• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.251-263
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• 2005

Modern volcanoes, Laoheishan and Huoshaoshan, have erupted during $1720\~1721$ in the Wudalianchi volcanic group, NE china. They comprise scoria and spatter cones that consist of potassium-rich phono-tephritic pyroclastic deposits and lavas, and include wide lava flow fields. The Laoheishan scoria cone is a polygenetic multiple volcano that overlaps earlier and later edifices with more complicated internal structures produced in greater scale and in earlier time than the Huoshaoshan. There is a funnel-shaped crater in the center of the later edifice of the Laoheishan scoria cone. The Huoshaoshan spatter cone is a monogenetic simple volcano with a central pit crater. The volcanic sequences indicate eruption processes that followed a repeated pattern that progressed through 5 stages of explosive and effusive eruption including lava fountains and Strombolian eruptions in the Laoheishan, and a recognizable pattern of 2 stages that started with Strombolian eruption and progressed through lava effusion in the Huoshaoshan.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.373-376
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• 2006

본 연구의 목적은 동해 울릉분지의 제4기 후기 퇴적물 내의 유기물, 공극수와 메탄의 특징 및 상호작용을 규명하는데 있다. 연구지역에서 채취한 코어퇴적물을 원소 분석한 결과 C/N 및 C/S 비(wt. %)는 퇴적물 내 유기물이 주로 해양조류 기원을 가지고, 일반적인 해양 또는 정체 환경에서 퇴적되어Tdam을 지시한다. 그러나 Rock-Eval 열분석 결과는 유기물 기원이 육상식물(Type III)이고, 열적 성숙단계가 미성숙단계임을 보여준다. 이러한 원소분석과 열분석간의 상반된 결과는 유기물이 침강하는 동안 또는 퇴적 후 이루어진 강한 산화작용에 기인한 것으로 추정된다. 퇴적물 내 공극수의 황산염 농도가 퇴적물의 심도가 증가할수록 감소하며, 감소하는 경향은 크게 두 가지 (적선성, concave down)로 나누어진다. 이는 모든 코어에서 황산엽 환원작용이 일어나고 있음을 지시한다. 또한 직선선의 황산엽농도 구배는 무산소 메탄 산화작용(AMO)의 전형적인 특징이다. 황산염 농도의 수직적 구배를 이용하여 SMI(sulfate-methane interface) 심도를 계산하면, 남부울릉분지의 코어 (03GHP-01, 03GHP-02; <3.5mbsf)가 북부울릉분지 코어(01GHP-05, 01GHP-07, 03GHP-03, 03GHP-04, 03GHP-05; > 6mbsf)보다 낮은 값을 갖는다. 위와 같은 SMI 심도차는 메탄의 상부 분산량과 밀접한 관련있는 것으로 추정된다. 메탄가스의 탄소 안정동위원소 $({\delta}^{13}C)$ 분석값들은 -83.5%o에서 -69.5%o의 범위를 가지고 있고, 이산화탄소 환원작용($CO)_2$ reduction)에 의한 생물 (biogenic) 기원임을 지시한다.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.23-29
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• 2001

An Obstacle Avoidance System(OAS) of Underwater Vehicle(UV) in diving and steering plane is investigated. The concept of Imaginary Reference Line(IRL), which acts as the seabed in the diving plane, is introduced to apply the diving plane avoidance algorithm to the steering plane algorithm. Furthermore, the distance to the obstacle and the slope information of the obstacle are used for more efficient and safer avoidance. As for the control algorithm, the sliding mode controller is adopted to consider the nonlinearity of the equations of motion and to get the robustness of the designed system. To verify the obstacle avoidance ability of the designed system, numerical simulations are carried out on the cases of some presumed three-dimensional obstacles. The effects of the sonar and the clearance factor used in avoidance algorithm are also investigated. Through these, it is found that the designed avoidance system can successfully cope with various obstacles and the detection range of sonar is proven to bea significant parameter to the performance of the avoidance.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.22 no.1
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• pp.69-77
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• 2015

Purposes: The purpose of the study was to evaluate knowledge of hepatitis C and compliance with therapeutic guidelines and their correlation. Methods: Participants included a total of 197 subjects with chronic hepatitis C from 4 general hospitals. Subjects were asked 25 items of knowledge on hepatitis C and 17 items of compliance with therapeutic guidelines. The collected data was analyzed for frequency, percentage, average, standard deviation, t-test, ANOVA and Pearson's correlation coefficient. with the help of SPSS 21.0 program. Results: The subject's knowledge on chronic hepatitis C expressed as percentage was 67.1%. Compliance of the research participants gained $3.96({\pm}0.76)$ points in general on a 5-point scale. Learned compliance was higher when the patients were 45 years old and over. female and with spouse. There was a statistically significantly positive correlation between knowledge and compliances. Conclusions: Development of educational programs requires consideration of patient characteristics, particularly education on the male patients under 45 years of age.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.433-438
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• 2019

