• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.8
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• pp.483-488
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• 2016

Ultrasound imaging by using piezoelectric materials, such as lead zirconium titanate (PZT) has been one of the most preferred modes of imaging in the medical field due to its simple, low cost and non-ionizing radiation in comparison to other imaging techniques. Recently, the market demand for portable ultrasound is becoming larger with applications in developing countries, disaster area, military, and emergency purposes. However, most of ultrasound probes used is bulky and high power consumable, so unsuitable for such applications. In this study, the 3 layered ceramic specimen consisted of 128 pitches of $420{\mu}m$ in width and $450{\mu}m$ in thickness were prepared by using the Ti-rich PZT compositions co-fired at $1,050^{\circ}C$. Their electrical and ultrasound pulse-echo properties were investigated and compared to the single layer specimen. The 3 layered ultrasound probe showed 1.584 V of Vp-p, which is 3.2 times higher than single layered one, implying that it would allow effectively such a portable ultrasound probe system. The result were discussed in terms of higher capacitance, lower impedance and higher dielectric coefficient of the 3 layered ultrasound probe.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.481-487
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• 2020

Radiation measurement technology has steadily improved and its usage is expanding in various industries such as nuclear medicine, security search, satellite, nondestructive testing, environmental industries and the domain of nuclear power plants (NPPs). Especially, the simultaneous measurements of gamma rays and neutrons can be even more critical for nuclear safety management of spent nuclear fuel and monitoring of the nuclear material. A semiconductor detector comprising cadmium, zinc, and tellurium (CZT) enables to detect gamma-rays due to the significant atomic weight of the elements via immediate neutron and gamma-ray detection. Semiconductor sensors might be used for nuclear safety management by monitoring nuclear materials and spent nuclear fuel with high spatial resolution as well as providing real-time measurements. We aim to introduce a portable nuclide-analysis device that enables the simultaneous measurements of neutrons and gamma rays using a CZT sensor. The detector has a high density and wide energy band gap, and thus exhibits highly sensitive physical characteristics and characteristics are required for performing neutron and gamma-ray detection. Portable nuclide-analysis device is used on NPP-decommissioning sites or the purpose of nuclear nonproliferation, it will rapidly detect the nuclear material and provide radioactive-material information. Eventually, portable nuclide-analysis device can reduce measurement time and economic costs by providing a basis for rational decision making.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4065-4083
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• 2021

Super-resolution can improve the clarity of low-resolution (LR) images, which can increase the accuracy of high-level compute vision tasks. Portable devices have low computing power and storage performance. Large-scale neural network super-resolution methods are not suitable for portable devices. In order to save the computational cost and the number of parameters, Lightweight image processing method can improve the processing speed of portable devices. Therefore, we propose the Enhanced Information Multiple Distillation Network (EIMDN) to adapt lower delay and cost. The EIMDN takes feedback mechanism as the framework and obtains low level features through high level features. Further, we replace the feature extraction convolution operation in Information Multiple Distillation Block (IMDB), with Ghost module, and propose the Enhanced Information Multiple Distillation Block (EIMDB) to reduce the amount of calculation and the number of parameters. Finally, coordinate attention (CA) is used at the end of IMDB and EIMDB to enhance the important information extraction from Spaces and channels. Experimental results show that our proposed can achieve convergence faster with fewer parameters and computation, compared with other lightweight super-resolution methods. Under the condition of higher peak signal-to-noise ratio (PSNR) and higher structural similarity (SSIM), the performance of network reconstruction image texture and target contour is significantly improved.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.606-608
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• 2006

This paper describes a 8bit 10MS/s low power pipelined analog-to-digital converter(ADC). To reduce power consumption in proposed ADC, a high gain op-amp that consumes large power in MDAC(multiplying DAC) of conventional pipelined ADC is replaced with simple comparator and current sources. Moreover, differential charge transfer amplifier technique with latch in the sub-ADC reduces the power consumption to less than half compared with the conventional sub-ADC which use high speed comparator. The proposed ADC shows the power consumption of 1.8mW at supply voltage of 1.8V. This proposed ADC is suitable to apply to the portable display device. The circuit was implemented with 0.18um CMOS technology and the core size of circuit is 2.5mm${\times}$1mm.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.107.2-107
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• 2001

