• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.160-165
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• 2019

The conduct of seafarer is major cause of marine accidents. This study models the behavior of the seafarer based on the Hidden Markov Model (HMM). Additionally, through the path analysis of the behavior estimated by the model, the kind of situations, procedures and errors that may have caused the marine accidents were interpreted. To successfully implement the model, the seafarer behaviors were observed by means of the summarized verdict reports issued by the Korean Maritime Safety Tribunal, and the observed results converted into behavior data suitable for HMM learning through the behavior classification framework based on the SRKBB (Skill-, Rule-, and Knowledge-Based Behavior). As a result of modeling the seafarer behaviors by the type of vessels, it was established that there was a difference between the models, and the possibility of identifying the preferred path of the seafarer behaviors. Through these results, it is expected that the model implementation technique proposed in this study can be applied to the prediction of the behavior of the seafarer as well as contribute to the prioritization of the behavior correction among seafarers, which is necessary for the prevention of marine accidents.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.12
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• pp.71-83
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• 1996

This paper describes facial component detection and skew correction algorithm for face recognition. We use a priori knowledge and models about isolated regions to detect eye location from the face image captured in natural office environments. The relations between human face components are represented by several rules. We adopt an edge detection algorithm using sobel mask and 8-connected labelling algorith using array pointers. A labeled image has many isolated components. initially, the eye size rules are used. Eye size rules are not affected much by irregular input image conditions. Eye size rules size, and limited in the ratio between gorizontal and vertical sizes. By the eye size rule, 2 ~ 16 candidate eye components can be detected. Next, candidate eye parirs are verified by the information of location and shape, and one eye pair location is decided using face models about eye and eyebrow. Once we extract eye regions, we connect the center points of the two eyes and calculate the angle between them. Then we rotate the face to compensate for the angle so that the two eyes on a horizontal line. We tested 120 input images form 40 people, and achieved 91.7% success rate using eye size rules and face model. The main reasons of the 8.3% failure are due to components adjacent to eyes such as eyebrows. To detect facial components from the failed images, we are developing a mouth region processing module.

• Journal of KIISE
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• v.43 no.1
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• pp.80-86
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• 2016

A speech-act is a behavior intended by users in an utterance. Speech-act classification is important in a dialogue system. The machine learning and rule-based methods have mainly been used for speech-act classification. In this paper, we propose a speech-act classification method based on the combination of support vector machine (SVM) and transformation-based learning (TBL). The user's utterance is first classified by SVM that is preferentially applied to categories with a low utterance rate in training data. Next, when an utterance has negative scores throughout the whole of the categories, the utterance is applied to the correction phase by rules. The results from our method were higher performance over the baseline system long with error-reduction.

• Journal of Korean Clinical Health Science
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• v.9 no.1
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• pp.1478-1485
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• 2021

Purpose. To analysis of astigmatism in Korean adults from 20 to 29 years old. Methods. From January 2019 to February 2020, one hundred two subjects were performed in refraction test using the Auto-Refractometry. Results. In the type of astigmatism based on refractive error, the male's right eye was 4.26% simple myopic astigmatism and 95.74% complex myopic astigmatism, and the left eye was 2.22% simple myopic astigmatism and 97.78% complex myopic astigmatism. However, in the female's right eye, simple myopic astigmatism was 2.27%, complex myopic astigmatism was 97.73%, and left eye was simple myopic astigmatism was 2.17%, complex myopic astigmatism was 97.83%. The types of astigmatism in men and women similar to other. The mean refractive astigmatism values were -0.922±-0.798 diopter and -0.877±-0.707 diopter for male right and left eye, and -0.765±-0.599 diopter and -0.853±-0.586 diopter for female. On the other hand, the refraction values of the right and left eyes of men and women have statistical significance(p=0.000). The mean power comparative between refractive astigmatism and corneal astigmatism power were -0.186±-0.745 diopter, -1.091±-0.589 diopter in male and -1.140±-0.593 diopter, -1.140±-0.534 diopter in female. Therefore, the mean power values of the refractive astigmatism and corneal astigmatism of men and women were statistical significance(p=0.000). At the 0.75 diopter or more, which can have clinical symptoms of astigmatism power, males have 60.86% and 72.09% of the right and left eyes, and females have 47,64% and 60.10% of the right and left eyes. At 0.75 diopter or more, which can have clinical symptoms of corneal astigmatism power, males have 68.75% and 74% of the right and left eyes, and females have 86.50% and 82.35% of the right and left eyes. In the type of astigmatism axis, both men and women had a high frequency of the rule astigmatism. However, men had a high frequency of against-the-rule astigmatism and women showed a high frequency of oblique astigmatism. Conclusions. In this study, the complex myopic astigmatism and with-the rule astigmatism was the most common of all subjects. However, there was a statistical significance between right and left eyes of all subjects. The corneal astigmatism was higher refractive values in both males and females than refractive astigmatism. This study suggests that the analysis of the astigmatism can provide the useful diagnosis information for the correction of visual acuity.

