• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1047-1048
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• 2006

In this paper, we present an iterative phase offset estimation algorithm based on a space-time block code and turbo coded system. External single phase estimator receives soft information from the turbo decoder and estimates phase offset with LMS algorithm. The estimated phase offset value is used for space-time decoder. Simulation results show the phase estimation gain in a flat fading channel.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.951-962
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• 2020

One hundred ninety-five countries reached agreement on a new climate treaty in Paris, France to reduce the carbon emissions. South Korea has been selected as a target country for reducing greenhouse gas (GHG) obligations since 2020. In this context, the Korean government developed several GHG emissions reduction programs using forests called the "Forest carbon offset scheme (FCOS)." The forest management method is one of the tools to implement FCOS. Most of the participants registered forest management as the preferred methodology to participate in the FCOS. For a successful implementation of the FCOS, it is necessary to explore the optimal methods by considering the cost-effective aspect of conducting the forest management as a tool to increase carbon absorption. In this context, this study investigated the value optimized FCOS projects based on the forest management methodology in South Korea. Three forest management scenarios, 1) extending the final age of maturity of Pinus densiflora stands (S1), 2) extending the final age of maturity of Quercus acutissima stands (S2), and 3) reforestation with new species (Pinus densiflora to Quercus acutissima) (S3), were examined and evaluated to identify the optimal carbon absorption and value optimized economic perspective. The results of the scenario-based modelling indicated that S3 showed value optimized from an economical perspective, and S2 was the most effective method to absorb carbon among the scenarios. It is anticipated that this paper will contribute to provide valuable information by presenting innovative approaches as a value optimized FCOS implementing tool in a GHG reduction program in South Korea.

• Journal of Broadcast Engineering
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• v.8 no.2
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• pp.146-152
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• 2003

ATSC DTV receivers use repetitive data segment syncs or Gardner algorithm as a tuning recovery circuit. Many multipath signals can induce timing-offset in the symbol timing recovery circuit using Gardner algorithm and this timing-offset shifts sampling instant to the wrong points, causing the performance of the equalizer to become nr. When many echoes exist, the optimal sampling instant will be the Point at which the main-path has a peak value. In this paper, by using channel correlation techniques, we find the optimal sampling instant, thereby compensating the timing offset and improving DTV reception performance. We analyzed the Performance enhancement of DTV receivers using the timing offset compensator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3A
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• pp.254-259
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• 2010

In this paper, we propose a low-complexity carrier frequency offset (CFO) estimation algorithm for OFDM based wireless LAN, IEEE 802.11a. The complexity of the arctangent operation to calculate the argument of auto-correlation for CFO estimation is reduced by a novel range pointer method. The proposed algorithm estimates fine CFO value first and then based on the fine CFO value, simple criteria is used for the boundary decision of integer CFO estimation. The simulation results show that the performance of the proposed algorithm is slightly better than the conventional method while the computational complexity is reduced by 50%. Furthermore, the proposed method can be easily implemented for the low complex next generation MIMO-OFDM based WLAN systems.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.307-316
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• 2024

On January 1, 2024, an earthquake with a moment magnitude of 7.5 occurred on the Noto Peninsula in Japan. The earthquake caused significant surface displacement on the Noto Peninsula. The surface displacement is measured by global navigation satellite system (GNSS) base stations, but there are limitations in obtaining information in areas where base stations do not exist. Therefore, in this study, we aim to determine the horizontal land surface displacement across the Noto Peninsula using offset tracking, which can detect rapidly occurring displacement. As a result of analyzing the Noto Peninsula using the offset tracking technique, it was found that more horizontal surface displacement occurred in the northwest region than in the northeast region of the Noto Peninsula, where the epicenter was located, and the surface displacement value reached a maximum of 2.9 m. The results of this study can be used to calculate surface displacement values in areas where surface displacement data are not available through ground GNSS base stations.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.26-30
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• 1996

This paper proposes a novel method to reduce the torque ripple due to the non-ideality of the current sensing parts in vector-controlled inverter-fed PMSM(Permanent Magnet Synchronous Motor) drive systems. The motor output torque equations are derived in terms of their offset voltages and different voltage transducing gains. And the effects of phase current errors on motor torque are analyzed for both salient PMSM and non-salient PMSM. The proposed method can eliminate the torque ripple by nulling the offset voltages and setting the voltage transducing gains to the same value. To verify the proposed method, digital simulations are carried out for non-salient PMSM.

• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.1
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• pp.31-45
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• 1996

For the purpose of study on the printability of domestic art papers, the physical properties of domestic coated paper for offset printing were investigated. 25 kinds of sample papers were prepared and were examined in accordance with KS and TAPPI standard testing method i.e., basis weight, density, opacity, gloss, roughness, smoothness, brightness, and K&N absorption. IGT printability tester was used to obtain the printability parameters, such as maximum ink requirement of paper Y, limiting printing density D print through, and density smoothness constant m value.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.3
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• pp.1-10
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• 2000

This paper proposes a novel video coding system with rate control based on fractal algorithm To overcome the demerits of excessive amounts of coded bit generated by previous fractal coding methodology. the proposed system classifies the Image into three classes such as background, motion compensation, and fractal coding area. The motion vector for motion compensation, and the fractal offset value that is difference value between the predicted offset and the least-square approximated value are coded with variable length code The decision method which determines threshold value of partitioning quadtree is applied to the bit-rate control algorithm considering the quantity of currently generated bits and fixed channel bandwidth Experimental result shows that the proposed system enhances compression ratio 1.8 times higher than previous method for the same image quality, and performs efficient rate control for fixed channel bandwidth.

• Journal of Korea Technology Innovation Society
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• v.16 no.1
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• pp.252-278
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• 2013

Many countries implement an offset program as a method of the acquisition of modern military technology for enhancement of the domestic military strength. Offset agreements are made based on the value, not a monetary unit. The value should be above minimum threshold fixed by the related regulation. Hence, technology valuation model which is objective and reasonable is required vitally. At present, some defense related organizations such as DTaQ, ADD valuate the proposed technology by using their own method. However, due to the lack of differentiation of valuation analysis indicators for various technologies, existing offset valuation models are inadequate to consider whole characteristics of such technologies. In this paper, we developed four sets of offset valuation analysis indicators considering the characteristics of each technology, parts production, depot maintenance, military equipment performance upgrade, and R&D related technology, by using the Delphi method. Also, we structurized those indicators in each technology by using the factor analysis. Through applying developed indicators, it is expected that technology valuation in the offset program would be more credible and accurate. Ultimately, it gives greater bargaining power to negotiators in the procedure of the offset negotiation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.881-893
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• 2000

An analytical synthesis technique for offset slider-rocker 4-bar linkages is devised where transmission angles are used as essential synthesis parameters. Finding the location where both the maximum and the minimum transmission angles arise leads to establishing the algorithm for limiting transmission angles of the slider-rocker linkage which has different offsets according to the direction of the slider. Position analysis by the algorithm gives formula for the dimensional synthesis for the linkage. Application to examples shows that the algorithm and the formula yield proper slider-rocker linkages with regard to limiting transmission angles to the maximum value.