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A study on the Enhanced System Dependence Graph for slicing of object-oriented Program (객체지향 프로그램 슬라이싱을 위한 개선된 시스템 종속성 그래프에 대한 연구)

  • 류희열;김은정
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10d
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    • pp.115-117
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    • 2002
  • 객체지향 프로그램 슬라이싱을 위한 Loren D Larsen and Marry Jean Harrold가 제안하는 방법은 절차적 프로그램 슬라이싱을 위한 시스템 종속성 그래프 표현방법에 객체지향 패러다임을 표현할 수 있도록 확장하며 2단계 마킹 알고리즘을 적용하여 슬라이스를 계산한다. 시스템 종속성 그래프를 이용한 슬라이싱 방법은 클래스 멤버 변수와 전역변수 및 인스턴스 변수에 대하여 각 메소드 호출 및 진입정점에 actual_in, actual_out, formal_in, formal_out 정점들이 추가되어 복잡도가 증가한다. 본 논문에서는 이들 변수를 클래스 정점의 멤버간선으로 연결하여 각 메소드의 문장에서 사용하면 진출간선 정의하면 진입간선으로 연결하여 정점과 간선들의 개수를 최소화할 수 있도록 시스템 종속성 그래프를 개선하였다. 제안하는 시스템 종속성 그래프는 그래프 복잡도의 최소화와 2단계 알고리즘에 의한 정확한 슬라이스 계산이 장점이다. C++ 예제 프로그램을 적용하여 그래프 복잡도의 감소와 정확한 슬라이스 계산을 기존의 방법과 비교하여 개선됨을 확인하였다.

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A Novel Ring-based Multicast Framework for Wireless Mobile Ad hoc Network

  • Yubai Yang;Hong, Choong-Seon
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04a
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    • pp.430-432
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    • 2004
  • Multicasting is an efficient means of one to many (or many to many) communications. Due to the frequent and unpredictable topology changes, multicast still remains as challenge and no one-size-fits-all protocol could serve all kinds of needs in ad hoc network. Protocols and approaches currently proposed on this issue could be classified mainly into four categories, tree-based, meshed-based, statelessness and hybrid. In this article, we borrow the concept of Eulerian ring in graph theory and propose a novel ring-based multicast framework--Hierarchical Eulerian Ring-Oriented Multicast Architecture (HEROMA) over wireless mobile Ad hoc network. It is familiar with hybrid protocol based on mesh and tree who concentrates on efficiency and robustness simultaneously. Architecture and recovery algorithm of HEROMA are investigated in details. Simulation result is also presented, which show different level of improvements on end-to-end delay in scenario of small scale.

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Weighted Maxmin Fair Routing Algorithm in Connection-Oriented Network: Soft QoS(SQS) Service (연결지향 네트워크에서의 가중치 최소극대 공정 라우팅 알고리즘)

  • Won, Hyeon-Kwon;Kwon, Oh-Heum
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.11b
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    • pp.1237-1240
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    • 2002
  • 본 논문에서는 ATM과 같은 연결 지향적 고속네트워크에서, 가중치를 가진 Flow들의 대역폭 할당과 라우팅문제에 있어 공정성과 처리량에 대하여 고려해 보았다. 가중치클 고려치 않은 Flow들에 대한 최적경로설정문제에 대하여, 기존의 QoS 서비스와 Best-Effort 서비스에서 연구된 라우팅알고리즘에서 벗어나, 본 논문은 가중치를 가진 Flow들에 대하여 Soft-QoS서비스를 지원함에 있어서 공정성과 최대 처리량을 정의하고, 또한 이를 바탕으로 가중치 최소극대 대역폭 할당과 가중치 최소극대 공정라우팅 알고리즘을 제안한다. 종단간 최적경로를 설정하는데, 최소비용으로 Bottleneck-Link를 구하고 대역폭을 할당하기 위하여 그래프 상의 노드에 두 가지 색을 사용하는 그래프문제(Graph Coloring)와 최악의 경우를 감안하면서 경로를 선택하는 최소극대화 문제(Maxmin)를 결부시켜 살펴본다. 나아가 Soft-QoS 서비스의 최대값과 최소값을 고려한 가중치를 가진 Weighted-Flow들의 대역폭 할당과 경로설정에 있어, 동적인 네트워크 환경에 보다 효율적으로 접근 가능한 근사 알고리즘을 제안한다.

