• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.475-478
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• 2004

본 논문에서는 multistatic 소나망의 효과도 분석을 하였다. 특히 본 논문에서는 multistatic 소나망의 탐지 성능 분석을 통해 효용성을 알아보았다. Multistatic 소나망은 송/수신기가 분리된 일종의 다중 분산 센서 시스템으로, 최적의 탐지 성능을 갖기 위해서는 적절한 융합 규칙 및 센서 배치가 필요하다. 분산 센서 융합 기법으로 bayesian 결정 기법을 기반으로 한 융합 기법을 적용하였으며, 실제 해양 환경하에서의 탐지 성능 분석을 위해 개선된 bistatic 표적 강도 모델과 거리 종속 전송 손실 모델을 이용한 multistatic 소나망 탐지 모델을 제안하였다. 기존 소나망과의 모의 비교 실험을 통해 multistatic 소나망의 우수성을 입증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.622-624
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• 2013

모바일 헬스케어는 다양한 스마트 디바이스를 활용한 개인건강관리 기술을 말한다. 특히 스마트폰 보급과 근거리 무선 통신 기술의 발전으로 모바일 헬스케어와 관련한 여러 디바이스와 서비스들이 개발되고 있다. 그러나 이러한 디바이스와 서비스들이 대부분 자체적인 규격에 의해 굿현 되고 있으며 이로인해 기기 간 호환이 안 되고 서비스가 종속되는 등의 문제가 있다. 특히 규제가 엄격한 의료 서비스와 거리를 둔 일상적 생활에서의 건강관리 기기나 서비스들은 그 문제가 더욱 심각하다. 본 논문에서는 이러한 모바일 헬스케어 환경에서의 문제점 해결을 위한 표준 요소와 그 현황에 대해 살펴보고 관련 표준의 모바일 헬스케어 적용 모델을 제안 한다.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.417-420
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• 2004

동해는 크게 북한한류계수의 지배적인 영향을 받는 북부해역, 동한난류계수의 지배적인 영향을 받는 남부해역과 이들이 만나서 극전선이 형성되는 중부해역 등 세 해역으로 구분할 수 있고 이러한 환경에서의 해군 함정의 대잠탐지환경은 같은 동해라 하더라도 크게 다를 것으로 예상된다. 본 연구에서는 저주파 거리종속 모델인 RAM 을 이용하여 평균해황 하에서 각 해역에서의 전달손실 값을 비교하였다. 음원을 수심 100m, 수신기 수심을 10m와 100m로 설정하여 실험을 하였으며 아울러 평균해황이 아닌 일정시기에 관측한 순간해황 자료를 통한 모델결과도 같이 분석하였다. 실험결과, 연안에 위치한 음원으로부터 음파가 외해로 전달됨에 따라 냉난수대간의 수온전선 영향을 받게되며 수온전선을 통과하면서 남부해역에서의 음파는 중부 및 북부해역 보다 난류의 영향을 더 많이 받게된다. 따라서 북부보다는 중부해역이, 중부보다는 남부해역에서의 전달손실값이 더 커지게 된다. 특히 이러한 경향은 북한한류계수가 발달하여 난류와 수온전선이 형성되는 8월에 더 큰 것으로 나타났다.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.52-60
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• 2005

This paper attempted to investigate not only the correlativity of land price and residential environment elements but also the effect that the residential environment elements influence on the land price, focusing on the Suyoung-Gu and Haeundae-Gu which are representative residential and waterfront area in Pusan. For this purpose, regression analysis and correlation analysis as the residential environment elements in independent variable and the land price in dependent variable were carried out. First of all, from the correlation analysis between the land price and the residential environment elements, it become clear that the variables such as the land use, the distance to arterial road and, the distance to subway station have high correlativity with land price in all the research area. Then from the individual power of explanation and accumulative power of explanation of the each variable to the land price through the regression analysis, it was become clear that 7 variables which are the land use, the distance to trunk road, the distance to subway station etc. have 67% of the power of explanation to land price at the Suyoung-Gu, and 50.5% at the Haeundae-Gu. Moreover, researchers had an special interest in the correlativity between the distance to the coastal line and land price as well as the power of explanation of the distance to the coastal line for the land price. It means that researchers expected the variable of the distance to the coastal line have a strong correlativity and high power of explanation for land price. However, from the regression analysis and correlation analysis, it was become clear that the variable of the distance to the coastal line have a weak correlativity, and low power of explanation which is just form 6.4% to 7.6% in all the research area. In other words, it might be said that the variable of the distance to the coastal line is not so important one to presume the land price.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.221-231
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• 2021

This paper identify factors of migration of employees' household who work for relocated public institutions. As a factors of migration, we consider individual and household characteristics, the gravity model of distance and population and so on. Considering discrete dependant variable and structure of data, we employ the logistic multilevel model and random intercept model. The result indicates employees' who are female, 30s and 40s, higher education level(PhD) and whose spouse are unemployed tend to transfer their residential registration to new city near relocated public institution. Regarding regional variable, the distance from employee's previous residential location and number of migration of prior year are statistically significant. Also the model indicate regional economy, educational and residential environment of new city influence employee's decision for transferring residential registration.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.337-346
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• 2023

