• Title/Summary/Keyword: SLC

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Analysis and design of a FSK Demodulator with Digital Phase Locked Loop (디지털 위상고정루프를 이용한 ESK복조기의 설계 및 성능 분석)

  • 김성철;송인근
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.2
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    • pp.194-200
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    • 2003
  • In this paper, FSK(Frequency Shift Keying) demodulator which is widely used for FH-SS system is designed and the experimental results are analyzed. The performance of the ADPLL(All-digital Phase-Locked-Loop), which is the main part of the demodulator circuit, is analyzed by the computer program. Using Maxplus-II tool provided by altera. co., ltd, each part of the ADPLL is designed and all of them is integrated into EPM7064SLC44-10 chip. And the simulation results are compared with the characteristics of the implemented circuits for analysis. There is about 2${\mu}\textrm{s}$ difference in time constant of the PLL. This difference is not critical in the demodulator. And the experimental results show that the transmitted data is well demodulated when the phase difference between the FSK modulated signal and the reference signal is about 180 degree.

Comparison of Drift Reduction Methods for Pedestrian Dead Reckoning Based on a Shoe-Mounted IMU

  • Jung, Woo Chang;Lee, Jung Keun
    • Journal of Sensor Science and Technology
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    • v.28 no.6
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    • pp.345-354
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    • 2019
  • The 3D position of pedestrians is a physical quantity used in various fields, such as automotive navigation and augmented reality. An inertial navigation system (INS) based pedestrian dead reckoning (PDR), hereafter INS-PDR, estimates the relative position of pedestrians using an inertial measurement unit (IMU). Since an INS-PDR integrates the accelerometer signal twice, cumulative errors occur and cause a rapid increase in drifts. Various correction methods have been proposed to reduce drifts. For example, one of the most commonly applied correction method is the zero velocity update (ZUPT). This study investigated the characteristics of the existing INS-PDR methods based on shoe-mounted IMU and compared the estimation performances under various conditions. Four methods were chosen: (i) altitude correction (AC); (ii) step length correction (SLC); (iii) advanced heuristic drift elimination (AHDE); and (iv) magnetometer-based heading correction (MHC). Experimental results reveal that each of the correction methods shows condition-sensitive performance, that is, each method performs better under the test conditions for which the method was developed than it does under other conditions. Nevertheless, AC and AHDE performed better than the SLC and MHC overall. The AC and AHDE methods were complementary to each other, and a combination of the two methods yields better estimation performance.

A Study on Performance Improvement of Adaptive SLC System Using Eigenanalysis Method and Comparing with RLS Method (Eigenanalysis 방식의 적응 SLC(sidelobe canceller) 시스템의 적용에 따른 성능향상 및 RLS 방식과외 비교에 관한 연구)

  • Jung, Sin-Chul;Kim, Se-Yon;Lee, Byung-Seub
    • Journal of Advanced Navigation Technology
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    • v.5 no.2
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    • pp.111-122
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    • 2001
  • In this paper, we study the performance of eigencanceller which use a eigenvector and eigenvalue in order to update a weighter vector. Eigencanceller can suppress directional interferences and noise effectively while maintaining specified beam pattern constraints. The constraints and optimal weight vector of eigencanceller vary by using interference and noise or desired signal, interference signal and noise as array input signal. From the analysis results in the steady state, We show that weight vectors in each case are simplified the form of projection equation that belongs to desired subspace orthogonal to interference subspace and eigencanceller has the better performance than RLS method through mathematical analysis and simulation.

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A Study on Performance Improvement of Adaptive SLC System using Eigenanalysis Method (Eigenanalysis 방식을 이용한 적응 SLC(sidelobe canceller)시스템의 성능향상에 관한 연구)

  • 김세연;정신철;이병섭
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.5
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    • pp.694-704
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    • 2001
  • In this work, We evaluate the performance of eigencanceller which can suppress directional interferences and noise effectively while maintaining specified beam pattern constraints. The constraints and optimal weight vector of eigencanceller vary by using interference and noise or desired signal, interference and noise as array input signal. From the analysis results in the steady state, We show that weight vectors in each case are simplified the form of projection equation that belongs to desired subspace orthogonal to interference subspace and eigencanceller has the better performance than DMI method through mathematical analysis and simulation.

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On Performance of Adaptive Array and Sidelobe Canceller (간섭 신호 제거를 위한 Adaptive Array 및 측엽 제거 기법의 특성 분석)

  • Seo, Jeong-Uk;Lee, Sang-Cheol;Choe, Yeong-Gyun
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.21 no.2
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    • pp.61-70
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    • 1984
  • This paper examines the array antenna theory, basic relations between the array size (aperture) and its beamwidth and resultant patterns. This paper also provides array antenna system design criteria, mainly maximizing the signal-to-noise ratio (SNR) and its corresponding optimum array structure and weight functions. Explicit new expressions for array performance are also illustrated in terms of the array output SNR. An example is provided for a 37-element planar array to explicitly illustrate the beam-forming and nulling operations of the array. Fundamentals of sidelobe canceller (SLC) systems have been discussed along with a derivation of new SLC equations for optimum weights.

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A Case of Adult-onset Type II Citrullinemia Confirmed by Mutation of SLC25A13 (SLC25A13 유전자 돌연변이로 확진된 성인형 제 2형 시트룰린혈증 1례)

  • Jeung, Min Sub;Yang, Aram;Kim, Jinsup;Park, Hyung-Doo;Lee, Heon Ju;Jin, Dong-Kyu;Cho, Sung Yoon
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.16 no.1
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    • pp.34-41
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    • 2016
  • Adult-onset type II citrullinemia (CTLN2) is characterized by episodes of neurologic symptoms associated with hyperammonemia leading to disorientation, irritability, seizures, and coma. CTLN2 is distinct from classical citrullinemia, which is caused by a mutation of the argininosuccinic acid synthetase (ASS) gene. The serum citrulline level is elevated, while the activity of ASS in liver tissue is decreased. CTLN2 is known to have a poor prognosis if the proper treatment is not taken. We reported a female aged 37 years who developed recurrent attacks of altered consciousness, aberrant behavior, and vomiting. We initially suspected the patient had CTLN2 because of the signs of hyperammonemic encephalopathy, such as altered mentality, memory disturbance, and aberrant behaviors provoked by exercise-induced stress and excessive intravenous amino acid administration. Through her peculiar diet preferences and laboratory findings that included hyperammonemia and citrullinemia, we diagnosed the patient as CTLN2, and SLC25A13 sequencing revealed known compound heterozygous mutations (IVS11+1G>A, c.674C> A). Her parents were heterozygous carriers, and we identified that her older sister had the same mutations. The older sister had not experienced any episodes of hyperammonemia, but she had peculiar diet preferences. The patient and her sister have been well with conservative management. When considering the clinical course of CTLN2, it was meaningful that the older sister could be diagnosed early in an asymptomatic period and that preemptive treatment was employed. Through this case, CTLN2 should be considered in adults who present symptoms of hyperammonemic encephalopathy without a definite etiology. Because of its rare incidence and similar clinical features, CTLN2 is frequently misdiagnosed as hepatic encephalopathy, and it shows a poor prognosis due to the lack of early diagnosis and proper treatment. A high-carbohydrate diet, which is usually used to treat other urea cycle defects, can also exaggerate the clinical course of CTLN2, so proper metabolic screening tests and genetic studies should be performed.

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