• Journal of Information Processing Systems
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• 제17권4호
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• pp.707-720
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• 2021

To improve the accuracy of the recommendation system, multi-criteria recommendation systems have been widely researched. However, it is highly complicated to extract the preferred features of users and items from the data. To this end, subjective indicators, which indicate a user's priorities for personalized recommendations, should be derived. In this study, we propose a method for generating recommendation candidates by predicting multi-criteria ratings from reviews and using them to derive user priorities. Using a deep learning model based on convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM), multi-criteria prediction ratings were derived from reviews. These ratings were then aggregated to form a linear regression model to predict the overall rating. This model not only predicts the overall rating but also uses the training weights from the layers of the model as the user's priority. Based on this, a new score matrix for recommendation is derived by calculating the similarity between the user and the item according to the criteria, and an item suitable for the user is proposed. The experiment was conducted by collecting the actual "TripAdvisor" dataset. For performance evaluation, the proposed method was compared with a general recommendation system based on singular value decomposition. The results of the experiments demonstrate the high performance of the proposed method.

• 한국통신학회논문지
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• 제24권8A호
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• pp.1099-1106
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• 1999

본 논문에서는 다중사용자/다중경로 환경에서 다중반송파 CDMA 시스템의 오류확률을 해석적으로, 구하고, 다중 사용자, 다중반송파, 다중경로에 의한 간섭의 영향을 분석하였다. 또한 다중반송파 시스템에 대한 역상관 검출기(decorrelating detector)를 결합한 다중반송파/다중사용자/다중경로 결합 검출 방식을 제시하고 성능 및 역상관 과정에 의한 백색가우시안 잡음(AWGN)의 증가를 분석하였다. 제안한 결합 검출 방식의 오류 확률은 하나의 상용자만이 있는 경우의 이상적인 성능에 근접하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.240-242
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• 2004

A channel allocation algorithm of multi-user OFDM(orthogonal frequency division multiplexing) system is presented. The proposed algorithm is to reduce the complexity of the system, using the GNN(gradual neural network) with gradual expansion scheme and the algorithm attempts to allocate channel with good channel gain to each user. The method has lower computational complexity and less iteration than other algorithms.

• Current Optics and Photonics
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• 제2권1호
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• pp.39-46
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• 2018

Visible-light communication (VLC) combined with advanced illumination can be expected to become an integral part of next-generation communication networks. One of the major concerns in VLC implementation is developing resource-allocation schemes in a multi-user scenario. However, the scheduling for heterogeneous quality of service (QoS) traffic has not been studied so far, for the indoor VLC downlink system. In this paper, we creatively introduce effective-bandwidth and effective-capacity theory into the multi-user scheduling (MUS) problem, to guarantee the user's statistical delay QoS. We also take account of the aggregate interference (AI) in the indoor VLC downlink system, and analyze its impact on the user-centric MUS problem for the first time. Simulations show that the AI has a nonnegligible influence on the scheduling result, and that the proposed scheduling scheme could guarantee the user's QoS requirement under the premise of ensuring sum capacity.

• 한국지능시스템학회논문지
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• 제17권5호
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• pp.712-717
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• 2007

홈 서버와 가정용서비스 로봇, 다양한 Device를 포함하는 홈 네트워크 시스템을 이용하여 가정환경 내에서 발생 가능한 다양하게 분산된 임무들을 수행하는데 있어서 Multi-Agent 시스템을 응용하는 것은 효율적이라고 알려져 있다. 이러한 시스템에서 휴먼 인터페이스와 물리적 서비스 제공의 중추 역할을 하는 것은 바로 지능형 서비스 로봇이다. 따라서, 기존의 Multi Agent System을 응용하여 Multi Agent Robot System을 정의할 수 있다. 가정이라는 'open'된 특성의 환경에서 Multi Agent Robot System이 사용자에게 좀 더 효율적인 서비스를 제공하기 위해서는 존재하는 모든 Agent 간의 유기적인 정보교환과 협력이 필요하다. 이것을 위하여 자율구동하며 사용자에게 물리적 서비스를 제공할 수 있는 다수의 로봇들을 Agent로 정의하고, 로봇 Agent간의 통신과, 로봇 이외의 Agent로써의 역할을 감당할 수 있는 홈 서버 등의 Agent와 로봇 Agent들의 통신을 사용자 interface에 직접 표현할 수 있는 시뮬레이터를 설계, 제시한다.

