• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.397-401
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• 2005

A different alternative method for simulating bit error rate(BER) performance of Satellite Digital Multimedia Broadcasting(DMB) in tunnel environments is presented. The method based on a channel model obtained by ray-tracing is able to support BER estimation over the channel presents arbitrary statistics that are difficult to fit to an analytic expression. The BER performance for System E over the tunnel fading channel that obtained by ray-tracing is predicted by the monte-carlo method. It can be observed that the BER performance for a straight tunnel channel is better than that for a line-of-sight(LOS) area in curved tunnel. Also, the BER performance for LOS areas in a curved tunnel outperforms that for non-line-of-sight(NLOS) areas in a curved tunnel. The BER performances for straight, curved LOS and curved NLOS tunnel channels are better than that for a Rayleigh channel(K=0) and less than that for a Rician channel with K=3. Moreover, for BER=10-3, it can be seen that there is approximately a $1{\sim}1.5\;dB$ difference between those three types of tunnel channels and a Rayleigh channel.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.1
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• pp.8-15
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• 2005

It is well known that intaking alcohol chronically and heavily causes many formsof physical systemic distress including serious chronic alcoholic liver disease such as alcoholic hepatitis, fatty liver, liver cirrhosis and hepatoma. Carbohydrate-deficient transferrin (CDT) is known as a specific marker in detecting and monitoring alcohol associated disease. Weanalyzed various alcohol-associated parameters to evaluate the clinical usefulness of CDT. The first patient group consisted of fifty patients, who had been diagnosed with alcoholic liver disease from January 2003 to June 2004 at Chungnam National University Hospital. The second group consisted of 12 patients with non-alcoholic liver disease. The third group consisted of 19 teetotalerswho had visited the hospital for the purpose of routine healthcare checks. Various hepatic parameters such as CDT, $\small{\Gamma}$-GT (gamma-glutamyl transferase), AST (aspartate aminotransferase) and ALT (alanine aminotransferase) were compared in the three groups. CDT and AST increased in direct proportion to the amount and duration of alcohol consumption with high significance, but $\small{\Gamma}$-GT and ALT showed arbitrary patterns with no statistical significance. The sensitivities of CDT, $\small{\Gamma}$-GT, AST and ALT were 74 %, 96 %, 68 % and 58 %, respectively and the specificities were 95 %, 74 %, 68 % and 79 % in order respectively. The correlation study of CDT with $\small{\Gamma}$-GT, AST and ALT showed a very low value of correlation coefficients, implying that CDT could be taken as an independent parameter in evaluating alcohol liver disease compared to $\small{\Gamma}$-GT, AST and ALT. This present study suggested that CDT coud be one of the most useful parameters in reflecting the amount and duration of alcohol consumption as well as being another independent parameter in assessing and following up patients with alcoholic liver disease. Moreover we recommend it is the best method of measuring both CDT and $\small{\Gamma}$-GT in patients with alcoholic liver disease.

• Journal of the Korea Computer Graphics Society
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• v.19 no.4
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• pp.13-22
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• 2013

A motion capture system is widely used in movies, computer game, and computer animation industries because it allows for creating realistic human motions efficiently. The inertial motion capture system has several advantages over more popular vision-based systems in terms of the required space and cost. However, it suffers from low accuracy due to the relatively high noise levels of the inertial sensors. In particular, the accelerometer used for measuring gravity direction loses the accuracy when the sensor is moving with non-zero linear acceleration. In this paper, we propose a method to remove the linear acceleration component from the accelerometer data in order to improve the accuracy of measuring gravity direction. In addition, we develop a simple method to calibrate the joint axis of a link to which an inertial sensor belongs as well as the position of a sensor with respect to the link. The calibration enables attaching inertial sensors in an arbitrary position and orientation with respect to a link.

