• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.275-280
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• 2002

In order to control glucose concentration during fed-batch culture for antibiotic production, we applied so called “software sensor” which estimates unmeasured variable of interest from measured process variables using software. All data for analysis were collected from industrial scale cultures in a pharmaceutical company. First, we constructed an estimation model for glucose feed rate to keep glucose concentration at target value. In actual fed-batch culture, glucose concentration was kept at relatively high and measured once a day, and the glucose feed rate until the next measurement time was determined by an expert worker based on the actual consumption rate. Fuzzy neural network (FNN) was applied to construct the estimation model. From the simulation results using this model, the average error for glucose concentration was 0.88 g/L. The FNN model was also applied for a special culture to keep glucose concentration at low level. Selecting the optimal input variables, it was possible to simulate the culture with a low glucose concentration from the data sets of relatively high glucose concentration. Next, a simulation model to estimate time course of glucose concentration during one day was constructed using the on-line measurable process variables, since glucose concentration was only measured off-line once a day. Here, the recursive fuzzy neural network (RFNN) was applied for the simulation model. As the result of the simulation, average error of RFNN model was 0.91 g/L and this model was found to be useful to supervise the fed-batch culture.

• Journal of the Korea Society for Simulation
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• v.6 no.1
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• pp.109-122
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• 1997

The Off-Dock Container Yard (ODCY)s in Pusan are located at 48 different places, and it causes serious problems in the container cargo transport and inland traffic near Pusan district. Hence, the analysis and evaluation of ODCY operation is important. Therefore, this paper proposes a simulation model which evaluates the operation of ODCY. It also proposes a simulation model using an object-oriented approach which includes the system is modeled with object-class hierarchy and SIMPLE++, an object-oriented simulation software, is used to develop the model.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.2
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• pp.73-90
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• 2018

Various navigation systems are integrated with the Global Navigation Satellite System (GNSS) to improve navigation performance so that continuous navigation information can be obtained even when navigation performance is degraded or navigation is not available due to the outage of GNSS. Time and cost can be reduced by evaluating performance of the integrated navigation system through Modeling and Simulation (M&S) software prior to the deployment of the integrated navigation system. The measurements of the navigation system should be generated to evaluate performance through of the navigation system M&S software. This paper proposes a method of designing a navigation environment generation module in M&S software of the integrated navigation system. To show applicability of the proposed method to M&S software design of the integrated navigation system, functions are verified through MATLAB. And then visual C++ based M&S software for the integrated navigation system is implemented to check the operation of the navigation environment generation module. The reference trajectory is generated and true measurements of Global Positioning System (GPS), Korea Positioning System (KPS), and enhanced Long range navigation (eLoran) are generated from the reference trajectory. The navigation results obtained from the true measurements are compared with the reference trajectories. The results show that the measurements generated using the design generation module by the proposed method are valid and the navigation environment generation module can be applied to M&S software of the integrated navigation system.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.113-122
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• 2009

Software is getting more complex due to a variety of requirements that include desired functions and properties. Therefore, verifying and testing the software are complicated problems. Moreover, if the software is already implemented, inserting and deleting tracing/logging code into the source code may cause several problems, such as the code tangling and the code scattering problems. This paper proposes the Aspect DEVS Verification Framework which supports the verification and testing process. The Aspect DEVS Verification Framework utilizes Aspect Oriented Programming features to handle the code tangling and the code scattering problems. By applying aspect oriented features, a user can find and fix the inconsistency between requirement and implementation of a software without suffering the problems. The first step of the verification process is the building aspect code to make a software act as a generator. The second step is developing a requirement specification using DEVS diagrams and implementing it using the DEVSIM++. The final step is comparing the event traces from the software with the possible execution sequences from DEVS model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1217-1222
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• 2010

This paper describes the Model-Based Development(MBD) process behind the flight control software of a close-range unmanned aerial vehicle(KUS-9). An integrated development environment was created using a commercial tool(MATLAB $Simulink^{(R)}$), which was utilized to design models for linear/nonlinear simulation, flight control law, operational logic and HILS(Hardware In the Loop Simulation) system. Software requirements were validated through flight simulations and peer reviews during the design process, whereas the models were verified through the application of a DO-178B verification tool. The integrity of automatically generated C code was verified by using a separate S/W testing tool. The finished software product was embedded on two different types of hardware and real-time operating system(uC/OS-II, VxWorks) to perform HILS and flight tests. The key findings of this study are that MBD Technology enables the development of a reusable and an extensible software product and auto-code generation technology allows the production of a highly reliable flight control software under a compressed time schedule.

