• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.6
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• pp.265-271
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• 2013

Czochralski (CZ) growth process is one of the most important techniques for growing high quality sapphire single crystal for LED application. In this study, the inductively-heated CZ growth processes for the sapphire crystal of 300 mm length have been analyzed numerically using finite element method. The hot zone structures were modified with the crucible geometry change and the additional insulation layer installed above the crucible. The results show that the solid-liquid interface height decreased from about 80 mm at initial stage to 40 mm after mid-stage due to achieve the growth speed balance. Also the optimal input power of the modified system was similar with the original one due to the compensation effects of the crucible geometry and additional insulation. The crystal temperature grown by the modified CZ grower was increased about 10 K than the original one. Therefore the sapphire crystal of 300 mm height was grown successfully.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.19-28
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• 2004

This paper shows how to compensate the skew from the traffic sign included in the natural image and extract the text. The research deals with the Process related to the array image. Ail the process comprises four steps. In the first fart we Perform the preprocessing and Canny edge extraction for the edge in the natural image. In the second pan we perform preprocessing and postprocessing for Hough Transform in order to extract the skewed angle. In the third part we remove the noise images and the complex lines, and then extract the candidate region using the features of the text. In the last part after performing the local binarization in the extracted candidate region, we demonstrate the text extraction by using the differences of the features which appeared between the tett and the non-text in order to select the unnecessary non-text. After carrying out an experiment with the natural image of 100 Pieces that includes the traffic sign. The research indicates a 82.54 percent extraction of the text and a 79.69 percent accuracy of the extraction, and this improved more accurate text extraction in comparison with the existing works such as the method using RLS(Run Length Smoothing) or Fourier Transform. Also this research shows a 94.5 percent extraction in respect of the extraction on the skewed angle. That improved a 26 percent, compared with the way used only Hough Transform. The research is applied to giving the information of the location regarding the walking aid system for the blind or the operation of a driverless vehicle

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.468-478
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• 2018

The goal of this study is to propose a new directivity for business training based on an analysis of the learner's satisfaction, the cause of the learning effect and the cause of reenrollment in smart learning courses. The data from 878 learners of 11 companies was analyzed by ANOVA and multiple regression analysis and the following results were obtained. First of all, the satisfaction of studying by smart learning showed various results depending on the motivation, process and contents of studying. According to the results, high rates of satisfaction were observed when the people take an active part in studying, as reflected in the frequency and time of studying. Also, when the learning contents were presented in an animated manner, the satisfaction of the students was increased. Second, the motivation of the students to participate in the smart learning and study process was reflected in the frequency, time and quality of their studies, thus confirming the learning effect. Lastly, the satisfaction and effectiveness of studying by smart learning are the causes of reenrollment. Based on the analysis results, it was concluded that the corporation's support and proper compensation are needed to increase the rate of satisfaction and the effectiveness of smart learning from the corporation's perspective. Also, from the viewpoint of the smart learning system operators, it is necessary to find ways of developing the learning contents.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.109-122
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• 2000

As the full-motion videos in MPEG are widely available nowadays, an editor that could easily edit such kind of media data is required to develop various multimedia applications. In order to concatenate and apply a transition effect to two video streams encoded in MPEG, they should be decoded first since there are dependencies in the frames in MPEG-encoded video stream. Since this decode-edit-encode process requires a huge amount of computing/storage resources, a new editing scheme that could apply various transition effects to MPEG video streams directly while keeping the quality of video data is strongly required. This paper proposes a new editing scheme that could apply three transition effects (such as fade-in, fade-out, and dissolve) to MPEG video streams in a compressed domain. In the proposed scheme, an extension of previous method in which the frames are partially decompressed and transition effects are applied is adopted for I- and P-frames. In addition, a new processing scheme for B-frame that could apply the transition effects in DCT domain directly using an approximation of motion compensation based on the motion vector to reference frames. Since this processing scheme could apply the transition effects in a compressed domain directly, the editing process could be speed-up about $3{\sim}4$ times faster than previous decode-edit-encoding method while keeping the quality of video data as good as the source data. The proposed scheme could be used to build a software-only MPEG video editing system that helps to edit MPEG video data even on a low-cost desk-top computer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.436-444
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• 2017

The purpose of this study is to investigate the research trends related to work rehabilitation in the field of occupational therapy based on studies published in the American Journal of Occupational Therapy (AJOT). Thirty five articles in the AJOT from January, 2000, to June, 2016, were reviewed. Descriptive statistics were used to classify the articles according to their study methodology, evidence level, study subjects, and so on. When they were categorized according to the study methodology, eight studies (22.9%) were published as review or meta-analyses and 7 studies (20%) as qualitative and naturalistic inquiries. Group comparison/correlational and experimental outcome methods were used in 4 studies (11.4%). 3 studies (8.6%) were conducted using a case study/single-subject design or survey. 14 studies (40.0%) were evidence level V ones and 7 studies (33.3%) dealt with mental illness. When they were classified according to the study subjects, 25 studies (71.4%) were related to the work-rehabilitation process and 10 studies (28.6%) were related to the meaning and value of work. Through this study, we were able to determine the main research trends, study methodology, study participants, and evidence level related to vocational rehabilitation in the field of occupational therapy. Additionally, it is necessary to examine studies in the field of vocational rehabilitation, which have a high level of evidence and include various kinds of participants, as well as the process of vocational rehabilitation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.82-89
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• 2012

