• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.260-263
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• 2013

A semiconducting single-walled carbon nanotube (SWCNT) field-effect transistor (FET) in a top-gate model was constructed. The effect of different high-${\kappa}$ dielectric materials ($Al_2O_3$, $HfO_2$ and HfSiON) and various temperatures with a wide range from 50K to 500K on the performance of such nominal device were investigated. Several key device parameters including the on/off ratio of the current, transconductance ($g_m$), subthreshold swing, and carrier mobility were used to evaluate the device performance. The simulated results fit well with the experiment results previously published.

• Journal of Power Electronics
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• v.5 no.4
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• pp.247-256
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• 2005

In order to harvest power in an efficient manner from a micro piezoelectric (PZT) device for charging the battery of a remote system, a new AC/DC resonant pulse power converter is proposed. The proposed power converter has two stages in the power conversion process. The first stage includes N-type MOSFET full bridge rectifier. The second stage includes a boost converter having an N-type MOSFET and a P-type MOSFET. MOSFETs work in the $1^{st}$ or $3^{rd}$ quadrant region. A small inductor for the boost converter is assigned in order to make the size of the power converter as small as possible, which makes the on-interval of the MOSFET switch of the boost converter ultimately short. Due to this short on-interval, the parasitic junction capacitances of MOSFETs affect the performance of the power converter system. In this paper, the performance of the new converter is analytically and experimentally evaluated with consideration of the parasitic capacitance of switching devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1466-1470
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• 2007

MEMS design flow based on DFM concept is presented and applied to gyroscope design as a test case. It is purposed to contribute to the yield improvement by considering the process-related parameters from the design phase. After defining the performance requirements, the sensitivity analysis should be done on the draft design(s) to find out the key parameters related with the device performance. By doing so, TEG can be designed for the selected process and/or material parameters. Through a set of test runs, the process capability is characterized and the material properties are extracted using the TEG. Then we can estimate the virtual yield of the current process for the designed device by running Monte Carlo analysis where the process and/or material property variations are considered. The estimated yield will make us redesign the device to be more robust or improve the current process to have the smaller variations.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.393-400
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• 2003

Various types of dampers are widely adopted to reduce the seismic damages in bridges. However, dampers may be the improper solution especially in moderate seismic regions because dampers are costly for installation and require constant maintenance during life cycle. In this study, energy-dissipating sacrificial device is proposed, which sacrifices easily substitutable bridge members and dissipates the excessive energy during seismic excitations. In turns, the inelastic behavior of sacrificial members reduces the input energy of the major members, such as piers in bridges, and may prevent the major members from serious malfunction. A simplified mechanical model is developed to represent the behavior of sacrificial devices installed in a bridge. The hysteresis energy of piers is analyzed to certify performance of device under seismic loads applied to this mechanical model. The results from this study show that the proposed sacrificial energy-dissipating device can decrease excessive hysteresis energy and reduce the damage of piers under seismic excitation. Therefore, economical enhancement of the seismic performance of bridges may be possible by employing the proposed sacrificial energy-dissipating devices.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.117-119
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• 2021

With the development of the industry, the use of drones in specific mission flight is being actively studied. These drones fly a specified path and perform repetitive tasks. if the drone system will detect objects in real time, the performance of these mission flight will increase. In this paper, we implement object detection system and mount GPU acceleration to maximize the efficiency of limited device resources with drone video using Tensorflow Lite which enables in-device inference from a mobile device and Mobile SDK of DJI, a drone manufacture. For performance comparison, the average processing time per frame was measured when object detection was performed using only the CPU and when object detection was performed using the CPU and GPU at the same time.

• Current Applied Physics
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• v.18 no.12
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• pp.1592-1599
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• 2018

The present study deals with the effect of dual cathode buffer layer (CBL) on the performance of bilayer of 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC) and fullerene (C70)-based organic solar cell (OSC) with low donor concentration. OSC devices with CBLs have been fabricated using thermal vapor deposition technique. We report the use of lithium fluoride (LiF) and molybdenum trioxide ($MoO_3$) as CBLs. The insertion of LiF between C70 and aluminium (Al) electrode enhances the power conversion efficiency (PCE) of device from 1.89% to 2.47% but quenching of photogenerated excitons is observed at interface of C70 and LiF layers. Incorporation of $MoO_3$ between LiF and Al electrode further enhances PCE of device to 3.51%. This has also improved the material quality and device properties, by preventing the formation of gap states and diminishing exciton quenching.

• Electronics and Telecommunications Trends
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• v.36 no.2
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• pp.56-64
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• 2021

Many computer vision algorithms are computationally expensive and require a lot of computing resources. Recently, owing to machine learning technology and high-performance embedded systems, vision processing applications, such as object detection, face recognition, and visual inspection, are widely used. However, on-devices need to use their resources to handle powerful vision works with low power consumption in heterogeneous environments. Consequently, global manufacturers are trying to lock many developers into their ecosystem, providing integrated low-power chips and dedicated vision libraries. Khronos Group-an international standard organization-has released the OpenVX standard for high-performance/low-power vision processing in heterogeneous on-device systems. This paper describes vision libraries for the embedded systems and presents the OpenVX standard along with related trends for on-device vision system.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.19-23
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• 2013

This study is concerned with air-conditioning system in use of thermoelectric device. It is introduced that the well designed structures for better cooling & heating performance with high efficiency. And also it is performed that the system performance test of four types trial products for the use of hybrid commercial vehicle. System performance is affected by many component parts, especially heat sink design & power control method. It is applied that dual extrusive fin tube with buffer zone for the effective radiating of circulating liquid in tube. And also it is applied that power supply method with constant-current system. It is attained that system cooling capacity is 1.2kW, COP is 0.95.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.328-333
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• 2009

In this paper, we have developed high performance SPD(surge protective device) and evaluated the characteristics in comparison with typical SPD used in the inside and outside of the country. The new SPD was composed of MOV(metal oxide varistor), GDT(gas discharge tube) and impedance such as resistors, capacitors or varistors. To estimate operating the characteristic of the SPD which was developed, it was measured surge voltage caused by fault current or surge according to IEC 61000-4-5. As a result it was found that the power supply was cut off by high performance SPD when caused a short-circuit. In addition we could know that it could prevent ELB(earth leakage breaker)'s malfunction caused by surge.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.9-16
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• 2007

Input devices of wearable computer are difficult to use, so a lot of alternative pointing devices have been considered in recent years. In order to resolve this problem, this paper proposed a dynamic gain control method which is able to improve the performance of wearable pointing device and showed an experimental result comparing this method with conventional method. Also the effects of methods were compared in terms of device (wearable and desktop). The result of calculating throughputs(index of performance) by Fitts' law showed that the pointing performance in dynamic gain condition was improved 1.4 times more than normal gain.