• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2005년도 춘계종합학술대회
• /
• pp.189-192
• /
• 2005

본 논문에서는 병렬 데이터베이스 아키텍처로 널리 사용되고 있는 공유 데이터베이스 시스템에 대하여 각 구성요소에 대한 고장을 고려한 신뢰도 모델을 모델링 한다. 각 구성요소인 데이터베이스, 메모리, 프로세서, 버스는 개별적으로 고장이 날 수 있으며, 복구 모델을 이용하여 복구 될 수 있다. 시스템이 동작하는 한 복구가 가능하며, 데이터베이스가 고장 나거나, 시스템 구성요소인 프로세서, 메모리, 버스가 하나라도 고장 나면 전체 시스템이 다운되는 것으로 가정한다. 이러한 고장 및 복구조건을 고려한 시스템의 신뢰도 분석을 페트리 네트의 확장 모델이며 모델링 기능이 풍부한 마르코프 reward 모델을 이용하여 수행한다. Stochastic Reward Net(SRN)이 갖고 있는 variable cardinality, enabling 함수, 시간천이 우선순위 등의 기능을 이용하여 신뢰도 모델을 개발한다.

• 시스템엔지니어링학술지
• /
• 제4권2호
• /
• pp.1-13
• /
• 2008

The development of hull curved plate forming automation system in ship production field begins from the need of stakeholders such as enterprise organization, who need the reduction of cost and time and improvement of productivity, and end users who work for this production process. Even though hull curved plate forming automation system has small scale, it is reasonable to consider the system as an interdisciplinary system, because the system includes all of hardware, software, human and information and has a specified objective to be performed. In this paper, introduction of 4 leading Model-Based Systems Engineering (MBSE)methodologies is described and SysML(Systems Modeling Language), which is designed to analyze, specify, design, and verify complex systems, is introduced in order to support those methodologies. Especially, SysML is applied to system modeling of hull curved plate forming automation system and focused on. The structure diagrams and behavior diagrams based on operational context of the automation system are used to make system architecture. The performed application of SysML to the hull curved plate forming automation system shows an example of applying SysML to the development of other autonomous systems in ship production domain.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.147-149
• /
• 2006

We designed an intelligent intrusion detection scheme that works based on target system's operational states and doesn't depend on humans' analysis. As a prior work, we presents a scheme to describe computer system's operational states. For this, Hidden Markov Model is used. As input to modeling, huge amount of system audit trail including data on events occurred in target system connected to network and target system's resource usage monitoring data is used. We can predict system's future state based on current events' sequence using developed model and determine whether it would be in daniel or not.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2004년도 학술대회지
• /
• pp.68-72
• /
• 2004

A practical method to investigate the user interface of web based Flexible Manufacturing System(FMS) on the internet environment is established. Because the industrial FMS controller requires a lot of gadget, such as switch, dial, button, etc., for actual work-site flexible operation sufficiently, the user interface of the controller is significantly complex. The support for operational convenience of FMS controller can increase productivity and efficiency of the user, operational personnel of FMS. While most FMS provide their application programming interface(API) and graphical user interface(GUI) with adequate mechanism itself when used in stand alone, there is increasing demand for FMS that can operate with the intuitional user interface find virtual reality(V/R) environment. This thesis considers the intuitional user interface of Web-based FMS first, and from this, goes a step further, improves as virtual reality environment of FMS on the internet environments by using the feature based modeling technique approach and cartoon rendering. The feature-based modeling technique approach is applied to FMS line which is consist of facilities such as machining center, CNC lathe, autonomous guided vehicle, rail guided vehicle, and various controllers. In this study, the FMS established the intuitional user interface is able to obtain not only the operational convenience but also the enough productivity and significant efficiency.

• 한국산업융합학회 논문집
• /
• 제23권4_2호
• /
• pp.661-667
• /
• 2020

The optimal shape modeling of core parts through 3D modeling and structural analysis for the development of small and medium-sized ships. The goal is to improve the efficient structure of the hydraulic system for controlling the rudder among the core steering parts in small and medium-sized ships. Through 3D modeling and structural analysis, a new concept of tiller parts and a double-acting hydraulic cylinder control system were proposed and operational structural stability was evaluated. Structural analysis of the three different tiller designs that can be replaceable onto existing fishing vessels was conducted to derive the final shapes. The emphasis was placed on evaluating the structural stability of the key drive components, the tiller, pin, and cylinder rodin the maximum torque condition of the hydraulic cylinder.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.1413-1418
• /
• 2004

This paper shows the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system, electrical power is transferred from a primary winding in the form of a coil or track, to one or more isolated pick-up coils that may relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. The coupling between the primary and secondary is then presented to include the effects of parameter and operational frequency variation.

• Coupled systems mechanics
• /
• 제5권1호
• /
• pp.21-39
• /
• 2016

Wastewater process models are the essential tools for understanding relevant aspects of wastewater treatment system. Wastewater process modeling provides more options for upgrades and better understanding of new plant design, as well as improvements of operational controls. The software packages (BioWin, GPS-X, Aqua designer, etc) solve a series of simulated equations simultaneously in order to propose several solutions for a specific facility. Research and implementation of wastewater process modeling in combination with computational fluid dynamics enable testing for improvements of flow characteristics for WWTP and at the same time exam biological, physical, and chemical characteristics of the flow. Application of WWTP models requires broad knowledge of the process and expertise in modeling. Therefore, an efficient and good modeling practice requires both experience and set of proper guidelines as a background.

• 조명전기설비학회논문지
• /
• 제23권7호
• /
• pp.57-66
• /
• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems

• 한국농공학회논문집
• /
• 제58권3호
• /
• pp.71-80
• /
• 2016

The component-based modeling framework for agricultural water-resources management (COMFARM) is a user-friendly, highly interoperable, lightweight modeling framework that supports the development of watershed-specific domain components. The objective of this study was to evaluate the suitability of the COMFARM for the design and creation of a component-based modeling system of agricultural reservoir watersheds. A case study that focused on a particular modeling system was conducted on a watershed that includes the Daehwa and Dangwol serial irrigation reservoirs. The hydrologic modeling system for the study area was constructed with linkable components, including the modified Tank, an agricultural water supply and drainage model, and a reservoir water balance model. The model parameters were each calibrated for two years, based on observed reservoir water levels. The simulated results were in good agreement with the observed data. In addition, the applicability of the COMFARM was evaluated for regions where reservoir outflows, including not only spillway release but also return flow by irrigation water supply, substantially affect the downstream river discharge. The COMFARM could help to develop effective water-management measures by allowing the construction of a modeling system and evaluation of multiple operational scenarios customized for a specific watershed.

• International Journal of Aeronautical and Space Sciences
• /
• 제16권4호
• /
• pp.624-635
• /
• 2015

Design space exploration has been much neglected in aircraft conceptual design phase, which often leads to a waste of time and cost in design, manufacture and operation process. It is necessary to explore design space based on operational system-of-systems (SoS) simulation during the early phase for a competitive design. This paper proposes a methodology to analyze aircraft performance parameters in four steps: combination of parameters, object analysis, operational simulation, and key-parameters analysis. Meanwhile, the design space of an unmanned aerial vehicle applied in earthquake search and rescue SoS is explored based on this methodology. The results show that applying SoS simulation into design phase has important reference value for designers on aircraft conceptual design.