This paper proposes a method of improving deep learning based numbers and characters recognition performance on parts of drawing through image preprocessing. The proposed character recognition system consists of image preprocessing and 7 layer deep learning model. Mathematical morphological filtering is used as preprocessing to remove the lines and shapes which causes false recognition of numbers and characters on parts drawing. Further.. Further, the used deep learning model is a 7 layer deep learning model instead of VGG-16 model. As a result of the proposed OCR method, the recognition rate of characters is 92.57% and the precision is 92.82%.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.143-144
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• 2001

경기육괴의 남서부에 해당하며 옥천구조대의 북쪽에 위치한 백동-홍성 일대의 충청남도 일원에는 선캠브리아기의 편마암복합체내에 초염기성암체들이 소규모 렌즈상의 암체로 이 지역에 우세한 구조선 방향인 북북동 방향으로 배열되어 산출된다. 이들 초염기성암채들이 조산대에 형성되는 알파인형이며 전형적인 상부 맨틀기원의 암석이 부분용융된 맨틀 잔여물로서 지표로의 이동과정에서 변성작용을 받아 대부분은 사문석화 혹은 활석화된 것으로 보고되어 있다. 본 연구의 주대상인 변성염기성암을 포함하는 백동지역의 초염기성암은 홍성도폭내 덕정리 편암암체 내에 주변 편마암체와 단층으로 접하면서 나타난다. 덕정리 편마암체는 주로 각섬석 화강편마암으로 구성되어있다. 백동지역의 초염기성암내에는 변성염기성암이 층상으로 협재되어 나타난다. 이들 변성염기성암은 석류석, 단사휘석, 각섬석, 사장석으로 주로 이루어진 석류석 각섬암이며 금홍석도 포함하고 있다. 많은 석류석 주변에는 사장석과 각섬석으로 이루어진 심플렉타이트가 발달되어있다. 석류석 각섬암내 심플렉타이트가 형성되지 않은 석류석 가장자리로부터 계산된 변성 온도-압력 조건은 590-72$0^{\circ}C$, 9-l0kb이며 심플렉타이트가 잘 형성된 석류석 주변부로부터는 490-$600^{\circ}C$, 4-6.3kb의 변성 온도-압력 조건이 계산되었다. 이에 반해 변성염기성암을 포함한 초염기성암체 주변에 나타나는 석류석-각섬석 화강편마암으로 부터는 570-78$0^{\circ}C$, 11.6-l6kb의 변성 온도-압력 조건을 얻었다. 석류석 각섬암에서 석류석내에 포획물로 나타나는 휘석(Xjd, 4-11)이 기질에 나타나는 휘석(Xid, 1-6)보다 높은 제이다이트 성분을 갖는다. 이는 석류석 중심부가 석류석 주변부보다 변성압력 조건이 높았을 가능성을 지시한다. 즉 연구지역의 석류석 각섬암은 주변의 각섬석 화강편마암과 같이 에콜로자이트상-상부각섬암상-고압백립암상의 점이대에 해당하는 변성작용을 받은후 초염기성암의 사문암화 작용시기에 1차 후퇴변성작용을 그리고 그후의 활석화 시기에 심플렉타이트를 형성하는 2차 후퇴변성작용을 받았다. 이러한 후퇴변성작용시기에 많은 유체가 침입하였고 그 결과 초염기성암내의 변성염기성암이 주변 화강편마암보다 후퇴변성작용을 강하게 받았을 것으로 예상된다. 변성염기성암의 변성연대를 구하기 위해 두 석류석 각석암 시료에 대해 석류석-전암 Sm-Nd 등시선 연령을 구하였다. 두 개의 석류석 각섬암으로부터 계산된 전암-석류석 연령은 297.9$\pm$5.7(2$\sigma$)Ma 그리고 268.7$\pm$3.3(2$\sigma$)Ma를 나타낸다. 석류석의 Sm-Nd 폐쇄온도가 700-75$0^{\circ}C$임을 고려할 때 두 석류석 각섬암으로부터 계산된 연대는 최고 변성작용 혹은 초기 냉각 시기를 지시할 가능성이 높다. 한편 전암의 두 동위원소 자료로부터 계산된 전암의 연령은 408Ma이다. 이러한 연구 결과는 연구지역의 석류석 각섬암이 시루리아기 후기 혹은 데본기 초기에 관입 후 석탄기 후기에서 페름기 중기에 주변 화강편마암과 함께 섭입작용을 받았을 가능성을 지시한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.2
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• pp.103-113
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• 2001

