• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1470-1473
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• 2006

연속된 두 장의 레이더 반사도(합성 CAPPI)를 이용하여 설정된 두 윈도우 사이의 최대 상관계수를 찾아 냄으로써 강수의 움직임을 파악하는 기존의 TREC(Tracking Radar Echoes by Correlation) 기법은 단지 통계적인 상관법을 이용하여 산출된 TREC 벡터를 외삽하기 때문에 강우 시스템의 이동양상을 물리적으로 표현하는데 한계를 가질 뿐만 아니라 강수가 직선운동을 하는 것처럼 묘사될 수밖에 없는 기법의 한계성을지니고 있다. 본 연구에서는 도플러 레이더로부터 생산되는 시선속도를 이용하여 바람장을 산출하고 이를 TREC 벡터와 연계시켜 단시간 예보모형을 개선하고자 하였다. 시선속도는 레이더로부터 멀어지거나 다가오는 물체의 속도성분이며, 이를 이용하여 강수 영역 내의 바람장을 산출할 수 있다. 이러한 바람장 정보와 연계한 TREC 벡터의 개선은 단시간 강우 예보모형의 개선을 통하여 짧은 시간에 급격한 발달하는 집중호우 등에 대한 보다 정확한 예보를 가능하게 한다.

• The Journal of the Acoustical Society of Korea
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• v.25 no.8
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• pp.389-394
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• 2006

Mid-Frequency bistatic reverberation level is modeled using ray theoretic algorithms. The algorithm assumes multiple forward/backward scatter along with reciprocity in the Propagation paths. The environments modeled are assumed to be range independent in bathymetry, bottom scattering and surface scattering. Mid-Frequency bistatic scattering algorithm is used as a scattering model. A comparison of predicted reverberation versus time with measured data is presented to verify the bistatic reverberation model. The result demonstrates that it is possible to obtain reasonable reverberation Predictions in experimental site.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.273-277
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• 2005

본 연구는 한국어 어말어미 산출시 나타나는 대뇌 활성화 영역을 살펴보기 위하여 실시되었다. 두 가지 실험이 실시되었다 실험 1은 어말어미의 기본형을 주고 이를 의문형, 명령형으로 산출하는 고립단어 실험을 실시하였다. 통제 조건으로 모음변환조건(C1)과 아라비아문자보기(C2)를 사용하였다. 실험 1의 결과 ‘어말어미-C1’ 조건에서 좌반구의 측두엽과 전두엽부분의 의 활성화 superior temporal gyrus와 inferior frontal gyrus의 활성화가 관찰되었다. ‘어말어미-C2’ 의 조건에서 우반구에서 후두엽의 활성화와 좌반구에서의 후두엽, 전두엽, lingual G, Cuneus, fusiform G, inferior occipital G에서의 활성화를 관찰할 수 있었다. 실험 2는 명령형과 의문형 어미의 형태점화효과와 관련된 대뇌 활성화 영역을 관찰하기 위하여 Er-fMRI 기법을 이용하여 실시되었다. 실험 조건은 어미동일조건, 어간반복조건, 무관련 조건으로 구성되었다. 피험자들은 점화자극이 제시된 후 신호가 제시되고 나오는 표적단어를 의문형 또는 명령으로 산출하도록 하는 과제를 실시하였다. 뇌 활성화 영역을 분석한 결과 의문형과 명령형을 산출할 때의 활성화 영역에서 $^{\ast}^{\ast}^{\ast}$를 볼 때의 영역을 빼기 (substraction)한 결과 공통적으로 좌반구 브로카 영역이 활성화되었고, 의문형과 명령형 안에서 어미동일조건에서 무관련 조건을 뺀 경우에는 좌반구의 superior temporal G 영역의 활성화가 관찰되었다. 이들 결과를 종합해 볼 때 어말어미 산출 그 자체와 직접 관련되는 영역으로는 좌반구의 측두엽과 전두엽 부분이 관찰되었다. 특히 한국어 어말어미 산출시 나타나는 형태점화 양상과 관련된 대뇌영역으로 발견된 브로카 영역에서의 활성화는 어미 변환과 관련된 영역이라기보다는 산출시 관련되는 articulation, motor coordinate관련 영역으로 추정되고, 측두엽의 활성화는 형태소, 의미 관련 지식의 data base로 추정된다. 또한 우반구 전두엽 부분에서 관찰된 활성화는 억제관련 영역으로 짐작된다.

