• 제목/요약/키워드: free A-module

검색결과 273건 처리시간 0.027초

Restrictions on the Entries of the Maps in Free Resolutions and $SC_r$-condition

  • Lee, Kisuk
    • 통합자연과학논문집
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    • 제4권4호
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    • pp.278-281
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    • 2011
  • We discuss an application of 'restrictions on the entries of the maps in the minimal free resolution' and '$SC_r$-condition of modules', and give an alternative proof of the following result of Foxby: Let M be a finitely generated module of dimension over a Noetherian local ring (A,m). Suppose that $\hat{A}$ has no embedded primes. If A is not Gorenstein, then ${\mu}_i(m,A){\geq}2$ for all i ${\geq}$ dimA.

Loose Coupling Approach of CFD with a Free-Wake Panel Method for Rotorcraft Applications

  • Lee, Jae-Won;Oh, Se-Jong;Yee, Kwan-Jung;Kim, Sang-Hun;Lee, Dong-Ho
    • International Journal of Aeronautical and Space Sciences
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    • 제8권1호
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    • pp.1-9
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    • 2007
  • As a first step toward a complete CFD-CSD coupling for helicopter rotor load analysis, the present study attempts to loosely couple a CFD code with a source-double panel method. The far-field wake effects were calculated by a time-marching free vortex wake method and were implemented into the CFD module via field velocity approach. Unlike the lifting line method, the air loads correction process is not trivial for the source-doublet panel method. The air loads correction process between the source-doublet method and CFD is newly suggested in this work and the computation results are validated against available data for well-known hovering flight conditions.

SA-SUPPLEMENT SUBMODULES

  • Durgun, Yilmaz
    • 대한수학회보
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    • 제58권1호
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    • pp.147-161
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    • 2021
  • In this paper, we introduced and studied sa-supplement submodules. A submodule U of a module V is called an sa-supplement submodule in V if there exists a submodule T of V such that V = T + U and U ∩ T is semiartinian. The class of sa-supplement sequences ������ is a proper class which is generated by socle-free modules injectively. We studied modules that have an sa-supplement in every extension, modules whose all submodules are sa-supplement and modules whose all sa-supplement submodules are direct summand. We provided new characterizations of right semiartinian rings and right SSI rings.

DDR2 SDRAM을 이용한 비메모리 검사장비에서 정시성을 보장하기 위한 메모리 컨트롤러 개발 (Development of Memory Controller for Punctuality Guarantee from Memory-Free Inspection Equipment using DDR2 SDRAM)

  • 전민호;신현준;강철규;오창헌
    • 한국항행학회논문지
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    • 제15권6호
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    • pp.1104-1110
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    • 2011
  • 현재의 반도체 검사장비는 테스트 패턴 프로그램을 위한 메모리로 시스템 설계가 간단하고 리프레시가 필요 없는 SRAM(static random access memory) 모듈을 채용하고 있다. 그러나 SRAM 모듈을 이용한 시스템 구성은 용량이 커질수록 장비의 부피가 증가하기 때문에 메모리 대용량화 및 장비의 소형화에 걸림돌이 되고 있다. DRAM(dynamic random access memory)을 이용하여 반도체 검사 장비를 제작할 경우 SRAM 보다 비용과 장비의 면적이 줄어드는 장점이 있지만 DRAM의 특성 상 메모리 셀 리프레시가 필요하여 정시성을 보장해야 하는 문제가 있다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해 DDR2 SDRAM(double data rate synchronous dynamic random access memory)을 이용한 비메모리 검사장비에서 정시성을 보장해 주는 알고리즘을 제안하고 알고리즘을 이용한 메모리 컨트롤러를 개발하였다. 그 결과, DDR2 SDRAM을 이용할 경우 SRAM을 이용할 때 보다 가격과 면적이 줄어들어 가격측면에서는 13.5배 그리고 면적측면에서는 5.3배 이득이 있음을 확인하였다.

