• Title/Summary/Keyword: frequency-response

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EEG Signal Analysis on Correlation between Mathematical Task Type and Musical Stimuli (음악적 자극과 수학적 과제 유형과의 상관관계에 대한 뇌파분석)

  • Jung, Yu-Ra;Jang, Yun-Seok
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.4
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    • pp.773-778
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    • 2020
  • In this paper, we analyzed the effects of musical stimuli on humans in performing mathematical tasks through EEG measurements. The musical stimuli were divided into preferred music and non-preferred music, and mathematical tasks were divided into memorization task and procedure task. The data measured in the EEG experiments was divided into frequency bands of Theta, SMR, and Mid-beta because of the concentration. In our results, preferred music causes more positive emotional response than no music and non-preferred music regardless of the type of mathematical task.

A research study on the cultivation of professionals in the foodservice industry (외식산업 전문인력 양성에 관한 연구(공급자 관점에서))

  • Yun, Ji-Yeon;Hong, Wan-Soo;Kim, Tea-Hee
    • Journal of the Korean Home Economics Association
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    • v.45 no.1
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    • pp.91-99
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    • 2007
  • The purpose of this study was to determine a is finding the process for the development of professionals in the foodservice industry. The Questionnaire used in this study was designed to measure the capabilities of professional foodservice employees, investigate the importance and accomplishments of curriculum of the major subject, and determine areas matters of the for improvement in the of field. It was distributed to 101 professors (include lecturers) of foodservice departments, from February 1 to 28, 2006. A total of 101 usable questionnaires were received amounting to a 100 percent response rate. Statistical data analysis was completed using SPSS Win(11.0) for frequency, t-test, one sample t-test, and IPA(importance performance analysis). The results were as is follows. Regarding the As regard capabilities of professional foodservice employees, they remarked that the fair values and creative thinking are the most important. Regarding the curriculum of the major subject, generally the importance degree is higher than the accomplishment degree. The areas improvement are as follows: development of curriculum, securing the excellent faculty, academic-industrial cooperation, expanding and improving the university facilities in university, and increasing the experience during the term.

A Study on Excitation System for Synchronous Generator using Current Mode Controlled PWM Converter (전류제어형 PWM컨버터를 이용한 동기발전기용 여자시스템에 관한 연구)

  • 장수진;류동균;서민성;김준호;원충연;이진국
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.3
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    • pp.32-39
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    • 2003
  • The output voltage of synchronous generator is regulated constantly by field current control in excitation system High frequency PWM converter (current control mode buck converter) type excitation systam fer synchronous generator is able to control exciter current when the load change happened. This paper deals with the design and evaluation of the excitation system for a synchronous generator to improve the steady state and transient stability. The simulation and experimental results show that the proposed excitation system is able to improve the response time by the DVR(digital voltage regulator) of 50[kW] synchronous generator.

Analysis of a Three Phase PWM AC/DC Converter With Input Current Waveform and Power Factor Correction (입력 전류 파형과 역률 개선 제어기법에 의한 3상 PWM 컨버터 해석)

  • 이수흠;배영호;최종수;백종현
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.1
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    • pp.93-102
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    • 1998
  • This paper describes to control system for AC to DC converter which has been widely used to power source in industrial factory and domestics. In this paper, three-phase PWM AC to DC Boost converter that operates with unity power factor and sinusodial input line currents is presented. The current control of this converter is based on the predicted current control strategy with fixed switching frequency and the line currents track to reference currents within one sampling time interval. By using this control strategy low ripples in the output current and the voltage as well as fast dynamic response are achieved with small dc link capacitance employed.ployed.

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A Study on the Landscape Adjectives for Urban Landscape Analysis (도시경관분석을 위한 경관형용사 목록 작성)

  • 주신하;임승빈
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.1
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    • pp.1-10
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    • 2003
  • The purpose of this study is to categorize a landscape adjective list for urban landscape analysis. For this purpose, four methods are used. The first method is to survey the foreign landscape adjective lists such as Feimer's EACL & LACL, VRM suggested vocabulary, and IEA and LI's aesthetic factors, which are commonly used in domestic research. The second method is to analyze vocabulary in Korean linguistic textbook the third is to investigate Korean adjective lists from 36 domestic research. The last is to survey adjectives used to express the urban landscapes. 24 landscapes from BunDdang, GwaCheon, YakSoo and ApGuJeong were presented to 40 subjects, whose responses were collected and categorized. The frequency analysis of the adjectives and landscape factors were processed by SJTOOL, which was programmed for Korean vocabulary analysis. The results of this study can be summarized as follows: Foreign adjective lists were mainly focused on the physical features of landscapes and they also had linguistic problems caused by the translations. Therefore, it is undesirable to use the foreign adjective list directly to analyze Korean urban landscapes. The vocabulary from the linguistic textbook has more variety, but it includes many adjectives irrelevant to the urban landscape. More types of adjectives were used in the researches(890 adjectives/295 types), compared with the result of response survey(1,406 adjectives/270 types). Because some adjectives were partly confusing, it is desirable to categorize the adjectives. The categorized adjectives could therefore be more useful and practical for urban landscape analysis.

