• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.7
• /
• pp.2972-2991
• /
• 2016

WLAN is the best choice in the place where complex network is hard to set up. Intelligent terminals are more and more assembled in some areas now. However, according to IEEE 802.11n/802.11ac, the access-point (AP) can only serve one user at a single frequency channel. The spectrum efficiency urgently needs to be improved. In theory, AP with multi-antenna can serve multiple users if these users do not interfere with each other. In this paper, we propose a user clustering scheme that could achieve multi-user selection through the mutual cooperation among users. We focus on two points, one is to achieve multi-user communication with multiple antennas technique at a single frequency channel, and the other one is to use a way of distributed users' collaboration to determine the multi-user selection for user clustering. Firstly, we use the CSMA/CA protocol to select the first user, and then we set this user as a source node using users' cooperation to search other proper users. With the help of the users' broadcast cooperation, we can search and select other appropriate user (while the number of access users is limited by the number of antennas in AP) to access AP with the first user simultaneously. In the network node searching, we propose a maximum degree energy routing searching algorithm, which uses the shortest time and traverses as many users as possible. We carried out the necessary analysis and simulation to prove the feasibility of the scheme. We hope this work may provide a new idea for the solution of the multiple access problem.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.6
• /
• pp.195-202
• /
• 2005

An adaptive segmentation algorithm is used to efficiently target decisions in local non-stationary images. Until now, several adaptive approaches have been proposed as a method of segmentation. However, they can't be directly used for radar target detection because a radar signal has different characteristics from general images. Generally, a histogram of radar signal shows that targets have a relatively small number of frequency functions compared to the background and distribution of background, which have several shapes as the environment changes. In this paper, we propose an adaptive segmentation algorithm using a histogram chord which is a right-down line from maximum pick of frequency function. The proposed method provides thresholds which are optimum for several radar environments because the used chord for threshold search is not significantly effected by interference conditions. Simulation results show that the proposed method is superior to the traditional algorithms, global threshold method and distribution median method, with respect to detection performance.

• Journal of dental hygiene science
• /
• v.19 no.3
• /
• pp.190-197
• /
• 2019

Background: The Internet has advantages in terms of accessibility and amount of information, and the search for health information over the Internet is increasing exponentially. The purpose of this study is to analyze the information generated about some dental treatment on the internet by year. Methods: Naver Knowledge (JisikIn in Korean) which is an interactive search service was selected as the first search site in Korea. Scaling, wisdom tooth extraction, and endodontic treatment that can be paid by Korean health insurance were selected. Finally, 4,729 questions about scaling, 23,963 wisdom teeth extraction questions and 17,733 endodontic treatment questions were extracted. The question contents, the information about the questioner and the answerer, and an error of answers were investigated. Frequency analysis was used and chi-square test was used if necessary. Results: The most frequently asked questions were discomfort and dissatisfaction after the treatment. The need for treatment was the second in questions of the wisdom tooth extraction and endodontic treatment, but the health insurance benefit was the second in dental scaling. Most of the questioners didn't disclose personal information. The public answered the most in 2013~2014, but the highest percentage of the respondents was experts in 2017. Responses were mostly personal experience, but showed a tendency to decrease with years, and professional knowledge showed an increasing tendency. The error of the answer has also gradually decreased. Conclusion: Questions about dental care over the Internet are increasing exponentially, experts are responding increasingly, and errors in answers are decreasing. Nevertheless, it is necessary to pay attention to the related expert group to prevent misinformation.

