• Title/Summary/Keyword: variable gain

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Design Study of a Simulation Duct for Gas Turbine Engine Operations (가스터빈엔진을 모의하기 위한 시뮬레이션덕트 설계 연구)

  • Im, Ju Hyun;Kim, Sun Je;Kim, Myung Ho;Kim, You Il;Kim, Yeong Ryeon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.124-131
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    • 2019
  • A design study of gas turbine engine simulation duct was conducted to investigate the operating characteristics and control gain tunning of the Altitude Engine Test Facility(AETF). The simulation duct design involved testing variable spike nozzle and ISO standard choking nozzle to verify the measurements such as mass flow rate and thrust. The simulation duct air flow area was designed to satisfy Ma 0.4 at the aerodynamic interface plane(AIP) at engine design condition. The test conditions for verifying the AETF controls and measurement devices were deduced from 1D analysis and CFD calculation results. The spike-cone driving part was designed to withstand the applied aero-load, and satisfy the axial traversing speed of 10 mm/s at whole operation envelops.

Chinese SOEs and the Completion of Cross-border M&As: The Moderating Role of M&A Experience

  • Luo Jing;Young-Gon Cho;Jaekyung Ko
    • Journal of Korea Trade
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    • v.26 no.6
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    • pp.118-135
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    • 2022
  • Purpose - The purpose of this study is to investigate the relationships among Chinese state-owned enterprises (SOEs), previous M&A experience, and the probability of deal completion in cross-border mergers and acquisitions (CBMAs). Since Chinese SOEs tend to be recognized by host countries as agents of their home country government, this study argues that SOEs will face difficulties in completing CBMA deals. However, the study expects that these difficulties may vary depending on whether the firm has previous M&A experience because firms can gain the knowledge and capabilities necessary to implement subsequent M&As successfully from past M&A experience. Design/methodology - To investigate our argument, we conduct a logistic regression using a sample of 363 CBMA deals from 304 Chinese publicly listed firms during 2007 to 2017. We used SOEs as an independent variable, experience of domestic and foreign M&As as moderating variables, respectively, and CBMA deal completion as the dependent variable. Findings - The study shows a negative and significant relationship between Chinese SOEs and the completion likelihood of CBMA deals. We find that this negative relationship is strengthened when the firm had prior domestic M&A experience, whereas foreign M&A experience alleviated the negative relationship. Originality/value - The issue of government ownership has remained unclear since government intervention has both advantages and disadvantages in pursuing CBMAs. Our findings support literature that argues Chinese SOEs face legitimacy concerns in the host countries, thereby lowering their CBMA deal completion likelihood. Furthermore, the study enriches the literature by identifying different moderating effects of domestic and foreign M&A experience on the negative relationship between SOEs and CBMA deal completion.

Effects of Extrusion Condition of Barley on the Growth and Nutrient Utilization in Growing Pigs

  • Piao, X.S.;Chae, B.J.;Kim, J.H.;Jin, J.;Cho, W.T.;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.5
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    • pp.783-787
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    • 1999
  • To study the effects of different extrusion conditions of barley on growth performance, nutrient digestibility and nutrient excretion in feces, a total of 150 growing pigs ($Landrace{\times}Duroc{\times}Large$ White; average 24.4 kg body weight) were allotted to five treatments, in a completely randomized block design. The experimental diets were based on corn-soybean and 30% of barley was included in each diet; barley was the only extruded ingredient. The treatments were 1) no extrusion (Control); 2) extrusion at $100^{\circ}C$ without preconditioning (ENLT); 3) extrusion at $150^{\circ}C$ without preconditioning (ENHT); 4) extrusion at $100^{\circ}C$ with preconditioning (ECLT); 5) extrusion at $150^{\circ}C$ with preconditioning (ECHT). Temperature in the barrel was controlled within ${\pm}5^{\circ}C$ by feed rate with the addition of water at the rate of $3{\ell}\;per\;min$. in the extruder for each treatment. For the 6 week experimental period, extrusion of barley improved the average daily gain (ADG) and digestibilities of dry matter, crude protein and gross energy in growing pigs. As compared to control, significant improvements in ADG (p<0.05) were shown in the groups of feeding extruded barley at high temperature (ENHT and ECHT). There were also significant differences in the digestibilities of DM, CP and P between extrusion temperatures. Barley extruded at high temperature gave better digestibilities of DM, CP and GE than barley extruded at low temperature. Extruded barley diet groups showed significantly (p<0.05) lower excretions of DM, nitrogen (N) and P per kg gain as compared to the ground barley group. DM, N and P excretion per kg gain were also significantly lower in pigs fed barley extruded at $150^{\circ}C$ than at $100^{\circ}C$. In conclusion, extrusion considerably improved the nutritive value of barley and it appeared that temperature is the most important variable.

