• Title/Summary/Keyword: Speeding

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Cogging Force Verification of the Back-yoke Length of a Moving-coil-type Slotless Linear Synchronous Motor

  • Kim, Yong-Jae;Jung, Sang-Yong
    • Journal of Magnetics
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    • v.14 no.1
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    • pp.47-51
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    • 2009
  • The coreless linear synchronous motor (coreless LSM) has been widely used as a driving source of semiconductor production processes for machine speeding up, positioning accuracy and simple maintenance. However, this coreless LSM suffers the disadvantage of decreased thrust force created by the leakage of magnetic flux. With the goal of increasing the generated thrust force and decreasing the cogging force, the slot of the core part was removed and a moving-coil-type slotless LSM (moving-coil-type slotless LSM) is proposed in this paper. Although this moving-coil-type slotless LSM with a back-yoke at the primary side demonstrated an increase in the generated thrust force, it remained capable of generating the cogging force when the primary side was moved due to the position between the permanent magnet and the back-yoke. Therefore, we attempted to decrease the cogging force of the moving-coil-type slotless LSM. We found that the back-yoke length at the primary side needs to be made $0.5{\tau}$ longer than the integral multiple of the magnetic pole pitch in order to decrease the cogging force created by the moving-coil-type slotless LSM.

A Basic Study on Road Safety Assessment through an Analysis of Drivers' Driving Characteristics (운전자 주행특성 분석을 통한 도로 안전성 평가에 관한 기초연구)

  • Lim, Joon-Bum;Lee, Soo-Beom;Park, Jun-Tae;Park, Jin-Ho
    • Journal of the Korean Society of Safety
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    • v.26 no.5
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    • pp.136-140
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    • 2011
  • In this study, to investigate the dangerous driving on the curves, a driving test was performed in 10 km from Jinan and to Jeonju(Bugui Gas Station~Whasim Intersection), on the national highway No. 26. For the dangerous driving felt by the driver when a driver is driving on the curves, lateral acceleration and yaw rate were analyzed. And then, the reference value of lateral acceleration and yaw rate was computed. Through observing the driving speed and the characteristics of ordinary drivers using the applicable roads or following them as they drive, the driving test was performed again and the section exceeding the reference value set as above was computed. On the dangerous driving area, exceeding the reference value, total 10 accidents took place from 2006 till 2010, and slipping caused by speeding accounted for more than 70% of the accidents. It was concluded that the result of an analysis through recording drivers' driving characteristics, was reliable.

Application of Contract Net Protocol to the Design and Simulation of Network Security Model

  • Suh, Kyong-jin;Cho, Tae-ho
    • Proceedings of the KAIS Fall Conference
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    • 2003.11a
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    • pp.197-206
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    • 2003
  • With the growing usage of the networks, the world-wide Internet has become the main means to exchange data and carry out transactions. It has also become the main means to attack hosts. To solve the security problems which occur in the network such as Internet, we import software products of network security elements like an IDS (Intrusion Detection System) and a firewall. In this paper, we have designed and constructed the General Simulation Environment of Network Security model composed of multiple IDSes and a firewall which coordinate by CNP (Contract Net Protocol) for the effective detection of the intrusion. The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls tie execution of agents or a contractee, who performs intrusion detection. In the Network Security model, each model of simulation environment is hierarchically designed by DEVS (Discrete EVent system Specification) formalism. The purpose of this simulation is to evaluate the characteristics and performance of CNP architecture with rete pattern matching algorithm and the application of rete pattern matching algorithm for the speeding up the inference cycle phases of the intrusion detection expert system.

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Acceleration and Deceleration Profile Development of Reflecting Road Design Consistency (설계일관성을 반영한 감가속도 프로파일 개발 - 지방부 다차로도로를 중심으로 -)

  • Choi, Jaisung;Lee, Jong-Hak;Chong, Sang Min;Cho, Won Bum;Kim, Sangyoup
    • International Journal of Highway Engineering
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    • v.15 no.6
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    • pp.103-111
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    • 2013
  • PURPOSES : Previous Speed Profile reflects the patterns of speeds in sections of tangents to curves in the roads. However these patterns are uniform of speeds and Acceleration/Deceleration. In oder to supplement these shortcomings. this study made a new profile which can contain factors of Acceleration/Deceleration through theories of Previous Speed Profiles. METHODS : For sakes, this study developed the speed prediction model of Rural Multi-Lane Highways and calculated Acceleration/Deceleration by appling a Polynomial model based on developed speed prediction model. Polynomial model is based on second by second. Acceleration/Deceleration Profile is developed with the various scenarios of road geometric conditions. RESULTS : The longer an ahead tangent length is, The higher an acceleration rate in curve occurs due to wide sight distance. However when there are big speed gaps between two curves, the longer tangent length alleviate acceleration rate. CONCLUSIONS : Acceleration/Deceleration Profile can overview th patterns of speeds and Accelerations/Decelerations in the various road geometric conditions. Also this result will help road designer have a proper guidance to exam a potential geometric conditions where may occur the acceleration/deceleration states.

