• Journal of the Korea Society of Computer and Information
• /
• v.11 no.5 s.43
• /
• pp.19-27
• /
• 2006

This paper presents a query processing model in a wrapper based on the XML view tree. The query processing in a wrapper requires view composition, query translation into local sources, and generation of XML documents from local query results. We present a query processing model based on the view tree, where the XML views and the XML query is represented by the view tree. Since the view tree keeps the structure of a virtual XML document, it is easy to navigate the path expression. The view tree is also used as a template for schema generation and XML document generation as a query result. Moreover this conceptual uniform abstraction for the XML view and the user query makes it easy to support a multi-level XML view and to implement our composition mechanism.

• Journal of the Society of Naval Architects of Korea
• /
• v.28 no.1
• /
• pp.182-188
• /
• 1991

The modified arc-length algorithms for the automatic incremental solution of nonlinear finite element equations proposed by Riks are presented, which comprise the cylindrical arc-length method and the normal arc-length method. These methods are developed to trace the nonlinear path of large displacement problems such as a pre and post bucking/collapse response of general structures. These methods are applied to analyse the nonlinear behavior of arch and shell problems in parallel with the standard and modified Newton-Raphson method.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10c
• /
• pp.610-612
• /
• 2003

본 논문은 무선 셀룰러 시스템 환경에서 일정구간을 이동하는 지하철, 기차와 같이 규칙적인 이동 패턴을 보이는 운송 매체에 탑승한 사용자들의 이동성을 지원하기 위해 PGLT(Profile­based Group Location Tracking) 기법을 제안한다. 최근 무선 통신 기술의 발전으로 인한 이동 사용자(Mobile Terminal, MT)의 급증은 시그널링 트래픽의 증가로 이어져 결국 위치 관리 비용까지 높아지게 되었다. MT들이 동시에 새로운 등록 영역으로 이동할 때 GLT(Group Location Tracking) 위치 관리 기법에서는 기존 IS­41의 각 사용자들의 개별적인 위치 갱신 요청 대신에 그룹을 이용한 위치 갱신 요청으로써 위치 관리 비용을 줄였다. 그러나 본 논문에서 제안하는 PGLT 기법은 GLT 기법을 향상시킨 기법으로서, 사용자들의 규칙적인 이동 패턴 특성을 살린 프로파일 정보를 이용하여 그룹에 대한 위치 갱신 비용까지도 줄일 수 있다. MSRP­VLR(Mobility Scheduler on Regular Path)과 RMB(Regular path Movement Buffer)를 이용하여 일정구간을 이동하는 TV(Transportation Vehicle)가 위치 갱신 요청을 하면, MSRP­VLR은 이동 경로에 대한 프로파일 정보를 보내어 TV의 RMB에 저장함으로써 그 경로를 이동 시 그룹에 대한 위치 갱신 요청을 할 필요가 없게 된다. 따라서 PGLT 기법은 GLT 기법의 그룹 위치 갱신 비용을 줄임으로써 일정구간을 이동하는 TV에 탑승한 많은 사용자들에 대한 위치 관리 비용을 현저히 줄일 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.1A
• /
• pp.73-79
• /
• 2002

In this paper, two interference suppression schemes (LCCMA, HIC) applied to the MC-CDMA system were proposed. The proposed schemes have advantages that it don't requires the other's spreading code and can be used even in mobile. The proposed HIC combines the proposed interference suppressor with PIC. Simulation is performed in various environments using the Monte Carlo method. Simulation results show that there is 1.4~3 times capacity increase in corresponding simulation environments. Also this scheme can take advantage of path diversity whereas the system using EGC, MRC, and PIC cannot. Therefore, as the number of path increase, a considerable performance improvement can be attained.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.6A
• /
• pp.885-892
• /
• 2000

A multi-used detector(MUD) using a radial basis function(RBF) network is proposed in a multicarrier-code division multiple access (MC-CDMA) system. In the proposed scheme, a RBF network is connected to the frequency domain in order to effectively utilize the frequency diversity. Simulations have been performed over the frequency selective and multipath fading channel. From these simulations, the proposed receiver is verified to be used for making the performance improvement in combating near-far effects and increasing the number of active users. The system capacity is increaed about 1.8 times at a BER of $10^{-3}$ under a single cell when the proposed scheme is compared with MUD using a parallel interference canceller(PIC).

