• Journal of Biosystems Engineering
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• v.29 no.1
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• pp.9-20
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• 2004

On the basis of design theory of soil inversion, two types of moldboard plow with secondary soil mover was designed and constructed to invert furrow slice at same position with furrow bottom. A series of soil bin experiment was carried to investigate the performance of prototypes. First prototype of new concept plow showed two kinds of problems during the preliminary experiment. For the plowing depth of 6cut the prototype did not invert the furrow slice, instead it just cut furrow bottom and the furrow slice returned to the original position. For the plowing depth of 8cm, there was soil clogging problem at the rear part of plow. From the above results it was concluded that the first prototype can not be used for the inversion of furrow slice at same position with furrow bottom. Second prototype could invert furrow slice at the same position with furrow bottom, but the performance was affected by soil moisture content soil hardness and plowing speed very much. For the higher soil moisture content, for the higher soil hardness and higher plowing speed, the prototype showed higher soil inversion performance. For the second prototype the inversion ratio was almost 100%, inversion angle was in the range of 90 to 100 degree and side displacement was less than 4 cm. But the furrow slice was not continuous, it was cut in the length of 30 to 40 cm. The reason why the furrow slice was cut in that length is blamed for the design of moldboard surface. The specific draft of prototype was in the range of 37.24 kN/㎡ to 42.14 kN/㎡ this value is a little higher than that of the conventional plow, or from 30.38 kN/㎡ to 33.32 kN/㎡. But the difference was not so big. The inversion performance of the second prototype for the field experiment was much better than that of soil bin experiment due to the better soil and operational conditions. Sticky and compacted soil conditions, and higher plowing speed was suitable for the plowing operation of the second prototype

• Computers and Concrete
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• v.11 no.5
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• pp.383-397
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• 2013

Two-dimensional tensile stresses are occurring at the back of the anchorage of the tendons of prestressed concrete bridges. A new method named "tensile stress region" for the design of the reinforcement is presented in this paper. The basic idea of this approach is the division of an anchor block into several slices, which are described by the tensile stress region. The orthogonal reinforcing wire mesh can be designed in each slice to resist the tensile stresses. Additionally the sum of the depth of every slice defined by the tensile stress region is used to control the required length of the longitudinal reinforcement bars. An example for the reinforcement design of an anchorage block of an external prestressed concrete bridge is analyzed by means of the new presented method and a finite element model is established to compare the results. Furthermore the influence of the transverse and vertical prestressing on the ordinary reinforcement design is taken into account. The results show that the amount of reinforcement bars at the anchorage block is influenced by the layout of the transverse and the vertical prestressing tendons. Using the "tensile stress region" method, the ordinary reinforcement bars can be designed more precisely compared to the design codes, and arranged according to the stress state in every slice.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.275-279
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• 2015

There are several methods to record three dimensional (3D) information of objects such as lens array based integral imaging, synthetic aperture integral imaging (SAII), computer synthesized integral imaging (CSII), axially distributed image sensing (ADS), and axially distributed stereo image sensing (ADSS). ADSS method is capable of recording partially occluded 3D objects and reconstructing high-resolution slice plane images. In this paper, we present a computational method for depth extraction of partially occluded 3D objects using ADSS. In the proposed method, the high resolution elemental stereo image pairs are recorded by simply moving the stereo camera along the optical axis and the recorded elemental image pairs are used to reconstruct 3D slice images using the computational reconstruction algorithm. To extract depth information of partially occluded 3D object, we utilize the edge enhancement and simple block matching algorithm between two reconstructed slice image pair. To demonstrate the proposed method, we carry out the preliminary experiments and the results are presented.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.306-333
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• 2010

