• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.145-165
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• 2023

Recommendation system plays a significant role on relieving difficulties of selecting information among rapidly increasing amount of information caused by the development of the Internet and on efficiently displaying information that fits individual personal interest. In particular, without the help of recommendation system, E-commerce and OTT companies cannot overcome the long-tail phenomenon, a phenomenon in which only popular products are consumed, as the number of products and contents are rapidly increasing. Therefore, the research on recommendation systems is being actively conducted to overcome the phenomenon and to provide information or contents that are aligned with users' individual interests, in order to induce customers to consume various products or contents. Usually, collaborative filtering which utilizes users' historical behavioral data shows better performance than contents-based filtering which utilizes users' preferred contents. However, collaborative filtering can suffer from cold-start problem which occurs when there is lack of users' historical behavioral data. In this paper, hybrid music recommendation system, which can solve cold-start problem, is proposed based on the playlist data of Melon music streaming service that is given by Kakao Arena for music playlist continuation competition. The goal of this research is to use music tracks, that are included in the playlists, and metadata of music tracks and playlists in order to predict other music tracks when the half or whole of the tracks are masked. Therefore, two different recommendation procedures were conducted depending on the two different situations. When music tracks are included in the playlist, LightFM is used in order to utilize the music track list of the playlists and metadata of each music tracks. Then, the result of Item2Vec model, which uses vector embeddings of music tracks, tags and titles for recommendation, is combined with the result of LightFM model to create final recommendation list. When there are no music tracks available in the playlists but only playlists' tags and titles are available, recommendation was made by finding similar playlists based on playlists vectors which was made by the aggregation of FastText pre-trained embedding vectors of tags and titles of each playlists. As a result, not only cold-start problem can be resolved, but also achieved better performance than ALS, BPR and Item2Vec by using the metadata of both music tracks and playlists. In addition, it was found that the LightFM model, which uses only artist information as an item feature, shows the best performance compared to other LightFM models which use other item features of music tracks.

• Information Systems Review
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• v.21 no.4
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• pp.99-123
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• 2019

The software industry is a high value-added industry in the knowledge information age, and its importance is growing as it not only plays a key role in knowledge creation and utilization, but also secures global competitiveness. Among various SW available in today's business environment, Open Source Software(OSS) is rapidly expanding its activity area by not only leading software development, but also integrating with new information technology. Therefore, the purpose of this research is to empirically examine and analyze the effect of factors on the switching behavior to OSS. To accomplish the study's purpose, we suggest the research model based on "Push-Pull-Mooring" framework. This study empirically examines the two categories of antecedents for switching behavior toward OSS. The survey was conducted to employees at various firms that already switched OSS. A total of 268 responses were collected and analyzed by using the structural equational modeling. The results of this study are as follows; first, continuous maintenance cost, vender dependency, functional indifference, and SW resource inefficiency are significantly related to switch to OSS. Second, network-oriented support, testability and strategic flexibility are significantly related to switch to OSS. Finally, the results show that willingness to secures SW competitiveness has a moderating effect on the relationships between push factors and pull factor with exception of improved knowledge, and switch to OSS. The results of this study will contribute to fields related to OSS both theoretically and practically.

• Journal of Internet Computing and Services
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• v.16 no.6
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• pp.11-21
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• 2015

As growing interest in Human-Computer Interaction(HCI), research on HCI has been actively conducted. Also with that, research on Natural User Interface/Natural User eXperience(NUI/NUX) that uses user's gesture and voice has been actively conducted. In case of NUI/NUX, it needs recognition algorithm such as gesture recognition or voice recognition. However these recognition algorithms have weakness because their implementation is complex and a lot of time are needed in training because they have to go through steps including preprocessing, normalization, feature extraction. Recently, Kinect is launched by Microsoft as NUI/NUX development tool which attracts people's attention, and studies using Kinect has been conducted. The authors of this paper implemented hand-mouse interface with outstanding intuitiveness using the physical features of a user in a previous study. However, there are weaknesses such as unnatural movement of mouse and low accuracy of mouse functions. In this study, we designed and implemented a hand mouse interface which introduce a new concept called 'Virtual monitor' extracting user's physical features through Kinect in real-time. Virtual monitor means virtual space that can be controlled by hand mouse. It is possible that the coordinate on virtual monitor is accurately mapped onto the coordinate on real monitor. Hand-mouse interface based on virtual monitor concept maintains outstanding intuitiveness that is strength of the previous study and enhance accuracy of mouse functions. Further, we increased accuracy of the interface by recognizing user's unnecessary actions using his concentration indicator from his encephalogram(EEG) data. In order to evaluate intuitiveness and accuracy of the interface, we experimented it for 50 people from 10s to 50s. As the result of intuitiveness experiment, 84% of subjects learned how to use it within 1 minute. Also, as the result of accuracy experiment, accuracy of mouse functions (drag(80.4%), click(80%), double-click(76.7%)) is shown. The intuitiveness and accuracy of the proposed hand-mouse interface is checked through experiment, this is expected to be a good example of the interface for controlling the system by hand in the future.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.101-117
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• 2013

