• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.391-394
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• 2017

Persons with low vision impairment refers to visual and visual impairments that can not be remedied by medical or optical methods due to inherited or acquired eye disease. People with low vision impairments account for more than 240 million people in the world and have only a few remaining eyesight. We will discuss the improvement of information accessibility of low visually impaired people and future research methods through research on Web UI/UX in mobile web environment for low visibility handicapped in the environment where information can be accessed through existing screen reader (TTS) and screen enlargement function.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.587-592
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• 2002

A new digital correlator fur an airborne synthetic aperture radiometer was designed in order to replace the conventional analog correlator unit which will become very complicated while the number of channels is increasing. The digital correlator uses digital IQ demodulator instead of the intermediate frequency (IF) phase shifter to make the correlation processing performed digitally at base band instead of analogly at IF. This technique has been applied to the digital receiver in softradio. The down-converted IF signals from each pair of receiver channels become low rate base-band digital signals after under-sampled, Digitally Down-Converted (DDC), decimated and filtered by FIR filters. The digital signals are further processed by two digital multipliers (complex correlation), the products are integrated by the integrators and finally the outputs from the integrators compose of the real part and the imaginary part of a sample of the visibility function. This design is tested by comparing the results from digital correlators and that from analog correlators. They are agreed with each other very well. Due to the fact that the digital correlators are realized with the help of Analog-Digital Converter (ADC) chips and the FPGA technology, the realized volume, mass, power consumption and complexity turned out to be greatly reduced compared with that of the analog correlators. Simulations show that the resolution of ADC has an influence on the synthesized antenna patterns, but this can be neglected if more than 2bit is used.

• Journal of IKEEE
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• v.26 no.3
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• pp.401-407
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• 2022

Recently, image processing technology for autonomous driving by recognizing objects and lanes through camera images to realize autonomous vehicles is being studied. Haze reduces the visibility of images captured by the camera and causes malfunctions of autonomous vehicles. To solve this, it is necessary to apply the haze removal function that can be processed in real time to the camera. Therefore, in this paper, the fog removal method of Sim with excellent performance is implemented with hardware capable of real-time processing. The proposed hardware was designed using Verilog HDL, and FPGA was implemented by setting Xilinx's xc7z045-2ffg900 as the target device. As a result of logic synthesis using Xilinx Vivado program, it has a maximum operating frequency of 276.932MHz and a maximum processing speed of 31.279fps in a 4K (4096×2160) high-resolution environment, thus satisfying the real-time processing standard.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.40.3-41
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• 2021

Minor mergers leave behind long lived, but extremely faint and extended tidal features including tails, streams, loops and plumes. These act as a fossil record for the host galaxy's past interactions, allowing us to infer recent accretion histories and place constraints on the properties and nature of a galaxy's dark matter halo. However, shallow imaging or small homogeneous samples of past surveys have resulted in weak observational constraints on the role of galaxy mergers and interactions in galaxy assembly. The Rubin Observatory, which is optimised to deliver fast, wide field-of-view imaging, will enable deep and unbiased observations over the 18,000 square degrees of the Legacy Survey of Space and Time (LSST), resulting in samples of potentially of millions of objects undergoing tidal interactions. Using realistic mock images produced with state-of-the-art cosmological simulations we perform a comprehensive theoretical investigation of the extended diffuse light around galaxies and galaxy groups down to low stellar mass densities. We consider the nature, frequency and visibility of tidal features and debris across a range of environments and stellar masses as well as their reliability as an indicator of galaxy accretion histories. We consider how observational biases such as projection effects, the point-spread-function and survey depth may effect the proper characterisation and measurement of tidal features, finding that LSST will be capable of recovering much of the flux found in the outskirts of L* galaxies at redshifts beyond local volume. In our simulated sample, tidal features are ubiquitous In L* galaxies and remain common even at significantly lower masses (M*>10^10 Msun). The fraction of stellar mass found in tidal features increases towards higher masses, rising to 5-10% for the most massive objects in our sample (M*~10^11.5 Msun). Such objects frequently exhibit many distinct tidal features often with complex morphologies, becoming increasingly numerous with increased depth. The interpretation and characterisation of such features can vary significantly with orientation and imaging depth. Our findings demonstrate the importance of accounting for the biases that arise from projection effects and surface-brightness limits and suggest that, even after the LSST is complete, much of the discovery space in low surface-brightness Universe will remain to be explored.

