• Journal of Ginseng Research
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• v.17 no.3
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• pp.224-227
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• 1993

Weight (g/root) and bulk density (g/$cm^3$) of tap root in 15-root-grade of 4-year-old white ginseng were investigated by specific gravity and weight-volume method. Bulk density measured by specific gravity ranged from 0.8 to 1.2g/$cm^3$ with almost normal distribution in frequency (number 1 of roots). Bulk density measured by volume-weight method had significant correlation with root weight. The percentage of high bulk density root (above 1.0) showed significant positive correlation with mean root weight or mean bulk density of root weight, indicating that the growth conditions for large root provide the better compactnes of root tissue.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.419-424
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• 2019

In this paper, we proposed an algorithm to estimate the desired target in wideband jamming signal environment. In order to suppress the jamming signal, we use the spatial time adaptive algorithm and QR decomposition to obtain the optimal weight. The spatial time adaptive algorithm of adaptive array antenna system multiplies the tap delay signal by a complex weight to obtain a weight. In order to minimize the power consumption because of the inverse matrix, optimal weight is obtained by using QR decomposition. Through simulation, we compare and analyze the performance of the proposed algorithm and the existing algorithm. In the target estimation of [-40o,0o,+40o], the proposed algorithm estimated all three targets, but the existing algorithm estimated only [0o] due to of the jamming signal. We prove that the proposed algorithm improves performance by removing the jamming signal and estimating the target accurately.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.19-29
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• 1996

Human exposure to volatile compounds in tap water can occur from inhalation and dermal absorption as well as direct ingestion. The relative contribution to total human exposure from these pathways has been considered to be important especially for VOC's (volatile organic compounds). In an attempt to reduce the uncertainty of the risk assessment, it has been suggested that the exposure assessment process could be significantly improved by adopting Monte-Carlo simulation. However, there is no actual data in Korea for each exposure parameter to determine the level of exposure, and the distributional pattern. Therefore, we surveyed water use patterns and behavior related to multi-route exposure to VOC's in household tap water in Korea, and compared these values to the those in western countries. In the first survey, we calculated daily water intake using data from a sample of 1322 persons of several cities in Korea. In the second survey, we obtained questionnaire data on exposure time for showering, bathing and household activities, and tap water intake from 851households in Korea. In the last survey, we measured the exposure parameters (exposure time, water use rate etc.) related to showers, baths, toilets, dish washing, washing and cooking, and tap water intake was surveyed. Also, the subjects were measured their body weight, height and tidal volume, etc. A diary, a flow meter and a measuring cup were used to measure these values as precisely as possible. Average daily water intake was ranged 0.79-1.71 L/day for adults in three surveys. Tap water intake measured by log-sheet during one week in third survey was 1.26 (average), 1.98 L/day (90 percentlie), respectively. These results were comparable with results from EPA (1.4, 2L/day). The average amount of water used by housewives in the third survey was 515.0 $\pm$ 564.6L/day. In usual activity, the amount of water used in the bathroom, the laundry and the kitchen was 140.0 $\pm$ 538.9, 148.0 $\pm$ 174.5, 229.3 $\pm$ 205.4 L/day, respectively. Exposure parameters such as water intake rate, exposure duration, body weight, inhalation rates in surveyed data of Korean people differed from those published from western countries. This could be attributed to variations in lifestyle, dietary habits and physiological characteristics.

• Corrosion Science and Technology
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• v.22 no.3
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• pp.201-213
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• 2023

Corrosion management of an aircraft and its engine relies on rinsing and cleaning using tap water. Few studies have reported effects of tap water species on corrosion behaviors of structural materials. In this study, a series of experiments were conducted based on the design of experiment. Solutions with different levels of chloride and sulfate ions were prepared using a full factorial design. Two structural materials (aluminum alloy and steel) were used for an alternate immersion test. Weight loss was then measured. In addition, a silver specimen was utilized as a sensor for chloride deposition measurement. The silver specimen was examined using the electrochemical reduction method, XPS, and SEM-EDS. Surface analysis revealed that levels of chloride and sulfate ions were sufficient for the formation of silver chloride and silver surface. Statistical analysis of weight loss and chloride deposition rate showed significant differences in measured values. Concentration of chloride ions greatly affected corrosion behaviors of structural materials. Sulfate ion hindered the adsorption reaction. These results emphasize the importance of controlling ion concentration of tap water used for cleaning and rinsing an aircraft.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.110-115
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• 2011

