• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.766-768
• /
• 2005

Interstate electric power system, as an alternative for energy cooperation under regional economic bloc, has been hotly debated before progressing the restructure in electric power industry and rapidly expanded in many regions after 1990s. Especially, since northeast asia has strong supplementation in resource, load shape, fuel mix etc., interconnection of electric power systems in this region may bring considerable economic benefits. For the economic analysis, we implement ORIRES model developed by ESI, Russia. ORIRES is a linear programming (LP) model for electric power system operation and planning. Since ORIRES requires data relatively less than other model, it is suitable for northeast asia that has considerable restriction against required data acquisition. In this paper, we perform an economic analysis on interconnection in northeast asia.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.366-368
• /
• 2002

This paper presents a technique that can obtain an optimal solution for the Security-Constrained Economic Dispatch (SCED) problems using the Interior Point Method (IPM) while taking into account of the power flow constraints. The SCED equations are formulated by using only the real power flow equations from the optimal power flow. Then an algorithm is presented that can linearize the SCED equations based on the relationships among generation real power outputs, loads, and transmission losses to obtain the optimal solutions by applying the linear programming (LP) technique. Finally, the application of the Primal Interior Point Method (PIPM) for solving the optimization problem based on the proposed linearized objective function is presented. The results are compared with the Simplex Method and the Promising results ard obtained.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.04a
• /
• pp.96-103
• /
• 2000

This research is a new design method, which will be presented as a basic concept for a more efficient minimum weight design of grillages, as an attempt to describe true collapse mechanism in as overall search as possible. It serves as introduction to the numerical technique of Linear Programming(LP) and Automatic Modified Direct Plastic Frame Analysis(AMDPFA). Attention is directed to both analysis and design, and emphasis is placed on the physical significance of Systematic Searching Techniques(SST) involved. In weight minimum grillages design, the parameterisation study in optimum beam configuration which was carried out over the range of beam sections for a given plastic section modulus likely to occur in structures by suing an adaptive stochastic optimisation technique, Genetic Algorithms.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.24-29
• /
• 1996

If the LP problem doesn't have the optimal soultion uniquely, the solution fo the primal-dual barrier method converges to the interior point of the optimal face. Therefore, when the optimal vertex solution or the optimal basis is required, we have to perform the additional procedure to recover the optimal basis from the final solution of the interior point method. In this paper the exisiting methods for recovering the optimal basis or identifying the optimal solutions are analyzed and the new methods are suggested. This paper treats the two optimal basis recovery methods. One uses the purification scheme and the simplex method, the other uses the optimal face solutions. In the method using the purification procedure and the simplex method, the basic feasible solution is obtained from the given interior solution and then simplex method is performed for recovering the optimal basis. In the method using the optimal face solutions, the optimal basis in the primal-dual barrier method is constructed by intergrating the optimal solution identification technique and the optimal basis extracting method from the primal-optimal soltion and the dual-optimal solution.

• Structural Engineering and Mechanics
• /
• v.88 no.6
• /
• pp.535-549
• /
• 2023

Deep extreme learning machine (DELM) and multi-verse optimization algorithms (MVO) are hybridized for designing an optimal and adaptive control framework for uncertain buildings. In this approach, first, a robust model predictive control (RMPC) scheme is developed to handle the problem uncertainty. The optimality and adaptivity of the proposed controller are provided by the optimal determination of the tunning weights of the linear programming (LP) cost function for clustered external loads using the MVO. The final control policy is achieved by collecting the clustered data and training them by DELM. The efficiency of the introduced control scheme is demonstrated by the numerical simulation of a ten-story benchmark building subjected to earthquake excitations. The results represent the capability of the proposed framework compared to robust MPC (RMPC), conventional MPC (CMPC), and conventional DELM algorithms in structural motion control.

• Journal of Energy Engineering
• /
• v.25 no.3
• /
• pp.114-129
• /
• 2016

Since the release of mid-term domestic GHG goals until 2020, in 2009, some various GHG reduction policies have been proposed to reduce the emission rate about 30% compared to BAU scenario. There are two types of modeling approaches for identifying options required to meet greenhouse gas (GHG) abatement targets and assessing their economic impacts: top-down and bottom-up models. Examples of the bottom-up optimization models include MARKAL, MESSAGE, LEAP, and AIM, all of which are developed based on linear programming (LP) with a few differences in user interface and database utilization. The bottom-up model for electric sector requires demand management, regeneration energy mix, fuel conversation, etc., thus it has a very complex aspect to estimate some various policies. In this paper, we suggest a bottom-up BAU model for electric sector and how we can build it through step-by-step procedures such that includes load region, hydro-dam and pumping storage.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.402-402
• /
• 2019

