• Title/Summary/Keyword: Jeju area

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A study on appearance frequencies and fishing ground exploration of trawl vessels obtained by analyzing AIS data of vessels in the sea around Jeju Island (AIS data 분석에 의한 제주도 주변 해역에서의 예망 어선들의 출현빈도와 어장탐색)

  • LEE, Chang-Heun;AHN, Jang-young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.138-144
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    • 2019
  • The purpose of this paper is to explore the fishing grounds of trawl fishery, which are operating in the waters around Jeju Island, and to investigate the monthly shifting changes of the explored fishing grounds. Information on AIS of fishing vessels operating near Jeju Island was collected and analyzed from October 16, 2016 to October 16, 2017. Thus, the location of fishing vessels with the same operational characteristics as those in this industry was extracted and displayed on Google Maps' location drawings to analyze the dense distribution of fishing vessels according to the frequency of their appearance. In the distribution of fishing vessels that appeared in October, a wide range of fishing grounds connecting the upper and lower waters of the 221 and 222 sea of fishing area was found to have gradually expanded and increased density, showing the widest range and highest density in December, and then gradually decreasing from January 2017 to near extinction in May. The distribution of fishing vessels that appeared in the left and lower waters of the 243 sea estuary increased not only in November and December, but also in the appearing sea areas gradually moved to the 242 sea and the range of their appearance was extended to the 241 sea. In other words, the highly dense fishing area in December indirectly shows that it is winter fishing grounds for these industries. The distribution of these dense fishing vessels gradually moved north and west with each passing day, reducing their density and reaching a near extinction in August. However, in September, the density was gradually restored again. Fishing vessels that appeared in high density in the northern waters of the 224 sea east of the Yeoseo island in December were thought to be fishing vessels, whose density decreased over time, almost disappeared in May, and reappeared in July and August, showing a certain degree of density, and then decreased again.

A Cross-sectional Epidemiological Study on Trends in the Prevalence of Allergic Diseases among Children and Adolescents in the Jeju Area in 2008 and 2013 (2008년, 2013년 제주지역 소아청소년의 알레르기질환 유병률 추세에 대한 횡단면적 역학연구)

  • Lee, Hye-Sook;Hong, Sung-Chul;Kim, Jeong Hong;Kim, Jae-Wang;Lee, Keun-Hwa;Lee, Jaechun
    • Research in Community and Public Health Nursing
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    • v.26 no.2
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    • pp.160-168
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    • 2015
  • Purpose: This study was to find epidemiological trends in the prevalence of allergic diseases among children and adolescents in Jeju Province, Korea. Methods: Two questionnaire surveys of the same method were conducted, respectively, in 2008 and in 2013 with five years' interval with 1,296 participants in 2008 and 878 in 2013 who were elementary and secondary students sampled at random from the same five schools. 'International Study of Asthma and Allergies in Childhood (ISAAC)' was applied to the parents with their written consent to the survey. Results: The results of analysis showed an increasing trend in the prevalence of lifetime asthma (8.6% in 2008 and 10.4% in 2013) and in the prevalence of lifetime allergic rhinitis (25.3% in 2008 and 31.1% in 2013) (p=.003), and a decreasing trend in the prevalence of lifetime atopic dermatitis (32.0% in 2008 and 26.8% in 2013) (p=.011). Conclusion: This research showed an increasing trend in the prevalence of asthma and allergic rhinitis among children and adolescents in Jeju Province compared to that 5 years ago, but represented a declining trend in the prevalence of atopic dermatitis.

Distribution of Water Masses and Characteristics of Temperature Inversion in the Western Seas of Jeju Island in Spring (봄철 제주도 서부해역의 수괴 분포와 수온역전 특징)

