• 제목/요약/키워드: IT capacity

검색결과 12,284건 처리시간 0.039초

아동의 인지발달과 기억변인과의 관계 연구 (A Study of Relationship between Memory Variable and Cognitive Development in Children)

  • 명정옥
    • 대한가정학회지
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    • 제25권1호
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    • pp.121-127
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    • 1987
  • The purpose of this study was to investigate the importance of mental capacity and to see whether it can be a barometer to predict childrne's cognitive development. The instruments used were Pictoral Test of Intelligence to select homogeneous samples, Cucui Scale for their M-power and Conservation Test. The results showed that M-power develops as age increases, and it can be a strong variable to predict their cognitive development. It has been demonstrated that capacity increases developmentally but whether this reflects changes in capacity perse, or in the efficient use of that capacity is a debatable issue. More study needs to be repeated for this matter.

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상시진동을 이용한 교량 내하력 추정 알고리즘의 실험적 성능 검증 (Experimental Performance Verification of Load Carrying Capacity Algorithm of Bridges using Ambient Vibration)

  • 이우상;박기태;한성호
    • 한국안전학회지
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    • 제25권3호
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    • pp.83-90
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    • 2010
  • In this study, it is conducted that the performance verification of the ambient load carrying capacity algorithm using long-term measurement systems of bridges. For this purpose, a steel-box type model bridge is fabricated and the public load carrying capacity of a steel-box model bridge is estimated by conducting the numerical analysis and load test. In addition, we compare the public load carrying capacity with the estimated result of a steel-box model bridge using the ambient load carrying capacity algorithm. By the assessment result, it is shown that the estimated ambient load carrying capacity is the difference of approximately 6.0 percentages as compared with the public load carrying capacity.

Power Allocation and Capacity Analysis of Secondary User in Heterogeneous Spectrum Sharing Systems

  • Lim, Sungmook;Ko, Kyunbyoung
    • International Journal of Contents
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    • 제12권1호
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    • pp.70-75
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    • 2016
  • In this paper, we considered heterogeneous spectrum sharing system where the number of subcarriers of the primary user (PU) was twice as much as that of the secondary user (SU). In this case, due to non-orthogonality and inter-carrier interference (ICI) from SU to PU, it is difficult to satisfy the interference constraint of PU. In order to mitigate ICI and satisfy the interference constraint, we proposed a new transmission scheme of the SU with power allocation scheme. The proposed scheme will only generate subcarrier-by-subcarrier interference. Therefore, it can easily satisfy the interference constraint of the PR and enhance the capacity of the SU. In addition, we derived the ergodic capacity of the SU. Based on numerical results, we confirmed that the proposed schemes could guarantee SU with a reliable capacity while satisfying the interference constraint of the PU. In addition, the derived capacity well matched the numerical results.

전압조정 측면에서 본 소형 열병합발전 배전계통 도입량 평가 (Evaluation of Interconnection Capacity of SCOGNs to the power Distribution Systems from the Viewpoint of Voltage Regulation)

  • 최준호;김재철
    • 대한전기학회논문지:전력기술부문A
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    • 제48권9호
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    • pp.1096-1102
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    • 1999
  • This paper discusses the evaluation of interconnection capacity of small cogeneration(SCOGN) systems to the power distribution systems from the viewpoint of voltage regulation. Power utilities are required to keep the customers' voltage profile over a feeder close to the rated value under all load conditions. However, it is expected that the interconnection of SCOGNs to the power distribution systems impacts on the existing voltage regulation method and customers' voltage variations. Therefore, SCOGNs should be integrated to the automated power distribution systems to prevent interconnection problems and supply high quality electricity to the customers. For these reasons, we should proceed with the evaluation of interconnection capacity of SCOGNs to the power distribution systems. However, it is generally impossible to perform actual testing on the power distribution systems, and standardized methodologies and guidelines are not developed to evaluate it. The criterion indexes for voltage regulation and variations are presented in order to evaluate the interconnection capacity of SCOGNs to the power distribution systems. In addition, the evaluation methodology of interconnection capacity of SCOGNs for power distribution systems is presented. It is expected that the resulted of this paper are useful for power system planners to determine the interconnection capacity of SCOGNs and dispersed storage and generation (DSG) systems to the power distribution systems.

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구조물의 진동제어를 위한 MR-damper의 최적 제어력 산정 (Calculating a MR Damper's Optimal Capacity for a Control of Structural Vibration)

  • 허광희;전승곤;김충길;전준용;이진옥;서상구
    • 한국지진공학회논문집
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    • 제20권3호
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    • pp.163-169
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    • 2016
  • In the case where a MR-damper is employed for vibration control, it is important to decide on how much control capacity should be assigned to it against structural capacities (strength and load, etc). This paper aims to present a MR-damper's control capacity suitable for the capacities of the structure which needs to be controlled. First, a two span bridge was built equipped with a MR-damper, which constitutes a two-span MR-damper control system. Then, inflicting an earthquake load on the system, a basic experiment was performed for vibration control, and a simulation was also carried out reflecting specific control conditions such as MR-damper and rubber bearing. The comparison of the results against each other proved their validity. Then, in order to calculate an optimal control capacity of the MR-damper, structural capacity was divided into eleven cases in total and simulated. For each case, an additional load of 30 KN was inflicted everytime, thereby increasingly strengthening structural capacity. As a result of the study, it was found that the control capacity of MR-damper of 30 KN was safely secured only with lumped mass of more than 150 KN(case 6). Therefore, it is concluded the MR-damper showed the best performance of control when it exerted its capacity at around 20% of structural capacity.

