• 제목/요약/키워드: graphical representation

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상태.공간 방식에 의한 항공기 동특성 해석 교육 시뮬레이터 개발 (Development of the Educational Simulator for Aircraft Dynamic Characteristic Analysis with the State-Space Method)

  • 윤선주
    • 한국항공운항학회지
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    • 제17권1호
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    • pp.9-16
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    • 2009
  • The analysis of an aircraft flight dynamics is recently very convenient because of the introduction of state-space method and a well-developed package software. The representation of a dynamic system is described as a simple form of matrix calculation and the unique form of model is available for the linear or nonlinear, time variant or time invariant, mono variable or multi variable system with state-space method. And this analysis can be simplified with the specific functions of a package software and it is very simplified to execute the simulation of the dynamic characteristics for an aircraft model with an interactive graphical treatment. The purpose of this study is to develope an educational flight simulator for the students who need to analyze the dynamic characteristics of an aircraft that is primarily to execute the simulation for the analysis of the transient response and frequency response of an aircraft stability. Furthermore the dynamic characteristics of an aircraft motion is set up as dynamical animation tool for the control response on 3-axis motions of an aircraft.

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ROC 곡면에서 VUS의 판단기준 (Standard Criterion of VUS for ROC Surface)

  • 홍종선;정의석;정동근
    • 응용통계연구
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    • 제26권6호
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    • pp.977-985
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    • 2013
  • 현실세계에는 두 가지 범주 이상으로 분류되는 경우가 많이 존재한다. 본 논문은 분류범주가 세 종류인 분류모형을 시각적으로 표현하는 방법인 ROC 곡면과 이 곡면 아래의 체적을 나타내는 VUS 통계량을 고려한다. 바젤 II에 기반한 부도확률에 관한 AUC 통계량의 판단기준을 ROC 곡면에서의 VUS에 대하여 확장하여, VUS에 의한 판별력 판단기준 13단계를 제안한다. 제안한 판단기준 각 단계에서의 VUS값에 대응하는 AUC, K-S 통계량 그리고 세 분포의 평균차이에 대한 범위를 탐색하고, 이들의 관계를 살펴봄으로써 VUS 통계량의 판별력 판단기준을 설정한다.

이동통신 액세스망 설계 (Mobile Access Network Design)

  • 김후곤;백천현;권준혁;정용주
    • 경영과학
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    • 제24권2호
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    • pp.127-142
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    • 2007
  • This study deals with the optimal design of mobile access network connecting base stations(BSs) and mobile switching centers(MSCs). Generally mobile operators constitute their access networks by leasing communication lines. Using the characteristic of leased line rate based on administration region, we build an optimization model for mobile access network design which has much smaller number of variables than the existing researches. And we develop a GUI based optimization tool integrating the well-known softwares such as MS EXCEL. MS VisualBasic, MS PowerPoint and Ip_solve, a freeware optimization software. Employing the current access network configuration of a Korean mobile carrier, this study using the optimization tool obtain an optimal solution for both single MSC access network and nation-wide access network. Each optimal access network achieves 7.45% and 9.49% save of lease rate, respectively. Considering the monthly charge and total amount of lease line rate, our optimization tool provides big amount of save in network operation cost. Besides the graphical representation of access networks makes the operator easily understand and compare current and optimal access networks.

Shipyard Spatial Scheduling Solution using Genetic Algorithms

  • Yoon Duck Young;Ranjan Varghese
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.35-39
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    • 2004
  • In a shipyard, there exist various critical decision making components pertaining to various production hindrances. The most prominent one is best-fit spatial arrangement for the minimal spatial occupancy with better pick-ability for the erection of the ship in the dock. During the present research, a concept have been conceived to evade the gap between the identification oj inter-relationships among a set of blocks to be included on a pre-erection area, and a detailed graphical layout of their positions, is called an Optimal Block Relationship Diagram A research has been performed on generation of optimal (or near Optimal) that is, with minimal scrap area. An effort has been made in the generation of optimal (or near-optimal) Optimal Block Relationship Diagram with the Goldberg's Genetic Algorithms with a representation and a set of operators are 'trained' specifically for this application. The expected result to date predicts very good solutions to test problems involving innumerable different blocks to place. The suggested algorithm could accept input from an erection sequence generator program which assists the user in defining the nature and strength of the relationships among blocks, and could produce input suitable for use in a detailed layout stage.