  • Kang, So-Young;Moon, Jae-Hong
    • Ocean and Polar Research
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    • v.44 no.3
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    • pp.191-207
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    • 2022
  • Using the results of CTD casts made in Spring from 2017 to 2021, in this study we investigated the water mass distribution and occurrence of temperature inversion in the western seas of Jeju Island in spring. The distribution of water masses was characterized by cold and fresh water in the northwest and warm and saline water in the southeast, forming a strong thermohaline front running in the southwest-to-northeast direction. Strong temperature inversion mainly occurred in the frontal boundary when the cold water intrudes beneath the warm water at depths of 30-50 m. Analysis of the mixing ratio demonstrated that Jeju Warm Water is dominantly distributed in the western seas of Jeju Island, but its ratio can be modified depending on the southward extension of Yellow Sea Cold Water (YSCW). Results of in situ measurement showed that in 2020, the YSCW largely expanded to the western seas of Jeju Island, occupying approximately 40 % of the mixing ratio. Due to the expansion of YSCW, a strong thermohaline front was formed in the study area, thereby causing thick and strong temperature inversion. On the other hand, in 2018 the mixing ratio of YSCW was minimum (~18%) during the study period of 2017-2021, and thus a relatively weak frontal boundary was formed, without the occurrence of temperature inversion. The observational results also suggest that the interannual changes of water mass distribution and the associated temperature inversion in the western seas of Jeju Island are closely related with wind-driven Yellow Sea circulation in spring, which is the summer monsoon transition period.

The studies on the preference for attachment to the habitat marine environment and habitat space of Sulculus diversicolor supertexta in Jeju Island (제주도 오분자기의 서식 해양 환경과 서식공간에 대한 부착 선호도에 관한 연구)

  • HEO, Nam-hee;KIM, Keun-hyoung;KANG, Kyoung-Bum;KIM, Suk-jong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.2
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    • pp.106-112
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    • 2022
  • As a series of basic research to draw the pilot design measures for developing the habitat apparatus of Sulculus diversicolor supertexta inhabiting the coastal area of Jeju island, this study conducted a water tank experiment to understand the habitat marine environment of Sulculus diversicolor supertexta and the preference of habitat space focusing on the research fisheries performing the discharge of marine products. In the composition degree of marine algae in both fisheries, Donggwi-ri showed the highest gulfweed (79.3%) as brown algae and there were some coralline algae (17.2%) as red algae. Hansu-ri yielded the highest gulfweed (48.1%) as brown algae, which was followed by sea lettuce (10.4%) as green algae. In the preference of habitat space, the shelter angles 40° showed the highest adhesion as number of 82.9, which was followed by 60° and 70° as 69.2 and 68.2 respectively (P<0.05) by reviewing the environmental characteristics of habit of Salculus diversicolor supertexta in the coastal fishery of Jeju Island, when considering the adhesion rate in each of five shelters with different angles. In the future, there should be continuous research and monitoring for designing the fish shelters suitable for the coastal fisheries of Jeju island, and it would be also necessary to add the field-centered sustainable concrete research.

Estimation of the Traffic Flow in the Korea Coastal Waterway by Computer Simulation (우리나라 연안의 해상교통관제시스템 설치를 위한 기초연구 시뮬레이션에 의한 우리나라 연안의 해상교통량 추정)

  • 구자윤;박양기;이철영
    • Journal of the Korean Institute of Navigation
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    • v.12 no.1
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    • pp.85-112
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    • 1988
  • From the point of view of safety of life and property at sea and the protection of the marine environment, the Vessel Traffic Management System along the Korea coastal waterway is inevitably introduced. But the establishing priority per area must be evaluated under the restricted budget. In this case, the estimated traffic flow has a major effect on priority evaluation. In the former paper , an algorithm was proposed for estimating the trip distribution between each pair of zones such as harbours and straits. This paper aims to formulate a simulation model for estimating the dynamic traffic flow per area in the Korea coastal waterway. The model consists of the algorithm constrined by the statistical movement of ships and the observed data, the regression analysis and the traffic network evaluations. The processed results of traffic flow except fishing vessel are summarized as follows ; 1) In 2000, the traffic congestions per area are estimated, in proportion of ship's number (tonnage), as Busan area 22.3%(44.5%), Yeosu area 19.8%(11.2%), Wando-Jeju area18.1%(6.8%), Mokpo area 14.9%(9.9%), Gunsan area 9.1%(9.3%), Inchon area 8.1%(7.7%), Pohang area 5.5%(8.5%), and Donghae area 2.2%(2.1%). 2) For example in Busan area, the increment of traffic volume per annum is estimated 4, 102 ships (23 million tons) and the traffic flow in 2000 is evaluated 158, 793 ships (687 million tons). 3) consequently, the increment of traffic volume in Busan area is found the largest and followed by Yeosu, Wando-Jeju area. Also, the traffic flow per area in 2000 has the same order.

