• Korean Management Science Review
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• v.34 no.1
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• pp.47-56
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• 2017

We focus on the Real time Fire Scheduling Problem (RFSP), the problem of determining the sequence of targets to be fired at, for the objective of minimizing threatening probability to achieve tactical goals. In this paper, we assume that there are m available weapons to fire at n targets (> m) and the weapons are already allocated to targets. One weapon or multiple weapons can fire at one target and these fire operations should start simultaneously while the finish time of them may be different. We suggest mathematical modeling for RFSP and several heuristic algorithms. Computational experiments are performed on randomly generated test problems and results show that the suggested algorithms outperform the firing method which is generally adopted in the field artillery.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2337-2340
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• 2002

This paper presents the method of AGV(Automatic guided vehicle)'s moving environment(plane, corner, edge) recognition using SONAR sensor configuration. As for the SONAR sensor, the Crosstalk effect has been generally considered as an inevitable noisy phenomenon in the indoor environment. However, this effect can be used as a clue for classifying and localizing targets in the indoor environment if those can be controlled and used well. EERUF(error eliminate rapid ultrasonic firing) is a method for firing multiple ultrasonic sensors in mobile robot application and multi-echo mode of POLARIOD Device can reduce the Crosstalk effect. Here, Crosstalk effect was reduced using EERUF and applied to the AGV with a simple wall-following algorithm in the indoor environment. This method was tesed by a typical AGV with multi SONAR sensors in the laboratory environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.399-402
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• 2008

It is well known that helium saturated propellants significantly effects the dynamics of propulsion system, thruster cross coupling, water hammer and thruster performance. Especially for the propulsion systems, which have multiple high thrust engines, such as HTV(H-II transfer vehicle), the effect is more important. Therefore full-saturated propellants should be used at ground tests of HTV propulsion system and evaluate its effects. HTV is an advanced space vehicle being developed by Japan Aerospace Exploration Agency(JAXA) to enhance cargo delivery capabilities of the fleet of vehicles visiting the International Space Station(ISS). This paper presents an overview of the successful effort of the testing with saturated propellants(MMH/MON3) for HTV propulsion system during the ground firing tests.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.720-723
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• 1997

This paper presents a cooperative control method for multiple robots. This method is based on local sensors. The proposed method integrates all information obtained by local perception through a set of sensors and generates commands without logical conflicts in designing control logic. To control multiple robots effectively, a global control strategy is proposed. These methods are constructed by using AND/OR logic and transition firing sequences in Petri nets. To evaluate these methods, the object-searching task is introduced. This task is to search an object like a box by two robots and consists of two sub-tasks, i.e., a wall tracking task and a robot tracking task. Simulation results for the object-searching task and the wall tracking task are presented to show the effectiveness of the method.

• The Journal of Advanced Prosthodontics
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• v.12 no.3
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• pp.167-172
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• 2020

PURPOSE. The aim of the present study was to investigate the passive fit of metal substructure after repetitive firing processes in implant-supposed prosthesis. MATERIALS AND METHODS. Five implants (4 mm diameter and 10 mm length) were placed into the resin-based mandibular model and 1-piece of screw-retained metal substructure was produced with the direct metal laser sintering (DMSL) method using Co-Cr compound (n = 10). The distance between the marked points on the multiunit supports and the marginal end of the substructure was measured using a scanning electron microscope (SEM) at each stage (metal, opaque, dentin, and glaze). 15 measurements were taken from each prosthesis, and 150 measurements from 10 samples were obtained. In total, 600 measurements were carried out at 4 stages. One-way ANOVA test was used for statistical evaluation of the data. RESULTS. When the obtained marginal range values were examined, differences between groups were found to be statistically significant (P<.001). The lowest values were found in the metal stage (172.4 ± 76.5 ㎛) and the highest values (238.03 ± 118.92 ㎛) were determined after glaze application. When the interval values for groups are compared with pairs, the differences between metal with dentin, metal with glaze, opaque with dentin, opaque with glaze, and dentin with glaze were found to be significant (P<.05), whereas the difference between opaque with metal was found to be insignificant (P=.992). CONCLUSION. Passive fit of 1-piece designed implant-retained fixed prosthesis that is supported by multiple implants is negatively affected by repetitive firing processes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.41-47
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• 2012

