• ETRI Journal
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• v.35 no.4
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• pp.644-654
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• 2013

In this paper, a signal detection scheme for cognitive radio (CR) based on the Bussgang theorem is proposed. The proposed scheme calculates the statistical difference between Gaussian noise and the primary user signal by applying the Bussgang theorem to the received signal. Therefore, the proposed scheme overcomes the noise uncertainty and gives scalable complexity according to the zero-memory nonlinear function for a mobile device. We also present the theoretical analysis on the detection threshold and the detection performance in the additive white Gaussian noise channel. The proposed detection scheme is evaluated by computer simulations based on the IEEE 802.22 standard for the wireless regional area network. Our results show that the proposed scheme is robust to the noise uncertainty and works well in a very low signal-to-noise ratio.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.666-673
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• 2017

In this paper, we propose a 360 content pilot service platform of cultural assets based on MPEG-V standard realistic media testbed. MPEG-V is that the standard format of sensory effect metadata(SEM) such like wind, light and flash, and communication protocol between sensory effect machines are defined, and it is possible to increase the sense of presence and immersion with 360 VR content. The proposed platform consists of software which is composed of the content player and the sensory effect reappearance server, and hardware which is the sensory effect machines. Also, the pilot service case using the proposed platform, and the features and advantages of the proposed platform are described.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.9
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• pp.787-794
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• 2012

The visible light communication is considered as a next generation communication technology, when utilizes LED and PD for communication. Since it is easy to provide LOS communication environment along with cheap deployment cost, the positioning system based on VLC has been actively studied. However, the existing positioning system using VLC requires a complex computation and an additional deployment cost due to sensors for example. In this paper, we propose a new positioning system based on VLC which does not require additional complexity and the cost. In addition, the procedure for operating LED panels for positioning and the recognition schemes of pilot signal are proposed. The performance of recognition schemes of pilot signal is analyzed through the computer simulations.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.146-157
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• 2019

This study, as a pilot study to implement and extend the marine healing which has been rapidly extending oversea areas into the domestic market, has collected seven major marine healing resources such as ocean water, sand, salt, mud, seaweeds, forest, and weather targeting selected four pilot municipalities and established a GIS DB. Furthermore, web GIS based marine healing portal has been established to support the easier utilization of the GIS DB and various marine healing related contents, thereby facilitating expansion of related industry. The portal includes marine thematic maps as well as research papers, related therapy manuals, and various activities and programs of the pilot municipalities. It is expected that the portal would contribute to the expansion of the domestic marine healing industry significantly through the pilot operation of the portal, not to mention of the needs of subsequent studies for expansion of the marine GIS DB and securing more various contents.

• Research in Community and Public Health Nursing
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• v.33 no.1
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• pp.1-12
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• 2022

Purpose: This secondary data analysis study evaluated the effects of ICT enhanced home-visit nursing in long-term care insurance on health-related quality of life among community-dwelling older adults. Methods: This study included data of 131 older adults who had experienced a pilot service for ICT enhanced home-visit nursing. ICT enhanced home-visit nursing refers to a method of sharing health records and teleconference between a visiting nurse and a doctor during the home-visit nursing services to community-dwelling older adults. Health-related quality of life and influencing factors were analyzed by t-tests, logistic regression analysis using the Stata 17/SE program. Results: After a pilot service for ICT enhanced home-visit nursing, their health-related quality of life increased. The teleconferencing method had a significant effect on the increase in health-related quality of life. Conclusion: The findings indicate a pilot service for ICT enhanced home-visit nursing can be applied to the domestic community-based healthcare service model in terms of health management. In the future, the advanced service model of a pilot service for ICT enhanced home-visit nursing in which subjects conduct detailed for each health problem, and a well-designed evaluation system should be developed.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.4
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• pp.353-362
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• 2024

In this study, several studies were conducted on the construction of gas conversion process system for a pilot plant using a small-scale hydrogen liquefaction system. The pilot plant considered in this study includes a liquefier, a storage tank, an evaporator, a gas booster, and a gas storage tank. First, the suspected leak area of the container was checked using the sprayed method of helium gas. The small-scale hydrogen liquefaction system was designed based on the analysis results of the pre-cooling system and the liquefaction system. Additionally, the program was developed to maintain pressure within vessel for an automatic production of liquid hydrogen. The evaporator for liquid hydrogen was manufactured based on the designed analysis data, and the pollution of gas in the vessel was analyzed through a gas recovery line system.