Growth Performance of Early Finishing Gilts as Affected by Different Net Energy Concentrations in Diets

  • Lee, Gang Il;Kim, Kwang-Sik;Kim, Jong Hyuk;Kil, Dong Yong
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.11
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    • pp.1614-1623
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    • 2015
  • The objectives of the current experiment were to study the response of the growth performance of early finishing gilts to different net energy (NE) concentrations in diets, and to compare the NE values of diets between calculated NE values and measured NE values using French and Dutch CVB (Centraal Veevoederbureau; Central Bureau for Livestock Feeding) NE systems. In a metabolism trail, the NE concentrations in five diets used for the growth trial were determined based on digestible nutrient concentrations, digestible energy, and metabolizable energy using a replicated $5{\times}5$ Latin square design with 10 barrows (initial body weight [BW], $39.2{\pm}2.2kg$). In a growth trial, a total of 60 early finishing gilts (Landrace${\times}$Yorkshire; initial BW, $47.7{\pm}3.5kg$) were allotted to five dietary treatments of 8.0, 9.0, 10.0, 11.0, and 12.0 MJ NE/kg (calculated, as-is basis) with 12 replicate pens and one pig per pen in a 42-d feeding experiment. The NE and amino acid (AA) concentrations in all diets were calculated based on the values from NRC (2012). Ratios between standardized ileal digestible AA and NE concentrations in all diets were closely maintained. Pigs were allowed ad libitum access to feed and water. Results indicated that calculated NE concentrations in diets (i.e., five dietary treatments) were close to measured NE concentrations using French NE system in diets. The final BW was increased (linear and quadratic, p<0.05) with increasing NE concentrations in diets. Furthermore, average daily gain (ADG) was increased (linear and quadratic, p<0.01) with increasing NE concentrations in diets. There was a quadratic relationship (p<0.01) between average daily feed intake and NE concentrations in diets. Feed efficiency (G:F) was also increased (linear, p<0.01) as NE concentrations in diets were increased. The NE intake per BW gain (kcal NE/kg of BWG) was increased (linear, p<0.01) with increasing NE concentrations in diets that were predicted from both French and Dutch CVB NE systems. Linear regression indicated that predictability of daily NE intake from the BW of pigs was very low for both French ($R^2$, 0.366) and Dutch CVB ($R^2$, 0.374) NE systems. In conclusion, increasing NE concentrations in diets increase BW, ADG, G:F, and NE intake per BW gain of early finishing gilts. The BW of early finishing gilts is not a good sole variable for the prediction of daily NE intake.

RF performance Analysis for Galileo Receiver Design (갈릴레오 수신기 설계를 위한 RF 성능 분석에 관한 연구)

  • Chang, Sang-Hyun;Lee, Il-Kyoo;Park, Dong-Pil;Lee, Sang-Wook
    • Journal of Satellite, Information and Communications
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    • v.5 no.1
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    • pp.58-62
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    • 2010
  • This paper presents the effects of RF performance parameters on the Galileo receiver design via simulation after reviewing the requirements of the Galileo receiver structure. At first, we considered the general requirements, structure and characteristics of the Galileo system. Then we designed the Galileo receiver focused on performance requirement of 16 dB C/N which is equal to 15 % Error Vector Magnitude(EVM) by using Advanced Design System(ADS) simulation program. In order to verify the function of Automatic Gain Control(AGC)), we measured the IF output power level by changing the input power level at the front - end of the receiver. We analyzed the performance degradation due to phase noise variations of Local Oscillator(LO) in the Galileo receiver through EVM when the minimum sensitivity level of -127 dBm is applied at the receiver. We also analyzed the performance degradation according to variable Analog-to-Digital Converter(ADC) bits within the Dynamic range, -92 ~ -139 dBm, which has been defined by gain range (-2.5 ~ +42.5 dB) in the AGC operation. The results clearly show that the performance of the Galileo receiver can be improved by increasing ADC bits and reducing Phase Noise of LO.

Backgrounding steers on temperate grasses mixed with vetch and/or using energy supplementation

  • de Oliveira Lazzarotto, Eduardo Felipe Colerauz;de Menezes, Luis Fernando Glasenapp;Paris, Wagner;Molinete, Marcos Luis;Schmitz, Gean Rodrigo;Baraviera, Jose Henrique Ignacio;Farenzena, Roberta;de Paula, Adalberto Luiz
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.6
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    • pp.800-807
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    • 2019
  • Objective: The aim was to evaluate backgrounding beef steers on oat + ryegrass pastures mixed with vetch and/or using energy supplementation. Methods: A randomized block design with three treatments and three replications was used. The treatments were: grass + supplement (oat + ryegrass + supplementation), legume + supplement (oat + ryegrass + vetch + supplementation) and grass + legume (oat + ryegrass + vetch). A continuous grazing system with a variable stocking rate was used. Twenty-seven intact crossbred steers (1/4 Marchigiana, 1/4 Aberdeen Angus and 2/4 Nellore) aged 7 months old and average weight of 190 kg were used. Steers were supplemented at 1% of the body weight of ground corn. The experiment lasted 84 days, between May and August 2014. Behavioral assessments were performed two times per experimental period, for 24 hours. Results: The forage mass was different between treatments, being greater for steers fed without legume. The accumulation rate, forage allowance, and stocking rate did not differ between treatments due to the adequate adjustment of forage allowance. The final weight of animals, as well as the dry matter intake (kg/d), did not differ between treatments. However, forage intake was higher for non-supplemented animals in relation to supplemented steers. Supplement intake did not alter the total digestible nutrient intake due to pasture quality. Animals fed grass + supplement had higher live weight gain per area than those fed grass + legume. Animals without supplementation spent more time in grazing. Conclusion: Feeding behavior was not altered by mixing with vetch or supplementation. Non-supplemented animals started the grazing peak earlier and spent more time in grazing than those supplemented; however, the average daily gain was similar between treatments. The live weight gain per hectare was 47% higher in pastures in which the animals received supplementation compared with those mixed with vetch, a consequence of the substitutive effect.

