• Title/Summary/Keyword: representing measure

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Influence of Corrosion Potential and Current Density on Polarization Curve Variations using Polycarbonate[III]

  • Park, Chil-Nam;Yang, Hyo-Kyung;Kim, Sun-Kyu;Kim, Myung-Sun;Cheong, Kyung-Hoon
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.1
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    • pp.43-50
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    • 2000
  • In this study, experiments were carried out to measure the variations in the corrosion potential and current density of polarization curves using polycarbonate. The results were particularly examined to identify the influences affecting the corrosion potential including various conditions such as temperature, pH, catalytic enzyme, and salt. The lines representing the active anodic dissolution were only slightly shifted in the potential direction by temperature, pH, enzyme, and salt. The tafel slope for the anodic dissolution was determined based on the polarization effect with various conditions. The slope of the polarization curves describing the active-to-passive transition region were noticeably shifted in direction. Also, from the variation in the conditions, the optimum conditions were established for the most rapid transformation, including temperature, pH, corrosion rate, and resistance of corrosion potential. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity(Ir/If). The value of Ir/If was then used in measuring the extent of the critical corrosion sensitivity of the polycarbonate. The potentiodynamic parameters of the corrosion were obtained using a Tafel plot.

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Spectrum Representation Based on LPC Cepstral VQ for Low Bit Rate CELP Coder (LPC Cepstral 벡터 양자화에 의한 저 전송율 CELP 음성부호기의 스펙트럼 표기)

  • 정재호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.761-771
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    • 1994
  • This paper focuses on how spectrum information can be represented efficiently in a very low bit rate CELP speech coder. To achieve the goal, an LPC cepstral coefficients VQ scheme representing the spectrum information in a CELP coder is proposed. To represent the spectrum information using LPC cepstrums, three different cepstral distance measures having different spectral meanings in the frequency domain are considered, and their performances are compared and analyzed. The experimental results show that spectrum information in low bit rate CELP coders can be represented very efficiently using the proposed LPC cepstral vector quantization scheme.

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A Case Study on Design Characteristics of Museums in Jeju - Focused on Landscape Management Guideline of Jeju Special Self-governing Province - (제주지역 박물관의 의장적 특징에 관한 사례연구 -제주특별자치도 경관관리지침을 중심으로-)

  • Park, Chung-Keun
    • Journal of the Korean Institute of Rural Architecture
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    • v.15 no.1
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    • pp.47-56
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    • 2013
  • As architecture has a role of vessel that contains human life, architecture of museums in a region must be a vessel that contains identity of the region. Jeju Province possesses excellent natural landscape acknowledged by the world. As such, architectural design of museums in Jeju region, differentiated in terms of natural, humanistic and cultural characteristics from other regions, must include identity of Jeju. Jeju has established and is operating so many museums with different themes that it is referred to as the heaven of museums. In addition, museums as cultural facilities must be the measure of cultural level representing regional identity and perform the role of advance guard that leads architectural culture of the region. Also, such excellent architectural asset is an important landscape element that increases value of the region. Based on Landscape Management Guideline established in 2009 by Jeju Special Self-governing Province under such critical mind, this study will support design problems and improvements of museums through case study and analysis on design characteristics of national and private museums in Jeju. Accordingly, the purpose of this study is to provide basic data to be pursued by future museums that contain identity of Jeju, based upon the results of analysis described above.

Effects of Strong Wind at Heading Stage on Glume Development and Yield Components of Rice (벼 출수기 강풍이 영화발육과 수량형질에 미치는 영향)

  • 최상진
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.3
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    • pp.219-225
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    • 1981
  • Strong wind of 6.5m/s from electric fan was applied to rice at heading stage to find out the nature of wind damage to panicle. Damaged panicles caused by typhoon were sampled out of field to measure the yield and milling components. Wind-treated glumes were developed into two forms, fertile and sterile, and each of them showed all degree of glume discoloration. The number of fertile grains were higher than sterile grains in a damaged panicle. Averagesdegree of glume discoloration was higher in not flowered glume than in flowered glume. The more recently flowered glumes resulted the higher degree of discoloration among flowered glume. The percent of sterile grain to total number of grains was the highest at stage of just flowering. The glume discoloration representing wind damage at heading state advanced in degree in ten days after treatment compared to that just after treatment. Grain length and grain width were decreased with the increased degree of glume discoloration, while grain thickness was not changed greatly. Chalkiness was a little higher in damaged grain than in normal grain without definite trends by degree of discoloration. Ripening ratio, 1000 grain weight and yield decreased with increased degree of glume discoloration in damaged panicle by typhoon. Decreasing order in yield was white rice, rough rice and brown rice. Ratio of brown rice to rough rice increased, white rice to brown rice decreased, and milling recovery was not changed greatly with increased degree of 히ume discoloration.

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The effect of slide presentation of representative cultural space to enhance students' cultural discriminating abilities - focusing on oriental latticeworks - (디자인의 문화적 특성 판별력을 향상시키기 위한 시각교재의 효과 - 동양의 창살을 중심으로 -)

  • 김경숙;이연숙;정현원;심재희;박지연;김연정
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 1999.04a
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    • pp.75-78
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    • 1999
  • The purpose of the study wast to determine the effect of slides exposure of different cultural architecture and interiors on students discriminating abilities of cultural differences among China, Japan, and Korea. Pre-test post-test experimental design was used. To measure students cultural discriminating abilities, a scale of 48 graphic items representing latticeworks of 3 countries was designed. For the treatment, 20 pictures showing representative architecture and interior spaces of each country thereby a total of 60 slides was selected. Subjects were 118 undergraduate students majoring in interior design. After measuring students' critical ability, the slide images were shown in country's order without explanation. After the exposure, post measures with the same instruments were done. To find the statistically significant difference, paired t-test was used. result indicated that the slide exposure have direct and positive influence on students cultural discriminating abilities. Therefore the model can be efficiently used in the educational setting to give student experience of cultural diversity.

