• Title/Summary/Keyword: Earth Systems

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Using the Gyeong-in Ara Waterway to Revitalize Coastal Shipping (연안해운 활성화 측면에서의 경인아라뱃길 활용 방안)

  • Lee, Choong-Hyo;Sun, Il-Suck
    • Journal of Korea Port Economic Association
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    • v.32 no.2
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    • pp.39-57
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    • 2016
  • Many countries are developing transportation technologies aimed at reducing environmental pollution and the environmental burden. For example, environmentally friendly transportation routes and methods are being used to improve inland waterways in Europe. Against this backdrop, a case study was conducted on special cargo (weight cargo, earth and sand, etc.) on Korea's Gyeong-In Ara Waterway, an inland waterway connecting the Han River and the West Sea, serving a distribution function. The results of the analysis showed that coastal shipping could be promoted using the waterway, including a positive synergy among environmental, economic, and social aspects. That is, by shifting from overland transportation to marine transportation, it is possible to reduce environmental pollution, ease traffic congestion, decrease traffic accidents, and shorten the licensing period for the weight cargo demand of the northern area of the Han River. In this respect, the Gyeong-in Ara Waterway could become an environmentally friendly transportation route, promoting coastal shipping in Korea. However, for this to occur, support systems such as subsidies for marine transportation and using the inland waterway are required, as happens in the EU. Furthermore, existing policies to promote coastal shipping should be improved and applied more broadly.

An Experimental Study on Frost Heaving Pressure Characteristics of Frozen Soils (동결토의 동상팽창압 특성에 관한 실험적 연구)

  • 신은철;박정준
    • Journal of the Korean Geotechnical Society
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    • v.19 no.2
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    • pp.65-74
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    • 2003
  • Most of land reclamation projects are being implemented along the south and west coastal lines of the Korean Peninsula. The earth structures and in-ground LNG tank, and buildings can be constructed using artificial freezing method on the reclaimed land to control the uplift pressure caused by capillary forces. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable frost heaving pressure was developed. Decomposed granite soils, silty soil, and sandy soil were used in the laboratory freeze test which is sometimes subjected to thermal gradients under closed-systems. A major concern has been the ability to predict the frost heaving pressure over the results of relatively short-term laboratory tests. The frost heaving pressure arising within the soil samples and the temperature of the samples inside were monitored with time elapse. The degree of saturation versus heaving pressure curve is presented for each soil sample and the maximum pressure is closely related to this curve. TDR apparatus was used to measure the volumetric water content by the measurement of unfrozen water contents of frozen soils. Unfrozen water increased in soils containing a high percentage of fine-grained particles. In fine-grained soils with strong attractive farces between soil grains and water molecules, additional water is attracted into the pores leading to further volume changes and ice segregation.

Separation of the Heavy Metals by macrocycles- mediated Emulsion Liquid Membrane Systems (거대고리 화합물을 매질로한 에멀존 액체막게에 의한 중금속이온의 분리)

  • 정오진
    • Journal of Environmental Science International
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    • v.2 no.1
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    • pp.61-72
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    • 1993
  • Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsionsystem. First, one must effective extraction of the post transition metals, $Cd^{2+}$. $Pb^{2+}$ and $Hg^{2+}$ , into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several $A^-$ species such as $SCN^-$, $1^-$, $Br^-$ and $Cl^-$ is the order of the changing degree of solvation for $A^-$ and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of $Cd^{2+}$, $Pb^{2+}$, and $Hg^{2+}$ ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.

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Characteristics for Horizontal Displacement of Temporary Earth Retaining Wall on Marine Sediments (해성퇴적층 지반의 가시설토류벽 수평변위 특성에 관한 연구)

  • Kim, Younghun;Kim, Chanki;Choi, Sungyeol;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.11
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    • pp.37-45
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    • 2010
  • In this study, the value of numerical analysis was compared to the measured value of horizontal displacement during construction. And also, the value was reviewed by comparing with numbers calculated by SUNEX program and EXCAV program. When comparing to suggested values of the maximum horizontal displacement in clayey layer, the displacement caused by the IPS system is larger than one by the Strut girder type system. When comparing the result of SUNEX program to that of EXCAV program, the SUNEX program interprets larger value. It could be concluded the result of SUNEX program is closer to the suggested value, 0.5%H, in clayey layer. The result also shows that the internal friction angle(${\Phi}$) is the key factor of developing horizontal displacement rather than type of supporting systems or materials. That means small horizontal displacement occurs in sandy layer having large value of the internal friction angle, whereas vice versa in clayey layer having small value of the internal friction angle. Therefore, the result of EXCAV program is larger in sandy layer and vice versa in clayey layer. When comparing the measured result during construction to the value of 0.5%H, the measured result is 1.4 times greater than the value of 0.5%H. In contrast, the result of SUNEX program is only 78.1% of the value of 0.5%H and the one of EXCAV program is just 18.1% of that. This result shows the calculated value by SUNEX or EXCAV program is smaller than the observed value by measuring during construction. In result, more careful attention is needed to determine the behavior of the ground. To better analyze the behavior of the ground, more precise finite element method is required.