An Efficient Motion Vector Coding Algorithm for the Video Sequence with Slow Motion (저속 동영상에 효과적인 움직임 벡터 부호화 알고리듬)

  • Moon Yong ho;Kim Young kuk;Chang Jung hwan;Kim Jae ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.4C
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    • pp.269-275
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    • 2005
  • In this paper, we propose a new efficient motion vector coding algorithm for the video sequence with slow motion. In the proposed algorithm, the amount of motion for a given video sequence is determined by a Skip_rate parameter. The motion difference for slow motion is encoded with a combined codeword which is generated from the conventional codewords. The simulation results show that the proposed algorithm achieves approximately $15\%$ bits gain compared to the conventional methods. Moreover, additional memory and calculations for statistical observation are not required in the proposed algorithm.

Design and Implementation of Fuzzy PID Controller (Fuzzy PID 제어기 설계 및 구현)

  • Shin Wee-Jae
    • Journal of the Institute of Convergence Signal Processing
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    • v.6 no.2
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    • pp.89-94
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    • 2005
  • In this paper, we propose a fuzzy PID controller of new method. There are two problems in absolute digital PID controller. First, much calculation time need for obtain the sum of data at each period. Second, this is problem need much memory because to storage every data at the before period. We use the speed type PID digital controller to improvement such problems. In the propose controller doesn't use without adjustment the crisp output error and we doesn't use nile tables in the fuzzy inference process at the forward stage fuzzifier. We inference output member ship function by using the relation and range of two variable of PID gain parameters. We can obtained desired results through the simulation and a experiment of the hydraulic servo motor control system.

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Effect of variable degrees of jejunal resection upon different clinico-biochemical parameters in dogs

  • Dilawer, Muhammad Sohail;Khan, Muhammad Arif;Abidin, Zain ul;Azeem, Shahan;Majeed, Khalid Abdul;Shahbaz, Adeel;Khan, Aamir Riaz
    • Korean Journal of Veterinary Research
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    • v.51 no.4
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    • pp.309-313
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    • 2011
  • Dogs are considered to be the best companions of human beings due to their loyalty, obedience and pleasant disposition. Jejunum is the largest part of small intestine mainly involved in absorption of nutrients. Jejunal resection up to 80% allows normal weight gain while resection up to 90% increased morbidity and mortality. In the present study, 20 dogs were divided into 4 groups based on the degree of jejunal resection i.e. A (70% resection), B (80% resection) and C (100% resection) while group D served as control. Dogs in the 70% and 80% jejunal resection group showed normal growth and function while 100% jejunal resection resulted in weight loss and alteration of hematological and biochemical parameters.

Variables Affecting on Learners' Satisfaction and Effects of EMI (전공 영어강의 만족도 및 학습효과 인식에 영향을 미치는 변인에 관한 연구)

  • Jin, Sung-Hee;Kim, Hakil
    • Journal of Engineering Education Research
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    • v.16 no.3
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    • pp.10-19
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    • 2013
  • Recently, Korean universities have increased the number of English Medium Instruction (EMI) lectures in order to allow students to gain both specialized knowledge and enhanced English ability. Previous researches on effective EMI lectures have focused on exploring the effects of learners' cognitive and affective characteristics on learning outcomes. Whereas the input variables of learning have been investigated as predicting variables of effects in EMI lectures, there has been a few research for investigating process variables to yield learning outcomes. The purpose of this study is to analyze the structural relationships among variables affecting on learner satisfaction and effects. The participants are 209 engineering students from various majors. Independent variables are defined as English motivation, English competency, and English confidence, a mediated variable is Cognitive engagement, and dependent variables are Learning satisfaction and Educational effect perception. The results show that the relationships are statistically significant: learners' English competency & English confidence ${\rightarrow}$ Cognitive engagement ${\rightarrow}$ Learning satisfaction ${\rightarrow}$ Educational effect perception. Especially, the structural model confirms that the effect of learners' English confidence on Learning satisfaction and Educational effect perception is mediated by the level of learners' Cognitive engagement. Further, the implication for effective EMI lectures is discussed based on the observed research results.