• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.125-125
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• 2020

European Space Agency's Sentinel-1 has an improved spatial and temporal resolution, as compared to previous satellite data such as Envisat Advanced SAR (ASAR) or Advanced Scatterometer (ASCAT). Thus, the assumption used for low-resolution retrieval algorithms used by ENVISAT ASAR or ASCAT is not applicable to Sentinel-1, because a higher degree of land surface heterogeneity should be considered for retrieval. The assumption of homogeneity over land surface is not valid any more. In this study, considering that soil roughness is one of the key parameters sensitive to soil moisture retrievals, various approaches are discussed. First, soil roughness is spatially inverted from Sentinel-1 backscattering over Yanco sites in Australia. Based upon this, Artificial Neural Networks data (feedforward multiplayer perception, MLP, Levenberg-Marquadt algorithm) are compared with Fractal approach (brownian fractal, Hurst exponent of 0.5). When using ANNs, training data are achieved from theoretical forward scattering models, Integral Equation Model (IEM). and Sentinel-1 measurements. The network is trained by 20 neurons and one hidden layer, and one input layer. On the other hand, fractal surface roughness is generated by fitting 1D power spectrum model with roughness spectra. Fractal roughness profile is produced by a stochastic process describing probability between two points, and Hurst exponent, as well as rms heights (a standard deviation of surface height). Main interest of this study is to estimate a spatial variability of roughness without the need of local measurements. This non-local approach is significant, because we operationally have to be independent from local stations, due to its few spatial coverage at the global level. More fundamentally, SAR roughness is much different from local measurements, Remote sensing data are influenced by incidence angle, large scale topography, or a mixing regime of sensors, although probe deployed in the field indicate point data. Finally, demerit and merit of these approaches will be discussed.

• Tribology and Lubricants
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• v.39 no.6
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• pp.221-227
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• 2023

A rotordynamic system consists of components that undergo rotational motion. These components include shafts, impellers, thrust collars, and components that support rotation, such as bearings and seals. The motion of this type of rotating system can be modeled as two-dimensional motion and, accordingly, the equation of motion for the rotordynamic system can be represented using complex coordinates. The directional frequency response function (dFRF) can be derived from this complex coordinate system and used as an effective analytical tool for rotating machinery. However, the dFRF is not widely used in the field because most previous studies and commercial software are based on real coordinate systems. The objective of the current study is to introduce the dFRF and show that it can be an effective tool in rotordynamic analysis. In this study, the normal frequency response function (nFRF) and dFRF are compared under rotordynamic analysis for isotropic and unisotropic rotors. Results show that in the nFRF, the magnitude of the response is the same for both positive and negative frequencies, and the response is similar under all modes. Consequently, the severity of the mode cannot be identified. However, in the dFRF, the forward and backward modes are clearly distinguishable in the frequency domain of the isotropic rotor, and the severity of the mode can be identified for the unisotropic rotor.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.1-12
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• 2014

Recently, the reenaction of place's memories that were considered sense of place based on its historical and structural characteristic were assumed important topics for recovering and making the park from industrial sites, such as factory, industrial complex, industrial city, labor residential development, landfill, etc., to the public all over the world. This research aimed to conduct some preliminary data for making the park's sense of place highly. So, after conducting the structural forms of sense of place for Seoul Forest and Seonyudo Park that were designed and built by considering its place memories actively, park planning and design implications that were considered its sense of place were suggested. The research results those were derived from the structural forms of sense of place for Seoul Forest and Seonyudo Park's are the following. First, the Structural Equation Modeling(SEM) on Seoul Forest and Seonyudo Park were determined that the natural-physical, artificial-physical, and experiential environmental factors' satisfaction of Seoul Forest and Seonyudo Park have an effect on forming the Sense of Place. In addition, the sense of place was affected by the willingness to visit. Second, according to its physical environment, the experiential factors, such as plays, exercises and etc., were more important relatively. Therefore, experiential factors should be considered significantly with physical factors to make the sense of place highly. Third, even the places were under similar category, the factors' and valuables' relative importance were changed. As the results of structural equation modeling said, specific valuables' related with each factors would be differentiated due to the places' characteristics. For example, the results were showed that natural-physical factor was more important than artificial-physical factor in Seoul Forest. On the other hand, artificial-physical factor was more important than the natural- physical factor. This research carries some significance for applying a quantitative research method(structural equation modeling) to various place to conduct the sense of place's structural model, for suggesting relative specific methods to make the sense of place, and for being a step forward to substance of sense of place. If further studies conduct focusing on various places to draw the forming models of sense of place that were based this research's analysis methods and results, those researches would contribute to make the urban place meaningful, characteristically and affectionately. Furthermore, those researches would contribute in making a humane and competitiveness city.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.53-65
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• 2001