• Steel and Composite Structures
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• v.5 no.2_3
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• pp.181-192
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• 2005

The effective length method for flexural (column) buckling has been used for many decades but its use is somewhat limited in various contemporary design codes to moderately slender structures with elastic critical load factor (${\lambda}_{cr}$) less than 3 to 5. In pace with the use of higher grade steel in recent years, the influence of buckling in axial buckling resistance of a column becomes more important and the over-simplified assumption of effective length factor can lead to an unsafe, an uneconomical or a both unsafe and uneconomical solution when some members are over-designed while key elements are under-designed. Effective length should not normally be taken as the distance between nodes multiplied by an arbitrary factor like 0.85, 1.0, 2.0 etc. Further, the classification of non-sway and sway-sensitive frames makes the conventional design procedure tedious to use and, more importantly, limited to simple regular frames. This paper describes the practical use of second-order analysis with section capacity check allowing for $P-{\delta}$ and $P-{\Delta}$ effects together with member and system imperfections. Most commercial software considers only the $P-{\Delta}$ effect, but not member and frame imperfections nor $P-{\delta}$ effect, and engineers must be very careful in their uses. A verification problem is also given for validation of software for this type of powerful second-order analysis and design. It is a trend for popular and advanced national design codes in using the second-order analysis as a norm for analysis and design of steel structures while linear analysis may only be used in very simple structures.

• The Journal of Art Theory & Practice
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• no.1
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• pp.23-48
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• 2003

Art theorists support art productions by, introducing them to the public, explaining their meanings, and playing a crucial part in the development of art. These tasks seem like their opus. Because the principles of art production and the artistic languages are quite different from the ordinaries, we need 'interpreters' who can mediate us and the artists. Art works need interpretation. And the interpretation includes not only the characteristics of the given art work, but the customs, history, and the unique qualities of the race that produced the art work. The former director of the Korean National Museum, Choi Soon-woo wrote on the characteristics of Korean art as those that stem from the poised, arbitrary, and non-elaborate state of mind. The statement of the former Director of the National Museum has its weight far greater than just a personal opinion. In fact, we encounter the same resonance of this statement over and over reproduced in the mass media. The problem lies on that it deals with not only a single art work, but the entire Korean art. And going further, this kind of remarks are already infused into every sector of our thought on art appreciation. In this paper, I argue for a re-reading of the characteristics of Korean beauty based on two reasons. First, the characteristic of art work is contemporary, thus we cannot define the characteristics of entire Korean art in a few words without the context of the period of its making. Second, Director Choi defined the characteristics that I pointed out above as 'natural' and 'nature-friendly.' Nature or being natural is not an usual word that defines the characteristics of art work, which stands for the opposite side of the nature in the binary opposition of nature/culture. To delve into these misunderstandings of Korean beauty in the popular notions of Korean art, I suggest the re-reading of three major articles on Korean art: Ryoo Jong-yeol's "Korean race and its art," Ko You-seup's reiteration of Ryoo's thesis called "Discourses in Korean Art History and Aesthetics," and Yoon Hee-soon's antithesis of Ryoo Jong-yeol titiled "Studies on Korean Art History."

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1443-1448
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• 2006

As computers and networks become popular, distributing information on the Internet is common in our daily life. In the past, e-mail has been the primary choice of exchanging information but messengers are gaining popularity abroad and domestically because of their nature of getting immediate responses. Information leakage by invasion that is enemy of evil in communication of communications division Server and Agent between each agents that become burden of communication for effective administration of data for most of existing messenger is becoming an issue. In this paper, we design a secure messenger system that could be obtained maximum security. It use ECC based on ElGamal methodology using PKI for secure communication. For the message encryption and decryption between the same group non, each group is kept distinct by drawing an elliptic curve and an arbitrary point is chosen on the curve.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.71-81
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• 2013

