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A Study on the Reliability Evaluation and Rehabitation of Solar Insolation Data by Field Measurement in Korea (국내 태양에너지 측정데이터의 신뢰성 평가 및 보정에 관한 연구)

  • Jo, Dok-Ki;Kang, Young-Heack
    • Journal of the Korean Solar Energy Society
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    • v.25 no.3
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    • pp.11-18
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    • 2005
  • The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by the solar system users as well as by research institutes. But the quality of solar insolation data is not always good. This reports on an attempt to identify systematic error in such data using clear-day analysis for data rehabilitation. Clear-day analysis is successful in uncovering solar insolation data of questionable quality. It is not proven that rehabilitation process can improve the quality of data for daily or monthly means, but it is suggested that the method can be used to improve the quality of data for monthly means of several years for use in many applications of solar energy planning. Earlier studies finding a maximum ETR of about 0.80 are confirmed.

Analyses of the Impact of Atmospheric Conditions to Daylight Illuminance in a Small Space (기상인자의 변화에 따른 소규모 공간에서의 주광조도분석)

  • Kim, Soo-Young
    • Journal of the Korean Solar Energy Society
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    • v.24 no.2
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    • pp.17-23
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    • 2004
  • Daylight illuminance levels in a small space were calculated using the Superlite program under limited conditions of the turbidity and thickness of condensible water of atmosphere. Three sky conditions(clear sky with direct sun, clear sky with no direct sun, overcast sky with no direct sun) were used. The atmospheric conditions significantly impacted the illuminance levels under especially a clear sky with direct sun. The overcast sky with no direct sun provided no difference for the illuminance levels in the space. As the calculation points moved away from a window, reflected illuminance levels gradually increased but direct illuminance levels significantly decreased.

Supratentorial Clear Cell Ependymoma Mimicking Oligodendroglioma : Case Report and Review of the Literature

  • Lee, Byoung-Hun;Kwon, Jeong-Taik;Park, Yong-Sook
    • Journal of Korean Neurosurgical Society
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    • v.50 no.3
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    • pp.240-243
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    • 2011
  • Clear cell ependymomas (CCEs) are rare variants of ependymomas. Tumors show anaplastic histological features and behave as an aggressive manner. CCEs have a predilection for extraneural metastases and early recurrence, and they demonstrate characteristic radiographic features. These tumors should be radiologically and pathologically differentiated from oligodendrogliomas. On microscopic examination, CCEs are composed of sheets of cells and resemble oligodendroglioma. However, upon closer examination, the nature of CCEs can be detected earlier, resulting in prompt treatment of the tumor. Although we report only one case, we emphasize the importance of early diagnosis and treatment. Future description of more cases of these rare cancers is necessary to aid in their diagnosis and treatment.

Clear Cell Sarcoma of the Kidney - a Case Report - (신장의 투명세포 육종 1예)

  • Park, Jae-Hyun;Jung, Jae-Hee;Lee, Ah-Won;Song, Young-Tack
    • Advances in pediatric surgery
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    • v.7 no.2
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    • pp.162-165
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    • 2001
  • Clear Cell Sarcoma of the Kidney(CCSK) is a rare malignant childhood tumor with frequent metastasis to the bone. We report a case of right sided in a 5 month-old girl. A radical nephrectomy was performed. It was clinical stage III with renal capsular invasion and lymph node metastasis by the classification of NWTS-5. Histologic examination revealed the classic pattern of CCSK. Postoperative adjuvant chemotherapy with doxorubicin and radiotheraphy were applied.

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Prediction of the Summer Effective Sky Temperatrure during the Clear Day on Osan City (오산시의 맑은날 하절기 등가 하늘온도 예측)

  • Byun, Ki-Hong
    • Journal of the Korean Solar Energy Society
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    • v.30 no.5
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    • pp.100-106
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    • 2010
  • The purpose of this study is to predict the effective sky temperature on Osan City during the summer. The north latitude, east longitude of Osan City is $37^{\circ}06'$ and $127^{\circ}02'$. The altitude from the sea level is 48m. Empirical relations of the effective sky temperature suggested by Duffie and Beckman are compared on clear days. For the effective sky temperature prediction, data measured by the Korea Meteorological Administration is used as an input to the Bliss model. Both Hottel and Krondratyev model are used to calculate the water vapor emissivity. The results using Hottel's model match well with the empirical relation proposed by Bliss. The results show maximum, minimum, and average values depending on water vapor emissivity model. The maximum deviation is about 10K and is due to total emissivity model.

