• Title/Summary/Keyword: Adaptive Capacity

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An Analysis on the Spatial Patterns of Heat Wave Vulnerable Areas and Adaptive Capacity Vulnerable Areas in Seoul (서울시 폭염 취약지역의 공간적 패턴 및 적응능력 취약지역 분석)

  • Choi, Ye Seul;Kim, Jae Won;Lim, Up
    • Journal of Korea Planning Association
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    • v.53 no.7
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    • pp.87-107
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    • 2018
  • With more than 10 million inhabitants, in particular, Seoul, the capital of Korea, has already experienced a number of severe heat wave. To alleviate the potential impacts of heat wave and the vulnerability to heat wave, policy-makers have generally considered the option of heat wave strategies containing adaptation elements. From the perspective of sustainable planning for adaptation to heat wave, the objective of this study is to identify the elements of vulnerability and assess heat wave-vulnerability at the dong level. This study also performs an exploratory investigation of the spatial pattern of vulnerable areas in Seoul to heat wave by applying exploratory spatial data analysis. Then this study attempts to select areas with the relatively highest and lowest level of adaptive capacity to heat wave based on an framework of climate change vulnerability assessment. In our analysis, the adaptive capacity is the relatively highest for Seongsan-2-dong in Mapo and the relatively lowest for Changsin-3-dong in Jongno. This study sheds additional light on the spatial patterns of heat wave-vulnerability and the relationship between adaptive capacity and heat wave.

Multivariate adaptive regression spline applied to friction capacity of driven piles in clay

  • Samui, Pijush
    • Geomechanics and Engineering
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    • v.3 no.4
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    • pp.285-290
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    • 2011
  • This article employs Multivariate Adaptive Regression Spline (MARS) for determination of friction capacity of driven piles in clay. MARS is non-parametric adaptive regression procedure. Pile length, pile diameter, effective vertical stress, and undrained shear strength are considered as input of MARS and the output of MARS is friction capacity. The developed MARS gives an equation for determination of $f_s$ of driven piles in clay. The results of the developed MARS have been compared with the Artificial Neural Network. This study shows that the developed MARS is a robust model for prediction of $f_s$ of driven piles in clay.

An Adaptive Subcarrier Allocation Scheme based on Comparison of Group Opportunity Cost (부반송파 그룹간 기회 비용 상호 비교에 기반한 적응 부반송파 할당 기법)

  • Kim, Young-Ok;Yoon, Byung-Wan;Lee, Young-Tark
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.55-58
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    • 2007
  • An adaptive subcarrier allocation scheme based on comparative superiority of opportunity cost between groups is proposed for the enhancement of system capacity and its simple implementation at the base station of a multiuser OFDM system. The proposed algorithm is similar to the blockwise or the decentralized subcarrier allocation algorithm proposed by Xiaowen et al and Alen et al, respectively. In the proposed algorithm, however, all subcarriers are grouped according to the coherence bandwidth and the comparative superiority concept, which swaps the groups between users if the system capacity is increased, is adopted for the enhancement of system capacity. In addition, the proposed algorithm provides a simple solution for the conflict problem among users by reallocating only the conflicted groups and unassigned groups instead of reallocating entire groups. Simulation results demonstrate that the proposed algorithm increases the system capacity effectively over a static, an adaptive blockwise, and a decentralized subcarrier allocation algorithms.

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Collision Avoidance Scheduling for Capacity Improvement of Adaptive OFDMA Systems (OFDMA 시스템에서 전송률 향상을 위한 충돌 회피 스케줄링)

  • Kim, Young-Ju;Song, Hyoung-Joon;Kwon, Dong-Young;Hong, Dae-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.11
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    • pp.9-14
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    • 2008
  • In this paper, we propose a collision avoidance scheduling to increase the multiuser diversity gains in the adaptive orthogonal frequency division multiple access (OFDMA) system. The scheduling policy is based on the minimum collision criterion which investigates the differences of user channels. The paper includes the derivation of capacity expressions for the adaptive OFDMA system with the proposed scheduling. The analysis shows that the capacity of the system depends on the number of collisions between the selected users to be simultaneously served. Numerical results show that the proposed scheduling provides improved capacity performance over existing ones.

Health Vulnerability Assessment for PM10 in Busan (부산지역 미세먼지에 대한 건강 취약성 평가)

  • Lee, Won-Jung;Hwang, Mi-Kyoung;Kim, Yoo-Keun
    • Journal of Environmental Health Sciences
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    • v.40 no.5
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    • pp.355-366
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    • 2014
  • Objectives: This study seeks to evaluate the vulnerability assessment of the human health sector for $PM_{10}$, which is reflected in the regional characteristics and related disease mortality rates for $PM_{10}$ in Busan over the period of 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), vulnerability to $PM_{10}$ is comprised of the categories of exposure, sensitivity, and adaptive capacity. The indexes of the exposure and sensitivity categories indicate positive effects, while the adaptive capacity index indicates a negative effect on vulnerability to $PM_{10}$. Variables of each category were standardized by the rescaling method, and each regional relative vulnerability was computed through the vulnerability index calculation formula. Results: The regions with a high exposure index are Jung-Gu (transportation region) and Saha-Gu (industrial region). Major factors determining the exposure index are the $PM_{10}$ concentration, days of $PM_{10}{\geq}50$, ${\mu}g/m^3$, and $PM_{10}$ emissions. The regions that show a high sensitivity index are urban and rural regions; these commonly have a high mortality rate for related disease and vulnerable populations. The regions that have a high adaptive capacity index are Jung-Gu, Gangseo-Gu, and Busanjin-Gu, all of which have a high level of economic/welfare/health care factors. The high-vulnerability synthesis of the exposure, sensitivity, and adaptive capacity indexes show that Dong-Gu and Seo-Gu have a risk for $PM_{10}$ potential effects and a low adaptive capacity. Conclusions: This study presents the vulnerability index to $PM_{10}$ through a relative comparison using quantitative evaluation to draw regional priorities. Therefore, it provides basic data to reflect environmental health influences in favor of an adaptive policy limiting damage to human health caused by vulnerability to $PM_{10}$.

