• Title/Summary/Keyword: non-cooperative

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Performance of Opportunistic Incremental NOMA Relay System in Fading Channels (페이딩 채널에서 기회전송 증가 NOMA 릴레이 시스템의 성능분석)

  • Kim, Nam-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.69-76
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    • 2016
  • In this paper, we investigate the system performance of a cooperative relaying system of Non-orthogonal multiple access (NOMA) with successive interference cancellation (SIC), which is considered promising application in fifth generation (5G) cellular networks. Previous studies have focused on the selected relays, however we include the maxmin relay selection and derive analytical outage probability of opportunistic incremental relaying systems. For the realistic mobile environment, the distributions of relays are modeled as a homogeneous Poisson point process (PPP). And maximal ratio combining (MRC) is adapted to improve the system performance at the destination node. Analytical results demonstrate the outage probability improves with the near/far user power ratio, and the cooperative relaying scheme can achieve low outage probability in comparison to the no relaying scheme. It is also conformed that the increase of the intensity of PPP cause higher gains of the spacial diversity and hence the performance improves.

Attitude and Recognition of Medical Doctors Who Employed by University Hospital on Traditional Korean Medicine (대학부속병원 근무 의사들의 한의학에 대한 인식)

  • Lee, Eun Joo;Park, Han Sol;Lee, So Young;Bae, Da Jung;Lee, Tag Gun;Shin, Hyeun Kyoo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.5
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    • pp.773-777
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    • 2012
  • Since 2010, in general hospital, they can install western medical post, traditional Korean medical post, and dental post. So the environment is made for the Cooperative medical system between traditional Korean medicine(TKM) and western medicine(WM) to be performed. So we found out about how doctors think about TKM and what is needed for TKM & WM cooperative system to work well. When we found out about how recognition changed about TKM during their medical school years and after they became doctors, positive answer increased from 25.6% to 30%, negative answer decreased from 41.9% to 32.0%, severely negative increased from 9.3% to 16%. They changed to positive about TKM after they became doctors. But severely negative also increased. The element they lose faith in TKM is their doubt about the scientific aspects of TKM. On the other hand, severely negative recognition was also raised. 73.8% of respondents thought the most effective treatment of TKM was for myalgia. 33.3% of them answered the chance to encounter TKM was the mass media, indicating its limitation. 60.5% of them considered major reason for negative evaluation of TKM is its non-scientific aspects and only 30.9% said TKM treatment could be recommended to patients at the hospital. Doctors in WM for recognition on TKM is mostly negative and major reason is its non-scientific aspects. As the solution to this problem, scientification of TKM is suggested through research projects. These connections must be resolved to smoothly work interdisciplinary system of TKM and WM.

Effect of SIC Errors to Cooperative NOMA systems (SIC 에러가 협동 NOMA 시스템에 미치는 영향)

  • Kim, Nam-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.5
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    • pp.35-42
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    • 2017
  • NOMA (Non-orthogonal multiple access) system is the most promising multiple access technology to satisfy the requirements of the spectral efficiency and the performance of 5G cellular systems. NOMA system simultaneously serves multiple users in the power domain, and adapts SIC (Successive interference cancellation) at the receivers to cancel the interference from multiple users. Since in a realistic wireless fading channel the perfect SIC is impossible, the study of the effect of the imperfect SIC to a NOMA system is necessary. This paper considers a cooperative NOMA system with SIC error, and the performance of the system is analytically derived. And the optimum power allocation to minimize the system performance is obtained. When the transmit power is fixed, the distances between a base station and the relay is considered for different SIC errors. The derived analytical results are verified through Monte Carlo simulation, and the results are perfectly matched.

