• Title/Summary/Keyword: Short-term irregularity

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Characterizing Yarn Thickness Variation by Correlograms

  • Huh You;Kim Jong S.;Kim Sung H.;Suh M. W.
    • Fibers and Polymers
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    • v.6 no.1
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    • pp.66-71
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    • 2005
  • The surface evenness and texture are closely related with the irregularity of yam thickness. Besides, yam thickness variation has an important role to influence the yam performance and the textile process efficiency. Thus, the information not only on the yam thickness, but also on the short- term irregular characteristics that have not been known before is required for enhancing the qualities of textile products. This paper reports the results of a study about the yam thickness and its variation for various types of yam on the basis of a new measurement system applying a laser slit beam as a light source. The new method delivers effective information on the irregularity. The analysis of the measured signal confirms that the visual shade created by the yam doubling and twisting can be measured and the yam thickness characteristics can be represented by corre­lograms. Depending on yam types, correlograms have different shapes and can be approximated to an exponentially decaying function with or without fluctuating magnitude. In addition, the effective information on the yam irregularity can be influ­enced by the sampling length interval of the measuring device used for tests.

Short Term Load Forecasting Algorithm for Lunar New Year's Day

  • Song, Kyung-Bin;Park, Jeong-Do;Park, Rae-Jun
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.591-598
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    • 2018
  • Short term load forecasts complexly affected by socioeconomic factors and weather variables have non-linear characteristics. Thus far, researchers have improved load forecast technologies through diverse techniques such as artificial neural networks, fuzzy theories, and statistical methods in order to enhance the accuracy of load forecasts. Short term load forecast errors for special days are relatively much higher than that of weekdays. The errors are mainly caused by the irregularity of social activities and insufficient similar past data required for constructing load forecast models. In this study, the load characteristics of Lunar New Year's Day holidays well known for the highest error occurrence holiday period are analyzed to propose a load forecast technique for Lunar New Year's Day holidays. To solve the insufficient input data problem, the similarity of the load patterns of past Lunar New Year's Day holidays having similar patterns was judged by Euclid distance. Lunar New Year's Day holidays periods for 2011-2012 were forecasted by the proposed method which shows that the proposed algorithm yields better results than the comprehensive analysis method or the knowledge-based method.

Antecedents of Consumer Participation in Sharing Economy at Distribution Markets

  • CAI, Yunwei;CHOI, Nak-Hwan
    • Journal of Distribution Science
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    • v.20 no.9
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    • pp.127-139
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    • 2022
  • Purpose: As sharing economy is becoming increasingly relevant to people's lives, we want to understand why people participate in the sharing economy. We propose and validate three factors that are likely to influence consumers' choice of participating in the sharing economy at distribution market. Also, we found antecedents that affect these variables. These antecedents include appointment and return convenient, extended operating time, variety-seeking need, usage irregularity, other's clean usage, and feeling of membership between users. Research design, data, and methodology: This research collected 341 questionnaire data from participants in China. These participants were asked about the usage of DiDi, the most popular shareware in China. The data analysis and hypothesis testing were conducted using SPSS and Amos. Results: Usage convenience, usefulness of short-term usage, and trust in other users were found to have a positive impact on consumers' intention to participate in the sharing economy. In addition, we found that all the antecedents affect these variables positively. Conclusions: This research provides new driving factors for consumer participation in the sharing economy. Moreover, these findings will help managers develop marketing strategies for inducing the consumers to participate in the sharing economy.

Effect of Exercise Training on Aging Atrophyin Rat Skeletal Muscle III. Effect of Short Term Exercise Training for Senile Rat (흰쥐 골격근의 노화성 위축에 대한 운동훈련의 영향 III.노화 흰쥐에 적용한 단기간의 운동훈련의 영향)

  • 박승한;박원학;정형재
    • Biomedical Science Letters
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    • v.2 no.1
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    • pp.91-108
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    • 1996
  • The present study was designed to examine effect of short term treadmill and weight-training on aging arophy in the rat skeletal muscle. Male rats of 24 months old were used. Each groups included control, treadmill and weight-training for 4 weeks by using treadmill apparatus and body press apparatus. The histo and cytochemical, ultrastructural and stereological changes in senile skeletal muscles of the rat were observed in the present study. During the training period the body weight and muscular weight in all groups remained constant. The volume density of muscle fiber type IIC and IIB were increased, that of type IIA was decreased, but type I remained constant in treadmill-training group. In weight-training rat, the density of type IIA and IIB were increased, both those of type IIC was decreased. But, all changes of muscle fiber type is not significant. Senile control group some usual formation of mild contraction band, liposuscin pigment and muscular splitting were observed. After treadmill-training, histological and ultrastructural changes occurred in the muscle fiber, such as irregularity of the sarcolemma, interfibrillar vacuolization, longitudinal splitting, and widened I-bond. After weight-training, the changes occurred in the trained muscle fiber, such as appearances of many lysosomes and autophagic vacuoles, severe contraction band, and breakup of myofibrils. Histo and cytochemical studies showed that the activities of succinic dehydrogenase and acid phosphatase remained constant, activities of $Mg^{++}$-ATPase decrease with training. Stereological changes were not observed in the volume and numerical density of all subject component, but the surface density of mitochondrial inner membrane was increased with treadmill-training. These experimental results suggested that endurance training during short-term may result in the adaptible response in senile skeletal muscles. On the other side, weight-training is bad for senile skeletal muscle.

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A Study on the D-InSAR Method for Micro-deformation Monitoring in Railway Facilities (철도시설물 미소변형 모니터링을 위한 D-InSAR 기법 연구)

  • Kim, Byung-Kyu;Lee, Changgil;Kim, Winter;Yoo, Mintaek;Lee, Ilhwa
    • Journal of the Korean Geotechnical Society
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    • v.38 no.11
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    • pp.43-54
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    • 2022
  • The settlement at the railroad foundation is often the leading cause of track irregularity and potential derailment. The control of such deformation is considered necessary in track maintenance practice. Nevertheless, the monitoring process performed by in situ surveying requires an excessive amount of manpower and cost. The InSAR, a remote sensing technique by RADAR satellite, is used to overcome such a burden. The PS-InSAR technique is preferred for a long-term precise monitoring method. However, this study aims to obtain relatively brief analysis results from only two satellite images using the D-InSAR technique, while a minimum of 25 images are required for PS-InSAR. This study verifies the precision of D-InSAR within a few millimeters by inspecting railroad facilities and land settlements in Korea Railroad Research Institute's test track with images from TerraSAR-X Satellite. Multiple corner reflectors were adopted and installed on an embankment and the building roof to raise the surface reflectivity. Those reflectors were slightly adjusted periodically to verify the detecting performance. The results revealed the optimum distance between corner reflectors. Further, the deformation of railway tracks, slopes, and concrete structures was analyzed successively. In conclusion, this study indicates that the D-InSAR technique effectively monitors the short-term deformation of a broad area such as railway structures.