• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2139-2142
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• 1999

765kV substations which will be the core installation of the bulk power transmission system in Korea for the upcoming $21^{st}$ century, were designed of outdoor full GIS type to minimize required area. As principal equipment, main transformers of 2,000 MVA per bank and 50kA 8,000A gas insulated switchgears of up-to-date technology were adopted in designing substations to transmit bulk power of 10GW. Dual digital protective relay systems and distributed indication and control systems with fiber optic LAN were used.

• Structural Engineering and Mechanics
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• v.91 no.3
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• pp.291-300
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• 2024

This paper predicts the combined resonance behavior of the truncated conical shells (TCSs) under transverse and parametric coupled excitation. The motion governing equation is formulated in the framework of high-order shear deformation theory, von Kármán theory and Hamilton principle. The displacements and boundary conditions are characterized by a set of displacement shape functions with double Fourier series. Subsequently, the method of varying amplitude (MVA) is utilized to derive the approximate analytical solution of system response of TCSs. A comparative analysis is conducted to verify the accuracy of the current computational method. Additionally, the interaction mechanism of combined resonance, parametric resonance and primary resonance is examined. And the effect of damping coefficient, the external excitation, initial phase, axial motion speed, temperature variation, humidity variation, material properties and semi-vortex angle on the vibration mechanism are analyzed.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.4
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• pp.421-429
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• 2000

In present, ATM integrated switching system has been developed to a mixed modules that complexed switching system including maintenance, operation based on B-ISDN/LAN service and plug-in module, , which runs on workstation computer system. Meanwhile, workstation has HMI operation system feature including file system management, time management, graphic processing, TMN agent function. The workstation has communicated with between ATM switching module and clients. This computer system architecture has much burden messages communication among processes or processor. These messages communication consume system resources which are socket, message queue, IO device files, regular files, and so on. Therefore, in this paper we proposed new performance modeling with this system architecture. We will analyze the system bottleneck and improve system performance. In addition, in the future, the system has many additional features should be migrated to workstation system, we need previously to evaluate system bottleneck and redesign it. In performance model, we use queueing network model and the simulation package is used PDQ and C-program.

• The Korean Journal of Petroleum Geology
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• v.11 no.1 s.12
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• pp.9-17
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• 2005

In the main target area of the block II, Targe-scale faults occur below the unconformity developed around 1 km in depth. The contrast of seismic velocity around the unconformity is generally so large that the strong multiples and the radical velocity variation would deteriorate the quality of migrated section due to serious distortion. More than 15 kinds of data processing techniques have been applied to improve the image resolution for the structures farmed from this active crustal activity. The bad and noisy traces were edited on the common shot gathers in the first step to get rid of acquisition problems which could take place from unfavorable conditions such as climatic change during data acquisition. Correction of amplitude attenuation caused from spherical divergence and inelastic attenuation has been also applied. Mild F/K filter was used to attenuate coherent noise such as guided waves and side scatters. Predictive deconvolution has been applied before stacking to remove peg-leg multiples and water reverberations. The velocity analysis process was conducted at every 2 km interval to analyze migration velocity, and it was iterated to get the high fidelity image. The strum noise caused from streamer was completely removed by applying predictive deconvolution in time space and ${\tau}-P$ domain. Residual multiples caused from thin layer or water bottom were eliminated through parabolic radon transform demultiple process. The migration using curved ray Kirchhoff-style algorithm has been applied to stack data. The velocity obtained after several iteration approach for MVA (migration velocity analysis) was used instead or DMO for the migration velocity. Using various testing methods, optimum seismic processing parameter can be obtained for structural and stratigraphic interpretation in the Block II, Yellow Sea Basin.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.121-130
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• 2004

In these days, multiple-path generation method is highly demanded in practice and research areas, which can represents realistically travelers behavior in choosing possible alternative paths. The multiple-path generation algorithm is one of the key components for policy analysis related to ATIS, DRGS and ATMS in ITS. This study suggested a method to generate multiple Possible paths from an origin to a destination. The approach of the suggested method is different from an other existing methods(K-shortest path algorithm) such as link elimination approach, link penalty approach and simulation approach. The result of the multi-label vine-building shortest path algorithm(MVA) by Kim (1998) and Kim(2001) was used to generate multiple reasonable possible paths with the concept of the rational upper boundary. Because the MVA algorithm records the cost, back-node and back-back node of the minimum path from the origin to the concerned node(intersection) for each direction to the node, many potential possible paths can be generated by tracing back. Among such large number of the potential possible paths, the algorithm distinguishes reasonable alternative paths from the unrealistic potential possible paths by using the concept of the rational upper boundary. The study also shows the very simple network examples to help the concept of the suggested path generation algorithm.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.1022-1029
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• 2018

