• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.764-766
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• 1998

An evaluation method for oxygen permeable characteristics of the membrane covering to each cathode of multiple cathode - single anode type dissolved oxygen sensor, which has high reproducibility and is capable of measuring multiple components in solutions. For this purpose, a measuring circuit for the multiple cathode type DO sensor was designed to lower the noise signal by adapting a digital LPF to readout the sensor output accurately. Digital LPF is designed by setting up the transfer function to set the cutoff frequency to 10Hz, and the transfer function is programmed by C language, and then the filtering characteristics are evaluated with the simulation and experiments. Using this LPF added measuring circuit for the multiple cathode type DO sensor, we have obtained the calibration factor for each cathode to calibrate the variation of the output signals. The calibration factor was obtained by measuring the sensor output signal followed by oxygen partial pressure, using the same oxygen permeable membrane at each cathode of the multiple cathode type DO sensor.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.473-481
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• 2007

Energy efficiency is one of the most critical concerns for wireless sensor networks. By allowing sensor nodes in close proximity to cooperate in transmission to form a virtual multiple-input multiple-output(MIMO) system, recent progress in wireless MIMO communications can be exploited to boost the system throughput, or equivalently reduce the energy consumption for the same throughput and BER target. However, these cooperative transmission strategies may incur additional energy cost and system overhead. In this paper, assuming that data collectors are equipped with antenna arrays and superior processing capability, energy efficiency of relevant traditional and cooperative transmission strategies: Single-input-multiple-output(SIMO), space-time block coding(STBC), and spatial multiplexing(SM) are studied. Analysis in the wideband regime reveals that, while receive diversity introduces significant improvement in both energy efficiency and spectral efficiency, further improvement due to the transmit diversity of STBC is limited, as opposed to the superiority of the SM scheme especially for non-trivial spectral efficiency. These observations are further confirmed in our analysis of more realistic systems with limited bandwidth, finite constellation sizes, and a target error rate. Based on this analysis, general guidelines are presented for optimal transmission strategy selection in system level and link level, aiming at minimum energy consumption while meeting different requirements. The proposed selection rules, especially those based on system-level metrics, are easy to implement for sensor applications. The framework provided here may also be readily extended to other scenarios or applications.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.112-117
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• 2007

In this paper, we focus on the total transmission power minimization problem for downlink beamforming multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems while ensuring each user's QoS requirement. Although the linear integer programming (LIP) solution we formulate provides the performance upper bound of the margin adaptive (MA) optimization problem, it is hard to be implemented in practice due to its high computational complexity. By regarding each user's equivalent channel gain as approximate independent values and using iterative descent method, we present a heuristic MA resource allocation algorithm. Simulation results show that the proposed algorithm efficiently converges to the local optimum, which is very close to the performance of the optimal LIP solution. Compared with existing space division multiple access (SDMA) OFDM systems with or without adaptive resource allocation, the proposed algorithm achieves significant performance improvement by exploiting the frequency diversity and multi-user diversity in downlink multiple-input single-output (MISO) OFDM systems.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1415-1425
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• 2016

This paper presents a new approach for fault diagnosis in three-level neutral point clamped inverters. The proposed method is based on the average values of the positive and negative parts of normalized output currents. This method is capable of detecting and locating multiple open-circuit faults in the controlled power switches of converters in half of a fundamental period of those currents. The implementation of this diagnostic approach only requires two output currents of the inverter. Therefore, no additional sensors are needed other than the ones already used by the control system of a drive based on this type of converter. Moreover, through the normalization of currents, the diagnosis is independent of the load level of the converter. The performance and effectiveness of the proposed diagnostic technique are validated by experimental results obtained under steady-state and transient conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.675-676
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• 2013

This paper presents a design method for multiple-output combinational digital logic systems using time domain based on multiplexing and common multi-terminal extension decision diagrams. The common multi-terminal extension decision diagrams represents extension valued multiple-output functions, while time domain based on multiplexing systems transmit several signals on a single lines. The proposed method can reduce the 1)hardware, 2)logic levels and 3)pins. In the logic system design, we use two types of decision diagrams, that is the common binary decision diagrams and common multi-terminal extension decision diagrams.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.155-158
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• 2000

Circuit configurations for realizing of biquadratic current transfer functions using current conveyors (CCIIs) are presented. The circuits are composed of three multiple-output CCIIs and four passive elements (two resistors and two grounded capacitors), and when current controlled conveyors (CCIIs) in place of CCIIs are employed, the circuit can be realized using three multiple-output CCIIs and two grounded capacitors. Use of grounded capacitors is suitable for integrated implementation. The cutoff frequency of a realized filter with current gain K can be tuned independently of Q by the value of K.

• 전기의세계
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• v.29 no.10
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• pp.678-688
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• 1980

This paper is concerned with the computer design of the multiple-output switching functions by using the improved MASK method in order to obtain the paramount prime implicants (prime implicants of the multiple-output switching function) and new algorithm to design the optimal logic network. All the given minterms for each function are considered as minterms of one switching function to simplify the desigh procedures. And then the improved MASK method whose memory requirement and time consuming are much less than any existing known method is applied to identify the paramount prime implicants. In selecting the irredundant paramount prime implicants, new cost criteria are generated. This design technuque is suitable both for solving a problem by hand or programming it on a digital computer.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.3
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• pp.357-363
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• 1986

In the design of PLA's of VLSI, as the number of subsets of functions from which common preme implicants must be determined increases, the execution time increases by a factor of O(2\ulcorner. When the number of functions N is a large number, this poses a serious problem in minumization of multiple-output logic functions. In this paper a new algorithm that minimizes multiple-output logic functions is proposed. The algorithm requires less number of Fortran statements, less execution time, and less memory area than existing methods. The bases of this algorithm are explained and verified, and the sequential operation for preparation of the program is discussed.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.271-280
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• 2002

In this paper, the input-output interconnection method of the multiple-valued signal processing circuit using Perfect Shuffle technique and Kronecker product is discussed. Using this method, the circuit design method of the multiple-valued Reed-Muller Expansions (MRME) which can process the multiple-valued signal easily on finite fields GF$(p^m)$ is presented. The proposed input-output interconnection methods show that the matrix transform is an efficient and the structures are modular. The circuits of multiple-valued signal processing of MRME on GF$(p^m)$ design the basic cells to implement the transform and inverse transform matrix of MRME by using two basic gates on GF(3) and interconnect these cells by the input-output interconnection technique of the multiple-valued signal processing circuits. The proposed multiple-valued signal processing circuits that are simple and regular for wire routing and possess the properties of concurrency and modularity are suitable for VLSI.

• Journal of electromagnetic engineering and science
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• v.18 no.2
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• pp.144-144
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• 2018