• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.34-43
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• 2006

This paper shows modeling methods for VBR video trace. It is well known that VBR video trace is characterized as longterm correlated and highly intermittent burst data. To analyze this, we attempt to model it using neural network with auxiliary linear structures derived from residual threshold. For testing purpose, we generate VBR video trace from chaotic nonlinear function combined with the geometric random noise. The modeling result of the generated data shows that the attempted method represents more accurately than the traditional neural network. However, we also found that combining hRU to the attempted modeling method can yield a closer agreement to statistical features of the generated data than the attempted modeling method alone.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.361-372
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• 1994

Vanadium containing MFI type zeolites have been prepared hydrothermally or by the impregnation method with $NH_4VO_3$ solution after dealumination of HZSM-5. Incorporation of vanadium into the framework of zeolite has been demonstrated by XRD, DTA, FT-IR and ESR analyses. Upon $NH_4VO_3$ impregnation and calcination of dealuminated zeolite, vanadium substitution into the framework could be performed like a hydrothermally synthesized zeolite. Vanadium in zeolite is able to pass redox cycles at high temperatures, and it is shown that vanadium is probably fixed and atomically dispersed in the structure of zeolite. The catalytic benzene hydroxylation, hexanes and alcohols oxidation were used for evaluating the properties of vanadium incorporated MFI zeolite.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.112.2-112.2
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• 2013

지식경제부의 청정제조기반 산업원천개발사업의 일환으로 진행 중인 "초고진공펌프 개발" 과제 중 제 3세부 과제인 "고진공펌프종합특성평가시스템 설계, 진단기술 개발" 과제에서 5년 동안 진행되고 있는 전반적인 연구수행결과 및 구축 완료된 종합특성평가시스템을 활용한 고진공펌프의 상용화를 위한 신뢰성 평가에 관하여 소개한다. 고진공펌프개발 총괄 과제의 대명제는 "국제적 신뢰성을 가지는 상용화 제품의 완성"이며, 10(3) mbar~10(-10) mbar 영역의 국내 진공펌프 개발 수준의 선진화를 위한 모든 특성평가장치의 국제적 신뢰성이 있는 완벽한 성능평가의 구현을 포함한다고 볼 수 있으며, 전체 사업 추진기간 동안 제품 개발 주체인 산업체에 상용화를 위한 신뢰성 기반기술의 완벽한 구현의 제공에 있다고 할 수 있다. 이러한 고진공펌프의 신뢰성 평가는 저진공펌프의 신뢰성 평가기술에 기반을 두고 있으며, 기 개발 완료된 특성평가뿐만 아니라 실질적으로 나노종합팹센터의 공정현장에서 판단할 수 있는 내구성진단 및 최종 제품의 기계적 신뢰성 진단기술의 복합적인 요인들의 집합적인 분석에 기인하고 있다고 판단할 수 있다. 상용화 단계의 내구성 및 신뢰성 확보를 위한 전제 조건은 대외적으로 공표할 수 있는 시험평가 데이터와 개발 주체에서 기밀 수준으로 유지해야만 하는 민감한 자료의 상시 생산 infra의 구축으로 볼 수 있다. 이러한 진공펌프개발이라는 과제의 대명제를 완성하기 위한 연구개발 등 최종 상용화에 필요한 국제 신뢰성, 공정대응성 확보 기술개발 등 핵심사업 추진내용을 소개하고자 한다.

• Journal of the Korean Society for information Management
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• v.33 no.3
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• pp.263-285
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• 2016

Nowadays, Social Network Service (SNS), which has been in the spotlight as a way of communication, has become a most effective tool to improve easy of information use and accessibility for users. In this paper, we chose Twitter as the most representative SNS services because of automatic crawling and investigated tweet data gathered from domestic and foreign National Archives - NARA of U.S.A., TNA of U.K.. NAA of Australia, and National Archives of Korea. We also conducted information genres analysis and trend analysis by timeline. Information genres analysis shows how archives satisfied users' information needs as well as trends analysis of tweets helps to understand how users' interestedness was changed. Based on comparison results, we distilled four characteristics of National Archives and suggested vitalization ways for National Archives of Korea.

• Journal of Korea Technology Innovation Society
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• v.14 no.1
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• pp.139-156
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• 2011

This study is aimed to analyze the effectiveness of competitive priorities by product innovation and estimate the relationship between competitive priorities and business performances in the Korean manufacturing industry. It is expected that results of the study would provide useful managerial implications to the selection of effective competitive priorities of the manufacturing firms. Analytical results showed that the product innovation would enhance the effectiveness of competitive priorities. In addition, elements of competitive priorities that significantly affect to business performances were shown to be different by sectoral type in the manufacturing industry.