• Journal of the Mineralogical Society of Korea
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• v.17 no.3
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• pp.221-233
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• 2004

Mineralogical characteristics and genesis of phlogopite in the talc deposits of the chungnam area were studied. Mica is one of the major impurity of talc ores in the study area. Talc-related micas show typical phlogopite composition, whereas talc-unrelated micas show wide compositional variations between biotite and phlogopite. Phlogopite mainly occurs in the black-wall type zone, especially in the nodular talc ores near the outer part of talc ore bodies. Interleaving textures of phlogopite and chlorite are easily observed under the optical microscope and back-scattered electron images. Interleaving textures of phlogopite and talc are observed also. Examination of the phlogopite by transmission electron microscope reveals that 14 $\AA$ layers of chlorite are randomly interlayered within the 10 $\AA$ layers of phlogopite, which suggests that the genesis of phlogopite is closely related to chlorite. Considering the occurrence and mineralogical characteristics of phlogopite, and the possible origin of K for the formation of phlogopite, phlogopite of the study area was formed by interaction between talc ore body and hydrothermal solution containing sufficient K at the late stage of talc formation. K might be introduced from the granitic gneiss at the contact zone between the talc ore body and the granitic gneiss under favorable structural condition for the potash metasomatism.

• KDI Journal of Economic Policy
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• v.31 no.1
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• pp.1-25
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• 2009

This paper attempts to estimate the natural rates of output and interest of Korea in a simple DSGE set-up with a few stylized New Keynesian features using Bayesian methods. The major findings of this paper are as follows. First, the estimates of output gaps are less volatile than the measures from conventional approaches, although they exhibit non-negligible variations depending on the model specification. Another key finding is that the hybrid type Phillips curve with a backward-looking component and/or habit formation in consumption may play an important role in characterizing the macroeconomic dynamics of Korea.

• 재활복지
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• v.20 no.4
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• pp.229-246
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• 2016

The aim of this study is to conduct superordinate word selection task to compare their performance and reaction time, and superordinate word writing task to compare the differences in their performance and error pattern in 40 elderly adults and 43 young adults. As a result, first, in both tasks, elderly adults had a smaller number of correct responses. Second, elderly adults showed slower reaction time than young adults. Third, in superordinate word writing task, elderly adults showed more relevant errors than irrelevant errors. The reason elderly adults had a smaller number of correct responses in both tasks was that the links among the pieces of information in the semantic lexicon weakened or deteriorated due to normal aging. Slower reaction time was based on neurophysiological changes of the brain and cognitive processing speed. In addition, the relevant errors showed that they could access the lexicon for target words and produce explanation the relevant characteristics, even though they could not retrieve the target words.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.309-322
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• 2018

Naturally occurring asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. It is proved that inhalation of asbestos fibers can lead to increase risk of developing several diseases such as lung cancer and malignant mesothelioma. The parent rocks of asbestos have been mainly associated with (ultra)mafic and carbonate rock. The previous studies on NOA were mainly limited to (ultra)mafic rock-hosted asbestos, but studies on carbonate rock-hosted asbestos are relatively rare in S. Korea. Therefore, this study was aimed to examine mineralogical characteristics of carbonate rock-hosted NOA at three sites including Muju and Jangsu, Jeonbuk province and Asan, Chungnam province. Types of rocks at the three sites mainly consisted of Precambrian metasedimentary rocks, carbonate rock, and Cretaceous and Jurassic granites. Asbestos-containing carbonate rock samples were obtained for mineralogical characterization. XRD, PLM, EPMA, SEM and EDS analyses were used to characterize mineralogical characteristics of the carbonate rock-hosted NOA. From the carbonate rock, fibrous minerals were occurred acicular and columnar forms in the three sites. Fibrous minerals were composed of mainly tremolite and associated minerals included possibly asbestos containing materials (ACM) such as talc, vermiculite, and sepiolite. The length and aspect ratios of tremolite were similar to the standard asbestiform (length >$5{\mu}m$, length:width = 3:1). These results indicate that both non-asbestiform and asbestiform tremolite with acicular forms occurred in carbonate rocks at three sites. Geological and geochemical characteristics and mineral assemblages indicate tremolite and associated minerals might be formed by hydrothermal alternation and/or hydrothermal veins of carbonate rocks due to intrusion of acidic igneous rocks.

