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排序方式: 共有1321条查询结果,搜索用时 15 毫秒
101.
Byung‐Ju Sohn Hye‐Sook Park Hyo‐Jin Han Myoung‐Hwan Ahn 《International journal of remote sensing》2013,34(10):3033-3042
The calibration of four MTSAT‐1R infrared channels was evaluated by comparing MTSAT measurements with Terra/MODIS inferred MTSAT‐equivalent brightness temperatures during August 2005 and August 2006. Theoretical relationships converting MODIS brightness temperatures to MTSAT‐equivalent values were obtained and used for the comparison. Results indicate that MTSAT two split window channels are well calibrated, and no serious systematic errors or biases are found; and the MTSAT water‐vapour channel shows a good linear relationship but with a warm bias up to 2 K. The significant cold bias of MTSAT 3.7 µm channel about ?6.7 K in August 2005 is found to be much removed in August 2006, after correction of the electrical crosstalk between MTSAT‐1R SWIR channel and WV channel starting from March 2006. Since then, calibration performances of MTSAT‐1R split window channels and shortwave IR channel seem to be comparable with MODIS calibration, while the water‐vapour channel shows more uncertainties up to 2 K of bias. 相似文献
102.
Entrepreneurship plays a critical role for the development and well-being of society. Illustration of its dynamic relationship with entrepreneurial attitudes and aspirations can provide a guideline for the cause of such activities. However, a time-lagged causal relationship among these concepts has not yet been established. In this study, we examine a dynamic relationship among early stage entrepreneurial attitudes, activities, and aspirations using Bayesian network (BN) analysis. In addition, we propose an early stage entrepreneurial activity index that can predict the percentage of both nascent entrepreneur and new business owner using the variables related to entrepreneurial attitudes of the previous year. This index, in turn, can be used to predict various aspects of entrepreneurial aspiration of the following year. The proposed index turns out to have very high prediction accuracy and is expected to provide effective policies to boost future entrepreneurial activity and aspiration. 相似文献
103.
Seung Bum Kim Chang Gil Lee Jung-Wuk Hong Hyun Woo Park Hoon Sohn 《Journal of Nondestructive Evaluation》2010,29(3):189-205
A guided wave based reference-free non-destructive testing (NDT) technique, which does not require direct comparison with
previously obtained baseline data for defect detection, has been recently developed and applied to simple plate-like structures
by the authors’ research group. In this study, the reference-free NDT technique is further advanced so that this technique
can also be applied to specimens with complex structural geometries such as holes, stiffeners, and varying thickness. A unique
damage-sensitive feature for each structural configuration has been extracted, and a suite of damage detection algorithms,
which is applicable to all the investigated structural geometries, has been proposed. Experiments as well as numerical simulations
are performed to investigate the applicability of the proposed NDT technique to structures with complex geometries. 相似文献
104.
Tae-Hyun Kim Jin-Goo Kang Jeong-Soo Sohn Kang-In Rhee Seoung-Won Lee Shun-Myung Shin 《Metals and Materials International》2008,14(5):655-658
The treatment of spent zinc-carbon batteries for the recovery of valuable metals followed by conversion to Mn−Zn ferrite has
been conducted employing two-stage alkali and acid leaching and co-precipitation method. In the first stage, leaching process
was carried out with 4 M NaOH, which resulted in a recovery of 63.4 %Zn and 0.1% Mn. Electrowinning of alkali leaching solution
containing 12.75 g/L Zn at a current density of 0.2 A/cm2 produced Zn metal of 15 nm to 30 nm size and 99.9% purity. The second stage leaching of residue with 3 M H2SO4 and 6 vol.% H2O2 at a solid/liquid ratio of 1∶10 indicated the leaching efficiency of 98.0% Zn, 97.9% Mn and 55.2% Fe. The obtained leaching
solution was finally adjusted to suitable mole ratios of Mn∶Zn∶Fe (1∶1∶4) by the addition of Zn and Fe sulfate salts followed
by pH control to produce Mn−Zn ferrite powder. The characterization of the ferrite powder showed uniform nano-crystalline
particles of about 20 nm size with spinel structure. 相似文献
105.