Although wildlife bridge are built as a way to reduce habitat fragmentation caused by road construction, there is still a lot of debate about their effectiveness. Monitoring methods such as footprint traps and camera traps are used evaluate the effectiveness of wildlife bridge, but there is a limit to evaluate of effectiveness. In this study, the degree of use the wildlfe bridge was surveyed by striped field mouse that is likely use the wildlife bridge and surrounding as a habitat with capture-mark-recapture method.(Apodemus agraius). The distance and route of movement were identified by connecting the capture points, and the environmental factors on the use of the wildlife bridge implemented a generalized linear model(GLM) with the capture number of captured as a dependent variable. Consequently of capture, no individuals crossing the wildlife bridge, striped field mouse use the wildlife bridge as a habitat.The environmental factors affecting the use of mice were vegetation cover(1~2m, 2~8m, over 8m), vegetation construction, maximum diameter at breast height were positively correlated and slope was nagatively correlated. In conclusion, it is expected that the effectiveness of the wildlife bridge will be further improved by planting shrubs and trees and preventing high slope and cut slope increasing the utilization of the rat, such as being used as a food source in the ecosystem.

• The Journal of the Acoustical Society of Korea
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• v.23 no.8
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• pp.576-582
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• 2004

A computer code that is based on the Pseudo-spectral finite difference algorithm using staggered grid is developed for the wave propagation modeling in the time domain. The advantage of a finite difference approximation is that any geometrically complicated media can be modeled. Staggered grids are advantageous as it provides much more accuracy than using a regular grid. Pseudo-spectral methods are those that evaluate spatial derivatives by multiplying a wavenumber by the Fourier transform of a pressure wave-field and performing the inverse Fourier transform. This method is very stable and reduces memory and the number of computations. The synthetic results by this algorithm agree with the analytic solution in the infinite and half space. The time domain modeling was implemented in various models. such as half-space. Pekeris waveguide, and range dependent environment. The snapshots showing the total wave-field reveals the Propagation characteristic or the acoustic waves through the complex ocean environment.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.234-246
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• 2017

The Seoul metropolitan government introduced the bus information systems, bus rapid transit to increase travel speed and punctuality but still suffer from insufficiency. This paper delivers a study verifying the external factors at near the bus stops. The dependent variable was set to the standard deviation of (1) travel time and (2) travel time to and from the bus stop in this study. The independent variables were set to (1) the number of routes, (2) traffic volume by bus type, (3) the number of bus bays, (4) the possibility of passing, (5) the distance to crosswalks and intersections, and (5) the presence of residential road. The results showed that the most significant factors included the link section speed, number of bus bay, distance to crosswalk, and the possibility of passing.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.789-796
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• 2006

Context-aware is the core in ubiquitous environment of sensor network to support intelligent and contextual adaptation service. The new context information model is demanded to support context-aware applications. The model should not depend on a specified application and be shareable between applications in the same environment. Also, it should support various context representation and complex context-aware. In this paper, we define the context information according to context-aware process. Also we design the knowledge of domain as well as applications using ontologies and rules. The domain spatial ontology and application knowledge are represented using the spatial object model and the rules of expanded ontologies, respectively. The expression of abundant spatial ontology represents the context information about distance between objects and adjacent object as well as the location of the object. The proposed context information model which is able to exhibit various spatial context and recognizes complex spatial context through the existing GIS. This model shows that it can adapt to a large scale outdoor context-aware applications such as air pollution and prevention of disasters as well as various context-aware applications.

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.48-56
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• 2006

Using a continuous injection tracer test at a multi-soil layer deposit, the difference of hydrodynamic dispersions in unsaturated and saturated zones were analyzed through breakthrough curves of Rhodamine WT, linear regression of concentration versus time, concentration variation rates versus time, and concentration ratio according to the distance from injection well. As a result of continuous injection tracer test, the difference of the maximum concentrations of Rhodamine WT in unsaturated and saturated zones were 13-15 times after 160 hours, and the increased rate of concentration versus time in unsaturated zone was about 10 times higher than in saturated zone. The fluctuation of Rhodamine WT breakthrough curve and concentration variation rate with time in saturated zone were larger than in unsaturated zone. Rhodamine WT concentration ratio with the distance from the injection well in saturation zone was linearly decreased faster than in unsaturated zone, and the elapsed time necessary for the concentration ratio less than 2 was longer in saturation zone. The differences resulted from the lower concentration and slower hydrodynamic dispersion of Rhodamine WT at the saturation zone of the multi-soil layer deposit, in which groundwater flow significantly flow and aquifer materials have high hydraulic heterogeneity. Effective porosity, longitudinal and transverse dispersivities were estimated $10.19{\sim}10.50%,\;0.80{\sim}1.98m$ and $0.02{\sim}0.04m$, respectively. The field longitudinal dispersivity is over 12 times larger than the laboratory longitudinal dispersivity by the scale-dependent effect.