• Communications for Statistical Applications and Methods
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• v.15 no.1
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• pp.65-76
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• 2008

Biplots are the multivariate analogue of scatter plots. They approximate the multivariate distribution of a sample in a few dimensions, typically two, and they superimpose on this display representations of the variables on which the samples are measured(Gower and Hand, 1996, Chapter 1). And the relationships between the observations and variables can be easily seen. Thus, biplots are useful for giving a graphical description of the data. However, this method does not give some concise interpretations between variables and observations when the number of observations are large. Therefore, in this study, we will suggest to interpret the biplot analysis by applying the K-means clustering analysis. It shows that the relationships between the clusters and variables can be easily interpreted. So, this method is more useful for giving a graphical description of the data than using raw data.

• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.107-130
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• 2024

Urban land surface temperature (LST) change is a major environmental factor that affects the thermal comfort, energy consumption, and health of urban residents. Most studies that explored the relationship between LST and urban built-environment form analyzed only midday LST. This study explores the diurnal variation of summertime LST in Seoul using ECOSTRESS data, which observes LST at various times of the day and analyzes whether the LST variation differs by built environment type. Launched in 2018, ECOSTRESS operates in a non-sun-synchronous orbit, observing LST with a high resolution of 70 meters. This study collected data from early morning (6:25) to evening (17:26) from 2019 to 2022 to build time-series LST. Based on greenery, water bodies, and building form data, eight types of Seoul's built environment were derived by hierarchical clustering, and the LST fluctuation characteristics of each cluster were compared. The results showed that the spatial disparity in LST increased after dawn, peaked at noon, and decreased again, highlighting areas with rapid versus stable LST changes. Low-rise and high-rise compact districts experienced fast, high temperature increases and high variability, while low-density apartments experienced moderate LST increases and low variability. These results suggest urban forms that can mitigate rapid daytime heating.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.332-340
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• 2009

In this study, the thermal insulation effectiveness of the greenhouse insulators by the installation methods was investigated to find the right installation way of the insulation materials. Physical properties of the insulators such as thickness, air transmissivity, apparent density, ultraviolet rays cutoff ratio, reflectance, thermal conductivity, moisture absorptivity were evaluated and the insulation ability of the insulators were measured by the module experiments. For the same insulator, the insulation ability of the case with the outward direction of the black colored face, i.e., with the inward direction of the white colored face, was better than that of vice versa. The case of the black colored both surfaces was better than the case of the white colored both surfaces. For aluminium reflection material, the case with the outward direction of the lustre face, i.e., with the inward direction of the non-lustre face, was better than that of vice versa. For the same material with the inner thin polyethylene foam (or polyester) and the chemical wool, the case with the outward direction of the inner thin polyethylene foam (or polyester), i.e., with the inward chemical wool, was better than that of vice versa. Addition of the inner thin polyethylene foam increased the insulation effect very much.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.232-245
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• 2017

In this study, the high-resolution numerical simulation results considering landuse characteristics are analyzed by using single layer Urban Canopy Model (UCM) in Weather Research Forecast (WRF). For this, the impact of urban parameters such as roughness length and anthropogenic heat in UCM is analyzed. These values are adjusted to Seoul metropolitan area in Korea. The results of assessment are verified against observation from surface and flux tower. Forecast system equipped with UCM shows an overall improvement in the simulations of meteorological parameters, especially temperature at 2 m, surface sensible and latent heat flux. Major contribution of UCM is appreciably found in urban area rather than non-urban. The non-urban area is indirectly affected. In simulated latent heat flux, applying UCM is possible to simulate the change similarly with observations on urban area. Anthropogenic heat employed in UCM shows the most realistic results in terms of temperature and surface heat flux, indicating thermodynamic treatment of UCM could enhance the skills of high resolution forecast model in urban and non-urban area.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.445-448
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• 2008

It is essential that concrete component is made up with aggregate, cement and water. But today, Public concern is increasing of a variety structure and ocean environmental, resource recycle. Also, According to heat of hydration rising, Concrete is make a causative of concrete-crack. Concrete-crack cause a falling-off in quality of concrete. consequently, High-performance concrete is evaluated by concrete material properties and carbonation resistance with different admixture(fixing fly-ash 20%), granulated blast furnace slag replacement ratio (30%, 45%) different W/B (26%, 30%, 34%) and XRD(X-ray Diffraction) analysis.