• Title/Summary/Keyword: Sea

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Flow and Mixing Behavior at the Tidal Reach of Han River (한강 감조구간에서의 흐름 및 혼합거동)

  • Seo, Il Won;Song, Chang Geun;Lee, Myung Eun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6B
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    • pp.731-741
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    • 2008
  • Previous studies on the numerical simulation at the tidal reach of Han River tend to restrict downstream boundary as Jeon-ryu station due to difficulties in gaining cross section data and tidal elevation values at Yu-do. But, in this study, geometries beyond the confluence of Gok-reung stream and Im-jin River are constructed based on the numerical sea map; tidal elevation at the downstream boundary, Yu-do is estimated by harmonic analysis of In-cheon tide gage station so that hydrodynamic and diffusion behavior have been analyzed. The domain ranging from Shin-gok submerged weir to Yu-do is selected (which is 36.8 km in length). RMA-2 and RAM4 developed by Il Won Seo (2008) are applied to simulate flow and diffusion behavior, respectively. Numerical results of flow characteristic are compared with the measured data at Jeon-ryu station. Simulation is carried out from June 23 to 25 in 2006 on the ground that hydrologic data is satisfactory and tidal difference is huge during that period. The result shows that reverse flow occurs 5 times according to the tidal elevation at Yu-do and the maximum reverse flow is observed up to Jang-hang IC, which is 32.9 km in length. Also analysis is focused on the process of generation and disappearance of reverse flow, the distribution of water surface elevation and velocity along the maximum velocity line, and the transport of nonconservative pollutant. Pollutant injected from Gul-po stream spreads widely across the river; however, the size of BOD cloud entering from Gok-reung stream is relatively small because water depth at the mid and left side becomes deeper and maximum velocity occurs along the right bank so that transverse mixing is completed quickly. Finally, mixing characteristic of horizontal salinity distribution is obtained by estimating the salinity input with analytical solution of 1D advection-dispersion equation.

Distributional Characteristics of the Population and Assessment of the Conservation Status of Michelia Compressa on Korea (국내 초령목 개체군의 분포특성과 보전지위평가)

  • Jong-Gab Kim;Dae-Shin Kim;Su-Kyoung Kim;Hyun-Mi Jeong;Young-Ki Song;Sung-Won Son;Jung-Goon Koh
    • Korean Journal of Environment and Ecology
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    • v.37 no.3
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    • pp.182-191
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    • 2023
  • This study was carried out to identify the distribution and growth characteristics and evaluate the conservation status of the Michelia compressa Maxim., a rare and endangered wild plant II, in the habitats in Korea. A total of 314 individuals were found in the natural habitats of Heuksan Island and Jeju Island and were divided into four populations. About 45.9% (144 individuals) were distributed in the range of 401m~500m above sea level. The average height of trees was 2.7(±4.8)m, the diameter at breast height was 12.6(±13.9)cm, and the number of branches was 1.0(±0.5) on average. 54.3% of the sapling individuals of M. compressa were distributed within a radius of 30 m from the mother tree, 25.8% were distributed between 31 m through 40 m, and most (90.1%) were distributed within a radius of 60 m. The fact that sapling individuals of M. compressa are not identified even around some mature individuals and appear only in extremely limited areas is estimated to be closely related to the growth conditions as well as the environment of the natural habitats. The dispersal of M. compressa is presumed to be related to the birds and natural seedlings because water puddles, a resting place for birds beyond the range of natural seedlings, characterize its habitats. The IUCN Red List evaluation criteria at the regional and national level of M. compressa corresponds to the Critically Endangered category, and the domestic population under the category of "CR B2ab(v); C2a(i); D."

Factors Limiting the Vertical Distribution of the Deep-Water Asian Eelgrass, Zostera asiatica on the East Coast of the Korean Peninsula (동해 연안 왕거머리말의 수직분포 제한 요인)