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Ensemble Engine: Framework Design for Visual Novel Game Production

  • Choi, Jong In;Kang, Shin Jin
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.5
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    • pp.11-17
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    • 2019
  • In this study, we propose an ensemble engine, which is a framework for game engine optimized for visual novels genre, focusing on storytelling among various game genres. The game of Visual Nobel genre is based on multi-ending story and features branching of various scenarios according to user's choice. The proposed engine supports various multi-scenarios and multi-endings based on nodes according to the characteristics of these genres. In addition, it provides a convenient and intuitive user interface that not only enhances user immersion but also provides VR function to maximize the sense of presence. We will demonstrate the usefulness of the proposed game engine by designing the framework of a game engine suitable for this feature and actually creating variety stories automatically.

INFRA-RPL to Support Dynamic Leaf Mode for Improved Connectivity of IoT Devices (IoT 디바이스의 연결성 향상을 위한 동적 leaf 모드 기반의 INFRA-RPL)

  • Seokwon Hong;Seong-eun Yoo
    • IEMEK Journal of Embedded Systems and Applications
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    • v.18 no.4
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    • pp.151-157
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    • 2023
  • RPL (IPv6 Routing Protocol for Low-power Lossy Network) is a standardized routing protocol for LLNs (Low power and Lossy Networks) by the IETF (Internet Engineering Task Force). RPL creates routes and builds a DODAG (Destination Oriented Directed Acyclic Graph) through OF (Objective Function) defining routing metrics and optimization objectives. RPL supports a leaf mode which does not allow any child nodes. In this paper, we propose INFRA-RPL which provides a dynamic leaf mode functionality to a leaf node with the mobility. The proposed protocol is implemented in the open-source IoT operating system, Contiki-NG and Cooja simulator, and its performance is evaluated. The evaluation results show that INFRA-RPL outperforms the existing protocols in the terms of PDR, latency, and control message overhead.

A Ranking Algorithm for Semantic Web Resources: A Class-oriented Approach (시맨틱 웹 자원의 랭킹을 위한 알고리즘: 클래스중심 접근방법)

  • Rho, Sang-Kyu;Park, Hyun-Jung;Park, Jin-Soo
    • Asia pacific journal of information systems
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    • v.17 no.4
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    • pp.31-59
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    • 2007
  • We frequently use search engines to find relevant information in the Web but still end up with too much information. In order to solve this problem of information overload, ranking algorithms have been applied to various domains. As more information will be available in the future, effectively and efficiently ranking search results will become more critical. In this paper, we propose a ranking algorithm for the Semantic Web resources, specifically RDF resources. Traditionally, the importance of a particular Web page is estimated based on the number of key words found in the page, which is subject to manipulation. In contrast, link analysis methods such as Google's PageRank capitalize on the information which is inherent in the link structure of the Web graph. PageRank considers a certain page highly important if it is referred to by many other pages. The degree of the importance also increases if the importance of the referring pages is high. Kleinberg's algorithm is another link-structure based ranking algorithm for Web pages. Unlike PageRank, Kleinberg's algorithm utilizes two kinds of scores: the authority score and the hub score. If a page has a high authority score, it is an authority on a given topic and many pages refer to it. A page with a high hub score links to many authoritative pages. As mentioned above, the link-structure based ranking method has been playing an essential role in World Wide Web(WWW), and nowadays, many people recognize the effectiveness and efficiency of it. On the other hand, as Resource Description Framework(RDF) data model forms the foundation of the Semantic Web, any information in the Semantic Web can be expressed with RDF graph, making the ranking algorithm for RDF knowledge bases greatly important. The RDF graph consists of nodes and directional links similar to the Web graph. As a result, the link-structure based ranking method seems to be highly applicable to ranking the Semantic Web resources. However, the information space of the Semantic Web is more complex than that of WWW. For instance, WWW can be considered as one huge class, i.e., a collection of Web pages, which has only a recursive property, i.e., a 'refers to' property corresponding to the hyperlinks. However, the Semantic Web encompasses various kinds of classes and properties, and consequently, ranking methods used in WWW should be modified to reflect the complexity of the information space in the Semantic Web. Previous research addressed the ranking problem of query results retrieved from RDF knowledge bases. Mukherjea and Bamba modified Kleinberg's algorithm in order to apply their algorithm to rank the Semantic Web resources. They defined the objectivity score and the subjectivity score of a resource, which correspond to the authority score and the hub score of Kleinberg's, respectively. They concentrated on the diversity of properties and introduced property weights to control the influence of a resource on another resource depending on the characteristic of the property linking the two resources. A node with a high objectivity score becomes the object of many RDF triples, and a node with a high subjectivity score becomes the subject of many RDF triples. They developed several kinds of Semantic Web systems in order to validate their technique and showed some experimental results verifying the applicability of their method to the Semantic Web. Despite their efforts, however, there remained some limitations which they reported in their paper. First, their algorithm is useful only when a Semantic Web system represents most of the knowledge pertaining to a certain domain. In other words, the ratio of links to nodes should be high, or overall resources should be described in detail, to a certain degree for their algorithm to properly work. Second, a Tightly-Knit Community(TKC) effect, the phenomenon that pages which are less important but yet densely connected have higher scores than the ones that are more important but sparsely connected, remains as problematic. Third, a resource may have a high score, not because it is actually important, but simply because it is very common and as a consequence it has many links pointing to it. In this paper, we examine such ranking problems from a novel perspective and propose a new algorithm which can solve the problems under the previous studies. Our proposed method is based on a class-oriented approach. In contrast to the predicate-oriented approach entertained by the previous research, a user, under our approach, determines the weights of a property by comparing its relative significance to the other properties when evaluating the importance of resources in a specific class. This approach stems from the idea that most queries are supposed to find resources belonging to the same class in the Semantic Web, which consists of many heterogeneous classes in RDF Schema. This approach closely reflects the way that people, in the real world, evaluate something, and will turn out to be superior to the predicate-oriented approach for the Semantic Web. Our proposed algorithm can resolve the TKC(Tightly Knit Community) effect, and further can shed lights on other limitations posed by the previous research. In addition, we propose two ways to incorporate data-type properties which have not been employed even in the case when they have some significance on the resource importance. We designed an experiment to show the effectiveness of our proposed algorithm and the validity of ranking results, which was not tried ever in previous research. We also conducted a comprehensive mathematical analysis, which was overlooked in previous research. The mathematical analysis enabled us to simplify the calculation procedure. Finally, we summarize our experimental results and discuss further research issues.

