• Journal of the Korea Society of Computer and Information
• /
• v.22 no.9
• /
• pp.33-40
• /
• 2017

In this paper, we propose a sink-location management and data-routing scheme to effectively support the mobile sink in solar-powered WSN. Battery-based wireless sensor networks (WSNs) have a limited lifetime due to their limited energy, but solar energy-based WSNs can be supplied with energy periodically and can operate forever. On the other hand, introduction of mobile sink in WSNs can solve some energy unbalance problem between sink-neighboring nodes and outer nodes which is one of the major challenges in WSNs. However, there is a problem that additional energy should be consumed to notify each sensor node of the location of the randomly moving mobile sink. In the proposed scheme, one of the nodes that harvests enough energy in each cluster are selected as the cluster head, and the location information of the mobile sink is shared only among the cluster heads, thereby reducing the location management overhead. In addition, the overhead for setting the routing path can be removed by transferring data in the opposite direction to the path where the sink-position information is transferred among the heads. Lastly, the access node is introduced to transmit data to the sink more reliably when the sink moves frequently.

• Korean System Dynamics Review
• /
• v.8 no.1
• /
• pp.67-95
• /
• 2007

This paper focuses on prototype management models of location conflict concerned with crematory facilities in Korea. Using causal loops and stock-flow diagrams, it examines behavioral patterns of key variables, which would contribute to developing objective evaluation criteria. After a series of simulation works, the paper finds that the top priority should be given to how to improve neighboring residents' perception, ahead of specific compensation issues. Otherwise, they are open to vicious cycles or impasse. Juxtaposing individual cases together, Pusan and Cheongju examples which experienced the extreme confrontation in the initial stage could succeed in resolving crematory location conflict, especially between local residents and the public authorities, as the latter has repeatedly guaranteed to the former higher standards of participation. The opposite was almost true for Seoul and Ulsan cases, both of which were drawn into a crematory location whirlpool, incrementally losing resident's participation base. These results imply that the proposed management models would enhance mutual understanding among major stake-holders in relatively a shorter time, not to mention the overall cost.

• The KIPS Transactions:PartC
• /
• v.8C no.5
• /
• pp.677-682
• /
• 2001

In a microcell environment having frequent inter-cell movement of a subscriber, the amount of signalling traffic rapidly increases due to the treatment of location update and other necessary actions. As a way to reduce such an overhead, this paper presents an algorithm that dynamically allocates subscribers paging and location areas each of which has a different size and shape, depending on the characteristics of subscriber mobility. Mathematical analysis results show that this algorithm allows reduced area management cost, compared to conventional algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.8B
• /
• pp.1444-1455
• /
• 1999

In the standard location strategy such as IS-41 and GSM, Home Location Register(HLR) and Visitor Location Register(VLR) databases are used to manage the location of mobile terminals. The primary goal that location management schemes investigate is to reduce the cost of database access and the traffic for signaling network. When mobile terminals move frequently, one of problems in the standard location management scheme is that HLR database is highly updated and the traffic in signaling network can be occurred significantly due to high message transfer rate between HRL and VLR. As a solution to these problems, this paper proposes the location management scheme using VLR Gateway(VG) to reduce the both traffics of HLR update and signaling network which are resulted from location registration requirements of mobile terminals whenever they cross their registration area boundary. VG is a kind of database that is placed between HLR and VLR. It integrates one or more registration area defined in a system into one group and plays a role on behalf of HLR in a integrated registration scope so that the call delivery and the movement of mobile terminals are possible without HLR access in the scope. In order to evaluate performance of IS-41 and proposed scheme, we simulate two schemes based on wide range of call to mobility ratio. Its experiment result shows that in the proposed scheme total database cost increased slightly whereas HLR and signaling traffic decreased remarkably.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.11 no.2
• /
• pp.37-45
• /
• 2015

The technology development of MANET and dissemination of P2P services has been made very widely. In particular, the development of many application services for the integration of P2P services in MANET has been made actively. P2P networks are commonly used because of the advantages of efficient use of network bandwidth and rapid information exchange. In P2P network, the infrastructure managing each node in the middle does not exist and each node is a structure playing a role as the sender and receiver. Such a structure is very similar to the structure of the MANET. However, it is difficult to provide reliable P2P service due to the high mobility of mobile nodes. In this paper, we propose location-based routing technique in order to provide efficient file sharing and management between nodes. GMN managing the group is elected after network is configured to the area of a certain size. Each node is assigned an identifier of 12 bit dynamically to provide routing which uses location information to the identifier. ZGT is managed in the GMN in order to provide management of group nodes and distributed cache information. The distributed cache technique is applied to provide a rapid retrieval of the sharing files in the each node. The excellent performance of the proposed technique was confirmed through experiments.

