• Korean Journal of Radiology
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• v.23 no.8
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• pp.794-802
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• 2022

Objective: To evaluate the feasibility of single-shot whole thoracic time-resolved MR angiography (TR-MRA) to identify the feeding arteries of pulmonary arteriovenous malformations (PAVMs) and reperfusion of the lesion after embolization in patients with multiple PAVMs. Materials and Methods: Nine patients (8 females and 1 male; age range, 23-65 years) with a total of 62 PAVMs who underwent percutaneous embolization for multiple PAVMs and were subsequently followed up using TR-MRA and CT obtained within 6 months from each other were retrospectively reviewed. All imaging analyses were performed by two independent readers blinded to clinical information. The visibility of the feeding arteries on maximum intensity projection (MIP) reconstruction and multiplanar reconstruction (MPR) TR-MRA images was evaluated by comparing them to CT as a reference. The accuracy of TR-MRA for diagnosing reperfusion of the PAVM after embolization was assessed in a subgroup with angiographic confirmation. The reliability between the readers in interpreting the TR-MRA results was analyzed using kappa (κ) statistics. Results: Feeding arteries were visible on the original MIP images of TR-MRA in 82.3% (51/62) and 85.5% (53/62) of readers 1 and 2, respectively. Using the MPR, the rates increased to 93.5% (58/62) and 95.2% (59/62), respectively (κ = 0.760 and 0.792, respectively). Factors for invisibility were the course of feeding arteries in the anteroposterior plane, proximity to large enhancing vessels, adjacency to the chest wall, pulsation of the heart, and small feeding arteries. Thirty-seven PAVMs in five patients had angiographic confirmation of reperfusion status after embolization (32 occlusions and 5 reperfusions). TR-MRA showed 100% (5/5) sensitivity and 100% (32/32, including three cases in which the feeding arteries were not visible on TR-MRA) specificity for both readers. Conclusion: Single-shot whole thoracic TR-MRA with MPR showed good visibility of the feeding arteries of PAVMs and high accuracy in diagnosing reperfusion after embolization. Single-shot whole thoracic TR-MRA may be a feasible method for the follow-up of patients with multiple PAVMs.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.310-339
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• 2015

In this paper, the possibility of a terrestrial fixed 4K UHD (Ultra High Definition) and mobile HD (High Definition) convergence broadcasting service through a single channel employing the FEF (Future Extension Frame) multiplexing technique in DVB (Digital Video Broadcasting)-T2 (Second Generation Terrestrial) systems is examined. The performance of such a service is also investigated. FEF multiplexing technology can be used to adjust the FFT (fast Fourier transform) and CP (cyclic prefix) size for each layer, whereas M-PLP (Multiple-Physical Layer Pipe) multiplexing technology in DVB-T2 systems cannot. The convergence broadcasting service scenario, which can provide fixed 4K UHD and mobile HD broadcasting through a single terrestrial channel, is described, and transmission requirements of the SHVC (Scalable High Efficiency Video Coding) technique are predicted. A convergence broadcasting transmission system structure is described by employing FEF and transmission technologies in DVB-T2 systems. Optimized transmission parameters are drawn to transmit 4K UHD and HD convergence broadcasting by employing a convergence broadcasting transmission structure, and the reception performance of the optimized transmission parameters under AWGN (additive white Gaussian noise), static Brazil-D, and time-varying TU (Typical Urban)-6 channels is examined using computer simulations to find the TOV (threshold of visibility). From the results, for the 6 and 8 MHz bandwidths, reliable reception of both fixed 4K UHD and mobile HD layer data can be achieved under a static fixed and very fast fading multipath channel.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.1
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• pp.33-40
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• 2018

Purpose: The main objective of this paper is, to assess environment, care process, and patient-related factors associated with patient falls. The study also aims at identifying various factors that would affect inpatient falls and, therefore, helping both caregivers and designers contribute to better prevent inpatient falls in their own areas of expertise. Methods: A retrospective analysis of inpatient falls that occurred in the unit of General Medicine in the United States has been conducted and environment, care process, patient-related factors associated with those falls have been analyzed at the same time. Results: The study identified several factors associated with inpatient falls. They range from environmental factors to care process- and patient-related factors. Patient visibility and patient accessibility can matter to patient falls and where those falls occur, along with patient days per room, the percentage of patient days with high fall risk patients per room, the percentage of high fall risk patients per room. Implications: The findings of the study can provide design implications that can be incorporated into design process and design decisions to promote fall prevention in inpatient care units. Inpatient falls can be effectively reduced when caregivers and designers work together to understand the complex nature of inpatient falls and the importance of multidisplinary efforts among various experts in the areas of healthcare.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.13-21
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• 2016

The vertical distributions of aerosol extinction coefficient were estimated using the scaling height retrieved at Gwangju, Korea ($35.23^{\circ}N$, $126.84^{\circ}E$) during a spring season (March to May) of 2009. The aerosol scaling heights were calculated on a basis of the aerosol optical depth (AOD) and the surface visibilities. During the observation period, the scaling heights varied between 3.55 km and 0.39 km. The retrieved vertical profiles of extinction coefficient from these scaling heights were compared with extinction profile derived from the Light Detection and Ranging (LIDAR) observation. The retrieve vertical profiles of aerosol extinction coefficient were categorized into three classes according to the values of AODs and the surface visibilities: (Case I) the AODs and the surface visibilities are measured as both high, (Case II) the AODs and the surface visibilities are both lower, and (Others) the others. The averaged scaling heights for the three cases were $3.09{\pm}0.46km$, $0.82{\pm}0.27km$, and $1.46{\pm}0.57km$, respectively. For Case I, differences between the vertical profile retrieved from the scaling height and the LIDAR observation was highest. Because aerosols in Case I are considered as dust-dominant, uplifted dust above planetary boundary layer (PBL) was influenced this discrepancy. However, for the Case II and other cases, the modelled vertical aerosol extinction profiles from the scaling heights are in good agreement with the results from the LIDAR observation. Although limitation in the current modelling of vertical structure of aerosols exists for aerosol layers above PBL, the results are promising to assess aerosol profile without high-cost instruments.

