• 한국지반환경공학회 논문집
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• 제2권1호
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• pp.31-35
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• 2001

여과지속시간에 영향을 미지는 여과지의 유효경과 규조류 크기 사이의 관계를 기 보고된 데이터와 몇몇 정수장의 실 운영 데이터를 이용하여 평가하였다. 단일여재를 사용하는 정수장의 경우에 여과지속시간이 15시간 이하일 확률이 10~60%, 이중여재를 사용하는 정수장의 경우, 여과지속시간이 30시간 이하일 확률이 10~20%로 나타났다. 여과 폐색 발생 기간중 Synedra의 점유율은 64~92%인 것으로 나타났다. 이중여재의 유효경은 0.71~1.40mm이고 균등계수는 125~167이었다. 단일여재의 유효경은 0.52~0.65mm이고 균등계수는 0.25~1.40이었다. 계산된 이중여재의 침투깊이는 2.58~15.4cm이었으며, 단일여재의 경우에는 1.29~2.17cm이었다. 그리고 평균 여과지속시간은 이중여재가 40.1~83.3 시간, 단일여재가 13.9~34.9 시간으로 나타났다. 단일여재에서 Synedra의 수가 400cells/ml을 초과하면 여과지속시간은 5시간 이하로 나타났으며, 이중여재의 경우에는 70시간 이상으로 나타났다.

• 한국결정성장학회지
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• 제15권6호
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• pp.239-243
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• 2005

The effect of pH and particle size on the dispersion stability of ultra-fine $BaTiO_3$ suspensions in aqueous medium have been investigated by means of zeta potential, sediment experiments, and powder properties (particle analysis, specific surface area) etc. Zeta potential as a function of pH for two particles of different size increases from -75 to +10 mV with decreasing pH from 8.5 to 1.4. The curve of zeta potential for small particle (150 nm) has slow slope than that of large particle (900nm), giving IEP (isoelectric point) value of pH=1.6 for small particle and pH=1.9 for large particle respectively, which means that it is more difficult to control zeta potential with pH fur small particle than large particle. The dispersion stability of $BaTiO_3$ particles in aqueous medium was found to be strongly related with the agglomeration of colloidal suspensions with time through the sedimentation behaviors of colloidal particles with time and pH value.

• Journal of Pharmaceutical Investigation
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• 제39권3호
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• pp.201-205
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• 2009

Triglyceride solid lipid with medium chain fatty acid, tricaprin (TC), was used as a core matrix of lipid nanoparticles (LN) to solubilize water-insoluble paclitaxel and enhance the stability of nanoparticles by immobilization of incorporated drug in the solid core during storage at low temperature. In the present study, TC-LN containing paclitaxel was prepared by hot melt homogenization method using TC as a core lipid and phospholipids as stabilizers. The particle size of TC-LN containing paclitaxel was less than 200 nm and its zeta potential was around -40 mV. Calorimetric analysis showed TC core could be solidified by freezing and thawing in the manufacturing process in which the hot dispersion should be prepared at elevated temperature and subsequently cooled to obtain solid lipid nanoparticles. The melting transition of TC core was observed at $27.5^{\circ}C$, which was lower than melting point of TC bulk. The particle size of TC-LN remained unchanged when kept at $4^{\circ}C$. Paclitaxel containing TC-LN showed comparable anticancer activity to the Cremophore ELbased paclitaxel formulation against human ovarian (OVCAR-3) and breast (MCF-7) cancer cell lines. Thus, lipid nanoparticles with medium chain solid lipid may have a potential as alternative delivery system for parenteral administration of paclitaxel.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.73-78
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• 2004

For the preliminary stages of ship design it is necessary to develop a basic design, which specifies the main particulars of the vessel. based on the requirements given by the owner. An efficient design enables the shipyard to make a rough estimate of the construction costs and to put forward a favourable quote during the call for tenders. The parametric determination of the main particulars of the vessel involves the application of empirical formulae. These formulae have been created after detailed tests and research by maritime research institutions and researchers had been carried out. Here, the design of a medium sized Bulk Carrier (26000t dwt) with a service speed of 17 knots for carrying rice and rock phosphate has been illustrated. Medium sized Bulk Carriers (25,000t dwt - 50,000t dwt) are in steady demand among small shipping companies. They have a size advantage, in that port size restrictions do not affect their design tremendously. Nevertheless, structurally. they are one of the most difficult to build. During design, the rules of the maritime regulatory bodies were strictly adhered to.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.532-537
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• 2008

In order to investigate the factors affecting the culture of mouse preantral follicles in vitro, we examined the effect of culture media, protein supplements, and culture period on their growth. The oocyte diameter (initial size: $55.6{\pm}2.5{\mu}m$) was progressively increased during culture, and the maximum size ($72.0{\pm}2.4{\mu}m$) was reached on day 10 of the in vitro culture. The chromatin configuration in the germinal vesicle (GV) oocyte progressively shifted from a non-surrounded nucleolus (NSN) to a surrounded nucleolus (SN). On day 10 of the culture, most of the oocytes progressed to the SN pattern. The survival and metaphase II rates of the oocytes in alpha-minimal essential medium (alpha-MEM) were significantly higher (p<0.05) than those in Waymouth and tissue culture medium (TCM)-199. As a protein source, fetal bovine serum (FBS) was more suitable for the culture of mouse preantral follicles as compared to human follicular fluid (hFF) and bovine serum albumin (BSA); the optimal concentration of FBS was 5%. These results suggest that in a culture of mouse preantral follicles, alpha-MEM and 5% FBS are an optimal medium and a protein source, respectively; further, the 10 days of culture is required for the complete growth of oocytes in this culture system.

