• Title/Summary/Keyword: Temperature Trend

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Simulation of the Mixed Layer in the Western Equatorial Pacific Warm Pool

  • Jang, Chan-Joo;Noh, Yign
    • Ocean and Polar Research
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    • v.24 no.2
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    • pp.135-146
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    • 2002
  • The upper ocean in the western equatorial Pacific warm pool during TOGA-COARE IMET IOP was simulated using a one-dimensional turbulence closure ocean mixed-layer model, which considered recent observations, such as the remarkable enhancement of turbulent kinetic energy near the ocean surface. The shoaling/deepening of the mixed layer and warming/cooling subsurface water in the model were in reasonable agreement with the observations. There was a significant improvement in simulating the cooling trend of the sea surface temperature under a westerly wind burst with heavy rainfall over previous simulations using bulk mixed-layer models. By contrast the simulated sea surface salinity (SSS) departed significantly from the observed SSS, especially during a westerly burst and the subsequent restratification period, which might be due to 3-D control processes, such as downwelling/upwelling or advection.

Technical Trend of Multi-function for Nano-magnetic Material (다기능성 나노자성복합소재 기술동향)

  • Kim, Yu-Sang
    • Journal of the Korean institute of surface engineering
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    • v.45 no.1
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    • pp.43-52
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    • 2012
  • Recently, it has been developed for Eco-environment, Super light, Multi-functional nano materials. As needed mobile parts in Smart phone or TV, computer, information communication for high pass signal, multi-function, Magnetic thin film materials have been developed. As last, magnetic powder, sintered and sputtering parts were thick and low purity than electroplating layer, low pass signal and noise were resulted, vibrated TV screen. Because chemical complex temperature was high and ununiform surface layer, it has been very difficult for data pass in High Frequency (GHz) area. Large capacity data pass is used to GHz. Above GHz, signal pass velocity is dependent on Skin Effect of surface layer. If surface layer is thick or ununiform, attachment is poor, low pass signal and cross talk, noise are produced and leaked. It has been reported technical trend of Electrochemically plating and Surface treatment of Metal, Polymer, Ceramic etc. by dispersion/complex for Multi functional nano-magnetic material in this paper.

The Development of CD Trend Recording System (CD 동향기록 시스템 개발)

  • Jang, Me-Hea;Yoon, Kap-Koo;Choe, Hang-Soeb;Lee, Seung-Jae
    • Proceedings of the KIEE Conference
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    • 1997.07b
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    • pp.465-467
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    • 1997
  • The CD Trend Recorder, developed as a substitution of the existing SCR (Stript Chart Recorder), acquires various outputs (e.g. frequency voltage, current, power, temperature, pressure, etc) simultaneously using PC up to 32 different outputs, display, and analyze them just like the existing SCR. It stores the data in CD-ROM so th various data can be stored permanently this system has built-in MMI program and to monitor and analyze the data in real-t expert system link the data to the do where needs the data to display, analyze, in the new medium at the same time.

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Technology Trend and Requirement of Mobile Displays Using Low-Temperature Poly-Si (LTPS) Technologies

  • Kwon, Oh-Kyong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.409-412
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    • 2007
  • A lot of research for system-on-panel(SOP) have been done to integrate display systems including data driver, gate driver, timing controller, DC-DC converter, and smart functions such as embedded touch screen, ambient brightness sensing and luminance control, finger printing on the glass. Recently, the cost of an one-chip driver IC with various functions has decreased rapidly, and new mobile display interface technologies have been introduced. So it is necessary to examine the feasibility of SOP for practical mobile applications. In this paper, we will re-examine LTPS technologies for mobile displays in terms of various aspects and discuss the practical limitations on SOP technology and future technology trend of mobile displays.

