• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.75-82
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• 2023

In collaborative filtering systems, the item rating prediction values calculated by the systems are very important for customer satisfaction with the recommendation list. In the time-aware system, predictions are calculated by reflecting the rating time of users, and in general, exponentially lower weights are assigned to past rating values. In this study, to find out whether the influence of rating time on the rating value varies according to various factors, the correlation between user rating value and rating time is investigated by the degree of user rating activity, the popularity of items, and item genres. As a result, using two types of public datasets, especially in the sparse dataset, significantly different correlation index values were obtained for each factor. Therefore, it is confirmed that the influence weight of the rating time on the rating prediction value should be set differently in consideration of the above-mentioned various factors as well as the density of the dataset.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.131-141
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• 2023

Changes in consumer needs and behaviors according to lifestyle changes lead to consumption culture, affecting the automobile market. However, research and research to provide options tailored to the lifestyle of consumers in related markets are still insufficient. Focusing on pickup truck accessories applied to pickup trucks that reflect lifestyle the most among vehicle types, this study first examined the theoretical background of the aftermarket market and lifestyle of pickup trucks. Second, through image mapping, the market possibilities and opportunity factors of pickup trucks were discovered through market size analysis and possibilities, and through this, user types could be classified. Third, interviews were conducted with those representing user types, the contents were organized, and interviews were conducted centering on related groups to create a persona of a user group, and what needs each group's persona wanted. Finally, a design concept suitable for the issue keywords and insights derived for each user lifestyle type was presented. In this study, the user type was divided into ① outdoor activity type, ② hobby activity type, and ③ small-scale work type, and a design case study was conducted by applying the concept suitable for the keyword for each group. For the outdoor activity type, a variable storage structure and a living space-type accessory design were presented, and for the hobby type, a modular decktop design and a sports coupe-type hardtop design were presented. For the small business type, a partition that is easy to fix the load and a stepper design that is easy to board the cargo box were presented. It is expected that the size of the pickup truck aftermarket will be expanded by diversifying the option designs that users want by lifestyle by applying them to the development of pickup truck accessories that fit the lifestyle of pickup truck users in the automobile market, which is currently mass customized.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.5
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• pp.68-80
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• 2016

This study analyzed the influence of the perception of physical environment on user satisfaction and park use when people use the park to improve their health. The study is focused on neighborhood parks in Suseong-gu, Daegu city. Statistical analyses were employed to data collected from 143 visitors on site. First of all, in the perception evaluation of the physical environment of the park, accessibility and pedestrian environment are the highest at 4.04, while water space and attractions in the park as the lowest parts are at 2.32 and 2.66. After conduct factor analysis to type 22 physical environmental awareness components, five main factors--Comfort, Availability, Amenity, Facilities convenience and Visuality--were classified. Then, satisfaction and influence on park use were analyzed. As a result, the factors affecting user satisfaction were comfort, availability, amenity and facility convenience. Among them, the category of amenity was the most influential factor at 0.315. The factors affecting the park use were availability and amenity. Availability factor had a higher influence at 0.396 than amenity at 0.293. Therefore, in order to improve satisfaction and park use for health improvement, it is necessary to secure sufficient green areas and create a pleasant environment. Also, it is necessary to improve the quality of walkability from homes to parks, trail improvement and other improvements.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.43-47
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• 2018

Traditional electroencephalography (EEG)-based authentication systems generally use external stimuli that require user attention and relatively long time for authentication. The aim of this study is to investigate the feasibility of biometric authentication based on EEG without using any external stimuli. Seventeen subjects took part in the experiment and their EEGs were measured while repetitively closing and opening their eyes. For identifying each subject, we calculated inter- and intra-subject cross-correlation using changes in alpha activity (8-13 Hz) during eyes closed as compared to eyes open. In order to optimize the number of recording electrodes, we calculated authentication accuracy by progressively reducing the number of electrodes used in the analysis. Significant increase in alpha activity was observed for all subjects during eyes closed, focusing on occipital areas, and spatial patterns of changed alpha activity were considerably different between the subjects. A mean authentication accuracy of 92.45% was obtained, which was retained over 75% when using only 8 electrodes placed around occipital areas. Our results could demonstrate the feasibility of the proposed novel authentication method based on resting state EEGs.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.136-137
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• 2009

Japanese waterfront project consisted actively from an early stage in 1980's, and the project which activated an area in a destination in a various part of Japan was implemented. For a study to however conscious whether the user in water front be of the waterside space in such waterfront project paper its number is very small. A questionnaire survey was put into effect targeted for 17 points of Japanese typical waterfront project paper completed in about 1990 by this research. With the foundation of this, a member item mean, it was possible to classify development paper of 17 results factor analysis is by 4 kind type of the aquarium type, the natural type, the middle type and the artificial type. And it was possible to classify the motive item conscious of the waterside space by 7 kinds, a view, smell, hearing, sense of touch, the taste, existence of facilities and activity behavior. When seeing the motive item in the center, sight was highest by 57% and about 8%, sense of touch, hearing and olfactory three senses had the lowest taste by 1%. "With aquarium" existence of facilities including etc was about 12 %, and activity behavior including Hitoshi who" can clear a quay" was about 6 %, and it appeared.

