• Advances in nano research
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• 제2권1호
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• pp.1-14
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• 2014

Dislocations are basic crystal defects and represent one-dimensional native nanostructures embedded in a perfect crystalline matrix. Their structure is predefined by crystal symmetry. Two-dimensional, self-organized arrays of such nanostructures are realized reproducibly using specific preparation conditions (semiconductor wafer direct bonding). This technique allows separating dislocations up to a few hundred nanometers which enables electrical measurements of only a few, or, in the ideal case, of an individual dislocation. Electrical properties of dislocations in silicon were measured using MOSFETs as test structures. It is shown that an increase of the drain current results for nMOSFETs which is caused by a high concentration of electrons on dislocations in p-type material. The number of electrons on a dislocation is estimated from device simulations. This leads to the conclusion that metallic-like conduction exists along dislocations in this material caused by a one-dimensional carrier confinement. On the other hand, measurements of pMOSFETs prepared in n-type silicon proved the dominant transport of holes along dislocations. The experimentally measured increase of the drain current, however, is here not only caused by an higher hole concentration on these defects but also by an increasing hole mobility along dislocations. All the data proved for the first time the ambipolar behavior of dislocations in silicon. Dislocations in p-type Si form efficient one-dimensional channels for electrons, while dislocations in n-type material cause one-dimensional channels for holes.

• 전기학회논문지
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• 제65권4호
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• pp.576-585
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• 2016

The current control methods of Y-connected 7 Phase BLDC motor are sine wave current control and square wave control. The sine wave current control method needs dq axis transformation of $7{\times}7$ matrix for current control and very complex. Also this method is not suitable for multi Phase BLDC motor of trapezoidal back emf wave. Therefore, in Y connected multi phase BLDC motor, the square wave current control methods are required. Generally, in the 3Phase BLDC system, Average current control method is used for current control. The average current is obtained that the summation of absolute value of each phase current magnitude is divided by the number of conduction phase. However, if average current control method is applied to multi-phase system, there is a problem that each phase currents are different. This problem affects unbalance of each phase torque and fluctuation of total torque. This paper proposed each phase current control method of Y connected 7Phase BLDC system. Proposed method is used for PI controller of each phase for each phase current control. This method can perfect square wave current control. Also, configuration of the method is easier than DQ axis transformation. Proposed method is verified through simulation and experiments.

• 복식
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• 제45권
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• pp.85-102
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• 1999

The purpose of this study is reviewing and researching the origins of knitwear the history of patterned knits. Aithough historians know little about the origins of knitting many believe it was practiced as early as the 4th century by nomads roaming North Africa. later Arab raders adopted the craft which helped then while away the hours as they traveled across deserts in camel carabans, Its origins lie in the need for close-fitting and elasticated covering for the body in particular the head hand and feet. it first developed in the Mediterranean countries and later in Central and particularly Northern Europe. Early evidence of multicolored knitting is said to date back to the Egyptian Copts of 600-800 A.D. medieval knitting is developed through the Church and monastery. The increasing demand for knitted products already observable in the fourteenth and fifteenth centries and the number of preserved knitted articles increases inexcavated materialos from Europe. The improvements in technique stimulated the developement of the hand knitting industry in the early sixteenth century. The best-known source of production is the guild organization and their mass production consisted of the carpets cushion coverings and other small items for furnishing interiors but mainly of clothing. The demand for knitted goods was such that in the late sixteenth century it was mechanised, The knitting frame invented in 1589 by William Lee English priest was the most perfect machine of this period. The mass production of fully-fashioned and seamless garments in the late nineteenth and twentieth century was dangerously competitve to traditionally woven and sewn cloth in. As fashions changed knitwear has had an almost continuous ruse in public favour and the popularity of sports has encourage the fashion for flexible easy-fitting and absorbent garments.

