• 한국가시화정보학회지
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• 제20권1호
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• pp.18-28
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• 2022

In this study, a cavity shape measurement experiment was conducted by changing the diameter and the angle of attack of a disk cavitator. Since the gravity effect is proportional to the cavity volume, the larger the cavity, the greater the effect. It is concluded that the gravity effect becomes smaller as the cavitation number decreases because of a short cavity maintaining time. The cavity centerline rises in case of the positive angle of attack and descends in case of the negative angle of attack. Since the effect of the angle of attack is inversely proportional to the square of the cavity radius, the effect of the angle of attack becomes dominant in the vicinity of the cavitator. It is judged that the horizontal section of the cavity centerline cannot be extended because the factors affecting the gravity effect and the angle of attack effect are different.

• 한국안광학회지
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• 제17권4호
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• pp.395-401
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• 2012

목적: 발효자색고구마와 블루베리(blueberry)에서 추출한 안토시아닌의 시력보호 및 VDT 증후군 개선효과를 알아보고자 연구하였다. 방법: 실험은 안과질환 및 전신질환이 없고, 굴절이상이 -4.00 D 이상인 19~21세 남 여 20명을 대상으로 실시하였다. 40 mg의 발효자색고구마 및 블루베리 추출 안토시아닌과 대조군으로 위약을 각각 복용, 2시간 후에 근업(VDT)을 2시간 동안 실시하였다. 시력검사는 안토시아닌을 복용하기 전과 2시간 근업 후 각각 타각적 굴절검사 방법으로 측정하였다. 근업 2시간 후 VDT 증후군으로 두통, 안통 및 안정피로, 목, 어깨, 허리 등의 자각증상의 정도를 심함, 보통, 약간, 없음 등으로 구분하여 문진하였다. 결과: 2시간동안 VDT 작업 후 시력보호 효과는 우위안에 대한 굴절 값은 발효 자색고구마 추출 안토시아닌에서는 $0.031{\pm}0.21$ D, 블루베리 추출 안토시아닌에서는 $0.006{\pm}0.32$ D 만큼 근시도가 감소하였고, 위약에서는 $0.144{\pm}0.28$ D(t=2.27, p=0.03) 만큼 유의하게 근시도가 증가하였다. 결론: 발효자색고구마 추출 안토시아닌이 근업 후 굴절이상 값의 증가를 억제하고, 비우위안보다 우위 안에서 시력을 보호하는 것으로 생각된다.

• 한국보육지원학회지
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• 제12권2호
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• pp.127-142
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• 2016

The purpose of this study is to analyze the effect of marital conflicts perceived by fathers on preschoolers' behavior problems, and to investigate the mediating effect of paternal child rearing behavior. This study used survey data on 4 year-old infants which was conducted in 2012(5th year) by KICCE. Correlation analysis and structural equation were conducted using SPSS 23 and AMOS 23 for the data analysis, and the results of this study are as follows. First, marital conflicts perceived by fathers and preschoolers behavior problems showed a positive correlation, and they especially showed a greater positive correlation with offensive behavior, anxiety/depression, and other problems. On the other hand, it was identified that paternal child rearing behavior has a negative correlation with marital conflict and preschoolers' behavior problems when paternal child rearing behavior is compassionate and dominant. Secondly, it was identified that warm parenting behavior of fathers mediates the effect of marital conflicts on preschoolers' behavior problems. However, it was verified that the mediating effect of controlling parenting behavior is not significant. On the other hand, it was identified that the mediating effect of warm parenting behavior of fathers has a greater effect on internalized problems than external problems.

• Wind and Structures
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• 제16권1호
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• pp.93-115
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• 2013

This paper describes a study of the influence of a dynamically flexible building structure on pressures inside and net pressures on the roof of low-rise buildings with a dominant opening. It is shown that dynamic interaction between the flexible roof and the internal pressure results in a coupled system that is similar to a two-degree-of-freedom mechanical system consisting of two mass-spring-damper systems with excitation forces acting on both the masses. Two resonant modes are present, the natural frequencies of which can readily be obtained from the model. As observed with quasi-static building flexibility, the effect of increased dynamic flexibility is to reduce the first natural frequency as well as the corresponding peak value of the admittance, the latter being the result of increased damping effects. Consequently, it is found that the internal and net roof pressure fluctuations (RMS coefficients) are also reduced with dynamic flexibility. This model has been validated from experiments conducted using a cylindrical model with a leeward end flexible diaphragm, whereby good match between predicted and measured natural frequencies, and trends in peak admittances and RMS responses with flexibility, were obtained. Furthermore, since significant differences exist between internal and net roof pressure responses obtained from the dynamic flexibility model and those obtained from the quasi-static flexibility model, it is concluded that the quasi-static flexibility assumption may not be applicable to dynamically flexible buildings. Additionally, since sensitivity analyses reveal that the responses are sensitive to both the opening loss coefficient and the roof damping ratio, careful estimates should therefore be made to these parameters first, if predictions from such models are to have significance to real buildings.