Facial expressions decide an image for the individual, and the ability to interpret emotion from facial expressions is the core of human relations, hence recognizing emotion through facial expression is important enough to change attitude and decisions between individuals within social relations. Children with unstable attachment development, seniors, autistic group, ADHD children and depression group showed low performance results in facial expression recognizing ability tasks, and active interventions with such groups anticipates possibilities of prevention and therapeutic effects for psychological disabilities. The quantified figures that show detailed change in position of lips, eyes and cheeks anticipates for possible applications in diverse fields such as human sensibility ergonomics, korean culture and art contents, therapeutical and educational applications to overcome psychological disabilities and as methods of non-verbal communication in the globalizing multicultural society to overcome cultural differences.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.11
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• pp.1548-1562
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• 2003

This paper is the first of several companion papers which compare the methods of Air-fuel ratio determination. There are many methods which calculate Air-Fuel ratio from exhaust emission. Most of them are based on the simple chemical equations, which use balance of atom, and the error of the calculation is negligible as far as the instrumentation accuracy is guaranteed. They assume homogeneous mixture and complete combustion to the extent of oxygen availability. Because of these simple assumptions, they cannot offer the information about the fuel distribution state and the malfunction of instrument. For these limitations, Eltinge offered new one based on stricter mathematical model. This result coincides with the others very well and gives more information about the mixture state and instrumentation. Consequently this might be a general solution for Air-fuel ratio determination and exhaust composition. The objects of the calculation, however, were not commercial fuels except gasoline and the compensation method of unburned hydrocarbon was not appropriate to recent analyzer. Moreover he did not consider the fuel which contains oxygen, such as methanol, ethanol and blend of gasoline-alcohol. In this paper, Eltinge chart is expanded to the arbitrary fuel composition as the reference exhaust compositions for the purpose of further discussions about Air-fuel ratio determination methods and the charts fur gasoline, diesel, methanol, M85, liquefied petroleum gas(LPG), natural gas(NG), propane, butane are illustrated.

• Magazine of the Korean Society of Agricultural Engineers
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• v.26 no.3
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• pp.35-45
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• 1984

Generally speaking, agriculture exist in a climatic environment of uncertainty. Namely, normal rainfall value, as given by the mean values, does not exist. Thought on exists, itl does not affect like extreme Precipitation value on the part of agriculture and of others. Therefore, it is important that we measure the duration and severity index of drought caused by extreme precipitation deficit. In this purpose, this study was dealt with the calculation of drought duration and severity indexs by the method of monthly weighting coefficient. There is no quantitive definition of drought that is universally acceptable. Most of the criteria was used to identify drought have been arbitrary because a drought is a 'non-event' as opposed to a distinct event such as a flood. Therefore, confusion arises when an attempt is made to define the drought phenomenon, the calculation of duration, drought index is based on the following four fundamental question, and this study was dealt with the answers of these four questions as they related to this analytical method, as follows. First, the primary interest in this study is to be the lack of precipitation as it relates to agricultural effective rainfall. Second, the time interval was used to be month in this analysis. Third, Drought event, distinguished analytically from other event, is noted by monthly weighting coefficient method based on monthly rainfall data. Fin-ally, the seven regions used in this study have continually affected by drought on account of their rainfall deficit. The result from this method was very similar to the previous papers studied by many workers. Therefore, I think that this method is very available in Korea to identify the duration of drought, the deficit of precipitation and severity index of drought, But according to the climate of Korea exist the Asia Monsoon zone. The monthly weighting coefficient is modify a little, Because get out of 0.1-0.4 occasionally.

• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.263-279
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• 2015

The introduction of real numbers is one of the most difficult steps in the teaching of school mathematics since the mathematical justification of the extension from rational to real numbers requires the completeness property. The author elucidated what questions about real numbers can be unanswered as the "institutional didactic void" in school mathematics defining real numbers as the union of the rational and irrational numbers. The pre-service teachers' explanations on the extension from rational to real numbers and the raison d'$\hat{e}$tre of arbitrary non-recurring decimals showed the superficial and fragmentary understanding of real numbers. Connecting school mathematics to university mathematics via the didactic void, the author discussed how pre-service teachers could break the illusion of transparency about the real number.