  • KIM, JONG-HYEOB;KIM, HYEGWANG;KIM, SEUNG HYEON;KIM, YOUNG KYUN;LEE, KUN-SEOP
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.25 no.4
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    • pp.117-131
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    • 2020
  • Although most species in genus Zostera inhabit shallow coastal areas and bays with weak wave energy, the Asian eelgrass, Zostera asiatica is distributed in deep water depth (8-15 m) unlike other seagrasses on the eastern coast of Korea. To examine factors limiting distribution Z. asiatica in relatively deep coastal areas, a transplantation experiment was conducted on October 2011, in which Z. asiatica shoots were transplanted from the reference site (donor meadow, ~9 m) to the shallow transplant site (~3 m). We compared shoot density, morphology, and productivity of Z. asiatica as well as environmental factors (underwater irradiance, water temperature, and nutrients) between the reference and transplant sites from October 2011 to September 2012. Shoot density and shoot height of transplants dramatically decreased within a few months after transplantation, but were similar with Z. asiatica in the reference site during spring. Shoot productivity were significantly higher in the transplant site than in reference site because of high light availability and nutrient concentrations. Transplants showed photoacclimatory responses such as higher rETRmax and Ek and lower photosynthetic efficiency in the transplant site than those in the reference site. Most of Z. asiatica transplant in the shallow transplant site disappeared in summer, which may be due to the high wave energy and physical damages induced by typhoons (TEMBIN and SANBA) in August and September 2012. According to the results of this study, Z. asiatica could not survive in shallow areas despite of more favorable light and nutrient conditions. Thus, Z. asiatica may restrictively occur in deep areas to avoid the intense physical stresses in the shallow area on the east coast of Korea.

Comparison of Dissolved Ammonium Analytical Method in Seawater: Spetrophotometry and Fluorometry (해수 중 용존 암모늄 분석방법 비교: 분광광도법과 형광법)

  • SON, PURENA;PARK, JOONSEONG;RHO, TAEKEUN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.25 no.4
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    • pp.81-96
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    • 2020
  • Berthlot's reaction spectrophotometric method is generally used for the analysis of dissolved ammonium in seawater, but in recent years, a fluorescence method using an orthophthaldialdehyde-sulfite (OPA) fluorescent reagent is actively used internationally. In this study, we investigated the effects of the detection limit between the analysis methods, the reagent refractive index inherent in the spectrophotometric method, and the use of different calibration curves to understand the cause of the difference in dissolved ammonium concentration (about 0.31 𝜇M) observed in the seawater samples and a nutrient reference material between two institutions (KIOST (spectrophotometric method, one-order linear regression gradient only), Australia CSIRO (fluorescence method, quadratic formula)) conducted onboard the Australian R/V Investigator in 2017. The method detection limit (0.063 𝜇M) and the reagent refractive index background value (0.054 𝜇M) of the spectrophotometric method measured in this study could explain the difference in dissolved ammonium concentration values of the two institutes about 20% and 17%, respectively. However, when the concentration of the calibration curve of the spectrophotometric method was calculated using the same quadratic as the fluorescence method or the slope and intercept of linear regression, the difference in the dissolved ammonium concentration between the two institutions was reduced to less than the detection limit of the spectrophotometric method. Therefore, the difference in the concentration of dissolved ammonium between the two institutions, found in the nutrient reference materials and the seawater field sample during the international onboard nutrient inter-comparison experiment, may be attributed to be the effect of the different calibration curves used in the two methods rather than the effect of the difference in two analytical methods. When comparing the dissolved ammonium data from seawater samples in the future, it is recommended to pay attention to the information on the baseline, number of standard solutions, and calibration curve used in the analysis.

Suicide Method, the Recent Stressors, Psychiatric Diagnosis of Suicide Attempters and Suicide Completers (자살시도자와 자살 사망자의 자살 방법, 스트레스 요인 및 정신과적 진단)