• Journal of Pharmaceutical Investigation
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• 제40권1호
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• pp.23-31
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• 2010

In our previous work on levodopa delivery at pH 2.5 using iontophoresis, we found that cathodal delivery showed higher permeation than anodal delivery and electroosmosis plays more dominant role than electrorepulsion. In this work, we studied the transdermal transport of levodopa at very low pH (pH=1.0) where all levodopa molecules are cations, and evaluated some factors which affect the transdermal transport. The transport study at pH 2.5 was also conducted for comparison. The contribution of electrorepulsion and electroosmosis on flux was also evaluated. Using stable aqueous solution, the effect of electrode polarity, current density, current type and drug concentration on transport through skin were studied and the results were compared. We also investigated the iontophoretic flux from hydroxypropyl cellulose (HPC) hydrogel containing levodopa. In vitro flux study was performed at $33^{\circ}C$, using side-by-side diffusion cell. Full thickness hairless mouse skin were used. Current densities applied were 0.2, 0.4 or $0.6\;mA/cm^2$. Contrary to the pH 2.5 result, anodal delivery showed higher flux, indicating that electrorepulsion is the dominant force for the transport, overcoming the electroosmotic flow which is acting against the direction of electrorepulsion. Cumulative amount of levodopa transported was increased as the current density or drug concentration was increased. When amount of current dose was constant, continuous current was more beneficial than pulsed current in promoting levodopa permeation. Similar transport results were obtained when hydrogel was used as the donor phase. These results indicate that iontophoretic delivery of zwitterion such as levodopa is much complicated than that can be expected from small ionic molecules. The results also indicate that, only at very low pH like pH 1.0, electrorepulsion can be the dominant force over the electroosmosis in the levodopa transport.

• Ocean and Polar Research
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• 제30권3호
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• pp.289-301
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• 2008

Community structure of heterotrophic protists and their grazing impact on phytoplankton were studied in Northwest Pacific Ocean during October, 2007. The study area was divided into four regions based on physical properties (temperature and salinity) and chlorophyll-a distribution. They were Region I of North Equatorial Currents, Region II of Kuroshio waters, Region III of shelf mixed water, and Region IV of Tsushima warm current from East China Sea. The distribution of chlorophyll-a concentrations and community structure of heterotrophic protists were significantly affected by physical properties of the water column. The lowest concentration of chlorophyll-a was identified in Region I and II, where pico-sized chlorophyll-a was most dominant (>80% of total chlorophyll-a). Biomass of heterotrophic protists was also low in Region I and II. However, Region III was characterized by low salinity and temperature and high chlorophyll-a concentration, with relatively lower pico-sized chlorophyll-a dominance. The Highest biomass of heterotrophic protists appeared in Region III, along with the relatively less important nanoprotists. In Region I, II and IV, heterotrophic dinoflagellates were dominant among the protists, while ciliates were dominant in Region III. Community structure varied with physical(salinity and temperature) and biological (chlorophyll-a) properties. Biomass of heterotrophic protists correlated well with chlorophyll-a concentration in the study area ($r^2=0.66$, p<0.0001). The potential effect of grazing activity on phytoplankton is relatively high in Region I and II. Our result suggest that biomass and size structure of heterotrophic protists might be significantly influenced by phytoplankton size and concentration.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.311-314
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• 2006

The supersonic flow around tandem cavities was investigated by three- dimensional numerical simulations using the Reynolds-Averaged Navier-Stokes(RANS) equation with the $\kappa-\omega$ thrbulence model. The flow around a cavity is characterized as unsteady flow because of the formation and dissipation of vortices due to the interaction between the freestream shear layer and cavity internal flow, the generation of shock and expansion waves, and the acoustic effect transmitted from wake flow to upstream. The upwind TVD scheme based on the flux vector split using van Leer's limiter was used as the numerical method. Numerical calculations were performed by the parallel processing with time discretizations carried out by the 4th-order Runge-Kutta method. The aspect ratio of cavities are 3 for the first cavity and 1 for the second cavity. The ratio of cavity interval to depth is 1. The ratio of cavity width to depth is 1 in the case of three dimensional flow. The Mach number and the Reynolds number were 1.5 and $4.5{\times}10^5$, respectively. The characteristics of the dominant frequency between two-dimensional and three-dimensional flows were compared, and the characteristics of the second cavity flow due to the fire cavity flow cavity flow was analyzed. Both two dimensional and three dimensional flow oscillations were in the 'shear layer mode', which is based on the feedback mechanism of Rossiter's formula. However, three dimensional flow was much less turbulent than two dimensional flow, depending on whether it could inflow and outflow laterally. The dominant frequencies of the two dimensional flow and three dimensional flows coincided with Rossiter's 2nd mode frequency. The another dominant frequency of the three dimensional flow corresponded to Rossiter's 1st mode frequency.

