• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.4
• /
• pp.360-370
• /
• 2013

When best-effort traffic users are supported in a downlink small-cell network, conventional schemes assign the channels experiencing low co-channel interference at each base station and provide a better downlink performance to the user near its serving base station, so that conventional schemes are not suitable to fairly support all users. In this paper, we propose a decentralized frequency reuse scheme for a small-cell network, where each basestation chooses a set of channels to fairly support the best-effort traffic users regardless of the distances to their serving basestation. After performing the conventional scheme that each basestation selects the channels which are not used in its adjacent basestations, it updates assigned channels improving the performance of low throughput users in a fully distributed manner with mitigating the overall throughput performance loss. The computer simulation demonstrates that the average throughput performance of the 10th percentile throughput users is improved up to 15% in some case compared to that of the conventional scheme, while allowing the overall throughput loss around 3%.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.220-220
• /
• 2006

• The Journal of Industrial Distribution & Business
• /
• v.10 no.3
• /
• pp.45-58
• /
• 2019

Purpose - The purpose of this study was to investigate the effects of the chatbot's characteristics (ease of use, social presence, playfulness, usefulness) on service value, customer satisfaction and reuse intention when consumers purchased fashion products in the mobile shopping environments. Research design, data, and methodology - Data were collected from Korean consumers from ages 20 to 59 who have experienced using chatbot in a mobile shopping for fashion products. After a pilot survey to 53 customers, the preliminary questionnaire was revised for the final test, and the final questionnaire was administered to 1500 customers. Out of these, 300 were collected. After deleting 48 incomplete ones, 252 questionnaires were used in the statistical analysis. Frequency analysis and exploratory factor analysis using SPSS 23.0 and confirmatory factor analysis and structure equation analysis using AMOS 18.0 were employed for data analyses. Results - First, four factors were extracted for the chatbot's characteristics: ease of use, social presence, playfulness and usefulness. Second, regarding the effect of chatbot's characteristics on service value when purchasing fashion products in the mobile shopping environment, ease of use, playfulness and usefulness of chatbot significantly affected service value. Social presence did not have significant effects on service value. Third, in terms of the effect of the chatbot's characteristics on customer satisfaction when purchasing fashion products in the mobile shopping environment, social presence, playfulness and usefulness of chatbot significantly had an effect on customer satisfaction. Ease of use did not have a significant effect on customer satisfaction. Fourth, service value of chatbot when purchasing fashion products in mobile shopping environment was found to have an effect on customer satisfaction with chatbot. Fifth, service value of chatbot on reuse intention when purchasing fashion products in the mobile shopping environment was found to have an effect on reuse intention of chatbot. Sixth, customer satisfaction with chatbot had a significant impact on the reuse intention of the chatbot when purchasing fashion products in the mobile shopping environment. Conclusions - The present study provide dimensions on the chatbot's characteristics and these may provide helpful data for further studies in this area and for marketers as well.

• Journal of Internet Computing and Services
• /
• v.16 no.5
• /
• pp.19-27
• /
• 2015

Due to the advantages of fast read/write operation and low power consumption, SSD(Solid State Drive) is now widely adopted as storage device of smart phone, laptop computer, server, etc. However, the shortcomings of SSD such as limited number of write operations and asymmetric read/write operation lead to the problem of shortened life span of SSD. Therefore, the block replacement policy of SSD used as cache for HDD is very important. The existing solutions for improving the lifespan of SSD including the LARC scheme typically employ the LRU algorithm to manage the SSD blocks, which may increase the miss rate in SSD due to the replacement of frequently used block instead of rarely used block. In this paper we propose a novel block replacement scheme which considers the block reuse interval to effectively handle various data read/write patterns. The proposed scheme replaces the block in SSD based on the recency decided by reuse interval and age along with hit ratio. Computer simulation using workload trace files reveals that the proposed scheme consistently improves the performance and lifespan of SSD by increasing the hit ratio and decreasing the number of write operations compared to the existing schemes including LARC.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.5
• /
• pp.1-14
• /
• 1997

We consider transmission beamforming techniques for frequency-division-duplex (FDD) wireless communication systems using adaptive arrays to improve the signal quality of the array transmission link. We develop a simple effective transmission beamforming technique based on an approximated frequency tranlsation (AFT) to derive the tranmsiion beamforming weights from the uplink channel vector. This technique exploits the invariance of the short-time averaged fast fading statistics to small frequency translations. A simple approximate relationship that relates the transmission channel vector to the reception channel vector is derived. We have developed its practical alternative in which the frequency translation of the channel vector is performed at the principal angle of arrival (AOA) of the u;link synthestic angular spectrum instead of the mean AOA. To analyze the performance of the proposed methods, we consider the power loss incurred by applying the estimated channel vector instead of the true downlink channel vector. The performance is analyzed as a function of the mean AOA, the angular spread, the number of elements, frequncy difference between the uplink and the downlink, and the angle distribution. Their performance is also compared with that of the direct weight reuse method and the AOA based methods.

