• Current Optics and Photonics
• /
• 제1권4호
• /
• pp.378-388
• /
• 2017

We present a graphical method for determining a pair of optical materials and powers to design an achromatic and athermal lens system with corrected Petzval curvature. To graphically obtain the solutions, a three-dimensional (3D) glass chart is proposed. Even if a particular material combination is unavailable, we can select an element suitable for a specific lens and continuously change the element powers of an equivalent single lens for aberrations correction. Thus, we can iteratively identify the materials and powers on a 3D glass chart. By designing a fisheye lens using this method, an achromatic and athermal system with flat Petzval curvature is obtained, over the specified waveband and temperature ranges.

• Design & Manufacturing
• /
• 제6권2호
• /
• pp.74-78
• /
• 2012

A multi-cavity injection mold system of protein chip for point-of-care with cavity temperature and pressure sensors was proposed in this work. In advance of manufacturing for the multi-cavity injection mold system, a single cavity injection mold system to mold protein chip was considered. Injection molding analysis for the presented system was performed to optimize the process of the molding and suggest guides to design. On the basis of the results for the single cavity system, a multi-cavity injection mold system for protein chip was analyzed, designed and manufactured with cavity temperature and pressure sensors. Results of balanced filling for protein chip models were obtained from the presented mold system.

• 한국지능정보시스템학회:학술대회논문집
• /
• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
• /
• pp.78-82
• /
• 2001

Most of current Internet auction systems are simple server programs that partly automated the function of the conventional auction house. These system do not provide sufficient independence, distribution and parallelism between the functions of the conventional auction house. In there are automated by server program, but still users need to execute a repetitive task to monitor the dynamic progress of a certain auction, decide proper bid price, and submit the bid. Another problem is that they support only single as English auction and Dutch auction, but they do not support the double auctions are superior to the single auction with respect to speed., efficiency, and the fair distribution of profit. In this paper, we present design and implement of an agent-based continuous double auction system, called CoDABot, in order to mitigate the limitations of current auctions system. CoDABot supports continuous double auction, provides various bidding agent for users to select, and has been implemented into a multi-agent system that realize more independent, distributed, and parallel subsystems.

• 한국인공지능학회지
• /
• 제9권2호
• /
• pp.23-28
• /
• 2021

In this paper, we studied a system that can efficiently build security management for single-person households using Arduino, ESP32-CAM and PIR sensors, and proposed an Android app with an internet connection. The ESP32-CAM is an Arduino compatible board that supports both Wi-Fi, Bluetooth, and cameras using an ESP32-based processor. The PCB on-board antenna may be used independently, and the sensitivity may be expanded by separately connecting the external antenna. This system has implemented an Arduino-based Unauthorized intrusion system that can significantly help prevent crimes in single-person households using the combination of PIR sensors, Arduino devices, and smartphones. unauthorized intrusion system, showing the connection between Arduino Uno and ESP32-CAM and with smartphone applications. Recently, if daily quarantine is underway around us and it is necessary to verify the identity of visitors, it is expected that it will help maintain a safety net if this system is applied for the purpose of facial recognition and restricting some access. This technology is widely used to verify that the characters in the two images entered into the system are the same or to determine who the characters in the images are most similar to among those previously stored in the internal database. There is an advantage that it may be implemented in a low-power, low-cost environment through image recognition, comparison, feature point extraction, and comparison.

• 한국유체기계학회 논문집
• /
• 제17권1호
• /
• pp.47-53
• /
• 2014

This paper aims to present the design and performance evaluation of a counter-rotating tidal turbine using CFD and to compare its performance with single rotor. The device scale is 10kW and the rotating part consists of two rotors which rotate in opposite direction. Compared with conventional single rotor, the counter-rotating system shows higher power efficiency at high stream velocity but lower efficiency at low stream velocity. The added counter-rotated rotor together helps improve the energy absorption capacity but has influence on the upstream rotor that reduces its performance. In terms of power capture, the designed counter-rotating tidal turbine is more advantageous in high speed tidal condition.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
• /
• pp.459-462
• /
• 2008

This paper describes the design of single body type repeater antenna for isolation enhancement between donor and receptor antennas. The antenna system consists of cavity, triangular patch antenna and cavity reflector. The antenna satisfies return-loss and isolation specifications in the desired band while the broadside gain is a little bit short from the spec.

