• Journal of Intelligence and Information Systems
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• v.21 no.4
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• pp.93-110
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• 2015

The recommender system is a system which recommends products to the customers who are likely to be interested in. Based on automated information filtering technology, various recommender systems have been developed. Collaborative filtering (CF), one of the most successful recommendation algorithms, has been applied in a number of different domains such as recommending Web pages, books, movies, music and products. But, it has been known that CF has a critical shortcoming. CF finds neighbors whose preferences are like those of the target customer and recommends products those customers have most liked. Thus, CF works properly only when there's a sufficient number of ratings on common product from customers. When there's a shortage of customer ratings, CF makes the formation of a neighborhood inaccurate, thereby resulting in poor recommendations. To improve the performance of CF based recommender systems, most of the related studies have been focused on the development of novel algorithms under the assumption of using a single profile, which is created from user's rating information for items, purchase transactions, or Web access logs. With the advent of big data, companies got to collect more data and to use a variety of information with big size. So, many companies recognize it very importantly to utilize big data because it makes companies to improve their competitiveness and to create new value. In particular, on the rise is the issue of utilizing personal big data in the recommender system. It is why personal big data facilitate more accurate identification of the preferences or behaviors of users. The proposed recommendation methodology is as follows: First, multimodal user profiles are created from personal big data in order to grasp the preferences and behavior of users from various viewpoints. We derive five user profiles based on the personal information such as rating, site preference, demographic, Internet usage, and topic in text. Next, the similarity between users is calculated based on the profiles and then neighbors of users are found from the results. One of three ensemble approaches is applied to calculate the similarity. Each ensemble approach uses the similarity of combined profile, the average similarity of each profile, and the weighted average similarity of each profile, respectively. Finally, the products that people among the neighborhood prefer most to are recommended to the target users. For the experiments, we used the demographic data and a very large volume of Web log transaction for 5,000 panel users of a company that is specialized to analyzing ranks of Web sites. R and SAS E-miner was used to implement the proposed recommender system and to conduct the topic analysis using the keyword search, respectively. To evaluate the recommendation performance, we used 60% of data for training and 40% of data for test. The 5-fold cross validation was also conducted to enhance the reliability of our experiments. A widely used combination metric called F1 metric that gives equal weight to both recall and precision was employed for our evaluation. As the results of evaluation, the proposed methodology achieved the significant improvement over the single profile based CF algorithm. In particular, the ensemble approach using weighted average similarity shows the highest performance. That is, the rate of improvement in F1 is 16.9 percent for the ensemble approach using weighted average similarity and 8.1 percent for the ensemble approach using average similarity of each profile. From these results, we conclude that the multimodal profile ensemble approach is a viable solution to the problems encountered when there's a shortage of customer ratings. This study has significance in suggesting what kind of information could we use to create profile in the environment of big data and how could we combine and utilize them effectively. However, our methodology should be further studied to consider for its real-world application. We need to compare the differences in recommendation accuracy by applying the proposed method to different recommendation algorithms and then to identify which combination of them would show the best performance.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.143-150
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• 2019

Playing musical instruments has long been a hobby enjoyed by many, whether amateur or professional. However, a lot of long and arduous practice is required if one wants to acquire the skills of musical artist and truly enjoy the pleasure of playing. This repetitive and tedious practice is often a hindrance to the process of learning a musical instrument, and numerous educators have put a lot of research and effort into making the process easier and more fun for students. In addition, various media practice tools are being developed to keep the students engaged and having fun. The core elements of this content primarily include controlling the speed of backing tracks in accordance with the skill level of students and providing a backing ensemble that enables them to enjoy the fun of playing. This paper studies and compares various MIDI playback techniques capable of controlling speed and pitch in smartphone applications. Modern applications of these techniques are seen in music educational contents, as well as entertainment contents. It also discusses the development and launching of Upbeat, a drum-loop metronome that automatically increases speed by applying different techniques to its respective smartphone operating systems, Android OS and iOS.

• (The) Research of the performance art and culture
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• no.39
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• pp.701-748
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• 2019

Gwanak-yeongsanhoesang, called as Samhyeon-yeongsanhoesang or Pyojeongmanbangjigok, is played by the musical instrumental organization, Samhyeonyukgak or by a large scale wind ensemble added Sogeum and Ajaeng. This study aims to analyze the structure and form of Piri melody which plays major melody of Sangnyeongsan in Gwanak-yeongsanhoesang, and to examine the relationship between Piri melody and Daegeum yeoneum grasping the structure and function of yeoneum. In Sangnyeongsan of Gwanak-yeongsanhoesang, the criterion for grouping the phrases of Piri melody is yeoneum. Especially, Daegeum yeoneum carries out the function of finishing the phrase of Piri playing the major melody by ornamenting or extending it, and presenting the motives or motive elements of the next phrase while Piri rests. The types of a, b, g, and i in the various shapes of the minimum melodic fragment of Piri are important motive elements that constitute a phrase of Piri melody. Especially, main motive a-type (仲→無) contrasts with b type (林→潢) which forms a strong tension by transposing 2 degrees upward. In addition, a-type gradually descends towards the end of music by changing to g-type (仲→林) or to i-type (太→林) which is 3 degrees below, which is related to the gradual descent cadence of Korean traditional music. A phrase of Piri melody of Sangnyeongsan in Gwanak-yeongsanhoesang consists of a combination of the types a, b, g, i, and cadence (x-type), and each phrase is structured in the repeating tension-relaxation. Looking at the structure of Piri phrases by similar types, each phrase has a logical variation structure through the methods such as omission and addition of notes, and crossing of melodies. The shape of the minimum melodic fragment of Daegeum yeoneum can be divided into a back-yeoneum of a~b types and a front-yeoneum of x1~x3. The x-types ornament Jungnyeo (仲), the cadence tone of Piri melody or are simply used as the extending back-yeoneum, and types a and b have the function of a front-yeoneum that prepares the beginning of the next phrase of Piri melody. The combination types of the minimum melodic fragment of Daegeum yeoneum appear mostly as the shape of back-yeoneum + front-yeoneum. In addition, the front-yeoneum of the type a and b appears independently without back-yeoneum, and the x3 type has a shape of the back-yeoneum without the front-yeoneum. Looking at the structure of Daegeum yeoneum by similar types, it can be seen that Daegeum yeoneum is also composed of a variation structure of omission and addition of notes like Piri melody.