Effect of Homogenization Pressure and Supplementation with Sucrose Fatty Acid Ester on the Physical Properties of Dairy Cream-based Emulsions

  • Seo, Chan-Won;Kang, Shin-Ho;Shin, Yong-Kook;Yoo, Byoungseung
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.476-486
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    • 2018
  • In this study, the droplet size distribution, rheological properties, and stability of dairy cream-based emulsions homogenized with different sucrose fatty acid ester (SFAE, a non-ionic small-molecule emulsifier) concentrations (0.08%, 0.16%, and 0.24% w/w) at different homogenization pressures (10 MPa and 20 MPa) were examined. Homogenization at a high pressure resulted in a smaller droplet size and narrower droplet size distribution. The D[4,3] (volume-weighted mean) and D[3,2] (surface-weighted mean) values of the emulsions decreased with an increase in the SFAE concentration. The flow properties of the emulsions homogenized with SFAE showed shear-thinning (n=0.21-0.46) behavior. The apparent viscosity (${\eta}_{a,10}$) and consistency index (K) of the homogenized emulsions were lower than those of the control sample that is non-homogenized and without SFAE, and decreased with an increase in SFAE concentration. The storage modulus (G') and loss modulus (G") of all emulsions homogenized with SFAE were also lower than those of the control sample. The stability of all emulsions with SFAE did not show any significant change for 30 d at $5^{\circ}C$. However, the emulsions stored at $40^{\circ}C$ were unstable over the storage period. Therefore, the addition of SFAE enhanced the stability of dairy cream emulsions during storage at refrigeration temperature ($5^{\circ}C$).

Acid and Chemical Induced Conformational Changes of Ervatamin B. Presence of Partially Structured Multiple Intermediates

  • Sundd, Monica;Kundu, Suman;Jagannadham, Medicherla V.
    • BMB Reports
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    • v.35 no.2
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    • pp.143-154
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    • 2002
  • The structural and functional aspects of ervatamin B were studied in solution. Ervatamin B belongs to the $\alpha+\beta$ class of proteins. The intrinsic fluorescence emission maximum of the enzyme was at 350 nm under neutral conditions, and at 355 nm under denaturing conditions. Between pH 1.0-2.5 the enzyme exists in a partially unfolded state with minimum or no tertiary structure, and no proteolytic activity. At still lower pH, the enzyme regains substantial secondary structure, which is predominantly $\beta$-sheet conformation and shows a strong binding to 8-anilino-1-napthalene-sulfonic acid (ANS). In the presence of salt, the enzyme attains a similar state directly from the native state. Under neutral conditions, the enzyme was stable in urea, while the guanidine hydrochloride (GuHCl) induced equilibrium unfolding was cooperative. The GuHCl induced unfolding transition curves at pH 3.0 and 4.0 were non-coincidental, indicating the presence of intermediates in the unfolding pathway. This was substantiated by strong ANS binding that was observed at low concentrations of GuHCl at both pH 3.0 and 4.0. The urea induced transition curves at pH 3.0 were, however, coincidental, but non-cooperative. This indicates that the different structural units of the enzyme unfold in steps through intermediates. This observation is further supported by two emission maxima in ANS binding assay during urea denaturation. Hence, denaturant induced equilibrium unfolding pathway of ervatamin B, which differs from the acid induced unfolding pathway, is not a simple two-state transition but involves intermediates which probably accumulate at different stages of protein folding and hence adds a new dimension to the unfolding pathway of plant proteases of the papain superfamily.

Power Control Scheme Based on Non-Cooperative Game in a Heterogeneous Network (이종 네트워크에서의 비협력 게임 기반 전력 할당 기법)

  • Bae, Insan;Lee, Jinnyoung;Jang, Sungjin;Kim, Jaemoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.11
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    • pp.771-778
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    • 2014
  • We propose Femto-cell power control scheme in HeNet with Game Theory. The Femto-cell which provide high quality with low power is issued by many benefits, however there is a bunch of interferences when many Femto-cells use overlapped bandwidth with Macro-cell. We defined base station of cellular networks and mobile users as players of Game Theory, and configured interference effect among each other as power utility function. Futhermore, we showed enhanced overall system performance, lower power usage and interference decrease by using optimal power.

