• 제목/요약/키워드: domain theory

검색결과 802건 처리시간 0.02초

S/W 재사용을 위한 새로운 접근법으로서의 Domain Theory의 개요 (Outline of Domain Theory As a New Approach to Software Reuse)

  • 함동한;김진삼;하수정;조진희
    • 한국IT서비스학회:학술대회논문집
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    • 한국IT서비스학회 2002년도 추계학술대회
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    • pp.425-430
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    • 2002
  • Over the years, several different approaches have been proposed to enhance the practice of software reuse. These approaches vary in reuse abstraction levels or application domains they focus on. However, it seems that they do not adequately meet the needs of software designers in planning and managing reuse. One reason may be the lack of conceptually well-established framework supporting work domain analysis and modeling. As a new viable solution to this problem, Sutcliffe and his colleagues developed Domain Theory , which is introduced in this paper. Utilizing multidisciplinary perspective, such as cognitive psychology, management science, human-computer interaction, and software engineering. it provides a schematic framework that defines a comprehensive library of generic and reusable models of domain knowledge in terms of generic tasks and meta-domains. It also provides useful methods and guidelines for software reuse, emphasizing the concept of abstraction process in a designer s mind. This paper firstly gives a brief overview of fundamentals of software reuse. Next, it explains the foundation of domain theory and discusses its applicability to software reuse. In particular, the taxonomy of meta-domains and the types of generic tasks are described in more detail. Finally, the future research framework, which primarily addresses the problem of how to apply the domain theory to various work domains, is proposed.

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The Effect of Domain Wall on Defect Energetics in Ferroelectric LiNbO3 from Density Functional Theory Calculations

  • Lee, Donghwa
    • 한국세라믹학회지
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    • 제53권3호
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    • pp.312-316
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    • 2016
  • The energetics of defects in the presence of domain walls in $LiNbO_3$ are characterized using density-functional theory calculations. Domain walls show stronger interactions with antisite defects than with interstitial defects or vacancies. As a result, antisite defects act as a strong pinning center for the domain wall in $LiNbO_3$. Analysis of migration behavior of the antisite defects across the domain wall shows that the migration barrier of the antisite defects is significantly high, such that the migration of antisite defects across the domain wall is energetically not preferable. However, further study on excess electrons shows that the migration barrier of antisite defects can be lowered by changing the charge states of the antisite defects. So, excess electrons can enhance the migration of antisite defects and thus facilitate domain wall movement by weakening the pinning effect.

INVARIANCE OF DOMAIN THEOREM FOR DEMICONTINUOUS MAPPINGS OF TYPE ( $S_+$)

  • Park, Jong-An
    • 대한수학회보
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    • 제29권1호
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    • pp.81-87
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    • 1992
  • Wellknown invariance of domain theorems are Brower's invariance of domain theorem for continuous mappings defined on a finite dimensional space and Schauder-Leray's invariance of domain theorem for the class of mappings I+C defined on a infinite dimensional Banach space with I the identity and C compact. The two classical invariance of domain theorems were proved by applying the homotopy invariance of Brower's degree and Leray-Schauder's degree respectively. Degree theory for some class of mappings is a useful tool for mapping theorems. And mapping theorems (or surjectivity theorems of mappings) are closely related with invariance of domain theorems for mappings. In[4, 5], Browder and Petryshyn constructed a multi-valued degree theory for A-proper mappings. From this degree Petryshyn [9] obtained some invariance of domain theorems for locally A-proper mappings. Recently Browder [6] has developed a degree theory for demicontinuous mapings of type ( $S_{+}$) from a reflexive Banach space X to its dual $X^{*}$. By applying this degree we obtain some invariance of domain theorems for demicontinuous mappings of type ( $S_{+}$). ( $S_{+}$).

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Deformation in transversely isotropic thermoelastic medium using new modified couple stress theory in frequency domain

  • Lata, Parveen;Kaur, Harpreet
    • Geomechanics and Engineering
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    • 제19권5호
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    • pp.369-381
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    • 2019
  • The objective of this paper is to study the two dimensional deformation in transversely isotropic thermoelastic medium without energy dissipation due to time harmonic sources using new modified couple stress theory, a continuum theory capable to predict the size effects at micro/nano scale. The couple stress constitutive relationships have been introduced for transversely isotropic thermoelastic medium, in which the curvature tensor is asymmetric and the couple stress moment tensor is symmetric. Fourier transform technique is applied to obtain the solutions of the governing equations. Assuming the deformation to be harmonically time-dependent, the transformed solution is obtained in the frequency domain. The application of a time harmonic concentrated and distributed sources have been considered to show the utility of the solution obtained. The displacement components, stress components, temperature change and couple stress are obtained in the transformed domain. A numerical inversion technique has been used to obtain the solutions in the physical domain. The effects of angular frequency are depicted graphically on the resulted quantities.

