• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.579-585
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• 2009

In spite of the proven effectiveness of ramp metering system, it has not been successfully implemented in Korean setting. The purpose of this paper is to select target locations to introduce ramp metering into the Korean expressway system. For this, domestic standards to introduce ramp metering have been presented after reviewing those of the US. The major criteria are level of service (LOS), the existence of detour route, space for queue build-up and opened ramp. 15 different locations were selected and AHP has been used to make priority among them. Intuitively, the result of priority was in accordance with the congestion and traffic volume. The core results identified in this paper is expected to be used in different cities and expressway networks elsewhere.

• The Korean Journal of Franchise Management
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• v.6 no.1
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• pp.21-41
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• 2015

The purpose of the study is to review the real situations of the income-gap between urban and rural areas which is focused on as one of the biggest issues revealed in the process of Chinese economic development and to find out which factors will alleviate or deteriorate such income-gap, also to find out such factors will effect differently on the regional characteristics. To analyze it, six factors such as industrialization-ratio, urbanization-ratio, tertiary industry-ratio, the level of both governmental educational support and agricultural support, and Chinese dual-economic structure are considered as explanatory variables, and OLS regression analysis was implemented to the factor data for the period of 1986-2007 about Chinese 31 districts(castles and cities). The results of the analysis show that both industrialization factors and urbanization factors affect significantly to alleviate income-gap between urban and rural areas, and as predicted, they also shows that dual-economic structure between urban and rural areas is the most biggest factors to enlarge the above mentioned income-gap. However, in accordance to the different level of economic development in eastern, central, and western districts the study shows that such factors will affect them differently respectively. The contents are as follows; In eastern district governmental educational support factor will affect the most great influence to alleviate the income-gap, in central district industrialization factor will affect the most great influence to alleviate the gap, and western district governmental agricultural support factor will affect the most great influence to alleviate the gap. Therefore, in solving the issue of income-gap between urban and rural areas in China we recommend that it is necessary for more differential policy in considering regional characteristics than unilateral policy to Chinese whole areas.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.24-34
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• 2021

Estimation of the presence of people in real time is extremely useful for businesses in providing better services. Many companies and researchers have attempted various researches in order to count the number of floating population in specific space. Recently, as part of smart cities and digital twins, commercialization of measuring floating populations using Wi-Fi signals has become active in the public and private sectors. This paper explains the floating population measuring system from the perspective of general consumers(non-experts) who uses current population data. Specifically, it presents a method of estimating the floating population based on MAC-address values collected from smartphones. By distinguishing Real MAC-address and Random MAC-address values, we compare the estimated number of smartphone devices and the actual number of people caught on CCTV screens to evaluate the accuracy of the proposed method. And it appeared to have a similar correlation between the two datas. As a result, we present a method of estimating the floating population based on analyzing Wi-Fi Probe Requests

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.707-715
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• 2023

This study utilized CART algorithm, a decision tree analysis method, to comparatively analyze factors affecting housing and residential environment satisfaction by region using data from Ministry of Land, Infrastructure and Transport's housing survey in 2020. First, in terms of residential environment satisfaction, accessibility to medical facilities and school district showed higher importance in metropolitan cities and areas compared to other regions, whereas safety from accident showed the opposite trait, showing difference between region. Second, housing characteristics were important in housing satisfaction, indoor environment level satisfaction and indoor safety and hygiene being important in almost all regions, while residential environment characteristics were more important in residential environment satisfaction and influencing factors were relatively evenly distributed. In order to generalize these regional characteristics, research using time series data needs to be conducted later.

• Convergence Security Journal
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• v.22 no.1
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• pp.81-92
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• 2022

The rapidly growing IoT market is expanding not only in general households but also in smart homes and smart cities. Among the major protocols used in IoT, ZigBee accounts for more than 90% of the smart home's door lock market and is mainly used in miniaturized sensor devices, so the safety of the protocol is very important. However, the device using Zig Bee is not satisfied with the omnidirectional safety because it uses a fixed key during the authentication process that connects to the network, and it has not been resolved in the recently developed ZigBee 3.0. This paper proposes a design method that provides omnidirectional safety to the ZigBee authentication protocol and can be quickly applied to existing protocols. The proposed improved ZigBee authentication protocol analyzed and applied the recently developed OWE protocol to apply ECDH, which has low computational volume and provides omnidirectional safety in IoT. Based on this, it provides the safety of the ZigBee authentication protocol, and it is expected that it will be able to provide user convenience as it does not require a separate certificate or password input.

