• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.6
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• pp.1059-1063
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• 2010

Shimming is an important technique in development of nuclear magnetic resonance (NMR) magnets where image resolution is highly dependent on magnetic field homogeneity. Classically, shimming may be categorized into two types: 1) active shimming that incorporates with extra coils and precise tuning of their currents; and 2)passive shimming that incorporates with pieces of steel placed in a bore of a main magnet and their uniform magnetization under homogeneous external fields. Additional magnetic fields, produced by the coils and/or the steel sheets, compensate original magnetic field from the main magnet in such a way that the total field becomes more homogeneous. In this paper, we developed a passive shimming method based on linear programming optimization. Linear programming is well known to be highly efficient to find a global minimum in various linear problems. We firstly confirmed the linearity of magnetization of ferromagnetic pieces under a presence of external magnetic fields. Then, we adopted the linear programming to find optimized allocation of the steel pieces in the inner bore of a main magnet to improve field homogeneity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.710-714
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• 2007

The wheat-gluten vendor's Shears Sound which was ever able to hear barely at the conventional market place or some specific gala period is a familiar sound to us, also a delightful sound even without any reason. The blunt Shears Sound spreading faraway attracts the mind of hearer and it makes neighbors gathering. Nevertheless, it becomes to be left as being a forgotten sound little by little to our society that rapidly growing with high degree. In this Study, as for an acoustic analysis of the wheat-gluten Shears Sound, as being a forgotten our own sound, in order to examine the difference according to the character of various shears, after making 26 pieces of various Shears and we had ever measured, appraised on the sound pressure level by each wave-form and frequency of respective Shears Sounds at the semi-anechoic chamber, W University. At the study result, the acoustic character of wheat-gluten vendor's Shears Sound was able to be grasped, and we could find out 4 pieces of Shears which were judged as more superior in acoustic capability than the existing wheat-gluten Shears among the 26 pieces of various Shears.

• Journal of Korea Multimedia Society
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• v.20 no.12
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• pp.1890-1900
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• 2017

Tangram game consists of seven pieces of polygons such as triangle, square, and parallelogram. Typical methods of image processing for object recognition may suffer from the existence of side thickness and shadow of the puzzle pieces that are dependent on the pose of 3D-shaped puzzle pieces and the direction of light sources. In this paper, we propose an image processing method that recognizes simple convex polygon-shaped objects irrespective of thickness and pose of puzzle objects. Our key algorithm to remove the thick side of piece of puzzle objects is based on morphological operations followed by logical operations with edge image and background image. By using the proposed object recognition method, we are able to implement a stable tangram game applications designed for tablet computers with front camera. As the experimental results, recognition rate is about 86 percent and recognition time is about 1ms on average. It shows the proposed algorithm is fast and accurate to recognize tangram blocks.

• Geomechanics and Engineering
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• v.8 no.1
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• pp.53-66
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• 2015

Plastic wastes, particularly polyethylene terephthalate (PET) generated from used bottled water constitute a worldwide environmental issue. Reusing the PET waste for geotechnical applications not only reduces environmental burdens of handling the waste, but also improves inherent engineering properties of soil. This paper investigated factors affecting shear strength improvement of PET-mixed residual soil. Four variables were considered: (i) plastic content; (ii) plastic slenderness ratio; (iii) plastic size; and (iv) soil particle size. A series of unconfined compression tests were performed to determine the optimum configurations for promoting the shear strength improvement. The results showed that the optimum slenderness ratio and PET content for shear strength improvement were 1:3 and 1.5%, respectively. Large PET pieces (i.e., $1.0cm^2$) were favorable for fine-grained residual soil, while small PET pieces (i.e., $0.5cm^2$) were favorable for coarse-grained residual soil. Higher shear strength improvement was obtained for PET-mixed coarse-grained residual soil (148%) than fine-grained residual soils (117%). The orientation of plastic pieces in soil and frictional resistance developed between soil particles and PET surface are two important factors affecting the shear strength performance of PET-mixed soil.

• Fashion & Textile Research Journal
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• v.9 no.2
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• pp.243-248
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• 2007

This study is about the fabric attached to the relics excavated from the Shimchun-ri tomb of the 4th century and the Moonsan-ri tombs of the 5th century. We studied 5 pieces of fabric from the Shimchun-ri tomb: one piece was silk and the other four pieces were hemp. We were able to observe 8 pieces from the four tombs in Moonsan-ri, All of them except one ramie were silk. The two kinds of bast fiber found in the tombs of Shimchun-ri and Moonsan-ri were hemp and ramie, and they were found to be plain woven with S-twist thread which thickness is uneven. The density was more fine compared to the hemps found in the Kaya or Shinra tombs of the similar era. All of the silk textiles found in the Shimchun-ri and Moonsan-ri tombs used non-twisted thread, and were plain woven. Also, we found degummed and raw silk from the tombs. The average density of the silk textiles from these tombs are similar to other areas of the same time, and studies show that they used non-twisted thread in plain woven silk found in other tombs. Therefore, we can conclude that they usually used non-twisted thread when producing silk textiles.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1249-1262
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• 2020

Along with the increase of the importance of information used in practice, adversaries tried to take valuable information in diverse ways. The simple and fundamental solution is to encrypt the whole data. Since the cost of encryption is increasing along with the size of data, the cost for securing the data is a burden to a system where the size of the data is not small. For the reason, in some applications where huge data are used for service, service providers do not use any encryption scheme for higher security, which could be a source of trouble. In this work, we introduce a new type of data securing technique named Trapdoor Digital Shredder(TDS) which disintegrates a data to multiple pieces to make it hard to re-construct the original data except the owner of the file who holds some secret keys. The main contribution of the technique is to increase the difficulty in obtaining private information even if an adversary obtains some shredded pieces. To prove the security of our scheme, we first introduce a new security model so called IND-CDA to examine the indistinguishability of shredded pieces. Then, we show that our scheme is secure under IND-CDA model, which implies that an adversary cannot distinguish a subset of shreds of a file from a set of random shreds.

