• Smart Structures and Systems
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• v.15 no.2
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• pp.425-445
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• 2015

Parametric identification of structures is one of the important aspects of structural health monitoring. Most of the techniques available in the literature have been proved to be effective for structures with small degree of freedoms. However, the problem becomes challenging when the structure system is large, such as bridge structures. Therefore, it is highly desirable to develop parametric identification methods that are applicable to complex structures. In this paper, the LSE based techniques will be combined with the substructure approach for identifying the parameters of a cable-stayed bridge with large degree of freedoms. Numerical analysis has been carried out for substructures extracted from the 2-dimentional (2D) finite element model of a cable-stayed bridge. Only vertical white noise excitations are applied to the structure, and two different cases are considered where the structural damping is not included or included. Simulation results demonstrate that the proposed approach is capable of identifying the structural parameters with high accuracy without measurement noises.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.243-252
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• 2022

Objectives: Very limited previous research has investigated the utility weights of prostate-related diseases in the general population in Korea. The purpose of this study was to calculate the utility of prostate-related health states in the Korean general public using the standard gamble (SG) method. Methods: Seven health states for hypothetical prostate cancers, 1 for benign prostate hyperplasia, and 1 for erectile dysfunction were developed based on patient education material and previous publications. In total, 460 responses from the Korean general population were used to analyze the utility of prostate-related health states. Computer-assisted personal interviews were conducted, and utility values were measured using a visual analogue scale (VAS) and SG. Mean utility values were calculated for each prostate-related health state. Results: The mean utility values of prostate cancer derived from SG ranged from 0.281 (metastatic castration-refractory prostate cancer) to 0.779 (localized prostate cancer requiring prostatectomy). The utility value of benign prostate hyperplasia was 0.871, and that of erectile dysfunction was 0.812. The utility values obtained using the SG method in all conditions were higher than the values obtained by VAS. There were no significant demographic variables affecting utility values in multivariate analysis. Conclusions: Our findings might be useful for economic evaluation and utility calculation of screening and interventions for prostate-related conditions in the general population.

• 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.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.194-195
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• 2019

배터리는 사용 기간과 회수가 증가함에 따라 수명이 점차 감소한다. SOH(State-Of-Health)는 배터리의 초기 상태와 현재 상태를 비교하여 배터리의 수명 상태를 나타내는 지표이며, 이는 배터리를 사용함에 있어서배터리의 현재 충전상태를 나타내는 SOC(State-Of-Charge)와 함께 정확한 추정을 필요로 한다. 본 논문에서는 리튬이온 배터리를 C-rate에 따라 노화시키며 각 C-rate별 SOH 추정 경향성을 분석하였다. 배터리의 SOC와 SOH는 확장 칼만 필터를 병렬적으로 사용하는 이중 확장 칼만 필터를 활용하여 추정한다. 배터리의 노화실험은 완전충전과 완전충전을 반복하는 전류 프로파일을 인가하였으며, 실험은 상온(25℃)에서 실행하였다.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2267-2272
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• 2014

Background: Cancer is one of the most common causes of death in Turkey. Nurses are essential providers of preventive care for patients, especially breast, cervical and colorectal cancer screening as part of routine preventive practice. The aim of this study was to assess knowledge of these cancers among nurses in Karabuk State Hospital. Materials and Methods: This cross-sectional and descriptive study was performed from April 1 to July 30, 2013. The study sample consisted of 226 nurses working in Karabuk State Hospital. Results: Mean age of the nurses was $32.07{\pm}8.39$. 62.4% of nurses practiced breast self examination when they remembered it, while 39.8% of them did not take a Pap smear test since they did not think it was necessary. 64.2% of nurses would like to receive information about cancer and screening tests. Majority of them had given true answers to questions on breast, cervical and colorectal cancer. There were significant relationships between cancer knowledge scores and marital status, working experience, and level of education. Conclusions: Nurses possess adequate knowledge about breast cancer but they need more information on cancer risk estimation. Awareness may be raised in nurses by establishing continuing education programs regarding the risk factors, symptoms, protection methods, early diagnosis, and scanning of breast, cervix and colon cancers.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.665-674
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• 2018

