• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.47-54
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• 2006

The current power generation is very suitable renewable energy for the application to Korean western and south coastal regions where characterized as having high current speed. Being different from tidal power generation that needs tremendous dam structure to preserve water, the current power generation utilizes the ocean current flow without damaging to estuary area and its environment. There are still many areas to understand the characteristics of current power generation for the actual field installation. As designing muti module with several rotors, the interaction between rotors will occur that would affect the efficiency and RPM of each rotor. In this study, the interactions caused by gaps between rotors in multi module are studied.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.349-353
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• 2009

The effects of packaging materials on preserving the functional component of pine bud beverage stored under UV (ultraviolet) light exposure conditions were studied. The order of UV light blocking properties of the selected packages was: opaque can> opaque PET (polyethylene terepthalate) with green lamination=transparent PET with 10% PEN (polyethylene naphthalate) blending> transparent PET, and did not depend on film thickness in specified range. At 20${^{\circ}C}$, the order of preserving degree of original color and endobornyl acetate, which is quality index of pine bud beverage, was the same as above. Exposure to UV light can cause of deterioration of functional food components, but green color lamination and blending of PEN materials with transparent PET help to preserve the UV sensitive pine bud beverage components. However, the treated PET bottles have poorer preservation capabilities than the opaque cans. Transparent PET with PEN blending, in particular, will be very useful packaging material for colorful functional beverage preservation by helping to protect the ingredients while attracting consumer attention.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.3150-3156
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• 1999

In this paper, VTQM(Variable Threshold Quantization Method) is proposed, which enhances PSNR by composing the advantages of round-off and truncation quantization methods. From vast experiments, PSNR's of JPEG images with the method are compared with that of standard JPEG methods. At the boundary which affects the compression ratio, VTQM quantizes with a new threshold to reduce the length of compressed data; otherwise, VTQM employs the round-off quantization method to preserve the original image information. As a result, VTQM reduces bit rate while preserving the image quanity. The experimental results show that VTQM enhances PSNR by 0.2-0.3dB., 0.4-0.5dB, with the same bit rate than those of the traditional truncation and round-off quantization methods, respectively.

• Journal of Agricultural Extension & Community Development
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• v.19 no.2
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• pp.465-495
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• 2012

This study aims to propose the policy direction for agriculture and fisheries heritage system in Korea. The agriculture and fisheries heritage system is defined as traditional agricultural activity systems and landscapes which should be preserved, sustained and handed down and evolved from the co-adaptation of a community with its cultual, agricultural, biological environment. The key characteristics of the agriculture and fisheries heritage system of Korea are as follows; Firstly, this system designates software and hardware factor of heritage in integrative manner. secondly, this system seeks to preserve and utilize such heritages simultaneously. Thirdly, this system intends to strengthen the role of people in rural area. Fourthly, this system makes use of new engine of growth in agricultural community. This system is designed by comparing and reviewing several related domestic and foreign systems including FAO' GIAHS.

• Structural Engineering and Mechanics
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• v.33 no.2
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• pp.179-191
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• 2009

This paper is aimed at combining wavelet multiresolution analysis and nonstationary Kanai-Tajimi model for the simulation of earthquake accelerograms. The proposed approach decomposes earthquake accelerograms using wavelet multiresolution analysis for the simulation of earthquake accelerograms. This study is on the basis of some Iranian earthquake records, namely Naghan 1977, Tabas 1978, Manjil 1990 and Bam 2003. The obtained results indicate that the simulated records preserve the significant properties of the actual accelerograms. In order to investigate the efficiency of the model, the spectral response curves obtained from the simulated accelerograms have been compared with those from the actual records. The results revealed that there is a good agreement between the response spectra of simulated and actual records.

• Journal of Wetlands Research
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• v.3 no.1
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• pp.29-38
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• 2001

We have studied the Yang-San peatland area to make a conservation plan. Since the peatland has its own unique ecosystem, which provides important resources in studying transformations of ecosystem, vegetation, weather, and many other things, it is not enough to emphasize the importance of preserving this area. Based on our investigation, we propose the followings to preserve the Yang-San peatland area and use in environmentally sustainable manner. First, it should be designated as a Wetland preservation area to make a conservation system between government and citizens. Second, a monitoring system is essential to observe the change of ecosystem and prohibit trespassing. Third, a comprehensive and precise investigation is in need how to restore the ecosystem. Fourth, an educational information about the ecosystem should be provided through pamphlets, postcards, visiting centers etc.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.758-762
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• 2011

In this paper an efficient algorithm is proposed to remove additive white Gaussian noise(AWGN) with edge preservation. A function is used to separate the filtering mask to two sets according to the direction information. Then, we calculate the mean and standard deviation of the pixels in each set. In order to preserve the details, we also compare standard deviations between the two sets to find out smaller one. Corrupted pixel is replaced by the mean of the filtering window's median value and the smaller set's mean value that the rate of change is faster than the other one. Experiment results show that the proposed algorithm outperforms with significant improvement in image quality than the conventional algorithms. The proposed method removes the Gaussian noise very effectively.

• The Journal of Fisheries Business Administration
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• v.37 no.2 s.71
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• pp.19-32
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• 2006

The sea environment must be preserved for maintaining various coastal resources. In order to preserve the sea environment, this study is to find problems in the process of producing photocatalyst materials, which can purify sea pollution, and to develop the heuristic algorithm satisfying those problems. The heuristic algorithm of this paper is developed through constructing the mathematical model and analyzing the mathematical structure of variables and constraints in that model. The algorithm developed in this paper consists of the first process of initializing, the second process of lot combination and the third process of improving solutions. Some experimental results are given to verify the effectiveness of the heuristic algorithm developed in this paper.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.39-46
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• 1999

Disturbances acting on the track-following servo system of an optical disk drive inherently contain significant periodic components that cause tracking errors of a periodic nature. Such disturbances can be effectively rejected by employing a repetitive controller, which must be implemented carefully in consideration of system stability. Plant uncertainty makes it difficult to design a repetitive controller that will improve tracking performance yet preserve system stability. In this paper, we examine the problem of designing a repetitive controller for an optical disk drive track-following servo system with uncertain plant coefficients. We propose a graphical design technique based on the frequency domain analysis of linear interval systems. This design method results in a repetitive controller that will maintain system stability against all admissible plant uncertainties. We show simulation and experimental results to verify the validity of the proposed design method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.5
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• pp.214-218
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• 2014

Macroglossia can create dental and skeletal instability after orthodontic treatment or orthognathic surgery for mandibular prognathism. In relevant literature, partial glossectomy is suggested for a good post-treatment prognosis. Most of the published partial glossectomy cases are two-staged surgery, because of concern about postoperative airway obstruction. As orthognathic surgical techniques and fixation method develop, however, concerns about postoperative airway obstruction have lessened. In this case, mandibular setback surgery and partial glossectomy were performed simultaneously, leading to stable recovery without any postoperative respiratory problems. After surgical technique to preserve the tongue tip, we achieved good outcomes without postoperative side effects of lingual hypoesthesia, pronunciation disorder and dyskinesia. We report this case with a literature review.