• Title/Summary/Keyword: 평균파고

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Wave Tendency Analysis on the Coastal Waters of Korea Using Wave Hind-Casting Modelling (파랑후측모델링을 이용한 연안 파랑경향성 분석)

  • Kang, Tae-Soon;Park, Jong-Jip;Eum, Ho-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.7
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    • pp.869-875
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    • 2016
  • The purpose of this study is to analyze the long-term wave characteristics and tendencies of coastal waters near Korea based on wave hind-casting modelling. Wave hind-casting modelling was performed with a wind data set from ECMWF (2001~2014), which provides data from 1979 to the present. The results of numerical modelling were verified with observed data collected using wave buoys installed by the Korea Meteorological Administration (KMA) and Korea Hydrographic and Oceanographic Agency (KHOA) in offshore waters. The results agreed well with observations from buoy stations, especially during event periods such as typhoons. The quantitative RMSE value was 0.5 m, which was significant. Consequently, the results of a wave tendency analysis for 14 years (2001~2014) showed an increased appearance ratio for waves of more than 2 m in height at all regional domains. The mean appearance ratio was 0.082 % per year, which implies that coastal waves have been increasing continuously. This coastal wave tendency analysis data can be used to evaluate coastal vulnerability due to recent climate change and the design of coastal erosion prevention structures.

Assessment of Wave Power Potential in the Kangwon and Dongnam Regions, Korea (강원권 및 동남권 지역의 파력발전 잠재성 평가)

  • Jang, Mi-Hyang;Choi, Yo-Soon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.4
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    • pp.91-105
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    • 2013
  • This study performed an assessment of wave power potential in the Kangwon and Dongnam regions encompassing the East Sea and part of South Sea. Annual electricity production and economic effects of 28 wave energy converters with 750kW capacity were analyzed using significant wave height and peak wave period data(created from the NOAA's NWW3 model) and InVEST software(developed by Stanford University and University of Minnesota). Annual electricity production was estimated to be up to 1,207MWh/year and at least 163MWh/year. The spatial pattern of annual electricity production showed that the sea far from land has higher wave power potential than the sea near coast. The net present value(NPV) of 28 wave energy converters was calculated by considering an operation period of 25 years. When assuming that the electricity produced from wave energy converters is transferred to onshore power plants through underwater cables, the NPV was estimated to be up to 5,883USD(6,600,000KRW) and at least -63,494USD(-71,000,000KRW). In contrast, the NPV increased up to 28,095 USD(31,600,000KRW) when assuming that the electricity is utilized in the Ulleungdo and Dokdo. In addition, it was found that the break-even line of NPV in the East Sea becomes closer towards the land according to the increment of electricity price. The NPV of wave energy converters near the Ulleungdo and Dokdo will be 88,158 USD(99,000,000KRW) if the increment of electricity price is 100KRW.

Spawning Behavior and Embryonic Development, Larvae of the Ice Goby, Leucopsarion petersii Reared in Aquarium (실내 수조에서의 사백어 Leucopsarion petersii(Pisces: Gobiidae) 산란행동 및 배와 자치어 형태)

  • Myoung, Jung-Goo;Oh, Sung-Yong;Choi, Hi Jeong;Park, Yong-Joo;Kim, Min Seok;Lee, Yong Uk
    • Korean Journal of Ichthyology
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    • v.34 no.1
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    • pp.57-63
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    • 2022
  • On April. 2016, the anadromous icy goby caught at Shinbong-cheon, Tongyeong shi, Gyeongsangnam-do transported to the laboratory of Korea Institute of Ocean Science and Technology (KIOST) and observed spawning behavior and egg development and larvae. In aquarium, males make the nest under stone and waiting female entering. Fertilized eggs attached under the stone in the nest. Male protected the fertilized eggs until hatching. The size of the club-shaped eggs were 3.2~3.4 mm in the major axis and 0.6~0.8 mm in minor axis (n=10). The eyed eggs were hatched after 168 hrs in a range of water temperatures (18.0~20.0℃). The total lengths of newly hatched larvae were 4.1~4.4 mm (n=5) and these larvae had 32~33 (12~13+20) myotomes and transparent oval yolk. Three days after hatching, the pre-larva (4.9 mm in total length) has opening mouth and rectum. Post-larva with 5.2 mm total length have melanophore on air bladder, rectum, base of membranous caudal fin and 9~10 melanophores ventral row on the tail.

