• Title, Summary, Keyword: mean annual frequency

Search Result 133, Processing Time 0.045 seconds

Climatological Variability of Temperature and Precipitation in Jeju (제주지역 기온과 강수량의 기후 변동 특성)

  • Kim, Seong-Su;Jang, Seung-Min;Baek, Hee-Jeong;Choi, Heung-Yeon;Kwon, Won-Tae
    • Journal of the Korean earth science society
    • /
    • v.27 no.2
    • /
    • pp.188-197
    • /
    • 2006
  • The characteristics of variability of temperature and precipitation in Jeju were investigated using data observed in Jeju station for from 1924 to 2004. Annual mean temperature change for the last 81 years is $0.02^{\circ}C$ increase per year. After 1980, the increase is $0.05^{\circ}C$ per year, larger than the former. The increase of the minimum temperature is larger than that of the maximum temperature in Jeju and has resulted in the increase of mean temperature. The frequency of climate extreme occurrence of temperature and rainfall was also investigated. The temporal variation of frequency of the extremely higher temperature has increased in the 1980's with global warming. The appearance of the extremely lower minimum temperature has decreased during the summers and winters. The facts that the frequencies of rainy days has decreased and heavy rainfall days of more than 80 mm per day in precipitation has increased indicate the increase of rainfall intensity.

Estimation of PM10 source locations in Busan using PSCF model (PSCF 모델을 활용한 부산지역 PM10의 발생원 추정)

  • Do, Woo-Gon;Jung, Woo-Sik
    • Journal of Environmental Science International
    • /
    • v.24 no.6
    • /
    • pp.793-806
    • /
    • 2015
  • The purpose of this study is to find out the air flow patterns affecting the PM10 concentration in Busan and the potential sources within each trajectory pattern. The synoptic air flow trajectories are classified into four clusters by HYSPLIT model and the potential sources of PM10 are estimated by PSCF model for each cluster from 2008 to 2012. The potential source locations of PM10 are compared with the distribution of PM10 anthropogenic emissions in east Asia developed in 2006 for the NASA INTEX-B mission. The annual mean concentrations of PM10 in Busan decreased from $51ug/m^3$ in 2008 to $43ug/m^3$ in 2012. The monthly mean concentrations of PM10 were high during a spring season, March to May and low during a summer season, August and September. The cluster2 composed of the air trajectories from the eastern China to Busan through the west sea showed the highest frequency, 44 %. The cluster1 composed of the air trajectories from the inner Mongolia region to Busan through the northeast area of China showed the second high frequency, 26 %. The cluster3 and 4 were composed of the trajectories originated in the southeast sea and the east sea of Busan respectively and showed low frequencies. The concentrations of in each cluster were $47ug/m^3$ in cluster1, $56ug/m^3$ in cluster2, $42ug/m^3$ in cluster3 and $37ug/m^3$ in cluster4. From these results, it was proved that the cluster1 and 2 composed of the trajectories originated in the east and northeast area of China were the causes of high PM10 concentrations in Busan. The results of PSCF and CWT model showed that the potential sources of the high PM10 concentrations were the areas of the around Mongolia and the eastern China having high emissions of PM10 from Beijing, Hebei to Shanghai through Shandong, Jiangsu.

A 17- Year Clinicostatistical Analysis of Cleft Lip and/or Palate Patients in Clinics for Maxillo-Oral Disorders, Tohoku University Dental Hospital (동북대학 치학부속병원 악구강기능치료부에 있어서 구순구개열 환자의 임상통계 -1987년부터 2002년까지-)

