decomposability. Finally, we show that quasisimility preserves local spectrum.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.1
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• pp.47-53
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• 1994

Cycle simulation of the air-conditioner was carried out using a number of candidate alternatives to R22;R32/R125/R134a(30/10/60, by mass percent), R32/R125/R134a(10/70/20), R32/R134a(25/75), R32/R134a(30/70), R32/R125(60/40), R290(propane) and R134a. In this study, we considered only the basic parts of the air-conditioner such as the compressor, the evaporator, the condenser and the capillary tube, for the purpose of analysis. The performance characteristics of alternatives considered here were examined by comparing with the case using R22 at the constant volumetric flow rate condition. The results of our analysis revealed that the use of refrigerant mixtures, R32/R134a(30/70) and R32/R125/R134a(30/10/60), was appropriate for the alternatives to R22 in view of the cooling capacity and the COP. For the case of using R134a and R290, the COP was observed to increase under the same volumetric flow rate condition, but the cooling capacity was substantially decreased. Therefore the use of R134a and R290 should be accompanied with increasing considerably the size of compressor in order to maintain the same cooling capacity of R22.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.539-545
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• 2000

A 40-Mb/s, 64-state, R= 1/2, 3 bit soft decision Viterbi decoder based on Radix-4 method has been designed and fabricated using a FLEX10K CPLD chip in this paper. In order to implement the high-speed Viterbi decoder, the architectures of adder-compare-select(ACS), branch metric calculation(BMC), trace back(TB) are present. In practical designed by ASIC, the speed is faster than that of CPLD by 6~7 times. Therefore, 40 Mb/s Viterbi decoder architecture can be used for high-speed wireless multimedia communications with 200 Mb/s.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.455-459
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• 1996

The genetic parameters for various economic traits were estimated in a White Leghorn population selected for part period egg production over 16 generations. In early part of selection, egg number had moderate to high heritability (0.26 to 0.51) while age at sexual maturity, egg weight and body weight at 20 and 40 weeks of age had high heritability (0.54 to 0.83). The sire component heritability for all the traits except 20 week body weight declined in later periods of selection. Sex linked gene effects for egg number and age at sexual maturity were more important in early periods of selection in comparison to the later periods, while maternal effects remained important for 20 week body weight in all the periods. Egg number was negatively correlated with egg weight ($r_{G(S)}=-0.36$), age at sexual maturity ($r_{G(S)}=-0.84$) and 40 week body weight ($r_{G(S)}=-0.84$), while it was positively correlated with 20 week body weight ($r_{G(S)}=-0.34$) in base generation. The genetic association between egg number and 40 week body weight changed not only in magnitude but also in direction in later periods. The genetic correlation of egg number with egg weight as well as with age at sexual maturity also decreased in magnitude in later periods of selection.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.403-414
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• 2010

Reducing women's bone mineral density (BMD) has close relationship to risk in osteoporosis. This study was carried out to identify bone density risk factors affecting women's BMD, and to analyze the relationship of age, between BMD and menopause, BMI, blood pressure lifestyle and dietary habits for bone health by physical measurement and questionnaires. The study subjects, 128 women living in Seoul, were divided into 4 age group; 30~39 years (17), 40~49 years (54) and 50~59 years (36) and 60~69 years (21). There were significant differences in mean height, BMI, systolic blood pressure, menache and menopause age and menopause ratio and BMD T-score among the 4 age groups. BHD was significantly decreased according to increasing age and BMI and menopause. The rate of BMD risk subjects was significantly different increasing with age and BMI. The rate of risk group were 0%, 13%, 22.2% and 71.4%, by age groups and 0%, 16.2%, 33.3% and 52.9% by BMI respectively. BMD of menopause groups was significantly decreased from 1.23 (40 years) to 1.34 (60 years). p < 0.001. Also systolic blood pressure were significantly increased from 116.5 mmHg (30 years) to 130.81 mmHg (60 years). The T-score of normal group also decreased significantly from 1.27 to 0.13 (60years) with age. There were significant negative correlation between BMD and age (r = -0.409) menopause (r = -0.346), BMI (r = -0.218) systolic blood pressure (r = -0.193), salty taste eating out (r = -0.185) (p < 0.05). There were significant positive correlation between BMD and meat fish and walking time. In conclusion, bone density decreased with age. Most of the 50 years' subjects were in risk group. BMI, menopause, systolic blood pressure, frequency alcohol consuming. To prevent osteoporosis, over 40 years needed to be educated to maintain normal weight and the improvement of eating and living habits.

• Journal of Korean Academy of Nursing
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• v.40 no.3
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• pp.453-461
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• 2010

Purpose: In this study differences in behavioral problems between children at risk for Attention Deficit Hyperactive Disorder (ADHD) and normally developing children were identified. Further, relationships between parental stress, depression, and child behavioral problems according to ADHD symptoms were explored. Methods: Participants were 222 elementary school children and their parents. The ADHD risk group was determined by the Korean-ADHD Rating Scale. Data were collected using the Korean-ADHD Rating Scale, Korean version of Child Behavior CheckList (K-CBCL), Parenting Stress Index, and Beck Depression Inventory. Data were analyzed using t-test, Pearson correlation coefficients, and regression analysis. Results: 1) The ADHD risk group showed higher levels of behavioral problems, parenting stress, and maternal depression than the normal group. 2) There were significant relationships between ADHD scores and parenting stress (r=.66), maternal depression (r=.35), internal behavioral problems (r=.47), and external problems (r=.55), but, ADHD risk scores were negatively correlated with social competence (r=-.40). 3) The regression analysis revealed that ADHD levels affected the child's internal behavioral problems, mediated by maternal depression ($\beta$=.29, p<.001). Conclusion: The study results show that higher risk scores for ADHD indicate a significant effect for behavioral problems. Also, parenting stress and depression influence child's behavioral problems. These results suggest that identification of children at risk for ADHD and development of parental education programs would contribute to the prevention of behavioral problems and aggravation of the ADHD symptoms.