Accuracy Assessment of Tide Models in Terra Nova Bay, East Antarctica, for Glaciological Studies of DDInSAR Technique (DDInSAR 기반의 빙하연구를 위한 동남극 테라노바 만의 조위모델 정밀도 평가)

  • Han, Hyangsun;Lee, Joohan;Lee, Hoonyol
    • Korean Journal of Remote Sensing
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    • v.29 no.4
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    • pp.375-387
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    • 2013
  • Accuracy assessment of tide models in polar ocean has to be performed to accurately analyze tidal response of glaciers by using Double-Differential Interferometric SAR (DDInSAR) technique. In this study, we used 120 DDInSAR images generated from 16 one-day tandem COSMO-SkyMed DInSAR pairs obtained for 2 years and in situ tide height for 11 days measured by a pressure type wave recorder to assess the accuracy of tide models such as TPXO7.1, FES2004, CATS2008a and Ross_Inv in Terra Nova Bay, East Antarctica. Firstly, we compared the double-differential tide height (${\Delta}\dot{T}$) for Campbell Glacier Tongue extracted from the DDInSAR images with that predicted by the tide models. Tide height (T) from in situ measurement was compared to that of the tide models. We also compared 24-hours difference of tide height ($\dot{T}$) from in situ tide height with that from the tide models. The root mean square error (RMSE) of ${\Delta}\dot{T}$, T and $\dot{T}$ decreased after the inverse barometer effect (IBE)-correction of the tide models, from which we confirmed that the IBE of tide models should be corrected requisitely. The RMSE of $\dot{T}$ and ${\Delta}\dot{T}$ were smaller than that of T. This was because $\dot{T}$ is the difference of tide height during temporal baseline of the DInSAR pairs (24 hours), in which the errors from mean sea level of the tide models and in situ tide, and the tide constituents of $S_2$, $K_2$, $K_1$ and $P_1$ used in the tide models were canceled. This confirmed that $\dot{T}$ and ${\Delta}\dot{T}$ predicted by the IBE-corrected tide models can be used in DDInSAR technique. It was difficult to select an optimum tide model for DDInSAR in Terra Nova Bay by using in situ tide height measured in a short period. However, we could confirm that Ross_Inv is the optimum tide model as it showed the smallest RMSE of 4.1 cm by accuracy assessment using the DDInSAR images.

Growth of two mud shrimps (Upogebia major and Austinogebia wuhsienweni) settled in Boryeong and Hongseong tidal flat (보령과 홍성 갯벌에 착저한 쏙 2종(Upogebia major and Austinogebia wuhsienweni)의 성장)

  • Song, Jae-Hee;Ahn, Hyun-Mi;Jeung, Hee-Do;Chung, Sang-Ok;Kang, Hee-Woong
    • Korean Journal of Environmental Biology
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    • v.37 no.2
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    • pp.217-227
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    • 2019
  • The purpose of this study was to investigate the initial growth, burrowing depth, and relative growth of mud shrimps (Upogebia major and Austinogebia wuhsienweni), living in damaged high density tidal flat shellfish farms form 2008 in the Western coast of Korea. By August, young mud shrimps (Upogebia major), which had settled down on the tidal flats in early May, grew to more than 10 mm in carapace length (CL). At the end of the first year, their CL and total length (TL) increased to 14.21 mm and 42.28 mm, respectively. The inhabiting depth of the young mud shrimps (Upogebia major) increased rapidly up to about 6 months after stocking (5 cm in July, 12.5 cm in September, and 28 cm in November, respectively). The inhabiting depth of adult mud shrimps in their burrows was about 10-93 cm during the year. As results, the analysis of the relative growth between the carapace length (CL) - the total length (TL) and the CL - total wet weight (TWW), the total wet weight of mud shrimps at Boryeong Saho (inner part of the Cheonsu-bay) was estimated to be 1.2-4 g heavier than those of Boryeong Jugyo (Outer part of the Cheonsu-bay) tidal flat. The young mud shrimps primarily grew from April to October. It is therefore crucial to observe whether the settlement of young mud shrimps on tidal shellfish farms from May to June to minimize the damage of shellfish farms by newly stocked young mud shrimps. In addition, it is recommended that young mud shrimps grown in fisheries be harvested before they dig deep into the sediment until early December.

Internal Waves and Surface Mixing Observed by CTD and Echo Sounder in the mid-eastern Yellow Sea (황해 중동부해역에서 CTD와 음향탐지기로 관측한 내부파와 표층 혼합)

