• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8B
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• pp.1105-1114
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• 2010

The Proxy Mobile IPv6 (PMIPv6) has been standardized by the IETF NETLMM WG for network-based mobility management. The PMIPv6 can provide IP mobility for Mobile Nodes (MNs) with low handover latency and less wireless resource usage. But, since the PMIPv6 is basically designed for local mobility management, it cannot support directly global mobility management between different PMIPv6 domains. In the PMIPv6, since all traffic is routed through a Local Mobility Anchor (LMA), it causes a long end-to-end delay and triangular routing problem. Therefore, in this paper, we propose a fast network-based global mobility management scheme and route optimization scheme with a new network entity, called Global Mobility Agent (GMA). Numerical analysis and simulation results show that the proposed scheme is able to support global mobility between different public domains with low handover latency and low end-to-end delay, compared with the PMIPv6.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.214-215
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• 2013

Current competition among companies than regional, the time constraints, it is globalization, Tilt the efforts of many to be operated by building the efficient distribution system to reduce logistics costs and improve customer service it is reality's there. Therefore, the need for industrial complexes environmentally friendly can be cost competitive companies perform cavitation region's increased. To build the distribution center these logistics system through a joint of freight and appropriate policy is required. In particular, efficient operation through the system construction of industrial complexes in the logistics system is very important in terms of friendly low-cost urban logistics, the environment. Since the traffic volume which is Jipufa and utilization of network is transported by a more appropriate technicians and means suitable operating model can efficiency is improved. However, despite these advantages, research network design has not been actively conducted due to the complexity of the problem. Therefore, in this study, by analyzing the logistics system, and presents the operating model through a simulation and basic settings for the model of the logistics complex based on the analysis result, the construction of infrastructure of logistics industry complex it is intended to present the article.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.263-268
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• 2016

A rapid increase of data amount, used in ship-to-ship transmission of safety and logistics information, ships in the inland sea have trouble transmitting real-time information transmission due to an increase in traffic load caused by data transmitted by land station and offshore ships. In this study, therefore, communication is carried out by adaptively controlling the detailed beam width based on the distribution of offshore ships in land station durable in marine environment. Then after the adaptive sector system enabling real-time communication support between ships concentrated in an inland sea and land station is applied, the performance verification is conducted based on the respective Call Blocking Rates of an omnidirectional antenna, fisted sector system, and adaptive sector system. The performance verification result shows that adaptive sector system has better performance than the fixed sector system as the density of ship, q value, increases, and that the smaller the beam width is, the better performance of adaptive sector system will be.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.285-298
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• 2009

According to the development of ubiquitous technologies, sensor networks is used in various area. In particular, medical field is one of the significant application areas using sensor networks, and recently it has come to be more important according to standardization of the body sensor networks technology. There are special characteristics of their own for medical sensor networks, which are different from the one of sensor networks for general application or environment. In this paper, we propose a hierarchical medical sensor networks structure considering own properties of medical applications, and also introduce transmission mechanism based on hierarchical structure. Our mechanism uses the priority and threshold value for medical sensor nodes considering patient's needs and health condition. Through this way Cluster head can transmit emergency data to the Base station rapidly. We also present the new key establishment mechanism based on key management mechanism which is proposed by L. Eschenauer and V. Gligor for our proposed structure and transmission mechanism. We use key provisioning for emergency nodes that have high priority based on patients' health condition. This mechanism guarantees the emergency nodes to establish the key and transmit the urgent message to the new cluster head more rapidly through preparing key establishment with key provisioning. We analyze the efficiency of our mechanism through comparing the amount of traffic and energy consumption with analysis and simulation with QualNet simulator. We also implemented our key management mechanism on TmoteSKY sensor board using TinyOS 2.0 and through this experiments we proved that the new mechanism could be actually utilized in network design.

• Archives of design research
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• v.17 no.3
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• pp.313-322
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• 2004

Product design has direct effects on sales, exciting consumer's interest in purchasing. With the draft bill of Road Traffic Law passing the National Assembly, drivers have been entirely prohibited by the law from using a cell phone while driving since June 30, 2001, As a result, the demand for and the sales of hands-free Kit products for vehicles have been skyrocketing, and more and more of them have been introduced in the market and competing each other in sales. In these situations, the study attempted to present a case study showing the whole process of product design by a small company, which intended to gain an advantage over the competitors in the sector of hands-free products for vehicles with differentiated design. The product whose design development process was presented in the study has many characteristics. Among them it is the most remarkable in removing the connection between the cell phone terminal and the stationary hands-free product. The study was aimed to increase the investment value of design by helping understand that the ultimate goal of technology is commercialization and that how great the role of design is from the beginning to the final stage of product development. It also emphasized the point that one of the goals of design development should lie in providing a more accurate perception of the importance of design to the industry, by establishing a design process throughout the whole stages of product development including initiation, designing and commercialization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2806-2811
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• 2013

New technologies such as multi-antenna and small cell were proposed as key technology for the next generation mobile system to cope with the explosively increasing mobile data traffic. In particular, heterogeneous mobile communication network which can improve spatial reuse factor by exploiting macro and small cells simultaneously is attracting attention. However, the heterogeneous network has a problem that the utilization of small cells becomes low because the transmit power of macro base stations is much higher than that of small base stations and then the probability that mobile stations are attached to the macro base stations becomes high. This problem is dominant in uplink. The concept of cell range expansion bias to mitigate the problem was proposed by 3GPP and the corresponding standardization is in progress. In this paper, we analyze the downlink performance of the heterogeneous mobile communication network based on a system level simulator with the cell range expansion bias in terms of average cell spectral efficiency.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.847-854
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• 2001

