• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.3
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• pp.214-219
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• 2013

This paper proposes the robust high-gain observer based SOC estimatro for uncertain RC model of Li-Ion batteries. In general, RC battery model has inevitable uncertainties and it cause some negative effect to estimate the accurate SOC of Li-Ion batteries. The proposed estimator overcomes such weakness with two techniques; high-gain observer design technique and sliding mode control technique. A high-gain observer provides the robustness against model uncertainties to the proposed estimator. A sliding mode control technique helps the proposed estimator by reducing the side effect of adopting a high-gain observer such as peaking phenomenon and perturbation. The performance of the proposed estimator is verified by some simulation.

• Korean Journal of Construction Engineering and Management
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• v.1 no.2 s.2
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• pp.108-116
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• 2000

The absence of systematic project procedures in the domestic SOC projects has caused many problems. Therefore, it has been raised the needs for the effective project management of the projects which helps the participants to have systematic procedures at each phase of the SOC projects. The purpose of this research is to build the current model of procurement management process for the airport facilities and to derive inherent problems, and the building direction of the effective procurement management is suggested for the future research. The result of this research could be used for delivering the effective SOC projects and for establishing interrelationships between procurement and other phases of the projects for the integrated project management. The procurement process of the Inchon International Airport was investigated and the as-is model was built. Through the analysis of the as-is model, and the questionnaires and the interviews with the participants of the SOC projects, the problems of the current procurement process has been derived.

• Journal of Families and Better Life
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• v.21 no.2
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• pp.131-144
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• 2003

Selective Optimization with Compensation (SOC), a concept defined by Baltes and Baltes, is known to predict successful aging. This study was conducted to find out which factors affect Korean elderly people SOC The data for this study were obtained from a survey conducted between March and May 2001, on a sample of middle-class male and female participants over 60 years old. Two hundred and fifty four completed questionnaires were used for final analyses. Descriptive statistics, t-test, ANOVA, Duncan test, Pearson correlations, multiple regressions, multiple response frequencies and sequential threshold methods were used to analyze the data. In order to measure successful aging, the Selective Optimization with Compensation Scale developed by Baltes, Baltes, Freud, and Lang (1996) was used. The SOC scale consists of four subscales, Elective Selection, Loss-based Selection, Optimization, and Compensation. The major findings are summarized in the following. First, the level of SOC by various socio-demographic variables was examined. It tuned out that health status is the most important variable in predicting SOC. Also important was satisfaction with family life. Second, significant correlations were found between SOC and duration of the marriage (negative), practicing a religion, health, and economic stability (all positive). Third, religion and health status affected SOC, but health was a stronger predictor Those who practiced a religion and were healthy had a higher score in SOC as a whole. Fourth, the participants were divided into three groups by their SOC score, and their idea.; of successful aging were compared. The top- and middle-score groups considered satisfaction with family life to be more important, whereas the bottom-score group regarded the social status as more important.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.353-359
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• 2016

Soil organic carbon (SOC) retention has gradually gotten attention due to the need for mitigation of increased atmospheric carbon dioxide and the simultaneous increase in crop productivity. We estimated the statistical maximum value of soil organic carbon (SOC) fixed by clay content using the Korean detailed soil map database. Clay content is a major factor determining SOC of subsoil because it influences the vertical mobility and adsorption capacity of dissolved organic matter. We selected 1,912 soil data of B and C horizons from 13 soil series, Sangju, Jigog, Jungdong, Bonryang, Anryong, Banho, Baegsan, Daegog, Yeongog, Bugog, Weongog, Gopyeong, and Bancheon, mainly distributed in Korean upland. The ranges of SOC and clay content were $0-40g\;kg^{-1}$ and 0 - 60%, respectively. Soils having more than 25% clay content had much lower SOC in subsoil than topsoil, probably due to low vertical mobility of dissolved organic carbon. The statistical analysis of SOC storage potential of upland subsoil, performed using 90%, 95%, and 99% maximum values in cumulative SOC frequency distribution in a range of clay content, revealed that these results could be applicable to soils with 1% - 25% of clay content. The 90% SOC maximum values, closest to the inflection point, at 5%, 10%, 15%, and 25% of clay contents were $7g\;kg^{-1}$, $10g\;kg^{-1}$, $12g\;kg^{-1}$, and $13g\;kg^{-1}$, respectively. We expect that the statistical analysis of SOC maximum values for different clay contents could contribute to quantifying the soil carbon sink capacity of Korean upland soils.

