• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.97-113
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• 2004

In this paper we shall study moving boundary problems, and we introduce an approach for solving a wide range of them by using calculus of variations and optimization. First, we transform the problem equivalently into an optimal control problem by defining an objective function and artificial control functions. By using measure theory, the new problem is modified into one consisting of the minimization of a linear functional over a set of Radon measures; then we obtain an optimal measure which is then approximated by a finite combination of atomic measures and the problem converted to an infinite-dimensional linear programming. We approximate the infinite linear programming to a finite-dimensional linear programming. Then by using the solution of the latter problem we obtain an approximate solution for moving boundary function on specific time. Furthermore, we show the path of moving boundary from initial state to final state.

• Asian review of World Histories
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• v.3 no.1
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• pp.37-58
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• 2015

The paper examines, in the light of current historiography, the recent trends in the application and applicability of the World Historical studies on the Indian Ocean scenario. Calling for the combination of the breadth of the World Historical studies with the analysis of a historical scenario in its specific spatio-temporal context-instead of a synchronic approach-the present study takes a close look at commerce and politics in the western Indian Ocean in the light of an early 14th century Latin Crusade tract, How to Defeat the Saracens by William of Adam (Guillelmus Ade, Tractatus quomodo Sarraceni sunt expugnandi), a Dominican friar. The text offers remarkable insights into the interlocking of the Indian Ocean and the South Asian subcontinent with the Mamluk Sultanate, the Ilkhanid realm and the Crusades. The paper argues for what is now termed as braided and connected histories.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2871-2877
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• 2013

Objectives: To evaluate the safety, efficacy, and invasiveness of lobectomy by video-assisted thoracoscopic surgery (VATS) in the treatment of stage I/II non-small cell lung cancer (NSCLC). Methods: A total of 148 patients presenting with Stage I or II NSCLC were enrolled into our study, comprising 71 who underwent VATS and 77 patients undergoing conventional thoracotomic lobectomy, in combination with systematic lymph node resection. Results: It was found that VATS was superior to conventional thoracotomy in terms of the duration of surgery, intraoperative blood loss, frequency of the need to administer postoperative analgesia, thoracic intubation indwelling time, post-operative hospital stay, and survival rate (P<0.05). We saw no obvious difference in the number of resected lymph nodes with either approach. Conclusions: VATS lobectomy is a safe and reliable surgical approach for the treatment of Stage I/II NSCLC, characterized by significantly minimal invasiveness, rapid post-operative recovery, and markedly lower loss of blood.

• International Journal of Contents
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• v.2 no.1
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• pp.17-21
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• 2006

In this paper, we describe a concept-based question-answering system in which concept rather than keyword itself makes an important role on both question analysis and answer extraction. Our idea is that concepts occurred in same type of questions are similar, and if a question is analyzed according to those concepts then we can extract more accurate answer because we know the semantic role of each word or phrase in question. Concept frame is defined for each type of question, and it is composed of important concepts in that question type. Currently the number of question type is 79 including 34 types for person, 14 types for location, and so on. We experiment this concept-based approach about questions which require person s name as their answer. Experimental results show that our system has high accuracy in answer extraction. Also, this concept-based approach can be used in combination with conventional approaches.

• Journal of applied mathematics & informatics
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• v.28 no.3_4
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• pp.697-710
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• 2010

In this paper, we prove existence of infinitely many positive and concave solutions, by means of a simple approach, to $3^{th}$ order three-point singular boundary value problem {$x^{\prime\prime\prime}(t)=\alpha(t)f(t,x(t))$, 0 < t < 1, $x(0)=x'(\eta)=x^{\prime\prime}(1)=0$, (1/2 < $\eta$ < 1). Moreover with respect to multiplicity of solutions, we don't assume any monotonicity on the nonlinearity. We rely on a combination of the analysis of the corresponding vector field on the phase-space along with Knesser's type properties of the solutions funnel and the well-known Krasnosel'ski$\breve{i}$'s fixed point theorem. The later is applied on a new very simple cone K, just on the plane $R^2$. These extensions justify the efficiency of our new approach compared to the commonly used one, where the cone $K\;{\subset}\;C$ ([0, 1], $\mathbb{R}$) and the existence of a positive Green's function is a necessity.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.80-89
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• 2014

A stochastic optimal power flow (S-OPF) model considering uncertainties of load and wind power is developed based on chance constrained programming (CCP). The difficulties in solving the model are the nonlinearity and probabilistic constraints. In this paper, a limit relaxation approach and an iterative learning control (ILC) method are implemented to solve the S-OPF model indirectly. The limit relaxation approach narrows the solution space by introducing regulatory factors, according to the relationship between the constraint equations and the optimization variables. The regulatory factors are designed by ILC method to ensure the optimality of final solution under a predefined confidence level. The optimization algorithm for S-OPF is completed based on the combination of limit relaxation and ILC and tested on the IEEE 14-bus system.

• Journal of Power System Engineering
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• v.8 no.4
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• pp.49-56
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• 2004

To design very large ships, such as very large drillships, we have to estimate the hydroelastic responses of the very large ships in waves. A numerical procedure is described for estimating the hydroelastic responses of very large ships advancing with slow speed in waves. The developed numerical approach is based on a combination of the three-dimensional source distribution method and the finite element method, including fluid-structure interaction by regarding a very large ship as many hull elements connected with elastic beam elements. Numerical results are compared with experimental and numerical ones obtained in the literature. The results of comparison confirmed the validity of the proposed approach.

• Journal of Power System Engineering
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• v.13 no.3
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• pp.59-64
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• 2009

This study presents a new approach to pressure control of a impression cylinder for roll coater which is a kind of face pressure control between blanket roll and impression roll. Roll-to-Roll method for printing is a very useful tool for mass production such as RFID elements, smart sensors and solar cell devices. In this study, a decupling control strategy of the roll coater which is a combination of a cylinder system, a dry system and two pressure regulators with two pneumatic cylinders was discussed. Also, the characteristics of component such as a pressure regulator having a pressure reducing function and the movement of a blanket roll and a impression cylinder were analyzed using the Matlab software. From this results, the techniques of a shock and a vibration reduction were suggested.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.1
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• pp.99-109
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• 2003

Attitude control law synthesis for the three-axis attitude maneuver of a flexible spacecraft model is presented in this study. The basic idea is motivated by previous works for the extension into a more general case. The new case includes gravitational gradient torque which has significant effect on a wide range of low earth orbit missions. As the first step, the fully nonlinear dynamic equations of motion are derived including gravitational gradient. The control law design based upon the Lyapunov approach is attempted. The Lyapunov function consists of a weighted combination of system kinetic and potential energy. Then, a set of stabilizing control law is derived from the basic Lyapunov stability theory. The new control law is therefore in a general form partially validating the previous work in some sense.

• Journal of the Korean housing association
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• v.19 no.1
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• pp.9-16
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• 2008

This study aims to construct the design competence by means of a topological approach. To this end, the linguistic concept of 'competence and performance' in Chomskian sense is borrowed and applied to the study. The usability of this method is then tested against the sample apartment plans from Gangnam-gu area in Seoul, and it is found that this enabled a middle-ground approach to a more productive grammar that overcomes the limits in Glassie's and Stiny's grammar systems. Through a series of analyses on the sample plans, it could be clarified that there appear classificatory levels in the competence that controls the planning of the building, zoning of the unit, and layout of LDK combination. At the end, it is evaluated that the generative grammar, constructed in this research, is the possible world in designers' minds, and this retrospective remodelling of the architectural competence could illuminate the 'design decision flow' that generates the sample plans.