• Title/Summary/Keyword: Coupling Metric

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Evaluation Metrics for Ontology Modules Based on the Relationship Type (관계 유형에 기반한 온톨로지 모듈 평가 메트릭)

  • Oh, Sun-Ju
    • The Journal of Society for e-Business Studies
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    • v.15 no.2
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    • pp.19-35
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    • 2010
  • In response to an increased need, various methods for ontology modularization have been proposed. However, few studies have focused on evaluative methods for ontology modules. In this study, we devise novel metrics to measure ontology modularity. To evaluate the ontology modules, we introduce cohesion and coupling based on the theory of software metrics. A cohesion metric and two coupling metrics were used to measure cohesion and coupling for ontology modules. These metrics were also used to check consistency between the ontology modules and the original ontology. The new metrics support a more detailed relationship between classes in ontology modules. We validate the proposed metrics using the well known verification framework and perform the empirical experiments to complement previous investigations. This study offers ontology engineers valuable criteria with which to select and use ontology modules and modularization techniques.

SLNR-based Precoder Design in Multiuser Interference Channel with Channel Estimation Error

  • Seo, Bangwon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.1
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    • pp.40-52
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    • 2020
  • In this paper, we consider a precoder design problem for multiuser interference channel. Most of the conventional schemes for precoder design utilize a signal-to-interference-plus-noise ratio (SINR) as a cost function. However, since the SINR metric of a desired transmitter-receiver pair is a function of precoding vectors of all transmitters in the multiuser interference channel, an analytic closed-form solution is not available for the precoding vector of a desired transmitter that maximizes the SINR metric. To eliminate coupling between the precoding vectors of all transmitters and to find a closed-form solution for the precoding vector of the desired transmitter, we use a signal-to-leakage-plus-noise ratio (SLNR) instead as a cost function because the SLNR at a transmitter is a function of the precoding vector of the desired transmitter only. In addition, channel estimation errors for undesired links are considered when designing the precoding vector because they are inevitable in a multiuser interference channel. In this case, we propose a design scheme for the precoding vector that is robust to the channel estimation error. In the proposed scheme, the precoding vector is designed to maximize the worst-case SLNR. Through computer simulation, we show that the proposed scheme has better performance than the conventional scheme in terms of SLNR, SINR, and sum rate of all users.

Load Balancing for Zone Routing Protocol to Support QoS in Ad Hoc Network

  • Chimmanee, Sanon;Wipusitwarakun, Komwut;Runggeratigul, Suwan
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1685-1688
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    • 2002
  • Application Routing Load Balancing (ARLB) is a novel load balancing mode that combines QoS routing and load balancing in per application to support QoS far real-time application based on wired network. Zone Routing Protocol (ZRP) is a recent hybrid proactive/reactive routing approach in an attempt to achieve scalability of ad-hoc network. This routing approach has the potential to be efficient in the generation of control traffic than traditional routing schemes. Up to now, without proper load balancing tools, the ZRP can actually guarantee QoS for delay-sensitive applications when congestion occurred in ad-hoc network. In this paper, we propose the ARLB to improve QoS fur delay-sensitive applications based on ZRP in ad-hoc network when congestion occurred and to be forwarding mechanism fur route coupling to support QoS for real-time applications. The critical point is that the routing metric of ARLB is originally designed for wired network environment. Therefore, we study and present an appropriate metric or cost computation routing of ARLB for recently proposed ZRP over ad-hoc network environment.

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Storm-Time Behaviour of Meso-Scale Field-Aligned Currents: Case Study with Three Geomagnetic Storm Events

