• ETRI Journal
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• v.30 no.1
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• pp.47-58
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• 2008

In sensor networks, analyzing power consumption before actual deployment is crucial for maximizing service lifetime. This paper proposes an instruction-level power estimator (IPEN) for sensor networks. IPEN is an accurate and fine grain power estimation tool, using an instruction-level simulator. It is independent of the operating system, so many different kinds of sensor node software can be simulated for estimation. We have developed the power model of a Micaz-compatible mote. The power consumption of the ATmega128L microcontroller is modeled with the base energy cost and the instruction overheads. The CC2420 communication component and other peripherals are modeled according to their operation states. The energy consumption estimation module profiles peripheral accesses and function calls while an application is running. IPEN has shown excellent power estimation accuracy, with less than 5% estimation error compared to real sensor network implementation. With IPEN's high precision instruction-level energy prediction, users can accurately estimate a sensor network's energy consumption and achieve fine-grained optimization of their software.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1429-1433
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• 2004

Recently, a dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOK corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque form input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element methode and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test methode when applied rated torque.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.859-871
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• 2003

In this paper we introduce some adaptive M-estimators using selector statistics to estimate the slope of regression model under the symmetric and continuous underlying error distributions. This selector statistics is based on the residuals after the preliminary fit L$_1$ (least absolute estimator) and the idea of Hogg(1983) and Hogg et. al. (1988) who used averages of some order statistics to discriminate underlying symmetric distributions in the location model. If we use L$_1$ as a preliminary fit to get residuals, we find the asymptotic distribution of sample quantiles of residual are slightly different from that of sample quantiles in the location model. If we use the functions of sample quantiles of residuals as selector statistics, we find the suitable quantile points of residual based on maximizing the asymptotic distance index to discriminate distributions under consideration. In Monte Carlo study, this adaptive M-estimation method using selector statistics works pretty good in wide range of underlying error distributions.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.717-721
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• 2010

Soil volume conversion factors are used for estimation of an excavated the soil volume which will be removed or added in levelling the ground surface of a construction site. An accurate evaluation method will help us reduce a construction cost and time consuming. In this study, we performed the laboratory tests, including grain size measurement, water content, specific gravity, porosity, density and XRD tests, to suggest reliable soil volume conversion factors and weathering indices in field using nondestructive methods. The weathering index and soil volume conversion factor L are obtained for different types of soils. At results, the CIW index is the best method measuring the weathering index and the factor L is relative to natural porosity, void ratio, density and dry density.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.647-658
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• 2009

It is already known from the previous study that flood seems to have heavier tail. Therefore, to make prediction of future extreme label, some agreement of tail behavior of extreme data is highly required. The LH-moments estimation method, the generalized form of L-moments is an useful method of characterizing the upper part of the distribution. LH-moments are based on linear combination of higher order statistics. In this study, we have formulated LH-moments of five distributions useful in hydrology such as, two types of three parameter kappa distributions, beta-${\kappa}$ distribution, beta-p distribution and a generalized Gumbel distribution. Using LH-moments reduces the undue influences that small sample may have on the estimation of large return period events.

• The Korean Journal of Food And Nutrition
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• v.3 no.2
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• pp.177-184
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• 1990

General components, amino acids and minerals contained in T kind of edible wild grasses were estimated. Samples were collected from the field of Kapyong area, Kyung-ki, Korea. Results of the estimation were summarized as follows ; 1) A relatively large amounts of protein and fat were contained in the edible parts of each sample. 2) The most abundant amino acids in the edible parts of each sample were glutamic acid (26.6%), serine(18.7%), valise(22.4%), respectively. 3) A high level of calcium and iron was found in the edible parts of each samples. Especially calcium was abundant in the leaves of Rumex coreanus Nakai and iron was abundant in the Commelina communis L. Both copper and zinc were abundant in the Sanguisorba officinalis L.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.619-628
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• 2015

In this paper, we consider a method for estimating a stripe-type defect and the reconstruction of a defect-free L/S type mask used in lithography. Comparing diffraction patterns of defected and defect-free masks, we derive equations for the estimation of the location and size of the defect. We construct an analytical model for this problem and derive closed form equations to determine the location and size using phase retrieval problem solving techniques. Consequently, we develop an algorithm that determines a defect-free mask pattern. An example shows the validity of the equations.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.270-275
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• 2017

This paper proposes a double-phase-locked-loop (PLL) to improve the performance of position estimation in hall sensor-based permanent magnet synchronous motor control. In hall sensor-based control, a PLL is normally used to estimate the rotor position. The proposed Double-PLL consists of two PLLs, including a reset type integrator. The motor control is more accurate and has better performance than conventional PLL, such as a small estimated position ripple. The validity of the proposed algorithm is verified by simulations and experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.464-471
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• 2000

The number of quantization bits of the input signals $X_k$,$Y_k$ need to be optimally determined through the trade-off between the H/W complexity and the BER performance in Turbo codes applications. Also, an effective means to incorporate a channel reliability $L_c$ in the Log-MAP-based Turbo decoding is highly required. because it has a major effect on both the complexity and the performance. In this paper, a novel bit-shifting approach that substitutes for the multiplying is proposed so as to effectively incorporate. $L_c$ in Turbo decoding. The optimal number of quantization bits of $X_k$,$Y_k$ is investigated through Monte-Carlo simulations assuming that bit-shifting approach is adopted. In addition. The effects of an incorrect estimation of noise variance on the performance of Turbo codes is investigated. There is a confined range in which the effects of an incorrect estimation can be ignored.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.47-54
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• 2005

A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.