• 한국항행학회논문지
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• 제19권5호
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• pp.345-353
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• 2015

본 논문에서는 차세대 항행시스템인 ADS-B (automatic dependent surveillance - broadcast)의 성능 개선을 위해, 정보융합 기법을 제안하였다. ADS-B는 기존의 레이더에 비해 성능이 우수하지만, GNSS (global navigation satellite system) 정보에 의존하기 때문에 GNSS가 가지는 오차가 ADS-B 데이터에 포함된다. 본 논문에서는 이런 오차를 극복하기 위해 ADS-B의 데이터에 MLAT(multilateration)와 WAM (wide area multilateration)의 데이터를 융합하여 ADS-B의 성능을 개선하였다. 정보융합을 하면 기존의 데이터에 비해 정확성이 우수한 데이터를 얻을 수 있다. 기존의 정보융합 기법은 부 필터로 칼만필터나 IMM 필터를 사용하지만, 제안된 기법에서는 Robust IMM 필터를 사용하여 항공기 위치추적 성능을 향상시켰다. 또한 실제 ADS-B 데이터를 사용하여 시뮬레이션 결과 대비 신뢰도를 높였다.

• 한국항공운항학회지
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• 제20권2호
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• pp.26-31
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• 2012

A new operational concept for the CNS/ATM using the digital data communication technology and satellite navigation system is being implemented globally and the United States is the first country to apply UAT ADS-B system for general aviation. Korea also has plan to build ADS-B system for aeronautical surveillance to monitor low altitude flight of light aircraft and ultra-light flying device and the research to develop UAT ADS-B equipment is being carried out. This paper presents the application method of UAT ADS-B to support test operation with case study of foreign UAT ADS-B operation and survey of domestic environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권5호
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• pp.1373-1387
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• 2012

Contextual advertising is an important revenue source for major service providers on the Web. Ads classification is one of main tasks in contextual advertising, and it is used to retrieve semantically relevant ads with respect to the content of web pages. However, it is difficult for traditional text classification methods to achieve satisfactory performance in ads classification due to scarce term features in ads. In this paper, we propose a novel ads classification method that handles the lack of term features for classifying ads with short text. The proposed method utilizes a vocabulary expansion technique using semantic associations among terms learned from large-scale search query logs. The evaluation results show that our methodology achieves 4.0% ~ 9.7% improvements in terms of the hierarchical f-measure over the baseline classifiers without vocabulary expansion.

• 한국게임학회 논문지
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• 제16권6호
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• pp.69-78
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• 2016

FPS 게임 속 시가지 맵에서 간판, 현수막, 벽보 등의 옥외광고가 흔히 등장한다. 본 논문은 실제 상권들의 옥외광고를 FPS 게임의 시가지 맵에 자동으로 배치하는 방법을 제안한다. 옥외광고는 실제 제품이나 기업의 광고이며 서버에서 관리된다. 실제 광고가 업데이트 되는 경우 게임 소스를 수정하지 않고도 자동으로 배치된다. 광고의 배치에 있어서 플레이어의 위치와 실제 상권의 위치의 관계, 실제 상점의 서비스 형태 등을 활용한다. 수집한 속성들에 우선순위 점수를 부여하여 높은 순위가 우선적으로 맵에 배치된다. 제안하는 배치 방법은 플레이어의 위치를 기반으로 광고를 배치하므로 친근감 유발과 함께 광고 효과를 높일 수 있다.

• ETRI Journal
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• 제43권2호
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• pp.324-331
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• 2021

Space-based automatic dependent surveillance-broadcast (ADS-B) is an important emerging augmentation of existing ground-based ADS-B systems. In this paper, the problem of space-based ultra-long-range reception processing of ADS-B signals is described. We first introduce a header detection method for accurately determining the pulse position of a weak ADS-B signal. We designed a signal encoding method, shaping method, and fitness function. We then employed a genetic algorithm to perform high-precision frequency and phase estimations of the detected weak signal. The advantage of this algorithm is that it can simultaneously estimate the frequency and phase, meaning a direct coherent demodulation can be implemented. To address the computational complexity of the genetic algorithm, we improved the ratio algorithm for frequency estimation and raised the accuracy beyond that of the original ratio algorithm with only a slight increase in the computational complexity using relatively few sampling points.

