• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.2
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• pp.28-33
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• 2007

In the power plant facility which use soft coal as a power source the fan pitch blade control hydraulic actuator is used to control the inlet and outlet gas to regulate the internal pressure of the furnace and control the frequence. Sometimes malfunctions of this equipment lead to the decline of boiler thermal efficiency and unexpected power plant trip. In order to localize the fan pitch blade control hydraulic actuator specially for the 500MW large scale boiler, Analysis and modelling of the system is carried out mathematically. The responses of the system are examined by using matlab simulation fur the variation of the major parameters in view of reverse engineering. Consequently the validity of the established parameters are examined.

• Journal of Distribution Science
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• v.13 no.6
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• pp.17-23
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• 2015

Purpose - Transnational corporations (TNCs) have influenced drastic changes (financial services, manufacturing, labor, technology transfer) in Central Eastern Europe (CEE). This paper examines the indirect changes in the CEE pattern of industrial development and market distribution. Research design, data, and methodology - Over 25 years, neighboring (or rival) countries competed to attract TNCs as a double-edged strategy for privatization and debt reduction. Through their experience attracting foreign direct investment (FDI), many countries started to reflect aspects of national capitalism. Countries also began to realize in 2010 that TNCs sought to enter markets with more favorable conditions for export-oriented manufacturing. Results - The analysis reveals that TNC investment strategies were aimed at eliminating local competition to acquire industrial "brown fields" to convert into "green fields." CEE countries have since strengthened their national systems and the support of large-scale state-owned enterprises and small and medium-sized start-up enterprises. Conclusions - CEE has changed based on industrial development and a regional structure of TNC market distribution and associated government policies. The pattern toward flexible markets gives countries the ability to further their economies.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.30-30
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• 2000

In the three axis control of satellite by using reaction wheel and gyro, a Gyro carries out measuring of the attitude angie and the attitude angular velocity. The Gyro is operated by the electronic part and the mechanic actuator. The digital part of the electronic part is consisted of the FPGA (Field Programmable Gate Array), which is one of the methods for designing VLSI (Very Large Scale Integrated Circuit), and the mechanic actuator processes the input/output data by the dynamic model. In the research of the mixed mode of Gyro, the simulation is accomplished by SABER of the mixed mode simulator and the results for the practical implementation of the satellite ACS (Attitude Control System) interfaced with the data processing are proposed.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.539-539
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• 2000

This paper shows how to implement force reflection for a needle insertion problem. The target is a needle spine biopsy simulator for tumor inspection by needle insertion. Simulated force is calculated from the relationship of volume graphic data and the orientation and Position of the needle, and it is generated using PHANTOM$^{TM}$. To generate realistic force reflection, the directional force of the needle has been generated by tissue model. The other rotational force is generated using a pivot to keep the needle in the initial inserted direction after puncturing the skin. Since the used haptic device has limitation for generating high stiffness and large damping, scale downed model and digital filter are used to stabilize the system.m.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.6
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• pp.152-160
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• 1996

This paper focuses on development and evaluation of a performance management algorithm for IEEE 802.4 token bus networks to serve large-scale integrated manufacturing systems. Such factory automation networks have to satisfy delay constraints imposed on time-critical messages while maintaining as much network capacity as possible for non-time-critical messages. This paper presents a network performance manager that adjusts queue capacity as well as timers by using a set of fuzzy rules and fuzzy inference mechanism. The efficacy of the performance management has been demonstrated by a series of simulation experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.664-669
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• 1994

This paper focuses on development and implementation of a performance management algorithm for IEEE802.4 token bus networks to serve large-scale integrated manufacturing systems. Such factory automation networks have to satisgy delay constraints imposed on time-critical messages while maintaining as much network capacity as possible for non-time-critical messages. This paper presents a network perfomance manager that adjusts queue apacity as well as timers by using a set of fuzzy rules and fuzzy inference mechanism. The efficacy of the performance management has been demonstrated by a series of simulation experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.173-184
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• 1997

As the scale of the switching software gets large, it takes much time and is hard to compile and the manage it. We implement the compilation management system for the mobile switching software on network file system and describe its structure and functions in this paper. The compilation management system distributes its task of compilation to the each network system equally to reduce the comilation time and also simplifies the management of the communications among the systems, compilation manager, and the software devedlopers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1373-1387
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• 2012

Contextual advertising is an important revenue source for major service providers on the Web. Ads classification is one of main tasks in contextual advertising, and it is used to retrieve semantically relevant ads with respect to the content of web pages. However, it is difficult for traditional text classification methods to achieve satisfactory performance in ads classification due to scarce term features in ads. In this paper, we propose a novel ads classification method that handles the lack of term features for classifying ads with short text. The proposed method utilizes a vocabulary expansion technique using semantic associations among terms learned from large-scale search query logs. The evaluation results show that our methodology achieves 4.0% ~ 9.7% improvements in terms of the hierarchical f-measure over the baseline classifiers without vocabulary expansion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3068-3078
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• 2015

Although the massive MIMO system supports a high throughput, it requires a lot of channel information for channel compensation. For the reduction of overhead, the massive MIMO system generally uses TDD as duplexing scheme. Therefore, the massive MIMO system is sensitive to rapidly changing fast fading in according to time. For the improvement of reduced SINR by fast fading, the adaptive power control is proposed. Unlike the conventional scheme, the proposed scheme considers mobility of device for adaptive power control. The simulation of the proposed scheme is performed with consideration for mobility of device. The result of the simulation shows that the proposed scheme improves SINR. Since SINR is decreased in according to the number of device in the network by unit of cell, each base station can accommodate more devices by the proposed scheme. Also, because the massive MIMO system with high SINR can use high order modulation scheme, it can support higher throughput.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4641-4657
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• 2017

Named Data Networking (NDN) has emerged and become one of the most promising architectures for future Internet. However, like traditional IP-based networking paradigm, NDN may not evade some typical network threats such as malicious data aggregates (MDA), which may lead to bandwidth exhaustion, traffic congestion and router overload. This paper firstly analyzes the damage effect of MDA using realistic simulations in large-scale network topology, showing that it is not just theoretical, and then designs a fine-grained MDA mitigation mechanism (MDAM) based on the cooperation between routers via alert messages. Simulations results show that MDAM can significantly reduce the Pending Interest Table overload in involved routers, and bring in normal data-returning rate and data-retrieval delay.