• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.05a
• /
• pp.122-125
• /
• 2005

The AutoForm previously used the membrane element and it accomplished sheet metal forming analysis. The membrane analysis has been widely applied to various sheet metal forming processes because of its saving time effectiveness. However, it's well known that the membrane analysis can not provides correct information for the processes which considerable bending effects. From this time research it tried to compare the formation analysis result which uses the shell element which is applied newly in the AutoForm and actual products. The shell element is compromise method between continuum analysis and membrane analysis. The Finite element method by using shell element is the most economical numerical method. From analysis results, FEA by using shell element can estimate accurately the problems happened in actual auto-body panel.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.3
• /
• pp.202-207
• /
• 2016

Checkpoint placement is an effective fault tolerance technique against transient faults in which the task is re-executed from the latest checkpoint when a fault is detected. In this paper, we propose a new checkpoint placement strategy separating data saving and fault detection processes that are performed together in conventional checkpoints. Several fault detection processes are performed in one checkpoint interval in order to decrease the latency between the occurrence and detection of faults. We address the placement method of fault detection processes to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for a real-time task having the proposed checkpoints, and derive the optimal fault detection and checkpoint interval.

• Transactions of Materials Processing
• /
• v.17 no.2
• /
• pp.130-134
• /
• 2008

Resource and energy saving is a very important practice for the future as well as for today. Weight saving of structural parts, which are formed by extrusion, plays a key role in manufacturing field. The cross-sections of extruded parts with industrial aluminum are constant in the axial direction by conventional extrusion method. Especially, these aluminum parts used and manufactured in the car industry need other processes to vary the cross-section in the axial direction. However, applications of these parts are often limited by high cost. If the cross-section of the parts is variable by only extrusion with newly developed method, the application of extruded aluminum parts will actually increase. Therefore, a new CNC extruder that can control the section area of a car part was invented for the first time in the nation. Using the extrusion machine, the experiment was performed to validate its workability during the variable section extrusion process. Also, numerical analysis was carried out to investigate the flow mode with different speeds of main ram and various pocket shapes of a die-set in the variable section extrusion process.

• International Journal of High-Rise Buildings
• /
• v.6 no.1
• /
• pp.83-89
• /
• 2017

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.5 s.236
• /
• pp.609-616
• /
• 2005

While the SIMPLE algorithm is most widely used for the simulations of flow phenomena that take place in the industrial equipments or the manufacturing processes, it is less adopted for the simulations of the free surface flow. Though the SIMPLE algorithm is free from the limitation of time step, the free surface behavior imposes the restriction on the time step. As a result, the explicit schemes are faster than the implicit scheme in terms of computation time when the same time step is applied to, since the implicit scheme includes the numerical method to solve the simultaneous equations in its procedure. If the computation time of SIMPLE algorithm can be reduced when it is applied to the unsteady free surface flow problems, the calculation can be carried out in the more stable way and, in the design process, the process variables can be controlled based on the more accurate data base. In this study, a modified SIMPLE algorithm is presented fur the free surface flow. The broken water column problem is adopted for the validation of the modified algorithm (MoSIMPLE) and for comparison to the conventional SIMPLE algorithm.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.4
• /
• pp.304-308
• /
• 2009

This paper presents the deadline driven CPU-Power management scheme for the Real-Time Embedded OS: named TMO-eCos. It used the scheduling scenarios generated by a task serialization technique for hard real- time TMO system. The serializer does a off-line analysis at design time with period, deadline and WCET of periodic tasks. Finally, TMO-eCos kernel controls the CPU speed to save the power consumption under the condition that periodic tasks do not violate deadlines. As a result, the system shows a reasonable amount of power saving. This paper presents all of these processes and test results.

• Journal of the Korea Society for Simulation
• /
• v.23 no.4
• /
• pp.211-218
• /
• 2014

The Test and Evaluation (T&E) system became more important due to its advancement and complexity of the weapon system. Time and cost saving T&E related studies are in progress mainly with advanced countries. By utilizing the Modeling and Simulation (M&S) technology recently, we may save time and money. Also, overcome security and safety limitations. There are many M&S based research activities in South Korea but it is way behind of the system that some countries already have developed. i.e.; United States. This area of study requires new way of developing strategies in the T&E system of Korea. This study is to design the Operational T&E system for weapon systems based on modeling of processes. And we modeled the processes of operational performance evaluation through utilizing resources and performance modules of weapon systems and combined it with the simulation engine for 3D visualization. Through this, we propose the Operational T&E system for weapon systems based on modeling of processes that represent operational performances visually.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.905-909
• /
• 2002

Commutators of a starting motor for automobiles has been produced through various processes such as forging, segmenting, and assembling. And the conventional method producing an automotive motor commutator is not appropriate for saving material and cost, because it makes each segment separated one by one. Therefore a new process design is required in oder to avoid the assembling process. In this study, a new process design of the commutator of an automotive starting motor has been carried out to save material and manufacturing time by FE analysis. In the FE analysis, three forging processes are proposed for producing the copper(ASTM Cl1000) commutators of a starting motor. And forging experiments are performed to make an unsegmented commutator in order to verify the theoretically proposed process. And then, in order to get the final product, the forged commutator is passed through various postprocessing such as resin terming, and machining. From the experimental result, the forging process proposed from the FE analysis is verified to be an economical method for producing the commutator of an automotive starting motor.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2002.05a
• /
• pp.149-153
• /
• 2002

The commutator of an automotive fuel pump motorhas been produced through various processes such as forging, segmenting, and assembling. And the conventional method producing the commutator of an automotive fuel pump motor is not appropriate for saving material and cost, because it makes each segment separated one by one. Therefore a new process design is required in order to avoid the assembling process. In this study, a new process design of the commutator has been carried out to save material and manufacturing time by FE analysis. In the FE analysis, three forging processes are proposed for producing copper(ASTM C11000) commutator of an automotive fuel pump motor. And forging experiments are performed to make an unsegmented commutator in order to verify the theoretically proposed process. And then, in order to get the final product the forged commutator is passed through various postprocessing such as machining, bending, resin forming, and shearing process. From the experimental result the forging process proposed from the FE analysis is verified to be an economical method for producing the commutator for an automotive fuel pump motor.

• The Korean Journal of Food & Health Convergence
• /
• v.6 no.1
• /
• pp.1-8
• /
• 2020

The foremost problem in the agricultural industry in Ukraine is the issue of improving its energy resources efficiency. The existence of this problem is related to the substantial technological inferiority of the industry to those present in the developed countries, especially in terms of creation of no-waste production technologies of agricultural products. The direct effect on the solving of this issue has the necessity to ensure minimal energy costs during treatment of plant objects. This article presents the research results on the effect of electromagnetic energy on activation of plants development. It was found that each such object has its own individual energy resource and that forceful increase of the latter has specific maximum values and gives rise to the plant development process. At the same time, the implementation of the research results is hindered by some factors, among the most major of which are the following: lack of reliable and complete data on the bioenergy resources of plants, its "natural" chart; unavailability of research on the energy sources interaction processes and its effect on the physiological potential of biological objects, at least at the level of low series, absence of the appropriate electrotechnical equipment, including electromagnetic energy sources.