A Study on the relationship between dynamic capability & technology innovation performance

  • Lim, Heon-Jin;Park, Hyun-Yong
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.12
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    • pp.211-218
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    • 2018
  • In this paper, we propose that investigating the relationship between the dynamic capacity and the technological innovation performance of firms. Based on the previous research, we divide the dynamic capacity into the adaptive capacity, absorption capacity, and productive capacity. Among the 3,400 companies responding to the technical statistics of SMEs in 2011, we performed multiple regression analysis with 2,807 except service industries. As a result, the absorptive capacity and productive capacity have a positive effect on the technological innovation performance at the 99% level, whereas the adaptive capacity has a negative effect on the technological innovation performance at the 95% level. The implications of this study are as follows. First, in order to improve the performance of technological innovation, it is important to strengthen the absorption capacity and productive capacity of companies. Absorption capacity shows that it is important to secure sufficient R & D manpower and R & D cost to utilize internal knowledge as well as to bring outside knowledge into the capacity to assimilate and utilize external knowledge. Second, the ability to commercialize a product is a capability to commercialize a technology that has succeeded in development, showing that the technology development organization must have the capability of post-development commercialization as well as technology development. Finally it shows the negative effect on adaptation capacity and innovation performance. Companies actively utilize external sources of information in order to respond to and adapt to the rapidly changing business environment. However, the results of this study show that a strategic approach is needed to use external sources of information and technology development resources. Especially as the use of external information resources and technology development resources increases.

Capacity Analysis on Cellular CDMA System with Adaptive Array Antenna in the Presence of Angle Estimation Error (각도추정 오차가 있는 경우 적응배열 안테나를 사용한 셀룰러 CDMA 시스템의 용량분석)

  • 정영모
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6A
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    • pp.900-909
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    • 2000
  • Adaptive array antennas are one of the most promising techniques for improving the capacity of CDMA mobile communication system. In this paper, the uplink and downlink capacity for asynchronous W-CDMA system with adaptive array antenna is analyzed when an angle estimation error is present. From the results, it is found that the capacities are decreased by the angle estimation error. Specifically, when 5 degrees of error is present at 9 element adaptive array, the capacities are found to decrease by 5.2% in the uplink and 11.6% in the downlink. Also, in this paper, an attempt for comparing the capacities on different channel environments has been made. However, it is found that the increase of the Rice factor hardly effects the capacity due to the power control.

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The Large Capacity Steganography Using Adaptive Threshold on Bit Planes (비트 플레인별 적응적 임계값을 이용한 대용량 스테가노그라피)

  • Lee, Sin-Joo;Jung, Sung-Hwan
    • The KIPS Transactions:PartB
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    • v.11B no.4
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    • pp.395-402
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    • 2004
  • In this paper, we proposed a new method of the large capacity steganography using adaptive threshold on bit planes. Applying fixing threshold, if we insert information into all bit planes, all bit planes showed different image quality. Therefore, we first defined the bit plane weight to solve the fixing threshold problem. We then proposed a new adaptive threshold method using the bit plane weight and the average complexity to increase insertion capacity adaptively. In the experiment, we inserted information into the standard images with the same image quality and same insertion capacity, and we analyzed the insertion capacity and image duality. As a result, the proposed method increased the insertion capacity of about 6% and improved the image quality of about 24dB than fixed threshold method.

Capacity Enhancement through Adaptive Antenna Array for a Multicarrier DS/CDMA System

  • Kim, Jin-Young
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.433-436
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    • 2000
  • In this paper, capacity of a multicarrier DS/CDMA system is analyzed and simulated in a Nakagami fading channel. It is confirmed that the adaptive antenna array is a very efficient solution to enhance system capacity of a multicarrier DS/CDMA system. The results in this paper can be applicable to receiver design for the third and fourth mobile communication systems.

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Capacity Maximizing Adaptive Subcarrier Selection in OFDM with Limited Feedback (OFDM 용량 극대화를 위한 적응 부 반송파 선택에 관한 연구)

  • Mun Cheol;Jung Chang-Kyoo;Park DongHee;Kwak Yoonsik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.5
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    • pp.905-911
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    • 2005
  • We propose an efficient adaptive subcarrier selection scheme, in which the active subcarriers and their modulation and coding schemes (MCSs) are selected at the receiver, and subsequently conveyed to the transmitter using limited feedback We theoretically show that capacity maximization can be achieved by selecting subcarriers with highest signal-to-noise ratios (SNRs) and adapting the number of active subcarriers according to channel environments. Furthermore, an ordering based adaptive subcarrier selection algorithm is proposed to select the optimal active subcarriers with low complexity. Numerical results show that the proposed adaptive subcarrier selection scheme provides higher capacity than that obtained by water-filling approaches, even with limited feedback.