• Title/Summary/Keyword: modal operators

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Constructivist interpretation on the modal logic (양상 논리에 대한 구성주의적 해석)

  • Eun, Eun-suk
    • Journal of Korean Philosophical Society
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    • v.116
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    • pp.257-280
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    • 2010
  • I try to formalize the system of modal logic and interpret it in view of constructivism through this study. As to the meaning of a sentence, as we saw, Frege endorsed extensions in view of the fact that they are enough to provide for a compositional account for truth, in particular that (1) the assignment of extensions to expressions is compositional ; (2) the assignment of extensions to sentences coincides with the assignment of truth values. But nobody would be willing to admit that a truth value is what a sentence means and that consequently all true sentences are synonymous. So, if what we are after is meaning in the intuitive sense, then extensions would not do. This consideration has later become the point of departure of modal and intensional semantics. So, it is clear that the language of modal logic do not allow for an extensional interpretation. ${\square}$ is syntactically on a par with ${\vdash}$, hence within the extensional framework it would have to denote a unary truth function. This means that if modal logic is to be interpreted, we need a semantics which is not extensional. The first attempt to build a feasible intensional semantics was presented by Saul Kripke. He came to the conclusion that we must let sentences denote not truth values, but rather subsets of a given set. He called elements of the underlying set possible world. Hence each sentence is taken to denote the set of those possible world in which it is true. This lets us explicate necessity as 'truth in every possible world' and possibility as 'truth in at least one possible world'. But it is clear that the system of modal logic is not only an enlargement of propositional logic, as long as the former contains the new symbols, but that it is of an other nature. In fact, the modal logic is intensional, in that the operators do not determine the functions of truth any more. But this new element is not given a priori, but a posteriori from construction by logicist.

Improvement of Vibration Response of a Sensor Plate of Loose Parts Monitoring System in Nuclear Power Plants (원전 금속이물질 감시계통 센서 플레이트의 진동 특성 개선 연구)

  • Seo, Jung-Seok;Han, Soon-Woo;Lee, Jeong-Han;Kang, To;Park, Jin-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.27 no.2
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    • pp.148-154
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    • 2017
  • This paper discussed design for resonance avoidance of sensor plates of loose-parts monitoring systems (LPMS) in nuclear power plants (NPP). An LPMS monitors impact of loose parts in primary loop of NPP by using accelerometers, which is mounted on sensor plates. Resonance of the plates may cause false alarms at frequencies over 10 kHz, which can be misunderstood as impact signals of loose parts with small mass and cause unnecessary response of NPP operators. Modal analysis was carried out for the existing sensor plate and design parameters affecting natural frequencies were chosen. Frequency response functions of plates were analyzed by changing the parameters and the optimized plate design for avoiding resonance was determined. Experiments was carried out for the plate specimen with improved design and verified the proposed approach and design.

Global Optimum Searching Technique Using DNA Coding and Evolutionary Computing (DNA 코딩과 진화연산을 이용한 함수의 최적점 탐색방법)

  • Paek, Dong-Hwa;Kang, Hwan-Il;Kim, Kab-Il;Han, Seung-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.6
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    • pp.538-542
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    • 2001
  • DNA computing has been applied to the problem of getting an optimal soluting since Adleman's experiment. DNA computing uses strings with various length and four-type bases that makes more useful for finding a global optimal solutions of the complex multi-modal problems This paper presents DNA coding method finding optimal solution of the multi-modal function and compares the efficiency of this method with the genetic algorithms(GA). GA searches efffectively an optimal solution via the artificial evolution of individual group of binary string and DNA coding method uses DNA molecules and four-type bases denoted by the A(Ademine) C(Gytosine);G(Guanine)and T(Thymine). The selection, crossover, mutation operators are applied to both DNA coding algorithm and genetic algorithms and the comparison has been performed. The results show that the DNA based algorithm performs better than GA.

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Statically compensated modal approximation of a class of distributed parameters systems

  • Imai, Jun;Wada, Kiyoshi;Sagara, Setsuo
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.416-419
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    • 1995
  • A finite-dimensional approximation technique is developed for a class of spectral systems with input and output operators which are unbounded. A corresponding bounding technique on the frequency-response error is also established for control system design. Our goal is to construct an uncertainty model including a nominal plant and its error bounds so that the results from robust linear control theory can be applied to guarantee a closed loop control performance. We demonstrate by numerical example that these techniques are applicable, with a modest computational burden, to a wide class of distributed parameter system plants.

