• Title/Summary/Keyword: 우세

Search Result 1,997, Processing Time 0.029 seconds

Origin of Layering and Its Relation to Magma Convection in the Skaergaard Intrusion (Skaergaard 암체에서 layering의 기원과 그의 마그마 대류와의 관계)

  • Yun D. Jang
    • Economic and Environmental Geology
    • /
    • v.34 no.6
    • /
    • pp.627-648
    • /
    • 2001
  • At least two distinct types of layering are present in the middle zone of the Skaergaard intrusion; alternating plagioclase-rich and pyroxene-rich, macro-rhythmic layers, and smaller scale, modally-graded, rhythmic layers. The macro-rhythmic layers are ubiquitous in the middle zone of the Layered Series, but are not observed in the lower and upper zone of the Layered Series or in the wall or roof tories of the intrusion. They range from 0.3 to 17.3 m in thickness, have sharp upper and lower boundaries, and can be traced laterally for over 2 ]fm in outcrop. Although individual macrorhythmic layers are not internally graded, many contain smaller-scale, modally-graded layers. Modally-graded. rhythmic layers are a common feature of the Layered Series but are not abundant in either the Upper Border Series or the Marginal Border Series. They range in thickness from 1 to 50 cm and can be traced laterally in outcrop for up to 100 m. Their lateral termination ranges from abrupt to gradational, and they are often associated with cut and fill structures and crossbedding suggestive of current activity. They are characterized by sharp lower and gradational upper contacts, and by strong intra-layer modal grading with olivine, ilmenite, and magnetite concentrated at the base, pyroxene concentrated above the base, and plagioclase concentrated at the top. The layers are also grain-size graded with the maximum size for each phase occurring at the horizon in the layer where the phase is most abundant. Modally-graded, rhythmic layers in the middle zone of the Layered Series occur within both plagioclase-rich and pyroxene-rich macro-rhythmic layers.

  • PDF

A Study on Vibration Propagation Characteristics in Tunnel Blasting (터널발파의 진동 전달 특성에 관한 연구)

  • 서영춘;양형식;하태욱
    • Explosives and Blasting
    • /
    • v.19 no.1
    • /
    • pp.41-52
    • /
    • 2001
  • 본 연구에서는 터널발파 진동의 전달 특성을 규명하기 위하여 네 곳의 도로터널의 '터널내부','터널외부','터널직상부 진행방향', '터널직상부' 진행직각방향'의 네 방향으로 발파진동을 계측하였다. 지발당장약량을 해당 지발당장약량과 최대 지발당장약량으로 구분하였으며, 지반의 진동 전달 특성을 확인하기 위하여 자승근 환산거리와 입방근 환산거리로 회귀분석 하였다. 또한 PPV, 거리별 우세진동수를 구하였다. 터널상부 진행방향의 진동 수준이 가장 크게 나타났으며, 진동의 감쇠도 크게 이루어졌다. 터널내부는 비교적 고주파성분이 우세하였으나 나머지는 일반적인 경향을 보였다 최대 지발당장약량을 적용한 입방근 환산거리의 경우가 거리별 감쇠특성 및 상관성이 다른 비교대상에 비하여 가장 우세하게 나타났다. 따라서 최대 지발당장약량을 적용한 입방근 환산거리 방식으로 설계하는 것이 바람직하다고 판단된다.

  • PDF

Changes of Tidal Currents Characteristics and their Effects on Bed Sediment Transport near the Mokpo Coastal Zone (목포해역의 조류특성 변화 및 소류사 이동에 미치는 영향성)

