• The Journal of the Korea Contents Association
• /
• v.19 no.9
• /
• pp.135-143
• /
• 2019

Purpose of this study is enhancing usability of online video platform by analyze link-depth and advertisement frequency. In this study, researcher checked market share of video platform which publishing web-drama, and compare their link-depth and advertisement frequency. As a result, access to the latest content has two to three link-depth. So it does not worsen usability. but, if contents doesn't show on main page or search result, it requires more than five to six steps. Image advertisement show up more than twice on every platform. 'Youtube' and 'Naver TV' show up pre-roll video advertisement in video player before offering contents. In this video platform information structure, directory searching needs high link-depth level and advertisement frequency. It will increase user's bounce rate and decrease return visit rate. So researcher suggests prototype using drop-down menu to reduce link-depth and enhance information structure.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.12
• /
• pp.53-59
• /
• 2014

In order to obtain basic data for reasonable design of rockfall prevention net unreasonably being designed according to experiences, this paper determined a standard cross section and analyzed the effects of parameters such as inclination and height of slope faces, rockfall weight, separation distance on rockfall behaviors such as bounce height, kinetic energy and passage rate. The weight of rockfall changed from 400 kg to 700 kg and then to 1,000 kg. With the height of 20 m as the standard, the test was conducted with the inclination at $63^{\circ}$ and $55^{\circ}$ which may affect rockfall behaviors. Analysis was made while changing the fall height of rockfall from 3 m to 15 m and then to 20 m, thereby analyzing and evaluating changes in maximal kinetic energy occurring in the base of slope. According to the analysis result, in designing a rockfall prevention wire net, a design considering various conditions including inclination of the slope, expected size or weight of rockfall, situation of the slope and the shape of rockfall, and rockfall trace is judged necessary beyond the current uniform application.

• Journal of the Korean Geographical Society
• /
• v.35 no.5
• /
• pp.717-729
• /
• 2000

Housing prices in the Korean housing market dropped at an unprecedented magnitude in 1998 after the economic crisis. With the support of housing policies to boost depressed housing markets, house prices managed to bounce back after the mid-1999. During the period of housing price decline and of its recovery, the degrees of house price changes were not even across the country. The cities could be classified into four groups regarding the differential rates of house price changes. The cities which had higher rates of decrease also had higher rates of increase. On the other hand, some other cities continuously experienced a price fall during the recovery period although the rate of housing price changes were relatively low after the economic crisis. Throught the processes of administering housing market depression due to the crisis of the economy, the cities which could fully redeem the level of house prices in housing markets between the Seoul Metropolitan area and the other parts of the country has been widened.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.25 no.3
• /
• pp.125-130
• /
• 2019

Shock and vibration inputs are transmitted from the vehicle through the packaging to the fruit. Inside, these cause sustained bouncing of fruits against each other and container wall. These steady state vibration input may cause serous fruit injury, and this damage is particularly severe whenever the fruit inside the package is free to bounce, and is vibrated at its resonance frequency. The determination of the resonance frequencies of the fruit and vegetables may help the packaging designer to determine the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. Instrumentation and technologies are described for determining the vibration response characteristics of the pears for exporting with frequency range from 10 to 200 Hz, sweep rate of 1 octave/min, sweep method of logarithmic up and down and acceleration levels of 0.2, 0.4, 0.6, 0.8 and 1.0 G considering the domestic transportation environment. The resonance frequency of the pears ranged from 49.04 to 87.16 Hz and the amplitude at resonance was between 0.96 and 4.02 G in test frequency band and acceleration level. The resonance frequency and amplitude at resonance frequency band of the pears decreased with the increase of the sample mass. The multiple nonlinear regression equations for predicting the resonance frequency of the pears were developed using the independent variables such as mass, input acceleration.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.5
• /
• pp.593-600
• /
• 2014

In this paper, Radar cross section (RCS) calculations of advanced naval vessels model with RCS reduction methods are simulated and RCS results are discussed. Especially, this paper are mainly focusing on the facts influencing on RCS, the ways minimizing RCS and material characteristics of RCS changing-rate. RCS analysis results are given for a DDG-1000 type advanced naval vessels, which show that as the elevation angle increased 10 degree, the mean RCS value increased 23.91 dBsm. Also, as the superstructure angle increased 6 degree, the mean RCS value reduced 1.27 dBsm. Finally, the radar absorbing material attachment at the front and back superstructure have been reduced 2.27 dBsm in terms of mean RCS value.

