• 제목/요약/키워드: Global Minimum

검색결과 594건 처리시간 0.023초

The Colorectal Cancer Mortality-to-Incidence Ratio as a Potential Cancer Surveillance Measure in Asia

  • Sunkara, Vasu;Hebert, James R
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권9호
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    • pp.4323-4326
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    • 2016
  • Background: The cancer mortality-to-incidence ratio (MIR) has been established as an important measure of health disparities in local and global circumstances. Past work has corroborated a linkage between the colorectal cancer MIR and the World Health Organization (WHO) Health System ranking. The literature further documents many Asian countries having incomplete cancer registries and a lack of comprehensive colorectal cancer screening guidelines. Materials and Methods: The colorectal cancer MIR values for 23 Asian countries were calculated from data obtained from the 2012 GLOBOCAN database. The 2000 World Health Organization (WHO) Health System rankings were used as a proxy for health system infrastructure and responsiveness. A regression equation was calculated with the MIR as the dependent variable and the WHO Health System ranking as the independent variable. Predicted MIR values were next calculated based on the regression results. Actual MIR values that exceeded 0.20 from the predicted MIR were removed as 'divergent' points. The regression equation was then re-plotted. Goodness-of-fit for both regressions was assessed by the R-squared test. Results: Asian countries have a relatively wide colorectal cancer MIR range, from a minimum of 0.24 to a maximum of 0.86. For the full dataset, the adjusted R-squared value for this regression was 0.53. The equation was then used to calculate a predicted MIR, whereby two data points were identified as 'divergent' and removed. The adjusted R-squared for the edited dataset increased to 0.66. Conclusions: Asian countries have a marked range in their colorectal cancer MIR values and there is a strong correlationwith the WHO Health System ranking. These results corroborate the contribution of the MIR as a potentially robust tool in monitoring changes in colorectal cancer care for Asian nations.

실변수 유전자 알고리즘을 이용한 사인형 주름 웨브 보의 최적구조설계 (Optimum Structural Design of Sinusoidal Corrugated Web Beam Using Real-valued Genetic Algorithm)

  • 손수덕;이승재
    • 한국강구조학회 논문집
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    • 제23권5호
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    • pp.581-593
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    • 2011
  • 스티프너로 보강된 플레이트 거더 대신에 주름 웨브를 사용하는 근본적인 장점은 얇은 판으로 형성된 편평한 웨브에서 발생하는 좌굴에 관한 불안정 문제를 해결할 수 있는 것 뿐 아니라 수직 스티프너의 필요성도 함께 해결 됨으로써 경제적인 장점을 제공받게 된다. 따라서 본 연구에서는 사인형 주름 웨브를 가진 보의 구조설계 기법과 실변수 알고리즘을 이용하여 최적화 문제를 다루도록 한다. 구조설계과정과 설계변수들은 EN 1993-1-5, DASt-R015 및 Pasternak 등(2004)을 통해서 구성하며, 주름 웨브의 전단좌굴에 대한 유효한 설계가능영역에 대해 비교, 고찰한다. 구조설계 최적화를 위해서, 목적함수는 사인형 주름 웨브 보의 중량으로 정의하여 최소중량최적화를 수행하며, 제약조건으로는 세장비, 부재력 저항능력 및 보의 허용처짐에 대해서 고려한다. 최종적으로 등분포 하중의 단순보 모델을 해석 대상으로 채택하며, 유전자 연산에 있어서 효율적인 확률변수에 대해 연구한다.

Status, Utilization and Economic Valuation of Non-timber Forest Products of Arunachal Pradesh, India

  • Sharma, Dhruba;Tiwari, B.K.;Chaturvedi, S.S.;Diengdoh, Evamary
    • Journal of Forest and Environmental Science
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    • 제31권1호
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    • pp.24-37
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    • 2015
  • Non-timber forest products are important component of subsistence and livelihood of tribal communities living in and near forests. This is of particular significance in the state of Arunachal Pradesh having more than 80% of geographical area under forest cover and predominantly inhabited by tribal people. Purpose of this study was to document the status and utilization pattern and to assess the economic value of NTFPs of the state. Present study was carried out in eight districts of Arunachal Pradesh viz., Changlang, East Kameng, Lower Subansiri, Tawang, Tirap, Upper Siang, West Kameng and West Siang covering 34 villages and 350 households. Altogether, 135 plant based and 36 animal based non-timber forest products were recorded. Among plant based NTFPs, 54 species were collected for leaves, 30 for stem and 22 for fruits. Most of the animal based NTFPs (93%) were collected/hunted for food. Average 20~40 kg of NTFPs was collected annually per household. Maximum plant based NTFP collection was recorded from West Siang followed by West Kameng and Tawang. Similarly, highest collection of animal based NTFPs was recorded from West Siang followed by Tirap and Lower Subansiri. NTFP contributed more than 50% of annual income of the people of East Kameng, Tirap, Lower Subansiri and Upper Siang districts. An illiterate and unemployed person with minimum agricultural land was more dependent on forests for his livelihood than a literate jobholder. The study concludes that a large section of people of Arunachal Pradesh are dependent on NTFPs for their livelihood however due to its unscientific harvesting, the availability of NTFPs is receding with time. There is an urgent need to promote cultivation and scientific harvesting of NTFPs in order to conserve the plant and animal diversity of this global biodiversity hotspot and for ensuring livelihood security of the people living in this area.

