• Journal of Ginseng Research
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• 제17권3호
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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.

• 한국정보전자통신기술학회논문지
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• 제12권4호
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• pp.419-424
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• 2019

본 논문에서는 광대역 재밍 신호 환경에서 원하는 목표물을 추정하기 위한 알고리즘을 제안 한다. 재밍 신호를 억제하는 방법으로, 본 연구에서는 시공간적응 알고리즘과 QR분해를 사용하여 최적의 가중치를 획득한다. 시공간적응 알고리즘은 적응배열안테나시스템에서 탭 지연 신호에 복소 가중치를 곱하여 가중치를 생성하고, 역행렬로 인한 전력소모를 최소화하기 위해서 QR분해를 이용하여 최적의 가중치를 획득한다. 모의실험을 통하여, 본 연구에서 제안한 알고리즘과 기존 알고리즘의 성능을 비교 분석한다. [-40o,0o,+40o]의 목표물 추정에서 본 연구에서 제안 한 알고리즘이 3개의 목표물을 모두 추정하였지만 기존 알고리즘은 재밍 신호 때문에 [0o]에서만 추정하였다. 본 연구의 제안 알고리즘이 재밍 신호를 제거하고 원하는 목표물을 정확히 추정하여 성능이 향상되었음을 입증하였다.

• Environmental Analysis Health and Toxicology
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• 제11권1_2호
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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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• 제22권3호
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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.

• 원예과학기술지
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• 제29권2호
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• pp.110-115
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• 2011

미세다공성의 옹기 화병의 절화수명 연장효과를 알아보기 위하여 거베라 절화를 식물재료로 하여 관행의 자기 및 유리 화병과 절화수명을 비교하였다. 수돗물과 절화보존제가 들어있는 유리, 자기, 옹기 화병에 거베라 'Honeymoon'과 'Golden Time'을 꽂고 절화수명과 미생물 수를 조사하였다. 그 결과, 두 품종 모두 옹기 화병에서 절화수명이 길었으며, 절화보존용제가 수돗물에 비해 절화수명을 연장시켰다. 특히 절화보존제를 넣은 옹기 화병에서 두 품종 모두 절화수명이 14일 이상으로 가장 길었다. 누적 흡수량은 절화보존용제를 넣은 옹기 화병에서 'Honeymoon'이 19.2mL, 'Golden Time'이 15.8mL로 가장 많았다. 생체중은 대체로 옹기에 꽂은 절화가 다른 재질의 화병에 꽂은 것에 비해 컸으며, 절화보존제 처리가 생체중 감소를 지연시켰다. 특히 옹기에 절화보존제를 처리한 경우 처리 8일 후에도 초기 생체중의 89% 수준을 유지하여 수분 흡수가 원활했음을 알 수 있었다. 미생물수 측정 결과, 'Golden Time'은 옹기 화병 내의 보존용액의 총균수가 다른 재질의 화병에 비해 적게 나타났다. 'Golden Time'의 총균수는 8일째 옹기 화병 내의 보존용액에서 435cfu/mL 정도로 자기나 유리 화병 내의 보존용액보다 20-30% 수준으로 낮게 나타났다. 이상의 결과로 옹기 화병은 보존용액 내 미생물의 증식을 지연시켜 절화 거베라의 물올림을 유지시켜 주기 때문에 도관 폐쇄에 의한 화경굽음 현상이 억제되었고, 절화수명도 길어졌다고 볼 수 있다. 따라서 미세다공성의 옹기는 화병의 좋은 재질이며, 절화보존제는 그 기능을 향상시킬 수 있을 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.565-568
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• 2008

본 논문에서는 2007년 11월 거제 연안에서 실해역 실험을 통하여 취득한 데이터를 이용하여 수중음향통신을 위한 적응 결정궤환 등화기의 비트 오율 성능 분석 결과에 대해서 논한다. 전방먹임 필터 탭수, 되먹임 필터 탭 수, 훈련신호열 길이, 시간 지연 등의 변수를 변화시키면서 비트 오율을 분석한 결과, 전달 거리 9.7km, 4km에서 각각 $4{\times}10^{-2}\;and\;1.5{\times}10^{-2}$ 비트 오율을 얻었다.

• 한국가축번식학회지
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• 제18권3호
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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.

• 한국통신학회논문지
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• 제38A권5호
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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.

• 한국건설순환자원학회논문집
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• 제5권4호
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• pp.122-128
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• 2010

정수 슬러지는 해양투기가 금지됨에 따라 매립되거나, 성토재, 복토재 등과 부가가치가 거의 없는 용도로 활용되고 있다. 정수슬러지는 하수슬러지와는 달리 유기물의 함유량이 높지 않은 무기성 슬러지이며, 적절히 가공할 경우 유용한 자원으로 사용할 수 있음에도 불구하고 적절히 활용되지 못하고 있다. 본 연구팀은 정수슬러지를 인산으로 수열반응하여 인공제올라이트를 합성하였다. 합성된 제올라이트는 다공성으로 탈취능이 매우 우수한 분말이지만, 건축자재로 사용하기 위해서는 일정한 형상으로 고화할 필요성이 있다. 본 연구에서는 합성한 인공제올라이트의 특성과 이를 다양한 고화제로 고화하여 그 특성을 분석한 것이다. 실험결과 소석회가 가장 적절한 고화특성을 보이고 있었으며, 최적 사용조건은 전체 분말 중량의 30-60%인 것으로 나타났다. 고화체의 탈취 성능은 원료인 인공제올라이트에는 못미치지만 매우 우수한 것으로 나타나 건축물용 탈취 재료로서의 사용가능성을 확인할 수 있었다.

• Environmental Analysis Health and Toxicology
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• 제2권1_2호
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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.