• 한국국방경영분석학회지
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• 제29권1호
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• pp.57-75
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• 2003

Policy-based networking offers a network manager the ability to manage the network in a holistic and dynamic fashion rather than force a network manager to manage the network by dealing with each device individually. Policy-based networking is focusing on users and applications instead of emphasizing devices and interfaces. An important part of the policy-based networking is to simplify the task of administration and management for different disciplines. The Defense Information System(DIS) of today are complex and heterogeneous systems. Operational needs are not a trivial task and Quality of Service(QoS) is not generally guaranteed. So, important data may be missed or congested by trivial data. Policy-based networking provide a way to support QoS and simplify the management of multiple devices deploying complex technologies. This paper suggest implementation of policy-based networking in DIS to improvement of performance, and implementation is progressed step by step. Especially this paper is focusing on the providing QoS with policy-based networking using Lightweight Directory Access Protocol(LDAP) Server.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.22-24
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• 2008

This paper presents a numerical model of internal flows in a lubricant supplying and scavenging flow path of an aero-engine lubrication system. The numerical model was built in the General Analysis Software of Aero-engine Lubrication System, GASLS, developed by Northwestern Polytechnical University. The lubricant flow flux, pressure and temperature distribution at steady state were calculated. GASLS is a general purpose computer program employed a 1-D steady state network algorithm for analyzing flowrates, pressures and temperatures in a complex flow network. All kinds of aero-engine lubrication systems can be divided into finite correlative typical elements and nodes from which the calculation network be developed in GASLS. Special emphasis is on how to use combined elements which is a type of typical elements to replace some complex components like bearing bores, accessory gearboxes or heat exchangers. This method can reduce network complexity and improve calculation efficiency. Final computational results show good agreement with experimental data.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.351-361
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• 2021

This study proposes an intelligent control of manufacturing robot with dual arm based on neural network for smart factory implementation. In the control method of robot system, the perspectron structure of single layer based on neural network is useful for simple computation. However, the limitations of computation are emerging in areas that require complex computations. To overcome limitation of complex parameters computation a new intelligent control technology is proposed in this study. The performance is illustrated by simulation and experiments for manufacturing robot dual arm robot with eight axes.

• 한국분무공학회지
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• 제28권3호
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• pp.119-125
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• 2023

In this research, a network model was developed to predict combustion instability in an annular gas turbine combustor (GT24) for power generation. The model consisted of various acoustic elements such as several ducts and area changes which could represent a real combustor with a complex geometry, applied mass, momentum, and energy equations to each element. In addition, a one-dimensional network model through a cylindrical coordinate system has been proposed to predict various acoustic modes. As a result of the analysis, the key resonant frequencies such as longitudinal, circumferential, and complex modes were derived from the EV combustor of GT24, and the reliability of the current model was verified through comparison with the 3D Helmholtz solver.

• 대한전자공학회논문지TC
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• 제49권1호
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• pp.31-46
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• 2012

유비쿼터스 컴퓨팅 환경을 구현하기 위해서 가장 핵심이 되는 기술은 USN(Ubiquitous Sensor Network)기술로써 RFID(Radio Frequency Identification)와 무선 센서 네트워크(Wireless Sensor Network WSN)를 이용한 다양한 센서 기술과 프로세서 집적 기술 그리고 무선 네트워크 기술을 이용해서 실제 물리적 환경 정보를 원격에서 손쉽게 수집하고 모니터링 하는 것을 가능하게 함으로써 기존 가상 공간의 IT 기술을 다양한 실제 환경에서 확대할 수 있도록 한다. 그러나 RFID와 WSN은 이러한 기술적 유사성과 상호 영향에도 불구하고 별 개의 연구로 인식되었으며 RFID와 WSN의 기술적인 융합에 대한 연구는 미비한 수준이다. 이러한 문제점을 인식한 EPCglobal에서는 국제 표준인 EPCglobal Network를 기반으로 RFID와 WSN 기술을 효율적으로 통합/연동할 수 있는 EPC 센서 네트워크(EPC Sensor Network)를 제안하였다. 제안된 EPC 센서 네트워크는 미들웨어에서 복합 이벤트 처리(Complex Event Processing) 기법을 이용하여 RFID와 WSN을 통해 발생되는 데이터를 단일 환경에서 통합하고, 발생된 이벤트를 EPCglobal Network를 기반으로 연동하는 기술이다. 하지만 이러한 EPC 센서 네트워크는 미들웨어에서 복합 이벤트를 검출하기 위해 복합 이벤트를 구성하는 모든 기본 이벤트가 발생하지 못하는 경우에도 계속적인 검사를 수행하기 때문에 연산 비용이 증가되는 문제점이 있다. 또한 센서 데이터의 표현을 위해 RFID 태그의 EPC를 기반으로 센서 데이터를 하나의 결합된 쌍으로 표현한다. 이것은 센서 데이터를 처리하는데 있어 반드시 EPC가 있어야 함을 의미한다. 즉, 센서 데이터만을 위한 관리 기능은 제공하지 못하는 문제점이 있다. 이러한 EPC 센서 네트워크의 문제점들을 해결하기 위하여 본 논문에서는 RFID/WSN 통합 관리 시스템을 제안한다. 제안하는 RFID/WSN 통합 관리 시스템은 첫 번째, RFID와 WSN 데이터를 인터넷 표준 프로토콜인 SIP(Session Initiation Protocol) 기반의 통합 관리 시스템을 제안하였다. 두 번째, 미들웨어에서 불필요한 복합 이벤트 검출 연산을 위하여 복합 이벤트의 최소 조건을 정의하고 조건을 만족하는 경우에만 복합 이벤트를 검출하는 알고리즘을 제안하였다. 제안하는 기법들의 성능을 평가하기 위하여 SIP 기반의 통합관리시스템을 구현하여 성능을 평가하였다.