Geochemical Environments of Copper-bearing Ore Mineralization in the Haman Mineralized Area (함안지역 함 동 광화작용의 지화학적 환경)

  • Choi, Sang-Hoon
    • Economic and Environmental Geology
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    • v.42 no.1
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    • pp.1-8
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    • 2009
  • The Haman mineralized area is located within the Cretaceous Gyeongsang Basin along the southeastern part of the Korean peninsula. Almost all occurrences in the Haman area are representative of copper-bearing polymetallic hydrothermal vein-type mineralization. Within the area are a number of fissure-filling hydrothermal veins which contain tourmaline, quartz and carbonates with Fe-oxide, base-metal sulfide and sulfosalt minerals. The Gunbuk, Jeilgunbuk and Haman mines are each located on such veins. The ore and gangue mineral paragenesis can be divided into three distinct stages: Stage I, tourmaline + quartz + Fe-Cu ore mineralization; Stage II, quartz + sulfides + sulfosalts + carbonates; Stage III, barren calcite. Equilibrium thermodynamic data combined with mineral paragenesis indicate that copper minerals precipitated mainly within a temperature range of $350^{\circ}C$ to $250^{\circ}C$. During early mineralization at $350^{\circ}C$, significant amounts of copper ($10^3$ to $10^2\;ppm$) could be dissolved in weakly acid NaCl solutions. For late mineralization at $250^{\circ}C$, about $10^0$ to $10^{-1}\;ppm$ copper could be dissolved. Equilibrium thermodynamic interpretation indicates that the copper in the Haman-Gunbuk systems could have been transported as a chloride complex and the copper precipitation occurred as a result of cooling accompanied by changes in the geochemical environments ($fs_2$, $fo_2$, pH, etc.) resulting in decrease of solubility of copper chloride complexes.

(Design and Implementation of Integrated Binding Service of Considering Loads in Wide-Area Object Computing Environments) (광역 객체 컴퓨팅 환경에서 부하를 고려한 통합 바인딩 서비스의 설계 및 구현)

  • 정창원;오성권;주수종
    • Journal of KIISE:Information Networking
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    • v.30 no.3
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    • pp.293-306
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    • 2003
  • In recent years, distributed computing environments have been radically changing to a structure of global, heterogeneous, federative and wide-area systems. This structure's environments consist of a let of objects which are implemented on telecommunication network to provide a wide range of services. Furthermore, all of objects existing on the earth have the duplicated characteristics according to how to categorize their own names or properties. But, the existing naming or trading mechanism has not supported the binding services of duplicated objects, because of deficiency of independent location service. Also, if the duplicated objects which is existing on different nodes provide the same service, it is possible to distribute the client requests considering each system's load. For this reason, we designed and implemented a new model that can not only support the location management of replication objects, but also provide the dynamic binding service of objects located in a system with minimum overload for maintaining load balancing among nodes in wide-area object computing environments. Our model is functionally divided into two parts; one part is to obtain an unique object handle of replicated objects with same property as a naming and trading service, and the other is to search one or more contact addresses by a location service using a given object handle. From a given model mentioned above, we present the procedures for the integrated binding mechanism in design phase, that is, Naming/Trading Service and Location Service. And then, we described in details the architecture of components for Integrated Binding Service implemented. Finally, we showed our implement environment and executing result of our model.

Significance of Modern Analog Studies for Exploration and Development of Oil Sand (오일샌드 탐사 및 개발을 위한 현생유사퇴적환경 연구의 중요성)

  • Choi, Kyung-Sik
    • The Korean Journal of Petroleum Geology
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    • v.14 no.1
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    • pp.12-20
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    • 2008
  • Oil sands in Canada are representative example of unconventional resources whose reserve estimates are as large as those in Saudi Arabia. Typical reservoir rocks of oil sands consist of channel-related deposits formed in a tide-dominated depositional setting. The tidal deposits are commonly characterized by spatially complicated and heterogeneous properties. Successful engineering methods to develop oil sands require in-depth understanding in the spatial distribution of reservoir properties. Geological model for oil sand reservoir characterization can be built on the basis of comparative studies of ancient and modem analogues. In particular, modern analogue studies become increasingly indispensable, since they provide better understanding in the reservoir-rock forming process and more importantly in the external mechanism responsible for the reservoir heterogeneity. Tide-dominated environment along the west coast of Korea is considered as one of the most excellent modem analogues of oil-sand forming depositional environment. Korean tidal environment provides insights on the origin of mud breccia, facies and stratigraphic architecture which are key issues to the characterization of oil sand reservoirs.

