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  • Title/Summary/Keyword: Classical model

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Internet Marketing Strategy and Performance in the Korean Small Export Firms (한국 중소수출기업의 인터넷 마케팅 전략과 성과에 관한 연구)

  • Ko, Kyung-Sun
    • International Commerce and Information Review
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    • v.4 no.1
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    • pp.107-128
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    • 2002
  • In order to clarify the relationship between the Internet utilization of the Korean small export firms for export marketing and it's performance, first, a research model and hypothesis have been made on a theoretical basis. This research hypothesis has been examined through gathering survey data and a statistical analysis based on MANOVA. The conclusion, as well as the main point of this thesis, is that, in most cases, there was a significant statistical connection between the variables of export performances and Internet-utilized export marketing strategies, which are both based on the classical AIDA model of effective hierarchy of communication for sales and advertising. This conclusion brings forth a substantial topic as well as provides meaningful implications for the Korean small export firms when putting together a marketing strategy using the Internet. It is also hoped that this will come as a reference for other researchers henceforth. However, there is an issue of lack of representativeness when considering that the samples were chosen on the basis of the convenience sampling method. Another issue may be that a portion of the subjects were not related to actual trade, but were, in fact, Web masters who operated e-trade systems. Furthermore, there are also numerous problems of missing data, and 6 out of the 8 main hypotheses possessed the issue of fitness level with the data. Therefore, in order to enhance both the representative and fitness levels of the data of further research for this topic, future respondents will have to have special trade knowledge, as well as technical knowledge of e-trade. However, unless the Internet begins to greatly contribute to export marketing of corporations, this type of enterprising spirit by corporations in gathering suitable respondents will not surface. Although not used in examining the hypotheses of this particular thesis, the relationship between competitive and circumstantial variables, which were added to the upcoming survey, and export performances will soon be analyzed and announced in order to atone for some of the standards this thesis fell short of.

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Classification of human actions using 3D skeleton data: A performance comparison between classical machine learning and deep learning models (스켈레톤 데이터에 기반한 동작 분류: 고전적인 머신러닝과 딥러닝 모델 성능 비교)

  • Juhwan Kim;Jongchan Kim;Sungim Lee
    • The Korean Journal of Applied Statistics
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    • v.37 no.5
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    • pp.643-661
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    • 2024
  • This study investigates the effectiveness of 3D skeleton data for human action recognition by comparing the classification performance of machine learning and deep learning models. We use the subset of the NTU RGB+D dataset, containing only frontal-view recordings of 40 individuals performing 60 different actions. Our study uses linear discriminant analysis (LDA), support vector machine (SVM), and random forest (RF) as machine learning models, while the deep learning models are hierarchical bidirectional RNN (HBRNN) and semantics-guided neural network (SGN). To evaluate model performance, cross-subject cross-validation is conducted. Our analysis demonstrates that action type significantly impacts model performance. Cluster analysis by action category shows no significant difference in classification performance between machine learning and deep learning models for easily recognizable actions. However, for actions requiring precise differentiation based on frontal-view joint coordinates such as 'clapping' or 'rubbing hands', deep learning models show a higher performance in capturing subtle joint movements compared to machine learning models.

Aspects of Chinese Poetry in Korea and Japan in the 18th and 19th Centuries, as Demonstrated by Kim Chang Heup and Kan Chazan (김창흡과 간챠잔을 통해서 본 18·19세기 한일 한시의 한 면모)

  • Choi, Kwi-muk
    • Journal of Korean Classical Literature and Education
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    • no.34
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    • pp.115-147
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    • 2017
  • This paper compared and reviewed the poetic theories and Chinese poems of the Korean author Kim Chang Heup and his Japanese counterpart, Kan Chazan. Kim Chang Heup and Kan Chazan shared largely the same opinions on poetry, and both rejected archaism. First, they did not just copy High Tang poetry. Instead, they focused on the (sometimes trivial) scenery right in front of them, and described the calm feelings evoked by what they had seen. They also adopted a sincere tone, instead of an exaggerated one, because both believed that poetry should be realistic. However the differences between the two poets are also noteworthy. Kim Chang Heup claimed that feelings and scenery meet each other within a literary work through Natural Law, and the linguistic expressions that mediate the two are philosophical in nature. However, Kan Chazan did not use Natural Law as a medium between feelings and scenery. Instead the Japanese writer said the ideal poetical composition comes from a close observation and detailed description of scenery. In sum, while Kim Chang Heup continued to express reason through scenery, Kan Chazan did not go further than depicting the scenery itself. In addition, Kim Chang Heup believed poetry was not only a representation of Natural Law, but also a high-level linguistic activity that conveys a poetic concern about national politics. As a sadaebu (scholar-gentry), he held literature in high esteem because he thought that literature could achieve important outcomes. On the other hand, Kan Chazan regarded it as a form of entertainment, thereby insisting literature had its own territory that is separate from that of philosophy or politics. In other words, whereas Kim Chang Heup considered literature as something close to a form of learning, Kan Chazan viewed it as art. One might wonder whether the poetics of Kim Chang Heup and Kan Chazan reflect their individual accomplishments, or if the characteristics of Chinese poetry that Korean and Japanese poets had long sought after had finally surfaced in these two writers. This paper argued that the two authors' poetics represent characteristics of Chinese poetry in Korea and Japan, or general characteristics of Korean and Japanese literatures in a wider sense. Their request to depict actual scenery in a unique way, free from the ideal model of literature, must have facilitated an outward materialization of Korean and Japanese literary characteristics that had developed over a long time.