• 전자공학회논문지SC
• /
• 제44권4호통권316호
• /
• pp.21-26
• /
• 2007

본 논문에서는 광범위하게 적용되고 있는 단상 인버터 시스템에 대한 강인성을 향상시키기 위해 외란관측기 기반의 PI-제어기 설계 방법을 제안한다. 출력 단에 모터나 정류기와 같은 가변부하가 존재할 경우, 인버터의 출력 전압은 변동하기 쉬우며 바람직하지 않은 과도현상을 보일 수 있다. 본 논문에서는 가변부하에 의해 발생하는 출력 전압의 변화를 시스템의 외란에 의한 결과를 간주하여 부하 전류와 시스템의 불학실성에 의한 오차 (파라미터 변화나 잘못된 모델링과 같은)를 보상하는 외란관측기 기반 제어기를 설계한다. Matlab Simuink의 SimPowerSystem을 이용하여 단상 인버터 시스템에 대한 외란관측기 기반 제어기의 성능을 입증한다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 하계종합학술대회 논문집
• /
• pp.809-812
• /
• 1999

The pendulum is a SIMO(Single-input multi-output) system that both angle of pendulum and position of cart controlled simultaneously by one actuator. In this paper, propose a hybrid neuro-controller to apply to pendulum system. We design the conventional optimal controller and the neural network as a identifier, which can identify the uncertainty of plant not modeled, respectively. Then we combine them into a novel controller, with a structure that the error between plant and identifier is added in conventional optimal control input Finally, the paper shows the validity of the proposed controller through computer simulations and experiments.

• 한국시뮬레이션학회논문지
• /
• 제8권3호
• /
• pp.1-16
• /
• 1999

This paper deals with a discrete simulation optimization method for designing a complex probabilistic discrete event system. The proposed algorithm in this paper searches the effective and reliable alternatives satisfying the target values of the system to be designed through a single run in a relatively short time period. It tries to estimate an autoregressive model, and construct mean and confidence interval for evaluating correctly the objective function obtained by small amount of output data. The experimental results using the proposed method are also shown.

• 제어로봇시스템학회논문지
• /
• 제6권2호
• /
• pp.207-216
• /
• 2000

This paper introduces an effective system design method to develop a customer oriented product using a design optimization process and to select a set of critical design paramenters,. The process results in the development of a successful product satisfying customer needs and reducing development risk. The proposed scheme adopted a five step QFD(Quality Function Deployment) in order to extract design parameters from customer needs and evaluated their priority using risk factors for extracted design parameters. In this process we determine critical design parameters and allocate them to subsystem designers. Subsequently design engineers develop and test the product based on these parameters. These design parameters capture the characteristics of customer needs in terms of performance cost and schedule in the process of QFD, The subsequent risk management task ensures the minimum risk approach in the presence of design parameter uncertainty. An application of this approach was demonstrated in the development of weld quality monitoring system. Dominant design parameters affect linearity characteristics of weld defect feature vectors. Therefore it simplifies the algorithm for adopting pattern classification of feature vectors and improves the accuracy of recognition rate of weld defect and the real time response of the defect detection in the performance. Additionally the development cost decreases by using DSP board for low speed because of reducing CPU's load adopting algorithm in classifying weld defects. It also reduces the cost by using the single sensor to measure weld defects. Furthermore the synergy effect derived from the critical design parameters improves the detection rate of weld defects by 15% when compared with the implementation using the non-critical design parameters. It also result in 30% saving in development cost./ The overall results are close to 95% customer level showing the effectiveness of the proposed development approach.