• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.611-614
• /
• 2006

Resolution 122 requires to study power limitation applicable for HAPS ground stations to facilitate sharing with space station receivers in 47/48GHz bands. ITU-R Recommendation 1481-1 recommends to improve the side lobe characteristics of HAPS ground station antenna for sharing between FSS system and HAPS system. Thus, in this paper, we propose maximum allowable off-axis e.i.r.p. level of HAPS ground station antennas by considering power limitation to HAPS ground station in Resolution 122 in order to reduce unfeasible separate distance between HAPS and GSO FSS service coverage and improve the side lobe characteristics of HAPS ground station antennas in Recommendation SF.1481-1.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.1
• /
• pp.233-241
• /
• 2013

One fundamental issue in ad hoc networks is the alternative node election problem, which reflects how well a sensor network is monitored or tracked by sensors. In this paper, we proposed EEAP(Energy-Efficient Alternative Paths). This is a method of selecting an alternative node for path routing management. When some node disconnection on the path routing, using pre-selected backup node provides immediately recover the path recovery. When selecting an alternative node of Step-Parents head node on the path management, the node's energy level and distance information are cared in context-awareness. This is not only increased the system's capacity cost effectively, but also reduce transmission power entire nodes consume energy. As a result, each node could efficiently management and improves the life time for mobile host and extends system coverage.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.4
• /
• pp.846-851
• /
• 2007

The wireless sensor network is one of the most practical and cost-effective solutions for monitoring systems covering wild and wide area such as wildfire monitoring. However, the RF distance between sensor nodes is very short due to the need of low power consumption of the sensor node, so the number of sensor nodes to be deployed in the target area is more than tens of thousands. In this paper, we design and analyze the deployment issues as well as re-deployment problem occurred when the battery is exhausted. We also propose the needs and solutions for coverage problem in dynamic deployment. By the experimental evaluations, we analyze the packet success ratio between sensor nodes under various environments such as obstacles and variable distances.

• International Journal of Computer Science & Network Security
• /
• v.21 no.12
• /
• pp.1-8
• /
• 2021

In Mobile Ad-Hoc Network (MANET) Application, routing protocol is essential to ensure successful data transmission to all nodes. Ad-hoc On-demand Distance Vector (AODV) Protocol is a reactive routing protocol that is mostly used in MANET applications. However, the protocol causes Route Request (RREQ) message flooding issue due to the broadcasting method at the route request stage to find a path to a particular destination, where the RREQ will be rebroadcast if no Request Response (RREP) message is received. A scalable neighbor-based routing (SNBR) protocol was then proposed to overcome the issue. In the SNBR protocol, the RREQ message is only rebroadcast if the number of neighbor nodes less than a certain fix number, known as drop factor. However, since a network always have a dynamic characteristic with a dynamic number of neighbor nodes, the fix drop factor in SNBR protocol could not provide an optimal flooding problem solution in a low dense network environment, where the RREQ message is continuously rebroadcast RREQ message until reach the fix drop factor. To overcome this problem, a new broadcasting method as Dynamic SNBR (DSNBR) is proposed, where the drop factor is determined based on current number of neighbor nodes. This method rebroadcast the extra RREQ messages based on the determined dynamic drop factor. The performance of the proposed DSNBR is evaluated using NS2 and compared with the performance of the existing protocol; AODV and SNBR. Simulation results show that the new routing protocol reduces the routing request overhead, energy consumption, MAC Collision and enhances end-to-end delay, network coverage ratio as a result of reducing the extra route request messages.

• Journal of Cadastre & Land InformatiX
• /
• v.48 no.2
• /
• pp.185-195
• /
• 2018

In the Seoul Metropolitan City, the PM(pariculate matter) application used by the citizens provides the PM concentration of the nearest monitoring stations located on the PM monitoring stations. Currently, the selecting method of the PM monitoring network considered by the Ministry of Environment is based on considering the monitoring station distribution and population density only. In this study, we analyzed the distance between PM monitoring station and the administrative center point in addition to the above considerations. The number of test sites was verified and the range of coverage of each monitoring stations was indicated by using the Voronoi algorithm and hexagon grid. The spatial position problem of the PM monitoring station was suggested by spatial data analysis. The variables of spatial data analysis are single-family houses, apartments, $1^{st}$ class neighborhood, $2^{nd}$ class neighborhood, garbage disposal plant, hazardous material disposal facility, factory, and the density map. The analysis result of the selection criterion considering the additional variables for new PM monitoring stations was presented, in addition to the selection criteria provided by the Ministry of Environment.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.26 no.6
• /
• pp.221-234
• /
• 2023

This study was conducted to develop a habitat assessment system for the endangered wildlife II Kirengeshoma koreana Nakai through in-depth interviews with experts based on field surveys and environmental characteristics through spatial data analysis and literature research. Evaluation factors were selected based on the survey results of 31 variables for 23 K. koreana habitats. Afterwards, the importance and evaluation range for each assessment factor were selected. The selection of survey variables, assessment factors, importance of each factor and assessment range was conducted through in-depth interviews with experts at each stage. As a result, the assessment factors and importance were 16% for precipitation of the wettest month, 10% for vegetation zone, 12% for vegetation type, 10% for crown canopy vitality, 14% for tree layer coverage, 13% for drainage grade, 12% for soil depth, and 13% for distance to stream including dry stream. This study provides basic ecological information and a habitat assessment system for K. koreana habitats. Therefore, it can be used as primary data for preparing an endangered wildlife conservation policy, preparing a habitat improvement plan, and selecting an alternative habitat.