  • Sea Hyun O;Jihye Ahn;Seo Jihyo;Hyerin Gu;Minjeong Kim;Hyeyeon Jang;Seog Ju Kim
    • Sleep Medicine and Psychophysiology
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    • v.29 no.1
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    • pp.15-20
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    • 2022
  • Objectives: Suicide is the major public mental health concerns all over the world. The comparison of suicide attempters and suicide completers could be the fundamental evidence for the suicide prevention. The aim of this study is to explore the differences between suicide attempters and suicide completers in terms of the stressors, suicide methods, and psychiatric diagnosis. Methods: Two types of secondary data were collected for the analyses. Data of the suicide attempters (n = 680) were gathered by intensive reviewing the medical records of Samsung Medical Center, Seoul, Republic of Korea. Data of suicide completers (n = 11,722) were collected by the psychological autopsy data which were gathered by Korean Foundation for Suicide Prevention. Suicidal methods, psychiatric disorders and stressors before suicidal attempt were compared between suicide attempter and completers. Results: Suicide completers were older and male predominant compared to suicidal attempt. Hanging or gas intoxication were more commonly used in the suicide completion, while wrist cutting or drug intoxication were more common in suicide attempters. All types of stressors were found to be high in suicide completers than suicide attempters. However, the proportion of economic and physical stress were greater in suicide completers, while the proportion of family stress were greater in suicide attempters. According to the recorded diagnoses, the rates of depressive disorders, sleep-wake disorders, substance-related disorders were higher in suicide completers, while the rates of anxiety disorders and trauma- and stressor-related disorders, bipolar and related disorders and somatic symptom disorders were higher in suicide attempters. However, after controlling the gender and age, there were no significant differences in diagnosis between suicide attempters and suicide completers. Conclusion: These findings implicate that suicide attempters and completers differed in suicide methods and type of stress. The results suggests that economic stressors, physical illness might raise the risk of suicide completion.

An Analytical Study on Rational use of Undersea Space (해저공간의 합리적 활용을 위한 분석적 연구)

  • Won-Jo Jung;Nam-Ki Park
    • Journal of Navigation and Port Research
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    • v.47 no.3
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    • pp.147-154
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    • 2023
  • This study aims to determine the necessity, role, utilization, and operation and management plan in relation to the underwater space platform where humans can newly reside. It provides a comprehensive opinion on the need for creating undersea space and operation plans based on opinions of industry-university-affiliated organizations involved in the R&D project of the Ministry of Maritime Affairs and Fisheries for the utilization of undersea space and external experts participating in marine technology development. In this study, a survey was conducted on researchers participating in the construction of a Korean submarine space platform. FGI was conducted on marine technology development experts. Results were then derived. As a result of the analysis, the need for subsea space construction was found to be high. As for the role of subsea space, the most common opinion was to develop technology for utilizing subsea space and to secure marine science research functions. It was found that the creation of subsea space would have a positive impact on the domestic industry, especially the deep-sea development industry and the shipbuilding/offshore structure industry. In terms of utilization, after the end of the seabed space test bed, the response to utilization as a marine observation base and marine ecosystem research had the highest proportion. As for expected inconvenience, discomfort in the psychological environment was the highest. Experts suggest that securing a continuous budget is most important for stable operation in the future and that securing a manpower budget is essential for itemized budgets. In addition, it was judged that it would be appropriate to establish a prior agreement from the time of the prior agreement and prepare a countermeasure before proceeding with the project in order to ensure ownership issues, consignment management issues, and cost issues when using the project after the end of the project.

Discuss on the Historical Development and Change of Chinese Piquancy Addiction (중국사람들의 매운 맛 기호의 역사적 추이에 대한 논술)

  • Zhao, Rong-Guang
    • Journal of the Korean Society of Food Culture
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    • v.23 no.2
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    • pp.293-300
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    • 2008
  • It determines Chinese addiction to piquancy that the Chinese traditional food production laid excessively particular stress on agriculture coming into being long before in the history and the state of Chinese food living was that the people were very difficult to live. The history of Chinese addiction to piquancy could be traced back to prehistory. And in Chinese “hot” is separated from “peppery” and it refers in particular to the piquancy more than general peppery. The character of “Hot” appeared after Han Dynasty in Chinese. Capsicum was brought to China from the sea in the middle of Ming Dynasty. Then it surpassed the formers soon and became the most popular and addictive piquancy food in China. Capsicum has many names in China, such as “$F{\bar{a}}nji{\bar{a}}o$”, “$H{\bar{a}}iji{\bar{a}}o$”, “$L{\grave{a}}ji{\check{a}}o$”, “$L{\grave{a}}h{\breve{u}}$”, “$L{\grave{a}}zi$”, etc., and they indicate the geographical and humanistic character of the distribution. (eight books on preserving one’s health) is the earliest history record about capsicum in existent Chinese history record that was finished in 1591. In this article the author puts new opinion forward on the record in this book. It is because the hottest piquancy of capsicum, capsicum’s better adaptability and low cost to plant combine with Chinese piquancy addiction at large that capsicum can replace the status of pepper and other traditional peppery flavorings soon and cause worldwide attention to the Chinese piquancy addiction finally. The human common characters of unchangeable inertia, depending to fully grow addiction and aggrieved delight are the most important reasons to cause piquancy addiction that has formed a custom through long-repeated practice and this custom do not change with condition change. The unbalanced spread process of capsicum in China shows that the region is poorer and the addictive degree is deeper.