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Macroscopic Analysis of Traffic Flow in the Korean Coastal Waterway (한국연안의 해상교통류분석(I))

  • 이철영;문성혁;최종화;박양기
    • Journal of the Korean Institute of Navigation
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    • v.10 no.2
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    • pp.31-55
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    • 1986
  • Generally, the development of shipping is characterized by the amount of traffic flow (traffic volume) and seaborne cargo in the sea. Movement of ships is an essential element of constructing the traffic flow which is represented the dynamic movement of ships in the sea, but on the other band the numbers of arriving and departing the port is the basic factor consisting of the static movement of ships. The amount of cargoes by coastal vessels and ocean trade vessels have increased tremendously with the great growth of the Korean economy these days. This increase of the seaborne cargoes has made the Korean coastal traffic flow so congested that this can be a cause of large pollution as well as great marine casualities such as a loss of human lives and properties . And also the future coastal traffic is expected to increase considerably according to our economic development and high dependence upon foreign trade. Under the circumstance, to devise the safety of coastal traffic flow and to take a proper step of a efficient navigation, there is a necessity for analyzing and surveying the coastal traffic trend and the characteristics of cargo movement. In order to grasp the dynamic movement of ships in the Korean coast, O/D analysis is executed. This paper aims to secure the basic data necessary for a comprehensive plan and estimation of vessel traffic management system for the enhancement of safety, order and efficiency of vessel traffic in the Korean coast. The analyzed results of the traffic flow and seaborne cargoes of the Korean coast are summarized as follows : 1) The congestion by the vessels occurred around the ports such as-in proportion of ship's number (proportion of tonnage) -Incheon 18.5%(14.8%), Pohang 5.9% (9.9%), Samil 5.2%(8.3%), Mokpo 8.6%(0.8%), Pusan 13.5%(36.4%), Ulsan 9.1%(16.2%). 2) It is found that the area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed thatthe area adjacent to Incheon, Pusan, Ulsan, Channel of Hanryu and South-western area are heavily congested. 3) It is confirmed that the coastal vessels are main elements constituting the coastal traffic and that there are much traffic flow among five ports as following through the precise O/D analysis of ship's coastal movement. Incheon-Samil, Ulsan, Pusan, Jeju Pusan -Samil, Ulsan, Incheon, Jeju Pohang -Samil, Inchoen, Jeju Pohang -Samil, Incheon, Jeju Ulsan -Samil, Incheon, Jeju Samil -Ulsan, Pusan, Incheon 4) The amount of cargoes to abroad are in proportion about 81% of total and the amount of coastal cargoes are about 19%. Of those, cargoes in and out to Japan are about 26% and to South-east Asia are about 27%. 5) The chief items of foreign cargoes are oil(38.33%), iron ore(13.98%), bituminoous coal(12.74%), grain(8.02%), lumber(6.45%) in the import cargoes and steel material(21.96%), cement(17.16%), oil(6.81%), fertilizer(3.80%) in the export cargoes. 6) The 80.5% of total export cargoes and 92.4% of total import cargoes are flowed in five main ports. 7) The chief items of coastal cargoes are oil (42.45%), cement(16.86%), steel material (6.49%), anthracite(6.31%), mineral product(4.3%), grain, and fertilizer. Almost 92.24% of total import and export oil cargoes in Korea is loaded and unloaded at the port of Samil & Ulsan.

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Geophysical Studies on the Geological Structure in the Southern Sea of Korea (한국남해(韓國南海)의 지질구조(地質構造)에 관(關)한 지구물리학적(地球物理學的) 연구(硏究))

