• Progress in Medical Physics
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• v.23 no.2
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• pp.81-90
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• 2012

The effect of setup uncertainties on CTV dose and the correlation between setup uncertainties and setup margin were evaluated by Monte Carlo based numerical simulation. Patient specific information of IMRT treatment plan for rectal cancer designed on the VARIAN Eclipse planning system was utilized for the Monte Carlo simulation program including the planned dose distribution and tumor volume information of a rectal cancer patient. The simulation program was developed for the purpose of the study on Linux environment using open source packages, GNU C++ and ROOT data analysis framework. All misalignments of patient setup were assumed to follow the central limit theorem. Thus systematic and random errors were generated according to the gaussian statistics with a given standard deviation as simulation input parameter. After the setup error simulations, the change of dose in CTV volume was analyzed with the simulation result. In order to verify the conventional margin recipe, the correlation between setup error and setup margin was compared with the margin formula developed on three dimensional conformal radiation therapy. The simulation was performed total 2,000 times for each simulation input of systematic and random errors independently. The size of standard deviation for generating patient setup errors was changed from 1 mm to 10 mm with 1 mm step. In case for the systematic error the minimum dose on CTV $D_{min}^{stat{\cdot}}$ was decreased from 100.4 to 72.50% and the mean dose $\bar{D}_{syst{\cdot}}$ was decreased from 100.45% to 97.88%. However the standard deviation of dose distribution in CTV volume was increased from 0.02% to 3.33%. The effect of random error gave the same result of a reduction of mean and minimum dose to CTV volume. It was found that the minimum dose on CTV volume $D_{min}^{rand{\cdot}}$ was reduced from 100.45% to 94.80% and the mean dose to CTV $\bar{D}_{rand{\cdot}}$ was decreased from 100.46% to 97.87%. Like systematic error, the standard deviation of CTV dose ${\Delta}D_{rand}$ was increased from 0.01% to 0.63%. After calculating a size of margin for each systematic and random error the "population ratio" was introduced and applied to verify margin recipe. It was found that the conventional margin formula satisfy margin object on IMRT treatment for rectal cancer. It is considered that the developed Monte-carlo based simulation program might be useful to study for patient setup error and dose coverage in CTV volume due to variations of margin size and setup error.

• Journal of the Korean Chemical Society
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• v.68 no.3
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• pp.151-159
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• 2024

Indian spices are well known for their numerous health benefits, flavour, taste, and colour. Recent Advancements in chemical technology have led to better extraction and identification of bioactive molecules (phytochemicals) from spices. The therapeutic effects of spices against diabetes, cardiac problems, and various cancers has been well established. The present in silico study aims to investigate the binding affinity of 29 phytochemicals from 11 Indian spices with two prominent proteins, BCL3 and CXCL10 involved in invasiveness and bone metastasis of breast cancer. The three-dimensional structures of 29 phytochemicals were extracted from PubChem database. Protein Data Bank was used to retrieve the 3D structures of BCL3 and CXCL10 proteins. The drug-likeness and other properties of compounds were analysed by ADME and Lipinski rule of five (RO5). All computational simulations were carried out using Autodock 4.0 on Windows platform. The proteins were set to be rigid and compounds were kept free to rotate. In-silico study demonstrated a strong complex formation (positive binding constants and negative binding energy ΔG) between all phytochemicals and target proteins. However, piperine and sesamolin demonstrated high binding constants with BCL3 (50.681 × 10³ mol^-1, 137.76 × 10³ mol^-1) and CXCL10 (98.71 × 10³ mol^-1, 861.7 × 10³ mol^-1), respectively. The potential of these two phytochemicals as a drug candidate was highlighted by their binding energy of -6.5 kcal mol^-1, -7.1 kcal mol^-1 with BCL3 and -6.9 kcal mol^-1, -8.2 kcal mol^-1 with CXCL10, respectively coupled with their favourable drug likeliness and pharmacokinetics properties. These findings underscore the potential of piperine and sesamolin as drug candidates for inhibiting invasiveness and regulating breast cancer metastasis. However, further validation through in vitro and in vivo studies is necessary to confirm the in silico results and evaluate their clinical potential.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.667-678
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• 2002