Dynamic Spectrum Load Balancing for Cognitive Radio in Frequency Domain and Time Domain

  • ;손성환;;김재명
    • 한국ITS학회 논문지
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    • 제8권3호
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    • pp.71-82
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    • 2009
  • As a solution to spectrum under-utilization problem, Cognitive radio (CR) introduces a dynamic spectrum access technology. In the area, one of the most important problems is how secondary users (SUs) should choose between the available channels, which means how to achieve load balancing between channels. We consider spectrum load balancing problem for CR system in frequency domain and especially in time domain. Our objective is to balance the load among the channels and balance the occupied time length of slots for a fixed channel dynamically in order to obtain a user-optimal solution. In frequency domain, we refer to Dynamic Noncooperative Scheme with Communication (DNCOOPC) used in distributed system and a distributed Dynamic Spectrum Load Balancing algorithm (DSLB) is formed based on DNCOOPC. In time domain, Spectrum Load Balancing method with QoS support is proposed based on Dynamic Feed Back theory and Hash Table (SLBDH). The performance of DSLB and SLBDH are evaluated. In frequency domain, DSLB is more efficient compared with existing Compare_And_Balance (CAB) algorithm and gets more throughput compared with Spectrum Load Balancing (SLB) algorithm. Also, DSLB is a fair scheme for all devices. In time domain, SLBDH is an efficient and precise solution compared with Spectrum Load Smoothing (SLS) method.

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함수의 정의역 변형에 의한 신호간의 거리 측정 방법 (A Modified Domain Deformation Theory for Signal Classification)

  • 김성수
    • 대한전기학회논문지:전력기술부문A
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    • 제48권3호
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    • pp.342-349
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    • 1999
  • The metric defined on the domain deformation space better measures the similarity between bounded and continuous signals for the purpose of classification via the metric distances between signals. In this paper, a modified domain deformation theory is introduced for one-dimensional signal classification. A new metric defined on a modified domain deformation for measuring the distance between signals is employed. By introducing a newly defined metric space via the newly defined Integra-Normalizer, the assumption that domain deformation is applicable only to continuous signals is removed such that any kind of integrable signal can be classified. The metric on the modified domain deformation has an advantage over the $L^2$ metric as well as the previously introduced domain deformation does.

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이론정련 지식기반인공신경망을 이용한 귀납적 학습 (Inductive Learning using Theory-Refinement Knowledge-Based Artificial Neural Network)

  • 심동희
    • 한국멀티미디어학회논문지
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    • 제4권3호
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    • pp.280-285
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    • 2001
  • 귀납적학습 알고리즘과 분석적학습 알고리즘을 결합한 지식기반인공신경망이 제안된 후, 이를 개선한 TopGen, TR-KBANN, THRE-KBANN과 같은 영역이론정련알고리즘이 제시되었다. 그러나 이들은 모두 KBANN과 같이 영역이론이 있을 경우에만 사용할 수 있다. 본 연구에서는 영역이론이 없이 예제만 있는 경우 KBANN으로 표기하는 알고리즘을 제시하였다. KBANN으로 표현된 영역 이론은 THRE-KBANN으로 정련화될 수 있다. 이 알고리즘을 귀납적 학습에서 사용하는 몇 개의 문제영역에 적용하여 실험한 결과 C4.5보다 좋은 성능을 나타냈다.

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GLOBAL GRADIENT ESTIMATES FOR NONLINEAR ELLIPTIC EQUATIONS

  • Ryu, Seungjin
    • 대한수학회지
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    • 제51권6호
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    • pp.1209-1220
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    • 2014
  • We prove global gradient estimates in weighted Orlicz spaces for weak solutions of nonlinear elliptic equations in divergence form over a bounded non-smooth domain as a generalization of Calder$\acute{o}$n-Zygmund theory. For each point and each small scale, the main assumptions are that nonlinearity is assumed to have a uniformly small mean oscillation and that the boundary of the domain is sufficiently flat.

Time-Domain Analysis of Wireless Power Transfer System Behavior Based on Coupled-Mode Theory

  • Shim, Hyunjin;Nam, Sangwook;Lee, Bomson
    • Journal of electromagnetic engineering and science
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    • 제16권4호
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    • pp.219-224
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    • 2016
  • In this paper, coupled-mode theory (CMT) is used to obtain a transient solution analytically for a wireless power transfer system (WPTS) when unit energy is applied to one of two resonators. The solutions are compared with those obtained using equivalent circuit-based analysis. The time-domain CMT is accurate only when resonant coils are weakly coupled and have large quality factors, and the reason for this inaccuracy is outlined. Even though the time-domain CMT solution does not describe the WPTS behavior precisely, it is accurate enough to allow for an understanding of the mechanism of energy exchange between two resonators qualitatively. Based on the time-domain CMT solution, the critical coupling coefficient is derived and a criterion is suggested for distinguishing inductive coupling and magnetic resonance coupling of the WPTS.