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Four-Channel Differential CMOS Optical Transimpedance Amplifier Arrays for Panoramic Scan LADAR Systems (파노라믹 스캔 라이다 시스템용 4-채널 차동 CMOS 광트랜스 임피던스 증폭기 어레이)

  • Kim, Sang Gyun;Jung, Seung Hwan;Kim, Seung Hoon;Ying, Xiao;Choi, Hanbyul;Hong, Chaerin;Lee, Kyungmin;Eo, Yun Seong;Park, Sung Min
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.82-90
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    • 2014
  • In this paper, a couple of 4-channel differential transimpedance amplifier arrays are realized in a standard 0.18um CMOS technology for the applications of linear LADAR(laser detection and ranging) systems. Each array targets 1.25-Gb/s operations, where the current-mode chip consists of current-mirror input stage, a single-to-differential amplifier, and an output buffer. The input stage exploits the local feedback current-mirror configuration for low input resistance and low noise characteristics. Measurements demonstrate that each channel achieves $69-dB{\Omega}$ transimpedance gain, 2.2-GHz bandwidth, 21.5-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -20.5-dBm), and the 4-channel total power dissipation of 147.6-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations. Meanwhile, the voltage-mode chip consists of inverter input stage for low noise characteristics, a single-to-differential amplifier, and an output buffer. Test chips reveal that each channel achieves $73-dB{\Omega}$ transimpedance gain, 1.1-GHz bandwidth, 13.2-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -22.8-dBm), and the 4-channel total power dissipation of 138.4-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations.

An Experimental Study of Comfortable Pitch and Loudness with Target Matching: Effects on Electroglottographic and Acoustic Measures

  • Choi, Seong Hee
    • Phonetics and Speech Sciences
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    • v.4 no.4
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    • pp.139-146
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    • 2012
  • This study was designed to examine comfort levels of pitch and loudness with target matching and their effects on electroglottographic (EGG) and acoustic measures. Twelve speakers, six males and six females, were instructed to produce /a/ sustained vowel for three seconds at a comfortable pitch and loudness level without any instruction and with a target matching procedure of either a certain f0 or SPL separately with visual and auditory feedback. The range of pitch for females and males were presented by progressing up and down randomly at intervals of 5Hz from 150 Hz to 310 Hz (total 33 frequency targets) and from 85 Hz to 190 Hz (total 22 frequency targets), respectively. The loudness levels were 65, 75, 85, 95 dB (total of four intensity targets) for both males and females. Subjective estimations of comfortable levels were obtained using a 10-point equal-appearing interval rating scale following each phonation. The results showed that males and females demonstrated similar trends in loudness levels with greatest comfort at 75 dB, whereas pitch comfort ratings showed a greater variability with females having a wider range with target matching. In the comfort levels of individuals, most male and female speakers rated higher comfort at soft, rather than loud phonations. On the other hand, most male speakers perceived highest comfort levels below the comfort pitch levels they phonated under natural conditions. Higher frequency ranges, however, were perceived to be more comfortable than those of natural condition in most female speakers, although the comfortable pitch levels in spontaneous phonations were within the comfort level ranges determined by targeted phonations. When comparing acoustic (%jitter, %shimmer, SNR) and EGG measures (CQ%) between spontaneous comfortable phonations and targeted phonations produced by the same subject at similar f0 and intensity, no significant differences were observed (p>0.05). Thus, target matching procedures may be considered a compatible and alternative method to reduce the variability of comfortable pitch and loudness levels by eliciting consistent comfortable phonations.

Improving Work Functioning and Mental Health of Health Care Employees Using an E-Mental Health Approach to Workers' Health Surveillance: Pretest-Posttest Study