In this paper, a new radiating structure with a multi-layered two-dimensional metallic disk array was proposed for shaping the flat-topped element pattern. It is an infinite periodic planar array structure with metallic disks finitely stacked above the radiating circular waveguide apertures. The theoretical analysis was in detail performed using rigid full-wave analysis, and was based on modal representations for the fields in the partial regions of the array structure and for the currents on the metallic disks. The final system of linear algebraic equations was derived using the orthogonal property of vector wave functions, mode-matching method, boundary conditions and Galerkin's method, and also their unknown modal coefficients needed for calculation of the array characteristics were determined by Gauss elimination method. The application of the algorithm was demonstrated in an array design for shaping the flat-topped element patterns of $\pm$20$^{\circ}$ beam width in Ka-band. The optimal design parameters normalized by a wavelength for general applications are presented, which are obtained through optimization process on the basis of simulation and design experience. A Ka-band experimental breadboard with symmetric nineteen elements was fabricated to compare simulation results with experimental results. The metallic disks array structure stacked above the radiating circular waveguide apertures was realized using ion-beam deposition method on thin polymer films. It was shown that the calculated and measured element patterns of the breadboard were in very close agreement within the beam scanning range. The result analysis for side lobe and grating lobe was done, and also a blindness phenomenon was discussed, which may cause by multi-layered metallic disk structure at the broadside. Input VSWR of the breadboard was less than 1.14, and its gains measured at 29.0 GHz. 29.5 GHz and 30 GHz were 10.2 dB, 10.0 dB and 10.7 dB, respectively. The experimental and simulation results showed that the proposed multi-layered metallic disk array structure could shape the efficient flat-topped element pattern.

• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.66-74
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• 2012

This paper presents development of a three-dimensional marine controlled-source electromagnetic (mCSEM) modeling algorithm and its application to a salt and reservoir model to examine detectability of mCSEM for a reservoir under complex subsurface structures. The algorithm is based on the finite difference method, and employs the secondary field formulation for an accurate and fast calculation of modeling responses. The algorithm is verified for a two-layer model by comparing solutions not only with analytic solutions but also with those from other 3D modeling algorithm. We calculate and analyze electric and magnetic fields and their normalized responses for a salt and reservoir model due to three sources located at boundaries between a salt, a reservoir, and background. Numbers and positions of resistive anomalies are informed by normalized responses for three sources, and types of resistive anomalies can be informed when there is a priori information about a salt by seismic exploration.

• Journal of Korea Water Resources Association
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• v.47 no.7
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• pp.599-614
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• 2014

In this study, two dimensional finite volume model was parallelized to improve computing time, which has been developed to be able to apply for the mixed meshes of triangle and quadrilateral. MPI scheme which is free from limitation of the number of cores was applied, and non-blocking point-to-point communication was used for fluxes and time steps calculation domain. The developed model is applied to analyze dam break in a L-shaped experimental channel with $90^{\circ}$ bend and Malpasset dam breach event to calibrate the consistency between parallelized model and existing model and examine the speed-up and efficiency of computing time. Computational speed-up about the size of the input data was considered by simulating 4 cases classified by the number of meshes, Consequently, the simulation results reached a satisfactory accuracy compared to measured data and the results from existing model, and achieved more than 3 times benefit of computational speed-up against computing time of existing model. Simulation results of 3 cases classified by the size of input data lead us to the conclusion that it is important to use proper size of input data and the number of process in order to minimize the communication overhead.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.37-49
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• 2003

Most 3D display systems heavily depend on binocular disparity to produce 3-dimensional depth of a scene. In principle, the vergence angle of the object on fixation and binocular disparity of non-fixated objects vary with the inter-pupillary distance(IPD) of the observer. However, most stereo systems provide the identical stereo image pairs regardless of the observers' IPD, which may result in variation in the perceived depth. In this study, we manipulated the vergence angle of the fixated object and binocular disparity of the non-fixated object. The range of the individual difference in the perceived depth was found to be increased with the increase of disparity for both the fixated and non-fixated objects, and the individual difference was well fitted by the regression line of the observers' IPD. These results suggest that individual difference in the perceived depth from the identical stereo images should be greatly reduced if the stereo system calibrates the disparity of the object by the observers' IPD in generating the stereo images and the regression line found in this study might be useful in the calibrating the disparity of the images.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1145-1154
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• 2014