Previous studies on Wolseong fortress have focused on capital system of Silla Dynasty and on the recreation of Wolseong fortress due to the excavations in and around Wolseong moat. Since the report on the Geographical Survey of Wolseong fortress was published and GPR survey in Wolseong fortress was executed as a trial test in 2004, the academic interest in the site has now expanded to the inside of the fortress. From such context, the preliminary research on the fortress including geophysical survey had been commenced. GPR survey had been conducted for a year from March, 2007. The principal purpose of the recent 3D GPR survey was to provide visualization of subsurface images of the entire Wolseong fortress area. In order to obtain 3D GPR data, dense profile lines were laid in grid-form. The total area surveyed was $112,535m^2$. Depth slice was applied to analyse each level to examine how the layers of the remains had changed and overlapped over time. In addition, slice overlay analysis methodology was used to gather reflects of each depth on a single map. Isolated surface visualization, which is one of 3D analysis methods, was also employed to gain more in-depth understanding and more accurate interpretations of the remain The GPR survey has confirmed that there are building sites whose archaeological features can be classified into 14 different groups. Three interesting areas with huge public building arrangement have been found in Zone 2 in the far west, Zone 9 in the middle, and Zone 14 in the far east. It is recognized that such areas must had been used for important public functions. This research has displayed that 3D GPR survey can be effective for a vast area of archaeological remains and that slice overlay images can provide clearer image with high contrast for objects and remains buried the site.

• Journal of Acupuncture Research
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• v.29 no.5
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• pp.75-85
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• 2012

Objectives : Indirect moxibustion is one of the thermotherapy in Korean medicine and buffer of ginger and mankshood slice are common materials to be used. However it is difficult to control the power of thermal stimulation and the stimulation is greatly influenced by the characteristic of buffer. So we research on the buffer characteristic of indirect moxibustion according to the thickness, diameter and water content changes. Methods : We used thermocouples to measure temperature from surface to depth of 2, 4, 6, 8, 10, 12, 14mm on tissue model and calculated peak temperature($^{\circ}C$). The data were analyzed with student t-test and one-way ANOVA(p<0.05). Results : 1. The peak temperature of indirect moxibustion with ginger were determined by thickness of ginger slice and temperature changes according to the thickness at intervals of 1mm but according to the diameter at intervals of 4mm. 2. The peak temperature of indirect moxibustion with mankshood were determined by thickness of mankshood slice also. The peak temperature of mankshood moxibustion was higher than that of ginger moxibustion. 3. In this study, 2mm-thick-ginger slice and 3mm-thick-mankshood slice were suitable for indirect moxibustion. Variation in the thickness of which is more efficient to control the power of thermal stimulation on indirect moxibustion. 4. The more water loss we got on ginger slice, the higher peak temperature we measured at the surface of moxibustion. But the thermal stimulation was not conducted more than 2mm in the depth. 5. The thickness and water content of buffer are important in indirect moxibustion. Conclusions : The temperature of indirect moxibustion depends on the thickness of buffer than the diameter of it. Therefore, it is more efficient according to the thickness of buffer so that we control the power of thermal stimulation. And water content of buffer is one of the important factor in indirect moxibustion.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.1-7
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• 1983

In order to identify the stress distribution on the furrow slice a small soil bin instrumented with soil stress meters was designed and constructed. From a series of experiments conducted in the soil bin the following results were obtained. 1) Neither the cutting conditions nor the soil conditions affected the direction of the principal stress. 2) The magnitude of the principal stress increased as the tillage depth increased. However, no effects due to lift angles were shown on the magnitude of the principal stresses. 3) The maximum principal stress increased with increase of the moisture and clay contents in the soil. 4) In the clay soil, the maximum principal stresses were distributed uniformly over the tillage depth. However, as the sand content increased, the maximum principal stresses decreased gradually on the top layer so that the distribution over the tillage depth became a trapezoidal shape.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.701-704
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• 2005

Aquifer Thermal Energy Storage (ATES) can be a cost-effective and renewable geothermal energy source, depending on site-specific and thermohydraulic conditions. To design an effective ATES system having influenced by groundwater movement, understanding of thermo hydraulic processes is necessary. The heat transfer phenomena for an aquifer heat storage are simulated using FEFLOW with the scenario of heat pump operation with pumping and waste water reinjection in a two layered confined aquifer model. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at the both wells during 365 days. The average groundwater velocities are determined with two hydraulic gradient sets according to boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions of three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.00 1 are shaped circular, and the center is moved less than 5m to the groundwater flow direction in 365 days simulation period. However at the hydraulic gradient of 0.01, the contour center of the temperature are moved to the end of boundary at each slice and the largest movement is at bottom slice. By the analysis of thermal interference data between two wells the efficiency of the heat pump system model is validated, and the variation of heads is monitored at injection, pumping and no operation mode.

