• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.56-62
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• 2021

MSRDS(Microsoft Robotics Developer Studio) provides the ability to simulate these technologies. SPL(Simple Programming Language) of MSRDS provides many functions for sensor programming to control autonomous robots. Sensor programming in SPL can be implemented in two types of schemes: procedure sensor notification and while-loop schemes. We considered the three programming schemes to control the robot movement after studying the advantages and disadvantages of the sensor notification procedure and the while-loop scheme. We also created simulation environments to evaluate the performance of the three considered schemes when applied to four different mazes. The simulation environment consisted of a maze and a robot with the most powerful sensor, i.e., the LRF(Laser Range Finder) sensor. We measured the required travel time and robot actions (number of turns and number of collisions) needed to escape the maze and compared the performance outcomes of the three considered schemes in the four different mazes.

• Advances in nano research
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• v.15 no.5
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• pp.411-422
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• 2023

In the present study, the axial vibration of the nanorods is investigated in the framework of the doublet mechanics theory. The equations of motion and boundary conditions of nanorods are derived by applying the Hamilton principle. A finite element method is developed to obtain the vibration frequencies of nanorods for different boundary conditions. A two-noded higher order rod finite element is used to solve the vibration problem. The natural frequencies of nanorods obtained with the present finite element analysis are validated by comparing the results of classical doublet mechanics and nonlocal strain gradient theories. The effects of rod length, mode number and boundary conditions on the axial vibration frequencies of nanorods are examined in detail. Mode shapes of the nanorods are presented for the different boundary conditions. It is shown that the doublet mechanics model can be used for the dynamic analysis of nanotubes, and the presented finite element formulation can be used for mechanical problems of rods with unavailable analytical solutions. These new results can also be used as references for the future studies.

• Mycobiology
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• v.29 no.2
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• pp.80-84
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• 2001

Nine species of genus Ganoderma different in cultural characteristics each other were separated by histo-anatomical differences. Differences among the species and geographic distribution of G. lucidum were also analyzed to provide the criteria for the classification of Korean cultivation or wild type strains. Korean cultivation and wild type strains were quiet different from other species as well as Taiwan and North American G. lucidum strains in histo-anatomical traits of Ganoderma. Pore color of Korean G. lucidum strains was less brown than those of Taiwan and North American strains. Shapes of pores were round or circular in Korean strains but ellipsoidal or angular in Taiwan or North American strains. Pore numbers of Korean strains were more than those($4{\sim}6/mm$) of Taiwan or North American strains. Hardness of the pileus of Korean strains was much more than that of Taiwan or North American strains. Such characteristics of Korean strains were different from those of other species of Ganoderma. Korean G. lucidum strains could be classified into the other group because they had many different traits in growth characteristics of fruiting bodies and histo-anatomical characteristics from those of Taiwan or North American G. lucidum and other species of G. lucidum complex.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.399-409
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• 2013

The purpose of this study is to compare how the number of panels, the amount of flare and the flare starting point affect the silhouette of the gored skirt. This study consisted of (1) creation of 3D body representations (2) comparison of silhouette between 3D virtual gored skirt and actual gored skirt by pilot experiment (3) pattern drafting of twenty-seven different gored skirts for 3D body representations (4) a computer simulation of twenty-seven different gored skirts for visualization and assessment (5) visual inspection of twenty-seven different 3D virtual gored skirts (6) comparison of ham shapes and measurements for the node and size analysis. A visual inspection of twenty-seven different 3D virtual gored skirts showed clear differences by the amount of flare and the flare starting point ; however, there was notably less difference in the width of ham among six-piece, eight-piece and ten-piece panels. This demonstrated that there was less influence on the number of panels than the amount of flare width of ham and extent of ham for the 3D virtual gored skirt.

• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.175-187
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• 2013

Moonpools are vertical wells in a floating body used onboard many types of vessels like Exploration and drilling vessels, Production barges, Cable-laying vessels, Rock dumping vessels, Research and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modelled and tested in the wave basin. The pretensions of the lines are varied by altering the touchdown points and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs calculated for various situations provide better insight to the designer.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.4
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• pp.50-58
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• 1987

