• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.237-240
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• 2004

When the concrete structures are in contact with seawater, concentration of chloride for estimating chloride diffusion coefficient can be defined as the chloride concentration of sea water. However, in case the concrete structures, constructed in the seashore, aren't directly in contact with seawater, it is difficult to establish the interface concentration of chloride. In addition, marine concrete structures are greatly affected by salt attack such as rebar corrosion, among the cause of salt attack, airborne sea salt is primary factor. Therefore, in this study, salt attack environment by airborne sea salt was investigated in terms of a seasonal distribution at 33 spots, 6 areas in the East, West, South coast for 1 year. Results indicated that in the South coast, the amount of the airborne sea salt is comparatively higher in summer. in the West coast. higher in winter. On the other hand, in the East coast, the amount of the airborne sea salt is rarely affected by a season.

• 한국해양학회지
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• 제16권1호
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• pp.12-23
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• 1981

A numerical experiment is made in order to clarify the mechanism of the upwelling phenomenon along the coast near the poleward edge of the western boundary current. The possibility of the upwelling is suggested from the analysis of the observational data in the east of Honshu, Japan, and in the south eastern coast of Korean Peninsula. This upwelling phenomenon is very deep and can be traced to the bottom layer. The upwelling phenomenon seems to be a general oceanic feature which characterizes the region along the west coast near the poleward edge of the western boundary current. This experiment is simulating the oceanic condition of the transition region between Kuroshio front and the Oyashio front in the east of Honshu, Japan. The possible explanations of the causes of the upwelling are as follows;In the interior of the modeled ocean the cold heavy water supplied from the north and the warm light water from the south make the north-south gradient of the pressure field and accelerate the eastward current to produce the h-orizontal divergence feld near the west coast. The divergence is compensated by the upwelling near the separation region. Another one is that the upwell-ed cold water strengthen constantly the pressure gradient which is balanced by the northward current and is weakened by the horizontal diffusion.

• 수산해양기술연구
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• 제56권4호
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• pp.322-339
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• 2020

Temporal and spatial fluctuations of surface water temperature in Yeosu Bay for the period from 2010 to 2011 were studied using the data from temperature monitoring buoys deployed at 32 stations in the south coast of Korea. Temperatures in the northern part of the bay are higher in summer and lower in winter than in the southern part of the bay. The lowest and highest temperature of the annual mean are found at the eastern coast of POSCO and at the west of Dae Island, respectively. Cold water masses appear at estuarine area when the discharge of Sumjin river is affluent. Amplitude of temperature fluctuation whose period is less than semi-diurnal is largest at Hadong coast and around Dae Island. Spectral analysis of surface water temperature shows a significant peak at a periodic fluctuation of 0.5 to 24 days and about 15-day period of predominant fluctuation is most frequent in Yeosu Bay. From the cross-correlation analysis of temperature fluctuations, Yeosu Bay can be classified into six areas; the south area affected by South Sea of Korea, the mixed area in the center of the bay, the estuarine area affected by river discharge at the north of the bay, the hot waste water area near Hadong coast, the area around Dae Island and the area near Noryang Channel affected by the water in Jinju Bay, respectively.

• Acta Via Serica
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• 제3권2호
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• pp.23-48
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• 2018

The Silk Road usually implies a network of trade and communications that stretched from east to west and connected China and the countries of the Far East via Central Asia and the Middle East to the eastern Mediterranean, or through the northern coast of the Caspian Sea and the Volga basin to the Black Sea coast. However, at certain historical stages, a network of maritime and overland routes stretching from north to south, commonly called the Volga-Caspian trade route, also played a significant role in international trade and cultural contacts. The geopolitical realities of the early Middle Ages relating to the relationship of Byzantium, the Sassanid Empire, and the West Turkic Khaganate, the advance of the Arab Caliphate to the north, the spread of Islam in the Volga region, the glories and fall of the Khazar State, and the Scandinavian campaigns in the Caucasus, closely intertwined with the history of transport and communications connecting the north and south through the Volga-Caspian route. In a later era, the interests of the Mongolian Uluses, and then the political and economic aspirations of the Ottoman Empire, the Safavid State, and Russia, collided or combined on these routes. The article discusses trade contacts existing between the north and the south in the 15th and first half of the 17th century along the routes on the western coast of the Caspian Sea.

