• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.8
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• pp.1155-1160
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• 2013

The rapid growth of smart phones has made location-based services (LBSs) widely available. However, the use of LBS can raise privacy issues, as LBS can allow adversaries to violate the location privacy of users. There has been a considerable amount of research on preserving user location privacy. Most of these studies try to preserve location privacy by achieving what is known as location K-anonymity. In this paper, we propose a hierarchical clustering-based spatial cloaking algorithm for LBSs. The proposed algorithm constructs a tree using a modified version of agglomerative hierarchical clustering. The experimental results show, in terms of the ASR size, that the proposed algorithm is better than Hilbert Cloak and comparable to RC-AR (R-tree Cloak implementation of Reciprocal with an Asymmetric R-tree split). In terms of the ASR generation time, the proposed algorithm is much better in its performance than RC-AR and similar in performance to Hilbert Cloak.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.6
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• pp.491-494
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• 2016

A design method is proposed to minimize the scattering cross section(SCS) of the electromagnetic cloak based on the quasi-conformal mapping. Often times in such cloaking structures, parts that require refractive index below one are approximated with free space because of the difficulty involved with realization. In this process, preformance degradation is inevitable. In this work, the size of the cloak is optimized to compensate for the deterioration, and thus to minimize the scattering cross section of a diamond shaped conductor. Proposed cloak is fabricated using a 3D printer, and verified by measuring the cloaking performance of a diamond shaped aluminum target.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.211-216
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• 2017

The purpose of this study is to evaluate the usefulness of a newly fusion model designed cloak shield to reduce the radiation exposure of the assistant during CT(computed tomography) of severely injured patient. Radiation dose was measured in the heart, both axillary and thyroid areas using newly designed cloak shield and existing shield with head phantom and human phantom under the same conditions as brain vascular CT scan. The newly designed cloak shield was measured higher for radiation shielding rate than the existing shields, 61.9 % for heart, 46.2 % for left axillary, 69.8 % for right axillary and 71.1 % for thyroid gland, respectively. a newly developed fusion model of cloak shields are useful for reducing radiation exposure. It is expected to make a significant contribution to reduction of radiation exposure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.409-410
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• 2014

• Journal of electromagnetic engineering and science
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• v.13 no.2
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• pp.73-85
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• 2013

In this paper we present an alternative approach to addressing the problem of designing cloaks for radar targets, which have been dealt with in the past by using the transformation optics (TO) algorithm. The present design utilizes realistic materials, which can be fabricated in the laboratory, and are wideband as well as relatively insensitive to polarization and incident angle of the incoming wave. The design strategy, presented herein, circumvents the need to use metamaterials for cloak designs that are inherently narrowband, dispersive and highly sensitive to polarization and incident angle. A new interpretation of the TO algorithm is presented and is employed for the design of radar cross section-reducing absorbers for arbitrary targets, and not just for canonical shapes, e.g., cylinders. The topic of performance enhancement of the absorbers by using graphene materials and embedded frequency structure surfaces is briefly mentioned. The design procedure for planar absorbing covers is presented and their performance as wrappers of general objects is discussed. A number of test cases are included as examples to illustrate the application of the proposed design methodology, which is a modification of the classical TO paradigm.

• The Research Journal of the Costume Culture
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• v.3 no.2
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• pp.193-199
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• 1995

The purpose of this research was to study the origins and the meanings of the Kokal (고깔). Comparative linguistic analytical approaches were employed to trace the development of the word, the Kokal(고깔). Results of this study revealed that the kotkal(곳갈, 곧갈) was a general term referring to a variety of head coverings in eh period of Choson Dynasty. This broad meanings of the Kotkal(곳갈,곧갈) of the Chosun Dynasty period has been changed to a narrow sense meanings a conical cap made of folds of the material, mainly used by some of the Buddhist monks in modern Korean. Also, the phonetic value of the Kotkal(곳갈,곧갈) of the Choson Dynasty period changed to the Kokal(고깔) in modern Korean. A variety of words for the Kokal(고깔) was found in the different languages such as Latin, English, French, Turkish, German, Mongolian, and Chinese. The examination and analysis of this study indicated that the origin of the Korean word Kotkal(곳갈,곧갈) or Kokal(고깔) and the meanings of it were derived from LL. Cuculla(monk's cowl)

