• ETRI Journal
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• v.26 no.5
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• pp.443-451
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• 2004

Since the publication of Alamouti's famous space-time block code, various quasi-orthogonal space-time block codes (QSTBC) for multi-input multi-output (MIMO) fading channels for more than two transmit antennas have been proposed. It has been shown that these codes cannot achieve full diversity at full rate. In this paper, we present a simple feedback scheme for rich scattering (flat Rayleigh fading) MIMO channels that improves the coding gain and diversity of a QSTBC for 2$^n$ (n=3, 4, ${\cdots}$) transmit antennas. The relevant channel state information is sent back from the receiver to the transmitter quantized to one or two bits per code block. In this way, signal transmission with an improved coding gain and diversity near to the maximum diversity order is achieved. Such high diversity can be exploited with either a maximum-likelihood receiver or low-complexity zero-forcing receiver.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4C
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• pp.299-304
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• 2008

For perpendicular magnetic recording channels, it is hard to expect improving the performance by using the PRML or NPML. Hence, we exploit LDPC code to improve the performance. In this paper, we examine a single message-passing detector/decoder matched to the combination of a perpendicular magnetic recording channel detector and an LDPC code decoder. We examine the performance of channel iteration with joint LDPC code on perpendicular magnetic recording channel, and simplify the complexity of the message-passing detector algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.16-18
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• 2005

We show how to rapidly build a framework supporting weak code mobility by using Active XML [I]. Weak code mobility is important in mobile applications area by offering functionality at a low bandwidth cost and with little overhead imposed to the user peer architecture. Starting from already known principles involving code nobility, we give a new definition for the functionality transfer p개cess and we materialize it in a working prototype.

• Nuclear Engineering and Technology
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• v.36 no.2
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• pp.165-174
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• 2004

The distributed resistance model has been recently implemented into the MATRA-LMR code in order to improve its prediction capability over the wire-wrap model for a flow blockage analysis in the LMR. The code capability has been investigated using experimental data observed in the FFM (Fuel Failure Mock-up)-2A and 5B for two typical flow conditions in a blocked channel. The predicted results by the MATRA-LMR with a distributed resistance model agreed well with the experimental data for wire-wrapped subchannels. However, it is suggested that the parameter n in the distributed resistance model needs to be calibrated accurately for a reasonable prediction of the temperature field under a low flow condition. Finally, the analyses of a blockage for the assembly of the KALIMER design are performed. Satisfactory results by the MATRA-LMR code were obtained through and rerified a comparison with results of the SABRE code.

• Journal of Korea Multimedia Society
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• v.25 no.1
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• pp.10-28
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• 2022

In this paper, we present an entry-level COVID-19 stand-alone digitial signage player (CoSiP) which performs not only conventional digital signage functionalities but also fever detection, face mask wearing detection, and KI-pass QR code checking. The overall design of CoSiP is proposed, and implementation of a temperature checking algorithm using a low cost thermal sensor is elaborately presented. Through experiments over datasets and against a developed CoSiP device, it is shown that the fever detection, face mask wearing detection, KI-pass QR code checking as well as signage functionalities of the proposed CoSiP work properly and reliably.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.97-99
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• 1999

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.742-748
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• 2009

Zigbee wireless communication technology has features which are low cost, low power and coping ability against a high delay time when the automatic wireless system is manufactured. Therefore, in this paper, we research a method improving the data transmission reliability of the industrial equipment control and management system using zigbee wireless communication technology. we used a convolutional code with code rate R=1/2, constraint K=5 and generation polynomial constant g1=(10111) and g2=(10011) as a reliability method. From the transmission simulation at LOS environment, we are able to predict the transmission error performance according to the distance difference. Furthermore, At the PER performance analysis, we can get the result that this system reliability with convolutional code is improved about 5 times than the existing system. From these results, we can prove that the convolutional code is the solution to improve the system reliability of the industrial equipment control and management system using zigbee wireless communication technology.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.58-68
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• 2000