• 정보보호학회논문지
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• 제10권3호
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• pp.11-28
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• 2000

In these days it is rapidly increasing that multi-user, multi-layered commercial software developments for companies or public institutions. Security services are necessary for most of systems and the access control service is the essential of security services. Current access control methods that are used as access control policies are classified as Discretionary Access Control Mandatory Access Control and Role Based Access Control. However there are some inefficiencies when those methods are applied to current multi-user, multi-layered systems. Therefore it is required that a new access control method that takes complex system resources into account from the side of policy. In this paper extending previous Role Based of 'Behavior' and a basic model of the method. And we simply implement the method on the mobile agent based workflow management system that is a representative example of multi-user. multi-layered softwares and shows implementation results to tap possibilities of real-world application.

• Journal of Mechanical Science and Technology
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• 제19권10호
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• pp.1864-1874
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• 2005

This paper describes a wearable multi-modal user interface design and its implementation for a teleoperated field robot system. Recently some teleoperated field robots are employed for hazard environment applications (e.g. rescue, explosive ordnance disposal, security). To complete these missions in outdoor environment, the robot system must have appropriate functions, accuracy and reliability. However, the more functions it has, the more difficulties occur in operation of the functions. To cope up with this problem, an effective user interface should be developed. Furthermore, the user interface is needed to be wearable for portability and prompt action. This research starts at the question: how to teleoperate the complicated slave robot easily. The main challenge is to make a simple and intuitive user interface with a wearable shape and size. This research provides multi-modalities such as visual, auditory and haptic sense. It enables an operator to control every functions of a field robot more intuitively. As a result, an EOD (explosive ordnance disposal) demonstration is conducted to verify the validity of the proposed wearable multi-modal user interface.

• 제어로봇시스템학회논문지
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• 제5권1호
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• pp.79-87
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• 1999

For its simplicity and cost effectiveness in implementation, the Inverted DGPS is well suited for some specific applications like automatic vehicle location systems, where the monitoring station needs accurate position of the vehicles in the street. In the Inverted DGPS, the user sends its GPS position and associated satellite informations to the reference station, and the corrections are made at the reference station to get differentially corrected user position. A fundamental requirement in IDGPS is that the user and the reference station must use the same satellites when the corrections are made. But in practice, it is not often satisfied. Inverted DGPS is also suffered from performance degradation as the baseline become large like DGPS. IDGPS system using multi-reference station can resolve this problem. In this paper a simple multi-reference IDGPS algorithm is proposed and some experiments and analysis are peformed. Experiment results show that IDGPS can achieve the positioning performance as accurate as the DGPS can provide.

• 대한전자공학회논문지TC
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• 제49권8호
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• pp.12-18
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• 2012

본 논문에서는 하향링크 다중사용자(multi-user, MU) 다중입출력(multi-input multi-ouput, MIMO) 시스템에 블록 Tomlinson-Harashima 전처리기(block Tomlinson-Harashima precoder, BTHP)를 적용했을 때, 시스템의 송신 전력에 대한 정확한 분석 결과를 제공하였다. 각 사용자별로 상위 사용자들로부터 전달되는 간섭신호를 BTHP를 통해 제거하는 과정에서 큰 간섭신호 가정을 이용한 기존의 분석과는 달리, 실제로 전달되는 간섭신호의 통계적 특성을 분석함으로써 향상된 정확도를 갖는 분석 방법을 제안하였고, 모의실험을 통해 제안한 분석 결과가 기존 결과보다 정확함을 확인하였다.

• 한국정보통신학회논문지
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• 제22권10호
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• pp.1379-1385
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• 2018

기존의 다중사용자 중첩 전송은 순시 채널 전력의 조건에 따라 데이터 심벌의 전력 할당 계수와 사용자별 수신 신호 처리 방법을 결정한다. 그러나 순시 채널 전력의 이용은 시스템의 복잡도를 증가시킬 수 있기 때문에 본 논문에서는 평균 채널 전력을 이용하는 고정적 다중사용자 중첩 전송을 고려한다. 고정적 다중사용자 중첩 전송 기법은 시간에 따라 느리게 변화하는 평균 채널 전력의 조건을 기반으로 데이터 심벌의 전력 할당 계수와 사용자별 수신 신호 처리 방법을 결정하기 때문에 시스템 복잡도를 감소시킬 수 있다. 본 논문에서는 고정적 다중사용자 중첩 전송에 대한 평균 심벌 오차율을 분석한다. 특히, 레일레이 페이딩 채널을 가정하여 M-ary 직교 진폭 변조에 대한 평균 심벌 오차율의 표현식을 유도한다. 또한, 수치적 결과를 통하여 열악한 채널 환경에 있는 사용자에서 고정적 다중사용자 중첩전송과 기존의 다중사용자 중첩 전송의 평균 심벌 오차율 성능이 유사함을 보였다.