중국의 BeiDou 위성항법시스템의 항법신호 분석에 관한 연구 (A Study on the Navigation Signal Characteristics of China Beidou Satellite Navigation System)

  • 고광섭;최창묵
    • 한국정보통신학회논문지
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    • 제19권8호
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    • pp.1951-1958
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    • 2015
  • 본 논문은 2012년 12월에 항법서비스 시작, 2020년 개발완료 예정인 중국의 BeiDou 글로벌위성항법시스템에 대한 특성분석과 항법신호의 실험 및 실측 데이터의 통계적 분석에 중점을 둔 연구이다. 정상 운영 중인 14개의 BeiDou 항법위성 중 한반도 서남지역에서 사용 가능한 위성 수는 6~7개 정도로 3차원 위치정보를 얻기 위한 최소 위성수인 4개 이상임을 확인하였다. 그럼에도 불구하고 가용위성이 일부구역으로 편중되고 있고, 신호강도는 아직 안정적이지 못한 것으로 나타났다. 항법신호가 안정적인 경우, 실험 및 실측 기간에 확인 된 BeiDou 위성항법시스템의 항법 정밀도는 5m 수준으로 매우 양호하게 나타났다. 위치분포는 정규분포에 근사한 것으로 나타나 향후 항법위성의 증가와 함께 BeiDou 위성항법시스템이 더욱 안정적인 항법정보를 제공하게 될 것으로 전망된다.

통신중계를 위한 다수 소형 무인항공기의 최적배치 (Optimal Positioning of Small UAVs for Communication Relay)

  • 정준호;김승균;오현동;석진영
    • 한국항공우주학회지
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    • 제42권6호
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    • pp.461-467
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    • 2014
  • 본 논문은 지상이나 해상의 선단 간의 통신 품질을 향상시키기 위하여 소형 무인항공기를 통신중계의 노드로 활용하기 위한 연구를 다룬다. 지상과 해상 공간에서의 무인항공기에 의한 공중 통신중계는 일반적인 통신 한계거리를 넘어서거나 혹은 제한된 위성통신만 가능한 경우에 선단 간의 통신을 효과적으로 보장할 수 있다. 이러한 공중 통신중계를 위한 전자장비는 이미 개발과 양산이 이루어지고 있지만 효과적인 통신중계를 위해 무인항공기를 운용할 지점이나 궤적을 설계하는 연구는 미비하다고 볼 수 있다. 이러한 문제를 해결하기 위하여, 본 논문은 선단 사이의 무선통신 성능을 향상시키기 위한 무인항공기의 배치를 최적화하기 위한 알고리즘을 제안한다.

열적 수직 구조의 장기 변화로부터 유추한 동해 심층수 형성 모드의 변환: 1차원 모델 연구 (Mode Change of Deep Water Formation Deduced from Slow Variation of Thermal Structure: One-dimensional Model Study)

  • 채영기;승영호;강석구
    • Ocean and Polar Research
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    • 제27권2호
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    • pp.115-123
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    • 2005
  • Recently, it has been observed in the East Sea that temperature increases below the thermocline, and dissolved oxygen increase in the intermediate layer but decrease below it. The layer of minimum dissolved oxygen deepens and the bottom homogeneous layer in oxygen becomes thinner. It emerges very probably that these changes are induced by the mode change of deep water formation associated with global warming. To further support this hypothesis, a one-dimensional model experiment is performed. First, a thermal profile is obtained by injecting a cold and high oxygen deep water into the bottom layer, say the bottom mode. Then, two thermal profiles are obtained from the bottom mode profile by assuming that either all the deep water introduce into the intermediate layer has been initiated, say the intermediate mode, or that only a part of the deep water has been initiated into the intermediate layer, say the intermediate-bottom mode. The results, from the intermediate-bottom mode experiment are closest to the observed results. They show quite well the tendency for oxygen to increase in the intermediate layer and the simultaneous thinning of the bottom homogeneous layer in oxygen. Therefore, it can be said that the recently observed slow variation of the thermal structure might be associated with changes in the deep water formation from the bottom mode to the intermediate-bottom mode.

