• Title/Summary/Keyword: 해면변화

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Effect of a Barrier on Tides in the Youngsan Estuary (영산강하구(榮山江河口)의 방조제건설(防潮堤建設) 조위변화(潮位變化))

  • Choi, Byoung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.2
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    • pp.113-124
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    • 1984
  • This study represents results of analysis of sea level record at Mokpo for the years 1956~1982. The results are believed to be the first detailed analysis for the Port of Mokpo. The tidal constants are obtained from separate yearly extended harmonic analysis. The variability of these yearly analysis gives estimates of effects on astronomical tide due to Youngsan Barrier. Multiple statistics of sea level record for the years 1965~1980 and 1981~1982 are presented separately to evaluate the distribution of sea level frequency due to the construction of Barrier. Some of preliminary results are presented and indication of further studies are discussed.

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On the Variation of Sea Level Due to Meteorological Disturbances on the Coast of Korea. I. Storm Surges Caused by Typhoon Billie, 1970, on the West and South Coasts of Korea (한국연안에 있어서 기상 교란에 의한 해면변화 I. 태풍 빌리호(1970년)와 남 서해안의 이상고조현상)

  • Hwang, Chin-Pung
    • 한국해양학회지
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    • v.6 no.2
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    • pp.92-98
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    • 1971
  • Storm surges caused by typhoon Billie, 28 Aug. ∼ 2 Sep. 1970, on the west and south coasts of Korea are studied with the tidal data. Tracks and frequencies of the typhoons which affected the Korean peninsula and the yearly maximum tidal deviation at tide stations for the past twelve years are also reviewed. It is assumed that most of the typhoons affecting the Korea peninsula cause variations of sea level along almost all of the coast of Korea. Maximum storm surges at each tide station on the south coast appeared to be caused by typhoons during the summer, and by the north westerly monsoon and extraordinary cyclones on the west coast during spring and winter. In the coastal waters of the west coast where depths are shallower and the bottom configuration is flat, sea level variation is mostly caused by atmospheric pressure and wind effect. When a typhoon travels as in case of typhoon Billie, sea level ascends generally on the south coast and it descends on the west coast before the typhoon approaches near to the coasts. Considering the large tidal range on the western and southern coasts, it is assumed that the extraordinary destructive surges can be occurred when the tide is high water. Reviewing the monthly mean sea level variations on the each coast, hazards to be caused by storm surges can more fluently occur during the summer.

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The Environmental Change at Kimpo Alluvial Plain during the Upper Holocene (김포충적평야의 홀로세 후기 환경변화)

  • 윤순옥;김혜령
    • The Korean Journal of Quaternary Research
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    • v.15 no.2
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    • pp.83-91
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    • 2001
  • The environmental change during the upper Holocene was restored at Kimpo alluvial plain on the left bank of Han-river near the Yellow Sea according to the results of pollen analysis and carbon dating, based on the sea-level change from Ilsan area. Pollenzone I (5.8~7.0 m.a.s.l.) was the period of AP-dominance, including mostly Alnus. Study area was under the lagoon or swamp environment influenced by Flandrian transgression during 5,000~3,200 BP. Pollenzone II (7.0~7.4 m.a.s.l.) was the period of Spore & NAP-dominance. It represents that the vegetational environment was changed to drier condition by falling underwater surface caused by sea-level regression, and influenced by human activity during 3,200~2,300 BP. Subzone I a represented the characteristics of the climax of transgression. During subzone I b, herbs with the dominant Alnus were increased gradually, and it was correlated to the stagnation of high sea-level. Subzone II a was the dominant period of Spore by the gradual falling of sea-level. After that, the study area in swamp was emerged to the lowland by the fallen sea-level and herbs, especially Gramineae increased suddenly during Subzone II b. The sudden increase of NAP such as Artemisia, Chenopodiaceae and Umbelliferae with Gramineae during this period indicates the beginning of agriculture at this study area.