We propose portable equipment that monitors a current and potential on high-potential power transmission lines. In the equipment, a current and voltage sensor are attached to a hollow insulator that supports a power transmission line: A current on a power line is detected by an air-core solenoidal coil clamped to the line and the detected current signal is transmitted to the ground station by using optical data link, A potential on a power transmission line is detected by a high resistance element, zinc oxide (ZnO) that acts as a potential divider between the power line and the ground. The equipment does not require high potential insulators and magnetic cores which. This leads to the following advantages of the equipment: (a) It is easily installed owing to its small size and its simple structure; (b) It operates in low ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.114.6-114
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• 2001

According to expansion of wireless communication system and mobile device, interest has been growing in personal navigation system integrated with wireless system. In portable consumer electronics, such as cellular phones, GPS and PDA, one of major design factors is the power consumption. Solutions of reducing the power dissipation are low voltage, low system clock power management and so on. This paper develops a GPS receiver based on the advanced power management algorithm that achieves very low average power consumption. Both RF and DSP chips are powered down and reactivated only when the position fixing is required. In order to run, the developed includes the RTC calibration function and the fast reacquisition function using XMC (eXtended Multiple Correlator) ...

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.376-385
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• 2021

Probabilistic risk assessment (PRA) has improved its elemental technologies used for assessing external events since the Fukushima Daiichi Nuclear Power Station Accident in 2011. HRA needs to be improved for analyzing tasks performed under extreme conditions (e.g., different actors responding to external events or performing operations using portable mitigation equipment). To make these improvements, it is essential to understand plant-specific and scenario-specific conditions that affect human performance. The Nuclear Risk Research Center (NRRC) of the Central Research Institute of Electric Power Industry (CRIEPI) has developed an HRA guide that compiles qualitative analysis methods for collecting plant-specific and scenario-specific conditions that affect human performance into "narratives," reflecting the latest research trends, and models for analysis of tasks under extreme conditions.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.226-229
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• 2000

In this paper, we describe implementation of 32-Bit RISC Core for portable communication/information equipment, such as cellular telephones and personal digital assistants, notebook, etc. The RISC core implements the ARM$\^$R/V4 instruction set on the basis of low power techniques in architecture level and logic level. It operates with 5-stage pipeline, and has harvard architecture to increase execution speed. The processor is modeled and simulated in RTL level using VHDL. Behavioral Cache and MMU are added to the VHDL model for instruction level verification of the processor. The core is implemented using Mentor P'||'&'||'R tools with IDEC C-631 Cell library of 0.6$\mu\textrm{m}$ CMOS 1-poly 3-metal CMOS technology.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.46-53
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• 2007

Direct Methanol Fuel Cell, DMFC is a potential power source for portable IT application. DMFC works at low temperature ($<100^{\circ}C$) without fuel processing. Methanol has high energy density, fuel economy, and easiness to handle. This paper focuses high efficient catalyst to increase utilization in the electrode, new membrane reducing methanol crossover, new material parts, and optimization of system integration. Lightweight and small-sized DMFC based on new materials, efficient stack, and improved system control will be applied to the 50W prototype system for the notebook computer.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.127-129
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• 2006

The distributed control system is used in wide control fields. Factory automation, home network and building automation are good examples. Lonworks that Echelon company has been developing and providing since 1991 is one of popular distributed control systems. Lonwork system is support various communication media, especially it has a feature that supports communication through the power line. When Constructing Lonworks network in a construction field, the experts, who can treat Lonworks bring laptops that LNS and Lonmaker installed, install the network. However this way takes long time to construct the network and needs the experts. To resolve this problem, this paper suggests that a design of Lonworks network installation machine that is easy to use for everyone and portable. Non-experts can install Lonworks network by using this machine so they can reduce fare for installation of network and time to install.