• Title/Summary/Keyword: 양적 대칭

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Asymmetric Adjustment in Domestic Petroleum Prices Before and After the Opinet (국내석유제품가격의 국제유가 대칭성 분석 -Opinet(오피넷) 개통을 중심으로)

  • Koh, Yukyung
    • Environmental and Resource Economics Review
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    • v.22 no.4
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    • pp.581-612
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    • 2013
  • Opinet is the system that has announced the daily domestic petroleum price data from April 2008. This study's goal is to examine if the domestic petroleum(gasoline and diesel) prices adjust their prices asymmetrically comparing before-Opinet with after-Opinet. The results of this study found the evidence of asymmetric domestic petroleum prices before the Opinet and the evidence of symmetric domestic petroleum prices after the Opinet. Also the domestic petroleum prices after the Opinet adjust upward/downward nearly twice as fast when its actual value is below/above its equilibrium. According to this study, the domestic petroleum market works more efficiently than before.

An Efficient Medical Image Compression Considering Brain CT Images with Bilateral Symmetry (뇌 CT 영상의 대칭성을 고려한 관심영역 중심의 효율적인 의료영상 압축)

  • Jung, Jae-Sung;Lee, Chang-Hun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.39-54
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    • 2012
  • Picture Archiving and Communication System (PACS) has been planted as one of the key infrastructures with an overall improvement in standards of medical informationization and the stream of digital hospitalization in recent days. The kind and data of digital medical imagery are also increasing rapidly in volume. This trend emphasizes the medical image compression for storing large-scale medical image data. Digital Imaging and Communications in Medicine (DICOM), de facto standard in digital medical imagery, specifies Run Length Encode (RLE), which is the typical lossless data compressing technique, for the medical image compression. However, the RLE is not appropriate approach for medical image data with bilateral symmetry of the human organism. we suggest two preprocessing algorithms that detect interested area, the minimum bounding rectangle, in a medical image to enhance data compression efficiency and that re-code image pixel values to reduce data size according to the symmetry characteristics in the interested area, and also presents an improved image compression technique for brain CT imagery with high bilateral symmetry. As the result of experiment, the suggested approach shows higher data compression ratio than the RLE compression in the DICOM standard without detecting interested area in images.

Constitutive Models for Decomposed Granite Soil and Their Application to Tunnelling Problem (화강토의 구성방정식 및 터널 해석에의 적용)

  • ;D. M. Potts
    • Journal of the Korean Geotechnical Society
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    • v.17 no.1
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    • pp.131-139
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    • 2001
  • 화강토와 관련된 지반문제의 거동예측을 위한 수치해석의 적용이 양적인 면에서는 많이 확대되어왔지만 해석결과에 지대한 영향을 미치는 구성방정식 등 수치해석 모델링을 개선하고자 하는 노력은 부족하였다. 화강토 거동의 특징은 내재적 결합력으로 인한 구조화의 거동을 나타내는 것이며, 항복면이 평균유효응력 축에 대칭이고 Non-associated 소성거동을 보인다는 점이다. 본 연구에서는 이러한 화강토 거동을 표현하기 위하여 일반화된 한계상태모델을 도입하고, 이를 화강토의 경화거동 모델링이 가능하도록 확장하였다. 제안된 모델을 이용한 삼축시험의 유한요소 시뮬레이션 결과는 측정결과와 좋은 일치를 보였다. 화강토 지반내 터널에 대한 유한요소해석을 수행한 결과, 비선형 탄성모델과 조합된 확장된 한계상태모델이 현장계측결과와 잘 일치하는 결과를 주었다.