  • Cho, Kyu Jang;Shin, Byung Woo
    • Economic and Environmental Geology
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    • v.14 no.2
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    • pp.77-91
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    • 1981
  • An airborne magnetometer survey was carried out over an offshore area of about $200,000km^2$ from the southeastern, southern and western part of Korea. Detailed magnetic studies on the geological structure of the southern part of above area ($100,000km^2$) was accomplished. Residual aeromagnetic map was made in order to delineate magnetic provinces, magnetic lineaments and sedimentary basins by application of least square method using computer system. To determine the depth of the sedimentary basins pseudo-gravimetric method was applied. 1. The area studied is divided into four magnetic provinces for the purpose of interpretation on the basis of the magnetic maps. 2. Near shore area and its attached islands of southern part (fiirst and second magnetic province) can be regarded as being the extension from the land geology due to presentation of strong magnetic anomalies and shallow magnetic basements. 3. Magnetic lineament 1-1 is strong magnetic anomalous region which is presumably relevant to volcanic activities in Cretaceous. The depth of magnetic basement of the lineament was determined to 1,500 m. Negative magnetic anomalous zones B1-1 and B1-2 which represent Tertiary basins showed depth of magnetic basement 3 km and 4 km each. The latter can be interpreted as extension of the Taiwan basin which is consisted of Tertiary sediments. 4. Magnetic lineament 2-1 coincide with Rainan-Fukien massif running NE-SW direction. A lineament located in central part of magnetic lineament 2-1 is well connected with extension of Sobacksan anticlinal axis on land. Volcanic rocks in Gyongsang system concentrated along this lineament. 5. The characteristics of magnetic pattern in the southern Yellow sea basin of western part of Jeju island show weaker magnetic anomalies and deeper magnetic basements than first and second magnetic provinces indicating geological structure of this basin seems to be quite different from that of Jeju strait. 6. In southern part of Jeju island, smoother magnetic pattern develope southward. Maximum depth of magnetic basement in sedimentary basins BIV-1 and BIV-2 were determined down to 6,000 m increasing its thickness toward Taiwan up to 11,000 m in the shelf area off Taichung, Taiwan. Judging from the fact that hydrocarbon was founded in the Tertiary sediments of western coastal area of Taiwan, it can be expected that hydrocarbon will be existed in these sedimentary basins of southern part of Jeju island.

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Analysis of groundwater level variability in the middle mountain area of Pyoseon watershed in Jeju Island using normalized standard deviation and cross correlation coefficient (정규화된 표준편차 및 교차상관계수를 이용한 제주도 표선유역 중산간지역의 지하수위 변동성 분석)

  • Shin, Mun-Ju;Moon, Soo-Hyoung;Moon, Duk Chul
    • Journal of Korea Water Resources Association
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    • v.53 no.5
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    • pp.337-345
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    • 2020
  • In order to provide information for proper management of groundwater resources, an analysis of the effects of precipitation and groundwater withdrawal on groundwater levels is needed. In this study, we analyzed the correlation of precipitation-groundwater level and groundwater withdrawal-groundwater level using time series data converted by normalized standard deviation (Nor.St.Dev) and cross correlation coefficient (CCC) for nine groundwater monitoring wells in the middle mountainous area in the southeastern Jeju Island. First, the CCCs of precipitation-groundwater level were estimated using daily time series data, and the low CCCs of up to 0.3 were obtained. However, the result of using the Nor.St.Dev showed a clearer correlation by obtaining a CCC of up to 0.8. In addition, in most cases, precipitation variability and groundwater level variability had positive CCCs, whereas groundwater withdrawal variability and groundwater level variability had negative CCCs. Therefore, the groundwater level in this study area was largely influenced by precipitation with little effect of groundwater withdrawal. Lastly, as a result of analyzing the relative effects of Seongpanak and Gyorae rainfall station on the groundwater level, the rainfall at the relatively downstream Gyorae rainfall station has more influence. The analysis method used in this study can be easily used for analyzing the effects of precipitation and groundwater withdrawal on groundwater level variability in other regions in the future.

The Status of Contact Lens Wearing, Management and Eye Health Awareness Among Female University Students in Jeju Area (제주지역 여대생들의 콘택트렌즈 착용 및 관리 실태와 눈건강 인식)

  • Choi, Ji Young;Song, Yun Young;Byun, Jong Chul
    • Journal of Korean Ophthalmic Optics Society
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    • v.21 no.3
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    • pp.203-214
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    • 2016
  • Purpose: The purpose of this study is to analyze the status of contact lens wearing, management and awareness of eye health knowledge among female university students in Jeju area and to utilize the basic data for education and management of contact lens. Methods: Data for this study were collected from the 236 female university students in Jeju area who have a contact lens experience from May 1, 2016 to June 11, 2016. Results: We found the status of contact lens wearing and management of subjects and there were different correlations between discomfort and awareness of eye health knowledge among the subjects who have different characteristics. There were also correlations in discomfort, the average days of contact lens wear per week, initial wearing day and action when they have any discomfort in some contact lens wearers. Conclusions: We realized the status of contact lens wearing and management of female university students and it suggests appropriate contact care education and sustainable management system are need to be established for considering daily average wearing time, the type and material of contact lens wear and main discomfort and so on.