• Title/Summary/Keyword: Diurnal

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Characteristics of Surface High Ozone Concentration on Pusan Coastal area, Korea (부산 해안지역의 고농도 오존 발생 특성에 관한 연구)

  • 전병일
    • Journal of Environmental Science International
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    • v.9 no.4
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    • pp.295-302
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    • 2000
  • This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone, nitrogen dioxide and meteorological data for 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was the highest at Dongsamdong in Spring(35.4ppb), at Kwangbokdong in Fall(25.1ppb) and the lowest Dongsamdong(22.2ppb) and Kwangbokdong(16.0ppb) in Winter. Relative standard deviation indicating clearness of observation site was 0.42 at Dongsamdong and 0.49 at Kwangbokdong that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong and Kwangbokdong showed maximum at 1500~1600LST and minimum 0700~0800LST that typical pattern of ozone concentration. In ozone episode period(Sept. 10~15, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface. During the episode days peak ozone concentrations are much higher than the normal values, wind speeds are always lower, and solar radiation is high with the exception of the September episode.

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A Study on the Characteristics of Surface Ozone Concentration at Dongsamdong, Pusan (부산 동삼동 지역의 지표오존농도 특성 연구)

  • Jeon, Byung Il
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.21-29
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    • 1999
  • This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone and meteorological data of 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was highest in Spring(35.4ppb) and lowest in Winter(22.2ppb). Relative standard deviation indicating clearness of observation site was 0.42 that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong showed maximum at 15~16LST and minimum 07~08LST that typical pattern of ozone concentration. In ozone episode period(May 18~23, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface.

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Synoptic Weather Patterns and Variation of Ozone Concentrations Association with High Ozone Days at Five Major Cities in Korea (고농도 오존이 발생하는 날의 종관 기상 패턴과 주요 5대 도시별 오존 농도 변화)

  • 김유라;윤일희;김희종
    • Journal of Environmental Science International
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    • v.10 no.6
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    • pp.437-444
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    • 2001
  • The characteristic features of surface ozone concentration and the forecasting procedure of high ozone days have been studied. The ozone concentration was continuously measured during 3 years (1997~1999) at air quality monitoring stations in five major cities in Korea. The diurnal variation of surface ozone concentration on high ozone days is characterized by low ozone concentration at night. The ozone concentration Increases continuously after sunrise, In reach a peak at 1500~1600 LST. Thereafter it decreases steadily to a low concentration at sunset. The diurnal and annual maximum of the surface ozone concentration at Seoul were observed in May and June, respectively. The favorable synoptic condition for the high ozone day is divided into 4 different synoptic weather patterns: a high-pressure system from the Sea of Okhotsk, the Pacific subtropical high extending westward, a moving high-pressure system covering the Korean peninsula. and a synoptic system In front of a typhoon. Most of high ozone days occur under the high pressure system in Korea.

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Characteristics of air pollution concentration on Dongsamdong, Pusan (부산 동삼동 지역의 대기오염농도 특성)

  • 전병일
    • Journal of Environmental Science International
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    • v.8 no.3
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    • pp.281-286
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    • 1999
  • This study was conduced to examine the monthly and seasonal variation of $SO_2$, TSP, $O_3$ concentration in Dongsamdong, Pusan coastal area. And the characteristics of air pollution of this area was compared to Kwangbokdong in Pusan and Taehadong in Ullungdo. Monthly mean concentration of $SO_2$ and TSP showed lower than Kwangbokdong, $O_3$ was higher than Kwangbokdong. In case of $SO_2$, seasonal variation of Dongsamdong was remarkabler thn Kwangbokdong and the concentration difference of early morning and daytime was higher than Kwangbokdong. Taehadong showed very lower concentration as background area. In case of TSP, Dongsamdong was lower concentration and smaller diurnal change than Kwangbokdong, Taehadong showed very lower concentration as backgound area. In case of $O_3$, Dongsamdong was 10ppb higher than Kwangbokdong at daytime maximum concentration, diurnal change of concentration was higher, too. In case of frequency distribution of concentration, $SO_2$, and TSP at Dongsamdong showed higher frequency in low concentration class and $O_3$ showed in high concentration class as compared with Kwangbokdong.

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Chronopharmacology in Clinical Medicine (임상에서 시간약물학)

  • Lee, Heon-Jeong;Kim, Leen
    • Sleep Medicine and Psychophysiology
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    • v.11 no.2
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    • pp.67-72
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    • 2004
  • Circadian rhythm is a global phenomenon, the control mechanisms of which are manifested at every level of biological organization, from genes and intracellular mechanisms to networks of cell populations, and to all central neuronal systems at the organismic level. In pharmacotherapy, the pharmacokinetic parameters such as drug absorption and distribution, drug metabolism, and renal elimination show diurnal variations. The symptoms and signs in diseases like asthma, myocardiac infarction, angina pectoris, hypertension and stroke also show diurnal fluctuations. These observations require drug treatment considering the circadian rhythm of body function and disease. Circadian time has to be taken into account as an important variable influencing a drug's pharmacokinetics and/or its effects or side effects in clinical practice.

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The cooling effect of a paddy field area during summer (여름철 논에서의 기온저감 효과)

  • Song, Chul-Min;Kim, Jin-Soo;Park, Jong-Hwa;Jeong, Gu-Young
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1497-1500
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    • 2006
  • The cooling effect of paddy fields was compared with those of other land-use areas (upland, urban park, and urban residential area) during midsummer. The temperature were monitored using data logger at one hour intervals in study sites. Diurnal temperature range of study areas in clear days was larger than in cloudy days. Also, diurnal temperature ranges in paddy field, upland, and park areas were larger than those in the urban residential area during clear days. The paddy field or upland area has shown more remarkable cooling effect compared to urban residential areas: Mean duration of temperature below $25^{\circ}C$ in the paddy field area is longer(7 to 8 hours) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area is sooner than in the residential area; Mean daily minimum temperature in the paddy field area is much lower than in the residential area.

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Acoustic Telemetrical Tracking of the Response Behavior of Red Seabream (Chrysophrys major) to Artificial Reefs (음향 텔레메트리 기법에 의한 참돔의 인공어초에 대한 반응행동 추적)

  • SHIN Hyeon-Ok;TAE Jong-Wan;KANG Kyoung-Mi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.5
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    • pp.433-439
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    • 2004
  • The movement range and diurnal behavior of red seabream (Chrysophrys major) tagged by the ultrasonic pinger externally were measured by acoustic telemetry techniques in the marine ranch of Tongyeong on 20 March to 30 October, 2003. The movement of fishes was monitored with the radio-acoustic linked positioning (RAP) buoy system and VR2 receivers. The test fishes showed behavior. pattern going to deep waters and returning to shallow waters. They moved gradually to deep waters as time goes by. They had a tendency to move wider range in night-time than day-time. It was found that the test fishes rarely showed a significant response to the artificial reefs.

Numerical Analysis of Wind Driven Current and Mesoscale Air Flow in Coastal Region with Land Topography (육상지형을 고려한 연안해역에서의 중규모 기상장과 취송류에 관한 수치해석)

  • Lee, Seong-Dae
    • Journal of Ocean Engineering and Technology
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    • v.20 no.5 s.72
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    • pp.23-29
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    • 2006
  • A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the current. In this paper, three-dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flaw over the coastal regions. The surface temperature of the inland area was determined through a surface heat budget consideration with the inclusion of a layer of vegetation.A series of numerical experiments were then carried out to investigate the diurnal response of the air flaw and wind-generated circulation to various types of surface inhomogeneities.