• 한국해안해양공학회지
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• 제7권3호
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• pp.248-256
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• 1995

표층밀도분류에 대한 수치계산에서 문제로 되는 것은 자유수면의 처리, 레이놀즈응력/플럭스항, 특히 난류변동성분에 미치는 부력효과 등에 관련된 것이며, 이것에 대한 보다 집중적인 연구가 필요하다. 또한, 농도장이나 온도장에서의 난류변동성분을 측정하는 데 있어서의 어려움으로 인한 실험자료의 부족으로 수치 계산으로부터 얻어진 예측결과의 충분한 검증은 이루어지지 않고 있다. 본 연구에서는 2차원 표층밀도분류에 대한 유동특성을 조사하기 위하여 난류의 비등방성을 고려하여 난류응력을 직접 계산하는 대수응력모델을 적용하여 수치계산을 행하고, 그 결과를 실험결과와 비교ㆍ검토하였다. 검토한 결과 대수응력모델은 전 영역모델은 전 영역에서 2차원 표층밀도분류의 유동특성을 양호하게 재현하였으며, 특히 부력효과로 인한 성층화가 발생하는 부력 탁월영역에서 난류유동장의 흐름특성을 합리적으로 예측함을 입증하였다.

• 패션비즈니스
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• 제15권3호
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• pp.51-66
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• 2011

The purpose of this study is to investigate the effect of the traditional color sentiment on the contemporary clothing color by studying the pictures of street fashion of Dalian in China, in view of the clothing color of women in their 20-30 years of age having highest purchasing power, along with traditional Chinese color. The clothing color is various in frequency depending on the items in street fashion. Due to the seasonal impact of summer, the most frequent item was one-piece dress with the Multi of various color patterns, followed by White, Black, PB, R and B category. In the top color, the White was most prevalent color due to the seasonal factor, followed by Black, Grey, Multi, R, Y, RP category. Achromatic color is more dominant with the ratio of 7:3, comparing with its counterpart, which consists of R and Y category of V, B, P, VP tone. In the bottom color, Dp tone of PB shows most high frequency, followed by Black. This results illustrate that Chinese women prefer blue jeans and to be looked as slimmer by using of the dark colors. In the accessories, colors of bags and shoes show different results. The bag colors show the high frequency of Dk tone, YR category, and the chromatic colors are little bit dominant than achromatic ones with the ratio of 5.3:4.7. On the contrary, the shoes colors show the highest frequency in Black, the achromatic colors are more dominant than chromatic ones with the ratio of 6.6:3.4. These results somewhat diverge from the international color trend. Color trend in Dalian street fashion in which the high frequency of V tone is observed through all the colors of the items followed by P, VP, Lgr tone in sequence. In the light of Chinese traditional color preference, this result denotes that the traditional color preferences of red, yellow are still affecting the contemporary color choices of clothing in Chinese women. The high incidence of PB category in the bottom and one-piece dress does not seem to have its origin form traditional Chinese color sentiment.

• Genes and Genomics
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• 제40권12호
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• pp.1331-1338
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• 2018

Although there have been plenty of dominance deviation analysis, few studies have dealt with multiple phenotypes. Because researchers focused on multiple phenotypes (final weight and backfat thickness) of Landrace pigs, the classification of the genes was possible. With genome-wide association studies (GWASs), we analyzed the additive and dominance effects of the single nucleotide polymorphisms (SNPs). The classification of the pig genes into four categories (overdominance in final weight, overdominance in backfat thickness and overdominance in final weight, underdominance in backfat thickness, etc.) can enable us not only to analyze each phenotype's dominant effects, but also to illustrate the gene ontology (GO) analysis with different aspects. We aimed to determine the additive and dominant effect in backfat thickness and final weight and performed GO analysis. Using additive model and dominance deviation analysis in GWASs, Landrace pigs' overdominant and underdominant SNP effects in final weight and backfat thickness were surveyed. Then through GO analysis, we investigated the genes that were classified in the GWASs. The major GO terms of the underdominant effects in final weight and overdominant effects in backfat thickness were ion transport with the SLC8A3, KCNJ16, P2RX7 and TRPC3 genes. Interestingly, the major GO terms in the underdominant effects in the final weight and the underdominant effects in the backfat thickness were the regulation of ion transport with the STAC, GCK, TRPC6, UBASH3B, CAMK2D, CACNG4 and SCN4B genes. These results demonstrate that ion transport and ion transport regulation genes have distinct dominant effects. Through GWASs using the mode of linear additive model and dominance deviation, overdominant effects and underdominant effects in backfat thickness was contrary to each other in GO terms (ion transport and ion transport regulation, respectively). Additionally, because ion transport and ion transport regulation genes are associative with adipose tissue accumulation, we could infer that these two groups of genes had to do with unique fat accumulation mechanisms in Landrace pigs.