• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.157-163
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• 2016

If trace-driven or execution-driven simulation is used for the performance analysis of asymmetric multi-core processors, excessive time and much disk space are necessary. In this paper, statistical simulations are performed for asymmetric multi-core processors with various hardware configurations. For the experiment, SPEC 2000 benchmark programs are used for profiling and synthesis, which is supplied as input for the simulation of asymmetric multi-core processors. As a result, the performance of asymmetric multi-core processor obtained by statistical simulation is comparable to that of the trace-driven simulation with a tremendous reduction in the simulation time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.171-177
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• 2013

Due to the demand for high speed 3D graphic rendering, video file format conversion, compression, encryption and decryption technologies, the importance of digital signal processor system is growing rapidly. In order to satisfy the real-time constraints, high performance digital signal processor is required. Therefore, as in general purpose computer systems, digital signal processor should be designed as multicore architecture as well. Using UTDSP benchmarks as input, the trace-driven simulation has been performed and analyzed for the 2 to 16-core digital signal processor architectures with the cores from simple RISC to in-order and out-of-order superscalar processors for the various window sizes, extensively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.85-91
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• 2013

For location based service and context awareness services, accurate indoor positioning technology is essential. The TDOA method that uses the range difference between signal source and receivers for estimating the location of the signal source, has estimation error due to measurement error. In this paper, a new algorithm is proposed to select the real root among calculated roots using the range difference information, and the estimated position of the signal source shows good accuracy compared to the existing method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.143-148
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• 2013

A novel ultracompact polarization beam-splitter (PBS) combining two plasmonic multimode interference couplers (P-MMICs) and DFB guiding structure is implemented. The $2{\times}1$ and $1{\times}2$ P-MMICs are designed to collect the polarized powers of TE and TM modes reflected by or transmitted through an internal DFB structure. The simulation results show that the designed DFB-assisted PBS is very short (about $75{\mu}m$), and has a low insertion loss, a high extinction ratio, and a broad bandwidth of 20 nm.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.251-256
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• 2017

Recently, multicore processor system is widely adopted not only in general purpose computers but also in embedded systems and mobile devices in order to improve performance. Since the power dissipation issue of multicore processor system is very significant, it must be estimated accurately in the early design stage. In this paper, a fast power analysis tool for a high performance multicore processor based on the trace-driven simulator has been developed. To achieve it, the power dissipation of each hardware unit per core are added. Using SPEC 2000 benchmarks as input, the trace-driven simulation has been performed to estimate the average power dissipation per instruction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.191-197
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• 2017

According to the ubiquitous usage of smartphone, so many smartphone applications have been developed, and especially data communications and position measurement technologies without additional equipments have been developed using acoustic signal. But there is a limitation to select the frequency of the acoustic signal due to the smartphone hardware, and there is non-linearity in the electronic circuits in a sound generation devices, the audible sound generated from the speaker is not avoidable. And it causes critical difficulty to the commercial system deployment. In this paper, a simulation technique to calculate the power of the audible acoustic signal by human is applied to several types of acoustic signals to evaluate the loudness. These could be referred when the acoustic communications or positioning systems are designed, for the purposed of inaudible sounding to human.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.105-109
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• 2018

In this paper, the performance enhancement of a time-modulated array is described. The proposed time-modulated array is based on the topology of a conventional array but uses apodized discrete time switching, instead of phase shifters, to achieve beamforming functions with side-band suppression. Numerical simulations are carried out to examine the performance of this beamforming system based on apodized time sequence of 16 elements linear array. Numerical results reveal that the proposed method provides a more flexible and accurate way of producing desired beampatterns with low or ultralow side-lobe level (SLL) compared with the conventional methods.

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.6-9
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• 2015

A new cross disciplinary conception of transitional aero-optics is built up during analyzing and measuring the linkage between the hypersonic boundary layer transition on a flat plate and the jittering characteristics of the small-aperture beam through that boundary layer. Based on that conception, the Small-Aperture Beam Technique (SABT) and high-speed Imaging Camera System (ICS) used in aero-optical studies are considered as new techniques for the assessment of the hypersonic transition in the boundary layer on a flat plate. In the FD-20 gun tunnel, for the free stream parameters with Mach number of 8 and unit Reynolds number of $1{\times}10^7$ (1/m), those two optical techniques are used to measure the jitter of the small-aperture beam. At the same free stream parameters, the distribution of the heat transfer along the centerline of the flat plate is also measured by the thin film resistance gauge technique. The results show the similarity of the increase trend between the heat transfer and the jitter of the small-aperture beam in the transitional region. It helps us to surmise that it may be feasible to diagnose the transition in a hypersonic boundary layer on a flat plate by means of those above optical techniques.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.3
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• pp.22-28
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• 2008

It proposes the novel design conditions to maximize the power coupling of active directional couplers with mismatched access guides. To verify the validity and accuracy of the conditions proposed, a new coupling efficiency is defined and it depends on the reflection coefficients occurred at the discontinuous input/output interfaces. The numerical results reveal that the phase-matched condition and the minimum-gap condition for those couplers are no longer suitable to optimize the design parameters and a new criterion is needed.

• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.90-95
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• 2011

In order to protect human lives from disease, various biosensors having the potential to analyze a variety of biomolecules have been utilized. Biosensors constitute one of the most promising ways to monitor and detect various biomolecules corresponding to diseases. In this study, we demonstrate that the reaction of streptavidin molecules with biotin on a gold electrode can be detected using the twoelectrode method with a gold electrode and a platinum reference electrode. We also show the characteristics of the electrical current response. While detecting 2-${\mu}M$ streptavidin molecules dissolved in phosphate buffered saline(PBS) solution, we found that an analytical biosensor can operate on the principle of detecting an antigen-antibody reaction event of protein molecules using the two-electrode method. We think that the "potential step" method might be useful to detect the occurrence of any antigen-antibody reactions and can be combined with other devices or ICs such as BJTs, MOSFETs, and OP-amps for the detection of biomolecules of diseases.