제주계통 단독운전 시 주파수 안정도 유지를 위한 풍력발전 운전용량 산정 방법에 관한 연구 (A Study on the Assessment of Operational Capacity Limit of Wind Turbine for the Frequency Stability of Jeiu Island System)

  • 황교익;전영환
    • 전기학회논문지
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    • 제56권2호
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    • pp.233-239
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    • 2007
  • As the Kyoto Protocol, which aims at reducing greenhouse gases in accordance to the UNFCCC, came into force, research on environment friendly energy resources has been a matter of concern worldwide. As a general power generation system, among renewable energy resources, that is interconnected and operated with power system, the wind turbine is emerging as an effective alternative. Since power capacity of the wind turbine has been steadily increasing and its relative importance is also increasing in total facility capacity, we cannot ignore its effect. Because controlling generation output in the wind turbine is not as easy as in the synchronous machine due to its facility characteristics and it generates irregular output fluctuations when interconnected with power system, system interconnection was difficult. But the effect of large capacity wind turbine on isolated power system like Jeju island is serious problem on the frequency stability. Accordingly, it is necessary to analyze the effects of wind turbine on system interconnection and assess the optimum capacity of wind turbine that satisfies the most important principle of stable power supply. This paper have analyzed the effects of wind turbine capacity increases on the system and suggested the method of the capacity to achieve its steady operation. And It is applied to the Jeju island.

Orthogonal NOMA Strong Channel User Capacity: Zero Power Non-Zero Capacity Transmission

  • Chung, Kyuhyuk
    • 전기전자학회논문지
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    • 제23권2호
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    • pp.735-738
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    • 2019
  • Recently, orthogonal non-orthogonal multiple access (O NOMA) with polar on-off keying (POOK) has been proposed to mitigate the severe effect of the superposition. However, it is observed that the performance of the O NOMA strong channel user is better than that of the perfect successive interference cancellation (SIC), i.e., the performance of a single user transmission with binary phase shift keying (BPSK). Can the performance of the BPSK modulation be better that that of itself? It is not normal. It should be clearly understood theoretically, with the ultimate bound, i.e., the channel capacity. This paper proves that the channel capacity of the O NOMA strong channel user is non-zero with zero power allocation. Thus, it is shown that the interference is transformed effectively into the meaningful signal.

MIMO Capacity, Level Crossing Rates and Fades: The Impact of Spatial/Temporal Channel Correlation

  • Giorgetti, Andrea;Smith, Peter J.;Shafi, Mansoor;Chiani, Marco
    • Journal of Communications and Networks
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    • 제5권2호
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    • pp.104-115
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    • 2003
  • It is well known that Multiple Input Multiple Output (MIMO) systems offer the promise of achieving very high spectrum efficiencies (many tens of bit/s/Hz) in a mobile environment. The gains in MIMO capacity are sensitive to the presence of spatial and temporal correlation introduced by the radio environment. In this paper, we examine how MIMO capacity is influenced by a number of factors e.g., a) temporal correlation b) various combinations of low/high spatial correlations at either end, c) combined spatial and temporal correlations. In all cases, we compare the channel capacity that would be achievable under independent fading. We investigate the behaviour of "capacity fades," examine how often the capacity experiences the fades, develop a method to determine level crossing rates and average fade durations and relate these to antenna numbers. We also evaluate the influence of channel correlation on the capacity autocorrelation and assess the fit of a Gaussian random process to the temporal capacity sequence. Finally we note that the particular spatial correlation structure of the MIMO channel is influenced by a large number of factors. For simplicity, it is desirable to use a single overall correlation measure which parameterizes the effect of correlation on capacity. We verify this single parameter concept by simulating a large number of different spatially correlated channels.

도시지역 CSOs 저감을 위한 저류조 및 이송관로의 최적 용량결정에 관한 연구 (Study on the determination of optimum size of storage tank and intercepting capacity for CSOs reduction in urban area)

  • 이관용;최원석;이용재;구원석;송창수
    • 상하수도학회지
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    • 제26권6호
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    • pp.735-745
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    • 2012
  • Storage method is one of major measures for reduction of CSOs pollutant loads and several projects have been done nationwide. But systematic analysis of intercepting capacity has not been studied to determine optimum size of storage facility. In this research, not only storage volume but also intercepting capacity which means flow capacity from intercepting facility to CSOs storage facility was studied and optimum sizing method for storage facility was proposed. The result shows that pollutants reduction efficiency can be increased significantly by increasing intercepting capacity and it might reduce storage volume and total construction costs. Intercepting capacity for the study area was evaluated and it was shown as equivalent to 83 % probability rainfall intensity.

지진피해를 받은 철근콘크리트 건물의 잔존내진성능평가 (Evaluation of Post-earthquake Seismic Capacity of Reinforced Concrete Buildings suffering from earthquakes)

  • 강대언;이원호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.105-108
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    • 2005
  • In damage investigation of building structures suffering from earthquake, estimation of residual seismic capacity is essential in order to access the safety of the building against aftershocks and to judge the necessity of repair and restoration. It has been proposed that an evaluation method for post-earthquake seismic capacity of reinforced concrete buildings based. on the residual energy dissipation capacity (the residual seismic capacity ratio )in lateral force-displacement curve of structural members. The proposed method was adopted in the Japanese 'Damage Level Classification Standard' revised in 200l. To evaluate the residual seismic capacity of RC column, experimental tests with positive and negative cyclic loading was carried out using RC building column specimen. Parameters used by the experiment are deformability and member proportion. From the test results, it is appropriated that the residual seismic capacity of RC buildings damaged by earthquakes is evaluated using the method in the Guideline.

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