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Implementation of GA Processor with Multiple Operators, Based on Subpopulation Architecture (분할구조 기반의 다기능 연산 유전자 알고리즘 프로세서의 구현)

  • Cho Min-Sok;Chung Duck-Jin
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.5
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    • pp.295-304
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    • 2003
  • In this paper, we proposed a hardware-oriented Genetic Algorithm Processor(GAP) based on subpopulation architecture for high-performance convergence and reducing computation time. The proposed architecture was applied to enhancing population diversity for correspondence to premature convergence. In addition, the crossover operator selection and linear ranking subpop selection were newly employed for efficient exploration. As stochastic search space selection through linear ranking and suitable genetic operator selection with respect to the convergence state of each subpopulation was used, the elapsed time of searching optimal solution was shortened. In the experiments, the computation speed was increased by over $10\%$ compared to survival-based GA and Modified-tournament GA. Especially, increased by over $20\%$ in the multi-modal function. The proposed Subpop GA processor was implemented on FPGA device APEX EP20K600EBC652-3 of AGENT 2000 design kit.

An Application and Evaluation of Hub-and-spoke Strategy for Rail Freight Service in European Networks (철도화물서비스를 위한 Hub-and-spoke 운송전략의 적용과 평가: 유럽 사례를 중심으로)

  • 정승주
    • Journal of the Korean Society for Railway
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    • v.7 no.3
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    • pp.264-270
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    • 2004
  • The hub-and-spoke strategy is widely used in the field of transportation. At the field of rail transportation, however, it is difficult that we find an application case of this strategy because of modal characteristics. According to the fast growth of containerization and the development of transshipment technology, presently, the hub-and-spoke strategy is introduced by operators on actual European rail freight transportation. However, it is hardly to find empirical studies evaluating the applicability of transportation strategy. In this context, this study analyzed the applicabilities of hub-and-spoke strategy in the actual network of European rail freight. For the application and evaluation of the characteristics of hub-and-spoke strategy, it utilized a service network design model for rail freight. Utilizing this model, it analyzed the efficiency of furnished rail freight services, the potential locations of hubs, the characteristics of O-D flows by the types of trains and service links, and the types of paths of O-D flows. Finally, it proposed some implications and the further study topics.

Knowledge Preconditions for Composition of Semantic Web Services (시맨틱 웹서비스 조합을 위한 지식 전제조건)

  • Kim Sang-Kyun;Lee Kyu-Chul
    • Journal of KIISE:Software and Applications
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    • v.32 no.9
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    • pp.888-900
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    • 2005
  • Several researches have been proposed to formalize the knowledge preconditions problem - j.e., an action or a plan is epistemically feasible. However, since the feasibility is only checked at design-time and is assumed that it will also 1)e feasible at run-time, it is not suitable in the context of Semantic Web services composition, where many agents should share the limited resources required for the execution of Web services composition. Therefore, in this paper, we formalize a transactionally executable Web services composition which enables to guarantee its atomicity. Moreover, in order to formalize the transactional executability, we propose $TL-ALCFK_{NF}$ which extends TL-ALCF with the modal operators K and A. Based on $TL-ALCFK_{NF}$, we show how to carry out the epistemic reasoning with TL-ALCF as a language to represent Semantic Web services composition.

A Study on the Efficiency of Container Ports in the Mediterranean Sea (지중해 컨테이너항만의 효율성 분석에 관한 연구)

  • Ibrahim, Ousama Ibrahim Hassan;Kim, Hyun Deok
    • Journal of Korea Port Economic Association
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    • v.37 no.2
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    • pp.91-105
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    • 2021
  • The current increasing size of container vessels affects the container port's situation. The containerization has changed the inter-modal handling process, which brought more flexibility and comfortableness in the shipping industry sector. Thus, it is very crucial to analyze the efficiency of container ports in the regional sphere. Such kind of efficiency analysis provide a powerful management tool for port operators and shipping managers in the Mediterranean market, and it also helps to form an information for planning new regional and national port operations. This paper aims to analyze the ports' technical efficiency of Mediterranean major container ports. It is conducted to establish the model of port performance and efficiency through the empirical test of the various factors. Regarding to the panel data collected from the 48 DMUs (decision making units), this study attempts to provide the empirical basis of the port efficiency relative to another factors in the total port performance. Due to the complexity of the various activities carried out at container ports, the study focuses only on the technical efficiency at the level of the Mediterranean container port. Unlike the practice of cross-sectional data analysis, originally established by Charnes et al. (1985), the panel data in DEA window analysis applications are used. The main focus of this study is the relative technical efficiency of 12 container ports from 7 countries in the Mediterranean market. The selection of ports under study is based on their high handling capability and rankings in World Top 100 (Containerization International, 2018).