  • Kang, Ju Whan;Moon, Seung Rok;Park, Seon Jung;Ko, Jin Seok
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2004.05b
    • /
    • pp.1007-1011
    • /
    • 2004
  • 영산강하구언과 영암 및 금호방조제 건설에 의해 목포해역에서는 조석확폭현상이 발생하여 만조위가 상승함에 따라 저지대에 침수피해를 야기시킨 바 있다. 이는 목포구의 'tidal choking effect' 기능이 상실됨에 기인한다는 결론을 선행인구(강주환, 1996)에서 얻은 바 있다. 본 인구에서는 선행연구에 비해 전체 영역이 확대되었으며 격자크기가 작아졌을 뿐 아니라 관심영역에는 세부역을 도입하여 더욱 세밀한 격자체계를 구성하였다. 이에 따라 조간대 처리가 한층 정밀해졌으며, 천해조 경계조건 부여와 함계 낙조우세를 실제에 가깝게 재현시킬 수 있게 되었다. 또한 방조제 건설후 낙조우세가 심화되는 자정을 모의할 수 있게 됨에 따라 소류사 이동양상의 변화된 패턴 역시 파악할 수 있었으며, 만조위 상승에 따른 침식유발 효과와 더불어 인근 해역의 침식 원인을 부분적으로 규명할 수 있었다.

  • PDF

EEG Asymmetry Changes in Elderly Women in Stimulus of Odors (향 자극 시 연령에 따른 뇌파의 비대칭성 변화에 관한 연구)

  • 민병찬;진승현;강인형;남경돈;김수용;김철중
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 2001.11a
    • /
    • pp.144-148
    • /
    • 2001
  • 본 연구에서는 쾌한 향과 불쾌한 향에 대한 좌우 반구의 차이를 보여 주는 비대칭 지수를 사용하여, 두 반구 사이의 변화를 살펴보았다. 중년층과 장년층 여성을 대상으로, 100%의 Basil oil, Lavender oil, Lemon oil, Jasmin oil, Ylangylang oil(KIMEX co. Ltd), Sketol의 총 6가지 종류의 천연향을 제시한 후, 주관적 평가를 통해 쾌한 향과 불쾌한 향을 구분한 후, 이 두 향에 대한 뇌파의 비대칭도를 비교 분석하였다. 그 결과, 중년층의 경우, 주관적 평가에서 쾌한 향으로 나타난 lemon향을 제시했을 때, 불쾌한 향을 제시한 경우에 비해 세타파와 알파파에서 우반구 부분이 우세한 경향을 보여 주었고, 장년층에 비해 중년층은 마찬가지로 세타파와 알파파에서 쾌한 향 자극 시 우반구가 우세함을 보여 주었다.

  • PDF

Estimation of Benthos Distribution Using Optic Satellite Data (광학위성자료를 이용한 저서생물 분포 추정)

  • Ryu, Joo-Hyung;Kim, Kye-Lim;Shin, Sang-Ho;Koo, Bon-Joo
    • Proceedings of the KSRS Conference
    • /
    • 2009.03a
    • /
    • pp.314-317
    • /
    • 2009
  • 고해상도 위성자료를 이용하여 갯벌의 다양한 퇴적환경을 공간자료화하거나 표층 생물상 분포를 파악하기 위한 연구는 여러 연구자들에 의해 수행되어졌다. 그러나 갯벌 속에 존재하는 저서생물에 대한 양을 추정하는 연구는 미미한 실정이다. 따라서 본 연구에서는 태안 근소만에 대하여 위성자료를 이용하여 갯벌의 DEM과 퇴적상 등의 분포를 공간자료화하고 이들로부터 생물상과 관련이 있는 노출시간 등의 2차 주제도를 제작하였다. 또한, 현장조사에 의해 얻어진 갯벌 생물 종/개체수와 갯벌의 퇴적환경 공간자료를 비교분석하여 갯벌 저서생물의 공간적 연관성을 파악하였다. 노출시간은 4개의 등급으로 구분하였으며 퇴적상 현장조사와 연계하여 우점종을 분석한 결과, 노출시간이 가장 긴 노출시간 I 등급 지역은 두토막눈썹참갯지렁이와, 칠게와 가재붙이가 대표종으로 분석되었다. II 지역의 모래 우세지역에는 쏙이 그리고 펄 우세지역에는 세가시육질꼬리옆새우가 우점종으로 나타났다. III과 IV 지역은 조하대쪽으로 모래 성분이 전체적으로 우세하게 나타났는데 펄털콩게와 바지락이 우정하고 있는 것으로 분석되었다.

