• Journal of Power Electronics
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• 제18권3호
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• pp.910-922
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• 2018

Conventional battery state-of-charge (SoC) estimation methods either involve sophisticated models or consume considerable computational resource. This study constructs an enhanced coulomb counting method (Ah method) for the SoC estimation of lithium-ion batteries (LiBs) by expanding the Peukert equation for the discharging process and incorporating the Coulombic efficiency for the charging process. Both the rate- and temperature-dependence of battery capacity are encompassed. An SoC mapping approach is also devised for initial SoC determination and Ah method correction. The charge counting performance at different sampling frequencies is analyzed experimentally and theoretically. To achieve a favorable compromise between sampling frequency and accumulation accuracy, a frequency-adjustable current sampling solution is developed. Experiments under the augmented urban dynamometer driving schedule cycles at different temperatures are conducted on two LiBs of different chemistries. Results verify the effectiveness and generalization ability of the proposed SoC estimation method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.981-985
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• 1987

In this paper, we predicted the quantities of ass output messages with the generalized estimation equation based on regression model. And, to know the generalization of equation, we measured the deviation of errors between the observed and the estimated values. As a result, the proposed equation applied to sample data showed linear characteristics in some cases.

• 보건행정학회지
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• 제31권4호
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• pp.451-461
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• 2021

Background: Readmissions related to lack of quality care harm both patients and health insurance finances. If the factors affecting readmission are identified, the readmission can be managed by controlling those factors. This paper aims to identify factors that affect readmissions of convalescent rehabilitation patients. Methods: Health Insurance Review and Assessment Service claims data were used to identify readmissions of convalescent patients who were admitted in hospitals and long-term care hospitals nationwide in 2018. Based on prior research, the socio-demographics, clinical, medical institution, and staffing levels characteristics were included in the research model as independent variables. Readmissions for convalescent rehabilitation treatment within 30 days after discharge were analyzed using logistic regression and generalization estimation equation. Results: The average readmission rate of the study subjects was 24.4%, and the risk of readmission decreases as age, length of stay, and the number of patients per physical therapist increase. In the patient group, the risk of readmission is lower in the spinal cord injury group and the musculoskeletal system group than in the brain injury group. The risk of readmission increases as the severity of patients and the number of patients per rehabilitation medicine specialist increases. Besides, the readmission risk is higher in men than women and long-term care hospitals than hospitals. Conclusion: "Reducing the readmission rate" is consistent with the ultimate goal of the convalescent rehabilitation system. Thus, it is necessary to prepare a mechanism for policy management of readmission.

• 전기학회논문지
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• 제57권12호
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• pp.2255-2262
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• 2008

This paper presents a design parameter calculation methodology and its realization to construction for the damped oscillatory impulse current generator(ICG) modelled as damping factor $\alpha$. Matlab internal functions, "fzero" and "polyfit" are applied to find a which are solutions of second order nonlinear equation related with three wave parameters $T_{1},T_{2}$ and $I_{os}$. The calculation results for standard impulse current waveforms such as 4/10${\mu}s$, 8/20${\mu}s$ and 30/80${\mu}s$ show very good accuracy and this results make it possible to extend to generalization in the design of damped oscillatory lCG with any capacitor. 8/20${\mu}s$ ICG based on the calculated design circuit parameters is fabricated in consideration of the nonlinear load(MOV) variation. Comparisons of the tested waveforms with the designed estimation show error within 10% for the waveform tolerance recommended in IEC 60060-1 and IEEE std. C62.45.

• 농업과학연구
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• 제7권2호
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• pp.131-144
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• 1980

수자원개발(水資源開發)의 계획(計劃) 및 설계(設計)를 위한 하천(河川)의 월유출량(月流出量) 추정방법(推定方法)인 전월단위(全月單位)의 사변수(四變數) 선형회귀모형(線型回歸模型)을 일반화(一般化)하여 유출량(流出量) 기록(記錄)의 Extension, 무계기(無計器) 하천(河川)의 유출량(流出量) 추정(推定) 등(等)에 이용(利用)할 수 있도록 하였으며 금강(錦江) 수계(水系)에 적용(適用)한 결과(結果)는 다음과 같다. 1. 선형회귀모형(線型回歸模型)은 물수지방정식(收支方程式)을 중첩(重疊)의 원리(原理)가 적용(適用)되는 선형(線型)(linear)으로 취급(取扱)하여 통계적(統計的)으로 모형(模型)을 설정(設定)하고 유역(流域) Response의 물리적(物理的) System 및 그 변화(變化)를 연역적(演譯的)으로 정성적(定性的)(qualitatively), 개략적(槪略的)(lumped)인 해석(解析)을 하려는 것이다. 각(各) 회귀계수(回歸係數)들이 각(各) parameter들의 phisical properties의 의미(意味)를 내포(內包)하는 일종(一種)의 grey box로 해석(解析)하려는 statistically deterministic model이다. 2. 금강(錦江) 수계(水系)의 4개(個) 수문지점(水文地點)의 선형회귀모형(線型回歸模型)의 방정식(方程式)은 다음과 같다. 통계적(統計的) 기준(基準)에 따라 판정(判定)한 결과(結果) 고도(高度)의 유의성(有意性)이 있는 모형(模型)으로 판정(判定)되었으며 특(特)히 유출량(流出量) 기록(記錄)이 짧은 경우에도 이용(利用)할 수 있다. 각(各) parameter들의 회귀계수(回歸係數)는 유역면적(流域面積)에 따라 질서(秩序)있게 변화(變化)하는 것을 알 수 있다. 즉(卽) 강우량(降雨量)(Pn)의 경우 유역(流域)이 커질수록 interception, detention storage에 의(依)한 손실(損失)도 커지며, 토양수분변화량(土壤水分變化量) (Qn-1)의 경우 유역(流域)이 커질수록 유역(流域)의 저류능(貯溜能)이 커지므로 기저유출(基底流出)도 커지며, 증발산량(蒸發散量)(En)의 경우 유역이 커질수록 Coverage의 나지화(裸地化) 면적(面積)이 커지므로 증발산량(蒸發散量) 손실(損失)도 커진다. 3. 선형회귀모형(線型回歸模型)의 정성적(定性的)인 phisical properties가 유역면적(流域面積)에 따라 변화(變化)하는데 착안(着眼)하여 모형(模型)을 일반화(一般化)하여 수계별(水系別) 유역면적별(流域面積別)로 회귀계수(回歸係數)를 구(求)하여 무계기(無計器) 하천(河川)에서도 월유출량(月流出量) 추정(推定) 모형(模型)을 설정(設定)할 수 있게 하였다. 금강수계(錦江水系)의 선형회귀모형(線型回歸模型)의 일반화도표(一般化圖表)는 다음 Fig.10과 같다.