• 한국해양학회지:바다
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• 제12권1호
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• pp.1-8
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• 2007

유기물 증가에 미치는 환경인자를 중심으로 그 수평분포 특성, 원인, 주요오염원의 영향권에 대하여 검토하기 위해 표층 해수와 표층 퇴적물을 조사하였으며, 그 결과를 요약하면 다음과 같다. 유기물변동에 영향을 미치는 환경인자에 대한 주요 오염원은 크게 섬진강과 동천 등의 담수, 광양시 생활하수, 여수산업단지로 크게 나누어볼 수 있었다. 해수와 퇴적물의 환경인자에 대한 수평분포 특성과 해수의 흐름 등을 고려하여 이들 주요 오염원의 영향권을 구분한 결과, (I) 섬진강 담수의 영향을 많이 받는 해역, (II) 광양시와 동천의 영향이 큰 해역, (III) 여수 산업단지의 영향을 많이 받는 해역으로 나누어졌다. 그리고, 오염원의 영향권 별 수질환경인자의 특성으로는 섬진강 담수의 영향을 많이 받는 해역은 낮은 염분, 높은 농도의 $NO_3-N$과 $SiO_2-Si$, 담수와 생환하수의 영향이 큰 해역은 낮은 염분, 높은 농도의 $NO_3-N,\;NH_4-N,\;SiO_2-Si$, 여수 산업단지의 영향을 많이 받는 해역은 표층해수의 경우 높은 수온, 높은 농도의 $NH_4-N$과 $PO_4-P$, 퇴적물의 경우 높은 농도의 $NH_4-N,\;PO_4-P,\;SiO_2-Si$로 특징 지울 수 있을 것으로 보인다.

• 대한가정학회지
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• 제41권4호
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• pp.57-69
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• 2003

This study focused on individual differences in social support among older adults. The purposes of this study were to investigate sex and age group differences in social support and to examine the effects of intergenerational social support on life satisfaction among the rural elderly. Data were from 545 elderly over 60 years of age living separately from adult children in the rural area. With regard to sex differences in support exchanges, no significant differences were found in support-giving and support-receiving. Men reported giving more financial support to children than women, while women reported receiving more financial support from children than men. With regard to age group differences in support exchanges, there was less support-giving in older age group. Older parents in their 60s reported giving more financial, instrumental, and emotional support and receiving less financial support than the group of age 70＋ Regression analyses showed that life satisfaction of both men and women was affected by support size and the frequency of contact with children. Giving financial and instrumental support was significantly associated with life satisfaction of men, but giving and receiving each type of social support had no effects on life satisfaction of women. Life satisfaction of parents in their 60s was found to be positively associated with support size, giving financial support and receiving emotional support, and negatively associated with giving instrumental support. In the group of age 70＋, the frequency of contact with adult children and giving financial support had positive influences on life satisfaction.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.659-665
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• 2016

The effects of three different feeding systems on beef cattle production performance, rumen fermentation, and rumen digesta particle structure were investigated by using 18 Limousin (steers) with a similar body weight ($575{\pm}10kg$) in a 80-d experiment. The animals were equally and randomly divided into three treatment groups, namely, total mixed ration group (cattle fed TMR), SI1 group (cattle fed concentrate firstly then roughage), and SI2 group (cattle fed roughage firstly then concentrate). The results showed that the average daily gain was significantly higher in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). Consumption per kg weight gain of concentrate, silage, and combined net energy (NEmf) were significantly decreased when cattle received TMR, unlike when they received SI1 and SI2 (p<0.05), indicating that the feed efficiency of TMR was the highest. Blood urea nitrogen (BUN) was significantly decreased when cattle received TMR compared with that in cattle receiving SI1 (p<0.05), whereas there was no difference compared with that in cattle receiving SI2. Ammonia nitrogen concentration was significantly lower in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). The rumen area of cattle that received TMR was significantly larger than that of cattle receiving SI1 (p<0.05), but there was no difference compared with that of cattle receiving SI2. Although there was no significant difference among the three feeding systems in rumen digesta particle distribution, the TMR group trended to have fewer large- and medium-sized particles and more small-sized particles than those in the SI1 and SI2 groups. In conclusion, cattle with dietary TMR showed increased weight gain and ruminal development and decreased BUN. This indicated that TMR feeding was more conducive toward improving the production performance and rumen fermentation of beef cattle.

• 기술사
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• 제34권4호
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• pp.30-35
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• 2001

The 8-VSB modulation technology developed by ATSC was adapted for national terrestrial DTV broadcasting. It uses same bandwidth of 6㎒ as the one of NTSC TV broadcasting. The simulcast on the both of analog and digital is mandated for some period, some shortage within the limited frequency resource . ATSC transmission technology is excellent in long distance broadcasting, but it is even poorer than other transmission technology In mobile receiving. The design of transmission system in the ATSC broadcasting is food enough with the provision of wide area service without Interference from adjacent channel. To provide adequate DTV service within the broadcasting area, transmission technology is an important factor

• 한국통신학회:학술대회논문집
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• 한국통신학회 1984년도 추계학술발표회논문집
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• pp.7-10
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• 1984

In this paper, the advantages of buffer insertion access method in comparison with other access methods to local area networks are analyzed. Sending and Receiving protocols in a data link layer are designed by a software method, We have derived both qeueing delays and the response time for the performance model that is proposed in this paper, and using the computer simulation, analyzed the performance for the proposed model in terms of the throughput rate- response time characteristrics. Based on the proposed model, the hardware design is implemented.

