• Journal of the Institute of Convergence Signal Processing
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• v.18 no.2
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• pp.62-67
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• 2017

In this paper, we propose a fast motion estimation algorithm which is important in performance of video encoding. Even though so many fast algorithms for motion estimation have been published due to tremendous computational amount of full search algorithm, efforts for reducing computations of motion estimation still remain. In the paper, we propose an algorithm that reduces unnecessary computations only, while keeping prediction quality the same as that of the full search. The proposed algorithm does not calculate block matching error for each candidate directly to find motion vectors but divides the calculation procedure into several steps and calculates partial sum of block errors for candidates with high priority. By doing that, we can find the minimum error point early and get the enhancement of calculation speed by reducing unnecessary computations. The proposed algorithm uses smaller computations than conventional fast search algorithms with the same prediction quality as the full search algorithm.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.72-79
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• 2021

This basic study introduces the concept of S-BRT and develops dwell time estimation models that consider road geometry and S-BRT characteristics for a signal operation strategy to meet the S-BRT's operational goal of high speed and punctuality. Field surveys of low-floor buses similar in shape to S-BRTs and data collection of passengers, station elements, vehicle elements, and other factors that can affect stop times were used in a regression analysis to establish statistically significant dwell time estimation models. These dwell time estimation models are developed by categorizing according to the locations of the signal or sidewalk that have the most impact on the dwell time. In this way, the number of people boarding and alighting the bus at the crowded door and the number of people boarding and alighting the bus at the front door considering the internal congestion was analyzed to affect the dwell time. The estimation dwell time models in this study can be used in the establishment of strategies that provide priority signals to S-BRTs.

• Journal of Technology Innovation
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• v.19 no.3
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• pp.57-83
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• 2011

We suggested industry-specific priorities of R&D investment with R&D investment elasticity to GDP calculated from the ripple effect of 28 large-sized industry R&D investment, using a Computable General Equilibrium(CGE) Model. Priority orders apply to only 12 industries, because 16 industries with less than 1% of total investment have been excluded. First, R&D investment elasticity to GDP says that priorities are ordered as Basic metal products, Chemicals, drugs and medicines, Food, beverages and tobacco products, Electronic and electrical equipment, Transportation equipment, Precision instruments, Electrictity, gas, steam and water supply, General machinery and equipment, Communications and broadcasting, Construction, Other services, and Real estate and business services. These priorities show the status quo of Korean industry structures well. The GDP growth rate to 2030 year reference equilibrium, which is an auxiliary index, says a similar priority to results from R&D investment elasticity to GDP. In the end, two criteria of priority order can be functioned as a good index for National Science and Technology Commission deciding what industry to invest and what budget to allocate.

• Environmental Engineering Research
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• v.14 no.3
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• pp.186-194
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• 2009

Understanding the environmental fate of human and animal pharmaceuticals and their risk assessment are of great importance due to their growing environmental concerns. Although there are many potential pathways for them to reach the environment, effluents from sewage treatment plants (STPs) are recognized as major point sources. In this study, the removal efficiencies of the 43 selected priority pharmaceuticals in a conventional STP were evaluated using two simple models: an equilibrium partitioning model (EPM) and STPWIN$^{TM}$ program developed by US EPA. It was expected that many pharmaceuticals are not likely to be removed by conventional activated sludge processes because of their relatively low sorption potential to suspended sludge and low biodegradability. Only a few pharmaceuticals were predicted to be easily removed by sorption or biodegradation, and hence a conventional STP may not protect the environment from the release of unwanted pharmaceuticals. However, the prediction made in this study strongly relies on sorption coefficient to suspended sludge and biodegradation half-lives, which may vary significantly depending on models. Removal efficiencies predicted using the EPM were typically higher than those predicted by STPWIN for many hydrophilic pharmaceuticals due to the difference in prediction method for sorption coefficients. Comparison with experimental organic carbon-water partition coefficients ($K_{ocs}) revealed that log KOW-based estimation used in STPWIN is likely to underestimate sorption coefficients, thus resulting low removal efficiency by sorption. Predicted values by the EPM were consistent with limited experimental data although this model does not include biodegradation processes, implying that this simple model can be very useful with reliable Koc values. Because there are not many experimental data available for priority pharmaceuticals to evaluate the model performance, it should be important to obtain reliable experimental data including sorption coefficients and biodegradation rate constants for the prediction of the fate of the selected pharmaceuticals.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.254-261
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• 2007

