• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2448-2454
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• 2008

Urban areas face congestion problems that diminish personal mobility and freight-transportation productivity. An increasing number of experts suggest that separating freight traffic from passenger traffic makes sense in terms of economics, the environment, and safety. Some experts suggest that underground freight transportation are the solution. The objective of this paper is to review the potential benefits and limitations of freight pipelines as a viable mode of cargo transport that can alleviate congestion on urban highways.

• Electronics and Telecommunications Trends
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• v.8 no.4
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• pp.79-96
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• 1993

개인 통신의 최고급 형태인 UPT(Universal Personal Telecommunication) 서비스를 실현하기 위해서 3 종류의 이동성 즉 개인 이동성, 단말기 이동성, 서비스 이동성에 대해 고려해야 한다. 본 고에서는 UPT 서비스 구현에 있어서 3 종류의 이동성에 대한 정의와 더불어 UPT 서비스에서 각 이동성의 적용 및 관리 방안 등을 ITU-TS, 논문 등에서 제시한 여러 방법을 중심으로 정리하였다.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.909-914
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• 2005

This paper proposes an efficient antenna selection scheme for PRT (Personal Rapid Transit) remote control in a wireless MIMO-OFDM systems. Using high correlation among neighboring sub-carriers, transmit antennas are selected by calculation based on the channel response of the center sub-carrier in each subgroup. This scheme reduces complexity of selection algorithm and significantly reduces the feedback channel information with small performance degradation. Especially, when feedback channel rate between a control base and a train is fixed, the proposed scheme can provide a significant advantage in high mobility.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.4 no.1
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• pp.28-37
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• 1993

The future Personal Communication Service(PCS) is the total personal information communication service to satisfy the importance of information in a highly information - oriented society. Compared with the conventional communication method, it is necessary to provide considerable intelligence to the commu- nication network in order to implement the PCS which guarantees the mobility of each individual. Consequen- tly, the PCS needs a fast large database system which stores the information of each individual. To achieve this goal, this paper presents the parallel implementation of deductive database systems as a main - memory database system.

• Journal of Communications and Networks
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• v.6 no.3
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• pp.245-257
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• 2004

Driven by the growing number of the mobile subscribers, efficient channel resource management plays a key role for provisioning multimedia service in the next generation personal communication systems. To reuse limited channel resources, diminishing the coverage areas of cells seems to be the ultimate solution. Thus, however, causes more handover events. To provide seamless connection environment for mobile terminals and applications, this article presents a novel handover scheme called the intelligent channel reservation (ICR) scheme, which exploits the location prediction technologies to accurately reserve channel resources for handover connections. Considering the fact that each mobile terminal has its individual mobility characteristic, the ICR scheme utilizes a channel reserving notification procedure (CRNP) to collect adequate parameters for predicting the future location of individual mobile terminals. These parameters will be utilized by the handover prediction function to estimate the expected handover blocking rate and the expected number of idle channels. Based on the handover prediction estimations, a cost function for calculating the damages from blocking the handover connections and idling channel resources, and a corresponding algorithm for minimizing the cost function are proposed. In addition, a guard channel decision maker (GCDM) determines the appropriate number of guard channels. The experimental results show that the ICR scheme does reduce the handover-blocking rate while keeping the number of idle channels small.

• Korean Journal of Social Welfare
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• v.57 no.4
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• pp.253-274
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• 2005

The purpose of this study was to explore the experiences of people with disabilities using Personal Assistance Services (PAS) in Korea. A qualitative study based on face-to-face interviews with people with mobility disabilities was conducted. Nine consumers with disabilities participated in the study. Study participants pointed out five changes in their life after using PAS: 1) increase in daily life activities, 2) increased perceived control, 3)increased psychological self-reliance, 4) growth of relationships with others in terms of both degree and frequency, and 5) more equalized relationships with family, Finally, article makes recommendations regarding the future provision of PAS.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.130-136
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• 2021