• Journal of the Korea Safety Management & Science
• /
• v.21 no.4
• /
• pp.51-58
• /
• 2019

The LBS(Location Based Service) technology plays an important role in reducing wastes of time, losses of human lives and economic losses by detecting the user's location in order by suggesting the optimal evacuation route of the users in case of safety accidents. We developed an algorithm to estimate indoor location, movement path and indoor location changes of smart phone users based on the built-in sensors of smartphones and the dead-reckoning algorithm for pedestrians without a connection with smart devices such as Wi-Fi and Bluetooth. Furthermore, seven different indoor movement scenarios were selected to measure the performance of this algorithm and the accuracy of the indoor location estimation was measured by comparing the actual movement route and the algorithm results of the experimenter(pedestrian) who performed the indoor movement. The experimental result showed that this algorithm had an average accuracy of 95.0%.

• The KIPS Transactions:PartC
• /
• v.11C no.2
• /
• pp.213-218
• /
• 2004

Recently MIP becomes more important for the macro mobility support in the emergence of the global system such as IMT-2000. However this Protocol suffers from many weaknesses on the location management. MIPv4 regional registration is presented for the local registration of MNs. MIPv6 can benefit from the reduced mobility signaling with external networks by employing a local MAP, that is called HMIPv6. The total signaling cost of HMIPv6 is rapidly increased by the number of CNs of an MN when the MN moves around between MAPs. In this paper, we propose a new location management scheme in MIPv6 that reduces the total signaling cost in the location update based on HMIPv6 Here the MN does not send the BU to CNs and HA when it moves around between MAPs. Instead it informs the current location by transferring the modified BU to the previous MAP. According to the results of the performance analysis, we determine the upper bound for the number of forwarding links allowed among adjacent MAPs without the BU information.

• Journal of the Korea Safety Management & Science
• /
• v.26 no.2
• /
• pp.43-53
• /
• 2024

This study analyzes the importance-performance analysis (IPA) of the 10 dimensions of the smart construction safety management system, and analyzes which dimensions are important and which dimensions are performing to determine key improvement tasks, incremental improvement tasks, Maintenance and reinforcement tasks and continuous maintenance tasks were derived. Among the 10 dimensions of the smart construction safety management system, the dimensions that are recognized as important by all field managers and field workers and have high performance are the automatic risk displacement measurement system, smart environmental sensor system, and heavy equipment seizure prevention system. However, areas that were perceived as having high importance but low performance were worker location tracking systems, smart safety helmet chin muscles, and smart safety ring fastening. Among the smart construction safety management systems perceived by field managers, areas for key improvement with high importance and low performance included worker location tracking system and smart safety ring fastening. Among the smart construction safety management systems perceived by field workers, the area for key improvement with high importance and low performance was the automatic risk displacement measurement system.

• International journal of advanced smart convergence
• /
• v.7 no.3
• /
• pp.61-65
• /
• 2018

A Location Register(LR) system manages each subscriber's location information, which continuously changes in mobile cellular network. For this purpose, the LR database system provides backup management facilities. The objectives of this paper are to identify the problems of the current LR system through rigorous analysis, to suggest solutions to them. I proposed efficient backup methods that takes into account the characteristics of LR database transactions. In the proposed backup method, I use two kinds of dirty flags in order to solve the performance degradation problem caused by frequent registration- location operations.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.5
• /
• pp.1179-1186
• /
• 1996

A previous location area scheme was proposed for cellular network, in which the size of location area of a user is dynamically determined by is current mobility and call arrival rate as the burden of system reaches the minimum. This scheme, however, doesn't consider other individual's movement pattern respectively because of allocating location area with a system's fixed pattern. When mobile subscribers move fast, this scheme allocates especially so large location area to reduce the number of location registration that it makes much paging cost. In this paper, we suggest new dynamic location area management which allocates location area according to each subscriber's mobility regarding its current location as center point. This new scheme allocates fast subscriber larger location area, which resulted in reducing the number of location registration. And small area paging reduces paging cost.