K-Means Clustering을 활용한 냉수대 발생 분포에 관한 연구

김범규(Bum-Kyu Kim),윤홍주(Hong-Joo Yoon),이준호(Jun Ho Lee) 한국전자통신학회 2021 한국전자통신학회 논문지 Vol.16 No.2

본 연구에서는 한국 남동해역에 발생하는 냉수대의 공간적인 분포를 구분하기 위해 2016 ∼ 2018년의 고리, 양포의 해양 관측 부이 수온자료와 GHTSST Level 4 재분석 해수면 온도자료를 K-means clustering 기법을 활용하여 분석하였다. 부이자료는 남동해역에서 고리와 양포 지점의 수온변화 및 냉수대 발생을 파악하기 위해 활용하였다. 그 결과 냉수대 발생 시점에 고리와 양포의 수온이 동일하게 감소하였다. 이에 냉수대 발생시 SST의 변화를 보기 위해 수온의 역수와 SST의 분산을 비교하였다. 수온이 변화하는 시점에 SST의 분산도 증가하는 것을 나타내었는데 이를 통해 냉수대 발생시 해역의 SST의 수온분포에 변화가 있다는 것을 알 수 있었다. 냉수대 발생해역을 분류하기 위해 K-means clustering을 활용하였다. Elbow 기법을 활용하여 분류를 위한 최적의 K값을 찾아낸 후 분류를 진행한 결과 연안의 차가운 해수가 존재하는 지역을 찾아낼 수 있었다. 이를 통해 냉수대 발생해역의 공간적인 분포 및 확산범위를 추정하여 향후 냉수대로 인한 피해 파악 및 공간적인 확산 예측연구에 활용할 수 있을 것이라 판단된다. In this study, in order to analyze the spatial distribution of cold water occurred in the Southeast Sea of Korea, the K-means clustering method was used to analyze the ocean observatory buoy of Gori and Yangpo and GHTSST Level 4 from 2016 to 2018. The buoy data was used to identify the change in sea water temperature and the cold water occurrence at Gori and Yangpo in the Southeast Sea. As a result, the sea water temperature of Gori and Yangpo decreased equally at the cold water occurrence. Therefore, the reciprocal of the sea water temperature and the variance of SST were compared to see the changes of SST when the cold water occurs. When the reciprocal of the sea water temperature increases, the dispersion of SST also increases. Through this, it can be seen that there is a change in the water temperature distribution of SST in the sea when the cold water occurs. After that, K-means clustering was used to classify the cold water. After analyzing the optimal K value for clustering by using the Elbow method, it was possible to classify a region with cold water. Through this, it is estimated that the spatial distribution and diffusion range of the cold water, and it can be estimated and used in future studies to identify damage caused by the cold water and predict spatial spread.

한국 서해 중부 연안역의 수질환경 특성

임동일,강미란,장풍국,김소영,정회수,강양순,강영실 한국해양과학기술원 2008 Ocean and Polar Research Vol.30 No.4

Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (>30~40 m in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area. Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (>30~40 m in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area.

태풍 통과에 따른 한국 연근해 수온 변동

서영상,김동순,김복기,이동인,김영섭,김일곤 한국환경과학회 2002 한국환경과학회지 Vol.11 No.7

While typhoons were passing by the coastal and offshore waters around the Korean peninsula, the variations of the sea surface temperature (SST) were studied. To study on the variation, the data related to the 22 typhoons among 346 typhoons which occurred in the western Pacific during 1990∼1999, daily measured field SSTs at coastal and offshore, and imageries from advanced very high resolution radiometer on NOAA satellite during 1990∼1999 were used. The average variations of the SSTs were -0.9℃ at coastal waters and -2℃ at offshore around the Korean peninsula while the typhoons were passing by. In very near coastal waters from the land, the SST was not changed because the bottom depth of the coastal waters was shallower than the depth of thermalcline, while the typhoon was passing. The temporal and spatial variation of SSTs at coastal waters in summer were depended on the various types of the typhoons' paths which were passing through the Korean peninsula. When a typhoon passed by the western parts including the Yellow Sea of the Korean peninsula, upwelling cold water occurred along the eastern coastal waters of the peninsula. The reason was estimated with the typhoon that was as very strong wind which blew from south toward north direction along the eastern shore of the peninsula, led to the Ekman transport from near the eastern coastal area toward the offshore. While cold water was occurring in the eastern coast, a typhoon passed over the coastal area, the cold water disappeared. The reason was estimated that the cold water was mixed up with the surrounding warm water by the effect of the typhoon. While a cold water was occurring in the eastern coast, a typhoon passed by the offshore of the eastern coast, there were the increasing of the SST as well as the disappearing of the cold water. While a typhoon was passing by the offshore of the eastern coast, the cold water which resulted from the strong tidal current in the western coast of the peninsula was horizontally spread from the onshore to the offshore. We think that the typhoon played the role of the very strong wind which was blowing from north toward south. Therefore, the Ekman transport occurred from the onshore toward the offshore of the western coast in the Korean peninsula.

