• Title/Summary/Keyword: Seasonal characteristics

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Effects of Seasonal and Membership Characteristics on Public Bicycle Traffic : Focusing on the Seoul Bike (계절 및 회원 특성이 공공자전거 통행에 미치는 영향분석 : 서울시 따릉이를 대상으로)

  • Jang, Jae min;Lee, Soong bong;Lee, Young-Inn;Lee, Mu Young
    • International Journal of Highway Engineering
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    • v.20 no.4
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    • pp.47-58
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    • 2018
  • PURPOSES : Seoul introduced public bicycles to reduce environmental pollution and create a healthy society. Because the use of bicycles is highly weather dependent, and bicycles are rented by the people, member characteristics and seasonal influences should be considered. This study analyzed bicycle traffic characteristics considering seasonal and member characteristics and highlighted some implications. METHODS : The Yeouido and Sangam districts, which have multiple business districts, were taken as the areas of interest. In order to reflect seasonal and membership characteristics, the traffic volume, time of use, and characteristics of each zone were categorized by season (spring, summer, autumn, winter) and membership type (season, daily, group). In addition, we analyzed the pattern of traffic volume and usage time according to the traffic purpose after separating rental locations into residential, business, subway, and park, reflecting the land characteristics. RESULTS : The results revealed that seasonal characteristics were high for bicycle traffic, time of use, and occupancy rate for park locations in spring and autumn. In terms of membership characteristics, group and daily users appeared as major visitors for park locations, and the trends of commuter pass users showed that bicycle use meets the purpose of introducing public bicycles. CONCLUSIONS : Traffic characteristics differed according to seasonal and membership characteristics. It is necessary to involve and extend the users of the commuter pass. Situations in which commuter pass users cannot function as a group or in which daily users monopolize bicycles (especially near parks, near subway stations, etc.) must be avoided.

The Analysis on Annual, Seasonal tendency of Outpatients in ophthalmology & Otolaryngology & Dermatology clinic of Korean Medical hospital from 2012 to 2016 (2012년부터 2016년까지 대전지역 대학 한방병원 안이비인후피부과 외래환자에 대한 연도별, 계절별 경향성 분석)

  • An, Jae-Hyun;Jung, Hyun-A
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.2
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    • pp.19-37
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    • 2017
  • Objectives : The study designed to analyze annual, seasonal tendency of outpatients in ophthalmology & otolaryngology & dermatology clinic of Korean Medical hospital from 2012 to 2016. Methods : We investigated annual, seasonal population-social characteristics such as sex or age, departmental characteristics such as ophthalmology, otolaryngology, dermatology, many others, main diagnosis, cost characteristics of treatment period and frequency of treatment those who were received treatment as outpatients in Dunsan Korean Medical Hospital ophthalmology & otolaryngology & dermatology clinic from March 2012 to March 2016. The data was obtained from EMR chart, and statistical analysis was performed using SPSS 19.0. Results : We analyzed population-social characteristics, utilization of new patients in the year, in the season, and we obtained various results. Conclusions : In the analysis of annual, seasonal utilization patterns that outpatients offered in ophthalmology & otolaryngology & dermatology clinic of Korean Medical hospital from 2012 to 2016, the report draws 3 different conclusions.

Seasonal changes in zooplankton community in the coastal waters off Incheon

  • Youn, Seok-Hyun;Choi, Joong-Ki
    • Journal of the korean society of oceanography
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    • v.38 no.3
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    • pp.111-121
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    • 2003
  • The seasonal succession of zooplankton communities in the coastal area off Incheon, Kyeonggi Bay, was investigated with the samples collected at intervals of 10 to 15 days from January 1999 to December 2000. Total abundance of zooplankton communities showed remarkable seasonal variations, ranged from 1,100 to $120,400{\;}indiv./\textrm{m}^3$, and annual mean abundance was $22,000{\;}indiv./\textrm{m}^3$. There were several times of the total abundance during a year, and the timing ofhigh abundances were about the same in 1999 and 2000. During the study period except summer, the abundance of dinoflagellate Noctiluca scintillans and copepod Acartia hongi contributed to the most part of total zooplankton. Whereas, during summer, smaller copepod Oithona davisae and Paracalanus crassirostris were dominant species. Zooplankton communities in the coastal waters off Incheon showed typical characteristics of coastal-estuarine communities, which were dominated by a few species, and abrupt seasonal variations in abundance. We suggest that the seasonal succession and abundance variations of zooplankton communities were caused by the seasonal variations in water temperature and by the seasonally varying phytoplankton biomass in the study area.

Seasonal Load Characteristics on 22.9[tV] Bus for Load Modeling (부하모델링을 위한 22.9[kV]모선의 계절별 부하특성에 관한 연구)

  • Ji, P.S.;Lee, J.P.;Lim, J.Y.;Kim, K.D.;Park, S.W.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.304-306
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    • 2000
  • Load modeling, micro method, needs field test to identify the validity of methodology applied to modeling. This paper presents seasonal field test method and measurement results on serveral substations. Seasonal load characteristics were analyzed by the developed substation load model and correlation coefficients of seasonal load of substation under base, peak and average load time.