• 환경정책연구
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• 제14권2호
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• pp.27-47
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• 2015

투입 산출변수의 외생적 흐름에 기초한 전통적인 자료포락분석은 생산활동의 모든 내부과정을 'black box'로 간주하며 각 생산단계의 상호작용에 대한 정보를 고려하지 못한 한계를 지닌다. 이에 생산과정을 세분화하고 각 생산단계의 효율성을 연계하여 추정하는 Network DEA 방식이 최근 활발히 적용되고 있으며 특히 환경효율성의 추정과정을 생산 및 저감활동으로 구분한 연구가 대표적이다. 본고는 한국의 51개 산업단지를 대상으로 Network DEA에 기초한 환경효율성 추정을 시도하였으며, 분석결과 추정치의 변별력, 비효율의 발생단계, 기타 외생변수와의 통계적 관련성 등의 관점에서 전통적 DEA 추정결과에 비해 우수한 점을 확인할 수 있었다.

• 한국농공학회지
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• 제35권3호
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• pp.23-35
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• 1993

The objectives of this paper were to validate the proposed network flow model using field data and to demonstrate the model applicability for various purposes. The model was tested with data from the Banweol watershed, where an intentive streamflow gauging system has been established. Model parameters were not calibrated with field data so that it can be validated as ungaged conditions. Three different schemes were employed to represent the drainage system of the tested watershed : a single, complex, and detailed network. The single network assumed the watershed as a cell, while complex and detailed networks considered several cells. The results from different schemes were individually compared satisfactorily to the observed daily stages at the Banweol reservoir located at the outlet of the watershed. The results from three schemes were in close agreement with each other, Justifying that the model performs very well for different network schemes being used. Daily streamflow from three network schemes was compared for a selected reach within the watershed. The results were very close to each other regardless of network formulation. And the model was applied to simulate daily streamflow before and after the construction of a reservoir at a reach. The differences were discussed, which reflected the influences of the dam construction upon the downstream hydrology. Similar appliocations may be possible to identify the effects of hydraulic structures on streamflow.

• 한국주거학회논문집
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• 제27권5호
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• pp.25-35
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• 2016

he objective of this study was to investigate home network systems presently applied in multi-housing complexes and resident's usage to improve the utilization of these systems and services as well as maintenance methods. Subjects were 27 housing complexes equipped with home network systems in west Pangyo area. The investigation methods of communal network systems were observed and photographed. Unit systems were investigated through photography, interviews, and observation focusing on the utilization of Wall-Pads by visiting one unit of each housing complex. The results are as follows: (1) Most housing complexes that we investigated were built with high-grade IT infrastructure. Also, remote meter reading, electronic security, vehicle access, and building access systems were established. Wall-Pads with similar functions were installed in 23 housing complexes, excluding private rental housing complexes. (2) Even though people were well aware of the need for common systems within their housing complexes, only 10~20% of Wall-Pad menus were used. (3) Low utilization rates of home network stem from Wall-Pad menus which were user-unfriendly, and a lack of user training for the complex's common system and unit system. Therefore, to promote active use of home network systems, the systems must be diversified in accordance with user characteristics. In addition, the Wall-Pad menus should be reorganized to be user-friendly.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.147-147
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• 2021

A partition of water distribution network (WDN) into district metered areas (DMAs) brings the efficiency and efficacy for water network operation and management (O&M), especially in monitoring pressure and leakage. Traditionally, the DMA configurations (i.e., number, shape, and size of DMAs) are permanent and cannot be changed occasionally. This leads to changes in water quality and reduced network redundancy lowering network resilience against abnormal conditions such as water demand variability and mechanical failures. This study proposes a framework to automatically divide a WDN into dynamic DMA configurations, in which the DMA layouts can self-adapt in response to abnormal scenarios. To that aim, a complex graph theory is adopted to sectorize a WDN into multiscale DMA layouts. Then, different failure-based scenarios are investigated on the existing DMA layouts. Here, an optimization-based model is proposed to convert existing DMA layouts into dynamic layouts by considering existing valves and possibly placing new valves. The objective is to minimize the alteration of flow paths (i.e., flow direction and velocity in the pipes) while preserving the hydraulic performance of the network. The proposed method is tested on a real complex WDN for demonstration and validation of the approach.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 1998년도 국제 컨퍼런스: 국가경쟁력 향상을 위한 디지틀도서관 구축방안
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• pp.475-505
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• 1998

With rapid progresses in information technologies, managing enterprise network resources as a whole becomes more important. Telecommunication Management Network (TMN) has been used to integrate network elements. TMN is complex to develop and manage because it has a centralized management service. Common Object Request Broker Architecture (CORBA) can overcome this complexity by the use of transparent distributed object processing mechanism. Therefore, the main objective of this paper is to integrate TMN service with CORBA. A network management repository is built for this integration. In addition, a prototype that can partially support network management service is implemented to illustrate the usefulness of this repository.