김천시내 약수의 보관일수에 따른 미생물조사 연구

류재기 김천대학교 2009 김천대학교 논문집 Vol.30 No.-

A microbial experiment was conducted at four mineral springs where manypeople use in Gimcheon city, in order to prevent water-borne disease and supplyclean water. This experiment was also conducted to set up a standardization ofdrinkable period in both cold storage and room temperature storage. After observ-ing the number of bacterial colonies for 7 days, the appropriateness of drinkablewater was examined. This research was done in a germfree condition. When this water was drunkenin the home the drinkable time of this water can be more advanced than the results.From the results of the test of spring water in Gimcheon there was no significantdifference between the water of cold storage and the water of the room tempera-ture storage. But after 7 days in the room temperature the spring water of WongukMaul was evaluated as unfit on 6th day. From 7th day except Mt. Dalbong everyspring water was evaluated as unfit. In the case of cold storage keeping from 7thday except Mt. Dalbong every spring water was evaluated as unfit. A sample mineral springs were collected from a total of four locations, and gramnegative bacilli, general bacteria and Fungus were detected from all of the fourplaces. In the case of 3-5 day storage, it turned out that all the places were notsafe from drinking except Mt. Dalbong. Therefore, it is considered that it will besafe to drink mineral water within five days in cold storage and to settle expirationdate. This research was done in an aseptic condition, when this water was drunken inthe home the drinkable time of this water can be more advanced than the results.

냉·온수적용이 편마비환자의 손기민성에 미치는 영향

황성수,조은숙,고지영,장은정,주재욱,손정일,심희정,이종현,Hwang, Seong-Soo,Cho, Eun-Sook,Ko, Ji-Young,Jang, Eun-Jung,Joo, Jae-Uk,Son, Jung-Il,Sim, Hee-Jung,Lee, Jong-Hyeon 대한고유수용성신경근촉진법학회 2011 PNF and Movement Vol.9 No.1

Background : This study was to investigate effect of hot and cold water for the hand dexterity. Methods : A total of 37 subjects having hemiplegia(men=6, women=11) and normal(men=10, women=10) were participated in this study. After both hands was soaked in the small tube for 1 minute, we measured 'making dots in circles(BOTMP)', 'lifting small objects(JHFT)', 'disk turning(MMDT)' test. Results : In the case of normal's dominant hand, there were statistically significant differences in all tests after soaked in the hot water but there were statistically significant differences in 'disk turning' test after soaked in the cold water. In the case of hemiplegia's unaffected hand, there were statistically significant differences in 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. In the case of hemiplegia's affected hand, there were statistically significant differences in 'lifting small objects', 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. Conclusion : The hot and cold water were affected in the hand dexterity. Especially, in the case of both normal and hemiplegia, there were statistically significant differences in 'disk turning' test after soaked in the cold and hot water. Therefore, We were founded that affected in gross movement than fine movement.

Treatment of surface water using cold plasma for domestic water supply

Dung Van Nguyen,Phong Quoc Ho,Toan Van Pham,Tuyen Van Nguyen,Lavane Kim 대한환경공학회 2019 Environmental Engineering Research Vol.24 No.3

This paper presents the results of using cold plasma to treat surface water for domestic use purpose. Experimental results showed that cold plasma was an effective method for destroying bacteria in water. After treatment with cold plasma, concentration of coliform and Escherichia coli dramatically reduced. Besides, cold plasma significantly removed water odor, increased dissolved oxygen and decreased the concentration of chemical oxygen demand. However, cold plasma significantly raised the concentration of nitrite and nitrate. Other disadvantages of treating with cold plasma were conductivity increase and pH reduction. Pretreatment steps of coagulation, flocculation, sedimentation and sand filtration followed by disinfection with cold plasma exhibited a high efficiency in surface water treatment. All parameters of surface water after treatment by using the prototype satisfied with the allowance standard of domestic water quality.

