콘텐츠 큐레이션 플랫폼 성능평가 알고리즘

최종호 한국정보전자통신기술학회 2018 한국정보전자통신기술학회논문지 Vol.11 No.6

In this paper, a performance evaluation algorithm of contents curation platform is proposed. The evaluation starts with setting the initial-final conditions, and measures four performance evaluation parameters. These parameters are response rate of service, accuracy of response result, precision of analysis result, and recall rate of analysis result. To verify the effectiveness of the proposed algorithm, a database of 118,738 cases was constructed and the contents was opened on the Internet. In this experiment, 6,975,365 pageviews were applied to analysis user behavior. Through the measurement of four parameters, it was confirmed that the integrated and unit evaluation of content curation platform can be performed objectively. 본 논문에서는 콘텐츠 큐레이션 플랫폼의 성능평가 알고리즘을 제안하였다. 성능평가는 초기조건과 종료조건을 설정하고, 4개의 파라미터를 측정하여 수행하였다. 성능평가에 사용되는 파라미터는 서비스 응답속도, 응답결과 정확도, 분석결과 정밀도, 분석결과 재현율이다. 제안한 성능평가 알고리즘의 유효성을 확인하기 위해 118,738건의 데이터베이스를 직접 구축한 후, 인터넷에서 콘텐츠를 오픈하여 이를 클릭한 사용자 행위를 기반으로 실험을 수행하였다. 실험에 사용된 페이지 뷰는 6,975,365건이었다, 실험결과, 4개의 파라미터를 이용하면 콘텐츠 큐레이션 플랫폼의 종합평가와 단위평가가 객관적으로 수행될 수 있음을 확인하였다.

How to Use BWIM Data in Fatigue Evaluation of a Medium-span Steel Bridge

이상현,안이삭,박연철,김호경 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.6

For fatigue evaluation of in-service steel bridges, the repetitive stress range and the number of stress cycles can be estimated using fi eld-measured data. The bridge weigh-in-motion (BWIM) with the structural analysis model is widely used for the fatigue evaluation of bridges. The actual loading parameters included in BWIM data should be appropriately integrated for accurate fatigue life evaluation. This study conducted parametric studies on fatigue evaluation to identify the relative infl uences of three representative loading parameters in BWIM data: multi-truck eff ect, driving lane, and axle load confi guration. In addition, the relative signifi cance of each parameter for realistic fatigue evaluation of the examined bridge was discussed by comparing the fatigue evaluation results using strain data measured simultaneously with the BWIM.

Smart health evaluation of slewing bearing based on multiple-characteristic parameters

Hua Wang,Mingmin Tang,Xiaodiao Huang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

A rotational connection between two substructures generally consists of a slewing bearing which is very often used for heavy loads atlow speeds. Slewing bearing condition monitoring is a good method to identify the inception and propagation of structural defects at anearly stage for timely remedy, and ultimately, enable condition-based “intelligent” maintenance instead of schedule-based. The traditionalhealth evaluation accuracy is not high based on single vibrating signal. We present a new strategy for health evaluation of slewing bearingbased on multiple characteristic parameters and the artificial neural networks, and we applied the genetic algorithm to model multiparametershealth evaluation. Seventy days fatigue life test was carried out using a special slewing bearing test table and 70 sets data waschosen to input the networks evaluation model for training and evaluation. Test results show that the ANN (Artificial neural network)with GA (Genetic algorithm) optimization converges more easily, takes fewer iterations and shorter training time, and has higher precisionand good stability. And the output of multi-parameters health evaluation network model shows a better agreement with the target. The evaluation results were in accordance with the experiment. Therefore, this methodology can be used to evaluate the health state ofslewing bearing.