In recent years, as frequency and intensity of severe weather disasters such as flash flood have been increasing, providing accurate and prompt information to the public is very important and needs of user-friendly monitoring/warning system are growing. This paper introduces a method that re-produces radar observations as multimedia contents and applies reproduced data to mesh-up services. In addition, a accurate GIS matching technique to help to track the exact location going on serious atmospheric phenomena is presented. The proposed method create multimedia contents having structures such as two dimensional images, vector graphics or three dimensional volume data by re-producing various radar variables obtained from a weather radar. After then, the multimedia formatted weather radar data are matched with various detailed raster or vector GIS map platform. Results of simulation test with various scenarios indicate that the display system based on the proposed method can support for users to figure out easily and intuitively routes and degrees of risk of severe weather. We expect that this technique can also help for emergency manager to interpret radar observations properly and to forecast meteorological disasters more effectively.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.28-35
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• 2008

Purpose: The pedicle of transverse rectus abdominis myocutaneous(TRAM) flap and deep inferior epigastric arterial perforator flap is deep inferior epigastic artery (DIEA) and accurate anatomic knowledge about perforator of DIEA is very important for the elevation of these flap. The authors investigated a detailed vascular network of perforator of DIEA in Koreans. Methods: 24 fresh cadavers were studied. Among them, 15 were examined based on the plain X-ray examination for the distribution and location of perforator of DIEA. And 9 fresh cadavers were examined based on the 3-dimensional computed tomography(CT) study for the distance between ending point of perforator of DIEA and mother artery, the distance between most medial mother artery and midline, the distance between most lateral mother artery and midline, and the running type of perforators of DIEA. Results: Based on the plain X-ray examination, suitable(external diameter$${\geq_-}0.5mm$$) perforators of DIEA are located between the level of umbilicus and 8 cm below it. Based on the 3D-CT study, average distance between the ending point of perforator of DIEA and the mother artery is 30.26 mm on the left, 28.62 mm on the right, respectively. The average distance between most medial mother artery and midline is 17.13 mm on the left, 15.76 mm on the right, respectively. The average distance between most lateral mother artery and midline is 56.31 mm on the left, 50.90 mm on the right, respectively. The main running course of suitable perforators of DIEA is type a, which is a direct musculocutaneous perforator vessel from main vascular axis passing outward to join the subdermal plexus, directly. Conclusion: 3-dimensional computed tomography study as well as plain X-ray examination provided more accurate and detail informations about perforators of DIEA in Koreans. These informations will help us understand the detailed vascular anatomy and operation with ease and safe in the lower abdomen of Koreans.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.4
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• pp.13-27
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• 1988

Two version of the TUMMAC(Tokyo University Modified Marker-And-Cell) method, i.e., $TUMMAC-IV_{vm1}$ and TUMMAC-VI are applied to two water-wave problems. The ship wave of a Series 60 model($C_B=0.6$) and of the fore-body of a HSVA tanker model are simulated by the $TUMMAC-IV_{vm1}$ method are the results are compared with the experimental results. From the comparison with the experimental data it is ascertained that the $TUMMAC-IV_{vm1}$ method is useful for the analysis of the realized by the TUMMAC-VI method is useful for the analysis of the characteristics of nonlinear ship waves. Three-dimensional wave breaking is realized by the TUMMAC-VI method in the simulation of a flow about a vertical rectangular cylinder. From the results of this simulation, it is shown that the TUMMAC-VI method is very available for the simulation of 3-dimensional wave breaking phenomena.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.2
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• pp.111-118
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• 2013

Purpose of present study is to investigate the effects of thread pitch in coronal portion in scalloped implant with 2 different connections on loading stress using 3 dimensional finite element analysis. Scalloped implant with 4 different thread pitches (0.4mm, 0.5mm, 0.6, and 0.7mm) in the coronal part was modeled with 2 different implant-abutment connections. Platform matching connection had the same implant and abutment diameter so that they were in flush contact at the periphery while platform mismatching connection had smaller abutment diameter than implant so that their connection was made away from periphery of implant-bone interface. Occlusal loading of 100N force was applied vertically and 30 degree obliquely to all 8 models and the maximum von Mises bone stress was identified. Loading stress as highly concentrated in cortical bone. Platform mismatching scalloped implant with small thread pitch (0.4mm) model had consistently lowest maximum von Mises bone stress in vertical and oblique loads. Platform matching model had lowest maximum von Mises bone stress with 0.6mm thread pitch in vertical load and with 0.4mm thread pitch in oblique load. Platform mismatching connection had important roles in reducing maximum von Mises bone stress. Scalloped implant with smaller coronal thread pitch showed trend of reducing maximum von Mises bone stress under load.