• 제목/요약/키워드: Stability and Consistency

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ECAM Control System Based on Auto-tuning PID Velocity Controller with Disturbance Observer and Velocity Compensator

  • Tran, Quang-Vinh;Kim, Won-Ho;Shin, Jin-Ho;Baek, Woon-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.2
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    • pp.113-118
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    • 2010
  • This paper proposed an ECAM (Electronic cam) control system which has simple and general structure. The proposed cam controller adopted the linear and polynomial curve-fitting method to generates a smooth cam profile curve function. Smooth motion trajectory of master actuator guarantees the good performance of slave motion and has an important effect on the interpolation quality of ECAM. The auto-tuning PID velocity controller was applied to overcome the uncertainties in ECAM, and the gains of the controller are updated continuously to ensure the consistency of system performance under varying working conditions. The robustness of system against the varying load torque disturbances and noises is guaranteed by using the load torque disturbance observer to suppress the disturbance on master actuator. The velocity compensator was applied to compensate the degradation of performance of slave motion caused from the varying driving speed of master motion. The stability and validity of the proposed ECAM control system was verified by simulation results.

Development of Premarital Preparation Evaluation Scale (결혼준비도 척도 개발 연구-기혼 남.녀를 중심으로)

  • 김혜선;신수아
    • Journal of the Korean Home Economics Association
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    • v.40 no.3
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    • pp.41-53
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    • 2002
  • The purpose of this study was to develop a scale for evaluation of premarital preparation. The subjects were 412 married couples(196 males and 216 females) who had been married for 1-37ears. They were selected from Seoul, Incheon, Daejeon, Gwangju, Pusan, and DaeGu. The questionnaire was composed of 82 items. The data was analyzed by frequencies, percentages, factor analysis, Pearson's r, and Cronbach'$\alpha$. The major findings were as followings; 1. The 54 items of 82 items scale were selected through item discriminant method. The discriminant coefficients of the items(Cromer's V ranged from .33 to .68. 2. The 7 factors that were extracted from the factor analysis explained 42% of premarital preparation. The subscales were labelled as rearing child$.$financial management role division, maturity, understanding each other$.$love$.$sex, views about marriage, understanding his/her family and friends, capacity of communication and conflict resolution, and independence from parents. The criterion validity of this scale was assessed by the correlation between this premarital preparation scale and marital stability. All coefficients were significant(ranged from r=.10 to .44, p<.01, p<.001). 3. The internal consistency of this scale was acceptable(Cronbach's $\alpha$=.91).

Design of a Smart Gas Sensor System for Room Air-Cleaner of Automobile (Thick-Film Metal Oxide Semiconductor Gas Sensor)

  • Kim, Jung-Yoon;Shin, Tae-Zi;Yang, Myung-Kook
    • Journal of Electrical Engineering and Technology
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    • v.2 no.3
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    • pp.408-412
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    • 2007
  • It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

Studies on Rheological Properties of Weak Flour Containing Mulberry Powder (오디가루를 첨가한 소맥분의 유변학적 특성)

  • Park, Hayag-Mi;Kang, Kun-Og;Lee, Hyun-Joo
    • The Korean Journal of Community Living Science
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    • v.23 no.1
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    • pp.51-59
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    • 2012
  • This study was conducted to investigate the rheological properties of mulberry powder on the weak flour using color, Rapid Visco Amalyzer(RVA), farinogram, alveogram. The lightness(L value) and yellowness(b value) decreased and the redness(a value) increased with increment of mulberry powder content. On the RVA data, the weak flour with 1% of mulberry powder showed the highest initial pasting temperature and peak viscosity, while the addition of mulberry powder reduced final viscosity. On the farinogram data, the consistency of the flour containing mulberry powder was decreased with increments of mulberry powder. This meant that mulberry powder could weaken the batter. Water absorption of the samples with mulberry powder was decreased more than the control. The development time of flour with mulberry powder was also decreased more than control, but the differences were not significant. The stability of the flour with adding mulberry powder was decreased. The Pmax value of the flour was decreased significantly by adding mulberry powder. Extensibility and swelling index were both increased, but there were no significant differences.

