• 한국공간구조학회논문집
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• 제20권2호
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• pp.77-85
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• 2020

This paper examined the dynamic instability of a shallow arch according to the response characteristics when nearing critical loads. The frequency changing feathers of the time-domain increasing the loads are analyzed using Fast Fourier Transformation (FFT), while the response signal around the critical loads are analyzed using Hilbert-Huang Transformation (HHT). This study reveals that the models with an arch shape of h = 3 or higher exhibit buckling, which is very sensitive to the asymmetric initial conditions. Also, the critical buckling load increases as the shape increases, with its feather varying depending on the asymmetric initial conditions. Decomposition results show the decrease in predominant frequency before the threshold as the load increases, and the predominant period doubles at the critical level. In the vicinity of the critical level, sections rapidly manifest the displacement increase, with the changes in Instantaneous Frequency (IF) and Instant Energy (IE) becoming apparent.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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• pp.90-95
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• 1991

The Uniform Building Code (UBC) is the most widely used requirements for earthquake resistant design in the United States. In this paper, a mid-rise steel building is analyzed by applying 12 sets of actual strong-motion earthquake data that have been scaled to acne 2B levels. The simply extrapolated ground motion displacements are used for the dynamic loads. The results of dynamic analyses for a 10-story steel building are compared with the static and dynamic analysis requirements of UBC-88. It was found that computed lateral fortes using UBC-88 static procedure differed by about 60 percent depending on whether the natural period was computed using the UBC empirical method or the UBC recommended Rayleigh's method. The lateral fortes computed from the UBC response spectra were more than 10 times greater than those computed by UBC static procedures. The lateral forces obtained from both linear and nonlinear analyses using 1989 Loma Prieta ground mot ions compared very well with UBC response spectra results.

• 대한수학회논문집
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• 제13권3호
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• pp.603-627
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• 1998

The leaky bucket scheme is a promising method that regulates input traffics for preventive congestion control. In the ATM network, the input traffics are bursty and transmitted at high-speed. In order to get the low loss probability for bursty input traffics, it is known that the leaky bucket scheme with static leaky rate requires larger data buffer and token pool size. This causes the increase of the mean waiting time for an input traffic to pass the policing function, which would be inappropriate for real time traffics such as voice and video. We present the leaky bucket scheme with dynamic leaky rate in which the token generation period changes according to buffer occupancy. In the leaky bucket scheme with dynamic leaky rate, the cell loss probability and the mean waiting time are reduced in comparison with the leaky bucket scheme with static leaky rate. We analyze the performance of the proposed leaky bucket scheme in discrete-time case by assuming arrival process to be Markov-modulated Bernoulli process (MMBP).

• 한국자동차공학회논문집
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• 제3권1호
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• pp.143-154
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• 1995

This study investigates the response characteristics of a four-cylinder four-stroke turbocharged diesel engine by using computer simulation and experiments when a rapid acceleration is applied to the fuelpump rack. In the theoretical analysis, linearization method is used to avoid the difficulty on the complex nonlinear functions. Comppressor exit pressure, pressure and temperature of turbine inlet, and turbocharger speed are chosen as the independent variables of transfer functions which represent the dynamic characteristics of the turbocharger system, and expressed as the functions with respect to the time. Experiments on the same eigine system are also carried out to prove the validity of theoretical study. Further, this study carried an experiment for improving transient response performance by injecting air into the inlet manifold under the rapid accelerating conditions. The effects of air injection on the response performances are also represented at varying conditions such as injection pressure, injection period, accelerating rate, accelerating time, engine speed and load.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (A)
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• pp.847-849
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• 2002

인공면역시스템에서 중요한 특징중의 하나는 지속적으로 변화하는 환경에서 자기(self)의 유동적인 패턴을 동적으로 학습하고 비자기(non-self)에 대한 새로운 패턴을 예측하는데 있다. 본 논문은 자기적 용(self-adaptation)의 인공면역체계 특성을 기반으로하여 설계된 dynamics(동적 클론선택 알고리즘, dynamic clonal selection algorithm)의 역할을 논한다. 시스템의 세가지 중요한 변수인 자기내성 기간(Tolerisation Period). 연역 반응 임계값(activation threshold). 수명(life span)에 따라 변화하는 dynamics의 성능을 네트워크 침입에서 흔히 발견되는 시나리오를 모의실험하여 평가한다

