• Informatization Policy
• /
• v.20 no.3
• /
• pp.3-17
• /
• 2013

As electronic marketplaces grow and a large number of consumers exchange their opinions on products and services on the Internet, many studies have been conducted in the area of online consumer reviews. This paper analyzes the research trend of the online consumer reviews by investigating those studies in an attempt to provide future research directions. Many researchers have focused on the effects of online reviews on consumer behaviors as well as the usefulness of the online reviews. In particular, review contents, characteristics of reviewers/consumers and features of products/services have been identified as influencing factors on the effects of the online consumer reviews. For the review contents, the number and the volume of the contents have increasing effects on the online reviews, while the direction (positive vs. negative) of the contents has resulted in conflicting effects of the review. The reputation and trustfulness of reviewers, consumers' prior knowledge on the products, consumers' product involvement, and types of the products were investigated as these factors influence the effectiveness of the online consumer reviews. Social media (such as Facebook and Twitter) nowadays play an important role to disseminate online reviews among consumers. Thus, it is necessary to study how social media influence the effects of online reviews on consumers. Since some firms abuse the online reviews for their own sakes, we recognize the necessity for empirical studies on the side effects of the online reviews.

• Journal of KIISE:Computer Systems and Theory
• /
• v.30 no.10
• /
• pp.523-532
• /
• 2003

Video on Demand(VOD) services cause high resource consumption in a video seuer, because multimedia are characterized by continuous playback, a high bandwidth requirement, and long playback duration. Patching has been proposed to save the network I/O bandwidth of a video server. To achieve true VOD, patching uses multicasting to share video streams, thereby providing immediate VOD services to users without any service latency. A communication channel is used to either multicast the entire video as a regular channel or multicast only the leading portion of a video as a Patching channel. This paper Proposes a buffering patching technique that divides regular channels, as used in patching, into sub-regular channels and regular channels to shorten the holding time of the channels. In the proposed technique, the last portion of video data, corresponding to the size of the buffering window, is not transferred by sub-regular channels, but rather downloaded and buffered in the user buffer from the latest regular channel. When simulations were performed to compare the performance of the proposed technique with that of conventional patching, the results indicated that the proposed technique was superior in terms of the defection rate, average service latency, and fairness, although the amount of video data buffered at each user station was higher than that with patching.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.9
• /
• pp.2524-2532
• /
• 1999

In this paper, we present a new buffer pool management scheme designed for video type news objects to build a cost-effective News On Demand storage server for serving users requests beyond the limitation of disk bandwidth. In a News On Demand Server where many of users request for video type news objects have to be serviced keeping their playback deadline, the maximum numbers of concurrent users are limited by the maximum disk bandwidth the server provides. With our proposed buffer cache management scheme, a requested data is checked to see whether or not it is worthy of caching by checking its average arrival interval and current disk traffic density. Subsequently, only granted news objects are permitted to get into the buffer pool, where buffer allocation is made not on the block basis but on the object basis. We evaluated the performance of our proposed caching algorithm through simulation. As a result of the simulation, we show that by using this caching scheme to support users requests for real time news data, compared with serving those requests only by disks, 30% of extra requests are served without additional cost increase.

• The KIPS Transactions:PartA
• /
• v.8A no.4
• /
• pp.517-522
• /
• 2001

The appearance of web technology has accelerated a role of the development of the multimedia technology, the computer communication technology and the multimedia application contents. And serveral researches of WBI (Web-based Instruction) system have combined the technology of the digital library and LOD. Recently WBI (Web-based Instruction) model which is based on web has been proposed in the part of the new activity model of teaching-learning. And the demand of the customized coursewares which is required from the learners is increased, the needs of the efficient and automated education agents in the web-based instruction are recognized. But many education systems that had been studied recently did not service fluently the courses which learners had been wanting and could not provide the way for the learners to study the learning weakness which is observed in the continuous feedback of the course. In this paper we propose "Design of Multi-agent System for Course Scheduling of Learner-oriented using Weakness Analysis Algorithm". First proposed system monitors learner's behaviors constantly, evaluates them, and calculates his accomplishment. From this accomplishment the multi-agent schedules the suitable course for the learner. And the learner achieves a active and complete learning from the repeated and suitable course.le course.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.6
• /
• pp.681-689
• /
• 2019

The 46th Davos Forum of the World Economic Forum (WEF) predicts the continued growth of the 4th industry in the future. Currently, the 4th industry is attracting attention in various academic and practical fields. As a core technology of the 4th industry, Big Data is regarded as a major resource to lead the 4th industrial revolution along with artificial intelligence. As the growing interest in Big Data, researches on it are actively being done. However, literature studies on existing Big Data are focused on qualitative research, and quantitative research is insufficient. Therefore, this study aims to analyze the big data research flow in MIS field and to make academic thirst for quantification. This study has collected 145 abstracts of big data papers published in major journals in MIS field and confirmed that a majority of papers are published in Decision Support Systems Journal. Text mining and text network analysis were performed only for DSS journals to eliminate bias. As a result of the analysis, it was found out that researches on combining big data in the management field between 2012 and 2014, and researches on system development and analysis method for using big data from 2015 to 2017 were conducted.

