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        검색결과 11

        1.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study is to compare noise reduction quantities between before/after two-layer low noise pavement implementation using equivalent noise level analysis and to analyze the noise reduction effects of the two layer low noise pavement with a statistical method such as the Anderson-Darling Test.METHODS: In order to compare and to analyze noise reduction effects between before/after two-layer low noise pavement implementation, data acquisition as noise levels on a roadside and an apartment rooftop was conducted in the study area. The equivalent noise level was estimated in order to compare noise reduction quantities and the Anderson-Darling Test was carried out for estimating noise reduction effects of the two-layer low noise pavement.RESULTS: The equivalent noise levels of before/after two-layer low noise pavement implementation for the roadside during the daytime are 65.355 dB and 63.520 dB and during the nighttime are 62.463 dB and 59.088 dB. The equivalent noise levels for the apartment rooftop during daytime are 57.301 dB and 59.088 dB and during the nighttime are 54.616 dB and 52.464 dB. Also two-layer low noise pavement decreased the noise reduction effects estimated with the statistical method as the Anderson-Darling test for the roadside during the daytime by around 66.68% and decreased noise reduction effects on the roadside during the nighttime by 0.70%. Moreover it reduced noise reduction effects in the apartment rooftop during the daytime and nighttime by 0% and 96.32%, respectively.CONCLUSIONS : Based on the result of this study, two-layer low noise pavement can positively affect noise reduction during both the daytime and nighttime according to the results of estimating the equivalent noise levels and the Anderson-Darling test.
        4,200원
        2.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted in autumn to determine phosphorus (P) fraction in sediments of Daechung Lake, to elucidate controlling factors for sedimentary P, and to compare with the other areas. For this study, sediment samples were collected at 6 sites only once on November 2014 using ponar grab and analyzed for solid-phase P (Loosely adsorbed, Fe-bound, Al-bound, detrital apatite, and refractory organic P) by sequential extraction. Total phosphorus (TP) was relatively high in front of Daechung Dam and Hoinam where fish farm was run until 1997. The dominant sedimentary P form was Al-bound P, followed by Fe-bound P, which could be released from sediment to water column during suboxic state. Based on principal component analysis, Al-bound P, Fe-bound, and TP were controlled by grain size of sediments. Loosely adsorbed, detrital apatite, and refractory organic P were relatively highly accumulated at the mouth of major tributaries where suspended sediments were delivered. Sedimentary P concentrations in Daechung Lake sediments were not higher than in other lake sediments. Therefore, based on these results, major controlling factors were grain size and input of suspended sediments from tributaries.
        4,000원
        3.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The tributaries of Daechung Lake play an important role in controlling eutrophication in the lake, which is used for agricultural purposes and as potable water. However, water quality properties were not extensively studied in the tributaries of Daechung Lake. The objectives of this study are to investigate spatial and temporal properties of water quality and to characterize streams which could threaten water quality of Daechung Lake. For this study, water samples were weekly or monthly collected from February 2014 to October 2014 in 9 streams. Water quality parameters analyzed in this study include biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen and phosphorus (TN and TP), suspended solids (SS), and chlorophyll a. Based on temporal distribution and principal component analysis, BOD, COD, TOC, SS, and TP were controlled by not only river discharge that increased during summer due to heavy rain fall, but also due to anthropogenic input (e.g., bridge construction and/or agricultural activity). Dilution is also one of the factors explaining TN and conductivity, both of which decreased with increased discharge. Generally, concentrations of contaminants (BOD, COD, TOC, TN and TP) in the tributaries were higher than those of Daechung Lake. However, pollution load indicated that only the main channel of Geum River and Sook Stream may largely influence lake waters, attributed mostly to their large volumes. This implies that the main channel and Sook Stream are the major influences on the water quality of Daechung Lake.
        4,600원
        4.
        2009.08 구독 인증기관·개인회원 무료
        In the present study, we have developed a high-frequency plant regeneration system for Italian ryegrass via callus culture using mature seeds as explants. Optimal embryogenic callus induction was found to occur in MS medium containing 5 ㎎ 1?¹ 2,4-D, 0.5 ㎎ 1?¹ BA, 500 ㎎ 1?¹ L-proline, 1 g 1?¹ casein hydrolysate, 30 g 1?¹ sucrose, 7 ㎎ 1?¹ AgNO₃, 2 ㎎ 1?¹ CuSO₄ and solidified with 3 g 1?¹ Gelrite. The highest regeneration rate was obtained in MS medium containing 1 ㎎ 1?¹ 2,4-D, 5 ㎎ 1?¹ BA, 500 ㎎ 1?¹ L-proline, 1 g 1?¹ casein hydrolysate, 1 ㎎ 1?¹ thiamine-HCl, 30 g 1?¹ sucrose, 7 ㎎ 1?¹ AgNO₃, 2 ㎎ 1?¹ CuSO₄ and solidified with 3 g 1?¹ Gelrite. By using the most effective treatment determined for each parameter, the highest rates of embryogenic callus formation (48.9%) and regeneration (47.6%) were obtained with the Hwasan 101 cultivar. The overall plant regeneration rates of the examined cultivars ranged from 7.5% to 23.2%. Thus, optimization of regeneration frequency using mature seeds as explant material may offer a simple and efficient protocol for Italian ryegrass that may improve molecular breeding of this species.
        5.
        2009.05 구독 인증기관·개인회원 무료
        The current status of insect pollinator use was surveyed. Honeybee was larger than mason bee and bumblebee in average use area per farm household at kinds of insect pollinator. Insect pollinator was used at 19 crops. Among them, tomato was the most used crop, which was 44.9%, and in order to apple 26.7%, strawberry 13.1%, red-pepper 7.7% and watermelon 3.7%. In the use of insect pollinators, bumblebee, which was 56.9%, was higher than honeybee (31.3%) and mason bee (11.8%). The most farmers were a positive intention except for 1.5% of farmer in the use of insect pollinator for crop pollination. The best advantage in insect pollinator use was improvement of seed setting percentage, which was 28.3% and the worst problem was low activity at bad weather, which was 25.8%. And also, 97% of farmers have an intention to use continuously insect pollinator.
        7.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One of the problems facing international companies is the question of whether to use standardized international advertising or to adapt advertising messages in each country. This paper provides empirical evidence for whether or not to be able to use standardized advertising based on a comparison of evaluative criteria for automobiles and toothpaste among American, Japanese, and Korean consumers. There appears to be a similar pattern among respondents of the three countries in rank of attribute importance. Especially, the result of toothpaste shows an almost identical pattern. The findings do support the idea that international advertising can be standardized due to the similarities among world-wide consumers.
        4,200원
        8.
        1990.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Korean economic growth in exports has been phenomenal in the past two decades. This paper deals with a series of export studies of small- and medium-sized manufacturing firms in Korea which look at export behavior and the conditions which influence export sales in these firms. Profiles of the firms are provided, in addition to discussions of the key influences on initiating exports, channels selection, profitability, and attitudes toward exporting.
        4,900원