• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.37-44
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• 1997

A dadaptive refinement tetrahedron mesh has been presented for using in full band GaAs monte carlo simulation. A uniform tetrahedron mesh is used without regard to energy values and energy variety in case of the past full band simulation. For the uniform tetrahedron mesh, a fine tetrahedron is demanded for keeping up accuracy of calculation in the low energy region such as .GAMMA.-valley, but calculation time is vast due to usin gthe same tetrahedron in the high energy region. The mesh of this study, thererfore, is consisted of the fine mesh in the low energy and large variable energy region and rough mesh n the high energy. The density of states (DOS) calculated with this mesh is compared with the one of the uniform mesh. The DOS of this mesh is improved th efive times or so in root mean square error and the ten times in the correlation coefficient than the one of a uniform mesh. This refinement mesh, therefore, can be used a sthe basic mesh for the full band GaAs monte carlo simulation.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.295-297
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• 2007

We design a new rate-3/2 full-diversity orthogonal space-time block code (STBC) for QPSK and 2 transmit antennas (TX) and 4 transmit antennas (TX) by enlarging the signalling set from the set of quaternions used in the Alamouti[I] and extendedcode and using additional members of the set of orthogonal matrices or Quasi-orthogonal matrices and higher than rate-5/4. Selective power scaling of information symbols is used to guarantee full-diversity while maximizing the coding gain (CG) and minimizing the transmitted signal peak-to-minimum power ratio (PMPR). The optimum power scaling factor is derived analytically and shown to outpetform schemes based only on constellation rotation while still enjoying a low-complexity maximum likelihood (ML) decoding algorithm.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1275-1276
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• 2015

Full wave electromagnetic simulation or fabricated models of an antenna are used to predict its radiation characteristics. In this work estimation of radiated power of an antenna based on its electrical model is presented. The computed radiated power using the electrical model have good agreement with the radiated power results obtained through the full wave electromagnetic simulation of the antenna model. The presented approach offers the advantage of saving of computation time of the full wave EM simulation.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.579-589
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• 1998

Full turnover-based storage policy (FULL) is often used to minimize the travel time needed to perform storage/retrieval operations in automated storage/retrieval systems (AS/RSs). This paper presents an approach for determining the required storage capacity for a unit load AS/RS under the FULL. An analytic model is formulated such that the total cost related to storage space and space shortage is minimized while satisfying a desired service level. To solve the model, some analytic properties are derived and based on them, an iterative search algorithm which always generates optimal solutions is developed. To illustrate the validity of the approach, an application is provided when the standard economic-order-quantity inventory model is used.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.451-458
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• 2015

The deployment density of AP increases as well as the density WLAN stations due to increase of WLAN use and the real performance of WLAN is degraded. To improve the performance, there are many PHY/MAC technologies and OFDMA and full duplex are promising technologies among them. In conventional OFDMA WLAN MAC relate works, there are some limitations in terms of channel utilization and collision probability. Thus, it need to research for effective channel allocation protocol. Full duplex can transmit data on the same time and same frequency resource so it can allocate channel more flexible than half duplex. In this paper, we prose the OFDMA FD-MAC(Full Duplex MAC) protocol that it allocates the sub-channels based on the idle channel information for full duplex pair. In addition, it shows the throughput improvement by performance analysis.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.317-323
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• 2014

Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.187-190
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• 2005

This study was conducted to investigate the plant growth and seed yield between rain-shelter plastic house and out-door cultivation, and analysed the effect of harvesting time on seed quality. In rain-shelter plastic house cultivation, emergence date was 3 days and flowering date was 8 days earlier than out-door cultivation. Seed yield of rain-shelter plastic house cultivation was increased $25\%$ compared to out-door cultivation and it's more beneficial than out door cultivation. The crude fat content was higher and seed was whiter and better quality in rain-shelter plastic house cultivation than out-door cultivation. In out-door cultivation, the crude fat content was steadily increased until 40 days after full bloom, but the seed color was getting dark which was harvested at 30 days after full bloom and the color was turn to the dark brown when the seed was harvested at 40 days after full bloom. Harvesting of safflower seed's quality is best between 20 days and 30 days after full bloom.

• KIEAE Journal
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• v.14 no.5
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• pp.103-109
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• 2014

Apartment housing should require the systematic maintenance to provide the decent living condition during its life. Each household should participate the maintenance activities and pay for the repair. Therefore, the required cost for repair would be needed to plan in the repair schedule because each household could not pay the much repair money at a time. After apartment constructed, a long term repair plan would be prepared in repair time, repair scope and a required cost. A few studies are said that the repair cost depends on the building deterioration, elapsed year and management factors. The above factors are not be certain to affect the repair management while it may be important to prepare the required money and the repair time. In this paper, it aimed at analyzing the correlation between the repair management and the management factors, especially total area, number of household. This would educe the unit cost per number of household and management area in the individual boiler and elevator with full change and full repair. The unit cost per number of household and area for full change are about 199,000 won/household and $1,954won/m^2$ in the individual boiler respectively. The unit cost of the elevator for full change is 94,000 won/household and $5,429won/m^2$ respectively. Second, this study shows that the elapsed year after construction would not be related the repair unit cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.10
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• pp.2411-2429
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• 2013

In this paper, we extend the case of information exchange error mitigation for the distributed orthogonal space-time block code (DOSTBC) for two transmit antennas to distributed quasi-orthogonal space-time block code (DQOSTBC) for four transmit antennas. A rate 1 full-diversity DQOSTBC for four transmit antennas is designed. The code matrix changes according to different information exchange error cases, so full diversity is maintained even if not all information exchange is correct. We also perform analysis of the pairwise error probability. The performance analysis indicates that the proposed rate 1 DQOSTBC outperforms rate 1/2 DOSTBC for four transmit antennas at the same transmission rate, which is confirmed by the simulation results.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.2
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• pp.28-38
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• 2001

A numerical method for the assessment and correction of tunnel wall interference effects on forced-oscillation testing is presented. The method is based on the wall pressure signature method using computed wall pressure distributions. The wall pressure field is computed using unsteady three-dimensional full Navier-Stokes solver for a 70-degree pitching delta wing in a wind tunnel. Approximately-factorized alternate direction implicit (AF-ADI) scheme is advanced in time by solving block tri-diagonal matrices. The algebraic Baldwin-Lomax turbulence, model is included to simulate the turbulent flow effect. Also, dual time sub-iteration with, local, time stepping is implemented to improve the convergence. The computed wall pressure field is then imposed as boundary conditions for Euler re-simulation to obtain the interference flow field. The static computation shows good agreement with experiments. The dynamic computation demonstrates reasonable physical phenomena with a good convergence history. The effects of the tunnel wall in upwash and blockage are analyzed using the computed interference flow field for several reduced frequencies and amplitudes. The corrected results by pressure signature method agree well with the results of free air conditions.