• Title/Summary/Keyword: training models

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Aspect-Based Sentiment Analysis Using BERT: Developing Aspect Category Sentiment Classification Models (BERT를 활용한 속성기반 감성분석: 속성카테고리 감성분류 모델 개발)

  • Park, Hyun-jung;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.1-25
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    • 2020
  • Sentiment Analysis (SA) is a Natural Language Processing (NLP) task that analyzes the sentiments consumers or the public feel about an arbitrary object from written texts. Furthermore, Aspect-Based Sentiment Analysis (ABSA) is a fine-grained analysis of the sentiments towards each aspect of an object. Since having a more practical value in terms of business, ABSA is drawing attention from both academic and industrial organizations. When there is a review that says "The restaurant is expensive but the food is really fantastic", for example, the general SA evaluates the overall sentiment towards the 'restaurant' as 'positive', while ABSA identifies the restaurant's aspect 'price' as 'negative' and 'food' aspect as 'positive'. Thus, ABSA enables a more specific and effective marketing strategy. In order to perform ABSA, it is necessary to identify what are the aspect terms or aspect categories included in the text, and judge the sentiments towards them. Accordingly, there exist four main areas in ABSA; aspect term extraction, aspect category detection, Aspect Term Sentiment Classification (ATSC), and Aspect Category Sentiment Classification (ACSC). It is usually conducted by extracting aspect terms and then performing ATSC to analyze sentiments for the given aspect terms, or by extracting aspect categories and then performing ACSC to analyze sentiments for the given aspect category. Here, an aspect category is expressed in one or more aspect terms, or indirectly inferred by other words. In the preceding example sentence, 'price' and 'food' are both aspect categories, and the aspect category 'food' is expressed by the aspect term 'food' included in the review. If the review sentence includes 'pasta', 'steak', or 'grilled chicken special', these can all be aspect terms for the aspect category 'food'. As such, an aspect category referred to by one or more specific aspect terms is called an explicit aspect. On the other hand, the aspect category like 'price', which does not have any specific aspect terms but can be indirectly guessed with an emotional word 'expensive,' is called an implicit aspect. So far, the 'aspect category' has been used to avoid confusion about 'aspect term'. From now on, we will consider 'aspect category' and 'aspect' as the same concept and use the word 'aspect' more for convenience. And one thing to note is that ATSC analyzes the sentiment towards given aspect terms, so it deals only with explicit aspects, and ACSC treats not only explicit aspects but also implicit aspects. This study seeks to find answers to the following issues ignored in the previous studies when applying the BERT pre-trained language model to ACSC and derives superior ACSC models. First, is it more effective to reflect the output vector of tokens for aspect categories than to use only the final output vector of [CLS] token as a classification vector? Second, is there any performance difference between QA (Question Answering) and NLI (Natural Language Inference) types in the sentence-pair configuration of input data? Third, is there any performance difference according to the order of sentence including aspect category in the QA or NLI type sentence-pair configuration of input data? To achieve these research objectives, we implemented 12 ACSC models and conducted experiments on 4 English benchmark datasets. As a result, ACSC models that provide performance beyond the existing studies without expanding the training dataset were derived. In addition, it was found that it is more effective to reflect the output vector of the aspect category token than to use only the output vector for the [CLS] token as a classification vector. It was also found that QA type input generally provides better performance than NLI, and the order of the sentence with the aspect category in QA type is irrelevant with performance. There may be some differences depending on the characteristics of the dataset, but when using NLI type sentence-pair input, placing the sentence containing the aspect category second seems to provide better performance. The new methodology for designing the ACSC model used in this study could be similarly applied to other studies such as ATSC.

Application of Support Vector Regression for Improving the Performance of the Emotion Prediction Model (감정예측모형의 성과개선을 위한 Support Vector Regression 응용)

