• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1B
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• pp.11-17
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• 2003

In this paper, we presented the dynamic random access channel allocation method under the priority based scheduling policy in order to improve the system performance of HIPERLAN/2 standardized by ETSI According to the scheduling policy, AP scheduler primarily allocates the resource to the collision MT This scheduling policy bring about decreasing the transmission delay of collision MT Dynamic RCH(random access channel) allocation method decreases the collision probability by increasing the number of RCH slots in case of low traffic. While it increases the maximum throughput by increasing the number of the data transmission slots in case of high traffic Therefore dynamic allocation method of RCH slots decreases the scheduling delay and increases the throughput When we evaluate the performance of presented method based on standards, we saw that the presented method improve the performance of the MAC protocol in terms of throughput and transmission delay.

• Knowledge Management Research
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• v.20 no.3
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• pp.155-171
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• 2019

In the entertainment industry which has great uncertainty, it is essential to predict public preference first. Thanks to various mass media channels such as cable TV and internet-based streaming services, the reality audition program has been getting big attention every day and it is being used as a new window to new entertainers' debut. This phenomenon means that it is changing from a closed selection process to an open selection process, which delegates selection rights to the public. This is characterized by the popularity of the public being reflected in the selection process. Therefore, this study aims to implement a machine learning model which predicts the winner of , which has recently been popular in South Korea. By doing so, this study is to extend the research method in the cultural industry and to suggest practical implications. We collected the data of winners from the 1st, 2nd, and 3rd seasons of the Produce 101 and implemented the predictive model through the machine learning method with the accumulated data. We tried to develop the best predictive model that can predict winners of by using four machine learning methods such as Random Forest, Decision Tree, Support Vector Machine (SVM), and Neural Network. This study found that the audience voting and the amount of internet news articles on each participant were the main variables for predicting the winner and extended the discussion by analyzing the precision of prediction.

• Journal of Broadcast Engineering
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• v.27 no.3
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• pp.361-368
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• 2022

Quaternary tree plus multi-type tree (QT+MTT) structure was adopted in the Versatile Video Coding (VVC) standard as a block partitioning tool. QT+MTT provides excellent coding gain; however, it has huge encoding complexity due to the flexibility of the binary tree (BT) and ternary tree (TT) splits. This paper proposes a fast inter coding unit (CU) partitioning algorithm for BT and TT split types based on prediction accuracy functions using the mean of the absolute error (MAE). The MAE-based decision model was established to achieve a consistent time-saving encoding with stable coding loss for a practical low complexity VVC encoder. Experimental results under random access test configuration showed that the proposed algorithm achieved the encoding time saving from 24.0% to 31.7% with increasing luminance Bjontegaard delta (BD) rate from 1.0% to 2.1%.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.1
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• pp.41-50
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• 2024

Korea is facing a significant problem with historically low fertility rates, which is becoming a major social issue affecting the economy, labor force, and national security. This study analyzes the factors contributing to the regional gap in fertility rates and derives policy implications. The government and local authorities are implementing a range of policies to address the issue of low fertility. To establish an effective strategy, it is essential to identify the primary factors that contribute to regional disparities. This study identifies these factors and explores policy implications through machine learning and explainable artificial intelligence. The study also examines the influence of media and public opinion on childbirth in Korea by incorporating news and online community sentiment, as well as sentiment fear indices, as independent variables. To establish the relationship between regional fertility rates and factors, the study employs four machine learning models: multiple linear regression, XGBoost, Random Forest, and Support Vector Regression. Support Vector Regression, XGBoost, and Random Forest significantly outperform linear regression, highlighting the importance of machine learning models in explaining non-linear relationships with numerous variables. A factor analysis using SHAP is then conducted. The unemployment rate, Regional Gross Domestic Product per Capita, Women's Participation in Economic Activities, Number of Crimes Committed, Average Age of First Marriage, and Private Education Expenses significantly impact regional fertility rates. However, the degree of impact of the factors affecting fertility may vary by region, suggesting the need for policies tailored to the characteristics of each region, not just an overall ranking of factors.

• Journal of Life Science
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• v.22 no.2
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• pp.259-265
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• 2012

A bacterial strain, CK214, exhibiting high motility on an LB agar (1.5%, w/v) surface was isolated from the environment. The formation of unusual agar shrinking around colonies on agar plates was observed. The strain grew on minimal media containing pure agar as a sole carbon source. The cell-free culture supernatant of CK214 generated a reduced form of sugar in the in vitro reaction with the use of pure agar as a substrate, suggesting the secretion of an agar-degrading enzyme. The CK214 strain showed swarming motility on the solid media containing a wide range of concentrations of agar (0.5, 1.0, 1.5, 2.0% w/v). Various tests, including Gram staining, API analysis, and phylogenetic analysis based on 16S rDNA sequences identified that the CK214 strain was a G(+) rod-shaped bacterium grouped in genus Paenibacillus. Electron microscopic analysis demonstrated that the P. CK214 strain is peritrichously flagellated. Through transposon random mutagenesis, several agar-degrading activity defective mutants (ADMs) were generated. These mutants will be used in the future experimentation for the study of the correlation between agar-degrading activity and motility.

