• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.424-426
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• 2005

임베디드 소프트웨어의 품질 향상을 위해 소프트웨어에 대한 테스트가 필요하다. 이때 임베디드 소프트웨어가 가진 다양한 제약성을 고려해야 하며, 이를 위해 시스템 수준에서의 테스트를 수행하는 것이 가장 적합하다고 할 수 있다. 시스템 테스트에서는 SUT(System Under Test)의 하드웨어 구성에 따라 센서, 스위치, 액추에이터 등이 시스템과 연결되어 작동하여야 한다. 특히 온도센서나 습도센서 등과 같이 외부의 환경정보를 시스템의 입력으로 사용하는 임베디드 시스템을 테스트하기 위해서는 테스트 자동화 도구 내부에 환경을 관리하고, 정해진 환경 시나리오에 따라 시스템에 입력을 주는 모듈이 요구된다. 본 논문에서는 임베디드 시스템에 구성되어 있는 센서의 기능을 대신하는 가상 환경 관리자(Virtual Environment Operator)를 설계하고 구현하였다. 구현된 가상 환경 관리자의 도입으로 테스트 스크립트의 간결화와 현실 세계를 반영하는 다양한 테스트가 가능한 테스트 환경을 구축하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.940-943
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• 2010

여러 장치들과 연동하여서 동작하는 네트워크 시스템 개발 시, 회귀테스트는 전체 시스템의 안정성을 보장하기 위한 가장 필요한 테스트이다. 그러나 서비스가 진행 중이거나 연동을 위한 추가적인 장비가 필요할 경우 테스트의 제약을 받게 된다. 본 논문에서는 회귀성 테스트에서 발생하는 시간과 비용을 줄이기 위한 가상 시스템에서 네트워크 시뮬레이터를 제안한다. 네트워크 시뮬레이터는 테스트에 대한 시나리오를 분석하여 테스트에 따른 실제 장비에서의 메시지들을 구성하며, 테스트 시나리오에 맞게 이벤트를 발생시킴으로서 가상으로 회귀성 테스트를 가능하게 한다. 설계된 네트워크 시뮬레이터는 우선적으로 모바일 환경에서 테스트를 시행하여, 가상 이벤트 구성과 동작의 기능을 검증하는데 사용되었다.

• Computational Structural Engineering
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• v.10 no.4
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• pp.155-164
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• 1997

A reactor pressure vessel, which contains fuel assemblies and reactor vessel internals, has the thermal stress resulting from the cool-down and heat-up of the vessel wall in combination with the pressure stress from system pressure resulting in large stresses. The combination of the pressure stress and thermal stress along with a decrease in fracture toughness may cause through-wall propagation of a relatively small crack. Therefore, it is necessary to define the relations between operating pressure and temperature during cool-down and heat-up. In this study, theory of fracture mechanics for a pressure/temperature limit curve is investigated and a numerical procedure for generating it is developed. Plant-specific limit curves for the Kori unit 1 plant, the oldest nuclear power plant in Korea, have been obtained for several cooling and heating rates and their results are discussed.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.42-55
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• 2006

In most multimedia systems, the environment is considered as a passive background. In virtual environment simulating real world, however, terrain affects many events such as wind, rain, cloud. Therefore, it is necessary to model terrain and meteorological phenomenon in order to simulate realistic virtual environment. In those modeling, not only height and location information but also environmental factors such as temperature and humidity are important. An event is composed of many activities and subevents based on causality and consists of precondition , procedure and effects. Each part of an event is formulated in terms of a number of parameter variables, which correspond to its associated factors on existence or states of entities and relation. This paper represents terrain and environmental factor using contour map. Moreover, we define various events and their procedures in terms of causality in virtual environment.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.1 s.1
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• pp.157-163
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• 2001

The objective of the present study is to predict the characteristics of the fire and smoke propagations in a clean room. Numerical calculations have been performed by using the finite volume method to obtain temperature and velocity distributions in the clean room. In odor to account for the turbulent flow characteristics, the standard $k-{\varepsilon}$ model is used. From this study, it was found that the fire propagation could be fully developed only after 150 seconds when the ventilation system in the clean room was off. And the smoke mass fraction showed a similar distribution as the gas temperature. Since the simulated fire was proceeded up to $20{\sim}30%$ of the room within 60 seconds. it could be recommended that the occupants should be evacuated from the room within 30 seconds.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.147-157
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• 2018