A hybrid algorithm for the synthesis of computer-generated holograms

  • Nguyen The Anh;An Jun Won;Choe Jae Gwang;Kim Nam
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.60-61
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    • 2003
  • A new approach to reduce the computation time of genetic algorithm (GA) for making binary phase holograms is described. Synthesized holograms having diffraction efficiency of 75.8% and uniformity of 5.8% are proven in computer simulation and experimentally demonstrated. Recently, computer-generated holograms (CGHs) having high diffraction efficiency and flexibility of design have been widely developed in many applications such as optical information processing, optical computing, optical interconnection, etc. Among proposed optimization methods, GA has become popular due to its capability of reaching nearly global. However, there exits a drawback to consider when we use the genetic algorithm. It is the large amount of computation time to construct desired holograms. One of the major reasons that the GA' s operation may be time intensive results from the expense of computing the cost function that must Fourier transform the parameters encoded on the hologram into the fitness value. In trying to remedy this drawback, Artificial Neural Network (ANN) has been put forward, allowing CGHs to be created easily and quickly (1), but the quality of reconstructed images is not high enough to use in applications of high preciseness. For that, we are in attempt to find a new approach of combiningthe good properties and performance of both the GA and ANN to make CGHs of high diffraction efficiency in a short time. The optimization of CGH using the genetic algorithm is merely a process of iteration, including selection, crossover, and mutation operators [2]. It is worth noting that the evaluation of the cost function with the aim of selecting better holograms plays an important role in the implementation of the GA. However, this evaluation process wastes much time for Fourier transforming the encoded parameters on the hologram into the value to be solved. Depending on the speed of computer, this process can even last up to ten minutes. It will be more effective if instead of merely generating random holograms in the initial process, a set of approximately desired holograms is employed. By doing so, the initial population will contain less trial holograms equivalent to the reduction of the computation time of GA's. Accordingly, a hybrid algorithm that utilizes a trained neural network to initiate the GA's procedure is proposed. Consequently, the initial population contains less random holograms and is compensated by approximately desired holograms. Figure 1 is the flowchart of the hybrid algorithm in comparison with the classical GA. The procedure of synthesizing a hologram on computer is divided into two steps. First the simulation of holograms based on ANN method [1] to acquire approximately desired holograms is carried. With a teaching data set of 9 characters obtained from the classical GA, the number of layer is 3, the number of hidden node is 100, learning rate is 0.3, and momentum is 0.5, the artificial neural network trained enables us to attain the approximately desired holograms, which are fairly good agreement with what we suggested in the theory. The second step, effect of several parameters on the operation of the hybrid algorithm is investigated. In principle, the operation of the hybrid algorithm and GA are the same except the modification of the initial step. Hence, the verified results in Ref [2] of the parameters such as the probability of crossover and mutation, the tournament size, and the crossover block size are remained unchanged, beside of the reduced population size. The reconstructed image of 76.4% diffraction efficiency and 5.4% uniformity is achieved when the population size is 30, the iteration number is 2000, the probability of crossover is 0.75, and the probability of mutation is 0.001. A comparison between the hybrid algorithm and GA in term of diffraction efficiency and computation time is also evaluated as shown in Fig. 2. With a 66.7% reduction in computation time and a 2% increase in diffraction efficiency compared to the GA method, the hybrid algorithm demonstrates its efficient performance. In the optical experiment, the phase holograms were displayed on a programmable phase modulator (model XGA). Figures 3 are pictures of diffracted patterns of the letter "0" from the holograms generated using the hybrid algorithm. Diffraction efficiency of 75.8% and uniformity of 5.8% are measured. We see that the simulation and experiment results are fairly good agreement with each other. In this paper, Genetic Algorithm and Neural Network have been successfully combined in designing CGHs. This method gives a significant reduction in computation time compared to the GA method while still allowing holograms of high diffraction efficiency and uniformity to be achieved. This work was supported by No.mOl-2001-000-00324-0 (2002)) from the Korea Science & Engineering Foundation.

