• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.328-334
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• 2021

The article examines the economic essence and approaches to determining the efficiency of the enterprise. The author in the study considers the effectiveness and from the standpoint of qualitative analysis of the effectiveness of change and implementation of enterprise development goals. It is established that the tool for ensuring qualitative impacts on the efficiency of the enterprise is the innovative development of the economic space of the enterprise. The article considers the dominant innovations that have influenced the means and methods of production. An organizational and economic mechanism has been recommended to coordinate the costs of innovation activities in order to ensure the efficiency of enterprises. The object of management in the organizational and economic mechanism is the innovation process in the enterprise: from the design of strategic goals of innovation, search and commercialization of innovations, to building and implementing innovation potential. The efficiency of the enterprise under the condition of realization of innovative potential will be characterized by steady competitive advantages and strategically-oriented behavior in the market.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.324-330
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• 1996

We examined the formal oxidation states of Pb and Cu in the Pb2CuO4 slab of Pb2Sr2ACu3O8(A=Y1-xCaxor Nd1-xSrx) and their possible changes by oxygen incorporation in the Cu layer of the slab by performing tight-binding band electronic structure calculations on the Pb2CuO4+δ slab. Our results show that the most likely oxidation state of Pb is +2 and that of Cu is +1 for the Pb2CuO4 slab prior to oxidation. With small δ values, the oxygen incorporation occurs by the formation of such chain fragments as in YBa2Cu3O7-y along the a+b axis. The four-coordinate Cu atoms in the chain fragments are in the +3 oxidation states. For values of δ larger than 0.5, however, an additional oxygen (Oad) goes to the site along the b axis to form short Pb-Oad distances oxidizing Pb2+ to Pb4+. This change in the Pb oxidation state leads to the suppression of superconductivity due to the decrease of holes in the CuO2 layer.

• 스마트미디어저널
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• 제12권3호
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• pp.77-84
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• 2023

산림 화재는 현대의 급격한 기후 변화에 따른 대표적인 자연 재해이다. 화재로 인한 산림 훼손으로 산림 조성이 미비한 시점에 겨울철 해빙기와 폭우 등으로 산사태가 발생하는 이차적인 피해가 발생한다. 대부분 국가에서는 산림 관리를 위해 CCTV 중심의 모니터링 시스템으로 제한적인 면적만 관리하고 있다. 산사태 징후를 예측하기 위해 사전에 3차원 공간 좌표를 포함하고 있는 마커를 위험지역의 경사면에 장착한 후, 주기적인 드론 촬영으로 3차원 맵핑 및 안식각을 검출한다. 이를 위해서 마커의 인식범위 및 화각을 정의하고, 산사태 징후를 사전에 예측하는 방법을 제시하였다.

• Tribology and Lubricants
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• 제39권3호
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• pp.102-110
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• 2023

This study aims to quantify the variation in the performance of a tilting pad journal bearing (TPJB) owing to the elastic deformation of its pad. To this end, we first defined a parameter, "elastic preload", and predicted the changes in the performance of the TPJB, as a function of the preload amount. We used the iso-viscosity Reynolds equation, which ignores the temperature rise due to viscous shear in thin films, and the resultant thermal deformation of the bearing structure. We employed a three-dimensional finite element model to predict the elastic deformation of the bearing pad, and a transient analysis, to converge to a static equilibrium condition of the flexible pads and journal. Conducting a modal coordinate transformation helped us avoid heavy computational issues arising from a mesh refinement in the three-dimensional finite element pad model. Moreover, we adopted the Hertzian contact model to predict the elastic deformation at the pivot location. With the aforementioned overall strategy, we predicted the performance changes owing to the elastic deformation of the pad under varying load conditions. From the results, we observed an increase in the preload due to the pad elastic deformation.