• BMB Reports
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• v.54 no.7
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• pp.344-355
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• 2021

Mucins are high molecular-weight epithelial glycoproteins and are implicated in many physiological processes, including epithelial cell protection, signaling transduction, and tissue homeostasis. Abnormality of mucus expression and structure contributes to biological properties related to human cancer progression. Tumor growth sites induce inhospitable conditions. Many kinds of research suggest that mucins provide a microenvironment to avoid hypoxia, acidic, and other biological conditions that promote cancer progression. Given that the mucus layer captures growth factors or cytokines, we propose that mucin helps to ameliorate inhospitable conditions in tumor-growing sites. Additionally, the composition and structure of mucins enable them to mimic the surface of normal epithelial cells, allowing tumor cells to escape from immune surveillance. Indeed, human cancers such as mucinous carcinoma, show a higher incidence of invasion to adjacent organs and lymph node metastasis than do non-mucinous carcinoma. In this mini-review, we discuss how mucin provides a tumor-friendly environment and contributes to increased cancer malignancy in mucinous carcinoma.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.6
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• pp.257-263
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• 2015

Recently two seismic cloaking methods of earthquake engineering have been suggested. One is the seismic wave deflection method that makes the seismic wave bend away and the other is the shadow zone method that makes an area that seismic waves cannot pass through. It is called as seismic cloaking. The fundamental principles of the seismic cloaking by variable refractive index were explained. A two-dimensional cylindrical model which was composed of 40 layers of different density and modulus was tested by numerical simulation. The center region of the model to be protected is called 'cloaked area' and the outer region of it to deflect the incoming wave is called 'cloaking area' or 'cloak area.' As the incoming surface wave is approaching to the cloaking area, the refractive index is decreasing and, therefore, the velocity and impedance are increasing. Then, the wave bends away the cloaked area instead of passing it. Three cases are tested depending on the comparison between the seismic wavelength and the diameter of the cloaked region. The advantage and disadvantage of the method were compared with conventional earthquake engineering method. Some practical requirements for realization in fields were discussed.

• The Research Journal of the Costume Culture
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• v.9 no.3
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• pp.523-531
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• 2001

The objective of this study was to trace the origins of the costume terminologies and to identify the meanings of the names of costumes of the Chosun Period. Such terms as dukgai 得盖, murot gai 무롯지 or murukai 무루깨, bal 발, bigya 비갸, bium 비음, samachi 사마치, chiene 처네, chienui 薦衣 were included in this research can be summarized as follows: It appeared that similar words to dukagai were found in the languages such as the language of the arctic regions, Mongolians, English, Sumerian, and Latin. It is considered that dukgai of Chosun was related to L. toga. The word murot gai or murukai as a kind of head covering had its origins in Korean meaning to cover or to wear. Also it was found that the word bal was derived from L.palla meaning a robe, cloak or mantle. Korean bal 발 meant a dang jugori 당저고리 or dang go ui, a kind of women\`s formal outer dress. It was found that word bium or biim, a garment of Yi Chosun was similar to Ass. birmu, a garment. The word, samachi of Yi Chosun was derived from the Manchurien word samachi meaning a kind of military skirt. The word, chiene 처네 or chienui was derived from the Chinese chien (Equatopms. See Full-text) that means a skirt, a child\`s covering, a sheet, and women\`s underwear.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.894-896
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• 2013

오늘날 전세계의 사람이 이용하는 SNS 상에 존재하는 보안 위협은 정보주체의 개인정보를 유출하고 스팸, 피싱 등의 2 차 피해를 야기하는 등 치명적인 결과를 초래한다. 본 논문에서는 잊혀질 권리와 SNS의 개념을 파악하고 SNS 상에 존재하는 보안 위협에 대해 논의하며 보안 위협을 해소하고 SNS 환경에서의 잊혀질 권리를 실현할 수 있는 UPP, Dual Watermarking Scheme, FaceCloak 등 기술적 방안을 제시한다.