• Korean Journal of Optics and Photonics
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• v.20 no.3
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• pp.166-174
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• 2009

When the object distance of a zoom lens with finite object distances is varied, we can fix the image at a fixed image plane by moving only one zoom lens group (autofocus group) without moving all zoom lens groups for the autofocus. We theoretically formulated and numerically calculated the moving distances of the autofocus group by using Gaussian brackets and a paraxial ray tracing method. The solutions of this method can be consistently and flexibly used in the initial design for the moving distance of autofocus group within these zoom loci in all types of zoom lens. Finally, in order to verify the usefulness of this method, we show that the moving distance of an autofocus group can be rapidly and diversely obtained in one example of $M_{5n}$ zoom lens type.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.381-382
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• 2015

Small devices such as MLCC, sample inspection on the processing is not easy. If you can proceed with the sample inspection, the production process will be able to maximize the MLCC production efficiency. In this study, to minimize the interference of operator, and to maximize the operating efficiency of the equipment. Use image processing techniques for its extracts the position and angle of the MLCC. Implements an automatic inspection system with the high productivity.It is possible to inspect the final six MLCC devices. And once we Pick-Up to 200 Chip to check the accuracy of 98.4%. Based on the results of various studies are in progress to be expected to be applicable to the automatic inspection equipment side development of a variety of small devices.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.57-66
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• 2010

CAS Client personalization means to issue CAS ID or Key for CAS service, which is Core Technology for CAS operation. Protocol A.1 on TTA.KR-07.0079 XCAS, stores CAS Client personalization data from CAS server in XCAS server, and transmits the personalization data by request of XCAS HOST for CAS Client personalization. However, this may increase Network Traffic and CAS Client image management in XCAS server. In this thesis, to complement this, CAS Client personalization is executed on CAS Server by separating CAS service field. Therefore this can distribute Image management and Network Traffic of XCAS server.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1121-1128
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• 2016

Our country of agriculture suffers problems such as aging, population decline, agricultural decline etc. To solve this problem, in the country, it is interest in Smart Farm System, a convenient and efficient system for the production through the convergence of ICT technology and agriculture. However, because of expensive construction costs and difficulty in securing human resources and training for Operating system, they are struggling to spread the actual farmers. Therefore, it is necessary to develop smart farm techniques suitable for such customized domestic environment. This study designed a system for collecting environment date in a greenhouse based on the low-cost embedded devices, and designed and implemented for the Web application that a user can easily use system. The implementation of the system lowers deployment costs and is expected to increase largely the spread of Smart Farm it can be easily accessed by using the smart phone.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.83-89
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• 2011

Diesel engines can produce higher fuel efficiency and lower $CO_2$ emission, they are subject to ever more stringent emission regulation. However, there are two major emission concerns fo diesel engines like such as particulate matter (PM) and nitrogen oxides (NOx). Moreover, it is not easy to satisfy the regulations on the emission of NOx and PM, which are getting more strengthened. One of the solutions is to apply the new combustion concept using multistage injection such as HCCI and PCCI. The other solution is to apply after-treatment systems. For example, lean NOx trap catalyst, Urea-SCR and others have various advantages and disadvantages Especially, Urea-SCR system have advantages such as a high conversion efficiency and a wide operation conditions. Hence the key factor to implementation of Urea-SCR technology, good mixing of urea(Ammonia) and gas, reducing Ammonia slip. Urea mixer components are required to facilitate evaporation and mixing because the liquid state of urea poses significant barriers for evaporation, and the distance to mixer is the most critical that affect mixer performance. In this study, to find out the distance from injector to mixer and simulation factor, a laser diagnostics and high speed camera are used to analyze urea injector spray characteristics and to present a distribution of urea solution in transparent manifold In addition, Droplet Uniformity Index is calculated from the acquired images by using image processing method to clarify the distribution of spray.

• Journal of Biosystems Engineering
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• v.37 no.6
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• pp.411-419
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• 2012

Purpose: Nondestructive evaluation of seed viability is a highly demanded technique in the seed industry. In this study, hyperspectral imaging system was used for discrimination of viable and non-viable radish seeds. Method: The spectral data with the range from 400 to 1000 nm measured by hyperspectral reflectance imaging system were used. A calibration and a test models were developed by partial least square discrimination analysis (PLS-DA) for classification of viable and non-viable radish seeds. Either each data set of visible (400~750 nm) and NIR (750~1000 nm) spectra and the spectra of the combined spectral ranges were used for developing models. Results: The discrimination accuracy of calibration was 84% for visible range and 76.3% for NIR range. The discrimination accuracy of test was 84.2% for visible range and 75.8% for NIR range. The discrimination accuracies of calibration and test with full range were 92.2% and 92.5%, respectively. The resultant images based on the optimal PLS-DA model showed high performance for the discrimination of the nonviable seeds from the viable seeds with the accuracy of 95%. Conclusions: The results showed that hyperspectral reflectance imaging has good potential for discriminating nonviable radish seeds from massive amounts of viable seeds.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.83-96
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• 1993