To examine the availability of onggi (earthenware) as a floral vase, we compared the vase life of cut gerberas (Gerbera jamesonii) with generally used vases made of glass and porcelain. After holding cut gerbera 'Honeymoon' and 'Golden Time' in vases made of glass, porcelain, and onggi containing holding solution (tap water or preservative solution), vase life, fresh weight, and water uptake of cut flowers, and total number of microbes in holding solution were collected. In onggi vase, vase life of both the cultivars was longer than the other vases and floral preservative prolonged vase life compared with tap water. Cut gerberas applied with preservative solution in onggi vase maintained their ornamental value for more than 14 days. Cumulative water uptake by cut gerberas was greatest in onggi vase, where 'Honeymoon' and 'Golden Time' absorbed water by 19.2 and 15.8 mL, respectively, for 10 days. Fresh weight of cut flowers in onggi vase was greater than those of the others, and the preservative solution delayed the reduction of fresh weight compared with tap water. Especially, onggi vase with preservative solution maintained 89% of the initial fresh weight at the 8th day of the treatments due to smooth water uptake with comparison with 71% in porcelain. Total number of microbes in the holding solution was smallest in onggi vase. At the 8th day, microbes number in onggi vase was 435 cfu/mL, that was 20-30% level of those of glass and porcelain vases. In conclusion, onggi vase inhibited microbial proliferation in holding solution, maintained water uptake by cut flower, and delayed bending of flower stalks due to vascular blockage, and then prolonged vase life in gerbera. Therefore, onggi with numerous micropores will be a good material for flower vase and preservative solution can improve its function.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.565-568
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• 2008

In this paper, we present bit error rate(BER) performance of an adaptive decision feedback equalizer(DFE) with experimental data. The experiment was performed at the shore of Geoje in November 2007. The BER performance of the adaptive DFE whose tap weight is updated by RLS is described with change of feedforward tap number, feedback tap number, traning seqence length and delay, which shows that the uncoded average BER is $4{\times}10^{-2}\;and\;1.5{\times}10^{-2}$ with transmission range 9.7km and 4km, respectively.

• Korean Journal of Animal Reproduction
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• v.18 no.3
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• pp.183-189
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• 1994

We examined early development in loach(Misgurnus mizolepis) embryos with parthenogenetic agents well-known in mammals. Female loach was superovulated with an intraperitoneal injection of 15 IU human chorionic gonadotrophin (hCG) per gram body weight. After 13 h of hCG injection, the oocytes were obtained from the abdomen. The oocytes were activated with 10% ethanol in tap water or fish Ringer's solution for 5, 10 and 15 minutes(eTW5, 10, 15 and eFRS5, 10, 15), respectively. The activation rates were 29% and 10% in eFRS10 and eFRS15, 5% and 6% in eTW10 and eTW15 by judging the cleaved blastomeres. Whereas, no parthenogenetic embryo was produced by tap water or fish Ringer's solution alone. The activation rate with the fish Ringer's solution was higher than that of tap water. No embryonic development was observed by calcium ionophore, A23187, at concentrations of 10, 20, 40 and 100$\mu$M when treated for 1, 2.5 and 5 minutes, respectively. The activation agents did not cause early development as in mammalian eggs. Therefore, the results suggest that fresh water fish may have a different egg activation pathway from that of mammals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.5
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• pp.416-425
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• 2013

A hybrid PN code phase acquisition system based on a least-mean-square adaptive filter, interpreted as a channel estimator is proposed and analyzed for direct-sequence spread-spectrum systems under frequency selective Rayleigh fading channels. Closed form expressions are derived for the filter tap weights and detection/false alarm probabilities. Compared to previously proposed systems, the proposed system achieves smaller mean acquisition times, is more robust to the operating signal-to-noise ratio and allows for multiplication free tap weight updates.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.122-128
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• 2010

On the international provision on prohibition of ocean dumping of waste, tap water sludge has been buried or recycled on th low value added product as landfill. Due to the tap water sludge having high inorganic content, differing from the sewage sludge, it is possible to use as a usable resource by suitable process. We have studied on hydro thermal processing of tap water sludge with phosphoric acid and finally synthesize a artificial zeolite having a deodorization property. To use it as a building material, it has to be solidification. This study is on the properties of artificial zeolite synthsized and solidification properties by various types of solidifier. It is showed that the slaked lime is the best on setting property and its optimum content is 30-60 weight proportion. Solid by solidified by slaked lime has low strength and excellent deodorization performance, so it is possible to use as a functional pannel as gypsum board.

• Environmental Analysis Health and Toxicology
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• v.2 no.1_2
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• pp.33-42
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• 1987

Experiments were performed to investigate effects of ethanol and saccharin on the immune system in rats. 4% ethanol and 0.02, 0.20, 2.00% saccharin solution in 4% ethanol were provided ad libitum by tap water for 4 weeks. Rats were sensitized and challenged with sheep red blood cells (S-RBC). Immune responses were evaluated by relative immuno organ weight, antibody production, Arthus reaction, delayed type hypersensitivity, and rosette forming cell. Ethanol exposure decreased thymus weight and delayed type hypersensitivity. A combined solution of ethanol and saccharin decreased water intake, growth rate, spleen weight, thymus weight, humoral and cellular immune response. Especially, a 2% saccharin solution in 4% ethanol very significantly suppressed cellular immunity.