• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.11
• /
• pp.1946-1958
• /
• 2011

Wireless Sensor Network (WSN) is made up of a number of sensor nodes and base stations. Traffic flow in WSN appears self-similar due to its data delivery process, and this impacts queue length greatly and makes queuing delay worse. Active queue management can be designed to improve QoS performance for WSN. In this paper, we propose self-similar traffic rate estimating algorithm named Power-Law Moving Averaging (PLMA) to regulate packet marking probability. This algorithm improves the availability of the rate estimation algorithm under the self-similar traffic condition. Then, we propose an adaptive Proportional Integral algorithm (SSPI) based on the estimation of the Self-Similar traffic rate by PLMA. Simulation results show that SSPI can achieve lower queue length jitter and smaller setting time than PI.

• Journal of Ocean Engineering and Technology
• /
• v.16 no.6
• /
• pp.1-6
• /
• 2002

The integration of Geographic Information Systems (GIS) with the hydrodynamic model was conducted in order to revitalize the use of geographical information and to aid in the understanding of tidal circulation patterns. A 2D finite difference numerical model was used to simulate n tidal circulation in the Suyoung Bay in Busan, Korea. CIS, especially the ArcView S/W is used to input the data of the numerical model, and is also used for the visualization of model outputs on the ground in the loosely coupled method. In this paper, an electronic navigational chart (ENC), which provides more accurate information in the ocean and coastal areas than any other digital information, is used as a base map for this integration. With the help of GIS, the integration can support th understanding of oceanographic information.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.6 no.4
• /
• pp.246-251
• /
• 2006

In this paper, we introduce an implementation method of the CBS (Cycle Base Simulator), which describes the operation of a DSP (Digital Signal Processor) at a pipeline cycle level. The CBS is coded with C++, and is verified by comparing the results from the CBS and HDL simulation of the DSP with the various test vectors and application programs. The CBS shows the data about the internal registers, status flags, data bus, address bus, input and output pin of the DSP, and also the control signals at each pipeline cycle. The developed CBS can be used in evaluating the performance of the target DSP before the RTL(Register Transfer Level) coding as well as a reference for the RTL level design.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.125-130
• /
• 1999

In this paper, it is presented a new technique to the design and real-time implementation of fuzzy control system based-on digital signal processors in order to improve the precision and robustness for system of industrial robot. Fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the real of industrial processes. In this thesis, a self-organizing fuzzy controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variable of the controller, In the synthesis of a FLC, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult, SOFC is proposed for a hierarchical control structure consisting of basic level and high level that modify control rules.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.1262-1266
• /
• 2004

The current combining of computer and geographic information technology. The result of such research oil determinate objective factors of hydrologic-topographical parameters through joining hydrology and GIS(Geographic Information System). In this study, we wish to offer the base data to determinate hydrologic-topographical parameters request of runoff model analysis in this basin. First, we computed the CN(curve number) by using GIS, and then classify the digital map of soil group and landuse on the Sulma river basin. Second, we used Avenue Script to calculate the height of efficient GIS work before using the Clark model to work out flood runoff flow.

• Journal of Information Technology Applications and Management
• /
• v.24 no.4
• /
• pp.153-170
• /
• 2017

As the digital economy goes global, firms are trying to find suppliers that can address their managerial goals and strategies. The alternatives are not confined to domestic firms. Firms have been trying to connect to foreign partners worldwide. Although offshore outsourcing grants firms various benefits, they present big cultural challenges. However, there is little research on the impact of cultural or country factors on outsourcing. The goal of this paper is to synthesize the outsourcing success literature and develop propositions for outsourcing success in the context of offshore outsourcing. This paper proposes that cultural effects should be included in evaluating the success of offshore outsourcing. Knowledge sharing and the scope of outsourcing are adopted in the base outsourcing success model from previous literature. In the extended model partnership quality is included as a mediator and organizational capability and outsourcing relationship type are also included as moderator. Finally, the integrated framework of offshore outsourcing success includes cultural factors as moderators of the relationships between outsourcing success antecedents and the success of offshore outsourcing. Reasoning for propositions, managerial implications, and future research directions are discussed.

• Proceedings of the Safety Management and Science Conference
• /
• 2003.11a
• /
• pp.97-103
• /
• 2003

In recent years, environments of business are changing due to epoch-making development of information technology and the advent of digital economy ages. It is an active confrontation as to the environments for information. Unlike the large scale enterprises in those days, hower, many small & medium enterprises especially the enterprises which are engaged in the manufacturing industry-aren't participate in information's rank due to the lack of funds, manpower, insufficient management environments, and manager or staff's lack of cognition as to information. So, this paper make a base of establishment for ISP through the establishment of ERP that is used to management activity for small & medium manufacturing enterprises. A way for small & medium enterprises' ERP construction is SMERP S/W for the small & medium enterprises' ERP package which is offered by the Korea chamber of commerce & industry. And, that is applied to the real management environment.

• Journal of Communications and Networks
• /
• v.15 no.4
• /
• pp.398-406
• /
• 2013

In this paper, we investigate two types of in-phase and quadrature-phase (IQ) data transfer methods for cloud multiple-input multiple-output (MIMO) network operation. They are termed "after-precoding" and "before-precoding". We formulate a cloud massive MIMO operation problem that aims at selecting the best IQ data transfer method and transmission strategy (beamforming technique, the number of concurrently receiving users, the number of used antennas for transmission) to maximize the ergodic sum-rate under a limited capacity of the digital unit-radio unit link. Based on our proposed solution, the optimal numbers of users and antennas are simultaneously chosen. Numerical results confirm that the sum-rate gain is greater when adaptive "after/before-precoding" method is available than when only conventional "after-precoding" IQ-data transfer is available.

• Journal of Communications and Networks
• /
• v.18 no.2
• /
• pp.135-149
• /
• 2016

Cloud radio access network (C-RAN) refers to the virtualization of base station functionalities by means of cloud computing. This results in a novel cellular architecture in which low-cost wireless access points, known as radio units or remote radio heads, are centrally managed by a reconfigurable centralized "cloud", or central, unit. C-RAN allows operators to reduce the capital and operating expenses needed to deploy and maintain dense heterogeneous networks. This critical advantage, along with spectral efficiency, statistical multiplexing and load balancing gains, make C-RAN well positioned to be one of the key technologies in the development of 5G systems. In this paper, a succinct overview is presented regarding the state of the art on the research on C-RAN with emphasis on fronthaul compression, baseband processing, medium access control, resource allocation, system-level considerations and standardization efforts.

• Information and Communications Magazine
• /
• v.14 no.3
• /
• pp.75-86
• /
• 1997

This manuscript describes the high level system design for the DCP system. The DCP HS and BS transceivers are composed of five systems, including the RF/IF unit, the Analog Front End(AFE), the baseband modem, the voice codec and the micro-controller. In the following, the core transceiver architecture with the primary functions at these subsystem is described.