• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.321-325
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• 2004

Linear motor feed drive systems have been broadly used in machine tools or precision automatic feed systems. Recently, modem machine tools require high speed and high precision feed drive system to achieve high productivity. Unfortunately, a feed drive system, even though it was optimum designed, may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slides system. This paper presents a feed rate optimization of a machine tool feed slide system, which is driven by a linear motor, for its minimum vibrations. Firstly, a 4-degree-of-freedom lumped parameter model is proposed for the vibration analysis of a linear motor driven machine tool feed drive system. Next, a feed rate optimization of the feed slide is carried out for minimum vibrations. The feed rate curve optimization strategy is to find out the most appropriate acceleration profile with jerk continuity. Of course, the optimized feed rate should approximate to the desired one as possible. A genetic algorithm with variable penalty function was used in this feed rate optimization.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.747-755
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• 2009

The feed resource for animals is a major cost determinant for profitability in livestock production enterprises, and thus any effort at improving the efficiency of feed use will help to reduce feed cost. Feed conversion ratio, expressed as feed inputs per unit output, is a traditional measure of efficiency that has significant phenotypic and genetic correlations with feed intake and growth traits. The use of ratio traits for genetic selection may cause problems associated with prediction of change in the component traits in future generations. Residual feed intake, a linear index, is a trait derived from the difference between actual feed intake and that predicted on the basis of the requirements for maintenance of body weight and production. Considerable genetic variation exists in residual feed intake for cattle and pigs, which should respond to selection. Phenotypic independence of phenotypic residual feed intake with body weight and weight gain can be obligatory. Genetic residual feed intake is genetically independent of its component traits (body weight and weight gain). Genetic correlations of residual feed intake with daily feed intake and feed conversion efficiency have been strong and positive in both cattle and pigs. Residual feed intake is favorably genetically correlated with eye muscle area and carcass weight in cattle and with eye muscle area and backfat in pigs. Selection to reduce residual feed intake (excessive intake of feed) will improve the efficiency of feed and most of the economically important carcass traits in cattle and pigs. Therefore, residual feed intake can be used to replace traditional feed conversion ratio as a selection criterion of feed efficiency in breeding programs. However, further studies are required on the variation of residual feed intake during different developmental stage of production.

• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.990-994
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• 2004

Effects of addition of a mycotoxin detoxifier in poultry feed were studied in broilers. Aflatoxins were present in the poultry feed as 28 ppb (normal feed), 78 ppb (contaminated feed) and 170 ppb (highly contaminated feed). The mycotoxin detoxifier was used in 3 concentrations i.e. 1, 3 and 5 kg/ton of feed. Aflatoxins reduced the body weight in broiler chicken and treatment of contaminated feed with low level of detoxifier improved the body weight equivalent to that of normal feed. Higher level of detoxifier proved better than lower level addition in alleviating the effects of highly contaminated feed. Addition of detoxifier also resulted in improvement of FCR to the level of normal feed. Antibody levels against Newcastle disease virus on day 28 of age were significantly lower in chicken fed on contaminated feed. Addition of detoxifier in feed improved the antibody levels in chicken. Mortality was highest in groups given contaminated feed throughout the study period of 7 weeks. Significant mortality was also observed in groups given highly contaminated feed for 2 weeks. Mortality in chicken given detoxifier added contaminated feed was lowest and similar to the group given normal feed. The study shows that mycotoxin detoxifier containing oxyquinol, dichloro-thymol and micronized yeast can effectively neutralize the ill-effects of aflatoxins in poultry feed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.962-966
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• 2004

Ball screw feed drive systems have been broadly used in machine tools or precision automatic feed systems. Recently, modern machine tools require high speed and high precision and drive system to achieve high productivity. Unfortunately, a feed drive system, even though it was optimum designed, may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slide system. This paper presents a feed rate optimization of a machine tool feed slide system, which is driven by a ball screw, for its minimum vibrations. Firstly, a 6-degree-of-freedom lumped parameter model was proposed for the vibration analysis of a ball screw driven machine tool feed drive system. Next, a feed rate optimization of the feed slide was carried out for minimum vibrations. The feed rate curve optimization strategy is to find out the most appropriate acceleration profile having finite jerk. Of course, the optimized feed rate should approximate to the desired one as possible. A genetic algorithm with variable penalty function was used in this feed rate optimization.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1028-1032
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• 2004

In order to prevent machine tool feed slide system from transient vibrations during operations, machine tool designers usually adopt some typical design solutions; box-in-box typed feed slides, optimizing moving body for minimum weight and dynamic compliance, and so on. Despite all efforts for optimizing design, a feed drive system may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slides system. This paper presents a feed rate optimization of a ball screw driven machine tool feed slide system for its minimum vibration. Firstly, a ball screw feed drive system was mathematically modeled as a 6-degree-of-freedom lumped parameter system. Next, a feed rate optimization of the system was carried out for minimum vibrations. The main idea of the feed rate optimization is to find out the most appropriate smooth acceleration profile with jerk continuity. A genetic algorithm was used in this feed rate optimization

• 수산해양교육연구
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• 제23권3호
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• pp.526-532
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• 2011

The formula feed has been valuated its superiority in the aquaculture industry. However, the fish farmer is preferred the raw feed than the formula feed yet. The objectives of this study are to clarified the reason of lower usage of formula feed in aquaculture. We referred to the literature and the enquete, and inspected on-site for this study. Two types of managements, formula feed-usage or not, were compared and analyzed. The results show that the perception of formula feed are changing even though the quality of formula feed is not clear and the growth efficiency is lower than raw feed, because the domestic supply of raw feed was not smooth and the cost was raised.

