• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.184-184
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• 2003

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1461-1472
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• 2000

Recently, the mobile users seem to be rapidly increasing and then the capacity limit will be reached at close hand. In these situations, to provide them with good quality of service in the coming future, newly planned cell design is needed. In the next generation mobile communication systems, namely IMT-2000, good quality services will be possible only by designing the cell structure hierarchically with the help of appropriate cell planning. In the research process, the standardization reports on the future mobile cellular IMT-2000 system (3GPP) are investigated and the parameters, that are essential to cell planning, are also researched. Modeling of IMT-2000 radio link and the numerical analysis on that make it possible to calculate the forward/reverse link budget, system capacity call blocking probability Erlang capacity and cell coverage. In planning the cell of IMT-2000 system, various parameters are considered, such as hierarchical cell structure, number of users, data service forms and propagation area environments. From the results, efficient cell planning methods are proposed. Through this thesis efficient cell planning and maximum capacity will be achieved in the beginning of commercial IMT-2000 service.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.101-108
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• 2007

In this paper, we propose and verify an adaptive block watermarking algorithm based on JPEG2000 DWT, which determines watermarking for the original image by two scaling factors in order to overcome image degradation and blocking problem at the edge. Adaptive block watermarking algorithm uses 2 scaling factors, one is calculated by the ratio of present block average to the next block average, and the other is calculated by the ratio of total LL subband average to each block average. Signals of adaptive block watermark are obtained from an original image by itself and the strength of watermark is automatically controlled by image characters. Instead of conventional methods using identical intensity of a watermark, the proposed method uses adaptive watermark with different intensity controlled by each block. Thus, an adaptive block watermark improves the visuality of images by 4$\sim$14dB and it is robust against attacks such as filtering, JPEG2000 compression, resizing and cropping. Also we implemented the algorithm in ASIC using Hynix 0.25${\mu}m$ CMOS technology to integrate it in JPEG2000 codec chip.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.1
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• pp.159-167
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• 2011

The purpose of this study is to understand graffiti images in fashion trends since 2000 and to play a guiding role in the development of fashion designs. The methods of this study are an academic literature review as well as practical study through actual case studies about. The formative characteristics of graffiti in fashion since 2000 are summarized as amusement, abstract and improvisation as follows. First, amusement graffiti is humble, weak and unfinished, but the immature and informal characters give people vitality, composure and enjoyment. It stirs up memories of childhood and induces a close affinity and comfort, and so It expresses relaxing and cozy desire. Second, abstract graffiti represents ambiguity and obscurity beyond form. It is born by reacting to equality, symmetry, mechanism, man-created beauty and the completeness of modernism. The characteristics are disorder, uncertainty, incompletion, uniformity, freedom, nature and so on. Third, improvisation graffiti is deeply related to 'indeterminacy' of post modernism which cannot forecast a perfection. This is more important as a process than an effect. Improvisation pursues humanism which denies perfection and determinacy by reaction of new technology.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.183-186
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• 2005

We present results of the VLBA observation toward the radio continuum and water maser emissions in a nearby LINER galaxy NGC 1052. The jet structure observed in 2000 is similar to that in 1998, and the two jet structures in 1998 and 2000 support the sub-luminal motion with apparent velocity of 0.26c. Distribution of water maser spots are located ${\~}$0.05 pc shifted to southwest from the component which is supported to be the nucleus, and no rapid positional change of the water maser gas with respect to the central engine is seen from 1995 to 2000. The maser gas is positionally coincident with a plasma torus, and the position of the maser gas relative to the nucleus is stable from 1995 to 2000. The maser gas in NGC 1052 could be explained to be associated with the nuclear circumnuclear torus or disk like the situation found in the nucleus of NGC 4258.

• Journal of Oriental Neuropsychiatry
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• v.11 no.1
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• pp.83-96
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• 2000

Objectives: In order to study the effect of the oriental medical therapy on the patients who visited Neuropsychiatry and oriental medical differentiation of symptoms and signs with ABR (Autonomic Bioelectric Response recorder)-2000, these clinical studies were performed. Methods: Sixty six patients with headache were classified into three groups; the first is tension headache, the second is migraine headache, the last is the others, each group was investigated of a various characteristic, the effect of the oriental medical therapy and stress was measured by ABR-2000. Result: 1. According to the statics, the tention headache's rate was higher than migraine; on the whole woman's rate was higher than man's. however in the migraine the rate of sex was equal. 2. According to the cause facter, oversensitiveness, overexertion, dyspepsia, etc. were numorous in the order. 3. According to the oriental medical differentiation of symptoms and signs, the rate of stagnation of the liver-qi' s fire-transmission(肝鬱化火) and deficiency of qi(氣虛), these two types were highest. result of analyzing ABR-2000 is that stagnation of the liver-qi's fire-transmission(肝鬱化火) is the highest stress. 4. According to treatment rate, 80.3 percent of patients satisfied of treatment.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.4
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• pp.48-53
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• 2001

A three-stage low noise amplifier(LNA) for the Base-station of the IMT-2000 is designed and implemented. In the first stage, a GaAs HJt-FET which has good noise characteristics is made use of. Monolithic microwave integrated circuits(MMICS) are used in the second and the third stage to achieve both the high gain and high output power. Although the balanced amplifier is used to reduce the input VSWR, it is done only in the first stage because we have to minimize the noise figure attributed to the phase difference of the balanced amplifier. It is shown that the implemented LNA has the gai over 39.74dB, the gain flatness less than ±0.4dB, the noise figure below 0.97dB, input and output VSWRs less than 1.2, and OIP₃(output third order intercept point) of 38.17dBm in the operating frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1134-1142
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• 2003

This paper presents a hardware implementation of the STS diversity system, utilizing FPGAs and introduces the function and the design method of each of the modules of the system. In order to improve the performance of the implemented STS system which is an open loop transmit diversity system under fading environment, the exact estimation of the communication channel is essential. Therefore, we propose the optimal forgetting factor to estimate pilot channel in this paper, It is shown in this paper that the pilot channel is estimated using the forgetting factor of 0.7 without increasing the integration range of the pilot channel even when the power of pilot channel is not sufficiently large in CDMA 2000 1x signal environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1C
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• pp.72-80
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• 2003

This paper proposed the method of finding optimal weight vectors for enhancing the performance of an adaptive array antenna system by adopting a novel beam-forming algorithm in CDMA (code division multiple access) channel. This algorithm is a liberalized power method, based on power method, with the total computational load, O(4N). Where, N denotes the number of antenna elements. The performance of the proposed algorithm is shown in terms of SER (symbol error rates), allowable capacity, and the convergence characteristic in IS2000 1X CDMA channel. As a result of simulations, the adaptive way antenna system allows 6-10 times more users than the conventional one in a cell of a base station. Furthermore, the proposed algorithm shows superior performance to the conventional one regarding symbol error rates, converging characteristics, and computational load.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.304-307
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• 2006

A plane stress yield function YLD2000(Yoon et al., 2000) is applied to the finite element analysis S/W Z-Stamp because it is required to conduct proper consideration of aluminum alloy which has anomalous behavior. In the previous study, verification of the yield function and developed S/W is implemented. In this paper, two real parts of automobile body are additionally considered to verify the validity of Z-Stamp. The one is the benchmark problem #2 of Numisheet 2005 and the other is a small member part. In case of benchmark problem, formability simulation result and try-out result are compared with each other. In case of the small member part, formability analysis is implemented to predict the problem during the developing time.