• Computers and Concrete
• /
• v.21 no.4
• /
• pp.399-406
• /
• 2018

The present study focuses on the performance of basalt fiber reinforced concrete (BFRC) lining in tunnel situated in sandstone rock when subjected to internal blast loading. The blast analysis of the lined tunnel is carried out using the three-dimensional (3-D) nonlinear finite element (FE) method. The stress-strain response of the sandstone rock is simulated using a crushable plasticity model which can simulate the brittle behavior of rock and that of BFRC lining is analyzed using a damaged plasticity model for concrete capturing damage response. The strain rate dependent material properties of BFRC are collected from the literature and that of rock are taken from the authors' previous work using split Hopkinson pressure bar (SHPB). The constitutive model performance is validated through the FE simulation of SHPB test and the comparison of simulation results with the experimental data. Further, blast loading in the tunnel is simulated for 10 kg and 50 kg Trinitrotoluene (TNT) charge weights using the equivalent pressure-time curves obtained through hydrocode simulations. The analysis results are studied for the stress and displacement response of rock and tunnel lining. Blast performance of BFRC lining is compared with that of plain concrete (PC) and steel fiber reinforced concrete (SFRC) lining materials. It is observed that the BFRC lining exhibits almost 65% lesser displacement as compared to PC and 30% lesser displacement as compared to SFRC tunnel linings.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.4
• /
• pp.59-70
• /
• 2020

The purpose of this study is to construct the ACD model for the block trading volume duration. The ACD model based on the block trading volume duration is referred to as Volume ACD (VACD) in this study. By integrating with GARCH-type models, the VACD based GARCH type models, which include VACD-GARCH, VACD-IGARCH and VACD-FIGARCH models, are set up. This study selects Chunghwa Telecom (CHT) Inc., offering the America Depository Receipt (ADR) in NYSE, to investigate the block trading volume duration in Taiwanese equity market. The empirical results indicate that the long memory in volume duration series increases dependence at level of volatility clustering by VACD (2,1)-FIGARCH (3,d,1) model. Moreover, the VACD (2,1)-IGARCH (1,1) exhibits relatively better performance of prediction on capturing block trading volume duration. This volatility model is more appropriate in this study to portray the change of the CHT Inc. prices and provides more information about the volatility process for investment strategy, which can be a reference indicator of financial asset pricing, hedging strategy and risk management.

• Korean Journal of Heritage: History & Science
• /
• v.36
• /
• pp.335-346
• /
• 2003

With the development of media and computer, Motion Capture system, recently used in the entertainment and computer graphics, is emerging as a new recording method. Motion Capture is a system that records time-varying position of sensors which are attached to a objects and translates it to 3-D coordinate on computer. The motion of object displays the time-varying positions of each sensors that are graphed, or the line connected man-shaped model's movements on the computer monitor. And by adding computer graphic character to it, the various angled images, which are difficult to be perceived on the stage, can be easily recorded. Recently in Japan, Motion Capture system is being actively studied in order to use it in recording and preserving the intangible cultural assets of dance and art. Especially, Warabiza in Tazawako art village at Akita plays the leading role in this area through the project to symbolize and establish the archive of cultural dance, further, Ritsumeikan Univ. is develops the system for coupling the motion capture system to Labanotation. This article introduces the motion capture and it's related studies in Japan, which are being actively studied as a new recording method of intangible cultural assets.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.850-858
• /
• 1993

Germinatin and early growth of tobacco seedlings in trays containing many cells is increasing in popularity . Since 100 % germination is not likely , a major problem is to locate and replace the content of those cells which contain either no seedling or a stunted seedling with a plug containing a viable seedling. Empty cells and seedlings of poor quality take up valuable space in a greenhouse. They may also cause difficulty when transplanting seedlings into the field. Robotic technology, including the implementation of computer vision, appears to be an attractive alternative to the use of manual labor for accomplishing this task. Operating AGBOT, short for Agricultural ROBOT, involved four steps : (1) capturing the image, (2) processing the image, (3) moving the manipulator, (4) working the gripper. This research seedlings within a cell-grown environment. the configuration of the cell-grown seedling environment dictated the design of a Cartesian robot suitable for working ov r a flat plane. Experiments of AGBOT performance in transferring large seedlings produced trays which were more than 98% survived one week after transfer. In general , the system generated much better than expected.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.19 no.2
• /
• pp.83-90
• /
• 2024