• Geomechanics and Engineering
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• v.34 no.4
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• pp.397-408
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• 2023

Pipe pile walls are commonly used as retaining structures for excavation projects, particularly in densely populated coastal cities such as Hong Kong. Pipe pile walls are preferred in reclaimed land due to their cost-effectiveness and convenience for installation. However, the pre-bored piling techniques used to install pipe piles can cause significant ground disturbance, posing risks to nearby sensitive structures. This study reports a well-documented case history in a reclamation site, and it was found that pipe piling could induce ground settlement of up to 100 mm. Statutory design submissions in Hong Kong typically specify a ground settlement alarm level of 10 mm, which is significantly lower than the actual settlement observed in this study. In addition, lateral soil movement of approximately 70 mm was detected in the marine deposit. The lateral soil displacement in the marine deposit was found to be up to 3.4 and 3.1 times that of sand fill and CDG, respectively, mainly due to the relatively low stiffness of the marine deposit. Based on the monitoring data and site-investigation data, a 3D numerical analysis was established to back-analyze soil movements due to the installation of the pipe pile wall. The comparison between measured and computed results indicates that the equivalent ground loss ratio is 20%, 40%, and 20% for the fill, marine deposit and CDG, respectively. The maximum ground settlement increases with an increase in the ground loss ratio of the marine deposit, whereas the associated influence radius remains stationary at 1.2 times the pipe pile wall depth (H). The maximum ground settlement increases rapidly when the thickness of marine deposit is less than 0.32H, particularly for the ground loss ratio of larger than 40%. This study provides new insights into the pipe piling construction in reclamation sites.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.803-811
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• 2023

BACKGROUND/OBJECTIVES: Nutrition knowledge has been reported to have a weak positive effect on healthy eating behavior. This study aimed to determine if there was a difference in nutrition knowledge depending on the choice of science subject in high school and whether that affected the actual eating habits of college students in Japan. SUBJECTS/METHODS: The subjects were 514 college students, the majority first-year students, in 3 cities in Japan. A questionnaire survey was conducted on elective subjects in science in high school, diet (11 items), lifestyle (5 items), and nutrition knowledge (34 questions). The preliminary survey was conducted on 47 students in the fall of 2019, and the full-scale survey was conducted in May-June and October-November 2021 at the end of lectures for the first-year students. RESULTS: The students in the high-score group (24-31 points, n = 180) had a higher intake of vegetables (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.12-2.82; P = 0.015) and breakfast (OR, 1.64; 95% CI, 1.03-2.60; P = 0.035), and a reduced intake of fast food (OR, 0.27; 95% CI, 0.14-0.51; P < 0.001) than those in the low-score group (6-19 points, n = 150). Only the biology and chemistry students had significantly higher nutrition scores than the other groups (all: P < 0.001), but no significant difference was found between the other groups. Understanding nutrition learned in elementary and junior high school is appropriate, while molecular structure, recommended amount, and food poisoning were insufficient. CONCLUSIONS: Knowledge of nutrition appears to have a positive effect on the actual eating habits of college students. Although biology and chemistry in high school may help students understand the foundations of good nutrition, specialized food education may be required to make informed dietary choices.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.20 no.3
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• pp.163-169
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• 2009

The concept of library is newly interpreted and designed under the environment of U-City. The basic notion of the library should not changed its kernel nevertheless, the new technologies like ubiquitous computing services are applied to the library, which functions in terms of information services, continuous learning programs and communities of practice(CoP). The library is fit for any technologies or environments as organism. Actually the library has been shown in terms of new information technologies with the changes of the times. It leads to comprehend the library as its appearance not as it is. The libraries including even cities have evolved toward ubiquitous(computing) environment. On the other words, the libraries have sought ubiquitous at the past, now they are still chasing it.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.1-16
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• 2022

Recently, e-scooters have been attracting attention as eco-friendly modes of transportation in cities due to an increasing interest in the environment. Accordingly, various studies on usage behavior are being conducted, but studies that reflect individual travel attitudes are insufficient. Therefore, this study surveyed commuters in Seoul and analyzed respondents' traveling attitudes through factor analysis. It also built a binary logistic regression model for the intention to use shared e-scooters to determine how individual travel behaviors are affected. In particular, the model results showed that age, the main mode of transportation (car), walking time to the bus stop, and four travel attitude variables (disutility of travel, preference to self-drive, internet/smartphone friendliness, and willingness to pay extra money for services) significantly affected the intention to use shared e-scooters. This study is expected to be used as basic data, with aspect to travel behavior, for the efficient operation and use of shared e-scooters in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.321-328
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• 2010

The study performed an actual fire experiment in order to propose the heat release rate of automobile that is the most basic architectural element for the fire safety design in a tunnel, whose importance has been recognized as the underground traffic tunnels are planned in Korean metropolitan cities. The heat release rate of a van is measured by the large scale calorimeter, in which the law of oxygen consumption is applied, and the fire expansion characteristics in a tunnel by placing two passenger cars nearby one another in the tunnel. As the results, the heat release rate of the van was revealed to be 5.9 MW, and carbon monoxide was emitted 482 ppm at a maximum. In case of two passenger car experiment for the fire expansion characteristics, the adjacent car was ignited about 3 minutes 30 seconds after the fire occurrence, and the complete fire was developed after 15 minutes. The maximum heat release was 9 MW. The results from the actual fire experiment can be an important input data for future quantitative analysis as well as an element applicable to a tunnel disaster preventive equipment design.