• Herbal Formula Science
• /
• v.31 no.1
• /
• pp.67-79
• /
• 2023

Objectives : The purpose of this study was to confirm the consumption trends of Korean medicine for health food consumption of consumers by using the Naver DataLab Shopping Insight service. Methods : In this study, the search data for the category of Korean herbal ingredients in the health food field of Naver Datalab shopping insight site was collected and sorted in order of frequency from August 1st, 2017 to June 22nd, 2022. The frequently searched keywords were organized based on the inclusion of Korean Pharmacopoeia (KP), Korean Herbal Pharmacopoeia (KHP), and Food Code. Results : 67,804 keywords were collected, and the most frequent keywords appearing for more than 200 days among the top 500 were 827 (1.184%). Among the frequent keywords, there were 149 keywords related to traditional medicine names included in the KP and KHP, and five prescriptions were included. 60 keywords were not included in the KP and KHP, and the keyword with the highest search frequency was "kujibbongnamu" (Maclura tricuspidata). Conclusions : The findings of this study provide information on the consumer's interest in traditional korean medicine (TKM) and natural products (NP), and can be used as a basis for understanding the demand for TKM and NP in the online shopping market.

• Journal of Korean Physical Therapy Science
• /
• v.29 no.4
• /
• pp.43-53
• /
• 2022

Background: It is suggested that the decline in functional level due to aging influences the increase in traffic accidents among elderly drivers. Among the functions related to the driving behavior of older drivers, physical function is related to muscle strength and motor control, and aging causes deterioration of motor control and a defect in motor output variability. Method: Data Search The online databases used for literature search are PubMed, ProQuest(PML), NDSL, and literature searches were conducted from April 19 to April 26, 2022. For the search, 'aging', 'driving', and 'braking' were used in the investigation. Results: The physical functions related to the braking ability of elderly drivers were analyzed in muscle strength, reaction ability, motor control, and other related factors. In terms of muscle strength, 3 studies analyzed the above factors. 8 studies analyzed the above factors for response ability. For motor control, two studies analyzed the above factors. In addition, related factors were analyzed in one piece. Conclusion: As a result of the analysis, physical function for reaction ability showed the highest frequency, followed by the strength item with the highest frequency. This study suggests that factors that can increase physical function must be included in the development of a rehabilitation program for the driving ability of the elderly.

• Journal of Information Technology and Architecture
• /
• v.11 no.1
• /
• pp.63-73
• /
• 2014

As the advance of WWW, unstructured data including texts are taking users' interests more and more. These unstructured data created by WWW users represent users' subjective opinions thus we can get very useful information such as users' personal tastes or perspectives from them if we analyze appropriately. In this paper, we provide various analysis efficiently for unstructured text documents by taking advantage of OLAP (On-Line Analytical Processing) multidimensional cube technology. OLAP cubes have been widely used for the multidimensional analysis for structured data such as simple alphabetic and numberic data but they didn't have used for unstructured data consisting of long texts. In order to provide multidimensional analysis for unstructured text data, however, Text Cube model has been proposed precently. It incorporates term frequency and inverted index as measurements to search and analyze text databases which play key roles in information retrieval. The primary goal of this paper is to apply this text cube model to a real data set from in an Internet site sharing hotel information and to provide multidimensional analysis for users' reviews on hotels written in texts. To achieve this goal, we first build text cubes for the hotel review data. By using the text cubes, we design and implement the system which provides multidimensional keyword search features to search and to analyze review texts on various dimensions. This system will be able to help users to get valuable guest-subjective summary information easily. Furthermore, this paper evaluats the proposed systems through various experiments and it reveals the effectiveness of the system.

• Language and Information
• /
• v.10 no.1
• /
• pp.21-46
• /
• 2006

This study proposes a Word Sense Disambiguation (WSD) algorithm, based on concept learning with special emphasis on statistically meaningful lowest frequency words. Previous works on WSD typically make use of frequency of collocation and its probability. Such probability based WSD approaches tend to ignore the lowest frequency words which could be meaningful in the context. In this paper, we show an algorithm to extract and make use of the meaningful lowest frequency words in WSD. Learning method is adopted from the Find-Specific algorithm of Mitchell (1997), according to which the search proceeds from the specific predefined hypothetical spaces to the general ones. In our model, this algorithm is used to find contexts with the most specific classifiers and then moves to the more general ones. We build up small seed data and apply those data to the relatively large test data. Following the algorithm in Yarowsky (1995), the classified test data are exhaustively included in the seed data, thus expanding the seed data. However, this might result in lots of noise in the seed data. Thus we introduce the 'maximum a posterior hypothesis' based on the Bayes' assumption to validate the noise status of the new seed data. We use the Naive Bayes Classifier and prove that the application of Find-Specific algorithm enhances the correctness of WSD.

