• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.754-764
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• 2016

To understand and analyze SNS(Social Network Service) two important classes of networks, small-world and scale-free networks have gained a lot of research interests. In this study, a generalized network generation method is developed, which can produce small-world network, scale-free network, or network with the properties of both small-world and scale-free by controlling two input parameters. By tuning one parameter we can represent the small-world property and by tuning the other one we can represent both scale-free and small-world properties. For the network measures to represent small-world and scale-free properties clustering coefficient, average shortest path distance and power-law property are used. Using the model proposed in this study we can have more clear understanding about relationships between small-world network and scale-free network. Using numerical examples we have verified the effects of two parameters on clustering coefficient, average shortest path distance and power-law property. Through this investigation it can be shown that small-world network, scale-free network or both can be generated by tuning two input parameters properly.

• KIEAE Journal
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• v.11 no.4
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• pp.37-45
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• 2011

In order to have better understanding of the concept and meaning of soundscape, it is very important to consider entirely the objectives, activities, historical development processes and accomplishments of world soundscape project leading by R. Murray Schafer. Therefore, the ultimate purpose of this study is to inquire into the concrete development processes and practical activities of the soundscape in order to correspond to Schafer's conception of a tuning of the world. The establishment of WSP is based on noise pollution, listening attitudes and noisy music. Schafer formulated 5 types of item as a target, and wrote down concrete activities to achieve the goals. Especially, he devised the conceptual, educational, political and social strategies as the practical strategies of WSP. It is obtained various products by the activities of WSP from the planning starting year in 1969 to the stagnation period in 1979. That is, there are the social survey on noise-vancouver 1969, the book of noise, Okeanos, a study of community noise by-laws in canada 1972, the music of the environment, the vancouver soundscape, european sound diary, five village soundscapes, handbook for acoustic ecology and so on. The research activities of WSP arouse inspiration in many people interested in sound. Specially, it is emphasized the importance of increasing for their social roles in order to more actively improve and create the quality of sound environment. Also, it shows us the directions on how to lead our furture sound.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.15-23
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• 2017

The WGS conversion project of cadastral drawing (promoted by the Ministry of Land) is not able to reflect the cadastral registration due to subtle differences such as area and location. When converting the digital cadastral region to the world geodetic system, the boundary point coordinates must be changed to the legal coordinate units. However, there is a phenomenon that occurs in which the minute area changes do not coincide with the area registered in the cadastral registration when the coordinate unit is changed. In this study, we have developed a method to adjust many parcels collectively by applying a passive fine-tuning method used in cadastral resurvey project to solve these problems. Total 1, total 2+1, interval 1, interval 2+1, etc. were classified based on the number of parcels that need to be considered for the range of adjustment and the area condition. The analysis of the experimental area (after developing SW for comparison of each method) showed that the total 2+1 method is suitable for the location accuracy and the interval 2+1 method is suitable for the temporal efficiency.

• ETRI Journal
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• v.40 no.4
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• pp.421-434
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• 2018

The application of deep neural networks (DNNs) to connect the world with cyber physical systems (CPSs) has attracted much attention. However, DNNs require a large amount of memory and computational cost, which hinders their use in the relatively low-end smart devices that are widely used in CPSs. In this paper, we aim to determine whether DNNs can be efficiently deployed and operated in low-end smart devices. To do this, we develop a method to reduce the memory requirement of DNNs and increase the inference speed, while maintaining the performance (for example, accuracy) close to the original level. The parameters of DNNs are decomposed using a hybrid of canonical polyadic-singular value decomposition, approximated using a tensor power method, and fine-tuned by performing iterative one-shot hybrid fine-tuning to recover from a decreased accuracy. In this study, we evaluate our method on frequently used networks. We also present results from extensive experiments on the effects of several fine-tuning methods, the importance of iterative fine-tuning, and decomposition techniques. We demonstrate the effectiveness of the proposed method by deploying compressed networks in smartphones.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.246-252
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• 2012

Recently, concern over climate change and global politics associated with traditional fossil fuel energy sources has driven significant increase in wind energy utilization over the past decade around world. Generally, life-time of wind turbine system should be guaranteed for twenty years. Therefore, performance deterioration of wind turbine system occurs owing to aging effects for long term operation. In this work, a new type of auto tuning algorithm for overcoming the problem of performance deterioration is proposed. Furthermore, various simulations are carried out to verify the feasibility of the proposed scheme.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.45-52
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for $NO_x$ controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2,\;NO_x$ and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective rear pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing $NO_x$ emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.102-108
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for NOx controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2$, NOx and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective back-pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing NOx emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1E
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• pp.15-23
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• 1997

Zero-Crossings with Peak Amplitudes(ZCPA) model motivated by human auditory periphery was proposed to extract reliable features speech signals even in noisy environments for robust speech recognition. In this paper, some practical considerations for digital hardware implementations of the ZCPA model are addressed and evaluated for recognition of speech corrupted by several real world noises as well as white Gaussian noise. Infinite impulse response(IIR) filters which constitute the cochliar filterbank of the ZCPA are replaced by hamming bandpass filters of which frequency responses are less similar to biological neural tuning curves. Experimental results demonstrate that the detailed frequency response of the cochlear filters are not critical to performance. Also, the sensitivity of the model output to the variations in microphone gain is investigated, and results in good reliability of the ZCPA model.

• Journal of Navigation and Port Research
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• v.30 no.2
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• pp.137-143
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• 2006

The optimum grillage design belongs to nonlinear constrained optimization problem. The determination of beam scantlings for the grillage structure is a very crucial matter out of whole structural design process. The performance of optimization methods, based on penalty functions, is highly problem-dependent and many methods require additional tuning of some variables. This additional tuning is the influences of penalty coefficient, which depend strongly on the degree of constraint violation. Moreover, Binary-coded Genetic Algorithm (BGA) meets certain difficulties when dealing with continuous and/or discrete search spaces with large dimensions. With the above reasons, Real-coded Micro-Genetic Algorithm ($R{\mu}GA$) is proposed to find the optimum beam scantlings of the grillage structure without handling any of penalty functions. $R{\mu}GA$ can help in avoiding the premature convergence and search for global solution-spaces, because of its wide spread applicability, global perspective and inherent parallelism. Direct stiffness method is used as a numerical tool for the grillage analysis. In optimization study to find minimum weight, sensitivity study is carried out with varying beam configurations. From the simulation results, it has been concluded that the proposed $R{\mu}GA$ is an effective optimization tool for solving continuous and/or discrete nonlinear real-world optimization problems.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.555-562
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• 1997

With only the classical PID controller applied to control of a DC motor, good (target) performance characteristic of the controller can be obtained if all the model parameters of DC motor and operating conditions such as external load torque, disturbance, etc. are known exactly. However, in case when some of system parameters or operating conditions are uncertain or unknown, the fixed PID controller does not guarantee good performance, which is assumed with precisely known system parameters and operating conditions. In view of this and the robustness enhancement of DC motor control system, we propose a PID learning controller which consists of a set of learning rules for PID gain tuning and learning of an auxiliary input. The proposed PID learning controller is shown to drive the state of uncertain DC motor system with unknown system parameters and external load torque to the desired one world wide asymptotically. Computer simulation and experimental results are given to demonstrate the effectiveness of the proposed PID learning controller, thereby showing its superiority to the conventional fixed PID controller.