• Title/Summary/Keyword: research front

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A Subthreshold CMOS RF Front-End Design for Low-Power Band-III T-DMB/DAB Receivers

  • Kim, Seong-Do;Choi, Jang-Hong;Lee, Joo-Hyun;Koo, Bon-Tae;Kim, Cheon-Soo;Eum, Nak-Woong;Yu, Hyun-Kyu;Jung, Hee-Bum
    • ETRI Journal
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    • v.33 no.6
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    • pp.969-972
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    • 2011
  • This letter presents a CMOS RF front-end operating in a subthreshold region for low-power Band-III mobile TV applications. The performance and feasibility of the RF front-end are verified by integrating with a low-IF RF tuner fabricated in a 0.13-${\mu}m$ CMOS technology. The RF front-end achieves the measured noise figure of 4.4 dB and a wide gain control range of 68.7 dB with a maximum gain of 54.7 dB. The power consumption of the RF front-end is 13.8 mW from a 1.2 V supply.

Classification of Lower Body Types of Female Adults aged 18 to 69 based on 3D Body Scan Data - Focusing on the Front Type, Lateral-Front Type, and Lateral-Back Type -

  • Kim, Min Kyoung;Nam, Yun Ja
    • Fashion & Textile Research Journal
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    • v.18 no.1
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    • pp.91-102
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    • 2016
  • This study classified the lower body types of female adults aged 18 to 69. The lower body was divided into front, lateral front, and lateral back. In order to understand the shape and somatotype of each segment, 592 people were analyzed based on girth, height, length, depth, width, angle and cross section distance for each segment. For data analysis, SPSS 18.0 was performed for descriptive statics, principal component analysis, K-means cluster analysis, ANOVA, and Duncan's test (as verification). Factor analysis was performed based on index values, calculation values, angles, and cross section distances. The measured items resulted in a.) 16 items were extracted to 5 factors in the case of the front factor (FF) of the lower body, and b.) 24 items were extracted to 6 factors in the case of lateral front factor (LFF) and lateral back factor (LBF). Each factor was put through K-means cluster analysis, classifying the lower bodies into one of four types of based on the front type (FT), the lateral front type (LFT), and the lateral back type (LBT) respectively. This study proposed an understanding of various lower body shapes by segmenting and classifying the lower body shapes for each type.

Front-End Design for Underwater Communication System with 25 kHz Carrier Frequency and 5 kHz Symbol Rate (25kHz 반송파와 5kHz 심볼율을 갖는 수중통신 수신기용 전단부 설계)

  • Kim, Seung-Geun;Yun, Chang-Ho;Park, Jin-Young;Kim, Sea-Moon;Park, Jong-Won;Lim, Young-Kon
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.166-171
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    • 2010
  • In this paper, the front-end of a digital receiver with a 25 kHz carrier frequency, 5 kHz symbol rate, and any excess-bandwidth is designed using two basic facts. The first is known as the uniform sampling theorem, which states that the sampled sequence might not suffer from aliasing even if its sampling rate is lower than the Nyquist sampling rate if the analog signal is a bandpass one. The other fact is that if the sampling rate is 4 times the center frequency of the sampled sequence, the front-end processing complexity can be dramatically reduced due to the half of the sampled sequence to be multiplied by zero in the demixing process. Furthermore, the designed front-end is simplified by introducing sub-filters and sub-sampling sequences. The designed front-end is composed of an A/D converter, which takes samples of a bandpass filtered signal at a 20 kHz rate; a serial-to-parallel converter, which converts a sampled bandpass sequence to 4 parallel sub-sample sequences; 4 sub-filter blocks, which act as a frequency shifter and lowpass filter for a complex sequence; 4 synchronized switches; and 2 adders. The designed front-end dramatically reduces the computational complexity by more than 50% for frequency shifting and lowpass filtering operations since a conventional front-end requires a frequency shifting and two lowpass filtering operations to get one lowpass complex sample, while the proposed front-end requires only four filtering operation to get four lowpass complex samples, which is equivalent to one filtering operation for one sample.

A study on the consumer's perception of front-of-pack nutrition labeling

  • Kim, Woo-Kyoung;Kim, Ju-Hyeon
    • Nutrition Research and Practice
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    • v.3 no.4
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    • pp.300-306
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    • 2009
  • The goal of this research is to investigate the present situation for front of pack labeling in Korea and the perception of consumers for the new system of labeling, front of pack labeling, based on the consumer survey. We investigated the number of processed foods with front of pack labeling in one retailer in Youngin-si. And we also surveyed 1,019 participants nationwide whose ages were from 20 to 49; the knowledge of nutrition labeling, the knowledge of 'front of pack labeling', and the opinion about the labeling system. The data were analyzed using SAS statistics program. The results were as follows: 13.4% of processed foods had front of pack labeling, and 16.8% of the consumers always checked the nutrition labeling, while 32.7% of the consumers seldom checked it. In addition, 44.3% of the consumers think that 'front of pack labeling' is necessary, and 58.3% of the consumers think it is important to show the percentage of daily value as a way of 'front of pack labeling'. However, 32% of the consumer think the possibility of 'front of pack labeling' is slim. Meanwhile, 58.3% of the consumers think that it is important to have the color difference according to contents. The number of favorite nutrients in the front of pack was four or five. It seems that the recognition of current nutrition labeling has the influence on the willingness of using the future 'front of pack labeling'. Along with our study, the policy for 'front of pack labeling' has to be updated and improved constantly since 'front of pack labeling' helps consumer understand nutrition facts.

