• Title/Summary/Keyword: coast type

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A Study on the Climatic Type in Korea by the Characteristics of Temperature Distribution (기온분포의 특성에 의한 우리나라의 기후형에 관한 연구)

  • 민병언
    • Journal of the Korean Institute of Navigation
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    • v.3 no.1
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    • pp.29-46
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    • 1979
  • The climate of a given region is determined by the combination of the various climatic elements. But among them, the temperature is the most important element to classify the climatic type. The author attempted to classify the climatic types in Korea by making a analysis of the characteristics of temperature distribution. To accomplish the study, the author analyzed the daily and yearly range of temperature, the warmest and coldest months, continentality and oceanicity, thermal anomaly, and relative temperature, etc. The data of 153 weather stations are used for the analysis of the above five criteria. As a result of the study, the climate of Korea can be divided into three types, namely, the continental, coastal and intermediate(or transitional) type. The Pronounced continental type is appeared in the northern part of highland area. And the coastal type is limited to the east and south coast areas, and the southern part of the west coast area. The continentality is larger, and the oceanicity smaller, than those of Siberia, Mongolia and the inland area of China where the continental climate is most remarkable in the world. The reason why the west coast area is more continental than the east coast area may be due to the terrain effect and the warm current going north along the east coastline.

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Characteristics and prediction methods for tunnel deformations induced by excavations

  • Zheng, Gang;Du, Yiming;Cheng, Xuesong;Diao, Yu;Deng, Xu;Wang, Fanjun
    • Geomechanics and Engineering
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    • v.12 no.3
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    • pp.361-397
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    • 2017
  • The unloading effect from excavations can cause the deformation of adjacent tunnels, which may seriously influence the operation and safety of those tunnels. However, systematic studies of the deformation characteristics of tunnels located along side excavations are limited, and simplified methods to predict the influence of excavations on tunnels are also rare. In this study, the simulation capability of a finite element method (FEM) considering the small-strain characteristics of soil was verified using a case study. Then, a large number of FEM simulations examining the influence of excavations on adjacent tunnels were conducted. Based on the simulation results, the deformation characteristics of tunnels at different positions and under four deformation modes of the retaining structure were analyzed. The results indicate that the deformation mode of the retaining structure has a significant influence on the deformation of certain tunnels. When the deformation magnitudes of the retaining structures are the same, the influence degree of the excavation on the tunnel increased in this order: from cantilever type to convex type to composite type to kick-in type. In practical projects, the deformation mode of the retaining structure should be optimized according to the tunnel position, and kick-in deformation should be avoided. Furthermore, two methods to predict the influence of excavations on adjacent tunnels are proposed. Design charts, in terms of normalized tunnel deformation contours, can be used to quantitatively estimate the tunnel deformation. The design table of the excavation influence zones can be applied to determine which influence zone the tunnel is located in.

Basic Data Advancement for Improving the Accuracy of Estimating the Damage Cost Caused by Strong Winds on the Korean Peninsula during Typhoon Periods (한반도 태풍시기 강풍유발 피해액 산정의 정확도 향상을 위한 기초자료의 고도화)

  • Yun, Hee-Seong;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.31 no.1
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    • pp.87-97
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    • 2022
  • In this study, type analysis was conducted along with the advancement of basic data to calculate the maximum damage caused by strong winds during the typhoon period. The result of the damage by region showed that in 2012, the difference in damage was clearly distinguished as the region was classified in detail. In addition, the result of the annual damage in 2011 was strong on the west coast, and in 2016, the damage to the southeast coast was significant. In 2012, the 3-second gust was relatively stronger on the west and southeast coasts than in 2011, and the winds blew stronger along the southeast coast in 2016. Monthly damage data showed that the damage to the west coast was high in August, and the damage to the southeast coast was high in October from 2002 to 2019. The 3-second gust showed the result of wide expansion throughout the southern coast of the Korean Peninsula in October. As a result, the damage differs for type bacause the intensities and paths of typhoons vary depending on their characteristics, the 3-second gust blows differently by region based on regional characteristics, and the sale price is considered in metropolitan cities.

