• Asian-Australasian Journal of Animal Sciences
• /
• 제10권2호
• /
• pp.170-177
• /
• 1997

Two experiments were conducted to evaluate the effects of different extrusion conditions of corn and soybean meal on physico-chemical properties, ileal digestibility of amino acid and growth performance in weaned pigs. In Expt. 1, to compare physico-chemical properties and ileal digestibility of extruded corn and soybean meal, ground corn (2 mm screen) and soybean meal were separately extruded in four different conditions: (1) no preconditioning, low water supply (3.0 l/min) (NCLW), (2) no preconditioning, high water supply (7.0 l/min) (NCHW). (3) preconditioning (steam 3.0 l/min) with low water supply (3.0 l/min) (CLW), and (4) preconditioning (steam 3.0 l/min) plus high water supply (7.0 l/min) (CHW). Twenty-five cannulated pigs ($L{\times}Y{\times}D$, 7.62 kg BW for soybean meal, 8.80 kg BW for corn) were employed to determine nutrients digestibility of the extruded feedstuffs. In Expt. 2, a total of 90 pogs ($L{\times}Y{\times}D$, 9.18 kg BW) were used for a 28 d feeding trial to compare growth performance of pigs as affected by different extrusion conditions. Before mixing, corn and soybean meal were blended and extruded by the same conditions as described in Expt. 1. corn extruded with NCLW showed the highest (p < 0.05) degree of gelatinization (DG), compared to the lowest values observed for NCHW. Extrusion of corn with preconditioning (CLW and CHW) increased (p < 0.05) the DG as compared to the extrusion condition of NCHW. Extruded SBM with NCLW showed the lowest (p < 0.05) degree of texturization among treatments. The ileal digestibility of GE in SBM was higher with NCHW and CHW as compared to NCLW. The ileal digestibility of CP was lower in extruded corn, but was higher in extruded SBM, compared to untreated sample. Lysine digestibility of extruded corn (except corn with NCHW) was in general significantly improved. Extrusion of SBM resulted in no improvements in ileal digestibility of amino acids, but extruded SBM with NCLW had lower lysine digestibility compared to other treatments. In growth responses, pigs fed a diet with CLW had higher, but not significant, average daily gain (ADG) than other treatments during first 2 weeks. From d 15 to 28, pigs fed a diet with CHW had significantly less (p < 0.05) average daily feed intake (ADFI) than others except NCHW. In conclusion, the proper extrusion condition for corn and SBM in terms of ileal digestibility of amino acids and growth performance of weaning pigs seems to be the combination of preconditioning and a low water supply (3.0 l/min).

• 한국가금학회지
• /
• 제32권1호
• /
• pp.67-72
• /
• 2005

관행적인 산란계 사료와 관행적 산란계 사료에서 칼슘 공급제를 배제한 저 칼슘사료의 2가지 배합사료를 급여하면서 각각 오후 3$\~$4시에 일반적인 관행사료의 칼슘 공급제 배합량의 1$\~$3배의 칼슘 공급제(석회석)를 추가로 공급할 경우 산란능력과 사료섭취량, 사료효율 및 난각질에 미치는 영향을 조사하기 위하여 480수의 갈색산란계를 공시하여 10주간 사양시험을 실시한 결과 산란율은 처리간에 유의적인 차이가 없었으며, 평균난중은 처리간에 유의성은 인정되었으나(P<0.05)처리 간에 일정한 경향은 보이지 않았다. 칼슘공급제가 들어있지 않은 배합사료의 1일 1수당 섭취량은 2가지 배합사료에서 모두 칼슘공급제의 추가공급량이 증가할수록 유의적으로 감소하였으나(P<0.05), 칼슘공급제를 포함한 사료의 섭취량은 칼슘공급제의 추가공급량이 증가할수록 유의적으로 증가하였다(P<0.05). 칼슘공급제가 들어있지 않은 배합사료의 산란 kg당 요구율은 2가지 배합사료에서 모두 칼슘공급제의 추가공급량이 증가할수록 감소하는 경향을 보였으나, 칼슘공급제를 포함한 사료의 산란 kg당 요구율은 칼슘공급제의 추가공급량이 증가할수록 유의적으로 증가하였다(P<0.05).계란의 비중은2가지 배합사료에서 모두 칼슘공급제의 추가공급량이 증가할수록 유의적으로 증가하는 경향을 보였고(P<0.05), 난각 파괴강도와 난각 후도는 모두 처리간에 유의성은 인정되지 않았으나 칼슘 공급제 추가공급량이 증가할수록 증가하는 경향을 보였다. 결론적으로 고칼슘의 관행산란계사료를 계속 급여하는 대신 관행산란계 사료에서 칼슘 공급제를 배제한 저칼슘의 사료를 급여하면서 칼슘 요구량이 증가하는 오후 3$\~$4시 이후에 충분한 칼슘 공급제를 추가 공급하면 사료섭취 량과 사료요구율을 감소시키고 난각질을 개선할 수 있을 것으로 보인다.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제10권4호
• /
• pp.276-281
• /
• 2010

A 2.5 V feed-forward second-order deltasigma modulator for audio application is presented. A 9-level quantizer with a tree-structured dynamic element matching (DEM) was employed to improve the linearity by shaping the distortion resulted from the capacitor mismatch of the feedback digital-toanalog converter (DAC). A chopper stabilization technique (CHS) is used to reduce the flicker noise in the first integrator. The prototype delta-sigma analogto-digital converter (ADC) implemented in a 65 nm 1P8M CMOS process occupies 0.747 $mm^2$ and achieves 109.1 dB dynamic range (DR), 85.4 dB signal-to-noise ratio (SNR) in a 24 kHz audio signal bandwidth, while consuming 14.75 mW from a 2.5 V supply.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제55권6호
• /
• pp.287-290
• /
• 2006

A class-E CMOS RF(Radio frequency) power amplifier with a 1.8 Volt power supply is designed using $0.25{\mu}m$ standard CMOS technology. To drive the class-E power amplifier, a Class-F RF power amplifier is used and the reliability characteristics are studied with a class-E load network. After one year of operating the power amplifier with an RF choke, the PAE(Power Added Efficiency) decreases from 60% to 47% and the output power decreases 29%. However, when a finite DC-feed inductor is used with the load, the PAE decreases from 60% to 53% and the output power decreases only 19%. The simulated results demonstrate that the class-E power amplifier with a finite DC-feed inductor exhibits superior reliability characteristics.