• 한국식생활문화학회지
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• 제22권5호
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• pp.597-602
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• 2007

For the hotel industry, the situations having difficulties in management are becoming we planed by the rises of the cost and labor costs, the imbalance between supply and demand, stiffening competitions between the hotels. Therefore, there has been a plan for a great change to attract customers, escaping from the existing form of management in order to secure competitive powers in the food and beverage field. For that purpose, we plan to investigate into the preference of buffet restaurants in ten 5star hotels in Seoul. By the analysis, we also plan to present the menu concepts that stand out and are preferred by the customers in managing semi-buffet restaurants. Therefore, the linear and planar coordinate values of the H Hotels and I Hotels came out both positive(+) as results of a similarity analysis using MOS, we can predict that they would be positioning on the same dimension. Furthermore we can predict that the menu of antipasto, sushi, sashimi and desserts would be positioning on the same dimension as a result of analysis of the most preferred menu by customers for each station in managing a semi-buffet restaurant. Based on these results, there must be continuous supervision over the menu of buffet restaurants.

• Journal of Astronomy and Space Sciences
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• 제31권1호
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• pp.41-50
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• 2014

The Earth is not perfectly spherical and its rotational axis is not fixed in space, and these geophysical and kinematic irregularities work as dominant perturbations in satellite orbit propagation. The International Earth Rotation Service (IERS) provides the Conventions as guidelines for using the Earth's model and the reference time and coordinate systems defined by the International Astronomical Union (IAU). These guidelines are directly applied to model orbital dynamics of Earth satellites. In the present work, the effects of the latest conventions released in 2010 on orbit propagation are investigated by comparison with cases of applying the previous guidelines, IERS Conventions (2003). All seven major updates are tested, i.e., for the models of the precession/nutation, the geopotential, the ocean tides, the ocean pole tides, the free core nutation, the polar motion, and the solar system ephemeris. The resultant position differences for one week of orbit propagation range from tens of meters for the geopotential model change from EGM96 to EGM2008 to a few mm for the precession/nutation model change from IAU2000 to IAU2006. The along-track differences vary secularly while the cross-track components show periodic variation. However, the radial-track position differences are very small compared with the other components in all cases. These phenomena reflect the variation of the ascending node and the argument of latitude. The reason is that the changed models tested in the current study can be regarded as small fluctuations of the geopotential model from the point of view of orbital dynamics. The ascending node and the argument of latitude are more sensitive to the geopotential than the other elements. This study contributes to understanding of the relation between the Earth's geophysical properties and orbital motion of satellites as well as satellite-based observations.

• 대한기계학회논문집B
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• 제24권11호
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• pp.1437-1446
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• 2000

A numerical analysis on the freeze coating process of a non-isothermal finite dimensional plate with a binary alloy is performed to investigate the growth and decay behavior of the solid and the mushy layer of the freeze coat and a complete procedure to calculate the process is obtained in this study. The continuously varying solid and mushy layers are immobilized by a coordinate transform and the resulting governing differential equations are solved by a finite difference technique. To account for the latent heat release and property change during solidification, proper phase change models are adopted. And the convection in the liquid melt is modeled as an appropriate heat transfer boundary condition at the liquid/mushy interface. The present results are compared with analytic solutions derived for the freeze coating of infinite dimensional plates and the discrepancy is found to be less than 0.5 percent in relative magnitude for all simulation cases. In addition the conservation of thermal energy is checked. The results show that the freeze coat grows proportional to the 1.2 square of axial position as predicted by analytic solutions ar first. But after the short period of initial growth, the growth rate of the freeze coat gradually decreases and finally the freeze coat starts to decay. The effects of various non-dimensional processing parameters on the behavior of freeze coat are also investigated.

