• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.157-164
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• 2003

A simulation-based approach that can be used to systematically model the uncertainties of seismic loading and geotechnical property is presented in the context of reliability analysis of slope stability. The uncertainty of seismic loading is studied by generating a large series of hazard-compatible artificial motions, and by using them in subsequent response analyses. The stochastic nature of spatially varying material properties and also the uncertainty arising from insufficient information are treated in the framework of random fields. The simulation-based analyses indicate that in a seismically less active region, a moderate variability in soil properties has a relatively large effect as much as characterization of earthquake hazard on the computed risk of slope failure and excessive slope deformations.

• 대한원격탐사학회지
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• 제19권5호
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• pp.381-392
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• 2003

Multi-temporal approaches using sequential data acquired over multiple years are essential for satisfactory discrimination between many land-cover classes whose signatures exhibit seasonal trends. At any particular time, the response of several classes may be indistinguishable. A harmonic model that can represent seasonal variability is characterized by four components: mean level, frequency, phase and amplitude. The trigonometric components of the harmonic function inherently contain temporal information about changes in land-cover characteristics. Using the estimates which are obtained from sequential images through spectral analysis, seasonal periodicity can be incorporates into multi-temporal classification. The Normalized Difference Vegetation Index (NDVI) was computed for one week composites of the Advanced Very High Resolution Radiometer (AVHRR) imagery over the Korean peninsula for 1996 ～ 2000 using a dynamic technique. Land-cover types were then classified both with the estimated harmonic components using an unsupervised classification approach based on a hierarchical clustering algorithm. The results of the classification using the harmonic components show that the new approach is potentially very effective for identifying land-cover types by the analysis of its multi-temporal behavior.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.180-180
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• 2015

Weather radar has been widely used in measuring precipitation and discharge and predicting flood risks. The radar rainfall estimate has one of the essential problems in terms of uncertainty and accuracy. Previous study analyzed radar errors to reduce its uncertainty or to improve its accuracy. Furthermore, a recent analyzed the effect of radar error on rainfall-runoff using spatial error model (SEM). SEM appropriately reproduced radar error including spatial correlation. Since the SEM does not take the time dependence into account, its time variability was not properly investigated. Therefore, in the current study, we extend the SEM including time dependence as well as spatial dependence, named after Spatial-Temporal Error Model (STEM). Radar rainfall events generated with STEM were tested so that the peak runoff from the response of a basin could be investigated according to dependent error. The Nam River basin, South Korea, was employed to illustrate the effects of STEM on runoff peak flow.

• Earthquakes and Structures
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• 제10권3호
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• pp.681-697
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• 2016

The model of two-temperature magneto-thermoelasticity for a non-simple variable-thermal-conductivity infinitely-long solid cylinder is established. The present cylinder is made of an isotropic homogeneous thermoelastic material and its bounding plane is traction-free and subjected to a time-dependent temperature. An exact solution is firstly obtained in Laplace transform space to obtain the displacement, incremental temperature, and thermal stresses. The inversion of Laplace transforms has been carried out numerically since the response is of more interest in the transient state. A detailed analysis of the effects of phase-lags, an angular frequency of thermal vibration and the variability of thermal conductivity parameter on the field quantities is presented.

• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.91-102
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• 2021

In this paper, a fully reconfigurable Software Defined Radio (SDR) for multi-constellation and multi-frequency Global Navigation Satellite System (GNSS) receivers is presented. The reconfigurability with respect to the data structure, variability of signal and receiver parameters, and receiver's internal functionality is presented. The configuration file, that is modified to lead to an entirely different operation of the SDR in response to specific target signal scenarios, directly determines the operating characteristics of the SDR. In this manner, receiver designers can effectively reduce the effort to develop many different combinations of multi-constellation and/or multi-frequency GNSS receivers. Finally, the implementation of the presented fully reconfigurable SDR is included with the experimental processing results such as acquisition, tracking, navigation for the received signals in the realistic fields.

• 신재생에너지
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• 제19권3호
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• pp.13-21
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• 2023

Smart windows are capable of varying their visible light transmittance (VLT) in response to changing environmental conditions. The VLT variability of architectural windows is highly valuable because it enables indoor lighting and energy environments to align with external changes. However, challenges such as high installation costs and assurance of glass visibility have prompted the exploration of alternative solutions, including models incorporating partially applied smart windows., Prior research focused on useful daylight illuminance (UDI) analysis for south-facing office buildings, pointing out suitable areas for smart-window implementation to enhance lighting control. In this study, we broadened this scope by determining optimal smart-window application zones under changing building orientation. Furthermore, we studied the correlation between building orientation and smart-window deployment areas.