• ETRI Journal
• /
• 제26권5호
• /
• pp.486-492
• /
• 2004

The emergence of wide channel bandwidth wireless standards requires the use of a highly linear, wideband integrated CMOS baseband chain with moderate power consumption. In this paper, we present the design of highly linear, wideband active RC filters and a digitally programmable variable gain amplifier. To achieve a high unity gain bandwidth product with moderate power consumption, the feed-forward compensation technique is applied for the design of wideband active RC filters. Measured results from a $0.5{\mu}m$ CMOS prototype baseband chain show a cutoff frequency of 10 MHz, a variable gain range of 33 dB, an in-band IIP3 of 13 dBV, and an input referred noise of 114 ${\mu}Vrms$ while dissipating 20 mW from a 3 V supply.

• 전기학회논문지
• /
• 제64권12호
• /
• pp.1737-1741
• /
• 2015

A multi-channel CMOS transimpedance amplifier(TIA) array is realized in a $0.18-{\mu}m$ CMOS technology for the applications of panoramic scan LADAR systems. Each channel consists of a PIN photodiode and a feed-forward TIA that exploits an inverter input stage followed by a feed-forward common-source amplifier so as to achieve lower noise and higher gain than a conventional voltage-mode inverter TIA. Measured results demonstrate that each channel achieves $76-dB{\Omega}$ transimpedance gain, 720-MHz bandwidth, and -20.5-dBm sensitivity for $10^{-9}$ BER. Also, a single channel dissipates the power dissipation of 30 mW from a single 1.8-V supply, and shows less than -33-dB crosstalk between adjacent channels.

• 한국태양에너지학회 논문집
• /
• 제30권3호
• /
• pp.33-38
• /
• 2010

The evaporative desalination system using solar thermal energy would be the efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, because of using the latent heat of the refrigerant 123 instead of the sensible heat of present hot water. The system was comprised of the single-stage fresh water production unit on the capacity of 1ton/day with shell and tube type evaporator, heaters instead of solar collector to supply the proper heat to refrigerant, and refrigerant and brine circulation systems. Various operating flowrate and temperature ranges were varied in the experiments to get the optimum design data. The results showed that the optimum flow rate of brine feed rate to evaporator was 1.2Liter/min, and the yield of fresh water was increased as higher temperature of feed brine. It was confirmed that the circulation flowrate of heating source of refrigerant was decrease of one fifth of the present warm water system, and very efficient system for solar desalination.

• 한국정밀공학회지
• /
• 제31권10호
• /
• pp.905-911
• /
• 2014

A Loss-in-Weight (LIW) feeder, a type of automated measuring device, is a continuous feeder used in many mass production industries. Due to its versatility, there have been constant demands of LIW feeders in food production supply lines as well as chemical and pharmaceutical industries. In this paper, the process of designing a LIW feeder system with better performance will be examined and compared with commercial products. This system is characterized by low pass Butterworth filter and feed forward PI control. The filter is for noise disposal caused by dynamic condition of a LIW feeder. The feed forward PI control, based on linearity feature of feeders, is adequate for stable driving of the system. At the end, a possible evaluation method of LIW system will be proposed to verify the specific achievement of this paper.

• 전자공학회논문지SC
• /
• 제46권1호
• /
• pp.63-67
• /
• 2009

전하 펌프의 전류 부정합은 위상 고정 루프의 주파수 성분에 기준 스퍼를 발생시킴으로써 특성을 떨어뜨리게 한다. 전류 부정합은 캐스코드 출력단과 같이 전하 펌프의 출력 저항을 높여줌으로써 감소시킬 수 있다. 그러나 공급 전압이 낮아짐에 따라 트랜지스터를 쌓기 힘들어지게 된다. 본 논문에서는 전류 부정합을 줄이기 위한 새로운 방법을 제안하였다. 제안한 방법은 출력 단의 채널 길이 변조에 의한 전류 변화를 피드포워드 방식으로 보상해 주는 것이다. 새로운 방법에 대한 시뮬레이션은 CMOS $0.18{\mu}m$ 공정을 이용하였다.

• 한국기계가공학회지
• /
• 제13권3호
• /
• pp.42-48
• /
• 2014

The auxiliary-feed-water pump (AFWP) used to supply water during a station black out situation at nuclear power plants should meet the seismic qualification regulations stipulated in IEEE Std 323 and 344, so as to withstand earthquakes or dangerous situations. Here, we establish a model for the estimation of the structural integrity of this type of pump. If the natural frequency that results from a modal analysis is less than 33 Hz, we adopt a dynamic analysis, instead of a static analysis. A dynamic analysis was carried out taking into consideration seismic conditions such as the floor response spectra (FRS), an operation-base earthquake (OBE), and a safe-shutdown earthquake (SSE). Finally, an analytical estimation of the structural integrity of an AFWP is made through a comparison of calculated values and allowable values. If the result is less than the allowable stress, the pump is deemed to have good structural integrity. In addition, future studies will involve a stability check for rotor accidents that may occur during the operation of the pump.