• Title/Summary/Keyword: Change point

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A Study on Thermo-Physical Properties of Microencapsulated Phase Change Material Slurry (마이크로캡슐 잠열 축열재 혼합수의 열물성에 관한 연구)

  • 임재근;최순열;김명준
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.962-971
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    • 2004
  • This paper has dealt with thermo-physical properties of microencapsulated phase change material slurry as a latent heat storage material having a low melting point. The measured results of the thermo-physical properties of the test microencapsulated phase change material slurry, those are, density, specific heat, thermal conductivity and viscosity, were discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). The measurements of these properties of microencapsulated phase change material slurry have been carried out by using a specific-gravity meter, a water calorimeter, a differential scanning calorimeter(DSC), a transient hot wire method and rotating type viscometer, respectively. It was clarified that the additional properties law could be applied to the estimation of the density and specific heat of microencapsulated phase change material slurry and also the Euckens equation could be applied to the estimation of the thermal conductivity of this slurry.

Current Issues on Climate Change and Water (기후변화의 쟁점과 물)

  • Yun, Zuwhan
    • Journal of Korean Society on Water Environment
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    • v.25 no.5
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    • pp.641-650
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    • 2009
  • The IPCC's standing on the anthropogenic warming is discussed in this article. The differences between the climate alarmist and skeptics have been addressed in terms of scientific and policy stand point of view. The political and economical significances of climate change have been discussed, too. Although atmospheric temperature and rainfall precipitation are two most important factors in the climate change, most of the recent attentions have drawn on mainly temperature and $CO_2$ issue. In spite of argues on the uncertainty in anthropogenic warming related to $CO_2$, the inevitable climate change should correspondingly change the humanity in near feature.

A Study on the Incroyables and Merveilleuses Costume after the French Revolution (프랑스혁명 이후의 Incroyables와 Merveilleuses 복식에 대한 연구)

  • 이유경
    • The Research Journal of the Costume Culture
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    • v.12 no.3
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    • pp.429-440
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    • 2004
  • The age after the French Revolution was the period of experiment and change in dress for both men and women. Directly after the close of the Reign of Terror, Directoire(1795-1799) became the extreme fashion known as incroyables and merveilleuses which mean 'impossible' or 'unimaginable'. This study aimed to investigate the sociocultural phenomena which affect to clothing change through the French Revolution period and clothing analysis of incroyables and merveillues. Furthermore, this study will contribute to establishing the theory of clothing culture and help predicting clothing change in accordance with social circumstances. Incroyables and merveilleuses represent extreme opposites in sleekness of attire and grooming. Incroyables required an unkempt, wrinkled appearance and a contrived carelessness. Merveilleuseses show the exaggerated transparency and simplicity in the fashions of female. Also, they devoted to the worship of the antique and the masculine fashions. This fashion madness appeared as the result of revolutionary social change. Their costume showed characteristics of the transition period between French Revolution and Classic period. However, they simply carried existing tendencies to the point of caricature by an enthusiastic overstatement.

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Analysis of Phase Change Materials for Production of Changable Mold for Free-form Concrete Segment (FCS 가변형 몰드 생산을 위한 PCM 분석)

  • Lee, Donghoon;Kim, Sunkuk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.150-151
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    • 2014
  • A mold of free-form concrete segment can be used only one time. Thus, the construction duration and cost are increased. The materials of the mold such as wood and metal have limitations due to the implementation and reuse. The review of the material of the mold for free-form concrete segment is needed to reduce duration and production cost. Phase change material can be used both to implement free-shape by heating and to produce mold after cooling. After using Phase change material can be re-used to mold by heating. The scope of this study is many kind of phase change materials for molding. The aim of this study is to analyze the phase change materials for production of changable mold for free-form concrete segment. In this study, the paraffin wax that is melted at 64℃ was selected by considering both the energy efficiency and the weather of Korea.

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Speaker Change Detection by Normalization of Phonetic Characteristics (음소 특성 정규화를 통한 화자 변화 검출)

  • Kim Hyung Soon;Park Hae Young;Park Sun Young
    • MALSORI
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    • no.47
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    • pp.97-107
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    • 2003
  • Speaker change detection is to detect automatically a point of time at which speaker was replaced. Since feature parameters used for speaker change detection depend not only on speaker characteristics but also on phonetic characteristics, spoken contents included in the feature parameters inevitably causes performance degradation of speaker change detection. In this paper, to alleviate this problem, a method to normalize phonetic variations in speech feature parameters is proposed for emphasizing changes due to speaker characteristics. Experimental results show that the proposed method improves the performance of speaker change detection.