  • Lee, Sang-Ho;Choi, Byoung-Ju;Jeong, Woo Jin
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.1
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    • pp.1-12
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    • 2013
  • Acoustic backscatter profiles were measured by Eco-sounder along an east-west section in the mid-eastern Yellow Sea and at an anchoring station in the low salinity region off the Keum River estuary in September 2012, with observing physical water property structure by CTD. Tidal front was established around the sand ridge developed in 50 m depth region. Internal waves measured by Eco-sounder during low tide period in the eastern side of the sand ridge were nonlinear depression waves with wave height of 15 m and mean wavelength of 500 m. These waves were interpreted into tidal internal waves that were produced by tidal current flowing over the sand ridge to the southeast. When weakly non-linear soliton model was applied, propagation speed and period of these internal depression wave were 50 m/s and 16~18 min. Red tides by Dinoflagelates Cochlodinium were observed in the sea surface where strong acoustic scattering layer was raised up to 7 m. Hourly CTD profiles taken at the anchoring station off the Keum River estuary showed the halocline depth change by tidal current and land-sea breeze. When tidal current flowed strongly to the northeast during flood period and land-breeze of 7 m/s blew to the west, the halocline was temporally raised up as much as 2 m and acoustic profile images showed a complex structure in the surface layer within 5-m depth: in tens of seconds the declined acoustic structure of strong and weak scattering signals alternatively appeared with entrainment and intrusion shape. These acoustic profile structures in the surface mixed layer were observed for the first time in the coastal sea of the mid-eastern Yellow Sea. The acoustic profile images and turbidity data suggest that relatively transparent low-layer water be intruded or entrained into the turbid upper-layer water by vertical shear between flood current and land breeze-induced surface current.

Characteristic of Wave Diffraction and Reflection for Irregular Waves in SWASH Model Around Small Port Structures (소규모 항만 구조물 주변에서 불규칙파에 대한 SWASH 모형의 반사 및 회절)

  • Kwon, Kyong Hwan;Park, Chang Wook;Park, Il Heum;Kim, Jong Hoon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.6
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    • pp.468-477
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    • 2019
  • The numerical model of Boussinesq approximation, which is mainly used for evaluating the port calmness due to the irregular waves, has a limit of applicability of lattice size in ports such as marinas with narrow port openings of around 30m. The SWASH model controls the partial reflection according to the depth, porosity coefficient and structure size when applying the reflected wave incident on the structure and terrain. In this study, the partial reflection evaluation at the front of the structure according to the bottom shape and the shape of the structure are examined. In order to evaluate the reproducibility of the model due to the diffraction waves entering the term, the area of incidence at right angles and inclination of the structure is constructed and compared with the diffraction theory suggested by Goda et al. (1978). The experimental results of the sectional structure reflectances calculated as the depth mean show reflectances similar to the approximate values of the reflectances presented by Stelling and Ahrens (1981). It is considered that the reflected wave is well reproduced according to the control of the reflected wave at the boundary and the shape and topography of the structure. Compared with previous studies to examine the diffraction of the wave incident from the breakwater opening, the wave incidence angle and the shape of the diffraction wave are very similar to the theoretical values, but both oblique and rectangular incidence In the case where the direction concentration is small, the diffraction degree is underestimated in some sections with the crest ratio of 0.5 to 0.6.

REPORT OF EXPERIENCE WITH KIMURA'S DISEASE (기무라씨 질환, 5 예 보고)

