• ETRI Journal
• /
• 제9권2호
• /
• pp.24-35
• /
• 1987

A Design and Fabrication of 565 Mbit/s Optical Fiber Transmission Link We calculated the transfer functions of optical channel components and formulated the optimum transfer function of optical receiver for optical transmission to show a design rule of fiber optical link for digital transmission. And we evaluated various causes of sensitivity degradation to determine the receiver specification. Also we fabricated and demonstrated a 565Mbit/s single mode fiber optic link, 27km, to show the practicality of designed fiber optic link. The output power of the transmitter was above -3dBm, and the sensitivity of the optical receiver was -37.8dBm which is the same value we expected. Also the dynamic range was more than 25dB.

• Journal of Communications and Networks
• /
• 제9권2호
• /
• pp.150-158
• /
• 2007

We consider channel-coded multi-input multi-output (MIMO) orthogonal frequency-division multiplexing (OFDM) transmission and obtain a condition on its signal for it to attain the maximum diversity and coding gain. As this condition may not be realizable, we propose a suboptimal design that employs an orthogonal transform and a space-frequency interleaver between the channel coder and the multi-antenna OFDM transmitter. We propose a corresponding receiving method based on block turbo equalization. Attention is paid to some detailed design of the transmitter and the receiver to curtail the computational complexity and yet deliver good performance. Simulation results demonstrate that the proposed transmission technique can outperform the conventional coded MIMO OFDM and the MIMO block single-carrier transmission with cyclic prefixing.

• Journal of Electrical Engineering and information Science
• /
• 제2권5호
• /
• pp.114-120
• /
• 1997

A design method is newly presented for the creation of planar type filters which shapes will be nonuniform transmission line with continuously varying characteristic impedances. Those filters yield frequency characteristics of the bandstop filter in transmission, and have not nay discontinuities. The design is achieved by the control of wave propagation in view to both reflection an transmission properties on the dispersive nonuniform line within the desired frequency band. The developed algorithm is based on optimized perturbations of inherent nulls of lobes from the solution of first-order nonlinear differential equation for reflection coefficients of the nonuniform line, and an appropriate distribution of reflection coefficient which affects to filter length and bandwidth. Practical measurements for designed wideband microstrip and stop filter show very good agreement with theoretical results.

• International Journal of Automotive Technology
• /
• 제8권5호
• /
• pp.593-598
• /
• 2007

A new continuously variable transmission for bicycles(B-CVT) is developed by using a traction drive mechanism having inner and outer spherical rotors. The B-CVT has high power efficiency, large torque capacity, improved drivability and good packageability. The ratio change mechanism for the B-CVT is very simple, in contrast with other traction drive CVTs. After completing a conceptual design, a performance analysis and a detail design, a prototype of the B-CVT has been manufactured. The prototype has rated power of 100 watts, pedal speed of 6 rad/s and an overall speed ratio of 1.0-4.0. A bench test and an actual bicycle test have been performed to verify the practicability of the B-CVT.

• 대한기계학회논문집A
• /
• 제20권2호
• /
• pp.431-439
• /
• 1996

본 연구에서 탐구된 새로운 설계조건과 설계원칙들을 적용함으로써 세탁기용 트랜스미션으로 대표되는 기계 시스템을 효과적으로 설계할 수 있었다. 개발된 자동설계 프로그램을 이용함으로써 다양한 설계시뮬레이션을 단기간에 수행할 수 있었으며 설계 실무자로 하여금 설계변수와 상태변수 등에 관한 민감도를 파악하게 하는데 매우 효과적이었다. 본 연구에서 새롭게 제안된 시스템 설계조건들과 설계원치기들은 세탁기용 트랜스미션 뿐만 아닌 일반적인 기계시스템 설계시에도 적용될 수 있는 것으로 판단된다.

