• Health Policy and Management
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• v.29 no.3
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• pp.312-322
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• 2019

Background: Since 2003, Korea has consistently shown the highest suicide rate among the Organization for Economic Cooperation and Development countries, and suicide remains the major cause of death. In particular, men are 2-3 times more likely to commit suicide than women, which called the 'gender paradox of suicide.' The areas with frequent suicide have spatially clustered patterns because suicide with a social contagion spreads around the neighborhood. The purpose of this study was twofold. The first was to estimate the hotspot areas of age-standardized male suicide mortality from 2008 to 2015. The second was to analyze the relationship between the hotspot areas and the regional characteristics for study years. Methods: The data was collected through the Korean Statistical Information Service. The study areas were 227 si gun gu administrative districts in Korea. The hotspot area was used as a dependent variable. Socio-demographic variables (number of marriages per 1,000 population, number of divorces per 1,000 population, and urbanization rate), financial variables (financial independence and social security budget), and health behaviors (EuroQol-5 dimension [EQ-5D], and depression experience rate) were used as independents variables. Results: The hotspot areas were commonly located in Gangwon-do, Chungcheongnam-do, Gyeongsangbuk-do, and Chungceongbuk-do. According to the results of panel logit regression, the number of divorces per 1,000 population, social security budget, and EQ-5D were statistically significant variables. Conclusion: The results of hotspot analysis showed the need for establishing a prevention zone of suicide using hotspot areas. Also, medical resources could be considered to be preferentially placed in the prevention zone of suicide. This study could be used as basic data for health policymakers to establish a suicide-related policy.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.310-314
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• 2008

The light from the exterior considerably deteriorates the performance of displays including PDP (plasma display panel). Thus semi-conductor industries have developed a special optical film that can block or absorb the exterior light. In this paper, we propose a new inspection system for tracing the defects of the film. Our system is able to inspect a $1.5\;m\;{\times}\;1\;m$ area for 10 sec with $127\;{\mu}m\;{\times}\;50{\mu}m$ spatial resolution.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.395-403
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• 2022

Flat-panel detector (FPD) used in digital radiographic imaging systems was used to perform a quantitative power spectrum evaluation as a result of the thickness change of polymethyl methacrylate (PMMA), a tissue equivalent. As the PMMA thickness increases with the resolution-chart phantom image, the effect of the scattering line increases, indicating that the modulation characteristics decrease, and the image is bright. The results show that the noise of the image increases, and noise-power spectral images are obtained by Fourier transform to confirm by spatial frequency. Thus, it can be verified that the PMMA thickness and noise are proportional through the result of evaluating the change of resolution characteristics and representing the 2D noise-power spectrum as one-dimensional values by evaluating the change of scattering line with MTF as the PMMA thickness increases in the image.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.368-374
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• 2024

During an X-ray examination, the beam of radiation is dispersed in many directions. We believe that managing radiation dose is about providing transparency to users and patients in the accurate investigation and analysis of radiation dose. The purpose of measuring the radiation dose as a function of location is to ensure that medical personnel using the equipment or participating in the operating room are minimally harmed by the different radiation doses depending on their location. Four mobile diagnostic X-ray units were used to analyze the radiation dose depending on the spatial location. The image intensifier and the flat panel detector type that receives the image analyzed the dose by angle to measure the distribution of the exposure dose by location. The radiation equipment used was composed of four units, and measuring devices were installed according to the location. The X-ray (C-arm) was measured by varying the position from 0 to 360 degrees, and the highest dose was measured at the center position based on the abdominal position, and the highest dose was measured at the 90° position for the head position when using the image intensifier equipment. The operator or medical staff can see that the radiation dose varies depending on the position of the diagnostic radiation generator. In the image intensifier and flat panel detector type that accepts images, the dose by angle was analyzed for the distribution of exposed dose by position, and the measurement method should be changed according to the provision of dose information that is different from the dose output from the equipment according to the position.

• Korean Journal of Remote Sensing
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• v.27 no.1
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• pp.33-41
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• 2011

In the information communication technology, it is world-widely apparent that trend movement from internet web to smartphone app by users demand and developers environment. So it needs kinds of appropriate technological responses from geo-spatial domain regarding this trend. However, most cases in the smartphone app are the map service and location recognition service, and uses of geo-spatial contents are somewhat on the limited level or on the prototype developing stage. In this study, app for extraction of corner point features using geo-spatial imagery and their linkage to database system are developed. Corner extraction is based on Harris algorithm, and all processing modules in database server, application server, and client interface composing app are designed and implemented based on open source. Extracted corner points are applied LOD(Level of Details) process to optimize on display panel. Additional useful function is provided that geo-spatial imagery can be superimposed with the digital map in the same area. It is expected that this app can be utilized to automatic establishment of POI (Point of Interests) or point-based land change detection purposes.