• 대한전자공학회논문지TE
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• 제37권5호
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• pp.77-84
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• 2000

본 논문에서는 광범위한 이동통신채널환경에 적용할 수 있는 나카가미-m 페이딩 채널로 다중경로 페이딩 채널을 모델화하고, 수신신호와 수신기 내의 PLL(Phase Locked Loop)에서 발생된 참조신호와의 위상차를 위상에러로 가정하고 이러한 에러를 보정하기 위해 PLL을 이용한 새로운 RAKE수신기를 제안하였으며, 제안된 수신기로부터, RAKE수신기의 브랜치수 L, MIP(Multipath Intensity Profile)의 지수감소율 δ, PLL의 이득 γ/sub n/에 따른 DS/SS(Direct Sequence/spread Spectrum) 시스템의 성능을 분석하였다. 그 결과, 제안된 RAKE수신기의 L이 증가되고, 5가 감소할수록 시스템의 성능이 개선되었으며 또한 PLL이득이 30㏈가 되었을 때 위상이 일치하게 되어 완전동기된 시스템과 동일한 성능을 나타냈다. 따라서 제안된 RAKE수신기로 위상에러를 보정할 수 있고, 수신기 내의 PLL에서 요구되는 이득의 상한이 30㏈임을 입증하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권9호
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• pp.953-958
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• 2015

라즈베리파이는 복수개의 입출력 주변 장치를 지원할 수 있는 신용카드 크기 정도의 단일보드 컴퓨터로 이기종간 상호연동을 위한 완전한 플랫폼으로 사용할 수 있으므로 다양한 응용에 적용될 수 있다. 라즈베리파이에 와이파이 기능을 결합하면 원격통신이 가능하여 무선센서 노드를 구성하는데도 매우 적합하다. 또한 데이터처리와 의사결정을 인공지능에 기반을 둘 수 있으므로 화재 감시나 화재발생 신뢰도 판단 등과 같은 예제를 이미 개발된 테스트베드에서 수행해 볼 수 있다. 본 논문은 건물 내의 능동적 화재안전감시를 위한 센서 웹노드로서 라즈베리파이 이용에 대한 연구 결과이다. UV 불꽃감지센서가 촛불 크기 정도의 불꽃을 감지하면 라즈베리파이는 GCM 서버를 통해 지정된 스마트폰으로 현장상황을 알리는 푸쉬 메시지를 보낸다. 모바일 앱은 오작동 알람 여부를 판별하기 위한 실시간 비디오 영상을 제공할 수 있도록 개발되었다. 만약 긴급 상황이라면 긴급통화로 즉시 도움을 요청할 수 있도록 구현하였다.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권12호
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• pp.675-680
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• 2016

다양한 모바일 기기와 모바일 플랫폼 기술의 발전에 따라 online social network(OSN) 사용자 수는 꾸준히 증가하고 있다. OSN 사용자들은 서비스를 통해 자유로운 의사소통과 정보 공유, 그리고 인맥 확대와 같은 사회적 활동을 할 수 있게 되지만, 이는 새로운 사용자 프라이버시 문제를 야기 한다. 이와 같은 사용자 프라이버시 침해 우려를 막기 위해 다양한 분산 OSN 아키텍처들이 소개되어 왔지만, 이 또한 기술적으로 사용자에게 자신의 데이터에 대해 완벽한 통제권을 부여하지 못한다. 본 논문은 OSN 사용자 정보에 대한 통제권의 부재를 해결하기 위해 personal data storage(PDS)를 사용한다. 또한 사용자 친구들을 각기 다른 프라이버시 레벨을 가지는 친구 그룹으로 그룹핑 한 뒤 각기 다른 사용자 친구 그룹들이 자신의 그룹 프라이버시 레벨에 맞는 사용자의 차등된 텍스트 데이터를 제공받도록 함으로써 사용자 프라이버시와 서비스 유틸리티 모두를 고려한 시스템 아키텍처를 제안하였다.

• 한국작물학회지
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• 제15권
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• pp.61-67
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• 1974

1. 질소 인산 가리의 증시에 따라 수량구성요소는 각각 증대되였으나 등숙률만은 질소의 증시로 저하되는 경향이었다. 2. 전엽의 정도가 클수록 정조중 등숙률 및 완전현미 1,000입중이 저하되었으며 전엽처리간에 유의차가 인정되었다. 3. 엽위별 엽신이 등숙률 정조중 및 완전현미 1,000 입중을 통한 생산에 미치는 영향은 지엽이 61.87-60.18-65.1%, 제2위엽이 17.50-20.65-23.41%, 제3위엽이 12.71-12.73-10.11%, 제4위엽은 7.93-6.44-0.87%로서 하위엽일수록 그의 생산효과가 낮아지는 경향을 보였다.

