• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.399-406
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• 2019

This study aims to find geometric parameters that the radiologist can change from time to time to reduce dose in angiography examinations. Depending on the geometric characteristics, the values calculated by effective dose were compared, while filming in fluoroscopy mode and Digital subtraction angiography, respectively. The study found that the lower the dose was in FPS mode, the lower the dose was reduced to 30-40%. Doses according to the X-ray angle were measured highest in AP View and lower as the angle went in the head direction. The greater the FOV, the higher the dose was 1.2-1.6 times, and the closer the distance between the X-ray tube and the table, the greater the dose was about 10%. Source-image intensifier distance (SID) get longer to 100 mm, dose of each fluoroscopy and Digital subtraction angiography increase up to 25-30%. In conclusion, various geometric characteristics in angiography examinations are parameters that can be applied by radiographers as frequently as possible, and appropriate geometric properties can be considered and applied in various situations, resulting in appropriate dose reduction.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.28-34
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• 2019

In this study, pin-fin arrays, which are widely used for cooling turbine blades, were studied. The vortex generator in pin-fin arrays is located in front of the circular tube. The cross-section of the vortex generator is NACA-9410. The purpose of this study is to analyze heat transfer performance and flow characteristics of pin-fin arrays. The position of vortex generator is changed with the vertical flow direction on the bottom wall. Pin-fin arrays were calculated with 6000, 10000 and 15000 Reynolds number. The commercial program ANSYS v18.0 CFX and the turbulence model $k-{\omega}$ SST were used. As a result, the heat transfer performance increased up to 5.8% and pressure loss increased less than 1%.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.533-541
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• 2020

This study aims for investigating the consumers' reaction to the New Hanbok Style of K-pop idol groups. We collected YouTube videos and user comments that include 'Black Pink New Hanbok' as a keyword, applying social network analysis and sentiment analysis. First, the New Hanbok of Black Pink was designed as a mini-dress to make it easier to dance and turned out that it reinterpreted traditional elements modernly. Second, the issue about revealing costumes appeared as a keyword in domestic reactions, it did not appear in international reaction. Third, as a result of sentiment analysis, international audience viewed New Hanbok outfit more positively than domestic audience. This study is significant in that it suggests the direction to which New Hanbok should head to by investigating extensive consumers' reaction and finding out the positive and negative elements of New Hanbok.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.25-35
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• 2021

We are able to watch international multimedia anytime and anywhere, if we have the devices to connect Internet. Netflix and Youtube are the most massive and the most visited streaming platforms in the world. So If audiences are not familiar with the exotic culture such as behaviors, contexts, sarcasm, history and the current issues, It would happen a consequence that they entirely have to rely on subtitles in order to get inform. This research hereby aims to compare Korean transcriptions of the same movies streamed by the two selected platforms(Netflix and Youtube). As a result, good translation is that translators should use appropriate omissions and detailed explanations in limited time and space so that audience can concentrate on the vedio. If translators study the work in depth and spend enough time working on it, the quality of translation will definitely increase. Finally, this study contributed to the revitalization of the video translation market, which is still in the past, through the misinterpretation of videos produced at a low unit price and with minimal time without guidelines for video translation.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.139-148
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• 2021

The study examines public attitude and reaction regarding administrative integration in Daegu and Gyeongbuk area. Specifically, it employs social big data including textual comments on online news articles and YouTube video clips. The collected data are analyzed in order to compare two periods, that is, before and after the inauguration of the Public Opinion Committee for One Daegu-Gyeongbuk. As a result, we have found that people's favorable response to administrative integration has gradually increased since the launch of the Committee. However, it still lacks specific administrative procedures and discussion topics among the frequently used words in the collected data. Thus, the Committee needs to provide a variety of information and materials related to administrative integration.

• Journal of Sensor Science and Technology
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• v.9 no.2
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• pp.96-105
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• 2000

Fiber optic TR-EFPI(total reflected extrtinsic Fabry-Perot interferometric) sensor was developed to measure the strain of structures, such as building, bridge, aircraft, etc. It has been difficult to distinguish the increase and decrease of the strain from the conventional fiber optic EFPI sensor because their signals only have a sinusoidal wave pattern related to the change of strain. Also, the absolute strain could not be measured by the simple fiber optic EFPI sensor. In this study, in order to measure the magnitude of strain with the direction of strain, the fiber optic sensor was simply constructed with the total reflected EFPI sensor probe. This probe was manufactured with a single mode fiber and a mirror coated fiber in a silica glass capillary tube. The output signal of this fiber optic TR-EFPT sensor can give the information about the magnitude and the direction of strain. The loading-unloading test was performed by the universal testing machine with alluminum beam specimen to compare the strain from fiber optic TR-EFPI sensor with the value from electrical strain gauge. In the result of this experiment. the strain from fiber optic TR-EFPI sensor had a good agreement with the values from the electrical strain gauge.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.172-180
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• 2007