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The Publishing and the Emergence of Nationalism in Modern Korea (근대 민족주의의 형성과 개화기 출판)

  • Chae, Baek
    • Korean journal of communication and information
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    • v.41
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    • pp.7-40
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    • 2008
  • The aim of this study is to examine the role of publishing in emerging process of nationalism in modern Korea. In the process of coping with the imperialist invasion, the Korean nationalism had begun to emerge. With the Patriotic Enlightenment movement from 1905 till 1910, the publishing in Korea had become activated remarkably. With the books of enlightenment the Korean society could try to overcome the traditional China-centered world view and try to build up a new recognition of 'others'. In addition the books of enlightenment provided information on the various aspects of modern nationalism. And the republishing the Korean classical books seemed to have been very conducive to improve national self-esteem of Korea. The books on history contributed to building up new national identity which was an indispensable to the nationalism. The Korean history was reinvented from the nationalistic viewpoint. The biographies of historic heros presented some historic model of overcoming the national crisis. In conclusion the publishing in modern Korea played an important role in emerging process of the Korean nationalism.

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A Study on Developing and Validating the Modern Physics Conceptual Diagnostic Survey for Pre-Service Physics Teachers based on the 2015 Revised National Science Curriculum (2015 개정 과학과 교육과정에 기초한 예비 물리교사를 위한 현대물리 개념 진단지 개발 및 타당화 연구)

  • Kim, Wanseon;Kim, Sung-Won
    • Journal of The Korean Association For Science Education
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    • v.40 no.3
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    • pp.253-269
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    • 2020
  • This study aims to develop items to diagnose pre-service physics teachers' understanding of the conceptual knowledge of modern physics, based on the achievement criteria presented in the 2015 revised national science curriculum, and to identify the validity and reliability of the newly developed items. Data were collected from 467 pre-service physics teachers in the Physical Education Department or Science Education Department (Physics Education Major) of 15 universities across the nation. In this study the content validity, substantive validity, the internal structure validity, generalization validity, and the external validity proposed by Messick (1995) were examined by various statistical tests. The results of the MNSQ analysis showed that there was no nonconformity in the 23 items. The internal structure validity was confirmed by the standardized residual variance analysis, which shows that the 22 items was unidimensional. The generalization validity was confirmed by differential item functioning (DIF) analysis about groups lectured or not modern physics/quantum mechanics. In addition, item analysis and test analysis based on classical test theory were performed. The mean item difficulty is 0.66, mean item discrimination is 0.47 and mean point biserial coefficient obtained was 0.41. These results for item parameters satisfied the criteria respectively. The reliability of the internal consistency of the KR-20 is 0.77 and the Ferguson's delta obtained was δ = 0.972. By Rasch model analysis, the item difficulty (item measures) was discussed.

Estimation and Weighting of Sub-band Reliability for Multi-band Speech Recognition (다중대역 음성인식을 위한 부대역 신뢰도의 추정 및 가중)

  • 조훈영;지상문;오영환
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.6
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    • pp.552-558
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    • 2002
  • Recently, based on the human speech recognition (HSR) model of Fletcher, the multi-band speech recognition has been intensively studied by many researchers. As a new automatic speech recognition (ASR) technique, the multi-band speech recognition splits the frequency domain into several sub-bands and recognizes each sub-band independently. The likelihood scores of sub-bands are weighted according to reliabilities of sub-bands and re-combined to make a final decision. This approach is known to be robust under noisy environments. When the noise is stationary a sub-band SNR can be estimated using the noise information in non-speech interval. However, if the noise is non-stationary it is not feasible to obtain the sub-band SNR. This paper proposes the inverse sub-band distance (ISD) weighting, where a distance of each sub-band is calculated by a stochastic matching of input feature vectors and hidden Markov models. The inverse distance is used as a sub-band weight. Experiments on 1500∼1800㎐ band-limited white noise and classical guitar sound revealed that the proposed method could represent the sub-band reliability effectively and improve the performance under both stationary and non-stationary band-limited noise environments.