• 한국항행학회논문지
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• 제20권3호
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• pp.203-209
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• 2016

자동종속 감시 시스템 (ADS-B; automatic dependent surveillance - broadcast) 시스템과 다변측정 항공감시 시스템(MLAT, multilateration) 시스템은 통신/항행/감시 및 교통관리 (CNS/ATM; communications, navigation, and surveillance/air traffic management)의 다양한 분야 중에서 감시분야에 속한다. ADS-B와 MLAT는 위성 및 디지털 통신 기술을 기반으로 구현되어 레이더 보다 성능이 뛰어나지만, 여전히 오차는 가지고 있다. 우는 이러한 오차를 줄이기 위해 reweighted convex combination method를 제안한다. Reweighted convex combination method는 기존의 convex combination method를 개선한 정보융합 기법으로 시스템에 주어지는 가중치를 재조정하여 항공기 추적 성능을 향상시킨다. reweighted convex combination method을 ADS-B와 MLAT에 적용 시켰을 때, 평균 51.51 %의 성능향상이 있었다.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1600-1609
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• 2017

The accelerator-driven subcritical system (ADS) is driven by a neutron source from spallation reactions introduced by the injected proton beam. Part of the neutron source has energy as high as a few hundred MeV to a few GeV. The effects of high-energy source neutrons ($E_n$ > 20 MeV) are usually approximated by energy cut-off treatment in practical core calculations, which can overestimate the predicted proton beam current in the ADS design. This article intends to quantize this effect and propose a way to solve this problem. To evaluate the effects of high-energy neutrons in the subcritical core, two models are established aiming to cover the features of current experimental facilities and industrial-scale ADS in the future. The results show that high-energy neutrons with $E_n$ > 20 MeV are of small fraction (2.6%) in the neutron source, but their contribution to the source efficiency is about 23% for the large scale ADS. Based on this, a neutron source efficiency correction factor is proposed. Tests show that the new correction method works well in the ADS calculation. This method can effectively improve the accuracy of the prediction of the proton beam current.

• 기본간호학회지
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• 제17권4호
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• pp.450-459
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• 2010

Purpose: The purposes of this study were to identify awareness and attitudes toward advance directives (ADs) among Korean adults and to examine various opinions in the utilization of ADs among young, middle-aged, and older adults. Methods: Data were collected using a structured questionnaire from 384 adults selected by a quota sampling method on the basis of age. Results: The majority of participants preferred that they themselves would be the primary decision maker. Most of them were unaware of the option of ADs but supported the utilization of ADs. Most of the participants preferred detailed descriptions on end-of-life decisions in ADs but wanted to allow some leeway in following it. Significant differences were found among age groups in terms of the preferences regarding the utilization of ADs. Conclusion: It is suggested that nurses make efforts to educate the general public about ADs and facilitate advance care planning, which focuses on the process of communication on end-of-life preferences within the social network of relationships.

• 한국해양공학회지
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• 제17권6호
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• pp.16-22
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• 2003

In this paper, the method of determining the economically-optimal design section of rubble mound breakwater, using ADS program, was studied to supplement the deterministic approach. First of all, the design waves are computed, according to the return periods, using the Weibull distribution from the data of waves at the location of the breakwater. In order to take an optimal section, according to the return periods, the ADS program was used. The restriction conditions and objective functions are decided from the references of the specifications and standard manuals for Coastal and Harbor Construction Work. Results from this study support the ADS program as an appropriate method for determining the economically-optimal section of rubble mound breakwater, comparing the construction costs and the initial and damage repair costs for its life time.

• Journal of Hospice and Palliative Care
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• 제25권4호
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• pp.139-149
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• 2022

Purpose: The purpose of this study was to promote awareness of the need for advance directives (ADs) and to provide baseline data for the development of a nurse training program about ADs. Methods: Nurses at eight long-term care hospitals in Busan and South Gyeongsang Province (N=143) were recruited using the random sampling method from December 2018 to January 2019. Data were obtained using a structured self-reported questionnaire to assess their knowledge, experience, and attitudes regarding ADs. Data were analyzed in SPSS 22.0 using descriptive statistics, the t-test, analysis of variance, the Scheffé test, Pearson's correlation coefficient, and stepwise multiple regression analysis. Results: The mean scores were 7.79±1.39 points for knowledge, 1.92±2.00 points for experience, and 2.80±0.24 points for attitudes regarding ADs. Knowledge and experience (r=0.32, P<0.001) had a positive correlation with knowledge and attitudes (r=0.17, P=0.39). Conclusion: According to the results, nurses generally had a high level of knowledge regarding ADs, which resulted in a positive attitude toward ADs. However, they had little experience with ADs. Therefore, nurses' must develop both direct and indirect experience with ADs using a practical training program to strengthen their clinical competency regarding ADs.