• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1969-1977
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• 2016

We study the connection time of vehicle-to-mobile roadside unit (V2MR) communications which can reduce the significant cost of the fixed RSU by installing a gateway of mobile network into a transit bus called the mobile RSU. In the V2MR communications, the connectivity of a commute vehicle can be improved via ad-hoc connection to a nearby mobile RSU. In this paper, we present a new analysis model to estimate the connection time between a commute vehicle and a mobile RSU, when there is a bus station in the overlapping route. Since the connection time between two vehicles is highly dynamic and unpredictable, our analysis will provide a fundamental basis of connection-time estimation of V2MR communications. Numerical results obtained from VEINS simulation show that our analysis can estimate the connection time of V2MR communications with the average error below 1.0 percent. Moreover, we show that the average connection time of V2MR communications can be extended to approximately 3.85 times of that of V2R communications.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.44-57
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• 2019

It is crucial to understand how people make decisions on mode choice and to accurately predict their behaviors in transportation planning. One of avenues for advancing modeling is, in particular, taking into account for taste heterogeneity in modeling that can incorporate different decision-making processes across group. In this study, we hypothesize that how people make decisions on mode choice would differ by destination in that land use characteristics are heterogeneous by zone even if zones are all in the same area. To this end, we apply Latent Class Modeling (LCM) to commute trips in Seoul by using 2010 household travel diary survey, investigate types of latent classes with the aid of characteristics of destination, and analyze how those classes differently response to factors. The LCM identifies two classes: in the first one, modal split of auto and public transit (bus and metro) is almost half-and-half and the trip destinations are characterized by relatively more residence facilities and less business/commercial facilities; in the second one, public transit has a notably high share and trip destinations are characterized by relatively more business/commercial facilities. In addition, it turns out that demographic and socio-economic variables affect mode choice differently by class.

• Land and Housing Review
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• v.15 no.2
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• pp.73-87
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• 2024

To evaluate the efficiency of commuting patterns, various commuting indicators such as excess commute and commuting potential utilized have been developed and used. It is crucial to calculate these indicators reasonably to reveal the differences in commuting patterns among metropolitan areas and to consider these in the process of formulating commuting policies. However, commuting indicators are generally calculated at the administrative district level, and thus, they are not free from the problem of the modifiable areal unit problem (MAUP). This issue can undermine the rationality of comparing commuting efficiency between metropolitan areas, making it necessary to handle the calculation of commuting indicators carefully. Therefore, this study utilises Monte Carlo Simulation to calculate optimal, actual, and maximum commuting distances, and thereby presents the excess commute and the commuting potential utilized. To apply Monte Carlo Simulation to the context of South Korea, a constrained Monte Carlo Simulation is conducted, where residential and workplace locations used in the simulation are selected based on the actual locations of buildings. The analysis is conducted on 13 metropolitan areas with established metropolitan plans using the 2016 Household Travel Survey data. The commuting indicators calculated through the simulation showed minimal differences compared to the results obtained through conventional methods. The comparison of commuting efficiency among metropolitan areas revealed that even if the degree of spafial balance between residential and workplace locations is similar, the actual commuting patterns can differ significantly. It is suggested that further research considering characteristics such as the area of each metropolitan region will be necessary in the future.

• International Journal of Human Ecology
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• v.14 no.1
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• pp.71-85
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• 2013

The purpose of this study was to investigate Korean college students' housing values and housing expectations as well as considerations for housing in their 20s and to explore influences on housing values and expectations. Items related to four housing functions were developed in conjunction with Maslow's hierarchy of human needs to measure housing values. An on-site questionnaire survey was administered to students of a university-A located in Chungbuk province between May 28, 2012, and June 17, 2012. Among the total 476 responses, 465 responses from Korean students were used for further data analyses. The findings are as follows: (1) Among housing functions, those related to shelter functions were perceived as most important followed by function as a place for self-esteem. (2) More than 70 percent of the respondents expected to rent a housing unit in their 20s and more than half of the respondents expected non-traditional and relatively affordable compact size structure types such as studio, Officetel or Gosiwon. (3) Price, location and transportation were found to be the most important considerations when choosing housing in their 20s. (4) Convenience in use of public transportation and commute time were found to be the most important in location choice, and maintenance conditions and security systems were the most important for building choice. (5) Female respondents tended to consider personal safety, security systems, neighborhood facilities, and distance from family more important than male respondents when choosing housing, while male respondents considered parking space more important than females.