• Smart Media Journal
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• v.4 no.4
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• pp.111-119
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• 2015

As a variety of HMD(Head Mounted Display) has come out, the production of 3D images onto which VR(Virtual Reality) technologies are grafted has been contributed to activating the production of image contents depending on a tangible or immersing type. VR-based image contents have enlarged their applicability across the entertainment industry from animation and game to realistic images. At the same time, the solution development for producing VR image contents has also gained elasticity. However, among those production solutions which have been used until now, fixed stereo camera based photographing has a limit that the binocular disparity of a user is fixed. This does not only restrict a way of expression a producer intends to direct, but also may cause the effect of 3D or space not to be sensed enough as view condition is not considered enough in a user's side. This study is aimed at resolving with skills applying in the latter part of 3D image production the problem that convergence points may be adjusted with restriction, which tends to happen at the time of the production of VR image contents. The later stage of the 3D imaging work analyzes and applies to game engines the significance of adjusting convergence points through the visualization of binocular disparity so that it is available to implement a function that the points could be controlled at random by a user.

• Journal of Korea Multimedia Society
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• v.8 no.7
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• pp.943-952
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• 2005

This paper proposes a user's mobility based cooperative proxy caching policy for effective resource management of continuous media objects in mobile environments. This policy is different from the existing proxy caching policies in terms of how to exploit users' mobility. In other words, existing caching policies work based on the information about objects by referring to users' requests within a specified domain whereas the proposed caching policy runs by utilizing a number of users' requests across several domains. So, the proposed policy is applicable to random requests in mobile environments. Moreover, we also propose a replacement policy based on weights and playback time. To check the efficiency of the proposed caching policy, the proposed replacement policy is run with different size of caching unit: object or segment. The result of performance evaluation tells that segment sizes, ratio of users' mobility and weights are major factors for the efficient operation of the cooperative caching.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.2
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• pp.105-112
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• 2013

This study is to understand difference in news preferences targeting internet newspaper readers across the country. 146 random readers were chosen for the survey from Oct. 17 to 18 in 2012. The analyses were based on job categories, genders, and ages. As the result of the analysis, students read the internet newspapers the most. According to gender and age, job category was also significant. Males were mostly studiers, then office workers, and professionals, and females were mostly students, then office workers, unemployed, and housewife. The research confirmed that internet newspaper readers read real-time news conveniently whenever, wherever. This suggests a theological basis for media policy by implying paid paper-based newspaper readers are shifting to free, internet-based newspapers using cellular phones.

• Asian Journal for Public Opinion Research
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• v.8 no.3
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• pp.265-296
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• 2020

Macao, a special administrative region of China, has been able to maintain the records of zero deaths and keep confirmed cases under 50 since the outbreak of COVID-19 for more than half a year as of July 2020, despite being the world's most densely populated city. The current paper utilizes the dialogic public relations theory to analyze the situation using both literature review on how the various government actions and strategies during the pandemic were corresponding to the theory, and a quantitative random digital dialing (RDD) telephone survey, with a sample of 502 Macao residents aged 18 or above, to study the public reactions towards the government pandemic prevention actions. Survey results show a high level of public satisfaction towards epidemic prevention performance, as well as some forms of collaborative information redissemination behavior in social media platforms. Literature review and analysis from dialogic theory found that spirit of mutual equality, collaboration with local community, immediacy of presence in crisis time, engagements with stakeholders through maximum media channels and networks, supportiveness to public with both useful information and practical social support like subsidy program, as well as commitment to transparent and genuine communication, are all the dialogic communications strategies that describe what the Macao government has done in the crisis of COVID-19. The dialogic strategies that could be learned from the Macao government may be used as a reference for similar urbanized and densely populated cities in other territories.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2553-2562
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• 2013

It is difficult for TCP congestion control algorithm to ensure the bandwidth and delay bound required for media streaming services in broadband wireless network environments. In this paper, we propose the COIN TCP (COncave INcrease TCP) scheme for providing a high-quality media streaming services. The COIN TCP concavely increases the congestion window size by adjusting the increment rate of congestion window, that is inversely proportional to the amount of data accumulated in the router queue. As a result, our scheme can quickly occupy the available bandwidth and prevent the heavy congestion. It also improves the link utilization by adjusting the decrement rate of congestion window according to the packet loss rate with the random loss. Through the simulation results, we prove that our scheme improves the total throughput in broadband wireless network.