• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.268-272
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• 2013

The purpose of this study was to assess the effects of reconstruction kernel, and slice thickness on the accuracy of spiral CT-based volume assessment over a range of object sizes typical of synthetic simulated tumor. Spiral CT scanning was performed at various reconstruction kernels (soft tissue, standard, bone), and slice thickness (1, 2, 3 mm) using a phantom made of gelatin and 10 synthetic simulated tumors of different sizes (diameter 3.0-12.0 mm). Three-dimensional volume assessments were obtained using an automated software tool. Results were compared with the reference volume by calculating the percentage error. Statistical analysis was performed using ANOVA and setting statistical significance at P < 0.05. In general, smaller slice thickness and larger sphere diameters produced more accurate volume assessment than larger slice thickness and smaller sphere diameter. The measured volumes were larger than the actual volumes by a common factor depending on slice thickness; in 100HU simulated tumors that had statistically significant, 1 mm slice thickness produced on average 27.41%, 2 mm slice thickness produced 45.61%, 3 mm slice thickness produced 93.36% overestimates of volume. However, there was no statistically significant difference in volume error for spiral CT scans taken with techniques where only reconstruction kernel was changed. These results supported that synthetic simulated tumor size, slice thickness were significant parameters in determining volume measurement errors. For an accurate volumetric measurement of an object, it is critical to select an appropriate slice thickness and to consider the size of an object.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.977-982
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• 2007

There have been many efforts in automatic object recognition using computing technologies. Especially in the development of automated construction equipment, automatic object recognition is very important issue for the proper equipment maneuvering. 3D laser scanning, which uses (time-of-flight) method to construct the 3-dimensional information, is applied to the civil earth work environment for its high accuracy, quick data collection, and object recognition capability that will be developed by the authors in the future. The 3D earth model is also used as a fundamental information for intelligent earth work task planning. This paper presents the analysis of the 3D laser scanner market and selection of the most optimum 3D scanner for the intelligent earth work planning. As well as the hardware configuration for the automated 3D earth modeling is developed but also the software structure and detailed user interface are designed in this research. In addition, it is presented in this paper that the accuracy comparison test between TotalStation(R) which is a traditional survey tool and ScanStation(R). The accuracy test is done by relative distance measurement using known targets.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.204-211
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• 2021

In this study, information on vegetation was collected using a point cloud through a 3-D Terrestrial Lidar Scanner, and the physical shape was analyzed by reconfiguring the object based on the refined data. Each filtering step of the raw data was optimized, and the reference volume and the estimated results using the Alpha Shape and Voxel techniques were compared. As a result of the analysis, when the volume was calculated by applying the Alpha Shape, it was overestimated than reference volume regardless of data filtering. In addition, the Voxel method to be the most similar to the reference volume after the 8th filtering, and as the filtering proceeded, it was underestimated. Therefore, when re-implementing an object using a point cloud, internal voids due to the complex shape of the target object must be considered, and it is necessary to pay attention to the filtering process for optimal data analyzed in the filtering process.

• Journal of the military operations research society of Korea
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• v.23 no.2
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• pp.1-14
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• 1997

TPNSim++ is the object-oriented framework for the discrete event simulation of military systems, developed by authors. The simulation world view of TPNSim++ is on the basis of activity scanning. TPNSim++ is implemented as C++ class library under Windows 95/NT. It uses the extended timed Petri nets which are called TPNSim nets for simulation modeling tool. The aim of this study is to conduct a comparative study of TPNSim++ and SLAM II in the simulation of military maintenance systems for the validation and the applicability of TPNSim++. From this study, TPNSim++ and SLAMII have given the same results under the equivalent assumption. Thus we can get the validation of TPNSim++ and its applicability to the simulation of maintenance systems.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1782-1787
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• 2003

A face recognition is currently the field which many research have been processed actively. But many problems must be solved the previous problem. First, We must recognize the face of the object taking a location various lighting change and change of the camera into account. In this paper, we proposed that new method to find feature within fast and correct computation time after scanning PC camera and ID card picture. It converted RGB color space to YUV. A face skin color extracts which equalize a histogram of Y ingredient without the Luminance. After, the method use V' ingredient which transforms V ingredient of YUV and then find the face feature. The result of the experiment shows getting correct input face image from ID Card picture and camera.

• Proceedings of the Acoustical Society of Korea Conference
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• 1985.10a
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• pp.47-49
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• 1985

In most of ultrasonic NDT(Non-Destructive Testing) equipments using A-scan display technic, it is one of the inconveniences that the user must be proficient in reading the displayed signals for the accurate decisions. In this study, a simple microprocessorized NDT machine for the flaw detection was developed. The operation of system is based on the conventional NDT system. The microprocessor detects the time delay between transmitted pulse and echos by counter-measure method. Then according to the scanning position, the location of flaw orthe other side of testing object is plotted on the CRT. The main advantages of the developed system are simplicity in handling, recording capability of measured data, and low cost.

• Journal of the Ergonomics Society of Korea
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• v.4 no.1
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• pp.11-16
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• 1985

The object of this research is to develop an Interactive Computerized Graphic Program for graphic output of velocity, acceleration and motion range of body-task reference point (e.g., C.O.G., joint location, etc.). Human motions can be reproduced by scanning (rate = 60Hz) the vidicon image, and the results are stored in an Apple II P.C. memory. The results of this study can be extended to simulation and reproduction of human motions for optimal task design.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.239-244
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• 2001

Today, Ultrasonic is used as an important non-destructive test tool of semiconductor reliability evaluation and failure analysis. The semiconductor packaging trend goes to develop thin package, this trend makes difficult to inspect to defect in semiconductor package. One of the important problem in all semiconductor is moisture absorption in the atmosphere. This moisture causes crack or delamination to package when the semiconductor package is soldered on PCB. Reliability evaluation of semiconductor's object is investigating the effect of this moisture. For that reason, this study is investigating the effect of this moisture and reliability evaluation of semiconductor after preconditioning test and scanning acoustic microscope.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.230-236
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• 1998

Thermal environment of greenhouse was investigated by thermo-tracer in this study. The Thermo-tracer is a high-sensitivity infrared thermometer of non-contact type. The infrared energy emitted from the measured object is converted into an electrical signal by the detector(HgCdTe) and display as a color or black & white thermal image by way of optical scanning, The experiment was conducted for Venlo-type greenhouse with pad & fan system. The temperature difference between measured by Thermo-trace and measured by HOBO sensor is maximum 0.8$^{\circ}C$. Thermo-trace is possible to use for the thermal environment analysis and diagnosis of a cooling and heating system of greenhouse.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.464-471
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• 2011

We tried to analyze sound field of the interior of housing installed with an impeller using the Boundary Element Method (BEM) with the Kirchhoff-Helmholtz integral equation. In order to increase the accuracy of our analysis, reverse engineering technology, which has been developed in recent years. We measured and treated geometrical data with 3D scanning of the practical research object. After modeling by the reverse engineering, we analyzed variation of the BPF as adding vibration frequency and variation of the sound field of the interior of housing by changing the number of impeller blades. We also tried an analysis of free degree variation. Then, we proposed the analysis accuracy and noise reducing method by analysis result.