Tuberculosis (TB) remains a serious health issue around the word. Adenovirus (Ad)-based vaccine and modified vaccinia virus Ankara (MVA)-based vaccine have emerged as two of the most promising immunization candidates over the past few years. However, the performance of the homologous and heterologous prime-boost immunization regimens of these two viral vector-based vaccines remains unclear. In the present study, we constructed recombinant Ad and MVA expressing an Ag85B-TB10.4 fusion protein (AdH4 and MVAH4) and evaluated the impact of their different immunization regimens on the humoral and cellular immune responses. We found that the viral vector-based vaccines could generate significantly higher levels of antigen-specific antibodies, $IFN-{\gamma}$-producing splenocytes, $CD69^+CD8^+$ T cells, and $IFN-{\gamma}$ secretion when compared with bacillus Calmette-$Gu{\acute{e}}rin$ (BCG) in a mouse model. AdH4-containing immunization regimens (AdH4-AdH4, AdH4-MVAH4, and MVAH4-AdH4) induced significantly stronger antibody responses, much more $IFN-{\gamma}$-producing splenocytes and $CD69^+CD8^+$ T cells, and higher levels of $IFN-{\gamma}$ secretion when compared with the MVAH4-MVAH4 immunization regimen. The number of $IFN-{\gamma}$-producing splenocytes sensitive to $CD8^+$ T-cell restricted peptides of Ag85B (9-1p and 9-2p) and Th1-related cytokines ($IFN-{\gamma}$ and $TNF-{\alpha}$) in the AdH4-MVAH4 heterologous prime-boost regimen immunization group was significantly higher than that in the other viral vector-based vaccine- and BCG-immunized groups, respectively. These results indicate that an immunization regimen involving AdH4 may have a higher capacity to induce humoral and cellular immune responses against TB in mice than that by regimens containing BCG or MVAH4 alone, and the AdH4-MVAH4 prime-boost regimen may generate an ideal protective effect.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.77-84
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• 2022

A submarine power cable is a transmission cable for carrying electric power below the surface of the water. Recently, submarine cables transfer power from offshore renewable energy schemes to shore, e.g. wind, wave and tidal systems, and these cables are either buried in the seabed or lie on the ocean floor, depending on their location. Since these power cables are used in the extreme environments, they are made to withstand in harsh conditions and temperatures, and strong currents. However, undersea conditions are severe enough to cause all sorts of damage to offshore cables, these conditions result in cable faults that disrupt power transmission. In this paper, we explore the design criteria for such cables and the procedures and challenges of installation, and cable transfer splicing system. The specification of submarine cable designed with 3 circuits of 154kV which is composed of the existing single circuit and new double circuits, and power capacity of 100MVA per cable line. The determination of new submarine cable burial depth and cable arrangement method with both existing and new cables are studied. We have calculated the permission values of cable power capacity for underground route, the values show the over 100MW per cable line.

• Journal of Cardiovascular Imaging
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• v.31 no.1
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• pp.18-23
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• 2023

BACKGROUND: Three-dimensional (3D) transesophageal echocardiogram (TEE) is the gold standard for the diagnosis of degenerative mitral regurgitation (dMR) and preoperative planning for transcatheter mitral valve repair (TMVr). TEE is an invasive modality requiring anesthesia and esophageal intubation. The severe acute respiratory syndrome coronavirus 2 pandemic has limited the number of elective invasive procedures. Multi-detector computed tomographic angiography (MDCT) provides high-resolution images and 3D reconstructions to assess complex mitral anatomy. We hypothesized that MDCT would reveal similar information to TEE relevant to TMVr, thus deferring the need for a preoperative TEE in certain situations like during a pandemic. METHODS: We retrospectively analyzed data on patients who underwent or were evaluated for TMVr for dMR with preoperative MDCT and TEE between 2017 and 2019. Two TEE and 2 MDCT readers, blinded to patient outcome, analyzed: leaflet pathology (flail, degenerative, mixed), leaflet location, mitral valve area (MVA), flail width/gap, anterior-posterior (AP) and commissural diameters, posterior leaflet length, leaflet thickness, presence of mitral valve cleft and degree of mitral annular calcification (MAC). RESULTS: A total of 22 (out of 87) patients had preoperative MDCT. MDCT correctly identified the leaflet pathology in 77% (17/22), flail leaflet in 91% (10/11), MAC degree in 91% (10/11) and the dysfunctional leaflet location in 95% (21/22) of patients. There were no differences in the measurements for MVA, flail width, commissural or AP diameter, posterior leaflet length, and leaflet thickness. MDCT overestimated the measurements of flail gap. CONCLUSIONS: For preoperative TMVr planning, MDCT provided similar measurements to TEE in our study.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1299-1303
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• 1995

The detection and measurement of partial discharge activity prevalent in the solid insulating systems of high-voltage generator stator windings has, for many years, been a recognized method of assessing the insulation condition of such systems. Partial discharge activity occurs at sites of degradation within, or at the surface of, stator's insulation systems under high voltage stressing. However, partial discharge pulses suffer from attenuation and distortion when transmitted along windings, because of the complex L-C network between windings. The mode of transmission varies with the signal frequency and is dependant on the geometrical configurations of windings. This paper reports the investigated results of the signal propagation characteristics along the windings when both sinusoidal signals and simulated partial discharge pulses are injected at the various positions of stator windings within the 25 MVA, 11 kV hydro generator. The on-line identification technique of partial discharge location in generator windings is also proposed in this study.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.710-715
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• 2004

The design problem of manufacturing system is addressed, adopting the closed queueing network model with multiple loops and re-entrant flows. The entire design problem is divided into two hierarchical sub-problems of (1) determining the station configuration and (2) optimizing the lot constitution; then they are tackled by neighbor search algorithm (NSA) and greedy mean value analysis (GMVA), respectively. Unlike the conventional MVA concerning multi-class closed queueing networks, the GMVA doesn't stick to a fixed lot proportion; rather it tries to find the optimal balance. The NSA, on the other hand, improves the object function value by altering the station configuration successively with its superior neighbor. The moderate time complexity, presented in big-${o}$ notation, enables us to apply the method even to the large-size practical cases, and the CPU time of an enlarged problem can be approximated by the same equation. The validity of our analytic approach is backed up by simulation studies with a widespread simulation package.