• Title/Summary/Keyword: Gas station

Search Result 476, Processing Time 0.028 seconds

국내 석유제품가격의 변동에 대한 소비자의 인식과 비대칭 분석 비교

  • O, Seon-A;Heo, Eun-Nyeong
    • Environmental and Resource Economics Review
    • /
    • v.21 no.1
    • /
    • pp.69-92
    • /
    • 2012
  • This paper analyzed price asymmetry of domestic petroleum products by distribution stage. Analyzing the asymmetry by distribution stage, we can investigate the gap between analysis results and consumers' perception. For the first stage, we analyzed asymmetries between retail prices including tax and the spot prices of crude oil. The results show that retail price increases more quickly in response to the crude oil prices rise than to the crude oil prices fall as consumers' perception. For the second stage, we analyzed asymmetry of international petroleum product prices in Korean Won with the change in the crude oil spot prices. The results show that international petroleum product prices increase higher in response to the crude oil prices increase than to the crude oil prices decrease. For the final stage, we examined the asymmetry of wholesale price and retail price with the change in the international petroleum product prices in Korean Won. The results show that wholesale prices increase more quickly in response to the crude oil prices rise than to the international petroleum product prices fall. The retail prices, however, decrease more quickly in response to the crude oil prices fall than to the international petroleum product prices rise.

  • PDF

Correlation and Hysteresis Analysis between Air and Water Temperatures in the Coastal Zone - Masan Bay (연안해역 기온과 수온의 상관관계 및 이력현상 분석)

  • Cho, Hong-Yeon;Lee, Khil-Ha;Cho, Kyung-Jun;Kim, Jun-Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.19 no.3
    • /
    • pp.213-221
    • /
    • 2007
  • In response to anthropogenic global warming due to a buildup greenhouse gas, the effect of the air temperature on water temperature has been noticed and some efforts have been made to build an air/water temperature relationship at the Masan Bay area by the Ministry of Maritime Affairs & Fisheries (MOMAF). As a result of analyzing the auto- and cross-correlation coefficient between air/water temperature, high correlation $(\sim0.9)$ is shown and the correlation coefficient of air temperature is higher than that of water temperature at the lag time less than approximately 10 days. Separate functions are fitted to the air/water relationship at the Masan Bay to take hysteresis into account. The slopes of the straight line for the rising limb are 0.829 and 0.774 for MA1 and MA2 station respectively, while 1.385 and 1.444 ($\sim1.75$ times larger) for the falling limb. Consequently, the seasonal hysteresis should be considered in order to determine an air/water relationship and accurately estimate the water temperature using the air temperature at Masan Bay.

Current Status of the Synchrotron Small-Angle X-ray Scattering Station BL4C1 at the Pohang Accelerator Laboratory

  • Jorg Bolze;Kim, Jehan;Huang, Jung-Yun;Seungyu Rah;Youn, Hwa-Shik;Lee, Byeongdu;Shin, Tae-Joo;Moonhor Ree
    • Macromolecular Research
    • /
    • v.10 no.1
    • /
    • pp.2-12
    • /
    • 2002
  • The small-angle X-ray scattering (SAXS) beamline BL4C1 at the 2.5 GeV storage ring of the Pohang Accelerator Laboratory (PAL) has been in its first you of operation since August 2000. During this first stage it could meet the basic requirements of the rapidly growing domestic SAXS user community, which has been carrying out measurements mainly on various polymer systems. The X-ray source is a bending magnet which produces white radiation with a critical energy of 5.5 keV. A synthetic double multilayer monochromator selects quasi-monochromatic radiation with a bandwidth of ca. 1.5%. This relatively low degree of monochromatization is sufficient for most SAXS measurements and allows a considerably higher flux at the sample as compared to monochromators using single crystals. Higher harmonics from the monochromator are rejected by reflection from a flat mirror, and a slit system is installed for collimation. A charge-coupled device (CCD) system, two one-dimensional photodiode arrays (PDA) and imaging plates (IP) are available its detectors. The overall performance of the beamline optics and of the detector systems has been checked using various standard samples. While the CCD and PDA detectors are well-suited for diffraction measurements, they give unsatisfactory data from weakly scattering samples, due to their high intrinsic noise. By using the IP system smooth scattering curves could be obtained in a wide dynamic range. In the second stage, stating from August 2001, the beamline will be upgraded with additional slits, focusing optics and gas-filled proportional detectors.