At present it has been cleared that even carefully polished surfaces have irregularities on them which are large compared with molecular dimensions by the progress of a scanning electron microscope. When two solids are placed together, the real area of contact is very small, so that the local pressure is high and, in general, exceeds the yield pressure of the metal. Plastic flow of the solid occurs at the summits of the irregularities so that the real area of contact is proportional to the applied load. There is adhesion at local resions of contact and the friction is, in a large measure, the force required to shear them. On this view point, the friction experiment with different specimens which are carbon steel, copper and constantan was attempted to know the characteristics of temperature change in contact with different metals. Various experiments are summerized as follows; 1) With metals of high melting point, momentary 1000 .deg. C may last below $10^{-4}$ of a second. It is thought that above phenomena back up previous adhesion theory in wear. 2) As a general rule, surface temperature in contact with different metals becomes high when the load increases while it is observed that surface temperature decreases when the load increases with shapes of specimens.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1205-1223
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• 2018

Image enhancement is an emerging method for analyzing the images clearer for interpretation and analysis in the spatial domain. The goal of image enhancement is to serve an input image so that the resultant image is more suited to the particular application. In this paper, a novel method is proposed based on Mamdani fuzzy inference system (FIS) using multiple fuzzy membership functions. It is observed that the shape of membership function while converting the input image into the fuzzy domain is the essential important selection. Then, a set of fuzzy If-Then rule base in fuzzy domain gives the best result in image contrast enhancement. Based on a different combination of membership function shapes, a best predictive solution can be determined which can be suitable for different types of the input image as per application requirements. Our result analysis shows that the quality attributes such as PSNR, Index of Fuzziness (IOF) parameters give different performances with a selection of numbers and different sized membership function in the fuzzy domain. To get more insight, an optimization algorithm is proposed to identify the best combination of the fuzzy membership function for best image contrast enhancement.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.1
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• pp.55-74
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• 2006

The external contour of an implant can have significant effects on the load transfer characteristics and may result in different bone failure rates for different implant system. The purpose of this study was to investigate the effects of crest module shape and occlusal load direction on bone failure modes of five commercially available dental implant systems. Five different implant systems with internal connection; ITI (Model 1), Astra (Model 2), Bicon (Model 3), Friadent (Model 4), and Paragon (Model 5), comparable in size, but different in thread profile and cest module shapes, were compared using the finite element method. Conclusively, in the internal connection system of the implant-abutment connection methods, the stress-induced pattern at the supporting bone according to the abutment connection form had differenence among them, and implants with narrowing crestal module cross-sections at the top of the cortical bone created more favorable load transfer characteristics in this region. But it is considered that the future study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.

• Geomechanics and Engineering
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• v.22 no.5
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• pp.441-448
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• 2020

This paper presents a study on the undrained shear strength (s_u) of various sands treated with a biopolymer by employing an extensive series of laboratory fall-cone penetration values covered a range of about 15 mm to 25 mm. In the tests, two sizes (0.15 mm-0.30 mm, and 1.0 mm-2.0 mm) and shapes (rounded, angular) of sand grains, Xanthan gum (XG), and distilled water were used. The XG biopolymer in 0.0%, 1.0%, 2.0%, and 3.0% by dry weight were mixed separately with four different sands, and water. The tests results obtained at the same water content revealed an increase in the su values at different levels with an increase in the XG content. Treating the sands with the XG biopolymer addition was concluded to have a greater efficacy on finer and more angular grains than coarser and more rounded grains in the samples. Overall, the present study indicates that different amount of the XG biopolymer has an important potential to be utilized for increasing the s_u values of samples with various size/shape of sand grains and water content.

• The Journal of the Acoustical Society of Korea
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• v.24 no.8
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• pp.469-480
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• 2005

There have been always some difficulties in target setting and conditioning of acoustic performances or the Korean traditional music hall due mainly to the lack of the information on the sound radiation characteristics of Korean musical sources. As the 2nd experiment succeeding the previous study[1], the radiation characteristics of eight typical Korean traditional musical sources were investigated if precision. The selected musical sources were Geomungo, Haegeum (string), Piri, Taepyeongso (woodwind), Buk, Kwaengguari, Jing (drum), and male Pansori Chang (vocal Performance). The results show that the directivity pattern of each instrument is different and has their own directivity characteristics. Measured directional and spectral characteristics of traditional Korean music sources were implemented into the computation of architectural acoustic measures. Significant differences in the acoustic measures at receiver positions were observed between the results in using the omni-directional source and the directional one. In order to investigate the acoustical characteristics of the instruments depending on the spatial variation four different shapes of halls were introduced including rectangular, fan. horse-shoe and geometrical shapes. Room acoustical parameters such as RT, SPL, C80, LF, STI were calculated at each type or hall. As the results, It was found that the rectangular hall has the most high clarity. lateral energy and STI values among low shapes of halls. It is thought that the suggested source data and design method can be used as a basic reference in the future acoustic design of performance halls for the Korean traditional music.