• The Research Journal of the Costume Culture
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• v.16 no.6
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• pp.1142-1155
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• 2008

The purpose of this study is to analyze the effects of playful aspects through the research into characteristics and playful expressional tendency that are expressed in the contemporary fashion illustration. This study covered from 1995, the beginning point of play trend spreading, to 2006 and the fashion magazines, illustrator's collections, and about 1800 pieces of work which have been revealed on the internet web site were collected. At the next stage, 443 pieces of work were selected by researcher for a questionnaire. As a result of the questionnaire, ultimately frequency was more than n=5, so it examined playful expression characteristics, the methods and the effects of the modern fashion illustration based on 335 pieces of work(75.6% of total sample) which were selected by the majority of expert group. It showed the biggest part of playful expression tendency in the modern fashion illustration was 'simplification', and second one was 'exaggeration'. 'Immature expression' and 'fantastic expression' which are included in kidult expression were next. Hopefully, this study would be helpful for creative expression of the fashion illustration which is fit for spreading play trend in modern society.

• Journal of the Korean Society of Costume
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• v.51 no.6
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• pp.147-165
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• 2001

Haute couture denotes a luxurious made-to-order dressmaker's shop. In principle, it refers to a place that is registered with the Paris Apparel Association and has met the size and criteria specified by the association. The features of modern fashion expressed in haute couture have been contemplated by categorizing them into mixed impression appearing in haute couture work pieces. turning the collection event into a spectacle and commercialization for the succession of haute couture. Mixed impression manifested in the haute couture has engendered (1) the creative and dynamic feature (2) eclecticism with popular culture (3) mixed impression of reactionism (4) ethnic characteristics. From the above considerations, one could say that the factors drive the very existence of haute couture and comprise three elements of impeccable backgrounds, They are (1) organizing ability and protective policies of the French fashion industry, (2) relentless experimental spirit of the haute couture designers and (3) Paris that supports creativity and fashion fabrication, have coincided with rising up of the value of persistence on originality of work pieces in accordance with diversifying cultural transformations. consumer-oriented patterns by way of capital symbolized by consumers and restructuring of company operation by each shop. This report describes comprehensive understanding of haute couture, creativity and dynamic power of the haute couture work pieces. Akin to the efforts to maintain the existence of high-grade cultures throughout the overall cultures themselves, haute couture, on the basis of these factors, should also become the motive power through which luxurious culture in fashion is created in the days ahead.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.29-34
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• 2001

To investigate the effect of co-transfer of trophoblastic vesicle (TV) with frozen-thawed in vitro Produced (IVP) bovine embryo on pregnancy rate, IVP blastocysts were transferred to synchronized recipients. Elongated blastocysts were recovered at Day 13 to 15, and dissected more than 4 pieces to removed the embryonic disc. Throphoblastic fragments were cultured for 48 hours to make throphoblastic vesicles (TVs). TVs were cryopreserved in ethylene glycol or vitrification solution and frozen-thawed TVs were co-transferred to recipients with frozen-thawed IVP embryos. 1 The recovery rate of elongated blastocyst on Day 13 to 15 was 22.5% (18/80) and the size of recovered elongated blastocysts was 0.2∼5.0mm. 2. Eighteen elongated blastocysts were dissected into 88 pieces and 61.4% of those pieces were formed to TV (54/88) 3. The viability of frozen-thawed TV in ethylene glycol was higher than in vitrified solution (92.8% vs. 68.8%) 4. The pregnancy rate in co-transfer with frozen-thawed TV and IVP blastocyst was better than transfer only IVP blastocysts (50.0% vs. 23.1%).

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.1117-1128
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• 2010

The purpose of this study is to know recent studies about conservative treatment of osteoarthritis in knee joint. We reviewed and analyzed 71 theses published by korean research institution since 2000. These theses were classified by year, field of study and subject. The results of this study are as follows. 1. We found 24 oriental medical theses about osteoarthritis in knee joint since 2000. 2. Classified by the major field of study, the journal of korea acupuncture and moxibustion society accounted for 17 pieces in oriental medical journals. 3. In oriental medicine, the most subject is acupuncture(19 pieces). 13 pieces in it is about pharmacopuncture. 4. 47 theses are published in medical journals after 2000. 5. 35 associations dealt with this theme, the korean society of physical medicine is major. 6. Most subject is kinesitherapy, followed by pharmacotherapy, massotherapy, taping therapy, physiotherapy and insole. We found several therapies were effective through oriental and western medical theses. Combined oriental medicine and western conservative therapy like kinesitherapy make better effect on osteroarthritis of knee joint.