• 한국수산과학회지
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• 제42권4호
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• pp.354-359
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• 2009

The productivity of ultra-small rotifer, Synchaeta kitina was investigated at the exchange rate of culture water (10, 20, 30, 40 and 50%) and initial inoculation densities (250, 600 and 900 inds. per mL) in semi-continuous culture. Also, the possibility of mass culture was investigated in a 100 L culture tank. Tetraselmis suecica was used as the feed for S. kitina in all experiments. The production of S. kitina increased with an increase in exchange rate of culture water. The highest production ($82.0{\times}10^5$ inds.) was achieved at 40% exchange rate of culture water. The production of S. kitina increased with an increase of initial inoculation density during the first week and the highest total production ($17.4{\times}10^6$ inds.) was achieved at 900 inds. per mL of initial inoculation density. However, on the second week, all treatments were not significantly different in total production (P>0.05). During the two weeks, total production of S. kitina at 900 inds. per mL of initial inoculation density was higher than at 600 inds. of initial inoculation density, but there was no significant difference (P>0.05). In the 100 L culture tank, density of S. kitina was kept from 516 to 890 inds. per mL and S. kitina was daily harvested $15.5{\times}10^6$ to $26.7{\times}10^6$ during the experimental period. The production cost for 100 million rotifers in semi-continuous culture was 63,656 won. The results from this study indicate that the optimal exchange rate of culture water and initial inoculation density for the semi-continuous culture of ultra-small rotifer, S. kitina are 40% and 600 inds. per mL, respectively.

• 터널과지하공간
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• 제4권1호
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• pp.17-23
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• 1994

This study consists of two procedures on back analysis and forward analysis which is a basic tool of the former. For a safe and economical construction of underground structures, it is required to identify the structural parameters and analyze the structural behavior as exactly as possible. In this paper, a boundary element method to analyze the behavior of multi-alyered underground structures is studied, in which body forces and initial stresses are considered. That is, each layer is discritized into subregions using infinite fundamental solutions, and terms of body forces and initial stresses are transformed into boundary integral where the applied direct integral method is used. And the system of equations containing body forces and initial stresses are considered. That is, each layer is discritized into subregions using infinite fundamental solutions, and terms of body forces and initial stresses are transformed into boundary integral where the applied direct integral method is used. And the system of equations containing body forces and initial stresses are composed, then the method to solve unknowns is used with applying compatibility and equilibrium conditions between interfaces. As well, the direct search method is applied in back analysis problems. By Powell's method as a technique to search unknown parameters, assuming displacements calculated from boundary element analysis as in-situ displacements, elastic moduli and initial stresses are presumed. As consequences of this study, the results of boundary element analysis of the behavior of multilayered structure considering body forces and initial stresses are agreed with those of finite element analysis. And results of back analysis of elastic moduli and initial stresses in each layers are agreed with exact values with a little difference. Therefore, it is known that this study can be efficiently applied for analyzing the behavior of underground structures including back analysis problems.

• 한국구조물진단유지관리공학회 논문집
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• 제15권4호
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• pp.136-145
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• 2011

준설매립후 연직배수공법을 적용하여 지반개량을 수행하는 대규모 국가산업단지 조성 프로젝트를 대상으로, 각 심도별 채취된 불교란 시료를 이용하여 물리즉 특성 및 압밀 특성 등을 분석하기 위한 실내시험을 실시하였으며, 수평 압밀계수 및 현장 초기 응력 산정을 위한 콘 관입 및 소산시험을 수행하였다. 지층을 구성하고 있는 하부의 원지반 점토층과 상부의 준설 매립층은 유사한 해성점토로 구성되어 있으나, 초기 간극비와 초기 함수비, 초기 응력상태, 방향별 투수성과 압축성 등의 압밀특성에 있어서는 시간경과에 따른 압밀거동에 있어 매우 큰 차이를 보이는 다층 지반의 특성을 띠고 있다. 압밀과 관련된 응력이력이 다른 두지층의 초기응력을 산정하기 위하여 콘 관입시험 및 소산시험시의 간극수압 측정결과를 분석하였으며, 이를 통해 압밀이 진행중인 하부 원지반 점토층에서의 매립하중과 상부 성토에 의한 각 심도별 과잉간극수압 분포 및 이를 통한 초기응력을 산정할 수 있었다.

