• Nuclear Engineering and Technology
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• 제48권3호
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• pp.831-839
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• 2016

Seismic qualification by test is widely used as a way to show the integrity and functionality of equipment that is related to the overall safety of nuclear power plants. Another means of seismic qualification is by direct integration analysis. Both approaches require a series of time histories as an input. However, in most cases, the possibility of using real earthquake data is limited. Thus, artificial time histories are widely used instead. In many cases, however, response spectra are given. Thus, most of the artificial time histories are generated from the given response spectra. Obtaining the response spectrum from a given time history is straightforward. However, the procedure for generating artificial time histories from a given response spectrum is difficult and complex to understand. Thus, this paper presents a simple time-domain method for generating a time history from a given response spectrum; the method was shown to satisfy conditions derived from nuclear regulatory guidance.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2010년도 학술발표회
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• pp.1439-1442
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• 2010

Time-lag recurrent neural networks model (Time-Lag RNNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$) and mean relative humidity ($RH_{mean}$). And, for the performances of Time-Lag RNNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of Time-Lag RNNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE using Time-Lag RNNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using Time-Lag RNNM.

• 한국음향학회지
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• 제37권1호
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• pp.21-30
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• 2018

수동 시역전 기법은 시공간적인 집속효과를 통해 다중경로 채널응답에 의한 인접 심볼간 간섭의 영향을 줄임으로써 수중통신 시스템의 오류 성능을 향상시킬 수 있는 방법이다. 이러한 수동 시역전 기법은 일반적으로 시역전 결합에 사용되는 수신신호가 많을수록 큰 공간 다이버시티 이득을 얻기 때문에 많은 수의 수신기를 사용할 때 우수한 통신 성능을 얻을 수 있다. 본 논문에서는 제한된 개수의 수신기를 사용하더라도 많은 수의 수신기를 사용할 때와 근접한 통신 성능을 얻을 수 있는 수신기의 개수와 조합에 대해 분석한다. 분석을 위해 2015년 5월에 제주 남서쪽 해역에서 수행된 SAVEX15(Shallow-water Acoustic Variability Experiment 2015) 실험 데이터를 활용한다. 음향채널이 존재하는 채널 특성 때문에 에너지가 집중되는 수심이 존재하였고 에너지가 집중되는 수심에 존재하는 수신기를 포함하여 수동 시역전 결합을 할 때, 일부의 수신기만을 사용하여 최적에 가까운 통신 성능을 도출할 수 있음을 보인다.

• 한국산업정보학회논문지
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• 제11권5호
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• pp.105-118
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• 2006

패션계에서 크게 성공한 스페인의 Zara, 그리고 미국의 Limited Brands사는 고객의 취향이나 유행이 매우 빠르게 변화한다는 것에 착안하여 성공한 기업들이다. 변화에 유연하게 대응하는 민첩한 조직(agile organization)과 고객 요구사항에 신속하게 대응하는 감지-반응 기업(adaptive enterprise)에 대한 논의는 이전부터 제기되어왔으며 최근에는 실시간 기업(RTE; Real-Time Enterprise)이라는 개념으로 확산되고 있다. 이에 본 논문에서는 패션산업의 특성을 고려한 패션산업의 실시간기업화, 즉 RTE 가 되기 위한 도입 방안을 제시하였다. 패션산업이 실시간기업화 되기 위해서는 종단간 프로세스들이 지연시간 없이 운영되어야 하며 또한 RTE의 세 가지 중요한 속성인 가시성(visibility), 지능성(intelligence), 그리고 민첩성(agility)이 확보되어야 한다. 패션산업에서의 실시간기업화를 위해 이 두 가지 축, 즉 사이클론 모델의 세 단계와 RTE 속성을 축으로 하여 여기에 패션산업의 핵심 업무인 패션머천다이징을 적용, 패션산업의 실시간기업화를 위해 추진해야할 항목들을 도출하였으며 구현 및 기술관점에서 현재까지의 솔루션들을 정리하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.524-529
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• 1989

In this paper, an approximate sojourn time distribution is obtained for cyclic service systems. We consider symmetric and limited service systems in which each queue has an infinite capacity. The combined service time is defined which consists of the frame service time and server waiting time that is approximated by two cases of the uniform and exponential distributions. The approximate sojourn time distribution is obtained from the Pollaczek-Khinchine formula where the combined service time is used for the service time in the M/G/I model. And some numerical examples are given to validate the suggested approximate analysis.