• Journal of the Mineralogical Society of Korea
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• v.7 no.2
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• pp.111-127
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• 1994

양남 지역의 제 3 기층인 하서리 응회암층의 중.상부에 부존되는 벤토나이트들은 원암의 암상과 화학조성에 의존되는 광호 양상과 광물상을 나타낸다. 벤톤나이트들은 대부분 안산암질 원암의 기원을 시사하는 희유 및 희토류 원소들의 함유 양상을 보이고, 현무암질 원암의 벤토나이트는 최상부의 일부 층준에만 그 산출이 국한된다. 이 지역의 벤토나이트는 주로 유리질 내지 라필리 응회암이 속성 변질된 것으로 이 과정에서 SiO2와 알칼리 (Na, K) 성분들이 고갈되는 화학 성분상의 유동 양상이 인지된다. 벤토나이트는 주된 광물 성분인 스멕타이트 이외에 흔히 단백석 및 석영같은 규산 광물과 휼란다이트, 모데나이트 및 클리높틸로라이트간은 불석광물들을 수반한다. 스멕타이트는 대부분 몰노릴로나이트 유형이지만 최상부 층준의 현무암질원 벤토나이트와 비교하여 논트로나이트의 광물 화학, X-선회절 양상, 층간 화학 및 염화학적 특성 등이 논의되었다. 이 지역 벤토나이트의 형성과정은 (1) 화산쇄설물의 급속한 퇴적, (2) 비이상적으로 높은 매몰 온도(<8$0^{\circ}C$) 조건, (3) 규산 광물의침전에 의한 공극수 내외 H4SiO4의 제거, (4) 원암의 낮은 Si/al 함유비와 높은 Fe 함유도 등에 의해서 조장된 것으로 해석된다.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.305-313
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• 2024

For effective bi-static sonar operation, detection performance analysis must be performed reflecting the characteristics of sound propagation due to the ocean environment and target information. However, previous studies analyzing bistatic sonar detection performance have either not considered the ocean environment and target characteristics or have been conducted using simplified approaches. Therefore, in this study, we compared and analyzed the bistatic detection performance in Yellow sea and Ulleung basin both with and without considering target characteristics. A numerical analysis model was used to derive an accurate bistatic target strength for the submarine-shaped target, and signal excess was calculated by reflecting the simulated target strength. As a result, significant changes in detection performance were observed depending on the source and receiver locations as well as the target strength.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.589-601
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• 2016

Sea surface currents were estimated by applying the Maximum Cross Correlation (MCC), Zero-mean Sum of Absolute Distances (ZSAD), and Zero-mean Sum of Squared Distances (ZSSD) algorithms to Himawari-8/Advanced Himawari Imager (AHI) thermal infrared channel data, and the comparative analysis was performed between the results of these algorithms. The sea surface currents of the Kuroshio Current region that were retrieved using each algorithm showed similar results. The ratio of errors to the total number of estimated surface current vectors had little difference according to the algorithms, and the time required for sea surface current calculation was reduced by 24% and 18%, relative to the MCC algorithm, for the ZSAD and ZSSD algorithms, respectively. The estimated surface currents were validated against those from satellite-tracked surface drifter and altimeter data, and the accuracy evaluation of these algorithms showed results within similar ranges. In addition, the accuracy was affected by the magnitude of brightness temperature gradients and the time interval between satellite image data.