• Title/Summary/Keyword: Level set methods

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Predicting movie audience with stacked generalization by combining machine learning algorithms

  • Park, Junghoon;Lim, Changwon
    • Communications for Statistical Applications and Methods
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    • v.28 no.3
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    • pp.217-232
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    • 2021
  • The Korea film industry has matured and the number of movie-watching per capita has reached the highest level in the world. Since then, movie industry growth rate is decreasing and even the total sales of movies per year slightly decreased in 2018. The number of moviegoers is the first factor of sales in movie industry and also an important factor influencing additional sales. Thus it is important to predict the number of movie audiences. In this study, we predict the cumulative number of audiences of films using stacking, an ensemble method. Stacking is a kind of ensemble method that combines all the algorithms used in the prediction. We use box office data from Korea Film Council and web comment data from Daum Movie (www.movie.daum.net). This paper describes the process of collecting and preprocessing of explanatory variables and explains regression models used in stacking. Final stacking model outperforms in the prediction of test set in terms of RMSE.

A Physics-Based Modelling of Multipbase Fluid Phenomena (물리적 모델에 기반한 다상 유체 현상 애니메이션)

  • Song, Oh-Young;Shin, Hyun-Cheol;Ko, Hyeong-Seok
    • Journal of the Korea Computer Graphics Society
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    • v.10 no.3
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    • pp.52-60
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    • 2004
  • This paper presents a physically based technique for simulating complex multiphase fluids. This work is motivated by the "stable fluids" method developed by Stam to handle gaseous fluids. We extend this technique to water, which calls for the development of methods for modeling multiphase fluids and suppressing dissipation. We construct a multiphase fluid formulation by combining the Navier-Stokes equations with the level set method. By adopting constrained interpolation profile (CIP)-based advection, we reduce the numerical dissipation and diffusion significantly. We further reduce the dissipation by converting potentially dissipative cells into droplets or bubbles that undergo Lagrangian motion. Due to the multiphase formulation, the proposed method properly simulates the interaction of water with surrounding air, instead of simulating water in a void space. Moreover. the introduction of the non-dissipative technique means that, in contrast 10 previous methods, the simulated water does not unnecessarily lose mass and its motion is not damped to an unphysical extent. Experiments showed that the proposed method is stable and runs fast. It is demonstrated that two-dimensional simulation runs in real-time.

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Mining Structure Elements from RNA Structure Data, and Visualizing Structure Elements

  • Lim, Dae-Ho;Han, Kyung-Sook
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2003.10a
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    • pp.268-274
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    • 2003
  • Most currently known molecular structures were determined by X-ray crystallography or Nuclear Magnetic Resonance (NMR). These methods generate a large amount of structure data, even far small molecules, and consist mainly of three-dimensional atomic coordinates. These are useful for analyzing molecular structure, but structure elements at higher level are also needed for a complete understanding of structure, and especially for structure prediction. Computational approaches exist for identifying secondary structural elements in proteins from atomic coordinates. However, similar methods have not been developed for RNA due in part to the very small amount of structure data so far available, and extracting the structural elements of RNA requires substantial manual work. Since the number of three-dimensional RNA structures is increasing, a more systematic and automated method is needed. We have developed a set of algorithms for recognizing secondary and tertiary structural elements in RNA molecules and in the protein-RNA structures in protein data banks (PDB). The present work represents the first attempt at extracting RNA structure elements from atomic coordinates in structure databases. The regularities in the structure elements revealed by the algorithms should provide useful information for predicting the structure of RNA molecules bound to proteins.

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A Physics-Based Modelling of Multiphase Fluid Phenomena (물리적 모델에 기반한 다상 유체 현상 애니메이션)

