• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.100-104
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• 2003

The SVDD(support vector data description) is one of the most well-known one-class support vector learning methods, in which one tries the strategy of utilizing balls defined on the kernel feature space in order to distinguish a set of normal data from all other possible abnormal objects. The major concern of this paper is to consider the problem of modifying the SVDD into the direction of utilizing ellipsoids instead of balls in order to enable better classification performance. After a brief review about the original SVDD method, this paper establishes a new method utilizing ellipsoids in feature space, and presents a solution in the form of SDP(semi-definite programming) which is an optimization problem based on linear matrix inequalities.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.222-228
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• 2019

In recent years, in order to enhance the problem-solving skills required by the industrial field, universities have introduced the Problem-Based Learning(PBL) method to solve the problems caused by the lack of creativity, problem solving ability and self-directed learning. This study applied PBL class methods such as 'learning based on individual specific problems', 'self-directed learning', and 'small-group learning of small members' to practical design of fashion design. To do this, I conducted a questionnaire after conducting research based on the PBL module for one semester in a practical class of fashion design major at P University. As a result of the survey, the satisfaction and achievement of the class conducted by PBL learning method was improved than the existing teaching method. As such, if PBL class is used as a way of solving problems through close communication between professors and learners, it is expected to be established as a learner-centered education method that can improve creativity and professionalism.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.278-283
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• 2013

Background: Problem-based learning (PBL) has introduced as an important part of pharmacy education in Korea as it is effective method to help students gain and apply knowledge with development of problem-solving, critical-thinking, and decision-making skills. In order to provide the effective PBL, a number of trained facilitators and suitable PBL rooms are required. However, these become a barrier in Korea as most pharmacy schools have one or two faculty members who majored in clinical pharmacy. Objective: This study was performed to implement and evaluate a modified PBL in gastrointestinal (GI) pharmacotherapy class facilitated by one instructor. Methods: A general information of traditional PBL for 6 hours through 3 days is introduced before initiating GI pharmacotherapy class. After 3 hour-GI pharmacotherapy classes for 6 weeks, modified PBL was implemented with one instructor to facilitate PBL for four small groups with 19 pharmacy students simultaneously. Modified PBL was incorporated with weekly mini-case discussion and presentation. Results: Students completed 15-question survey to evaluate modified PBL course, student performance, group performance, and facilitator performance. Eighty-four percent of students answered modified PBL was helpful to understand what they have learned. Mean score in group performance was higher than that of individual performance during modified PBL course. Overall, students reported modified PBL was useful in knowledge building. Conclusion: Modified PBL model without individual group facilitators in one classroom helped students to achieve self-directed, independent learning skills in an interactive and engaging environment.

• Management Science and Financial Engineering
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• v.16 no.1
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• pp.47-57
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• 2010

We present a new integer programming formulation and a class of valid inequalities for solving the one-dimensional facility layout problem, which leads to a very efficient solution method for the problem.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.47-56
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• 1994

The dynamic feedback is well-known to be much more powerful tool in control than the static one. This paper deals with the dynamic feedback linearization of the nonlinear systems which are not (static) feedback linearizable. The dynamic feedback linearization problem is however too difficult to solve at momemt. Thus we introduce a restricted class of the dynamic feedback (pure integrators followed by the static feedback) which is often used to study the problems using dynamic feedback and obtain the necessary and sufficient conditions of the linearization problem using this class of the dynamic feedback.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.439-446
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• 2015

Recently, the importance of one-class classification problem is more increasing. However, most of existing algorithms have the limitation on providing the information that effects on the prediction of the target value. Motivated by this remark, in this paper, we suggest an efficient one-class classifier using hyper-rectangles (H-RTGLs) that can be produced from intervals including observations. Specifically, we generate intervals for each feature and integrate them. For generating intervals, we consider two approaches : (i) interval merging and (ii) clustering. We evaluate the performance of the suggested methods by computing classification accuracy using area under the roc curve and compare them with other one-class classification algorithms using four datasets from UCI repository. Since H-RTGLs constructed for a given data set enable classification factors to be visible, we can discern which features effect on the classification result and extract patterns that a data set originally has.

• Kyungpook Mathematical Journal
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• v.56 no.1
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• pp.121-123
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• 2016

In this paper, we compute the number of distinct centralizers and commutativity degree of a class of finite groups. These computations produce a further class of examples of groups answering one question raised by Belcastro and Sherman and another one raised by Lescot.

• Nonlinear Functional Analysis and Applications
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• v.27 no.4
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• pp.813-837
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• 2022

In this paper we consider inverse problem for a general class of nonlinear stochastic differential equations on Hilbert spaces whose generating operators (drift, diffusion and jump kernels) are unknown. We introduce a class of function spaces and put a suitable topology on such spaces and prove existence of optimal generating operators from these spaces. We present also necessary conditions of optimality including an algorithm and its convergence whereby one can construct the optimal generators (drift, diffusion and jump kernel).

• East Asian mathematical journal
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• v.37 no.5
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• pp.613-617
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• 2021

Abstract. For a positive square-free integer m, let K = ℚ($\sqrt{m}$) be a real quadratic field. The relative class number H_d(f) of K of discriminant d is the ratio of class numbers 𝒪_K and 𝒪_f, where 𝒪_K is the ring of integers of K and 𝒪_f is the order of conductor f given by ℤ + f𝒪_K. In 1856, Dirichlet showed that for certain m there exists an infinite number of f such that the relative class number H_d(f) is one. But it remained open as to whether there exists such an f for each m. In this paper, we give a result for existence of real quadratic field ℚ($\sqrt{m}$) with relative class number one where the period of continued fraction expansion of $\sqrt{m}$ is 6.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.351-361
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• 2008

This paper presents a delay-margin based traffic engineering (TE) approach to provide end-to-end quality of service (QoS) in multi-protocol label switching (MPLS) networks using differentiated services (DiffServ) at the link level. The TE, including delay, class, and route assignments, is formulated as a nonlinear optimization problem reflecting the inter-class and inter-link dependency introduced by DiffServ and end-to-end QoS requirements. Three algorithms are used to provide a solution to the problem: The first two, centralized offline route configuration and link-class delay assignment, operate in the convex areas of the feasible region to consecutively reduce the objective function using a per-link per-class decomposition of the objective function gradient. The third one is a heuristic that promotes/demotes connections at different links in order to deal with concave areas that may be produced by a trunk route usage of more than one class on a given link. Approximations of the three algorithms suitable for on-line distributed TE operation are also derived. Simulation is used to show that proposed approach can increase the number of users while maintaining end-to-end QoS requirements.