In this paper, we propose a blind equalization method for advanced terrestrial digital multimedia broadcasting (AT-DMB) systems which use hierarchical modulation. The AT-DMB system adopts hierarchical 16-ary quadrature amplitude modulation (16-QAM) to ensure backward-compatibly with the differential quadrature phase shift keying (DQPSK) signal of the legacy terrestrial digital multimedia broadcasting (T-DMB) systems and to support higher transmission rate. Due to the hierarchical modulation, the conventional T-DMB signal and the additional signal have different error rate at same signal to noise ratio (SNR). By weighting the decided symbols differently according to the reliability of the symbols, i.e., high priority symbol with low error rate and low priority symbol with high error rate, we can improve the channel estimation accuracy. In this paper, we analyze SNR loss by hierarchical modulation and confirm it through simulations. Moreover, through simulations, we verify that the proposed weighting method improve BER compared to the no-weighting method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.4
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• pp.351-358
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• 2006

The farming and fishing village roads is located in a mountainous geographical feature, a resident's movement zone is followed by many restrictions in economic activities or social activities. Establishment of general planning gets into guide of long-term development direction for road in farming and fishing villages area. This study examined and analyzed a regional characteristics such as a regional environment and traffic condition, etc. and an actual condition of farming and fishing village roads, selected a factor affecting a priority to open a road, calculated a weight per each factor by AHP & Statistical analysis techniques, converted it into GIS database, and determined a priority for paying forming and fishing village roads. It is that development precedence and estimation calculation are decided applying result of research, GIS and AHP and statistical processing techniques.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.173-184
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• 2014

Riparian areas are significant functional grounds for inhabiting ecological system on the river such as the self-regulation of the water quality and the foundation of important corridors. For such functional device to operate, consecutive land purchase scheme that prioritizes targeted areas with high pollutant load rate imposes sustainable development of the ecological riparian belt. The purpose of this study is focused on measuring the methodology for selecting land purchse order before establishing riparian belt in accordance with pollution loading estimation and the basin approach. The Yeongsan and Seomjin river which includes targeted areas of the land purchase have been classified into the large-medium-small(standard basin) influence areas based on their catchment rage, which than sub-divided the research area of Juam lake by 38 small basins and 223 units. Small basins with the high pollution load rates have been assessed as the first prioritized targets. For the second priority, the condition of the point pollutant sources, original area of the targets, original restored area were concerned. The final decision of the land purchase order targeted only those within 50 meter range from the basin. To validate the accumulated data, the on-site investigation went along the targeted zones, which the result shows that all prioritized areas included both point and non-point pollutant sources, and had not a small originally restored areas.

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.103-112
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• 2006

Priority-based network service has been widely adopted for the Internet traffic management in the context of IETF differentiated services, and computing optimal prices for such priority-based service is the key topic in many pricing literature. While the equilibrium analysis has been commonly used to this end, many have criticized the validity of the underlying assumption of equilibrium analysis that user utility functions are precisely known. In this paper, we propose a solution for bridging the gap between the existing theoretical work on optimal pricing and the unavailability of precise user utility information in real networks. In the proposed method, the service provider obtains more and more accurate estimates of user utility functions from the initial imprecise knowledge by iteratively changing the price of service levels and observing the users' decisions under the changed price. Our contribution is two-fold. First, we have developed a general principle for estimating the user utility functions. Second, we have developed a novel method for setting the prices that can optimize the extraction of the knowledge about user utility functions. The extensive simulation results demonstrate the effectiveness of our method.

• Journal of Korea Water Resources Association
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• v.51 no.10
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• pp.929-939
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• 2018

In North Korea, hydropower which occupies about 63% of power generation is a major electric power source, and North Korea has many advantages in the geographical for developing hydroelectric power. In this study, Information on the basin and dam capacity for 33 potential development site of hydroelectric dam was analyzed using DEM, and potential annual power generation was estimated by applying results of long-term runoff simulation with MWSWAT model for recent 30-year. The potential annual power generation at 33 dam was estimated to be about 28% of the current hydroelectric power in North Korea. In addition, a priority of dam development in each province was assessed by estimating the scale of an industry and prospecting the population change in the future. And a priority for dam development within the province was estimated based on the dam capacity and the potential annual power generation. The priority of each province was ranked in order of Pyeongannamdo, Hamgyungnamdo, Hamgyungbukdo, Hwanghaebukdo, Pyeonganbukdo, Jagangdo, Ryanggangdo, Hwanghaenamdo, and Gangwondo. The results of this study can be used as an initial review data for advancing to hydropower development project in North Korea.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.12
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• pp.736-748
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• 2003

Dynamic voltage scaling(DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. The energy efficiency of a DVS algorithm largely depends on the performance of the slack estimation method used in it. In this paper, we propose novel DVS algorithms for periodic hard real-time tasks based on an improved slack estimation algorithm. Unlike the existing techniques, the proposed method can be applied to most priority-driven scheduling policies. Especially, we apply the proposed slack estimation method to EDF and RM scheduling policies. The experimental results show that the DVS algorithms using the proposed slack estimation method reduce the energy consumption by 20∼40 % over the existing DVS algorithms.