  • Awuor, Adero Ochieng;Baki, Paul;Olwendo, Joseph;Kotze, Pieter
    • Journal of Astronomy and Space Sciences
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    • v.36 no.3
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    • pp.133-147
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    • 2019
  • Challenging Minisatellite Payload (CHAMP) satellite magnetic data are used to investigate the latitudinal variation of the storm-time meso-scale field-aligned currents by defining a new metric called the FAC range. Three major geomagnetic storm events are considered. Alongside SymH, the possible contributions from solar wind dynamic pressure and interplanetary magnetic field (IMF) $B_Z$ are also investigated. The results show that the new metric predicts the latitudinal variation of FACs better than previous studies. As expected, the equatorward expansion and poleward retreat are observed during the storm main phase and recovery phase respectively. The equatorward shift is prominent on the northern duskside, at ${\sim}58^{\circ}$ coinciding with the minimum SymH and dayside at ${\sim}59^{\circ}$ compared to dawnside and nightside respectively. The latitudinal shift of FAC range is better correlated to IMF $B_Z$ in northern hemisphere dusk-dawn magnetic local time (MLT) sectors than in southern hemisphere. The FAC range latitudinal shifts responds better to dynamic pressure in the duskside northern hemisphere and dawnside southern hemisphere than in southern hemisphere dusk sector and northern hemisphere dawn sector respectively. FAC range exhibits a good correlation with dynamic pressure in the dayside (nightside) southern (northern) hemispheres depicting possible electrodynamic similarity at day-night MLT sectors in the opposite hemispheres.

Analysis of Object-Oriented Metrics to Predict Software Reliability (소프트웨어 신뢰성 예측을 위한 객체지향 척도 분석)

  • Lee, Yangkyu
    • Journal of Applied Reliability
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    • v.16 no.1
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    • pp.48-55
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    • 2016
  • Purpose: The purpose of this study is to identify the object-oriented metrics which have strong impact on the reliability and fault-proneness of software products. The reliability and fault-proneness of software product is closely related to the design properties of class diagrams such as coupling between objects and depth of inheritance tree. Methods: This study has empirically validated the object-oriented metrics to determine which metrics are the best to predict fault-proneness. We have tested the metrics using logistic regressions and artificial neural networks. The results are then compared and validated by ROC curves. Results: The artificial neural network models show better results in sensitivity, specificity and correctness than logistic regression models. Among object-oriented metrics, several metrics can estimate the fault-proneness better. The metrics are CBO (coupling between objects), DIT (depth of inheritance), LCOM (lack of cohesive methods), RFC (response for class). In addition to the object-oriented metrics, LOC (lines of code) metric has also proven to be a good factor for determining fault-proneness of software products. Conclusion: In order to develop fault-free and reliable software products on time and within budget, assuring quality of initial phases of software development processes is crucial. Since object-oriented metrics can be measured in the early phases, it is important to make sure the key metrics of software design as good as possible.

Understanding Physical Mechanism of 2022 European Heat Wave (2022년 발생한 기록적인 유럽 폭염 발생의 역학적 원인 규명 연구)

  • Ju Heon Kim;Gun-Hwan Yang;Hyun-Joon Sung;Jung Hyun Park;Eunkyo Seo
    • Atmosphere
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    • v.33 no.3
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    • pp.307-317
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    • 2023
  • This study investigates the physical mechanisms that contributed to the 2022 European record-breaking heatwave throughout May-August (MJJA). The European climate has experienced surface warming and drying in the recent decade (1979~2022) which influences the development of the 2022 European heatwave. Since its spatial pattern resembles the 2003 European heatwave which is a well-known case developed by the strong coupling of near-surface conditions to land surface processes, the 2022 heatwave is compared with the 2003 case. Understanding heatwave development is carried out by the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis version 5 (ERA5) and daily maximum surface temperature released by NCEP (National Centers for Environmental Prediction) CPC (Climate Prediction Center). The results suggest that the persistent high pressure along with clear sky tends to increase the downward shortwave radiation which leads to enhanced sensible heat flux with the land surface dryness. Terrestrial Coupling Index (TCI), a process-based multivariate metric, is employed to quantitatively measure segmented feedback processes, separately for the land, atmosphere, and two-legged couplings, which appears to the development of the 2022 heatwave, can be viewed as an expression of the recent trends, amplified by internal land-atmosphere interactions.

A Metric of Component Extraction for Package based Object Oriented Codes (패키지 중심의 객체지향 코드의 컴포넌트 추출을 위한 메트릭)

  • 이종호;류성열
    • The Journal of Society for e-Business Studies
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    • v.8 no.2
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    • pp.113-129
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    • 2003
  • Component-based software development (CBSD) has been recognized effective reuse techniques for software development by many of researchers and companies. The purpose of CBSD is to produce a high quality software system quickly through using verified software component which is contained fine-grained business logics. This paper suggests the metrics and techniques for to extract component and its interface from legacy object oriented application. For extract component, we apply metrics to measure complexity, cohesion and coupling to the legacy system.

