• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1053-1056
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• 2008

An application of CSG (Constructive Solid Geometry) modeling technique in Machining Simulation is introduced in this paper. The current CSG model is based on z-buffer CSG Rendering Algorithm. In order to build a CSG model, frame buffers of VGA (Video Graphic Accelerator) should be used in term of color buffer, depth buffer, and stencil buffer. In addition to using CSG model in machine simulation Stock and Cutter Swept Surface (CSS) should be solid. Method to create a solid Cuboid stock and Ball-end mill CSS are included in the present paper. Boolean operations are used to produce the after-cut part, especially the Difference operation between Stock and CSS as the cutter remove materials form stock. Finally, a small program called MaSim which simulates one simple cut using this method was created.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.451-455
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• 2014

In LTE (Long Term Evolution)/LTE-A (Long Term Evolution-Advanced) networks, hierarchical macro/femto-cell structure is adopted to enhance system capacity. Such a femto-cell is deployed as a Closed Subscriber Group (CSG) eNB. However, the inbound handover to CSG cell experiences longer delay than normal handover because it spends more time detecting the associated CSG cells due to its sparse deployment. Most of all the legacy UEs (User Equipments) have been implemented without considering the inbound CSG handover. Accordingly, they may not meet the performance requirements on the cell discovery described in the LTE/LTE-A standards. Therefore, in this paper, the performance of the CSG femto-cell detection is evaluated using computer simulation. The evaluation results will provide a basis to tackle the latency problem of inbound CSG handover.

• Journal of the Korean Geotechnical Society
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• v.21 no.10
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• pp.61-71
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• 2005

Cemented Sand and Gravel (CSG) is a material made by simple mixing of rock-based raw materials such as excavated soil and riverbed gravel together with cement and water. The use of CSG material for cofferdam and large dam is gradually increasing in Japan because a quarry and aggregate plants can be diminished. Also, the CSG method can reduce dam construction cost, construction duration and destruction of environment. In this paper, the basic strength characteristics of CSG, such as compressive strength, modulus of elasticity and stress-strain curve were investigated by unconfined compression test and large triaxial compression test. From the results of the experimental study, the correlation equations between elastic modulus and unit cement, age are proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.293-301
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• 2005

The CSG(Cemented Sand and Gravel) method is construction technique using as raw materials earth and gravel generated from a local construction site, mixing them with cement and rolling with vibration rollers. Recently, The use of this method for cofferdam and large dam is gradually increasing in Japan. The purpose of an CSG mix design is to develop project specific properties to meet the structure design requirements. But uniform mix design of CSG method has not yet been established. The experience of practitioners from the geotechnical and concrete disciplines has given rise to two genernal approaches to mix design for CSG. This paper reports the concept of how to set the mix design according to modified Proctor compaction test process and the test results on properties such as compaction, compressive strength and modulus of elasticity that obtained by unconfined compression test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.158-164
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• 2012

Heterogeneous Network and CSG cell are hot issues in the 3GPP LTE/LTE-Advanced system. In this paper, we analyze the system information measurement methods which are essential for handover to CSG cell. Since there have been no sufficient discussion about this problem, we present and analyze five possible solutions. Moreover, we propose a novel solution to reduce system information measurement delay. In the proposed Autonomous Measurement with Parallel Small Gap(AMPSG) method, the UE measures system information of neighbor cells in a parallel manner. As a result, the proposed method shows better delay performance. Therefore, the proposed AMPSG method can reduce handover delay since the UE have to measure the system information of neighbor cells before CSG handover decision.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.1
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• pp.33-40
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• 2010

The cemented sand and gravel (CSG) method is a construction technique that adds cement and water to rock-like materials, such as rivered gravel or excavation muck which that can be obtained easily at areas adjacent to dam sites. This study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in CSG blocks that were manufactured by using CSG materials to develop environmentally friendly CSG method. The two types of CSG-0 without cement and CSG-100 with $100\;kg/m^3$ of cement were designed to evaluate compaction, unconfined compressive strength and growth of plants with cement content by using modified E compaction. To analyze growth properties of plants, germination ratio, visual cover, plant height and root length were measured in 4 weeks and 8 weeks after sowing. As the results, the germination regardless kinds of plants started within 5~7days and the germination ratio were in the range of 50~60 %. The visual cover of kinds of plants by visual rating system were in the range of 7~8 and the visual cover of tall fescue and perennial ryegrass was higher than that of lespedeza cuneata. The plant height and root length for tall fescue and perennial ryegrass in 8 weeks after sowing were in the range of 22~26 cm, 12~15 cm and 4~6 cm, 3~5 cm, respectively.

