• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.2
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• pp.127-131
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• 2007

The control of electrical appliances residing in the home network can be accomplished via Internet with the UPnP expansion without modifying an existing UPnP. In this paper, we propose the Internet Gateway that consists of an UPnP IGD(Internet Gateway Device) DCP(Device Control Protocol) and an UPnP Bridge as a system to control electrical appliances of home network. UPnP IGD DCP is to enable the configurable initiation and sharing of Internet connections as well as assuring advanced connection-management features and management of host configuration service. It also supports transparent Internet access by non-UPnP-certified devices. UPnP Bridge searches for local home network devices by sending control messages, while control point of UPnP Bridge looks up devices of interest on the Internet, subsequently furnishing the inter-networking controlling among devices which belong to different home network systems. With our approach, devices on one home network can control home electrical appliances on the other home network via Internet through IGD DCP with control commands of UPnP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.5
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• pp.1249-1259
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• 1998

This paper proposes an efficient channel assignment method for real-time service in the IEEE 802.11 Wireless LAN system, and analyzes the supportability to real-time service and the channel utilzation of that through computer simulations. The improved MAC(Medium Access Control) protocol employing the proposed channel assignment method achieved good throughput over contention period as well as contention-free period by making real-time terminals transmit the information about their desiring value before starts of data transmissions. For performance evaluation of the proposed method, a simulation analyzing the variation of allocated bandwidths to terminals using real-time service and their buffer sizes wasexecuted. Real-time data traffics was modeled s 7-stae transition VBR sources, and asynchronous data traffics modeled as Poisson processes. In the simulation, the proposed method showed smaller variation of the bandwidth of each terminal and samller buffer size than the existing method, and also recorded good throughput over contention period.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11B
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• pp.1016-1022
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• 2003

The EPON has been actively studied as one of the access networks for the economic configuration of FTTH. The EPON must support the dynamic bandwidth allocation to the subscribers in order to support the QoS due to its base on Ethernet technology EFM SG, which is actively working for the standardization of EPON, also recently decided to select DBA. Therefore in this paper, we designed a ONU buffer scheduling algorithm(AIWFQ) and a scheme of DBA(Class-based FCFS) for the OLT suitable for embodying MPCP of the EPON. In this paper, we proposed methods that the EPON system can make use of by measuring end to end process delay time and the buffer size in order to implement the algorithm by using the OPNET.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.272-278
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• 2004

The EPON has been actively studied as one of the access networks for the economic configuration of FTTH. The EPON must support the dynamic bandwidth allocation to the subscribers in order to support the QoS due to its base on Ethernet technology. EFM SG, which is actively working for the standardization of EPON, also recently decided to select DBA. Therefore in this paper, we designed a ONU buffer scheduling algorithm (AIWFQ) and a scheme of DBA(Class-based FCFS) for the OLT suitable for embodying MPCP of the EPON. In this paper, we proposed methods that the EPON system can make use of by measuring end to end process delay time and the buffer size in order to implement the algorithm by using the OPNET.

• Journal of Information Management
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• v.40 no.3
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• pp.1-21
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• 2009

This study aims to suggest some idea for construction of headings in authority records to improve conventional method for authority control. The reference structure between established form and other forms was replaced by the link structure based on access points and adopting standard authority numbers was considered. Additional elements such as work information to distinguish homonym and notational system of the headings to promote sharing of authority records were also addressed. Authority records management system was constructed to test structure of headings suggested in this study, too. Through this research, we confirmed that management, identification, and sharing of authority records were considerably improved compared with the conventional authority control system.

• The Journal of Industrial Distribution & Business
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• v.9 no.10
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• pp.51-61
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• 2018

Purpose - Korean women suffered from serious experience at unfair personnel practice in the work and coexistence between work and home affairs. The study examined woman workers' career plateau perception and success who worked for local public enterprises, that is to say, regional public corporation invested by local government, and investigated mediating effect of dual commitment as well as control effect of self-efficacy from point of view of various access to variables. Research design, data, and methodology - The study investigated women employees of regional public corporation by empirical analysis. The author collected 337 copies from 380 copies and made use of 325 copies after excluding copies with improper answer. SPSS 24.0 and AMOS 24.0 were used. Results - The study investigated effect of career plateau (structure and content) upon subjective career success (job satisfaction and career commitment) according to questionnaire material: First, not only structural plateau but also content career plateau had negative influence upon dual commitment (structure and career). Second, dual commitment had positive influence upon subjective career success from point of view of organizational commitment and career commitment. Third, structural career plateau had positive influence upon career success, and content career plateau had positive influence upon job satisfaction. Fourth, structural career plateau did not have significant influence upon job satisfaction, content career plateau and career satisfaction. Fifth, subordinate variables (organizational commitment and career commitment) had mediating influence upon career plateau cognition and subjective career success. Sixth, self efficacy did not control career plateau cognition and subjective career success. Conclusions - Women employee's career plateau cognition mediated dual commitment to have influence upon career success and to be likely to help career success theory study. Career plateau had negative influence upon dual commitment and career success of women workers. The study shall give base of counteraction from point of view of control and motivation of women workers thinking of career plateau.

