• The Mathematical Education
• /
• v.62 no.3
• /
• pp.417-433
• /
• 2023

In the 2022 revised mathematics curriculum, a new content on 'Movement of a point' was added. Therefore, this study analyzed the contents of the movement of a point presented in Finnish mathematics textbooks as elements of spatial orientation. Analysis was conducted by dividing it into direction, distance, and route. As a result of the study, in Finnish textbooks, directions were expressed in various ways, such as linguistic, visual, and coded expressions. In the case of distance, activities to move as much as the distance or compare the distance were presented using the number of cells, length, steps, coordinate points, ratio, etc. In the case of routes, activities such as moving according to instructions, making routes, finding the route, and modifying the route were presented using unconditional movement and conditional movement. In particular, the movement of a point could be linked not only to various mathematical content areas such as 'number and arithmetic' and 'change and relationship', but also to digital literacy and programming education. Knowing that the movement of a point can be presented in various ways according to the direction, distance, and route, it is expected that it can be used to organize the contents of the 2022 revised mathematics textbook.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2005.11a
• /
• pp.311-314
• /
• 2005

Our city structure is being complicated from the development of industry and the increase in population. It makes the ground space overcrowded, so underground space is systematized for use. Because this underground space has very complicated configuration, people have difficulty in finding the route in the underground space. Therefore It is demanded to comprehend configuration of the various space structure, predict pattern of the moving and analyze induction factor of the moving. When people are in the conflagration or dangerous situation, they are in the habit of using the route which they are used to go to and from. It is needed to analyze moving pattern of the pedestrian who usually use the underground space for the sake of dealing with conflagration in the underground space. Finally, this study suggested that general characteristic, distribution, moving route of the pedestrian and factors influencing that they choose the route which the research finds out.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.45 no.6
• /
• pp.131-138
• /
• 2008

Mobile Ad hoc NETworks (MANETs) refer to autonomous networks in which wireless data communications are established between multiple nodes in a given coverage area without a base station or centralized administration. Because of node mobility and limited battery life, the network topology may changes frequently. Selecting the most reliable path during route discovery process is important to improve performance in ad hoc networks. In this paper, an enhanced routing protocol based on AODV(Ad hoc On-demand Distance Vector routing) by monitoring variation of receiving signal strength is proposed. New metric function that consists of node mobility and hops of path is used for routing decision. For preventing route failure by node movement during data transmission, a new route maintenance named as LRC (Local Route Change) is presented. If the node movement is detected, the routing agent switches path to its neighbor node in LRC. Simulation results show that the performance of the proposed routing scheme is superior to previous AODY protocol.

• The korean journal of orthodontics
• /
• v.42 no.3
• /
• pp.118-128
• /
• 2012

Objective: The aim of this study was to investigate and compare the in vivo effects of prostaglandin E2 (PGE2) administered by different methods on orthodontic tooth movement and bone metabolism macroscopically, histopatologically, and biochemically. Methods: Forty-five young adult New Zealand rabbits were randomly divided into 3 experimental groups (n = 10/group), 1 positive control group (n = 10), and 1 negative control group (n = 5). The experimental rabbits were fitted with springs exerting 20-g reciprocal force on the maxillary incisors and PGE2 (10 ${\mu}g/mL$) was administered by the intravenous, submucosal, or intra ligamentous route aft er appliance insertion and on days 1, 3, 7, and 14 thereafter. All rabbits were sacrificed on day 21 and their premaxillae were resected for histologic evaluation. Results: Tooth movement was observed in the experimental and positive control groups, but the intraligamentous PGE2 group had the highest values of all analyzed parameters, including serum calcium and phosphorus levels and osteoclastic and osteoblastic populations (p < 0.001). Conclusions: Sub mucosal and intraligamentous PGE2 administration significantly increases orthodontic tooth movement and bone metabolism, but the intraligamentous route seems to be more effective.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.4 no.1
• /
• pp.14-19
• /
• 2009

In Mobile Ad-hoc Network, link failure and packet loss may occur frequently due to its nature of mobility and limited battery life. In this paper, an enhanced robust routing protocol based on AODV(Ad hoc On-demand Distance Vector routing) by monitoring variation of receiving signal strength is proposed. New metric function that consists of node mobility and hops of path is used for routing decision. For preventing route failure by node movement during data transmission, a new route maintenance is presented. If the node movement is detected, the routing agent switches local path to its neighbor node. Simulation results show that the performance of the proposed routing scheme is superior to previous AODV protocol.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10c
• /
• pp.31-33
• /
• 2004

We suggest an enhanced automatic route shortening method for dynamic source routing (DSR) protocol. DSR is a request / response based protocol which has low routing overhead owing to node movement. The original automatic route shortening is performed on the only nodes that belong to the source route of packets. On the contrary, our suggested method allows all neighbor nodes hearing the packet to participate in automatic route shortening. It makes all possible route shortenings be performed. So we maintain maximal short routes of ongoing data connections. Simulation results show that our method pays small extra overhead for ARS, but increases the ratio of packet transmissions and ARS' are performed from 2 to 5 times as much as original ARS.

• The Journal of Engineering Research
• /
• v.7 no.1
• /
• pp.37-51
• /
• 2005

An and hoc network is a collection of wireless mobile nodes forming a temporary network without the centralized administration. Due to the limited transmission range of wireless work interface, multiple networks "hops" maybe needed for one node to exchange data with adjacent node. In recent years, a variety of new routing protocol about ad hoc network was developed. This paper presents a new routing protocol based on the Dynamic Source Routing which is not suitable for the high mobility ad hoc network. The Enhanced DR adapts quickly to routing changes when node movement is frequent. When a trunk route is broken, this protocol will utilize the alternative route saved in the route to discovery quickly the new route. It improves the performance of the existing DSR algorithm, so that the negative impacts from weakness of DSR are reduced.

• 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%.

• Journal of KIISE:Information Networking
• /
• v.33 no.1
• /
• pp.49-58
• /
• 2006

When the movement of a node breaks the route in ad-hoc network, on-demand routing protocol performs the local route recovery or a new route search for the route maintenance. And when it performs the new route search or the local search, the packet which is transmitted can be delayed. There are ARMP and RPAODV as the methods reducing the delay resulted from the route-breakage. They predict the route-breakage and construct an alterative local route before the occurrence of the route-breakage. When the link state is unstable, the success rate of the alternative local route that can avoid the route-breakage can give a direct effect on the route-breakage and the transmission delay, To estimate the performance of routing protocols avoiding route-breakage, we suggest the numerical formulas of AODV, the representative on-demand routing protocol, and ARMP, RPAODV. To verify the efficiency and accuracy of the proposed numerical formulas, we analysis and compare with the results of the computer simulation and that of the numerical formulas.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.553-556
• /
• 2000

This paper suggests the way to perform the handover by predicting the movement route of the mobile terminal by considering the movement pattern of the user. By considering the fact that the most users has the constant movement pattern, the channels needed fur the handover can be reserved, and the required quality of service (QoS) is maintained during handover. The suggested algorithm makes the channel allocation schemes more efficient.