• 제목/요약/키워드: Alternative Machines

검색결과 95건 처리시간 0.021초

GT 셀 형성을 위한 효율적 Ρ-median 접근법 (Efficient Ρ-median approach to GT cell formation)

  • Won, Youkyung
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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    • pp.40-43
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    • 2000
  • This paper is concerned with development of an efficient Ρ-median approach applicable to large cell formation(CF) problems. A two-phase methodology that seeks to minimize the number of exceptional elements is proposed. In phase I, two efficient Ρ-median formulations which contain fewer binary variables than existing Ρ-median formulations are constructed. These make it possible to implement large CF problem within reasonable computer runtime with commercially available linear integer programming codes. Given the initial cell configuration found with the new p-median formulations, in phase II bottleneck machines and parts are reassigned to reduce the number of exceptional elements. This procedure has the flexibility to provide the cell designer with alternative solutions. Test results on large CF problems show a substantial efficiency of the new Ρ-median formulations.

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Support Vector Machine을 이용한 기업부도예측 (Bankruptcy Prediction using Support Vector Machines)

  • 박정민;김경재;한인구
    • Asia pacific journal of information systems
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    • 제15권2호
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    • pp.51-63
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    • 2005
  • There has been substantial research into the bankruptcy prediction. Many researchers used the statistical method in the problem until the early 1980s. Since the late 1980s, Artificial Intelligence(AI) has been employed in bankruptcy prediction. And many studies have shown that artificial neural network(ANN) achieved better performance than traditional statistical methods. However, despite ANN's superior performance, it has some problems such as overfitting and poor explanatory power. To overcome these limitations, this paper suggests a relatively new machine learning technique, support vector machine(SVM), to bankruptcy prediction. SVM is simple enough to be analyzed mathematically, and leads to high performances in practical applications. The objective of this paper is to examine the feasibility of SVM in bankruptcy prediction by comparing it with ANN, logistic regression, and multivariate discriminant analysis. The experimental results show that SVM provides a promising alternative to bankruptcy prediction.

Improved Suter Transform for Pump-Turbine Characteristics

  • Dorfler, Peter K.
    • International Journal of Fluid Machinery and Systems
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    • 제3권4호
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    • pp.332-341
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    • 2010
  • Standard dimensionless parameters cannot simultaneously represent all operation modes of a pump-turbine. They either have singularities at E=0 and multiple values in the 'unstable' areas, or else get singular at n=0. P. Suter (1966) introduced an alternative set of variables which avoids singularity and always remains unique-valued. This works for non-regulated pumps but not so well for regulated machines. A modification by C.S. Martin avoids distortion at low load. The present paper describes further improvements for the representation of torque, and for closed gate (where Suter's concept does not work). The possibility to interpolate across all operation modes is likewise useful for representing other mechanical parameters of the machine. Practical application for guide vane torque and pressure pulsation data is demonstrated by examples.

대체에너지 시스템의 출력 평준화를 위한 EMB용 초고속 전동발전기 (High Speed Motor/Generator of an Electro-Mechanecal Battery for Power Averaging of Alternative energy system)

  • 장석명;윤인기;류동완;최상규;윤기갑
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.337-339
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    • 2001
  • High speed brushless permanent magnet (PM) machines are a key technology for electric drives and motion control systems for many application, since they are conductive to high efficiency, high power density small size and low weight. Proposed slotless PM machine is constructed without stator winding slots. Its stator magnetic material is in the form of a ring and winding have a toroidal configuration and its rotor consists of a 4-pole Halbach array or radially magnetized PM rotor.

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Economic Effect of Local Feed Utilization in Korea

  • Lee, Byung Oh;Yang, Jeong Hee;Park, Sang Youn;Lee, Byeong Soon
    • International Journal of Advanced Culture Technology
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    • 제6권4호
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    • pp.214-225
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    • 2018
  • Rice straw is the principal forage for Korean cattle. Limited supply of domestic forage forces Korea to depend on imported forage. Utilizing locally available domestic feed as an alternative would lead to self-sufficiency and stability in cattle farm management. Locally available feed can be utilized as forage. The challenge of collecting local feed has been overcome by machines that have been developed to harvest feed. Local feed can be completely consumed in the production regions, thus reducing transportation costs and increasing price competitiveness. Hitherto, studies have focused on feed technologies and price competitiveness, among other factors, while the substitution of forage has not been examined. This study conducts a quantitative analysis to estimate the extent to which local feed can replace existing forage. We find that local feed is cheaper, and abundantly available, and can thus replace high-quality forage.

슬롯 수에 따른 100MW급 권선형 동기발전기 발전특성 및 운전특성 비교 (Operation and Generation Characteristic of 100MW-Class Wound Rotor Synchronous Generator According to Number of Slots)

  • 김창우;박요한;최장영
    • 전기학회논문지
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    • 제68권4호
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    • pp.523-531
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    • 2019
  • This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.