• Journal of Preventive Medicine and Public Health
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• v.50 no.1
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• pp.60-65
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• 2017

Objectives: We examined the prevalence of tobacco use and exposure to secondhand smoke among middle-school students in Korea using the Global Youth Tobacco Survey (GYTS) in 2013. Methods: The GYTS in Korea was conducted between July and August 2013 by the Korea Centers for Disease Control and Prevention. Data were collected using a self-administered anonymous questionnaire from a nationally representative sample of middle-school students aged 13-15 years in sampled classrooms. Results: The GYTS in Korea was completed by 4235 students aged 13-15 years in 43 middle schools. Approximately one in five of the students (17.8%) reported that they had tried cigarettes in the past, while 5.2% reported currently being cigarette smokers. Current cigarette smoking was higher in boys (7.5%) than in girls (2.6%). Of the students, 29.7% had been exposed to secondhand smoke at home, 47.4% inside enclosed public places, and 53.9% in outdoor public places. Of the current cigarette smokers, 25.7% bought their cigarettes from a store despite a law prohibiting this. Additionally, 58.0% of students noticed point-of-sale tobacco advertisements or promotions, 66.8% of current cigarette smokers wanted to stop smoking, and 70.9% of students had been taught about the dangers of tobacco use in school. Conclusions: These findings provide an opportunity to develop, implement, and evaluate a comprehensive tobacco control policy. The results suggest that youth have relatively easy access to cigarettes and are regularly exposed to secondhand smoke in public places, as well as to point-of-sale tobacco advertisements and promotions. Strict enforcement of the ban on tobacco sales to youth, expanding smoke-free areas, and advertising bans are needed to reduce tobacco use among youth.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.445-454
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• 2002

Torque ripple control of brushless DC motors has been the persisting issue of the servo drive systems in which the speed fluctuation, vibration and acoustic noise should be minimized. In this paper, a novel approach to achieve the ripple-free torque control with maximum efficiency based on the d-q reference frame is presented and analyzed. The proposed approach can provide the optimized phase current waveforms over wide speed range incorporating cogging torque compensation without an access to the neutral point of the motor windings. Moreover, the undesirable errors caused by the assumptions such as 3 phase balance or symmetry of the phase back EMF between electrical cycles, which are related with the manufacturing imperfections, can be also eliminated. As a result, the proposed approach provides a simple and clear way to obtain the optimal motor excitation currents. A hysteresis current control system is employed to produce high-frequency electromagnetic torque ripples for compensation. The validity and applicability of the proposed control scheme to real situations are verified through the simulations and experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.4
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• pp.1076-1089
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• 2012

Home automation networks are good environments for merging sensor networks and consumer electronics technologies. It is very important to reduce the energy consumption of each sensor node because sensor nodes operate with limited power based on a battery that cannot be easily replaced. One of the primary mechanisms for achieving low energy operation in energy-constrained wireless sensor networks is the duty-cycle operation, but this operation has several problems. For example, unnecessary energy consumption occurs during synchronization between transmission schedules and sleep schedules. In addition, a low duty-cycle usually causes more performance degradation, if the network becomes congested. Therefore, an appropriate control scheme is required to solve these problems. In this paper, we propose UDC (Unsynchronized Duty-cycle Control), which prevents energy waste caused by unnecessary preamble transmission and avoids congestion using duty-cycle adjustment. In addition, the scheme adjusts the starting point of the duty-cycle in order to reduce sleep delay. Our simulation results show that UDC improves the reliability and energy efficiency while reducing the end-to-end delay of the unsynchronized duty-cycled MAC (Media Access Control) protocol in sensor-based home automation networks.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.146-151
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• 2013

With the development of mobile internet, requirements of positioning accuracy for the LBS (Location Based Service) are becoming more and more higher. The LBS is based on the position of each mobile device. So, it requires a proper acquisition of accurate user's indoor position. Thus indoor positioning technology and its accuracy is crucial for various LBS. In general, RSSI (Received Signal Strength Indicator) measurements are used to obtain the position information of mobile unit under WLAN environment. However, indoor positioning error increases as multiple AP's configurations are becoming more complex. To overcome this problem, an enhanced indoor localization method by AP (Access Point) selection criteria adopting DOP (Dilution of Precision) is proposed.