Tidal Front in the Main Tidal Channel of Kyunggi Bay, Eastern Yellow Sea

  • Lee, Heung-Jae;Lee, Seok;Cho, Cheol-Ho;Kim, Cheol-Ho
    • Journal of the korean society of oceanography
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    • v.37 no.1
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    • pp.10-19
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    • 2002
  • The detailed structure of a tidal front and its ebb-to flood variation in the main tidal channel of the Kyunggi Bay in the mid-west coast of Korea were investigated by analyzing CTD data and drifter trajectories collected in late July 1999. A typical tidal front was formed in water about 60 m deep at the mouth of the channel. Isotherms and isohalines in the upper layer above the seasonal pycnocline in the offshore stratified zone inclined upward to the sea surface to form a surface front, while those in the lower layer declined to the bottom front. The location of the front is consistent with $100 S^3/cm^2$ of the mixing index H/U defined by Simpson and Hunter (1974), where H is the water depth and U is the amplitude of tidal current. The potential energy anomaly in the frontal zone varied at an ebb-to flood tidal cycle, showing a minimum at slack water after ebb but a maximum at slack water after flood. This ebb-to flood variation in potential energy anomaly is not accounted for by the mixing index. We conclude that on- and offshore displacement of the water column by tidal advection is responsible for the ebb-to-flood variation in the frontal zone.

A Study of Computer Simulation of Back-and-Forth Patrol

  • Hur, Seong-Pil
    • Journal of the military operations research society of Korea
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    • v.14 no.1
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    • pp.53-62
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    • 1988
  • A patroller is to protect a patrol area with a certain length front D by proceeding at constant speed on courses parallel to the patrol front, traveling back and forth between area boundaries and reversing course at each area boundary. Transitors enter the area uniformly distributed across the patrol front on a course perpendicular to the patrol front. Any transitor that closes the patroller to within his sweep radius R is detected. This paper use plane trigonometry to derive the theoretical probailities of detection and develop a Monte Carlo computer simulation Model.

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A Study of Computer Simulation of Back-and-Forth Patrol

  • Hur, Seong-Pil
    • Journal of the military operations research society of Korea
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    • v.13 no.2
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    • pp.53-62
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    • 1987
  • A patroller is to protect a patrol area with a certain length front D by proceeding at constant speed on courses parallel to the patrol front, traveling back and forth between area boundaries and reversing course at each area boundary. Transitors enter the area uniformly distributed across the patrol front on a course perpendicular to the patrol front. Any transitor that closes the patroller to within his sweep radius R is detected. This paper use plane trigonometry to derive the theoretical probailities of detection and develop a Monte Carlo computer simulation Model.

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FRONT PROPAGATION RATE OF DENSITY CURRENTS: DENSIMETRIC FROUDE NUMBER VERSUS DIMENSIONLESS FRONT VELOCITY

  • Choi, Sung-Uk
    • Water Engineering Research
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    • v.3 no.1
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    • pp.9-22
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    • 2002
  • In general, two dimensionless numbers are used in predicting the front propagation rate of density currents: the densimetric Froude number and the dimensionless front velocity. The former expresses the front speed in terms of the characteristic length and reduced gravitational acceleration. Previous papers report that the range of this dimensionless number is wide. The other is the dimensionless front velocity, which is a function of the buoyancy flux per unit width. This paper presents the state of the art review of the dimensionless numbers for the front propagation rate of density currents. Values of the densimetric Froude number are found to be consistent when the proper characteristic length is used for normalization. Then, the densimetric Froude number and the dimensionless front velocity are compared by using the experimental data of density currents over a horizontal surface.

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Millimeter-wave LTCC Front-end Module for Highly Integrated Transceiver (고집적 송수신기를 위한 밀리미터파 LTCC Front-end 모듈)

  • Kim, Bong-Su;Byun, Woo-Jin;Kim, Kwang-Seon;Eun, Ki-Chan;Song, Myung-Sun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.10 s.113
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    • pp.967-975
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    • 2006
  • In this paper, design and implementation of a very compact and cost effective front-end module are presented for IEEE 802.16 FWA(fixed Wireless Access) in the 40 GHz band. A multi-layer LTCC(Low Temperature Co-fred Ceramic) technology with cavity process to achieve excellent electrical performances is used to fabricate the front-end module. The wirebond matching circuit design of switch input/output port and waveguide transition to connect antenna are optimally designed to keep transmission loss low. To reduce the size of the front-end module, the dielectric waveguide filter is developed instead of the metal waveguide filter. The LTCC is composed of 6 layers(with the thickness of a layer of 100 um) having a relative dielectric constant of 7.1. The front-end module is implemented in a volume of $30{\times}7{\times}0.8mm^3$ and shows an overall insertion loss < 5.3 dB, and image rejection value > 49 dB.

FINER-SCALE SST FRONT OF THE SOUTHERN ECS IN WINTERTIME FROM SATELLITE AND SHIPBOARD DATA

  • Chang, Yi;Shimada, Theruhisa;Sakaida, Futoki;Kawamura, Hiroshi;Chan, Jui-Wen;Liu, Dong-Chan;Lee, Ming-An
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.740-743
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    • 2006
  • We identify two distinct finer-scale frontal bands: 'Mainland China Coastal Front' (MCCF) and 'Kuroshio Front' (KF). The MCCF is along the 50-m isobath with large temperature gradient. The front is a boundary between the Mainland China Coastal Current and the offshore shelf waters. On the other hand, the KF is extending from the northeastern coast of Taiwan toward the northeast and into the shelf of south ECS. It forms a broad semicircle-shape and curving along 100-m isobath, it also deviates from eastward at around 26.5N-122E and leaves the shelf of ECS. This front should be the boundary between the Kuroshio water and the other shelf waters.

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