• Membrane Journal
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• v.17 no.3
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• pp.197-209
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• 2007

In this study, a multi-staged pilot-scale membrane plant was constructed and operated for the separation of $CO_2$ from LNG-fired boiler flue gas of 1,000 $Nm^3/day$. The target purity and recovery ratio of $CO_2$ required for the pilot plant were 99% and 90%, respectively. For this purpose, we previously developed the asymmetric polyethersulfone hollow fibers and evaluated the effects of operating pressure and feed concentration of $CO_2$ on separation performance[1,2]. The permeation data obtained were also analyzed in relation with the numerical simulation data using counter-current flow model[3,4]. Based on these results, we designed and prepared the demonstration plant consisting of dehumidification process and four-staged membrane process. The operation results using this plant were compared with the numerical simulation results on multi-staged membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery ratio of $CO_2$ in the final stage permeate stream were ranged from $95{\sim}99%$ and $70{\sim}95%$, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for $CO_2$ recovery from flue gas.

• Membrane and Water Treatment
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• v.9 no.1
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• pp.43-51
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• 2018

Hollow fiber (HF) membranes are gaining wide interest over flat membranes due to their compaction and high area to surface volume ratio. This work addresses the fabrication of HF from polysulfone (PS) and polyethersulfone (PES) using N-methylpyrrolidone (NMP) as solvent in addition to other additives to achieve desired characteristics. The semi-pilot spinning system includes jacketed vessel, four spinneret block, coagulation and washing baths in addition to dryer and winder. Different parameters affecting dry-wet spinning phase inversion process were investigated. Dope compositions of PES, NMP and polyvinyl pyrrolidone (PVP) of varying molecular weights as additive were addressed. Some critical parameters of importance were also investigated. Those include dope flow rate, air gap, coagulation & washing baths and drying temperatures. The measured dope viscosity was in the range from 1.7 to 36.5 Pa.s. Air gap distance was adjusted from 20 to 45 cm and coagulation bath temperature from 20 to $46^{\circ}C$. The HF membranes were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and mechanical properties. Results indicated prevalence of finger like structure and average surface roughness from about 29 to 78.3 nm. Profile of stress strain characteristics revealed suitability of the fibers for downstream interventions for fabrication of thin film composite membrane. Different empirical correlations were formulated which enable deeper understanding of the interaction of the above mentioned variables. Data of pure water permeability (PWP) confirmed that the fabricated samples fall within the microfiltration (MF)-ultrafiltration (UF) range of membrane separation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.93-100
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• 2004

This study was carried out for analyzing pathological and epidemiological factors of osteoporosis and doing pilot test using trial compounds of tuna bone and oriental herbs based on the factors. Osteoporosis is originated from osteoblast, osteoclast, organic and inorganic factors etc. Therefore the pathology of osteoporosis is not simple because the cytokine, growth factors and hormones of the components are various a lot. Taking a view of epidemiological factors of type I osteoporosis, ageㆍmenarcheㆍcholesterolㆍBMI etc. have definite relation to them. So we can approach to aging or consumptive disease in oriental medicine, specifically differential diagnosis of blood depletion with deficiency of qi, deficiency of kidney, deficiency of yin, bony weakness etc. And it should be considered together with rules for maintaining good health or habit concomitantly. Therefore IL1ㆍ6 or TNF αㆍβ are generally used as molecular biological index for osteoblast and osteoclast because the most important index is bone mineral density and strength, but the factors like collagen and noncollagen protein must be accounted as biomarkers. Trial compounds generally showed favorable effects on accompanying subjective symptoms of osteoporosis in the pilot test for menopausal woman. But if she didn't have specific symptoms of osteoporosis there wasn't any specific change. And osteocalcin was increased in case of being under standard level, but wasn't changed in case of normal level. Therefore these trial compounds can be used as a funcdonal diet for type I osteoporotic patients or preventive measures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.2797-2820
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• 2015

In order to accommodate huge number of antennas in a limited antenna size, a large scale antenna array is expected to have a three dimensional (3D) array structure. By using the Active Antenna Systems (AAS), the weights of the antenna elements arranged vertically could be configured adaptively. Then, a degree of freedom (DOF) in the vertical plane is provided for system design. So the three-dimension MIMO (3D MIMO) could be realized to solve the actual implementation problem of the massive MIMO. However, in 3D massive MIMO systems, the pilot contamination problem studied in 2D massive MIMO systems and the inter-cell interference as well as inter-vertical sector interference in 3D MIMO systems with vertical sectorization exist simultaneously, when the number of antenna is not large enough. This paper investigates the interference management towards the above challenges in 3D massive MIMO systems. Here, vertical sectorization based on vertical beamforming is included in the concerned systems. Firstly, a cooperative joint vertical beams adjustment and pilot assignment scheme is developed to improve the channel estimation precision of the uplink with pilots being reused across the vertical sectors. Secondly, a downlink interference coordination scheme by jointly controlling weight vectors and power of vertical beams is proposed, where the estimated channel state information is used in the optimization modelling, and the performance loss induced by pilot contamination could be compensated in some degree. Simulation results show that the proposed joint optimization algorithm with controllable vertical beams' weight vectors outperforms the method combining downtilts adjustment and power allocation.