최근 기후변화에 따른 용수사용량의 계절별 변화가 나타나고 있다. 따라서, 효율적인 용수 관리에 대한 관심은 배수지 및 송수 시스템의 운영을 넘어 정수장의 운영에서도 그 변화가 나타나고 있다. 수질관리 측면에 다소 집중되었던 정수장 운영의 중요도는 수량을 함께 관리하는 방향으로 변화할 것으로 전망되며, 따라서 취수 단계에서부터 용수 공급의 전 과정을 고려하는 지능형 정수장 관리시스템이 주목받고 있다. 상수도 공급을 위한 정수장의 운영은 크게 원수의 취수 및 도수, 정수처리, 정수된 용수의 저장, 배수 및 급수의 과정으로 구분할 수 있다. 이때, 원수의 취수와 도수, 정수처리 과정에는 상대적으로 긴 시간이 소요되므로, 정수장의 운영 관리자는 이러한 지연시간을 감안해서 배수지의 상태를 예측하여 취수계획을 결정해야 한다. 한편, 정수장 시설을 운영하기 위해서는 전력이 소모되며, 산업전력 단가는 시간대별 변동폭이 큰 것으로 알려져 있다. 따라서, 정수장의 효율적인 운영을 위해서는 용수의 수요예측과 배수지 수위변동, 취수 및 정수설비의 규모 등을 고려하는 동시에, 전력 단가가 낮은 시간대에 설비를 집중적으로 운영할 수 있는 계획을 수립해야 한다. 본 연구에서는 선형계획법(Linear Programming, LP)을 이용하여, 수요예측을 바탕으로 장기취수계획을 수립하기 위한 방안을 세 가지로 구분하였으며, 각각의 장단점을 다음과 같이 예상하였다. 1) 24시간 간격으로 시간당 취수계획을 수립하는 최적화 방안, 2) 24시간의 시간당 취수계획을 1시간 간격으로 수립하는 실시간 최적화 방안, 3) 전체 모의기간 동안의 시간당 취수계획을 한번에 수립하는 최적화 방안. 24시간 간격 최적화는 수립 및 적용이 간단한 반면, 실시간 수요변화를 고려할 수 없어 단위시간(24시간) 후반부의 최적화 효율이 떨어지는 단점이 있다. 1시간 간격의 실시간 최적화는 수요변화를 가장 정확히 반영하는 반면, 최적화 수행 횟수가 증가하는 단점이 있다. 전체 모의기간 최적화는 장기 수요예측을 고려한 탄력적 취수계획을 수립하는 반면, 수요예측의 불확실성에 따른 오차 발생위험이 크다. 본 연구에서는 국내 H 정수장을 대상으로 각각의 최적 취수계획 수립 방안을 정수장 운영의 안정성, 탄력성, 경제성 등을 기준으로 비교, 분석하였다.

• The KIPS Transactions:PartC
• /
• v.15C no.4
• /
• pp.273-280
• /
• 2008

In WSN(Wireless Sensor Network) many routing algorithms such as LEACH, PEGASIS and PEDEP consisting of sensor nodes with limited energy have been proposed to extend WSN lifetime. Under the assumption of perfect fusion, these algorithms used convergecast that periodically collects sensed data from all sensor nodes to a base station. But because these schemes studied less energy consumption for a convergecast as well as fairly energy consumption altogether, the minimum energy consumption for a convergecast was not focused enough nor how topology influences to energy consumption. This paper deals with routing topology and energy consumption for a single convergecast in the following ways. We chose major WSN topology as MSC(Minimum Spanning Chain)s, MSTs, PEGASIS chains and proposed LECSEN chains. We solved the MSC length by Linear Programming(LP) and propose the LECSEN chain to compete with MST and MSC. As a result of simulation by Monte Carlo method for calculation of the topology length and standard deviation of link length, we learned that LECSEN is competitive with MST in terms of total energy consumption and shows the best with the view of even energy consumption at the sensor nodes. Thus, we concluded LECSEN is a very useful routing topology in WSN.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37B no.9
• /
• pp.734-740
• /
• 2012

In this paper, we propose a method for throughput improvement in multirate multihop wireless networks with intra-session network coding. A multirate transmission supports several rates so that it has a tradeoff between transmission rate and transmission range, therefore multirate can cope with the performance degradation. We present the rate selection method with intra-session network coding in multirate nodes. The effective transmission rate is calculated by using intra-session network coding, and then its maximum effective transmission rate is selected. Concurrent transmission set is determined by selected transmission rate and then the linear programming is formulated for throughput calculation in multihop wireless networks. We evaluate the performance by using MATLAB and lp_solve programs in two topologies. It is shown that the throughput of the proposed method is improved.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.2
• /
• pp.173-182
• /
• 1993

This paper presents an algorithm to derive the representative unit hydrograph for the real environment of a watershed. For a given watershed, the conventional methods give several different unit hydrographs by storm events. In this study the LP model is somewhat modified based on the previous study by Mays et also as follows: the objective function is designed to minimize the sum of weighted residuals. An additional constraint of moving average is added to prevent the unit hydrograph from the occurence of oscillation which was not active in Mays's paper. Configuration of rainfall matrix was improved to reduce its dimension in accordance with Diskin's review point. In spite of the superiority of LP approach in terms of representativeness, all the methods were very sensitive to the validity of baseflow separation and rainfall-loss. Several methods of the separations for rainfall excesses and direct runoffs were applied and no preferred methods were identified. This is the matter of judgement considering catchment and rainfall characteristics. This algorithm was applied to a real watershed of the Wi stream in the Nak-dong river. Compared with the IHP results by conventional methods, this optimized representative unit hydrograph demonstrated relatively smaller and shorter values in terms of the peak discharge and the basin lag respectively, and the oscillation of its falling limb successfully eliminated owing to the additional constraints of moving averages.