• Archives of design research
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• v.14 no.1
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• pp.35-46
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• 2001

Recently varieties of user groups are formed as the number of people using cyber chatting gets increased and there are many changes in the range and field of its use. But because most of the cyber chatting systems are being operated to enlarge the additional sonics use, the using environments are stereotyped. And as its function is being various as well, it can not provide with a user-centered environment. So this thesis compares and analyzes the problems derived from the usability evaluation for solving the problems in using cyber chatting systems, and presents the guidelines of emotion-intended user interface design for improving the usability as the result of the analysis. First, this study investigates cyber chatting systems as a means of web communication tools through the existing literatures. Secondly, this study finds out the problems in using them through satisfaction evaluation, heuristic evaluation, performance evaluation, and observation evaluation and presents a way of solving the provisional problems in using them as the analysis of the result of usability evaluation. And this was proceeded for the purpose of applying and activating the better usability evaluation of cyber chatting systems later. Through the usability evaluation, it is found out that the structuralization of chatting function, the screen visibility by the size and arrangement of the compositional elements of a screen, and the improvement and development of the proper metaphor use of images and functions by the communication environment are necessary.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.135-140
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• 2008

Purpose: Fatty liver is one of the most commonly found disease by abdominal ultrasonography. The status of fatty liver is classified into mild, moderate and severe degrees. The study was conducted to investigate the clinical significance of fatty liver using ultrasonography. Materials and method: Test set consisted of 2,185 patients who visited D healthcare center in Daejeon to receive an abdominal ultrasonic test from January to December 2007. Out of the 2185 patients, 524 patients was diagnosed as fatty liver (290 male and 234 female patients). They were divided into three groups, group I for mild degree. II for moderate degree, and III for severe degree, depending on the echo of liver parenchyma, the sound attenuation, and the visibility of intrahepatic blood vessels and diaphragm. Then the correlation of obesity indices, liver function tests and metabolic syndrome was analyzed for males and females separately. Results : As for the degree of fatty liver, 350 cases (66.8%) were classified as group I, 153 cases (29.2%) as group II, and 21 cases (4.1%) as group III. In addition, severe degree of fatty liver was more frequently found in males than in females. The mean ages of three groups for males were 46.1, 44.5, and 39.1, and those for females were 48.8, 50.2, 52.4, respectively. Males with lower mean ages have severely of fatty liver for both males and females. Conclusion: The results in this study show that the classification into three degrees of fatty liver in ultrasonography practice is helpful to treat and observe the progress of fatty liver. In addition, careful examination is required to measure the severity of fatty liver as well as detection of it. A standardized method to classify the degree of fatty liver is also needed for more objective measurement.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.1
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• pp.63-76
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• 1999

The main objective of this study was to develop a concept of service marketing promotion in nursing that is derived from the concepts of service marketing theory. This research was a descriptive study, at the factor isolation level. The principle of concept derivation suggested by Walker and Avant (1988) and the Hybrid model suggested by Schwarz-Barcott and Kim (1993) were employed as the research method. The data were collected from December, 1997 to April. 1998 at a large general hospital located in Seoul. The procedures of this study were as follows: First. at the theoretical phase: the meaning, attributes, and definition of service marketing promotion were identified through an extensive review of the literature. Second, at the empirical phase: fieldwork was done to identify the promotional activities and events in nursing. Top nurse managers from 4 units (Director of Nursing, Head nurses of inpatient nursing unit, outpatient nursing unit. and home care nursing unit) were interviewed and the content of the interview was analyzed to identify the meaning and attributes of promotion in nursing. Other methods such as brochures and other audio-visual materials which were relevant to nursing promotion were used to supplement the interviews. Finally, the results of the theoretical and empirical analyses were intergrated to develop a concept of service marketing in nursing practice. A final definition of service marketing promotion in nursing was identified as follows. 1. Promotion as a marketing function in nursing service is concerned with communication to target markets on all information related to nursing service in order to satisfy the objectives of both a nursing service organization and the target markets. 2. The goals of nursing service promotion include: 1) increasing visibility of nursing services and delivering the information on nursing services, 2) affirming the value of nursing services, so it can contribute to formulation of reimbursement policy for nursing services. 3) advancing the general image of the nursing profession and nursing services. 4) achieving and attaining a desirable positioning for nurses among health care professionals. and 5) creating and stimulating the demand for nursing services. 3. In order to obtain these goals it is necessary to provide information on nursing services, to persuade target markets. to remind them about nursing services. and to establish a collaborative relationship with related departments. 4. The tools used to carry out the above functions of promotion in nursing are the providing nursing services, public relations and publicity. QA of nursing, advertising, and sales promotion. 5. The target markets of nursing service include the nursing customer markets. the internal markets, the influence markets. the recruitment markets. the supplier markets. and the nursing referral markets. In conclusion, the concept of promotion in other service marketing areas can be applied to the promotion of nursing service marketing. The promotion of nursing service is more than just effective communication in nursing service. it is the effective use of the concepts of service marketing promotion. Promotion of nursing service will contribute to create and expand nursing services.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.169-177
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• 2015