• 전자공학회논문지 IE
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• v.45 no.1
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• pp.7-14
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• 2008

In this paper, a new high resolution XGA-SLM is implemented through modification of a commercial TFT-LCD beam projector and its optical modulation characteristics as a spatial light modulator(SLM) is also analyzed. That is, the optics module, projection lamp and fans are removed from a commercial beam projector and instead, some electric circuits to compensate their removal are manufactured and then, by inserting them into the beam projector, a new XGA-SLM is finally implemented. From some characteristic experimental results of the implemented high resolution TFT-LCD SLM, the proposed TFT-SLM is found to have an good optical linearity in amplitude and phase modulation characteristics as a function of the input gray levels. Especially, through implementation of the suggested TFT-LCD panel, the implemented SLM is proposed as a new relatively low-cost and high resolution SLM for optical information processing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.716-725
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• 2004

In this paper, a new multiview stereoscopic 3D display system using a VHLS(volume holographic lenticular sheet) is suggested. The VHLS, which acts just like an optical direction modulator, can be implemented by recording the diffraction gratings corresponding each directional vector of the multiview stereoscopic images in the holographic recording material by using the angularly multiplexed recording property of the conventional volume hologram. Then, this fabricated VHLS is attached to the panel of a LCD spatial light modulator and used to diffract each of the multiview image loaded in a SLM to the corresponding spatial direction for making a 3D stereo view-zone. Accordingly, in this paper, the operational principle and characteristics of the VHLS are analyzed and an optimized 4-view VHLS is fabricated by using a commercial photopolymer. Then, a new VHLS-based 4-view stereoscopic 3D display system is implemented. Through some experimental results using a 4-view image synthesized with adaptive disparity estimation algorithm, it is suggested that implementation of a new VHLS-based multiview stereoscopic 3D display system can be possible.

• Health Policy and Management
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• v.21 no.1
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• pp.23-43
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• 2011

Access to health care is complicated to define. It is a multidimensional process. In addition to the matters of quality of care, geographical accessibility and availability of the right type of care, finance, and acceptability are all involved. The purposes of this paper are to measure the geographic distances between patient residency locations and health service organizations in which the patients hadvisited, and to investigate the association between geographical distance measures and variables involved in health service utilization. The study used the first and the second wave of the 2008 Korea Health Panel Survey. The samples of analyses were patients who had visited outpatient or used ambulatory health services, and the total observations (visit numbers) analyzed were 229,128. We divided the samples into a frequent-visit illness group (Group 1) and a non-frequent visit illness group (Group 2) based on over 5,000 total visit numbers. We exploited three level analyses using xtmixed of STATA${\Box}$ 11.1 command with/without interaction terms among age, sex, and occupation. Geographical distances were measured using the Haversine method. Group 1 was tended to older and lower equivalent income than those of Group 2, but the geographic difference were not observed in terms of area deprivation index and standard mortality ratios. Amongst group 1, diabetes mellitus patients travelled far to visit health care organizations, and arthritis patients were more deprived in terms of the personal and areal characteristics. The study revealed that residents in rural areas traveled about 10 times more long distances than those whom lived in larger cities after adjusting for various variables, which we used for analyses. This study contributed to the practical understanding of health service utilizations using empirical analyses, and found that the types of diseases and socioeconomic characteristics of patients tended to define the amount of travel distance to healthcare organizations.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.655-668
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• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.28-35
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• 2023

Moiré patterns emerge due to the interference between the non-emission area of the LED screen and the grid line in an image sensor of a video recording device when taking a video in the presence of the LED screen. To reduce the moiré intensity, we have fabricated an anti-moiré filter using hollow glass microspheres (HGMs) by slot-die coating. The LED screen has a large non-emission area because of a large pitch (distance between LED chips), causing more severe moiré phenomenon, compared with a display panel having a very narrow black matrix (BM). It is shown that HGMs diffuse light in such a way that the periodicity of the screen is broken and thus the moiré intensity weakens. To quantitatively analyze its moiré suppression capability, we have calculated the spatial frequencies of the moiré fringes using fast Fourier transform. It is addressed that the moiré phenomenon is suppressed and thus the amplitude of each discrete spatial frequency term is reduced as the HGM concentration is increased. Using the filter with the HGM concentration of 9 wt%, the moiré fringes appeared depending sensitively on the distance between the LED screen and the camera are almost completely removed and the visibility of a nature image is enhanced at a sacrifice of luminance.