  • Moon Cheol-Hyun;Kochi Shako
    • Korean Journal of Cleft Lip And Palate
    • /
    • v.7 no.1
    • /
    • pp.35-46
    • /
    • 2004
  • The frequency of abnormality at birth is average 1-1.5%, and of these, cleft lip & palate is known to be the most frequent congenital abnormality, Cleft is considered to be due to multi-factorial heredity correlated with genetic and environmental factors, Cleft patients require the collaborative treatment with several medical departments, Clinics for Maxillo-Oral Disorders of Tohoku University Dental Hospital performs the total managements related to such as occlusion and language for the patients with congenital maxilla-facial abnormality, This study examined the patients with cleft lip and/or palate who came to the Clinics for Maxilla-Oral Disorders of Tohoku University Dental Hospital for the past 17 years from Jan. 1987 to Dec, 2002, and had the results as follows, 1. Annual mean number of patients The annual mean number of the patients for 17 years from Jan, 1987 to Dec, 2002 was 91 patients, ranging from 63 minimum to 116 maximum, 2, Gender and types of cleft There were 747(51%) males and 709(49%) females, with a male to female ratio 1,05:1. CLP was the most frequent cleft type as shown in 616 patients, and other patients manifested different complaints such as CL, CP, SMCP and MC in order. 3. The laterality in cleft type The lip cleft was frequently expressed orderly on left, right and both sides of CL patients while orderly being shown on left, both and right sides of CLP patients. Accordingly, lip cleft was most commonly found on the left side. 4. Address at first visit Of 1,456 subjects, 850(58.4%) patients were residing in Miyagi Prefecture, where this hospital is located. 5. Age at first visit 615(42.2%) patients came to the hospital at their age younger than 1 year old, comprising 282(19.4%) patients age younger than 2 months old and 333(22.9%) patients age between 2 month old and 1 year old. 6. Mother's age at birth For the mother's age at birth, 526(39.9%) patients were at the age of 25 to 30 years old, and 17(1.3%) patients were over 40 years old. 7. Birth weight 34.3%(443 patients) had a birth weight of 2500-3000gm and 56.0%(724 patients) had a 3000-4000gm. It was also found that 7.9%(102 patients) had a birth weight of less than 2500gm. 8. Familial expression The frequency of familial expression was 6.5%(94 patients).

  • PDF

The Characteristics of Dietary Habits of Obese, Overweight or Normal Subjects in Seoul (서울지역 중년에 있어서 정상체중군과 과체중군의 식생활 특성 비교)

  • 이미숙
    • Korean Journal of Community Nutrition
    • /
    • v.9 no.2
    • /
    • pp.161-172
    • /
    • 2004
  • The dietary habits of middle-aged obese, overweight and normal subjects were evaluated for the purpose of providing the background information of the degenerative disease control. A survey was conducted with 293 subjects (121 males and 172 females) between the ages 40-64 and they were divided into three groups of normal (BMI 18.5-22.9), overweight (BMI 23-24.9) and obese ($BMI\geq25$) based on the criteria of Korean Obesity Association (2000). The mean age of the subjects was $52.0\pm7.3(male)\;and\;51.9\pm6.9$ (female). Socioeconomic levels of subjects belong to the mid-upper class, since 71.9% of the males and 39.5% of the females received above a college education. More than 40% (44.6%) of males and 22.1% of females were obese, and educational background did not affect the obesity rate in males, whereas in females those who received lower education had a higher rate of obesity (p < 0.001). The subjects had a similar degree of drinking to the national average value. but had a lower degree of smoking. The obese group had the higher rate of drinking (p < 0.01) and smoking (p < 0.01). The annual increase in weight, more than 4 kg, was 8.8% for normal group and 30.9% for obese group. However, there were no differences in the mean annual increase in weight among the three groups. In females there were greater tendencies of weight changes in obese group (p < 0.05). About 44.9% of subjects responded that they were exercising regularly, and the obese group appeared to put into practice less than the other groups and to use more strenuous exercise. There was the greater rate of skipping dinner in the obese female group (p < 0.05). The unbalanced dietary pattern was found more with normal group than the other groups (p < 0.01). The food consumption frequency by food groups was not different among the groups. The obese group consumed less frequently meats, vegetables and fruits and had higher frequency in fish, legumes and their products, instant or fast food. In all subjects the higher rate of obesity was found with males than females and with those of heavier smoking and drinking, and in females the higher rate of obesity was found with lower education levels, skipping meals and having an unbalanced diet. In middle-aged subjects of this study with higher educational and socioeconomic background factors contributing to the effects of obesity may include smoking, drinking, educational background, skipping meals or unbalanced dietary pattern. The predictable characteristics for the development of obesity can be defined as sudden fluctuation of weights, exercise regularity and intakes of vegetables and fruits.