Rheological Properties of Exopolysaccharide Produced by Xanthomonas sp. EPS-1 (Xanthomonas sp. EPS-1이 생산하는 다당류의 리올로지 특성)

  • Son, Bong-Soo;Park, Seok-Kyu;Kang, Shin-Kwon;Lee, Sang-Won;Sung, Nack-Kie
    • Microbiology and Biotechnology Letters
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    • v.23 no.3
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    • pp.269-274
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    • 1995
  • For the screening of a new functional exopolysaccharide, sugar composition and rheological properties of exopolysaccharide produced from Xanthomonas sp. EPS-1 were investigated. The average molecular weight of exopolysaccharide was determined to be approximately 2.l $\times$ 10$^{6}$ dalton. The new exopolysaccharide EPS-1 was composed of mannose, glucose, galactose and gluco- samine. IR analysis showed that the exopolysaccharide EPS-1 was assumed to be polymer with carbohydrates. NMR analysis showed that exopolysaccharide EPS-1 was presumed to be 4 units of sugar and trace of CH$_{3}$ group. Exopolysaccharide EPS-1 solution showed a characteristic of non-Newtonian fluid properties. At the concentration of 1.0%, the consistency index and the flow behavior index were shown at 10.8352 poise-sec and 0.4419, respectively. All dispersions were pseudoplastic fluids described accurately by Power-law model. Exopolysaccharide EPS-1 was highly viscous at low concentration, with good stability over a wide range of pH 5 to 13. The excellent compatibility of exopolysaccharide EPS-1 was represented with salts such as sodium chloride.

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Design and Implementation of Web-based Monitoring System for an EAI Environment (EAI 환경에서의 웹기반 모니터링 시스템의 설계와 구현)

  • Ha, Eun-Ok;Kim, Yoon-Ho
    • The Journal of Society for e-Business Studies
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    • v.14 no.3
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    • pp.1-13
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    • 2009
  • EAI(Enterprise Application Integration) as an infrastructure of application integration had played an important role for many companies to make epochal changes, expense reduction, and new application services. The continuous monitoring and management of data covering whole environment of system operations should be well-supported so that the data consistency and system stability are guaranteed to implement and operate the services effectively. In this paper, the requirements and functions of monitoring system are defined for the stable EAI service. An actual web-based system is designed and implemented. This web-based monitoring system is broadly applicable to general EAI environments.

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Synthesis and Light-Emitting Properties of Zinc Chelate Compounds (아연 킬레이트 화합물의 합성 및 전계발광 특성)

  • Kim, Hong-Soo;Nam, Ki-Dae;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.18 no.4
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    • pp.292-297
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    • 2001
  • Zinc complexes with Bis[2-(o-hydroxyphenyl) benzothiazolato ligands (ZnPBS-0) and Bis[2- (o-hydroxynaphthyl) benzothiazolato ligands (ZnPBS-05) were synthesized, and luminescent properties of these materials were investigated. The emission band found that it strongly depends on the molecular structure of introduced ligand and was tuned from 525 nm to 535 nm by changing the ligand structures. Spreading of the ${\pi}-conjugation$ in 2-(o-hydroxyphenyl) group gives rise to a blue shift. On the other hand, spreading of the ${\pi}-conjugation$ in benzothiazole groups leads to a red shift. The EL properties also showed good consistency with their differences of ligand structure. Bright-blue EL emission with a maximum luminance of 8300 $cd/m^{2}$ at 11V was obtained from the organic light - emitting diodes (OLEDs) using ZnPBS-0 as emitting layer. It was also found that the newly synthesized materials were suitable to be used as emitting materials in organic EL device.

