검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 8

        2.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Economic indicators are a factor that affects air cargo volume. This study analyzes the different factors affecting air cargo volume by each Chinese cities according to the main characteristics. The purpose of this study is to help companies related to China, airlines, and other stakeholders predict and prepare for the fluctuations in air cargo volume and make optimal decisions. To this end, 20 economic data were used, and the entire data was reduced to 5 dimensions through factor analysis to build a dataset necessary and evaluated the influencing factors by multi regression. The result shows that Macro-Economic Indicators, Production/Service indicators are significant for every cities and Chinese manufacture/Customer indicators, Korean manufacture/Oil Price indicators, Trade/Current indicators are significant for each other city. All adjusted R2 values are high enough to explain our model and the result showed excellent performance in terms of analyzing the different factors which affects air cargo volume. If companies that are currently doing business with China can identify factors affecting China's cargo volume, they can be flexible in response to changes in plans such as plans to enter China, production plans and inventory management, and marketing strategies, which can be of great help in terms of corporate operations.
        4,000원
        3.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        난의 종류별로 심비디움, 심비디움 교배종, 덴팔레, 온시디움, 호접란, 그리고 나도풍란의 음이온 발생량을 조사하였으며, 심비디움 20, 40, 60, 80%와 심비디움 교배종 25, 50, 75, 100%의 투입율에 따른 음이온 발생량의 변화를 조사하였다. 그 결과 심비디움 332개 /cm3, 심비디움 교배종 323개/cm3로 심비디움 속이 가 장 발생량이 많았으며, 그 다음이 덴팔레 250개/cm3, 온시디움 203개/cm3, 나도풍란 119개/cm3, 호접란이 77개/cm3 순이었다. 투입율 증가에 따라 심비디움은 40%, 심비디움 교배종은 75%까지는 음이온 발생량이 증가하였으나, 그 이상 투입율에서는 다소 감소하는 경 향이었다. 따라서 식물 종류별로 음이온 발생량을 상호 비교하기 위해서는 식물 투입율이 40% 이하가 적절하 며, 상대습도 등을 감안할 경우 약 30% 정도가 가장 적절한 것으로 보인다.
        4,000원
        5.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        Domestic sewerage treatment plant is operated by activated sludge method and its modified method by using microorganism. In most cases, a method of using microorganism is directly controlled by the operator based on individual judgment through factors of DO, pH and ORP. In addition, under aerobic condition in bioreactor, energy consumption including excessive air injection is learned to be somewhat plenty. In order to solve this problem, in most of the process, improvement of internal recycling and activated environmental factor of microorganism were researched extensively. However, as factors are changed depending on various conditions, it is not sufficient as an indicator of judgment. As such, a research on operation of bioreactor that measures metabolic change in short time by directly measuring activated condition of microorganism using NADH fluorometer is required in reality.It is considered that the method like this could supplement problem of energy consumption being occurred in the existing treatment method and operational optimization of bioreactor would be enabled by controlling optimal air volume. Therefore, in this study, in order to obtain optimal operational indicator of bioreactor, proper air volume control test was performed and through batch test and site evaluation, possibility of NADH sensor being utilized as operational control indicator of bioreactor is intended to be analyzed. In order to compare with measured value, DO, ORP that are operational control indicator of existing bioreactor were used. As MLSS concentration was increased through batch test, NADH value was increased and site evaluation also showed similar tendency to batch test. Resultantly, it could be confirmed that changing level of NADH fluorometer was a sensor that could measure bioreactor condition effectively and optimized scale of bioreactor is considered to be utilized.
        6.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        The impact of a considerable increase in traffic volume on the emission and concentrations of air pollutants was investigated at three beaches (Haeundae (HB), Gwanganri (GB), and Songjeong (SB)) in Busan during beach opening period (BOP) in 2011. During the BOP, passenger car was the major vehicle type, followed by taxi, and van. CO was the major contributor of total air pollutant emissions followed by NOx, VOC, and PM10. For the temporal variation of the emission of air pollutants during the BOP, it was generally the highest in the afternoon followed by the evening and morning, except for SB. For the spatial variation of their emission, it was the highest at GB followed by SB and HB. The emissions of air pollutants during the BOP were generally higher than those during the Non-BOP, except for HB. In contrast, the significant impact of the traffic volume increase on the concentrations of air pollutants at monitoring sites near the three beaches during the BOP were not found compared to the Non-BOP due to the significant distances between monitoring sites of air pollutants and monitoring sites of traffic volume at the beaches.
        7.
        2010.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the emissions of the air pollutants from the automobile in Suwon city. To estimate emissions due to by automobile the data of express highway and the national road used an observation traffic volume, and the other roads used a method by Vehicle kilometer traveled(VKT). In the emissions due to by automobile from Suwon city, CO was highest 36,290.4 ton/year, NOx at 19,392.1 tons, HC 5,095.4 tons and PM 2,788.7 tons was highly order. SOx emissions in the whole Suwon city by fuel types was investigated with 178ton/year from the Diesel motorcar, 26.9 ton/year and 6.2 ton/year from the gasolines and LPG automobiles, respectively. VOC emissions from the automobile was investigated with 366.4 ton/year (29.22%) from Gwonseon-gu, 329.2 ton/year (26.25%) Yeongtong-gu, 319.9 ton/year (25.51%) Jangan-gu, 238.6 ton/year (19.03%) Paldal-gu.
        8.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        Under controlled conditions in an environmental chamber, 24 experiments were performed to compare the ability of a Variable-Air-Volume/Bypass Filtration System(VAV/BPFS) to remove indoor pollutants and to conserve energy with the ability of conventional Variable Air Volume(VAV) system. The specific conclusions of this paper were; first, the VAV/BPFS was more efficient than the VAV system in removing particulate matter, TVOC, and target VOCs. The total effective removal rate of PM for the VAV/BPFS was two times as high as that of the VAV system. The total effective removal rate of TVOC for the VAV/BPFS was 20 percent higher than that of the VAV system. Also each target VOC concentration was reduced by using the VAV/BPFS. Second, clean air delivery rate was increased by using VAV/BPFS due to additional filtration rate. Otherwise, the VAV/BPFS decreased outdoor supply air rate above 25 percent relative to the rate of VAV system. Third, total energy consumption by the VAV/BPFS was lower than that of the VAV system during the period with indoor thermal load, occupied time. The energy saving of the VAV/BPFS ranged from 11 to 16 percent. The VAV/BPFS improves indoor air quality more efficiently than the VAV system, and it reduced energy consumption. Retrofitting the VAV system with the VAV/BPFS was easy. The use of VAV/BPFS is, therefore, recommended for buildings with VAV system as well as for buildings at designing stage.