Sun-Yeob Kim

A Study on Visitors Tracking Method Using Wireless Communication

Wireless sensor networks are rapidly growing. Wireless sensor networks are composed of a large number of radio frequency equipped sensor devices that autonomously form networks through which sensor data is transported. These sensor devices are used in various real life applications. Recent advances in wireless communications and electronics have enabled the development of low-cost, low-power, small-size sensor nodes. These sensor nodes are deployed in a wide area and are used to monitor a given field of interest for changes in the environment. Location tracking in wireless sensor networks is an important application area. The focus of this paper is on location tracking using wireless communication. In this paper, we present a visitor tracking method based on wireless sensor networks.

A Study on the MSNR Cryptographic Processor Design Appropriate for the RFID/USN Environment

Creation of RFID/USN environment has increased very rapidly due to activation of ubiquitous. Security environment suitable for RFID/USN environment, however, failed to comply with the speed of security thread increase in reality. Therefore, this thesis presented MSNR suitable for RFID/USN. MSNR presented showed increase in processing rate of 1.3 times compared to existing AES and showed 2 times of improvement in performance in terms of overall system efficiency. Therefore, MSNR is considered as the cryptographic algorithm suitable to overcome conditions of environmental resource conditions such as RFID/USN.

An Analysis of Receiving Sensitivity of PIN Receiver for Optical Communication System

It is essential to various evaluate about statistic character of the signal and additional noise for optimization of the optical communication system. We expressed various error probability with the m which was bandwidth and a bit numerical function and carried out performance evaluation of a PIN receiver. This research analyzed the receiving sensitivity of the PIN receiver and verified reception sensitivity through computer simulation in the optical communication system. As a result, the receiving sensitivity for PIN receiver are photon/bit for given error probability.

A Study on 900MHz RFID Reader Platform

The RFID market seems to grow mostly in the logistics and distribution areas. The areas and small sized work places requires multi-steps based system. In the environment, the performance of RFID READER is the most important factor. If RFID READER fails to operate frequency well, it will be difficult to apply RFID technology to work places and manage multi-readers used in a narrow place. This work reveals that making possible multiple readers environment and reporting the state of the entire upgrade are of significant in terms of the system`s functions. This thesis studied RFID reader platform with self-diagnosis function.

A Study on the Optical Receiver System for Digital Transmission System

In optical system, the signal and additive noise for statistical properties of a variety of ways to evaluate the performance of the system is essential for the optimization. In this paper, performance analysis of spectrum-sliced optical system in the optical pre-amplifier in the receiver the received signal by including the error limits for the bit that is, the bit error rate (BER: Bit Error Rate) required to maintain the average optical power represents the number of photons per bit is included in this paper to digital form, noticeable signal the receiver to calculate the sensitivity of the method for the calculation was performed. The general strength of the transmission of the modulated signal and digital signal transmission was required for the comparison of optical power. As shown in Figure 3, the general strength of the digital signal transmission system for transmitting a modulated signal compared with the case is improved by at least 10dB.

A Study on Support System of Small Capital Foundation by Focusing on Coffee Shops

With the development of the policy on support of small business owners, it is necessary to expand the social support policy on the weak in society. But, if the policy focuses on social welfare in its direction, it rather allows small business owners to highly rely on the government and thereby to give up their economic activities and fall into poverty. Therefore, the government’s policy on support of small business owners requires the harmony of social welfare perspective and competition perspective. The issues were investigated with examples of the support system, and were divided into the issue of administration support and the issue of foundation capital support for investigation.

A Study on RFID Reader Platform with Self-diagnosis Function

RFID reader platform with self-diagnosis function studied in this paper has an automatic state recognition function, a report function, and an automatic upgrade function. Also, since it uses frequency operation policy in multiple reader environments, it will be frequently used in the large operation environment and multi-readers environment. Therefore, the technology can meet the demands not only in the domestic RFID market, but in the global market.

A Study on the Optical Filters Bandwidth with Error Probability in Preamplifier System

In this paper, the bandwidth of the filters used in optical communication systems and systems for the correlation between the error probability has been studied. Preamplifier that occurs in the system error probability as a function of the sensitivity of the receiver on the receiver sensitivity was shown for the various error probability calculation is performed. In addition, the channel data rate on the probability of various errors, changes in the function of the optimal bandwidth for the receiver filter was calculated, as required to operate at optimal range of the filter bandwidth, data rate per channel in a 10Gb/s the range of when is between 0.2 and 3.5nm.

A Study on the Technical Regulation for Spurious Emission of Weak Field Strength Radio Receiver

A output strength is limited according to the frequency used in order to protect other wireless stations from interference caused by radio waves emitted from the low power wireless installations. For receivers, unwanted spurious emission is regulated, and regulations in Korea define that additional spurious emission for receivers in the low power wireless installations under 1GHz should be -54dBm, but no regulations have been established yet for low power wireless installations over 1GHz. It is presently required to set domestic standards for devices over 1GHz on account of the expansion of the communication market and its service.

A Study on the Twofish Security Processor Design Using USB Interface Device

Since most cryptographic systems are PCI type, it is not suitable for users except experts to handle security system. In particular, most security programs used have not been verified against crack and are exposed to attack of virus or hacker. In this regard, this thesis designed Twofish cryptographic algorithm that uses USB, which can be easily used by users at general computers. Users can use security system easily using USB. In addition, Twofish cryptographic algorithm with various variable key lengths can be applied to various security system. Such Twofish cryptographic algorithm can improve performance for encryption and decryption, and increase efficiency of mobile security system in addition to USB.