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Time Series Models for Daily Exchange Rate Data (일별 환율데이터에 대한 시계열 모형 적합 및 비교분석)

  • Kim, Bomi;Kim, Jaehee
    • The Korean Journal of Applied Statistics
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    • v.26 no.1
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    • pp.1-14
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    • 2013
  • ARIMA and ARIMA+IGARCH models are fitted and compared for daily Korean won/US dollar exchange rate data over 17 years. A linear structural change model and an autoregressive structural change model are fitted for multiple change-point estimation since there seems to be structural change with this data.

A Study on the Change of Urban Spatial Structure and Transformation of circumjacent Lot by Course of the Construction of Railroads and the Dismantlement of Eupseong in the Early 20th Century (20세기 초 철도부설과 읍성해체에 따른 도시공간구조와 주변 필지 변화에 관한 연구)

  • Kim, Dae-Jung;Cho, Jae-Mo
    • Journal of architectural history
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    • v.28 no.2
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    • pp.31-40
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    • 2019
  • Considering the situation in the early 20th century when the existing urban system centered on urban areas began to change, the biggest factors causing urban structural changes in urban areas are construction of railroad and urban dismantling. The change process of Eupseong, in the microscopic viewpoint, can be understood as a process of change in the course of dismantlement of town's demarcation, improvement of accessibility and urban expansion due to the construction of railroads, process of urban expansion following the crumbling boundaries and structural changes. This study aimed to look at the transformation process of the Eupseong in the early 20th century, focusing on the demolition of the castle and the railway construction from a microscopic point of view of city.

Quantitative separation of impacting factors to runoff variation using hydrological model and hydrological sensitivity analysis (수문모형과 수문학적 민감도분석을 이용한 유량변동 요인의 정량적 분리)

  • Kim, Hyeong Bae;Kim, Sang Ug;Lee, Cheol-Eung
    • Journal of Korea Water Resources Association
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    • v.50 no.3
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    • pp.139-153
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    • 2017
  • The variation in runoff due to global climate change and urbanization should be identified quantitatively because these two factors have been significantly accelerated during the last three decades in South Korea. However, only a few research to analyze the impacts due to two factors over different time scales can be found. Therefore, in this study, the hydrological model based approach and the hydrological sensitivity approach were used to separate relative impacts by two factors on monthly, seasonal, and annual time scales at the Soyang River upper basin and the Seom River basin in South Korea. The 3 techniques such as the double mass curve method, the Pettitt's test, and the BCP analysis were performed to detect change point occurred by abrupt change in the collected observed runoff. After detection of change ponts, SWAT models calibrated on the natural periods were used to calculate the changes due to human activities. Also, 6 Budyko based methods were auxiliary to verify the results from hydrological based approach.

A Scene Change Detection using Motion Estimation in Animation Sequence (움직임 추정을 이용한 애니메이션 영상의 장면전환 검출)

  • Kwak, Sung-Keun
    • Journal of the Korea Computer Industry Society
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    • v.9 no.4
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    • pp.149-156
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    • 2008
  • There is the temporal correlation of a animation sequence between the motion vector of current block and the motion vector of previous block. In this paper, we propose the scene change detection algorithm for block matching using the temporal correlation of the animation sequence and the center-biased property of motion vectors. The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(sum of absolute difference) value by the predicted motion vector from the same block of the previous frame and the predictor candidate point on each search region. Simulation results show that the proposed algorithm has better detection performance, such as recall rate, then the existing method. The algorithm has the advantage of speed, simplicity and accuracy. In addition, it requires less amount of storage.

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Comparative study on long-term stability in mandibular sagittal split ramus osteotomy: hydroxyapatite/poly-ʟ-lactide mesh versus titanium miniplate

  • Park, Young-Wook;Kang, Hyun-Sik;Lee, Jang-Ha
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.8.1-8.6
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    • 2019
  • Background: Resorbable devices have recently been adopted in the field of orthognathic surgery with controversies about their postoperative skeletal stability. Hence, we determined the long-term skeletal stability of unsintered hydroxyapatite/poly-ʟ-lactic acid (HA/PLLA) mesh for osteofixation of mandibular sagittal split ramus osteotomy (SSRO), and compared it with that of titanium miniplate. Methods: Patients were divided into resorbable mesh and titanium miniplate fixation groups. A comparative study of the change in the mandibular position was performed with preoperative, 1-day, 6-month, and 2-year postoperative lateral cephalograms. Results: At postoperative 6 months-compared with postoperative 1 day, point B (supra-mentale) was significantly displaced anteriorly in the titanium-fixation group. Moreover, at postoperative 2 years-compared with postoperative 6 months, point B was significantly displaced inferiorly in the titanium-fixation. However, the HA/PLLA mesh-fixation group did not show any significant change with respect to point B postoperatively. Conclusions: The HA/PLLA mesh-fixation group demonstrated superior long-term skeletal stability with respect to the position of mandible, when compared with the titanium-fixation group.