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A Study on Price Asymmetries in Local Petroleum Markets (석유제품의 가격 비대칭성에 관한 연구)

  • Kim, Jin Hyung
    • Environmental and Resource Economics Review
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    • v.16 no.4
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    • pp.833-854
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    • 2007
  • Output prices tend to respond faster to input price increases than to decreases. The 'rockets and feathers' hypothesis of asymmetric price behavior in petroleum market is tested by a full adjustment error correction model. Using monthly data for the period January 1977 to June 2006, evidence is found that there is a significant degree of asymmetry in the adjustment of wholesale prices to increases and to decreases in crude oil price. A similar hypothesis in regard to the exchange rate is also rejected by the data. Using weekly data over the period examined, evidence of asymmetry for gasoline, diesel and heating oil is also found in the transmission of price changes from wholesale to retail: retail prices increase more quickly in response to the wholesale price increases than to wholesale price decreases.

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국내 석유제품가격의 변동에 대한 소비자의 인식과 비대칭 분석 비교

  • O, Seon-A;Heo, Eun-Nyeong
    • Environmental and Resource Economics Review
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    • v.21 no.1
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    • pp.69-92
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    • 2012
  • This paper analyzed price asymmetry of domestic petroleum products by distribution stage. Analyzing the asymmetry by distribution stage, we can investigate the gap between analysis results and consumers' perception. For the first stage, we analyzed asymmetries between retail prices including tax and the spot prices of crude oil. The results show that retail price increases more quickly in response to the crude oil prices rise than to the crude oil prices fall as consumers' perception. For the second stage, we analyzed asymmetry of international petroleum product prices in Korean Won with the change in the crude oil spot prices. The results show that international petroleum product prices increase higher in response to the crude oil prices increase than to the crude oil prices decrease. For the final stage, we examined the asymmetry of wholesale price and retail price with the change in the international petroleum product prices in Korean Won. The results show that wholesale prices increase more quickly in response to the crude oil prices rise than to the international petroleum product prices fall. The retail prices, however, decrease more quickly in response to the crude oil prices fall than to the international petroleum product prices rise.

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Global Science and Local Research: An Empirical Analysis of the Development of Physical Science in Korea (국제적인 과학과 국지적인 연구: 한국 물리학의 발전에 대한 경험적 연구)

  • Kim Ki-Wan
    • Journal of Science and Technology Studies
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    • v.5 no.1 s.9
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    • pp.31-53
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    • 2005
  • This paper argues that globalization of science can be put forward only through successful institutionalization of science at the national level and that the strengthened local research activities will contribute to a better integration into the global research community. In order to examine hypotheses derived from the theoretical arguments, this paper analyzes the development of physical science in Korea using mainly bibliometric method. The results show that the physical science in Korea has developed local characteristics represented by different research activities across sub-fields of physics. International research collaboration of the Korean physicists has not increased substantially during the time period studied, but an additional analysis indicates that the mode of international research collaboration may have been changed towards rather 'symmetric' way, resulting in the strengthened networks of the Korean physicists with international research community.

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Techniques of Oriental and Western Flower Arrangement through Historical Study (동서양 꽃꽂이의 역사적 고찰을 통해서 본 기법)

  • Lee, Jeong-Hwa
    • Journal of agriculture & life science
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    • v.43 no.6
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    • pp.53-57
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    • 2009
  • The Oriental flower arrangements have the beauty of a strict triangle in a symmetrical three-dimensional effect as the form of flower tribute to gods in ancient times and used frogs to fix flowers to a basin easily. Flower arrangements of a conical shape made by repeatedly piled flowers in ancient Egypt shows the origin of the present vertical form of the Western flower arrangements. Flower arrangements in ancient Greece formed in a smooth S shape, while Roman flower arrangements were rich and gorgeous in a lowering and thin shape horizontally. Persians were showing triangular forms similar to the Oriental three-dimensional effect. The basic form of flower arrangements in the age of Renaissance was also created upon the ancient one, descending to Art Nouveau when flower arrangements were widely expressed from mass to space aesthetics led by America in the 20th century influenced by mild color, simplicity and realistic description of the Oriental art in the late 19th century. The Western flower arrangements are focused on formation, same as the Oriental ones, yet they disregard naturality and based on practicality.