• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.165-187
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• 2004

Constraint Programming in AS and Optimization in OR started and have grown in different backgrounds to solve common decision-making problems in real world. This paper tries to integrate results from those different fields by suggesting a hybrid solver as an integration framework. Starting with an integrating modeling language, a way to implement a hybrid solver will be discussed using Warren's abstract machine and an finite domain constraint programming solver structures. This paper will also propose some issues rising when implementing the hybrid solver and provide their solutions.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.129-141
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• 2001

Kansei engineering or image technology is a tool to analyze relation between product design components and the impression or feeling of human for physical products. This paper attempts to construct the designer\`s aid tool for developing corporate identity(CI) symbol mark based on the hybrid Kansei engineering. It combines the forward Kansei engineering for translating consumer\`s feeling into design components of CI symbol mark and the backward Kansei engineering for evaluating consumer\`s feeling for CI symbol mark. The semantic differential(SD) evaluation experiment is carried out to find the relations between image and design. The backward Kansei engineering system is modelled by fuzzy neural network. This research is expected to contribute to the development of CI symbol mark that correspond to comsumer\`s image.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.700-702
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• 2000

The new design methodology of a hybrid fuzzy controller by means of the genetic algorithms is presented. In fuzzy controller which has been widely applied and used. in order to construct the best fuzzy rules that include adjustment of fuzzy sets, a highly skilled techniques using trial and error are required. To deal with such a problem, first, a hybrid fuzzy controller(HFC) related to the optimal estimation of control parameters is proposed. The HFC combined a PID controller with a fuzzy controller concurrently produces the better output performance than any other controller from each control output in steady state and transient state. Second, a auto-tuning algorithms is presented to automatically improve the performance of hybrid fuzzy controller, utilizing the simplified reasoning method and genetic algorithms. In addition, to obtain scaling factors and PID Parameters of HFC using GA, three kinds of estimation modes such as basic, contraction, and expansion mode are effectively utilized. The HFCs are applied to the first-order second-order process with time-delay and DC motor Computer simulations are conducted at step input and the performances of systems are evaluated and also discussed from performance indices.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.1-10
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• 2012

This paper proposes a modeling and controller design approach for a wind-diesel hybrid system including dump load. Wind turbine depends on nature such as wind speed. It causes power fluctuations of wind turbine. Excessive power fluctuation at stand-alone power grid is even worse than large-scale power grid. The proposed control scheme for power quality is fuzzy PI controller. This controller has advantages of PI and fuzzy controller. The proposed model is carried out by using Matlab/Simulink simulation program. In the simulation study, the proposed controller is compared with a conventional PI controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PI controller, and thus it contributes to a better quality wind-diesel hybrid power system.

• Ceramist
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• v.23 no.1
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• pp.54-88
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• 2020

Global effort has resulted in tremendous progress with energy harvesters that extract mechanical energy from ambient sources, convert it to electrical energy, and use it for systems such as wrist watches, mobile electronic devices, wireless sensor nodes, health monitoring, and biosensors. However, harvesting a single energy source only still pauses a great challenge in driving sustainable and maintenance-free monitoring and sensing devices. Over the last few years, research on high-performance mechanical energy harvesters at the micro and nanoscale has been directed toward the development of hybrid devices that either aim to harvest mechanical energy in addition to other types of energies simultaneously or to exploit multiple mechanisms to more effectively harvest mechanical energy. Herein, we appraise the rational designs for multiple energy harvesting, specifically state-of-the-art hybrid mechanical energy harvesters that employ multiple piezoelectric and triboelectric mechanisms to efficiently harvest mechanical energy. We identify the critical material parameters and device design criteria that lead to high-performance hybrid mechanical energy harvesters. Finally, we address the future perspectives and remaining challenges in the field.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.3
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• pp.169-176
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• 2017

To replace conventional DRAM, many researches have been done on nonvolatile memories. The DRAM&PCM hybrid memory is one of the effective structure because it can utilize an advantage of DRAM and PCM. However, in order to use this characteristics, pages can be replaced frequently between DRAM and PCM. Therefore, PCM still has major problem that has write-limits. Therefore, it needs an effective page management method for exploiting each memory characteristics dynamically and adaptively. So we aim reducing an average access time and write count of PCM by utilizing two locality for an effective page replacement. We proposed a page selection algorithm which is recently requested to write in DRAM and an algorithm witch uses two locality in PCM. According to our simulation, the proposed algorithm for the DRAM&PCM hybrid can reduce the PCM write count by around 22% and the average access time by 31% given the same PCM size, compared with CLOCK-DWF algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2078-2094
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• 2015

Now a days, Efficient processing of Broadcast Queries is of critical importance with the ever-increasing deployment and use of mobile technologies. BQs have certain unique characteristics that the traditional spatial query processing in centralized databases does not address. In novel query processing technique, by maintaining high scalability and accuracy, latency is reduced considerably in answering BQs. Novel approach is based on peer-to-peer sharing, which enables us to process queries without delay at a mobile host by using query results cached in its neighboring mobile peers. We design and evaluate cooperative caching techniques to efficiently support data access in ad hoc networks. We first propose two schemes: Cache Data, which caches the data, and Cache Path, which caches the data path. After analyzing the performance of those two schemes, we propose a hybrid approach (Hybrid Cache), which can further improve the performance by taking advantage of Cache Data and Cache Path while avoiding their weaknesses. Cache replacement policies are also studied to further improve the performance. Simulation results show that the proposed schemes can significantly reduce the query delay and message complexity when compared to other caching schemes.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.4
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• pp.201-208
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• 2016

Non-volatile counter is a counter that maintains the value without external power supply. It has been used for the applications related to warranty issues to count and record certain events such as power cycles, operating time, hard resets, and timeouts. It has been conventionally implemented with volatile memory-based counter and battery backup or non-volatile memory such as EEPROM. Both of them have a lifetime issue due to the limited lifetime of the battery and the endurance of the non-volatile memory cells, which incurs significant redundancy in design. In this paper, we introduce a hybrid architecture of volatile (SRAM) and non-volatile memory (EEPROM) cells to achieve required lifetime of the non-volatile counter with smaller cost. We conduct a design space exploration of the proposed hybrid architecture with the parameters of various kinds of non-volatile memories. The analysis result shows that the proposed hybrid non-volatile counter can extend the lifetime up to 6 times compared to the battery-backup volatile memory-based implementation.

• Journal of Power Electronics
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• v.16 no.2
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• pp.480-489
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• 2016

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.