• Korean Journal of Optics and Photonics
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• v.19 no.1
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• pp.60-67
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• 2008

An all-optical 4-bit Gray code to binary coded decimal (BCD) converter by means of commercially available numerical analysis tool (VPI) was demonstrated, for the first time to our knowledge. Circuit design approach was modified appropriately in order to fit the electrical method on an all-optical logic circuit based on a cross gain modulation (XGM) process so that signal degradation due to the non-ideal optical logic gates can be minimized. Without regenerations, Q-factor of around 4 was obtained for the most severely degraded output bit (least significant bit-LSB) with 2.5 Gbps clean input signals having 20 dB extinction ratio. While modifying the two-level simplification method and Karnaugh map method to design a Gray code to BCD converter, a general design concept was also founded (one-level simplification) in this research, not only for the Gray code to BCD converter but also for any general applications.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.139-144
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• 2004

The flight control system designed for an unmanned airship, which is under development by KARI, is in reduced. First, the dynamic characteristics of the airship are addressed, which are fairly different from those of the nominal aircraft. In order to implement autonomous flight for the unmanned airship, flight control logic is designed including autopilot and guidance law. The autopilot is designed under consideration of the velocity region of the unmanned airship. The guidance laws are implemented in main operational modes such as point navigation, station keeping and spiral up/down for emergency return. Their simulation results are also presented in order to validate performances of the flight control system.

• Korean Journal of Logic
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• v.18 no.2
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• pp.265-289
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• 2015

The idea that an effect counterfactually depends on its cause is simple and intuitive. However, this simple idea runs into various difficulties. The active route account, in order to avoid the difficulties, analyzes causation in terms of counterfactual dependence under certain control. In her recent article, Seahwa Kim criticizes Sungsu Kim's earlier attempt to defend the active route account from its counterexamples. Her criticisms are convincing, and defenders of the active route account or counterfactual analysis of causation in general need another defense. In response, a two-step defense is proposed. First, the scope of the active route account is restricted to 'proximate' causal relation. Second, a control over factors that are in proximate causal relation is offered to figure out 'distant' causal relation. The result is that with proper control, an effect indeed counterfactually depends on its cause.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.438-442
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• 2003

For an efficient sliding mode control system stability and chattering avoidance should be guaranteed. A continuation method using boundary layer is well known as one solution for this. However since not only model uncertainties and disturbances but also control task itself is variable. it is practically impossible to set controller parameters - control discontinuity, control bandwidth, boundary layer thickness - in advance. In this paper first an adaptation law of control discontinuity is introduced to assure system stability and then fuzzy logic based tuning algorithm of design parameters is applied based on monitored performance indices of tracking error, control chattering, and model precision. In the end maximum control bandwidth not exciting unmodeled dynamics and minimum control discontinuity, boundary layer thickness making system stable and free of chattering are found respectively. This eliminates control chattering and enhances control accuracy as much as possible under given control situation. In order to demonstrate the validity of the proposed algorithm safe headway maintenance control for autonomous transportation system is simulated. The control results show that the proposed algorithm guarantees system stability all the time and tunes control parameters consistently and in consequence implements an efficient control in terms of both accuracy and actuator chattering.

• Korean Journal of Logic
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• v.22 no.1
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• pp.87-124
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• 2019

A dialetheic approach to the sorites paradox is to understand a borderline case as a true contradiction. In order to accommodate this approach, the possibility of an alternative that does not involve a contradiction should be considered first. Beall presents an alternative that has all virtues of dialetheic solution without contradiction. I do not think his alternative has no contradiction. Using the inclosure schema I will show it. Furthermore, I will show that all alternatives which do not accept the existence of cut-off point imply a contradiction. This means that we have to accept a true contradiction as long as we accept the intuition of vagueness, especially, what is called 'tolerance'.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.999-1004
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• 2005

An algorithm for a hybrid controller consists of a sliding mode control part and a fuzzy logic part which ar purposely for nonlinear systems. The sliding mode part of the solution is based on "eigenvalue/vector"-type controller is used as the backstepping approach for tracking errors. The fuzzy logic part is a Mamdani fuzzy model. This is designed by applying sliding mode control (SMC) method to the dynamic model. The main objective is to keep the update dynamics in a stable region by used SMC. After that the plant behavior is presented to train procedure of adaptive neuro-fuzzy inference systems (ANFIS). ANFIS architecture is determined and the relevant formulation for the approach is given. Using the error (e) and rate of error (de), occur due to the difference between the desired output value (yd) and the actual output value (y) of the system. A dynamic adaptation law is proposed and proved the particularly chosen form of the adaptation strategy. Subsequently VSC creates a sliding mode in the plant behavior while the parameters of the controller are also in a sliding mode (stable trainer). This study considers the ANFIS structure with first order Sugeno model containing nine rules. Bell shaped membership functions with product inference rule are used at the fuzzification level. Finally the Mamdani fuzzy logic which is depends on adaptive neuro-fuzzy inference systems structure designed. At the transferable stage from ANFIS to Mamdani fuzzy model is adjusted for the membership function of the input value (e, de) and the actual output value (y) of the system could be changed to trapezoidal and triangular functions through tuning the parameters of the membership functions and rules base. These help adjust the contributions of both fuzzy control and variable structure control to the entire control value. The application example, control of a mass-damper system is considered. The simulation has been done using MATLAB. Three cases of the controller will be considered: for backstepping sliding-mode controller, for hybrid controller, and for adaptive backstepping sliding-mode controller. A numerical example is simulated to verify the performances of the proposed control strategy, and the simulation results show that the controller designed is more effective than the adaptive backstepping sliding mode controller.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.89-105
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• 2008