• The Korean Journal of Ecology
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• 제6권3호
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• pp.177-186
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• 1983

Vegetation types and their standing crop in the sand dune on the south coast of Korea was investigated by the method of Curtis, J.T. and McIntosh, R.P. (1951). The relationship between vegetation types and environmental factors was also analyzed. The dominant species in the vegetations of the south coast sand dune were Carex pumila, Calystegia soldamella, Imperata cylindrica var. koenigii, Vitex rotundifolia, Ixeris repens, Carex kobomugi, Zoysia macrostachya. The species density in the sand dune vegetation increased with the distance from the coast, psammophyte and rhizome psammophyte decreased with the distance from the coast but other plants increased. The standing crop of the sand dune vegetatiion was average $53.79g/m^2$. An individual standing crop of Vitex routundifolia and Carex kobomugi varied with the curve of secondary degree. The salt content of the sand dune soil from 2.95 to 11.78 mg %, and it was not significant differences among stands, but it was varied with the distance form the coast. Negative relationship between warmth index and aboveground standing crop was found and the formula y=283.8886 - 2.4910X could be estimated.

• Journal of Ecology and Environment
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• 제42권1호
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• pp.12-19
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• 2018

Background: The objective of this study was to determine the relationship between soil environmental factors and halophyte distribution in the west coast of South Korea. Soils of our study sites were categorized into two groups: salt marsh and estuary marsh. Results: Salinity was higher in the salt marsh group than that in the estuary marsh group. However, total nitrogen, silt, and clay contents were higher in the estuary marsh group than those in the salt marsh group. Although altitude had a wider range in the salt marsh group, the mean altitude was higher in the estuary marsh group than that in the salt marsh group. Annual halophytes of seed propagation species were distributed parallel to the coast line on salt marsh. Higher coverage of vegetation was found in the area closer to the coast line. Plant density was higher near dead parental plants in estuary marsh, showing less difference in area that was more distant from the coast line. Conclusions: Results of canonical correspondence analysis (CCA) for vegetation distribution and sediment environmental factors and germination analysis in the coast line showed significant relationship with halophyte distribution. Therefore, they can be used as an indicator of coastal plant movement due to sea level rise.

• 한국지형학회지
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• 제24권4호
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• pp.43-55
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• 2017

This study tries to examine papers on coastal terrace in the East Coast of South Korea and to summarize formative age and elevation of the terrace. Spatial and temporal variations of uplift rate in the Coast based on absolute age published are also reviewed. The terrace in the middle part in the Coast from Goseong to Samcheok distributes in an elevation of 10-20 m and its formative age is MIS 5a. The terraces during MIS 5e and 7 develop on an elevation of 20-35 m and 60-80 m, respectively. The mid-southern part in the Coast from Uljin to Yeongil Bay has the terraces with elevations of 10-25 m and 25-45 m and their ages are MIS 5a or 5c and 5e, respectively. The terraces with elevations of 10-25 m and 30-45 m correspond to MIS 5a and 5e, respectively, in the southern part in the Coast from Homigot to Busan. Assuming that elevation of sea level during the formation of each terrace is the same as in the present time, uplift rates in the Coast range from 0.05 to 1.36 m/ky with an average of approximately 0.33 m/ky. The highest and lowest rates since MIS 5 are found in the Gyeongju (approximately 0.39 m/ky) and Pohang (approximately 0.19 m/ky) areas. With a consideration of elevation of sea level at that time, however, the middle, midsouthern and southern parts in the Coast show uplift rates of 0.16-0.28 m/ky, 0.20-0.36 m/ky and 0.24- 0.36 m/ky since MIS 5, respectively, suggesting that the southern part in the Coast has experienced relatively higher uplift rate.