안전도시 모델의 평가지표에 관한 연구

이준학(Joon-Hak Lee),여옥경(Okkyung Yuh) 한국방재안전학회 2023 한국방재안전학회 논문집 Vol.16 No.2

코로나 19 이후 도시 안전에 대한 관심이 높아지면서, 여러 기관에서 도시의 안전성을 평가하는 지표가 개발되어 활용되고 있다. 용산구는 2021년 사회안전지수 평가에서 1위로 선정되어 한국에서 가장 안전한 도시로 선정되었으나, 2022년 이태원 참사로 인해, 많은 인명 피해가 발생하기도 하였다. 이것은 도시의 안전을 평가하는 지표가 담지 못하는 영역이 있으며, 이에 대한 연구가 필요함을 의미한다. 본 연구의 목적은 국내 ‧ 외 안전도시 모델을 살펴보고 이를 통해 각 모델의 차이점과 안전도시를 평가할 때 사용되는 지표를 검토하기 위한 것이다. 본 연구에서 11개 안전도시 모델을 수집하고 각 평가지표를 분석한 결과, 안전도시 모델은 세계보건기구의 국제안전도시와 유엔재해경감기구의 국제안전도시와 같이 기관에서 인증을 하는 “프로그램 기반의 안전도시 모델”과, 기관별 안전 관련 평가지표의 점수에 의해서 안전도시 순위 및 등급이 결정되는 “점수기반의 안전도시 모델”로 분류할 수 있으며, 안전한 도시가 되기 위해서는 이 두 가지 모델이 상호 보완적으로 활용될 때 도시 안전을 위협하는 제반 요소를 전방위적으로 대응할 수 있음을 알 수 있었다. 안전에 대한 위협이 다양해짐을 고려해볼 때 안전도시를 평가할 때 디지털 보안, 보건 안전, 인프라 안전, 개인 안전, 환경 안전, 교통 안전, 화재 안전, 범죄 안전, 생활안전, 자살, 감염병 등을 종합적으로 고려하는 것이 타당하는 결론을 얻었다. As interest in urban safety has increased since COVID-19, various institutions have developed and used indicators that evaluate the safety city model. Yongsan-gu was ranked No. 1 in 2021 by Social Safety Index evaluation and was selected as the safest city in Korea. However, the Itaewon disaster in Yongsan-gu in 2022 caused many casualties. The study of indicators for evaluating cities’ safety was necessary. This study aims to examine domestic and foreign safe city models and review the differences between each model and the indicators used to evaluate safe cities. As a result of collecting 11 safe city models and analyzing each evaluation index, safe city models can be classified into program-based safe city models, such as the World Health Organization’s International safe community and the UN Office for Disaster Risk Reduction’s International Safe city. Considering the diversification of threats to safety, it is reasonable to comprehensively consider digital security, health safety, infrastructure safety, personal safety, environmental safety, traffic safety, fire safety, crime safety, life safety, suicide, and infectious diseases when evaluating safe cities as evaluation parameters.

Fundamental Small-signal Modeling of Li-ion Batteries and a Parameter Evaluation Using Levy’s Method

Xiaoqiang Zhang,Mao Zhang,Weiping Zhang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

The fundamental small-signal modeling of lithium-ion (Li-ion) batteries and a parameter evaluation approach are investigated in this study to describe the dynamic behaviors of small signals accurately. The main contributions of the study are as follows. 1) The operational principle of the small signals of Li-ion batteries is revealed to prove that the sinusoidal voltage response of a Li-ion battery is a result of a sinusoidal current stimulation of an AC small signals. 2) Three small-signal measurement conditions, namely stability, causality, and linearity, are proved mathematically proven to ensure the validity of the frequency response of the experimental data. 3) Based on the internal structure and electrochemical operational mechanism of the battery, an AC small-signal model is established to depict its dynamic behaviors. 4) A classical least-squares curve fitting for experimental data, referred as Levy’s method, are introduced and developed to identify small-signal model parameters. Experimental and simulation results show that the measured frequency response data fit well within reading accuracy of the simulated results; moreover, the small-signal parameters identified by Levy’s method are remarkably close to the measured parameters. Although the fundamental and parameter evaluation approaches are discussed for Li-ion batteries, they are expected to be applicable for other batteries.