With the rapid development of the 4th industrial revolution, the large-sized facilities of agriculture have been developed with high-technologies. However, it is difficult to maintain the optimum environment in large-sized facilities. Although it is essential to control micro-climate properly in large-sized facilities, there are a lot of problems to utilize high-technologies and equipment because of insufficient education for farmers. Most farms have limitations to access to their farm because of prevention of epidemics, exposure of management know-how, and so on. Especially, it is difficult to understand internal environmental factors (airflow, temperature, humidity, etc.) for farmers because these factors are invisible. Recently, Virtual reality technology which allows users to experience various phenomena directly is attracting attention. Virtual reality is very useful technology to visualize airflow and temperature distribution and so on. However, there is no cases applied this technology to agricultural facilities. In this study, research trends of virtual reality in various fields were investigated. In particular, the limitation and possibility of virtual reality technology were analyzed for educating farmers. Finally, the development of virtual reality contents for smart-farm facility were suggested.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.383-390
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• 2018

The purpose of this study is to find out how the evolution of digital play in virtualization and digital play tools are combined with and stereotyping the properties of traditional play. Virtualization characteristics and play theory were examined and the case was derived in four types and analyzed in four play properties with Roser Cailliois. In the case of Agon, the targets of mutual competition are expanded to singular and plural, computer and oneself of the future, and Mimicry showed the ambiguity of the segments and boundaries crossing the on-off line boundary, and in the case of Alea, the diversity of accident occurrence by immediacy and simultaneity has been strengthened, and in the case of Ilinx, the maximization of immersion has been developed and experimented with a variety of techniques for the utilization of senses and tools and the virtuality for this. As a result, play is developing due to the tendency to expand and coexist in time and space by various fusion combinations.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.579-586
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• 2019

The purpose of this study is to determine the rapid saving of life through the drones when natural disasters such as earthquake and fire occur. Drones are equipped with riders, temperature, hazardous gas sensors and wireless cameras are registered with the application server for monitoring the disaster site and real-time monitoring functions are performed to identify the situation on site before rescuing personnel are active. When monitoring finds a person to save, the application server provides real-time image information for effective life-saving.

• 한국해양학회지
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• v.30 no.6
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• pp.543-549
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• 1995

The inverse method has been used to estimate a surface velocity field from sequential AVHRR/SST data. In the model, equation system was composed of heat equation and horizontal divergence minimization and the velocity field contained in the advective term of the heat equation, which was linearized in grid system, was estimated. A constraint was the minimization of horizontal divergence with weighting factor and introduced to compensate the null space(Menke, 1984) of the velocity solutions for the heat equation. The experiments were carried out to set up the range of weighting factor and the matrix equation was solved by SVD(Singular Value Decomposion). In the experiment, the scales of horizontal temperature gradient and divergence of synthetic velocity field were approximated to those of real field. The neglected diffusive effect and the horizontal variation of heat flux in the heat equation were regarded as random temperature errors. According to the result of experiments, the minimum of relative error was more desirable than the minimum of misfit as the criteria of setting up the weighting factor and the error of estimated velocity field became small when the weighting factor was order of $10^{-1}$

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.12
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• pp.295-300
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• 2018

The rapid development of IT, many conventional passive jobs have been automated. This automation increases the leisure time of many people and various services are being developed for them. In addition, with the advent of smart devices that are compact and portable, it is possible to use various internet services without any time and place discretion. Various studies based on virtualization are under way to efficiently store and process large data generated by many devices and services. Desktop Storage Virtualization (DSV), which integrates and provides users with on-premise-based distributed desktop resources during these studies, uses virtualization to consolidate unused resources within distributed, legacy desktops. This DSV is very important for providing high reliability to users. In addition, research on hierarchical structure and resource integration for efficient data distribution storage processing in a distributed desktop-based resource integration environment is underway. However, there is a lack of research on efficient operation in case of server failure in on-premise resource integration environment. In this paper, we propose Non-disruptive Server Management (NSM) which can actively cope with the failure of desktop server in distributed desktop storage environment based on on-premise. NSM is easy to add and remove desktops in a desktop-based integrated environment. In addition, an alternative server is actively performed in response to a failure occurrence.