• Communications for Statistical Applications and Methods
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• v.18 no.1
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• pp.71-77
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• 2011

In this paper, asymptotic results are investigated when a parametric transformation is applied to ARMA models. The conditions are determined to ensure the strong consistency and the asymptotic normality of maximum likelihood estimators and the correct coverage probability of the forecast interval obtained by the transformation and backtransformation approach.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2658-2679
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• 2018

This paper proposes a novel Random Scheduling Algorithm based on Subregion Coverage (RSASC), to solve the SET K-cover problem (an NP-complete problem). SET K-cover problem distributes the set of sensors into the maximum number of mutually exclusive subsets (MESSs) in such a way that each of them can be scheduled for lifetime extension of WSN. Sensor coverage divides the target region into different subregions. RSASC first sorts the subregions in the ascending order concerning their sensor coverage. Then, it forms the subregion groups according to their similar sensor coverage. Lastly, RSASC ensures the K-coverage of each subregion from every group by randomly scheduling the sensors. We consider the target-coverage and area-coverage applications of WSN to analyze the usefulness of our proposed RSASC algorithm. The distinct quality of RSASC is that it utilizes less number of deployed sensors (33% less) to form the optimum number of MESSs with the higher computational speed (saves more than 93% of the time) as compared to the existing three algorithms.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.406-412
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• 2010

In this paper, we formally define the problem of maximizing the coverage of sensor deployment, which is the optimization problem appeared in real-world sensor deployment, and analyze the properties of its solution space. To solve the problem, we proposed novel genetic algorithms, and we could show their superiority through experiments. When applying genetic algorithms to maximum coverage sensor deployment, the most important issue is how we evaluate the given sensor deployment efficiently. We could resolve the difficulty by using Monte Carlo method. By regulating the number of generated samples in the Monte Carlo evaluation of genetic algorithms, we could also reduce the computing time significantly without loss of solution quality.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.116-119
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• 2015

In this paper we propose an algorithm for environment monitoring using multiple mobile sensor (MS) nodes. Our focus is on maximizing sensing coverage of a group of MS nodes for monitoring a phenomenon in an unknown and open area over time. In the proposed algorithm, MS nodes are iteratively relocated to new positions at which a higher sensing coverage can be obtained. We formulated an integer linear programming (ILP) optimization problem to find the optimal positions for MS nodes with the objective of coverage maximization. The performance evaluation was performed to confirm that the proposed algorithm can enable MS nodes to relocate to high interest positions, and obtain a maximum sensing coverage.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.97-100
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• 2008

This study estimated the error involved in the areal average rainfall derived incomplete radar information due to radar partial coverage of a basin or sub-basin. This study considers the Han River Basin as an application example for the rainfall observation using the Ganghwa rain radar. Among the total of 24 mid-sized sub-basins of the Han River Basin evaluated in this study, only five sub-basins are fully covered by the radar and three are totally uncovered. Remaining 16 sub-basins are partially covered by the radar leading incomplete radar information available. When only partial radar information is available, the sampling error decreases proportional to the size of the radar coverage, which also varies depending on the number of clusters. It is general that smaller sampling error can be expected when the number of clusters increases if the total area coverage remains the same. This study estimated the sampling error of the areal average rainfall of partially-covered mid-sized sub-basins of the Han River Basin, and the results show that the sampling error could be at least several % to maximum tens % depending on the relative coverage area.

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.78-82
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• 1992

The changes in work function due to hydrogen and deuterium adsorption on W(123) plane are measured by means of Field Emission Method. In the case of hydrogen or deuterium adsorption, work function of W(123) plane at 78 K increase and after a maxium value, it decrease and saturated as increasing coverage. After annealing the tungsten emission tip at 200 K, the coverage corresponding to maximum change in work function was shifted toward low coverage and the effect of work function by terraces or steps of which orientation is [ O l l ] was observed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6B
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• pp.403-410
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• 2008

In this paper, we investigate the performance of MMR system in Non-transparent mode. The IEEE 802.16j MMR system has two node of operation, Single-frame (in band) and Multi-frame (out band) mode. In the analysis, we assume that channel interference between MR-BS and RS, or between RSs anywhere in the given area is ignored. The performance is presented in terms of the delay and the frame efficiency by varying number of RS and BS coverage to RS coverage ratio and the maximum coverage area of a BS by varying traffic density. Analytical results show that the Single-frame is more efficient than Multi-frame in frame efficiency and coverage extension.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.176-179
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• 2009

In this study, Urban Climate Simulation was performed using 3-Dimensional Urban Canopy Model. The characteristics of urban thermal environment was analyzed by classifying land coverage and increasing natural land coverage ratio. The results are as follows. The characteristics of the land coverage on urban thermal environment formation can be summarized by the effects like higher temperature on the artificial coverage, and the contrary effects on the natural coverage. When the water coverage 100% was made up, maximum temperature was declined by $5.5^{\circ}C$, humidity by the 6.5g/kg, wind velocity by 0.6m/s, convective sensible heat by $400W/m^2$ and the evaporative latent heat was increased by $370W/m^2$ compared to when artificial coverage 100% was formed. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analysing urban climate phenomenon.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.667-673
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• 2024

This study aims to diagnose the issues arising from the relationship between the out-of-pocket maximum in health insurance and private indemnity health insurance and propose policy tasks for institutional improvement. Through literature research, the study analyzed the damage to consumers caused by the non-payment of refunds exceeding the out-of-pocket maximum and the changing role of indemnity insurance due to the strengthening of health insurance coverage. The results confirmed that unilateral interpretation of insurance clauses and incomplete sales practices infringe upon consumer rights, and that insurance premiums do not decrease despite the reduction in coverage of indemnity insurance. Therefore, the study emphasized the urgency of institutional improvements such as rationalization of product structure, transparency of risk rate calculation, and reinforcement of consumer information provision, as well as the need for social consensus on the rational division of roles between health insurance and private insurance. This study is significant in that it provides policy implications for the developmental reorganization of the healthcare system.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.181-186
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• 2001

In this study, we observed air temperature to make clear that land coverage condition and forest form has a certain relationship to air temperature in a day in various green space. And with revolution analysis, interpreted relationship of air temperature distribution in the green space, of land coverage rate and air temperature, of volume of tree and temperature. With this experimental result, propose green plan, taking into consideration lower effect of air temperature. In this result lower zone is formed in forest and water area, higher zone is done in paved surface and barren ground. And arbor＋subarbor area, water area sur-rounded forest and small river is formed relative lower air temperature. In my opinion to promote efficiency lower air temperature area, it is need to make water area surrounded forest, to make forest form lower air temperature 2∼3 layer forest. Lower air temperature effect is in order of arbor, subarbor, shrub and is proportioned increasing of tree.