• 천문학회보
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• 제42권1호
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• pp.47.1-47.1
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• 2017

Thanks to the quasi-optics system of KVN, the relative astrometry at different frequencies can be effectively achieved. In this talk, as a part of the KVN special session, we are going to present an important method making it possible, so called the source frequency phase referencing (SFPR). Based on the background, we will show our recent activities using the SFPR for the Galactic Center (Sgr A*) study, from its advantages on astrometric studies to the remained issues.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.483-488
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• 2008

An active omni-directional raging system using an omni-directional vision with structured light has many advantages compared to the conventional ranging systems: robustness against external illumination noise because of the laser structured light and computational efficiency because of one shot image containing $360^{\circ}$ environment information from the omni-directional vision. The omni-directional range data represents a local distance map at a certain position in the workspace. In this paper, we propose a matching algorithm for the local distance map with the given global map database, thereby to localize a mobile robot in the global workspace. Since the global map database consists of line segments representing edges of environment object in general, the matching algorithm is based on relative position and orientation of line segments in the local map and the global map. The effectiveness of the proposed omni-directional ranging system and the matching are verified through experiments.

• 경영과학
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• 제22권2호
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• pp.13-34
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• 2005

Mobile banking service has emerged as an important profit source for both banks and mobile phone service companies. However, the growth of the mobile banking service is behind the expectation of banks and mobile phone companies. One plausible explanation for this laggard diffusion of mobile banking may be the lack of consumers' initial trust on the service. Therefore, this study investigates the critical factors in building trust and intention to use mobile banking services. Our research results show that propensity-to-trust, structural assurance, and relative advantages of services have significant impacts on consumers' initial trust in mobile banking service Furthermore, initial trust in mobile banking service is a critical factor for adopting mobile banking services Contrary to our expectation, however, reputation of banks and mobile phone companies are not significant in attracting consumers to mobile banking services.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권2호
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• pp.62-64
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• 2006

The emerging peer-to-peer (P2P) model has recently gained a significant attention due to its high potential of sharing various resources among networked users. Super-peer based unstructured P2P systems have been found very effective by dividing the peers into two layers, super-peer and ordinary-peer Super-peers deal with all queries instead of ordinary-peers. The existing P2P systems assume all super-peers have equal responsibility and capabilities even if all super-peers have relative advantages and disadvantages. In this paper, we suggest the ISP2P (Intelligent Super-peer based P2P) which allows to select the best super peer to ordinary-peers. We classify super peers according as the capacity of an ordinary-peer a super-peer. We show that these considerations could improve the performance of the response time and Provide higher quality results to all peers in the network.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.25-30
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• 1988

In this paper, we proposed the bidirectional mono-thermic test for the functional exploration of the vestibules by considering a temeprature variation in the semicirular canals constant for a short time and an inclination of the semicircular canal plan relative to the vertical. Through the proposed test we showed the evidence of an eventual asymmetry between the responses of right and left vestibules. In view of clinical practice, the proposed test has the advantages of saving the test time, of using only one temperature for the ear irrigation and of making only head movements to the given angle for the stimulation.

• 한국측량학회지
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• 제30권6_2호
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• pp.653-663
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• 2012

Using soft classification, it is possible to obtain the land cover proportions from the remotely sensed image. These land cover proportions are then used as input data for a procedure called "super-resolution mapping" to produce the predicted hard land cover layers at higher resolution than the original remotely sensed image. Superresolution mapping can be implemented using a number of algorithms in which the Hopfield Neural Network (HNN) has showed some advantages. The HNN has improved the land cover classification through superresolution mapping greatly with the high resolution data. However, the super-resolution mapping is based on the spatial dependence assumption, therefore it is predicted that the accuracy of resulted land cover classes depends on the relative size of spatial features and the spatial resolution of the remotely sensed image. This research is to evaluate the capability of HNN to implement the super-resolution mapping for SPOT image to create higher resolution land cover classes with different zoom factor.

• International Journal of Aeronautical and Space Sciences
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• 제7권1호
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• pp.84-90
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• 2006

The formation flying of satellites has been identified as an enabling technology for many future space missions. The application of conventional thrusters for formation flying usually results in high cost, limited life-time, and a large weight penalty. Various methods including the use of coulomb forces have been considered as an alternative to the conventional thrusters. In the present investigation, we investigate the feasibility of achieving the desired formation using Coulomb forces. This method has several advantages including low cost, light weight and no contamination. A simple controller based on the relative position and velocity errors between the leader and follower satellites is developed. The proposed controller is applied to circular formations considering the effects of disturbances in initial formation conditions as well as system nonlinearity. Results of the numerical simulation state that the proposed controller is successful in establishing circular formations of leader and follower satellites, for a formation size below 100 m.

• 아태비즈니스연구
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• 제3권2호
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• pp.42-48
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• 2012

This paper examined structural changes in export specialization of Japan, South Korea, Taiwan, and China at different levels of technological intensity. The study found significant differences across these Asian economies, with most pronounced changes for exports with high technological intensity. To account for the changing export specialization, the study applied the classical Ricardian model of comparative advantages to export patterns of Japan and South Korea. We found that the export specialization of Japan was mainly determined by differences in fixed effects across industrial sectors, with changes in relative labor productivity much less important. In contrast, changes in productivity turned out an essential factor for explaining the recent export specialization of South Korea.

• Earthquakes and Structures
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• 제1권3호
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• pp.253-267
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• 2010

A novel simple approach is presented for the seismic analysis of continuous buried pipelines subject to fault ruptures. The method is based on the minimization of the total dissipated energy during faulting, taking into account the basic factors that affect the problem, namely: a) the pipe yielding under axial and bending load, through the formation of plastic hinges and axial slip; b) the longitudinal friction across the pipe-soil interface; c) the lateral resistance of soil. The advantages and drawbacks of the proposed method are highlighted through a comparison with previous approaches, as well as with finite element calculations accounting for the 3D kinematics of the pipe-soil-fault systems under large deformations. Parametric analyses are also provided to assess the relative influence of the various parameters affecting the problem.

• 상하수도학회지
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• 제25권5호
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• pp.751-757
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• 2011

The monitoring technique based on electrical conductivity (EC) can provide researchers with some advantages in maintenance management and is cost-effective as compared with existing CSOs monitoring. In this study, the flow rate estimation using EC data was executed in two sites where storm overflow chamber had installed. In the result of A-site, R2 of second order multinomial between dilution ratio of EC and observed flow rate was showed the range of 0.68 ~ 0.77. And $R^{2}$ of B-site was 0.62 ~ 0.81. On the other hand, cumulative frequency of A-site was 43.4 ~ 52.2% in the relative error level of under 20%. And B-site was 10.1 ~ 46.5%. The flow rate estimation formula was improved through consideration of some parameters including antecedent dry days and rainfall duration. And difference between estimated flow rate and observed flow rate in total rainfall event was very small.