• Title/Summary/Keyword: Class Fragmentation

Search Result 29, Processing Time 0.023 seconds

Vertical class fragmentation in distributed object-oriented databases (분산 객체 지향 데이타베이스에서 클래스의 기법)

  • 이순미;임해철
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.22 no.2
    • /
    • pp.215-224
    • /
    • 1997
  • This paper addresses the vertical class fragmentation in distributed object-oriented databases. In the proposed vertical fragmentation, after producing the attribute fragment by partitioning attributes, then the method fragment is produced by gathering methods referring the attribute in each fragment. For partitioning attributes, we define query access matrix(QAM) and method access matrix(MAM) to express attributes that method refers, and extend QAM, MAM and attribute usage matrix(AUM) to universal class environment for representing relationship among other classes through class hierarchy and class composite hierarchy.

  • PDF

Design and Implementation of Distribution in Distributed Object-Oriented Databases (분산 객체지향 데이타베이스에서 분산 설계 및 구현)

  • Lee, Soon-Mi;Park, Hea-Sook;Ha, Yan
    • The KIPS Transactions:PartB
    • /
    • v.11B no.5
    • /
    • pp.611-618
    • /
    • 2004
  • This paper addresses the design and implementation of class distribution in distributed object-oriented databases. The proposed strategy of distribution consists of two-step design of fragments. One is class fragmentation and the other is allocation of fragments. In step of class fragmentation, we have defined partitioning algorithms to reflect the characteristics of object-oriented databases such as method, inheritance and composite-object. In step of allocation, we have defined the objective function for allocation considering system operating cost including storage, query processing and communication and implemented it using Genetic Algorithm.

ALMA observations of a proto-binary system, IRAS 04191+1523

  • Lee, Jeong-Eun;Lee, Seokho;Yoon, Sung-Yong;Dunham, Michael;Evans, Neal;Choi, Minho;Tatematsu, Ken;Bergin, Edwin
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.2
    • /
    • pp.46.4-47
    • /
    • 2016
  • About 50% of stars reside in binary or multiple systems. However, the formation mechanism of the multiplicity is poorly understood. Theoretical studies suggest two main mechanisms for the multiplicity: turbulent fragmentation and disk fragmentation. We can testify which mechanism is more plausible by measuring the separation between companions or the alignment of stellar spins. Here we present our ALMA Cycle 2 observational results of a proto-binary system, IRAS 04191+1523, which consists of two Class I sources. We detected disks around both Class I sources, which are located in a common dense filamentary structure traced by $C^{18}O$ J=2-1. Two protostellar disks are separated by ~900 AU and their rotational axes are almost perpendicular, which strongly support that this binary system formed by the turbulent fragmentation.

  • PDF

Automatic Dynamic Memory Management Techniques for Memory Scarce Java system (메모리가 적은 자바 시스템을 위한 자동 동적 메모리 관리 기법)

  • Choi, Hyung-Kyu;Moon, Soo-Mook
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.35 no.8
    • /
    • pp.378-384
    • /
    • 2008
  • Many embedded systems are supporting Java as their software platform via Java virtual machine. Java virtual machine manages memory automatically by providing automatic memory management, i.e. garbage collector. Because only scarce memory is available to embedded system, Java virtual machine should use small memory and manage it efficiently. This paper introduces two memory management techniques to exploit small memory in Java virtual machine which can execute multiple Java applications concurrently. First, compaction based garbage collection is introduced to overcome external fragmentation problem in presence of immovable memory area. Then garbage collector driven class unloading is introduced to reduce memory use of unnecessary loaded classes. We implemented these techniques in working embedded system and observed that they are very efficient, since more Java applications are able to be executed concurrently and memory use is also reduced with these techniques.

Examination of the Fragmentation Behavior of Hemin and Bilin Tetrapyrroles by Electrospray Ionization and Collision-induced Dissociation

  • Sekera, Emily R.;Wood, Troy D.
    • Mass Spectrometry Letters
    • /
    • v.9 no.4
    • /
    • pp.91-94
    • /
    • 2018
  • Bilin tetrapyrroles are metabolic products of the breakdown of porphyrins within a species. In the case of mammals, these bilins are formed by the catabolism of heme and can be utilized as either biomarkers in disease or as an indicator of human waste contamination. Although a small subset of bilin tandem mass spectrometry reports exist, limited data is available in online databases for their fragmentation. The use of fragmentation data is important for metabolomics analyses to determine the identity of compounds detected within a sample. Therefore, in this study, the fragmentation of bilins generated by positive ion mode electrospray ionization is examined by collision-induced dissociation (CID) as a function of collision energy on an FT-ICR MS. The use of the FT-ICR MS allows for high mass accuracy measurements, and thus the formulas of resultant product ions can be ascertained. Based on our observations, fragmentation behavior for hemin, biliverdin and its dimethyl ester, phycocyanobilin, bilirubin, bilirubin conjugate, mesobilirubin, urobilin, and stercobilin are discussed in the context of the molecular structure and collision energy. This report provides insight into the identification of structures within this class of molecules for untargeted analyses.

