• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.346-352
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• 2020

Versatile Video Coding (VVC), a next-generation video coding standard that is in the final stage of standardization, has adopted various techniques to achieve more than twice the compression performance of HEVC (High-Efficiency Video Coding). VVC adopted Bi-prediction with CU-level Weight (BCW), which generates the final prediction signal with the weighted combination of bi-predictions with various weights, to enhance the performance of the bi-predictive inter prediction. The syntax element of the BCW index is adaptively coded according to the value of NoBackwardPredFlag which indicates if there is no future picture in the display order among the reference pictures. Such syntax structure for signaling the BCW index could violate the flexibility of video codec and cause the dependency issue at the stage of bitstream parsing. To address these issues, this paper proposes an efficient BCW weight signaling method which enables all weights and parsing without any condition check. The performance of the proposed method was evaluated with various weight searching methods in the encoder. The experimental results show that the proposed method gives negligible BD-rate losses and minor gains for 3 weights searching and 5 weights searching, respectively, while resolving the issues.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.171-180
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• 2020

With the increase in industrialization and urbanization, scarcity of space for leisure life has become an important issue. Opportunities such as natural scenery and ecological experiences provided by waterfront spaces around streams are fundamental factors in the development of the community and creation of a hydrophilic park. In the past, on-site surveys have been conducted using human resources to quantify the number of river visitors, but the accuracy of the results was not sufficient owing to limitations in expenses, manpower, space, and time. In this study, to overcome this problem, we estimated the number of visitors using the location information related to hydrophilic parks. The study areas were Samrak Ecological Park and Daejeo Ecological Park located downstream of the Nakdong River. We compared and analyzed the pattern of the visitors by using the large communication data and the visiting pattern based on GPS location information. The GPS location information is based on Google Popular Times and Kakao visitor data. When the GPS location data were used, the pattern for weekday and weekend visitors was clearer than when the large communication data were used. Therefore, it is expected to be similar to the result of GPS location information if the number of visitors is extracted under the condition of precision of pCELL size and residence time of 30 minutes or more when using future communication big data. In addition, if revisions such as the Personal Information Protection Act are made to extract more accurate data, by estimating the number of visitors based on GPS data, more accurate indicators of the number of visitors can be derived.

• The Journal of Aerospace Industry
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• s.68
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• pp.80-94
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• 2006

유효경쟁시장은 사업자의 수와 시장구조 측면에서는 독과점적인 시장이더라도 기존사업자간 경쟁이 상당히 치열하거나 잠재적 진입에 의한 경쟁압력이 커서 특정사업자가 시장지배력을 보유하거나 이를 행사하기 어려운 시장상태를 말하며, 항공산업의 경우 일반적인 네트워크 산업과 마찬가지로 대규모 설비투자가 필요하고 높은 고정비용과 규모의 경제가 뚜렷한 특성을 갖고 있으며 네트워크효과도 강하게 나타나 비대칭적 규제가 필요한 대표적인 산업이라고 할 수 있다. 우리나라 경제당국은 평균비용이 장기적으로 하락하는 대규모 자본산업에서 자연독점이 발생할 경우, 그 피해는 자연히 소비자에게 돌아 갈 것이며, 미국과 EC의 경쟁법상의 유효경쟁의 개념으로 제시되고 있는 요소들을 보면 주로 어느 한 기업이 시장지배력을 행사하는 시장상황을 나열하여 규제함으로써 최대의 이익이 소비자에게 돌아가도록 규제하고 있다. 항공운송사업은 자본집약적 서비스산업으로 일반서비스 산업에 비해 상대적으로 일정수준까지 자본투자가 전제되어야 하는 자본집약적 특성을 지닌다. 따라서 항공운송산업의 성패는 대규모 자본을 통한 운송능력에 대한 효율화 정도에 따라 결정된다. 여기에 시장에 진입 시기와 독점 유지기간도 중요한 역할을 한다. 또한 항공운송산업은 정부의 면허사업으로 선발항공사가 수익노선을 선점하여 운항할 경우, 정부의 별도 허가에 의하여 복수취항이 이루어진다고 하더라도 운항편수 및 고객 선호 시간대를 미리 선점할 수가 있어 후발항공사에 비해 우월적 지위를 갖게 되어 공정경쟁이 극히 어렵다고 할 수 있는데, 이는 수십년간 아시아나의 압도적인 서비스/안전에 대한 높은 평가에도 불구 대한항공과 아시아나의 격차는 2000년 이후 일정하게 유지되고 있다는 점에서 확인할 수 있다. 국내 항공운송산업은 면허산업으로, 운수권의 확보에 따라 항공사의 매출 차이가 결정되는 바, 항공운송산업에서의 유효경쟁을 확보는 1차적으로는 정부의 운수권 배분을 통하여 실현되며 양사의 운수권 배분내역에 의하면 선발사업자에 대한 유효경쟁정책이 실현되지 않고 있다고 할 수 있다. 대부분의 노선에서 복수취항이 허용된다고 하더라도 강력한 스케줄, 가격(운임) 경쟁력, 선발항공사의 이점, 고객 선호도의 미반영 등으로 인하여 공정한 경쟁이 이루어지지 않을 가능성이 매우 높다. 이처럼 평균비용이 장기적으로 하락하는 항공산업에서 선발항공사에 대한 쏠림 현상이 가중된다면 향후 10년내에 국내 항공운송산업에 자연 독점이 발생할 가능성은 매우 크며 그 피해는 소비자에게 돌아갈 것이 자명하다. 결국 우리나라의 항공운수산업에서의 유효경쟁환경을 조성하기 위해서는 운수권 배분 절차에서의 비대칭규제의 원리가 상당기간 적용되어야 하며, 복수취항이 허용된 노선에서도 후발사업자가 공정하게 경쟁할 수 있도록 비대칭규제방안이 강구되어야 한다. 뿐만아니라 보충적으로 공정거래법상의 시장지배적 지위의 남용규제와 같은 비대칭규제도 강력하게 집행되어야 할 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.240-247
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• 2020