  • Kim, Seongjin;Ryoo, Eunchung;Jung, Min Kyu;Kim, Jae Kyeong;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.18 no.3
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    • pp.185-202
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    • 2012
  • .Since the value of information has been realized in the information society, the usage and collection of information has become important. A facial expression that contains thousands of information as an artistic painting can be described in thousands of words. Followed by the idea, there has recently been a number of attempts to provide customers and companies with an intelligent service, which enables the perception of human emotions through one's facial expressions. For example, MIT Media Lab, the leading organization in this research area, has developed the human emotion prediction model, and has applied their studies to the commercial business. In the academic area, a number of the conventional methods such as Multiple Regression Analysis (MRA) or Artificial Neural Networks (ANN) have been applied to predict human emotion in prior studies. However, MRA is generally criticized because of its low prediction accuracy. This is inevitable since MRA can only explain the linear relationship between the dependent variables and the independent variable. To mitigate the limitations of MRA, some studies like Jung and Kim (2012) have used ANN as the alternative, and they reported that ANN generated more accurate prediction than the statistical methods like MRA. However, it has also been criticized due to over fitting and the difficulty of the network design (e.g. setting the number of the layers and the number of the nodes in the hidden layers). Under this background, we propose a novel model using Support Vector Regression (SVR) in order to increase the prediction accuracy. SVR is an extensive version of Support Vector Machine (SVM) designated to solve the regression problems. The model produced by SVR only depends on a subset of the training data, because the cost function for building the model ignores any training data that is close (within a threshold ${\varepsilon}$) to the model prediction. Using SVR, we tried to build a model that can measure the level of arousal and valence from the facial features. To validate the usefulness of the proposed model, we collected the data of facial reactions when providing appropriate visual stimulating contents, and extracted the features from the data. Next, the steps of the preprocessing were taken to choose statistically significant variables. In total, 297 cases were used for the experiment. As the comparative models, we also applied MRA and ANN to the same data set. For SVR, we adopted '${\varepsilon}$-insensitive loss function', and 'grid search' technique to find the optimal values of the parameters like C, d, ${\sigma}^2$, and ${\varepsilon}$. In the case of ANN, we adopted a standard three-layer backpropagation network, which has a single hidden layer. The learning rate and momentum rate of ANN were set to 10%, and we used sigmoid function as the transfer function of hidden and output nodes. We performed the experiments repeatedly by varying the number of nodes in the hidden layer to n/2, n, 3n/2, and 2n, where n is the number of the input variables. The stopping condition for ANN was set to 50,000 learning events. And, we used MAE (Mean Absolute Error) as the measure for performance comparison. From the experiment, we found that SVR achieved the highest prediction accuracy for the hold-out data set compared to MRA and ANN. Regardless of the target variables (the level of arousal, or the level of positive / negative valence), SVR showed the best performance for the hold-out data set. ANN also outperformed MRA, however, it showed the considerably lower prediction accuracy than SVR for both target variables. The findings of our research are expected to be useful to the researchers or practitioners who are willing to build the models for recognizing human emotions.

Evaluation on Risk at the Port of Mokpo and its Approaches based on Relative Importance of Risk Factors for Marine Traffic Environment (해상교통환경 위험요소의 상대적 중요도를 고려한 목포항 및 진입수로의 위험도 평가)

  • Lee, Hong-Hoon;Kim, Chol-Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.4
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    • pp.375-381
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    • 2013
  • To assess the risk of marine traffic environments, with high confidential level, the risk factors comprising it should be identified and the risk acceptance criteria should be also provided. Furthermore, the relative importance of each risk factor(the weight of each risk factor on total risk) should be analyzed because the risk is expressed as the sum of risk factors comprising it. The twenty kinds of risk factors and its assessment criteria were suggested for the domestic marine traffic environments by an examination of the existing risk assessment models on the previous studies. The relative importance of each risk factor was also analyzed through the questionnaire using analytic hierarchy process by the marine traffic experts on the same studies. Based on these previous studies, the risk was evaluated at the port of Mokpo and its approaches on this study. The port of Mokpo and its approaches were divided into four sectors for the comparative evaluation, the result of the comparative evaluation on four sectors showed that the risk of the Jeongdeung-hae passage is the highest due to higher risk level of some risk factors(water movements, complexities, tug boats, pilotage, VTS) than the other sectors. The result of this evaluation is in accord with the analysis results of the other studies using various qualitative or quantitative risk analysis methods at the same sea areas.

The relationship between positive psychological capital and entrepreneurial intention among middle-aged and elderly individuals: Mediation of Risk Sensitivity and Moderating Effects of Asset Status (중·고령자의 긍정심리자본이 창업의지에 미치는 영향: 위험 감수성의 매개 및 자산상태의 조절 효과)

  • Choi, Ju-Choel
    • Journal of the Korea Convergence Society
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    • v.11 no.4
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    • pp.233-245
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    • 2020
  • This study aims to investigate the relationship between positive psychological capital and entrepreneurial intention among middle-aged and elderly individuals who are interested in starting their own business by focusing on the mediating effect of risk sensitivity and the moderating effect of asset status. To accomplish the study's objective, a questionnaire was administered to approximately 250 middle-aged and elderly people working in Seoul from December 1 to December 31, 2019. Collected data were analyzed using SPSS 26.0. Specifically, frequency analysis and descriptive statistics were conducted, and reliability of the constructs was assessed. Factor analysis was used to measure the goodness of fit of the model developed. Finally, a structural equation model was established, and analysis was conducted on the test of the hypotheses about the mediating, moderating, and adjusting effects using the AMOS statistical package. The results revealed that positive psychological capital had a positive impact on risk sensitivity, and the path analysis of self-efficacy and entrepreneurial intention as well as resilience and entrepreneurial intention showed results of 0.042 and 0.026, respectively, supporting mediating effects. In the causal relationship between positive psychological capital and entrepreneurial intention, asset status acted as a moderator given that the chi square difference between the models was 7.096. Thus, the findings provide implications for comprehensive training programs to boost positive psychological capital and asset status in middle-aged and elderly individuals who are preparing to establish their own business. Further studies are needed to cover broader geographic areas and compare/analyze other variables associated with business startups.