CNC tools contribute to the production of high-precision and consistent results. However, employing damaged CNC tools or utilizing compromised numerical control can lead to significant issues, including equipment damage, overheating, and system-wide errors. Typically, the assessment of external damage to CNC tools involves capturing a single viewpoint through a camera to evaluate tool wear. This study aims to enhance existing methods by using only a single manually focused Microscope camera to enable comprehensive external analysis from multiple perspectives. Applying the NeRF (Neural Radiance Fields) algorithm to images captured with a single manual focus microscope camera, we construct a 3D rendering system. Through this system, it is possible to generate scenes of areas that cannot be captured even with a fixed camera setup, thereby assisting in the analysis of exterior features. However, the NeRF model requires considerable training time, ranging from several hours to over two days. To overcome these limitations of NeRF, various subsequent models have been developed. Therefore, this study aims to compare and apply the performance of Instant NGP, Mip-NeRF, and DS-NeRF, which have garnered attention following NeRF.

• Korean Journal of Remote Sensing
• /
• v.29 no.3
• /
• pp.275-291
• /
• 2013

Monitoring the global Gross Primary Pproduction (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance ($R^2=0.8164$, $RMSE=0.6126g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$, $bias=-0.0271g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1295-1301
• /
• 2019

In this paper, we propose a novel method of denoising human motion using a bidirectional recurrent neural network (BRNN) with an attention mechanism. The corrupted motion captured from a single 3D depth sensor camera is automatically fixed in the well-established smooth motion manifold. Incorporating an attention mechanism into BRNN achieves better optimization results and higher accuracy than other deep learning frameworks because a higher weight value is selectively given to a more important input pose at a specific frame for encoding the input motion. Experimental results show that our approach effectively handles various types of motion and noise, and we believe that our method can sufficiently be used in motion capture applications as a post-processing step after capturing human motion.

• Journal of Korea Multimedia Society
• /
• v.15 no.9
• /
• pp.1093-1101
• /
• 2012

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding exploits inter-view correlations among pictures of neighboring views and temporal correlations among pictures of the same view. Multi-view video coding which uses many cameras requires a method to reduce the computational complexity. In this paper, we proposed an efficient prediction structure to improve performance of multi-view video coding. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several small groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experimental results show that the proposed prediction structure shows good performance in image quality and bit-rates. When compared to the performance of hierarchical B pictures of Fraunhofer-HHI, the proposed prediction structure achieved 0.07~0.13 (dB) of PSNR gain and was down by 6.5(Kbps) in bitrate.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.46 no.2
• /
• pp.61-71
• /
• 2009

In this paper, we propose a low-cost and compact motion capture system which enables to play motion games in PS2(Play Station 2). Recently, motion capture systems which are being used as a part in film producing and making games are too expensive and enormous systems. Now days, motion games using common USB camera are slow and have two-dimension recognition. But PSD sensor has a few good points, such as fast and low-cost. In recently year, 3D motion capture systems using 2D PSD (Position Sensitive Detector) optic sensor for motion capturing have been developed. One is Multi-PSD motion capture system applying stereo vision and another is Single-PSD motion capture system applying optical theory ship. But there are some problems to apply them to motion games. The Multi-PSD is high-cost and complicated because of using two more PSD Camera. It is so difficult to make markers having omni-direction equal intensity in Single-PSD. In this research, we propose a new theory that solves aforementioned problems. It can measure 3D coordination if separated two marker's intensity is equal to. We made a system based on this theory and experimented for performance capability. As a result, we were able to develop a motion capture system which is a single, low-cost, fast, compact, wide-angle and an adaptable motion games. The developed system is expected to be useful in animation, movies and games.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.6
• /
• pp.133-140
• /
• 2005

This paper presents a rapid face shape acquisition system. The system is composed of two cameras and one projector. The technique works by projecting a pattern on the object and capturing two images with two cameras. We use a 'one shot' system which provides 3D data acquired by single image per camera. The system is good for rapid data acquisition as our purpose. We use the 'absolutely coded pattern' using the hue and saturation of pattern lines. In this 'absolutely coded pattern' all patterns have absolute identification numbers. We solve the correspondence problem between the two images by using epipolar geometry and absolute identification numbers. In comparison to the 'relatively coded pattern' which uses relative identification numbers, the 'absolutely coded pattern' helps obtain rapid 3D data by one to one point matching on an epipolar line. Because we use two cameras, we obtain two images which have similar hue and saturation. This enables us to have the same absolute identification numbers in both images, and we can use the absolutely coded pattern for solving the correspondence problem. The proposed technique is applied to face data and the total time for shape acquisition is estimated.