• Earthquakes and Structures
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• 제22권3호
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• pp.289-304
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• 2022

During strong ground motions, adjacent structures with insufficient separation distances collide with each other causing considerable architectural and structural damage or collapse of the whole structure. Generally, existing design procedures for determining the separation distance between adjacent buildings subjected to structural pounding are based on approximations of the buildings' peak relative displacement. These procedures are based on unknown safety levels. This paper attempts to evaluate the influence of foundation flexibility on the structural seismic response by considering the variability in the system and uncertainties in the ground motion characteristics through comprehensive numerical simulations. Actually, the aim of this study is to evaluate the influence of foundation flexibility on probabilistic evaluation of structural pounding. A Hertz-damp pounding force model has been considered in order to effectively capture impact forces during collisions. In total, 5.25 million time-history analyses were performed over the adopted models using an ensemble of 25 ground motions as seismic input within OpenSees software. The results of the study indicate that the soil-structure interaction significantly influences the pounding-involved responses of adjacent structures during earthquakes and generally increases the pounding probability.

• Journal of Acupuncture Research
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• 제26권5호
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• pp.57-63
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• 2009

Objectives : Since the Front Points are treated as response zone, it can be used for the diagnosis and treatment of disease in viscera and bowels. Jeonjung($CV_{17}$) is the Front Point of SIMPO, it is related with cardiovascular, neuro-psychiatrical disease in aspect of Oriental Medicine. This research is for clarifying relations with palpation of the Jeonjung($CV_{17}$) and autonomic nerve system by comparing HRV and SRI(Stress Reaction Index). Methods : This study was proceeded for three months, from June 2009 to September 2009. Among 31 healthy volunteers, 13 subjects who complained the pressure pain around Jeonjung($CV_{17}$) are classified pressure pain group and 18 subjects who had no pain around Jeonjung($CV_{17}$) as normal group. All subjects had their HRV(SA-2000E: Medicore Co..Ltd. Korea) and SRI measured at visit. We studied the difference of HRV between two groups.(Statistics by Student t-test, p<0.05) Results : LF normalization of the pressure pain group were significantly higher than those of the normal group. HF normalization of the pressure pain group were significantly lower than those of the normal group. Compared with those of the normal group, total SRI of the pressure pain group were low but it's not significant. Conclusions : The results of HRV of the pressure pain group show that pressure pain around Jeonjung($CV_{17}$) is related to mental stress and autonomic disturbance.

• Korean Journal of Acupuncture
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• 제24권4호
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• pp.25-36
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• 2007

Objectives : Acupuncture restores the flow of vital energy in the body by stimulating the organ-specific meridians and enhances cardiac vagal activity and suppresses sympathetic activity. The purpose of this review is to summarize and evaluate the acupuncture studies on autonomic nervous system (ANS). Methods : We conducted a PubMed search to obtain a fair sample of acupuncture studies related ANS published in English in 2007. Each article was reviewed for study objectives and outcomes, as well as acupuncture points, experimental and control interventions. Results : We reviewed a total of 15 studies published from 1997 to 2007. In normal states, acupuncture enhanced either vagal or sympathetic tone depending on the stimulated acupuncture point sites. On the other hand, most of studies demonstrated that acupuncture restored the autonomic dysfunctions in various kinds of stressful states. Conclusions : We reviewed studies that contributed to an understanding of the autonomic mechanisms of acupuncture with the hope that this review will be of benefit to the future studies. Although the relationship between acupuncture and ANS response is still uncertain, acupuncture would be a noteworthy modality for modulating autonomic dysfunction.

• 정보처리학회논문지D
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• 제15D권3호
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• pp.361-374
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• 2008

최근의 유비쿼터스 컴퓨팅 환경에서 요구되는 새로운 패러다임의 소프트웨어인 적응형 소프트웨어는 외부 환경 즉 문맥의 변화를 인식하고 자신의 운영 상태를 평가하여 스스로 동작행위를 바꾸는 능력을 가진 소프트웨어이다. 적응형 소프트웨어를 개발하기 위해서는 문맥에 대한 분석 및 설계와 더불어 동적인 문맥에 따라 적절히 대응할 수 있는 소프트웨어의 구조 및 행위를 설계하는 과정이 필요하다. 이것은 일반적인 소프트웨어보다 소프트웨어가 적응해야 하는 상황을 모델링 하는 기술이 필요하기 때문에 더 많은 노력이 필요하다. 본 논문에서는 재사용을 통해 개발의 효율성을 높이고자 적응형 소프트웨어를 위한 프로덕트 라인 아키텍처와 아키텍처 산출물의 템플릿을 제안한다. 아키텍처 산출물들은 프로덕트 라인의 공통성과 가변성을 명시적으로 표현하여 체계적인 핵심자산의 재사용 활동을 지원한다.