홍성 인접 사문암 지역 내 토양성분차이

  • 민일식;송석환
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.09a
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    • pp.200-202
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    • 2002
  • This study was for comparisons of transitional element concentrations from the two different soil, serpentinite(SP) and granite area(GR), Kwangcheon and Hongseong area. Soils were collected by soil depths (10, 20 and 30cm) from the sites selected In the plant species(coniferous and deciduous species). In the soils, the SP was high in the Cr, Mn, Fe, Co, Ni and Zn concentrations, while the GR was high in the Cu, As, Sc and V. With the soil depths, the elements had high solubility, such as Cr, Co and Ni concentrations, were high in the SP, while the other elements were not clear. For the both species, the SP was high in the root and bolebark, while in the GR, not clear. Coniferous species in the same soil types, was higher than the deciduous In most elements. The more with increasing ages, the more with element accumulation in most plant parts except leaves. Comparisons between the soils and plant species, in the case of the element contents within the soils, the plant species in the same sites was similar trend. especially, clear in the SP

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A new type of clear orthodontic retainer incorporating multi-layer hybrid materials

  • Ahn, Hyo-Won;Kim, Kyung A;Kim, Seong-Hun
    • The korean journal of orthodontics
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    • v.45 no.5
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    • pp.268-272
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    • 2015
  • Clear thermoplastic retainers have been widely used in daily orthodontics; however, they have inherent limitations associated with thermoplastic polymer materials such as dimensional instability, low strength, and poor wear resistance. To solve these problems, we developed a new type of clear orthodontic retainer that incorporates multi-layer hybrid materials. It consists of three layers; an outer polyethylenterephthalate glycol modified (PETG) hard-type polymer, a middle thermoplastic polyurethane (TPU) soft-type polymer, and an inner reinforced resin core. The resin core improves wear resistance and mechanical strength, which prevent unwanted distortion of the bucco-palatal wall of the retainer. The TPU layer absorbs impact and the PETG layer has good formability, optical qualities, fatigue resistance, and dimensional stability, which contributes to increased support from the mandibular dentition, and helps maintain the archform. This new type of vacuum-formed retainer showed improved mechanical strength and rate of water absorption.

Case study on Hydraulic characteristics within Chlorine Contactors in Series (염소 접촉조 직렬 연결시 수리흐름 특성에 관한 연구)

  • Kang, Tea-Hun;Chae, Seon-Ha;Kim, Seong-Su;Wang, Chang-Keun
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.497-502
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    • 2011
  • In order to examine the effects of combination of plug flow reactors in series on hydraulic characteristics, comparative tracer tests were conducted for the cases of the existing clear well and clear wells combined in series. From the results of tests, $T_{10}$/T within existing clear well was 0.62~0.68 depending on inlet flowrate, and that in the case of combination in series was 0.69~0.78. While it would be minor improvement in contact efficiency, it would be appropriate to combine two clearwell with pipe in series for expansion.

What Does the Learning Region Mean for Economic Geography\ulcorner

  • Hassink, Robert
    • Journal of the Korean Regional Science Association
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    • v.15 no.1
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    • pp.93-116
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    • 1999
  • Recently the concept of learning has become very fashionable among academics from different economic disciplines. Economic geographers and spatial planners joined this fashion by increasingly speaking about the 'learning region'. This paper makes clear that this learning region'. This paper makes clear that this learning region concept has been launched from three angles; as spatial outcome of grand societal changes, as spatial concentration of entrepreneurial learning for innovation and as regional development concept. Despite the deficits and flaws such a young concept is faced with, such as vague definitions, the lack of empirical research and an insufficiently clear separation from existing concepts, the learning region concept might provide economic geography with more insight in agglomeration effects, stronger links with policy-making and more knowledge on path dependency and thus on unravelling the distinction between 'good' and 'bad' industrial agglomerations.

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Efficient Approach to Measure Crystallization Temperature in Amorphous Thin Film by Infrared Reflectivity

  • Wang, Wenxiu;Saito, Shin;Yakabe, Hidetaka;Takahashi, Migaku
    • Journal of Magnetics
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    • v.18 no.2
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    • pp.86-89
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    • 2013
  • This paper shows a new effective approach to measure crystallization temperature of soft magnetic underlayer (SUL) for next generation of heat assisted perpendicular recording media. This approach uses temperature dependent reflectivity, which shows a clear jump when samples are crystallized. To achieve this measurement, an optical system is set up using hot plate and infrared laser. Reflectivity of SUL $(Co_{70}Fe_{30})_{92}Ta_3Zr_5$ shows a clear jump at its amorphous-crystalline transition temperature. Experiment results show this effect is clear in infrared region, and is weak for visible light.