Comparison of Chemical Constituents of Upland Wasabia japonica Matsum Grown by Different Propagation Methods (번식방법(繁殖方法)에 따른 밭고추냉이의 성분비교(成分比較))

  • Kim, Sang-Yeol;Park, Kee-Choon
    • Korean Journal of Medicinal Crop Science
    • /
    • v.5 no.4
    • /
    • pp.294-301
    • /
    • 1997
  • Fatty acid, amino acid and organic acid contents were analyzed by gas chromatography, amino acid analyzer and high pressure liquid chromatography, respectively, in order to compare the chemical constituents of upland wasabi plant propagated by seed and auxiliary bud. Total fatty acid content and fatty acid composition of upland wasabi were not affected by the propagation methods. Generally, fatty acid content of leaf was higher than that of other parts such as enlarged stem, petiole, peduncle and root. In fatty acid composition, leaf had highest content of linolenic acid, 60-63%, in plant propagated by both seed and auxiliary bud, followed by palmitic acid, oleic acid and linoleic acid in the order. Similarly, total amino acid content was not influenced by propagation methods but plant propagated by seed had higher amount of amino acid content in enlarged stem, petiole and root than that by auxiliary bud -propagated plant. A total of 17 amino acids including 7 essential amino acids were identified in both seed and auxiliary bud propagations. Like total fatty acid content and fatty acid composition, leaf contained high amount of amino acids, especially glutamic acid, asparatic acid and leucine. Organic acid contents were similar in both propagation methods. The major organic acid in upland wasabi was acetic acid (60.0-78.2%), followed by succinic acid (9.9-29.7%) and malic acid (2.9-7.9%). Maleic acid content was least (0.5-2.6%). The result indicates that content and composition of fatty acid, amino acid, and organic acid in upland wasabi were not influenced by propagation methods.

  • PDF

The Effect of Traffic Volume on the Air Quality at Monitoring Sites in Gwangju (광주광역시 대기오염측정소 주변 교통량이 대기질에 미치는 영향)

  • Lee, Dae-Haeng;An, Sang-Su;Song, Hyeong-Myeong;Park, Ok-Hyun;Park, Kang-Soo;Seo, Gwang-Yeob;Cho, Young-Gwan;Kim, Eun-Sun
    • Journal of Environmental Health Sciences
    • /
    • v.40 no.3
    • /
    • pp.204-214
    • /
    • 2014
  • Objectives: Vehicular emissions are one of the main sources of air pollution in urban areas. Correlation analysis was conducted between air pollutants and traffic volume in order to identify causes of air pollution in Gwangju. Methods: Using traffic volumes and air quality monitoring data from 2002 to 2012 from nine stations (seven urban areas, two roadside areas), especially at three sites where traffic volumes were high, the correlation coefficients were obtained between air pollutants as PM-10 (particulate matter), $NO_2$, $SO_2$, CO and $O_3$ at the stations and traffic volumes near the air monitoring stations. Results: Due to traffic volume and distance between the station and the traffic road, concentrations of pollutants at roadside areas were higher than at urban areas, with the exception of $O_3$. The concentration of $O_3$ showed statistically significance with those of other gas materials as $NO_2$, $SO_2$, and CO in winter (p<0.001) and spring (p<0.05). During the period of October 7 to 20, 2012, excluding periods of yellow dust, smog and rainy season, the ratio of $NO/(NO+NO_2)$ showed the highest value 0.57 and 0.40 at Unam and Chipyeong of two roadside stations, followed by 0.35 at Nongseong with vehicular effects. The correlation coefficient between traffic volume and $O_3$, CO, $NO_2$ became higher when the data on mist and haze days were excluded, than when all hourly data were used in that period, at the three sites of Unam, Chipyeong, and Nongseong. Conclusions: Air quality showed a considerable effect from vehicles at roadside areas compared to in urban areas. Air pollutant diminishment strategies need to be aggressively adopted in order to protect atmospheric environment.