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Effect of Environment Factors on Growth and Mortality of Cupped Oyster, Crassostrea gigas (양식장 환경이 갯벌양식 굴 (Crassostrea gigas)의 성장과 폐사에 미치는 영향)

  • Park, Sang-Woo;Kim, Yong;Kim, Ji-Hye;Chung, Su-Whan;Han, Kyung-Nam
    • The Korean Journal of Malacology
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    • v.29 no.4
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    • pp.273-281
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    • 2013
  • In order to evaluate how the effects of aquacultural environment, such as temperature, salinity, DO, SS, Chlorophyll-a, COD and nutritive salts on Cupped oysters, an investigational study was conducted between September to December of 2011. During the study, different intermediate cage farms on the surface of the sea were used to culture and compare the growth and survival rate of the Cupped oysters in different fishing environments. The different intermediate cage farms used were Wonsando-ri, Chang-ri, and Pado-ri. In January of 2012, these oysters were transplanted to a horizontal net farm in a mudflat until July of that year. The adaptation rates of the Cupped oysters were tested at differential exposure times at varying intertidal periods. Wonsando-ri showed the highest water temperature and Chlorophyll-a levels, while the salinity was found to be within range of stable conditions among all three intermediate cage farms. Once the Cupped oysters were at the horizontal net farm, the growth was measured at distinct tidal exposure time of 1, 3, and 5 hours, whereby the growth rate was highest at 3, 1, and 5 hours, respectively. In addition, the oysters cultivated in intermediate cage farms had longer shell lengths compared to shell heights, while oysters cultured in the horizontal net farm had larger shell heights than shell lengths.

On Annual Variations of Sea Water and Air Temperatures, and Sea-Air Temperature Separation in the East Sea (Japan Sea) (동해의 수온, 기온 및 해면 온도차의 연변화)

  • KANG Yong Q.
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.4
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    • pp.374-380
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    • 1985
  • The annual variations of sea surface temperature (SST), air temperature (AT), and sea-air temperature separation (SST-AT) in the East Sea (Japan Sea) are studied by harmonic analysis of the monthly data in 2 by 2 degree rectangles. In the Tsushima Current region of the Japan Sea, the annual means of SST and AT are high due to warm water advection by the current, and the annual amplitudes of SST and AT are small because the annual variations of heat advection the the current and of the incoming solar radiation are almost out of phase each other. In summer the SST and the AT in the Japan Sea are almost the same, but in winter the SST is $6{\sim}10^{\circ}C$ higher than the AT. The physical processes responsible for the observed SST-AT in the Japan Sea and their consequences in the sea-air thermal interactions are discussed in this paper.

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Effects of Compositions of Saponin Fraction from Korean Red Ginseng in the Relaxation of Rabbit and Rat Corpus Cavernosum (토끼와 흰쥐 음경해면체 이완작용에 미치는 홍삼사포닌 분획별 효과)

  • Choi Young Deuk;Park Jin Ah;Choi Hyung Ki;Nam Ki Yeul
    • Journal of Ginseng Research
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    • v.23 no.1 s.53
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    • pp.13-20
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    • 1999
  • We previously reported that Korean red ginseng (KRG) has a relaxation effect on the smooth muscles of corpus cavernosum via nitric oxide (NO) pathway and calcium and potassium channels. However, it is suggested that the active ingredients of KRG might be different depending on the sources of preparation, and there might be differences in actions for different compositions. We first investigated the composition of KRG saponins according to the extractions of the various sources of KRG, then with these extractions the relaxation effects were evaluated in vitro and hemodynamical in vivo using New Zealand white rabbit and rat corpus cavernosum. The total compositions of ginsenoside $(G-Rb_1,\;-Rb_2,\;-Rc,\;-Rd,\;G-Re,\;-Rf,\;-Rg_1)$ in fractionated KRG saponin designated as TS-1, TS-2, TS-3 were $41\%,\;40\%,\;and\;62\%,$ respectively, and the ratios of PD saponin and PT saponin (PD/PT) were 1,55, 1.72, 2.25, and 2.61, the values of which were statistically significant. In vitro studies using the rabbit corpus cavernosal muscle strips, the KRG saponin relaxed cavernosal strips in a dose-dependent manner, and same results were observed in in vivo studies, that KRG saponin increased the intracavernosal pressure in the rat. There was difference in the efficacy according to fractionation techniques. The differences in the total contents of ginsenosides did not affect relaxation, rather PT saponin content was statistically related to the degree of cavernosal relaxation, and this action presumed to be mediated by NO pathway and calcium and potassium channels. In conclusion, KRG exerts relaxation which is a key step in erection via combination of effects on NO system or calcium and potassium channels. The efficacy of this action is different to the sources of ginseng, which is affected by the different composition of ginsenosides $(G-Rb_1,\;-Rb_2,\;-Rc,\;-Rd,\;G-Re,\;-Rf,\;-Rg_1).$ Thus the further studies on the active ingredients such as minor ginsenosides and non-saponin components of red ginseng with maximum potency should be sought.

