• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.23 no.6
• /
• pp.1461-1470
• /
• 1998

Bit allocation or quantizer assigning problem is a basic and essential issue in lossy picture coding. It could be represented as minimizing overall distortion with the given constraint that total bits should not exceed allowed bit-budget. Optimal solution can be found by Lagrangian method. However this method needs much computational time and memory. This paper presents an approximation method that uses the activity measure. The comparison between the existing activity measuring techniques are made, and mapping function from activity value to the quantizer is proposed. Under MPEG-1 Intra coding situation, simulations show almost identical results compared to the optimal ones obtained by Lagrangian method with reduced computational time.

• Fashion & Textile Research Journal
• /
• v.10 no.3
• /
• pp.364-370
• /
• 2008

This research aims to recognize necessity of modern expression of traditional pattern, understand the matter which is expressed when developing design using traditional pattern, and find the solutions. As the solutions, this research presents design of traditional pattern using symmetry concept and works on the possibility of symmetry as the pattern design. So this research carried out in-depth interview to textile designer working at Gyeongsangnam-do, analyzed the substances. The main results are as follows. First, the presented problems of developing common pattern design and designing using traditional pattern show the necessities for adequate harmony among conception of creative idea, traditional pattern and present pattern. As the solution, the efficient design principles are required. Second, the seven traditional figures can present design applying symmetry, also draw the 8 mapping models for the visuality and utilization. Third, the symmetry-applied traditional pattern design makes it possible for the traditional figure to be represented with the creative and modern sense and provides easier way to the design development by complementing the pattern design formation. As the result, symmetry-utilized traditional pattern design improvement shows the expectation that it will increase the design development ability and ease the figure drawing. In addition, the pattern development which can be applied to any figure presents the time efficiency as well as possibility of the high added value textile industry.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.07b
• /
• pp.715-717
• /
• 2005

Support vector machine(SVM)은 최근 각광받는 기계학습 방법 중 하나로서, kernel function 이라는 사상(mapping)을 이용하여 입력 공간의 벡터를 classification이 용이한 특징 (feature) 공간의 벡터로 변환하는 것을 근간으로 한다. SVM은 이러한 특징 공간에서 두 클래스를 구분 짓는 hyperplane을 일련의 최적화 방법론을 사용하여 찾아내며, 주어진 문제가 convex problem 인 경우 항상 global optimal solution 을 보장하는 등의 장점을 지닌다. 한편 bioinformatics 연구에서 주로 사용되는 데이터는 측정 오류 등 일련의 오류를 포함하고 있으며, 이러한 오류는 기계학습 방법론이 어떤 decision boundary를 찾아내는가에 영향을 끼치게 된다. 특히 SVM의 경우 이러한 오류는 특징 공간 벡터간의 관계를 나타내는 Gram matrix를 변화로 나타나게 된다. 본 연구에서는 입력 공간에 오류가 발생할 때 그것이 SVM 의 decision boundary를 어떻게 변화시키는가를 대표적인 두 가지 kernel function, 즉 linear kernel과 Gaussian kernel에 대해 분석하였다. Wisconsin대학의 유방암(breast cancer) 데이터에 대해 실험한 결과, 데이터의 오류에 따른 SVM 의 classification 성능 변화 양상을 관찰하여 커널의 종류에 따라 SVM이 어떠한 특성을 보이는가를 밝혀낼 수 있었다. 또 흥미롭게도 어떤 조건 하에서는 오류가 크더라도 오히려 SVM 의 성능이 향상되는 것을 발견했는데, 이것은 바꾸어 생각하면 Gram matrix 의 일부를 변경하여 SVM 의 성능 향상을 꾀할 수 있음을 나타낸다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.12
• /
• pp.1899-1904
• /
• 2017

This paper presents a new one-time password approach generated based on $4{\times}4$ pattern schedule. It demonstrates generation of passkey from initial seed of random codes and mapping out in table pattern schedule which will produce a new form of OTP scheme in protecting information or data. The OTP-2FA has been recognized by many organizations as a landmark to authentication techniques. OTP is the solution to the shortcomings of the traditional user name/password authentication. With the application of OTP, some have benefited already while others have had second thoughts because of some considerations like cryptographic issue. This paper presents a new method of algorithmic approach based on table schedule (grid authentication). The generation of OTP will be based on the random parameters that will be mapped out in rows and columns allowing the user to form the XY values to get the appropriate values. The algorithm will capture the values and extract the predefined characters that produce the OTP codes. This scheme can work in any information verification system to enhance the security, trust and confidence of the user.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.8
• /
• pp.1377-1383
• /
• 2008

Parameterization of a 3D triangular mesh is a fundamental problem in various applications of geometric modeling and computer graphics. There are two major paradigms in mesh parameterization: energy functional minimization and the convex combination approach. In general, the convex combination approach is wifely used because of simple concept and one-to-one mapping. However, the approach has some problems such as high distortion near the boundary and time complexity. Moreover, the stability of the linear system may not be preserved according to the geometric information of the mesh. In this paper, we present an extension of the convex combination approach based on the mean value coordinates, which resolves the drawbacks of the convex combination approach. This may be a more practical solution because it is able to generate a stable linear system in a short time.

