• Journal of Ecology and Environment
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• v.35 no.4
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• pp.307-311
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• 2012

This study was conducted to evaluate the dynamics of soil respiration (total soil and heterotrophic respiration) following fertilizer application in red pine forests. Fertilizer (N:P:K = 113:150:37 kg/ha), which reflects current practices in Korean forest, was applied in April 2011, and total soil and heterotrophic respiration rates were monitored from April 2011 to March 2012. Monthly variation of total soil and heterotrophic respiration rates were similar between the fertilizer and control treatments, as soil temperature was the dominant factor controlling the both rates. Total soil respiration rates during the study period were not significantly different between the fertilizer (0.504 g $CO_2\;m^{-2}\;h^{-1}$) and control (0.501 g $CO_2\;m^{-2}\;h^{-1}$) treatments. However, the proportion of heterotrophic respiration was higher in the fertilizer (78% of total soil respiration rates) than in the control (62% of total soil respiration rates) treatments. These results suggest that current fertilizer practices in Korea forest soil do not substantially affect total soil respiration rates.

• Korean Institute of Interior Design Journal
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• v.25 no.6
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• pp.61-69
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• 2016

A study on how fire officer's job satisfaction factors influence space satisfaction rates. This article will conduct regression analysis for the study on these three problems. 'What are the factors of fire officer's job satisfaction?', 'Does space satisfaction rates influence job satisfaction rates?', 'Which job satisfaction factor influence space satisfaction rate?' Therefore, variables were set based on the prior study, and before regression analysis was conducted, variables were purified through analysis on primary factor and reliability analysis, and hypothesis test was done via variable calculation. According to the prior study, factors that influence job satisfaction rates are as following; self-regulation of tasks, ethics and responsibility level, relationship with colleagues, job identity. And regression analysis showed that space satisfaction rates do not influence job satisfaction rates. The writer thinks that it's showing that Korean fire officers tend to prioritize colleague relationship and job identity over space improvements. And the factor that influence job satisfaction rates turned out to be the self-regulation of tasks, and the writer estimates that it's reflecting the hierarchical organization culture of current Korean fire officers. Therefore, future Korean fire station design plans need to consider a space plan that provides fire officer's private self-regulation of tasks.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.393-399
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• 2006

This study was aimed to design, formulate and characterize the moisture-activated patches containing acyclovir for antiviral action. Gel intermediates for film-type patches were prepared with mucoadhesive polymer, viscosity builders, enhancers and acyclovir. Patches containing acyclovir were characterized by in vitro measurement of drug release rates through a cellulose barrier membrane, and of drug flux through the hairless mouse skin. Film-type patches obtained were uniform in the thickness and showed a mucoadhesive property when contacted with moisture. The formulation was optimized, which consisted of $Cantrez^{\circledR}$ AN-169(2%), $Kollidon^{\circledR}$ VA 64(1%), $Natrosol^{\circledR}$(1%), hydroxypropyl-$\beta$-cyclodextrin(1%) and dimethylsulfoxide(0.5%). Release rates of acyclovir patches increased dose-dependently. The addition of terpenes such as d-limonene or cineole increased release rates of acyclovir, but decreased permeation rates. The permeation rates were enhanced by 2 and 2.5 times by the addition of glycyrrhizic acid ammonium salt and sodium glycocholate, respectively, compared with that of no enhancer. These results suggest that it may be feasible to deliver acyclovir through the skin or gingival mucosa from the moisture-activated patches.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.337-342
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• 1999

