• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.5
• /
• pp.2383-2389
• /
• 2011

Ubiquitous applications require hybrid continuous query processing which processes both on-line data stream and spatial data in the disk. In the hybrid continuous spatial query processing, disk access costs for the high-volume spatial data should be minimized. However, previous indexing methods cannot reduce the disk seek time, because it is difficult that the data are stored in contiguity with others. Also, existing methods for the space-filling curve considering data cluster have the problem which does not cluster available data for queries. Therefore, we propose the region storage structure for efficient data access in hybrid continues spatial query processing. This paper shows that there is an obvious improvement of query processing costs through the contiguous data storing method and the group processing for user queries based on the region storage structure.

• The Journal of the Korean bone and joint tumor society
• /
• v.1 no.1
• /
• pp.52-59
• /
• 1995

Metastatic cancer is the most common tumor of the skeleton. The prevalence of pathologic fracture may increase as patient survival is prolonged by improved cancer therapy. With recent advances in orthopaedic procedure and medical management of terminal cancer patients, it is generally agreed that aggressive treatment should be undertaken for patient with pathologic fracture secondary to metastatic disease, and a team approach should be utilized. The authors have reviewed twenty cases of pathologic fracture of the long bone due to metastatic tumor treated in the Department of Orthopedic Surgery, Yonsei University College of Medicine, from April 1989 to April 1994 and the following results were obtained. 1. The mean age at surgery was 58.4 years (ranged from 24years to 86years) and among 20 cases, 10 cases were male and the others were female. 2. The most frequent site of pathologic fracture in long bone is femur(15 cases, 75%), and followed by humerus(4 cases, 20%), tibia(1 case). 3. The frequently encountered primary tumors that metastases to long bone are those of the lung(7 cases, 35%), breast(4 cases, 20%), and prostate(2 cases, 10%). 4. The operative procedure was performed by resection of the tumor mass extensively, and we used polymethylmetacrylate for filling the dead space after resection, in all cases. 5. The mean survival period after operation is 9.2 months(ranged from 1 month to 4 years and 9 month). 6. The results of postoperative pain relief status were graded as fair to excellent in 17 cases(85%).

• Fire Science and Engineering
• /
• v.13 no.4
• /
• pp.20-29
• /
• 1999

This paper describes the smoke filling process of a fire field model based on a self-developed SMEP(Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of atrium space containing a ceiling heat flux. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k- epsilon turbulence model with buoyancy term. Compressibility is assumed and the perfect gas law is used. The results of the calculated upper-layer average temperature and smoke layer interface height has shown reasonable agreement compared with the zone models. The zone models used are the CFAST developed at the Building and Fire Research Laboratory NIST U.S.A. and the NBTC one-room of FIRECALC developed at CSIRO, Australia. The smoke layer interface heights that are important in fire safety were not as sensitive as the smoke layer temperature to the nature of ceiling heat flux condition.

• Tunnel and Underground Space
• /
• v.20 no.4
• /
• pp.233-240
• /
• 2010

Double Plug is constructed for preventing mixing of two different oils between two compartments in the underground oil storage cavern. And the gas and oil tightness of double plug is tested from the measurement of water leakage from double plug after the completion of double plug water filling. If water leakage is underestimated, it can increase construction cost and if water leakage is overestimated, it can increase operating cost. Therefore, optimum water leakage should be estimated to cut down the cost. In this study, hydraulic stability analysis was conducted to consider permeable properties of rock mass around double plugs and a water leak rate from double plug was estimated from the hydraulic stability analysis and case study. Finally, the reliability of estimation of water leak rate was proven by comparing estimated water leak rate with measured data.

• Journal of the Korea Computer Graphics Society
• /
• v.18 no.1
• /
• pp.29-34
• /
• 2012

High-quality tetrahedral meshes are crucial for FEM-based simulation of large elasto-plastic deformation and tetrahedral-mesh-based simulation of fluid flow. This paper proposes a volume meshing method that exploits an octree-based adaptive signed distance field to fill the inside of a polygonal object with tetrahedra, of which dihedral angles are good. The suggested method utilizes an octree structure to reduce the total number of tetrahedra by space-efficiently filling an object with graded tetrahedra. To obtain a high-quality mesh with good dihedral angles, we restrict the octree in such a way that any pair of neighboring cells only differs by one level. In octree-based tetrahedral meshing, the signed distance computation of a point to the surface of a given object is a very important and frequently-called operation. To accelerate this operation, we develop a method that computes a signed distance field directly on the vertices of the octree cells while constructing the octree using a top-down approach. This is the main focus of the paper. The suggested tetrahedral meshing method is fast, stable and easy to implement.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.4
• /
• pp.369-374
• /
• 2015

In order to efficiently optimize the problem involving complex computer codes or computationally expensive simulation, surrogate models are widely used. Because their accuracy significantly depends on sample points, many experimental designs have been proposed. One approach is the sequential design of experiments that consider existing information of responses. In earlier research, the correlation coefficients of the kriging surrogate model are introduced as weight parameters to define the scaled distance between sample points. However, if existing information is incorrect or lacking, new sample points can be misleading. Thus, our goal in this paper is to propose a weight function derived from correlation coefficients to generate new points robustly. To verify the performance of the proposed method, several existing sequential design methods are compared for use as mathematical examples.