  • Seel David J.;Park Yoon-Kyu;Lee Kwang-Min
    • Korean Journal of Head & Neck Oncology
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    • v.5 no.1
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    • pp.39-46
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    • 1989
  • Kimura's Disease is a chronic inflammatory and proliferative condition producing subcutaneous masses especially in the head and neck area. This report of our experience with 5 patients with this disease is the first in the Korean surgical literature. Kimura's Disease is thought to be part of the larger spectrum of the entity known as angiolymphoid hyperplasia with eosinophilia (ALHE). It is characterized pathologically by hyperplastic lymphoid follicles, eosinophilic infiltration, and vase 비 ar proliferation. It produces masses which are most common in the area of the parotid, submandibular gland and upper neck. These masses occupy the subcutaneous tissues but also extend into salivary tissue and into upper neck nodes. One of our patients had masses in the groin. The tumors are extremely vascular due to the presence of new proliferative vessels and sinusoids. The average age of our 5 patients was 35, but all but one case were younger than 38 years of age. The male: female ratio was 3 : 2, and the average duration of symptoms was 5,2years. All patients had peripheral blood eosinophilia. All had multiple masses, sometimes symmetrical. The management was surgery alone in one case, surgery and steroids in one case, surgery and radiotherapy in two cases, and all three modalities in one case. The relationship of this entity to ALHE and our experience in the management of this disease are presented. A clinicopathological discrepancy alerted us to the existence of Kimura's Disease. A nineteen-year old male presented with subcutaneous masses over both mastoid areas present for 3 years (Case III). When biopsy on each side was reported as 'eosinophilic granuloma' we submitted the slides to an internationally expert pathologist. Symmetrically occurring tumors in the peri-parotid subcutaneous areas did not fit any category of neoplasm or granuloma known to us. The diagnosis, made by Dr. Gist Fan at the Ochsner Clinic, was Kimura's Disease. We found two additional cases in a review of soft tissue eosinophilic granuloma previously reported at Presbyterian Medical Center, and since then have diagnosed two new cases. These five cases constitute the basis for this, the largest series to be reported in Korea. These vascular, tumor-like lesions of the skin, subcutaneous areas and subjacent structures of the head and neck have been a variety of names, such as angiolymphoid hyperplasia with eosinophilia, eosinophilic hyperplastic lymphogranuloma, angioblastic lymphoid hyperplasia with eosinophilia, histioid hemangioma, and epithelioid hemangioma. The history of this disease spectrum dates back to 1937 when Kimm and Szeto (1) reported 7 cases of 'eosinophilic hyperplastic lymphogranuloma' in the Proceedings of the Chinese Medical Journal. In 1948 Kimura and his associates(2) reported additional cases in Japan under the title 'On the unusual granulation combined with hyperplastic changes of lymphatic tissue.' From then until 1966 several hundred cases were reported in China and Japan. The first report from the West was by Wells and Whimster(3) in the British Journal of Dermatology, in 1969. These authors coined the term, angiolymphoid hyperplasia with eosinophilia (ALHE). Since that time a debate has ensued as to whether Kimura's Disease and ALHE are distinct entities, or whether Kimura's is part of the larger spectrum of ALHE, perhaps a later or advanced phase. From the clinical perspective, surgeons should be aware of the diagnosis of Kimura's Disease not only as part of the differential diagnosis of head and neck tumors but also because these lesions are indolent, and generally require conservative surgical removal as part of the management program. CASE I. A 37-year-old female company employee presented in August 1982 with submental swelling of 12 years' duration and with inguinal swelling of 7 years' duration. The submental mass measured 5x5cm. and the inguinal mass was 8x4cm. in size. Peripheral eosinophilia varying from 14% to 40% was found. On August 20, 1982, the submental mass was removed and a superficial groin dissection was done. In May 1983 an intraoral lesion of the palate was removed. The patient is free of disease. CASE II. A 23-year-old unemployed man visited this hospital for the first time in July, 1984, with swelling of the right cheek present for 6 years. The mass was soft and ill-defined but measured 10x20cm. and extended from the submandibular upper neck to the zygomatic arch, and from the mastoid to the cheek, over the parotid gland. Eosinophilia varying from 27% to 29% was noted in the peripheral blood. On March 21, 1986, the lesion was resected. The procedure comprised an extended superficial parotidectomy from the temporalis fascia to the upper neck. Post-operatively radiotherapy 3000 rad tissue dose was administered using the 6 MeV linear accelerator. The patient remains free of disease. CASE III. A 19-year-old student came to the clinic with masses over both mastoid areas, present 3 years. On the right there were two adjacent lesions, one over the mastoid, the other in the upper jugular level of the neck. On the left it was a single mass over the mastoid. Eosinophilia varied from 13 to 32% in the peripheral blood, and 11.6% in the bone marrow. Incisional biopsy revealed 'eosinophilic granuloma' and a trial of predisolone was employed. The mass increased in size so a small dose of radiation (600 rads) was used, with substantial regression,. The lesion on the left was excised and follwed by 1000 rads radiotherapy. Finally recurrent tumor on the right side was removed on November 5, 1985. The patient remains free of disease. CASE N. A 29-year-old local merchant had had swelling of both upper necks since childhood. At the time of his first visit on March 17, 1986, the right submandibular mass measured 5x3.5cm. and the ,right upper neck and parotid tail mass measured 2.5cm. On the left there were masses in the upper neck, the largest of which measured 2.5cm, and of the parotid tail, 2.0cm. in size.(See Fig. 1) Peripheral eosinophilia of 39% was recorded. Left side partial parotidectomy and resection of the upper neck and subdigstric mases was done on May 2, 1986. The mass involving the right parotid tail and upper neck nodes was removed on Angust 7,1986. Postoperatively the patient was placed on prednisolone 30 mg. per day. No definite masses are palpable. CASE V. A 66-year-old housewife informed us, at the time of her first visit in May, 1986, that she had had multiple neck masses since 10 years ago. On the right side there was a 2.5cm. subcutaneous mass of the upper neck, over the upper jugular chain. On the left there was a 9x4.5cm. mass involving the entire parotid, the post-auricular area and the upper neck. A third mass presented in the submental area and measured 3.5cm. (See Fig. 2) Eosinophilia of 51% was noted in the peripheral blood. partial excision of the left upper neck lesion and complete excision of the submental mass were performed on june 6, 1986. post-operatively she was placed on 20 mg. of prednisolone daily, but when the mass re-grew after two months she was referred to Radiation Therapy for a 2500 rad course of treatment. A barely palpable thickening remains.

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