A Study on Characteristics of Coastline Change in Eastern Coast Korea (한국 동해안의 변화특성)

  • 이종태
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.15 no.1
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    • pp.35-42
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    • 1979
  • This paper concerns the receding of the eastern coastline of Korean peninsula at a macroscopic point of view, the result is as following. 1. Eastern coast is gradually developed from maturity stage to full maturity stage. 2. The coastline recession due to sea level rise is amounted to the receding distance, x=0.045 m per yr. 3. The author proposes another classification from the new view point, which is classified by comparing quantities between river supplying sediment loads, and the littoral drifting due to wave actions. According this, eastern coast is receding(Type Q-A), and we could find it's geomorphological characteristics. 4. The general piofile of eastern coast sand beach is erosional storm profile(Type I) which accompany offshore bar. 5. From the wave measuring data of eastern coast(Hoopo port), I can derive the linear regression line of the exceedance probability of wave height from the log-normal distribution. $z=O. 113+4.335 log_lo H, r=0.983.$ Above equation made it possible to estimate $\omega[=P(H>H_c)]for the effective wave height H_c=2. Om4, 4. Om and their corresponding values are considerable (7.8%, 0.3%) 6. Eastern coastline certainly have the tendency of erosive and receding, owing to the sea level rise, poor sediment source and effective wave actions. It's very desirable to survey coastline evolution for a long time systematically, in order to make more elaborate diagnosis.

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The Characteristics of the Anomaly Level and Variability of the Monthly Precipitation in Kyeongnam, Korea (경남지방의 월강수량의 변동율과 Anomaly Level의 출현특성)

  • 박종길;이부용
    • Journal of Environmental Science International
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    • v.2 no.3
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    • pp.179-191
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    • 1993
  • This paper aims to know the characteristics of occurrence of the anomaly level and variability of the monthly precipitation in Kyeongnam, Korea. For this study, it was investigated 주e distribution of the annual and cont비y mean precipitation, the precipitation variability and its annual change, and the characteristics of occurrence of the anomaly level in Kyeongnam area the results were summarized as follows : 1) she mean of annual total precipitation averaged over Kyeongnam area is 1433.3mm. I'he spatial distribution of the annual total precipitation shows that in Kyeongnam area, the high rainfall area locates in the southwest area and south coast and the low rainfall area in an inland area. 2) Monthly mean precipitation in llyeongnam area was the highest in July(266.4mm) 각lowed by August(238.0mm), June(210.2mm) in descending order. In summer season, rainfall was concentrated and accounted for 49.9 percent of the annual total precipitation. Because convergence of the warm and humid southwest current which was influenced by Changma and typhoon took place well in this area. 3) The patterns of annual change of precipitaion variability can be divided into two types; One is a coast type and the other an inland type. The variability of precipitation generally appears low in spring and summer season and high in autumn and winter season. This is in accord with the large and small of precipitation. 4) The high frequency of anomaly level was N( Normal)-level and the next was LN( Low Informal) -level and 25(Extremely Subnormal)-level was not appeared in all stations. The occurrence frequency of N level was high in high rainfall area and distinguish성 in spring and summer season but the low rainfall area was not. hey Words : anomaly level, variability, precipitation, coast type, inland type.

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The Relationship of Froude Number and Developed Cloud Band Locations Near Yeongdong Region Under the Siberian High Pressure System (시베리아 고기압 영향으로 영동지역 부근에서 발달한 구름대의 위치와 Froude 수와의 관계)

  • Kim, Yu-Jin;Kim, Man-Ki;Lee, Jae Gyoo
    • Atmosphere
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    • v.29 no.3
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    • pp.325-342
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    • 2019
  • Precipitation and no-precipitation events under the influence of the Siberian high pressure system in Yeondong region, were analysed and classified as four types [obvious precipitation event (OP) type, obvious no-precipitation event (ON) type, ambiguous precipitation event (AP) type and ambiguous no-precipitation event (AN) type], according to the easiness in determining whether to have precipitation or not in Yeongdong region, to help in improving the forecast skill. Concerning the synoptic pressure pattern, for OP type, the ridge of Siberian high extends from Lake Baikal toward Northeast China, and there is a northerly wind upstream of the northern mountain complex (located near the Korean-Chinese border). On the other hand, for ON type, the ridge of Siberian high extends southeastward from Lake Baikal, and there is a westerly wind upstream of the northern mountain complex. The pressure pattern of AP type was similar to the OP type and that of AN type was also similar to ON type. Thus it was difficult to differentiate AP type and OP type and AN type and ON type based on the synoptic pressure pattern only. The four types were determined by U (wind speed normal to the Taebaek mountains) and Froude number (FN). That is, for OP type, average FN and U at Yeongdong coast are ~2.0 and ${\sim}6m\;s^{-1}$, and those at Yeongseo region are 0.0 and $0.1m\;s^{-1}$, respectively. On the contrary, for ON type, average FN and U at Yeongdong coast are 0.0 and $0.2m\;s^{-1}$, and those at Yeongseo region are ~1.0 and ${\sim}4m\;s^{-1}$, respectively. For AP type, average FN and U at Yeongdong coast are ~1.0 and ${\sim}4m\;s^{-1}$, and those at Yeongseo region are 0.0 and $0.2m\;s^{-1}$, whereas for AN type, average FN and U at Yeongdong coast are 0.1 and $0.6m\;s^{-1}$ and those at Yeongseo region are ~1.0 and ${\sim}3m\;s^{-1}$, respectively. Based on the result, a schematic diagram for each type was suggested.