Purpose: The objects of this study were to examine the thickness of labial plate of anterior maxillary teeth and the gingival biotype in Koreans and to evaluate whether there is a correlation between the gingival biotype and the thickness of labial plate. Materials and Methods: This study was performed on 335 teeth of 57 subjects at the Pusan National University Dental Hospital. Cone Beam Computed Tomography (CBCT) was used to measure the thickness of labial plate at 4 mm, 6 mm, 8 mm from the cementoenamel junction and the gingival biotype was determined by the visibility of periodontal probe. Results: Thin facial bone less than 1 mm was observed in 87% at 4 mm, 88% at 6 mm and 90% at 8 mm. In 21% of total objects, thin gingival biotype was observed. There is no correlation between the thickness of labial plate and gingival biotype. Conclusion: Additional thorough radiographic examination such as CBCT was mandatory for aesthetic dental implant in the anterior dentition besides clinical oral examination.

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.68-78
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• 2021

A subminiature catadioptric omnidirectional optical system (SCOOS) with 2 mirrors, 6 plastic aspherical lenses, and an illumination system of 6 light emitting diodes, to observe the 360° panoramic image of the inner intestine, is optically designed and evaluated for a capsule endoscope. The total length, overall length, half field of view (HFOV), and F-number of the SCOOS are 14.3 mm, 8.93 mm, 51°~120°, and 3.5, respectively. The optical system has a complementary metal-oxide-semiconductor sensor with 0.1 megapixels, and an illumination system of 6 light-emitting diodes (LEDs) with 0.25 lm to illuminate on the 360° side view of the intestine along the optical axis. As a result, the spatial frequency at the modulation transfer function (MTF) of 0.3, the depth of focus, and the cumulative probability of tolerance at the Nyquist frequency of 44 lp/mm and MTF of 0.3 of the optimized optical system are obtained as 130 lp/mm, -0.097 mm to +0.076 mm, and 90.5%, respectively. Additionally, the simulated illuminance of the LED illumination system at the inner surface of the intestine within HFOV, at a distance of 15.0 mm from the optical axis, is from a minimum of 315 lx to a maximum of 725 lx, which is a sufficient illumination and visibility.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.77-85
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• 2024

In this dissertation, a we designed and implemented a patrol robot that integrates a thermal imaging camera, speed dome camera, PTZ camera, radar, lidar sensor, and smartphone. This robot has the ability to monitor and respond efficiently even in complex environments, and is especially designed to demonstrate high performance even at night or in low visibility conditions. An orbital movement system was selected for the robot's mobility, and a smartphone-based control system was developed for real-time data processing and decision-making. The combination of various sensors allows the robot to comprehensively perceive the environment and quickly detect hazards. Thermal imaging cameras are used for night surveillance, speed domes and PTZ cameras are used for wide-area monitoring, and radar and LIDAR are used for obstacle detection and avoidance. The smartphone-based control system provides a user-friendly interface. The proposed robot system can be used in various fields such as security, surveillance, and disaster response. Future research should include improving the robot's autonomous patrol algorithm, developing a multi-robot collaboration system, and long-term testing in a real environment. This study is expected to contribute to the development of the field of intelligent surveillance robots.