• Title/Summary/Keyword: Response performance

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The Effects of Air Injection in Compressor Exit on the Response Performance of a Turbocharged Diesel Engine under the Operating Conditions of Rapid Acceleration. (터보과급디젤기관의 급가속 운전시 압축기출구에의 공기분사가 응답성능에 미치는 영향)

  • 박상규;최낙정
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.6
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    • pp.110-119
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    • 2000
  • In this paper, an experimental study is carried out under the operating conditions of low speed and rapid acceleration in order to investigate and improve the response characteristics of a turbocharged diesel engine with radial turbine driven by exhaust gas. A rapid acceleration for investigating the response performance is applied to the fuel-pump rack of the engine from 0-10% to 0-40% in steps of 10%, and accelerating time of 1, 2 and 3 seconds is applied to the engine. Further experiment for improving the low speed torque and acceleration performance is also performed by means of injecting air into the inlet manifold at compressor exit during the period of low speed and application of a rapid acceleration. The effects of air injection on the response performance are represented at subjected engine speed with the changes of response performance factors such as air injection pressure, air injection period, accelerating rate, accelerating time and load. From the experimental results obtained throughout this study, it is shown that air injection into the inlet manifold at compressor exit is closely related to the improvement of low speed and acceleration performance of a turbocharged diesel engine.

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Effect of Apartment Residents' Safety Awareness on Fire Response Performance: Focusing on the Moderating Effect of Control Offices' Control Competence (아파트 거주자의 안전의식이 화재대응성과에 미치는 영향 : 관리사무소의 관리역량 조절효과를 중심으로)

  • Kim, Jong-Nam;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.1
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    • pp.43-53
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    • 2020
  • The purpose of this study is to reduce the anxiety factors of fires by following evacuation tips in case of fire in an apartment household. This study analyzed the moderating effects of the control offices' competence in control on safety awareness and fire response. The study results were as follows. First, the residents and control staff's safety awareness had a positive effect on the fire response performance. This indicates that the higher the residents and control staff's safety awareness level, the higher the fire responsive performance. Second, the higher the control offices' control competence level, the better the apartment residents and control staff's safety awareness had a positive effect on the fire response performance. These results indicate that the higher the control office heads' leadership, the higher the apartment residents' housing satisfaction and that the more communicative the control office heads' attitude toward the residents, the better their attitude had a positive effect on the fire response performance. Lastly, the control offices' control competence was analyzed to have a moderating effects on the effect of the apartment residents and control staff's safety awareness level on the fire response performance. These results showed that the change in the model's R2 value showed an increasing trend in stages as the value increased more in the stage 2 than the stage 1 and even more in the stage 3 with the interaction terms of the moderating variables added. For this reason, the control offices' control competence which was a moderating variable was analyzed to have a moderating effect on the effect of residents and control staff's safety awareness level on the fire response performance.

A Study on the Design of Compensated Fuzzy Controller (보상형 퍼지 제어기 설계에 관한 연구)

  • 추연규;탁한호
    • Journal of the Korean Institute of Navigation
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    • v.24 no.3
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    • pp.141-145
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    • 2000
  • In servo-system which need fast response and accuracy, PID controller has a good steady-state performance, but has a poor transient response performance causing a load be changed. Compared to these features, FLC(Fuzzy Logic Controller) has a good transient response performance for changed load, but has a little Poor steady-state performance. In this paper, Compensated Fuzay Controller which consists of PID controller and FLC is proposed to modify these disadvantages and is examined through simulation to evaluate its functions.

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Simulation Study for the Performance Improvement of the Injector Module for Heavy-duty CNG Engines (대형 CNG 엔진용 인젝터 모듈의 성능 개선을 위한 연구)

  • Kim, Yong-Rae;Park, Won-A;Kim, Chang-Gi;Lee, Jang-Hee
    • Journal of the Korean Institute of Gas
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    • v.20 no.4
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    • pp.1-6
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    • 2016
  • A fuel supply system of heavy-duty CNG engine is composed as a module structure which is integrated by about 6 injectors. There are only one input and output passage for gas fuel supply in this injector module. The response performance for transient operation of an CNG engine is very poor because only one output fuel supply line is connected to the intake pipe after a throttle valve. In this study, a new guideline and internal flow design for the CNG injector module is suggested for the improvement of response performance by fluid dynamic simulations. As a result, the response performance of gas fuel supply can be improved by decreasing the total volume of internal flow passages and a same distance design from each injector to the exit of module shows good response performance and acquirement of linearity of fuel supply. But the injection order has little influence to injection performances.

