• Title, Summary, Keyword: Feeding Strategy

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A Study on Estimation Technique for Fault Location using Quadratic Interpolation in a Parallel Feeding AC Traction System (2차 보간법을 이용한 전기철도 급전계통의 고장점 산출 기법에 관한 연구)

  • Min, Myung-Hwan;An, Tae-Pung;Kwon, Sung-il;Jung, Hosung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.3
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    • pp.599-604
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    • 2017
  • Nowadays reactance method is being used as a technique for fault location in parallel feeding AC traction power system. However, implementation of this method requires a large number of field tests(ground fault) which is a huge burden on the operators. This paper presents a new estimation technique using quadratic interpolation to reduce number of times for field test and improves the accuracy of fault location. To verify a new technique, we solve AT feeding circuit and model it using PSCAD/EMTDC. Finally this paper conducts a comparative analysis of usefulness between a new technique and real field data.

Feeding Habits of the Redbanded Searobin Lepidotrigla guentheri in the Coastal Waters off Gori, Korea (고리 주변해역에서 출현하는 꼬마달재 (Lepidotrigla guentheri)의 식성)

  • Baeck, Gun-Wook;Huh, Sung-Hoi;Choi, Hee-Chan;Park, Joo-Myun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.4
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    • pp.372-377
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    • 2011
  • The feeding habits of the redbanded searobin Lepidotrigla guentheri were studied using 186 specimens collected from September to November, 2006, in the coastal waters off Gori, Korea. The sizes of L. guentheri ranged from 7.1 to 16.7 cm total length(TL). L. guentheri is a bottom-feeding carnivore that consumes mainly shrimp, especially Leptochela sydniensis, amphipods, and crabs. Its diet also includes small quantities of stomatopods, mysids, cumaceans, euphausiids, polychaetes, and copepods. Our feeding-strategy graphical method reveled that L. guentheri is a specialized feeder, with a narrow niche width. L. guentheri mainly consumed shrimp of all size classes and did not show significant ontogenetic changes in feeding habits. Smaller individuals(7-11 cm TL) secondly consumed amphipods, with the portion of amphipods in the total diet decreasing as body size increased. Prey size increased significantly as the fish grew in size.

Effects of Initial Inoculum Size, Liquid Volume and Medium Feeding Strategy on Panax ginseng Hairy Roots Growth

  • Jeong, Gwi-Taek;Park, Don-Hui;Hwang, Baek
    • 한국생물공학회:학술대회논문집
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    • pp.250-253
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    • 2000
  • We researched effects of growth on initial inoculum size, liquid volume, and medium feeding rate etc. Cell suspension inoculated at low cell concentrations showed a typical growth reduction, whereas root cultures showed an improvement in growth. In this paper, Hairy roots showed high growth rate at 0.4 % inoculum size and 100 mL liquid volume in 250 mL flask cultures.

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A Comprehensive Harmonic Rejection for DFIG Feeding Non-Linear Loads in Stand-Alone Applications

  • Nguyen, Ngoc-Tung;Lee, Hong-Hee
    • Proceedings of the KIPE Conference
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    • pp.258-259
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    • 2012
  • This paper proposes a new control strategy to eliminate the harmonic components of stator current for stand-alone DFIG system feeding non-linear loads. In this method, the LSC operates as an active filter which is controlled by employing a proportional-integral and a resonant controller. And also, the stator current is used as the feedback signal for the compensator instead of the load current, so that the additional current sensor at the load side can be removed. The experiment is verified to validate the effectiveness of the proposed compensating method.

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Feeding Difficulty and its influencing factors of Elders with Dementia in Long-term Care Facilities (요양시설 치매노인의 식사행동장애와 관련요인)

  • Hong, Hyun-Hwa;Gu, Mee-Ock
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1240-1252
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    • 2015
  • The purpose of this study was to investigate feeding difficulty and its influencing factors of elders with dementia in long-term care facilities. Participants were 158 elders with dementia residing in three nursing facilities. Data were collected from Aug. 18 to Sep. 12 in 2014. The feeding difficulty in dementia scale, Korean version-Activities of Daily Living and Mini-Mental State Exam-Korean version were used as instruments. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation and stepwise multiple regression by SPSS 17.0. Mean feeding difficulty score was $0.62{\pm}0.43$(range of 0-2). The highest feeding difficulty item was "patient require close supervision while feeding". The variables influencing the feeding difficulty was ADL(${\beta}=.312$), cognitive function(${\beta}=-.172$) which explained about 20.0% of total variance. The results suggest the need of developing feeding difficulty coping strategy according to dietary behavior phase, In addition, the development and testing the educational program for caregivers to help feeding difficulty of the elders with dementia in long-term facility are recommended.

