• Journal of Power Electronics
• /
• 제19권1호
• /
• pp.296-306
• /
• 2019

The flyback topology is being widely used in power adapters. The coupling capacitance between primary and secondary windings of a flyback transformer is the main path for common-mode (CM) noise conduction. A Y-cap is usually used to effectively suppress EMI noise. However, this results in problems in space, cost, and the danger of safety leakage current. In this paper, the CM noise behaviors due to the electric field coupling of the transformer windings in a flyback adapter with synchronous rectification are analyzed. Then a scheme with balance winding is proposed to reduce the CM noise with a transformer winding design that eliminates the Y-cap. The planar transformer has advantages in terms of its low profile, good heat dissipation and good stray parameter consistency. Based on the proposed scheme, with the help of a full-wave simulation tool, the key parameter influences of the transformer PCB winding design on CM noise are further analyzed. Finally, a PCB transformer for an 18W adapter is designed and tested to verify the effectiveness of the balance winding scheme.

• 한국산학기술학회논문지
• /
• 제16권11호
• /
• pp.7629-7634
• /
• 2015

이 연구의 목적은 일제강점기 공통도면을 사용해 계획된 군청사에 대해 본가-부속가 연결방식을 기준으로 그 배치유형을 정리하고 각 유형별 증 개축 방향을 고찰하는 것이다. 우선, 디지털이미지로 제공되는 국가기록원 소장 1910년대 작성된 군청사 관련 건축도면을 분석하여 공통형 군청사의 배치유형 세 가지를 확인하고, 기타 자료를 통해 두 가지 배치유형을 추가발굴한다. 이어서, 각 배치유형을 본가-부속가 연결방식을 기준으로 세분한 후 그 증 개축경향을 정리한다. 연구방법은 군청사 관련 건축도면 디지털이미지, 그 해제, 조선총독부와 각 도가 주고받은 문서, 신문과 잡지의 기사 도면 사진 등을 분석하는 문헌연구방법이다. 공통형 군청사의 다섯가지 배치유형은 13가지로 세분되고, 각 세분된 유형에서 증 개축은 각 부지의 지형 형상 기타 사정에 따라 달랐지만, 본가는 신축 및 증 개축 상황에서 항상 전면 중앙에 위치하여 관청사로서 상징성과 중심성을 유지하려는 노력은 일관된다. 공통형 군청사의 계획은 1930년대 초반까지도 꾸준히 이어진다.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2011년도 특별논문집
• /
• pp.117-126
• /
• 2011

The buckling assessment of plate panels described in common structural rules (CSR) is to be determined according to the buckling utilization factor with hull girder stresses calculated on net hull girder sectional properties. As the thickness requirement for the buckling assessment of plate panels is not explicitly given in CSR, a lot of time is spent to find the proper thickness of plate panels until reaching to an allowable buckling utilization factor. In this study, in order to reduce time and cost, the thickness requirement of plate panels satisfying buckling assessment was derived. The structural design system included with the thickness requirement for buckling assessment was developed. The system is called as Oil-tanker Automated Structural Investigation System (OASIS). The design result of longitudinal strength members using OASIS was verified by Nauticus Hull which is the rule scantling software of DNV. Finally, optimum design of a double hull tanker for the minimum weight using OASIS was presented.

• Current Optics and Photonics
• /
• 제2권3호
• /
• pp.241-249
• /
• 2018

We report a midinfrared dual-field-of-view (FOV) optical system design for an airborne electro-optical targeting system. To achieve miniaturization and weight reduction of the system, it has a common aperture and fore-optics for three different spectral wavelength bands: an electro-optic (EO) band ($0.6{\sim}0.9{\mu}m$), a midinfrared (IR) band ($3.6{\sim}4.9{\mu}m$), and a designation laser wavelength ($1.064{\mu}m$). It is free to steer the line of sight by rotating the pitch and roll axes. Our design co-aligns the roll axis, and the line of sight therefore has a fixed entrance pupil position for all optical paths, unlike previously reported dual-FOV designs, which dispenses with image coregistration that is otherwise required. The fore-optics is essentially an achromatized, collimated beam reducer for all bands. Following the fore-optics, the bands are split into the dual-FOV IR path and the EO/laser path by a beam splitter. The subsequent dual-FOV IR path design consists of a zoom lens group and a relay lens group. The IR path with the fore-optics provides two stepwise FOVs ($1.50^{\circ}{\times}1.20^{\circ}$ to $5.40^{\circ}{\times}4.32^{\circ}$), due to the insertion of two Si lenses into the zoom lens group. The IR optical system is designed in such a way that the location and f-number (f/5.3) of the cold stop internally provided by the IR detector are maintained when changing the zoom. The design also satisfies several important performance requirements, including an on-axis modulation transfer function (MTF) that exceeds 10% at the Nyquist frequency of the IR detector pitch, with distortion of less than 2%.