• Journal of the Korean Home Economics Association
• /
• v.35 no.1
• /
• pp.357-372
• /
• 1997

The purpose of this study was to 1) segment female adolescent consumers into consumer groups displaying different consumer decision-making styles 2) to determine the consumer characteristics(clothing involvement information search store patronage and demographic variables) that related to each consumer segment and 3) to identify the interrelationship between the consumer characteristics. Decision-making styles were measured by 32 seven-point Likert type scales adapted from Sproles & Kendall and Shim & Kot A total of 78 statements dealing with three aspects of consumer characteristics was adapted from previous research. Data were collected from 567 2nd grade female middle and high school students in Seoul via self-administered questionnaires. and were analysed by frequency factor analysis ANOVA cluster analysis χ2 -test and Duncan's multiple range test. The results of this study were as follows: As a results of cluster analysis and ANOVA on seven factors of desion-making styles(1. brand-consiousness 2. novelty/fashion-consciousness 3. recreational/hedonis-tic orientation, 4. impulsive/carelessness, 5. price-consciousness/value-for-money, 6. perfectionism/high quality orientation 7. habitual/brand-royal consciousness) three consumer groups were identified and labeled as puality-oriented/non-utlitarian shoppers price-oriented shoppers and apathetic shoppers. Quality-oriented/non-utilitarian shoppers showed the highest clothing involvement scores of all aspects the highest consumer knowledge/experience most active ongoing information search and prepurchase information search. They preferred department store and franchise store for apparel shopping and considered service/reliability atmosphere variety of goods as important store attributes, Price-oriented shoppers showed prepurchase information search and planned purchase behavior actively. They preferred factory outlet store specialty stre and considered price very important as store attributes. Apathetic shoppers showed the lowest scores of all aspects of clothing involvement and most passive behavior in information search activities except showing the highest planned purchase. They preferred regional markets.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.3
• /
• pp.143-154
• /
• 2014

For the purpose of drawing a representative type of utilizing idle farmlands, this study collected and analyzed newspaper articles about cases of utilizing idle farmlands in the past decade using Internet search engines. Prior to this, it clarified a concept of idle farmlands to raise accuracy of searching articles, and selected NAVER as a search engine. It set "idle farmland", "abandoned land", and "utilizing" as basic search words in search option, and also set search period from 1st of January in 2004 to 31st of December in 2013. This study primarily searched 1,593 articles, and extracted 165 articles excluding overlapped and unrelated articles. Furthermore, it investigated extracted articles by date, media, headline, content of use, region(province), particular area(city and country), main agent, item and keyword 1, 2, 3 for proper use. This study also examined frequencies by year according to indoor and outdoor environment as well as regional differences through frequencies by regional groups and chronology. Furthermore, it drew a diagram of frequency flow of keyword 2, 3 with each keyword 1 as the central figure in order to draw various types of using idle farmlands. Through the diagrams, this study drew 9 using types such as (1) community service. agriculture type, (2) high income. agriculture type, (3) sightseeing. landscape. agriculture type, (4) livestock. agriculture type, (5) weekend farm type, (6) high income. woodland type, (7) ecology. landscape. woodland type, (8) agricultural work-study type, (9) ecological environment type.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.1B
• /
• pp.24-33
• /
• 2002

The cell search scheme for W-CDMA consists of the following three stages: slot synchronization(1st stage), group identification and frame boundary detection(2nd stage), and long code identification(3rd stage). The performance of the cell search when a mobile station is switched on, which is referred to as initial cell search, is decreased by the initial frequency and timing error. In this paper, we propose the pipeline structured initial cell search scheme using time trackers to compensate for the impact of the initial timing error in the stage 2 and stage 3. The simulation results show that the performance of the proposed scheme is maximal 1.5dB better than that of the conventional one when the initial timing error is near ${\pm}T_c$/2.