Evaluation of Water Quality Characteristics of Saemangeum Lake Using Statistical Analysis (통계분석을 이용한 새만금호의 수질특성 평가)

  • Jong Gu Kim
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.4
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    • pp.297-306
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    • 2023
  • Saemangeum Lake is the largest artificial lake in Korea. The continuous deterioration of lake water quality necessitates the introduction of novel water quality management strategies. Therefore, this study aims to identify the spatiotemporal water quality characteristics of Saemangeum Lake using data from the National Water Quality Measurement Network and provide basic information for water quality management. In the water quality parameters of Saemangeum Lake, water temperature and total phosphorous content were correlated, and salt, total nitrogen content, pH, and chemical oxygen demand were significantly correlated. Other parameters showed a low correlation. The spatial principal component analysis of Saemangeum Lake showed the characteristics of its four zones. The mid-to-downstream section of the river affected by freshwater inflow showed a high nutrient salt concentration, and the deep-water section of the drainage gate and the lake affected by seawater showed a high salt concentration. Two types of water qualities were observed in the intermediate water area where river water and outer sea water were mixed: waters with relatively low salt and high chemical oxygen demand, and waters with relatively low salt and high pH concentration. In the principal component analysis by time, the water quality was divided into four groups based on the observation month. Group I occurred during May and June in late spring and early summer, Group II was in early spring (March-April) and late autumn (November-December), Group III was in winter (January-February), and Group IV was in summer (July-October) during high temperatures. The water quality characteristics of Saemangeum Lake were found to be affected by the inflow of the upper Mangyeong and Dongjin rivers, and the seawater through the Garuk and Shinshi gates installed in the Saemangeum Embankment. In order to achieve the target water quality of Saemangeum Lake, it is necessary to establish water quality management measures for Saemangeum Lake along with pollution source management measures in the upper basin.

A Study on the Musical Characteristics of Fishing songs in North Korea (북한 어업노동요의 음악적 특징)

  • Kim, Jeong-Hee
    • (The) Research of the performance art and culture
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    • no.39
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    • pp.279-323
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    • 2019
  • The musical characteristics of Fishing songs in North Korean which recorded on Anthology of North Korean Folk Songs were examined in this paper. The results are as follows. Among Fishing songs in North Korea, there are "Rowing Song," the "Song for Hauling Nets," and the "Song for Picking Up Fish" in songs related to walleye pollack fishing and in songs related to croaker fishing, the "Song for Dropping Anchor" and the "Full-Load-of-Fish Song" in songs related to croaker fishing, the "Song for Weighing Anchor," the "Song for Shaking Fish," the "Full-Load-of-Fish Rowing Song," and the "Song for Hanging Walleye Pollack" in songs related to walleye pollack fishing. There are the "Song for Setting a sail" and the "Song for catching shells" in Fishing songs in North Korea, too. In the rhythmic elements of Fishing songs in North Korea, the tempo of the "Songs for Setting a sail" is moderato, and that of the "Songs for Picking Up Fish" of songs related to anchovy or herring fishing is quite slow. "Rowing Songs"(croaker fishing) have various tempos but faster than moderato, and usually get faster and faster as time goes by. Most songs have 4/♩. time and there are some of 2, 3 or 5 time. Some songs use irregular time or 6 time overlapping 2 beats. The mode Menari is the most common tonal system used in fishing songs of North Korea. And the mode Susimga, the mode Changbutaryeong, the mode Nanbongga, and the mode Odolttogi are also used in the tonal system of Fishing songs in North Korea. There are shoutting intonations that have indefinite pitch, too. Modulation or interaction by the mode Changbutaryeong appeared in songs of the mode Menari. There is a tendency to favor a certain tonal system by category. Responsorial form is mostly used, but in the most cases, they were sung in solo. In responsorial songs, several calling songs overlap with the responding songs. Durchkomponiert form is sung by antiphon or in solo, but the case sung in solo originally seems to have been sung by antiphon or unison, if we consider the procedure of the work. The "Song for Picking Up Fish" of Seonbong-gun of North Hamgyeong Province and Yangyang-gun of Gangwon Province, the "Full-Load-of-Fish Song-Bongjuktaryeong" of Jeungsan-gun of South Pyeongan Province and "Full-Load-of-Fish Song-Baechigisory" of Taean-gun of South Chungcheong Province, "Rowing Song" of Nampo City and Ganghwa-gun of Gyeonggi Province are resembled. In neighboring areas, even if the songs of different categorys, sometimes share a same melody. In a certain category, sometimes a same melody is shared to a considerable distance. It was first identified that in anchovy or herring fishing or dybowskii' sand eel fishing, the "Song for Picking Up Fish" is widely shared in the East Sea Coast area.