  • Song, Oh-Young;Shin, Hyun-Cheol;Ko, Hyeong-Seok
    • Journal of the Korea Computer Graphics Society
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    • v.10 no.4
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    • pp.13-21
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    • 2004
  • This paper presents a physically based technique for simulating complex multiphase fluids. This work is motivated by the "stable fluids" method developed by Stam to handle gaseous fluids. We extend this technique to water, which calls for the development of methods for modeling multiphase fluids and suppressing dissipation. We construct a multiphase fluid formulation by combining the Navier-Stokes equations with the level set method. By adopting constrained interpolation profile (CIP)-based advection, we reduce the numerical dissipation and diffusion significantly. We further reduce the dissipation by converting potential1y dissipative cel1s into droplets or bubbles that undergo Lagrangian motion. Due to the multiphase formulation, the proposed method properly simulates the interaction of water with surrounding air, instead of simulating water in a void space. Moreover, the introduction of the non-dissipative technique means that, in contrast to previous methods, the simulated water does not unnecessarily lose mass and its motion is not damped to an unphysical extent. Experiments showed that the proposed method is stable and runs fast. It is demonstrated that two-dimensional simulation runs in real-time.

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A study on improvement of policing perfomance by usage parameter control in asynchronous transfer mode networks (ATM망에서 사용자 변수 제어에 의한 감시 성능 개선에 관한 연구)

  • 한길성;오창석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.6
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    • pp.1480-1489
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    • 1996
  • In ATM networks there are two methods in traffic control as schemes advancing the quality of service. One is reactive control after congestion and the other which is generally recommended, is preventive control before congestion, including connection admission control on call leel and usage parameter control, network parameter control, priority control and congestion control on cell level. In particular, usage parameter control is required for restricting the peak cell rate of bursy tracffic to the parameter negotiated at call set-up phase since the peak cell rate significantly influences the network quality of service. The scheme for progressing quality of service by usage parameter control is themethod using VSA(Virtual Scheduling Algorlithm) recommended ITU-T. The method using VSSA(Virtual Scheduling Suggested Algorlithm) in this paper is suggested by considering cell delay variation and token rate of leaky bucket, compared VSA and VSANT(Virtual Scheduling Algolithm with No Tolerance) with VSSA which polices violated cell probability of conformed peak cell rate and intentionally excessive peak cell rate. VSSA method using IPP(Interruped Poisson Process) model of input traffic source showed more quality of service than VSA and VSANT methods as usage parameter control because the suggested method reduced the violated cell probability of contformed peak cell rate and intentionally excessive peak cell rate.

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A Study on Ways to Vitalize Digital Contents Business through IP Holding Company

  • Jung, Jai-Jin
    • Journal of Digital Convergence
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    • v.9 no.1
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    • pp.107-114
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    • 2011
  • In order to have the highest level of a certain society's technology be evaluated as digital contents technology the value concept of such technology's social utilization must be established while active investment on the technology takes place and makes it the subject of social capitalization. This study wishes to discuss the strategies and methods of establishing and managing IP holding company which requires business activation with digital contents technology at its base, research ways of vitalizing IP holding company to expand social utility values of contents technology, suggest necessary systemic improvements and investment activation methods, management structure, and governance structure by investigating ways to stimulate the industrialization of contents technology through the establishment and management of this IP holding company, and finally come up with a realistic measure to establish and manage a IP holding company. Strategies on commercialization of digital contents technology and acceleration of technology development, as well as activation of venture business set-ups will be analyzed and suggested based on such suggestions while IP holding company's digital contents technology investment activation model will be established to produce means to realize discovering superior contents companies and activation of investment, and activating high quality contents production for the global market.

Assessment of The Accuracy of The MR Abdominal Adipose Tissue Volumetry using 3D Gradient Dual Echo 2-Point DIXON Technique using CT as Reference

  • Kang, Sung-Jin
    • Journal of Magnetics
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    • v.21 no.4
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    • pp.603-615
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    • 2016
  • In this study, in order to determine the validity and accuracy of MR imaging of 3D gradient dual echo 2-point DIXON technique for measuring abdominal adipose tissue volume and distribution, the measurements obtained by CT were set as a reference for comparison and their correlations were evaluated. CT and MRI scans were performed on each subject (17 healthy male volunteers who were fully informed about this study) to measure abdominal adipose tissue volume. Two skilled investigators individually observed the images acquired by CT and MRI in an independent environment, and directly separated the total volume using region-based thresholding segmentation method, and based on this, the total adipose tissue volume, subcutaneous adipose tissue volume and visceral adipose tissue volume were respectively measured. The correlation of the adipose tissue volume measurements with respect to the observer was examined using the Spearman test and the inter-observer agreement was evaluated using the intra-class correlation test. The correlation of the adipose tissue volume measurements by CT and MRI imaging methods was examined by simple regression analysis. In addition, using the Bland-Altman plot, the degree of agreement between the two imaging methods was evaluated. All of the statistical analysis results showed highly statistically significant correlation (p<0.05) respectively from the results of each adipose tissue volume measurements. In conclusion, MR abdominal adipose volumetry using the technique of 3D gradient dual echo 2-point DIXON showed a very high level of concordance even when compared with the adipose tissue measuring method using CT as reference.