Rotifer grazing rates in both species and community levels on bacteria and phytoplankton were determined by using representative models (fluorescent beads: 0.75$\mu m$ for bacteria and 10 $\mu m$ for phytoplankton) at biweekly intervals. One-year study at the lower part of the Nakdong River (Mulgum) indicated that the seasonal pattern of rotifer biomass was similar to that of total zooplankton biomass. Total mean biomass of rotifers was significantly higher than that of other groups (rotifers, 148$\pm $327 $\mu g$C/l; cladoceran. 25$\pm 69$$\mu g$C/l; copepodids. 58$\pm 159$$\mu g$C/l). For laboratory grazing experiments. mean specific filtering rate (SFR: $ml\cdot \; l^{-1}\cdot \; day^{-1}$) for rotifers varied from 0.001 to 0.726, and > 90% individuals of rotifer species took up fluorescent microspheres. The high SFRs were achieved by Brachionus angularis, B. calyciflorus, and Filinia longiseta. Community filtering rates (CFRs, $ml\cdot \; l^{-1}\cdot \; day^{-1}$) varied in the range from 2 ~ 1,670. Rotifer filtering rates on phytoplankton were much higher than bacterial filtering rates, especially in the late growing season (May. June, and November). Rotifers appear to be important in transferring both bacterial and phytoplankton carbon to higher trophic levels at the lower Nakdong River.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.727-729
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• 2002

In this paper, we proposed quad variable rates ADPCM coding method and its implementation on C6000 DSP, which is modified from the standard ADPCM of ITU G.726 for speech quality improvement considering the environmental noise Four coding rates, 16Kbps, 24Kbps, 32Kbps and 40Kbps are used for speech window samples and the rate decision threshold is decided by the environmental noise level. The object of the proposed method is to reduce the coding rate while retaining the speech quality and the speech quality is considerably close to 40Kbps single rate coder with the coding rate close to 16Kbps single rate coder under the environmental noise. The environmental noise level affects the coding rate and the noise level is calculated per every speech window samples. At high noise level, more samples are coded at higher rates to enhance the quality, but at low noise level, only the big speech signals are coded at higher rates and more speech samples are coded at lower coding rates to reduce the coding rates. The influence of the noise on tile speech signal is considerably high for small signals and the small signal has the higher ZCR (zero crossing rate). The method is simulated in PC and to be implemented on C6000 floating point DSP board in real time operations.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.39-46
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• 2000

This study was conducted to investigate the effect of hormones, protein sources and anti-oxidants on in vitro maturation (IVM) and in vitro fertilization(IVF) of bovine follicular oocytes. The rates of Holstein follicular oocytes classified as grade A and B(50.2% and 33.2%) were higher than those of Hanwoo cattle(40.3% and 32.0%, P<0.05). The cumulus cell expansion rates of oocytes cultured in TCM-199 and Ham's F-10 medium supplemented with 10% FCS and hormones were higher (81.9~87.6%) than those of non-treated groups (74.5~81.7%). The fertilization rates of oocytes cultured in TCM-199 and Ham's F-10 medim supplemented with 10% FCS, 1% BSA and 10% bFF was 53.8~55.0%, 51.4~52.6%, and 47.0~50.0%, respectively. The polyspermy rates was 13.6~14.2%, 10.0~11.1%, and 10.0%, respectively. When the oocytes were cultured in TCM-199 and Ham's F-10 medium with 50${\mu}{\textrm}{m}$ $\alpha$-tocopherol, the fertilization rates was 62.0 and 60.2%, respectively. In the maturation medium added of 100${\mu}{\textrm}{m}$ cysteamine, the fertilization rates was 64.7 and 66.7%, respectively. The fertilization and polyspermy rates of treated groups were higher than those of non-treated group. The results show that hormones, protein sources and anti-oxidants can provide a benefit for in vitro maturation and fertilization of bovine follicular oocytes.

• Korean Journal of Animal Reproduction
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• v.22 no.3
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• pp.213-219
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• 1998

This study was carried out to investigate on the improvement of fertilizing ability of in vitro matured oocytes from sperm density, motility and polyvinylpyrrolidine (PVP) concentration, by intracytoplasmic sperm injection(ICSI) into the bovine oocytes. 1. The in vitro fertilization and cleavage rates of oocytes from 1.0, 2.0, 3.0, 5.0 ($\times$106/ml) sperm concentration by IVF and ICSI of bovine oocytes were 45.0%~65.0%, 65.0%~90.0% and 10.0%~30.0%, 35.0%~70.0%, respectively. 2. The in vitro fertilization and cleavage rates of oocytes from 20, 40, 60, 80% of sperm motility by IVF and ICSI of bovine oocytes were 47.8%~75.0%, 78.3%~90.0% and 8.7%~25.0%, 34.8%~70.0%, respectively. 3. The in vitro fertilization and cleavage rates of oocytes from 0.01, 0.02, 0.03, 0.05% of PVP concentration by microinjection of single into the bovine oocytes were 72.7%, 90.9%, 83.3%, 76.9% and 45.5%, 72.7%, 58.3%, 61.5%, respectively and these values of 0.02% addition of PVP were higher than other concentrations of PVP. 4. The in vitro fertilization and developmental rates of oocytes by IVF and ICSI methods were 63.3%~64.6%, 26.7%~29.2% and 88.2%, 47.1%, respectively. This ICSI method was improved high fertilization rates of bovined oocytes.

