• Structural Engineering and Mechanics
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• 제46권1호
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• pp.75-90
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• 2013

In order to identify damage of highway bridges rapidly, a method for damage identification using dynamic response of bridge induced by moving vehicle and static test data is proposed. To locate damage of the structure, displacement energy damage index defined from the energy of the displacement response time history is adopted as the indicator. The displacement response time histories of bridge structure are obtained from simulation of vehicle-bridge coupled vibration analysis. The vehicle model is considered as a four-degree-of-freedom system, and the vibration equations of the vehicle model are deduced based on the D'Alembert principle. Finite element method is used to discretize bridge and finite element model is set up. According to the condition of displacement and force compatibility between vehicle and bridge, the vibration equations of the vehicle and bridge models are coupled. A Newmark-${\beta}$ algorithm based professional procedure VBAP is developed in MATLAB, and used to analyze the vehicle-bridge system coupled vibration. After damage is located by employing the displacement energy damage index, the damage extent is estimated through the least-square-method based model updating using static test data. At last, taking one simply supported bridge as an illustrative example, some damage scenarios are identified using the proposed damage identification methodology. The results indicate that the proposed method is efficient for damage localization and damage extent estimation.

• Smart Structures and Systems
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• 제15권1호
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• pp.227-244
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• 2015

This study develops a two stage procedure to identify the structural damage based on the optimized artificial neural networks. Initially, the modal strain energy index (MSEI) is established to extract the damaged elements and to reduce the computational time. Then the genetic algorithm (GA) and artificial neural networks (ANNs) are combined to detect the damage severity. The input of the network is modal strain energy index and the output is the flexural stiffness of the beam elements. The principal component analysis (PCA) is utilized to reduce the input variants of the neural network. By using the genetic algorithm to optimize the parameters, the ANNs can significantly improve the accuracy and convergence of the damage identification. The influence of noise on damage identification results is also studied. The simulation and experiment on beam structures shows that the adaptive parameter selection neural network can identify the damage location and severity of beam structures with high accuracy.

• ETRI Journal
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• 제30권5호
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• pp.634-643
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• 2008

One of the ubiquitous technology fields that have received the most attention recently from technology communities worldwide is mobile radio frequency identification (RFID). Mobile handsets loaded with RFID readers enable the identification and retrieval of information on RFID tagged objects. In Korea, a variety of mobile RFID services are currently being piloted, and their commercial roll-out looks imminent. The goal of this study is to propose, ahead of the commercial launch of mobile RFID services, a customer satisfaction index (CSI) model for this service category and to then measure the CSI to derive practical implications for their providers and pointers related to the improvement of service. A web survey was conducted on Korean mobile phone subscribers who had participated in a mobile RFID pilot program. Using the results of this survey, we tested the CSI model and its hypotheses by employing a partial least-squares-based structural equation model analysis and calculated the index. We further conducted an importance-performance analysis in order to provide insights that may be useful for improving the quality of mobile RFID services.

• 한국항해항만학회지
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• 제38권3호
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• pp.203-209
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• 2014

As a sense of practical field, most researchers emphasize the importance of safety management to prevent marine accidents. The purpose of this paper is to develope a new safety evaluation method using Safety Index (SI) which is to measure the emotional feeling of navigation officer by traffic situations. In this study, the questionnaires with SI are used to investigate the degree of sensing levels of navigation officers according to the navigation situations. In addition, the traffic data obtained from AIS (Automatic Identification System) data are used to give actual situations in the questionnaire investigation. As results of questionaries investigations based upon the AIS data, it is shown that the Safety Index can be used as a criterion to determine the safety levels of ship navigating in a coastal areas.

• 영재교육연구
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• 제15권1호
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• pp.67-84
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• 2005

과학영재 판별의 대안적 도구로서의 가능성을 찾아보기 위하여 영재 집단과 일반 집단의 뇌파검사를 실시하였다. 뇌파의 주성분 공간분석법인 PCA분석 자료의 집단별 차이점을 이용하여 과학영재 판별지수(Gifted Index: G-Index)를 개발하고 과학영재 판별의 가능성을 탐색하여 보았더니 76% 수준에서의 판별 효과를 얻을 수 있었다. 또 과학영재 판별이 가능한 기타 판별도구 성취도들 간의 상관관계를 바탕으로 하여 회귀분석을 시도한 결과는로 나타났다. 이를 근거로 한 영재 판별 확률식을 제안하면 $$P=\frac 1{1+e^{-[-0.018(TTCT)+0.057(IQ)+1.916(FASP)+0.682(V.T)+0.088(Exp.)+0.034(G-Index)-57.510]}}$$와 같고 이 회귀분석식을 적용한 결과 영재 집단 내에서의 판별 가능성이 95% 수준에서 매우 우수하였다. 따라서 과학영재 판별의 대안적 도구로서의 뇌파검사와 G-Index의 유용성을 확인할 수 있었다.

• 대한예방한의학회지
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• 제21권2호
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• pp.55-60
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• 2017

Objectives : This study was conducted to analysis correlation of pattern identification and body mass index (BMI) in obese adolescents. Methods : A total of 228 middle school students, 226 students were agreed and included study and two were excluded because of disagreement. It was conducted cold-heat pattern questionnaire, phlegm pattern questionnaire and after height and weight were measured. Firstly, out of 24 who did not respond to all of questionnaires. Secondary, out of 159 who are normal range on international obesity standard(BMI < $30kg/m^2$) Results : The average height and weight of 43 subjects was $159.65{\pm}9.45cm$, $70.10{\pm}8.47kg$ respectively. The average score of pattern identification was cold pattern score(CPS) was $2.70{\pm}1.61$, heat pattern score(HPS) was $3.30{\pm}1.99$, phlegm pattern score(PPS) was $3.95{\pm}5.02$. There was no significant correlation with BMI and CPS, HPS, PPS. Conclusions : In this study, there was no significant correlation of pattern identification and BMI in obese adolescents.