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Long-term Sediment Discharge Analysis in Yongdam Dam Watershed due to Climate Change

  • Felix, Micah Lourdes;Kim, Joocheol;Choi, Mikyoung;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.327-327
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    • 2020
  • Increase in Earth's surface temperature, higher rainfall intensity rate, and rapid changes in land cover are just some of the most evident effects of climate change. Flooding, and river sedimentation are two inevitable natural processes in our environment, and both issues poses great risks in the dam industry when not addressed properly. River sedimentation is a significant issue that causes reservoir deposition, and thus causes the dam to gradually lose its ability to store water. In this study, the long-term effects of climate change on the sediment discharge in Yongdam Dam watershed is analyzed through the utilization of SWAT, a semi-distributed watershed model. Based from the results of this study, an abrupt increase on the annual sediment inflow trend in Yongdam Dam watershed was observed; which may suggests that due to the effects of climate change, higher rainfall intensity, land use and land cover changes, the sedimentation rate also increased. An efficient sedimentation management should consider the increasing trend in sedimentation rate due to the effects of climate change.

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Trend of Environmental Qualification of Safety-Related Digital Equipment in Nuclear Power Plants (원자력발전소 안전 관련 디지털 기기의 내환경검증 (Environmental Qualification) 동향)

  • Jae Seung Ko;Sang Eun Kim;Sung-ryul Kim
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.20 no.1
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    • pp.7-15
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    • 2024
  • Environmental qualification is required for safety related electrical equipment under harsh environments located in nuclear power plants according to 10 CFR 50.49 and RG 1.89. As analog technology has recently been replaced by digital technology, NRC established RG 1.209 as a regulatory guideline for environmental qualification of safety related computer-based I&C system located in mild environments, requiring evaluation for electromagnetic compatibility, smoke exposure and type test for actual service conditions such as temperature and humidity. In this paper, the trend of environmental qualification for digital equipment is analyzed by comparing the environmental qualification requirements between digital and analog equipment.

Change of Climatic Productivity Index for Rice under Recent Climate Change in Korea (최근 8-9월의 기상특징과 기후생산력지수의 변화)

  • Shim, Kyo-Moon;Kim, Yong-Seok;Jung, Myung-Pyo;Choi, In-Tae
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.384-388
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    • 2014
  • Air temperature has increased, while sunshine hour has decreased during the grain filling period of most rice cultivars (August to September) during the past 12 years from 2001 through 2012 in Korea. Climatic Productivity Index (CPI) has fallen because of the decreased sunshine hour and increased air temperature during the grain filling period, and the degree of reduction was greater with earlier heading. For stable rice production, we will need to delay the heading of rice as a cultivation measure against the future climatic trend. Grain yield showed no significant trend for past 12 years. However, the year to year change in grain yield showed a similliar pattern with that of CPI. Especially, a linear function relating rice yield to CPI explained approximately 63% of variation in grain yield with the heading date of August $11^{th}$ period.

A Study on the Properties of Silk and Nylon 6 Fabrics by Tannic Acid Treatment

  • Yoa, Soojin;Kim, Jongjun
    • Journal of Fashion Business
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    • v.20 no.3
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    • pp.119-132
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    • 2016
  • Weighting of silk fabrics have long been practiced in silk fabric trading based on the primary consideration of price-weight, and secondary one of quality improvement in handle, luster, and drape properties. Recent trend of practicing weighting of silk fabrics is, however, focused on the improvement of the handle, luster, drape, and other properties. During the finishing processes of synthetic fiber, nylon, comprising amide structure, include the use of tannic acid, especially in the dyeing. A multitude of studies are being implemented in terms of improving fastness to washing, fastness to light of dyed nylon product, or the light fastness of nylon 6 itself. In this study, the effects of various tannic acid treatments on the physical properties related to the handle of nylon 6 and silk fabrics are examined and reviewed. The effects of treatment condition of the tannic acid, e.g., the concentration of the aqueous tannic acid solution, treatment time, and temperature were investigated. As the concentration of the aqueous solution of tannic acid increased, the bending rigidity values of the silk and nylon 6 fabrics increased. The treated fabrics felt stiff to the touch. Within the mild conditions of bending employed in the bending measurement of KES, nylon 6 treated fabric specimen exhibited a trend of improvement of bending resiliency within the range of small bending deformation. The weight of treated fabrics have all increased. The air-permeability values decreased as the treatment concentration increased. However, the decrease tendency of air permeability values may be alleviated by adjusting the fabric count during the tentering or expanding processes, either by tension adjustment or heat treatment. Optimum conditions of the treatment for nylon 6 are 1.25% tannic acid concentration, bath temperature of $85^{\circ}C$, pH 3.1, and those for silk fabric treatment are 1.25% tannic acid concentration, bath temperature of $85^{\circ}C$, pH 3.1. The treatment conditions will lead to the improvement in the properties of fabrics for summer.