• Journal of the Korean Society for information Management
• /
• v.38 no.3
• /
• pp.141-174
• /
• 2021

In this study, by examining the actual usage data of the university library website before and after COVID-19 outbreak, the usage behavior of users was analyzed, and the data before and after the virus outbreak was compared, so that university libraries can provide more efficient information services in a pandemic situation. We would like to suggest ways to improve it. In this study, the user traffic made on the website of University C was 'using Google Analytics', from January 2018 to December 2018 before the oneself of the COVID-19 virus and from January 2020 to 2020 after the outbreak of the virus. A comparative analysis was conducted until December. Web traffic variables were analyzed by classifying them into three characteristics: 'User information', 'Path', and 'Site behavior' based on metrics such as session, user, number of pageviews, number of pages per session time, and bounce rate. To summarize the study results, first, when compared with data from January 1 to January 20 before the oneself of COVID-19, users, new visitors, and sessions all increased compared to the previous year, and the number of sessions per user, number of pageviews, and number of pages per session, which showed an upward trend before the virus outbreak in 2020, increased significantly. Second, as social distancing was upgraded to the second stage, there was also a change in the use of university library websites. In 2020 and 2018, when the number os students was the lowest, the number of page views increased by 100,000 more in 2020 compared to 2018, and the number of pages per session also recorded10.46, which was about 2 more pages compared to 2018. The bounce rate also recorded 14.38 in 2018 and 2019, but decreased by 1 percentage point to 13.05 in 2020, which led to more active use of the website at a time when social distancing was raised.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.4
• /
• pp.295-302
• /
• 2016

Underwater acoustic communication channel is often defined as a multipath fading channel since the multipath arrivals from various paths interfere with each other and cause frequency dependent constructive or destructive interference in received signals. Therefore signal-to-noise ratio (SNR) of received signal fluctuates as a function of frequency. In addition, sea surface fluctuation induces frequency dependent time variant signal fading due to coherent component variation of surface bounce path. The frequency shift keying (FSK) system is known to be less sensitive and more robust under these interference and fading, and M-ary frequency shift keying (MFSK) system is adopted to increase a data rate. In this study, a bit error rate (BER) of 4 channels 4FSK system are examined in shallow sea multipath channel. Experimental results show that RS code reduces efficiently the BER of 4FSK system since frequency dependent time-varying fading is characterized to give burst errors. The BER of a different data rate or different source-to-receiver range depends on not only the channel coherent bandwidth but also frequency dependent multipath fading.

• Journal of Service Research and Studies
• /
• v.3 no.2
• /
• pp.33-44
• /
• 2013

As the Internet and mobile services increase, the use of wired/wireless web contents services increase and the demand for various contents explosively grows. To survive in competitive market, and to minimize the errors and warnings for web accessibility and standardization, and then to maximize the web usability, the periodical evaluation for web site should be performed with the events of web marketing and campaign. Through the web evaluation, the errors for technical programming language and contents offering can be found and diagnosed. In this paper, the quantitative and qualitative evaluation method for web site providing web contents are presented, and the analytic results for the 138 home pages in domestic are evaluated to validate the quantitative methodology. The accessibility, standardization, and usability factor are adopted for the evaluation in which accessibility is evaluated for perceivable, operable, understandable, and robust discipline with K-WAH(Korea-Web Accessibility Helper) tool, the standardization are measured for the number of errors and warnings in technical language with the W3C validator, and finally the usability factor is analyzed for the number of visits, average visit duration, and bounce rate with Google Analytics. In addition to, the quantitative analysis is also performed with the consideration of cost for construction and operation of web site. From the results, in the case of total score of 100 in conversion with relative weight, the average and standard deviation are evaluated to be 55 and 14, respectively. The correlation analysis indicates that the coefficient is estimated as 0.058, and then correlation between the quantitative results and cost is evaluated to be a little positive.

