• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.53-57
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• 1985

Many pictures must be taken for the presumption of the stereorelation of the cerebral artery, which obtained with ordinary cerebral angiography. And it is very difficult to understand the stereoimage and required many experiences. But it is able to presume the stereorelationship in only brief eye's training without the aid of the stereoscope using the prism. For the stereoview, we need the paired angiograms obtained only straight and tilting the X-ray tube. In practice, with this stereoview in cerebral angiogram, we could know the directions of the aneurysmal neck and fundus with the stereorelationship of the cerebral artery and indeed helps us greatly in operation field. In addition, we might guess the location and stereorelationships of the feeding artery and draining vein in arteriovenous malformation and other vascular tumors and it was great aid in diagnosis and operation. Now we present the methods of the pictures for the stereoview in cerebral angiogram and the methods for eye's training.

• Journal of The Korean Association of Information Education
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• v.8 no.3
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• pp.405-414
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• 2004

Even if Internet has been used very much, there is no method of music aptitude test for children. We develop the music aptitude test in the internet to make music aptitude test easily. We test children for music aptitude early. We provide children the learning and instruction environment. This research makes children improve the ability of music. We develop the music aptitude test system for children in the WWW for children to use it. This system is expected to be a great help for children to test music aptitude easily. This system establish a well-understood and maintenance through this system for replacing the data files of their children in a effective way.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1103-1106
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• 2005

The purpose of this research is design of Vision Box which can capture an image which inputs through the camera and understand movement of object included in captured image. In design, we tried to satisfy user's requirements. We made Vision Box can analyze movement of object in image captured by camera without additional instruments. In addition, it is possible that communicate with PLC and operate Vision Box by remote control. We could verify the Vision Box capability by using it to automobile engine pattern analysis. We expect the Vision Box will be used various industrial fields.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1608-1615
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• 1999

In this study, we investigate the inter cell interference of LMDS(Local multipoint Distribution Service) system cell in LMDS system design process. There are several interference sources in LMDS system but we consider co-channel adjacent interference, cross-polarization interference, tx/rx interworking interference as three major factors. As the summation of each interference, C/N is keep 19 dB in 2km range but decreased gradually over 2km. Based on theoretical results, we process the experimental test and get results that C/I=20 dB have to be maintained to transmit the data successfully under rain fall attenuation condition. This experiential results are similar to the theoretical analysis results we examined.

• Journal of Advanced Navigation Technology
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• v.6 no.4
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• pp.306-311
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• 2002

In this paper, we have proposed the Multi-Carrier (MC) CDMA system by adopting multi-interference cancellation techniques connecting an adaptive array antenna and a CCI canceller in cascade form. And, we have analyzed the BER performance of system in AWGN channel where MUI is a major interference degrading the performance of the proposed MC CDMA system. Also, we have evaluated the degree of performance improvement in the proposed MC CDMA system. As the result of analysis, a CCI canceller is better efficient than an adaptive array antenna in the performance improvement and that the performance improvement becomes large as the number of users increases when multi-interference cancellation techniques are used in cascade form. Also, we found that performance of $10^{-5}$ in a point of view BER could be achieved when $E_b/N_o$ is more than 10 dB.

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.417-422
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• 1998

In this paper we introduce a method to optimize panel parameters and drive signals in a matrix-adressed bistable twsited-nematic (BTN) liquid crystal display (LCD) panel. We measured the effect of data pulses on optical switching characteristics in a BTN LC cell to model the effect theoretically. We introduce a weighting function to model the effect of data pulses on the switching energy as a function of time. Once the weighting function is known, we can estimate the maximum number of lines for multiplexing operation at a given frame rate by calculating the minimum data pulse width. By characterizing a unit cell as we change panel parameters (for example, d/p ratio), we can optimize parameters for high-speed operation. We found that our theoretical predictions agree very well with experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7A
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• pp.666-673
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• 2006

In this paper, we evaluated the performance of 4 types of ARQ algorithms that have been adopted to offer reliable transmission between MAC layers. First of all, we implemented IEEE 802.16 ARQ algorithms with NS-2 network simulator and then evaluated the performances in various channel states. We used two performance measures to evaluate those performances. First, we used the total number of ARQ block in bytes that have been received without error. Second, we used ACK_Efficiency that is newly defined in this paper. From the results of simulation, we could be aware that each ARQ algorithm has different performance in a various channel states. For improving the transmission data rate in a specific channel state, we have to choose the right ACK interval as well as a suitable ARQ algorithm.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.31-37
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• 2004

As social demands on forest are diversified, we need some economic and pro-environmental methods of forest management. In this study, developing an FMS(Forest Management System) using GIS techniques, we aimed at making workers handle quickly and exactly their works related to forest, offering customers the exact information and making clients modify or renew the variously changing information about forest. Therefore, we can efficiently handle the works related to forest management. For this, we designed and developed the system to be in accord with working-level and we can handle various information efficiently and conveniently. Accordingly we can process and print out data based on each subject. In addition to that, we can preserve the consistency of data by connecting work zones and providing database through network.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.53-62
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• 2015

We surveyed butterfly community in a rural area of the southwestern part of Korea to investigate the changes of species composition and their abundances between 2001~2002 and 2014. The butterfly survey was conducted at the same site using a line transect method. There was a significant decrease of the numbers of species and individuals between 2001~2002 and 2014. We categorized each species based on six ecological traits: habitat type, habitat breadth, food plant type, food plant breadth, number of generation per year and overwintering stage. The comparison of number of species using these ecological traits showed no difference during the 10-yr time intervals. However, the comparison of number of individuals for the ecological traits showed the significant differences except for one trait, overwintering stage. We could suspect that the decrease of butterflies in the study area was resulted from the habitat change. To investigate the causal factors and the changes of butterfly fauna, we need a long-term monitoring of the local butterfly community.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.51-55
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• 2008

Purpose: To develop the program used in calculating and estimating anamorphic prisms used to construct an anamorphoser. Methods: If there is a program which can show the apex angle and the volume of prism which are decided by the refraction index of anamorphic prisms and the expanding ratio of incident beam, the production of anamorphic prisms can be done accurately. Moreover, it could become a convenient tool to the design and production of whole optical systems using anamorphic prisms. Developing this program, first, we had to induce formulas of prism that decide the apex angle and the arrangement angle of anamorphic prisms with the given refraction index of anamorphic prism and the given expanding ratio of incident beam. Then we programmed them by delphi 6.0 language so that they could be visualized on screen and easily confirmed. Results: We could develop the program used in calculating and estimating anamorphic prisms used to construct an anamorphoser. Conclusions: Judging from the results of applying this developed program to actual business, we could conclude that this program is useful in calculation and production of anamorphic prisms which are used as components of an anamorphoser because this program can offer a lot of accuracy and quickness to producers.