• Title/Summary/Keyword: Mismatch Problem

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Performance Analysis of SMMA Adaptive Blind Equalization Algorithm with A Flag (Flag를 가지는 SMMA 적응 블라인드 등화 알고리즘의 성능 분석)

  • Jeong, Young-Hwa
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.71-76
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    • 2014
  • In this paper, we propose a SMMA(Sliced-Multi Modulus Algorithm) adaptive blind equalization algorithm with Flag for high order QAM system. SMMA has improved characteristics by applying the multi contour to MMA. However, SMMA still has a limit that the mismatch problem causes the residual error in the steady state is large. In order to significantly reduce the residual error in the steady state, we propose SMMA, which is controlled by the binary Flag of '1 'or '0' obtained from SMMA and a decision-directed algorithm, and analyze the performance of the proposed algorithm. By computer simulation, it is confirmed that the proposed algorithm has improved performance highly in terms of a residual ISI and a residual error in the steady state compared with MMA and SMMA.

Coordinate Estimation of Mobile Robot Using Optical Mouse Sensors (광 마우스 센서를 이용한 이동로봇 좌표추정)

  • Park, Sang-Hyung;Yi, Soo-Yeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.9
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    • pp.716-722
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    • 2016
  • Coordinate estimation is an essential function for autonomous navigation of a mobile robot. The optical mouse sensor is convenient and cost-effective for the coordinate estimation problem. It is possible to overcome the position estimation error caused by the slip and the model mismatch of robot's motion equation using the optical mouse sensor. One of the simple methods for the position estimation using the optical mouse sensor is integration of the velocity data from the sensor with time. However, the unavoidable noise in the sensor data may deteriorate the position estimation in case of the simple integration method. In general, a mobile robot has ready-to-use motion information from the encoder sensors of driving motors. By combining the velocity data from the optical mouse sensor and the motion information of a mobile robot, it is possible to improve the coordinate estimation performance. In this paper, a coordinate estimation algorithm for an autonomous mobile robot is presented based on the well-known Kalman filter that is useful to combine the different types of sensors. Computer simulation results show the performance of the proposed localization algorithm for several types of trajectories in comparison with the simple integration method.

A downlink beam synthesized method considering phase matching between common overhead channel and traffic channel in FDD/CDMA systems (FDD/CDMA 시스템에서 공통채널과 통화채널의 위상정합을 고려한 순방향 빔 합성 기법)

  • 이준성;이충용
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.11
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    • pp.67-72
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    • 2004
  • In this paper, we propose a downlink beamforming method which is considered common pilot channel for coherent detection and dedicated traffic channel for desired user in FDD/CDMA systems. The existing downlink beamforming system produces phase mismatch between traffic and pilot signals at desired mobile as well as interference to other mobiles. A new downlink beamforming method can solve above problem based on least squares method between reference function and beamforming function. A numerical analysis shows that the proposed downlink beamforming method matches well and gives low BER performance.

A Study on education program for human resource development on concentrating the enterprise participation (참여기업 중심형 인력양성 교육 프로그램에 관한 연구)

  • Chae, Myeong-Suk
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.64 no.4
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    • pp.337-342
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    • 2015
  • The company of 4 core materials that are needed for photovoltaic generation is located in area around this university in Gunsan, Saemangeum. And also, it was almost completed the value chain about the production of Polysilicon, Ingot, Wafer, modules and the design, construction of generation system. The industry-academy-government has understood that because of the relative companies' production and investment, it leads to a supply and demand of manpower and thus will have field centered manpower education. This program will help the problem of lack of manpower in relative companies by establishing competitive major agreement like vocational education system. Also, the university and the participating company in joint have pushed ahead field business education to make the least of industrial-education's mismatch, the training of professional manpower connected with related industries to make the universities chemical characteristics, companies securing excellent manpower and contributed to the revitalization of the regional economy. In this paper, are aware that photovoltaic industry is a future strategic industry for the country, so we will train the immediately site adapting manpower for the area of photovoltaic material and system as our goal. This is shown results of education operation for 4 years.

Research for the interface circuit to reduce static current and rising time (접속 속도 향상 및 전력소모를 줄인 위성용 접속회로 연구)

  • Won, Joo-Ho;Ko, Hyoung-Ho
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.114-118
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    • 2016
  • In this paper, we present the advanced open collector circuit, interface circuit between aerospace electronics. Satellite is composed of a number of electronics, which were provided from various manufacturers. Each company manufactured its own electronics for satellite using its heritage and requirements for their electronics. Therefore each electronics may use different internal supplies. It make a problem between electronics because the supply is different from other electronics, such as the increasing of power dissipation because of the static current and the mismatch of interface voltage, the offset. Proposed circuit can reduce the static current and rising time, and also decrease the useless power dissipation caused by the static current for open collector circuit

Question Classification Based on Word Association for Question and Answer Archives (질문대답 아카이브에서 어휘 연관성을 이용한 질문 분류)

  • Jin, Xueying;Lee, Kyung-Soon
    • The KIPS Transactions:PartB
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    • v.17B no.4
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    • pp.327-332
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    • 2010
  • Word mismatch is the most significant problem that causes low performance in question classification, whose questions consist of only two or three words that expressed in many different ways. So, it is necessary to apply word association in question classification. In this paper, we propose question classification method using translation-based language model, which use word translation probabilities for question-question pair that is learned in the same category. In the experiment, we prove that translation probabilities of question-question pairs in the same category is more effective than question-answer pairs in total collection.

