• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.489-490
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• 2018

As the number of electric vehicles (EV) increases, there is an increasing interest in the post-vehicle application of the EV batteries. For the second use application of EV batteries, the state of health (SOH) at the end of automotive service has to be evaluated differently from the automotive perspective. It will be helpful to consider the driving conditions of EVs in understanding the performance deterioration trend of the battery. In this paper, we acquired the battery status information in real time during driving and compared the characteristics by the driving routes. The SOH from the BMS can be rescaled to percentage ratio to give a more general idea about the performance degradation.

• 한국전기전자재료학회논문지
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• 제32권1호
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• pp.58-63
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• 2019

Lithium-ion batteries used for IT, automobiles, and industrial energy-storage devices have battery management systems (BMS) to protect the battery from abnormal voltage, current, and temperature environments, as well as safety devices like, current interruption device (CID), fuse, and vent to obtain positive temperature coefficient (PTC). Nonetheless, there are harmful to human health and property and damage the brand image of the manufacturer because of smoke, fire, and explosion of lithium battery packs. In this paper, we propose a systematic protection algorithm combining battery temperature, over-current, and interconnection between protection elements to prevent copper deposition, internal short circuit, and separator shrinkage due to frequent and instantaneous over-current discharges. The parameters of the proposed algorithm are suggested to utilize the experimental data in consideration of battery pack operating conditions and malicious conditions.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.277-278
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• 2023

The need for maintenance of bridge infrastructure is increasing due to aging, and the cost of maintaining the infrastructure must be calculated for effective budget distribution. Therefore, in this study, representative defects according to bridge superstructure type are derived to calculate the cost for each repair method. First of all, the representative bridges, PSCI girder bridge, Rahmen bridge, Steel box girder bridge, and RC slab bridge, were selected as superstructures using BMS data, and repair methods for defects were presented. In addition, the cost of the repair method by superstructure type was compared. This result is expected to predict total maintenance costs in consideration of the maintenance cycle.

• Corrosion Science and Technology
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• 제3권4호
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• pp.166-171
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• 2004

Recent developments in Bridge Management Systems (BMS) and in Life-Cycle Cost (LCC) of bridges, have raised the need for evaluation procedure of future condition (Deterioration) of a bridge. Predicting future deterioration is not an easy task due to limited past data to extrapolate from and also due to difficulty in measuring actual deterioration such as section loss of steel on an actual steel bridge. Also, increase in live load and reduction of resistance are random variables, thus a probabilistic approach should be adopted for determining the future deterioration. Due to difficulties in evaluation of future deterioration on steel bridges, accepting uncertainties within a reasonable error, a deterministic procedure using bridge condition rating can be a useful tool for projection of future condition of bridges to identify repair and maintenance needs. The object of this paper is to determine applicability of evaluating deterioration of steel bridge components based on Bridge condition ratings. Bridge condition ratings of bridge components show wide variation for bridges of same age and does not directly correlate well with the age of the bridge and/or deterioration of the bridge. High uncertainty can be reduced by breaking down the rating and by sensitivity analysis. From refined condition rating data, generalized deterioration profile of structures based on age can be derived. Examples are shown for sample bridges in USA. Approximately, 3,000 short to medium span steel bridges were listed in the inventory database. Results show wide variation of rating factors but by subdividing the Bridge condition ratings for various categories general deterioration profiles of steel bridges can be determined.

• 전력전자학회논문지
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• 제24권3호
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• pp.139-146
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• 2019

As the number of electric vehicles (EVs) in Jejudo Island increases, the secondary use of EV batteries is becoming increasingly mandatory not only in reducing greenhouse gas emissions but also in promoting resource conservation. For the secondary use of EV batteries, their capacity and performance at the end of automotive service should be evaluated properly. In this study, the battery state information from the on-board diagnostics or OBD2 port was acquired in real time while driving three distinct routes in Jejudo Island, and then the battery operating characteristics were assessed with the driving routes. The route with higher altitude led to higher current output, i.e., higher C-rate, which would reportedly deteriorate state of health (SOH) faster. In addition, the SOH obtained from the battery management system (BMS) of a 2017 Kia Soul EV with a mileage of 55,000 km was 100.2%, which was unexpectedly high. This finding was confirmed by the SOH estimation based on the ratio of the current integral to the change in state of charge. The SOH larger than 100% can be attributed to the rated capacity that was lower than the nominal capacity in EV application. Therefore, considering the driving environment and understanding the SOH estimation process will be beneficial and necessary in evaluating the capacity and performance of retired batteries for post-vehicle applications.

• 한국전자통신학회논문지
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• 제11권5호
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• pp.479-484
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• 2016

본 논문은 Daisy Chain 구조의 CVM(:Cell Voltage Monitoring) 시스템에서, 다양한 DC Level을 갖는 Master IC와 Slave IC 사이에 명령 Data 신호의 전달을 가능하게 해주는 DC Level Shifter 설계를 소개한다. 설계한 회로는 래치 구조가 적용되어 고속 동작이 가능하고, 출력단의 Transmission Gate를 통하여 다양한 DC Level이 출력되도록 설계하였다. 시뮬레이션 및 측정 결과, 0V에서 30V까지의 DC Level 변화에 따른 제어 및 Data 신호의 전달을 확인하였다. Delay Time 오차는 약 170ns가 측정되었지만, 측정 Probe의 Capacitance 성분 및 측정 Board의 영향을 고려하면, 무시할 수 있을 정도의 오차로 간주된다.

