• Journal of the Institute of Convergence Signal Processing
• /
• v.5 no.1
• /
• pp.18-24
• /
• 2004

SPECT technology is used for the reconstructed image in the field of industry noncontact measurement system. One of the distortion problems in reconstructed image quality is a collimator characterictic. The image distortion is caused by a geometrical structure of the collimator. This paper indicated a correction method to remove the image distortion by the structure of the collimator, and compared with the existing correction method. The correction. method removed the image distortion to use deconvolution of projection data with the shift-variant blurring function in the frequency domain. In this pater, I simulated with the collimator angle and distance between the detector and the center of object. and verified with expeimental data. The validity and limitation of correction method is studied for actual industrial applications.

• Proceedings of the Optical Society of Korea Conference
• /
• 1999.08a
• /
• pp.128-129
• /
• 1999

Polygon Mirror Scanning(PMS) is composed of LED array, magnifying lens, polygon mirror and motor. It is important to correct the lens aberrations to gain the image we want to show. In this paper, we have simulated the lens aberration correction to reduce the spherical aberration . We have obtained a aspherical lens which is corrected the spherical aberration.

• Korean Journal of Remote Sensing
• /
• v.38 no.3
• /
• pp.283-298
• /
• 2022

As Synthetic Aperture Radar (SAR) image can be acquired regardless of the weather and day or night, it is highly recommended to be used for Automatic Target Recognition (ATR) in the fields of surveillance, reconnaissance, and national security. However, there are some limitations in terms of cost and operation to build various and vast amounts of target images for the SAR-ATR system. Recently, interest in the development of an ATR system based on simulated SAR images using a target model is increasing. Attributed Scattering Center (ASC) matching and template matching mainly used in SAR-ATR are applied to target classification. The method based on ASC matching was developed by World View Vector (WVV) feature reconstruction and Weighted Bipartite Graph Matching (WBGM). The template matching was carried out by calculating the correlation coefficient between two simulated images reconstructed with adjacent points to each other. For the performance analysis of the two proposed methods, the Synthetic and Measured Paired Labeled Experiment (SAMPLE) dataset was used, which has been recently published by the U.S. Defense Advanced Research Projects Agency (DARPA). We conducted experiments under standard operating conditions, partial target occlusion, and random occlusion. The performance of the ASC matching is generally superior to that of the template matching. Under the standard operating condition, the average recognition rate of the ASC matching is 85.1%, and the rate of the template matching is 74.4%. Also, the ASC matching has less performance variation across 10 targets. The ASC matching performed about 10% higher than the template matching according to the amount of target partial occlusion, and even with 60% random occlusion, the recognition rate was 73.4%.

• Archives of Plastic Surgery
• /
• v.46 no.3
• /
• pp.248-254
• /
• 2019

Background No head to head comparison is available between surgical lip lifting and upper lip filler injections to decide which technique yields the best results in patients. Despite the growing popularity of upper lip augmentation, its effect on societal perceptions of attractiveness, successfulness and overall health in woman is unknown. Methods Blinded casual observers viewed three versions of independent images of 15 unique patient lower faces for a total of 45 images. Observers rated the attractiveness, perceived success, and perceived overall health for each patient image. Facial perception questions were answered on a visual analog scale from 0 to 100, where higher scores corresponded to more positive responses. Results Two hundred and seventeen random observers with an average age of 47 years (standard deviation, 15.9) rated the images. The majority of observers were females (n=183, 84%) of white race (n=174, 80%) and had at least some college education (n=202, 93%). The marginal mean score for perceived attractiveness from the natural condition was 1.5 points (95% confidence interval [CI], 0.9-2.18) higher than perceived attractiveness from the simulated upper lip filler injection condition, and 2.6 points higher (95% CI, 1.95-3.24) than the simulated upper lip lift condition. There was a moderate to strong correlation between the scores of the same observer. Conclusions Simulated upper lip augmentation is amenable to social perception analysis. Scores of the same observer for attractiveness, successfulness, and overall health are strongly correlated. Overall, the natural condition had the highest scores in all categories, followed by simulated upper lip filler, and lastly simulated upper lip lift.

• Journal of computational fluids engineering
• /
• v.20 no.2
• /
• pp.96-102
• /
• 2015

In this study, the green water phenomena on rectangular shaped structure is numerically simulated by STAR-CCM+ to investigate the flow pattern including the velocity profiles in bubbly water flow. 5 phases of the formation of green water in front of and over the rectangular shaped structure is simulated at the design condition which is scaled down by 1:125 from FPSO operating in GOM. All numerical results are compared with the experimental results performed in a two dimensional wave flume. The water deformation due to the green water are obtained by the high speed CCD camera with employing the shadow graphy technique, which is allowed to take the bubbly water flow into images. A series of image taken by shadow graphy technique is analyzed with MQD method to calculate the velocity in bubbly water flow.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.11 no.2
• /
• pp.33-42
• /
• 2009