As the number of online game user has been rapidly increased thanks to the recent vitalization of online contents market, not only new business opportunity but also the opportunity to create high profits have been provided as well. However, the increase of the number of online game user and the rapid expansion of the market evoke a cutthroat completion among online game service providers, and also high barriers to entry to online game market have been erected. Thus, what kinds of efforts need for the business success and sales increase in online game market? In lots of researches regarding online contents business, the deepening of loyalty was considered as a critical factor for the business success. According to the study on user's behavior in online environment, users would experience the Flow while using online service, and then, if they were in state of the Flow, they would use the service constantly. High customer loyalty to online game means high will to use the online game too. The purpose of this research was i) to examine what factors enable users to be naturally immersed in online game while playing it, ii) to examine what properties of online game can make game more interesting and exciting, iii) to verify that such factors are critical in deepening customer loyalty, and iv) to suggest some essential factors to be fun and exciting games, on where the focus should be put, and the directionality for the development for sales expansion of online game developer or online game service provider. The research results are as below: First, the involvement and the perceived quality which were characteristics of brand appeared to be factors most affecting Flow. This shows that once game user get interested in online game that user has played frequently, even though new games are released, user will continuously flow the game not moving to new games, and also shows that users not only get more interested but also put more trust in games in the site to where users are frequently going than games in other sites, and consequently user can increasingly flow the game. Second, the compensation and graphics which are the characteristics of contents appeared to be factors affecting Flow. Proper compensation which is given to game users triggers fun and interests in game and makes them flow more and more. And graphics make users to feel game space as if real space and let them flow in game with more reality. Third, challenges, support, and the stability which are technical characteristics appeared to be factors affecting Flow. Challenges enable users to not only experience new virtual world but also solve various difficulties and obstacles. Once users feel fun and interests through this challenge, they can naturally flow games. In addition, the stability of network provides reliability in security and hacking. By doing so, it can induce users to flow more and more. Lastly, when aforementioned characteristics including contents characteristics, technical characteristics, and brand characteristics are organically combined each other, game users feel fun and total minutes are naturally increased, so that game users experience Flow, and consequently the customer loyalty will be deepened as well.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.91-102
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• 2014

The purpose of this research is to perform the consumer typological study of integrated emerging digital advertisement, where IT and advertisement industry were fused, and to propose the theoretical definition about consumer characteristic which is in need for collection of related market subdivision strategy in perspective of business marketing. For this, the Q methodology, the 'subjectivity' research of qualitative perspective, which discovers new theory by interpreting subjective system of thinking, preference, opinion, and recognition of inner side of respondents, was applied and analyzed. Compared to previous quantitative research that pursues hypothesis verification, this Q methodology is not dependent on operational definition proposed by researcher but pursues for analytic study completely reflecting objective testimony of respondents. For this reason, Q study analyzes in-depth the actual consumer type, which can be found at the initial market formation stage of new service, therefore this study is applicable for theorizing the consumer character as a mean of advanced research. This study extracted thirty 'IT integrated digital advertisement type (Q sample)' from thorough literature research and interviews, and eventually discovered a total four consumer types from analyzing each Q sorting research data of 40 respondents (P sample). Moreover, by interpreting subdivided intrinsic characteristic of each group, the four types were named as 'multi-channel digital advertisement pursuit type', 'emotional advertisement pursuit type', 'new media advertisement pursuit type', and Web 2.0 advertisement pursuit type'. The analysis result of this study is being expected for its value of usage as advanced research of academic and industrial research with the emerging digital advertisement industry as a subject, and as basic research in the field of R&D, Marketing program and the field of designing the advertisement creative strategy and related policy.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.934-947
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• 2011

