• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.25-33
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• 2008

In this paper, the transmit power minimization for Poisson distributed wireless ad-hoc relay networks in Rayleigh fading channels is considered. We investigate two power allocation methods one is a minimum power allocation (MPA) strategy and the other is an equal outage power allocation (EOPA) strategy. We analyze the total transmit power of two allocation methods under the given end-to-end outage probability constraint. Our results show that the MPA achieves more power saving than EOPA, and the power saving is more significant as the number of relay nodes increases.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.393-399
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• 1997

Single-phase and three-phase AC to DC power converters are becoming frequently used for high voltage/high power applications such as telecommunications. They often require input/output transformer isolation for safety, a unity input power factor for minimum reactive power, free input harmonic currents fed back to the AC Power distribution system and, finally, high efficiency and high power density for minimum weight and volume. The proposed boost converter for power factor correction (PFC) provides an unity input power factor, low harmonic distortion and high efficiency along with reduced volume and weight. Single-phase 220VAC input/380VDC 1KW output prototype is constructed and experimental results will be verified with those of PSpice simulation.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.38-43
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• 2013

We derive the Z-parameters for the two coupled antennas used for wireless power transfer under the assumption that the antennas are canonical minimum scattering antennas. Using the Z-parameter and the maximum power transfer efficiency formula, we determine the maximum power transfer efficiency of wireless power transfer systems. The results showed that the maximum power transfer efficiency increases as the mode number or the radiation efficiency increases. To verify the theory, we fabricate and measure two different power transfer systems: one comprises two antennas generating $TM_{01}$ mode; the other comprises two antennas generating $TM_{02}$ mode. When the distance between the centers of the antennas was 30 cm, the maximum power transfer efficiency of the antennas generating the $TM_{02}$ mode increased by 62 % compared to that of the antennas generating the $TM_{01}$ mode.

• Communications for Statistical Applications and Methods
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• v.14 no.2
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• pp.267-280
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• 2007

In this paper, we consider the robust estimation for diffusion processes when the sample is observed discretely. As a robust estimator, we consider the minimizing density power divergence estimator (MDPDE) proposed by Basu et al. (1998). It is shown that the MDPDE for diffusion process is weakly consistent. A simulation study demonstrates the robustness of the MDPDE.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.75-78
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• 2000

This paper presents a new algorithm for allocating the data path to achieve the minimum power consumption under the constraints of minimum hardware resources. In order to minimize the power consumption, the proposed algorithm tries to minimize the input transitions of functional units, unnecessary computations, and size of interconnects in a greedy manner during a]location. Experimental results using benchmarks indicate the proposed algorithm achieves 17.5% power reduction on average, when compared with the genesis-lp［1］high-level synthesis system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1777-1791
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• 2012

This paper considers a downlink cognitive radio (CR) network where one secondary user (SU) and one primary user (PU) share the same base station (BS). The spectrum of interest is divided into a set of independent, orthogonal subchannels. The communication of the PU is of high priority and the quality of service (QoS) is guaranteed by the minimum rate constraint. On the other hand, the communication of the SU is of low priority and the SU opportunistically accesses the subchannels that were previously discarded by the PU during power allocation. The BS assigns fractions ?? and 1 ?? of the total available transmit power to the PU and the SU respectively. Two power allocation schemes with opportunistic subchannel access are proposed, in which the optimal values of ??'s are also obtained. The objective of one scheme is to maximize the rate of the SU, and the objective of the other scheme is to maximize the sum rate of the SU and the PU, both under the PU minimum rate constraint and the total transmit power constraint. Extensive simulation results are obtained to verify the effectiveness of the proposed schemes.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.415-420
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• 2018

The Energy Efficiency Design Index (EEDI) introduced by the Marine Environment P rotection Committee(MEPC) in International Maritime Organization(IMO) has significantly assisted in regulating CO2 emissions. However, in adverse weather conditions, it can lead to accidents due to slow steaming of vessels and low engine propulsion power. In response to this issue, the MEPC presented guidelines for the minimum propulsion power of the main engine for maintaining the course of vessels in adverse weather conditions. However, the guidelines are only applicable for vessels with a deadweight of 20,000 tons, leaving out small and medium ships. This study evaluated vessels subject to the guidelines of minimum propulsion power and proposed revised guidelines. In addition, relevant cases of marine accidents were investigated with the aim of investigating the minimum propulsion power of main engine for medium and small ships not covered by the guidelines. In order to achieve this, engine propulsion power was analyzed according to the size of the affected vessels. The results obtained from this study could be used as a minimum power criterion that can be considered for ship building to reduce marine accidents in adverse weather for small and medium ships.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.37-42
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• 2007

This paper reconsiders established power conservation models for ubiquitous sensor networks that use relay nodes instead of direct communication and proposes novel network power consumption model with consideration of the channel level and radio chip level simultaneously. We estimate the effect of minimum hop-count policy in terms of network power consumption through simulation of various situations for low power RF module CC2420. It is observed that maximum RF power and minimum hop-count results in lower energy consumption relatively. Also, in total network energy consumption, which is included re-transmission, minimum hop count policy presents decrease by 33.1% of energy consumption in compare with the conventional model.

• East Asian mathematical journal
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• v.34 no.1
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• pp.29-37
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• 2018

We introduce formal symbols of product type, of zero class, and of minimum type and show that the formal power series representations for $e^p$ and $e^q$ are formal symbols of product type giving the same pseudodifferential operator, where p and q are formal symbols of minimum type and p - q is of zero class.

• East Asian mathematical journal
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• v.32 no.1
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• pp.35-41
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• 2016

We introduce formal symbols of product type and of minimum type and show that the formal power series representation for $e^p$ is a formal symbol of product type, where p is a formal symbol of minimum type.