A Study on Cooling Systems with Cold Water Panels in the Walls of Small Buildings

Dong-Hyun Cho(조동현),Myeong-Gi Jo(조명기) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.10

This study was conducted on cooling systems in which, for the first time at home and abroad, cold water panels are embedded in the walls of small buildings for radiant cooling by heat absorption with cold water. In summer, cold water is circulated through cold water (chiller) circulation tubes embedded in three walls (two side walls and one rear wall) of a building to implement radiant cooling by the coldness of the water. From the results of this study, the experimental and theoretical natural convection heat transfer coefficients were relatively well-matched over the entire experimental range, thereby verifying the reliability of the experimental results. The surface temperature reduction rate of the walls in which cold water panels are embedded was large whereas that of the walls where no cold water panels are embedded was very small.

엘리트 운동선수의 회복을 위한 냉욕: 효과, 현장 적용, 그리고 훈련 적응에 미치는 영향

김주영,김성호,성동준 한국웰니스학회 2017 한국웰니스학회지 Vol.12 No.4

본 연구는 선행연구를 바탕으로 하여 회복기 냉욕의 효과와 훈련 적응에 미치는 영향에 대해서 살펴보고, 현장에서 코치, 트레이너, 그리고 운동선수가 냉욕을 올바르게 적용할 수 있도록 가이드라인을 제공하고자 하는데 목적이 있다. 선행연구에서는 훈련 및 경기 후 적용되는 냉욕이 운동선수의 근육손상과 지연성 근육통증을 감소시키며, 근력과 지구력 같은 운동수행력을 회복하는데 있어서 효과적이라고 보고하였다. 냉욕이 이러한 결과를 나타내는 잠재적인 기전에 대해서는 정수압의 작용, 중추 피로 감소, 부교감 신경의 활성, 그리고 염증성 반응 및 산화 스트레스의 약화 등으로 다양하게 알려져 있다. 현장에서 냉욕을 적용하기 위해서는 온도, 시간, 시기, 그리고 자세 등을 고려해야 한다. 효과적인 냉욕을 위해서 온도는 10-15°C, 시간은 10-15분, 시기는 훈련이나 경기 직후, 그리고 자세는 앉은 상태에서 장골능선이나 어깨 높이까지 입수하는 것을 권장하고 있다. 한편, 몇몇의 연구에서는 반복적인 냉욕이 오히려 근육의 동화 반응과 미토콘드리아 생합성을 방해하여 훈련 적응을 감소시킬 수 있다고 보고하였지만, 아직까지 상반된 의견이 있기 때문에 이러한 논란은 추후에 좀 더 많은 연구를 통해 명확하게 밝혀져야 할 필요가 있다. The objective of the present study was to examine the effects of cold-water immersion during the recovery period and its impact on training adaptation based on prior studies. The study also aimed to develop guidelines that would allow coaches, trainers, and athletes to properly apply cold-water immersion in the field. In prior studies, cold-water immersion applied after training or competition was reported to be an effective method for reducing muscle damage and delayed-onset muscle soreness in athletes, as well as restoring exercise performance, muscle strength, and endurance. Potential mechanisms by which cold-water immersion induces these effects include the action of hydrostatic pressure, reduction of central fatigue, activation of the parasympathetic nervous system, and attenuation of inflammatory responses and oxidative stress. In order to apply cold-water immersion in the field, various factors, such as temperature, duration, timing, and treatment position must be considered. For effective cold-water immersion, the recommended temperature is 10-15°C, duration is 10-15 min, timing is immediately after training or competition, and immersion is performed up to the shoulder or iliac crest while in a sitting position. However, some studies have reported that repetitive cold-water immersion may actually reduce training adaptation by interfering with muscle anabolic responses and mitochondrial biogenesis. Since opinions differ, additional research is needed to clarify the effec

Genome-Wide Association Study for Cold Tolerance in Rice Seedlings under Cold-Water Treatment