• Korean Circulation Journal
• /
• v.53 no.11
• /
• pp.727-743
• /
• 2023

Although cardiac rehabilitation (CR) has been shown to improve exercise tolerance and prognosis in patients with cardiovascular diseases, there remains low participation in outpatient CR. This may be attributed to the patients' busy schedules and difficulty in visiting the hospital due to distance, cost, avoidance of exercise, and severity of coronary disease. To overcome these challenges, many countries are exploring the possibility of remote CR. Specifically, there is increasing attention on the development of remote CR devices, which allow transmission of vital information to the hospital via a remote CR application linked to a wearable device for telemonitoring by dedicated hospital staff. In addition, remote CR programs can support return to work after hospitalization. Previous studies have demonstrated the effects of remote CR on exercise tolerance. However, the preventive effects of remote CR on cardiac events and mortality remain controversial. Thus, safe and effective remote CR requires exercise risk stratification for each patient, telenursing by skilled staff, and multidisciplinary interventions. Therefore, quality assurance of telenursing and multi-disciplinary interventions will be essential for remote CR. Remote CR may become an important part of cardiac management in the future. However, issues such as cost-effectiveness and insurance coverage still persist.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.17 no.2
• /
• pp.109-123
• /
• 2014

Kaloula borealis is the species of Amphibia which belongs to Kaloula genus and it is the only species inhabiting in Korea. The population size and habitat of Kaloula borealis have been significantly decreased on a national scale due to the diversified developments and the uses of agricultural pesticides. Accordingly, the Ministry of Environment has designated and managed them as the class II of endangered species, in accordance with "Endangered Species Protection and Management Act"; however, a particular study focused on the ecological restoration of Kaloula borealis is desperately needed to prevent their extinction. This study was conducted to propose the HSI (Habit Suitability Index) of Kaloula borealis based on literature survey on ecology and habitats of Kaloula borealis, as well as their HSI. Factors to be investigated in HSI include: space, feed, cover, water(breeding) and threatening factors and the variables of each factor were also proposed. The distance from wetland, grassland, farm, stream and rice paddy, as well as the altitude of spawning pond were proposed as the variables of space, whereas the bed structure of forest and low-rise grassland were proposed as the variables of feeding. The variables of water (breeding) include the area of permanent and temporary wetlands, coverage of emerged pants (ratio of open water), water depth, water temperature, water quality, pH level, etc., whereas the presence of predator, distance from street and pollutants were proposed as the variables of threatening factor. The sub-standards by HSI factor of Kaloula borealis have been drawn from in-depth consultation with experts and based on this, the final HSI of Kaloula borealis was developed.

• Korean journal of communication and information
• /
• v.35
• /
• pp.362-393
• /
• 2006

The purpose of this manuscript was to investigate the effects of issue involvement and relation of perceivers to comparison targets on the magnitude of third person perceptions. The investigation was expected to help us to understand the underlying process of third person effect hypothesis. Data was collected from adult residents in Ohio, United States by telephone survey in 2003(n=524). Like most other third person effect studies, this study supported the hypothesis: Respondents perceived more media effects on others than themselves for both 'Negative media portrayals of smokers' and 'News coverage of Roman Catholic priest's sexual scandals'. Results of five hypothesis tests suggest that when relationship between a perceiver and a particular comparison target is present third person perception is explained more by cognitive components than motivational components. In this case, third person perception varies with comparison target's issue involvement while it is independent of social distance between the perceivers and the comparison target. Also, perceivers' issue involvement positively correlates with the magnitude of third person effect. Based on the results, it is concluded that when perceives or a comparison target is involved in a message cognitive processes accounting for the relationship can impact the magnitude of third person effect. An important theoretical implication of the study is that third person effect is, to some extent, related with framing effect and priming effect.

• KIPS Transactions on Software and Data Engineering
• /
• v.5 no.12
• /
• pp.653-662
• /
• 2016

This paper describes a test case generation algorithm for Simulink/Stateflow models based on the Rapidly exploring Random Tree (RRT) algorithm that has been successfully applied to path finding. An important factor influencing the performance of the RRT algorithm is the metric used for calculating the distance between the nodes in the RRT space. Since a test case for a Simulink/Stateflow (SL/SF) model is an input sequence to check a specific condition (called a test target in this paper) at a specific status of the model, it is necessary to drive the model to the status before checking the condition. A status maps to a node of the RRT. It is usually necessary to check various conditions at a specific status. For example, when the specific status represents an SL/SF model state from which multiple transitions are made, we must check multiple conditions to measure the transition coverage. We propose a unique distance calculation metric, based on the observation that the test targets are gathered around some specific status such as an SL/SF state, named key nodes in this paper. The proposed metric increases the probability that an RRT is extended from key nodes by imposing penalties to non-key nodes. A test case generation algorithm utilizing the proposed metric is proposed. Three models of Electrical Control Units (ECUs) embedded in a commercial vehicle are used for the performance evaluation. The performances are evaluated in terms of penalties and compared with those of the algorithm using a typical RRT algorithm.