• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2914-2922
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• 1997

For FA (factory automation) and ATE (automatic test equipment) in the industrial area, the standard bus needs to increase the system performance of multiprocessor environment. VME(versa module european package format) bus is appropriated to the standard bus but has features of small package and low board density. Beside, the density of board and semiconductor have grown to become significant issues that affect development time, project cost and field diagnostics. To fit this trend, in this paper, we composed Revision C.1 (IEEE std. P1014-1987) of the integrated environment for the main function such as arbitration, interrupt and interface between, VMEbus and several control modules Also the designed, VME system controller is implemented on FPGA that can be located even into slot 1. The control and function modules are coded with VHDL mid-fixed description method and then those operations are verified by simulation. As a result of experiment, we confirmed the most important that is the operation of Bus timer about Bus error signal should occur within $56{\mu}m$, and both control and function modules have the reciprocal operation correctly. Thus, the constructed VHDL library will be able to apply the system based VMEbus and ASIC design.

• Journal of Power Electronics
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• v.18 no.1
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• pp.212-224
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• 2018

For maintaining a reliable and secure power system, this paper describes the design and implement of a single-phase grid-connected inverter with an enhanced phase-locked loop (PLL) and excellent power control performance. For designing the enhanced PLL and power regulator, a full-bridge voltage-controlled inverter (VCI) is investigated. When the grid frequency deviates from its reference values, the output frequency of the VCI is unstable with an oscillation of 2 doubling harmonics. The reason for this oscillation is analyzed mathematically. This oscillation leads to an injection of harmonics into the grid and even causes an output active power oscillation of the VCI. For eliminating the oscillation caused by a PLL, an oscillation compensation method is proposed. With the proposed method, the VCI maintains the original PLL control characteristics and improves the PLL robustness under grid frequency deviations. On the basis of the above analysis, a power regulator with the primary frequency and voltage modulation characteristics is analyzed and designed. Meanwhile, a small-signal model of the power loops is established to determine the control parameters. The VCI can accurately output target power and has primary frequency and voltage modulation characteristics that can provide active and reactive power compensation to the grid. Finally, simulation and experimental results are given to verify the idea.

• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.98-103
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• 2020

Marfan syndrome (MFS), a connective tissue disorder caused by mutations in the fibrillin-1 (Fbn1) gene, has vascular manifestations including aortic aneurysm, dissection, and rupture. Its vascular pathogenesis is assumed to be attributed to increased transforming growth factor β (TGFβ) signaling and blockade of excessive TGFβ signaling has been thought to prevent dissection and aneurysm formation. Here, we investigated whether galunisertib, a potent small-molecule inhibitor of TGFβ receptor I (TβRI), attenuates aneurysmal disease in a murine model of MFS (Fbn1^C1039G/+) and compared the impact of galuninsertib on the MFS-related vascular pathogenesis with that of losartan, a prophylactic agent routinely used for patients with MFS. Fbn1^C1039G/+ mice were administered galunisertib or losartan for 8 weeks, and their ascending aortas were assessed for histopathological changes and phosphorylation of Smad2 and extracellular signal-regulated kinase 1/2 (Erk1/2). Mice treated with galunisertib or losartan barely exhibited phosphorylated Smad2, suggesting that both drugs effectively blocked overactivated canonical TGFβ signaling in Fbn1^C1039G/+ mice. However, galunisertib treatment did not attenuate disrupted medial wall architecture and only partially decreased Erk1/2 phosphorylation, whereas losartan significantly inhibited MFS-associated aortopathy and markedly decreased Erk1/2 phosphorylation in Fbn1^C1039G/+ mice. These data unexpectedly revealed that galunisertib, a TβRI inhibitor, showed no benefits in aneurysmal disease in MFS mice although it completely blocked Smad2 phosphorylation. The significant losartan-induced inhibition of both aortic vascular pathogenesis and Smad2 phosphorylation implied that canonical TGFβ signaling might not prominently drive aneurysmal diseases in MFS mice.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.6
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• pp.531-540
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• 2007

While determination of the solid propellant burning rates by ultrasound, it has been reported that the frequent data scatters were caused by two major factors; 1) variation in the acoustical properties, and 2) non-linear burning of a solid propellant sample under investigation. This work is carried out for the purpose of investigating the effect of non-linear burning of solid propellant samples. Specifically, we propose an ultrasonic measurement model that can predict the reflections from solid propellant surfaces with non-linear burning by the combination of two ingredients; 1) a pulse-echo ultrasonic measurement model for a planar, circular reflector imbedded in the second medium in an immersion set-up, and 2) an efficient model of non-linear burning surfaces with a number of small, planar circles. Then, we demonstrate the capability of the proposed measurement model by simulation of the surface echo signals from four different burning surfaces that have been generated by the combination of two factors; the base shape (flat or paraboloidal) and the surface roughness (perfectly smooth or randomly rough). From the simulation presented here, we can confirm the fact that the non-linear burning of the propellant can cause the waveform change of the burning surface echo and the corresponding spectrum variation.

