• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.3
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• pp.210-215
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• 2002

In this study, the computer program called Multi_Cycle, which simulates the steady-state performance (coefficient of performance, capacity, power consumption and etc.) of multi- airconditioning systems using R410A, was developed. In order to validate the simulation program, a series of case studies were carried out. The Multi_Cycle consists of several subroutines for simulating indoor units. outdoor unit, compressor, and expansion devices. and for estimating the thermodynamic and transport properties of the refrigerants and moist air. It would appear to be advantageous to use the Multi_Cycle for a performance analysis when considering various kinds of refrigerants and the complex operating conditions of each unit making up the multi-airconditioner cycle. Moreover, the Multi_Cycle would seem to be useful tool in optimizing a multi-airconditioning system and establishing economical and efficient operating conditions in the multi-airconditioner cycle. In the present study, the Multi_Cycle was programmed with Digital Visual Fortran for the main simulation code and Visual Basic for- the graphic user interface.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.848-851
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• 1997

A graphic simulation program is developed to assimilate the remote dismantling process of research nuclear reactors. This program makes extensive use of a commercial robot graphic instruction program. Firstly, a realistic graphic model of research reactors are built along with various dismantling equipments. Using the graphic instruction languages provided by IGRIP, then, a graphic process simulation program is developed that operates interactively with the user. Consequently, it is made possible for a process designer to visualize an arbitrary dismantling sequence and interactively modify the process. It is expected that the developed system will be utilized as an effective operator aid in both design and execution phases of remote dismantling of research reactor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.772-775
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• 2002

The remote handling and maintenance devices in the nuclear hot ceil should be checked prior to the hot operation in view of reliability and operability. In this study, the digital mock-up is implemented to analyze and define the process equipment maintenance processes instead of real mock-up, which is very expensive and time consuming. To do this, the parts of equipment and maintenance devices are modeled in 3-D graphics, assembled, and kinematics is assigned. Also, the virtual workcell of the spent fuel management process is implemented in the graphical environment which is the same as the real environment. This simulator has the several functions for verification such as analyses for the manipulator's working area, the collision detection, the path planning and graphic simulation of the processes etc. This graphic simulator of the maintenance devices can be effectively used in designing of the maintenance processes for the hot cell equipment and enhance the reliability of the spent fuel management.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.10a
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• pp.96-101
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• 1991

프리스트레스트 콘크리트 교량은 콘크리트와 PS 강재의 역학적 장점들을 십분 활용하여 경제적인 단면 구성이 가능한 반면, 서로 다른 두 재료의 복합적인 특성들 즉, 콘크리트의 크리이프 (creep), 건조수축 (shrinkage)과 PS 강재의 이완 (relaxation) 등과 같이 시간에 따라 변화하는 인자들로 인하여 복잡한 구조적 거동을 보여 해석상 어려움이 따른다. 이와같은 복합거동은 시공순서와 시공방법에 의해 시공중의 구조계와 지지조건 등이 변화하는 경우에는 더욱 복잡한 양상을 띄게 된다. 뿐만 아니라 박스 거더와 같은 박벽요소에서는 일반적인 보요소(beam element)로는 나타낼 수 없는 ？(warping)을 무시할 수 없으므로 ？ 자유도를 구현할 수 있는 특수한 기능의 구조해석용 프로그램의 개발이 절실히 요망된다. 그리고 시공단계별로 출력되는 많은 양의 수치결과들을 설계와 시공실무자에 지향된 형태로 조합, 변형시켜 그래픽 화면상에 나타내는 후처리 프로그램(Post-processor) 기능도 구조해석용 프로그램의 개발 못지않게 중요하다. 본 연구의 목적은 삼성종합건설과 서울대 토목공학과가 공동으로 ？(warping) 자유도를 포함한 7개의 자유도를 갖는 3차원 보요소를 사용하여 PS 콘크리트의 재료적 특성인 크리이프와 건조수축, 그리고 강재의 이완(relaxation)을 포함한 프리스트레싱력의 손실을 고려할 수 있고 시공 단계별 구조계의 변화 및 지지조건들의 다양한 변화를 효율적으로 모사할 수 있는 프로그램의 개발에 있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1636-1639
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• 2005

The process equipment and remote handling for the deep geological disposal of high-level radioactive waste(HLW) should be checked prior to the operation in view of reliability and operability. In this study, the concept of virtual environment workcell is implemented to analyze and define the feasible disposal process instead of real mock-up, which is very expensive and time consuming. To do this, the parts of process equipment for the disposal and maintenance will be modeled in 3-D graphics, assembled, and kinematics will be assigned. Also, the virtual workcell for the encapsulation and disposal process of spent fuel will be implemented in the graphical environment, which is the same as the real environment. This virtual workcell will have the several functions for verification such as analyses for the equipment's work space, the collision detection, the path planning and graphic simulation of the processes etc. This graphic virtual workcell of the HLW disposal process can be effectively used in designing of the processes for the hot cell equipment and enhance the reliability of the spent fuel management.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.579-592
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• 1994