• The Journal of Korean Institute of Information Technology
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• v.18 no.5
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• pp.55-64
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• 2020

Estimating the state of charge (SOC) of a battery is essential for increasing the stability and reliability of a photovoltaic system. In this study, battery SOC estimation methods were proposed using artificial neural networks (ANNs) with gradient descent (GD), Levenberg-Marquardt (LM), and scaled conjugate gradient (SCG), and an adaptive neuro-fuzzy inference system (ANFIS). The charge start voltage and the integrated charge current were used as input data and the SOC was used as output data. Four models (ANN-GD, ANN-LM, ANN-SCG, and ANFIS) were implemented for battery SOC estimation and compared using MATLAB. The experimental results revealed that battery SOC estimation using the ANFIS model had both the highest accuracy and highest convergence speed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.3
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• pp.293-296
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• 2012

SOC test methodology in ultra deep submicron (UDSM) technology with reasonable test time and cost has begun to satisfy high quality and reliability of the product. A novel hierarchical test architecture using IEEE standard 1149.1, 1149.7 and 1500 compliant facilities is proposed for the purpose of supporting flexible test environment to ensure SOC test methodology. Each embedded core in a system-on- a-chip (SOC) is controlled by test access ports (TAP) and TAP controller of IEEE standard 1149.1 as well as tested using IEEE standard 1500. An SOC device including TAPed cores is hierarchically organized by IEEE standard 1149.7 in wafer and chip level. As a result, it is possible to select/deselect all cores embedded in an SOC flexibly and reduce test cost dramatically using star scan topology.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.2
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• pp.46-54
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• 2003

SOC(Social Overhead Capital) projects such as road, power plant, airport or telecommunication facility construction require a large scale of cost, a long period of time and management of a number of sub-contractors. So systematic and efficient management tool in SOC projects is inevitable. Information system provides a valuable tool which can integrate and manage the large volume of information for SOC projects. This study investigates and analyzes the information system of nuclear power plant construction project. Based on this study, we can suggest the direction for designing information system for SOC projects.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.106-111
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• 2018

In this work, we propose techniques for estimating the SOC of Li-air battery. First, we describe and explain the operation principle of the Li-air battery. Energy density of the Li-air battery was compared with that of the Li-ion battery. The capacity and impedance value of the fully discharged voltage is analyzed, and the OCV value for SOC estimation is measured through the electrochemical characterization of the Li-air battery. Estimation value is obtained by SOC modeling through extended Kaman filter and is compared with the measurement value from the Coulomb counting method. Moreover, the performance of SOC estimation circuit is evaluated.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.79-81
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• 2019

전기자동차(EV)뿐만 아니라 ESS(Energy Storage System) 등의 사용량이 증가하면서 리튬이온배터리의 중요성은 점점 커지고 있다. 리튬 이온 배터리의 정확한 상태를 추정하는 것은 배터리의 안전하고 신뢰성 있는 작동을 위해 매우 중요하다. 본 논문에서는 AEKF(Adaptive Extended Kalman Filter)를 이용한 배터리 파라미터와 충전상태(SOC, State of Charge)를 추정하고, 이를 활용하여 배터리의 건강상태(SOH, State of Health)를 추정하는 간단한 알고리즘을 제시한다. AEKF에 파라미터 값을 적용하여 SOC를 추정하고, 추정된 SOC값과 전류 적산을 이용하여 SOH를 추정한다. SOC 오차에 따른 SOH 추정 값의 편차는 SOC 연산 간격을 늘리고 가중치 필터를 적용하여 최소화시킴으로써 결과의 정확성을 향상했다. 다양한 자동차의 표준 주행 패턴을 적용한 실험을 통해 제안된 방법을 이용하여 얻어진 SOH 추정 결과는 RMSE(Root Mean Square Error) 1.428% 이내임을 검증하였다.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.824-833
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• 2012

In this paper, a coordinated state-of-charge (SOC) control strategy for the energy storage system (ESS) operating under microgrid islanded mode to stabilize the frequency and voltage was proposed. The proposed SOC control loop is made up of PI controller, which uses a SOC state of the energy storage system as an input and an auxiliary reference value of secondary control as an output. The SOC controller changes the auxiliary reference value of secondary control to charge or discharge the ESS. To verify the proposed control strategy, PSCAD/EMTDC simulation study was performed. The simulation results show that the SOC of the ESS can be regulated at the desired operating range without degrading the stabilizing control performance by proposed coordinated SOC control method.