A Study on Trend Analysis in Sea Level Data Through MK Test and Quantile Regression Analysis (MK 검정 및 분위회귀분석을 통한 해수면 자료의 경향성 평가에 관한 연구)

  • Uranchimeg, Sumiya;Kim, Yong-Tak;Kwon, Hyun-Han;Hwang, Kyu-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.27 no.2
    • /
    • pp.94-104
    • /
    • 2015
  • Population and urban development along the coast is growing in South Korea, and particularly sea level rise is likely to increase the vulnerability of coastal areas. This study aims to investigate the sea level rise through Mann-Kendall(MK) test, ordinary linear regression(OR) and quantile regression analysis(QRA) with sea level data at the 20 tide stations along the coast of Korean Peninsula. First, statistically significant long-term trends were analysed using a non-parametric MK test and the test indicated statistically significant trends for 18 and 10 stations at the 5% significance level in the annual mean value of sea level and the annual maximum value of sea level, respectively. The QRA method showed better performance in terms of characterizing the degree of trend. QRA showed that an average annual rise in mean sea level is about 1-6 mm/year, and an average rise in maximum sea level is about 1-20 mm. It was found that upward convergent and upward divergent were a representative change given the nine-category distributional changes. We expect that in future work we will address nonstationarities with respect to sea level that were identified above, and develop a nonstationary frequency analysis with climate change scenarios.

Temperature-driven changes of pollinator assemblage and activity of Megaleranthis saniculifolia (Ranunculaceae) at high altitudes on Mt. Sobaeksan, South Korea

  • Lee, Hakbong;Kang, Hyesoon
    • Journal of Ecology and Environment
    • /
    • v.42 no.4
    • /
    • pp.265-271
    • /
    • 2018
  • Background: Temperature-driven variation in pollinator assemblage and activity are important information, especially at high altitudes, where rising temperature trends exceed global levels. Temporal patterns of pollinators in a flowering season can be used as a proxy to predict the changes of high-altitude plants' mutualistic relationships. We observed a spring temperature change in one population of a high-altitude endemic species, Megaleranthis saniculifolia on Mt. Sobaeksan, and related it to pollinator assemblage and activity changes. Methods: This study was conducted at two sites, each facing different slopes (NE and NW), for two times in the spring of 2013 (early-flowering, April 27-28, vs. mid-flowering, May 7-8, 2013). We confirmed that the two sites were comparable in snowmelt regime, composition of flowering plants, and flower density, which could affect pollinator assemblage and activity. Pollinator assemblage and activity were investigated at three quadrats ($1m^2$ with 5-m distance) for each site, covering a total of 840 min observation for each site. We analyzed correlations between the temperature and visitation frequency. Results: Twelve pollinator species belonging to four orders were observed for M. saniculifolia at both sites during early- and mid-flowering times. Diptera (five species) and hymenopteran species (four species) were the most abundant pollinators. Pollinator richness increased at both sites toward the mid-flowering time [early vs. mid = 7 (NE) and 3 (NW) vs. 9 (NE) and 5 (NW)]. Compared to the early-flowering time, visitation frequency showed a fourfold increase in the mid-flowering time. With the progression of spring, major pollinators changed from flies to bees. Upon using data pooled over both sites and flowering times, hourly visitation frequency was strongly positively correlated with hourly mean air temperature. Conclusions: The spring temperature change over a relatively brief flowering period of M. saniculifolia at high altitudes can alter pollinator assemblages through pollinator dominance and visitation frequency changes. Thus, this study emphasizes information on intra- and inter-annual variations in the mutualistic relationship between pollinators and M. saniculifolia to further assess the warming impacts on M. saniculifolia's reproductive fitness.