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FEM Analysis of Lumbar Interbody Fusion using the Cage and Screw in Relation to Bone Mineral Density (골밀도 변화에 따른 cage와 나사를 이용한 추체간 유합술의 유한요소 해석)

  • Kim H. S.;Park J. H.
    • Journal of Biomedical Engineering Research
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    • v.25 no.6
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    • pp.525-530
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    • 2004
  • Three dimensional finite element models of lumbar interbody fusion using rage and screws were constructed for the simulation of stress distribution and maximum displacement. It is also performed to investigate the efforts of osteoporosis and the location of cage on the stress distribution. It is known from the results that the increase of the strength of trabecular bone causes to decrease the stress of cortical bone and to increase the stress of trabecular bone. And it is found that the trend of stress distribution is changed by the change of location of cage and proper location of cage enhances the rate of operational success.

Animal Models for the Study of Post-Micturition Dribble in Aged Male (고령 남성의 배뇨 후 요실금 연구를 위한 동물 모델)

  • Seung Hwan, Jeon;Mi-Young, Park
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.4
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    • pp.307-315
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    • 2022
  • Since attaining middle age, many patients suffer from the post-micturition dribble (PMD) syndrome but do not receive proper treatment. This is because the etiology and treatment mechanisms of PMD differ from conventional lower urinary tract symptoms. Several pathophysiologies have been proposed, but the mechanisms we observed are the weakening of the bulbocavernosus muscle and dilation of the urethra due to atrophy of the cavernosal tissue. This study investigates the mechanism of PMD by observing anatomical changes in the corpus cavernosum and urethra. SD male rats were categorized by age into the young rats group (8 weeks old) and the old rats group (24 months or more). The ratio area of the bulbous urethra and corpus cavernosum to the total penis was statistically significant between both groups (P<0.05). Significant differences were obtained between the two groups for restored smooth muscle contents and several other parameters related to PMD mechanisms (nNOS, α-SMA) (P<0.05). The changes in size and parameters of the urethra and corpus cavernosum in young and old rats were confirmed. The results from this study are expected to contribute to the study of PMD in the future.

Holocene Sea Level Reflected from Marine Terrace in Geoje Island and its Influences on Coastal Morphogenesis (거제도 동부해안에서 파악되는 홀로세 고해수준면과 지형발달과정)

  • YANG, Jae-Hyuk
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.1
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    • pp.101-112
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    • 2011
  • Coastal terrace was developed at 7.2m height near Shinchon village in Geoje Island. It is located on the east side of southern coast in Korean Peninsula, where sea-level changes caused by ebb and flow of the tide, embayment are relatively low. Due to the breccia layer by mass-movement, dark grayish clayey formation, marine origin's rounded gravel are deposited sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various sedimentary environments. For the purpose of identifying the morphogenetic process, Grain size, Roundness, XRD, AMS dating analysis was attempted. As a result, after last glacial age, Holocene sea level rise to +5.6m(4,740±100yrs BP). At that time, various geomorphological features are considered to be formed.

RADIOGRAPHIC INTERPRETATION OF EXPERIMENTALLY PRODUCED BONY DEFECT ACCORDING TO kVp (관전압 변화에 다른 실험적 골결손부의 방사선사진상의 판독)

  • Nam Hye Kyung;Choi Karp Shik;Kim Chin Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.20 no.2
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    • pp.265-276
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    • 1990
  • The purpose of this experiment was to evaluate radiographic interpretation, of various sized 60 periapical and 60 cancellous lesions in 10 mandibular sections of 5 dogs according to kVp (65, 70, 75, 80 and 85 kVp). The results were as follows; The change of kilovoltage within 65kVp-85kVp range did not have influence on the radiographic interpretation of the same-sized bony defects at the constant radiographic density (p> 0.05). When the bony defects were less than the size of No.2 round bur, radiographic interpretation of bony defects prepared with No.2 round bur was easier than those prepared with No. 1 round bur at 80-85kVp in periapical region (p<0.05). However, in cancellous bone, this radiographic interpretation was easier at 65-75kVp (p<0.05). There were significant differences in the radiographic interpretation between the defects confined only to the cancellous, bone and the defects involved in the compact bone (p<0.05). However there were no significant differences between the defects confined only to the cancellous bone and the defects involved in junctional area of cancellous and compact bone (p>0.05). From the results of densitometric analysis, there was a difference in densitometric measurements at the same radiographic interpretation scores, and aluminum equivalent differences of 0.15-1.66㎜ thickness were needed for radiographic interpretation.

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