• Fashion & Textile Research Journal
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• v.6 no.2
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• pp.163-168
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• 2004

The domestic textile industry is currently making an active effort to present high value-added materials that can respond immediately to the wants and needs of consumers sensitive to the of originality of design and emotionally appealing fashion materials. This paper attempted to present the creative development of materials in the contemporary clothing culture in which consumers' needs are individualized and differentiated and the cycle of life in fashion materials is getting shorter. To be specific, the paper presented the texture of peculiar expression to diverse cotton materials using the Woolsmok technique in the processing of felt. The chosen Merino wool was felted to 8 kinds of cotton with different density and structure. The touch, texture, visibility and complex susceptibilities of new materials were presented as different materials of cotton and wool were transformed into one material. In felting cotton fiber through wool, the transformation of diverse textures was presented and compared in the method using the washing machine in an attempt to enhance the efficiency of the traditional craft technique and work. This study proposed the possibility of placing the new material made up of cotton and wool beyond the range of functionality of each simple material, activating it as the peculiar material and expanding it to the range of its use as fashion material in the clothing industry. It is expected that this material will become competitive material at home and abroad by being activated as the clothing material of artistry, workability and marketability that can satisfy the tastes of consumers who call for high quality and diversification.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4A
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• pp.219-226
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• 2012

We investigated the performance of a visible light communication (VLC) transceiver applicable to both of illumination and wireless communication. we considered the visibility of VLC, the easy connection for wireless communication and high-speed transmission and implemented VLC transceiver based on edge-emitting laser diode and silicon photodiode. The proposed VLC transceiver is designated to operate in a full duplex mode at high speed of 120 Mbit/s. The shielding method that is employed as a means to reduce the light cross coupling effect inside the VLC transceiver is proposed and its performance is experimentally measured. We also applied optical antenna to have the larger angle of field of view (FOV) to novel structure of VLC transceiver and examined and analyzed their bit error rate performance, photometric result with respect to the transmission distance, the coverage range and the tilt degree as transmission link characteristic between two transceivers without optical antenna and with optical antenna.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.74-83
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• 2008

As urban residents' standard of living has recently risen, efforts to improve urban landscapes have increased. It is very important to manage streetscapes to improve the urban landscape because they are one of the essential elements in city construction and urban landscaping. This study focuses on the indicators that manage streetscapes more accurately and realistically. To achieve this purpose, this study used dynamic simulations considering shape and layout of buildings, the primary factors in streetscapes. This study can be summarized as follows: 1. Two indicators to manage streetscape were investigated in previous studies: one to increase visual openness and the other to reduce visual overstimulation. These indicators had high correlation with scenic beauty. Therefore, increasing openness and reducing overstimulation are essential to improve streetscapes. 2. Two household tower type buildings should be arranged along roadsides to increase openness and scenic beauty. However, low tower buildings with two household are not suitable along roadsides because they create monotony and intervals are needed between buildings. 3. To increase openness, the angled arrangement of buildings is suggested $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for low buildings, $30^{\circ}{\sim}45^{\circ}(135^{\circ}{\sim}150^{\circ})$ for mid-sized buildings, and $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for high buildings. 4. To reduce overstimulation, the height and setback control regulations should be at an angle of less than $45^{\circ}$. This study suggests more accurate management guidelines by organizing the indicators that could effectively manage streetscapes and by overcoming limitations of reality shown in a static simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.3
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• pp.260-267
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• 2007

GPS adapter kit (GAK) is a GPS/INS guided range extension system to improve the accuracy and availability of existing dumb bombs. In this paper, a van test result of GPS/INS navigation module (NM) for guided bomb with GAK has been presented. The NM consists of a commercial MEMS IMU, embedded GPS receiver and navigation computer unit (NCU). The GPS receiver of NM was designed to use multiple antennas for satellite visibility and GPS attitude determination. The real-time navigation software was designed by modularized structure to guarantee the maintainability and extensibility. In order to evaluate the performance of the NM, a van test was preformed by using a high performance INS - Honeywell H-726 MAPS(Modular Azimuth Position System).The van test results show that the GAK NM with GPS attitude measurement gives better navigation performance than a conventional GPS/INS integration and good coasting capabilities under jamming environment.

• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.197-206
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• 2018

We present the analysis of KMT-2016-BLG-0212, a low flux-variation ($I_{flux-var}{\sim}20mag$) microlensing event, which is in a high-cadence (${\Gamma}=4hr^{-1}$) field of the three-telescope Korea Microlensing Telescope Network (KMTNet) survey. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q < $10^{-4}$) companions. Future high-resolution imaging should easily distinguish between these solutions.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1019-1028
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• 2021

Emergency exit guidance lights were designed and manufactured to quickly determine the location of the emergency exit in the event of a fire using a gas sensor, an illumination sensor, a temperature sensor, an Arduino Uno, and a Bluetooth module. This research was designed such that, when a fire breaks out, a red arrow appears as the illuminance value is low and a green arrow as the illuminance value is high to improve visibility when detecting high temperature and smoke. In addition, it is designed to prevent more serious conflagration by applying an alarm sound and text transmission algorithm using a communication module to transmit text messages indicating a 174Hz alarm sound and a fire location to prevent more serious conflagration.