• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.7
• /
• pp.97-103
• /
• 2002

In this paper, a Logarithmic Video Amplifier(LVA) for radar system or satellite communications is described. The proposed LVA is composed of a input stage, amplification stage, and output stage. As well as a novel series-parallel architecture is proposed for the purpose of wide dynamic range and high speed operation, a newly developed input stage is designed in order to control the voltage level between LVA and detector diode. The LVA is fabricated with a 1.5um 2-poly 2-metal n-well Bi-CMOS technology, and the chip area is 1310 um x 1540 um. From the experimental results, it consumes 190 mW at 10V power supply, the chip has 60 dB dynamic range and 100ns falling time.

• Journal of the Society of Naval Architects of Korea
• /
• v.45 no.1
• /
• pp.73-80
• /
• 2008

An improved method to measure the dynamic viscoelastic properties of elastomers is proposed. The method is based on the analysis of forced oscillation of a cylindrical sample loaded with inertial mass. No special equipment or instrumentation other than the ordinary vibration measurement apparatus is required. Typical measurement of the viscoelastic properties of a silicone rubber $Silastic^{(R)}$ S2 were measured over the wide frequency range from 10 Hz to 3 kHz under the action of wide region of deformation from $10^{-4}%$ to 5%. It was shown that modulus of elasticity and loss tangent fall on the single curves when the ratio of load mass to sample mass changed from 1 to 20.

• Journal of Information Technology Services
• /
• v.6 no.2
• /
• pp.19-33
• /
• 2007

The current advance of IT and the e-commerce triggers the wide practice of dynamic pricing in all industries although the price discrimination has been very cautiously applied in the limited areas in the past. The price discrimination which offers different prices for each customer depending on their preference and buying behaviors has recently gained attention as it could provide superior benefits to sellers. The wide adoption of price discrimination, on the other hand, is reported to face buyer resistances and complaints. Our limited understanding on the perception of price fairness, which we think is key concept in the price discrimination on the Internet-enabled transactions, motives us to investigate factors that affect the perception of price fairness. This study focuses on illusion of control and lateral customer relationship to investigate their effects on price fairness in online auction and group purchase context. By conducting laboratory experiments, our study demonstrates that customers' perception on illusion of control in price determination and advantageous lateral customer relationship significantly affect price fairness perception in both online auction and group purchase environment. The findings are expected to provide researchers and managers with useful insights to develop better pricing strategies and design effective dynamic pricing mechanisms.

• Journal of Sensor Science and Technology
• /
• v.19 no.4
• /
• pp.285-290
• /
• 2010

In this paper, a dynamic range(DR) extension technique based on a 3-transistor active pixel sensor(APS) and dual image sampling is proposed. The feature of the proposed APS is that the APS uses two or more photodiodes with different sensitivities, such as a high-sensitivity photodiode and a low-sensitivity photodiode. Compared with previously proposed wide DR(WDR) APS, the proposed approach has several advantages, such as no-external equipments or signal processing, no-additional time-requirement for additional charge accumulation, simple operation and adjustable DR extension by controlling parasitic capacitance and sensitivity of two photodiodes. Approximately 16 dB of DR extension was evaluated from the simulation for the situation of 10 times of sensitivity difference and the same size of parasitic capacitance between those two photodiodes.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.1667-1673
• /
• 2011

For performance evaluation of modified wide sleepers(MF-140 PSC sleepers), design moment for urban transit was calculated and then performance evaluation criteria were set up according to EN 13230-2. Next, static bend tests, dynamic tests at rail seat section of sleeper were carried out and static bend tests at center section of sleeper were fulfilled. The test results for modified wide sleepers were in excess of performance evaluation criteria and structural safety of sleepers was able to guaranteed from the results. As modifying depth of wide sleepers, construction convenience in underground will be expected to be improved and construction costs will be expected to be decreased.

• 제어로봇시스템학회:학술대회논문집
• /
• 1999.10a
• /
• pp.256-258
• /
• 1999

In this article, an integrable circuit technique for implementing square root extractor for analog signal processing is described. The realization method makes use of the characteristic of MOS translinear principle. The proposed scheme achieves a wide dynamic range, wide-band capability and high accuracy. Simulation results demonstrating the performance of the proposed scheme are also presented.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.403-407
• /
• 1999

In this paper we present an architecture, implementation, and performance evaluation of an adaptive communication system (ACS) for wide-area ATM clusters. Our approach capitalizes on thread-based programming model to overlap computation and communication and develop a dynamic message-passing environment with separate data and control paths. This leads to a flexible and adaptive message-passing environment that can support multiple flow control, error control, and multicasting algorithms. We show the performance of ACS applications and compare them with p4, PVM, and MPI applications.

• Journal of Korean Institute of Industrial Engineers
• /
• v.39 no.5
• /
• pp.351-360
• /
• 2013

Taguchi's robust design is a method for quality improvement by making a system insensitive to uncontrollable variations incurred by noise factors and it has received much attention in a wide range of engineering fields. Robust design can be broadly classified into static and dynamic ones. This paper is concerned with dynamic robust design. Taguchi suggested to use a signal-to-noise ratio as a robustness measure, but there has been much debate and criticism on its blind use. In order to cope with this drawback, many alternatives have been proposed. They are divided into performance measure modeling (PMM) and response function modeling (RFM) approaches. In this paper, both PMM and RFM approaches for dynamic robust design are reviewed. An example for illustration is provided as well.

• Journal of IKEEE
• /
• v.17 no.4
• /
• pp.478-483
• /
• 2013

This paper presents an adaptive Retinex algorithm for improving dynamic range of image representation. The proposed Retinex algorithm detects degraded brightness by using skewness and the degraded components are compensated with local statistics. In particular, we propose a new compensation function for dynamic range so that effectinve image representation can be achieved. Experimental results show that the proposed algorithm has the capability to improve the dynamic range with reduction of color degradation.

• Structural Engineering and Mechanics
• /
• v.61 no.1
• /
• pp.91-103
• /
• 2017

This paper analyzes the dynamic behavior of the deck of pergola bridges affected by moving loads, specifically high-speed trains. Due to their characteristic advantages, pergola bridges have become a widely used structural typology on high-speed railways. In spite of such wide-spread use, there are few technical bibliographies published in this field. The first part of this paper develops a simple analytical methodology to study the complex dynamic behavior of these double dimensional structures. The second part compares the results obtained by the proposed formulae and the dynamic response obtained with different and gradually more complex FE models. The results obtained by the analytical model are in close agreement with those obtained by the FE models, demonstrating its potential application in the early design stages of this kind of structure.