Climate Change Concerns in Mongolia

  • Dagvadorj, D.;Gomboluudev, P.;Natsagdorj, L.
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.47-54
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    • 2003
  • Climate of Mongolia is a driven force on natural conditions as well as socio-economic development of the country. Due to the precariousness of climate conditions and traditional economic structure, natural disasters, specially disasters of meteorological and hydrological origin, have substantial effect upon the natural resources and socio-economic sectors of Mongolia. Mongolia's climate is characterized by high variability of weather parameters, and high frequency and magnitude of extreme climate and weather events. During the last few decades, climate of the country is changing significantly under the global warning. The annual mean air temperature for the whole territory of the country has increased by $1.56^{\circ}C$ during the last 60 years,. The winter temperature has increased by $1.56^{\circ}C$. These changes in temperature are spatially variable: winter warming is more pronounced in the high mountains and wide valleys between the mountains, and less so in the steppe and Gobi regions. There is a slight trend of increased precipitation during the last 60 years. The average precipitation rate is increased during 1940-1998 by 6%. This trend is not seasonally consistent: while summer precipitation increased by 11 %, spring precipitation decreased by 17. The climate change studies in Mongolia show that climate change will have a significant impact on natural resources such as water resources, natural rangeland, land use, snow cover, permafrost as well as major economic activities of arable farming, livestock, and society (i.e. human health, living standards, etc.) of Mongolia. Therefore, in new century, sustainable development of the country is defined by mitigating and adaptation policies of climate change. The objective of the presentation is to contribute one's idea in the how to reflect the changes in climate system and weather extreme events in the country's sustainable development concept.

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Interdecadal Changes in the Boreal Summer Tropical-Extratropical Teleconnections Occurred Around Mid-to-late 1990s (1990년대 중·후반을 전후한 북반구 여름철 열대-중위도 원격상관의 장기 변화)

  • Lee, June-Yi
    • Atmosphere
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    • v.28 no.3
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    • pp.325-336
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    • 2018
  • This study investigates robust features of interdecadal changes in the Northern hemisphere summer tropical-extratropical teleconnection occurred around the mid-to-late 1990s by analyzing four different reanalysis data for atmospheric circulation and temperature, two precipitation reconstructions, and two sea surface temperature (SST) data during the satellite observation era of 1980~2017. For the last 38 years, there has been a significant increasing trend in anticyclonic circulation at lower and upper troposphere and 2 m air temperature with wavenumber-5 Rossby wave structure in the Northern Hemisphere (NH) extratropics. The increase has been accompanied with the significant weakening and northward shift of jet stream over Eurasia and the North Pacific. It is further found that there has been a significant interdecadal shift occurred around the mid-to-late 1990s in the two distinct modes of tropical-extratropical teleconnection: Western Pacific-North America (WPNA) and circumglobal teleconnection (CGT) pattern. After mid-to-late 1990s, the WPNA has played more important role in modulating the extratropical atmospheric circulation and surface climate, which has been preferentially occurred during the El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) decaying or transition summer such as 1998, 2010 and 2016. During these summers, severe heat waves were occurred over many parts of the NH extratropics due to the combined effect of the increasing trend in the barotropic anticyclonic circulation and the significant WPNA across the NH. Although weakened, the CGT also contributed to some of hot summers over many parts of the NH extratropics such as 1999, 2000, 2008, 2011, and 2012 when weak to moderate La $Ni{\tilde{n}}o$ was persisted.