• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.3
• /
• pp.1-8
• /
• 2008

In the event of a traffic accident, a fire accident, or a criminal act, anyone will be able to capture these important moments and use authentic photographs for evidence purposes. Digital watermarking is able to ensure that the digital photographs taken from a particular camera-phone are authentic and indeed. This paper presents a blind image watermarking technique for digital phone camera. This method is based on singular value decomposition (SVD) and wavelet decomposition. Experimental results show that the proposed technique performs well in security and robustness against JPEG compression.

• International Journal of Computer Science & Network Security
• /
• v.21 no.6
• /
• pp.127-136
• /
• 2021

In the systems and software modeling field, a conceptual model involves modeling with concepts to support development and design. An example of a conceptual model is a description developed using the Unified Modeling Language (UML). UML uses a model multiplicity formulation approach, wherein a number of models are used to represent alternative views. By contrast, a model singularity approach uses only a single integrated model. Each of these styles of modeling has its strengths and weaknesses. This paper introduces a partial solution to the issue of multiplicity vs. singularity in modeling by adopting UML use cases and class models into the conceptual thinging machine (TM) model. To apply use cases, we adopt the observation that a use-case diagram is a description that shows the internal structure of the part of the system represented by the use case in addition to being useful to people outside of the system. Additionally, the UML class diagram is recast in TM representation. Accordingly, we develop a TMUML model that embraces the TM specification of the UML class diagram and the internal structure extracted from the UML use case. TMUML modeling introduces some of the advantages that have made UML a popular modeling language to TM modeling. At the same time, this approach supplies UML with partial model singularity. The paper details experimentation with TMUML using examples from the literature. Our results indicate that mixing UML with other models could be a viable approach.

• Journal of Intelligence and Information Systems
• /
• v.22 no.4
• /
• pp.1-18
• /
• 2016

Collaborative Filtering (CF) predicts the focal user's preference for particular item based on user's preference rating data and recommends items for the similar users by using them. It is a popular technique for the personalization in e-commerce to reduce information overload. However, it has some limitations including sparsity and scalability problems. In this paper, we use a method to integrate social network information into collaborative filtering in order to mitigate the sparsity and scalability problems which are major limitations of typical collaborative filtering and reflect the user's qualitative and emotional information in recommendation process. In this paper, we use a novel recommendation algorithm which is integrated with collaborative filtering by using Social SVD++ algorithm which considers social network information in SVD++, an extension algorithm that can reflect implicit information in singular value decomposition (SVD). In particular, this study will evaluate the performance of the model by reflecting the real-world user's social network information in the recommendation process.

• Journal of applied mathematics & informatics
• /
• v.7 no.2
• /
• pp.493-506
• /
• 2000

Recently the first author and his coworker report a new finite element method for the Poisson equations with homogeneous Dirichlet boundary conditions on a polygonal domain with one re-entrant angle [7], They use the well-known fact that the solution of such problem has a singular representation, deduced a well-posed new variational problem for a regular part of solution and an extraction formula for the so-called stress intensity factor using tow cut-off functions. They use Fredholm alternative an Garding's inequality to establish the well-posedness of the variational problem and finite element approximation, so there is a maximum bound for mesh h theoretically. although the numerical experiments shows the convergence for every reasonable h with reasonable size y imposing a restriction to the support of the extra cut-off function without using Garding's inequality. We also give error analysis with similar results.

• Journal of applied mathematics & informatics
• /
• v.42 no.2
• /
• pp.321-331
• /
• 2024

We consider the numerical treatment of blow-up problems having non-monotonic singular solutions that tend to infinity at some point in the domain. The use of standard numerical methods for solving problems with blow-up solutions can lead to significant errors. The reason being that solutions of such problems have singularities whose positions are unknown in advance. To be able to integrate such non-monotonic blow-up problems, we describe and use a method of non-local transformations. To show the efficiency of the method, we present a comparison of exact and numerical solutions in addition to some comparison with the work of other authors.

• Iberoamérica
• /
• v.23 no.1
• /
• pp.1-31
• /
• 2021

The main purpose of this study is to examine the use of 'a gente' in Portuguese, and to discuss what to consider educationally. We examined the origin and style of 'a gente', grammaticalization process phase, personalization level, and variations in use in terms of linguistic and social aspects, and confirmed that 'a gente' is showing an increasingly high frequency of use in Brazil. And in order to find educational considerations, we observed how 'a gente' was handled in Portuguese textbooks for foreigners, and analyzed data obtained through interviews with three Korean students studying Portuguese in Brazil. Considering the importance and frequency of use of 'a gente', which is used in the third-person singular form, the section about 'a gente' in grammar and textbooks seems to be very insufficient. Therefore, the contents of textbooks that do not correspond to the actual use of language should be actively revised according to changes in the reality of language use. In addition, the instructor should not be bound by traditional use, but must include 'a gente' in the personal pronoun section of the textbook for efficient education, and actively reflect the more practical usage to educate.