Purpose : To improve the local control of patients with nasopharyngeal cancer, we have implemented 3-D conformal radiotherapy and forward intensity modulated radiation therapy (IMRT) to used of compensating filters. Three dimension conformal radiotherapy with intensity modulation is a new modality for cancer treatments. We designed 3-D treatment planning with 3-D RTP (radiation treatment planning system) and evaluation dose distribution with tumor control probability (TCP) and normal tissue complication probability (NTCP). Material and Methods : We have developed a treatment plan consisting four intensity modulated photon fields that are delivered through the compensating tilters and block transmission for critical organs. We get a full size CT imaging including head and neck as 3 mm slices, and delineating PTV (planning target volume) and surrounding critical organs, and reconstructed 3D imaging on the computer windows. In the planning stage, the planner specifies the number of beams and their directions including non-coplanar, and the prescribed doses for the target volume and the permissible dose of normal organs and the overlap regions. We designed compensating filter according to tissue deficit and PTV volume shape also dose weighting for each field to obtain adequate dose distribution, and shielding blocks weighting for transmission. Therapeutic gains were evaluated by numerical equation of tumor control probability and normal tissue complication probability. The TCP and NTCP by DVH (dose volume histogram) were compared with the 3-D conformal radiotherapy and forward intensity modulated conformal radiotherapy by compensator and blocks weighting. Optimization for the weight distribution was peformed iteration with initial guess weight or the even weight distribution. The TCP and NTCP by DVH were compared with the 3-D conformal radiotherapy and intensitiy modulated conformal radiotherapy by compensator and blocks weighting. Results : Using a four field IMRT plan, we have customized dose distribution to conform and deliver sufficient dose to the PTV. In addition, in the overlap regions between the PTV and the normal organs (spinal cord, salivary grand, pituitary, optic nerves), the dose is kept within the tolerance of the respective organs. We evaluated to obtain sufficient TCP value and acceptable NTCP using compensating filters. Quality assurance checks show acceptable agreement between the planned and the implemented MLC(multi-leaf collimator). Conclusion : IMRT provides a powerful and efficient solution for complex planning problems where the surrounding normal tissues place severe constraints on the prescription dose. The intensity modulated fields can be efficaciously and accurately delivered using compensating filters.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.1-8
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• 2010

Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.3
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• pp.171-180
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• 2015

This study was performed on the removal of Cs, one of the main high- radioactive nuclides contained in the high-radioactive seawater waste (HSW), by adsorption with IE911 (crystalline silicotitanate type). For the effective removal of Cs and the minimization of secondary solid waste generation, adsorption of Cs by IE911 (hereafter denoted as IE911-Cs) was effective to carry out in the m/V (ratio of absorbent weight to solution volume) ratio of 2.5 g/L, and the adsorption time of 1 hour. In these conditions, Cs and Sr were adsorbed about 99% and less than 5%, respectively. IE911-Cs could be also expressed as a Langmuir isotherm and a pseudo-second order rate equation. The adsorption rate constants (k₂) were decreased with increasing initial Cs concentrations and particle sizes, and increased with increasing ratios of m/V, solution temperatures and agitation speeds. The activation energy of IE911-Cs was about 79.9 kJ/mol. It was suggested that IE911-Cs was dominated by a chemical adsorption having a strong bonding form. From the negative values of Gibbs free energy and enthalpy, it was indicated that the reaction of IE911-Cs was a forward, exothermic and relatively active at lower temperatures. Additionally, the negative entropy values were seen that the adsorbed Cs was evenly distributed on the IE911.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.203-211
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• 2020

