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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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International Journal of Fuzzy Logic and Intelligent Systems
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Korean Institute of Intelligent Systems
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Volume & Issues
Volume 14, Issue 4 - Dec 2014
Volume 14, Issue 3 - Sep 2014
Volume 14, Issue 2 - Jun 2014
Volume 14, Issue 1 - Mar 2014
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Modern Probabilistic Machine Learning and Control Methods for Portfolio Optimization
Park, Jooyoung ; Lim, Jungdong ; Lee, Wonbu ; Ji, Seunghyun ; Sung, Keehoon ; Park, Kyungwook ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 73~83
DOI : 10.5391/IJFIS.2014.14.2.73
Many recent theoretical developments in the field of machine learning and control have rapidly expanded its relevance to a wide variety of applications. In particular, a variety of portfolio optimization problems have recently been considered as a promising application domain for machine learning and control methods. In highly uncertain and stochastic environments, portfolio optimization can be formulated as optimal decision-making problems, and for these types of problems, approaches based on probabilistic machine learning and control methods are particularly pertinent. In this paper, we consider probabilistic machine learning and control based solutions to a couple of portfolio optimization problems. Simulation results show that these solutions work well when applied to real financial market data.
Three-Dimensional Face Point Cloud Smoothing Based on Modified Anisotropic Diffusion Method
Wibowo, Suryo Adhi ; Kim, Sungshin ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 84~90
DOI : 10.5391/IJFIS.2014.14.2.84
This paper presents the results of three-dimensional face point cloud smoothing based on a modified anisotropic diffusion method. The focus of this research was to obtain a 3D face point cloud with a smooth texture and number of vertices equal to the number of vertices input during the smoothing process. Different from other methods, such as using a template D face model, modified anisotropic diffusion only uses basic concepts of convolution and filtering which do not require a complex process. In this research, we used 6D point cloud face data where the first 3D point cloud contained data pertaining to noisy x-, y-, and z-coordinate information, and the other 3D point cloud contained data regarding the red, green, and blue pixel layers as an input system. We used vertex selection to modify the original anisotropic diffusion. The results show that our method has improved performance relative to the original anisotropic diffusion method.
Synchronization of Dynamical Happiness Model
Bae, Youngchul ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 91~97
DOI : 10.5391/IJFIS.2014.14.2.91
Chaotic dynamics is an active research area in fields such as biology, physics, sociology, psychology, physiology, and engineering. Interest in chaos is also expanding to the social sciences, such as politics, economics, and societal events prediction. Most people pursue happiness, both spiritual and physical in many cases. However, happiness is not easy to define, because people differ in how they perceive it. Happiness can exist in mind and body. Therefore, we need to be happy in both simultaneously to achieve optimal happiness. To do this, we need to synchronize mind and body. In this paper, we propose a chaotic synchronization method in a mathematical model of happiness organized by a second-order ordinary differential equation with external force. This proposed mathematical happiness equation is similar to Duffing`s equation, because it is derived from that equation. We introduce synchronization method from our mathematical happiness model by using the derived Duffing equation. To achieve chaotic synchronization between the human mind and body, we apply an idea of mind/body unity originating in Oriental philosophy. Of many chaotic synchronization methods, we use only coupled synchronization, because this method is closest to representing mind/body unity. Typically, coupled synchronization can be applied only to non-autonomous systems, such as a modified Duffing system. We represent the result of synchronization using a differential time series mind/body model.
Locality-Sensitive Hashing for Data with Categorical and Numerical Attributes Using Dual Hashing
Lee, Keon Myung ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 98~104
DOI : 10.5391/IJFIS.2014.14.2.98
Locality-sensitive hashing techniques have been developed to efficiently handle nearest neighbor searches and similar pair identification problems for large volumes of high-dimensional data. This study proposes a locality-sensitive hashing method that can be applied to nearest neighbor search problems for data sets containing both numerical and categorical attributes. The proposed method makes use of dual hashing functions, where one function is dedicated to numerical attributes and the other to categorical attributes. The method consists of creating indexing structures for each of the dual hashing functions, gathering and combining the candidates sets, and thoroughly examining them to determine the nearest ones. The proposed method is examined for a few synthetic data sets, and results show that it improves performance in cases of large amounts of data with both numerical and categorical attributes.
Building a Fusion Information System for Safe Navigation
Hong, Taeho ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 105~112
DOI : 10.5391/IJFIS.2014.14.2.105
The International Maritime Organization has determined that more than 80% of maritime accidents are caused by human error. A variety of methods have been considered to reduce maritime accidents caused by such human error. Navigators operate by observing surrounding maritime situations and analyzing information using various navigational devices. This study proposes a system to ensure safe navigation by assisting navigators through the delivery of maritime safety information (MSI) between land and sea. In the future, supplementing the system through long-term on-the-ship tests is necessary by defining MSI in relation to maritime service portfolio regions.