• 한국대기환경학회지
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• 제21권1호
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• pp.15-26
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 m3, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included $O_3$, NO, NO$_2$, NO$_{x}$, CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of gaseous species with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$=5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The arriving time at maximum ozone concentration depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. However, the maximum concentration of ozone formed by photooxidation depended only on the initial toluene concentration.luene concentration.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.44-44
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• 2018

The seeds of soybean (Glycine max), adzuki bean (Vigna angularis), mung bean (Vigna radiata), and kidney bean (Phaseolus vulgaris L.) were examined the germination rate after 10 years of long-term storage ($-18^{\circ}C$) conservation. For soybean seeds, 2,313 accessions were examined and germination rate of 1,082 accessions was decreased with below 15% of initial germination rate. For 227 accessions of soybean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 589 accessions was increased and showed no change for 415 accessions after 10 years of long-term storage. For adzuki bean seeds, 2,058 accessions were examined and germination rate of 739 accessions was decreased with below 15% of initial germination rate. For 63 accessions of adzuki bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 535 accessions was increased and showed no change for 721 accessions after 10 years of long-term storage. For mung bean seeds, 438 accessions were examined and germination rate of 139 accessions was decreased with below 15% of initial germination rate. For 5 accessions of mung bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 155 accessions was increased and showed no change for 139 accessions after 10 years of long-term storage. For kdney bean seeds, 366 accessions were examined and germination rate of 7 accessions was decreased with below 15% of initial germination rate. For 65 accessions of kidney bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 201 accessions was increased and showed no change for 93 accessions after 10 years of long-term storage.

• Journal of Periodontal and Implant Science
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• 제23권3호
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• pp.526-534
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• 1993

The purpose of this study was to evaluate the changes of the tooth mobility and maximal bite force over 4 weeks following initial therapy on the periodontal disease. Tooth mobility and maximal bite force due to change of viscoelastic property of periodontium were influenced by inflammation of periodontal tissue. 10 patients with the chronic adult periodontitis participated in this study. Each tooth was divided into anterior areas, premolar areas and molar areas. Tooth mobility was tested using Periotest(Siemens Co. Germany) and maximal bite force was evaluated with MPM-3000(Nihon kohden Co. Japan). Tooth mobility and maximal bite force were recorded at the initial examination, 1, 2, 3 and 4 weeks following initial therapy. All data were analyzed statistically. The obtained results were as follows ; 1. The changes of the tooth mobility following initial therapy were generally decreased in maxilla, showing the significant decrease at 1 and 4 weeks on premolar areas (p<0. 05). 2. The changes of the tooth mobility following initial therapy were generally decreased in mandible, however this changes were not statistically significant. 3. The changes of the maximal bite force following initial therapy in maxilla were significantly increased at 3 and 4 weeks on anterior areas, at 4 weeks on premolar areas (p<0. 05). These were decreased at 1 week on molar areas, but generally increasing with time. 4. The changes of the maximal bite force following initial therapy in mandible were significantly increased at 3 and 4 weeks on anterior areas (p<0. 05, p<0. 01). These were decreased at 1 week on premolar but molar areas, and generally increasing with time. 5. As tooth mobility increased, maximal bite force decreased with significance (p<0. 01), and they had high negative correlation on anterior areas but low negative correlation on premolar and molar areas.

• 대기
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• 제32권4호
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• pp.367-379
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• 2022

In this paper, the evaluation of the performance of Korea Meteorological Administratio (KMA) Global Seasonal forecasting system version 6 (GloSea6) is presented by assessing the effects of larger ensemble size and carrying out the test using different initial conditions for hindcast in sub-seasonal to seasonal scales. The number of ensemble members increases from 3 to 7. The Ratio of Predictable Components (RPC) approaches the appropriate signal magnitude with increase of ensemble size. The improvement of annual variability is shown for all basic variables mainly in mid-high latitude. Over the East Asia region, there are enhancements especially in 500 hPa geopotential height and 850 hPa wind fields. It reveals possibility to improve the performance of East Asian monsoon. Also, the reliability tends to become better as the ensemble size increases in summer than winter. To assess the effects of using different initial conditions, the area-mean values of normalized bias and correlation coefficients are compared for each basic variable for hindcast according to the four initial dates. The results have better performance when the initial date closest to the forecasting time is used in summer. On the seasonal scale, it is better to use four initial dates, where the maximum size of the ensemble increases to 672, mainly in winter. As the use of larger ensemble size, therefore, it is most efficient to use two initial dates for 60-days prediction and four initial dates for 6-months prediction, similar to the current Time-Lagged ensemble method.