• 대한치과의사협회지
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• 제52권12호
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• pp.783-794
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• 2014

Since the introduction of non-thermal atmospheric pressure plasma in the field of the dentistry, numerous applications have been investigated. Especially with its advantages over existing vacuum plasma in terms of portability, low cost, and non-thermal damage, it can be directly applied in the oral cavity, giving number of potentials for dental application. First, possible application of non-thermal atmospheric pressure plasma in the field of dentistry is relation to dental caries and periodontal diseases. Teeth and alveolar bones are one of the strongest bony structures in our body, but it cannot be regenerated when they are damaged by dental caries or periodontal disease. Hence many studies to prevent such diseases have been carried out, though no perfect solution has been found yet. With recent studies of modifying surfaces through non-thermal atmospheric pressure application that can prevent attachment of bacteria, or studies on bactericidal effects of non-thermal atmospheric pressure plasma can be applied here to prevent oral pathogen and 'biofilm' attachment to the surface of teeth or directly eliminate the dental caries/periodontal disease causing germs. Secondly, non-thermal atmospheric pressure application will be useful on the surface of dental implant. It is well known that the success of dental implant surgery depends on the process known as 'osseointegration' that result from osteoblast attachment, proliferation and differentiation. As the application of non-thermal atmospheric pressure plasma on the surface of dental implant just before its introduction by the chair-side of dental surgery. Despite its long history, the generation of non-thermal atmospheric pressure plasma has been greatly increased with its application in dentistry.

• 건축역사연구
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• 제18권1호
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• pp.91-111
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• 2009

The purpose of this study is to analyze paejang system of the castle constructions In the late period of Chosun dynasty. Moreover, this study aimed to examine effects and influences of its constructional productivity. The results are as follow; 1. Paejang was originally a sort of military positions. Thereafter it had been adopted to the various fields like soonrapaes. Pae, which was a regular working unit organized with $30{\sim}50$ laborers, took charge of the works allocated with its own chargeable section. 2. The first adoption of paejang system was found at the construction of Ganghwa-oyseong in 1690. Since the period of King Yeongjo and Jeongjo, it was generally used as a working system. 3. Yoo Hyeongwon had early suggested that this system should be adopted as a reformative system because it had a perfect command system like Soko-je, the provincial military system. 4. At the constructions of Dongnae-upseong, Jeonjoo-upseong and Daegoo-upseong in the period of King Yeongjo, paes were organized to $40{\sim}60$units, and worked in the fields of masonry, carnage and picking of stones. 5. At the construction of Soowon-seong in the period of King Jeongjo, a large number of various paejangs participated in all of working fields. Especially masonry-paes were usually organized with over 100 units. 6. It was estimated that paejang system surely could guarantee saving labors and term of works. Moreover, it was a basis for the further development form of dogup-je, a contracted work system. 7. Paejang system was applied in the constructions of Buddhist temples since the middle period of 1700s and later, it was widely used in the constructions of palaces.

• 한국실내디자인학회논문집
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• 제15권6호
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• pp.213-220
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• 2006

Le Corbusier (1887-1965) is known as a great architect ranking with such master architects as Frank Lloyd Wright and Mies van der Rohe who produced great architectural achievements in an era from the dawning to the maturity of the modem architecture. His works are marked for their peculiarity in expressing his architectural concept as perceived through his artistic sensibility. He has brought the form of his architecture to perfect through the influence of Purism. His architectural concept has instigated him to construct the relations between structure, form and the notion of space through the 'Dom-ino' structural system and the 'Five Principles of the Modem Architecture.' As a result, he has become such an architect as has ripened his works by adopting the 'Modulor' for human measurement. During the decade from 1929 to 1939, he made public the 'Museum of Unlimited Growth' programs in an attempt to give a concrete form to his concept of 'unlimited space' spreading to all directions, which was actually visualized by the constructions of three art museums, located Ahmedabad and Chandigarh in India and Tokyo in Japan. Although a number of researches have so far been publicized on the works and the architectural ideas of Le Corbusier, no systematic research has yet been released on the idea of 'Museum of Unlimited Growth' as a matter of fact. Therefore, this study has set its purpose to grasp the peculiarities of his exhibition space design through an analysis on the characteristics of the 'Museum of Unlimited Growth' so designed as to reflect the concept of a space, which is centrifugally growing. With this purpose in mind, this research is also to suggest how the design of the 'Museum of Unlimited Growth' would influence the modem museum exhibit space. The contents of this study comprise the consideration on the early ideas of Le Corbusier, the typical features of the growing museum and the analysis as well as the integration of his works.