A Study on Enhancing the Performance of Detecting Lip Feature Points for Facial Expression Recognition Based on AAM (AAM 기반 얼굴 표정 인식을 위한 입술 특징점 검출 성능 향상 연구)

  • Han, Eun-Jung;Kang, Byung-Jun;Park, Kang-Ryoung
    • The KIPS Transactions:PartB
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    • v.16B no.4
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    • pp.299-308
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    • 2009
  • AAM(Active Appearance Model) is an algorithm to extract face feature points with statistical models of shape and texture information based on PCA(Principal Component Analysis). This method is widely used for face recognition, face modeling and expression recognition. However, the detection performance of AAM algorithm is sensitive to initial value and the AAM method has the problem that detection error is increased when an input image is quite different from training data. Especially, the algorithm shows high accuracy in case of closed lips but the detection error is increased in case of opened lips and deformed lips according to the facial expression of user. To solve these problems, we propose the improved AAM algorithm using lip feature points which is extracted based on a new lip detection algorithm. In this paper, we select a searching region based on the face feature points which are detected by AAM algorithm. And lip corner points are extracted by using Canny edge detection and histogram projection method in the selected searching region. Then, lip region is accurately detected by combining color and edge information of lip in the searching region which is adjusted based on the position of the detected lip corners. Based on that, the accuracy and processing speed of lip detection are improved. Experimental results showed that the RMS(Root Mean Square) error of the proposed method was reduced as much as 4.21 pixels compared to that only using AAM algorithm.

Modeling and Controller Design for Attitude Control of a Moving Satellite (이동하는 위성의 자세제어를 위한 모델링 및 제어기 설계)

  • Lee, Woo-Seung;Park, Chong-Kug
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.1
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    • pp.19-29
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    • 2000
  • Because the previous simulation tool for attitude control of satellite was designed for the modeling of rigid body and PD controller, the attitude error can be made more than the limitation value for keeping for communication link, and then the communication link can be lost at moving of satellite. So, for rapid attitude restoration and design of stable and modernized controller, the modelling of rigid body and flexible body structure for moving GEO and LEO satellites were performed. Also the minimum time controller is designed for the rapid restoration of attitude error at communication broken and to minimize the disconnection period from ground communication system during the satellite stationkeeping. The linear regulator is designed using the space state vector that is better than accuracy and stability of PD controller. Firstly the simulation was performed for comparison of the rigid and stability of PD controller. Firstly the simulation was performed for comparison of the rigid and flexible models using PD controller and the case of the pitch angle changing by ground command, and the case of the periodic north-south stationkeeping are performed for the analysis of response characteristics of each controller when the attitude is changed. As a result, the flexible body model represents more sililar results of real situation than the rigid body model. The minimum time controller can restore 7 times rapidly than PD controller for its lost attitude. The linear regulator has several merits for capability of adaptation against the external disturbance, stability and response time. In future, we can check the estimated results using this satellite model and controller for real operation. Futhermore the development of new controller and training can be supported.

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Building Cooperation Policing Systems and Roles of Private Security (협력치안체제구축과 민간경비의 역할)

  • Seok, Cheong-Ho
    • Korean Security Journal
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    • no.24
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    • pp.67-90
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    • 2010
  • Today, the police alone can not prevent a crime. And the police is limited to meet for people's the increased needs on public safety. So the police and the community needs the cooperation of a variety of resources. Police in cooperation with community resources to respond to the crime's most professional and the private sector is a private security. However, the role of private security for cooperation policing is insufficient in South Korea. So for this study to build a cooperative policing in South Korea as private security for the following four kinds of directions are presented. First, as a private security of the United States and Japan, specializes in diversified business sectors. Simple human-oriented private security of the building security get out. Instead, take the high-tech crime prevention or industry complex security should be changed to a professional organization. Second, the interaction between police and private security should be increased. Police and private security through regular meetings between the need for mutual interests and build consensus is needed. The role of private security companies to be represented on the Security Association of South Korea's active role in the matter. Third, efforts to improve the image of private security activities and the publiciy activity of private security is needed. Some of the private security in an effort to escape a negative image to the people and actively promote a positive image is necessary. Finally, for South Korea to the level the cooperation between the police and private security are required to develop system models. Front-line policing priority in the field and the mutual understanding between the police and private security in an effort to have a positive perception is needed. Equal partners, especially the police and private security to private security companies to have recognized experts in their own recruitment and training should be improved by strengthening the expertise.