• Journal of the Korean association of regional geographers
• /
• v.10 no.1
• /
• pp.206-214
• /
• 2004

The purpose of this paper is to elucidate the formation process of the Second Mujechi Moor at Mt. Jeongjok. For doing so, 1 analysed the formation process of valley which moor is located in, and the formation process of block field damming the valley: First, it is not a valley but a hollow which the Second Mujechi Moor located in. Hollow was formed as weathering bedrock weathered deeply along joints under warm and wet climatic conditions was denudated by rain wash. Second, the Second Mujechi Moor had been a marginal lake. Block stream developed during the last glacial period of Pleistocene, and it dammed the mouth of hollow. Afterwards sediments transported from slope filled the marginal lake, thus the lake changed to the moor where aquatic plants could grown. Third, the Second Mujechi Moor is drained and dried out by removal of matrix material from the block stream dam of the mouth of moor. For keeping moor's present conditions, we must control moor's drainage by filling open space in block stream with fine material.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.41.2-41.2
• /
• 2011

Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Metal Oxide Semiconductor) based electronic devices become much faster speed and smaller size than ever before. However, very narrow interconnect line width causes some drawbacks. For example, deposition of conformal and thin barrier is not easy moreover metallization process needs deposition of diffusion barrier and glue layer. Therefore, there is not enough space for copper filling process. In order to overcome these negative effects, simple process of copper metallization is required. In this research, Cu-V thin alloy film was formed by using RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane $SiO_2$/Si bi-layer substrate with smooth and uniform surface. Cu-V film thickness was about 50 nm. Cu-V layer was deposited at RT, 100, 150, 200, and $250^{\circ}C$. XRD, AFM, Hall measurement system, and XPS were used to analyze Cu-V thin film. For the barrier formation, Cu-V film was annealed at 200, 300, 400, 500, and $600^{\circ}C$ (1 hour). As a result, V-based thin interlayer between Cu-V film and $SiO_2$ dielectric layer was formed by itself with annealing. Thin interlayer was confirmed by TEM (Transmission Electron Microscope) analysis. Barrier thermal stability was tested with I-V (for measuring leakage current) and XRD analysis after 300, 400, 500, 600, and $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However V-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Thus, thermal stability of vanadium-based thin interlayer as diffusion barrier is good for copper interconnection.

• Advances in concrete construction
• /
• v.9 no.2
• /
• pp.217-225
• /
• 2020

The recovery of waste proves a solution with two impacts: the environmental impact by the reduction of pollution and the gain of the occupied space by this waste, and the economic impact by the use of these lasts in the building and in the area of public works. The present research consists in recovering a waste marble (thrown powder exposed to the different meteorological phenomena) generated by the quarry marble of Fil-fila, located at the east side of Skikda in the north-east of Algeria, and add it, as sand in the composition of sand concrete. To carry out this research, we analyzed the evolution brought by the substitution of ordinary sand by marble waste sand, with 25%, 50%, 75% and 100% on the properties in the fresh state (density, workability and air content) and in the cured state (compressive strength, tensile strength, surface hardness and sound velocity). For durability we tested water absorption by immersion and chloride penetration. The results obtained are compared with control samples of 0% of substitution rate. In order to have a good filling of the voids in the granular skeleton; we added a quantity of limestone recycled fines from the quarries and for a good workability a super-plasticizing additive. The results showed that the partial substitution modified both the fresh and the hardened characteristics of the tested concretes, the durability parameters also improved.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.6
• /
• pp.403-411
• /
• 2008

The alignment of facial images is crucial for 2D face recognition. This is the same to facial meshes for 3D face recognition. Most of the 3D face recognition methods refer to 3D alignment but do not describe their approaches in details. In this paper, we focus on describing an automatic 3D alignment in viewpoint of quantitative analysis. This paper presents a framework of 3D face alignment and normalization based on feature points obtained by Active Shape Models (ASMs). The positions of eyes and mouth can give possibility of aligning the 3D face exactly in three-dimension space. The rotational transform on each axis is defined with respect to the reference position. In aligning process, the rotational transform converts an input 3D faces with large pose variations to the reference frontal view. The part of face is flopped from the aligned face using the sphere region centered at the nose tip of 3D face. The cropped face is shifted and brought into the frame with specified size for normalizing. Subsequently, the interpolation is carried to the face for sampling at equal interval and filling holes. The color interpolation is also carried at the same interval. The outputs are normalized 2D and 3D face which can be used for face recognition. Finally, we carry two sets of experiments to measure aligning errors and evaluate the performance of suggested process.