• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.11
• /
• pp.5410-5426
• /
• 2019

With the advent of the fifth-generation (5G) era, Massive multiple-input multiple-output (MIMO) relay systems have experienced the rapid development. Recently, the performance analysis models of Massive MIMO relay systems have been proposed, which are mostly based on Rayleigh fading channels. In order to create a more suitable model for 5G Internet of Things scenarios, our study is based on the Rician fading channels, where line-of-sight (LOS) path exists in the channels. In this paper, we assume the channel state information (CSI) is perfect. In this case, we use statistical information to derive the analytical exact closed-form expression for the achievable sum rate of the uplink for the Massive MIMO two-hop relay system over Rician fading channels. Moreover, considering the different communication scenarios, we derive the analytical exact closed-form expression for the achievable sum rates of the uplink for other three scenarios. Finally, based on these expressions, we make simulations and analyze the performance under different transmit powers and Rician-factors, which provides a theoretical basis and reference for further research.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.11 no.1
• /
• pp.197-207
• /
• 2015

A new communication revolution such as social networking service (SNS) has been transforming the way of interaction between people in both of individual level and organizational level. Recently many people have switched to closed type SNS such as Naver Band and Kakao group due to the several reasons. The purpose of this study is to investigate the usage motivation and satisfaction of closed type SNS based on use and gratifications perspectives. Based on prior studies on use and gratifications of Internet-related media and SNS, information motivation, relationship motivation, pleasure/entertainment motivation, self-expression motivation, work motivation were identified as usage motivation of closed type SNS. According to the results, relationship motivation and work motivation were found to be significantly related to the satisfaction. But other motivation factors(information motivation, pleasure/entertainment motivation, self-expression motivation) are not significantly related to the satisfaction. Then satisfaction was found to be significantly related to the intention to use. This study contributes to give companies providing closed type SNS and using it as a marketing tool with the base of activation strategies and practical implications.

• Journal of Information Processing Systems
• /
• v.14 no.4
• /
• pp.824-836
• /
• 2018

The automatic extraction of temporal information from written texts is a key component of question answering and summarization systems and its efficacy in those systems is very decisive if a temporal expression (TE) is successfully extracted. In this paper, three different approaches for TE extraction in Uyghur are developed and analyzed. A novel approach which uses lexical semantics as an additional information is also presented to extend classical approaches which are mainly based on morphology and syntax. We used a manually annotated news dataset labeled with TIMEX3 tags and generated three models with different feature combinations. The experimental results show that the best run achieved 0.87 for Precision, 0.89 for Recall, and 0.88 for F1-Measure in Uyghur TE extraction. From the analysis of the results, we concluded that the application of semantic knowledge resolves ambiguity problem at shallower language analysis and significantly aids the development of more efficient Uyghur TE extraction system.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.10
• /
• pp.5171-5189
• /
• 2016

With the popularity of cloud computing, many data owners outsource their graph data to the cloud for cost savings. The cloud server is not fully trusted and always wants to learn the owners' contents. To protect the information hiding, the graph data have to be encrypted before outsourcing to the cloud. The adjacent vertex search is a very common operation, many other operations can be built based on the adjacent vertex search. A boolean adjacent vertex search is an important basic operation, a query user can get the boolean search results. Due to the graph data being encrypted on the cloud server, a boolean adjacent vertex search is a quite difficult task. In this paper, we propose a solution to perform the boolean adjacent vertex search over encrypted graph data in cloud computing (BASG), which maintains the query tokens and search results privacy. We use the Gram-Schmidt algorithm and achieve the boolean expression search in our paper. We formally analyze the security of our scheme, and the query user can handily get the boolean search results by this scheme. The experiment results with a real graph data set demonstrate the efficiency of our scheme.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2013.01a
• /
• pp.201-204
• /
• 2013

디지털 컨텐츠의 종류와 양이 폭발적으로 증가하면서 컨텐츠 선호도 투표는 강한 파급력을 지니게 되었다. 하지만 컨텐츠 소비자가 직접 투표를 해야 하는 현재의 방법은 사람들의 투표 참여율이 저조하며, 조작 위험성이 높다는 문제점이 있다. 이에 본 논문에서는 컨텐츠 소비자의 얼굴 표정에 드러나는 감정을 인식함으로써 자동으로 컨텐츠 선호도를 추론하는 시스템을 제안한다. 본 논문에서 제안하는 시스템은 기존의 수동 컨텐츠 선호도 투표 시스템의 문제점인 컨텐츠 소비자의 부담감과 번거로움, 조작 위험성 등을 해소함으로써 보다 편리하고 효율적이며 신뢰도 높은 서비스를 제공하는 것을 목표로 한다. 따라서 본 논문에서는 컨텐츠 선호도 추론 시스템을 구축하기 위한 방법을 구체적으로 제안하고, 실험을 통하여 제안하는 시스템의 실용성과 효율성을 보인다.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.363-366
• /
• 2005

In this paper, for detecting human faces under variations of lighting condition and facial expression, distance ranking feature and detection algorithm based on the feature are proposed. Distance ranking is the intensity ranking of a distance transformed image. Based on statistically consistent edge information, distance ranking is robust to lighting condition change. The proposed detection algorithm is a matching algorithm based on FFT and a solution of discretization problem in the sliding window methods. In experiments, face detection results in the situation of varying lighting condition, complex background, facial expression change and partial occlusion of face are shown

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2016.07a
• /
• pp.293-294
• /
• 2016

스마트폰, 블랙박스, CCTV 등을 통해 다양하고 방대한 영상 데이터가 발생하고 있다. 그중에서 사람의 얼굴 영상을 통해 개인을 인식 및 식별하고 감정 상태를 분석하려는 다양한 연구가 진행되고 있다. 본 논문에서는 디지털영상처리 분야에서 널리 사용되고 있는 SIFT알고리즘을 이용하여, 얼굴영상에 대한 특징점을 추출하고 이를 기반으로 성별, 나이 및 기초적인 감정 상태를 분류할 수 있는 시스템을 제안한다.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2005.09a
• /
• pp.23-28
• /
• 2005

The high-dimensionality and insufficiency of gene expression profiles and proteomic profiles makes feature selection become a critical step in efficiently building accurate models for cancer problems based on such data sets. In this paper, we use a method, called Discrete Function Learning algorithm, to find discriminatory feature vectors based on information theory. The target feature vectors contain all or most information (in terms of entropy) of the class attribute. Two data sets are selected to validate our approach, one leukemia subtype gene expression data set and one ovarian cancer proteomic data set. The experimental results show that the our method generalizes well when applied to these insufficient and high-dimensional data sets. Furthermore, the obtained classifiers are highly understandable and accurate.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.1
• /
• pp.209-214
• /
• 1997

In this paper, we propose a new preorder tree method for binary images, named the Compact Complementary Quadtree (CCQ). In the proposed method we use type codes for representing nodes in the quadtree instead of using the symbols G, B, and W. From the experimental results, we have confirmed that the CCQ has a higher compression ratio than of the DF-expression. CCQ can be effectively applied to progressive transmission of binary images such as line drawings, geographical maps, and halftones.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.3
• /
• pp.232-239
• /
• 1992

In this paper, an analytical expression of the excess MSE of ITLMS(Individual Tap LMS) which results from the random fluctuation of the distance between the actual and optimal coefficients due to noisy gradient estimates, is derived. The expression reveals that the excess MSE of the ITLMS algorithm is smaller that that of the LMS algorithm. The performance of the algorithm from the computer simulation for a fading time-dispersive channel verifies the theoretical results.