The flow-field for reactant distribution is an important design factor that influences the performance of polymer electrolyte membrane fuel cells (PEMFCs). Under-rib convection between neighboring channels has been recognized to enhance the performance of PEMFCs with serpentine flow-fields. This study presents a simple design method to generate multi-pass serpentine flow-fields (MPSFFs) that can maximize under-rib convection in a given cell area. Geometrical characterization indicates that MPSFFs lead to significantly higher under-rib convection intensities and more uniform conditions, such as reactant concentrations, temperature, and liquid water saturation, compared with conventional serpentine flow-fields. The implications of the enhanced under-rib convection due to MPSFFs on the performance of PEMFCs are discussed. 相似文献
106.
The kinetics of the carbochlorination of titania slag with chlorine gas and petroleum coke were determined. The porosity created, when easily chlorinated components of the slag such as iron oxide are rapidly reacted, had a significant effect on the chlorination of the slag. The effects of temperature, chlorine partial pressure, and initial particle size were determined, and a rate equation that incorporates these effects in the ranges of experimental conditions used in this work was developed. The results of this work show that the chlorination kinetics of titania slag are quite different from those of rutile with which most previous studies were concerned. 相似文献
107.
Low-power 3D graphics processors for mobile terminals 总被引:1,自引:0,他引:1
Ju-Ho Sohn Yong-Ha Park Chi-Weon Yoon Woo R. Se-Jeong Park Hoi-Jun Yoo 《Communications Magazine, IEEE》2005,43(12):90-99
A full 3D graphics pipeline is investigated, and optimizations of graphics architecture are assessed for satisfying the performance requirements and overcoming the limited system resources found in mobile terminals. Two mobile 3D graphics processor architectures, RAMP and DigiAcc, are proposed based on the analysis, and a prototype development platform (REMY) is implemented. REMY includes a software graphics library and simulation environment developed for more flexible realization of mobile 3D graphics. The experimental results demonstrate the feasibility of mobile 3D graphics with 3.6 Mpolygons/s at 155 mW power consumption for full 3D operation. 相似文献
108.
Sang‐Su Lee Jung‐Chan Na Sung‐Won Sohn Cheehang Park Dong‐Hoan Seo Soo‐Joong Kim 《ETRI Journal》2002,24(5):373-380
This paper presents a new method for a visual cryptography scheme that uses phase masks and an interferometer. To encrypt a binary image, we divided it into an arbitrary number of slides and encrypted them using an XOR process with a random key or keys. The phase mask for each encrypted image was fabricated under the proposed phase‐assignment rule. For decryption, phase masks were placed on any path of the Mach‐Zehnder interferometer. Through optical experiments, we confirmed that a secret binary image that was sliced could be recovered by the proposed method. 相似文献
109.
The nitrogen and carbon solubilities in the CaO-Al2O3-CaF2 slag system at 1723K were measured to understand the effect of CaF2 on the nitrogen and carbon dissolution behaviour using thermochemical equilibration technique. The nitride capacity in the CaOsatd.-Al2O3-CaF2 system was constant until XAl2O3 / XCaF2 = 0.23, followed by decrease with an increase in XAl2O3 / XCaF2 ratio, and then showed a constant value. The carbide capacity in the CaOsatd.-Al2O3-CaF2 system also showed the similar behaviour to the nitride capacity, however, the effect of CaF2 on the activity coefficient of nitride and carbide ions showed some differences in case of XCaF2 = 0.2. The effect of CaF2 on the activity coefficient of carbide and nitride ions would not be significant in case of CaO-rich region of XCaO / XCaF2 = 0.31. However, CaF2 could be expected to affect the activity coefficient of each ion in case of the Al2O3-rich region, causing compensating effect of the incorporated nitride (carbide) mechanism. The relationship between nitride and carbide capacity was also discussed. 相似文献
110.
Byung Joo Park Sung Woo Sohn Won Tae Kim Do Hyang Kim 《Journal of Alloys and Compounds》2009,483(1-2):260
Structural evolution during heat treatment of melt spun Ti36Y20Al24Co20 alloy was studied using differential scanning calorimetry, X-ray diffractometry and transmission electron microscopy. The as-melt spun Ti36Y20Al24Co20 specimen showed a hierarchical complex microstructure consisting of Ti-rich and Y-rich amorphous phases and crystallized with two-step process. Crystallization in the phase separated two phase mixture took place in a confined mode due to different thermal stability and complex microstructure, resulting in various nano-scaled microstructural formation ranging from fine distribution of crystalline particles in amorphous matrix to fine distribution of amorphous particles in crystalline matrix. 相似文献