Studies on the Improvements for GAYAKUM Sounding Boards (가야금(伽倻琴) 향판재(響板材)의 개선(改善)에 관(關)한 연구(硏究))

  • Hong, Byung-Wha
    • Journal of the Korean Wood Science and Technology
    • /
    • v.18 no.4
    • /
    • pp.65-78
    • /
    • 1990
  • For the purpose of Improving the sounding boards for the conventional GAYAKUM, I was making approximately 202 specimens of radial board, 371 specimens of tangential board by cutting along the grain and the part of stem and 31 specimens of the disjointed traditional GAYAKUM made in Paulownia coreana. And it was conducted to measure specific gravity, dynamic Young's modulus, internal friction, resonant frequency, velosity of sound and width of annual ring by the method of the frexural vibration in a free-free bar in the audio frequency range. And it confirmed the juvenile wood by measuring wood fiber length of specimens. It was also conducted to investigate dynamic properties and moisture absorption by various heat-treatment and to test dynamic Young's modulus and internal friction for the disjointed conventional GAYAKUM. The results obtained were summarized as follow: 1. The Juvenile wood is located within about 7 annual rings from the pith in Paulownia coreana. 2. As increased with the specific gravity, the dynamic Young's modulus had more and more increased, but the internal friction had slightly decreased. 3. I think that radial board would be good for sounding board wood. because radial board is higher than tangential board in dynamic Young's mudulus and internal friction is lower than tangential board. 4. The value of mean dynamic Young's modulus on the conventional GAYAKUM, radial board and tangential board of 604 samples is $0.4283\pm0.037(\times10^{11}dyne/cm^2)$, $0.4316\pm(\times10^{11}dyne/cm^2)$ and $0.4234\pm0.112(\times10^{11}dyne/cm^2)$ respectively. The value of the radial board showed little higher than that of conventional GAYAKUM, but It had a similar tendency between conventional GAYAKUM and tangential board. 5. The annual ring width by four aspect is more narrow in north and west than that of others. 6. The values of specific gravity and dynamic Young's modulus in the mature wood showed higher than those of juvenile wood. 7. As the grain angle in the butt wood more increased to bark from pith, the dynamic Young's modulus were low. Then it was not good for sounding board. 8. It appeared that the heat-treatment for sounding board wood had a more effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature. 9. As increased with the temperature, the rate of moisture absorption of heat-treatment wood had decreased. In conclusion, I thought that the sounding board wood for GAYAKUM would had the most effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature using the radial board of mature wood.

  • PDF

Development of the Wind Wave Damage Estimation Functions based on Annual Disaster Reports : Focused on the Western Coastal Zone (재해연보기반 풍랑피해예측함수 개발 : 서해연안지역)

  • Choo, Tai-Ho;Cho, Hyoun-Min;Shim, Sang-Bo;Park, Sang-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.1
    • /
    • pp.154-163
    • /
    • 2018
  • Not only South Korea but also Global world show that the frequency and damages of large-scale natural disaster due to the rise of heavy rain event and typhoon or hurricane intensity are increasing. Natural disasters such as typhoon, flood, heavy rain, strong wind, wind wave, tidal wave, tide, heavy snow, drought, earthquake, yellow dust and so on, are difficult to estimate the scale of damage and spot. Also, there are many difficulties to take action because natural disasters don't appear precursor phenomena However, if scale of damage can be estimated, damages would be mitigated through the initial damage action. In the present study, therefore, wind wave damage estimation functions for the western coastal zone are developed based on annual disaster reports which were published by the Ministry of Public Safety and Security. The wind wave damage estimation functions were distinguished by regional groups and facilities and NRMSE (Normalized Root Mean Square Error) was analyzed from 1.94% to 26.07%. The damage could be mitigated if scale of damage can be estimated through developed functions and the proper response is taken.