• (The) Research of the performance art and culture
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• no.22
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• pp.287-325
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• 2011

This paper studies the time-space and appreciation of the performance culture of Gwanseo region, which is considered to have formed a characteristic culture in late Joseon period. For this purpose, 4 gasa written in hangeul (Korean alphabet), as well as 4 yeonhaeng gasa, 108 articles of Gwanseoakbu were examined. Plus, among the 9 types of yeonhaengrok (Documents of Performance culture) written in Chinese character, those parts which describe the performance traits have been analyzed. Then, 'main list of terminology' has been deduced based on the categorization according to the following points : 1) subjects of performance and appreciation 2) time and period of performance 3) space of performance 4) contents of performance 5) background and motive for performance and 6) method of performance. Through this process, various 'nouns' and 'predicate verbs' in relation to performance culture emerged, which were systemized according to types of performance elements and categories. Major terminology includes predicate verbs and symbolic verbs such as nokuihongsang,' 'baekdaehongjang,' 'jeolsaekgeumga,' 'cheonga,' 'hwaryu,' 'gamuja,' and 'tongsoja,' as well as the terms already known such as gisaeng, iwon, yangbang, akgong, and jeonak, which refer to musicians and dancers. Subjects of performance were divided into performers and listeners, categorized into concert, music, and dance, according to performance form. In the case for music, it was divided into instrumental or vocal, solo or accompanied (byeongju, self-accompaniment). In the case for vocal music, noteworthy was the inclusion of profesional artist's singing (called gwangdae or uchang). The record of 23 names of popular artists from Gwanseo region, with mention of special talents for each person, reflects the degree of activeness and artistic level of the province. Depending on the appreciating patrons, the audience were indicated as the terms including 'yugaek (party guest),' jwasang,' 'on jwaseok,' and 'sonnim (guests).' It seems that appraisal for a certain performance was very much affected by the tastes, views, and disposition of the appreciating patrons. Therefore it is interesting to observe different comparative reviews of concerts of different regions given by literary figures, offering various criticism on identical performance. In terms of performance space, it has been divided into natural or architectural space, doing justice to special performance sites such as a famous pavilion or an on-the-boat performance. Specific terms related to the scale and brightness of stage, as well as stage props and cast, based on descriptions of performance space were found. The performance space, including famous pavilions; Yeongwangjeong, Bubyeokru, Baeksangru, Wolparu, and Uigeomjeong, which are all well-known tourist sites of Gwanseo province, have been often visited by viceroys. governors, and envoys during a tour or trip. This, and the fact that full-scale performances were regularly held here, and that more than 15 different kinds of boats which were used for boat concert are mentioned, all confirm the general popularity of boat concerts at the time. Performance time, categorized by season or time of day (am/pm/night) and analyzed in terms of time of occurrence and duration, there were no special limitation as to when to have a performance. Most morning concerts were held as part of official duties for the envoys, after their meeting session, whereas evening concerts were more lengthy in duration, with a greater number of people in the audience. In the case of boat concert, samples include day-time concert and performances that began during the day and which lasted till later in the evening. Major terminology related to performance time and season includes descriptions of time of day (morning, evening, night) and mention of sunset, twilight, moonlight, stars, candles, and lamps. Such terms which reflect the flow of time contributed in making a concert more lively. Terminology for the contents of performance was mostly words like 'instrumental,' 'pungak,' or 'pungnyu.' Besides, contextual expressions gave hints as to whether there were dance, singing, ensemble, solo, and duets. Words for dance and singing used in Gwanseo province were almost identical to those used for gasa and jeongjae in the capital, Hanyang. However, many sentences reveal that performances of 'hangjangmu' of hongmunyeon, sword dance, and baettaragi were on a top-quality level. Moreover, chants in hanmun Chinese character and folk songs, which are characteristic for this region, show unique features of local musical performance. It is judged that understanding the purpose and background of a performance is important in grasping the foundation and continuity of local culture. Concerts were usually either related to official protocol for 'greeting,' 'sending-off,' 'reports,' and 'patrols' or for private enjoyment. The rituals for Gwanseo province characteristically features river crossing ceremony on the Daedong river, which has been closely documented by many. What is more, the Gwanseo region featured continued coming and goings of Pyeongan envoys and local officers, as well as ambassadors to and fro China, which required an organized and full-scale performance of music and dance. The method of performance varied from a large-scale, official ones, for which female entertainers and a great banquet in addition to musicians were required, to private gatherings that are more intimate. A performance may take the form of 'taking turns' or 'a competition,' reflecting the dynamic nature of the musical culture at the time. This study, which is deduction of terminology in relation to the time-space and appreciation culture of musical performances of Gwanseo region in late Joseon period, should be expanded in the future into research on 'the performance culture unique to Gwanseo region,' in relation to the financial and administrative aspects of the province, as well as everyday lifestyle. Furthermore, it could proceed to a more intensive research by a comparative study with related literary documents and pictorial data, which could serve as the foundation for understanding the use of space and stage, as well as the performance format characteristic to Korean traditional performing arts.