Quasi-distributed Interference Coordination for HSPA HetNet

  • Zhang, Chi;Chang, Yongyu;Qin, Shuqi;Yang, Dacheng
    • ETRI Journal
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    • v.36 no.1
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    • pp.31-41
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    • 2014
  • The heterogeneous network (HetNet) has been discussed in detail in the Long-Term Evolution (LTE) and LTE Advanced standards. However, the standardization of High-Speed Packet Access HetNet (HSPA HetNet) launched by 3GPP is pushing at full steam. Interference coordination (IC), which is responsible for dealing with the interference in the system, remains a subject worthy of investigation in regard to HSPA HetNet. In this paper, considering the network framework of HSPA HetNet, we propose a quasi-distributed IC (QDIC) scheme to lower the interference level in the co-channel HSPA HetNet. Our QDIC scheme is constructed as slightly different energy-efficient non-cooperative games in the downlink (DL) and uplink (UL) scenarios, respectively. The existence and uniqueness of the equilibrium for these games are first revealed. Then, we derive the closed-form best responses of these games. A feasible implementation is finally developed to achieve our QDIC scheme in the practical DL and UL. Simulation results show the notable benefits of our scheme, which can indeed control the interference level and enhance the system performance.

A Study on Automatic Target Recognition Using SAR Imagery (SAR 영상을 이용한 자동 표적 식별 기법에 대한 연구)

  • Park, Jong-Il;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1063-1069
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    • 2011
  • NCTR(Non-Cooperative Target Recognition) and ATR(Automatic Target Recognition) are methodologies to identify military targets using radar, optical, and infrared images. Among them, a strategy to recognize ground targets using synthetic aperature radar(SAR) images is called SAR ATR. In general, SAR ATR consists of three sequential stages: detection, discrimination and classification. In this paper, a modification of the polar mapping classifier(PMC) to identify inverse SAR(ISAR) images has been made in order to apply it to SAR ATR. In addition, a preprocessing scheme can mitigate the effect from the clutter, and information on the shadow is employed to improve the classification accuracy.

Game Theoretic Approach for Energy Efficient Rate Scheduling on the interference channel (간섭채널에서 에너지 효율적인 전송률 스케줄링을 위한 게임이론적 접근)

  • Oh, Chang-Yoon
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.55-62
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    • 2014
  • A game theoretic approach is applied for studying the energy efficient rate scheduling. The individual utility function is defined first. Then, a non cooperative rate game is modeled in which each user decides the transmission rate to maximize its own utility. The utility function considered here is the consumed energy for the individual user's data transmissions. In particular, using the fact that the utility function is convex, we prove the existence of Nash Equilibrium in the energy efficient rate scheduling problem at hand. Accordingly, a non cooperative scheduling algorithm is provided. For better energy efficiency, the sum of the individual user's utility function is optimized Finally, the convergence analysis and numerical results to show the energy efficiency of the proposed algorithms are provided.

Performance Comparison of Orthogonal and Non-orthogonal AF Protocols in Cooperative Relay Systems

  • Bae, Young-Taek;Jung, Sung-Kyu;Lee, Jung-Woo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.4
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    • pp.1026-1040
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    • 2012
  • For a single relay channel, we compare the capacity of two different amplify-and-forward (AF) protocols, which are orthogonal AF (OAF) and non-orthogonal AF (NAF). The NAF protocol has been proposed to overcome a significant loss of performance of OAF in the high spectral efficiency region, and it was also theoretically proved that NAF performs better than OAF in terms of the diversity-multiplexing tradeoff. However, existing results have been evaluated at the asymptotically high signal to noise ratio (SNR), thus the power allocation problem between the source and the relay was neglected. We examine which protocol has better performance in a practical system operating at a finite SNR. We also study where a relay should be located if we consider the power allocation problem. A notable conclusion is that the capacity performance depends on both SNR and power allocation ratio, which indicates OAF may perform better than NAF in a certain environment.