• Title/Summary/Keyword: Fin systems

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A Numerical Study for the Heat and Mass Transfer in Silica gel/Water Adsorption Chiller's Adsorber (흡착식 냉동기의 흡착탑에서 열 및 물질전달에 관한 수치적 연구)

  • Kwon, Oh-Kyung;Yun, Jae-Ho;Kim, Joung-Ha;Kim, Yong-Chan;Joo, Young-Ju
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.341-346
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    • 2005
  • Nowadays, adsorption chillers have been receiving considerable attentions as they are energy-saving and environmental1y benign systems. A Fin & tube type heat exchanger in which adsorption/desorption take place is required more compact size. The adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objectives of this paper are to investigate the effect of fin pitch of fin & tube on the adsorption performance and to develop an optimal design fin & tube heat exchanger in the silica gel/water adsorption chiller. Previous study concluded that optimal particle size selected 0.5mm, type HO silica gel, and fundamental heat transfer & mass transfer experiments carried out. From the numerical results, the adsorption rate for the fin pitch 2.5mm is the highest than that for the fin pitch 5mm, 7.5mm and 10mm. Also cooling water & hot water temperature affect the adsorption rate.

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Effects of FIN-TECH use motivation on User Attitude and Word Of Mouth Intention: Focus on a Innovation Resistance Tendency and Type of Message (Rational, Emotional) (핀테크 이용 동기에 따른 이용자 태도와 구전의도의 관계 - 혁신저항과 메시지 유형의 조절효과 -)

  • Seol, Sang-Cheol;Jung, Sung-Gwang;Choi, Woo-Young
    • Management & Information Systems Review
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    • v.36 no.5
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    • pp.195-222
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    • 2017
  • Today's economy is becoming more and more convergence between different industries as the demarcation of the boundaries of all areas is leading to innovations such as mobile and social network services. So Fin-tech is a new technology that can combine the advantages of mobile and Internet with the technology revolution to easily handle financial and IT tasks. This Fin-tech is a compound word of finance and technology. The purpose of this study is to investigate the overall structural relationship between Fin-Tech use motivation (usefulness, enjoyment) on user attitude and word of mouth intention. In addition, we investigated how FinTech use motivation, user attitude, and word of mouth intention change according to innovation resistance tendency. And, we examined how the motivation, user attitude, and word of mouth intention of FinTech change according to the message type (rational and emotional). The main results of this study are as follows. First, the usefulness and enjoyment of motivation for using FinTech have a positive effect on user attitude, and user attitude also has a positive effect on word of mouse intention. Second, the relationship between FinTech use motivation, user attitude, and word of mouth intention was found to difference according to consumers' innovation resistance. Third, it was found that the relationship between FinTech use motivation, user attitude, and word of mouth intention differs according to type of message (rational, emotional). At the conclusion of the study, the summary of the research results, implications and limitations, and future research direction are described.

Mixed Control of Agile Missile with Aerodynamic Fin and Thrust Vectoring Control (유도탄의 유도명령 추종을 위한 혼합제어기 설계 : 공력 및 추력벡터제어)

  • 이호철;최용석;송택렬;송찬호;최재원
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.7
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    • pp.658-668
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    • 2004
  • This paper is concerned with a control allocation strategy using the dynamic inversion and the pseudo inverse control which generates the nominal control input trajectories. In addition, an autopilot design method is proposed by using time-varying control technique which is time-varying version of the pole placement of linear time-invariant system for an agile missile with aerodynamic fin and thrust vectoring control. The control allocation proposed in this paper is capable of extracting the maximum performance by combining each control effector, aerodynamic fin and thrust vectoring control. The adopted time-varying control technique for the autopilot design enhances the robustness of the tracking performance for a reference command. The main results are validated through the nonlinear simulations with aerodynamic data.

Mixed Control of Agile Missile with Aerodynamic fin and Side Thrust Control (유도탄의 유도명령 추종을 위한 혼합제어기 설계: 공력 및 측추력제어)

  • 최용석;이호철;송택렬;송찬호
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.10
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    • pp.947-955
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    • 2004
  • This paper is concerned with a mixed control with aerodynamic fin and side thrust control applied to an agile missile using a dynamic inversion and a time-varying control technique. The nonlinear dynamic inversion method with the weighting function allocates the desired control inputs(aerodynamic fin and side thrust control) to achieve a reference command, and the time-varying control technique plays the role to guarantee the robustness for the uncertainties. The proposed schemes are validated by nonlinear simulations with aerodynamic data.

Implementation of recognition system on extracting inferior goods of radiation fin (방열판 불량품 추출을 위한 식별 시스템 구현)

  • Sim, Woo-Sung;Huh, Do-Geun;Lee, Yong-Sik
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.1
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    • pp.91-97
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    • 2000
  • In this paper, the illuminator is designed to recognize the shape and the existence of holes of radiation fin in the point that the light reflection characteristics are different according to the roughness of the material. The threshold value, the positions of holes and the black pixel nembers in the positon are obtained under the illuminator, in accordance with the reference image, by applying binary conversion and hole segmentation algorithm, as they are suggested in this paper, The existence and shape of hole are recognized by calculating the distance and feature value in the test image, which is obtained from the parameters of reference image. It is programmed to apply to GUI(Graphic User the Interface) in windows. More than 98% of recognition rate is shown, as it is applied to three different sizes of the radiation fin.