• Korean Journal of Computational Design and Engineering
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• v.11 no.4
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• pp.235-245
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• 2006

This paper proposes a CSG-based representation scheme for heterogeneous objects including multi-material objects and Functionally Graded Materials (FGMs). In particular, this scheme focuses on the construction of complicated heterogeneous objects guaranteeing desired material continuities at all the interfaces. In order to create various types of heterogeneous primitives, we first describe methods for specifying material composition functions such as geometry-independent, geometry-dependent functions. Constructive Material Composition (CMC) and corresponding heterogeneous Boolean Operators (e.g. material union, difference, intersection. and partition) are then proposed to illustrate how material continuities are dealt with. Finally, we describe the model hierarchy and data structure for computer representation. Even though the proposed scheme alone is sufficient for modeling all sorts of heterogeneous objects, the proposed scheme adopts a hybrid representation between CSG and decomposition. That is because hybrid representation can avoid the unnecessary growth of binary trees.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1629-1637
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• 2015

To develop various usable water from coal seam gas (CSG) water that needs to be pumped out from coal seams for methane gas production, a feasibility study was carried out, evaluating and analysing a recent report (Coal Seam Gas Water Management Policy 2012) from Queensland State Government in Australia to suggest potential CSG water treatment options for fit-for-purpose usable water production. As CSG water contains intrinsically high salinity-driven total dissolved solid (TDS), bicarbonate, aliphatic carbon, $Ca^{+2}$, $Mg^{+2}$ and so on, it was found that appropriate treatment technologies are required to reduce the hardness below 60 mg/L as $CaCO_3$ by setting the reduction rates of $Ca^{+2}$, $Mg^{+2}$ and Na+ concentrations, as well as TDS reduction. Also, Along with fiber filtration and membrane separation, an oxidation degradation process was found to be required. Along with salinity reduction, as CSG water contains organic compounds (TOC: 248 mg/L, $C_6-C_9$: <20 mg/L and $C_{10}-C_{36}$: <60 mg/L), compounds with relatively high molecular weights ($C_{10}-C_{36}$) need to be treated first. Therefore, this study suggests a combined system design with filtration (Reverse osmosis) and oxidation reduction (electrolysis) technologies, offering proper operating conditions to produce fit-for-purpose usable water from CSG water.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1395-1407
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• 2014

Coal seam gas (CSG) production involves extracting methane from coal seams with ground water which is so called a primary by-product of this process, and is often rich in salts and other constituents. The predicted large volume and variable quality of this water make water management a topic associated with CSG production. In the past, the amount of this water used to be pumped into the vacant aquifer, or into the river during the life of individual production wells. Australian government make a strategies for management and beneficial use of the water. From this point of view, a detailed assessment has not been undertaken, it is necessary for water resource production to analysis the "Coal Seam Gas Water (CSG Water) Management Policy Study" published in Queensland, Australia.

• Earthquakes and Structures
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• v.10 no.3
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• pp.717-733
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• 2016

Trapezoidal Cemented Sand and Gravel Dam, namely Trapezoid CSG, is a new type of dam. Due to lack of dynamic studies in the field of CSG dam, this research was performed to analyze Trapezoidal CSG dam using dynamic Finite element method with ABAQUS Software. To investigate possible earthquake-induced damages, fragility curves are plotted based on damage index, the length of the cracks created at the dam base and the area of cracked elements in the dam. The seismic analysis indicated that minimum and maximum tensions are generated in the heel and toe of the dam, respectively. According to the fragility curves, with increase in PGA, the possibility of the exceeding the defined limit state is increased. However, the rate of increment is significantly reduced after PGA=0.4 g. Also, the same result is achieved for the second limit state. The "area of cracked elements" is more conservative criterion than the "crack length at the dam base", especially at PGA<0.4 g. As conclusion, CSG dams, despite of being made of poor materials in comparison with concrete dams, show good resistance, and even in some situations, better performance than the weighted concrete dams.