Observations of the Cheju Current

  • Suk, Moon-Sik;Pang, Ig-Chan;Teague, William J.;Chang, Kyung-Il
    • Journal of the korean society of oceanography
    • /
    • v.35 no.3
    • /
    • pp.129-152
    • /
    • 2000
  • The Cheju Current (CC), defined here as a mean eastward flow in the Cheju Strait, mostly carries water of high temperature and salinity originating from the Kuroshio in winter and spring, the Cheju Warm Current Water (CWCW). The strong core of the eastward component of the CC is found close to Cheju Island (Cheju-Do, hereafter) in winter and spring with a peak speed of about 17.0 cm/s. The eastward flow weakens towards the northern Cheju Strait, and a weak westward flow occurs occasionally close to the southern coast of Korea. The volume transport ranges from 0.37 to 0.45 Sv(1 Sv=10$^6$ m$^3$/s) in winter and spring. Seasonal thermocline and harocline are formed in summer and eroded in November. The occurrence of the CWCW is confined in the southern Cheju Strait close to Cheju-Do below the seasonal thermocline in summer and fall, and cold water occupies the lower layer north of the CWCW which is thought to be brought into the area from the area west of Cheju-Do along with the CWCW. Stratification acts to increase both the speed of the CC with a peak speed of greater than 30 cm/s and the vertical shear of the along-strait currents. The strong core of the CC detached from the coast of Cheju-Do and shifted to the north during the stratified seasons. The volume transport in summer and fall ranges 0.510.66 Sv, which is about 1.5 times larger than that in winter and spring. An annual cycle of the cross-strait sea level difference shows its maximum in summer and fall and minimum in winter and spring, whose tendency is consistent with the annual variability of the CC and its transport estimated from the ADCP measurements. Moored current measurements west of Cheju-Do indicate the clockwise turning of the CC, and the moored current measurements in the Cheju Strait for 1530 days show the low-frequency variability of the along-strait flow with a period of about 37 days.

  • PDF

Characteristics of Concentration Distribution of Coastal Urban Air Pollutants (연안 도시 대기오염 물질의 농도분포 특성)

  • 박종길;석경하;김지형;차주완
    • Journal of Environmental Science International
    • /
    • v.11 no.12
    • /
    • pp.1243-1252
    • /
    • 2002
  • This paper aims to find the characteristics of concentration distribution of coastal urban air pollutants. For this purpose, It was used the daily meteorological data and the hourly concentration data for $O_3$and NO$_2$ in Busan metropolitan city from 1994 to 1996. It was investigated the annual and monthly distribution of ozone and nitrogen dioxide concentration at each site in Busan, and also investigated the characteristics of concentration change of air pollutants with time under the sea breeze. As a results, the concentration of nitrogen dioxide and ozone tend to be increased every year and nitrogen dioxide concentration is higher than ozone concentration at all sites in Busan. The concentration of ozone is high in summer season and low in winter season, but the concentration of nitrogen dioxide have a reversed trend. The monthly peak concentration of ozone occurred in April and September, while the monthly minimum concentration of nitrogen dioxide occurred in August. Their trend were identified by sites near the coastline than sites stands apart from the coastline. The sea breeze occurred annual mean 81 day in Busan from 1994 to 1996. The main wind direction of sea breeze was classified into southwesterly and southeasterly. In case of southwesterly, It was pronounced the south wind and southwest wind. In case of southeasterly, the occurrence frequency of east wind was high. Especially, the concentrations of urban air pollutants, such as ozone and nitrogen dioxide, were high on time which the sea breeze flow, and the areas that ozone concentration was high moved from outside part to central part of city with time. In costal urban such as Busan, the wind direction of sea breeze is influenced the change of ozone and nitrogen dioxide concentration on time which the sea breeze flow at each site and also influenced the change of air pollutants concentration of sites on the pathway of sea breeze.