Fundamental Small-signal Modeling of Li-ion Batteries and a Parameter Evaluation Using Levy's Method

Zhang, Xiaoqiang,Zhang, Mao,Zhang, Weiping The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

The fundamental small-signal modeling of lithium-ion (Li-ion) batteries and a parameter evaluation approach are investigated in this study to describe the dynamic behaviors of small signals accurately. The main contributions of the study are as follows. 1) The operational principle of the small signals of Li-ion batteries is revealed to prove that the sinusoidal voltage response of a Li-ion battery is a result of a sinusoidal current stimulation of an AC small signals. 2) Three small-signal measurement conditions, namely stability, causality, and linearity, are proved mathematically proven to ensure the validity of the frequency response of the experimental data. 3) Based on the internal structure and electrochemical operational mechanism of the battery, an AC small-signal model is established to depict its dynamic behaviors. 4) A classical least-squares curve fitting for experimental data, referred as Levy's method, are introduced and developed to identify small-signal model parameters. Experimental and simulation results show that the measured frequency response data fit well within reading accuracy of the simulated results; moreover, the small-signal parameters identified by Levy's method are remarkably close to the measured parameters. Although the fundamental and parameter evaluation approaches are discussed for Li-ion batteries, they are expected to be applicable for other batteries.

초음파 파라미터를 이용한 사과의 기계적 특성 분석을 위한 기초 연구

이상대 ( Sang Dae Lee ),김기복 ( Ki Bok Kim ),박정길 ( Jeong Gil Park ),김만수 ( Man Soo Kim ) 전북대학교 농업과학기술연구소 2010 농업생명과학연구 Vol.41 No.1

This study was performed to develop the nondestructive evaluation technique for the mechanical properties of fruit using ultrasonic technique. Ultrasonic parameters such as sound velocity, peak amplitude, attenuation coefficient in maximum amplitude according to storage time were measured using the fabricated 100 kHz transmitting and receiving ultrasonic transducers. The mechanical properties such as rupture point and elastic modulus of apple were measured by universal testing machine. Multiple linear regression (MLR) models to estimate the mechanical properties of apple were developed using the ultrasonic parameters. The coefficients of determination of MLR models for rupture point and elastic modulus of apple were 0.5635 and 0.7089, respectively.

Comparison of Impedance Parameters and Occupational Therapy Evaluation in the Paretic and Non-paretic Upper Extremity of Hemiplegic Stroke Patients

Yoo, Chan-Uk,Kim, Jaehyung,Hwang, Youngjun,Kim, Gunho,Shin, Yong-Il,Jeon, Gyerok Korea Multimedia Society 2017 멀티미디어학회논문지 Vol.20 No.12

Many stroke patients undergoing rehabilitation therapy require a quantitative indicator for the evaluation of body function in paretic and non-paretic regions. In this study, the impedance parameters were acquired to assess the physical status in the upper extremity of thirty six stroke patients with hemiplegia caused by cerebral hemorrhage (10 patients) and cerebral infarction (26 patients), using bioelectrical impedance. Prediction marker (PM), phase angle (PA), PM/PA, and resistance (R) versus reactance ($X_c$) were utilized to evaluate the functional status of the paretic and non-paretic regions. In addition, the hand grip strength (HGS) and the pinch strength (lateral, palmer, tip) were measured on the upper extremity of hemiplegic stroke patients. PM was distributed in inversely proportional to HGS, but PA was distributed in proportional to HGS. However, there were a number of patients with HGS of 0, regardless of the impedance parameters (PM, PA, R vs. $X_c$). Paretic and non-paretic status in upper extremity of these patients could not be analyzed using impedance parameters. At the rehabilitation therapist's instructions, they were unable to move the hand and fingers of the paretic upper extremity by cranial nerve damage, motor nerve damage, and severe cognitive decline.