In this paper we introduce the correlation-aided distributed sample acquisition (CDSA) scheme for fast cell search in IMT-2000 W-CDMA cellular system. The proposed scheme incorporates the state symbol correlation process into the comparison-correction based synchronization process of the original DSA scheme to enable fast acquisition even under very poor channel environment. for its realization, each mobile station (MS) has to store in its memory a set of state sample sequences. which are determined by the long-period scrambling sequences used in the system and the sampling interval of the state samples. CDSA based cell search is carried out in two stages : First, the MS first acquires the slot timing by using the primary synch code (PSC) and then identifies the igniter code which conveys the state samples of the current cell . Secondly. the MS identifies the scrambling code and frame timing by taking the comparison-correction based synchronization approach and, if the identification is not done satisfactorily within preset time. it initiates the state symbol correlation process which correlates the received symbol sequence with the pre-stored state sample sequences for a successful identification. As the state symbol SNR is relatively high. the state symbol correlation process enables reliable synchronization even in very low chip-SNR environment. Simulation results show that the proposed CDSA scheme outperforms the 3GPP 3-step approach, requiring the signal power of about 7 dB less for achieving the same acquisition time performance in low-SNR environments. Furthermore, it turns out very robust in the typical synchronization environment where large frequency offset exists.

• Structural Engineering and Mechanics
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• v.46 no.6
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• pp.791-808
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• 2013

The main purpose of this paper is to develop seismic fragility curves for existing reinforced concrete, RC, buildings based on the post earthquake field survey and the seismic performance using capacity design. Existing RC buildings constitute approximately 65% of the total stock in Algiers. This type of buildings, RC, was widely used in the past and chosen as the structural type for the future construction program of more than 2 millions apartments all over Algeria. These buildings, suffered moderate to extensive damage after the 2003 Boumerdes earthquake, on May 21st. The determination of analytical seismic fragility curves for low-rise and mid-rise existing RC buildings was carried out based on the consistent and complete post earthquake survey after that event. The information on the damaged existing RC buildings was investigated and evaluated by experts. Thirty four (34) communes (districts) of fifty seven (57), the most populated and affected by earthquake damage were considered in this study. Utilizing the field observed damage data and the Japanese Seismic Index Methodology, based on the capacity design method. Seismic fragility curves were developed for those buildings with a large number data in order to get a statistically significant sample size. According to the construction period and the code design, four types of existing RC buildings were considered. Buildings designed with pre-code (very poor structural behavior before 1955), Buildings designed with low code (poor structural behavior, between 1955-1981), buildings designed with medium code (moderate structural behavior, between 1981-1999) and buildings designed with high code (good structural behavior, after 1999).

• International Journal of High-Rise Buildings
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• v.3 no.1
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• pp.65-71
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• 2014

Baku, the capital of Azerbaijan, has seen a boom in construction in recent years. The old Baku city has been rapidly transforming into a new hub of high-rise buildings and lively cultural centers hosting the Euro Vision Song Contest in 2012 and European Games in 2015. A major population shift to Baku from its suburbs and the countryside has resulted in the doubling of Baku's population in the 4 years between 2009 and 2013. As of January 2013, Baku's population reached four million people, 43% of the citizens in Azerbaijan according to The State Statistical Committee of Azerbaijan. With this trend, the city needs more high-rise buildings to accommodate rapidly increasing demands for more housing and business space. Until the Azerbaijan Seismic Building Code was published in 2010 and became effective, many different seismic criteria, in terms of building codes and seismic intensities, were used for all new high-rise projects in Baku. Some designers used the SNIP (Russian) code with seismic level 9 or level 8 with 1 point penalty. Others used the Turkish code with Seismic Zone 1, UBC 97 with Zone 2 through 4, or IBC with Sa = 0.75 g through 1.0 g. The seismic intensity is now clarified with the Azerbaijan Seismic Building Code. However, the Azerbaijan Seismic Building Code is appropriate for low-rise buildings applications but may be inappropriate for high-rise project applications. This is because the code-defined response spectrum yields unrealistically conservative seismic forces for high-rise buildings with long periods, as compared to those determined by other internationally accepted building codes. This paper provides observations and recommendations for code-based seismic load assessment of high-rise buildings in the Baku area.