Effective Behavioral Strategies for Pediatric Feeding Problems (섭식 문제 행동에 대한 효과적인 행동전략)

  • Chung, Kyong-Mee
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.11 no.sup1
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    • pp.143-148
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    • 2008
  • It is relatively common to have various feeding problem during infancy and childhood, even for typically developing children. Treatment outcome studies for pediatric feeding disorder consistently reported that applied behavior analaysis (ABA), a type of behavior intervention, is very effective and efficacious. Interdisciplinary team approach is necessary for severe feeding problems, but similar methods could be used through parent training for moderate and mild feeding problems. This article introduced assessment procedure to identify feeding problems as well as specific methods to deal with diver feeding issues. Each strategy can be used effectively only when it is combined with several other strategies including environmental rearrangement and should be developed individually upon each child's feeding issues. In addition, systematic and continuous parent trainings are mandatory. At the end, several treatments related issues were addressed.

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Improved Production of Medium-Chain-Length Polyhydroxyalkanoates in Glucose-Based Fed-Batch Cultivations of Metabolically Engineered Pseudomonas putida Strains

  • Poblete-Castro, Ignacio;Rodriguez, Andre Luis;Lam, Carolyn Ming Chi;Kessler, Wolfgang
    • Journal of Microbiology and Biotechnology
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    • v.24 no.1
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    • pp.59-69
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    • 2014
  • One of the major challenges in metabolic engineering for enhanced synthesis of value-added chemicals is to design and develop new strains that can be translated into well-controlled fermentation processes using bioreactors. The aim of this study was to assess the influence of various fed-batch strategies in the performance of metabolically engineered Pseudomonas putida strains, ${\Delta}gcd$ and ${\Delta}gcd-pgl$, for improving production of medium-chain-length polyhydroxyalkanoates (mcl-PHAs) using glucose as the only carbon source. First we developed a fed-batch process that comprised an initial phase of biomass accumulation based on an exponential feeding carbon-limited strategy. For the mcl-PHA accumulation stage, three induction techniques were tested under nitrogen limitation. The substrate-pulse feeding was more efficient than the constant-feeding approach to promote the accumulation of the desirable product. Nonetheless, the most efficient approach for maximum PHA synthesis was the application of a dissolved-oxygen-stat feeding strategy (DO-stat), where P. putida ${\Delta}gcd$ mutant strain showed a final PHA content and specific PHA productivity of 67% and $0.83g{\cdot}l^{-1}{\cdot}h^{-1}$, respectively. To our knowledge, this mcl-PHA titer is the highest value that has been ever reported using glucose as the sole carbon and energy source. Our results also highlighted the effect of different fed-batch strategies upon the extent of realization of the intended metabolic modification of the mutant strains.

Fed-Batch Sorbose Fermentation Using Pulse and Multiple Feeding Strategies for Productivity Improvement

  • Giridhar, R.;Srivastava, A.K.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.340-344
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    • 2000
  • Microbial oxidation of D-sorbitol to L-sorbose by Acetobacter suboxydans is of commercial importance since it is the only biochemical process in vitamin C synthesis. The main bottleneck in the batch oxidation of sorbitol to sorbose is that the process is severely inhibited by sorbitol. Suitable fed-batch fermentation designs can eliminate the inherent substrate inhibition and improve sorbose productivity. Fed-batch sorbose fermentations were conducted by using two nutrient feeding strategies. For fed-batch fermentation with pulse feeding, highly concentrated sorbitor (600g/L) along with other nutrients were fed intermittently in four pulses of 0.5 liter in response to the increased DO signal. The fed-batch fermentation was over in 24h with a sorbose productivity of 13.40g/L/h and a final sorbose concentration of 320.48g/L. On the other hand, in fed-batch fermentation with multiple feeds, two pulse feeds of 0.5 liter nutrient medium containing 600g/L sorbitol was followed by the addition of 1.5 liter nutrient medium containing 600g/L sorbitol at a constant feed rate of 0.36L/h till the full working capacity of the reactor. The fermentation was completed in 24h with an enhanced sorbose productivity of 15.09g/L/h and a sorbose concentration of 332.60g/L. The sorbose concentration and productivity obtained by multiple feeding of nutrients was found to be higher than that obtained by pulse feeding and was therefore a better strategy for fed-batch sorbose fermentation.

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A Study on a Catenary Impedance Estimation Technique using Boosting Current Compensation Based on Current Division Characteristics of an AT Feeding System

  • Jung, Hosung;Kim, Hyungchul;Chang, Sang-Hoon;Kim, Joorak;Min, Myung-Hwan;An, Tae-Pung;Kwon, Sung-Il
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1370-1376
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    • 2015
  • Generally, an autotransformer(AT) feeding system consists of double tracks, up and down, with the trolley wire and feeder wire of the up and down tracks connected in the sectioning post(SP). Consequently, load current or fault current flows on two tracks based on catenary impedance characteristics, making it difficult to estimate catenary impedance accurately. This paper presents a technique for the estimation of catenary impedance using boosting current compensation based on the current division characteristics of an AT feeding system to improve the operation performance of impedance relay. To verify the technique, we model an AT feeding system through a power analysis program (PSCAD/EMTDC) and simulate various operation and fault conditions. Through the simulation, we confirmed that the proposed technique has estimated catenary impedance with a similar degree of accuracy to the actual catenary impedance