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.23-26
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• 2014

The aim of this report is to evaluate accuracy using3D surgical simulationand digitally printedwafer in orthognathic surgery. 22-year-old female was diagnosed with mandibular prognathism and apertognathia based on 3D diagnosis using CT. Digital dentition images were taken by laser scanning from dental cast, and each STL images were integrated into one virtual skull using simulation software. Digitalized intermediate wafer was manufactured using CAD/CAM software and 3D printer, and used to move maxillary segment in real patient. Constructed virtual skull from 1 month postoperative CT scan was superimposedinto simulated virtual model to reveal accuracy. Almost maxillo-mandibular landmarks were placed in simulated position within 1 mm differences except right coronoid process. Thus 3D diagnosis, surgical simulation, and digitalized wafer could be useful method to orthognathic surgery in terms of accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.535-538
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• 2005

Today, most fixed-wing aircrafts are equipped with the antiskid brake system. It can modulate braking moments in the wheels optimally, when an aircraft is landing. So it can reduce landing distance and increase safeties. The antiskid brake system for an aircraft are mainly composed of braking moment modulators (hydraulic control valves) and brake control unit. In this paper, a Mark IV type - fully digital - brake controller is studied. For the development of its control algorithms, a 5-DOF (Degree of Freedom) aircraft landing model is composed in the form of matlab/simulink model at first. Then, braking moment control algorithms using wheel decelerations and slips are made. The developed algorithms are tested in software simulations using state-flow toolboxes in matlab/simulink model. Also, a real-time simulation systems are made, which use hydraulic brake systems of a real aircraft, pressure control valves and its controller as hardware components of HIL(Hardware In-the-Loop) simulation. Algorithms tested in software simulations are coded into the controller and the real-time landing simulations are made in very severe road conditions. The real-time simulation results are presented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.441-450
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• 2022

The introduction of autonomous underwater gliders (AUGs) specifically addresses the reduction of operational costs that were previously prohibited with conventional autonomous underwater vehicles (AUVs) using a "scaling-down" design philosophy by utilizing the characteristics of autonomous drifters to far extend operation duration and coverage. Long-duration, wide-area missions raise the cost and complexity of in-water testing for novel approaches to autonomous mission planning. As a result, a simulator that supports the rapid design, development, and testing of autonomy solutions across a wide range using software-in-the-loop simulation at faster-than-real-time speeds becomes critical. This paper describes a faster-than-real-time AUG simulator that can support high-resolution bathymetry for a wide variety of ocean environments, including ocean currents, various sensors, and vehicle dynamics. On top of the de facto standard ROS-Gazebo framework and open-sourced underwater vehicle simulation packages, features specific to AUGs for ocean mapping are developed. For vehicle dynamics, the next-generation hybrid autonomous underwater gliders (Hybrid-AUGs) operate with both the buoyancy engine and the thrusters to improve navigation for bathymetry mappings, e.g., line trajectory, are is implemented since because it can also describe conventional AUGs without the thrusters. The simulation results are validated with experiments while operating at 120 times faster than the real-time.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.332-336
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• 1992

We describe about the graphic simulation system which supports the determination of efficient multi-robot motions during cooperation. For the construction of the simulation software for multi-robot motions, two problems are presented. First problem is that all the robot motions must be determinded using both the desired object motions and the holonomic constraints with the object. To find the robot motions combined with the various object motion path, the robot motions are derived from the desired object path instead of a master robot path. Therefore robot motions can be easily modifiable with the various object motions. This type of motion determination is different from that of the master-slaves method using the master robot motions. The other is that the developments of robot application softwares need a heavy cost when the participated robots or the tasks given to the robots are changed. Based on object-oriented programming paradigm, we present useful software objects describing robot application programming environment. The object-oriented programming paradigm increases the software reusability, reliability, and extensibility, and also provides the structual concepts to cope with the various demands of robot application programming.

• Journal of the Korea Society for Simulation
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• v.14 no.1
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• pp.43-53
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• 2005

We developed the module of the software that robot designers can perform their work faster and more easily. The parametric modeler is founded on the virtual robot design program. The virtual robot design program is the powerful software which may be used to solve various problems of robot kinematics and dynamics. The parametric modeler in the software we developed is that all the positions of joints and links are changed automatically when the designer changes one joint or one link in the robot system. Without parametric method, robot-designers must change all the positions of connected joints and links. It might become time-consuming. However, it is very efficient for designers to use the method of batch-processing in performing design-changes of robot-links using the parametric modeler.