• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
• /
• pp.258-261
• /
• 2007

본 논문은 항공엔진이 전 운용범위 및 운용조건에서 성능요구조건을 만족할 수 있도록 설계 및 운용 한계를 설정하는 MEPS 기법에 관한 내용이다. 대기습도, 엔진품질, 추력설정부정확 및 성능감쇠 등의 영향이 산술적으로 반영되는 Direct Adder와 Root Sum Square로 반영되는 Random Adder에 대해 기술하였다. 본 기법을 4,000Ib급의 상용 터보팬 엔진개발에 적용하여, 각 Adder의 영향성을 분석하여 엔진설계 및 운용한계 설정을 위한 MEPS를 구축하였다.

• 대한산업공학회지
• /
• 제31권4호
• /
• pp.303-315
• /
• 2005

In this paper we address a design problem for hub-and-spoke networks and then consider a capacitated hub locations problem with direct shipment (CHLPwD). We determine the location of hubs, the allocation of nodes to hubs, and direct shipment paths in the network, with the objective of minimizing the total cost in the network. In this paper, CHLPwD is formulated as 0-1 integer programming. We develop an evolutionary algorithm here to solve the large sized CHLPwD. To do this, we present the representation and the genetic operators suitable for the problem and propose a heuristic method for the allocation of nodes to hubs. To enhance the search capability, problem-specific information is used in our evolutionary algorithm. The proposed algorithm is compared with the heuristic method in terms of solution quality and computation time. The experimental results show that our algorithm can provide better solutions than the heuristic.

• 전기학회논문지
• /
• 제67권11호
• /
• pp.1555-1561
• /
• 2018

Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

• 대한전기학회논문지
• /
• 제37권10호
• /
• pp.733-739
• /
• 1988

Adaptive controllers for linear system whose nominal values of coefficients only are known, that is corrupted by disturbance, are designed by signal synthesis model reference adaptive control (MRAC). This design is stemmed from the Lyapunov direct method. To reduce the model following error and to improve the conrergence rate of the design, an indirect suboptimal control law is de rived using the Hamilton Jacobi Beellman equation. Proper compensaton for the effects of time varying coefficients and plant disturbance are suggested. In the design procedure no complete identification of unknown coefficients are required.

• 복식
• /
• 제63권7호
• /
• pp.134-147
• /
• 2013

Today, the convergence of fashion design and digital technology has become a popular method and accordingly been tried variously in the fashion area. This study aimed to analyze the character of the collaboration with fashion and technology, and the meaning of technology as emotional expression methods. Selected designer's collections, literature and other related studies were reviewed in order to analyze the generative structure of the meaning and the binary-opposition in the convergence of body, fashion design and technology. Literatures and selected designer's collections were reviewed and quantitatively studies were performed to classify the convergence of human bodies, fashion design and technology through Greimas Semiotics rectangle based on binary-opposition of meaning and isotophy analysis. The research presents three types of fashion technology methods: mechanical movement, light/digital media, and virtual image. The convergence of fashion and technology was classified as the direct convergence and the indirect convergence. The direct convergence was characterized by variability and has automatic, independent movement, but the indirect convergence was shown closed and to have contradistinctive images.

• International Journal of Railway
• /
• 제1권2호
• /
• pp.64-71
• /
• 2008

The quality of track-bed fills of railways has been controlled by field measurements of density $({\gamma}_d)$ and the results of plate-load tests. The control measures are compatible with the design procedures whose design parameter is $k_{30}$ for both ordinary-speed railways and high-speed railways. However, one of fatal flaws of the design procedures that there are no simple laboratory measurement procedures for the design parameters ($k_{30}$ or, $E_{v2}$ and $E_{v2}/E_{v1}$) in design stage. A new quality control procedure, in parallel with the advent of the new design procedure, is being proposed. This procedure is based upon P-wave velocity involving consistently the evaluation of design parameters in design stage and the field measurements during construction. The Key concept of the procedure is that the target value for field compaction control is the P-wave velocity determined at OMC using modified compaction test, and direct-arrival method is used for the field measurements during construction. The procedure was verified at a test site and the p-wave velocity turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC${\pm}$2% as well as the p-wave velocity.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 추계학술대회 논문집
• /
• pp.81-84
• /
• 2001

An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. In some drawing or stamping simulation with inverse method, it is difficult to apply inverse scheme due to the large aspect ratio or steep vertical angle of inclination. The reason is that initial guesses are hard to make out with present method for those cases. In this paper, a direct mesh marring scheme to generate initial guess on the sliding constraint surface described by finite element patches is suggested for one step inverse analysis to calculate initial blank shape. Radial type mapping is adopted for the simulation of rectangular cup drawing process with large aspect ratio and parallel type mapping for the simulation of S-Rail forming process with steep vertical angle of inclination.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 The Korea-Japan Plastics Processing Joint Seminar
• /
• pp.73-77
• /
• 2003

The backlight unit(BLU) is used as a light source of TFT liquid-crystalline-display (TFT-LCD) module. In this backlight unit, one of important components is the light guide, which is usually made of transparent polymers. Currently the screen-printing method is mainly used for the light guide as a manufacturing process. However, it has limitation to the flexibility of three-dimensional optical design. In the present paper a new alternative manufacturing method for the light guide with low-cost is proposed. This manufacturing method is named as direct surface forming (DSF), which is very similar to the well-known hot embossing except for partial contact between mold and substrate. The results of this new manufacturing method are presented in terms of processing condition, dimensional accuracy, productivity, etc.

• Korea-Australia Rheology Journal
• /
• 제15권4호
• /
• pp.167-171
• /
• 2003

The backlight unit (BLU) is used as a light source of TFT liquid-crystalline-display (TFT-LCD) module. In this backlight unit, one of important components is the light guide, which is usually made of transparent polymers. Currently, the screen-printing method is mainly used for the light guide as a manufacturing process. However, it has limitation to the flexibility of three-dimensional optical design. In the present paper a new alternative manufacturing method for the light guide with low-cost is proposed. This manufacturing method is named as direct surface forming (DSF), which is very similar to the well-known hot embossing except for partial contact between mold and substrate. The results of this new manufacturing method are presented in terms of processing condition, dimensional accuracy, productivity, etc.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 D
• /
• pp.2187-2189
• /
• 2003

This paper presents a design method of the wavelet neural network(WNN) controller based on a direct adaptive control scheme for the intelligent control of chaotic systems. The conventional control methods such as optimal control, adaptive control and robust control may not be feasible when an explicit, faithful mathematical model cannot be constructed. Therefore, an intelligent control system that is an on-line trained WNN controller based on a direct adaptive control method is proposed to control chaotic systems whose mathematical models are not available. The gradient-descent method is used for training a wavelet neural network controller. Finally, the effectiveness and feasibility of the proposed control method is demonstrated with applications to the chaotic system.