Comparison of Memoryless Anti-collision Protocols for Tag Identification (태그 인식을 위한 무기억 충돌 방지 프로토콜의 비교 분석)

  • Yang, Eui-Sik;Lim, In-Taek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.565-568
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    • 2005
  • RFID system allows contactless identification of objects, where small tags are attached to objects and information of objects are transferred using radio frequency. In recent years, industries have incorporated several identification systems to its production processes, which allow collecting automatically information about goods. In order to communicate with a single tag out of a group of tags, the target tag has to be identified. Therefore the read has to attempt to obtain the unique identification code of each tag within its read range. This paper presents performance results of QT and QT-sl protocols, which are tag identification protocols incorporating memoryless property. The memoryless property is that the current response of each tag only depends on the current query of the reader but not on the past history of the reader's queries.

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The Development of a Speed Changeable Current Controller for Driving a 10kW BLDC Motor for Revolving and Elevating a Turret a Tank (전차의 포탑 선회, 고저 구동용 10kW BLDC 전동기 가변속 전류제어기 개발)

  • Park, Moo-Yurl;Koo, Bon-Min;Choi, Jung-Keying
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.947-950
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    • 2005
  • For revolving and elevating a turret of a tank, we substitute an existing oil pressure system with an electric system using a motor and applied the vector control method to this system. A switching method of an inverter for providing desired sinusoidal current to each phase of a motor, we adopted min-max pulse width modulation method which takes less computation time, rather than space vector pulse width modulation method. We designed a digital filter and applied it to the control system. Developed current controller is verified it's performance through a current control test, speed control test, frequency response and tracking a profile of speed test.

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An Adaptive Transversal Filter for GNSS Receiver: Implementation and Performance Evaluation

  • Lee, Geon-Woo;Choi, Jin-Kyu;Shin, Dong-Ho;Kim, Young-Il;Park, Chan-Sik;Hwang, Dong-Hwan;Lee, Sang-Jeong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.353-357
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    • 2006
  • One-sided and two-sided ATF for GNSS receiver are deigned, implemented and evaluated in this paper. The difference f filter characteristics such as the location of zeros and the frequency response is reviewed and examined with experiments. NLMS adaptation algorithm is adopted for updating the weighting coefficients of the 12-tap FIR filter. he performance of ATF is evaluated using real signals consisting of the signals from GPS simulator and the signal generator. The output of ATF is fed into the SDR to evaluate SNR and the position accuracy. The complexity of implementation is also compared and the effects of the time delay and the phase delay are examined. The experimental results show that one-sided and two-sided ATF give similar performance against single tone CWI.

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Performance Analysis of Optical Line Termination System in ATM based Passive Optical Network (ATM 기반 수동 광가입자 망에서의 광선로 종단 시스템의 성능 분석)

  • Park, Sang-Jo;Kang, Koo-Hong
    • Journal of KIISE:Information Networking
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    • v.29 no.1
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    • pp.40-47
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    • 2002
  • This paper analyzes the performance of an optical line termination system in ATM based Passive Optical Network(PON) using the operational analysis. We analyze it using system parameters such as utilization, throughput and routing frequency based on the buffer structure in each block of ATM-PON. Furthermore, we derive the mean response time and the visit ratio of each block, and then search the bottleneck block that hinders the system performance. We found that the 622Mbps 16x16 switching block is the bottleneck block for ATM-PON. In this bottleneck block, the loss probability increases rapidly when the cell arrival rate increases.

Effects of SiO$_2$ Buffer Layer on Properties of ZnO thin films and Characteristics of SAW Devices with a Multilayered Configuration of IDT/ZnO/SiO$_2$/Si (SiO$_2$ 완충층이 ZnO 박막의 물성 및 IDT/ZnO/SiO$_2$/Si 다층막 구조 표면탄성파 소자의 특성에 미치는 영향)

  • Lee, Jin-Bok;Lee, Myeong-Ho;Park, Jin-Seok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.9
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    • pp.417-422
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    • 2002
  • ZnO thin films were deposited on various substrates, such as Si-(111), SiO$_2$(5000 $\AA$ by thermal CVD)/Si-(100), and SiO$_2$(2000 $\AA$ by RF sputtering)/Si-(100). The (002)-orientation, surface morphology and roughness, and electrical resistivity of deposited films were measured and compared in terms of substrate. Surface acoustic wave(SAW) filters with a multilayered configuration of IDT/ZnO/SiO$_2$/Si were also fabricated and the IDT was obtained using a lift-off method. From the frequency-response characteristics of fabricated devices, the insertion loss and side-lobe rejection were estimated. The experimental results showed that the (002)-oriented growth nature of ZnO films, which played a crucial role of determining the characteristic of SAW device, was strong1y dependent upon the SiO$_2$buffer.