• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.1
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• pp.35-42
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• 2012

This paper is about the implementation of low cost WiMAX remote radio head system with Ethernet instead of optical link. We deployed a simplified frame structure on the data frames transmitted between a basestation and remote radio heads in order to maximize Ethernet link utilization which shows relatively lower maximum throughput compared to that of optical links. In addition, a synchronization mechanism was applied on a basestation and remote radio heads placed on remote sites in order for simultaneous data transmission and reception in all remote radio heads which are essential for proper communication with terminals. These schemes are implemented with FPGA. The results of experiment with a WiMAX Femtocell show that our remote radio head systems efficiently deliver radio frames with proper timing.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.485-488
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• 2003

This paper has been studied on an IPv6 Protocol for Embedded Systems such as Informational Appliances and Mobile Terminals. IPv6 Protocol has 128-bit IP address space. Therefore, all devices come to have a chance of acquiring IPv6 address. This IPv6 Protocol Stack is very compact and reliable because the larger of the stack is Embedded Systems, which have typically characteristics of low cost and low performance. Hence, we designed and implemented this Stack for This Embedded Systems.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.6
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• pp.455-462
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• 2004

This paper is concerned with the implementation of the active vibration suppression controller using analog circuit and microprocessor. The target active vibration controller is the positive position feedback(PPF) controller since it provides a simple algorithm suitable for both analog circuit and digital controllers. In this study, the analog PPF controller is realized using an operational amplifier and the digital PPF controller is realized using a low-cost micro-controller. The circuit diagrams are explained in detail. We then discuss the advantages and disadvantages of both methods from the view of practical implementation. Experimental results show that both implementation methods can be effectively used for the active vibration control but need to be chosen based on the mission objective.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.282-290
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• 2006

In this paper, we propose an enhanced Timing Estimator algorithm for 2.45GHz LR-WPAN receiver. Because an expensive and highly efficient oscillator can't be used for low-cost implementation, a Timing Estimator algorithm having stable operation in the channel environment with center frequency tolerance of 80 ppm is required. To enhance the robustness to frequency offset and the stability of receiver performance, multiple delay differential filter is adopted. By utilizing the characteristic that the correlation result between the output signal of Multiple delay differential filter and reference signal is restricted on the In-phase part of the correlator output, a coherent detection scheme instead of the typical noncoherent one is adopted for Timing Estimator. The application of the coherent detection scheme is suitable for LR-WPAN receiver aimed at low-cost, low-power, and low-complexity, since it can remove performance degradation due to squaring loss of I/Q squaring operation and decrease implementation complexity. Computer simulation results show that the proposed algorithm achieved performance improvement compared with the differential detection-based noncoherent scheme by 2dB in average.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.4
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• pp.342-348
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• 1999

This paper describes a low-cost single-phase active power filter, which consists of a half-bridge P\A미1 inverter with a s simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations w with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the p proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non l linear‘ load. The active power filter has advantage of low implementation cost and compact size. using a half-bridge i inverter and a simple control circuit with only one current sensor. So. it can be fabricated as a plug-in type.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.3
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• pp.480-488
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• 2019

In this paper, we propose an obstacle avoidance system for an unmanned ship to navigate safely in dynamic environments. Also, in this paper, one-dimensional low-cost lidar sensor is used, and a servo motor is used to implement the lidar sensor in a two-dimensional space. The distance and direction of an obstacle are measured through the two-dimensional lidar sensor. The unmanned ship is controlled by the application at a Tablet PC. The user inputs the coordinates of the destination in Google maps. Then the position of the unmanned ship is compared with the position of the destination through GPS and a geomagnetic sensor. If the unmanned ship finds obstacles while moving to its destination, it avoids obstacles through a fuzzy control-based algorithm. The paper shows that the experimental results can effectively construct an obstacle avoidance system for an unmanned ship with a low-cost LiDAR sensor using fuzzy control.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.10-16
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• 2022

As an important part of virtual production, In-camera VFX is the process of shooting actual objects and virtual three-dimensional backgrounds in real-time through computer graphics technology and display technology, and obtaining the final film. In the In-camera VFX process, there are currently only two types of medium used to undertake background imaging, LED wall and chroma key screen. Among them, the In-camera VFX based on LED wall realizes background imaging through LED display technology. Although the imaging quality is guaranteed, the high cost of LED wall increases the cost of virtual production. The In-camera VFX based on chroma key screen, the background imaging is realized by real-time keying technology. Although the price is low, due to the limitation of real-time keying technology and lighting conditions, the usability of the final picture is not high. The short-throw projection technology can compress the projection distance to within 1 meter and get a relatively large picture, which solves the problem of traditional projection technology that must leaving a certain space between screen and the projector, and its price is relatively cheap compared to the LED wall. Therefore, in the In-camera VFX process, short-throw projection technology can be tried to project backgrounds. This paper will analyze the principle of short-throw projection technology and the existing In-camera VFX solutions, and through the comparison experiments, propose a low-cost solution that uses short-throw projectors to project virtual backgrounds and realize the In-camera VFX process.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.103-113
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• 2020

The construction industry is undergoing a digital transformation in which Building Information Modelling (BIM) is a key technology. The potential of BIM in several areas such as design optimization, time management, cost management, and asset management/facility management (AM/FM) is widely acknowledged by the AECO (Architecture, Engineering, Construction, and Operation) industry around the world. However, BIM implementation in construction projects is faced with problems such as project delay and cost overruns. The lack of identification of risks in BIM projects and standard guidelines on mitigation techniques furthers poor performance, dissatisfaction, and disputes between employers and project participants, which results in low BIM adoption rates. Therefore, the objective of this paper is to identify the potential risks in BIM implementation under the primary categories - (1) technical, (2) contractual, (3) management-related, and (4) personnel-related risks in BIM projects and present solutions to reduce, manage, and mitigate risks. To meet the objective of this paper, a survey was designed and conducted in the Hong Kong construction industry in which over 140 respondents from different disciplines, with experience in BIM projects, have participated. Based on the analysis of the survey data, the most severe and frequently occurring BIM risks and their potential mitigation strategies were identified and discussed in this paper.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.93-103
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• 2011

Currently, the library system using the method of the software on the client / server and ASP by providing services in a manner of hardware and software, and cross-referencing, installation and deployment, Customization, Upgrade, risk management, and software licenses across the high-cost management of difficult and costly There is a problem. To solve these problems, SaaS based Integrated Management System for Digital Library, multi-tenant environments(SaaS Maturity Level 3 and above) as a key element in the implementation were developed. Therefore, almost no initial investment cost, easy, simple, low-cost IT services available on SaaS based software on-demand service model of how the system is implemented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2820-2827
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• 2015

HSMS communication system using low-cost micro controller units(MCUs) is an essential technique for online semiconductor equipment system developments. It is intended as an alternative to SEMI E4 (SECS-I) for applications where higher speed communication is needed and the facilitated hardware setup is convenient. In this paper, an HSMS communication system using low-cost MCUS is designed and implemented. Using a MCU with a low price but high-performance as a main board, a module which processes HSMS communication is designed, and a circuit is designed to process BCR independently with a microminiature MCU. To convert tag data which is recognized from BCR into data based on HSMS communication protocol, SECS-II message is designed. Lastly, an HSMS communication system is implemented based on these designs. A low-cost HSMS communication module developed in this study can be applied in realtime monitoring and controlling system for semiconductor processes.