Development of a Korean Speech Recognition Platform (ECHOS) (한국어 음성인식 플랫폼 (ECHOS) 개발)

  • Kwon Oh-Wook;Kwon Sukbong;Jang Gyucheol;Yun Sungrack;Kim Yong-Rae;Jang Kwang-Dong;Kim Hoi-Rin;Yoo Changdong;Kim Bong-Wan;Lee Yong-Ju
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.8
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    • pp.498-504
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    • 2005
  • We introduce a Korean speech recognition platform (ECHOS) developed for education and research Purposes. ECHOS lowers the entry barrier to speech recognition research and can be used as a reference engine by providing elementary speech recognition modules. It has an easy simple object-oriented architecture, implemented in the C++ language with the standard template library. The input of the ECHOS is digital speech data sampled at 8 or 16 kHz. Its output is the 1-best recognition result. N-best recognition results, and a word graph. The recognition engine is composed of MFCC/PLP feature extraction, HMM-based acoustic modeling, n-gram language modeling, finite state network (FSN)- and lexical tree-based search algorithms. It can handle various tasks from isolated word recognition to large vocabulary continuous speech recognition. We compare the performance of ECHOS and hidden Markov model toolkit (HTK) for validation. In an FSN-based task. ECHOS shows similar word accuracy while the recognition time is doubled because of object-oriented implementation. For a 8000-word continuous speech recognition task, using the lexical tree search algorithm different from the algorithm used in HTK, it increases the word error rate by $40\%$ relatively but reduces the recognition time to half.

EC-RPL to Enhance Node Connectivity in Low-Power and Lossy Networks (저전력 손실 네트워크에서 노드 연결성 향상을 위한 EC-RPL)

  • Jeadam, Jung;Seokwon, Hong;Youngsoo, Kim;Seong-eun, Yoo
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.6
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    • pp.41-49
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    • 2022
  • The Internet Engineering Task Force (IETF) has standardized RPL (IPv6 Routing Protocol for Low-power Lossy Network) as a routing protocol for Low Power and Lossy Networks (LLNs), a low power loss network environment. RPL creates a route through an Objective Function (OF) suitable for the service required by LLNs and builds a Destination Oriented Directed Acyclic Graph (DODAG). Existing studies check the residual energy of each node and select a parent with the highest residual energy to build a DODAG, but the energy exhaustion of the parent can not avoid the network disconnection of the children nodes. Therefore, this paper proposes EC-RPL (Enhanced Connectivity-RPL), in which ta node leaves DODAG in advance when the remaining energy of the node falls below the specified energy threshold. The proposed protocol is implemented in Contiki, an open-source IoT operating system, and its performance is evaluated in Cooja simulator, and the number of control messages is compared using Foren6. Experimental results show that EC-RPL has 6.9% lower latency and 5.8% fewer control messages than the existing RPL, and the packet delivery rate is 1.7% higher.

