• Title/Summary/Keyword: PFCs-free

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Improvement of Migration Fastness of Perfluorocarbons-free Synthetic Suede by Chitosan Pretreatment (키토산 전처리를 통한 과불화탄소 무함유 합성 스웨이드의 이염성 견뢰도 향상)

  • Lee, Hye Mi;Kim, Ah Rong;Kim, Dae Geun
    • Textile Coloration and Finishing
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    • v.31 no.4
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    • pp.258-267
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    • 2019
  • Synthetic suede without PFCs(perfluorinated compounds) are followed by subsequent high temperature treatment. But migration fastness of synthetic suede may be reduced due to sublimation of disperse dyes that results from the high temperature treatment. Therefore, in this study, chitosan treatment was used to improve the migration fastness before polyurethane dipping process. Polyester fiber was treated with sodium hydroxide aqueous solution before chitosan processing. This samples treated with a chitosan concentration upto 0.5% were dyed and coated with PUD(polyurethane dispersion). The migration fastness was most improved at 0.35% application. This is presumably due to the fact that the chitosan may increase the dye-binding capability through intermolecular hydrogen bonding.

A Study on the Design of Software Switching Mechanism for Develops the Flight Control Law (제어법칙 개발을 위한 소프트웨어 전환장치 설계에 관한 연구)

  • Kim, Chong-Sup;Cho, In-Je;Ahn, Jong-Min;Shin, Ji-Hwan;Park, Sang-Seon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1130-1137
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    • 2006
  • Relaxed Static Stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, the flight control systems are necessary to stabilizes the unstable aircraft and provides adequate handling qualities. The initial production flight control system are verified by flight test and it's always an elements of danger because of flight-critical nature of control law function and design error due to model base design method. These critical issues impact to flight safety, and it could be lead to a loss of aircraft and pilot's life. Therefore, development of an easily modifiable RFCS(Research Flight Control System) capable of reverting to a PFCS(Primary Flight Control System) of reliable control law must be developed to guarantee the flight safety. This paper addresses the concept of SSWM(Software Switching Mechanism) using the fader logic such as TFS(Transient Free Switch) based on T-50 flight control law. The result of the analysis based on non-real time simulation in-house software using SSWM reveals that the flight control system are switching between two computers without any problem.

A Study on the Design of Hardware Switching Mechanism using TCP/IP Communication (TCP/IP를 이용한 하드웨어 전환장치 설계에 관한 연구)

  • Kim, Chong-Sup;Cho, In-Je;Lim, Sang-Soo;Ahn, Jong-Min;Kang, Im-Ju
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.7
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    • pp.694-702
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    • 2007
  • The SSWM(Software Switching Mechanism) of I-processor concept using non-real time in-house software simulation program is an effective method in order to develop the flight control law in desktop or HQS environment. And, this system has some advantages compare to HSWM(Hardware Switching Mechanism) such as remove the time delay effectiveness and reduce the costs of development. But, if this system loading to the OFP(Operational Flight Program), the OFP guarantee the enough throughput in order to calculate the two control law at once. Therefore, the HSWM(Hardware Switching Mechanism) of 2-processor concept is necessary. This paper addresses the concept of HSWM of the HQS-PC interface using TCP/IP(Transmission Control Protocol/Internet Protocol) communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed in order to reduce the abrupt transient response and minimize the integrator effect in pitch axis. The result of the analysis based on HQS pilot simulation using HSWM reveals that the flight control systems are switching between two computers without any problem.

A Study on the Conversion Time to Minimize of Transient Response during Inter-Conversion between Control Laws (제어법칙 간 상호 전환 시 과도응답 최소화를 위한 전환시간에 관한 연구)

  • Kim, Chongsup
    • Journal of Aerospace System Engineering
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    • v.9 no.1
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    • pp.12-18
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    • 2015
  • The inter-conversion between different control laws in flight has a lot of risk. The SWM(Switching Mechanism) including logic and stand-by mode is designed to analyze the transient response of aircraft during inter-conversion between different control laws, based on the in-house software for non-real-time and real-time simulation. The SWM applies the fader logic of TFS(Transient Free Switch) to minimize the transient response of an aircraft during the inter-conversion, and applies the reset '0' type of the stand-by mode to prevent surface saturation due to integrator effect in the disengaged flight control law. The transition time is also important to minimize the objectionable transient response in the inter-conversion, as well as the transition control law design. This paper addresses the results of non-real-time simulation for the characteristics of transient response to different transition time to select the adequate transient time, and the real-time pilot evaluation, using SSWM(Software Switching Mechanism) and HSWM(Hardware Switching Mechanism), which is met for Level 1 flying qualities and assures safety of flight.

A Study on the Design and Validation of Switching Mechanism in Hot Bench System-Switch Mechanism Computer Environment (HBS-SWMC 환경에서의 전환장치 설계 및 검증에 관한 연구)

  • Kim, Chong-Sup;Cho, In-Je;Ahn, Jong-Min;Lee, Dong-Kyu;Park, Sang-Seon;Park, Sung-Han
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.7
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    • pp.711-719
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    • 2008
  • Although non-real time simulation and pilot based evaluations are available for the development of flight control computer prior to real flight tests, there are still many risky factors. The control law designed for prototype aircraft often leads to degraded performance from the initial design objectives, therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS(In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV(High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA(Variable stability. In flight Simulation Test Aircraft) programs. This paper addresses the concept of switching mechanism for FLCC(Flight Control Computer)-SWMC(Switching Mechanism Computer) using 1553B communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed to reduce abrupt transient and minimize the integrator effect in pitch axis control law. It hans been turned out from the pilot evaluation in real time that the aircraft is controllable during the inter-conversion process through the flight control computer, and level 1 handling qualities are guaranteed. In addition, flight safety is maintained with an acceptable transient response during aggressive maneuver performed in severe flight conditions.

Determination of halogen elements in plastics by using combustion ion chromatography (연소IC를 이용한 플라스틱 중 할로겐 물질 정량)

  • Jung, Jae Hak;Kim, Hyo Kyoung;Lee, Yang Hyoung;Lee, Lim Soo;Shin, Jong Keun;Lee, Sang Hak
    • Analytical Science and Technology
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    • v.21 no.4
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    • pp.284-295
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    • 2008
  • For plastics samples, a method using combustion ion chromatography was selected as a method for rapid low-cost analysis to test whether hazardous substances are contained or not. Using combustion ion chromatography, a verification test for F, Cl and Br compounds generated a linear calibration curve with a correlation coefficient of $r^2$ = 0.999~1.000 in the calibration range from 0.5 to 4.0 mg/kg. The detection limits were found to be 0.005~0.024 mg/kg and quantitative limits were found to be 0.014~0.073 mg/kg. The recoveries of combustion ion chromatography using certified reference material (CRM) were found to be 95.5~104.9%. Based on these results, a proficiency test was conducted together with several laboratories in and out of the country, to make comparative analysis of the results from each laboratory. As a result, the data supported the use of combustion ion chromatography as an effective analysis method to deal with regulations for halogen-free electronic products and for other hazardous substances in the electronic products.