• Journal of Biomedical Engineering Research
• /
• v.24 no.5
• /
• pp.459-464
• /
• 2003

The source current distribution in a heart was reconstructed from the magnetocardiogram (MCG) and its clinical usefulness was demonstrated. MCG was measured using 40-channel superconducting quantum interference device (SQUID) gradiometers for a patient of Wolff-Parkinson-White (WPW) syndrome, which has an accessory pathway between the atria and the ventricles. Reconstruction of source current distribution in a plane below the chest surface was performed using minimum norm estimation (MNE) algorithm and truncated singular value decomposition (SVD), In the simulation, we confirmed that the current distributions. which were computed for the test dipoles, represented well the essential feature of the test current configurations, In the current map of WPW syndrome, we observed abnormal currents that would bypass the atrioventricular junction at a delta wave. However, we could not observe such currents any more after the surgery. These results showed that the obtained current distribution using MCG signals is consistent with the electrical activity in a heart and has clinical usefulness.

• Journal of Astronomy and Space Sciences
• /
• v.5 no.2
• /
• pp.111-122
• /
• 1988

The short and long periodic perturbations and secular perturbation due to the geopotentials of degree $J_2$ and $J_3$ which affect orbital elements of a near-circular orbiting satellite are obtained by the analytical method. The singular points due to a small denominator e in the perturbation equations can be excluded using one of the methods introduced by Taff(1985), which substitutes $e_s=esin\omega,\;e_c=ecos\omega\;and\;\ell=\omega+M$ for the orbital elements e, $\omega$ and M. We determined the mean orbital elements of the meteorological satellite NOAA-10 using the Walter (1967)'s iterative procedure and compared with Brouwer's mean orbital elements determined at NASA. The mean orbital elements a, ⅰand $\Omega$ are consistent with those of NASA but the mean orgital elements e, $\omega$ and M have some deviations from those of NASA. According to the our results, it is not suitable for the polar orbiting satellites to use the Taff's proposal for excluding the singular points, which substitutes e, $\omega$ and M by $e_s=esin(\Omega+\omega),\;e_c=ecos(\Omega+\omega)\;and\;L=\Omega+\omega+M$.

• Journal of the Korean housing association
• /
• v.21 no.4
• /
• pp.99-109
• /
• 2010

The purpose of this study is to provide basic data needed for planning apartment community spaces in order to vitalize rental apartments. Indoor community spaces of 12 rental apartments in Seoul and Kyunggi were examined. The results are as follows. First, the layout types of indoor community spaces in rental apartment complexes were found out to be mostly the building type planned in the piloties of the apartment, or the singular type placed in a singular building. Depending on the layout type, the spaces were mostly concentrated at the outskirt of the complex or the in-between space of the main building, thus lowering their recognition. Thereby, they were not satisfactory for utilization of the spaces and association of residents. Second, Indoor community space legal establishment standard and square measure did not reflect resident's feature except elderly spaces, and there was problem in activation of space. Third, as for the spatial planning of indoor community space, although each space was categorized by the users' age, the furniture and appliance planning considering users was not satisfactory. The area calculation by the type of space did not reflect the users' characteristics, thus causing problems in using the facilities. Fourth, as for the management and programs of the indoor community space, spaces were managed after categorized by the major user classes such as children, seniors, and adolescents. Depending on eagerness of program managers of each apartment complex, the level of program management varied. The survey results showed that, in most cases, almost no programs were used or merely basic management and programs were being provided.

• Journal of the Korean Society for information Management
• /
• v.38 no.2
• /
• pp.113-127
• /
• 2021

The purpose of this study is to propose a personalized book recommendation system to promote the use of university libraries. In particular, unlike many recommended services that are based on existing users' preferences, this study proposes a method that derive evaluation metrics using individual users' book rental history and tendencies, which can be an effective alternative when users' preferences are not available. This study suggests models using two matrix decomposition methods: Singular Value Decomposition(SVD) and Stochastic Gradient Descent(SGD) that recommend books to users in a way that yields an expected preference score for books that have not yet been read by them. In addition, the model was implemented using a user-based collaborative filtering algorithm by referring to book rental history of other users that have high similarities with the target user. Finally, user evaluation was conducted for the three models using the derived evaluation metrics. Each of the three models recommended five books to users who can either accept or reject the recommendations as the way to evaluate the models.