The Korean military is having difficulty maintaining combat power due to the insufficient troop numbers caused by a demographic cliff and the reduction of the mandatory military service period. Recently, discussions on improving the military training system have increased significantly. This paper proposes an optimization model to establish military training schedules to improve combat power. The oblivion and learning effects on training tasks were quantified through a survey and applied to the model. The objective value, combat power, was calculated based on the total task scores of the unit members and the number of task failures after four weeks. The scenarios were configured by the change in educational conditions and initial scores of some tasks. As a result of scenario experiments, combat power has increased by at least 10% and up to 77%, which is sufficient to maintain combat power considering the change in troops. In addition, the planning of combat skill tasks has a significant impact on combat power. Through this research model, it is expected that military training managers will be able to establish a training schedule that maintains or improves the combat power of troops effectively.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.903-915
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• 2020

Long-term high-resolution hydro-meteorological data has been recognized as an essential element in establishing the water resources plan. The increasing demand for spatial precipitation in various areas such as climate, hydrology, geography, ecology, and environment is apparent. However, potential limitations of the existing area-weighted and numerical interpolation methods for interpolating precipitation in high altitude areas remains less explored. The proposed PRISM (Precipitation-Elevation Regressions on Independent Slopes Model) model can produce gridded precipitation that can adequately consider topographic characteristics (e.g., slope and altitude), which are not substantially included in the existing interpolation techniques. In this study, the PRISM model was optimized with SCEM-UA (Shuffled Complex Evolution Metropolis-University of Arizona) to produce daily gridded precipitation. As a result, the minimum impact radius was calculated 9.10 km and the maximum 34.99 km. The altitude of coastal weighted was 681.03 m, the minimum and maximum distances from coastal were 9.85 km and 38.05 km. The distance weighting factor was calculated to be about 0.87, confirming that the PRISM result was very sensitive to distance. The results showed that the proposed PRISM model could reproduce the observed statistical properties reasonably well.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.29-33
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• 2010

The purpose of LiDAR ground classification is to archive both goals which are acquiring confident ground points with high precision and describing ground shape in detail. In spite of many studies about developing optimized algorithms to kick out this, it is very difficult to classify ground points and describing ground shape by airborne LiDAR data. Especially it is more difficult in a dense forested area like Korea. Principle misclassification was mainly caused by complex forest canopy hierarchy in Korea and relatively coarse LiDAR points density for ground classification. Unfortunately, a lot of LiDAR surveying performed in summer in South Korea. And by that reason, schematic LiDAR points distribution is very different from those of Europe. So, this study propose enhanced ground classification method considering Korean land cover characteristics. Firstly, this study designate highly confident candidated LiDAR points as a first ground points which is acquired by using big roller classification algorithm. Secondly, this study applied weighted gradient kernel(WGK) algorithm to find and include highly expected ground points from the remained candidate points. This study methods is very useful for reconstruct deformed terrain due to misclassification results by detecting and include important terrain model key points for describing ground shape at site. Especially in the case of deformed bank side of river area, this study showed highly enhanced classification and reconstruction results by using WGK algorithm.