Improving Visual Object Query language (VOQL) by Introducing Visual Elements and visual Variables (시각 요소와 시각 변수를 통한 시각 객체 질의어(VOQL)의 개선)

  • Lee, Seok-Gyun
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.6
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    • pp.1447-1457
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    • 1999
  • Visual Object Query language(VOQL) proposed recently is a visual object-oriented database query language which can effectively represent queries on complex structured data, since schema information is visually included in query expressions. VOQL, which is a graph-based query language with inductively defined semantics, can concisely represent various text-based path expressions by graph, and clearly convey the semantics of complex path expressions. however, the existing VOQL assumes that all the attributes are multi-valued, and cannot visualize the concept of binding of object variables. therefore, VPAL query expressions are not intuitive, so that it is difficult to extend the existing VOQL theoretically. In this paper, we propose VOQL that improved on these problems. The improved VOQL visualizes the result of a single-valued attribute and that of a multi-valued attribute as a visual element and a subblob, respectively, and specifies the binding of object variables by introducing visual variables, so that the improved VOQL intuitively and clearly represents the semantics of queries.

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A Extraction of Multiple Object Candidate Groups for Selecting Optimal Objects (최적합 객체 선정을 위한 다중 객체군 추출)

  • Park, Seong-Ok;No, Gyeong-Ju;Lee, Mun-Geun
    • Journal of KIISE:Software and Applications
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    • v.26 no.12
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    • pp.1468-1481
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    • 1999
  • didates.본 논문은 절차 중심 소프트웨어를 객체 지향 소프트웨어로 재/역공학하기 위한 다단계 절차중 첫 절차인 객체 추출 절차에 대하여 기술한다. 사용한 객체 추출 방법은 전처리, 기본 분할 및 결합, 정제 결합, 결정 및 통합의 다섯 단계로 이루어진다 : 1) 전처리 과정에서는 객체 추출을 위한 FTV(Function, Type, Variable) 그래프를 생성/분할 및 클러스터링하고, 2) 기본 분할 및 결합 단계에서는 다중 객체 추출을 위한 그래프를 생성하고 생성된 그래프의 정적 객체를 추출하며, 3) 정제 결합 단계에서는 동적 객체를 추출하며, 4) 결정 단계에서는 영역 모델링과 다중 객체 후보군과의 유사도를 측정하여 영역 전문가가 하나의 최적합 후보를 선택할 수 있는 측정 결과를 제시하며, 5) 통합 단계에서는 전처리 과정에서 분리된 그래프가 여러 개 존재할 경우 각각의 처리된 그래프를 통합한다. 본 논문에서는 클러스터링 순서가 고정된 결정론적 방법을 사용하였으며, 가능한 경우의 수에 따른 다중 객체 후보, 객관적이고 의미가 있는 객체 추출 방법으로의 정제와 결정, 영역 모델링을 통한 의미적 관점에 기초한 방법 등을 사용한다. 이러한 방법을 사용함으로써 전문가는 객체 추출 단계에서 좀더 다양하고 객관적인 선택을 할 수 있다.Abstract This paper presents an object extraction process, which is the first phase of a methodology to transform procedural software to object-oriented software. The process consists of five steps: the preliminary, basic clustering & inclusion, refinement, decision and integration. In the preliminary step, FTV(Function, Type, Variable) graph for object extraction is created, divided and clustered. In the clustering & inclusion step, multiple graphs for static object candidate groups are generated. In the refinement step, each graph is refined to determine dynamic object candidate groups. In the decision step, the best candidate group is determined based on the highest similarity to class group modeled from domain engineering. In the final step, the best group is integrated with the domain model. The paper presents a new clustering method based on static clustering steps, possible object candidate grouping cases based on abstraction concept, a new refinement algorithm, a similarity algorithm for multiple n object and m classes, etc. This process provides reengineering experts an comprehensive and integrated environment to select the best or optimal object candidates.