• 복식
• /
• 제64권5호
• /
• pp.154-167
• /
• 2014

This study explored culture adaptive attitudes and donning practices of traditional dress among Chinese marriage immigrant women. Quantitative research was conducted on Korea-Chinese multicultural families. Participants were 291 married women in Seoul and Gyeonggi Province. The data was analyzed using frequency analysis, factor analysis, t-test and correlation analysis. The findings are as follows: First, positive relationship was found between Hanbok acceptance attitudes and Qipao transmission attitudes. The level of Qipao transmission attitudes was higher than Hanbok acceptance attitudes especially in the part of knowledge. Han Chinese showed stronger Qipao transmission attitudes than Korean Chinese. Immigrants without Korean nationality had stronger Qipao transmission attitudes. Higher education group and higher income group showed higher level both on Hanbok acceptance attitudes and Qipao transmission attitudes. Second, more than 50% of Chinese marriage immigrant women wore Hanbok once or twice per a year. On the other hand, only 24% of them wore Qipao. This result shows that there exists a gap in the Qipao transmission attitudes and donning practices. 44% of women wore both Hanbok and Qipao in their own wedding ceremony, 32% wore only Hanbok, and 19% wore only Qipao. 64% of women had an experience of wearing Hanbok on special days such as traditional holidays or family affairs, whereas only 29% had worn Qipao.

• Earthquakes and Structures
• /
• 제17권4호
• /
• pp.387-398
• /
• 2019

On the basis that ground motions may arrive at a structure from any horizontal direction and that different directions of seismic incidence would result in different structural dynamic responses, this paper focuses on orienting the crucial seismic incidence of transmission tower-line systems based on the wavelet energy method. A typical transmission tower-line system is chosen as the case study, and two finite element (FE) models are established in ABAQUS, with and without consideration of the interaction between the transmission towers and the transmission lines. The mode combination frequency is defined by considering the influence of the higher-order modes of the structure. Subsequently, wavelet transformation is performed to obtain the total effective energy input and the effective energy input rate corresponding to the mode combination frequency to further judge the critical angle of seismic incidence by comparing these two performance indexes under different seismic incidence angles. To validate this approach, finite element history analysis (FEHA) is imposed on both FE models to generate comparative data, and good agreement is found. The results demonstrate that the wavelet energy method can forecast the critical angle of seismic incidence of a transmission tower-line system with adequate accuracy, avoiding time-consuming and cumbersome computer analysis. The proposed approach can be used in future seismic design of transmission tower-line systems.

• 한국전자통신학회논문지
• /
• 제17권6호
• /
• pp.1025-1032
• /
• 2022

본 논문에서는 기존 유선기반 CCTV 감시시스템과 IP 카메라 시스템에서 발생되는 구축비용에 대한 부담을 절감하고자 무선 통신기술을 활용한 TDMA기반 PoE 무선 다중 IP 카메라 전송시스템 개발이며, 국산 무선통신기술을 활용한 고화질 영상의 원거리 무선 전송 기술에 대해 설계 및 구현 하고자 한다. 제안 관련 기술에 대한 선 IP 전송 시스템의 송수신 프로토타입과 무선 다중 IP 카메라 전송 단말장치 및 영상 수집 장치(SB-200)에 대해 기술하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
• /
• pp.38-39
• /
• 2006

KEPCO is executing a project in Cambodia consisting of two components, "Power Development Master Plan and Institutional Strengthening" and "Greater Mekong Sub-region (GMS) Power Project Preparation" upon request by the government of the Ministry of Industry, Mines and Energy of Cambodia, contracted on $29^{th}$ September 2005. This paper includes a basic design and review of economical efficiency for constructing the two (2) cross border 115 kV transmission lines, which run from the border of Vietnam and Laos to Cambodia, and four (4) 115kV substations. The main contents of the paper include the process of design and results of a review of line route selection, tower and hardware design regarding transmission line design, as well as the type of substation, and arrangement and specifications of equipment with expects to substation design. Also, long-term demand forecasting, and an economic analysis of the project area are included.

• 산업경영시스템학회지
• /
• 제23권57호
• /
• pp.87-92
• /
• 2000

This paper describes a three dimensional parametric modeling system for transmission gears of tractor. In conventional design and manufacturing, information about three dimensional shapes has been described in engineering drawings. However drawing based design presents several problems; 1) communication errors between the designer and the modeller or manufacturer. 2) time taken and costs incurred in the design process. To solve these problems the system of parametric design based modeling has been proposed. Developed system in this paper consists of four steps; 1) parametric design of transmission gears with a solid modeler. 2) evaluation of gear geometry and strength. 3) dynamic simulation for gear interference check. 4) gear stress analysis with a CAE software. The proposed system has been tested in the fields and found to be a useful system.