Effect of Neutral Salts on the Reactive Dyeing of Silk(I) -Effect of Cations- (중성염이 견의 반응염색에 미치는 영향(I) - 양이온의 영향-)

  • 도성국;박찬헌;권지윤
    • Textile Coloration and Finishing
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    • v.12 no.6
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    • pp.372-379
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    • 2000
  • Four kinds of neutral salts with different cations, LiCl, NaCl, KCl, and CsCl, were added to the dye bath to accurately understand the effect of cations on the reactive dyeing of silk with C. I. Reactive Black 5. The cations of salts added lowered the negative surface potential of the silk, improving equilibrium adsorption and the accessibility of the dyestuff to the fiber greatly and speeding up the dyeing rate in the order of $Li^+>Na^+>K^+>Cs^+$. The activation energy$(E_a)$ for the dyeing was in the order of$Li^+>Na^+>K^+>Cs^+$ but the activation free energy$(\Delta{G}^*)$, or the real energy barrier for the reaction, was in the order of $Li^+>Na^+>K^+>Cs^+$ because the degree of the contribution of E$^{a}$ to the activation entropy$(\Delta{S}^*)$ was $Li^+>Na^+>K^+>Cs^+$. It was found from this result that LiCl had the strongest lowering effect on the negative surface potential of silk. The decrease in $\Delta{S}^*$ should be attributed to the loosely bonded activated complex of dyestufffs, cations and fiber molecules at transition state. It was clarified from the Bronsted equation that salts had the ionic strength effect and the specific salt effect on the reactive dyeing.

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Speeding up the KLT Tracker for Real-time Image Georeferencing using GPS/INS Data

  • Tanathong, Supannee;Lee, Im-Pyeong
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.629-644
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    • 2010
  • A real-time image georeferencing system requires all inputs to be determined in real-time. The intrinsic camera parameters can be identified in advance from a camera calibration process while other control information can be derived instantaneously from real-time GPS/INS data. The bottleneck process is tie point acquisition since manual operations will be definitely obstacles for real-time system while the existing extraction methods are not fast enough. In this paper, we present a fast-and-automated image matching technique based on the KLT tracker to obtain a set of tie-points in real-time. The proposed work accelerates the KLT tracker by supplying the initial guessed tie-points computed using the GPS/INS data. Originally, the KLT only works effectively when the displacement between tie-points is small. To drive an automated solution, this paper suggests an appropriate number of depth levels for multi-resolution tracking under large displacement using the knowledge of uncertainties the GPS/INS data measurements. The experimental results show that our suggested depth levels is promising and the proposed work can obtain tie-points faster than the ordinary KLT by 13% with no less accuracy. This promising result suggests that our proposed algorithm can be effectively integrated into the real-time image georeferencing for further developing a real-time surveillance application.

A Case Study of Enhancing Flame Retardancy of Mixture Material (혼합물 소재의 난연성 향상을 위한 실험연구 사례)

  • Byun, Jai-Hyun;Jung, Chun-Sik;Kim, Donghak;Park, Kyu-Hwan
    • Journal of Korean Society for Quality Management
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    • v.47 no.3
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    • pp.631-639
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    • 2019
  • Purpose: In this paper we present a case study of applying quick and easy experimental design approach to develop a Halogen free flame retardant material for cellular phone charger cable. Methods: We employ sequential experimentation of mixture design, verification design, and factorial design. A quick and easy approach is adopted based on data investigation and graphical method instead of strict statistical analysis, which helped enhancing smooth communication with the engineers and speeding up the development process. Results: Flame retardant material in pellet type produced from the optimal condition is transported to the customer and tested, to pass the customer retardancy criteria. Conclusion: The quick and easy experimental design approach is considered to be useful in this case study.