• Korean Journal of Remote Sensing
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• v.23 no.5
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• pp.473-481
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• 2007

Joint Forest Management(JFM) is a concept of developing partnerships between fringe forest user groups and the Forest Department(FD) on the basis of mutual trust and jointly defined roles and responsibilities with regard to forest protection and development. In India, JFM was started during 1992 and it was implemented in many states. However success rate of JFM activity was not promising. Though there are many factors attributed to the failures, one of the main factors is the JFM site. This paper deals with the significant ground works to be done before planning for JFM using recent technologies such as remote sensing(RS) and Geographic Information System(GIS). Also it deals with the advantages of weighted overlay analysis in selecting suitable sites for JFM taking into consideration the various criteria. As a result of weighted overlay analysis, there were four types of suitability classes viz., less, moderate, highly and un-suitable. The moderately suitable class occupied maximum area(13209.64 ha) than less and highly suitable classes. If JFM is implemented on the suitability area, then the failure could be avoided in the future.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.299-303
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• 2015

Flexible space is an adaptable space that has been increasingly used in many office and academic buildings as it increases the use of the space available and reduces the unnecessary building area. However, the architectural, engineering and construction (AEC) industry lacks a formalized method that helps architects predict and update the space utilization of flexible space during the project development, as such prediction aims to maximize the use of the building space available without exceeding the target utilization policy. Consequently, current manual utilization prediction results in lower accuracy level and limits the maximized use of the flexible space, which has multiple space-use types that affect the prediction of utilization. To address this problem, we identified eight space-use type differentiators (SUTDs) based on the literature review and observations and discussed the use of them in automated space-use analysis (SUA), which can predict the utilization of flexible space via a computer program. This research builds on SUA and contributes to flexible space planning by providing a means of a more comprehensive and accurate SUA.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.281-292
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• 2017

Objective: This study aims to identify important physical design variables in designing a necklace type wearable device, and to present design guidelines to maximize comfort that a user feels upon wearing the device. Background: Interests in fitness culture and personal health are on the rise recently. In such a situation, demand for necklace type wearable devices is projected to increase a lot, as the devices enable users to use their hands freely and to enjoy various contents through connection with mobile devices. However, the necklace type wearable device's comfort was assessed to have the lowest comfort in a running situation, where human body moves up and down and left and right more than other devices wearable on other human body parts. Therefore, the usability of a necklace type wearable device was low. In this regard, studies on identification of the variables affecting user comfort upon wearing a necklace type wearable device and on physical design direction maximizing comfort and usability are needed. Method: A pretest and a main test were carried out to draw the direction of necklace type wearable device design. In the pretest, wearing evaluation on the diverse types of devices released in the market was conducted to draw physical design variables of the devices affecting comfort. Furthermore, variables significantly affecting the comfort of a device were selected through an analysis of variance (ANOVA). In the main test, anthropometry was performed, and information on anthropometric items corresponding to the design variables selected in the pretest was acquired. Based on the pretest results and the anthropometric information in the main test, the present study produced design guidelines maximizing the comfort of a necklace type wearable device with regard to major design variables upon dynamic tasks. Results: According to the pretest results, the variables having effects on comfort were the angle of side points, width, and height. Due to interactions between variables, those need to be simultaneously considered upon designing a device. Upon dynamic tasks, the angle of side points and width of a device was designed to be smaller than mean angle of the trapezius muscle and neck width, and thus attachment to human body was high. As height was designed to be larger than mean neck front and rear point width, comfort was higher due to feeling of stability. Conclusion: Because user sensitivity to comfort was high at human body's inflection points, a device needs to be designed for users not to feel high pressure on specific body parts with the device fitting human body shape well. A design considering user's situation is also required in further studies.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.550-566
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• 2017

Recent advances in wearable devices and quantified-self movement increase the number of personal informatics application that may cause an concern to health industry and user. In this light, the goal of this study is to identify more effective ways of design and evaluation of personal informatics application for self-tracking and delivering health information to users. For this goal, this study conducted areal-world study that processes such that user can assess, be aware of, and self-reflect on their data and behavior activity. In doing so, this study aims to determine the psychological effects of forms of health feedback (comparative vs. non-comparative) and presentation modes (text vs. image) on users' tendencies toward health conservation. Results from a between-subjects experiment revealed that health information in a comparative and textual format was more effective in encouraging health conservation in participants than identical information presented in a non-comparative and image format. In addition, participants' level of health consciousness emerged as a significant predictor. Through this analysis of quantitative data and inferences, this study make a number of contributions to the user affordance research and its methodology of health informatics study and designing personal informatics application that support user's behavior change in various contexts.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.25 no.1
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• pp.239-264
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• 2014

The study aims to study the user perception and satisfaction on the current church library services in Korea. 100 registered attendees and 10 priests, from three different groups were randomly selected for the survey. Three groups - the one with its own library, another with a community type library, and the other without church library - were compared. A literature review and survey were executed, and the questionnaires of the survey for analysis in this research contained demographic information, usage of church library, mission and function of the church library, library space, librarians, collection, community services of the church library, and perception on the effect of the library's community service on a specific religious activity (evangelism). The analysis revealed that the satisfaction level on church library service was relatively high (3.5 point on average, 5-point Likert scale), even though the frequency of using the church library service was relatively low. The study also found that users perceived the library as a community library or archives of the church, and study rooms and reading rooms as its major functions. It reveals that religious materials were preferred as the church library collection and the service of the church library to its community was perceived as being a effective and positive factor on evangelism. Applying church library service should be considered in order to enhance the understanding on the religion and effective results of evangelism.