• 한국의류산업학회지
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• 제17권5호
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• pp.815-827
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• 2015

This study analyzes the characteristics by age and type for middle aged and elderly women foot shapes aged 40-69 years. ANOVA, factor, and cluster analyzed middle aged and elderly women's foot shapes. The results of the study are as follows. First, higher age groups tended to have smaller foot lengths, ball/instep circumferences, circumferences, and ball heights with larger heel height values and higher degrees of gathering of toe 1 and toe 5 toward the feet reference axis. Second, foot lengths were 220 mm-240 mm and the ball circumference's size symbol in high frequency sections were distributed from E to EEEE in the 40s and 60s groups and from D to EEEE in the 50s group. Third, eight factors were extracted through the factor analyses of middle aged and elderly women's foot measurement items. Fourth, a cluster analyses classified the subjects into four types. Type 1 is a normal foot type with medium foot length and small ball circumference and type 2 is a long and flat foot type with a type with large foot length and ball circumference values as well as small ball height values. Type 3 is a thick foot type with a medium foot length, large ball circumference, large ball height and type 4 is a toe deformation foot type with medium foot length, small ball circumference, and a high degree of toe gathering toward the center.

• 간호행정학회지
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• 제19권1호
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• pp.108-117
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• 2013

Purpose: To analyze trends in salaries for registered nurses when compared with salaries for elementary school teachers from 2002 to 2009 and identify salary gaps of nurses according to workplace size and geographic location. Methods: Data were obtained from the Occupational Employment Statistics collected by the Korea Employment Information Services each year from 2002 to 2009. The study sample consisted of 2,281 registered nurses and 2,578 elementary school teachers. Linear multiple regression analyses were conducted to analyze salary trends and differences. Results: Elementary school teachers had higher monthly salaries than nurses with a baccalaureate degree after adjusting for years of work. Salary differences increased significantly by 40,000 won every year (p<.001). Nurses working in large facilities in Seoul had the highest salaries, whereas those in small/medium, non-Seoul facilities had the lowest salaries consistently over time. Salary differences between the two groups increased by 47,000 won every year (p=.001); salary differences between nurses in large, non-Seoul facilities and those in small/medium, non-Seoul facilities also increased by 40,000 won annually (p=.001). Conclusion: Geographical imbalances in the nurse workforce and nurse shortages in small/medium, non-capital facilities could be reduced by increasing the salary of nurses working in those facilities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.896-909
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• 2010

IEEE 802.11 medium access control (MAC) employs the distributed coordination function (DCF) as the fundamental medium access function. DCF operates with binary exponential backoff (BEB) in order to avoid frame collisions. However it may waste wireless resources because collisions occur when multiple stations are contending for frame transmissions. In order to solve this problem, a binary negative-exponential backoff (BNEB) algorithm has been proposed that uses the maximum contention window size whenever a collision occurs. However, when the number of contending stations is small, the performance of BNEB is degraded due to the unnecessarily long backoff time. In this paper, we propose the adaptive BNEB (A-BNEB) algorithm to maximize the throughput regardless of the number of contending stations. A-BNEB estimates the number of contending stations and uses this value to adjust the maximum contention window size. Simulation results show that A-BNEB significantly improves the performance of IEEE 802.11 DCF and can maintain a high throughput irrespective of the number of contending stations.

• 한국지형학회지
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• 제26권1호
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• pp.27-40
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• 2019

This study tries to reveal source areas of fluvial terrace deposits in Danyang and Geum River basins located in the northern and southern parts of the Sobaek Mountains, respectively, through geochemistry. The samples analyzed in this study show different grain size properties and can be grouped into the coarse, medium and fine samples. Grain size properties suggest that the coarse samples are typically fluvial deposits and geochemistry from the coarse samples is also similar to that from the bedrocks within the basins. The fine samples show geochemical properties different from the bedrocks and similar to loess deposits in Korea. However, different geochemical concentrations among the fine samples can be also recognized, indicating mixtures of loess materials with weathering products of the bedrocks. One sample among the medium samples is considered as fluvial deposit due to geochemical similarity to the bedrocks, while geochemistry from another sample among the medium samples indicates that loess materials were mixed with more abundant weathering products of the bedrocks than those in the fine samples.

• Mycobiology
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• 제38권3호
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• pp.189-194
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• 2010

This study investigated the cultural characteristics of Shimizuomyces paradoxus in different nutritional and environmental conditions. The highest mycelial growth was observed in Schizophyllum (mushroom) genetics complete medium plus yeast extract agar medium, and the optimal temperature and pH were $25^{\circ}C$ and pH 8.0, respectively. The optimal carbon and nitrogen sources were 1% dextrose and 1% peptone in agar. However, in liquid culture the highest dry mycelium weight was found for the potato dextrose agar and potato sucrose agar broths. The optimum inoculum size was five mycelial discs (5 mm) per 100 mL of broth, and the optimum liquid culture period was 25 days. This is the first ever report of S. paradoxus cultural characteristics.