Quality and Sensory Characteristics of White Bread added with Various Ginseng Products (인삼제품의 첨가에 따른 제빵적성 및 관능평가)

  • Song, Mi-Ran;Lee, Ka-Soon;Lee, Byeong-Chan;Oh, Man-Jin
    • Food Science and Preservation
    • /
    • v.14 no.4
    • /
    • pp.369-377
    • /
    • 2007
  • This study investigated the effect of ginseng products on the baking properties of white breads. Flour was substituted by ginseng products (ginseng at levels 2, 4, 6, and 8%, all w/w, of flour levels). Both ginseng powder (GP) and red ginseng powder (RGP) were used. Similarly, red ginseng extract (RGE) was substituted at levels of 1, 2, 3, and 4% (all w/w) of flour. The physical properties of each dough were assessed using farinograms, extensograms, and amylograms. Water absorption increased as the proportions of ginseng products rose. The dough surface areas and R/E (resistance/extensibility) values decreased, as did peak viscosities, at the proportions of ginseng products increased. The pH values during fermentation decreased as the proportions of ginseng products increased. The fermentation power of dough with GP was lower than that of control, and higher than that of dough with RGP or RGE, but the addition of ginseng products beyond certain levels weakened the gas retention power: The specific loaf volumes of breads with 2% GP were the highest at 5.41 mL/g. In breads with RGE, the specificloaf volume increased from 5.52 mL/g to 5.82 mL/g as RGE levels rose from 0% to 4%. Hardness increased with rising GP and RGP levels in breads with GP and RGP, but decreased with RGE levels in breads with RGE. The moisture contents of breads during storage tended to be higher than control in breads with ginseng products. Lightness increased with addition of GP and decreased upon addition of RGP or RGE, while redness and yellowness increased after addition of any ginseng products. In sensory evaluation tests, the sensory scores for texture, color, mouth feel, and overall acceptability, were high, when any ginseng product (GP, RGP or RGE) was present at 2%. Of these breads, the bread with 2% RGE attained the highest sensory score.

Different Photosynthetic Responses of Black Cherry (Prunus serotina) with Different Sensitivities to Ambient Ozone Concentrations under Natural Conditions (자연상태에서 대기 중 오존 농도에 상이한 민감성을 가진 Black Cherry(Prunus serotina)의 상이한 광합성 반응)

  • Yun, Myoung-Hui;Chevone, Boris I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.10 no.4
    • /
    • pp.132-140
    • /
    • 2008
  • Two different sensitivity classes of black cherry (Prunus serotina) under the natural growing environmental conditions were assessed adjacent to Air Monitoring Station located at Horton research center in Giles County, Virginia, USA. Ambient ozone concentrations, leaf gas exchange, and visible foliar injury were measured on-site during the growing seasons of 2000, 2001, and 2002. Ambient ozone exposures were sufficient to induce typical foliar visible injury corresponding with the reduction in photosynthetic activities only in sensitive black cherry. There were positive correlations between increasing cumulative ozone concentration and percent reduction in maximum net photosynthetic rates ($Pn_{MAX}$) under saturating light conditions and in quantum yield for carbon reduction (${\Phi}CO_2$) of sensitive black cherry compared to tolerant black cherry. There was a negative correlation between chlorophyll content and percent leaf injury in sensitive black cherry. Furthermore, $Pn_{MAX}$ was inversely related to percent leaf injury.

Radon-222 Concentrations of Metropolitan Subway Stations and Soils in the Seoul (서울 지하철역(地下鐵驛) 승강장(昇降場) 및 토양내(土壤內) 유해(有害)라돈함량(含量) 연구(硏究))

  • Hong, Young-Kook;Kim, Sung-Oh;Kim, Tong-Kwon
    • Economic and Environmental Geology
    • /
    • v.31 no.3
    • /
    • pp.215-222
    • /
    • 1998
  • The radon (Rn-222) potential of metropolitan subway stations and soils in Seoul city were delineated using alpha-track filter and EDA-200 radon detectors, respectively. The uranium (U) and thorium (Th) contents were also determined using a Multi Channel Analyzer to identify the sources of radon gas. The average U concentrations in Seoul varies according to basement rock types. For example, there is $9.40{\pm}10.11ppm$ in the Precambrian metasedimentary rock (PM), $9.08{\pm}2.85ppm$ in the Jurassic Kwanaksan granite (JK) and $4.94{\pm}1.43ppm$ in the Jurassic Seoul granite (JS). Uranium contents in soil samples are $10.30{\pm}4.74ppm$ in JK, $10.10{\pm}7.43ppm$ in PM and $6.69{\pm}3.95ppm$ in JS and these closely reflect the content of uraniferous minerals. The levels of soil radon are $604{\pm}273pCi/L$ in JK, $502{\pm}275$ in JS and $262{\pm}211pCi/L$ in PM. The soil radon concentrations are shown to reflect soil permeability and porosity rather than their U contents. The mean indoor radon contents in subway stations are $1.50{\pm}0.62pCi/L$ on the 4th line, $1.41{\pm}0.95pCi/L$ on the 3rd line, $0.84{\pm}0.13pCi/L$ on the 1st line and $0.80{\pm}0.25pCi/L$ on the 2nd line. The subway stations located in the JK have the highest average radon concentration with $2.04{\pm}0.65pCi/L$, where levels of $1.57{\pm}0.81pCi/L$ occur in the JS and $0.80{\pm}0.23pCi/L$ in the PM. The highest radon levels of 4.1 pCi/L occur mainly in Keongbokkung station on the 3rd line and these exceed 4 pCi/L of the US EPA action level.