Vertical Distribution of the Underwater Ambient Noise Level in the Korea East Coast Areas (한국동해안에서의 해중소음의 수직음압분포)

  • 박중희
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.21 no.1
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    • pp.7-11
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    • 1985
  • Underwater ambient noise in the depth 5m to 200m layers was measured at 14 point from the 24th of July to 2nd of August, 1984, in the Korean east sea areas. The underwater ambient noise pressure level was depended upon configuration of the sea bottom and sea condition, which was formed type of prevaling noise at a long distance from coast and type of intermittent and regional noise at a short distance from coast.

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A Comparison on the Forest Type of Coastal Disaster Prevention Forest Between the Coastal Areas in Korea (우리나라 해안별 해안방재림의 유형특성 비교)

  • Kim, Chan-Beom;Park, Ki-Hyung;Lee, Chang-Woo;Youn, Ho-Joong;Kim, Kyongha
    • Journal of Korean Society of Forest Science
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    • v.103 no.4
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    • pp.564-573
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    • 2014
  • The objective of this study was to select a representative coastal disaster prevention forest type for each coastal area. In this study, we used cluster analysis with the results obtained from investigation for density of growing stock, tree height, DBH, and forest width and length of major coastal disaster prevention forests distributed in the west, the south, and the east coasts. The results showed that the coastal disaster prevention forests for each coast were classified into two types: a forest type with small DBH and high growing stock density (W1) or with high tree height (W2) in the west coast, a forest type with small tree height (S1) or with large DBH (S2) in the south coast, and a forest type with small growing stock density (E1) or with small tree height and low DBH (E2) in the east coast. The coastal disaster prevention forests located in Gurye beach (Hwangchon-ri, Wonbuk-myeon, Taean-gun, Chungcheongnam-do) and in Gohsapo beach (Unsna-ri, Byeonsan-myeon, Buan-gun, Jeollabuk-do) were selected as the representative forests of W1 and W2, respectively. In addition, the coastal disaster prevention forests located in Namyang beach (Namyang-ri, Seolcheon-myeon, Namhae-gun, Gyeongsangnam-do) and in Donggo beach (Donggo-ri, Sinji-myeon, Wando-gun, Jeollanam-do) were selected as the representative forests of S1 and S2, respectively. Last, the coastal disaster prevention forests located in Bonggil beach (Bonggil-ri, Yangbuk-myeon, Gyeongju-si, Gyeongsangbuk-do) and in Anmeok beach (Gyeonso-dong, Gangneung-si, Gangwon-do) were selected as the representative forests of E1 and E2, respectively. Our finding is expected to be used as baseline data in establishing the most appropriate coastal disaster prevention forest for each coast.

A Study on the Method to Minimize Measuring Burial Depth Error for Submarine Cable (해저케이블 매설심도 측정오차 저감 방법에 관한 연구)

  • An, Yong-Ho;Kim, Yong-Hak;Han, Jeong-Yeol;Lee, You-Jin;Han, Byoung-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.2
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    • pp.329-334
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    • 2012
  • The distribution submarine cables are normally used for power supply at island, which are mostly installed in the southern coast of KOREA, and partially installed in the west coast and Jeju-Island. There are two way of submarine cable burying system, buried and unburied type. Since 2003, KEPCO is entirely being constructing the distribution submarine cable by buried type. In this case, 'burial depth' is key index for evaluating the suitability of the buried situation. Therefore, the measurement accuracy of 'burial depth' is a big issue for burying system in the distribution submarine cable. This paper demonstrates the measurement error of burial depth that is affected by electrical factor such as grounding type of submarine cable in case of magnetic field detection method, and indicates the method to reduce the measurement error in buried type of distribution submarine cable system.