• 대한안전경영과학회지
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• 제2권4호
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• pp.165-176
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• 2000

Broadband networks are designed to support a wide variety of services with different traffic characteristics and demands for Quality of Services. Bandwidth allocation methods can be classified into two major categories： static and dynamic. In static allocation, bandwidth is allocated only at call setup time and the allocated bandwidth is maintained during a session. In dynamic allocation, the allocated bandwidth is negotiated during a session. The purpose of this paper is to develop policies for deciding and for adjusting the amount of bandwidth requested for a best effort connection over such as ATM networks.. This method is to develop such policies that a good trade off between utilization and latency using cell delay variation to the forecast the incoming traffic in the next period. The performances of the different polices are compared by simulations.

• East Asian Economic Review
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• 제21권2호
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• pp.147-165
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• 2017

This study quantifies the dynamic interrelationship between the KOSPI index return and search query data derived from the Naver DataLab. The empirical estimation using a bivariate GARCH model reveals that negative contemporaneous correlations between the stock return and the search frequency prevail during the sample period. Meanwhile, the search frequency has a negative association with the one-week- ahead stock return but not vice versa. In addition to identifying dynamic correlations, the paper also aims to serve as a test bed in which the existence of profitable trading strategies based on big data is explored. Specifically, the strategy interpreting the heightened investor attention as a negative signal for future returns appears to have been superior to the benchmark strategy in terms of the expected utility over wealth. This paper also demonstrates that the big data-based option trading strategy might be able to beat the market under certain conditions. These results highlight the possibility of big data as a potential source-which has been left largely untapped-for establishing profitable trading strategies as well as developing insights on stock market dynamics.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.12-17
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• 2007

The dynamic false contour noise was analyzed with consideration for the phosphor decay time of an ac PDP by computer simulation based on the measurement of the 1/10 phosphor decay times of the primary colors red, green and blue at the main wavelengths of each phosphor. The noise level of dynamic false contour is strongly dependent on phosphor decay time. The noise level decreases incrementally with the phosphor decay time, whereas the noise width increases. The moving velocity of an object does not affect the noise level. The entire experiment was performed under the condition of 8 subfields ADS driving scheme, 2.5[${\mu}sec$] scan speed, and 5[${\mu}sec$] sustain period with VGA grade panel.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.918-923
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• 2007

Currently, automotive industries improve the vehicle performance and reduce the development period of vehicle using each module part for the high quality and performance of vehicles. However each component part doesn't generate the noise and vibration problems, sometime these problems are generated on the assembly status between vehicle chassis frame and each module part. On this study, in order to analysis the dynamic characteristics of a shield door module that is a typical module part of vehicles, the acquisition and evaluation process about the vibration and noise of shield door module is developed. Also the possibility to apply to shield door module of the developed process is verified by the comparison with the dynamic characteristics between plastic and steel module plate.

• 한국시스템다이내믹스연구
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• 제16권1호
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• pp.75-91
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• 2015

The price-volume in land by land categories is evaluated with dynamic approaches in the era of aging society This research tries to investigate in the respect of major factors such as real estate, macro-economics, and population that is simulated by land categories. The system dynamics approaches on price-volume in land are forecasted until 2020 using the data in the period of 2000-2014. In regard to methodologies, this research adopted system dynamics to evaluate the relationships between price-volume in land and aging society. The meaningful results have been found during the last over 10 year's analysis as the dynamic relations with major factors. Regarding land categories, this research tries to overcome former research limitations. As an implication from the price-volume in land, it confirmed that the multifaceted aspects show that system dynamics approach effectively simulated them by price-volume in land with the population of aging society.