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Effect of phase transformations on buckling behavior of subducting slab and tectonic implication (상전이가 섭입 슬랩의 좌굴에 미치는 영향과 지체구조적 암시)

  • Lee, Changyeol
    • Journal of the Geological Society of Korea
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    • v.54 no.6
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    • pp.657-675
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    • 2018
  • The apparent thickening of the subducting slab in the shallow lower mantle has been attributed to slab buckling. However, the scaling laws have not been quantitatively evaluated for the buckling behavior of the subducting slab when phase transformations are considered. Thus, two-dimensional dynamic subduction experiments are formulated to evaluate the effect of phase transformations on the buckling behavior of the subducting slab. The model calculations show that the phase transformation from olivine to wadsleyite at a depth of 410 km plays an important role in the development of slab buckling; increased slab pull due to the endothermic phase transformation accelerates slab sinking in the upper mantle and the subducting slab reaches the lower mantle in a shorter time than that of the experiments without the phase transformation. However, the phase transformation from ringwoodite to perovskite plus $magnesiow{\ddot{u}}stite$ at a depth of 660 km retards slab sinking into the lower mantle and the subducting slab tends to be accumulated in the transformation (transition) zone. Buckling analyses show that the scaling laws predict the buckling amplitude and period of the subducting slab with small relative errors even if the phase transformations are considered. The universal phenomenon of the slab buckling can explain apparent slab thickening in the shallow lower mantle and transformation zone under the subduction zones such as Java-Sunda and Northeast Japan. In addition, the buckling behavior of the subducting slab may be related to the periodic compressions and extensions in the Cretaceous Gyeongsang basin.

Development of an Image Processing System for the Large Size High Resolution Satellite Images (대용량 고해상 위성영상처리 시스템 개발)

  • 김경옥;양영규;안충현
    • Korean Journal of Remote Sensing
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    • v.14 no.4
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    • pp.376-391
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    • 1998
  • Images from satellites will have 1 to 3 meter ground resolution and will be very useful for analyzing current status of earth surface. An image processing system named GeoWatch with more intelligent image processing algorithms has been designed and implemented to support the detailed analysis of the land surface using high-resolution satellite imagery. The GeoWatch is a valuable tool for satellite image processing such as digitizing, geometric correction using ground control points, interactive enhancement, various transforms, arithmetic operations, calculating vegetation indices. It can be used for investigating various facts such as the change detection, land cover classification, capacity estimation of the industrial complex, urban information extraction, etc. using more intelligent analysis method with a variety of visual techniques. The strong points of this system are flexible algorithm-save-method for efficient handling of large size images (e.g. full scenes), automatic menu generation and powerful visual programming environment. Most of the existing image processing systems use general graphic user interfaces. In this paper we adopted visual program language for remotely sensed image processing for its powerful programmability and ease of use. This system is an integrated raster/vector analysis system and equipped with many useful functions such as vector overlay, flight simulation, 3D display, and object modeling techniques, etc. In addition to the modules for image and digital signal processing, the system provides many other utilities such as a toolbox and an interactive image editor. This paper also presents several cases of image analysis methods with AI (Artificial Intelligent) technique and design concept for visual programming environment.

Eruption Types and Textures of Pyroclastics from the Jugam Scoria Deposits, Ulleung Island, Korea (울릉도 죽암분석층에서 나온 화성쇄설물들의 조직과 분화유형)

  • Hwang, Sang Koo;Ahn, Ung San;Lee, So Jin;Oh, Kyung Sik
    • Economic and Environmental Geology
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    • v.52 no.5
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    • pp.459-469
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    • 2019
  • We present a quantitative evaluation of density, vesicularity and microtextures for coarse lapilli collected from the Jugam Scoria Deposits, northeastern Ulleung Island. Lapilli from the deposits have modal vesicularities of 61% in the lower part and 67% in the upper part, and vesicle populations dominated by non-interconnected subround vesicles. Clasts of modal vesicularity have margin-parallel zonation, with subaerially quenched rims interpreted to preserve "syn-fragmentation" magmatic textures in microlite-free sideromelane rims, grading "post-fragmentation" tachylitic interiors with vesicle and microlite textures that progressively coarsen from rim to interior. Degassing scenarios are linked to syn-fragmentation vesicle textures to demonstrate that the magmas degassed in dominantly closed systems. And diffusion-controlled cooling rates of trachyandesitic pyroclasts in contact with atmosphere are linked to post-fragmentation evolution of vesicle and microlite textures to infer about transportation and dispersal of the pyroclasts in low shooting jets. These textural analyses show that the Jugam eruptions were strictly applied to the strombolian type, analogous to the hawaiian type among any classical subaerial eruption type.