• Journal of Korea Water Resources Association
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• v.43 no.3
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• pp.309-323
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• 2010

As climate changes and abnormal climates have drawn research interest recently, many countries utilize the GCM, which is based on SRES suggested by IPCC, to obtain more accurate forecast for future climate changes. Especially, many research attempts have been made to simulate localized geographical characteristics by using RCM with the high resolution data globally. To evaluate the impacts of climate and landuse change on water resources in the Han-river basin, we carried out the procedure consisting of the CA-Markov Chain, the Multi-Regression equation using two independent variables of temperature and rainfall, the downscaling technique based on the RegCM3 RCM, and SLURP. From the CA-Markov Chain, the future landuse change is forecasted and the future NDVI is predicted by the Multi-Regression equation. Also, RegCM3 RCM 50 sets were generated by the downscaling technique based on the RegCM3 RCM provided by KMA. With them, 90 year runoff scenarios whose period is from 2001 to 2090 are simulated for the Han-river basin by SLURP. Finally, the 90-year simulated monthly runoffs are compared with the historical monthly runoffs for each dam in the basin. At Paldang dam, the runoffs in September show higher increase than the ones in August which is due to the change of rainfall pattern in future. Additionally, after exploring the impact of the climate change on the structure of water circulation, we find that water management will become more difficult by the changes in the water circulation factors such as precipitation, evaporation, transpiration, and runoff in the Han-river basin.

• Informatization Policy
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• v.22 no.1
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• pp.47-72
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• 2015

According to the progress of national informatization throughout the world, infringement and threaten of privacy are happening in a variety of fields, so government is providing information security policy. In particular, South Korea has enhanced personal impact assessment based on the law of personal information protection law(2011). But it is not enough to effect the necessary cost calculation standards and changeable factors to effect PIA. That is, the budgets for PIA was calculated lower than the basic budget suggested by Ministry of Government Administration Home affairs(2011). Therefore, this study reviewed the cost calculation basis based on the literature review, cost basis of similar systems, and reports of PIA and obtained to the standard with Delphi analysis. As a result, the standards of PIA is consisted to the primary labors and is utilized to how the weights by division of target system, construction and operating costs of target system, type of target systems, etc. Thus, the results of this study tried to contribute to ensure the reliability of PIA as well as the transparency of the budget for privacy in public sector.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.576-584
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• 2017

Traffic demand prediction result is a primary factor for decision making such as the traffic planning and operation. The existing traffic demand prediction 4-step model only covers the trip between the origin and the destination, and not the demand followed by the accessibility improvement, due to the characteristic of this model. Therefore, the purpose of this research is to improve the limitations of the existing model by developing the inter-city trip generation and trip distribution model with more accessibility. After calculating of the trip generation and trip distribution model with more accessibility, the sign of the accessibility coefficient was positive. Commuting was the most insensitive indicator, affected by external factors among the other trip purposes. The leisure trip was the most sensitive, affected by the trip fee. According to the result of comparison with each of estimated model and observational data, it was certain that the reliability and assumption of the model have been improved by discovering the reduced weighted average error rate, Root Mean Square Error (RMSE) and total error through the model with more accessibility compared with the existing one.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.991-999
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• 2018

In urban areas, the proportion of railway traffic in public transport is increasing. The congestion situation is repeated as the passengers concentrate on station and transfer facilities and the inconvenience of the passengers is increasing in terms of safety and convenience. Therefore, the importance of estimating the appropriate area of the station has been emphasized. The area estimation formula used in the metropolitan railway stations currently is a partial modification of the area estimation formula of Japan in the 1970s. It does not reflect changes in the social and cultural environment and patterns of passengers. The technical basis for major decision variables is insufficient. Therefore, the theoretical basis of the area estimation formula and the pedestrian environment satisfaction of the design guideline of metropolitan railway stations were analyzed in order to suggest improvement formula. The improved area estimation formula was verified by conducting field surveys on 5 stations of metropolitan railways and 15 stations of urban railways. The existing area estimation formula is LOS E grade for the main space. However, the LOS D grade is implemented when the improved area estimation formula is applied. Based on the results, the design factors for the area estimation formula are suggested.