• Journal of KIISE
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• v.42 no.5
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• pp.629-636
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• 2015

The types of errors corrected by a Korean spelling and grammar checker can be classified into isolated-term spelling errors and context-sensitive spelling errors (CSSE). CSSEs are difficult to detect and to correct, since they are correct words when examined alone. Thus, they can be corrected only by considering the semantic and syntactic relations to their context. CSSEs, which are frequently made even by expert wiriters, significantly affect the reliability of spelling and grammar checkers. An existing Korean spelling and grammar checker developed by P University (KSGC 4.5) adopts hand-made correction rules for correcting CSSEs. The KSGC 4.5 is designed to obtain very high precision, which results in an extremely low recall. Our overall goal of previous works was to improve the recall without considerably lowering the precision, by generalizing CSSE correction rules that mainly depend on linguistic knowledge. A variety of rule-based methods has been proposed in previous works, and the best performance showed 95.19% of average precision and 37.56% of recall. This study thus proposes a statistics based method using a conditional probability model with dynamic window sizes. in order to further improve the recall. The proposed method obtained 97.23% of average precision and 50.50% of recall.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.28-34
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• 2010

Conductive and radiative thermal model configurations of an imager of a geostationary satellite are presented. A two-plane method is introduced for three dimensional conductive coupling which is not able to be treated by thin shell plate thermal modeling technique. Especially the two-plane method is applied to massive matters and PIP(Payload Interface Plate) in the imager model. Some massive matters in the thermal model are modified by adequate correction factors or equivalent thickness in order to obtain the numerical results of thermal modeling to be consistent with the analytic model. More detailed nodal breakdown is specially employed to the object which has the rapid temperature gradient expected by a rule of thumb. This detailed thermal model of the imager is supposed to be used for analyses and test predictions, and be correlated with the thermal vacuum test results before final in-flight predictions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.25-31
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• 2014

Korean grammar checkers typically detect context-dependent errors by employing heuristic rules; these rules are formulated by language experts and consisted of lexical items. Such grammar checkers, unfortunately, show low recall which is detection ratio of errors in the document. In order to resolve this shortcoming, a new error-decision rule-generalization method that utilizes the existing KorLex thesaurus, the Korean version of Princeton WordNet, is proposed. The method extracts noun classes from KorLex and generalizes error-decision rules from them using the Tree Cut Model and information-theory-based MDL (minimum description length).

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.3
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• pp.148-156
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• 2015

Deck plates of ships or offshore structures would make out-of-plane distortion for their thin thickness. These distortions are usually straightened by thermal straightening such as flame heating method. After thermal straightening, the blocks are lifted and moved by cranes to assemble it at dry-dock stage. After this lifting process, out-of-plane deformation again happens frequently. And then, they continuously cause quality and accuracy problems in the final dry-dock process. So, it takes more time for repair and correction working. According to preceding research, the lifting process by cranes would offset the effect on thermal straightening. The target of this study is to develop a methodology analyzing the remaining efficiency of thermal straightening after block lifting. The development was based on the assumption of yield state at straightening region. Therefore the remaining efficiency was obtained by different stiffness slope while lifting & relieving. The efficiency formula was designed using inherent strain, and we made a table of zero-efficiency by cooling speed and class rule's steels. As a result, if the stress orthogonal to straightened line is calculated during lifting analysis by FEA, the efficiency can be obtained linearly to the values in the table. Finally, even optimized carling position can be designed by considering the regional data from series project and welding region on deck.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.771-781
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• 2018

This study deals with free vibrations analysis with stretching effect of nanocomposite beams reinforced by single-walled carbon nanotubes (SWCNTs) resting on an elastic foundation. Four different carbon nanotubes (CNTs) distributions including uniform and three types of functionally graded distributions of CNTs through the thickness are considered. The rule of mixture is used to describe the effective material properties of the nanocomposite beams. The significant feature of this model is that, in addition to including the shear deformation effect and stretching effect it deals with only 4 unknowns without including a shear correction factor. The governing equations are derived through using Hamilton's principle. Natural frequencies are obtained for nanocomposite beams. The mathematical models provided in this paper are numerically validated by comparison with some available results. New results of free vibration analyses of CNTRC beams based on the present theory with stretching effect is presented and discussed in details. The effects of different parameters of the beam on the vibration responses of CNTRC beam are discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.397-406
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• 2000

Genetic algorithm is used as a means of search, optimization md machine learning, its structure is simple but it is applied to various areas. And it is about an active and effective controller which can flexibly prepare for changeable circumstances. For this study, research about an action base system evolving by itself is also being considered. There is to have a problem that depended entirely on heuristic knowledge of expert forming membership function and control rule for fuzzy controller design. In this paper, for forming the fuzzy control to perform self-organization, we tuned the membership function to the most optimal using a genetic algorithm(GA) and improved the control efficiency by the self-correction and generation of control rules.