In this paper, we propose a development results of a D-type non-rechargeable lithium battery($Li/SOCl_2$) on improvement in a low cost protection circuit of discharge for domestic military power source. According to this study, we describe a new design and product with 8-bit microcontroller in the protection circuit which can estimate state of health of the battery regardless of occurring an initial voltage delay. Also this paper discuss and facilitate development as solution to a safety about the non-rechargeable lithium batteries. As a result, we verified a quality of the protection circuit by a development test and evaluation(DT&E) process.

• Smart Structures and Systems
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• v.23 no.1
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• pp.61-69
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• 2019

Offshore structures are generally exposed to harsh environments such as strong tidal currents and wind loadings. Monitoring the structural soundness and integrity of offshore structures is crucial to prevent catastrophic collapses and to prolong their lifetime; however, it is intrinsically challenging because of the difficulties in accessing the critical structural members that are located under water for installing and repairing sensors and data acquisition systems. Virtual sensing technologies have the potential to alleviate such difficulties by estimating the unmeasured structural responses at the desired locations using other measured responses. Despite the usefulness of virtual sensing, its performance and applicability to the structural health monitoring of offshore structures have not been fully studied to date. This study investigates the use of virtual sensing of offshore structures. A Kalman filter based virtual sensing algorithm is developed to estimate responses at the location of interest. Further, this algorithm performs a multi-sensor data fusion to improve the estimation accuracy under non-stationary tidal loading. Numerical analysis and laboratory experiments are conducted to verify the performance of the virtual sensing strategy using a bottom-fixed offshore structural model. Numerical and experimental results show that the unmeasured responses can be reasonably recovered from the measured responses.

• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.293-306
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• 1986

A Health Interview Survey at Chuncheon city was conducted to assess level of illness by stratified random sampling method. Sample size was 6,007 and the prevalence of illness in period of 15 days was studied. 1) Prevalence rate of illness among Chuncheon citizen was 20.8 percent, and that of acute condition was 10.8 percent and chronic condition, 10.0 percent. 2) There was significant difference in prevalence rate by sex, especially the prevalence rate of chronic illness. 3) High positive correlation was noted between aging and prevalence rate of chronic illness. But negative correlation was noted in case of acute illness. 4) Multiple regression analysis on morbid state by socioeconomic variables was not seen to be appropriate for this survey, especially the analysis of acute illness. 5) Estimation of anual prevalence rate could not be possible because of seasonal variation of disease prevalence.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.422-427
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• 1999

We are proposed for the computation of disease frequency measures and of their associated variances from data collected through prospective study of multiple dynamic cohort (herds) with a National Animal Health Monitoring System (NAHMS) in Gyeongnam. We can be estimated and calculated the annual incidence density for a group of herds and the 1-month risk of disease from the same within herd measure of monthly incidence density. We are proposed that the choice of measure to be estimated depend on the intended use of the information. From results in this study, Our study demonstrate that risk estimates are appropriates for producers and clinic veterinarian making decisions at the animal or herd level. Incidence density measures are appropriate for extrapolation to reference populations used for state and regional-level decision making.

• Computers and Concrete
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• v.5 no.1
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• pp.37-60
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• 2008

Structural health monitoring of existing infrastructure is currently an important field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical and important structures. The paper outlines two methods of system identification of beam-like reinforced concrete structures representing bridges, through static measurements, in a distributed damage scenario. The first one is similar to the stiffness method, re-cast and the second one to flexibility method. A least square error (LSE) based solution method is used for the estimation of flexural rigidities and damages of simply supported, cantilever and propped cantilever beam from the measured deformation values. The performance of both methods in the presence of measurement errors is demonstrated. An experiment on an un-symmetrically damaged simply supported reinforced concrete beam is used to validate the developed method. A method for damage prognosis is demonstrated using a generalized, indeterminate, propped cantilever beam.