• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9B
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• pp.808-817
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• 2004

Many researchers are now working in the Low-Rate WPAN environment. Low-Rate WPAN has as its goal the enhancing computer use by making many sensors available throughout the physical environment, but making them effectively invisible to the user. Low-Rate WPAN environment consists of wireless sensor devices that may move often. Movement of hosts results in a change in routes and the need of some mechanism for determining new routes. This paper suggests an approach to utilize location information to improve performance of a routing mechanism for Low-Rate WPAN Environment. Accordingly, we proved that the proposed mechanism results in a significant reduction in a number of routing messages when comparing with existing mechanisms.

• Journal of Information Processing Systems
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• v.15 no.5
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• pp.1131-1140
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• 2019

Characteristics of fruit tree canopies are important target information for adjusting the pesticide application rate in variable rate spraying in orchards. Therefore, the target detection of the canopy characteristics is very important. In this study, a canopy volume measurement method for peach trees was presented and a variable rate spraying system based on canopy volume measurement was developed using the ultrasonic sensing, one of the most effective target detection method. Ten ultrasonic sensors and two flow control units were mounted on the orchard air-assisted sprayer. The ultrasonic sensors were used to detect the canopy diameters and the flow controls were used to modify the flow rate of the nozzles in real time. Two treatments were established: a constant application rate of $300Lha^{-1}$ was set as the control treatment for the comparison with the variable rate application at a $0.095Lm^{-3}$ canopy. The tracer deposition at different parts of peach trees and the tracer losses to the ground (between rows and within rows) were analyzed in detail under constant rate and variable rate application. The results showed that there were no significant differences between two treatments in the liquid distribution and the capability to reach the inner parts of the crop canopies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.83-88
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• 2002

In the majority of case, speech recognition method tried recognition using only speech information In order to highten the recognition rate, we proposed recognition system that recognige digit using speech and image information. Through an experiment, this paper compared the recognition rate performed by existent speech recognition method and speech recognition method that includes image information. When we added the image information to the speech information, the speech recognition rate was increased about 6%. This paper shows that adding image information to speech information is more effective than using only speech information In digit recognition.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.229-235
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• 2020

Investors aim to maximize the return rate for their own investment, utilizing various information as possible as they can access. However those investors, especially individual investors, have limitations of interpretation of the domain-specific information or even the acquisition of the information itself. Thus, individual investors tend to make decision affectively and frequently, which may cause a loss in returns. This study aims to analyze analysts' target price and to suggest the strategy that could maximize individual's return rate. Most previous literature revealed that the optimistic bias exists in the analysts' target price and it is also confirmed in this study. In this context, this study suggests the upper limit of target rate of returns and the optimal value named 'alpha(α)' which performs the adjustment of proposed target rate to maximize excess earning returns eventually. To achieve this goal, this study developed an optimization problem using linear programming. Specifically, when the analysts' proposed target rate exceeds 30%, it could be adjusted to the extent of 59% of its own target rate. As apply this strategy, the investors could achieve 1.2% of excess earning rate on average. The result of this study has significance in that the individual investors could utilize analysts' target price practically.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.77-86
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• 2016

This paper describes a dual-mode reference-less CDR(Clock Data Recovery) operating at full / half-rate and its operation algorithm. Proposed reference-less CDR consists of a frequency detector, a phase detector, a charge pump, a loop filter, a voltage controlled oscillator, and a digital block. The frequency and phase detectors operate at both full / half-rate for dual-mode operation and especially the frequency detector is capable of detecting the difference between data rate and clock frequency in the dead zone of general frequency detectors. Dual-mode reference-less CDR with the proposed algorithm can recover the data and clock within 1.2-1.3 us and operates reliably at both full-rate (2.7 Gb/s) and half-rate (5.4 Gb/s) with 0.5-UI input jitter.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.174-180
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• 2021

The necessity of this study is as follows. A decrease in the number of newborns, an increase in the youth unemployment rate, and a decrease in the employment rate are having a fatal impact on universities. To help increase the employment rate of universities, we intend to utilize Big Data of university public information. Big data refers to the process of collecting and analyzing data, and includes all business processes of finding data, reprocessing information in an easy-to-understand manner, and selling information to people and institutions. Big data technology can be divided into technologies for storing, refining, analyzing, and predicting big data. The purpose of this study is to find the vision and special department of a university with a high employment rate by using big data technology. As a result of the study, big data was collected from 227 universities on www.academyinfo.go.kr site, We selected 130 meaningful universities and selected 25 universities with high employment rates and 25 universities with low employment rates. In conclusion, the university with a high employment rate can first be said to have a student-centered vision and university specialization. The reason is that, for universities with a high employment rate, the vision was to foster talents and specialize, whereas for universities with a low employment rate, regional bases took precedence. Second, universities with a high employment rate have a high interest in specialized departments. This is because, as a result of checking the presence or absence of a characterization plan, universities with a high employment rate were twice as high (21/7). Third, universities with high employment rates promote social needs and characterization. This is because the characteristic departments of universities with high employment rates are in the order of future technology and nursing and health, while universities with low employment rates promoted school-centered specialization in future technology and culture, tourism and art. In summary, universities with high employment rates showed high interest in student-centered vision and development of special departments for social needs.

• Journal of the Korean Data and Information Science Society
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• v.21 no.1
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• pp.173-177
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• 2010

It is well known that if the parent distribution has a nonnegative support and has increasing failure rate, then all the order statistics have increasing failure rate (IFR). The result is not necessarily true in the case of bivariate distributions with dependent structures. In this paper we consider a symmetric bivariate exponential distribution and show that, two marginal distributions are IFR and the distributions of the minimum and maximum are constant failure rate and IFR, respectively.

• Journal of information and communication convergence engineering
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• v.5 no.1
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• pp.54-58
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• 2007

A real-time frame-layer rate control algorithm with a token bucket traffic shaper is proposed for distortion variation minimization. The proposed rate control method uses a non-iterative optimization method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder. Experimental results indicate that the proposed control method provides better visual and PSNR performances than the existing rate control method.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.462-470
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• 2005

We propose a multi-rate and multi-BEP transmission scheme using adaptive overlapping pulse-position modulator (OPPM) and optical power controller in optical code division multiple access (CDMA) networks. The proposed system achieves the multi-rate and multi-BEP transmission by accommodating users with different values of OPPM parameter and transmitted power in the same network. The proposed scheme has advantages that the system is not required to change the code length and number of weight depending on the required bit rate of a user and the difference of bit rates does not have so much effect on the bit error probabilities (BEPs). Moreover, the difference of transmitted powers does not cause the change of bit rate. We analyze the BEPs of the four multimedia service classes corresponding to the com­binations of high/low-rates and low/high-BEPs and show that the proposed scheme can easily achieve distinct differentiation of the service classes with the simple system configuration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1555-1562
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• 1999

Various video rate control techniques have been proposed for the transmission of video under fixed channel capacity. In most techniques, the coding parameters and quantizer scaling factors are determined based on information derived from previously coded data. In this paper, an successfully used for video rate-control. Experimental results show that the proposed prediction-based rate control scheme can efficiently regulate the bit-rate caused by dramatic scene change and have better PSNR performance than the TM5 rate control mechanism.