• 대한임베디드공학회논문지
• /
• 제17권4호
• /
• pp.249-255
• /
• 2022

The COVID-19 virus appeared in 2019 and is extremely contagious. Because it is very infectious and has a huge impact on people's mobility. In this paper, multiple linear regression and random forest models are used to predict the number of COVID-19 cases using COVID-19 infection status data (open source data provided by the Ministry of health and welfare) and Google Mobility Data, which can check the liquidity of various categories. The data has been divided into two sets. The first dataset is COVID-19 infection status data and all six variables of Google Mobility Data. The second dataset is COVID-19 infection status data and only two variables of Google Mobility Data: (1) Retail stores and leisure facilities (2) Grocery stores and pharmacies. The models' performance has been compared using the mean absolute error indicator. We also a correlation analysis of the random forest model and the multiple linear regression model.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.255-257
• /
• 2004

The study for ubiquitous computing infra is proceeding actively, it make possible to use service and access network anywhere, anytime because of wire/wireless communication technology and progress of hardware. Domestically, study for the network mobility support technology which is the key technology for future ubiquitous computing realization have progressed, but that is insufficient. Especially, there is no study for independent mobility support study about railway wireless network. So, this study propose network mobility management technology for mobile network infra in railway and proper network model in train.

• Journal of Astronomy and Space Sciences
• /
• 제29권4호
• /
• pp.413-422
• /
• 2012

In recent years, a number of missions have been planned and conducted worldwide on the planets such as Mars, which involves the unmanned robotic exploration with the use of rover. The rover is an important system for unmanned planetary exploration, performing the locomotion and sample collection and analysis at the exploration target of the planetary surface designated by the operator. This study investigates the development of mobility system for the rover ground model necessary to the planetary surface exploration for the benefit of future planetary exploration mission in Korea. First, the requirements for the rover mobility system are summarized and a new mechanism is proposed for a stable performance on rough terrain which consists of the passive suspension system with 8 wheeled double 4-bar linkage (DFBL), followed by the performance evaluation for the mechanism of the mobility system based on the shape design and simulation. The proposed mobility system DFBL was compared with the Rocker-Bogie suspension system of US space agency National Aeronautics and Space Administration and 8 wheeled mobility system CRAB8 developed in Switzerland, using the simulation to demonstrate the superiority with respect to the stability of locomotion. On the basis of the simulation results, a general system configuration was proposed and designed for the rover manufacture.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제4권3호
• /
• pp.91-96
• /
• 2015

최근 IT 분야의 화두 중 하나는 '모빌리티(mobility)'이다. 이동성 및 가동성 등의 뜻을 가진 모빌리티는 사용자의 정보를 획득하여 사용자에게 서비스 이동의 자유로움을 제공할 수 있다는 의미이다. 본 논문에서는 모빌리티 환경에서 다양한 미디어를 다양한 디바이스로 이동할 수 있는 프로세스 오케스트레이션(MPO: Mobility Process Orchestration) 모델을 제안하고자 한다. 오케스트레이션 모델은 사용자 환경에 있는 디바이스를 오브젝트화하여 사용자에게 원하는 미디어를 원하는 디바이스에 MSMP(Multi Source Multi Platform)형태로 제공할 수 있는 구조와 기능을 제공한다. 이뿐만 아니라, 커리어그래피(Choreography)의 개념을 이용하여 다양한 미디어 형식에 맞는 디바이스만을 추출 및 오케스트레이션 하여 사용자에게 조화로운 서비스(Harmonizing Service)를 지향한다.

• 한국통신학회논문지
• /
• 제23권9A호
• /
• pp.2230-2239
• /
• 1998

Recently, mobility support of connectionless mobile ATM data service has been mainly studied in wireless ATM communication network. this paper shows the network model for the mobility support of connectionless data service in ATM network, and proposes the methods to minimize COIP (care of IP address) acquisition processing time for MH(mobile host)migration. Th echaracteristics of proposed methods, COIP acquisition probability and IP data communication sequence of proposed model, are discussed in this paper.

• 한국통신학회논문지
• /
• 제36권7A호
• /
• pp.662-668
• /
• 2011

본 논문에서는 MANET (Mobile Ad hoc Network)를 위한 가장 대표적인 라우팅 프로토콜인 AODV (Ad hoc On-demand Distance Vector)와 OLSR (Optimized Link State Routing)의 성능을 노드 이동성 모델에 따라 분석한다. 노드의 이동성은 망 토폴로지의 변화를 일으키므로 라우팅 프로토콜의 성능에 많은 영향을 미친다. 따라서, MANET 라우팅 프로토콜의 성능을 정확하게 평가하기 위해서는 노드의 이동 패턴에 가장 적합한 이동성 모델을 사용하는 것이 무엇보다 중요하다. 본 논문에서는 기존 MANET 라우팅 프로토콜 성능분석에 가장 많이 사용되고 있는 random way point 모델과 최근에 실제 인간의 이동 패턴과 가창 유사하다고 발표된 Levy walk 모델을 기반으로 AODV와 OLSR의 성능을 ns-2 시뮬레이션을 통해 비교 분석한다.