  • PDF

Development of a Prototype Patient Monitoring System with Module-Based Bedside Units and Central Stations: Overall Architecture and Specifications (모듈형 환자감시기와 중앙 환자감시기로 구성되는 환자감시시스템 시제품의 개발: 전체구조 및 사양)

  • Woo, E.J.;Park, S.H.;Jun, B.M.;Moon, C.W.;Lee, H.C.;Kim, S.T.;Kim, H.J.;Seo, J.J.;Chae, K.M.;Park, J.C.;Choi, K.H.;Lee, W.J.;Kim, K.S.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1996 no.05
    • /
    • pp.315-319
    • /
    • 1996
  • We have developed a prototype patient monitoring system including module-based bedside units, interbed network, and central stations. A bedside unit consists of a color monitor and a main CPU unit with peripherals including a module controller. It can also include up to 3 module cases and 21 different modules. In addition to the 3-channel recorder module, six different physiological parameters of ECG, respiration, invasive blood pressure, noninvasive blood pressure, body temperature, and arterial pulse oximetry with plethysmogaph are provided as parameter modules. Modules and a module controller communicate with up to 1Mbps data rate through an intrabed network based on RS-485 and HDLC protocol. Bedside units can display up to 12 channels of waveforms with any related numeric informations simultaneously. At the same time, it communicates with other bedside units and central stations through interbed network based on 10Mbps Ethernet and TCP/IP protocol. Software far bedside units and central stations fully utilizes gaphical user interface techniques and all functions are controlled by a rotate/push button on bedside unit and a mouse on central station. The entire system satisfies the requirements of AAMI and ANSI standards in terms of electrical safety and performances. In order to accommodate more advanced data management capabilities such as 24-hour full disclosure, we are developing a relational database server dedicated to the patient monitoring system. We are also developing a clinical workstation with which physicians can review and examine the data from patients through various kinds of computer networks far diagnosis and report generation. Portable bedside units with LCD display and wired or wireless data communication capability will be developed in the near future. New parameter modules including cardiac output, capnograph, and other gas analysis functions will be added.

  • PDF

Prediction of Change in Growth Rate of Algae in Jinhae Bay due to Cooling Water Discharge (냉배수 방류에 따른 진해만의 해조류 성장 속도 변화 예측)

  • Park, Seongsik;Yoon, Seokjin;Lee, In-Cheol;Kim, Byeong Kuk;Kim, Kyunghoi
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.27 no.2
    • /
    • pp.308-323
    • /
    • 2021
  • In this study, we aimed to evaluate the environmental changes in Jinhae Bay caused by cooling water using numerical modeling. Cooling water discharge volume from the results of Case 1 (10 m3 sec-1) showed that the environmental changes in Jinhae Bay were extremely insignificant throughout the study period. In the simulation conditions of Case 2 (100 m3 sec-1), there was a decrease in water temperature of approximately 1 - 3℃ within a 5 km radius from the discharge outlet. In Case 3 (1000 m3 sec-1), a decrease in water temperature of up to 4 - 5℃ was observed within a radius of 8 km from the discharge outlet and cooling water discharge spread throughout the Bay. Growth rate of microalgae decreased by up to 15 % in November, whereas it increased by up to 6 % near the Hangam Bay in Case 3. From the above results, we confirmed that the environmental changes in Jinhae Bay due to cooling water discharged from Tongyeong LNG station are extremely insignificant. Moreover, it is expected that cooling water discharge could be utilized as a counter measure for 'red tide bloom' or 'macroalgae growth'.