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A Role-driven Security and Access Control Model for Secured Business Process Management Systems

  • Won Jae-Kang;Kim Kwang-Hoon
    • 한국정보시스템학회지:정보시스템연구
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    • 제14권3호
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    • pp.1-8
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    • 2005
  • This paper formally defines a role-driven security and access control model of a business process in order eventually to provide a theoretical basis for realizing the secured business process management systems. That is, we propose a graphical representation and formal description of the mechanism that generates a set of role-driven security and access control models from a business process modeled by the information control net(ICN) modeling methodology that is a typical business process modeling approach for defining and specifying business processes. Based upon the mechanism, we are able to design and accomplish a secured business process management system that provides an unified resource access control mechanism of the business process management engine domain's and the application domain's. Finally, we strongly believe that the secured access control policies from the role-driven security and access control model can be easily transformed into the RBAC(Role-based Access Control) model that is a standardized security technology for computer and communications systems of commercial and civilian government organizations.

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온톨로지 기반의 전문가 시스템 구축을 위한 퍼지 추론 엔진 (Fuzzy Inference Engine for Ontology-based Expert Systems)

  • 최상균;김재생
    • 한국콘텐츠학회논문지
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    • 제9권6호
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    • pp.45-52
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    • 2009
  • 최근 제조업에서 제품 설계를 지원하는 디지털 전문가 시스템을 개발하는 사례가 일어나고 있다. 이 시스템은 제조업에서 엔지니어가 프로세스를 통제하고, 생산관리와 시스템 관리 등을 위하여 사용되고 있다. 본 논문에서는 전문가 시스템을 구축하기 위한 온톨로지 기반의 추론 엔진 개발에 대하여 논한다. 전문가 시스템은 한국어를 지원하고 다양한 기능을 가지며, 그래픽한 온톨로지 맵 인터페이스와 퍼지 룰 기능 정의 등의 기능을 갖도록 하였다. 또한, 온톨로지 맵 구축과 온톨로지 기반의 퍼지 추론 방법에 대하여 지식을 표현하는 방법에 대하여 설명한다.

An Analysis of the Exchange Rate Regime of Nepal: Determinants and Inter-Dynamic Relationship with Macroeconomic Fundamentals

  • DAHAL, Suresh Kumar;RAJU, G. Raghavender
    • The Journal of Asian Finance, Economics and Business
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    • 제9권7호
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    • pp.27-39
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    • 2022
  • The exchange rate is an important macroeconomic variable that influences internal and external balances. Nepal follows a dual exchange rate such that the Nepali rupee (NPR) is pegged with the Indian rupee (INR) but floats with the United States dollar (USD) and all other currencies. There have been very few studies on the exchange rate of Nepal, of which the majority focus on the bivariate relationship between exchange rate and another variable. However, this paper analyses the multivariate relationship between the USD-NPR exchange rate and major macroeconomic variables. Determinants of Nepal's exchange rate have been derived with multiple regression using the ordinary least square (OLS) approach. Since the explanatory variables could not significantly capture the movement of the dependent variable, a long-run relationship between Nepal and India's exchange rate has been analyzed using Engle-Granger cointegration to establish a relationship as suggested by a graphical representation. This explains that Nepal's exchange rate long run is determined by India's exchange rate than its own fundamentals. In addition, the macro-linkages of Nepal's macroeconomic variables have been analyzed using Standard Vector Autoregressive models followed by impulse response analysis which is useful for policy decisions. Some policy implications indicating the sustainability of Nepal's pegged regime have been drawn based on the empirical analysis.

Multimedia Document Databases : Representation, Query Processing and Navigation

  • Kalakota, Ravi S.;Whinston, Andrew B.
    • 정보기술과데이타베이스저널
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    • 제1권1호
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    • pp.31-62
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    • 1994
  • Information systems for application areas like office automation, customer service or computer aided manufacturing are usually highly interactive and deal with complex document structures composed of multiple media formats. For the realization of these systems, nonstandard database systems, which we call document databases, need to handle different types of coarse-and fine-grained document objects(like full-text documents, graphics and images), hierarchical and non-hierarchical relationships between objects(like composition-links and cross-references using hypertext structures) and document attributes of different types such as formatting/presentation information and access control. In this paper, we present the underlying data model for document databases based on descriptive markup languages that provide mechanisms for specifying the logical structure(or schema) of individual documents stored in the database. We then describe extensions to the data model for supporting notion of composite structures("join" operators for documents) --composition and hyperlinking mechanisms for representing compound documents and inter-linked documents as unique entites separate from their components. Furthermore, due to the interactive nature of the application domains, the database system in conjunction with clients(or browsers) has to support visual navigation and graphical query mechanisms. We describe the functionality of a new user interface paradigm called HyBrow for meeting the above mentioned requirements. The underlying implementation strategy is also discussed.discussed.