This study investigated the general characteristics of mobility disadvantaged persons with disabilities, and to suggest implications to ensure personal mobility with the greatest possible independence for the physically disabled in community. The survey questionnaire included the categories as follows: the general characteristics of the participants, the status of outing and mobility, usage of low-floor buses & taxi for the disabled, service improvement, and mobile support center. Data collected from 219 with physical disabilities were analyzed for this purpose by using descriptive statistics. The study results showed that 54.6% of the total tended to go out everyday, and 17.0% rarely. 53.4% could go out without any assistance, and the major obstacles not to go out were stairs and inconvenience of public transportation. 26.9% used low-floor buses, and 71.1% preferred to use taxi for the disabled. The average waiting time for the usage of low-flow buses and taxi was 66.57 minute and 42.65 minute, separately. 78.7% insisted that the function of mobile support center in the community should be expanded, whereas only 49.8% recognized the role of mobile support center. Based on the study results, the researchers suggested to facilitate access by persons with disabilities to mobility aids, and to improve the actual state of pedestrian environment. In addition, the function of mobile support center should be expanded to help the mobility disadvantaged persons live independently in community, thereby contributing to the promotion of their quality of life.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12A
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• pp.964-974
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• 2003

With increasing use of a personal mobile computer. the Mobile IPv6 is one of the main protocols that support mobility and complies with IPv6 specification. Similar to the mobile IPv6, the mobile IPv6 also has limitations on fast moving condition. The Hierarchical Mobile IPv6 is a solution that overcomes these limitations. The Hierarchical Mobile IPv6 is a micro mobility protocol that supports fast mobile IP handover and reduces signaling overhead with Mobility Anchor Point(MAP). But until now no paging method is applied to the Hierarchical Mobile IPv6 to reduce unnecessary signaling overhead and power consumption of mobile nodes. So, the paging mechanism for the Hierarchical Mobile IPv6 is proposed in this paper. the mechanism is implemented by making use of the destination option header and extension function and the last location algorithm. The results show that the Hierarchical Mobile IPv6 with the paging ability reduces the traffic of mobile networks by removing unnecessary binding update packet generated whenever handover takes place. Also, the larger the paging size is. the less the number of BU(Binding Update) massage generated.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.1
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• pp.63-76
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• 2015

This study conducted a survey to gauge the buying and wearing propensities of wearers of leg guards made for baseball catchers, as well as product characteristics of preferred leg guards. Data from the survey were analyzed to obtain basic data for the development of an advanced leg guard design. Degree of compression, horizontal distance, cross section view and outline 3D sketch were also analyzed from the 3D data of leg guards; in addition, mobility and kinematic analysis were conducted through a wearing test. The survey indicated that imported products dominate the current retail market because they are appreciated by customers in terms of fit, price, brand, and protection. Representative complaints of products were discomfort, pressure, and the heavy-weight of the leg guards in general attributed to overall structure and 3D shape. When the pressure was lower on the front area of knee, it feels better to wear and the average knee angular velocity during the up and down motion increased, which suggests a better design from a kinematic point of view. The knee is the primary part of the body responsible for any movement of the lower limbs; consequently, the degree of compression and support stability of the leg guards near the knee area are important factors to evaluate the performance of leg guards. The results of our study indicate significant opportunities for improvement in product design and the development of baseball leg guards along with an ergonomic design that considers the mobility of the knee, skin deformations is necessary to improve performance. The process followed in this study will be applicable to studies on other personal protective equipment for sports.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1032-1044
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• 1999

In the mobile communication systems such as PCS(Personal Communication Service), several strategies have been proposed to optimize the signalling traffic load by using the characteristics of traffic and mobile patterns for effective mobility management. According to IS-41 standard, LA(Location Area) consists of static and arbitrarily-defined set of cells, which do not take into account mobility patterns of mobile stations. In this paper, we propose an improved location management mechanism which contains the neighbor cells of the LA selectively using the mobility history of a mobile station and accommodates the LA size adaptively according to the speed of the mobile station. Also, we use the paging priorities for cells in LA to improve the paging efficiency. We compare the performance of conventional mechanism with that of the proposed mechanism using numerical analysis. The analysis results show that the proposed location management mechanism is better than conventional mechanism significantly.