• Nuclear Engineering and Technology
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• 제56권1호
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• pp.292-300
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• 2024

Kinetic simulations have been performed on an Inertial Electrostatic Confinement Fusion (IECF) device. These simulations were performed using the particle-in-cell (PIC) method to analyze the behavior of ions in an IEC device and the effects of some parameters on the Confinement Time (CT). CT is an essential factor that significantly contributes to the IEC's performance as a nuclear fusion device. Using the PIC method, the geometry of a two-grided device with variable grid radius, the number of cathode grid rings, variable pressure and different dielectric thickness for the feed stalk was simulated. In this research, with the development of previous works, the interaction of particles was simulated and compared with previous results. The simulation results are in good agreement with the previous results. In these simulations, it was found that with the increase of the dielectric thickness of the feed stalk, the electric field was weakened and as a result, the confinement time was reduced. On the other hand, with the increase of the cathode radius, the confinement time increased. Using the results, an IEC device can be designed with higher efficiency and more optimal CT for ions.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.401-410
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• 2017

In this work, we show that the excessive lattice heating problem due to parasitic pnp transistor action in the diode electrostatic discharge (ESD) protection device in the diode input protection circuit, which is favorably used in CMOS RF ICs, can be solved by adopting a symmetrical cathode structure. To explain how the recipe works, we construct an equivalent circuit for input human-body model (HBM) test environment of a CMOS chip equipped with the diode protection circuit, and execute mixed-mode transient simulations utilizing a 2-dimensional device simulator. We attempt an in-depth comparison study by varying device structures to suggest valuable design guidelines in designing the protection diodes connected to the $V_{DD}$ and $V_{SS}$ buses. Even though this work is based on mixed-mode simulations utilizing device and circuit simulators, the analysis given in this work clearly explain the mechanism involved, which cannot be done by measurements.

• 한국안전학회지
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• 제26권5호
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• pp.13-16
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• 2011

The vibration and shock of the opto-electronic protective device was induced mechanical failure or fail to work correctly. In order to identify the exciting frequency components of vibration and shock, vibration signals are measured and analyzed from the mechanical power press. In addition, the modal test for the opto-electronic protective device was performed to investigate the dynamic characteristics. Some FEM simulations were carried out and then anti vibration mount was made for opto-electronic protective device. Based on the results of simulations, some kind of rubber mounts were tested to demonstrate the reduction of vibration and shock. It was verified by the test that a considerable amount of vibration and shock were reduced.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.234-237
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• 2000

In this paper, a method to implement new Quasi-SOI LDMOSFET is introduced and the electrical characteristics of the device are studied. Key process steps of the device are explained briefly. By performing process and device simulations, electrical characteristics of the device are investigated, with emphasis on the optimization of the tilt angle of p$\^$0/ channel region. The electrical properties of the Quasi-SOI device are compared with those of bulk and SOI devices with the same process parameters. Simulated device characteristics are threshold voltage, off-state leakage current, subthreshold swing, DIBL, output resistance, lattice temperature, I$\_$D/-V$\_$Ds/, and cut-off frequency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1415-1435
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• 2018

Resource allocation in device-to-device (D2D) aided cellular systems, in which the proximity users are allowed to communicate directly with each other without relying on the intervention of base stations (BSs), is investigated in this paper. A new uplink resource allocation policy is proposed by exploiting the relationship between D2D-access probability and channel gain among variant devices, such as cellular user equipments (CUEs), D2D user equipments (DUEs) and BSs, etc., under the constraints of their minimum signal to interference-plus-noise ratio (SINR) requirements. Furthermore, the proposed resource-allocation problem can be formulated as the cost function of "maximizing the number of simultaneously activated D2D pairs subject to the SINR constraints at both CUEs and DUEs". Numerical results relying on system-level simulations show that the proposed scheme is capable of substantially improving both the D2D-access probability and the network throughput without sacrificing the performance of conventional CUEs.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.67-73
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• 2010

In this study, a camber angle generating mechanism for rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Rear left wheel and rear right wheel have 5 different camber angles in the simulations, respectively. Step steer and pulse steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle control of rear suspension. According to the results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel should have the proper orientation for improving the handling performance, respectively.

• 전자공학회논문지D
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• 제34D권11호
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• pp.37-47
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• 1997

Utilizing 2-dimensional device simulations incorporating lattic eheating models, we analyzed in detail the DC breakdown characterisics of NMOS trasistors with different structures, which are commonly used as ESD protection transistors. The mechanism leading to device failure resulting from electrostatic discharge was explained by analyzing the 1st and 2nd breakdown characteristics of LDD devices. Also a criteria for more robust designs of NMOS transistor structures against ESD was suggested by examining the characteristics changes with changes in structural parameters such as the LDD doping concentration, the drain junction depth, the distance between source/drain contacts, and the source junction area.

• 한국정보전자통신기술학회논문지
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• 제7권4호
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• pp.159-167
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• 2014

Local device-to-device (D2D) communication between two smart mobile devices is becoming increasingly popular. The first key step in starting a D2D communication is to discover and identify the remote target device to establish a link. However, existing device discovery mechanisms either require users to explicitly identify the ID of the target device or rely on inaccurate beamforming technology. This paper presents two novel device identification algorithms using a variety of embedded sensors. The algorithms only require that users to point two devices towards each other. This paper describes the algorithms, analyzes their accuracy using analytical models, and verifies the results using simulations.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.88.2-88.2
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• 2007

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.825-830
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• 2004

Kinematic calibration of Gough-Stewart platform using a new measurement device is presented in this paper. The device simultaneously measures components of position and orientation using commercially available gadgets. Additional kinematic parameters are defined to model the sources of inaccuracies for the proposed measurement device. Computer simulations reveal that all kinematic parameters of the Gough-Stewart platform and the additional kinematic parameters of the measurement device can be identified with the partial pose measurements of the device. Results also show that identification is robust for the initial errors and the noise in measurements. The device also facilitates the automation of easurement procedure.