• 제목/요약/키워드: approaches

검색결과 13,507건 처리시간 0.041초

Multi-Objective Soft Computing-Based Approaches to Optimize Inventory-Queuing-Pricing Problem under Fuzzy Considerations

  • Alinezhad, Alireza;Mahmoudi, Amin;Hajipour, Vahid
    • Industrial Engineering and Management Systems
    • /
    • 제15권4호
    • /
    • pp.354-363
    • /
    • 2016
  • Due to uncertain environment, various parameters such as price, queuing length, warranty, and so on influence on inventory models. In this paper, an inventory-queuing-pricing problem with continuous review inventory control policy and batch arrival queuing approach, is presented. To best of our knowledge, (I) demand function is stochastic and price dependent; (II) due to the uncertainty in real-world situations, a fuzzy programming approach is applied. Therefore, the presented model with goal of maximizing total profit of system analyzes the price and order quantity decision variables. Since the proposed model belongs to NP-hard problems, Pareto-based approaches based on non-dominated ranking and sorting genetic algorithm are proposed and justified to solve the model. Several numerical illustrations are generated to demonstrate the model validity and algorithms performance. The results showed the applicability and robustness of the proposed soft-computing-based approaches to analyze the problem.

우편요금제에 기초한 전력탁송 요금의 계산 (Evaluation of Power Wheeling Costs Based on the Postage Stamp Method)

  • 박종배;김발호;임주성;이상철
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 하계학술대회 논문집 C
    • /
    • pp.1015-1019
    • /
    • 1998
  • This paper presents the evaluation results of Korea Electric Power Corporation (KEPCO) system's power wheeling costs based on the postage stamp method. The results of several postage-stamp-based methodologies are compared where some of them are the conventional approaches. others are new approaches suggested in this paper. The approaches developed in this paper are suitable for a system where transmission transactions are occurred within a vertically integrated power system just like as Korea, Japan. etc. Also, they can overcome limitations related on the depreciation costs application. Test results show that the computed wheeling costs are around 4.0 [won/kWh] in 1995, and it is anticipated that the cost will increase when considering transmission network losses and ancillary costs.

  • PDF

전단벽구조체에 대한 변위기반 내진성능법의 평가 (Evaluation of Displacement-based Approaches for a Shear Wall Structure)

  • 최상현;현창헌;최강룡;김문수
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
    • /
    • pp.465-472
    • /
    • 2003
  • In this paper, the displacement-based seismic design approaches are evaluated utilizing shaking-table test data of a 1:3 scaled reinforced concrete (RC) bearing wall structure Provided by IAEA. The maximum responses of the structure are estimated using the two prominent displacement-based approaches, i.e., the capacity spectrum method and the displacement coefficient method, and compared with the measured responses. For comparison purpose, linear and nonlinear time history analyses and response spectrum analysis are also performed. The results indicate that the capacity spectrum method underestimates the response of the structure In inelastic range while the displacement coefficient method yields reasonable values in general.

  • PDF

Joint Beamforming and Jamming for Physical Layer Security

  • Myung, Jungho;Heo, Hwanjo;Park, Jongdae
    • ETRI Journal
    • /
    • 제37권5호
    • /
    • pp.898-905
    • /
    • 2015
  • In this paper, we consider a joint beamforming and jamming design to enhance physical layer security against potential multiple eavesdroppers in a multiple-input and single-output cellular broadcast channel. With perfect channel state information at the base station, we propose various design approaches to improve the secrecy of the target user. Among the proposed approaches, the combined beamforming of maximum ratio transmission and zero-forcing transmission with a combination of maximum ratio jamming and zero-forcing jamming (MRT + ZFT with MRJ + ZFJ) shows the best security performance because it utilizes the full transmit antenna dimensions for beamforming and jamming with an efficient power allocation. The simulation results show that the secrecy rate of this particular proposed approach is better than the rates of the considered conventional approaches with quality-of-service and outage probability constraints.

정밀부품의 비접촉 자동검사기술 개발 (Development of Non-Contacting Automatic Inspection Technology of Precise Parts)

  • 이우송;한성현
    • 한국공작기계학회논문집
    • /
    • 제16권6호
    • /
    • pp.110-116
    • /
    • 2007
  • This paper presents a new technique to implement the real-time recognition for shapes and model number of parts based on an active vision approach. The main focus of this paper is to apply a technique of 3D object recognition for non-contacting inspection of the shape and the external form state of precision parts based on the pattern recognition. In the field of computer vision, there have been many kinds of object recognition approaches. And most of these approaches focus on a method of recognition using a given input image (passive vision). It is, however, hard to recognize an object from model objects that have similar aspects each other. Recently, it has been perceived that an active vision is one of hopeful approaches to realize a robust object recognition system. The performance is illustrated by experiment for several parts and models.

