• Journal of Navigation and Port Research
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• v.35 no.8
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• pp.637-641
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• 2011

Ocean structure's power system is difficult to construct a stand-alone power system. Therefore, to manage effectively power system of ocean structure, it's important to construct power system which is connected fuel-cell with hybrid power system. This paper designs power system of fuel-cell for the sea based on hydrogen generation mechanism, calculation of using electric power, etc. Designed power system is analysed & simulated using LabVIEW program. And, this paper suggests design method of power system for ocean structure based on analysed & simulated results.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.209-214
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• 2006

The purpose of this study is to improve the stream water quality by the experimental hybrid constructed wetland system. It consisted of the water layer, sand bed planted reeds, irises and roses, gravel bed, yellow-soil media bed and a flow shifter (FS) which can reverse top and bottom flow in the middle of the wetland. The organic compounds and nitrogen removal efficiencies varied with the seasons, namely temperature change. In summer, the mean efficiencies of COD and TN in the outflow from this wetland system were 63.4 and 48.0% and shown the highest, respectively, whereas, the suspended solids and phosphorus removal efficiencies seemed to be less affected by temperature. As a result of inspecting the decreasing trend of pollutants, nitrification-denitrification in the wetland was the major removal mechanism for nitrogen, the nitrogen reduction was especially enhanced by the application of a FS in the wetland, and phosphorus reduction was mainly occurred as a consequence of adsorption of the yellow-soil media.

• Journal of Biosystems Engineering
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• v.36 no.3
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• pp.171-179
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• 2011

Facing the current hikes of labor wage and high oil price, it is needed to have energy-saving machinery which also enables us precise farm operations. Thus, it was necessary to develop a safe machine which allows secure and pleasant works along orchard slopes. In this study, a lifting utility with balance-controlled platform was developed. The platform utility could maintain to level the workbench while driving along slopes. Even the machine body was driven at the tilt angle ranges of ${\pm}20^{\circ}$, the platform bench could be maintained within ${\pm}0.5^{\circ}$ of a gimbal angle. In addition, the machine lifted up to 2.0 m using an electric-hybrid driving mechanism with a low noise. A tandem hybrid power source was developed with a DC 72 V, 100 AH for the Deep-Cycle batteries, charged with 3.5 kW gasoline generator as an auxiliary power source. HST, which is one of the CVT's, was adopted as a transmission device, and a crawer track was used for the safety of the vehicle against tip-over. The maximum lifting height of platform was is 2,500 mm, and the maximum extendable width was 2,900 mm.

• Korean Institute of Interior Design Journal
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• v.15 no.2 s.55
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• pp.81-90
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• 2006

This treatise makes clear not only a structural methodology of 'the conceptual blending theory' using in a linguistics could be applied to the similar process in a hybrid design but also both methods include the same meaning construction in the sense of a mutual educational system. Both methods have something in common that they are fundamentally focused on a metaphorical expression which implies poetic messages to be concentrated on a formal structure. Therefore, the purpose of this treatise is to examine the structural characteristics in the hybrid design in order to analyze the rhetorical expressions(metaphor, allegory) as symbols of communication. One of the those is intertextuality that expresses metaphorically by blending and borrowing codes and another is hypertextual space where various texts twines around each other making brand-new and diverse organizations, as the combined allegory with a number of hidden expression. Ultimately, it is important that this approach could verify whether it deals the illogical present state of a spacial form or structure with a kind of mechanism of a 'conceptual blending theory' or not.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1329-1336
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• 2000

A new fractal geometry of the traveling wave type cross antenna is newly presented. In the conventional type of the traveling wave antenna, the electrical length of the radiating conductor increases as the order of fractal expansion increases. But, increased length of the current path degrades the performance of the antenna from the various loss mechanism of the traveling wave type antenna. To reduce the antenna performance degradation, the new hybrid fractal antenna, which divides the entire fractal structure into some smaller ones and connects each smaller fractal group with a power divider is presented. The secondly, thirdly and fourthly expanded hybrid fractal cross antennas are fabricated and their performances are examined by measurements. Influences of the fractal order to the antenna performance are examined.