변수모델을 이용한 전달경로분석법(OPAX)과 전달률 함수를 사용한 전달경로분석법(OTPA)을 사용한 승차감 저해요인분석 (Analysis of the Cause of Hindrance for Ride Quality with OPAX and OTPA)

  • 김종식;신광수;최상일;임세빈;김진동;이상권
    • 한국소음진동공학회논문집
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    • 제24권12호
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    • pp.935-942
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    • 2014
  • The ride quality investigation is on-going topic in the car industry since its global standard has not evaluated and it is difficult to point out one part that hinders the ride quality. Since the traditional transfer path analysis that is widely used in car industry to investigate the ride quality requires a lot of test time to process the full data so that there are problems to conduct in industry. Based on these disadvantages, new approaches have developed such as OPAX(operational path analysis with eXogeneous inputs) and OTPA(operational transfer path analysis) for last decades. The OTPA only requires the operational data for evaluate the contribution of vibration sources and the OPAX has advantage of using parametric model to estimate the operating load and needs a minimum set of extra tests with excitation. In this paper, for evaluating the hindrance of ride quality two methods are used and the result is compared with another result of a car having higher ride quality.

oneM2M 표준 IoT 플랫폼 기반 스마트시티 데이터 마켓플레이스 설계 및 구현 (Design and Implementation of Smart City Data Marketplace based on oneM2M Standard IoT Platform)

  • 정승명;김성윤;이인송
    • 인터넷정보학회논문지
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    • 제20권6호
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    • pp.157-166
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    • 2019
  • oneM2M은 표준 API를 통해 디바이스 및 서비스 간 상호호환성을 보장하여 국내외 스마트시티 플랫폼 구축에 활용되고 있다. 스마트 시티에서 수집되는 데이터를 손쉽게 유통하기 위해서는 기존 표준에 있는 접근 제어 기능을 확장할 필요가 있다. 본 논문은 기존 oneM2M 표준의 접근 제어 기법과 비교해 데이터 판매자와 구매자 간 데이터 유통 시 사람의 개입이 최소화된 방안을 제시한다. 제시된 방안을 통해 oneM2M 데이터 마켓플레이스 API로 플랫폼에 확장 개발하고 데이터 마켓플레이스 포털과 연동하였다. 또한 스마트시티 시범 서비스를 개발하여 데이터 마켓플레이스 활용 예시를 제시하였다.

PC Cluster based Parallel Adaptive Evolutionary Algorithm for Service Restoration of Distribution Systems

  • Mun, Kyeong-Jun;Lee, Hwa-Seok;Park, June-Ho;Kim, Hyung-Su;Hwang, Gi-Hyun
    • Journal of Electrical Engineering and Technology
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    • 제1권4호
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    • pp.435-447
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    • 2006
  • This paper presents an application of the parallel Adaptive Evolutionary Algorithm (AEA) to search an optimal solution of the service restoration in electric power distribution systems, which is a discrete optimization problem. The main objective of service restoration is, when a fault or overload occurs, to restore as much load as possible by transferring the de-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints. This problem has many constraints and it is very difficult to find the optimal solution because of its numerous local minima. In this investigation, a parallel AEA was developed for the service restoration of the distribution systems. In parallel AEA, a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner are used in order to combine the merits of two different evolutionary algorithms: the global search capability of the GA and the local search capability of the ES. In the reproduction procedure, proportions of the population by GA and ES are adaptively modulated according to the fitness. After AEA operations, the best solutions of AEA processors are transferred to the neighboring processors. For parallel computing, a PC cluster system consisting of 8 PCs was developed. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through switch based fast Ethernet. To show the validity of the proposed method, the developed algorithm has been tested with a practical distribution system in Korea. From the simulation results, the proposed method found the optimal service restoration strategy. The obtained results were the same as that of the explicit exhaustive search method. Also, it is found that the proposed algorithm is efficient and robust for service restoration of distribution systems in terms of solution quality, speedup, efficiency, and computation time.

입자 군집 최적화법을 이용한 소형루프 전자탐사 자료의 층서구조 전기비저항 역해석 (Layered-earth Resistivity Inversion of Small-loop Electromagnetic Survey Data using Particle Swarm Optimization)

  • 장한길로
    • 지구물리와물리탐사
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    • 제22권4호
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    • pp.186-194
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    • 2019
  • 물리탐사 자료의 역산 해를 찾는데 흔히 이용되는 결정론적 해법은 지역 최소점에 빠져 적절한 해에 수렴하지 못할 가능성이 크다는 단점이 존재한다. 이 문제를 해결하기 위한 대안 중 하나는 확률론적 접근법에 기반한 전역 최적화 방법을 이용하는 것이며, 여러 방법들 중에서 입자 군집 최적화(Particle Swarm Optimization, PSO)법의 적용사례가 많이 소개되었다. 이 논문에서는 PSO법을 이용한 소형루프 전자탐사 자료의 층서 구조 전기비저항 역해석 알고리즘을 개발하고 합성자료를 이용하여 역산실험을 수행하였다. 실험결과 기존의 Gauss-Newton 알고리즘으로는 최적의 역산해를 찾는데 어려움이 있는 소형루프 전자탐사 자료의 역산 시도에 PSO 방법을 적용하면 성공률을 높일 수 있음을 확인하였다.