• ETRI Journal
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• v.28 no.6
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• pp.815-818
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• 2006

In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and update link state information. The triggering policy of link state updates significantly affects the volume of update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on link-usage statistics in order to reduce the volume of link state update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.317-323
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• 2016

Objectives: This study was performed to estimate domestic usage amount of insecticide for fruit cultivation to suggest job-exposure matrix(JEM) regarding farmers treating agricultural insecticide. Materials and Methods: The domestic usage amount of insecticide for fruit cultivation was investigated according to two research methods. The former method is to use agricultural pesticides published annually from Korea Crop Protection Association(KCPA) and the latter method is to apply cultivation area of fruit provided officially from Statistics Korea(SK). Results: It was found that its domestic usage amount has decreased gradually from the first sale to presence(2012). However, there is a significant difference of annual usage trend of insecticide for fruit cultivation between shipments and estimation. The annual usage trends of insecticide for fruit cultivation based on regional classification were different from those based on total aspect. Conclusions: The region which used insecticide for fruit cultivation the most in Korea was as follows: Gyeonsang-do, followed by Jeolla-do, Chungcheong-do, Jeju-do, Seoul/Gyeonggi-do and Gangwon-do. An averaged ratio of usage amounts of insecticide based on shipments and those based on estimation by cultivation area was $980{\pm}186%$, which means that usage amounts of insecticide estimated by shipments are ten times higher than those based on cultivation area.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.739-751
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• 2020

Seoul public bike program facilitates access to bicycles and offers potential for greater mobility and health for users. Furthermore, it would have positive impacts on transport congestion, energy use, and the environment. Hence, it is important to find future rental locations by taking to account both bike-demand and regional imbalance. This paper first finds eligible candidates of rental locations with the required spatial conditions such as a sufficient sidewalk width and accessibility of bike pick-up vehicles. And then, estimates public bike daily usage for each selected location via random forest based on Seoul public bike historical usage, Seoul geographical features, regional characteristics, and populations. This study contributes to a better comprehension of the Seoul public bike program, and would be useful in determining new public bike rental locations.

• Journal of the Korean Society for Library and Information Science
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• v.54 no.4
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• pp.53-82
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• 2020

With the increase in smartphone ownership and Internet usage using smartphones, the information environment is shifting from the existing PC to the smart mobile. The current undergraduate students are called Generation Z who prefer smartphones to PCs and video contents to texts. This study attempted to understand their usage behaviors of electronic resources in an academic library in a smart mobile environment. This study conducted a usage statistics analysis with 61,433 usage records of e-books, audiobooks, and e-learning contents and 1,595 records of users in the A academic library during 3 years from 2016 to 2018. The scope of the data includes the date of use, the subject, the year of publication, the channel of use, and each user's gender, affiliation, status, admission date, and graduation date. This study investigated not only the general characteristics of electronic resource use, but also the usage behaviors according to the user's demographic characteristics. Based on the findings, this study suggested practical service plans that are applicable in the near future and reflect changing circumstances.

• The Korean Journal of Applied Statistics
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• v.34 no.6
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• pp.969-977
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• 2021

We cluster the electricity consumption of households in A-apartment in Seoul, Korea using Hierarchical K-means clustering algorithm. The data is recorded from the advanced metering infrastructure (AMI), and we focus on the electricity consumption during evening weekdays in summer. Compare to the conventional clustering algorithms, Hierarchical K-means clustering algorithm is recently applied to the electricity usage data, and it can identify usage patterns while reducing dimension. We apply Hierarchical K-means algorithm to the AMI data, and compare the results based on the various clustering validity indexes. The results show that the electricity usage patterns are well-identified, and it is expected to be utilized as a major basis for future applications in various fields.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.2
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• pp.333-356
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• 2010

Small libraries, with their insufficient quantities of materials and lack of diversity within the collection compared to larger general public libraries, may need to be assessed and develop collections based on empirical analysis. This study suggests a method for collection evaluation with other cases analyzing ILL (interlibrary loan) data, which is especially heavy in Small libraries in addition to the holdings and circulation data that are traditionally used in collection development. Collecting and analyzing materials proceeded from 14 Small libraries which operate ILL in a city and tried to figure out features of each library comparing collection statistics with usage statistics including circulation and interlibrary loans. It also identified subject areas heavily used in a Small library, based on the analysis of collection and usage statistics, for the purpose of formulating future policy.

• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.191-197
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• 2005

Application of data mining techniques to the world wide web, referred to as web mining, has been the focus of several recent researches. With the explosive growth of information sources available on the world wide web, it has become increasingly necessary to track and analyze their usage patterns. In this study, we introduce a process of pre-processing and cluster analysis on web log data and suggest a distance measure considering the structural relationships between web contents. Also, we illustrate some real examples of cluster analysis for web log data and look into practical application of web usage mining for eCRM.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1584-1587
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• 2005

Although the picture quality of today's displays is very good already, a continuous improvement is desirable as the new larger display sizes increase the visibility of artifacts. A contributing factor for picture quality enhancement through smart video processing and algorithm design is the information gathered from video statistics. Interesting parameters gathered from video statistics are e.g. the image- and display load, the usage of the color gamut, the estimated power consumption and the occurrence of static image parts. Examples of applications that can benefit from video statistics are power calculations, color gamut mapping algorithms, dynamic backlight control for LCD panels and LED backlights for LCD panels.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.37-46
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• 1997

KOSIS(Korean Statistical Information System) was developed and serviced by National Statistical Office in Korea. In this paper, we report the survey results of the usage of KOSIS, and its improvement. Finally, we propose some recommendations for improvement of KOSIS, and discuss the usage of KOSIS in behalf of end-users.

• Journal of Korean Society for Quality Management
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• v.35 no.1
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• pp.136-141
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• 2007

For many products failures depend on age and usage and, in this case, failures are random points in a two-dimensional plane with the two axes representing age and usage. Models play an important role in decision-making. In this research, an accelerate failure test (AFT) model is proposed to deal with the two-dimensional data. The parameters are proposed to be estimated through maximum likelihood estimators.