Service ORiented Computing EnviRonment (SORCER) for deterministic global and stochastic aircraft design optimization: part 1

  • Raghunath, Chaitra;Watson, Layne T.;Jrad, Mohamed;Kapania, Rakesh K.;Kolonay, Raymond M.
    • Advances in aircraft and spacecraft science
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    • v.4 no.3
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    • pp.297-316
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    • 2017
  • With rapid growth in the complexity of large scale engineering systems, the application of multidisciplinary analysis and design optimization (MDO) in the engineering design process has garnered much attention. MDO addresses the challenge of integrating several different disciplines into the design process. Primary challenges of MDO include computational expense and poor scalability. The introduction of a distributed, collaborative computational environment results in better utilization of available computational resources, reducing the time to solution, and enhancing scalability. SORCER, a Java-based network-centric computing platform, enables analyses and design studies in a distributed collaborative computing environment. Two different optimization algorithms widely used in multidisciplinary engineering design-VTDIRECT95 and QNSTOP-are implemented on a SORCER grid. VTDIRECT95, a Fortran 95 implementation of D. R. Jones' algorithm DIRECT, is a highly parallelizable derivative-free deterministic global optimization algorithm. QNSTOP is a parallel quasi-Newton algorithm for stochastic optimization problems. The purpose of integrating VTDIRECT95 and QNSTOP into the SORCER framework is to provide load balancing among computational resources, resulting in a dynamically scalable process. Further, the federated computing paradigm implemented by SORCER manages distributed services in real time, thereby significantly speeding up the design process. Part 1 covers SORCER and the algorithms, Part 2 presents results for aircraft panel design with curvilinear stiffeners.

Service ORiented Computing EnviRonment (SORCER) for deterministic global and stochastic aircraft design optimization: part 2

  • Raghunath, Chaitra;Watson, Layne T.;Jrad, Mohamed;Kapania, Rakesh K.;Kolonay, Raymond M.
    • Advances in aircraft and spacecraft science
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    • v.4 no.3
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    • pp.317-334
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    • 2017
  • With rapid growth in the complexity of large scale engineering systems, the application of multidisciplinary analysis and design optimization (MDO) in the engineering design process has garnered much attention. MDO addresses the challenge of integrating several different disciplines into the design process. Primary challenges of MDO include computational expense and poor scalability. The introduction of a distributed, collaborative computational environment results in better utilization of available computational resources, reducing the time to solution, and enhancing scalability. SORCER, a Java-based network-centric computing platform, enables analyses and design studies in a distributed collaborative computing environment. Two different optimization algorithms widely used in multidisciplinary engineering design-VTDIRECT95 and QNSTOP-are implemented on a SORCER grid. VTDIRECT95, a Fortran 95 implementation of D. R. Jones' algorithm DIRECT, is a highly parallelizable derivative-free deterministic global optimization algorithm. QNSTOP is a parallel quasi-Newton algorithm for stochastic optimization problems. The purpose of integrating VTDIRECT95 and QNSTOP into the SORCER framework is to provide load balancing among computational resources, resulting in a dynamically scalable process. Further, the federated computing paradigm implemented by SORCER manages distributed services in real time, thereby significantly speeding up the design process. Part 1 covers SORCER and the algorithms, Part 2 presents results for aircraft panel design with curvilinear stiffeners.

Research on the Development Strategies of Confucius Institute for Expanding China's Foreign Trade

  • Yanni, Qiao;Jinge, Yao;Bae, Ki-Hyung
    • International Journal of Contents
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    • v.17 no.3
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    • pp.15-29
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    • 2021
  • The purpose of this paper is to explore how the Confucius Institute Chinese international promotion could better promote the development of China's foreign trade, by analyzing the distribution of the Confucius Institute worldwide, based on the theory of language economics, using SWOT analysis to analyze the advantages and disadvantages of the internal environment, opportunities and challenges of the external environment of Chinese international promotion of Confucius Institute. The following findings were gathered: as a language teaching institution and information exchange platform, Confucius Institute has the ability to share trade information and increase trade opportunities; to improve cultural identity and reduce transaction costs; to promote cultural communication and integration, and drive the development of related industries. The internal disadvantages were mainly reflected in the mismatch between the global regional distribution structure of Confucius Institutes, and the economic and trade structure, such as, the asymmetry between language, culture output, and demand. In addition, the management mechanism was not perfect. External opportunities were mainly new opportunities brought by economic globalization, cultural diversity, and the development of the Belt and Road initiative. External challenges were mainly influenced by the China threat theory and the fierce cultural competition among countries. The corresponding countermeasures were put forward based on the advantages of the platform and grasping the external opportunities: improving the quality of operation and speeding up the localization process; respecting cultural differences and realizing cultural common learning; seeking multilateral cooperation and enhancing the capacity for independent development.