The purpose of this study is to analyze products for good taste and convenience, which become an engine to constantly create customers. In addition, this study is aimed at investigating the relationship between the selective attributes of Home Meal Replacement, the perceived utilitarian value, and the repurchase intention, and drawing new suggestions on the Home Meal Replacement market from a new marketing perspective. Based on a total of 215 samples, this study reviewed the reliability and fitness of the research model and verified a total of 5 hypothesized using the Amos program. The result of study modeling was GFI=0.905, AGFI=0.849, NFI=0.889, CFI=0.945, and RMR=0.0.092 at the level of $x^2$=230.22 (df=126, p<0.001). First, the food quality (${\beta}$=0.221), convenience (${\beta}$=0.334), packing (${\beta}$=0.278), and employee service (${\beta}$=0.204) of home meal replacement consideration attributes had a positive (+) influence on perceived utilitarian value. Second, perceived utilitarian value (${\beta}$=0.584) had a positive (+) influence on repurchase intention. The factors to differentiate one company from other competitors in terms of the utilitarian value are the quality of food, convenience, wrapping, and services by employees. This study has illustrated the need to focus on the development of a premium menu to compete with other companies and to continue to research and develop nutritious foods that are easy to cook. Moreover, the key factors to have a distinct and constant competitive edge over other companies are the alleviation of consumer anxiety over wrapping container materials, the development of more designs, and the accumulation of service know-how. Therefore, it is necessary for a company to strongly develop the key factors based on its resources as a core capability.

• Journal of Nutrition and Health
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• v.45 no.6
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• pp.541-551
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• 2012

In our previous work, we reported consumers' perceptions of body shape and weight control. In an ongoing effort, we analyzed the purchasing behavior, intake patterns, future purchasing decisions, and degree of satisfaction in individuals consuming dietary formula for weight control (DF) or heath/functional foods (HFFs) by using the same survey questions. Portfolio analysis for marketing strategy was also investigated. Subjects were divided into two groups according to consumption of DF or HFF during the previous year : DF group (n = 89) and HFF group (n = 110). Average intake frequency was $1.7{\pm}0.7$ per day for HFFs and $1.5{\pm}0.9$ per day for the DF, and the most prevalent form was pill (58.2%) for HFFs and bar (42.7%) for DF. Duration of intake was $3.1{\pm}2.3$ months for HFFs versus $3.9{\pm}3.5$ months for DF. The average degree of satisfaction was $3.6{\pm}0.6$ on a 5-point scale, meaning 'relatively satisfied'. For the weight control method to be used in the future, 44.5% of the HFF group selected 'HFFs' while 47.2% of the DF group selected 'DF', showing a tendency to use the current product type in the future. The average planned period for the intake was $3.8{\pm}3.7$ months for HFFs and $3.0{\pm}2.4$ months for DF (p < 0.05). The HFF group emphasized efficacy, functional ingredients of the products, reliable products, and higher satisfaction, whereas the DF group emphasized the added materials in addition to weight control effects.

• Journal of Nutrition and Health
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• v.40 no.5
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• pp.475-482
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• 2007

This study was done to analyze nutrition counseling services in health promotion center and to investigate demands of subjects for nutrition services. Data was collected through the survey of 90 subjects. The results were as follows. The results of people receiving nutrition services showed that 58.5% of the counseling group and 46.4% of the non-counseling group answered having experience with nutrition services. And 50% of them received nutrition counseling through individual counseling. Diet therapy with health check-up results also appeared the highest in contents of nutrition counseling. As a source of nutrition information and health knowledge, subjects relied heavily or most on the TV, internet, books, magazines, and newspapers. On the other hand, they relied much less on advice from dietitians, nutritionists, medical doctors and nurses. The experience of receiving nutrition services and thinking about nutrition education related positively. It showed that the counseling group (95.1%) was significantly higher than the non-counseling group (80.5%) in necessity of nutrition assessment. But, necessity of nutrition counseling wasn't significantly different between the two groups. The method of nutrition counseling subjects preferred was individual consultation. The subjects answered to having need of analysis and evaluation of nutrient intake and calorie prescription in nutrition assessment and individual nutritional status results explanation in nutrition counseling. In conclusion all people visiting health promotion centers need nutrition service of some kind.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.439-443
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• 2002

