• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.2063-2076
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• 1996

In this thesis, in order to apply a punctured convolutional codes to the trellis coded modulation(TCM), an efficient punctured trellis coded modulation(PTCM) based on the decomposition of the metric into orthogonal components is presented. Also, a simulation is performed in an additive white Gaussian noise(AWGN) and a rician fading channel modeling the mobile satellite channel. The PTCM combines punctured convolutional coding with MPSK modulation to provide a large coding gain in a power-limited or bandwidth-limited channel. However, in general the use of the punctured convolutional code structure in the decoder results in a performance loss in comparison to trellis codes, due to difficulties in assigning metrics. But, the study shows no loss in performance for punctured trellis coded MPSK in comparison to TCM, and what is more, the punctured convolutional codes results in some savings in the complexity of Viterbi decoders, compared to TCM of the same rate. Also, the results shows that the punctured trellis coded .pi./8 shift 8PSK is an attractive scheme for power-limited and band-limited systems and especially, the Viterbi decoder with first and Lth phase difference metrics improves BER performance by the mobile satellite channel.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3396-3411
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• 2015

Sensors used in Wireless Sensor Networks (WSN) have mostly limited capacity which affects the performance of their applications. One of the data-gathering methods is to use mobile sinks to visit these sensors so that they can save their limited battery energies from forwarding data packages to static sinks. The main disadvantage of employing mobile sinks is the delay of data collection due to relative low speed of mobile sinks. Since sensors have very limited memory capacities, whenever a mobile sink is too late to visit a sensor, that sensor's memory would be full, which is called a 'memory overflow', and thus, needs to be purged, which causes loss of collected data. In this work, a method is proposed to generate mobile sink tours, such that the number of overflows and the amount of lost data are minimized. Moreover, the proposed method does not need either the sensor locations or sensor memory status in advance. Hence, the overhead stemmed from the information exchange of these requirements are avoided. The proposed method is compared with a previously published heuristic. The simulation experiment results show the success of the proposed method over the rival heuristic with respect to the considered metrics under various parameters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2173-2183
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• 1998

We consider a frequency-hopped multiple-access communication system that employs reed-solomon code over GF(Q) and M-ary FSK signaling ($M{\leq}Q$) in rayleigh fading channel. We investigate the tradeoff among the modulation symbol size (M), the number of frequency slots, and the code rate in maximizing the average number of successfully transmitted information bits per unit time and unit bandwidth (called normalized throughput). We find that it is desirabel to use a large M in noise-limited environment. In interference-limited environment, it is more improtant to prevent errors (hits) by increasing the number of frequency slots than to correct them with formward error correction techniques or to reduce the error rate by increasing M.

• The Korean Journal of Franchise Management
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• v.15 no.1
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• pp.1-10
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• 2024

Purpose: Despite the popularity of sales promotion as one of the key marketing tactics employed by many companies today, relatively little effort has been devoted to examining an interaction effect between promotion cues and promotion duration. Therefore, this study aims to examine how promotion cues and promotion duration will jointly affect consumers' attitudes toward promotions and purchase intentions. Research design, data, and methodology: The present study conducted an online experiment through the Qualtrics program in which a total of 141 participants were recruited from the Cloud panel members in the U.S. The experiment employed a 2(promotion cue: best-seller vs. limited edition) × 2(promotion duration: long vs. short) full factorial between-subjects design. Result: In the condition of best-selling sales promotion cue, a long promotion duration induced more positive promotion attitude and higher purchase intention, while in the condition of limited-edition sales promotion cue, the use of a short promotion duration contributed more positive promotion attitude and greater purchase intention. Conclusions: Marketers need to take the congruence between promotion cues and promotion duration into full consideration when designing effective sales promotion strategy.