Comparison of Impedance Parameters and Occupational Therapy Evaluation in the Paretic and Non-paretic Upper Extremity of Hemiplegic Stroke Patients

유찬욱,김재형,황영준,김건호,신용일,전계록 한국멀티미디어학회 2017 멀티미디어학회논문지 Vol.20 No.12

Many stroke patients undergoing rehabilitation therapy require a quantitative indicator for the evaluation of body function in paretic and non-paretic regions. In this study, the impedance parameters were acquired to assess the physical status in the upper extremity of thirty six stroke patients with hemiplegia caused by cerebral hemorrhage (10 patients) and cerebral infarction (26 patients), using bioelectrical impedance. Prediction marker (PM), phase angle (PA), PM/PA, and resistance (R) versus reactance (Xc) were utilized to evaluate the functional status of the paretic and non-paretic regions. In addition, the hand grip strength (HGS) and the pinch strength (lateral, palmer, tip) were measured on the upper extremity of hemiplegic stroke patients. PM was distributed in inversely proportional to HGS, but PA was distributed in proportional to HGS. However, there were a number of patients with HGS of 0, regardless of the impedance parameters (PM, PA, R vs. Xc). Paretic and non-paretic status in upper extremity of these patients could not be analyzed using impedance parameters. At the rehabilitation therapist's instructions, they were unable to move the hand and fingers of the paretic upper extremity by cranial nerve damage, motor nerve damage, and severe cognitive decline.

매개변수에 따른 산사태 위험도의 변화

이준대,권영철,배우석 한국지반환경공학회 2018 한국지반환경공학회논문집 Vol.19 No.1

In this study we performed risk evaluation based on parameters using the SINMAP, GIS-based extended program in order to predict ground disaster that is frequent recently. As for the risk evaluation, in order to understand the effects of parameters, we defined that the ranges of internal friction angles and T/R values as important variables had three and four patterns, respectively. The results of the interpretation were compared with those of the existing landslide in order to identify landslide flow and to evaluate the applicability of the parameters. The analysis of the geomorphologic saturated zone showed that the boundary saturated zone and the saturated zone were almost consistent with the site of avalanche of earth and rocks and the area of underground water convergence was correlated to the area where collapse started, indicating that the geomorphologic saturated zone may serve as an index for estimating possibility of landslide when used with slope distribution, colluvial soil, and structures inducing landslide in combination. When the lower limit of the internal friction angle increased more, the upper threshold decreased by 50 to 70% and the influence on the stability index was higher, but the influence was declined within the range of lower wetness index. The analysis of changes based on wetness index range showed that all the groups have similar SI distribution, except for the one in which mean altitude values are applied, indicating that the results are susceptible more by the internal friction angle than by the wetness index. 본 연구에서는 최근 발생하는 지반재해를 사전에 예측하기 위해 널리 사용되고 있는 GIS의 기반의 확장프로그램인 SINMAP을 이용하여 매개변수에 따른 위험도 평가를 수행하였다. 위험도평가는 매개변수의 영향을 파악하기 위해 중요변수인 내부마찰각과 T/R 값의 범위를 각각 3가지와 4가지 패턴으로 결정하였으며, 해석결과를 기존 산사태 결과와 비교하여 산사태 거동을 규명하고 매개변수의 적용성을 평가하였다. 지형학적 습윤대를 분석한 결과, 한계습윤대와 포화대가 토석류 영역과 거의 일치하고 있으며 지하수 수렴부가 붕괴시점부와 상관관계가 있는 것으로 나타나 지형학적 습윤대가 경사분포나 붕적토층의 존재여부, 산사태 유발구조물 등과 복합적으로 산사태 발생 가능성을 평가하기 위한 지표로 사용될 수 있을 것으로 판단된다. 내부마찰각의 하한계가 증가함에 따라 상한계불안정영역이 50~70%까지 감소되어 안정지수에 미치는 영향력이 큰 경향을 보였으나 낮은 습윤지수 범위에서는 그 영향력이 줄어드는 양상을 나타내었다. 습윤지수의 범위에 따른 변화를 분석한 결과, 고도평균값을 적용한 경우를 제외하면 모든 Group에서 유사한 안정지수 분포를 보이고 있어 습윤지수보다는 내부마찰각에 민감한 양상을 나타내고 있음을 알 수 있다.