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The Effect of Fermented Codonopsis lanceolata on the Memory Impairment of Mice (발효더덕 추출물이 흰쥐의 인지능 회복에 미치는 효과)

  • Park, Sung-Jin;Park, Dong-Sik;Kim, Seung-Seop;He, Xinlong;Ahn, Ju-Hee;Yoon, Won-Byung;Lee, Hyeon-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.11
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    • pp.1691-1694
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    • 2010
  • In the present study, we assessed whether the extracts of Codonopsis lanceolata and fermented C. lanceolata posses the cognition-enhancing effect in rats with impaired learning and memory by scopolamine treatment (1 mg/kg, i.p.), an antagonist of muscarinic acetylcholine (ACh) receptor. The fermented C. lanceolata extract (333, 667 mg/kg) significantly reversed the scopolamine-induced cognitive impairments in the passive avoidance test (p<0.05). Moreover, fermented C. lanceolata extract (333 mg/kg) also improved escape latencies in training trials of Morris water maze test (p<0.05). The water extract of fermented C. lanceolata showed significant anti-amnestic and cognitive-enhancing activities related to the memory processes, and these activities were parallel to treatment duration and dependent of the learning models.

Prevention of Habitual Drunk Driving through Analyzing Psychological Difference for each Group partitioned by the Number of DUI Records (음주운전 전력 집단별 심리적 메커니즘 차이 분석을 통한 음주운전 상습화 예방대책 연구)

  • Jang, Seok-Yong;Park, Won-Beom;Jung, Hun-Young;Ko, Sang-Seon;Baik, Sang-Keun
    • Journal of Korean Society of Transportation
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    • v.30 no.4
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    • pp.107-118
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    • 2012
  • This paper investigated habitual drunk drivers' characteristics by grouping them by the number of DUI records, and customized countermeasures for each group. Theoretical models to accommodate underlying causes for drunk driving, which adopted the form of a path analysis, were developed based on psychological variables. According to the psychological paths to drunk driving, each group showed different defense mechanisms and different senses of guilty, shame and embarrassment. This provided a rationale for differentiating countermeasures for each group. Habitual drunk drivers were found to have a strong propensity of self-justification due to their defense mechanism. Thereby, it would be useless to simply discourage them from drinking and driving. Rather, more active measures such as locking devices, invalidation of driver license, and group counseling should be taken to stop habitual drunk driving. Furthermore, since habitual drunk drivers showed high projection propensity, it is necessary to force them to participate in a sensibility training program, which might entail the amendment of related laws or regulations.

Comparison of Artificial Neural Network and Empirical Models to Determine Daily Reference Evapotranspiration (기준 일증발산량 산정을 위한 인공신경망 모델과 경험모델의 적용 및 비교)

  • Choi, Yonghun;Kim, Minyoung;O'Shaughnessy, Susan;Jeon, Jonggil;Kim, Youngjin;Song, Weon Jung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.6
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    • pp.43-54
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    • 2018
  • The accurate estimation of reference crop evapotranspiration ($ET_o$) is essential in irrigation water management to assess the time-dependent status of crop water use and irrigation scheduling. The importance of $ET_o$ has resulted in many direct and indirect methods to approximate its value and include pan evaporation, meteorological-based estimations, lysimetry, soil moisture depletion, and soil water balance equations. Artificial neural networks (ANNs) have been intensively implemented for process-based hydrologic modeling due to their superior performance using nonlinear modeling, pattern recognition, and classification. This study adapted two well-known ANN algorithms, Backpropagation neural network (BPNN) and Generalized regression neural network (GRNN), to evaluate their capability to accurately predict $ET_o$ using daily meteorological data. All data were obtained from two automated weather stations (Chupungryeong and Jangsu) located in the Yeongdong-gun (2002-2017) and Jangsu-gun (1988-2017), respectively. Daily $ET_o$ was calculated using the Penman-Monteith equation as the benchmark method. These calculated values of $ET_o$ and corresponding meteorological data were separated into training, validation and test datasets. The performance of each ANN algorithm was evaluated against $ET_o$ calculated from the benchmark method and multiple linear regression (MLR) model. The overall results showed that the BPNN algorithm performed best followed by the MLR and GRNN in a statistical sense and this could contribute to provide valuable information to farmers, water managers and policy makers for effective agricultural water governance.