• Korean journal of communication and information
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• v.19
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• pp.155-184
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• 2002

Mobile phone users have diversified human factors: their channel orientations are different, and the degrees of unwillingness to communicate vary. We examined the effect of human factors on the use of mobile phone, such as the diversity of mobile phone use, the appropriateness of mobile phone, and the aversion to mobile phone as well as the interpersonal communication network through mobile phone. For our sample we surveyed college students and their family members who are older than 400. We found that the more social presence a mobile phone user gets through the mobile phone, and the more familiar to the mobile phone he/she is, (1) the more diversified is the use of mobile phone service, (2) the higher is the level of acceptance of the mobile phone as an interpersonal communication media, and (3) the lower is the level of aversion to the mobile phone. In contrast, those who have some level of aversion to the face-to-face communication, seem to form very limited interpersonal communication network through mobile phone. Their use of mobile phone is also very limited.

• Korean Journal of Clinical Pharmacy
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• v.27 no.3
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• pp.178-185
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• 2017

Objective: Because of communication difficulties, the hearing-impaired face many disadvantages throughout their lives. One of those is limited access to health care services, particularly medication service. Though they suffer from problems related to taking medication properly, there have been few studies on their actual condition of medication use in Korea. This study is to investigate any obstacles to properly taking medications and, therefore, to suggest preliminary evidence for policy measures to improve safe medication use among the hearing-impaired. Methods: Study participants consisted of hearing-impaired individuals living in Seoul. We also interviewed two sign language interpreters in order to illuminate health care state of the hearing-impaired. In-depth interview for each study participant was recorded and was translated into a written script for analysis. Results: Study participants were comprised of four women (66.6%) and two men (33.3%). There were one participants in 20's, two participants in 30's, one 40's, and two 50's. Sign language interpreters were all women. One was in her 30's and the other was in her 40's. Communication difficulties have been found to be key barrier to use medication safely. A negative image of pharmacists also hinders safe medication usage, lowering access to local pharmacy and leading discretional self-medication. This article provides pharmacists with solutions to promote adherence in this population. Conclusion: The hearing-impaired had limited access to medication-related information as well as using services in a hospital and local pharmacy due to their disability. Institutional improvement for safe medication usage among the hearing-impaired is necessary.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.292.2-293
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• 2003

In the gene therapy. viral gene delivery systems are limited in use because of several drawbacks like host immune reactions. Hence, non-viral gene delivery systems such as cationic polymers or synthetic gene carriers are being widely investigated to overcome the problems in the use of viral vectors. We synthesized a new conjugate of polyethyleniminet carrying galactose moieties as a targeting ligand for asialoglycoprotein (ASGP) receptors of hepatocytes. (omitted)

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.33-36
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• 2001

Only do we have an earth! It is crucially important to improve our living environment and keep the sustained development of a city in the limited space. Some concrete examples will be analysized in the paper, elaborating upon how to make full use of roof space and various plants to create a better green-space. To create different activity space with unique characteristics for people, various plants, roof-space, water and buildings in the style of garden should be use when local conditions and design requirement should be considered.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.11a
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• pp.237-257
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• 1997

The great flowing of information has brought a necessity for good management to make the best use of it in the highly competitive information age. The aims of this study are to investigate the main information sources - divided into largely three groups: literature sources, communication and information technology facilities), trying to find problem areas associated with IRM, indicating possible solutions. The result shows that internal information sources were regarded the most important and most frequently used. For the use of foreign materials, the higher the level of position is, the more people use them. With respect to communication methods, internal information sources were thought most important. With the dramatic falling of the price despite enormously increased functions, IT facilities are becoming important sources. However, the study reveals the use of them is quite limited to a few well-known facilities, which indicates that management should pay attention to more efficient use of them and useful training and education methods.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.191-207
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• 2001

■ The 1/sup st/ Driver: Electronic Documents ■ EDI via VAN ■ Limited use of electronic processing ■ The 2/sup nd/ Driver: Internet Infrastructure ■ Web/EDI, HTTP, FTP, MIME ■ Open network ■ The 3/sup rd/ Driver: XML ■ Enables the definition of platform-independent protocols for the exchange of data ■ Business Processes and Documents in XML format ■ XML/EDI ■ XML message exchange: SOAP(omitted)