  • Ketelaar, Sarah M.;Nieuwenhuijsen, Karen;Bolier, Linda;Smeets, Odile;Sluiter, Judith K.
    • Safety and Health at Work
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    • v.5 no.4
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    • pp.216-221
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    • 2014
  • Background: Mental health complaints are quite common in health care employees and can have adverse effects on work functioning. The aim of this study was to evaluate an e-mental health (EMH) approach to workers' health surveillance (WHS) for nurses and allied health professionals. Using the waiting-list group of a previous randomized controlled trial with high dropout and low compliance to the intervention, we studied the pre- and posteffects of the EMH approach in a larger group of participants. Methods: We applied a pretest-posttest study design. The WHS consisted of online screening on impaired work functioning and mental health followed by online automatically generated personalized feedback, online tailored advice, and access to self-help EMH interventions. The effects on work functioning, stress, and work-related fatigue after 3 months were analyzed using paired t tests and effect sizes. Results: One hundred and twenty-eight nurses and allied health professionals participated at pretest as well as posttest. Significant improvements were found on work functioning (p = 0.01) and work-related fatigue (p < 0.01). Work functioning had relevantly improved in 30% of participants. A small meaningful effect on stress was found (Cohen d = .23) in the participants who had logged onto an EMH intervention (20%, n = 26). Conclusion: The EMH approach to WHS improves the work functioning and mental health of nurses and allied health professionals. However, because we found small effects and participation in the offered EMH interventions was low, there is ample room for improvement.

Analysis on the Noise Factors of Static Induction Photo-Transistor (SIPT) (1) - The SIPT's Equivalent Circuits for the Analysis on the Noise Factors - (정전유도(靜電誘導) 포토 트랜지스터의 잡음(雜音) 원인(原因) 분석(分析) (1) - 잡음(雜音) 원인(原因) 분석(分析)을 위한 SIPT 등가회로(等價回路) -)

  • Kim, Jong-Hwa
    • Journal of Sensor Science and Technology
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    • v.4 no.4
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    • pp.29-40
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    • 1995
  • In this paper, the noise equivalent cicuits that is necessary to the formulation of D.C. and noise characteristics, residual component and input capacitance so as to analyze on the noise factors of the SIT is proposed. The simplest noise equivalent circuit is the model representing the mechanism of the SIT and the measured values in this model were found as small as the values of the shot-noise. In the source resistance inserted equivalent circuit is conformed that the shot-noise will be reduced by the negative-feedback effect of the source resistance. In oder to analyze the correct noise reduction factor, I proposed the equivalent circuit which the formulas of the source and drain resistance was induced. In the experiment which affirm the equivalent circuits, the influence of the signal source resistance and output load resistance on the residual component is small and the residual component can be expressed by the equivalent input noise resistance. Moreover, the input capacitance is 13.6 pF when the load resistance is $0{\Omega}$ and the capacitance which does not concern with the SIT operation directly, that is, gate wire etc, is 10pF or so.

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A Design of Wide-Bandwidth LDO Regulator with High Robustness ESD Protection Circuit

  • Cho, Han-Hee;Koo, Yong-Seo
    • Journal of Power Electronics
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    • v.15 no.6
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    • pp.1673-1681
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    • 2015
  • A low dropout (LDO) regulator with a wide-bandwidth is proposed in this paper. The regulator features a Human Body Model (HBM) 8kV-class high robustness ElectroStatic Discharge (ESD) protection circuit, and two error amplifiers (one with low gain and wide bandwidth, and the other with high gain and narrow bandwidth). The dual error amplifiers are located within the feedback loop of the LDO regulator, and they selectively amplify the signal according to its ripples. The proposed LDO regulator is more efficient in its regulation process because of its selective amplification according to frequency and bandwidth. Furthermore, the proposed regulator has the same gain as a conventional LDO at 62 dB with a 130 kHz-wide bandwidth, which is approximately 3.5 times that of a conventional LDO. The proposed device presents a fast response with improved load and line regulation characteristics. In addition, to prevent an increase in the area of the circuit, a body-driven fabrication technique was used for the error amplifier and the pass transistor. The proposed LDO regulator has an input voltage range of 2.5 V to 4.5 V, and it provides a load current of 100 mA in an output voltage range of 1.2 V to 4.1 V. In addition, to prevent damage in the Integrated Circuit (IC) as a result of static electricity, the reliability of IC was improved by embedding a self-produced 8 kV-class (Chip level) ESD protection circuit of a P-substrate-Triggered Silicon Controlled Rectifier (PTSCR) type with high robustness characteristics.