• Progress in Medical Physics
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• v.24 no.1
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• pp.48-53
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• 2013

Monte Carlo method has been known as the most accurate method for calculating absorbed dose in the human body, and an anthropomorphic phantom has been mainly used as a method of simulating internal organs for using such a calculation method. However, various efforts are made to extract data on several internal organs in the human body directly from CT DICOM files in recent Monte Carlo calculation using Geant4 code and to use by converting them into the geometry necessary for simulation. Such a function makes it possible to calculate the internal absorbed dose accurately while duplicating the actual human anatomical structure. Thus, this study calculated the absorbed dose in the human body by using Geant4 associating with DICOM files, and aimed to confirm the usefulness by compare the result with the measured dose using a Gafchromic EBT2 film. This study compared the dose calculated using simulation and the measured dose in beam central axis using the EBT2 film. The results showed that the range of difference was an average of 3.75% except for a build-up region, in which the dose rapidly changed from skin surface to the depth of maximum dose. In addition, this study made it easy to confirm the target absorbed dose by internal organ and organ through the output of the calculated value of dose by CT slice and the dose value of each voxel in each slice. Thus, the method that outputs dose value by slice and voxel through the use of CT DICOM, which is actual image data of human body, instead of the anthropomorphic phantom enables accurate dose calculations of various regions. Therefore, it is considered that it will be useful for dose calculation of radiotherapy planning system in the future. Moreover, it is applicable for currently-used several energy ranges in current use, so it is considered that it will be effectively used in order to check the radiation absorbed dose in the human body.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.1 no.1
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• pp.1-8
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• 2005

Aquifer Thermal Energy Storage (ATES) can be a cost-effective and renewable geothermal energy source, depending on site-specific and thermohydraulic conditions. To design an effective ATES system having the effect of groundwater movement, understanding of thermohydraulic processes is necessary. The heat transfer phenomena for an aquifer heat storage are simulated by using FEFLOW with the scenario of heat pump operation with pumping and waste water reinjection in a two layered confined aquifer model. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at the both wells during 365 days. The average groundwater velocities are determined with two hydraulic gradient sets according to boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions of three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.001 are shaped circular, and the center is moved less than 5 m to the direction of groundwater flow in 365 days simulation period. However at the hydraulic gradient of 0.01, the contour center of the temperature are moved to the end of east boundary at each slice and the largest movement is at bottom slice. By the analysis of thermal interference data between two wells the efficiency of the heat pump system model is validated, and the variation of heads is monitored at injection, pumping and no operation mode.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.35-42
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• 2018

Direct volume rendering (DVR) is an important 3D visualization method for medical images as it depicts the full volumetric data. However, because DVR renders the whole volume, regions of interests (ROIs) such as a tumor that are embedded within the volume maybe occluded from view. Thus, conventional 2D cross-sectional views are still widely used, while the advantages of the DVR are often neglected. In this study, we propose a new visualization algorithm where we augment the 2D slice of interest (SOI) from an image volume with volumetric information derived from the DVR of the same volume. Our occlusion-based DVR augmentation for SOI (ODAS) uses the occlusion information derived from the voxels in front of the SOI to calculate a depth parameter that controls the amount of DVR visibility which is used to provide 3D spatial cues while not impairing the visibility of the SOI. We outline the capabilities of our ODAS and through a variety of computer tomography (CT) medical image examples, compare it to a conventional fusion of the SOI and the clipped DVR.