Emerging Machine Learning in Wearable Healthcare Sensors

  • Gandha Satria Adi;Inkyu Park
    • 센서학회지
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    • 제32권6호
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    • pp.378-385
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    • 2023
  • Human biosignals provide essential information for diagnosing diseases such as dementia and Parkinson's disease. Owing to the shortcomings of current clinical assessments, noninvasive solutions are required. Machine learning (ML) on wearable sensor data is a promising method for the real-time monitoring and early detection of abnormalities. ML facilitates disease identification, severity measurement, and remote rehabilitation by providing continuous feedback. In the context of wearable sensor technology, ML involves training on observed data for tasks such as classification and regression with applications in clinical metrics. Although supervised ML presents challenges in clinical settings, unsupervised learning, which focuses on tasks such as cluster identification and anomaly detection, has emerged as a useful alternative. This review examines and discusses a variety of ML algorithms such as Support Vector Machines (SVM), Random Forests (RF), Decision Trees (DT), Neural Networks (NN), and Deep Learning for the analysis of complex clinical data.

Support Vector Machines을 이용한 공급사슬관리의 지속적 협업 수준에 대한 의사결정모델 (A Decision Support Model for Sustainable Collaboration Level on Supply Chain Management using Support Vector Machines)

  • 임세헌
    • 한국유통학회지:유통연구
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    • 제10권3호
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    • pp.1-14
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    • 2005
  • 성공적인 공급사슬관리에 있어 성과에 따른 지속적 협업 통제는 매우 중요하다. 본 연구에서는 기계학습 알고리즘인 SVM(Support Vector Machiness)을 이용해 균형성과표에 기반한 공급사슬관리 성과에 따른 지속적 협업 통제 모델을 개발하였다. 우리는 지속적 협업 통제모델 개발에 있어 108명의 전문가를 상대로 실증조사를 수행하였다. 본 연구 수행에 있어 4가지 형태의 SVM 커늘 (1) linear, (2) polynomail, (3) Radial Basis Function(RBF), (4) sigmoid kernel을 이용해 공급사슬관리 지속적 협업 예측 정확도를 비교하였다. SVM 커늘 4가지 중 linear kernel의 예측성과가 가장 좋았다. 그리고 본 연구에서는 SVM linear kernel의 예측성과를 ANN(Artificial Neural Network)의 예측성과와 비교하였다. 분석결과 SVM linear kernel이 공급사슬관리에 있어 지속적 협업 예측에 우수한 예측성과를 보여주는 것을 발견하였다. 이러한 곁과는 SVM linear kernel이 공급사슬관리의 지속적 협업 예측 통제에 있어 우수한 대안을 제공해 줄 것이다. 그러므로 공급사슬관리를 추구하는 기업들은 분 모델을 통해 지속적 협업 통제에 유용한 정보를 얻을 수 있을것이다.

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IKONOS 영상을 이용한 토지피복분류 기법 분석 (An Analysis of Land Cover Classification Methods Using IKONOS Satellite Image)

  • 강남이;박정기;조기성;유연
    • 대한공간정보학회지
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    • 제20권3호
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    • pp.65-71
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    • 2012
  • 최근 고해상도 위성영상은 자연자원이나 환경 관리에 필요로 하는 토지 피복 및 이용 현황자료 등에 유용하게 사용되고 있는 실정이다. 이에 따라 고액의 투자가 필요로 하는 위성영상의 효율성을 높이기 위하여 영상자료의 분석과정이 중요해지고 있다. 따라서 본 연구에서는 전처리 과정 중 연구대상에 대한 통계값에 대한 계산 및 분석을 수행하였으며, 전통적인 분류 기법인 최대우도 분류 외에도 인공신경망 분류와 SVM 분류에 대하여 설명하고 고해상도 위성영상인 IKONOS영상에 각 분류기법을 적용하여 토지피복분류를 하였으며, 각각의 결과를 오차 행렬을 통해 정확도 분석을 수행하였다. 그 결과 다른 분류 기법에 비해 Support Vector Machines(SVM) 분류 기법이 전체 정확도가 약 86%정도로 가장 우위의 결과물을 도출하였다.

iATA 기반의 RAID5 분산 스토리지 서버의 설계 및 구현 (Design and Implementation of iATA-based RAID5 Distributed Storage Servers)

  • 왕숙미;임효택
    • 한국정보통신학회논문지
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    • 제14권2호
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    • pp.305-311
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    • 2010
  • iATA는 TCP/IP 네트워크상에서 ATA 명령어를 전달하기 위해 개발된 블록-레벨 프로토콜로서, 모바일 기기의 스토리지 한계를 극복하기 위한 대안으로 활용 될 수 있다. 본 논문은 RAID5 분산 스토리지 서버 개념을 iATA에 적용하여 스토리지 서버의 신뢰성과 속도를 개선하고자 한다. 분산 스토리지 서버중 하나의 서버가 다운된 경우에 나머지 서버 데이터의 XOR 함수를 적용하여 데이터 회복이 가능하며 이를 통해 데이터의 신뢰성을 높일 수 있다. 벤치마킹 실험과 시험을 통해 제안된 iATA 프로토콜은 제한된 스토리지를 가지고 있는 모바일 기기상에서 효율적이 고도 신뢰성 있는 가상 스토리지 프로토콜로서 사용될 수 있음을 보여주고 있다.