A Multi-Stage Approach to Secure Digital Image Search over Public Cloud using Speeded-Up Robust Features (SURF) Algorithm

  • AL-Omari, Ahmad H.;Otair, Mohammed A.;Alzwahreh, Bayan N.
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.65-74
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    • 2021
  • Digital image processing and retrieving have increasingly become very popular on the Internet and getting more attention from various multimedia fields. That results in additional privacy requirements placed on efficient image matching techniques in various applications. Hence, several searching methods have been developed when confidential images are used in image matching between pairs of security agencies, most of these search methods either limited by its cost or precision. This study proposes a secure and efficient method that preserves image privacy and confidentially between two communicating parties. To retrieve an image, feature vector is extracted from the given query image, and then the similarities with the stored database images features vector are calculated to retrieve the matched images based on an indexing scheme and matching strategy. We used a secure content-based image retrieval features detector algorithm called Speeded-Up Robust Features (SURF) algorithm over public cloud to extract the features and the Honey Encryption algorithm. The purpose of using the encrypted images database is to provide an accurate searching through encrypted documents without needing decryption. Progress in this area helps protect the privacy of sensitive data stored on the cloud. The experimental results (conducted on a well-known image-set) show that the performance of the proposed methodology achieved a noticeable enhancement level in terms of precision, recall, F-Measure, and execution time.

A systematic review of continuing education for emergency medical technicians (응급구조사의 보수교육에 대한 체계적 문헌고찰)

  • Kang, Min Seong;Kim, Woo-Jong;Choi, Bo Youl
    • The Korean Journal of Emergency Medical Services
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    • v.25 no.1
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    • pp.177-191
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    • 2021
  • Objectives: This study aimed to combine the satisfaction survey results and suggestion for continuing education of the emergency medical technicians through a systematic review of continuing education of the emergency medical technicians. Methods: This review focused on previous studies published until 2020 that were associated with the continuing education of emergency medical technicians. We followed the guidelines set for each phase of the study and selected the 26 studies that met the selection criteria for the analysis. Results: The level of satisfaction with continuing education for emergency medical technicians was low. The most frequently suggested method for continuing education was patient case presentation. The answers to the desired training subjects of the continuing education program varied. Finally, studies on continuing education have not been published continuously. Conclusion: To enhance the satisfaction and competence of continuing education, we need to provide various programs that reflect the needs of emergency medical technicians attending maintenance training. In addition, various methods should be considered to improve the attendance rate for continuing education, and further investigations and research should be actively conducted on continuing education in the future.

Effect of different underwater recovery methods on heart rate after circuit weight training

  • Park, Jun Sik;Kim, Ki Hong
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.222-227
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    • 2022
  • The purpose of this study was to investigate changes in heart rate according to recovery methods after circuit weight training exercise. Fourteen men in their twenties were selected as subjects, and three sets of circuit weight training were performed by cycling six sports, and two recovery conditions (dynamic and static) were performed immediately after exercise. Changes in heart rate did not have an interactive effect according to recovery method and time, and both conditions showed significant changes between sets 1 and 2, and between sets 3 and after recovery. In this study, the high heart rate of 2 sets and 3 sets was seen as a result of exercise stimulation, and the low heart rate of 1 set was thought to be due to the decrease in vagus nerve activity rather than the role of catecholamines. On the other hand, the heart rate after 20 minutes of exercise did not show any difference according to the recovery method, which could mean that the recovery process due to the aquatic environment can act more strongly than the process of dynamic recovery and static recovery. It is thought that the characteristics affected the sensory and circulation of the body, and thus the change of the afferent signal and the level of metabolic products generated in the active muscle.