• Macromolecular Research
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• v.17 no.11
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• pp.894-900
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• 2009

This study examined the charge carrier photogeneration and hole transport properties of blends of poly (9-vinylcarbazole) (PVK), $\pi$-conjugated polymer, with different weight proportions (0~29.4 wt%) of (PEA)$VOPO_4{\cdot}H_2O$ (PEA: phenethylammonium cation), a novel organic-inorganic hybrid material, using IR, UV-Vis, and energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), steady state photocurrent (SSPC) measurement, and atomic force microscopy (AFM). The SSPC measurements showed that the photocurrent of PVK was reduced by approximately three orders of magnitude by the incorporation of a small amount (~12.5 wt%) of (PEA) $VOPO_4{\cdot}H_2O$, suggesting that hole transport occurred through the PVK carbazole groups, whereas a reverse trend was observed at high proportions (>12.5 wt%) of (PEA)$VOPO_4{\cdot}H_2O$, suggesting that transport occurred via (PEA)$VOPO_4{\cdot}H_2O$ molecules. The transition to a trap-controlled hopping mechanism was explained by the difference in ionization potential and electron affinity of the two compounds as well as the formation of charge percolation threshold pathways.

• Journal of Power Electronics
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• v.19 no.1
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• pp.158-167
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• 2019

This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.536-564
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• 2019

Soft faults are inherent in wireless sensor networks (WSNs) due to external and internal errors. The failure of processes in a protocol stack are caused by errors on various layers. In this work, impact of errors and channel misbehavior on process execution is investigated to provide an error classification mechanism. Considering implementation of WSN protocol stack, inter-process correlations of stacked and peer layer processes are modeled. The proposed model is realized through local and global decision trees for fault diagnosis. A hybrid framework is proposed to implement local decision tree on sensor nodes and global decision tree on diagnostic cluster head. Local decision tree is employed to diagnose critical failures due to errors in stacked processes at node level. Global decision tree, diagnoses critical failures due to errors in peer layer processes at network level. The proposed model has been analyzed using fault tree analysis. The framework implementation has been done in Castalia. Simulation results validate the inter-process correlation model-based fault diagnosis. The hybrid framework distributes processing load on sensor nodes and diagnostic cluster head in a decentralized way, reducing communication overhead.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.61-73
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• 2023

Suction buckets are feasible options for offshore foundations to support subsea structures in deep water, enabling suction-induced installation by pumps. Recently, hybrid suction bucket foundations that combine single or multiple suction buckets with a mat foundation have been considered. The foundations effectively increase the load capacity while reducing construction costs. However, there is still insufficient experimental validation of hybrid suction bucket foundations regarding their bearing capacity. Furthermore, research on the horizontal load capacity under low vertical and moment loads is inadequate. In this study, we investigate the feasibility of using a hybrid suction bucket foundation for subsea installations in clay. We considered two types of hybrid suction bucket foundations: a circular mat with a single suction bucket and a square mat with multiple buckets. Centrifuge tests were performed to understand the hybrid suction bucket foundation characteristics under horizontal loads and their corresponding bearing capacity. Particularly, we verified the effect of the mat foundation and bucket embedment depth on the horizontal bearing mechanism and capacities. Results confirmed that the hybrid suction bucket foundation outperforms the single suction bucket.

• Journal of Surface Science and Engineering
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• v.42 no.5
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• pp.197-202
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• 2009

The electrodeposition in acidic aqueous electrolyte bath of cadmium telluride on gold electrodes has been studied by electrochemical analysis. Conventional cyclic voltammetry using potentiostat is considered as a reliable method to study electrochemical behavior of electrodeposition of CdTe. In this paper, the mechanism of CdTe deposition and its cyclic voltammetry were studied with the Te ion concentration, temperature, potential, and scan rate. We also investigated surface morphologies using FESEM and atomic composition of Cd and Te using EDS. Atomic composition of Cd and Te were varied with Te ion concentration in the electrolyte.