• The Journal of Korean Academy of Sensory Integration
• /
• v.16 no.2
• /
• pp.64-74
• /
• 2018

Objective : The purpose of this study is to examine the effects of therapeutic interventions on upper extremity function of children with cerebral palsy using systematic review methods and to suggest intervention trends in Korea. Methods : The subjects of the study were the researches published in the Korean Journal since 2008. Total 12 studies were selected through Korean research database engine such as DBpia, Scholar, KSDC, KISS and RISS for the systematic review. Key words were 'cerebral palsy', 'upper extremity function' and 'hand function'. The results of this study were analyzed by qualitative level and methodological quality level of evidence, and the results of each study were analyzed according to the PICO approach, that is Patient, Intervention, Comparison and Outcome. Results : For the level of evidence, Grade IV and V were most frequent. In terms of methodological quality, majority of the studies showed 'Fair' level. The subjects were the children with hemiplegia, and Single-subjects designs and case studies were frequent experimental design. Constraint-induced movement therapy (CIMT) was most frequently conducted among the intervention studies, and Jebsen-Taylor Hand Function Test was most frequently used evaluation tool. Eleven studies showed that the upper limb functions were significantly improved or were positively effective. Conclusion : Various intervention methods have been implemented to improve the upper limb functions of children with cerebral palsy. In the future, studies on intervention methods based on the type of paralysis and studies with high quality of evidence should be conducted in Korea.

• Management & Information Systems Review
• /
• v.37 no.4
• /
• pp.41-62
• /
• 2018

As the volume of unstructured data increases through various social media, Internet news articles, and blogs, the importance of text analysis and the studies are increasing. Since text analysis is mostly performed on a specific domain or topic, the importance of constructing and applying a domain-specific dictionary has been increased. The quality of dictionary has a direct impact on the results of the unstructured data analysis and it is much more important since it present a perspective of analysis. In the literature, most studies on text analysis has emphasized the importance of dictionaries to acquire clean and high quality results. However, unfortunately, a rigorous verification of the effects of dictionaries has not been studied, even if it is already known as the most essential factor of text analysis. In this paper, we generate three dictionaries in various ways from 39,800 news articles and analyze and verify the effect each dictionary on the accuracy of document classification by defining the concept of Intrinsic Rate. 1) A batch construction method which is building a dictionary based on the frequency of terms in the entire documents 2) A method of extracting the terms by category and integrating the terms 3) A method of extracting the features according to each category and integrating them. We compared accuracy of three artificial neural network-based document classifiers to evaluate the quality of dictionaries. As a result of the experiment, the accuracy tend to increase when the "Intrinsic Rate" is high and we found the possibility to improve accuracy of document classification by increasing the intrinsic rate of the dictionary.

• KIPS Transactions on Computer and Communication Systems
• /
• v.11 no.10
• /
• pp.373-380
• /
• 2022

This paper presents a deep learning based group synchronization that supports networked immersive interactions between remote users. The goal of group synchronization is to enable all participants to synchronously interact with others for increasing user presence Most previous methods focus on NTP-based clock synchronization to enhance time accuracy. Moving average filters are used to control media playout time on the synchronization server. As an example, the exponentially weighted moving average(EWMA) would be able to track and estimate accurate playout time if the changes in input data are not significant. However it needs more time to be stable for any given change over time due to codec and system loads or fluctuations in network status. To tackle this problem, this work proposes the Deep Group Synchronization(DeepGroupSync), a group synchronization based on deep learning that models important features from the data. This model consists of two Gated Recurrent Unit(GRU) layers and one fully-connected layer, which predicts an optimal playout time by utilizing the sequential playout delays. The experiments are conducted with an existing method that uses the EWMA and the proposed method that uses the DeepGroupSync. The results show that the proposed method are more robust against unpredictable or rapid network condition changes than the existing method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.5
• /
• pp.171-179
• /
• 2021

This study was a meta-analysis of previous studies that subjected stroke patients to the whole-body vibration exercise, in an attempt to evaluate the effectiveness of such exercise in improving their balance and walking ability. The electronic databases used for literature search were the National Assembly Library, Korean Educational Academic Information (RISS), Korean Academic Information (KISS), and Nuri Media (DBPIA). We also investigated a prior study of the whole-body vibration exercise applied to stroke patients from January 2010 to August 2020. In assessing the quality of the study, the RCT (randomized controls trials) study used the risk of bias 2 (RoB2) tool developed by the Cochrane group. Meta-analysis was performed using R software for statistical computing version 4.0.3. The results of the study confirmed that the overall effect size was 0.40, and the whole-body vibration exercise used had a moderate effect on the balance and gait of stroke patients, the effect size of balance was 0.44, and the effect size of gait was 0.36, showing a positive effect. These results indicated that the whole-body vibration exercise is an effective intervention for stroke patients, and further research is needed.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.9
• /
• pp.177-188
• /
• 2023

The purpose of this study is to develop and validate a scale for measuring digital literacy by identifying the factors consisting of digital literacy and extracting items for each factor. Preliminary items for the Delphi study were developed through the analysis of previous literature and the deliberation of the research team. As a result of two rounds of the expert Delphi study, 65 items were selected for the main survey. The validation of the items was carried out in the process of exploratory and confirmatory factor analyses, reliability test, and criterion validity test using the data collected in the main survey. As a result, a 4-factor structure composed of 31 questions(factor 1: digital technology & data literacy- 9 questions, factor 2: digital content & media literacy- 8 questions, factor 3: digital communication & community literacy- 9 questions, factor 4: digital wellness literacy - 5 questions) was confirmed. Also, the goodness of fit indices of the model were found to be good and the result of reliability test revealed the scale had a very appropriate level of Cronbach's alpha(α=.956). In addition, a statistically significantly positive correlations(p<.001) were found between digital literacy and internet self-efficacy and between digital literacy and self-directed learning ability, which were predicted in the existing evidence, therefore the criterion validity of the developed scale was secured. Finally, practical and academic implications of the study are provided and future study and limitations of the study are discussed.