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Characteristics of Seasonal Mean Diurnal Temperature Range and Their Causes over South Korea (우리나라에서 계절별 일교차의 분포 특성과 그 원인)

  • Suh, Myoung-Seok;Hong, Seong-Kun;Kang, Jeon-Ho
    • Atmosphere
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    • v.19 no.2
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    • pp.155-168
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    • 2009
  • Characteristics of seasonal mean diurnal temperature range (DTR) and their causes over South Korea are investigated using the 60 stations data of Korea Meteorological Administration from 1976 to 2005. In general, the seasonal mean DTR is greatest during spring (in inland area) and least during summer (urban and coastal area). The spatial and seasonal variations of DTR are closely linked with the land surface conditions (especially vegetation activity and soil moisture) and atmospheric conditions (cloud amount, precipitation, local circulation). The seasonal mean DTR shows a decreasing trend at the major urban areas and at the north-eastern part of South Korea. Whereas, it shows an increasing trend at the central area of the southern part. Decreasing and increasing trends of DTR are more significant during summer and fall, and during spring and winter. The decrease (increase) of DTR is mainly caused by the stronger increase of daily minimum (maximum) temperature than daily maximum (minimum) temperature. The negative effects of precipitation and cloud amount on the DTR are greater during spring and at the inland area than during winter and at the coastal area. And the effect of daytime precipitation on the DTR is greater than that of nighttime precipitation.

A Study on the Thermal Characteristics of Cheju Seasonal Installation (제주 태양열 계간 축열단지의 열적 특성에 관한 연구)

  • Han, Yu-Ri;Park, Youn-Cheol;Chun, Won-Gee;Kang, Yong-Heack;Lee, Sang-Nam
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.563-566
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    • 2006
  • An investigation has been carried for the thermal characteristics of the seasonal storage installation in Cheju. It features the solar collector area of $340m^2$ and the storage capacity of $600m^3$. Four different types of solar collector systems are compared for their performance of collecting solar energy throughout the year. Of these, two are made of tubular shaped vacuum collectors and the others are flat plate collectors. Results indicate that each system could play an important role in exploiting solar energy depending on the temperature range in its operation. Especially, the vacuum collectors outperformed the others when the inlet temperatures of the collector loop were raised beyond $40m^2$. This became more conspicuous as the return temperatures from the storage tank rose reflecting the seasonal variation. Due to the large heat capacity of the storage tank, temperature changes were rather small compared to those in the collecting loop regardless of seasonal fluctuations.

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The Temporal Distribution Characteristics of Some Important VOC Species from a Nonurban Site in Naju (대기중 휘발성유기화합물의 시간적 농도 변화에 대한 연구)

  • 김조천;김기현
    • Journal of Environmental Science International
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    • v.9 no.6
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    • pp.483-488
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    • 2000
  • In this study, the distribution characteristics of volatile organic compounds (VOCs) were investigated on the seasonal basis across spring, summer, and fall during the year of 1998. According to this analysis, most VOC species investigated exhibited strong temporal trends. Over diurnal scale, there distribution characteristics were affected by seasonal factors strongly. While they showed high day/night ratio pattern during spring, the pattern was reversed during fall. When the seasonal mean values were compared between the two seasons, the spring values were systematically higher than their counterparts in most cases. In addition when our VOC measurement date were compared with those reported from elsewhere, we were able to conclude that the VOC levels in the study area are comparable to the level weakly impacted by the regional emissions of VOCs. Although our data are not sufficient enough to systematically explain the atmospheric distribution and behavior of VOCs, the findings of strong correlations among some of VOC species suggests strong need for investigating their interactions in the earth\`s atmosphere.

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A Study on the Seasonal Load Characteristics in 22.9[kV] Bus (22.9[kV] 모선의 계절별 부하특성에 관한 연구)

  • 이종필;임재윤;지평식;김기동;김정훈
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.6
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    • pp.279-286
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    • 2001
  • A load modeling, micro method, is performed by component load modeling, load composition rate estimation and aggregation of component load model, etc. The load model obtained from this process must be applied to actual load bus to verify it and to get reliable load model. But it is difficult to apply every load bus due to al lot of load buses and complex experiment. This paper proposed the field test method in load bus to verify the load modeling. For appropriate field test, representative load buses are selected by the proposed algorithm considering the composition rate of user category in all load buses. The field tests were performed at selected load buses to obtain load characteristics of bus by time and seasonal without blackout. The results of measurement and analysis are presented in detail.

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Characteristics of the Seasonal Variation of the Radiation in a Mixed Forest at Kwangneung Arboretum (광릉수목원 혼합림에서 복사 에너지의 계절 변화 특성)

  • 김연희;조경숙;김현탁;엄향희;최병철
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.3
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    • pp.285-296
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    • 2003
  • The measurement of the radiation energy, trunk temperature, leaf area index (LAI), air temperature, vapor pres-sure, and precipitation has been conducted under a mixed forest at Kwangneung Arboretum during the period of 2001. Characteristics of the diurnal and seasonal variation of the radiative energy were investigated. The aerodynamic roughness length was determined as about 1.6 m and the mean albedo was about 0.1 The downward short-wave radiation was linearly correlated with the net radiation and its correlation coefficient was about 0.96. From this linear relation, the heating coefficient was calculated and its annual mean value was about 0.21 The albedo and heating coefficient was varied with season, surface characteristics, and meteorological conditions. The diurnal and seasonal variations of radiation energy were discussed in terms of the surface characteristics and meteorological conditions. In the daytime, during clear skies, net radiation was dominated by the shortwave radiation. In presence of clouds and fog, the radiation energy was diminished. At night, the net radiation was entirely dominated due to the net longwave radiation. There was no distinct diurnal variation in net radiation flux during the overcast or rainy days. The net radiation was strongest in spring and weakest in winter. The seasonal development in leaf area was also reflected in a strong seasonal pattern of the radiation energy balance. The timing, duration, and maximum leaf area and trunk temperature were found to be an important control on radiation energy budget. The trunk temperature was either equal or warmer than air temperature during most of the growing season because the canopy could absorb a substantial amount of sunlight. After autumn (after the middle of October), the trunk temperature was consistently cooler than air temperature.