• 대한전자공학회논문지
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• 제13권2호
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• pp.14-22
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• 1976

본연구는 서부휴전선이북에서 발생되고 있는 잡음파에도 불구 KBS텔레비젼방송의 양호한 시청을 보장하는 안테나를 얻기 위하여 시작되었으며 약 1년에 걸친 연구를 통하여 마침내 전후방비가 30dB정도일뿐 아니라 그 side lobe love 이 -3OdB 이하가 되는 안테나의 개발에 성공하였다. 이 안테나는 VHF TV의 고채널군 전체를 카바하기에 마땅하다고 생각되는 대수주기형으로 제작되었으며 이 안테나를 사용하는 경우 안테나의 후방에서 오는 잡음전파나 반사파에 의해서 수상이 방해되거나 고우스트 즉 2중화면이 나타나는 현상이 현저하게 개선된다는 것이 현지시경의 결과 확인되었다. 이 안테나는 또한 전 side lobe level이 매우 낮음으로써 그 이득이 높으며 TV 가시청지역 확대와 난시청범위의 축소에 그만큼 기여한 것으로 기대된다. This research was started to develop a VHF television antenna which secures good pictures in spite of the disturbance from tile rear side. In a year of research, an antenna which front to banck ratio is gyrator than 30dB and whose side lobe level is smaller than -30dB alas been developed. This new antenna was designed log-periodically for the sake of wide frequency bandwidth which is necessary to cover all tile high channel. And it was found having characteristics of anti-interference against the disturbance wave from tole behind, and anti-ghosts from the reflected waves. Furthermore, the gain of this new antenna is reasonablly high, because of its low side lobe level. After all, the developed antenna is silpposcd to increace the service area considervably and to improve the TV receiving certainly.

• 한국물환경학회지
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• 제22권2호
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• pp.314-320
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• 2006

Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

• 가족자원경영과 정책
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• 제10권4호
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• pp.163-177
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• 2006

The main purpose of this study was to examine TV viewers' behavior on receiving family-related images reflected in soap operas and find the relationship between TV viewers' family-related value and TV viewers' behavior on receiving family-related images reflected in soap operas with empirical data. The data were collected from 500 adults aged 20-49 living in Seoul area for 3 days(January 17 to 19 of 2006). Statistical methods used were frequency, percentage, regression analysis. The results showed that TV viewer's family-related values and socio-economic characteristics influenced the family-related image reception behavior. Especially viewers' values about child was the most significant variable affecting TV viewers' receptions of family-related images reflected in soap operas.

• 아시안잔디학회지
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• 제11권2호
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• pp.97-104
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• 1997

The objective of this study was to observe the differences in growth of creeping bentgrass turf to 'polymer coated urea fertilizer' and 'uncoated urea fertilizer', and to analyze durability of fertilizer effect with the 'polymer coated urea'. The experiment was initiated on June 3, 1996, at the Iowa State University Horticulture Research Station, north of Ames, Iowa. The experiment was conducted on an area of 'Penneagle' Creeping bentgrass(Agrostis palustris) maintained at fair-'way mowing height (1.3cm). The study was repeated at the same arrangement beginning on July 25, 1996. Visual quality data, clipping fresh and dry weight, and nitrogen(N) content in the clippings were taken weekly. Quality of the turf increased with increasing N rate. While quality ratings were higher for turf receiving polymer coated urea than for turf receiving uncoated urea at several times following treatment, but not significant. Fresh and dry clipping weights were quite variable during the trial. Visual quality rating and clipping yields improved with increasing rates of N but these differences were not statically significant between polymer coated and uncoated urea treatment. The durability of fertilizer efficiency in polymer coated urea was not last longer compare with uncoated urea from two weeks after treatment. Higher rates of N application increased the concentration of N in tissue but no significant differences between turf plots receiving polymer coated and uncoated urea. Key words: Polymer coated urea, Creeping bentgrass, Fertilizer, Turfgrass.

• ETRI Journal
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• 제32권1호
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• pp.11-21
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• 2010

A novel ultra-wideband (UWB) transceiver structure is presented to be used in wireless body area networks (WBANs). In the proposed structure, a data channel and a control channel are combined into a single transmission signal. In the signal, a modulation method mixing pulse position modulation and pulse amplitude modulation is proposed. A mathematical framework calculating the power spectrum density of the proposed pulse-based signal evaluates its coexistence with conventional radio systems. The transceiver structure is discussed, and the receiving performance is investigated in the additive white Gaussian noise channel. It is demonstrated that the proposed scheme is easier to match to the UWB emission mask than conventional UWB systems. The proposed scheme achieves the data rate requirement of WBAN; the logical control channel achieves better receiving performance than the logical data channel, which is useful for controlling and maintaining networks. The proposed scheme is also easy to implement.