Development of a Prototype Data Logger System to Operate under Extreme High Pressure
Yoo, Nam-Hyun ; Rhee, Sang-Yong ; Lee, Hyeong-Ok ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 113~121
DOI : 10.5391/IJFIS.2014.14.2.113
A subsea oil production system must be safely operated for 20-30 years after being installed. Because of the severe conditions of the subsea environment, such as extreme high pressure, low visibility, the possibility of unexpected impact by any object, and corrosion by seawater, subsea oil production systems should be monitored by subsea data logger systems and remotely operated vehicles to check for abnormal vibration and leakage to prevent a catastrophic accident. Because of the severity of subsea environmental conditions and the dominance of a few companies in the market, many people have thought that it would be difficult to develop a subsea data logger system. The primary objectives of the study described in this paper were to analyze existing subsea data logger systems to establish the requirements for a subsea data logger system, implement a prototype subsea data logger system, and conduct a test of the prototype subsea data logger system.
A Context-Awareness Modeling User Profile Construction Method for Personalized Information Retrieval System
Kim, Jee Hyun ; Gao, Qian ; Cho, Young Im ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 122~129
DOI : 10.5391/IJFIS.2014.14.2.122
Effective information gathering and retrieval of the most relevant web documents on the topic of interest is difficult due to the large amount of information that exists in various formats. Current information gathering and retrieval techniques are unable to exploit semantic knowledge within documents in the "big data" environment; therefore, they cannot provide precise answers to specific questions. Existing commercial big data analytic platforms are restricted to a single data type; moreover, different big data analytic platforms are effective at processing different data types. Therefore, the development of a common big data platform that is suitable for efficiently processing various data types is needed. Furthermore, users often possess more than one intelligent device. It is therefore important to find an efficient preference profile construction approach to record the user context and personalized applications. In this way, user needs can be tailored according to the user`s dynamic interests by tracking all devices owned by the user.
Development of a System for Transmitting a Navigator`s Intention for Safe Navigation
Hong, Taeho ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 130~135
DOI : 10.5391/IJFIS.2014.14.2.130
For the past three decades, ship-to-ship collision accidents have steadily increased on the coast of South Korea by about 20% annually. Marine accidents have become more likely and more devastating in areas with increasing marine traffic and rising numbers of high-speed ships. Over 30% of the marine accidents in South Korea are concentrated in spring, since Korea`s coast is often covered in dense fog at this time of the year. Fog is generated when a large temperature range exists within a day, and this daily temperature range has increased due to abnormal weather conditions. This research proposed a system for transmitting a navigator`s intention utilizing electronic methods. A navigator`s intention was expressed on the electronic navigation chart for easier understanding of the surrounding situation, and the effectiveness of the system was verified through practical tests.
Implementation of Fuzzy Self-Tuning PID and Feed-Forward Design for High-Performance Motion Control System
Thinh, Ngo Ha Quang ; Kim, Won-Ho ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 136~144
DOI : 10.5391/IJFIS.2014.14.2.136
The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.
Exact Controllability for Fuzzy Differential Equations in Credibility Space
Lee, Bu Young ; Youm, Hae Eun ; Kim, Jeong Soon ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 145~153
DOI : 10.5391/IJFIS.2014.14.2.145
With reasonable control selections on the space of functions, various application models can take the shape of a well-defined control system on mathematics. In the credibility space, controlability management of fuzzy differential equation is as much important issue as stability. This paper addresses exact controllability for fuzzy differential equations in the credibility space in the perspective of Liu process. This is an extension of the controllability results of Park et al. (Controllability for the semilinear fuzzy integro-differential equations with nonlocal conditions) to fuzzy differential equations driven by Liu process.
Lattices of Interval-Valued Fuzzy Subgroups
Lee, Jeong Gon ; Hur, Kul ; Lim, Pyung Ki ;
International Journal of Fuzzy Logic and Intelligent Systems, volume 14, issue 2, 2014, Pages 154~161
DOI : 10.5391/IJFIS.2014.14.2.154
We discuss some interesting sublattices of interval-valued fuzzy subgroups. In our main result, we consider the set of all interval-valued fuzzy normal subgroups with finite range that attain the same value at the identity element of the group. We then prove that this set forms a modular sublattice of the lattice of interval-valued fuzzy subgroups. In fact, this is an interval-valued fuzzy version of a well-known result from classical lattice theory. Finally, we employ a lattice diagram to exhibit the interrelationship among these sublattices.