A new diagnostics of plasma electron temperature and plasma density is introduced with the observation of the light emission along the tube of external electrode fluorescent lamps. With two different methods operating an external electrode fluorescent lamp of outer diameter 4.0 mm and length 860 mm for the back-light source of 37-inch LCD-TVs, the lighting modes and the plasma properties are investigated. In the center balance operation, the light-emission propagates simultaneously from both sides of the high voltage electrodes to the center of the lamp, while in conventional operation the light-emission propagates from the one end of a high voltage to the other ground electrode. In the operation value of luminance $10,000{\sim}15,000cd/m^2$, the electron plasma thermal energy $(kT_e)$ is about $1.3{\sim}2.7eV$ with the electron density $(n_e)$ is about $(1.6{\sim}3.6){\times}10^{16}m^{-3}$.

• Korean Security Journal
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• no.9
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• pp.201-235
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• 2005

This study is designed to contribute for development of Private Security Business by fact-finding in instruction and training of private security guard serviced in this realm and domestic and foreign guard service and modeling effective and rational instruction and training program based on drawn problem. For this study, basically I collected and analyzed documents, theses, and papers of the inside and outside of the country. For practical use of data, I used materials of private security related institutes and police agency. And for private security educating training programs of the inside and outside of the country, I collected materials on internet, and with the help of police agency and interpol. For korean private security company's educating training programs, I made a study with the interview of private security company's businessmen. This study's conclusion is as follows. In a domestic private security enterprise, when set theory instruction minimize instruction and training program and must set up instruction and training program as practical affairs center enemy instruction, and theory instruction must be composed for instruction me that it is connected to practical affairs instruction too. The instruction course of private security guard instruction and training program composed with a security outline, a security plan, an information-gathering, civilian expenses, a security way, terror and terrorism, a related law, security trial, electronic security, a security analysis technique, company introduction, instruction and training program about a professional tube with theory instruction. Practical affairs instruction composed with the selection and a preventive security, close contact attendance security, vehicle security, security driving the security martial arts and self-protection liquor, first aid, security equipment, a gun and shooting, a security protocol, customer satisfaction, facilities security and expenses, a fire fighting instruction, teamwork training, explosive and a dangerous substance, physical strength, a documentation practical affairs, service, instruction and training program about foreigh language instruction.

• Progress in Medical Physics
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• v.19 no.1
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• pp.35-41
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• 2008

The main benefit of proton therapy over photon beam radiotherapy is the absence of exit dose, which offers the opportunity for highly conformal dose distributions to target volume while simultaneously irradiating less normal tissue. For proton beam therapy two patient specific beam modifying devices are used. The aperture is used to shape the transverse extension of the proton beam to the shape of the tumor target and a patient-specific compensator attached to the block aperture when required and used to modify the beam range as required by the treatment plan for the patient. A block of range shifting material, shaped on one face in such a way that the distal end of the proton field in the patient takes the shape of the distal end of the target volume. The mechanical quality assurance of range compensator is an essential procedure to confirm the 3 dimensional patient-specific dose distributions. We proposed a new quality assurance method for range compensator based on image processing using X-ray tube of proton therapy treatment room. The depth information, boundaries of each depth of plan compensatorfile and x-ray image of compensator were analyzed and presented over 80% matching results with proposed QA program.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.230-237
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• 2011

In this study, the characteristic of fluid flow in the new type lung assist devices has been established using computational fluid dynamics(CFD). For the modeling, the hollow fiber was ignored, and vertical types and tangential types were used for the model. Which was to analyze the flow characteristics of the fluid flow model when there exists 1 and 2 input/output ports, and when the input/output ports is located at the center of the cylinder and at the tangential direction with the cylinder wall. The modeling results showed that it was possible to eliminate no-flow region(stagnant layer) as shown in the vertical type when an inlet and an outlet were installed on the tangential direction of the cylinder as shown in the tangential type. Also, in the tangential type, vortex-type flow appeared as dominant, and it showed a complicated flow not deviated to one side. When the number of input/output was two, there was no deviated flow, and complicated flows were generated all across the tube. From the test result, it was found that input/output of flow was tangential type and complicated flows with no stagnant layer would be generated when there are two inputs/outputs, respectively.