In this paper, we proposed a new method which analyzes and eliminates errors occurring by multi-reflection of ultrasonic firing in mobile robot application. This new method allows ultrasonic sensors to fire at rates that are three times faster than those customary in conventional applications readings due to ultrasonic noise disturbance. It is possible them to collect and predict sensor data much faster than conventional methods. Furthermore, this method's capability allows mobile robot to navigate in a complex and unknown environment and to collaborate in the same environment with multiple mobile robot, even if their ultrasonic sensors operate. And it's usefulness to avoid moving obstacles by capability of rapid collecting data. Finally, we present experimental results that demonstrate the performances of the new proposed method by experiments in a multi-reflective environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.252-255
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• 2007

Recently military industrial company, utilizing company funded R&D and goverment and industry contracts, has developed ACTS/DACS technology. This technology can be utilized to rapidly steer "smart" bullets, "smart" rounds, tactical missile, cruise missile and kill vehicles for both endo- and exoatmospheric applications. The ACTS/DACS typically consists of a Smart Bus Controller(SCB), a proprietary network firing bus, Smart Pyrotechnic Devices(SPD), rocket motors, and a structure. The SCB communicates with the SPDs over the propretary network firing bus. Each rocket motor contains an SPD which provides rocket motor ignition. Firing energy is stored locally in the SPD so surge currents do not occur in the system as rocket motors are fired. This approach allows multiple, truly simultaneous firings without the need for large, dedicated batteries. Each SPD also functions as a network tranceiver and high reliability fir set all in the space of a single-sided 10 millimeter diameter circuit. The present work develops a new means for igniting explosive materials. The volume of semiconductor bridge (SCB) is over 30 times smaller than a conventional hot wire. We believe that the present work has a potential for development of a new igniter such as smart pyrotechnic device.

• Journal of the military operations research society of Korea
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• v.33 no.1
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• pp.105-115
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• 2007

It is essential to give a fatal damage to the enemy force by using prompt and accurate fire in order to overcome the lack of artillery force. During the artillery fire operations, minimizing the firing time will secure the adapt ability in tactical operation. In this paper, we developed a mathematical model to schedule the artillery fire on the multiple targets to decrease total fire operation time. To design a program to describe a real firing situation, we consider many possible circumstances of changes such as commander's intention, firing constraints, target priority, and contingency plan to make a fire plan in an artillery unit. In order to work out the target sequencing problem, MIP is developed and the optimum solution is obtained by using ILOG OPL. If this analytical model is applied to a field artillery unit, it will improve the efficiency of the artillery fire force operations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.649-653
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• 2006

Engine Noise is composed of the mechanical and combustion noise. The contribution of combustion noise is generally bigger than the contribution of the mechanical noise at idle condition in DI diesel engine. That noise usually makes a roughness problem at the fundamental engine order. It is difficult to remove the modulation frequency so we have to directly reduce the combustion noise. The key effect of combustion noise reducing solution is the modification of the combustion pressure profile. It is accomplished by the multiple injection method and we solved the 400Hz combustion noise and improved the sound quality at idle condition in DI diesel engine.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.2
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• pp.68-77
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• 2004

This paper considers the workforce assignment problem to minimize both the deviations of workloads assigned to workers and to maximize the total preference between each worker and each machine. Because of the high expense of technology education and the difficulties of firing employees, there is no part time workers in semiconductor industry. Therefore, multi-skilled workers are trained for performing various operations in several machines. The bicriteria workforce assignment problem in this paper is not easy to obtain the optimal solution considering the aisle structure and it is belong to NP-class. The proposed heuristic algorithms are developed based on the combination of spacefilling curve technique, simulated annealing technique and graph theory focusing on the multiple-row machine layout. Examples are presented for the proposed algorithms how to find a good solution.