• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.452-457
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• 1999

The recent control system has been changed into the type of PLC(Programmable Logic Controller) control. Up to now, systematic approach of PLC programming or control logic design is not suggested. In this study, the design process of the control logic is systematized and concrete process in each step is suggested. This systematized approach lead developer to be convenient to implement control system. When some error is occurred in the system, this approach enable the developer to analyze the reason of error rapidly and the system is amended according to systematic information of the analysis. The example of control system implementation following this approach is introduced.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.5
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• pp.624-629
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• 1998

Evolutionary computation techniques can solve search problems using simulated evolution based on the ‘survival of the fittest’. Recently, the genetic programming (GP) which evolves computer programs using the genetic algorithm was introduced. In this paper, the genetic programming technique is used in order to design a rule based controller consisting of condition-action rules for an unknown system. No a priori knowledge about the structure of the controller is needed. Representation of a solution, functions and terminals in GP are analyzed, and a method of constructing a fuzzy logic controller using the obtained rule based controller is described. A simulation example using a nonlinear system shows the validity and efficiency of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1467-1474
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• 2009

What matters in the society of knowledge and information is not that they just know certain facts, but that when faced with new situations, they should be able to develop novel ideas, apply them and do the problems or the tasks confronting them. This cannot be achieved through learning of mere knowledge. Computer programming lessons have shown positive effects on general thinking ability, metacognitive aspects, and logical thinking. The ACM has suggested that 8th grade students at the first level (second year students of middle school) be educated in programming languages such as LOGO to raise their ability to think logically. Previous studies have confirmed educational programming languages such as LOGO and BASIC, which are currently used, are helpful in improving the ability to think logically and to solve problems. However these languages lack connectivity with later learning. Little research has been done on 'Dolittle', an educational programming language, newly developed, using object-oriented notions. Few studies have been made of the effects of 'Dolittle' on the ability to think logically. The following results were obtained. The research didn't lead to a statistically significant improvement of the students' cognitive development level. However, proportional logic and combinational logic, among the six subcategories of logic, improved through the introduction of 'Dolittle' programming lessons. This leads to the conclusion that in the processing of solving the problems given, the students learned by themselves and improved their ability to think logically.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.3
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• pp.232-239
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• 2006

This paper is for applying interactive fuzzy linear programming for the problem of product mix planning, which is one of the aggregate planning problem. We developed a modified algorithm, which has two-phase approach for interactive fuzzy linear programming to get a better solution. Adding two-phase method, we expect to obtain not only the highest membership degree, but also a better utilization of each constrained resource.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.2
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• pp.76-83
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• 2005

Thrusters are important actuators where air is rare. Since the maintenance or replacement of thrusters is not easy in such an environment, a thrusting system must be highly reliable. Redundant thrusters are used to meet the reliability requirement. In this paper, a reconfiguration problem for those redundant thrusters is discussed, especially the management or distribution logic of redundant thrusters is focused on. The logic has to be changed if faults occur at thrusters. Reconfiguration is to change the distribution logic to accommodate thrusters' faults. The authors propose a reconfiguration algorithm based on the linear programming method. The authors define the reconfiguration problem as an optimization problem. The performance index is a quantity related with total fuel consumption by thrusters. This algorithm can accommodate multiple faults. Numerical examples are given to show the advantage of the proposed algorithm over existing methods.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.557-560
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• 2003

In this paper, we developed an editor and running engine for the SoftPLC. LD is the most popular standard IEC 1131-3 PLC language in Korea and used over 90% among the 5 PLC languages. In this paper, we have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user is converted to IL, which is one of intermediate codes, and IL is converted to the standard C code which can be used in a commercial editor such as visual C++. In ISPLC, the detection of logical error in high level programming(C) is more efficient than PLC programming itself. ISPLC provide easy programming platform to such beginner as well as professionals. The study of code conversion of LD-> U->C is firstly tried in the world as well as KOREA.

• Journal of KIISE
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• v.41 no.10
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• pp.762-773
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• 2014

As the web of data is increasingly producing large RDFS datasets, it becomes essential in building scalable reasoning engines over large triples. There have been many researches used expensive distributed framework, such as Hadoop, to reason over large RDFS triples. However, in many cases we are required to handle millions of triples. In such cases, it is not necessary to deploy expensive distributed systems because logic program based reasoners in a single machine can produce similar reasoning performances with that of distributed reasoner using Hadoop. In this paper, we propose a scalable RDFS reasoner using logical programming methods in a single machine and compare our empirical results with that of distributed systems. We show that our logic programming based reasoner using a single machine performs as similar as expensive distributed reasoner does up to 200 million RDFS triples. In addition, we designed a meta data structure by decomposing the ontology triples into separate sectors. Instead of loading all the triples into a single model, we selected an appropriate subset of the triples for each ontology reasoning rule. Unification makes it easy to handle conjunctive queries for RDFS schema reasoning, therefore, we have designed and implemented RDFS axioms using logic programming unifications and efficient conjunctive query handling mechanisms. The throughputs of our approach reached to 166K Triples/sec over LUBM1500 with 200 million triples. It is comparable to that of WebPIE, distributed reasoner using Hadoop and Map Reduce, which performs 185K Triples/sec. We show that it is unnecessary to use the distributed system up to 200 million triples and the performance of logic programming based reasoner in a single machine becomes comparable with that of expensive distributed reasoner which employs Hadoop framework.

• The KIPS Transactions:PartA
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• v.19A no.1
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• pp.69-72
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• 2012

Logic programming based on classical or linear logic has traditionally lacked devices for expressing sequential tasks and sequential iterative tasks. Expressing sequential goal tasks has been addressed by a recent proposal of sequential goals of the form $G_1{\cap}G_2$ which is based on the game semantics of Japaridze. This paper proposes sequential iterative goal formulas of the form ${\cap}_x^LG$ where $G$ is a goal, $x$ is a variable, and $L$ is a list. ${\cap}_x^L$ is called a sequential bounded quantier. These goals allow us to specify the following task: sequentially iterate $G$ with $x$ ranging over all the elements of $L$.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.735-738
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• 1998

To develop an effective virtual prototyping methodology for the PLC(Programmable Logic Controller) based real-time systems, a conversion algorithm from RLL(Relay Ladder Logic) to statechart is presented in this paper. The RLL is the main programming language to represent the operation of the PLC, and the statechart is the most widely used tool in the field of virtual prototyping in order to represent the behaviour of real-time systems. A virtual prototyping for an example case is implemened to evaluate the benefit of the proposed algorithm.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.234-239
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• 2009

In this article we present the simulation results of induction motor speed regulation by direct torque control with a classic PI regulator. The MATLAB Simulink programming environment is used as a simulation tool. The results obtained, using a fuzzy logic, shows the importance of this method in the improvement of the performance of such regulation.