Affecting Factors on the Variation of Atmospheric Concentration of Polycyclic Aromatic Hydrocarbons in Central London

  • Baek, Sung-Ok;Roger Perry
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.E
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    • pp.343-356
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    • 1994
  • In this study, a statistical investigation was carried out for the evaluation of any relationship between polycyclic aromatic hydrocarbons (PAHss) associated with ambient aerosols and other air quality parameters under varying meteorological conditions. Daily measurements for PAHs and air quality/meteorological parameters were selected from a data-base constructed by a comprehensive air monitoring in London during 1985-1987. Correlation coefficients were calculated to examine any significant relationship between the PAHs and other individual variables. Statistical analysis was further Performed for the air quality/meteorological data set using a principal component analysis to derive important factors inherent in the interactions among the variables. A total of six components were identified, representing vehicle emission, photochemical activity/volatilization, space heating, atmospheric humidity, atmospheric stability, and wet deposition. It was found from a stepwise multiple regression analysis that the vehicle emission component is overall the most important factor contributing to the variability of PAHs concentrations at the monitoring site. The photochemical activity/volatilzation component appeared to be also an important factor particularly for the lower molecular weight PAHs. In general, the space heating component was found to be next important factor, while the contributions of other three components to the variance of each PAHs did not appear to be as much important as the first three components in most cases. However, a consistency for these components in their negative correlations with PAHs data was found, indicating their roles in the depletion of PAHs concentrations in the urban atmosphere.

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Light-Emitting Properties of Organic Electroluminescent Devices using Zinc Complexes (아연 착체를 이용한 유기 EL 소자의 전계발광 특성)

  • Kim, Hong-Soo;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.4
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    • pp.316-323
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    • 2003
  • Zinc complexes with bis[2-(o-hydroxyphenyl) naphtol [1,2] oxazolato ligands (ZnPBO-4) and its derivatives (ZnPBO-S) were synthesized, and luminescent properties of these materials were investigated. Both the fluorescent emission band and electroluminescent emission band were discussed based on their ligand structure differences. The emission band found that it strongly depends on the molecular structure of introduced ligand. It was tuned from 446 nm to 491 nm by changing the ligand structures. Spreading of the ${\pi}$-conjugation in 2-(o-hydroxyphenyl) group gives rise to a blue shift. The EL properties also showed good consistency with their differences of ligand structure. Bright-blue EL emission with a maximum luminance of 3,100 $cd/m^2$ at 12V, current density, 575 $mA/m^2$ was obtained from the organic light-emitting diodes (OLEDs) using ZnPBO-4 as emitting layer. It was also found that the newly synthesized materials were suitable to be used as emitting materials in organic EL device.

Time-series Analysis of Geodetic Reference Frame Aligned to International Terrestrial Reference Frame

  • Bae, Tae-Suk;Hong, Chang-Ki;Lee, Jisun;Altamimi, Zuheir;Sillard, Patrick;Boucher, Claude
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.5
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    • pp.313-319
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    • 2021
  • The national geodetic reference frame of Korea was adopted in 2003, which is referenced to ITRF (International Terrestrial Reference Frame) 2000 at the epoch of January 1, 2002. For precise positioning based on the satellites, it should be thoroughly maintained to the newest global reference frame. Other than plate tectonic motion, there are significant events or changes such as earthquakes, antenna replacement, PSD (Post-Seismic Deformation), seasonal variation etc. We processed three years of GNSS (Global Navigation Satellite System) data(60 NGII CORS stations, 51 IGS core stations) to produce daily solutions minimally constrained to ITRF. From the time series of daily solutions, the sites with unexpected discontinuity were identified to set up an event(mostly antenna replacement). The combined solution with minimum constraints was estimated along with the velocity, the offsets, and the periodic signals. The residuals show that the surrounding environment also affects the time series to a certain degree, thus it should be improved eventually. The transformation parameters to ITRF2014 were calculated with stability and consistency, which means the national geodetic reference frame is properly aligned to the global reference frame.