• Structural Engineering and Mechanics
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• 제9권6호
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• pp.557-568
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• 2000

As time-variant reliability approaches become increasingly used for service life prediction of the aging infrastructure, the demand for computer solution methods continues to increase. Effcient computer techniques have become well established for the reliability analysis of structural systems. Thus far, however, this is largely limited to time-invariant reliability problems. Therefore, the requirements for time-variant reliability prediction of deteriorating structural systems under time-variant loads have remained incomplete. This study presents a computer program for $\underline{REL}$iability of $\underline{T}$ime-Variant $\underline{SYS}$tems, RELTSYS. This program uses a combined technique of adaptive importance sampling, numerical integration, and fault tree analysis to compute time-variant reliabilities of individual components and systems. Time-invariant quantities are generated using Monte Carlo simulation, whereas time-variant quantities are evaluated using numerical integration. Load distribution and post-failure redistribution are considered using fault tree analysis. The strengths and limitations of RELTSYS are presented via a numerical example.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.621-624
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• 2009

The time delay in active and semi-active controls is an important research subject. Many researches on the time-delay control for deterministic systems have been made (Hu and Wang 2002, Yang et al. 1990, Abdel-Mooty and Roorda 1991, Pu 1998, Cai and Huang 2002), while the study on that for stochastic systems is very limited. The effects of the time delay on the control of nonlinear systems under Gaussian white noise excitations have been studied by Bilello et al. (2002). The controlled linear systems with deterministic and random time delay subjected to Gaussian white noise excitations have been treated by Grigoriu (1997). Recently, a stochastic averaging method for quasi-integrable Hamiltonian systems with time delay has been proposed (Liu and Zhu 2007). In the present paper, a stochastic optimal time-delay control method for stochastically excited nonlinear structural systems is proposed based on the stochastic averaging method for quasi Hamiltonian systems with time delay and the stochastic dynamical programming principle. An example of stochastically excited and controlled hysteretic column is given to illustrate the proposed control method.

• Journal of Information Processing Systems
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• 제10권2호
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• pp.300-313
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• 2014

Various Time Synchronization protocols for a Wireless Sensor Network (WSN) have been developed since time synchronization is important in many time-critical WSN applications. Aside from synchronization accuracy, energy constraint should also be considered seriously for time synchronization protocols in WSNs, which typically have limited power environments. This paper performs analysis of prominent WSN time synchronization protocols in terms of power consumption and test by simulation. In the analysis and simulation tests, each protocol shows different performance in terms of power consumption. This result is helpful in choosing or developing an appropriate time synchronization protocol that meets the requirements of synchronization accuracy and power consumption (or network lifetime) for a specific WSN application.

• Plant Biotechnology Reports
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• 제4권4호
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• pp.293-301
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• 2010

The feasibility of two strategies for transgene pyramiding using Agrobacterium-mediated transformation was investigated to develop a transgenic potato (Solanum tuberosum L. cv. Iwa) with resistance to potato tuber moth (PTM) (Phthorimaea operculella (Zeller)). In the first approach, cry1Ac9 and cry9Aa2 genes were introduced simultaneously using a kanamycin (nptII) selectable marker gene. The second approach involved the sequential introduction (re-transformation) of a cry1Ac9 gene, using a hygromycin resistance (hpt) selectable marker gene, into an existing line transgenic for a cry9Aa2 gene and a kanamycin resistance (nptII) selectable marker gene. Multiplex polymerase chain reaction (PCR) confirmed the presence of the specific selectable marker gene and both cry genes in all regenerated lines. The relative steady-state level of the cry gene transcripts in leaves was quantified in all regenerated lines by real-time PCR analysis. Re-transformation proved to be a flexible approach to effectively pyramid genes for PTM resistance in potato, since it allowed the second gene to be added to a line that was previously identified as having a high level of resistance. Larval growth of PTM was significantly inhibited on excised greenhouse-grown leaves in all transgenic lines, although no lines expressing both cry genes exhibited any greater resistance to PTM larvae over that previously observed for the individual genes. It is anticipated that these lines will permit more durable resistance by delaying the opportunities for PTM adaptation to the individual cry genes.

• Journal of information and communication convergence engineering
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• 제22권1호
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• pp.33-43
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• 2024

Automated text summarization (ATS) systems rely on language resources as datasets. However, creating these datasets is a complex and labor-intensive task requiring linguists to extensively annotate the data. Consequently, certain public datasets for ATS, particularly in languages such as Thai, are not as readily available as those for the more popular languages. The primary objective of the ATS approach is to condense large volumes of text into shorter summaries, thereby reducing the time required to extract information from extensive textual data. Owing to the challenges involved in preparing language resources, publicly accessible datasets for Thai ATS are relatively scarce compared to those for widely used languages. The goal is to produce concise summaries and accelerate the information extraction process using vast amounts of textual input. This study introduced ThEconSum, an ATS architecture specifically designed for Thai language, using economy-related data. An evaluation of this research revealed the significant remaining tasks and limitations of the Thai language.