So far, most of research on automated test data generation(ATDG) deals with programs without pointers. Recently, few works hove been done on ATDG in the presence of pointers, but they ore path-oriented techniques which require the specification of on entire program path to be tested or a program to be executed. This paper presents a new technique for generating test data even without specifying a program path completely. The presented technique is a static technique which transforms the test data generation problem into a SAT(SATisfiability) problem and makes advantage of SAT solvers for ATDG. For the ends, we transform a program under test into Alloy which is the first-order relational logic and then produce test data via Alloy analyzer.

• Korean Journal of Logic
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• v.17 no.2
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• pp.253-287
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• 2014

In First-Order Logic the English expressions, 'any', 'every', 'all', and 'each' are treated on a par but have different meanings in the natural language usages. Especially the expression 'any' is typically used only in the negative contexts, which linguists have paid attention to and attempted to provide an adequate explanation of. I shall show that the explanations so far mainly from linguists are not satisfactory and revive the philosophical insights concerning the logical features of 'any' provided by Zeno Vendler in 1962. I shall claim that the expression 'any' has what Vendler calls the 'freedom of choice' as its primary meaning and denotes what Kit Fine calls an 'arbitrary object'. It will be shown that the logical features of 'any' are manifested more evidently in the analysis of the Korean expression 'amwu'. I believe that this analysis has significant philosophical implications. As an instance I shall show that we can take a fresh perspective on the problem which involves the universal generalization rule and the preface paradox.

• Journal of the Korean Institute of Intelligent Systems
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• v.1 no.1
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• pp.9-25
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• 1991

This tutorial paper has been written for biologists, physicians or beginners in fuzzy sets theory and applications. This field is introduced in the framework of medical diagnosis problems. The paper describes and illustrates with practical examples, a general methodology of special interest in the processing of borderline cases, that allows a graded assignment of diagnoses to patients. A pattern of medical knowledge consists of a tableau with linguistic entries or of fuzzy propositions. Relationships between symptoms and diagnoses are interpreted as labels of fuzzy sets. It is shown how possibility measures (soft matching) can be used and combined to derive diagnoses after measurements on collected data. The concepts and methods are illustrated in a biomedical application on inflammatory protein variations. In the case of poor diagnostic classifications, it is introduced appropriate ponderations, acting on the characterizations of proteins, in order to decrease their relative influence. As a consequence, when pattern matching is achieved, the final ranking of inflammatory syndromes assigned to a given patient might change to better fit the actual classification. Defuzzification of results (i.e. diagnostic groups assigned to patients) is performed as a non fuzzy sets partition issued from a "separating power", and not as the center of gravity method commonly employed in fuzzy control. It is then introduced a model of fuzzy connectionist expert system, in which an artificial neural network is designed to build the knowledge base of an expert system, from training examples (this model can also be used for specifications of rules in fuzzy logic control). Two types of weights are associated with the connections: primary linguistic weights, interpreted as labels of fuzzy sets, and secondary numerical weights. Cell activation is computed through MIN-MAX fuzzy equations of the weights. Learning consists in finding the (numerical) weights and the network topology. This feed forward network is described and illustrated in the same biomedical domain as in the first part.

• Journal of architectural history
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• v.8 no.4 s.21
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• pp.95-112
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• 1999

This Study starts from a recognition that the architecture is based on the process demanded by substantial needs as well as pure theoretical logic system. So this study aims at proposing another point of view differentiating process and principle of architecture from pure theoretical logic system in the creative process of the Governor's Palace by analyzing drawings in chronological order. Even though the Governor's Palace had not been built because of discord between authorities of India and Le Corbusier, it is undoubtedly one of the best proposals which contains very concepts and ideas of later Le Corbusier's architectural intentions. In the first design stage, overall conception of the building was carried out in the sketches and drawings till Jan, 1954 and in the second stage, the elaboration of the project was pursued till Mar. 1995. The scheme tends to begin too large and general in character, becoming tighter and more complex under pressure from the client and adjustments required by the design process itself. For example, scale reduction, division and development of internal circulation system and applying his early 'Five Points'. So new solutions are searched by oscillating between compromise modifications and radically different solutions in contracting the first ideas. From all these, it is concluded that the early doctrine (Five Points) are adjusted and extended towards another stage by the use of restricted pilotis, the concept of fenetre en longueur transformed into a sub stricture of facade, sustained concept of le plan libre, les toits jardins extended towards concept of the urban area. And these formal intentions of the Governor's Place has been carried through other contemporary projects like Mill Owner's Association in 1954 and Villa Shodan in 1952.