• 인터넷정보학회논문지
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• 제17권2호
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• pp.59-65
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• 2016

색채 환경에 따라 인지반응의 상관관계를 분석한 결과가 다양한 산업분야에 적용되고 있다. 특히, 의학 분야에서 색채 환경기반 생체신호를 수집하여 환자 상태의 파악과 치료 그리고 뇌활동의 규명에 관련된 연구가 활발하게 진행되고 있다. 그러나 기존 연구들은 색채조명 또는 LED를 이용한 색채 환경을 구축하여 다양한 실험을 진행하고 있으나 다른 광원에 노출 되어 심리적인 영향을 주는 문제점을 갖고 있다. 따라서, 본 논문에서 제안하는 시스템은 HMD(Head-Mounted-Display)를 이용하여 피험자에게 완벽한 색채 환경조건을 제공하고자 한다. 그리고 인체반응정도 측정을 위해 기억력-주의력 테스트하는 동안 BMS(Bio-Medical-System)으로 생체정보를 수집하여 색채별 인체반응정도 측정뿐만 아니라 심리적인 변화에 대한 상관관계를 확인할 수 있는 시스템을 제안한다. 제안한 시스템을 통하여 수집하는 생체정보는 심전도(ECG), 호흡(Respiration), 산소포화도(SpO2), 임피던스(Bio-Impedance), 혈압(Blood-Pressure) 이며 데이터베이스에 저장한다. 이와함께, 인체의 인지반응을 측정하기위해 기억력-주의력 테스트는 앱으로 구현하여 색채 조건별 인지반응 정보를 측정하고 결과를 확인 할 수 있다. 제안한 시스템을 통하여 수집된 인체반응정보를 활용하여 생리학적 정보의 정량화하는 연구를 진행할 수 있으며, 색채 환경과 생리학적 정보의 상관관계를 분석하여 의학적 진단 및 치료에 응용이 될 것으로 기대한다. 향후 연구로 구축한 시스템을 통해 수집된 데이터를 분석 및 시각화 기능을 추가하고, 치매 질환의 예측 및 치료를 위한 시스템으로 확장하여 재활프로그램으로서의 유효성을 평가하고자 한다.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.533-542
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• 2016

교량의 유지관리 비용은 교량 건설 후 주기적으로 발생하게 되며 교량의 상태, 환경 조건 등 여러 요인들이 복합적으로 고려되어야 한다. 개축은 유지관리 단계에서 발생하는 조치 중 가장 최종적이며 대규모 비용이 투입되는 조치로서 교량 유지관리 의사 결정 지원을 위해서는 기본적인 개축 비용 산정 모델의 수립이 필수적이다. 본 연구에서는 교량의 개축 비용 산정을 위한 회귀 모델을 개발하였다. 이를 위해 교량관리시스템(Bridge Management System) 데이터베이스(database) 상의 교량 기본 제원을 분석하여 교량 형식별, 구성 요소별 대표 표본과 주요 영향 인자들을 정의하였다. 각 표본별 비용 산정변수를 고려하여 내역 작업을 수행하였다. 비용 산정 변수에 따른 대표 표본의 적산 결과를 회귀분석하여 상부구조, 하부구조, 기초 등의 신설 비용과 가교 설치 비용, 해체 폐기 비용에 대한 비용 모델을 도출하였다. 개발된 비용 모델을 활용하여 공용 중인 교량 형식별 개축 비용을 도출하고 단가를 산출하여 기존 문헌과의 비교 검토를 수행하였으며, 유지관리 의사결정에 효과적으로 활용될 것으로 기대된다.

• Journal of Korean Neurosurgical Society
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• 제61권6호
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• pp.753-760
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• 2018

Objective : We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs). Methods : We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans ($CK_{original}$) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at low-isodose levels (10-30% of prescription dose) for dose spillage. In each case, a modified CK plan ($CK_{modified}$) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared. Results : There were no differences in the conformity indices among the $CK_{original}$, $CK_{modified}$, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the $CK_{modified}$ plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the $CK_{original}$ plans (p<0.001), with no statistical differences in those volumes compared with GK plans (p=0.345). Conclusion : These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.882-883
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• 2013

With the development of the society, pure electric vehicles will be surely important of the future. Electric vehicle requires various technology like motor driving, battery management, operational efficiencies and so on. Battery management is indeed the most important to enhance battery's performance and life. This paper has deeply discussed and studied on the lithium-polymer battery management system of pure electric vehicle. First of all we have analyzed the characteristic of the lithium-polymer batteries and the factors influenced on the state of charge. Then a logical SOC measuring method has been raised, which is the combination of open circuit voltage and Ah integration. The next we will introduce the design of battery management system, the battery management system performs many functions, such as inspecting the whole process, when it's running cell equalization protecting and diagnosing the battery, estimating the state of charge. The module design style including microcontroller, data aquisition module, charging control module and serial communication module. To arrive at conclusions, the battery management system which this paper has introduced is reliable and economical.