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Quality Visualization of Quality Metric Indicators based on Table Normalization of Static Code Building Information (정적 코드 내부 정보의 테이블 정규화를 통한 품질 메트릭 지표들의 가시화를 위한 추출 메커니즘)

  • Chansol Park;So Young Moon;R. Young Chul Kim
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.5
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    • pp.199-206
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    • 2023
  • The current software becomes the huge size of source codes. Therefore it is increasing the importance and necessity of static analysis for high-quality product. With static analysis of the code, it needs to identify the defect and complexity of the code. Through visualizing these problems, we make it guild for developers and stakeholders to understand these problems in the source codes. Our previous visualization research focused only on the process of storing information of the results of static analysis into the Database tables, querying the calculations for quality indicators (CK Metrics, Coupling, Number of function calls, Bad-smell), and then finally visualizing the extracted information. This approach has some limitations in that it takes a lot of time and space to analyze a code using information extracted from it through static analysis. That is since the tables are not normalized, it may occur to spend space and time when the tables(classes, functions, attributes, Etc.) are joined to extract information inside the code. To solve these problems, we propose a regularized design of the database tables, an extraction mechanism for quality metric indicators inside the code, and then a visualization with the extracted quality indicators on the code. Through this mechanism, we expect that the code visualization process will be optimized and that developers will be able to guide the modules that need refactoring. In the future, we will conduct learning of some parts of this process.

The Complexity of the Static Structures of Object-Oriented Systems by Analyzing the Class Diagram of UML (UML 클래스 다이어그램의 분석에 의한 객체지향 시스템의 정적 구조 복잡도 연구)

  • Chung, Hong;Hong, Dong-Kwon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.6
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    • pp.793-799
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    • 2004
  • Many researches and validations for the complexity metrics of the object-oriented systems have been studied. Most of them are aimed for the measurement of the partial aspects of the systems, for example, the coupling between objects, the complexity of inheritance structures, the cohesion of methods, and so on. But the software practitioners want to measure the complexity of overall system, not partial. We studied the complexity of the overall structures of object-oriented systems by analyzing the class diagram of UML. The class diagram is composed of classes and their relations. There are three kinds of relations, association, generalization, and aggregation, which are making the structure of object-oriented systems to be difficult to understand. We proposed a heuristic metric to measure the complexity of object-oriented systems by putting together the three kinds of the relations. This metric will be helpful to the software developers for their designing tasks by evaluating the complexity of the structures of object-oriented system and redesigning tasks of the system.

The Complexity of Object-Oriented Systems by Analyzing the Class Diagram of UML (UML 클래스 다이어그램 분석에 의한 객체지향 시스템의 복잡도 연구)

  • Chung, Hong;Kim, Tae-Sik
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.6
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    • pp.780-787
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    • 2005
  • Many researches and validations for the complexity metrics of the object-oriented systems have been studied. Most of them are aimed for the measurement of the partial aspects of the systems, for example, the coupling between objects, the complexity of inheritance structures, the cohesion of methods, and so on. But the software practitioners want to measure the complexity of overall system, not partial. We studied the complexity of the overall structures of object-oriented systems by analyzing the class diagram of UML. The class diagram is composed of classes and their relations. There are three kinds of relations, association, generalization, and aggregation, which are making the structure of object-oriented systems to be difficult to understand. We proposed a heuristic metric to measure the complexity of object-oriented systems by putting together the three kinds of the relations. Tn analyze the complexity of the structure of a object-oriented system for the maintainability of the system, we measured the degree of understandability of it, the reverse engineering time to draw a class diagram from the source codes, and the number of errors in the diagram. The results of this experiment shows that our proposed metric has a considerable relationship with the complexity of object-oriented systems. The metric will be helpful to the software developers for their designing tasks by evaluating the complexity of the structures of object-oriented systems and redesigning tasks , of them for the future maintainability.