• International Journal of Internet, Broadcasting and Communication
• /
• 제12권4호
• /
• pp.93-101
• /
• 2020

Shipyards are potential environments for using IoT services, sensor networks, and delay tolerant networks. Simulations of those services and networks strongly rely on human mobility models. Results obtained with an unrealistic model may not reflect the true performance of applications, protocols, and algorithms in a shipyard. A lot of synthetic models for human movements have been studied but most of them are generic and focus on the daily movements of humans on city scales. Nevertheless, workers in shipyards have unique movement characteristics such as movement speed, pause time, and attractions places. For instance, workers usually move to some places, where they work, and rarely move to other places in the factory. Movement characteristics of workers not only depend on workers but also on tasks, which they do. For instance, workers, who paint ships, have similar movement speed and pause time. Hence, in this paper, human movements in shipyards are studied. We propose a new human mobility model called the human mobility mode in shipyards (MIS). In MIS, workers are classified into multiple types. Movement characteristics of a worker are similar to other workers in the same type. Based on the visiting probability, workers have some places, where they frequently visits, and some places, where they rarely visit. We analyze real mobility traces and studie to achieve human movement characteristics from real traces. The results show that MIS provides a well-match to the movement characteristic from real traces.

• 대한가정학회지
• /
• 제36권1호
• /
• pp.65-79
• /
• 1998

The purposes of this study were to establish a conceptual model on the woman's labor force participation and mobility in the labor market and to analyze the correlation between them. Included in those models were two independent variable sets. The one was related to household's financial conditions and the other was associated to the woman's role such as marital status, the number of children and the existence of young children. KHPS's national data was used and the Binomial Probit Model and Bivariate Probit Model were employed to analyse the effects of independent variables and the correlations between two dependent variables. The results of this study were as follows. The rate of women's labor force participation and the percentage of mobility willingness were 15.4% and 22.0%. Among the variables which have affected women's labor force participation were total wage income, non-wage income, expenditure on children's education and the subject judgement of their financial status. The existence of children under the age of 6 and marital status had significant influences on women's mobility willingness. The correlation between women's labor force participation and mobility willingness was very significant statistically. These findings clarified the status of woman as a secondary worker and pointed that a woman's economic activity would be subject to the woman's condition rather than her human capital.

• Journal of Information Processing Systems
• /
• 제3권1호
• /
• pp.1-7
• /
• 2007

In mobile ad hoc networks, an application scenario requires mostly collaborative mobility behavior. The key problem of those applications is scalability with regard to the number of multicast members as well as the number of the multicast group. To enhance scalability with group mobility, we have proposed a multicast protocol based on a new framework for hierarchical multicasting that is suitable for the group mobility model in MANET. The key design goal of this protocol is to solve the problem of reflecting the node's mobility in the overlay multicast tree, the efficient data delivery within the sub-group with group mobility support, and the scalability problem for the large multicast group size. The results obtained through simulations show that our approach supports scalability and efficient data transmission utilizing the characteristic of group mobility.

• 서비스연구
• /
• 제9권4호
• /
• pp.19-40
• /
• 2019

Mobility as a Service: MaaS 는 지능형 교통시스템(Intelligent Transportation System)의 일종의 서비스구상으로, 이는 출행 체험을 개선하는 것을 목표로 하며, 하나의 플랫폼에 다양한 교통 출행 방식을 집약하고, 사용자가 한 번의 지불을 통해 도어 투 도어(Door-To-Door)를 사용할 수 있는 전 과정 출행 서비스이다. 그러나, 독립적인 MaaS 플랫폼은 사용자 유동량이 적고 유보율이 낮다는 문제를 직면하기 쉬우며, MaaS의 서비스 모델은 아직 교통시장에 진입할 결정적 논리를 찾지 못하고 있는 실정이다. 본 논문은 공유 자전거(bicycle-sharing)의 각도에서 출발하여, 공유 자전거에 MaaS 이념을 적용하여 새로운 출행 서비스를 구축함으로써, 공유 자전거의 서비스 모델을 최적화하고, MaaS의 부족한 점을 보완하는 것을 연구의 목표로 하였다. 공유 자전거와 MaaS 개념을 결합한 후, 비즈니스 모델, 출행 모델 및 서비스 아키텍처 방면의 혁신에 중점을 두고, 사용자의 MaaS-based bicycle-sharing서비스 모델에 대한 체험의 예상 결과에 대해 시험하였다. 연구 결과에 따르면, MaaS-based bicycle-sharing은 조합 교통 방식, 출행과 환승, 결제 지불 등의 방면에서 사용자에게 보다 융통성 있고 편리한 출행 경험을 제공하고, 수요에 따른 출행 서비스와 지속적인 교통을 가능하게 한다는 것을 알 수 있었다.