• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.51-56
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• 2022

In space based constellation network, users are allowed to enter or leave the network arbitrarily. Hence, the number, identities and transmitted data of active users vary with time and have considerable impacts on the receiver's performance. The so-called problem of multiuser detection means identifying the identity of each active user and detecting the data transmitted by each active user. Traditional methods assume that the number of active users is equal to the maximum number of users that the network can hold. The model of traditional methods are simple and the performance are suboptimal. In this paper a Maximum A Posteriori Probability (MAP) based multiuser detection method is proposed. The proposed method models the activity state of users as Markov chain and transforms multiuser detection into searching optimal path in grid map with BCJR algorithm. Simulation results indicate that the proposed method obtains 2.6dB and 1dB E_b/N₀ gains respectively when activity detection error rate and symbol error rate reach 10^-3, comparing with reference methods.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.169-171
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• 1994

This paper is to find out more reliable analyzing method of heart rate variability. Heart rate variability analysis is to evaluate cardiovascular stability and also have used as an indicator of autonomic nervous system activity. In this study, time domain analysis, spectral analysis and state space analysis method are applied to analyze heart rate variability. Because of nonlinear characteristics of heart rate, we need not only spectral analysis, but also state space analysis. Fractal dimension of spectral estimation is useful indicator of autonomic nervous activity.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.81-81
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• 2003

We report the plasma blob events that were observed from KOMPSAT-1 (2250 LT, 685-km altitude) and from DMSP F15 (2130 LT,840-km altitude) in the low-latitude ionosphere. The global distribution of blobs showed a season-longitudinal dependence similar to the distribution of the equatorial plasma bubbles, although they were observed along the ${\pm}$15 dip latitudes. The blobs drifted upward relative to the ambient plasmas, and the electron temperatures and H+ proportions were lower within the blobs compared to those in the background. These characteristics of the plasma blobs are very similar to the characteristics of the equatorial plasma bubbles. Then, we suggest that the blobs were originated from the lower altitudes by the mechanism that drives an upward drift of the plasma bubbles. The blob events did not occur in a correlated way with the magnetic activity or daily variation of the solar activity.

• Journal of Astronomy and Space Sciences
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• v.16 no.1
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• pp.53-60
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• 1999

The purpose of this paper is to predict Sun Transit Outage phenomenon(Sunout). Sunout had been studied mainly for the case of Geostationary satellite and under the assumption of 'Quiet Sun'. In this paper, we predict sunout phenomenon more precisely for non-geostationary orbit as well as geostationary orbit and specially we considered the degree of solar activity. And we compare the result of the case of C-band and Ku-band. Also the result is applied to the two KoreaSat communication system through calculating the link budget.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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• pp.189-198
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• 2000

The emission lines of the ultraviolet region and the light curves of the optical region have been analyzed to investigate the distorted light curves of SZ Psc. The Mg II emission lines of the IUE spectra confirmed that the chromospheric activity of SZ Psc occurs on the K1 IV star. The distorted light curves in the optical region have been analyzed by the spot model where the spots are on the K1 IV star as the result of the chromospheric activity. The complete photometric solution could be deduced for SZ Psc by the good fitness with the spot model.

• Journal of The Korean Association For Science Education
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• v.17 no.4
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• pp.425-433
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• 1997

The purpose of this study was to examine for middle school science textbooks published by the sixth curriculum to analyze STS material, activity, and space devoted to STS. Because most teachers and students are dependent upon textbooks in teaching and learning, analyzing science textbooks will give basic information to ascertain the extent to which the current school science incorporate STS themes. Results indicated that lots of STS topics in the middle school science text books are related to applications of science. They also revealed that about 3% of the narrative space is devoted to STS topics, with a range of 0.7% to 5.2%. The coverage of STS topics increases as grade level increases.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.118-121
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• 2005

Arylsulfatase cloned from a marine bacterium, Pseudoalteromonas carrageenovora, was over-expressed in Escherichia coli. Most of the recombinant arylsulfatase was found in the cell lysate with induction up to $10{\mu}M$ IPTG. However, enzyme activity was observed both in the culture supernatant and cell lysate by induction with IPTG concentration of $50-5,000{\mu}M$. Most of the recombinant enzyme was localized in the periplasmic space with $10{\mu}M$ IPTG induction, while half of the enzyme was distributed in the periplasmic space with $50{\mu}M$ IPTG induction. Cell growth and arylsulfatase activity did not change with the induction time, and the level of recombinant arylsulfatase expression was maintained at 4-5 U/mL after 6 to 14 hr of culture.

• Journal of The Korea Institute of Healthcare Architecture
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• v.6 no.11
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• pp.97-106
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• 2000

The purpose of this study is to suggest the architectural planning data on the senile dementia facilities. The elderly with senile dementia can be medically classified into many types. And their activity pattern is so different from each other. And so, the space for them is differently designed according to their activity. The method of space design for the elderly with alzheimer type and the elderly with cerebro vascular type is suggested in this thesis.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.126.1-126.1
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• 2012

The middle-latitude ionization trough, the plasma density depletion in the subauroral region, has been extensively studied since its discovery in the 1960s. Our knowledge of the variability of the trough is mostly based on the observations in the northern hemisphere. Recently, the COSMIC observations enabled the investigation of the trough in both hemispheres at all local time. However, the investigation was limited to the period of the low solar activity. In this study, we investigate the variability of the trough location and morphology with local time, solar cycle, magnetic activity, and interplanetary magnetic field. For this purpose, we analyze the DMSP F15 data acquired during 2000-2010.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4853-4862
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• 2012

In Modern Cities, The 'Cultural spaces or facilities' are the core of the urban activity. And it is the field of urban life which can improve the quality of life and change the human's life style. Also in Contemporary society, Cultural spaces are required to express the social and psychological activity of the city life and the diversity and function of human beings. But most of them are located in the Metropolitan area. In these days, the needs of cultural spaces and facilities in 'Medium sized-cities' are growing. And many development plans are working in practice in that cities to accede to these requirements of social, human and current of the times. They include the exhibition spaces which perform function of the field of art and culture, that have powerful and infinite potentiality of the social development. At this Point, this study suggest that 'Optimum level' of exhibition spaces as Museum and Art-gallery in Medium sized-cities. To achieve this study, two phases are proceeded as follows. First, Check the social needs of it based on theoretical inquiry of Exhibition space. Second, Focused on Medium sized-cities, through a comparison between 12 Domestic cities and 4 Japan's cities. A population of their cities is from 500,000 to 1,000,000. We can get a data for Optimum level of Exhibition space. And last, Suggest the strategies of the location and planning of Exhibition space based on Second phase.