• Journal of Preventive Medicine and Public Health
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• v.55 no.4
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• pp.371-378
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• 2022

Objectives: No studies have examined the association between preterm birth rates and socioeconomic factors in Japan using nationwide statistical data. We analyzed the association between preterm birth rates and household occupation using Vital Statistics data. Methods: Aggregated Vital Statistics data from Japan from 2007 to 2019 were obtained from the Ministry of Health, Labour and Welfare. From the data, the number of births according to year, age group, gestational period, number of pregnancies, and household occupation were used in this study. Crude preterm birth rates and preterm birth rates adjusted by maternal age according to household occupation were calculated for each year. Poisson regression analysis was conducted to evaluate the association between household occupation and preterm births. Results: Unemployed households had the highest preterm birth rate, and households with an occupation classification of "full-time worker 2" (an employee at a large company, civil servant, or board member) had the lowest preterm birth rate throughout each period. Poisson regression analysis revealed that unemployed households were statistically significantly associated with a high preterm birth risk. In contrast, the preterm birth rate adjusted by maternal age remained stable throughout each period regardless of household occupation, and preterm birth rates were found not to have increased in recent years in Japan. Conclusions: Unemployed households had higher preterm birth rates than other household occupations. Further studies investigating the characteristics of unemployed households are needed to identify the reasons for this disparity.

• Communications for Statistical Applications and Methods
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• v.28 no.2
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• pp.119-134
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• 2021

Lung cancer is one of the leading causes of cancer deaths in the world. Investigation of mortality rates is pivotal to adequately understand the determinants causing this disease, allocate public health resources, and apply different control measures. Our study aims to analyze and forecast age-specific US lung cancer mortality trends. We report functions of mortality rates for different age groups by incorporating functional principal component analysis to understand the underlying mortality trend with respect to time. The mortality rates of lung cancer have been higher in men than in women. These rates have been decreasing for all age groups since 1990 in men. The same pattern is observed for women since 2000 except for the age group 85 and above. No significant changes in mortality rates in lower age groups have been reported for both gender. Lung cancer mortality rates for males are relatively higher than females. Ten-year predictions of mortality rates depict a continuous decline for both gender with no apparent change for lower age groups (below 40).

• Journal of Wetlands Research
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• v.14 no.1
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• pp.139-146
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• 2012

Stream ecosystems carry out significant functions such as water purification, especially denitrification. However, rapid landuse change since industrialization has altered ecological functions of streams. In this study, we aimed to investigate denitrification rates and their determinant factors in streams with different landuse patterns, and how denitrification rates vary with microtopology within streams. Ten fifth streams of each landuse were selected, and each stream was divided into four microtopological sites within streams - riparian zone, subsoil, and both head and tail parts of sand bars. In situ denitrification rates and physicochemical properties of soil were examined. Denitrification rates of agricultural, urban, and forest streams were $289.62{\pm}70.69$, $157.01{\pm}37.06$, $31.38{\pm}18.65mg$ $N_2O-N\;m^{-2}\;d^{-1}$ respectively. There were no significant differences in denitrification rates depending on microtopology, but the rates in riparian zone were the highest, and the rates in the head parts of sandbars were lower than those of tail parts. The determinant factors for denitrification rates included water temperature, silt and clay contents of soil, inorganic nitrogen, and organic carbon, and these factors all showed positive correlations with denitrification rates. Through this study, we find that landuse pattern in watershed region affects denitrification rates that is one of considerable functions of streams. In addition, estimation of denitrification rates taking into account for microtopology would contribute to developing ecological management and restoration strategy of streams.