• Journal of Korea Multimedia Society
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• v.21 no.12
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• pp.1467-1472
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• 2018

For the problem that the face image of surveillance video cannot be accurately identified due to the low resolution, this paper proposes a low resolution face recognition solution based on convolutional neural network model. Convolutional Neural Networks (CNN) model for multi-scale input The CNN model for multi-scale input is an improvement over the existing "two-step method" in which low-resolution images are up-sampled using a simple bi-cubic interpolation method. Then, the up sampled image and the high-resolution image are mixed as a model training sample. The CNN model learns the common feature space of the high- and low-resolution images, and then measures the feature similarity through the cosine distance. Finally, the recognition result is given. The experiments on the CMU PIE and Extended Yale B datasets show that the accuracy of the model is better than other comparison methods. Compared with the CMDA_BGE algorithm with the highest recognition rate, the accuracy rate is 2.5%~9.9%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.511-512
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.841-842
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• 2011

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.1-14
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• 2015

This study investigates the impact of enhanced regional meteorological fields on improvement of wind energy forecasting accuracy in the southwestern coast of the Korean Peninsula. To clarify the effect of detailed surface boundary data and application of analysis nudging technique on simulated meteorological fields, several WRF simulations were carried out. Case_LT, which is a simulation with high resolution terrain height and land use data, shows the most remarkable accuracy improvement along the shoreline mainly due to modified surface characteristics such as albedo, roughness length and thermal inertia. Case_RS with high resolution SST data shows accurate SST distributions compared to observation data, and they led to change in land and sea breeze circulation. Case_GN, grid nudging applied simulation, also shows changed temperature and wind fields. Especially, the application of grid nudging dominantly influences on the change of horizontal wind components in comparison with vertical wind component.

• Journal of Korean Neurosurgical Society
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• v.54 no.5
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• pp.431-433
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• 2013

Acute subdural hematoma is usually a neurological emergency that requires hematoma evacuation or close observation. However, spontaneous resolutions of an acute subdural hematoma without surgical interventions have been reported rarely. We report on a case who showed rapid resolution of an acute subdural hematoma with neurological improvement and review the relevant literatures.

• Journal of Biomedical Engineering Research
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• v.9 no.1
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• pp.87-92
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• 1988

In this paper, a new focusing method, to be called the pipelined sampled delay focusing (PSDF), is implemented. This method improves the lateral resolution in ultrasound imaging system. In PSDF, the analog belay lines are no longer necessary because sampling sum process can replace the conventional delay sum process. Also, the method offers continuous dynamic focusing on the resolution pixel basis, and eliminates the constraint that the maximum delay time is less than the sampling interval. Second order sampling is adopted in order to extend the sampling interval.

• Journal of IKEEE
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• v.22 no.2
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• pp.514-517
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• 2018

In sensor systems, ADC (analog-to-digital converter) demands high resolution, low power consumption, and high signal bandwidth. Sigma-delta ADC achieves high resolution by high order structure and high over-sampling ratio, but it suffers from high power consumption and low signal bandwidth. SAR (successive-approximation-register) ADC achieves low power consumption, but there is a limitation to achieve high resolution due to process mismatch. This paper surveys architecture improvement of ADC to overcome these problems.

• Macromolecular Research
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• v.14 no.5
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• pp.559-564
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• 2006

The improvement of spatial resolution is a fundamental issue in the two-photon, polymerization-based, laser writing. In this study, a voxel tuning method using a radical quencher was proposed to increase the resolution, and the quenching effect according to the amount of radical quencher was experimentally investigated. Employing the proposed method, the lateral resolution of the line patterns was improved almost to 100 nm. However, a shortcoming of the quenching effect was the low mechanical strength of polymerized structures due to their short chain lengths. Nano-indentation tests were conducted to evaluate quantitatively the relationship between mechanical strength and the mixture ratio of the radical quencher into the resins. The elastic modulus was dramatically reduced from an average value of 3.015 to 2.078 GPa when 5 wt% of radical quencher was mixed into the resin. Three-dimensional woodpile structures were fabricated to compare the strength between the resin containing radical quencher and the original resin.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.29-32
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• 2007

We analyzed the effect of cell resolution on the luminous efficacy through three-dimensional numerical simulation to understand the inherent discharge mechanism change in the plasma display panel. As the resolution increases from VGA to Full HD, the luminous efficacy decreases. With higher Xe content, VUV generation efficacy of Full HD becomes much lower than those of VGA or XGA cells, due to the increased plasma loss and lower electron heating. However a long electrode gap $140{\mu}m$ in Full HD cell with Ne-Xe [20%] results in the high luminous efficacy comparable to that of the XGA cell with $60{\mu}m$ gap. When comparing the effects of Xe content variation on the luminous efficacy of two different subpixel types, i. e., SDE (Segmented electrode in Delta color arrayed, Enclosed subpixel) [1] and conventional stripe barrier type in the XGA and Full HD cells, the luminous efficacy of SDE structure shows higher improvement in Full HD resolution compared with that of conventional type XGA cell, whose cause is identified as the reduced plasma loss.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.5-11
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• 1999

This paper reviews recent major activities on instrumentation and methodology of PET. The performance of the PET instrumentation can be expressed by four physical characteristics, 1) spatial resolution, 2) coincidence resolving time, 3) energy resolution, and 4) detection efficiency. The physical and technical aspects of PET systems are briefly discussed along with these characteristics. Toward high resolution PET the recent trend has been to design multiple rings of densely packed detector arrays with scintillators. In order to satisfy the sampling requirement in reconstruction, continuous detector units has been developed. Iterative image reconstruction algorithms have received considerable attention for improvement of both the sampling requirement and image quality toward the stationary PET. Better resolving time improves the maximum true coincidence rate, which is also increased with more detectors placed in coincidence with each other. It suggests that volume PET is promising for enhancement of detection efficiency. The scattered coincidence event rate may be reduced by using detectors with better energy resolution. The use of interplane septa, however, takes over improvement of energy resolution in 2D PET. Energy resolution becomes an important factor for image quality under the condition of septa removal such as volume PET. Toward full utilization of emitting photons, 3D reconstruction incorporating oblique rays has been studied, and volume reconstruction algorithms have been developed. Practical volume PET systems impose heavy burden not only to detector sets and coincidence circuits, but also to computers in the memory requirements and the data processing. In conclusion, there have been many ingenious methods in development of PET instrumentation, which are based on unique capability of PET. They will be expected to overcome technical limitations, and to approach the fundamental limits.