This paper presents the intelligent tracking algorithm for maneuvering target using the positional error compensation of the maneuvering target. The difference between measured point and predict point is separated into acceleration and noise. Fuzzy c-mean clustering and predicted impact point are used to get the optimal acceleration value. The membership function is determined for acceleration and noise which are divided by fuzzy c-means clustering and the characteristics of the maneuvering target is figured out. Divided acceleration and noise are used in the tracking algorithm to compensate computational error. The filtering process in a series of the algorithm which estimates the target value recognize the nonlinear maneuvering target as linear one because the filter recognize only remained noise by extracting acceleration from the positional error. After filtering process, we get the estimates target by compensating extracted acceleration. The proposed system improves the adaptiveness and the robustness by adjusting the parameters in the membership function of fuzzy system. To maximize the effectiveness of the proposed system, we construct the multiple model structure. Procedures of the proposed algorithm can be implemented as an on-line system. Finally, some examples are provided to show the effectiveness of the proposed algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.596-601
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• 2020

Silicon carbide is considered a potentially useful material for high-temperature electronic devices because of its large band gap energy and p-type or n-type conduction that can be controlled by impurity doping. Accordingly, the thermoelectric properties of -SiC powder prepared by refined diatomite were investigated for high value-added applications of natural diatomite. -SiC powder was synthesized by a carbothermal reduction of the SiO₂ in refined diatomite using carbon black. An acid-treatment process was then performed to eliminate the remaining impurities (Fe, Ca, etc.). n-Type semiconductors were fabricated by sintering the pressed powder at 2000℃ for 1~5h in an N2 atmosphere. The electrical conductivity increased with increasing sintering time, which might be due to an increase in carrier concentration and improvement in grain-to-grain connectivity. The carrier compensation effect caused by the remaining acceptor impurities (Al, etc.) in the obtained -SiC had a deleterious influence on the electrical conductivity. The absolute value of the Seebeck coefficient increased with increasing sintering time, which might be due to a decrease in the stacking fault density accompanied by grain or crystallite growth. On the other hand, the power factor, which reflects the thermoelectric conversion efficiency of the present work, was slightly lower than that of the porous SiC semiconductors fabricated by conventional high-purity -SiC powder, it can be stated that the thermoelectric properties could be improved further by precise control of an acid-treatment process.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.143-150
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• 2009

Fuel oil mostly used for a ship is made from crude oil by refining process. In order to produce plenty of high-quality fuel oil, the Fluid catalytic cracking(FCC) method is widely adopted to many refinery factories during the decomposition process from high molecule into lower molecule. The major constituents in spent FCC catalysts are Si, Al, Fe, Ti, alkali metals and some others. The spent catalyst is also composed small amounts of rare metals such as Ce, Nd, Ni and V. The big problem in FCC oil is mixing the catalyst in the oil. This reason is unstable separation of FCC catalyst in separator. Such a FCC catalyst will become a reason of heavy wear down in moving parts of engine. The impurity in oil is ash and deposit compound, such as Al, Si, Ni, Fe and V, which will accelerate the wear down on fuel pump, fuel injection valve cylinder liner and piston ring. It is important to find a basic reason of an engine trouble for preventing similar troubles anymore. Insurance compensation will be different according to the reason of an engine trouble which might be natural abrasion or other external causes. In this study, types and reasons of engine troubles related to fuel oil will be covered.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.315-323
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• 2010

In Wireless Sensor Networks (WSNs), various Data-Centric Storages (DCS) schemes have been proposed to store the collected data and to efficiently process a query. A DCS scheme assigns distributed data regions to sensor nodes and stores the collected data to the sensor which is responsible for the data region to process the query efficiently. However, since the whole data stored in a node will be lost when a fault of the node occurs, the accuracy of the query processing becomes low, In this paper, we propose an in-network aggregation query processing method that assures the high accuracy of query result in the case of data loss due to the faults of the nodes in the DCS scheme. When a data loss occurs, the proposed method creates a compensation model for an area of data loss using the linear regression technique and returns the result of the query including the virtual data. It guarantees the query result with high accuracy in spite of the faults of the nodes, To show the superiority of our proposed method, we compare E-KDDCS (KDDCS with the proposed method) with existing DCS schemes without the data-loss correction method. In the result, our proposed method increases accuracy and reduces query processing costs over the existing schemes.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.4
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• pp.51-56
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• 2016

Old-growth and giant tree is a nonrenewable resource with great value. The purpose of this study is to provide scientific and reasonable evaluations for the preservation and management of the old-growth and giant tree. Until now the research of old-growth and giant tree's value evaluation and authoritative index is so insufficient and imperfection. Combining with the particularity of the old-growth and giant tree, this study analyzed the main value factors of the old-growth and giant tree and objectively selected the evaluation indicators. According to the actual situation value appraisal model of the old-growth and giant tree was builded. The main value factors can be divided into economic value, cultural history, growing place, tree state, tree form, tree vigor, protection level, growth environment, tree species, tree canopy, and so on. The evaluate indicators can be selected and the indicators' weight can be calculate using analytic hierarchy process methods(AHP). Based on economic value and indicators' weight, tree's total value can be revealed. After calculation and analysis, Gyeongju Gyerim Zelkova serrata's value evaluation results is 491,503,300 won. The research results of this study can provide scientific basis and reference to the old-growth and giant trees' value appraisal and loss compensation, and arouse people's environmental awareness.