• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1199-1209
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• 2023

Where concrete structures are designed to have a service life of over 100 years, their performance must be monitored, for the prediction models available are fraught with uncertainties that need to be eliminated. The present study was conducted to meet that need by monitoring a pilot structure for low and intermediate radioactive waste storage. Long-term operation of the sensors was observed to be adequate to determine the value of the parameters that characterise structural durability, such as corrosion current density. The parameters analysed were correlated to calculate their reciprocal impact: where applied in conjunction with artificial intelligence tools, temperature, for instance, was found suitable for finding activation energy and expansion coefficients and detecting outliers. The results showed the pilot structure to perform satisfactorily.

• 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.

• 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.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.4
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• pp.33-42
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• 2014

Flame behaviors and interaction between pilot and main flames in a dual swirl combustor were investigated experimentally and numerically. Under the condition of fixed swirl angle of $45^{\circ}$ for main flame, the swirl angle of pilot flame, total heat release rate and equivalence ratio of main flame were used as major parameters. As a result, detailed flame stability diagram of dual swirl combustor was identified in terms of 5 flame modes with the changes in total heat release rate and equivalence ratio of main flame. It was found that the swirl angle of pilot flame plays the most important role in the changes in flame location and overall flow structure inside the combustor, and thus leads to the significant change in the interaction between pilot and main flame.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.158-165
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• 2004

This study concerns the succession process of protozoa populations in two activated sludge pilot plants. Protozoa populations with similar structures developed and succeeded each other in two plants. It was observed that initial sludge inoculum did not influence the protozoan composition but shorten the period of the plant stabilization. It seemed the protozoan in aeration tank was come from the influent. The composition of the influent sewage influenced the structure of protozoa in the pilot plants. The flagellates was very abundant during the initial starting phase. These rapidly decreased after growth peak. Then sarcodina, ciliates were increased in succession. In ciliates, free-swimming forms appeared at first and crawling forms and stalked forms were followed. After 36 days from the start, the sludge stabilization phase was characterized by a populations of ciliates dominated by stalked and crawling type and low value of effluent BOD was achieved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4524-4531
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• 2013

Recently, there are increased importance on introducing Tax Incremental Financing as a means of project financing for urban regeneration. Values of implementing this financing method based on future revenue has to be considered not just as self-financing methods but as possibilities building virtuous circular structure in urban developments. In respond to domestic problems in developments led by private sector, it reinforces public sector's roles by providing finance from the beginning of development. This provides concomitant structural & institutional supports for increasing not only social values for the public but also revenues for private developers. Therefore, this study starts with theoretical background study on TIF as well-known example, then analyzes PILOT used on Hudson Yard Development in NYC as an unique example sharing identical structural & conceptual characteristics. With these process, the study deducts suggestive implications on Tax Incremental Financing possibly reflected on domestic situation.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.13-19
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• 2019

This paper analyzed the SCMS and pilot policy, which is pursued by the U.S. government in connected vehicles. SCMS ensures authentication, integrity, privacy and interoperability. The SCMS Support Committee of U.S. government has established the National Unit SCMS and is responsible for system-wide control. Of course, it introduces security policy, procedures and training programs making. In this paper, the need for SCMS to be applied to C-ITS was discussed. The structure of the SCMS was analyzed and the U.S. government's filot policy for connected vehicles was discussed. The discussion of the need for SCMS highlighted the importance of the role and responsibilities of SCMS between vehicles and vehicles. The security certificate management system looked at the structure and analyzed the type of certificate used in the vehicle or road side unit (RSU). The functions and characteristics of the certificates were reviewed. In addition, the functions of basic safety messages were analyzed with consideration of the detection and warning functions of abnormal behavior in SCMS. Finally, the status of the pilot project for connected vehicles currently being pursued by the U.S. government was analyzed. In addition to the environment used for the test, the relevant messages were also discussed. We also looked at some of the issues that arise in the course of the pilot project.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.1
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• pp.51-57
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• 2020

The fighter pilot uses radar mounted on the fighter to obtain high-resolution SAR (Synthetic Aperture Radar) images for a specific area of distance, and then the pilot visually classifies targets within the image. However, the target configuration captured in the SAR image is relatively small in size, and distortion of that type occurs depending on the depression angle, making it difficult for pilot to classify the type of target. Also, being present with various types of clutters, there should be errors in target classification and pilots should be even worse if tasks such as navigation and situational awareness are carried out simultaneously. In this paper, the concept of operation and functional structure of radar system for fighter jets were presented to transfer the SAR image target classification task of fighter pilots to radar system, and the method of target classification with high accuracy was studied using the CNN ensemble model to archive higher classification accuracy than single CNN model.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.4
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• pp.87-99
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• 1993

Nowadays, the cartridge valve can be controlled proportionally in remote place by adopting proportional solenoid and it becomes widely used as control component in hydraulic systems. Especially, multi stage proportional valve is attractive because it consumes less input power though its characteristics might slightly be defected. But, the system parameter should be carefully chosen to obtain optimistic characteristics. This study concerning three stage proportional throttle control valve is purposed to examine the influences of paameters to the dynamic characteristics. The typical transient and frequency responses of proportional throttle control valve were inspected through the experiments and compared to those derived from the theoritical analyses. And it was confirmed that the analyses are appropriate. Then the influences of various system parameters to the dynamic characteristics were examined by means of simulations. For the analyses, the basic equations derived from lumped model were linearized and the linearized equations were transformed to the transfer functions between inputs and outputs. Then the transient responses and frequency responses were obtained from transfer functions. 1. It is appropriate to estimate the dynamic characteristics of valve which has relatively sophisticated structure by means of system analyses using linearized equations. 2. Though the valve has two pilot stages, fairly good characteristics can be obtained by carefully choosing system parameters. 3. Main valve very quickly follows the movement of second pilot valve when the parameters of main valve(the oil supply passage and discharge passage fpr second pilot valve) are appropriately chosen.

• Water for future
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• v.17 no.4
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• pp.303-310
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• 1984

One of the delicate problems in aquifer problems in aquifer management is the identification of the spatial distribution of the hydrological parameters. To determine the distribution of the transmissivity in a aquifer, several data are available; the local values of transmissivity around well, interference tests, some knowledge of geological structure. All this information has to be combined to find a plausible representation of the aquifer. According to a three phased optimization process calculation is carried out; geostatistical estimate of the parameter field on the basis of known well point values adjustable on a limited numerical model, and modification of the values ot pilot points by a minimization algorithm. This procedure, applied to a known case, has proved to be very useful.