• Proceedings of the Korea Association of Information Systems Conference
• /
• 2003.05a
• /
• pp.55-73
• /
• 2003

As the development of wireless technologies continue, mobile stock trading has become a new channel for companies to reach their customers. This study examines the factors affecting customer acceptance of mobile stock trading services. The research model based on the previous studies was established and the research hypotheses were generated. The sample was divided into users and nonuser groups. The test results show that relative advantage and social influence are positively related to intention to accept mobile services as well as in intention to reuse, security risk is negatively related to intention to reuse, frequency of trading is positively related to intention to reuse, cost burden is negatively related to the probability of using mobile stock trading services, and social influence is positively related to the probability of using mobile services. The results also support that information quality and response time are positively related to relative advantage, and interface quality is negatively related to complexity. It is considered that the study results may help managers to increase customer use of mobile stock trading services.

• Journal of Environmental Science International
• /
• v.29 no.11
• /
• pp.1109-1123
• /
• 2020

In this study, the amount of harmful fungi and bacteria contained in the drainage and culture medium from the paprika hydroponic facility is identified. In addition, by proposing the necessity of effective purification of discharged drainage, this study attempted to confirm the possibility of drainage reuse. Finally, this study provides basic data on the basis for calculating the need for purification facilities in the future, as well as improvements in horticulture facility for sustainable agriculture. As a result of the analysis, a total of 12 types of fungi were detected in paprika medium and 10 types of fungi were detected in the drainage, and their densities were 130 and 68, respectively. Among the fungi detected in the media and drainage of the paprika hydroponic facility, the fungi with the highest detection frequency are Fusarium, Phytophthora, and Pythium. In the case of bacteria, a total of 2 types of bacteria were detected in the paprika facilities, and the density was 28 and 23, respectively. Therefore, in order to reuse the drainage and settle the circulating hydroponic cultivation system, a water treatment process capable of appropriate treatment is required.

• Journal of the Korea Convergence Society
• /
• v.12 no.10
• /
• pp.287-294
• /
• 2021

This research is a research on the convergence of beauty marketing businesses to find out the impact of omnichannel in the beauty industry on consumer behavior. The target was 299 copies of the self-answer questionnaire for male and female in their 20s-30s living in Seoul, using the SPSS21.0 program to analyze frequency, explore factors, correlation, and multiple regression analysis. According to the study, Omnichannels were related to consumer behavior, and the sub factors of Omni channels could be divided into exposure, benefits, review, reservation, and convenience. All sub-elements of Omni channels, except exposure, have a positive impact on customer satisfaction during consumer behavior, and all sub-elements of Omni channels have a positive impact on reuse intent during consumer behavior. Customer satisfaction has been shown to have a positive impact on reuse intentions. Therefore, it will provide good feedback for revitalizing the beauty industry. Therefore, research on omnichannel marketing strategies and activation of beauty platform are needed.

• Journal of environmental and Sanitary engineering
• /
• v.22 no.4
• /
• pp.45-54
• /
• 2007

With the rapid development of economy, scientific technology, and medical technology, as the current society is also changing competitively, we are compelled to have many psychological and problems such as pressure, mental stress and tension as well as physical problems. Therefore, the more current industries develops, the more attention is given to health in preventive level rather than treatment level. Contemporary people have paid more attention to management of health and have a desire for beautiful and healthy life. In other words, their interest in consistent management of their health and beauty are getting stronger. To satisfy the desire to live healthily and beautifully, many natural therapies that can be applied for actual living have been developed, which the public are willing to accept. Therefore, this study is to specifically demonstrate the followings through interviews with the customers who have armoatherapy: What effect customers' knowledge on aromatherapy, frequency of use, expenses, experiences of side-effects, and perception on its effect on skin care will have on customer satisfaction and intention to reuse the service. The results are presented as follows: Though customers' perception on aroma is high, they usually use it only on their faces. So is should be promoted in various ways. It is demonstrated that customers' satisfaction has a significant effect on their intention to reuse it.

• Journal of Korean society of Dental Hygiene
• /
• v.11 no.5
• /
• pp.741-747
• /
• 2011

Objectives : The purpose of this study was to examine factors related to the satisfaction level of patients with dental hygienists services. Methods : Questionnaire survey was carried out targeting 157 dental hygienists. The collected data was performed frequency & percentage, independent t-test and Pearson's correlation coefficient analysis. Results : 1. The mean score of kind of dental hygienists was 3.07 out of a maximum 4 points and level medical treatment of dental hygienists 2.94, friendly of dental hygienists 2.75. 2. Regarding the correlation between kind, level medical treatment, friendly of dental hygienists had a statistically significant correlation of r=0.677 which was the highest correlation factor(p<0.01). 3. dental satisfaction, dental reuse intention between intention recommendation, they were statistically significant different with dental satisfaction(p<0.05) 4. Regarding the correlation between dental satisfaction, dental reuse intention, intention recommendation had a statistically significant correlation of r=0.705 which was the highest correlation factor(p<0.01). Conclusions : Dental care service, dental hygienists have significant and their to revisit and recommend.