This purpose of this study is to verity the impact of new logistics factors on the Intention of use and consumer happiness, the mediating effect of perceived benefits, and provide suggestions on how to improve the level of new distribution. Based on the previous theories of online experience, off-line experience, logistics experience, perceived benefits, Intention of use and consumer happiness, the study puts forward 6 key research hypotheses. Reliability and validity tests were carried out by using data collected on new logistics factors on the Intention of use and consumer happiness. The hypotheses are verified through structural equation modelling. The study on the impact of new logistics factors on the Intention of use and consumer happiness and the mediating effect of perceived benefits, indicates that online experience, off-line experience, logistics experience have positive effects on perceived benefits, the perceived benefits has positive effects on Intention of use and consumer happiness, and the Intention of use has positive effects on consumer happiness. Moreover, perceived benefits as the mediating variable have effects on the relationship between online experience, off-line experience, logistics experience and the Intention of use and consumer happiness. The study extended the existing previous studies to provide theoretical and practical implications by verifying the relationship between new logistics factors and the Intention of use and consumer happiness.

• Culinary science and hospitality research
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• v.15 no.3
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• pp.344-355
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• 2009

This study is to set up a hypothesis and a research model based on how much the relational benefits can affect customer satisfaction and long-term relationship with the theoretical and practical results of established precedent researches, to analyze the structural equation model on casual dining restaurant diners, to evaluate the research model and subsequently to provide marketing implications. First of all, social and psychological factors prove to be influential among relational benefits felt by diners-out. Secondly, customer satisfaction has influence on long-term commitment for a restaurant. In other words, the higher customer satisfaction level for a restaurant is, the stronger willingness a customer has to recommend or revisit the restaurant, as several precedent studies support. As demonstrated in indirect advantages, these social and psychological benefits felt by diners-out have mighty effects on long-term relationship orientation, and satisfaction levels prove to be an important medium which can make these influences. As a result, restaurant employees' attitude toward customers is the most important factor rather than economic benefits such as reduced price, free gifts and coupons are, since customers put social and psychological benefits forward like intimate terms with restaurant workers, a sense of stability, and a relief from uneasiness. Therefore, constant service education should be done from the start to cope with customers' demands fast and flexibly and increase customer satisfaction.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.103-114
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• 2012

EA, efficient and hierarchical Information Resource Management(IRM) tool of Korean public agencie is one of the core of carrying forward the e-Government initiative. The objective of the paper is to study empirically whether using EA Governance for Controlling EA is related with their EA competency or not. the 190 person in charge of Information System service division are included for analysis. The various hypotheses established are validated by structural equation in SPSS and AMOS 18.0. The results shows that EA management and EA utilization of EA competency level was affected by EA Function, EA Organization and EA Human Resource of exogenous variable EA Governance but EA implementation level was not affected by EA Organization and EA Human Resource. also we investigated that the EA management level of endogenous variable EA competency was affected positively by EA implementation level and the EA utilization level of was affected positively by EA management level by stages.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.223-233
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• 2003

The Purpose of this study was to Investigate the relationship between the space discrepancy of the mandibular dentition and craiofacial morphology in adults with good Angle class I occlusion. Dental casts of normal group, crowded group and spaced group were selected on the basis of dental crowding and spacing. Subjects with excessive space to accomodate the lower teeth were classified as spaced group(39). Subjects with a space discrepancy of more than 4mm were classified as crowded group(45). Normal subjects had little or no dental crowding and spacing(40). Various skeletodental measurements in lateral cephalograms were evaluated and compared by ANOVA, Pearson correlation analysis and multiple stepwise regression analysis. The results were as follows; 1. ANB angle was larger in crowded group than in spaced group. 2. Maxilla and mandible in crowded group were inclined more downward and forward than in spaced group, so crowded group was found to have vortical tendency. 3. Anterior cranial base length and mandibular body length were longer in spaced group than in crowded group. 4. According to the multiple stepwise regression analysis with space discrepancy as dependent variable, 40% of variance of space discrepancy could be explained by ANB angle, anterior facial height and ramus height. Multiple regression equation was as follows Space discrepancy=46.51-2.51ANB-0.58AFH+0.65RH