• Journal of the Korean Geosynthetics Society
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• v.6 no.3
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• pp.9-16
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• 2007

Soil vapor extraction (SVE) is an effective and cost efficient method of removing volatile organic compounds (VOCs) and petroleum hydrocarbons from unsaturated soils. Incorporating PVDs in an SVE system can extend the effectiveness of SVE to lower permeability soils by shortening the air flow-paths and ultimately expediting contaminant removal. With this approach, the real bounded system is replaced for the purposes of analysis by an imaginary system of infinite areal extent. The boundary conditions for the contaminant remediation model test include constant head and no flow condition. Due to these parallel boundaries conditions, image wells should be developed in order to maintain the condition of no flow across the impermeable boundary. It is also assumed that the flow is drawdown along the constant head boundary condition. The factors contributing to the difference between the theoretical and measured pressure heads were also analyzed. The flow factor increases as the flow rate is increased. The flow rate is the most important factor that affects the difference between the measured and theoretical pressure heads.

• Cross-Cultural Studies
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• v.49
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• pp.275-301
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• 2017

Based on the previous analysis by Wanghongjun(2008), this paper applies Optimality Theory (OT) to the field of partial reduplication in Korea to increase its scientific validity. Toward this end, I propose an alternative analysis of Korean partial reduplication, applied as a single process of prefixation. Reduplicated words by prefixation are divided into two types: with a heavy syllable of the stem, and another with the stem. The two types of partial reduplication are closely related by the sound features. In addition, I discussed Chinese partial reduplication from a prefixation perspective within the framework of OT and performed contrastive analysis of Korean and Standard Chinese processes of reduplication by focusing on constrained rankings. As a result, the alternative analysis showed a systematic relationship among the reduplicated words in Korean and Standard Chinese. Lastly, I explained that the coronal /t/ and liquid /l/ have a special functional hierarchy in both languages. This study can be re-explained based on the framework of OT according to a few major constraints, involving MAX-BR, MAX-IO. Their rankings show the adequacy of analysis.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.691-693
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• 2005

본 연구에서는 FMM 신경망의 학습 알고리즘에서 하이퍼박스 확장과정에 수반되는 중첩현상을 분석하고, 이에 대한 축소 과정의 특성과 이를 보완하기 위한 새로운 활성화 함수에 관하여 고찰한다. 하이퍼박스 중첩 영역에 속하는 패턴 데이터는 그 분류 결과가 왜곡될 수 있다. 왜냐하면 학습과정에서 하이퍼박스상의 특징범위는 특징값의 빈도요소를 고려하지 않음으로 인하여 극소수의 비정상적 데이터에 관해서도 동일 수준으로 민감하게 확장되기 때문이다. 본 논문에서는 특징집합에서 가중치와 빈도요소를 반영하는 모델로서 이러한 중첩현상의 영향을 개선하는 방법론을 소개한다. 제안된 이론은 단순화된 패턴집합에 대하여 그 유용성을 이론적으로 고찰하며, 실제 패턴분류 문제에 적용하여 실험적으로 평가한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.2
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• pp.88-97
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• 2003

Computer simulations of the recording and reading of holograms in an 8-bit phase-code multiplexing system are presented. From the computer simulation each recording time of eight holograms is obtained such that the strength of restored holograms is same. An analytic formula to predict the recording times is derived by fitting the formula to the computer simulation data. It is found that our analytic formula can predict the hologram recording time not only in 8-bit system but also in 16-bit and 32-bit systems in an error less than $\pm$8.4%. Optical experiments are also performed in a 4-bit phase code-multiplexing system. It is found that the strength of the restored holograms is more uniform compared with conventional methods.

• Optical Science and Technology
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• v.13 no.3
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• pp.18-27
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• 2009

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.2
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• pp.27-35
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• 1981

In this study, a numerical theory based on space charge overlapping model and experiments on the propriety of its theory were carried out to analyze the switching transient characteristic in amorphous coalcogenide thin film. Theoretical and experimental as well as analytical investigations were carried out on the switching behaviour in a transient state arising from a voltage pulse applied to amorphous chalcogenide thin films at room temperature. The results can be explained in terms ot a simple theoretical model of the electronic characteristics of switching. The injection of carriers are necessary to initiate the switching action and injected carriers contribute to the current flow as a space-charge limited current(SCLC) The proposed charge controlled switching characteristics can be explained by double injection space charge overlapping model.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.501-508
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• 2003

In this paper A new theory of linear loop transformation called Elimination of Data Dependency(BDD) is presented. The current framework of linear loop transformation cannot identify a significant fraction of parallelism. For this reason, a method to extract the maximum loop parallelism in perfect nested loops is presented. This technique is applicable to general loop nests where the dependence include both distance and directions.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.1
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• pp.89-98
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• 2000

본 연구에서는 비비례 감쇠시스템을 효율적으로 해석할 수 있도록 모드 가속도법(mode acceleration method)과 모드 절삭 보강법(modal truncation augmentation method)을 확장하고 그 사용성을 검증하였다,. 비례 감쇠시스템의 동응답해서에 널리 사용되는 모드 가속도법과 모드 절삭보강법은 누락된 고차모드의 영향을 보정하여 모드 중첩법의 결과를 개선하는 방법이다. 기존의 방법들로 비비례 감쇠시스템을 해석하는 경우 비비례 감쇠특성을 무시하지 않으며 정확하고 효율적으로 해석할 수 있도록 모드 가속도법과 모드 절삭보강법을 확장하였다. 비례 감쇠시스템에서는 모드 가속도법보다 모드 절삭보강법이 더 효율적인 반면에 비비례 감쇠시스템에서는 대부분의 경우에 있어서 확장된 두 방법의 효율성이 동일하다. 그러나 수치적 안정성은 확장된 모드 가속도법이 모드절삭 보강법보다 우수하다. 이와 같은 확장된 모드 가속도법과 모드 절삭보강법의 사용성 검？을 위해서 이론적 방법과 수치예제를 수행하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.4
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• pp.239-246
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• 2009

In this study, we analyze the mean waiting time on the nested open queueing network, where the population within each subnetwork is controlled by a semaphore queue. The queueing network can be transformed into a simpler queueing network in terms of customers waiting time. A major characteristic of this model is that the lower layer flow is halted by the state of higher layer. Since this type of queueing network does not have exact solutions for performance measure, the lower bound and upper bound on the mean waiting time are checked by comparing them with the mean waiting time in the transformed nested queueing network. Simulation estimates are obtained assuming Poisson arrivals and other phase-type arrival process, i.e., Erlang and hyper-exponential distributions. The bounds obtained can be applied to get more close approximation using the suitable approach.

• Composites Research
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• v.34 no.3
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• pp.143-147
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• 2021

Full width half maximum (FWHM) analysis of superimposed terahertz (THz) signals in the glass fiber reinforced polymer (GFRP) was studied to detect fine delamination inside GFRP. The THz signals were measured for each fine delamination size inside the GFRP using the reflection mode of the terahertz time domain spectroscopy (THz-TDS) system. Then, the FWHM of the superimposed THz signal reflected at the fine delamination was extracted. Thereafter, the complex refractive index of the GFRP was measured using transmission mode of the THzTDS system. Based on this, the FWHM of the superimposed THz signal at the fine delamination were calculated and compared with respect to the fine delamination size. From the theoretically calculated superimposed signals, the relationship between the fine delamination size and the FWHM in the superimposed THz signal was derived. Consequently, the fine delamination size could be predicted through the analysis of the FWHM extracted from the THz signal at the fine delamination.