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Part-time Jobs of Korean Married Women -The recent change in their state dependence- (기혼여성 시간제일자리의 상태의존성(state dependence) 변화)

  • Chung, Min Su
    • Journal of Labour Economics
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    • v.41 no.3
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    • pp.95-128
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    • 2018
  • This study tries to measure the change in the state dependence of the three labor supply choices (part-time, full-time, and the state of unemployed) in Korean married women's labor market by estimating the dynamic multinomial logit model based on MSL (maximum simulated likelihood) method. A component representing individual's unobserved characteristics has been introduced, because it is crucial to control for unobserved heterogeneity in assessing the state dependence. Estimation results show that the state dependences of the three alternatives have strengthened recently. Therefore, part-time job has become more likely to be functioning as an extra option to participate in labor market rather than a bridge(stepping stone) or shelter between unemployment and full-time job.

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Characteristics of Turbulent Nonpremixed Jet Flame in Cross Air Flow (주유동에 수직으로 분사되는 난류 비예혼합 분류 화염의 특성)

  • Lee, Kee-Man;Park, Jeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.1
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    • pp.125-132
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    • 2002
  • An experimental study on the characteristics of stability of propane turbulent nonpremixed jet flames discharged normal to air free-streams with uniform velocity profile is conducted. Experimental observations are focused on the flame shape, the stability considering two kinds of flame, lift-off distance, and the flame length according to velocity ratio. In order to investigate the mixing structure of the flame base at the lower limit, we employ the RMS technique and measure the species concentration by a gas chromatography. In the results of the stability curve and lifted flame, it is fecund that the dependency of nozzle diameter is closely related to the large-scale vortical structure representing counter-rotating vortices pair. Also, the detailed discussion on the phenomenon of blowout due to this large vortical motion, is provided.

Active Vibration Control of A Time-Varying Cantilever Beam Using Band Pass Filters and Artificial Neural Network (신경회로망과 능동대역필터를 이용한 시변 외팔보 능동 진동제어)

  • Hamm, Gil;Rhee, Huinam;Yoon, Doo Byung;Han, Soon Woo;Park, Jin Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.353-354
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    • 2014
  • An active vibration control technique of a time-varying cantilever beam is proposed in this study. A simple in-house coil sensor instead of expensive commercial sensors was used to measure the vibrational displacement of the beam. Active band pass filters and artificial neutral net works detect the frequencies, amplitudes, and phases of the main vibration mode. The time constants of the low pass filter representing the positive position feedback controller are updated in real-time, which generates the control voltage input to actuate the piezoelectric actuator and suppress the vibration. An experiment was successfully performed to verify the algorithm for a cantilever beam, which fundamental natural frequency arbitrarily varies between 9 Hz ~ 18 Hz. The present active vibration suppression technique can be applied to variety of structures which undergoes large variation of dynamic characteristics while operating.

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Condition Parameter-based On-line Performance Reliability (상태 파라메터 기반의 온라인 성능 신뢰도)

  • Kim, Yon-Soo;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.3
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    • pp.103-108
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    • 2007
  • This paper presents the conceptual framework for estimating and predicting system's susceptibility to failure as function of condition parameter value which is representing the current status of performance measure using on-line performance reliability. The performance of such system depends on one parameter with a probability distribution that degrades with time gracefully. Performance reliability represents the probability that physical performance will remain satisfactory over a finite period of time or usage cycles in the future. An empirical physical performance function is constructed to incorporate explanatory variables (operating and environmental conditions) over a time or usage dimension. This function enables one to model device performance and the associated classical reliability measures simultaneously, in the performance domain and time domain. The conditional performance reliability structure developed represents a tool to predict system performance over time or usage for next usage period. By enabling such a framework, it can bring us more efficient planning and execution in system's operation control as well as maintenance to reduce costs and/or increase profits.

Wear Comfort of Double Jersey for Sports Wear (이중양면편 스포츠용 소재의 착용쾌적성 평가)

  • Jeong, Su-Kyung;Hong, Kyung-Hi
    • Korean Journal of Human Ecology
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    • v.12 no.2
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    • pp.253-263
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    • 2003
  • The purposes of this study were to find out an evaluation scale that could predict wear comfort and to investigate the effect of the skin-contacting fiber type on the subjective sensation and microclimate. Sensorial evaluation was basically followed by the Human Perception Analysis (HPA) interviewing 144 consumers. Sixteen female subjects were participated in the sleeve wear test with and without wearing vapor permeable water repellent outerwear. Experimental sleeves were constructed using the same double knit by turning inside out to control other material effects except the skin-contacting fiber type, hence each different side of double knit, cotton side and the cotton/polypropylene blend side, was next to skin in each trial of the experiment. As results, it was noted that the term representing a combined feeling of thermal and wetness sensation, and muggy appeared to be a powerful language to measure perceptual responses of human subject among five dimensions of evaluation. although the ordinary users did not use the term very often. As for the comfort properties of double knits, it seemed that subjects slightly more preferred polypropylene/cotton blend to cotton as the skin-contacting fiber type when they wore outerwear and their skin were covered with sweat, although the result was rot statistically significant and need to be confirmed under higher work load.

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