An Introduction to the Study of the Outlook on the Highest Ruling Entity in Daesoonjinrihoe (II) - Focusing on 15 Godship and Yang-wui Sangje (Sangje in two Godship) - (대순진리회 상제관 연구 서설 (II) - 15신위와 양위상제를 중심으로 -)

  • Cha, Seon-keun
    • Journal of the Daesoon Academy of Sciences
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    • v.23
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    • pp.241-292
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    • 2014
  • This article as an attempt to analyze Jin-beop-joo(眞法呪, incantation of true law) and the view of Yang-wui Sangje(兩位上帝, Sangje in two Godship) corresponds to the second preliminary work prior to the research on the view of Sangje in Daesoonjinrihoe. The points of this article are as follows: First, Jin-beop-joo and 15 Godship(神位) based hereupon are one of the most essential elements comprising the view of Sangje in Daesoonjinrihoe. Since the other Jeungsan line religious orders except Daesoonjinrihoe does not use 15 Godship in explaining and understanding Jeungsan, this fact should be regarded as an important characteristic of Daesoonjinrihoe. Second, 15 Godship is the important installation to assemble Sangje and the other gods in the same place. In Buddhism temples and China-Taoism temples, the gods each are placed in a separate palace. Whereas Sangje and the gods are concentrated in the same place, Yound-Dae(靈臺) which is the shrine of Daesoonjinrihoe. This fact shows Sangje takes the reins to the gods visually. 15 Godship facilitates that system. Third, the number 15 of 15 Godship symbolizes the natural laws of the cosmos. Thus the shrine of Daesoonjinrihoe implies the law of universe emblematically. Forth, 15 Godship shows that the Highest God in Daesoonjinrihoe are located in the middle of the functional gods ruling over nature like mountain, sea, season, the Great Dipper, and Taoistic or Buddhistic gods like Ok-hwang Sangje(玉皇上帝, The Great Jade Emperor), Seoga-Yeorae(釋迦如來, Tathāgata Buddha), Kwan-seong-Jegoon(關聖帝君, Holy god Guan Yu), along with various envoys and ancestral gods. Besides, considering the fact that the majority of 15 Godship consists of the Eastern deities, it verifies the view of Sangje in Daesoonjinrihoe is built in the Eastern religions. Fifth, whereas the other Jeungsan line religious orders have a tendency of understanding Jeungsan as Ok-hwang Sangje, Daesoonjinrihoe worships Jeungsan as Gu-cheon Sangje(九天上帝), not as Ok-hwang Sangje. This accords with the following fact; Jeungsan is the highest ruling entity in Gu-cheon, whereas in Jinbeonju, which was handed down from Jeungsan, the highest ruling entitiy in Gu-cheon is expressed as a different being from Ok-hwang Sangje. Sixth, Daesoonjinrihoe understands Sangje as the form of two Godship, Yang-wui Sangje, which are Gu-cheon Sangje and Ok-hwang Sangje. Judging from the form of salutation, the status of these two Sangjes are the same. Yet, the object of belief is Gu-cheon Sangje as the highest God, while Ok-hwang Sangje is stipulated as the one who has wielded a true law succeeding to the Gu-cheon Sangje's will. The religious term of Yang-wui Sangje don't imply meaning Gu-cheon Sangje and Ok-hwang Sangje are the same rank. Yang-wui Sangje is the term expresses Sangje in two Godship and involves the orthodox heritage of Daesoonjinrihoe. Along with An Introduction to the Study of the Outlook on the Highest Ruling Entity in Daesoonjinrihoe (I), this article is written, while giving a thought to construct the religiography on the highest God in Daesoonjinrihoe. I hope this article accompanied with the previous one, can be contributed to the fertilization of the soil in the field of Daesoon religious studies.