The Web continues to grow fast rate in both a large aclae volume of traffic and the size and complexity of Web sites. Along with growth, the complexity of tasks such as Web site design Web server design and of navigating simply through a Web site have increased. An important input to these design tasks is the analysis of how a web site is being used. The is paper proposes a Page logging System(PLS) identifying reliably user sessions required in Web mining system PLS consists of Page Logger acquiring all the page accesses of the user Log processor producing user session from these data, and statements to incorporate a call to page logger applet. Proposed PLS abbreviates several preprocessing tasks which spends a log of time and efforts that must be performed in Web mining systems. In particular, it simplifies the complexity of transaction identification phase through acquiring directly the amount of time a user stays on a page. Also PLS solves local cache hits and proxy IPs that create problems with identifying user sessions from Web sever log.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.13-24
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• 2009

This study developed a high strength and performance concrete pavement material with low shrinkage and reflection of sunlight. Based on the literature review, a new mix-design of applying flash ash to improve the strength and performance of the concrete as well as to reduce the dry shrinkage is suggested. In addition, adding black pigment to reduce the reflection and technique of applying OAG (Optimized Aggregate Gradation) is also included. The result of the laboratory experiment indicates that the brightness and the reflection, which depends on the ratio of black pigment addition, did not deviate from the normal range. When OAG is considered for the mix-design, the strength and performance of the concrete improved greatly. In addition, the mix-design using fly ash reduced the dry shrinkage of concrete and improved the resistance to the permeation of chloride ion. Furthermore, the mix-design, which uses fly ash (25% replacement) and black pigment (3% addition) with the application of OAG, is found to be the most effective mix to reduce the shrinkage and reflection as well as improving the strength and performance of the concrete. The result of an economic analysis indicates that the initial construction cost of this proposed mix is more expensive than that of normal concrete pavement material. However, it can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.

• Journal of Korean Society of Rural Planning
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• v.26 no.4
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• pp.27-39
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• 2020

With the COVID-19 pandemic, the global economy has stagnated and our daily lives have changed. The rural economy is also experiencing damage, such as an average of 65% or more decrease in the number of visitors to rural experience resort villages due to the spread of COVID-19. In order to minimize the damage arising from the prolonged coronavirus, a hospitality system in response to changes in rural tourism behavior and consumer demand is needed to revitalize rural areas and maintain continuous economic independence. Therefore, this study attempted to find ways to utilize landscape resources such as education, culture, history, and ecology in order to complement the existing experience programs in connection with local resources and local environment. Wibong Village, which is the subject of the study, attempted to revitalize the village using the resources through the "Creative village creation" project in 2015. Due to poor management of historical resources, difficulty in operating experience programs, and response to changes in the natural environment, the rate of implementation of the project plan was very low. Currently, the demand for experience is also decreasing due to the COVID-19 effect, so it was judged that it was necessary to develop an experience village program suitable for the needs of experienced visitors by discovering additional local resources for the continuous operation of the experience village. In order to solve the problem of the use of landscape resources and the spatial composition of the study site, additional investigations of local resources were made, and an experience program course that could be operated by theme was proposed by configuring a space suitable for the use of landscape resources. By dividing the additionally investigated landscape resources into history, ecology, and region, an experiential course was created to separate the traffic lines, and the space composition for large-scale experienced visitors that had been previously operated was constructed in a form suitable for the post-corona era. In addition, at least two experiential tour courses that can be operated by period were proposed to maintain economic effects. Starting with this study, if further research on the creation and spatial composition of a rural experience village centered on the connection with the region, it will be used as research results that can be referenced in projects such as village creation, rural space planning, and living area analysis. It is expected that it will be able to effectively cope with the construction of a rural area suitable for the post-corona era, where demand is expected to increase in the future.

• Journal of Trauma and Injury
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• v.27 no.3
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• pp.50-56
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• 2014

Purpose: Rollover motor vehicle crashes have a higher injury severity and fatality than other motor vehicle crash types. From a left-quarter turn rollover accident of 25-passenger bus, we intend to assess the injury of the occupant and the injury severities according to the occupants' position. Methods: We carried out the 3 steps investigation of occupants' interview, visiting the repair shop and using the police report. We analyzed injuries sustained by occupants, and compared injury severities considering column, row in occupant's position and passenger interaction Results: The rollover involved 14 passengers in the bus who were all old women except a man driver. The most common injury was in the upper extremity, with six occurrences being a left clavicle fracture. Major injuries including hemothorax and pneumothorax were diagnosed at left side of the occupant. In the comparison of injury severity among driver's column (left side), mid column and passengercolumn, ISS of passenger column was the highest ($9.9{\pm}7.4$, $8.8{\pm}5.5$, and $10.3{\pm}4.0$, respectively, p>0.05). The injury severity of multiple occupants by row was higher than that of single occupant (10.8 vs. 3, p<0.05). Conclusion: An occupant must fasten their seat belt to prevent an injury by passenger interaction in the left-quarter turn rollover accident of a bus.