A History of Visualization for Biomedical Information of Meridian (경락경혈 의학정보의 시각화 방법에 대한 역사적 고찰)

  • Lee, Soon-Ho;Lee, In-Seon;Jo, Hee-Jin;Jung, Won-Mo;Lee, Ah-Reum;Kim, Song-Yi;Park, Hi-Joon;Lee, Hye-Jung;Huang, Long-Xiang;Chae, Youn-Byoung
    • Korean Journal of Acupuncture
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    • v.29 no.3
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    • pp.371-384
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    • 2012
  • Objectives : The meridian system is a systematic complex of empirical knowledge, which functions as a basis of acupuncture treatment. In this article, we reviewed the visualization methods of meridian and acupuncture points through the investigation of the characteristics of Diagram of Meridians, Mingtang Diagram, Diagram of Meridians and Collaterals, Bronze Statues and Diagram of Bronze Statue. Methods : We investigated the characteristics of Diagram of Meridians, Mingtang Diagram, Diagram of Meridians and Collaterals, and Bronze Statues. We reviewed the visualization methods of meridian and acupuncture points in those classical Diagrams and analyzed their relationships among them. Results : In order to explain the meridian and acupuncture points easily, ancient people usually used drawings which are named Mingtang Diagram, Diagram of Meridians and Collaterals, by their own characteristics. Owing to their limitations of drawings on the 2 dimensional plane, Chinese people designed the Bronze Statue for Acu-moxibustion and its first invention was invented in Tiansheng age of Song dynasty. For several decades and centuries, these models and drawings were inherited, also reflecting variations of meridian system. As the Bronze Statue has a deficiency in the educational use because of its limitations of mass production, Diagram of Bronze Statue drawn on the 2 dimensional plane was invented. At the beginning of Mingtang Diagram, Diagram of Meridians and Collaterals, Diagram of Bronze Statue and Bronze Statue, their own characteristics were significantly differed with other diagrams and statues. We found that both diagrams and statues were gradually combined with description of the relationship between internal organs and the skeletal structure and the meridian system. Conclusions : Our findings suggest that Diagram of Meridians, Mingtang Diagram, Diagram of Meridians and Collaterals, and Bronze Statues are the basic form of data visualization, one of the infographics. We suggest that ancient Chinese people intend to explain the empirical knowledge using the ancient infographics of meridian system, but have limitations on reflecting theorical or abstractional meaning.

Stress Analysis of an Edge-Cracked Plate by using Photoelastic Fringe Phase Shifting Method (광탄성프린지 위상이동법을 이용한 에지균열판의 응력 해석)

  • Baek, Tae-Hyun;Kim, Myung-Soo;Cho, Sung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.3
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    • pp.213-220
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    • 2000
  • The method of photoelasticity allows one to obtain principal stress differences and principal stress directions in a photoelastic model. In the classical approach, the photoelastic parameters are measured manually point by point. The previous methods require much time and skill in the identification and measurement of photoelastic data. Fringe phase shifting method has been recently developed and widely used to measure and analyze fringe data in photo-mechanics. This paper presents the test results of photoelastic fringe phase shifting technique for the stress analysis of a circular disk under compression and an edge-cracked plate subjected to tensile load. The technique used here requires four phase stepped photoelastic images obtained from a circular polariscope by rotating the analyzer at 0, 45, 90 and 135. Experimental results are compared with those or FEM. Good agreement between the results can be observed. However, some error may be included if the technique is used to general direction which is not parallel to isoclinic fringe.

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Performance of a Bayesian Design Compared to Some Optimal Designs for Linear Calibration (선형 캘리브레이션에서 베이지안 실험계획과 기존의 최적실험계획과의 효과비교)

  • 김성철
    • The Korean Journal of Applied Statistics
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    • v.10 no.1
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    • pp.69-84
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    • 1997
  • We consider a linear calibration problem, yi=α+β(xix0)+ϵi, i=1,2,,n yf=α+β(xfx0)+ϵ, where we observe (xi,yi)'s for the controlled calibration experiments and later we make inference about xf from a new observation yf. The objective of the calibration design problem is to find the optimal design x=(xi,,xn that gives the best estimates for xf. We compare Kim(1989)'s Bayesian design which minimizes the expected value of the posterior variance of xf and some optimal designs from literature. Kim suggested the Bayesian optimal design based on the analysis of the characteristics of the expected loss function and numerical must be equal to the prior mean and that the sum of squares be as large as possible. The designs to be compared are (1) Buonaccorsi(1986)'s AV optimal design that minimizes the average asymptotic variance of the classical estimators, (2) D-optimal and A-optimal design for the linear regression model that optimize some functions of M(x)=xixi, and (3) Hunter & Lamboy (1981)'s reference design from their paper. In order to compare the designs which are optimal in some sense, we consider two criteria. First, we compare them by the expected posterior variance criterion and secondly, we perform the Monte Carlo simulation to obtain the HPD intervals and compare the lengths of them. If the prior mean of xf is at the center of the finite design interval, then the Bayesian, AV optimal, D-optimal and A-optimal designs are indentical and they are equally weighted end-point design. However if the prior mean is not at the center, then they are not expected to be identical.In this case, we demonstrate that the almost Bayesian-optimal design was slightly better than the approximate AV optimal design. We also investigate the effects of the prior variance of the parameters and solution for the case when the number of experiments is odd.

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