• 한국융합학회논문지
• /
• 제10권7호
• /
• pp.155-162
• /
• 2019

오늘날의 공공도서관 이용 주체는 매우 다양화 되어가고 있으며, 다양한 연령 및 신체 조건의 이용자들을 고려하고 보다 편리하고, 쾌적한 환경을 갖춘 공공도서관을 만들기 위해 유니버설디자인의 필요성이 중요하게 인식되고 있다. 이에 본 연구는 공공도서관의 공용공간을 유니버설디자인의 원칙을 기준으로 서울시에 위치한 공공도서관 33개소를 대상으로 한 실태조사를 통해 적용 수준을 분석하고 개선방향을 다음과 같이 제시한다. 첫째, 유니버설디자인의 적용수준이 낮은 '쉽게 인지할 수 있는 정보'와 관련한 환경을 우선적으로 개선하여야 할 것이다. 둘째, 보다 수준 높은 유니버설디자인 환경을 만들기 위해서는 설계단계부터 이를 적용하는 것이 중요하다. 셋째, '사용상의 융통성' 관련 환경은 국내의 법적인 규제에 적용되는 항목이 적어 환경 수준을 제고하기 어려운 측면이 있으므로 도서관을 이용하는 이용자 전체에 대한 세심한 배려와 인식이 선행되어야 할 것이다.

• 한국조경학회지
• /
• 제23권4호
• /
• pp.40-49
• /
• 1996

The judgement of how good a memorial park is designed in terms of representing symbolic meanings through moonument depends on whether it decisively reflects peoples' common value and affection to specific event or place of the park. It is in fact, not easy to define the kind of value and affections peoples have in mind for the park. It is likely that most park design concepts are primarily based on designer' subjective view of the world by which the public is expected to understand, accept, and eventually share the common symbolic meanings of the park. AS memorial park design as the works of art might be appreciated not only in view of artistic performance of designer but in terms of its social meaning of the newly defined space. Two cases of park designs by author include issues on conceptual alternatives, experience of memorial space, symbolic use of materials, and perspectives on the direction of contemporary park design. It is noteworthy that authentic approaches should be challenged for a new way in which symbolic meanings could be given in rather contradictory style.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제40권2호
• /
• pp.50-60
• /
• 2014

Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evolution of dental implants. It also describes the types of implants that have been developed, and the parameters that are presently used in the design of dental implants. Finally, it describes the trends that are employed to improve dental implant surfaces, and current technologies used for the analysis and design of the implants.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
• /
• pp.649-655
• /
• 2009

Traffic safety and vibration serviceability of a railway bridge set a limitation to the application of long-span cable supported bridges even though the design trend of the bridge becomes longer and lighter. In the case of high speed railway, it becomes more severe for the high speed of the train and resonance of the structure. Therefore, the cable supported bridge does not exist in Korea high speed railway until now. On the other hand, in recent, Italia, Japan and China do design and construct the long-span cable supported bridges for high speed railway recently with overcoming of traffic safety and passenger comforts. In the present study, prior to analysis of traffic safety and passenger comforts, a extradosed bridge for common railway is re-designed for high speed railway. The difference of member forces and displacements by design live load, the difference of impact coefficient and variable stresses of cables are investigated.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
• /
• pp.117-122
• /
• 2003

This study deals with apartments, the representative form of residence in Korea, and analyzes the residential plane of 30-pyong apartments that are constructed by the 5 construction companies within in the past three years. It is discovered that these apartments show a certain form and that developing the frame work of interior elements according to the characteristics of family types of 30-pyong apartment residents and the process for such a frame work are needed. Therefore, by analyzing the differences of residential forms according to resident types, this investigation tries to approach the design centering around users. To summarize the steps and contents of this study, first, it draws the understanding and the study field of common residential space, second, it shows the characteristics of family types within residential space, third, it analyzes and verifies the differences of characteristics according to family types within the representative size and form of plane. This investigation is aimed to provide the reasons for developing different planes according to family types despite they may be of the same size, to show the frame of the study method for developing the plane design and the interior element design for users and to suggest the way of designing residence in a conditional approach applying the conditions of users within common residential space.

• 패션비즈니스
• /
• 제18권1호
• /
• pp.101-117
• /
• 2014

The purpose of this study is to investigate domestic and foreign fashion sock design trends and suggest a proposal for competitive fashion sock design developments. The methods of this study are undertaken by literature review and design trend analysis. For the design trend analysis, in the case of domestic cases, 209 pictures from 7 brands, and in the case of foreign cases, 870 pictures from 10 brands are being chosen. In terms of analysis criteria, the colors, patterns, lengths and images of both the domestic and foreign socks are being compared. As a result, among the fashion foreign socks, more than 4 colors are the most common, and dark & dark grayish, strong & deep color tones are the most popular. Also, the stylized, geometrical patterns, and casual, cute and unique images are generally used. In the case of domestic fashion socks, 2 colors are the most common with vivid, strong & deep color tones as the most popular. Furthermore the patterns are limited to geometric patterns, and the images of socks are inclined to be too casual. To enhance the competitiveness of Korean sock designs, the variety of patterns and images are essential.