정밀가공을 위한 CAD/CAM/CAT 일괄처리시스템 (CAD/CAM/CAT Turmaround System for Precision Machining)

  • 안중용;김승철;정성종
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1993년도 추계학술대회 논문집
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    • pp.417-422
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    • 1993
  • In order to minimize turnaround of machining in FMS lines, CAD/CAM/CAT integrated system called MascCAM was developed. Developing enhanced CAM and inspection modules in the MascCAM environment, 2D came, 2 $^{1}$2/ D prismatic parts and 3D free-formed surfaces were able to be automatically designed, manufactured and inspected on the machine tools by using AutoCAM and Z-map. Introducing Z-map technique, the MascCAM was able to be interfaceed with and CAD system. Developed QPPGT module generates a quick and fool-proof inspection work to users. A vertical and a horizontal machining center equipped with FANUC OMC were used for experiments. Performance of the system was confirmed by a large amount of experiments.

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1MHz 헬리컬 ECR장치를 이용한 무선전력전송 모듈 개발 (The Development of 1MHz wireless power transmission module using Helical ECR device)

  • 양해열;임성진;김성완;박재현;김창선
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2011년도 전력전자학술대회
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    • pp.62-63
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    • 2011
  • The wireless power transfer system using electromagnetic resonance is consists of PFC circuit, LLC resonant converter, high frequency DC-AC inverter and ECR devices for wirelessly transmitting the power. The output voltage of the module with free input voltage is 1MHz, 230Vp-p. As a experimental result, the wireless power transmission is confirmed and it is varified the validity of the experiment.

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Equifield line simulation and ion migration prediction for concrete under 2-D electric field

  • Liu, Chih-Chien;Kuo, Wen-Ten;Huang, Chun-Yao
    • Computers and Concrete
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    • 제12권4호
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    • pp.431-442
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    • 2013
  • This study attempted to find a proper method applicable to simulating practical equifield lines of two-dimensional Accelerate Lithium Migration Technique (ALMT), and evaluate the feasibility of using the theoretical ion migration model of one-dimensional ALMT to predict the ion migration behavior of two-dimensional ALMT. The result showed that the electrolyte or carbon plate can be used as matrix to draw equifield line graph similar to that by using mortar as matrix. Using electrolyte electrode module for simulation has advantages of simple production, easy measurement, rapidness, and economy. The electrolyte module can be used to simulate the equifield line distribution diagram in practical two-dimensional electrode configuration firstly. Then, several equifield line zones were marked, and several subzones under one-dimensional ALMT were separated from various equifield line zones. The theoretical free content distribution of alkali in concrete under two-dimensional electric field effect could be obtained from duration analysis.

Secure and Resilient Framework for Internet of Medical Things (IoMT) with an Effective Cybersecurity Risk Management

  • Latifah Khalid Alabdulwahhab;Shaik Shakeel Ahamad
    • International Journal of Computer Science & Network Security
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    • 제24권5호
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    • pp.73-78
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    • 2024
  • COVID-19 pandemic outbreak increased the use of Internet of Medical Things (IoMT), but the existing IoMT solutions are not free from attacks. This paper proposes a secure and resilient framework for IoMT, it computes the risk using Risk Impact Parameters (RIP) and Risk is also calculated based upon the Threat Events in the Internet of Medical Things (IoMT). UICC (Universal Integrated Circuit Card) and TPM (Trusted Platform Module) are used to ensure security in IoMT. PILAR Risk Management Tool is used to perform qualitative and quantitative risk analysis. It is designed to support the risk management process along long periods, providing incremental analysis as the safeguards improve.

데이터베이스를 활용한 CAD/CAM System개발에 관한 연구 (CAD/CAM System development using the Database)

  • 명태식;김태규;김옥현
    • 한국생산제조학회지
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    • 제8권2호
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    • pp.116-116
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    • 1999
  • In this study we propose a novel approach with which design engineers can define and design free-from surface more easily. Free-from surface is defined as a parameterics shape which consists of a set of contr ol points. Parametric shape which not only has the advantage of allowing users to perform design changes efficiently, but also provides designers with a natural design environment in which they can do their work more naturally and creatively. The objective of this study is to develop a PC level freeform surface modelling system which explicitly represents information of part geometry. In this study, freeform surface modeling system consist of three modules : freeform surface modeler, input/output modules and interface with Database. In recent year there are increasing demands for the 5-axis machining of a complicated shape. This study is the development of a CAM software system (or NC module) for the 5-axis machining of a general shape with a flat-end mill, a round-end mill, a ball-end mill.