  • PDF

Analysis of Growth Characteristics and Aboveground Carbon Storage for Zelkova serrata Artificial Forests in Gwangneung Experimental Forest (광릉시험림 내 느티나무(Zelkova serrata) 인공림의 생장특성 및 지상부 탄소저장량 분석)

  • Kim, Hyun-Seop;Bae, Sang-Won;Lee, Sang-Tae;Hwang, Jae-Hong
    • Journal of Korean Society of Forest Science
    • /
    • v.99 no.1
    • /
    • pp.144-152
    • /
    • 2010
  • This study was conducted to analyze the growth characteristics and aboveground carbon storage for old growth Zelkova serrata artificial forests (site1: age class IX, site2: age class VIII) in Gwangneung Experimental Forest. The trees were classified by crown classes for analyzing forest stand structure. The growth characteristics were analized through ringwidth increment by crown classes and stem analysis of dominant trees. There were a wide range of DBH (site1: 8~62 cm, site2: 14~40 cm) and height (site1: 8~26 m, site2: 12~26 m) distributions and revealed different growth characteristics by crown classes in both sites. The mean annual increment (MAI) of ringwidth for the last 5 years of dominant trees for site1 (3.3 mm) was higher than MAI of ringwidth of total growth period (2.3 mm) and MAI of ringwidth for the last 5 years of dominant trees for site2 (2.2 mm) was equal to MAI of ringwidth of total growth period (2.2 mm). Also, the growth increment of ringwidth by crown classes had significant differences between dominant tree and the others crown classes (p<0.01) in both sites. As a results of stem analysis of dominant trees in both sites, there were similar to their volume between site1 (1.106 $m^3$) and site2 (1.035 $m^3$). In spite of old age, the annual increment of volume has been increasing steadily until recent year. Meanwhile, total aboveground carbon storage of site1 (65.6 Mg C $ha^{-1}$) was higher than that of site2 (56.1 Mg C $ha^{-1}$). The proportion of dominant and co-dominant trees to total aboveground carbon storage was more than 90% and the greatest individual aboveground carbon storage by crown classes was dominant tree in all both sites. However, individual aboveground carbon storage of dominant tree in site1 had 0.054 Mg C $tree^{-1}$ more than site2 owing to the differences from average DBH of dominant trees by sites. We think that these results will contribute to the forest practice for Zelkova serrata artificial forests as a basic information.

Analysis of Tidal Asymmetry and Flood/Ebb Dominance around the Yeomha Channel in the Han River Estuary (한강하구 염하수로 주변에서의 조석·조류 비대칭과 창·낙조 우세 분석)

  • Yoon, Byung-Il;Woo, Seung-Buhm
    • Journal of Korea Water Resources Association
    • /
    • v.45 no.9
    • /
    • pp.915-928
    • /
    • 2012
  • Han River estuary (HRE) is located at the middle of the western coast of Korea, and tidal currents were measured at 4 stations in this estuary during the winter season, and previously observed tide data was analyzed. The results of amplitude ratio of $M_4/M_2$ showed that increasing upward to estuary in the HRE. Tide harmonic constants of relative phase $2M_2-M_4$ represent flood dominance, with under 180 degree. But this method has a limit of analysis that typically based on the non-linear distortion of the tidal current in tidal lagoon system where freshwater discharge is assumed to be relatively small. The results of statistically tidal current data indicated that ebb current velocity would be great unlike tide data. Ebb and flood duration time is calculated by slack time of tidal current showed that ebb duration time is longer than flood. The results of correlation of analysis show high value (0.9) between tidal current stations from Incheon harbor to north entrance of Yeomha channel. We reconstructed to find the reasons for the features of ebb dominance the results of harmonic analysis. As major component ($M_2$) in combination with shallow water component ($M_4$), the tidal curve was presented flood dominance that has a flood current is stronger. However, these curve were changed to ebb dominance add up the non-harmonic components that had ebb direction flow by calculated tidally averaged current. The characteristic of enhancement on ebb is showed around the Yeomha channel in the HRE, because averaged flow which acts seaward such as long-term tidal current components due to non-linear effect and freshwater which overcome the flood current.