• Journal of the Korea Convergence Society
• /
• v.10 no.11
• /
• pp.533-541
• /
• 2019

This study was designed to construct and test a structural equation model for related factors that affect to self-regulated learning in nursing students. The nursing students was asked to complete a questionnaire, and 273 data units were analyzed with Structural Equation Modeling. The hypothetical model fit indices for the model revealed a fit at a recommended level, and 5 of the 6 paths were statistically significant explaining 68% of the variance. Therefore, education that improves self-determination, interpersonal competence and achievement goal orientation will promote self-regulated learning of nursing students. Competence programs to build the self-autonomy and relationships should be developed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2022.06a
• /
• pp.139-140
• /
• 2022

자율운항선박은 사람이 없다는 전제를 두고 개발되고 있지만, 완벽한 자율운항이 되기까지는 많은 시간이 필요할 것이다. 이러한 경우, 발생 가능한 모든 경우의 수를 고려하여 시나리오를 구축하는 것이 중요한데, 자율운항 선박에 대한 사고는 아직 발생한 바가 없기 때문에 시나리오를 구축하는 것은 어렵다. 이에, 본 연구에서는 기존 조사된 해양사고 사고·사례를 통해 아직 발생한적 없지만 발생가능 확률이 높다고 생각되는 사고 시나리오를 구축하여야 한다. 이러한 시나리오가 있다면 자율운항선박 사이의 사고 등을 확률적으로 추정할 수 있다. 한편, 해양사고의 종류는 다양하나, 본 연구에서는 위험유해물질(HNS)을 적재된 자율운항선박으로 제한하며, 최종 목표는 자율운항의 기초 단계로, 무인화 선박에서 발생 가능한 사고경로를 예측하여 화학 사고를 예방하는 것이다. 본 연구의 목적으로는 기존의 해상 화학사고 원인을 분석하여 ETA기법을 적용한 자율운항 선박에서 발생 가능한 사고 시나리오를 구축하는 것이다. 연구방법으로는 자율운항 시 발생할 수 있는 가상경로를 화학반응식으로 식별하고, ETA기법을 이용하여 화학사고가지분석(CATA, Chemical Accident Tree Analysis)모델을 구축할 예정이다.

• Horticultural Science & Technology
• /
• v.32 no.1
• /
• pp.46-52
• /
• 2014

This study was conducted to compare colony forming unit (CFU) of microorganisms in closed and open soilless culture systems for estimating the possibility for potential disease occurrence. Samples were collected at four different positions in four commercial greenhouses with closed or open soilless culture system using rock wool or coir as substrate, respectively. The distance between sampling positions was 3 cm starting from the substrate and the surface area of each position was $25cm^2$. The CFU of fungi was significantly higher in the open system, while that of bacteria was not significantly different but showed relatively lower in the closed system. Samples collected at the plastic surface of the substrates where little environmental effects occurred from drainage showed lower CFU than any other positions. The principal component analysis showed that samples collected on the drainage pathway highly affected the changes in microbial population in the greenhouse. These results indicated that greenhouses with closed soilless culture are expected to have more advantageous conditions for restraining the microbial growth, resulting in the lower potential of disease occurence in greenhouse ecosystem.

• Journal of Korean Association for Spatial Structures
• /
• v.9 no.2
• /
• pp.45-52
• /
• 2009

This paper experimentally evaluates the strength characteristics of precast column-R.C. foundation anchor joint subjected to the cyclic horizontal load. The study presents differences in accurate stress transfer path and destruction mechanism between the concrete structural body applying the precast column-R.C. foundation anchor joint and the concrete structural body applying the steel joint. the result from width load experiment on reinforcing steel under the cyclic horizontal load provides the necessary minimum insertion length to construct the precast column-R.C. foundation anchor joint. This study also presents the accurate stress transfer path and destruction mechanism on the anchor joint th meet the customer's requirements, comparing stress transfer path and destruction mechanism provided by the experiment and those provided by the product manual. Eventually, this study presents all the necessary fundamental data to provide the construction design with accurate number of reinforcing steel, diameter of the steel, fixation length of the steel, etc. to build the optimum precast concrete column.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.12B
• /
• pp.1259-1266
• /
• 2010

M2M communication is considered as a key enabling technology to monitor the status of objects, vehicles, humans through auto-configuring wireless networks. In M2M network, there are active research activities to enhance the reliability on data while being collected from wireless sensor network. The reliability issue becomes more important as wireless sensor networks carry multimedia data, which is delay sensitive. The interference caused by the adjacent neighbor sensor nodes is a major factor in network performance degradation, which becomes more severe in multi-hop routing environment. In this paper, we propose inerfernce-free multipath routing protocol for M2M wireless network for enhancement of packet delay performance. The simulation results show that the proposed routing algorithm outperforms the existing routing protocols in terms of packet delay and throughput.