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Autopilot Design for Agile Missile with Aerodynamic Fin and Side Thruster

  • Choi, Yong-Seok;Lee, Ho-Chul;Choi, Jae-Weon
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.508-513
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    • 2003
  • This paper is concerned with a mixed control with aerodynamic fin and side thrusters applied to an agile missile using two-time scale dynamic inversion and linear time-varying control technique. The nonlinear dynamic inversion method with the weighting function allocates the desired control inputs (aerodynamic fin and side thrusters) to track a reference trajectory, and the time-varying control technique guarantees the robustness for the uncertainties. Closed-loop stability is achieved by the assignment of the extended-mean of these linear time-varying eigenvalues to the left half complex plane. The proposed schemes are validated by nonlinear simulations.

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Optimum Placement and Shape of UHF Monopole Antenna Mounted on UAV (무인항공기에 장착된 UHF 모노폴 안테나의 최적 위치 및 형상)

  • Choi, Jaewon;Kim, Jihoon;Chung, Eulho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.9
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    • pp.46-51
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    • 2013
  • In this paper, the optimum placement and shape of UHF antenna on the unmanned aerial vehicle (UAV) are analyzed by using the electromagnetic (EM) simulation on the various locations. The FEKO was used for the EM-simulation. In order to reduce the complexity of simulation and minimize the runtime and memory usage, the composite aircraft structure is simplified as the PEC model excluding the radome structure. The simulation was performed on the wing and ventral fin of UAV, and the antenna shape used the monopole, dipole, and bent monopole antennas. When the monopole antenna is mounted under the wing, two antennas need to be mounted under the right and left wings, and those antennas have to be switched as the direction of UAV wing to the line of sight (LOS) data-link (DL) ground antenna. In the case of mounting under the ventral fin, one antenna can be used regardless of the direction of UAV wing to the LOS DL ground antenna. Also, the antenna gain is improved by the blockage reduction. The antenna gain is further improved by using the bent monopole antenna. The optimum solution of UHF antenna placement and shape on UAV is to mount the bent monopole antenna under the ventral fin.

[Review] A Study on the Change of the Payments System : Focusing on the Strategies of Distribution Companies and Fin-tech Companies

  • So Hyung KIM
    • Journal of Distribution Science
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    • v.21 no.5
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    • pp.113-120
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    • 2023
  • Purpose: The purpose of the study is to examine how payment systems for traditional distribution channels pursue changes and how they collaborate in-depth with fintech companies. This study examines the changing payment system through the strategic partnership between distribution companies and fintech companies. Research Design, Data and Methodology: The study conducted research using a variety of secondary materials and existing literature and also utilized the interview method. More specific and in-depth research is conducted through various literature studies and secondary data. Findings and Results: The findings of the study are as follows. First, distributors have occasionally directly adopted simple payment systems due to changes in payment systems as a result of online advances. Second, distributors were found to collaborate with fintech companies when not directly using simple payment. Conclusions: Such maneuvers by distributors are aimed at first, providing convenience and simplicity for consumers. Second, developing the ability to apply big data for accumulating consumer information and third, producing a customer lock-in effect by reducing the fees charged for existing payment services. The present study will provide many domestic and international distributors with a new perspective and practical implications in terms of the distribution and finance industries.

Maximum Thrust Condition by Compliant Joint of a Caudal Fin for Developing a Robotic Fish (물고기 로봇 개발을 위한 유연한 꼬리 지느러미 관절의 강성에 따른 최대 추력 조건 연구)

  • Park, Yong-Jai;Jeong, U-Seok;Lee, Jeong-Su;Kwon, Seok-Ryung;Kim, Ho-Young;Cho, Kyu-Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.2
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    • pp.103-109
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    • 2012
  • Fish generates large thrust through an oscillating motion with a compliant joint of caudal fin. The compliance of caudal fin affects the thrust generated by the fish. Due to the flexibility of the fish, the fish can generate a travelling wave motion which is known to increase the efficiency of the fish. However, a detailed research on the relationship between the flexible joint and the thrust generation is needed. In this paper, the compliant joint of a caudal fin is implemented in the driving mechanism of a robotic fish. By varying the driving frequency and stiffness of the compliant joint, the relationship between the thrust generation and the stiffness of the flexible joint is investigated. In general, as the frequency increases, the thrust increases. When higher driving frequency is applied, higher stiffness of the flexible joint is needed to maximize the thrust. The bending angles between the compliant joint and the caudal fin are compared with the changes of the thrust in one cycle. This result can be used to design the robotic fish which can be operated at the maximum thrust condition using the appropriate stiffness of the compliant joint.

Hardware-In-the-Loop Simulation for Development of Fin Stabilizer

  • Yoon, Hyeon Kyu;Lee, Gyeong Joong
    • International Journal of Ocean System Engineering
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    • v.3 no.1
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    • pp.10-15
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    • 2013
  • A ship cruising in the ocean oscillates continuously due to wave action. In order to reduce the ship's roll, we developed a fin stabilizer as an anti-rolling device for a 500-ton-class high-speed marine vessel. During the development phase, it was necessary to set up control gains for the motion and hydraulic systems and assess the effectiveness of the anti-rolling performance on the ground. For this reason, a Target Simulator, which simulated the ship's motion, was given operator inputs such as the engine telegraph and waterjet deflection angle, and generated roll using a one-degree-of-freedom motion base. Hardware-In-the-Loop Simulation (HILS) was performed using the Target Simulator in order to confirm the various logics of the developed fin stabilizer, select initial control gains, and estimate the anti-rolling performance. In conclusion, it was confirmed that HILS was very helpful to develop the fin stabilizer because it could reduce the number of sea trial tests that were needed and could find many malfunctions in the factory a priori.