Student feedback to improve the United States Department of Agriculture Fresh Fruit and Vegetable Program

  • Lin, Yi-Chun;Fly, Alyce D.
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.321-327
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    • 2016
  • BACKGROUND/OBJECTIVES: Fruit and vegetable consumption of children in the United States falls below recommendations. The U.S. Department of Agriculture Fresh Fruit and Vegetable Program (FFVP) is a national free-fruit and vegetable school distribution program designed to address this problem. This permanent, legislated program provides funding to qualified elementary schools for provision of additional fruit and vegetables outside of school meals. The objective of this study was to understand children's perceptions of FFVP after the intervention and formulate recommendations that may improve success of the intervention. SUBJECTS/METHODS: Secondary data were obtained from 5,265 $4^{th}-6^{th}$ graders at 51 randomly-selected FFVP intervention schools in Indiana. Anonymous questionnaires were completed late in the 2011-2012 academic year. Multilevel logistic regressions were used to determine associations between students' perceptions of program effects (4 close-ended items) and their preference toward the program. Content analysis was applied to a single open-ended item for program comments. RESULTS: Over 47% of students reported greater intake of fruit and vegetables due to FFVP, and over 66% reported liking the program. Student-reported program effects were positively associated with preference for the program (P < 0.01). Themes that emerged during analysis of 3,811 comments, included, students liked: the opportunity to try different kinds of fruit and vegetables, types and flavors of fruits served, and benefits of eating fruit. Fewer students liked the types of vegetables and their benefits. A small group disliked the program citing poor flavor of vegetables and quality of fruits. Important suggestions for the program include serving more dipping sauces for vegetables, cooking vegetables, and providing a greater variety of produce. CONCLUSIONS: The degree that students liked FFVP may predict the program's effects on fruit and vegetable intake. FFVP may become more acceptable to students by incorporating their suggestions. Program planners should consider these options for achieving program goals.

Characteristics of Liquid Rocket Engine Simulation System Using Control Valve (제어밸브를 이용한 액체로켓엔진 모사시스뎀 특성)

  • Lee Joons-Youp;Jung Tae-Kyu;Han Sang-Yeop;Kim Young-Mog
    • Journal of the Korean Society of Propulsion Engineers
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    • v.9 no.3
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    • pp.74-84
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    • 2005
  • This paper include the investigation of finding the system characteristics of facility by simulating open-type turbo-pump fed system, which has commercial control valves, using AMESIM (Advanced Modeling Environment Simulation) commercial software. After developing a flight-type control valve on the basis of the results, the system characteristics of facility for control and valve tests is estimated. Especially, one of purposes of this paper is to find PID value of each commercial control valve in the facility for system test. To find suitable control logic, PI and PID modes are also compared. This paper also introduces design parameters of valve and equipment for thrust control and TDS simulation, which are using control valves.

Design of CFL Linearisation Chip for the Mobile Radio Using Ultra-Narrowband Digital Modulation (디지털 초협대역 단말기용 CFL 선형화 칩 설계)

  • Chong Young-Jun;Kang Min-Soo;Yoo Sung-Jin;Chung Tae-Jin;Oh Seung-Hyeub
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.7 s.98
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    • pp.671-680
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    • 2005
  • The CFL linearisation chip which is one of key devices in ultra-narrowband mobile radio transmitter using CQPSK digital modulation method is designed and implemented with $0.35{\mu}m$ CMOS technology. The reduced size and low cost of transmitter are available by the use of direct-conversion and CFL ASIC chip, which improve the power effi챠ency and linearity of transmitting path. In addition, low power operation is possible through CMOS technology The performance test results of transmitter show -25 dBc improvement of IMD level at the 3 kHz frequency offset and then satisfy FCC 47 CFR 90.210 E emission mask in the operation of CFL ASIC chip. At that time, the transmitting power is about PEP(Peak-to-Envelope Power) 5 W. The main parameters to improve the transmitting characteristic and to compensate the distortion in feed back loop such as DC-offset, loop gain and phase value are interfaced with notebook PC to be controlled with S/W.

Metabolic Characteristic of the Liver of Dairy Cows during Ketosis Based on Comparative Proteomics

  • Xu, Chuang;Wang, Zhe;Liu, Guowen;Li, Xiaobing;Xie, Guanghong;Xia, Cheng;Zhang, Hong You
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.1003-1010
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    • 2008
  • The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.