An Experimental Study on the Improvement of Turbocharger Lag by Means of Air Injection in a Turbocharged Diesel Engine

  • Choi, Nag-Jung;Oh, Seong-Mo
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.7
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    • pp.951-962
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    • 2010
  • An experimental study was performed to investigate the improvement of response performance of a turbocharged diesel engine under the operating conditions of low speed and fast acceleration. In this study, the experiment for improving the low speed and acceleration performance is performed by means of injecting air into the intake manifold of compressor exit during the period of low speed and application of a fast acceleration from low speed. The effects of air injection into the intake manifold on the response performance were investigated at various applicant parameters such as air injection pressure, accelerating rate, accelerating time, engine speed and load. The experimental results show that air injection into the intake manifold at compressor exit is closely related to the improvement of turbocharger lag under low speed and accelerating conditions of a turbocharged diesel engine. During the rapid acceleration period, the air injection into the intake manifold of turbocharged diesel engine indicates the improvement of the combustion characteristics and gas pressure in the cylinder. At low speed range of the engine, the effect of air injection shows the improvement of the pressure distribution of turbocharger and combustion pressure during the period of gas exchange pressure.

Sweet Area Determination by Performance Sensitivity Analysis for an Automotive Vehicle Suspension (자동차용 현가장치의 성능감도해석에 의한 안정승차영역의 결정)

  • Park, Ho;Hahn, Chang-Su;Kim, Byeong-Woo;Kim, Dong-Gyu
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.1
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    • pp.92-100
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    • 2003
  • Using a quarter car model, an analytic method for performance estimation of a vehicle suspension system with respect to frequency response, RMS response and performance index is presented. From frequency response function, compromization of response performance to the whole frequency range is verified and from RMS response and performance index, sensitivity of ride md handling characteristics are examined. Using a full car model, sweet area(stable ride area) are determined and performance sensitivity is estimated according to the change of feedback gains. In order to esimate the output sensitivity, response we is displayed using a 3-dimensional contour plot. Design data n suggested for optimal design parameter esimation, which maximize the performance of the given suspension system.

Verification and Improvement of Structural Behavior Response Performance Evaluation Method for the Standard Establishment of Adhesive Composite Waterproofing Sheets (점착형 복합 방수시트의 표준(안)제정을 위한 구조물 거동대응성능 시험방법 개선 및 검증 평가 연구)

  • Kim, Soo-Yeon;Park, Jong-Sun;Oh, Sang-Keun
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.4
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    • pp.377-386
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    • 2021
  • In April 2019, this study was enacted as a test method for the performance of waterproof layers in an environment where complex deterioration and structural behavior are simultaneously applied, but some existing standards were implemented to point out the errors of the method that should be supplemented. Thus, in establishing standards for (tentative) adhesive waterproofing sheets, field workability and quantification of test results were studied on the structural behavior response performance test methods included as test items. In addition, the performance evaluation of adhesive-type composite waterproof sheets was conducted based on the considered contents to review improvements such as applicability as an item of standard standards and field workability related problems.

Pulse-width Adjustment Strategy for Improving the Dynamic Inductor Current Response Performance of a Novel Bidirectional DC-DC Boost Converter

  • Li, Mingyue;Yan, Peimin
    • Journal of Power Electronics
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    • v.18 no.1
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    • pp.34-44
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    • 2018
  • This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC-DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.

Stress-strain Analysis of Waterproof Layer through Behavioral Response Performance Test (거동대응성능 시험을 통한 방수층의 응력-변형률 분석 연구)

  • Song, Je-Young;Jung, Suk-Joo;Seo, Hyun-Jae;Lee, Jung-Hun;Kim, Byoungil;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.92-93
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    • 2020
  • The test method to be developed is to determine whether the waterproof layer applied to the leak-prone part such as cracks and joints has defects such as tearing or lifting of the waterproof layer due to the influence generated from the behavior of the structure under complex deterioration conditions. This is to evaluate the performance of the waterproofing method afterwards. Therefore, by notifying only the pass or fail, the unique mechanical properties of the material or method used are notified to the test client to limit the physical properties of the test body, thereby determining and supplementing the weaknesses of the user material in advance to improve the high quality. We want to prevent damage from water leakage through production and distribution of materials.

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Dynamic response of railway vehicles under unsteady aerodynamic forces caused by local landforms

  • Chen, Zhengwei;Liu, Tanghong;Li, Ming;Yu, Miao;Lu, Zhaijun;Liu, Dongrun
    • Wind and Structures
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    • v.29 no.3
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    • pp.149-161
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    • 2019
  • When a railway vehicle runs in crosswinds, the unsteady aerodynamic forces acting on the train induced by the vehicle speed, crosswind velocity and local landforms are a common problem. To investigate the dynamic performance of a railway vehicle due to the influence of unsteady aerodynamic forces caused by local landforms, a vehicle aerodynamic model and vehicle dynamic model were established. Then, a wind-loaded vehicle system model was presented and validated. Based on the wind-loaded vehicle system model, the dynamic response performance of the vehicle, including safety indexes and vibration characteristics, was examined in detail. Finally, the effects of the crosswind velocity and vehicle speed on the dynamic response performance of the vehicle system were analyzed and compared.