• ALGAE
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• 제20권3호
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• pp.183-196
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• 2005

Nuclear SSU and ITS1 rDNA and plastid rbcL sequences were determined to identify the seven samples of Porphyra cultivated by means of natural seeding on the southwest coast of Korea and analyzed to access the phylogenetic relationships of them with the natural populations of P. tenera and P. yezoensis from Korea and Japan. SSU, rbcL and ITS1 data from 18, 21 and 31 samples, respectively, including previously published sequences were investigated in the study. Results from our individual and combined data indicated that the seven samples were all P. yezoensis and the entities except one from Muan 2 aquafarm strongly grouped together with the natural populations of P. yezoensis from the south and the west coast of Korea. The sample from Muan 2 seems to be derived from a strain of P. yezoensis introduced from Japan by Porphyra farmers, based on DNA sequence data.

• The Korean Journal of Ecology
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• 제24권4호
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• pp.219-222
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• 2001

The study was conducted to get the basic information for proper protection and management of black-faced spoonbill and their habitats in western coast of South Korea. The species was observed in 8 sites of western coast of South Korea in spring 2000. We confirmed breeding of this species at least 4 pairs in Seokdo island. This island is considered likely to be an imortant breeding site together with Yodo island, Hambakdo island and Yokdo island. Also, we observed breeding of herring gull in Seokdo island and small island nearby Boleumdo island for the first time in South Korea. Chilsando island, Cheonsuman bay and Gyeokyeolbiyeoldo island were considered as stopovers located on the Korean Peninsula route. The other sites were considered as summering sites of the black-faced spoonbill. Especially the birds were constantly observed from breeding season to postbreeding season in Seonduri and Yeochari of Ganghwado island. We have counted maximum 88 individuals gathered at Gaksiyeo in Seonduri and Yeochari on September 3, 2000. The species seemed to gather at these sites after breeding for migration to wintering ground in September. We also surveyed changes of the number of individuals as time of the ebb and flow on September 3 and 6, 2000, their time budgets were affected by the ebb and flow in these sites.

• Parasites, Hosts and Diseases
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• 제33권1호
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• pp.27-36
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• 1995

쭈쭈가무시병 환자의 유병률이 가장 높은 남해안 연안지역과 유병률이 낮은 동해안 연안 지역에서 매개 진드기 및 들쥐와 연관되는 제반 역학적 비교조사를 1993년 10월에 실시하였다 채집된 6 종의 들쥐(187개체) 중 등줄쥐(Apodemugrwin)가 양지역에서 모두 절대 우점종이었고 개체군 밀도에 있어서도 차이가 없었다(트랩 채집률 각각 20.4%, 19.4%). 국내 매개종으로 확인된 Leptotrombidiumpalldum과 L. sueuare는 모두 채집된 6종의 들쥐중 등줄쥐에 주로 기생하였는데, 두당 각각 59마리와 69마리가 기생하고 있었다 등줄쥐의 Rickettsia tsutsugamushi, 병원체에 대한 항체 양성률은 남해안 43.2% 동해안 63.6%로 동해안 지역에서 약간 높게 나타나 환자 발생과는 다른 양상을 보였다. 지역에 관계없이 등줄쥐의 감염률(항체 양성률)과 매개종인 L. suteuure와 L. poninw의 개체군 밀도간에 높은 상관관계를 보였다(r : 0.87). 이와같은 사실은 들쥐에 대한 양종의 매개 효율성(vectorefacacy)이 똑같이 높다는 것을 의미한다. 양지역간의 가장 중요한 역학적 차이는 매개종으로. 남해안 지역에서는 L. sueuore가 절대 우점종(74.9%)인 반면 에 동해안 지역에서는 L. pallidum이 절대 우점종(60.4%)이었다. 두종의 개체군 밀도에는 큰 차이가 없었다. 조사지역이 불충분하여 확실하게 결론지을 수는 없지만 L. sueuqre의 개체군 밀도가 높을수록 환자 유병률도 높게 나타나 L. sueuare가 인체에 대한 매개효율성(vectorefacacy)이 L. pallidum보다 월등하게 높은 중요한 매개종이라 생각된다.