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A Single Feedback Based Interference Alignment for Three-User MIMO Interference Channels with Limited Feedback

  • Chae, Hyukjin;Kim, Kiyeon;Ran, Rong;Kim, Dong Ku
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.692-710
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    • 2013
  • Conventional interference alignment (IA) for a MIMO interference channel (IFC) requires global and perfect channel state information at transmitter (CSIT) to achieve the optimal degrees of freedom (DoF), which prohibits practical implementation. In order to alleviate the global CSIT requirement caused by the coupled relation among all of IA equations, we propose an IA scheme with a single feedback link of each receiver in a limited feedback environment for a three-user MIMO IFC. The main feature of the proposed scheme is that one of users takes out a fraction of its maximum number of data streams to decouple IA equations for three-user MIMO IFC, which results in a single link feedback structure at each receiver. While for the conventional IA each receiver has to feed back to all transmitters for transmitting the maximum number of data streams. With the assumption of a random codebook, we analyze the upper bound of the average throughput loss caused by quantized channel knowledge as a function of feedback bits. Analytic results show that the proposed scheme outperforms the conventional IA scheme in term of the feedback overhead and the sum rate as well.

Modified TCP with Post-Checksum Field and Limited Error Control Algorithm for Memory-limited Tiny Sensor Node (메모리 크기 제약이 있는 센서 노드에서의 포스트 체크섬과 제한된 오류제어 알고리즘 연구)

  • Oh, Jong-Taek
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.141-145
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    • 2012
  • In a Ubiquitous sensor network environment, the sensor node is in general small and low price, and operating with power limited battery. The reliable TCP/IP protocol is used for transmitting sensed data from the sensor node. A new method was proposed in order to overcome the limitation of small embedded memory, but it is difficult to use for the case of frame error. In this paper, a new algorithm is proposed to manage the receiving frame error or loss, and it is appropriate to the sensor network to send sensed data periodically.

Weighted Least Square-Based Magnetometer Calibration Method Robust in Roll-Pitch Limited Conditions (롤피치 제한 조건에 강인한 가중 최소자승법 기반 마그네토미터 캘리브레이션 기법)

  • Jeon, Tae-Hyeong;Lee, Jung-Keun
    • Journal of Sensor Science and Technology
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    • v.26 no.4
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    • pp.259-265
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    • 2017
  • Magnetometer calibration must be performed before the use of three-axis magnetometers to ensure the accuracy of orientation estimation. Recently, one of the most popular calibration approaches is the ellipsoid fitting technique due to its high performance in calibration. To date, in fact, performances of the existing ellipsoid fitting methods have been evaluated with full range rotation data. However, in case of the calibration of magnetometers attached to vehicles, ships, and planes, it is very difficult to collect the full range rotation data since their allowable ranges in terms of roll and pitch are limited to small. This constraint may result in serious performance degradation of some ellipsoid fitting algorithms. Therefore, to be practical, this paper proposes a weighted least square-based magnetometer calibration method that is robust in roll-pitch limited conditions. Furthermore, the proposed method is a linear approach and thus is free from the well-known initial value issue in nonlinear approaches. Experimental results show the superiority of the proposed method to other ellipsoid-fitting calibration methods.

Effect of calcium hydroxide on inflammatory root resorption and ankylosis in replanted teeth compared with other intracanal materials: a review

  • Jahromi, Maryam Zare;Kalantar Motamedi, Mahmood Reza
    • Restorative Dentistry and Endodontics
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    • v.44 no.3
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    • pp.32.1-32.13
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    • 2019
  • Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

Financial Performance of Converted Commercial Banks from Non-Banking Financial Institutions: Evidence from Bangladesh

  • GAZI, Md. Abu Issa;RAHAMAN, Atikur;WALIULLAH, Shaikh Sabbir Ahmed;ALI, Md. Julfikar;MAMOON, Zahidur Rahman
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.923-931
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    • 2021
  • The aim of the present study is to analyze the financial performance of converted commercial bank from non-banking financial institution through a case study of Bangladesh Commerce Bank Limited as sample organization. It is observed that the bank is able to achieve a stable growth rate in total deposits, total loans and advances, and net income after tax during the period of 2015-2019. Researchers also calculated some ratio analysis and noticed that the financial position of Bangladesh Commerce Bank Limited was not so strong because bank's ROA, ROE, NIM and other ratios were below standard. Researchers used secondary data that were examined by using descriptive statistical tools and panel data regression model. Result shows that Bangladesh Commerce Bank has satisfactory operating efficiency, assets management efficiency, and gives loans to customers. In addition, the present study has tested some hypotheses regarding net income after tax, ROA and ROE with total assets, total loans, total deposits and interest income. These hypotheses have been accepted, which means there is no significant influence of the independent variable on the dependent variable. The study suggests that Bangladesh Commerce Bank Limited had the opportunities to make their financial position stronger by utilizing their good financial position and management efficiencies.