• Journal of the Korea Computer Industry Society
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• v.3 no.3
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• pp.321-330
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• 2002

A 2-D median filter has many applications in various image and video signal processing areas. The rapid development in VLSI technology makes it possible to implement a real-time or near real-time 2-D median filter with reasonable cost. For the efficient VLSI implementation, the algorithm should have characteristics such as small memory requirements, regular computations, and local data transfers. This paper presents an architecture of the real-time two-dimensional separable median filter which has appropriate characteristics for the VLSI implementation. For the efficient two-dimensional median filter, a separable two-dimensional median filtering structure and a bit-sliced pipelined median searching algorithm are used. A behavioral simulator is implemented with C language and used for the analysis of the presented architecture.

• Korean Journal of Remote Sensing
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• v.25 no.2
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• pp.155-163
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• 2009

An abundance of internal waves is observed by SAR in the Yellow Sea during summer. They are small scaled internal waves and are not relatively studied well compared to the ones in the East/South China Sea. These internal waves should be considered in the study of physio-biological properties of the Yellow Sea because the mixing of the stratified surface water caused by internal waves during summer is important for ocean biological environment, and they also affect the sediment transport and acoustic signal transmission in the continental shelf region. To understand the characteristics of internal waves, it is important to get the spatio-temporal information of internal waves simultaneously by executing in-situ measurements as well as the SAR observation. This study tracks the internal waves observed by SAR in the time series of temperature profile data by analyzing simultaneously acquired in-situ measurement data and RADARSAT SAR image on 29 May 2002.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.327-333
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• 2019

The Fuel-cut driving is started when the acceleration pedal released with transmission gear engaged. Fuel economy of the vehicle improves by active fuel-cut driving. A deep-learning technique is proposed to predict fuel-cut driving with vehicle speed, acceleration and road gradient data in the study. It's 3~10 of hidden layers and 10~20 of variables and is applied to the 9600 data obtained in the test driving of a vehicle in the road of 12km. Its accuracy is about 84.5% with 10 variables, 7 hidden layers and Relu as activation function. Its error is regarded from the fact that the change rate of input data is higher than the rate of fuel consumption data. Therefore the accuracy can be better by the normalizing process of input data. It's unnecessary to get the signal of vehicle injector or OBD, and a deep-learning technique applied to the data to be got easily, like GPS. It can contribute to eco-drive for the computing time small.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.927-934
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• 2019

Recently, mobile devices have evolved into small computers with various functions according to user requirements. Careful attention must be paid to the design of the power supply network for the stable operation of the application processor (AP), the wireless communication modem, the high performance camera, and the various interfaces of the mobile device to implement various functions of the mobile device. In this paper, we analyzed and verified the method of optimizing the design parameters such as the position, capacity, and number of decoupling capacitors to meet the target impedance required by the driver IC chip to ensure the stability of the power supply network of mobile devices that should be designed as wiring type due to mounting density limitation. The proposed wired power supply network design method can be applied to various applications including high-speed signal transmission line in addition to mobile applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.845-848
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• 2009

Power semiconductor devices are semiconductor devices used as switches or rectifiers in power electronics circuits. Theyare also caleed power devices or when used in integrated circuits, called power ICs. Some common power devices are the power diode, thyristor, power MOSFET and IGBT (insulated gate bipolar transistor). A power diode or MOSFET operates on similar principles to its low-power counterpart, but is able to carry a larger amount of current and typically is able to support a larger reverse-bias voltage in the off-state. Structural changes are often made in power devices to accommodate the higher current density, higher power dissipation and/or higher reverse breakdown voltage. The vast majority of the discrete (i.e non integrated) power devices are built using a vertical structure, whereas small-signal devices employ a lateral structure. With the vertical structure, the current rating of the device is proportional to its area, and the voltage blocking capability is achieved in the height of the die. With this structure, one of the connections of the device is located on the bottom of the semiconductor.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.35-45
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• 2006

RIn this paper. we describe real-time parallel processing simulator developed for the use of performance analysis of rolling missiles. The real-time parallel processing simulator developed here consists of seeker emulator generating infrared image signal on aircraft, real-time computer, host computer, system unit, and actual equipments such as auto-pilot processor and seeker processor. Software is developed according to the design requirements of mathematic model, 6 degree-of-freedom module, aerodynamic module which are resided in real-time computer. and graphic user interface program resided in host computer. The real-time computer consists of six TI C-40 processors connected in parallel. The seeker emulator is designed by using analog circuits coupled with mechanical equipments. The system unit provides interface function to match impedance between the components and processes very small electrical signals. Also real launch unit of missiles is interfaced to simulator through system unit. In order to use the real-time parallel processing simulator developed here as a performance analysis equipment for rolling missiles, we perform verification test through experimental results in the field.