The purpose of this study was to analyze the parental consultation. Also, it was to investigate the tendency divided into different subjects. The subjects were 2142 questions on korean academy of pediatric dentistry homepage. The questions were categorized into 7 subjects, 37 subdivided subjects and children age. The results were as follows: 1. Age group was divided into $0{\sim}6months$, $7{\sim}12months$, $13{\sim}24months$, $25{\sim}36months$, $3{\sim}6years$, $7{\sim}12years$ 12years and over 13 years. $13{\sim}24months$ and $3{\sim}6years$ age group had the largest number of questions. 2. The subject were growth & development, development disturbance & oral disease, behavior management, operative & endodontic treatment, dentition & occlusal guidance, traumatic injury & surgery and etc. Development disturbance & oral disease had the largest number of questions. 3. In subdivided subjects, operative & endodontic treatment showed the most, followed by development & eruption of teeth, traumatic injury, cross-bite, tooth brushing methods in sequence. 4. In age group within subdivided subjects, the most frequent question was neonatal & natal tooth in $0{\sim}6months$, development & eruption of teeth in $7{\sim}12months$, $13{\sim}24months$, operative & endodontic treatment in $25{\sim}36months$, $3{\sim}6years$, time & method of orthodontics in $7{\sim}12years$ and operative & endodontic treatment in over 13years. 5. The questions about cross-bite, traumatic injury and soft tissue disease were distributed evenly in age group.

• Journal of Korean Home Economics Education Association
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• v.28 no.3
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• pp.47-63
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• 2016

The purpose of this study is to suggest the basic information for diverse and balanced research and development in this field with understanding research trends related to safety education in home economics. In order to so, this study makes population and sampling by targeting cases which refer to 'safety' on 15 papers of academic journals related to home economics registered in the National Research Foundation from 2001 to 2015, 244 papers related to safety education area and 179 master doctorate thesis by searching keyword as 'safety'. Analysis contents are research trends of papers related to safety education by year and by subject and research trends of safety education by area and by research method. As a result of the study, first, the number of research papers related to safety education by year on home economics curriculum repeated increase and decrease and there have been consistent studies conducted on safety education with 14-52 papers per every year and yearly average 28.2 papers. On the other hand, the most number of studies conducted in 2015 with 52 papers which are twice as much of 26 papers in 2014. This seems to be affected by the announcement of safety comprehensive countermeasures from government and the emphasis of safety subject on 2015 curriculum revision of the Ministry of Education. Second, with regards to research trends by topic, 137 papers are related to safety education (29%), 336 papers are related to safety actual condition (71%). Accidents and recognition had a greater percentage in a paper before 2009 (74.4%) and studies are increased after 2009 (from 21 papers to 53 papers) in terms of development or evaluation of safety education program, development of education materials, development of education method etc. Subject area dealt with the most on the research of safety actual condition is regarding safety accidents or effective variables (23.2%). Subject regarding the variables are researches related to factors influencing family violence, internet addiction, spouse violence, willingness to purchase unsafe food, age harassment, or suicidal attempt etc. Next, researches related to safety recognition (13.9%), safety knowledge and attitude (7.4%), safety behaviors (6.3%), safety consciousness (2.3%) show in sequence. Subject area dealt with the most on the researches regarding safety education is development and evaluation of safety education program (11%) and this appears the most in 2015 by year (21.5%). Third, with regards to eight areas of safety education, there are 143 papers regarding public safety (33.8%), 106 papers regarding violence and personal safety (25.1%), 93 papers regarding general subject on safety or whole safety area (22%) and 58 papers regarding drug and internet addiction (13.7%) in sequence. And there is no paper related to first aid and 1 paper is related to occupational safety (0.2%). Occupational safety area is less researched nevertheless its included in home economic curriculum as relative chapter. First aid does not directly correlate with home economics curriculum but should be studied in preparation for accident which could happen in practical class. Forth, with regards to research trends by research method, quantitative research (89.1%) is mostly used and both research study (70.4%) and experimental research (18.7%) are used the most frequently. In particular, researches on the actual condition of safety education and experimental studies for effectiveness verification take most of research method. As qualitative studies, there are phenomenological study (3.1%) and case study (3.1%) related to actual conditions of safety accidents. 10 papers (2.4%) are mixture of quantitative and qualitative research and some research conducted research study and experimental research at the same time (0.9%). With regards to subject of study, human environments (87.5%) are more than physical environments (12.5) and students (48.4%) are more than teachers and school parents (20.6%). As the subject of physical environments, school (6.5%) is the most but home environment is none. As a result of the study, research for the development of evaluation tool for evaluating safety education, occupational safety and lifelong education should be conducted from this time forward. In addition, the object of study shall be expanded to both human environments in terms of entire life and physical environments for home. An in-depth qualitative research should be needed by observing and meeting with each student.