• Korean Journal of Remote Sensing
• /
• v.18 no.4
• /
• pp.209-220
• /
• 2002

We carried out studies on SAR image intensity and interferometric phase over oyster sea farms. Strong backscattering was observed in amplitude images, and that was considered as a radar signal double bouncing from horizontal bars. These sea farming structures are not visible in satellite optical images except IKONOS image, so that it demonstrates the value of radar remote sensing as an effective tool in support of sea farm detection. The intensity of the image is sensitive to system parameters including wavelength, polarization, and look direction, but does not correlate to tide height. We found that the strongest backscattering can be obtained by L-band HH-polarization with a look direction perpendicular to the horizontal bar. We also succeeded in generating 21 coherent JERS-1 SAR interferometric pairs over the oyster farms. The general trend of the fringe rate of the interferometric phases appeared to be governed by altitude of ambiguity. The general trend was modeled by an inverse function and removed to have a residual phase. The residual phase showed a linear relation with the tide height. The results demonstrate for the first time that SAR can possibly be used to estimate sea level. However, the r.m.s. error of a regression line is 11.7 cm, and that is so far too large to make reliable assessments of sea level in practical applications. Further studies is required to improve the accuracy specifically using multi-polarization SAR data.

• Journal of Distribution Science
• /
• v.10 no.5
• /
• pp.7-17
• /
• 2012

The recent announcement of the National Research Foundation of Korea (NRF) to cease journal accreditation operations as of the end of the year 2014 can easily influence the future of many research journals in Korea. Although this plan has not yet been formalized or structured, its facilitation would be the major turning point for the current Korean research and scholarly journals and publications. In addition, the NRF's plan to select and fund top 20 or more research journals over the five year period beginning 2015 suggests that the competition will most likely increase among Korean journals. Each journal would need to develop its unique strategy to improve and strengthen its competitiveness to become or maintain its position as a major research journal in Korea. The association of Korean Distribution of Science (KODISA) and its research journal, Journal of Distribution Science (JDS), has been continuously improving its reputation as a reputable journal in the distribution and related fields since its establishment in 1999. Due to demand, JDS has had to undergo several changes in its publication cycle first from semiannual publication to quarterly, then finally to monthly publications in 2012, and has become one of the major social science journals in Korea. Furthermore, with the redesigning of its webpage with English language in July of 2011, KODISA has made the published journals freely accessible and available to both domestic and foreign researchers, scholars, practitioners, and learners. These changes have resulted in the rapid increase in the bounce rate and the number of journal submissions by foreign scholars, with four research articles having been submitted by foreign scholars just in March of 2012 alone. However, although the changes and outcomes have resulted in a reasonable success so far, the achievement may only become a short-term success without continuously developing, improving, and implementing both effective and efficient strategies through critical, thorough, and frequent examinations and evaluations of both KODISA and JDS. As such, the purpose of this research is to carefully examine both KODISA and JDS to identify problematic factors and to develop appropriate strategies to change or modify those problems for further strengthening and improving their reputation and status. The paper examines and analyzes the past, present, and future of KODISA and JDS and their managerial, operational, and systematic procedures and operations. The narrow scope of research and inefficiencies in promoting the association and the journal and the improvement of impact factors are identified as the notable problems that could hinder JDS from being included in SCOPUS or SSCI in the near future. This type of examination and exploration has not been previously conducted, so the major limitation of this paper can be identified as not meticulously elaborating on the problems nor proving detailed recommendations based on the existing researches. This article asserted that solving the problem of the narrow scope of research would lead to facilitation of resolving other inefficient problems. Inclusion of international academic disciplines to the distribution and their related fields would be the viable initiation of expanding the research area, and this strategy could promote the journal as well as improve its impact factors. The narrow scope of research seems to be a good research topic and merit further exploration as an individual research project, because this kind of research could yield the creation of new understandings or theories.