• Steel and Composite Structures
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• v.21 no.5
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• pp.1121-1144
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• 2016

This paper presents a displacement-based finite element procedure for second-order distributed plasticity analysis of planar steel frames with semi-rigid beam-to-column connections under static loadings. A partially strain-hardening elastic-plastic beam-column element, which directly takes into account geometric nonlinearity, gradual yielding of material, and flexibility of semi-rigid connections, is proposed. The second-order effects and distributed plasticity are considered by dividing the member into several sub-elements and meshing the cross-section into several fibers. A new nonlinear solution procedure based on the combination of the Newton-Raphson equilibrium iterative algorithm and the constant work method for adjusting the incremental load factor is proposed for solving nonlinear equilibrium equations. The nonlinear inelastic behavior predicted by the proposed program compares well with previous studies. Coupling effects of three primary sources of nonlinearity, geometric imperfections, and residual stress are investigated and discussed in this paper.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.417-427
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• 2017

Power allocation is an important factor for cognitive radio networks to achieve higher communication capacity and faster equilibrium. This paper considers power allocation problem to each cognitive user to maximize capacity of the cognitive systems subject to the constraints on the total power of each cognitive user and the interference levels of the primary user. Since this power control problem can be formulated as a mixed-integer nonlinear programming (NP) equivalent to variational inequality (VI) problem in convex polyhedron which can be transformed into complementary problem (CP), we utilize modified projection method to solve this CP problem instead of finding NP solution and give a power control allocation algorithm with a subcarrier allocation scheme. Simulation results show that the proposed algorithm performs well and effectively reduces the system power consumption with almost maximum capacity while achieve Nash equilibrium.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.7-10
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• 2006

A quasi-equilibrium model is used in order to aid movement and ballistic analysis for a propellant actuated device(PAD) system. The validity of the model is examined by experiments of a PAD system. The appropriateness of its usage for application was explored by comparing the tendency of experiments and analysis results, and the coefficients of friction and heat loss were obtained. The design method developed will be applied to the design of PAD systems.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.1
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• pp.67-72
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• 2004

This paper addresses the bidding strategies of generating firms in a competitive market where the firms are provided with payment for generating reactive power. Reactive support for voltage control is an integral and critical part of power system operations. Since reactive support is unbundled in a competitive market under open access transmission, it is treated as one of ancillary services. The operation costs and opportunity costs for reactive support are compensated by payment to the firms, hence their bidding strategies will be affected. The opportunity costs are evaluated from the foregone profits of a generator in making sales in real power market by providing reactive support instead of real power. Game theory approach is used to analysis the transaction strategies of real power by the bimatrix method in this paper. Through computing the Nash equilibrium in a sample system, an incentive of a generator for improving the reactive generating capacity is found to be effective and the variations of the profits are analyzed as the demand power factor changes.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.167-174
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• 2000

Profiles of discontinuities through scanline method were investigated for the analysis of rock slope stability. Lower hemispheric projection method was used to evaluate the geometric stability and failure potential of these discontinuities. Also, safety factor was evaluated for the discontinuities of failure potential using by limit equilibrium analysis. Then, displacements of rock block due to the discontinuities were displayed by using the program UDEC(Universal Distinct Element Code) which applied the Distinct Element Method. When we determine the cut-slope in design, the characteristics of discontinuities is not represented only by strength parameters of intact rock. Therefore it is more reasonable method in assuring stability that first, construction would be preceded by the cut-slope of preliminary design, and then, cut-slope would be redetermined by elaborate site investigation in processing construction.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.483-490
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• 2002

This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement suggesting that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analysis were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of factor of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow rule are selected.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1226-1231
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• 2010

This paper looks at the influence of Financial Transmission Rights (FTRs) on the market value(Social Welfare; SW) in the competitive electricity market. The transmission line constraints make it difficult to compute the Nash Equilibrium (NE) due to causing a mixed strategy NE instead of a pure strategy NE. Computing a mixed strategy is more complicated in a multi-player game. The aim of this paper are to compute a mixed strategy NE and analyze SW in power transaction with FTRs. This paper introduces a formula and a technique for solving NE of multi-player game with FTRs. In addition, it analyzes the influence of holding of FTRs by generation company on SW and it proposes the SW at NE is influenced by Power Transfer Distribution Factor (PTDF) where holder of FTRs are located. The assertion is verified by calculating the mixed strategy utilizing the Cournot model widely used for studies on FTRs.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.675-685
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• 2013

Generation capacities and transmission line constraints in a competitive electricity market make it troublesome to compute Nash Equilibrium (NE) for analyzing participants' strategic generation quantities. The NE can cause a mixed strategy NE rather than a pure strategy NE resulting in a more complicated computation of NE, especially in a multiplayer game. A two-level hierarchical optimization problem is used to model competition among multiple participants. There are difficulties in using a mathematical programming approach to solve a mixed strategy NE. This paper presents heuristics applied to the mathematical programming method for dealing with the constraints on generation capacities and transmission line flows. A new formulation based on the heuristics is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations.

• East Asian Economic Review
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• v.25 no.3
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• pp.233-272
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• 2021

The Regional Comprehensive Economic Partnership (RCEP) agreement, signed in November 2020, comes shortly after the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) entered into force and the US-China Trade War escalated. We use a computable general equilibrium model to assess the long-term effects of these three developments on income, trade, economic structure, factor returns and employment across the world, and especially in Asia-Pacific countries. The results suggest that RCEP could generate income gains that will be almost twice as large as those of the CPTPP, and that the two agreements together will largely offset the substantial negative effects of the US-China Trade War for the world as a whole. All three policy developments, but especially RCEP, will deepen East Asian production networks and will raise productivity and increase wages and employment in much of East Asia. At the sectoral level, regional trade in non-durable and durable manufactures will experience the most growth.

• Journal of the Korean Professional Engineers Association
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• v.19 no.1
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• pp.3-11
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• 1986

The analysis of Geotechnical stability problems by the limit equilibrium method involve assuming the shape of the failure and then investigating many surfaces of the shape to identify the one on which failure seems most likely to occur. These arbitrary assumptions most frequently concern to the locations or directions of side force on slice and the overall factor of safety is considered identical to the local factor of safety. In this paper, let the factor of safety of a slope at wedge block stage differently, when an upper part of the potential sliding mass has a simple active stress field and the lower part of the passive stress field and overall factor of safety is obtained by the average of local factor and computer program based on the modified wedge Method is proposed for this thesis. The new algorithm based on tile modified new method is made for estimating the safety factor of Earth Dam. Compared with conventional method for many cases tile average values of the factor of safety determined by the modified new method are very nearly the same. For all of the cases studied the difference was found 0.03. Finally this new method is thought to be very useful in slope stability analysis.