• Journal of Powder Materials
• /
• v.26 no.3
• /
• pp.220-224
• /
• 2019

The aluminum (Al)/copper oxide (CuO) complex is known as the most promising material for thermite reactions, releasing a high heat and pressure through ignition or thermal heating. To improve the reaction rate and wettability for handling safety, nanosized primary particles are applied on Al/CuO composite for energetic materials in explosives or propellants. Herein, graphene oxide (GO) is adopted for the Al/CuO composites as the functional supporting materials, preventing a phase-separation between solvent and composites, leading to a significantly enhanced reactivity. The characterizations of Al/CuO decorated on GO(Al/CuO/GO) are performed through scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy mapping analysis. Moreover, the functional bridging between Al/CuO and GO is suggested by identifying the chemical bonding with GO in X-ray photoelectron spectroscopy analysis. The reactivity of Al/CuO/GO composites is evaluated by comparing the maximum pressure and rate of the pressure increase of Al/CuO and Al/CuO/GO. The composites with a specific concentration of GO (10 wt%) demonstrate a well-dispersed mixture in hexane solution without phase separation.

• Nonlinear Functional Analysis and Applications
• /
• v.27 no.4
• /
• pp.709-730
• /
• 2022

We consider the nonlinear matrix equation (NMEs) of the form 𝓤 = 𝓠 + Σ^k_i=1 𝓐^*_iℏ(𝓤)𝓐_i, where 𝓠 is n × n Hermitian positive definite matrices (HPDS), 𝓐₁, 𝓐₂, . . . , 𝓐_m are n × n matrices, and ~ is a nonlinear self-mappings of the set of all Hermitian matrices which are continuous in the trace norm. We discuss a sufficient condition ensuring the existence of a unique positive definite solution of a given NME and demonstrate this sufficient condition for a NME 𝓤 = 𝓠 + 𝓐^*₁(𝓤²/900)𝓐₁ + 𝓐^*₂(𝓤²/900)𝓐₂ + 𝓐^*₃(𝓤²/900)𝓐₃. In order to do this, we define 𝓕𝓖_w-contractive conditions and derive fixed points results based on aforesaid contractive condition for a mapping in extended Branciari b-metric distance followed by two suitable examples. In addition, we introduce weak well-posed property, weak limit shadowing property and generalized Ulam-Hyers stability in the underlying space and related results.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.11a
• /
• pp.801-802
• /
• 2009

Currently, XML and its schema language have become the standard for data representation and information exchange format on the current web. Unfortunately, problems happen when integrating different data sources since XML mainly supports the document structure but lack consideration on sharing knowledge of data. Meanwhile, Semantic Web technologies, such as Web Ontology Language (OWL), can include the structure as well as the semantics of the data. Therefore, finding a way to integrate XML data as OWL ontology receives a high interest nowadays. In this paper we present a mapping notation to convert XML Schema to OWL domain knowledge and an effective method to transform XML instances into OWL individuals. While keeping the XML original structure, our work also adds more semantics for the XML document. Moreover, whole of the transformation processes are done automatically without any user interference. Further, our transforming approach provides the solution for duplicate element names in XML document which has not mentioned in the previous work. Our results in existing OWL syntaxes can be loaded immediately by OWL editors and Semantic Web applications.

• Nonlinear Functional Analysis and Applications
• /
• v.28 no.2
• /
• pp.497-520
• /
• 2023

Numerous problems in science and engineering defined by nonlinear functional equations can be solved by reducing them to an equivalent fixed point problem. Fixed point theory provides essential tools for solving problems arising in various branches of mathematical analysis, such as split feasibility problems, variational inequality problems, nonlinear optimization problems, equilibrium problems, complementarity problems, selection and matching problems, and problems of proving the existence of solution of integral and differential equations.The theory of fixed is known to find its applications in many fields of science and technology. For instance, the whole world has been profoundly impacted by the novel Coronavirus since 2019 and it is imperative to depict the spread of the coronavirus. Panda et al. [24] applied fractional derivatives to improve the 2019-nCoV/SARS-CoV-2 models, and by means of fixed point theory, existence and uniqueness of solutions of the models were proved. For more information on applications of fixed point theory to real life problems, authors should (see [6, 13, 24] and the references contained in).

• Nuclear Engineering and Technology
• /
• v.55 no.2
• /
• pp.769-779
• /
• 2023

This paper describes an hp-angular adaptivity algorithm in the discrete ordinates method for Boltzmann transport applications with strong angular effects. This adaptivity uses discontinuous finite element quadrature sets with different degrees, which updates both angular mesh and the degree of the underlying discontinuous finite element basis functions, allowing different angular local refinement to be applied in space. The regular and goal-based error metrics are considered in this algorithm to locate some regions to be refined. A mapping algorithm derived by moment conservation is developed to pass the angular solution between spatial regions with different quadrature sets. The proposed method is applied to some test problems that demonstrate the ability of this hp-angular adaptivity to resolve complex fluxes with relatively few angular unknowns. Results illustrate that a reduction to approximately 1/50 in quadrature ordinates for a given accuracy compared with uniform angular discretization. This method therefore offers a highly efficient angular adaptivity for investigating difficult particle transport problems.