A case study is presented where a fluvial system is modeled in three dimensions and compared to data gathered from a study of the Arkansas River. The data is unique in that it documents changes that affected a straight channel that was excavated within the river by the U.S. Army Corps of Engineers. Excavation plan maps and sequential aerial photographs show that the channel underwent massive deposition and channel migration as it returned to a more natural, meandering path. These records illustrate that stability of fluvial system can be disrupted either by catastrophic events such as floods or by subtle events such as the altering of a stream's equilibrium base level or sediment load. SEDSIM, Stanford's Sedimentary Basin Simulation Model, is modified and used to model the Arkansas River and the geologic processes that changed in response to changing hydraulic and geologic parameters resulting from the excavation of the channel. Geologic parameters such as fluid and sediment discharge, velocity, transport capacity, and sediment load are input into the model. These parameters regulate the frequency distribution and sizes of sediment grains that are eroded, transported and deposited. The experiments compare favorably with field data, recreating similar patterns of fluid flow and sedimentation. Therefore, simulations provide insight for understanding and spatial distribution of sediment bodies in fluvial deposits and the internal sedimentary structure of fluvial reservoirs. These techniques of graphic simulation can be contributed to support the development of the new design criteria compatible with natural stream processes, espacially drainage problem to minimize environmental disruption.

• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.339-350
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• 2003

Engineering qualification model payload for a communications and broadcasting satellite(CBS) was developed by ETRI from May, 2000 to April, 2003. For. the purpose of functional test and verification of the payload, a real-time hardware-in-the-loop(HITL) CBS simulator(CBSSIM) was also developed. We assumed that the spacecraft platform for the CBSSIM is a geostationary communication satellite using momentum bias three-axis stabilization control technique based on Koreasat. The payload hardware is combined with CBSSIM via Power, Command and Telemetry System(PCTS) of Electrical Ground Support Equipment(EGSE). CBSSIM is connected with PCTS by TCP/IP and the payload is combined with PCTS by MIL-STD-1553B protocol and DC harness. This simulator runs under the PC-based simulation environment with Windows 2000 operating system. The satellite commands from the operators are transferred to the payload or bus subsystem models through the real-time process block in the simulator. Design requirements of the CBSSIM are to operate in real-time and generate telemetry. CBSSIM provides various graphic monitoring interfaces and control functions and supports both pre-launch and after-launch of a communication satellite system. In this paper, the HITL simulator system including CBSSIM, communications payload and PCTS as the medium of interface between CBSSIM and communications payload will be described in aspects of the system architecture, spacecraft models, and simulator operation environment.

• Tunnel and Underground Space
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• v.21 no.2
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• pp.128-137
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• 2011

The shut-in pressure calculated in common hydrofracturing test for vertical borehole equals generally to the minimum horizontal principal stress, so it should be considered as an essential parameter for determining the in-situ stress regime around the rock mass. It shows usually an ambiguous value in pressure-time history curves, however, because of the relationship between the behavior of hydraulic fractures and the condition of remote stress regime. In this study, a series of numerical analyses have been carried out to compare several methods for determining the shut-in pressure during hydrofracturing. The hydraulic-mechanical coupling has been applied to numerical analysis for simulating the fracture propagation by hydraulic pressure, and the different discontinuity geometry has been considered in numerical models to examine the effect of numerical element shape on fracture propagation pattern. From the numerical simulations with the four different discontinuity geometries, it was revealed that the shut-in pressure obtained from graphical methods rather than statistical method was relatively small. Consequently a care should be taken in selecting a method for determining the shut-in pressure when a stress anomaly around borehole and a fracture propagation with complicate mechanism are considered.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.338-344
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• 2010

A double rotation C-scanning system and a software program Under-Sodium MultiVIEW have been developed for the under-sodium viewing of a reactor core and in-vessel structures of a sodium-cooled fast reactor KALIMER-600. Double rotation C-scanning system has been designed and manufactured by the reproduction of double rotation plug of a reactor head in KALIMER-600. Hardware system which consists of a double rotating scanner, ultrasonic waveguide sensors, a high power ultrasonic pulser-receiver, a scanner driving module and a multi channel A/D board have been constructed. The functions of scanner control, image mapping and signal processing of Under-Sodium MultiVIEW program have been implemented by using a LabVIEW graphical programming language. The performance of Under-Sodium MultiVIEW program was verified by a double rotation C-scanning test in water.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.27-34
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• 2016

The application of computer graphics, which is characterized by reality, has even reinforced reality of image and motion expression in digital animation. But reality of digital animation succeeds to traditional aesthetic characteristics of animation for overcoming physical limitations of the real world and realizing imagination through transformation, rather than copying actuality as it is. But it does not succeed to drawing animation wholly. Digital animation adds cartoonish transformation, based on three-dimensional realistic expression and those animation situations look as if they get over realistic restrictions, while drawing animation constantly reminds of mediality in drawing motion, based on two-dimensional plane and handwork. n other words, cartoonish exaggeration that is intermittently inserted between these reinforced realities, expresses digital animation's own aesthetic characteristics as a dialectical sum by crashing into contrast coming from a cross between reality and imagination.