• 터널과지하공간
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• 제20권3호
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• pp.225-232
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• 2010

본 연구에서는 절리에 작용하는 수직변형과 전단 팽창을 고려할 수 있는 수정된 3차원 변형률 의존성 수리전도도 변화 방정식을 제안하였다. 현지 암반을 직교절리가 발달한 매질로 가정하기 때문에 제시된 방정식을 사용하여 수리전도도의 이방성을 평가할 수 있다. 현지암반의 변형계수를 필요로 하는 탄성계수감소비를 손쉽게 결정하기 위하여 GSI와 교란계수를 기초로 하는 경험식을 사용하였다. 현지 암반 내에 존재하는 절리는 일반적으로 전체좌표계와 평행하지 않고 기울어져 있는 경우가 많기 때문에 기울어진 방향에서의 수리전도도를 구하기 위하여 변형률 회전식을 사용하였다. 해석 결과 GSI가 증가함에 따라 수리전도도는 감소하는 것으로 나타났다. 교란계수는 수리전도도의 변화 거동에 영향을 미치는 것으로 나타났는데 특히 GSI가 50 이상인 암반의 수리전도도 변화에 큰 영향을 미치는 것으로 해석되었다. 절리의 경사도 수리전도도 변화에 영향을 미치는 것으로 나타났다.

• 한국콘텐츠학회논문지
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• 제15권9호
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• pp.84-95
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• 2015

본 논문은 공연예술 콘텐츠 조직이 공공 지원 축소라는 환경 불확실성에 유연하게 대처하며 지속적인 콘텐츠 활동을 영위할 수 있는 전략은 무엇인지를 알아보는 것이 목적이다. '창조경제, 문화융성'의 실현이 문화예술진흥기금의 고갈로 어려움에 처하고, 예술 콘텐츠 환경의 불확실성은 날로 증가하고 있다. 콘텐츠 진흥이란 훌륭한 콘텐츠가 원활하게 창조되고 매개되어 모두가 공연예술 콘텐츠를 풍부하게 향유하는 환경을 만드는 일이다. 영역과 경계를 넘어 다양한 정보를 획득하고, 정보 분석과 지식활동의 확산을 통해 환경에 대응하는 통합된 콘텐츠 진흥 전략이 필요하다. 외부 위기를 기회로 전환하여 불확실성에 대처하고, 내부 약점을 보완하여 혁신을 추진하면, 지속적인 공연예술 콘텐츠 활동이 가능하다. 경계탐색 전략은 환경 변화와 관련한 모든 정보를 취합하고 분석하는 지식활동의 방법으로 불확실성에 대처할 뿐 아니라 조직 내부의 강점들을 외부 환경에 노출시키는 방법으로 조직 활동의 정당성이 외부로 확산되는 혁신 전략이다.

• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.229-236
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• 2020

The trend of water vapor contents in atmosphere is one of key elements for studying climate change. The tropospheric products, i.e., ZTD values achieved through GPS data processing can retrieve the amount of water vapor with higher temporal and spatial resolution than any other instruments. In this study, the tropospheric products of KASINET for a time period from 2001 to 2014 are reprocessed using PPP strategy and the products from the CODE's 2nd reprocessing campaign. For consistency with reprocessing activities of other networks like EPN, the VMF1 mapping function and non-tidal loading effect due to atmospheric pressure are applied in the process. The reprocessing results are investigated through comparing with the CODE's 2nd reprocessing products by including some IGS stations in the process and also calculating weekly coordinate repeatability to see the quality of the processing. After removing outliers based on the variation of averaged formal error, all processed stations have similar variations of formal error about 2 mm which is lower than that of the IGS final product. Comparison results with the CODE's 2nd reprocessing products show that the overall mean difference is found to be -0.28±5.54 mm which is similar level of the previous studies. Finally, the ZTD trends of all KASINET stations are calculated and the averaged trend is achieved as 0.19 mm/yr. However, the trend of each month shows different amounts and directions from -1.26 mm/yr in May to 1.18 mm/yr in August. In conclusion, the reprocessed tropospheric product and applied strategy of this study has enough quality as one of reliable solution for a reference product for Korean Peninsula which is needed to use GPSbased tropospheric product for climate change research.