Graph neural network based multiple accident diagnosis in nuclear power plants: Data optimization to represent the system configuration

  • Chae, Young Ho;Lee, Chanyoung;Han, Sang Min;Seong, Poong Hyun
    • Nuclear Engineering and Technology
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    • v.54 no.8
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    • pp.2859-2870
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    • 2022
  • Because nuclear power plants (NPPs) are safety-critical infrastructure, it is essential to increase their safety and minimize risk. To reduce human error and support decision-making by operators, several artificial-intelligence-based diagnosis methods have been proposed. However, because of the nature of data-driven methods, conventional artificial intelligence requires large amount of measurement values to train and achieve enough diagnosis resolution. We propose a graph neural network (GNN) based accident diagnosis algorithm to achieve high diagnosis resolution with limited measurements. The proposed algorithm is trained with both the knowledge about physical correlation between components and measurement values. To validate the proposed methodology has a sufficiently high diagnostic resolution with limited measurement values, the diagnosis of multiple accidents was performed with limited measurement values and also, the performance was compared with convolution neural network (CNN). In case of the experiment that requires low diagnostic resolution, both CNN and GNN showed good results. However, for the tests that requires high diagnostic resolution, GNN greatly outperformed the CNN.

The Effect of Functional Impairment on Limitation of Flexion and Extension in Patients with Knee Osteoarthritis (퇴행성 슬관절염 환자의 굴곡 및 신전 제한이 기능 장애에 미치는 영향)

  • Park, Seung-Kyu;Park, Rae-Joon;Kim, Tae-Yeol
    • The Journal of Korean Physical Therapy
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    • v.13 no.3
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    • pp.643-651
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    • 2001
  • Osteoarthritis(OA) is a widespread, slowly developing disease with a high prevalence rate increasing with age. The most common big joints involved in OA is the knee, where the disease particulary strikes, causing difficulties in rising from a chair. climbing stairs, kneeling. standing, and walking. The primary complaints of these patients include pain, stiffness. instability, and loss of function. The purpose of this study was to assess the impact of self-reported symptoms and limited flexion, and limited extension on functional impairment in patients with knee osteoarthritis. In the data collection, a total of 206 who had visited the physiotherapy unit at six different departments of orthopedics were interviewed in K City from June to September, 2000. The results of the study summarized are as fellows: 1. There was a significant difference among different degree group of limited flexion(p<0.05). A group difference was demonstrated between <5 ${\sim}$ 15 and 16 > (F=16.21, p<0.05). In the relationship between the degree of limited flexion and the level of functional impairment, the h igher the range of limited flexion, the lower the level of functional impairment. 2. In the relationship between the degree of limited extension and the level of functional impairment, a group difference was revealed between the non-limitation group and the <10 and 11 < However, no significant difference was noted between 11 ${\sim}$ 20 and 21 >(F= 13.37, p<0.05). In conclusion, finding above suggest that functional impairment is closely correlated with limited tlexion and extenion

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The Study for the KOMPSAT-3 Image Data Compression

  • Lee S.G.;Lee S.T.
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.298-300
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    • 2005
  • Satellite payload on-board date compression unit are use for saving date storage space and reducing time to transmit payload data to the ground station. The KOMPSAT-3 payload will generate higher data rate than KOMPSAT-2 due to its better ground sample distance capacity. High input data rate and limited output transmission data rate might lead excessive compression and degraded image quality. This paper presents a trade-off study about data storage capacity and compression parameters for estimated KOMPSAT-3 system.

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Case Based Reasoning in a Complex Domain With Limited Data: An Application to Process Control (복잡한 분야의 한정된 데이터 상황에서의 사례기반 추론: 공정제어 분야의 적용)

  • 김형관
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10c
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    • pp.75-77
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    • 1998
  • Perhaps one of the most versatile approaches to learning in practical domains lies in case based reasoning. To date, however, most case based reasoning systems have tended to focus on relatively simple domains. The current study involves the development of a decision support system for a complex production process with a limited database. This paper presents a set of critical issues underlying CBR, then explores their consequences for a complex domain. Finally, the performance of the system is examined for resolving various types of quality control problems.

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Scheduling algirithm of data sampling times in the real-time distributed control systems

  • Hong, Seung-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.112-117
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    • 1992
  • The Real-time Distributed Control Systems(RDCS) consist of several distributed control processes which share a network medium to exchange their data. Performance of feedback control loops in the RDCS is subject to the network-induced delays from sensor to controller and from controller to actuator. The network-induced delays are directly dependent upon the data sampling times of the control components which share a network medium. In this study, a scheduling algorithm of determining data sampling times is developed using the window concept, where the sampling data from the control components dynamically share a limited number of windows.

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