Ultrasonographic Findings of the Shoulder in Asymptomatic High School Baseball Players (무증상 고교 야구 선수의 견관절 초음파 소견)

  • Hwang, Tae Hyok;Cho, Hyung Lae;Wang, Tae Hyun;Yang, Hee Soon
    • Journal of Korean Orthopaedic Sports Medicine
    • /
    • v.11 no.2
    • /
    • pp.75-81
    • /
    • 2012
  • Purpose: To evaluate the ultrasonographic (US) findings in both shoulders of asymptomatic high school baseball players and compare with healthy control. Materials and Methods: 42 individuals (age: $7.6{\pm}1.2$ years) participated in this study. We recruited two groups of high school male baseball players, 14 pitchers and 18 fielders without shoulder pain for recent 6 months as well as one control group of 10 untrained healthy high school students who were age-matched. Ultrasound measurements of thickness of the biceps and supraspinatus tendon and acromio-humral distance (AHD) at $0^{\circ}$ abduction were taken in dominant and nondominant shoulders. Results: On US examination, subacromial bursa effusion was observed in 7 of the dominant shoulders and in 2 of the nondominant shoulder of 32 baseball players and in none of the asymptomatic controls. The thickness of the biceps and supraspinatus tendons and AHD in both shoulders were significantly greater in the baseball players than in the controls (p<0.05). We also found that the biceps and supraspinatus tendon thickness and AHD of the dominant shoulder were significantly greater than the non-dominant shoulder in baseball players (p<0.05), but there were no differences between pitchers and fielders and between healthy controls. Conclusion: Subacromial effusion could be found even in the asymptomatic stage and the thickness of the biceps and supraspinatus tendons and AHD were significantly greater in the baseball players than in the healthy controls. Our data is useful reference guide for the ultrasonographic diagnosis of shoulder pathologies occurring in high school baseball players.

  • PDF

Chemical Speciation of Heavy Metals in Geologic Environments on the Abandoned Jangpoong Cu Mine Area (장풍 폐광산 주변 지질환경에서 중금속의 존재형태)

  • Lee In-Gyeong;Lee Pyeong-Koo;Choi Sang-Hoon;Kim Ji-Soo;So Chil-Sup
    • Economic and Environmental Geology
    • /
    • v.38 no.6 s.175
    • /
    • pp.699-705
    • /
    • 2005
  • In order to identify the speciation of As and trace elements which are contained weathered waste rocks on the abandoned Jangpoong Cu mine area, five fraction sequential extraction was carried out. Concentrations of the extraction solutions which were acquaired each fraction were mesured by ICP-AES. Mineral characters of weathered waste rocks were determinated by XRD. The weathered waste rocks could divide into two types (Type I and type II). Type land type II weathered waste rocks are mainly composed of a quartz and a calcite, respectively. The most dominant speciation of As, Co and Fe is residual phase. Most of the speciation of Cd, Mn and Zn is residual phase for type I and Fe-Mn oxide phase for type II. In case of Cu, residual phase is predominant in type I and sulfide is predominet in type II. The most dominant speciation of Pb for type I and type II is associated with the residual phase and Fe-Mn oxide phase, respectively. At pH 4-7 range, the order of relative mobility considers Zn>Cu>Cd>Pb>Co>AS in type I, and Cd>Cu>Zn>Pb>As>Co in type II.

Naturalness Assessment of Riverine Wetland by Vegetational Prevalence Index (식생우세도 지수에 의한 하천습지의 자연도 평가)

  • Chun, Seung-Hoon;Ko, Shin-Hye;Ahn, Hong-Kyu;Chae, Soo-Kwon
    • Journal of Wetlands Research
    • /
    • v.13 no.3
    • /
    • pp.535-545
    • /
    • 2011
  • This study was carried out to suggest the baseline data necessary for vegetation restoration by naturalness assessment of riverine wetland within stream corridor. We selected stream reach both of near nature and urbanized by Nonsan stream and Hongchun river as experimental site. Composition of vegetation community and land use pattern between two sites indicated considerable difference, which imply for many different watershed property and process disturbed each other at river ecosystem. Naturalness of the sampled reaches showed that near nature is in better condition for riverine wetland than urbanized of all two sites. However, the prevalence index of Hongchun river within its natural state was lower than that of Nonsan stream, because the index included some vegetation communities occurred at upland fringe and bank slope. In conclusion assessment system using prevalence index would be considered an effective method for evaluating of natural states of riverine wetland.