The purpose of this study was to research the development of jacquard fabrics by the Bi-Dan patterns of Dan-Chung as one of the traditional korean symbols. For performing this design study, it designed a surface design of the geometric images in Bi-Dan patterns using by EAT Jacquard Textile CAD system and simulated to fabrics for the clothing & bags. To consider the modern image of Bi-Dan patterns in the Dan-Chung motives, the theoretical background was made on the basic elements, compositions and symbolic meanings of Dan-Chung patterns. To merchandise the fashion items and see the visual image, these jacquard fabric simulations was processed by two-dimension modeling through YoungWoo CNI CAD. The applied weave structure was based on a single layer of 5 or 10 points-satin and a double layer of 8 points-satin. Among the fabric simulations of Bi-Dan patterns, the six simulated fabrics were woven into the real jacquard fabrics under the electronic Stabuli jacquard loom in $120{\sim}130$ picks per inch and 171 ends per inch. These developed jacquard fabrics of Bi-Dan patterns were appeared a contemporary yet ethnic feeling so that they could make use of the unique korean cultural products by the further commercialization.

• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.331-336
• /
• 1999

The optical sensors of Electro-Optical Camera (EOC) and Ocean Scanning Multi-spectral Imager (OSMI) aboard the Korea Multi-Purpose SATellite (KOMPSAT) will be placed in a sun synchronous orbit in 1999. The EOC and OSMI sensors are expected to produce the land mapping imagery of Korean territory and the ocean color imagery of world oceans, respectively. Utilization of the EOC and OSMI data would encompass the various fields of science and technology such as land mapping, land use and development, flood monitoring, biological oceanography, fishery, and environmental monitoring. Readiness of data support for user community is thus essential to the success of the KOMPSAT program. As part of testing such readiness prior to the KOMPSAT launch, we have performed the preliminary acceptance test for the KOMPSAT data processing system using the simulated EOC and OSMI data sets. The purpose of this paper is to demonstrate the readiness of the KOMPSAT data processing system, and to help data users understand how the KOMPSAT EOC and OSMI data are processed and archived. Test results demonstrate that all requirements described in the data processing specification have been met, and that the image integrity is maintained for all products. It is however noted that since the product accuracy is limited by the simulated sensor data, any quantitative assessment of image products can not be made until actual KOMPSAT images will be acquired.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.1 no.1
• /
• pp.35-39
• /
• 2008

In this paper, we have developed a propagation loss prediction software with GUI (Graphic User Interface) functions, based on the geometrical ray optics model, which can predict radio parameters for the deployment of wireless indoor network. The program has two numerical modules consisted with electrical image and ray launching methods to implement UTD theory. The simulated results are compared with reported data measured in the foreign building environments for office and '一' type corridor, and measured and simulated results for the propagation loss agree with each other quite well. Simulation results for '一' type corridor and 'T' type corridor propagation environment are shown for reference.

• Journal of the Optical Society of Korea
• /
• v.20 no.6
• /
• pp.653-662
• /
• 2016

An optimized multilayer superlens is designed, using a rigorous and efficient approach based on the method of moments (MoM) in conjunction with a simulated annealing (SA) algorithm. For the MoM solution, fast evaluation of closed-form Green's functions (GFs) in the spatial domain is performed by applying the complex-image (CI) technique, which obviates the time-consuming numerical evaluation of Sommerfeld integrals. The imaging capability of the superlens is examined with the correlation coefficient; results show that using circular polarization for the incident wave can improve this coefficient. To validate the proposed method, finite-element-based simulations are exploited, which reveal the method's accuracy and computational efficiency. Simulation results indicate that the designed structure is capable of producing two-dimensional sub-diffraction-limited images in the visible range, which may make it more versatile for practical applications. Finally, as a considerable finding, it is demonstrated for the proposed design that using circularly polarized illumination provides improved super-resolving performance, compared to linearly polarized illumination.

• Nuclear Engineering and Technology
• /
• v.55 no.10
• /
• pp.3700-3708
• /
• 2023

The stochastic origin ensembles method with resolution recovery (SOE-RR) has been proposed to reconstruct proton-induced prompt gammas (PGs), and the reconstructed PG image was used for range verification. However, due to low detection efficiency, the number of valid events is low. Such a low-count condition can degrade the accuracy of the SOE-RR method for proton range verification. In this study, we proposed two strategies to improve the reconstruction of the SOE-RR algorithm for low-count PG imaging. We also studied the number of iterations and repetitions required to achieve reliable range verification. We simulated a proton beam (10⁸ protons) irradiated on a water phantom and used a two-layer Compton camera to detect 4.44-MeV PGs. Our simulated results show that combining the SOE-RR algorithm with restricted volume (SOE-RR-RV) can reduce the error of the estimation of the Bragg peak position from 5.0 mm to 2.5 mm. We also found that the SOE-RR-RV algorithm initialized using a back-projection image could improve the convergence rate while maintaining accurate range verification. Finally, we observed that the improved SOE-RR algorithm set for 60,000 iterations and 25 repetitions could provide reliable PG images. Based on the proposed reconstruction strategies, the SOE-RR algorithm has the potential to achieve a positioning error of 2.5 mm for low-count PG imaging.