The orthophto map is seen as the form of picture with the uniform reduced scale as the current terrain map. Thus it provides a reasonable feeling of scene and is easy to be interpreted. Furthermore, digital orthophoto is currently used as the basic terrain information data of the Geo-Spatial Information System(GSIS). Therefore, the orhtophoto map has high potential use as a future terrain map. This paper studies the method of producing orthophoto map by using the digital satellite imagery data taken from SPOT satellite of France. The production of orthophoto map requires the process of generating orthophoto imagery with digital elevation model, which process is called digital differential rectification. As the final accuracy of orthophoto map depends on that of digital elevation model, the precise and efficient production method of digital elevation model should be preceded. This study investigated the method of producing digital elevation model directly from SPOT satellite imagery and generated ortho-image by resampling the original SPOT imagery through digital differential rectification. Finally, Simple orthophoto map was made by overlaying the ortho-image and the contour map from digital elevation model.

• Journal of Technologic Dentistry
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• v.21 no.1
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• pp.189-208
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• 1999

This is a study of view of college life on 1002 students in the dept. of the dental laboratory technology of 8 colleges in the country. Made a question survey on conclusion of college life, such as purpose of entering college and satisfaction, college life and sense of values and relationship to professors and analysed it through statistics. 1. Purpose of entering college and satisfaction of college. Most students motive to enter college was a preparatory step for future job as 73.3% of reponse rate. The dissatisfaction of college after entering was 42.5%, students of the metropolitan area showed 47.1%(p<.01) of response rate and college woman showed 48.2%(p<.05) of response rate. As for the datils of dissatisfaction of college than expected, the absence of romanticism and academic atmosphere was 38.1% and poor practice(facilities) was 32.4%. the students of the metropolitan area showed rater high rate(p<0.1) and sophomore students showed high rate(p<.05) as 40.6% 2. College Life and sense of values. Students showed the greatest interest in employment(27.0%) during attending and in deciding future plan(26.9%) after graduation. They responded a desirable attitude as a college students was a active and autonomous attitude as 34.0%. The best image of a college student was a student helping his/her peers with deep interest as 65.5%. The greatest trouble in college life was still future plan(27.7%). 3. Relationship to professors. Most responded they did not have professors to consult in the department as 72.4%. As a reason for this, insufficient oppartunity to talk with professors was the highest as 29.8%. They wanted any professor with much interest in employment of students as the best image of a professor(40.7%) and wanted to come into close relation with professors(30.9%).

• KIPS Transactions on Software and Data Engineering
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• v.8 no.2
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• pp.89-96
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• 2019

360 degree 3-dimensional lidar sensors and vision cameras are commonly used in the development of autonomous driving techniques for automobile, drone, etc. By the way, existing calibration techniques for obtaining th e external transformation of the lidar and the camera sensors have disadvantages in that special calibration objects are used or the object size is too large. In this paper, we introduce a simple calibration method between two sensors using a spherical object. We calculated the sphere center coordinates using four 3-D points selected by RANSAC of the range data of the sphere. The 2-dimensional coordinates of the object center in the camera image are also detected to calibrate the two sensors. Even when the range data is acquired from various angles, the image of the spherical object always maintains a circular shape. The proposed method results in about 2 pixel reprojection error, and the performance of the proposed technique is analyzed by comparing with the existing methods.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.3
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• pp.113-120
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• 2020

With the recent development of communication equipment, the demand for communication equipment is gradually increasing. Accordingly, various signal processing has been studied. In the case of an image, noise removal is an indispensable step because noise propagation problems may occur if noise is not removed in the pre-processing process. Salt and Pepper noise is a typical impulse noise with two extremes. Various studies have been conducted to remove such noise, and there are CWMF, MF and MMF. However, the existing methods are somewhat insufficient in the high-density noise region. Therefore, in this study, we have proposed an algorithm that filters the size of the mask according to the number of noises inside the 7×7 mask and filters it with a modified switching filter using the histogram distribution of the image. In the case of the proposed algorithm, noise can be effectively removed in a high-density noise region. For objective judgment, PSNR was used to compare and analyze with existing algorithms.