Job Shop 작업계획의 실제적 접근을 위한 할당규칙 (The New Dispatching Rules for Practical Approaches of Job Shop Scheduling)

  • 배상윤
    • 산업경영시스템학회지
    • /
    • 제25권3호
    • /
    • pp.41-49
    • /
    • 2002
  • In the study, for the practical approaches of job shop scheduling, we propose the new dispatching rules of job shop scheduling in order to complement the practical applications in the existing researches. The assumed situation for the practical approaches considers the following; relaxation of assumption for capacity constraint by machine flexibility, the addition of the common use of jig and fixture, unbalanced machine workloads and duedate tightness, and produces fast rescheduling that reflects unexpected situations. The performance of the new dispatching rules is compared and analyzed with the existing methods through the computer experiments in the assumed conditions. The results can be useful to improving a field application of the job shop scheduling.

플라이휠을 장착한 농형/권선형 전동기를 이용한 두 고조파 보상 시스템의 비교 (Comparison of Harmonic Compensation Based on Wound/Squirrel-Cage Rotor Type Induction Motors With Flywheel)

  • 김윤호;이경훈;양성혁;박경수
    • 한국철도학회논문집
    • /
    • 제4권1호
    • /
    • pp.16-22
    • /
    • 2001
  • This paper describes two different systems which can compensate harmonic currents generated in the power system. As non-linear loads increase gradually in industry fields, harmonic current generated in the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration, noise in the power machinery. Many approaches have been applied to compensate harmonic currents generated in the power network system. Among various approaches, in this paper, two kinds of approaches are compared and evaluated. They are flywheel compensator based on secondary excitation of wounded rotor induction motor(WRIM) and primary excitation of squirrel cage induction motor(SCIM). Both systems have a common structure. They use a flywheel as a energy storage device and use PWM inverters.

  • PDF

음질향상 기법과 모델보상 방식을 결합한 강인한 음성인식 방식 (A Robust Speech Recognition Method Combining the Model Compensation Method with the Speech Enhancement Algorithm)

  • 김희근;정용주;배건성
    • 음성과학
    • /
    • 제14권2호
    • /
    • pp.115-126
    • /
    • 2007
  • There have been many research efforts to improve the performance of the speech recognizer in noisy conditions. Among them, the model compensation method and the speech enhancement approach have been used widely. In this paper, we propose to combine the two different approaches to further enhance the recognition rates in the noisy speech recognition. For the speech enhancement, the minimum mean square error-short time spectral amplitude (MMSE-STSA) has been adopted and the parallel model combination (PMC) and Jacobian adaptation (JA) have been used as the model compensation approaches. From the experimental results, we could find that the hybrid approach that applies the model compensation methods to the enhanced speech produce better results than just using only one of the two approaches.

  • PDF

Are Macrophages in Tumors Good Targets for Novel Therapeutic Approaches?

  • Alahari, Samthosh V.;Dong, Shengli;Alahari, Suresh K.
    • Molecules and Cells
    • /
    • 제38권2호
    • /
    • pp.95-104
    • /
    • 2015
  • The development of cancer has been an extensively researched topic over the past few decades. Although great strides have been made in cancer prevention, diagnosis, and treatment, there is still much to be learned about cancer's micro-environmental mechanisms that contribute to cancer formation and aggressiveness. Macrophages, lymphocytes which originate from monocytes, are involved in the inflammatory response and often dispersed to areas of infection to fight harmful antigens and mutated cells in tissues. Macrophages have a plethora of roles including tissue development and repair, immune system functions, and inflammation. We discuss various pathways by which macrophages get activated, various approaches that can regulate the function of macrophages, and how these approaches can be helpful in developing new cancer therapies.

연기옵션을 고려한 옵션가치의 일반적 기회비용 모델 (The Multi-Period Opportunity Cost Model to Evaluate an Option Value based on a Deferral Option)

  • 김규태
    • 산업공학
    • /
    • 제18권2호
    • /
    • pp.184-192
    • /
    • 2005
  • In recent research there has been intense interest in understanding how real option valuation (ROV) approaches might usefully complement conventional discounted cash flow (DCF) techniques. However, investment decision makers in a real world have been worried about adopting the ROV approaches mainly because of difficulty in technically understanding the theory of the ROV approaches as indicated by many researchers. With this difficulty in mind, we propose the opportunity cost model as another discrete-time model to value a deferral option. The main advantage of observing a real options value in terms of the opportunity cost concept is to provide a technique for practitioners to estimate a wide range of real options values without sticking to a financial option modelling. The fundamental ground for developing the opportunity cost model proposed in this paper lies in the work of dissecting the structure of the real options value into three categories: capital gain, expected opportunity loss, and expected opportunity gain. At the end of the paper, we will present a short illustrative example to demonstrate the applicability of the model.