• 동의생리병리학회지
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• 제24권1호
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• pp.15-21
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• 2010

Previously standardization study for identifying 5 types of pattern identification of stroke patients has been performed and the Korean standard of pattern identification (II) was developed. In the present study we investigated the interactions between total indices designated by the Korean standard of pattern identification(KSPI II) and indices for PI of Cold-Heat and Deficiency-Excess. Indicators for Cold-Heat and Deficiency-Excess are isolated from 58 indices through the survey of oriental medicine doctors and their relationship with KSPI-II indices was analyzed by corresponding analysis method using data of 1581 stroke patients. Means and standard deviations indicated that 2 Cold indices, 14 Heat indices, 12 Deficiency indices, and 5 Excess indices were included for Cold-Heat and Deficiency-Excess pattern identification. The results of corresponding analysis shows the relationship of 57 indices and 4 types of pattern identification (excluding 1 index and 1 pattern among 58 indices and 5 patterns) using the cross-tabulation which was obtained from the clinical data. Most of Cold and Heat index were divided to dimension 1(inertia 51.9%) obtained from the result of corresponding analysis. Deficiency and Excess index were partially associated with dimension 2(inertia 31.7%). These data suggest that pattern identification of Cold-Heat plays an role in the standardization of pattern identification in stroke, although further studies are required by various trials such as analysis of surveys and clinical data.

• 수산해양기술연구
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• 제34권1호
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• pp.52-61
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• 1998

We studied behaviour pattern of anchovy (Engraulis japonicus) shoal by a method of shoal echo integration and tested species identification by a method of artificial neural network using the acoustic data collected in the East China Sea in March 1994 and in the southern coastal waters of the East Sea of Korea in March 1995. Between areas, frequency distribution of 10 shoal descriptors was different, which showed characteristics of shoal behaviour in size, bathymetric position and acoustic strength. The range and mean of shoal size distribution in length and height was wider and bigger in the southern coastal waters of the East Sea than in the East China Sea. Relative shoal size of China Sea. Fractal dimension of shoal was almost same in both areas. Mean volume reverbration index of shoal was 3 dB higher in the southern coastal waters of the East Sea than in the East China Sea. The depth layer of shoal distribution was related to bottom depth in the southern coastal waters of the East Sea, while it was between near surface and central layer in the East China Sea. Principal component analysis of shoal descriptors showed the correlation between shoal size and acoustic strength which was higher in the southern coastal waters of the East Sea, than in the East China Sea. Correlation was also found among the bathymetric positions of shoal to some degree higher in the southern coastal waters of the East Sea than in the East China Sea. The anchovy shoal of two areas was identified by artificial neural network. The contribution factor index (Cio) of the shoal descriptors between two areas were almost identical feature. The shoal volume reverberation index (Rv) was showed the highest contribution to the species identification, while shoal length and shoal height showed relatively high negative contribution to the species identification.

• 동의생리병리학회지
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• 제31권2호
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• pp.145-152
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• 2017

The purpose of this study was to investigate the clinical research of Cold-Heat of pattern identification(PI) focused on quantitative indicators for general people in Korea, through the review of OASIS, KISS, DBpia, NDSL database. Ten clinical researches were analyzed in this study. These research gradually started from 2004 to 2009 but there was no research after 2010. Diagnosis of Cold-Heat PI all was done through a questionnaire, 7 or most researches had not used the intervention methods. Quantitative indicators related to the Cold-Heat PI mentioned in the selected 10 researches are seven, these indicators include heart rate variability(HRV), electroencephalogram, Yangdorak, respiratory index, electrogastrography, acoustic analysis index, western health test index. Related to the HRV were 3 researches, but correlation of significant indicators was a few levels(R=0.026-0.090). So far, studies regarding at the quantitative indicators of the prior the Cold-Heat PI were few, and the results of the study showed that low statistical precision, a lack of biological basis. Refer to the current state, in the future, we expect that research of quantitative indicators of scientific evidence-based through calculated and precise research concerning Cold-Heat PI be regarded as important in Korean Medicine.

• Smart Structures and Systems
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• 제20권2호
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• pp.115-126
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• 2017

The modal identification of large civil structures such as bridges under the ambient vibrational conditions has been widely investigated during the past decade. Many operational modal analysis methods have been proposed and successfully used for identifying the dynamic characteristics of the constructed bridges in service. However, there is very limited research available on reliable criteria for the robustness of these identified modal parameters of the bridge structures. In this study, two time-domain operational modal analysis methods, the data-driven stochastic subspace identification (SSI-DATA) method and the covariance-driven stochastic subspace identification (SSI-COV) method, are employed to identify the modal parameters from field recorded ambient acceleration data. On the basis of the SSI-DATA method, the modal contribution indexes of all identified modes to the measured acceleration data are computed by using the Kalman filter, and their applicability to evaluate the robustness of identified modes is also investigated. Here, the benchmark problem, developed by Hong Kong Polytechnic University with field acceleration measurements under different excitation conditions of a cable-stayed bridge, is adopted to show the effectiveness of the proposed method. The results from the benchmark study show that the robustness of identified modes can be judged by using their modal contributions to the measured vibration data. A critical value of modal contribution index of 2% for a reliable identifiability of modal parameters is roughly suggested for the benchmark problem.