( Na-eun Kim ),( Soon-wook Kwon ),( Jeonghwan Seo ),( Tae-ho Ham ),( Joohyun Lee ) 한국육종학회 2021 Plant Breeding and Biotechnology Vol.9 No.4

Rice is a temperature-sensitive crop, its yield is severely affected by low temperature, especially cold stress at the seedling stage will delay heading. To understand the genetic basis of cold tolerance, we evaluated the cold tolerance at the seedling stage of 136 rice accessions. To evaluate cold tolerance, we treated rice seedlings with cold water irrigation for ten days and scored the cold tolerance on a 1-9 scale, based on their low-temperature response and subsequent recovery. The genome-wide association study for cold tolerance revealed seven QTLs on chromosomes 1, 3, 6, 7, 10, and 12. The genomic region of the qCWS7 on chromosome 7 overlapped with a previously reported QTL associated with cold tolerance in the germinating stage. Similarly, qCWS1-1, qCWS1-2, qCWS3, qCWS6, and qCWS10 overlapped with a previously reported QTL associated with drought-stress tolerance. Subsequent bioinformatic and haplotype analyses suggested that five candidate genes affect cold tolerance: Os01g0228600 encoding a cytosolic hydroxypyruvate reductase, Os03g0115000 encoding a cupredoxin domain containing protein, Os06g0612800 encoding a stress-associated protein (SAP) gene family, Os12g0552500 encoding a universal stress protein (USP), and Os10g0482900 encoding a thioredoxin fold domain containing protein.

동해 냉수대 발생역의 장기 변동 분석

김주연,한인성,안지숙,박명희 해양환경안전학회 2019 해양환경안전학회지 Vol.25 No.5

A long-term trend analysis of cold water masses along eastern coast of South Korea was performed during summer, based on wind speed, wind direction, and sea surface temperature (SST) data. Wind data collected over a 22-year period (1997-2011) were compared with another set of data collected over the successive 7-year (2012-2018), highlighting a general decrease in the frequency and speed of south winds. However, both the frequency and speed of these winds have been higher in June between 2012-2018, rather than between 1997-2011. The cold water season between July and August was faster during the 7-year period; moreover, the SSTs registered around Gangneung (EN) rose by 0.5℃-1.8℃, while those around Yeongdeok (EC) and Gijang (ES) increased by only 0.1℃-0.3℃. The number of cold water days during the 7-year period, compared to those recorded during previous years (1990-2011, satellite SST data by NOAA/AVHRR), decreased in the proximity of Yeongdeok and Gijang, but increased in the proximity of Kangneung. Additionally, the number of cold water days around Kangneung, Yeongdeok, and Gijang increased in June highlighting a geographical and temporal change in the occurrence of cold waters. These observation can be explained by variations in the pressure distribution that should have weakened the East Asian monsoon, affecting the direction and speed of winds that regulate the flow of cold waters. 본 연구에서는 여름철 동해안 냉수대 해역의 바람의 세기 및 방향과 수온의 장기 변동성을 살펴보았다. 바람분석 결과, 과거 22년(1997년~2011년)과 최근 7년(2012년~2018년)을 비교해 보면 여름철 동안 과거에 비해 최근에 남풍계열 바람의 빈도가 줄었고, 풍속도 약해지는 경향을 보였다. 그러나 6월의 바람은 남풍계열 바람의 빈도와 풍속이 과거에 비해 증가하는 경향을 보였다. 이는 7월과 8월에 주로 나타난 냉수대 시기가 빨라졌다고 분석되었다. 최근 7년 사이 강릉(EN) 해역에서 0.5℃~1.8℃의 수온 상승을 보였으며, 영덕(EC)과 기장(ES)은 0.1℃~0.3℃의 수온 상승을 보였다. 평년(1990년~2011년, NOAA/AVHRR 위성수온자료) 대비 최근 7년의 냉수대 출현일은 영덕과 기장에서 줄어드는 경향을 보였고, 강릉은 상대적으로 냉수대 출현일이 증가하는 추세를 보였다. 또한 강릉, 영덕, 기장 해역에서 6월에 냉수대 출현이 증가하는 경향을 보여 냉수대 발생 해역과 시기에 변화가 발생 된 것으로 분석된다. 이러한 결과는 우리나라 주변의 여름철 동아시아 몬순의 약화가 냉수대의 발생원인인 풍향과 풍속에 영향을 미쳤기 때문으로 판단된다.