• 한국가족관계학회지
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• 제23권1호
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• pp.3-24
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• 2018

Objective: This study examined the change of informal labeling self-respect, depression/anxiety, and aggression of adolescents over time and relationship between the intercept and the growth of the variables. Method: 4-year longitudinal panel data(n=2,699), Korea Youth Panel Survey (KYPS), were analyzed to verify the influence of informal labeling on self-respect, depression/anxiety, and aggression of adolescents. Through latent growth modeling, temporal change of the variables was examined. Results: Analytic results are as follow. First, the initial status of informal labeling had a negative impact on the initial status of self-respect. The slope of informal labeling also had a negative impact on the slope of self-respect. In contrast, the initial status of informal labeling did not have an significant impact on the slope of self-respect. Second, the initial status of informal labeling had a positive impact on the initial status of aggression. The slope of informal labeling had a negative impact on the slope of aggression. In contrast, the initial status of informal labeling did not have an significant impact on the slope of aggression. Third, the initial status of informal labeling had a positive impact on the initial status of depression/anxiety and a negative impact on the slope of depression/anxiety. The slope of informal labeling had a positive impact on the slope of self-respect. Conclusions: The results suggest the importance of informal labeling on self-respect, depression/anxiety, and aggression of adolescents.

• Journal of Audiology & Otology
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• 제25권4호
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• pp.209-216
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• 2021

Background and Objectives: We aimed to analyze treatment outcomes following different initial management approaches and confirm treatment regimens for acute low-tone sensorineural hearing loss (ALHL) that would yield the best results. Subjects and Methods: We retrospectively analyzed the medical records of 106 patients with ALHL who visited a university hospital's otology clinic from March 2013 to June 2019. Pure-tone averages at the initial visit and at 2 and 4 weeks after the initial visit were evaluated. Results: Forty-nine patients were enrolled in this study; of them, 41 (83.7%) exhibited complete recovery (CR) at 2 weeks and 43 (87.8%) exhibited CR at 1 month after the initial visit. Regression analysis revealed that CR at 2 weeks after the initial visit was associated with diuretic use [Exp(B): 10.309, 95% confidence interval (CI): 1.007-100]. An initial daily low-dose steroid use was marginally significant [Exp(B): 1.042, 95% CI: 0.997-1.092; p=0.066]. Isolated diuretic use [Exp(B): 25.641, 95% CI: 1.121-90.909; p=0.039] was an independent, good prognostic factor at 1 month after the initial visit. However, other treatment regimens did not affect the final results. Conclusions: A combination of initial daily administration of ≤30 mg prednisolone plus diuretics was sufficient as the first-line treatment for ALHL. High-dose steroids and salvage intratympanic steroid injections can be applied as a second choice; however, the predicted outcome would not be good in that case.

• 대한청각학회지
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• 제25권4호
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• pp.209-216
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• 2021

Background and Objectives: We aimed to analyze treatment outcomes following different initial management approaches and confirm treatment regimens for acute low-tone sensorineural hearing loss (ALHL) that would yield the best results. Subjects and Methods: We retrospectively analyzed the medical records of 106 patients with ALHL who visited a university hospital's otology clinic from March 2013 to June 2019. Pure-tone averages at the initial visit and at 2 and 4 weeks after the initial visit were evaluated. Results: Forty-nine patients were enrolled in this study; of them, 41 (83.7%) exhibited complete recovery (CR) at 2 weeks and 43 (87.8%) exhibited CR at 1 month after the initial visit. Regression analysis revealed that CR at 2 weeks after the initial visit was associated with diuretic use [Exp(B): 10.309, 95% confidence interval (CI): 1.007-100]. An initial daily low-dose steroid use was marginally significant [Exp(B): 1.042, 95% CI: 0.997-1.092; p=0.066]. Isolated diuretic use [Exp(B): 25.641, 95% CI: 1.121-90.909; p=0.039] was an independent, good prognostic factor at 1 month after the initial visit. However, other treatment regimens did not affect the final results. Conclusions: A combination of initial daily administration of ≤30 mg prednisolone plus diuretics was sufficient as the first-line treatment for ALHL. High-dose steroids and salvage intratympanic steroid injections can be applied as a second choice; however, the predicted outcome would not be good in that case.