Analysis on the Determinants of Hotel Occupancy Rate in Jeju Island (제주지역 호텔이용률에 영향을 미치는 결정요인 분석)

  • Ryu, Kang-Min;Song, Ki-Wook
    • Land and Housing Review
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    • v.9 no.4
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    • pp.10-18
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    • 2018
  • As the volatility increasement of the number of tourist, there was been controversy over supply-demand imbalance in hotel market. The purpose of this study is to analysis on determinants of hotel occupancy rate in Jeju Island. The quantitative method is based on cointegrating regression, using an empirical dataset with hotel from 2000 to 2017. The primary results of research is briefly summarized as follows; First, there are high relationship between total hotel occupancy rate and hotel occupancy of foreign tourist. The volatility of hotel occupancy is caused by foreigner user than local tourists though local tourist high propotion of hotel occupancy in Jeju Island. Second, hotel occupancy of local tourist has not relationship with demand and supply variables. Because some hotel users are not local tourists but local resident, and effects to other variables of hotel consumer trend, accommodation such as Guest house, Airbnb. Third, there are high relationship between foreign hotel occupancy rate and demand-supply variables. These research imply that total management of supply-demand is very important to seek stability of hotel occupancy rate in Jeju Island. Also it can provide a useful solution regarding mismatch problem between supply-demand as well as development the systematic forecasting model for hotel market participants.

Motion Correction in PET/CT Images (PET/CT 영상 움직임 보정)

  • Woo, Sang-Keun;Cheon, Gi-Jeong
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.172-180
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    • 2008
  • PET/CT fused image with anatomical and functional information have improved medical diagnosis and interpretation. This fusion has resulted in more precise localization and characterization of sites of radio-tracer uptake. However, a motion during whole-body imaging has been recognized as a source of image quality degradation and reduced the quantitative accuracy of PET/CT study. The respiratory motion problem is more challenging in combined PET/CT imaging. In combined PET/CT, CT is used to localize tumors and to correct for attenuation in the PET images. An accurate spatial registration of PET and CT image sets is a prerequisite for accurate diagnosis and SUV measurement. Correcting for the spatial mismatch caused by motion represents a particular challenge for the requisite registration accuracy as a result of differences in PET/CT image. This paper provides a brief summary of the materials and methods involved in multiple investigations of the correction for respiratory motion in PET/CT imaging, with the goal of improving image quality and quantitative accuracy.

A Study on State of Boundary Barriers Resources in Rural Villages (농촌마을 담장자원 조사연구)

  • Lim, Jong-Hyeon;Choi, Soo-Myung;Cho, Joong-Hyun
    • Journal of Korean Society of Rural Planning
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    • v.18 no.1
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    • pp.17-28
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    • 2012
  • Functional mismatch and thought and plan-less material use of recently built boundary barriers in rural areas should greatly degrade their amenity value as one of linear villagescapes, but, their present state-of-art basically necessary for problem-solving had never surveyed up to now. From this point of view, this study tried to investigate present stock quantities and qualities of boundary barriers in rural areas by sample studies on 21 case villages(7 types ${\times}$ 3 cases) and comparative analysis between the planned or improved and nots. Wall type was absolutely dominated in the structural terms, of which more than half was used cement block as building material and, therefore, grey-colored. More than half of total barrier length were fully shielded, while relatively partially shielded in the mountainous villages in open space and 'Cultural villages' with closed housing structures. Free standing style of barriers was shown along over two thirds of their total length, although not more than half in planned reclaimed villages. Especially, because of one-sided wall type structure, mismatched over-shieldness and poorer maintenance condition of the boundary barriers in peri-urban villages, there should be provided with very intensive improvement efforts for amenity barriers.

Effect of CFO on UFMC System (UFMC 시스템에서 CFO의 영향)

  • Lee, Kyuseop;Choi, Ginkyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.97-102
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    • 2016
  • The UFMC(Universal Filtered Multi-Carrier) is one of multi-carrier transmission technique as a candidate of transmission method for the recent 5G communication system. The UFMC can be considered as the system which has both the advantages of OFDM(Orthogonal Frequency Division Multiplex) and the simplicity of FBMC(Filter Bank Multi-Carrier). CFO(Carrier Frequency Offset) causes the problem to lower the BER performance due to a mismatch between the sub-carriers in multi-carrier transmission scheme. The effect of CFO on UFMC is not greater than the OFDM. But it still degrades the system performance caused by interference between the sub-band. In this paper, we analyze the SNR degradation due to changes in the value of EsNo and CFO on UFMC system.