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LandScient_EWS: Real-Time Monitoring of Rainfall Thresholds for Landslide Early Warning - A Case Study in the Colombian Andes

  • Roberto J. Marin;Julian Camilo Marin-Sanchez
    • 지질공학
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    • 제34권2호
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    • pp.173-191
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    • 2024
  • Landslides pose significant threats to many countries globally, yet the development and implementation of effective landslide early warning systems (LEWS) remain challenging due to multifaceted complexities spanning scientific, technological, and political domains. Addressing these challenges demands a holistic approach. Technologically, integrating thresholds, such as rainfall thresholds, with real-time data within accessible, open-source software stands as a promising solution for LEWS. This article introduces LandScient_EWS, a PHP-based program tailored to address this need. The software facilitates the comparison of real-time measured data, such as rainfall, with predefined landslide thresholds, enabling precise calculations and graphical representation of real-time landslide advisory levels across diverse spatial scales, including regional, basin, and hillslope levels. To illustrate its efficacy, the program was applied to a case study in Medellin, Colombia, where a rainfall event on August 26, 2008, triggered a shallow landslide. Through pre-defined rainfall intensity and duration thresholds, the software simulated advisory levels during the recorded rainfall event, utilizing data from a rain gauge positioned within a small watershed and a single grid cell (representing a hillslope) within that watershed. By identifying critical conditions that may lead to landslides in real-time scenarios, LandScient_EWS offers a new paradigm for assessing and responding to landslide hazards, thereby improving the efficiency and effectiveness of LEWS. The findings underscore the software's potential to streamline the integration of rainfall thresholds into both existing and future landslide early warning systems.

상한론(傷寒論)온톨로지 구축 방법론 연구 (Study on a Methodology for Developing Shanghanlun Ontology)

  • 정태영;김희열;박종현
    • 동의생리병리학회지
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    • 제25권5호
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    • pp.765-772
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    • 2011
  • Knowledge which is represented by formal logic are widely used in many domains such like artificial intelligence, information retrieval, e-commerce and so on. And for medical field, medical documentary records retrieval, information systems in hospitals, medical data sharing, remote treatment and expert systems need knowledge representation technology. To retrieve information intellectually and provide advanced information services, systematically controlled mechanism is needed to represent and share knowledge. Importantly, medical expert's knowledge should be represented in a form that is understandable to computers and also to humans to be applied to the medical information system supporting decision making. And it should have a suitable and efficient structure for its own purposes including reasoning, extendability of knowledge, management of data, accuracy of expressions, diversity, and so on. we call it ontology which can be processed with machines. We can use the ontology to represent traditional medicine knowledge in structured and systematic way with visualization, then also it can also be used education materials. Hence, the authors developed an Shanghanlun ontology by way of showing an example, so that we suggested a methodology for ontology development and also a model to structure the traditional medical knowledge. And this result can be used for student to learn Shanghanlun by graphical representation of it's knowledge. We analyzed the text of Shanghanlun to construct relational database including it's original text, symptoms and herb formulars. And then we classified the terms following some criterion, confirmed the structure of the ontology to describe semantic relations between the terms, especially we developed the ontology considering visual representation. The ontology developed in this study provides database showing fomulas, herbs, symptoms, the name of diseases and the text written in Shanghanlun. It's easy to retrieve contents by their semantic relations so that it is convenient to search knowledge of Shanghanlun and to learn it. It can display the related concepts by searching terms and provides expanded information with a simple click. It has some limitations such as standardization problems, short coverage of pattern(證), and error in chinese characters input. But we believe this research can be used for basic foundation to make traditional medicine more structural and systematic, to develop application softwares, and also to applied it in Shanghanlun educations.