This study presents Quaternary sedimentation pattern around Dok-Island volcanoes (Dok Island and Dok Seamount), based on analysis of high-resolution (chirp) echo characters. Echo facies If, showing sharp, continuous bottom echo without subbottom reflectors, is recorded mainly from the flat tops of the volcanoes. This facies indicates sands and gravels (re) deposited by shallow marine processes. Echo facies IIA in the basin floor and basal slopes of the volcanoes and Oki Bank is characterized by semi-prolonged bottom and several parallel subbottom echoes. This facies reflects hemipelagic settling with intermittent influences of turbidity currents in the slope areas. Echo facies IIC is recorded from acoustically-transparent debrite masses on the basal slopes of the volcanoes and Oki Bank. Echo facies IIIA is characterized by irregular hyperbolic echoes in the slope areas of the volcanoes. It suggests hard rock basement or irregular volcanic edifices. Echo facies IIIC shows regularly-overlapping hyperbolic bottom echoes. It is interpreted to represent rock-fall deposits (talus) accumulated in the mid-slope area. Echo characters and topography suggest that the tops of Dok-Island volcanoes were flattened and lowered by shallow-marine erosional processes. The eroded sediments were transported to and deposited in the base of slope and basin plain mainly by debris flows and turbidity currents along submarine canyons and valleys.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.441-456
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• 2021

The Cretaceous Duwon Formation was studied on the basis of sedimentologic analysis in order to unravel geologic conditions for the development of the streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. The Duwon Formation unconformably overlies the Paleoproterozoic gneiss (basement). Based on the sedimentologic analysis, the Duwon Formation is interpreted to have been deposited in gravelly braided stream (FA-1) near the basement, laterally transitional to sandy braided stream (FA-2) and floodplain environments (FA-3) with distance (< 7 km) from the basement. Lateral changes in sedimentary facies and the well development of calcrete nodules in FA-3, together with radial paleocurrent directions measured in FA-1, are suggestive of the deposition of the Duwon Formation in streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. Recent analysis of detrital zircon chronology suggests that sediments of the Duwon Formation were derived from the southwestern part of the Korean peninsula, including the western part of Yeongnam Massif and the southwestern part of Okcheon Belt. This implies the alluvial fan where the Duwon Formation accumulated had the large drainage basin. Because the large drainage basin can supply the significant amounts of water and temporarily store the sediments within the basin, watery floodwater carried sediments to the alluvial fan rather than the debris flows. Furthermore, the drainage basin largely composed of coarse-grained metamorphic and igneous rocks produced sand-grade sediments, preventing evolution of floodwater into debris flows. We suggest that combined effects of the large drainage basin and its coarse-grained metamorphic and igneous rocks provided favorable conditions for the development of streamflow-dominated alluvial fan, despite arid to semi-arid climatic conditions during sedimentation.

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.2
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• pp.179-187
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• 1997

Doppler log and current meter are based on the measurment of the doppler effect. Ship's speed over the ground measured by means of doppler log effect of underwater ultrasonic intends to get infulence by the difference of sound velocity, the ship's course, the sea bottom inclination, the trim and tranducer installation etc. This paper investigated on the error of speed over the ground by change of the trim comparing the real speed obtained by the mile post with the speed of single beam type doppler log on the trainning ship Kyeongyangho. The results are as follows ; 1. Indicating speed of doppler log is very much greatly influenced on variation of trim, but the real speed is less affected variation by trim. 2. The range of variation and error of speed over ground are smallest when ship's trim is 2.15m trim by the stern.

• The Journal of the Petrological Society of Korea
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• v.28 no.2
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• pp.53-69
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• 2019

In the Jirisan area of the Yeongnam Massif, Korea, several ductile shear zones are developed within Precambrian gneiss complex (Jirisan metamorphic rock complex). The ductile shear zones have a general NS- and NNE-striking foliation with westward dipping directions. The foliation developed in the shear zones cut the foliation in gneiss complex. The stretching lineations are well developed in the foliated plane of the shear zone, showing ENE-trend with gentle plunging angle to the ESE direction. Within shear zone, several millimetric to centimetric size of porphyroclasts are deformed strongly as a sigmoid form by ductile shearing. The sigmoid patterns of porphyroclasts in the shear zones indicate the dextral shearing. The spatial distribution of ductile shear zone is characterized by the dominant NS- and NNE-striking dextral sense in the central and eastern regions respectively. In the western part, it develops in NE-striking dextral sense which is the general direction of the Honam shear zone. The U-Pb concordant ages obtained from the two samples, the strongly sheared leucocratic gneiss, are $1,868{\pm}3.8Ma$ and $1,867{\pm}4.0Ma$, respectively, which are consistent with the U-Pb ages reported around the study area. We supposed that the ductile shearing in the study area is occurred about 230~220 Ma during late stage of the continental collision around Korea and is preceded by granitic intrusion related to subduction during 260~230 Ma, which are supported by compiling the age data from sheared gneiss, deformed mafic dyke intruded gneiss complex, and non-deformed igneous rocks.