• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.952-965
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• 1993

A simulation modeling is necessary for the optimal design of a rice processing plant, which consists of a facility (a silo system) of rice drying and storage and a rice mill plant. In a rice processing plant, the production scheduling and the decision on capcity of each unit based on a queuing theory is very important and difficult. In this study a process-oriented simulation model was developed for the design of a rice drying and storage system with SLAMSYSTEM. The simulation model is capable of simulating virtually all the processing activities and provides work schedules which minimize total processing time , mean flow time and bottleneck of the plant system and estimate drying time for a batch in a drying silo. Model results were used for determination the size and capacity of each processing unit and for analyzing the performance of the plant . The developed model was actually applied to construct a grain silo system for rice drying and storage.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.165-173
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• 2000

Analytic models have been developed to solve integrated production-distribution problems in supply chain management (SCM). As one of major constraints in analytic models, capacity, which is the total operation time in this paper has mostly been known or disregarded assuming infinite capacity. Also, as major factors, machine processing time to fabricate or assemble a part or product at a certain machine center in production system and vehicle processing time to deliver a product to a customer by a certain vehicle in distribution system have been fixed and regarded as a static factor, But in the real systems significant differences exit between capacity and the required time to achieve the production-distribution plan and between processing time and consumed time to process a part or product. In this paper, capacity and processing times in the analytic model are considered as dynamic factors and adjusted by the results from independently developed simulation model, which includes general production-distribution characteristics. Through experiments, we obtain the more realistic solutions reflecting stochastic natures by performing the iterative analytic-simulation procedure.

• Journal of Intelligence and Information Systems
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• v.6 no.1
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• pp.113-128
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• 2000

This paper presents a first year report of an ongoing multi-year project to develop a systolic parallel simulation system for dynamic traffic assignment. The fundamental approach to the simulation is systolic parallel processing based on autonomous agent modeling. Agents continuously act on their own initiatives and access to database to get the status of the simulation world. Various agents are defined in order to populate the simulation world. In particular existing modls and algorithm were incorporated in designing the behavior of relevant agents such as car-following model headway distribution Frank-Wolf algorithm and so on. Simulation is based on predetermined routes between centroids that are computed off-line by a conventional optimal path-finding algorithm. Iterating the cycles of optimization-then-simulation the proposed system will provide a realistic and valuable traffic assignment. Gangnum-Gu district in Seoul is selected for the target are for the modeling. It is expected that realtime traffic assignment services can be provided on the internet within 3 years.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.111-122
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• 2003

Military wargame simulation models must support the HLA in order to facilitate interoperability with other simulations, and using parallel simulation engines offer efficiency in reducing system overhead generated by propelling interoperability. However, legacy military simulation model engines process events using sequential event-driven method. This is due to problems generated by parallel processing such as synchronous reference to global data domains. Additionally. using legacy simulation platforms result in insufficient utilization of multiple CPUs even if a multiple CPU system is under use. Therefore, in this paper, we propose conversing the simulation engine to an object model-based parallel simulation engine to ensure military wargame model's improved system processing capability, synchronous reference to global data domains, external simulation time processing, and the sequence of parallel-processed events during a crash recovery. The converted parallel simulation engine is designed and implemented to enable parallel execution on a multiple CPU system (SMP).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.453-454
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• 2006

This paper describes a processing verification technique for developing about end-milling cutters. Developed software is processing verification module for manufacturing. By using cutting simulation method, we can obtain center points of finding wheel via Boolean operation between a grinding wheel and a cylindrical workpiece. The obtained CL data can be used for calculating NC data. After then, we can simulate by using designed grinding machine and NC data. This research has been implemented on a commercial CAD system by using the API function programming. The operator can evaluate the cutting simulation process and reduce the time of design and manufacturing.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.440-443
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• 2001

As inter-network traffics grows rapidly, the router systems as a network component becomes to be capable of not only wire-speed packet processing but also plentiful programmability for quality services. A network processor technology is widely used to achieve such capabilities in the high-end router. Although providing two such capabilities, the network processor can't support a deep packet processing at nominal wire-speed. Considering QoS may result in performance degradation of processing packet. In order to achieve foster processing, one chipset of network processor is occasionally not enough. Using more than one urges to consider a problem that is, for instance, an out-of-order delivery of packets. This problem can be serious in some applications such as voice over IP and video services, which assume that packets arrive in order. It is required to develop an effective packet processing mechanism leer using more than one network processors in parallel in one linecard unit of the router system. Simulation analysis is also needed for verifying the mechanism. We propose the packet processing mechanism consisting of more than two NPs in parallel. In this mechanism, we use a load-balancing algorithm that distributes the packet traffic load evenly and keeps the sequence, and then verify the algorithm with simulation analysis. As a simulation tool, we use DEVSim++, which is a DEVS formalism-based hierarchical discrete-event simulation environment developed by KAIST. In this paper, we are going to show not only applicability of the DEVS formalism to hardware modeling and simulation but also predictability of performance of the load balancer when implemented with FPGA.

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.13-22
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• 2017

This research proposes and applies a pipelining parallel processing technique to enhance the speed of visualizing the results of real-time simulations. Generally, a simulation with real-time visualization consists of three processes: executing a simulation model, transmitting simulation result, and visualizing simulation result. If we have these processes in serial, the latency from simulation to visualization will be very long, which degrades the speed of visualization of data from real-time simulation. Thus, the main purpose of this research is maximizing performance by adapting pipelining parallel processing technique to the real-time simulation visualization. Also we show that performance is improved by adding multi-threading technique to each process. This paper proposes a theoretical performance model and simulation results of the techniques and then we applied this to an air combat simulation model as a case study. As the result, it shows that the performance is greatly enhanced than the original model's execution time.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.649-657
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• 2009

Usually, The data transmission processing efficiency of the distributed system running on high speed networks depends on the system architecture and the data transmission processing system. In order to secure the real-time rate and the system reliability, the real-time distributed simulation system on the distributed environment has tried to satisfy the performance required by the data transmission processing system. However, the client/server-based data transmission processing system in the real-time simulation system has been difficult to satisfy the system stability, extensibility and maintenability, especially when system changes. So, it is natural to study another improved data transmission processing system to solve the problems at the existing real-time simulation system. After analyzing the existing real-time simulation system, this paper will propose the improved real-time data transmission system by using Software Design Pattern, which enhances extensibility, interoperability, reusability and maintenability of the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.499-502
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• 2014

This paper presents a comparison study between simulation and experiment for fault diagnostics of a spur gear. In simulation, fault diagnostics using transmission error (TE) was performed and concluded to be valid. In a real experiment, however, it is not as easy to detect faults of gears using TE as in simulation. In this paper, after seeding the various faults like tooth crack of different length, tooth breakage and spalling in test rig, TE was calculated. Then, several signal processing techniques were performed to overcome the limitations of an experiment in detecting the fault signals of TE. After signal processing, we could detect the various faults of spur gears and different amplitude of TE sparks from cracks of different length. Then we discussed the difference between simulation and experment.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.30-35
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• 2021

In this study, a machine simulation system was built using the actual scale of an AC-type 5-axis machine tool for mold surface machining that can be used in applications, such as, modeling and machine building, stroke, and collision detection. The validity of the 5-axis machine simulation system was verified by performing tool path generation, post-processing, machine simulation, prototype motion simulation, and an actual cutting experiment. This entire process was intended to activate the 5-axis machining in mold surface machining.