Design of Object Distribution in Distributed Object-Oriented Databases (분산 객체 지향 데이타베이스에서 객체의 분산 설계)

  • Lee, Soon-Mi;Oh, Suk
    • Journal of the Korea Society of Computer and Information
    • /
    • v.4 no.4
    • /
    • pp.170-176
    • /
    • 1999
  • This paper addresses the design of object distribution in distributed object-oriented databases. The proposed strategy of object distribution consists of two-step design of fragments. One step is class fragmentation and the other is allocation of fragments. We define partitioning algorithms to reflect the characteristics of object-oriented databases in the class fragmentation and define expressions to reduce the amount of data transfer by allocating fragments of other classes referred together to one site in the allocation of fragments

  • PDF

Allocation of Class Fragmentation (클래스 프래그먼트의 할당 기법)

  • 이순미
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 1998.10b
    • /
    • pp.42-44
    • /
    • 1998
  • 분산객체 지향 데이터베이스에서는 데이터 전송량 감소와 성능 향상을 위하여 클래스를 여러개의 플래그먼트로 분할하여 다른 사이트에 할당하는 분산 기법이 필요하다. 본 논문에서는 객체 지향의 특성을 고려한 클래스 플래그먼트의 할당 기법에 관하여 연구하였다. 계승 또는 복합 객체를 통하여 함께 사용되는 다른 클래스의 플래그먼트를 같은 사이트에 할당시킴으로써 사이트 간의 데이터 전송량을 감소시키는 할당 수식을 정의하였다.

Evaluation of regional ecosystem by landscape ecological measure - Case study in Yongin City - (경관지수를 이용한 지역생태계 평가 - 용인시를 대상으로 -)

  • Cho, Yong-Hyeon
    • Journal of Environmental Impact Assessment
    • /
    • v.9 no.4
    • /
    • pp.349-362
    • /
    • 2000
  • In the study, the feasibility of landscape ecological measures as indices system for interpretation and evaluation of regional ecosystem was investigated through the application to Yongin City. Each patch metrics well showed the class structure and supplemented the class metrics, and class metrics also showed well the landscape structure and supplemented the landscape metrics. And the change analysis through subtraction of two set of landscape ecological measurement in two point of time showed the dynamic trends very well. One of the dynamic trends in Yongin City was the rapid fragmentation. While there was no landcover data on Yongin City, using Landsat data and remote sensing techniques were proved to be efficient and effective to produce the digital landcover data.

  • PDF

A Study on the 'fragmentation' trend of modern film montage (현대영화 몽타주의 '파편화(fragmentation)' 경향 연구)

  • LEE, Jiyoung
    • Trans-
    • /
    • v.3
    • /
    • pp.29-53
    • /
    • 2017
  • The film scholar Vincent Amiel divides into three types of montage through his book The Aesthetics of Montage ; Montage narratif, Montage discursif, and Montage decorrespondances. These three categories are the concept that encompasses the aesthetic class to which most movies belong. Early films pursued the essential and basic functions of editing, which tend to be modified in the direction of enhancing the director's goals over time. In this way, "Expressive Montage" is one of most important concepts of montage, not as a 'methodology' that combines narrative but as a 'purpose'. In the montage stage, the expressive montage work is done through three steps of decision. The process of 'combining' to combine the selected films in a certain order, after the process of 'selection' which selects only necessary parts of the rush film, and 'connection' to determine the scene connection considering the duration of the shot. The connection is the final stage of the montage. There are exceptions, of course. When fiction films of classical narratives use close-ups, or when using models or objects of neutered animals, the film induces the tendency of a "montage decorrespondances" rather than a "montage narratif" or "montage discursif". This study attempts to analyze the tendency of montage of works with 'uncertain connection' through 'collage' used by close-ups and montage decorrespondances as 'fragmentation tendency of modern films'. The fragmentation of the montage in contemporary film breaks the continuous and structural nature of the film, and confuses the narration structure that is visible on the surface of the film. The tendency of the fragmentation of the montage, which started from this close-up, seems to give an answer to the extensibility of the modern image.

  • PDF

Comparison of Carbon Stock Between Forest Edge and Core by Using Connectivity Analysis (연결성 분석을 활용한 산림의 주연부와 내부의 탄소저장량 비교)

  • Sung, Sun-Yong;Lee, Dong-Kun;Mo, Yong-Won
    • Journal of Korean Society of Rural Planning
    • /
    • v.21 no.4
    • /
    • pp.27-33
    • /
    • 2015
  • Forest ecosystem is considered as an important stepping stone to minimize the impact of climate change. However, the rapid urbanization has caused fragmentation of forest ecosystem. The fragmentation of forest patch results in edge effect which brings about adverse impacts on forest function and structure. Degradation of forest ecosystem decreases carbon sequestration because edge effect reduces productivity. Therefore, we analyzed the impact of forest edge effect on forest ecosystem carbon stock change in Seongnam-si, Gyeonggi-do. We used connectivity analysis to determine forest edge and core area. The field study sites were selected with considering forest age, density, class and soil type. Secondly, forest carbon stock was calculated with allometric equation. The soil carbon stock was derived from Walkely-Black method. Lastly, Mann-Whitney test was conducted to validate differences between carbon stock in edge and core area. As a result of study, the connectivity analysis was effective to determine forest edge and core. The core and edge of forest patch showed different composition of tree species and soil properties. Carbon stock per tree in the edge area was lower than that in the core area. However, the difference of soil organic carbon content between the edge and core were relatively small. This assessment can be applied for the conservation of forest patch as well as quantitative assessment on the forest carbon stock change caused by fragmentation.