• 한국임상수의학회지
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• 제19권1호
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• pp.7-13
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• 2002

This study was examined the microbiological adequacy of fish feed treated with high-dose irradiation (5 kGy). 125 flounder (Paralichthys olivaceus) were grouped into 5 and then the fishes were fed the following feeds for 28 days: (1)standard feed; (2)standard feed, inoculated with Edwardsiella tarda ($1{\times}10^8-1{\times}10^9CFU/g$ of feed); (3)standard feed, inoculated with Vibrio anguilarum ($1{\times}10^8-1{\times}10^9CFIT/g$ of feed); (4)standard feed, inoculated with Streptococcus faecalis ($1{\times}10^8-1{\times}10^9CFU/g$ of feed); (5)standard feed, inoculated with Edwardsiella tarda, Vibrio anguillarum and Streptococcus faecalis, and then irradiated the mixed feed to 5 kGy. The flounders feed the mixed diet with Edwardsiella tarda, Wbrio anguillarum or Streptococcus faecalis inoculated feed were showed severe cumulative mortalities of 60, 48 and 52% respectively. The gross and histological changes were observed on the fishes. However, fishs fed with the feed of bacteria inoculation before irradiation demonstrated excellent protection against the bacteria-related disease. The results from experiments with bacteria inoculated feed indicated that the irradiation methods employed were capable of preventing contamination of the fishs with pathogenic bacteria.

• Animal Bioscience
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• 제35권2_spc호
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• pp.332-346
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• 2022

Shortage of protein feed resources is the major challenge to the world farm animal industry. Insects are known as an alternative protein source for poultry. A wide range of insects are available for use in poultry diets. Insect larvae thrive in manure, and organic waste, and produce antimicrobial peptides to protect themselves from microbial infections, and additionally these peptides might also be functional in poultry feed. The feed containing antimicrobial peptides can improve the growth performance, nutrient digestibility, intestinal health, and immune function in poultry. Insect meal contains a higher amount of essential amino acids compared to conventional feedstuffs. Black soldier fly, mealworm, housefly, cricket/Grasshopper/Locust (Orthoptera), silkworm, and earthworm are the commonly used insect meals in broiler and laying hen diets. This paper summarizes the nutrient profiles of the insect meals and reviews their efficacy when included in poultry diets. Due to the differences in insect meal products, and breeds of poultry, inconsistent results were noticed among studies. The main challenge for proper utilization, and the promising prospect of insect meal in poultry diet are also addressed in the paper. To fully exploit insect meal as an alternative protein resource, and exert their functional effects, modes of action need to be understood. With the emergence of more accurate and reliable studies, insect meals will undoubtedly play more important role in poultry feed industry.

• 에너지공학
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• 제27권1호
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• pp.12-20
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• 2018

FEED(Frond End Engineering Design) 프레임워크는 FEED 단계에서 수행할 활동과 산출물을 정의한 것이다. 그 동안 FEED에 대한 연구가 많이 수행되었으나 대부분 경험에 의존하여 연구마다 서로 조금씩 다른 내용을 주장하고 있는 상황이다. FEED가 무엇이고 어떻게 하는 것이 좋은지에 대한 절대적인 정의보다는 FEED를 해당 사업에 적합하게 정의하고 이에 필요한 활동과 산출물을 정의하는 것이 중요하다. 또한 FEED 프로세스도 경험보다는 국제시스템엔지니어링 프로세스 표준과 같은 확고한 기반위에서 개발하는 것이 필요하다. 본 연구에서는 FEED를 광물탄산화시스템 개발 사업에 적합하게 정의하고, 이를 만족시키기 위한 프로세스와 산출물을 개발하기 위한 방안을 시스템 엔지니어링 표준 프로세스에 기반하여 제시하였다.

• 한국건설관리학회논문집
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• 제16권5호
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• pp.65-76
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• 2015

해외 플랜트 사업에서의 고부가가치를 창출하기 위해서는 기획 타당성조사, 프로젝트종합관리, FEED 및 기본설계 등 분야의 기술경쟁력 강화가 시급하다. 특히, FEED 업무는 프로젝트 전체에 대한 영향력이 절대적이고, 또한 기자재 및 패키지 산업의 경쟁력 강화에도 결정적 역할을 한다. 그럼에도 불구하고, FEED 관련 선행연구들은 설계업무 중심의 프로세스 및 성과물을 위한 연구가 대부분이며, 프로젝트 전체에 영향을 미치는 관리적 관점의 FEED 업무에 대한 연구는 미흡한 실정이다. 따라서 본 연구에서는 발전플랜트 중 화력발전소를 대상으로 사업관리 관점의 FEED 업무 프로세스 구조 및 항목을 제안하였다. 도출된 FEED 관리 업무는 3개의 레벨로 나누어진 계층적 구조를 가지고 있으며, 업무 항목에 대한 전문가 검증을 실시하였다. 또한 FEED 관리 업무에 대한 평가지표별 평가를 통해 결과를 분석한 결과 설계 중심의 업무들은 역량이 높지만 중요도가 높은 관리적 관점의 FEED 업무들의 역량은 부족한 것으로 나타났다. 그러므로 본 연구에서 제안한 FEED 관리업무 프로세스 구조는 FEED 역량 강화를 위한 가이드라인이 될 것이라 기대한다.