• Korean Journal of Health Education and Promotion
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• v.28 no.2
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• pp.27-40
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• 2011

Objectives: This study was conducted to identify health-promoting behaviors and related factors by type of residence between two groups of college students: those who live in dormitories and those who commute from home. Methods: We used the data from 2,287 students (870 male, 1417 female) from 14 colleges in Daegu and Kyungpook areas and compared health-promoting practice scores, general characteristics, health environment, and parental support. Multiple regression analysis was performed with health-promoting practice scores as a dependent variable. Results: Dormitory residents presented significantly lower health-promoting practice scores than commuters in both gender. Multiple regression analysis showed that the factors associated with health-promoting behaviors were health environment (p<0.05) and parental influence/support (p<0.01) for male dormitory residents. For female dormitory residents interest in health(p<0.05), stress(p<0.05), and parental influence/support(p<0.01) were associated. Conclusions: Systematic development of health education programs would be needed for the practice of health promotion behavior of college dormitory students with the help of environmental and institutional support. We suggest a program for stress management, smoking, health behavior, and alcohol and a parental program to increase contact with their children for a positive parental influence and support.

• Communications of the Korean Mathematical Society
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• v.35 no.3
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• pp.855-866
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• 2020

For two essentially bounded Lebesgue measurable functions 𝜙 and ξ on unit circle 𝕋, we attempt to study properties of operators $S^k_{\mathcal{M}({\phi},{\xi})=S^k_{T_{\phi}}+S^k_{H_{\xi}}$ on H²(𝕋) (k ≥ 2), where $S^k_{T_{\phi}}$ is a k^th-order slant Toeplitz operator with symbol 𝜙 and $S^k_{H_{\xi}}$ is a k^th-order slant Hankel operator with symbol ξ. The spectral properties of operators S^k_{𝓜(𝜙,𝜙)} (or simply S^k_𝓜(𝜙)) are investigated on H²(𝕋). More precisely, it is proved that for k = 2, the Coburn's type theorem holds for S^k_𝓜(𝜙). The conditions under which operators S^k_𝓜(𝜙) commute are also explored.

• Bulletin of the Korean Mathematical Society
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• v.51 no.4
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• pp.1145-1153
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• 2014

Let G be a finite group and X be a union of conjugacy classes of G. Define C(G,X) to be the graph with vertex set X and $x,y{\in}X$ ($x{\neq}y$) joined by an edge whenever they commute. In the case that X = G, this graph is named commuting graph of G, denoted by ${\Delta}(G)$. The aim of this paper is to study the automorphism group of the commuting graph. It is proved that Aut(${\Delta}(G)$) is abelian if and only if ${\mid}G{\mid}{\leq}2$; ${\mid}Aut({\Delta}(G)){\mid}$ is of prime power if and only if ${\mid}G{\mid}{\leq}2$, and ${\mid}Aut({\Delta}(G)){\mid}$ is square-free if and only if ${\mid}G{\mid}{\leq}3$. Some new graphs that are useful in studying the automorphism group of ${\Delta}(G)$ are presented and their main properties are investigated.

• International Journal of Advanced Culture Technology
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• v.5 no.2
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• pp.44-53
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• 2017

The purpose of this study was to investigate the relationship between self-identity and smart phone addiction among University students. This study used descriptive cross sectional study to analyze the relationship between self-identity and smart phone addiction. Study participants included 357 University students located in C province who selected through volunteered, but 10 missing data were excluded and finally 347 participants completed the study. The study data were collected using self-identity tool made by Park A chung in 1996 which was composed of Independence, Proprioception, Future conviction, Goal orientation, Initiate, and Intimacy and Smart phone addiction tool made by National information society agency. The self-identity's Cronbach's alpha was .937 and Smart phone was .670. All data analyses were performed using SPSS 18.0. Results showed that most students were not addicted(97.1%) in Smart phone using and middle level(73.2%) of self identity. Also, there was a difference in self - identity level according to gender and grade(the ratio of smart phone general users, not at all addicted, was 90.79% for males and 98.53% for females), and there was difference in Smart phone addiction level according to gender and residence type(the ratio of Smart phone general users, not at all addicted, is 99.32% for commute, 97.04% for dormitory, and 89.66% for self governing). Also there were strongly related with self-identity and Smart phone addiction(p < .001). This results reveled that self-identity affect to Smart phone addiction, therefore it is important to raise self-identity to prevent Smart phone addiction for University students.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.245-252
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• 2016

The Service Platform for going to Kindergarten configured with Beacon Devices, Gateway attached to the BUS, Mobile Communication Network, and Application Server. In this paper, We understand the need for Commuting Kindergarten Services, And interface to Specification of Kindergartener's Beacon Identification, And so design to Gateway Resource Tree Functions. For the Service Interfacing, Commute alerts handled in Parental Cellphone through APP. The Service Platform can check the registered beacon data collection and operation management function.

• Survey Research
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• v.12 no.2
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• pp.27-50
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• 2011

It is increasingly important to estimate daytime population for the sake of urban administration and urban economy. The estimation of daytime population using a census data on commute, however, has its own limits, particularly when applying to the metropolis such as Seoul which is dominated by the service industry. This study suggests a pedestrian flow as another estimate of daytime population and presents a methodology of Seoul Pedestrian Flow Survey. The data of pedestrian flow gives us a view into hourly and spatial distribution of daytime population, which cannot be provided by the use of census data. In addition, comparing with a census-based daytime population on the borough level show some features of a pedestrian flow as another estimate of daytime population.