• Journal of Welding and Joining
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• 제15권2호
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• pp.72-80
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• 1997

The spatter generation rate of GMA welding with $CO_2$ gas shielding was measured with the change of welding conditions such as wire feeding rate and welding voltage and then the results were analized with the accompanying changes in metal transfer mode and in bead geometry. The spatter generation rate (SGR) was relatively low not only wit the short circuit transfer but with the truely globular transfer mode. However, the SGR resulted with the mixed mode were consistantly high. The resultant wave pattern of mixed mode was due to the coexistance of short-circuit and globular transfer and characterized by the frequent appearance of instantaneous short circuit. Considering the result of SGR and that of bead geometry, it could be concluded that when the wire feeding rate (or welding current) was either low or high, the optimum bead shape could be obtained along with the low spatter generation. However, in the middle range of wire feeding rate, the optimum bead shape was only obtained in the mixed mode condition resulting in the high spatter generation.

• 한국패류학회지
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• 제32권2호
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• pp.103-109
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• 2016

본 연구는 3년산 북방전복의 해상가두리의 먹이공급비율에 따른 성장 및 생존율을 조사하여, 미역과 다시마등의 천연먹이의 적정 공급율을 제안하여 북방전복 성패의 생산성 향상을 유도하고자 실시하였다. 먹이공급율은 실험전복 어체중량을 기준으로 일간공급율 (daily feeding rate, DFR) 5, 10, 15, 20% (5 DFR, 10 DFR, 15 DFR, 20 DFR) 를 설정하여, 해상가두리에서 2반복으로 13개월간 실시하였다. 해상가두리에서 사육한 전복 (최초 수용 시 평균각장 $73.77{\pm}11.27mm$) 성장에서 각장과 각폭의 성장율 (growth rate, GR), 일간성장율 (daily growth rate, DGR) 및 특수생장율 (specific growth rate, SGR) 과 체중의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 및 특수증중률 (specific weight gain, SWG), 그리고 생존율에서 5 DFR이 유의적으로 높았다 (P < 0.05). 생존율은 모든 실험구가 유의적 차이가 없었으며, 30%이하로 나타났다. 따라서 3년산 북방전복을 해상가두리에서 사육 시 미역, 다시마 등의 생먹이의 일간 공급율은 어체중량의 5-10%에서 공급되는 것이 성장에 유리하지만, 생존율을 향상 시킬 수 있는 다각적 검토가 필요하다.

• 유기물자원화
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• 제18권4호
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• pp.45-53
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• 2010

여러 가지 방법으로 전처리된 느타리 버섯 폐배지에 대한 줄지렁이 개체군의 섭식률 및 생장률을 조사하였다. 갓 발생한 버섯폐배지의 부숙기간을 달리하여 지렁이에게 급이하였을 경우, 20일 이상 부숙된 버섯 폐배지보다 10일 이하로 부숙된 버섯 폐배지에 대한 지렁이 개체군의 섭식량 및 생장률이 높았다. 분변토를 첨가한 버섯폐배지나 질소영양원으로서 요소비료를 첨가하여 부숙한 버섯폐배지는 지렁이 개체군의 섭식률과 생장률을 증대시키지 못하는 것으로 나타났다. 그러나 버섯폐배지를 분쇄하여 공급하였을 경우에는 섭식량 및 생장률이 증가하였다. 특히 분쇄된 버섯폐배지에 미강을 첨가하였을 경우에는 분쇄하지 않은 단순 버섯폐배지보다 생장률이 1.85배 증가하였다.

• Clinical and Experimental Pediatrics
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• 제53권5호
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• pp.634-638
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• 2010

Purpose: In Kyung Hee East-West Neo Medical Center, Seoul, Korea, efforts to raise rooming-in care success rate have been undertaken since when the hospital was established in 2006. We intended to analyze our experience over the past 3 years of period and to discuss the advantages of rooming-in. Methods: We analyzed the rooming-in practice rate, failure rate, and the breast feeding rate. Subjects were 860 normal healthy neonates from June 2006 to June 2009. Results: Among these 860 cases, 83 babies were required separation out of rooming-in in the middle of the course. Among these 83 cases, 70 cases had to stop the course due to poor condition of babies and 13 cases due to maternal condition. 70 cases of infant's causes consist of 68 cases of NICU admission and 2 cases of poor feeding support. The other 13 cases of separation include refusal by maternal condition. Therefore the success rate of rooming-in for the last 3 years was 90.3%, that is 777 cases among the total 860 cases. The percentage of exclusive breast feeding was 64%, that of mixed feeding with breast and formula feeding was 25%, and formula feeding only was 11%. Conclusion: We experienced successful rooming-in care for the last 3 years. Nursery facilities should educate and encourage the advantages of rooming-in, including the good formation of attachment between mother and infant, emotional stability, protection from infection, and increased breast feeding rate so that rooming-in care can be fully established.

• Fisheries and Aquatic Sciences
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• 제24권12호
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• pp.415-427
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• 2021

Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

• Clinical and Experimental Pediatrics
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• 제46권7호
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• pp.635-641
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• 2003

목 적 : 임신 시 모유 수유를 계획한 수유모의 모유 수유 실천과 이에 영향을 주는 요인을 알아보고자 본 조사를 시행하였다. 방 법 : 임신 시 모유 수유를 계획했던 1,128명 중에서 지역과 병원급을 층화하여 무작위 추출한 152명을 연구의 대상으로 하였다. 2001년 11월부터 2002년 3월까지 연구 대상자의 출산 후 4개월에 전화로 설문을 실시하여 결과를 분석하였다. 결 과 : 1) 임신 시 모유 수유를 계획한 수유모 중에서 출산 4개월 후의 모유 수유율은 37.5%였고, 실패 이유는 66.3%가 모유가 나오지 않거나 양이 적어서라고 대답하였고 그 외 수유모의 직장 또는 일 13.7%, 수유모의 질환 7.4%, 변이 묽어서 5.3%, 아기의 질병 4.2% 등이었다. 2) 수유모의 연령, 자녀의 유무, 모유 수유를 결정한 사람, 가족의 형태에 따른 차이는 없었으나, 임신 시 모유 수유를 4개월 이상으로 계획했던 경우 모유 수유율이 2.3(95% 신뢰구간 1.15-4.62)배로 유의하게 높았다(P<0.05). 3) 전문대졸 이상의 수유모의 모유 수유율이 고졸 수유모보다 0.43(95% 신뢰구간 0.21-0.86)배로 유의하게 낮았으며 취업 수유모의 모유 수유율이 0.37(95% 신뢰구간 0.17-0.83)배로 유의하게 낮았다(P<0.05). 4) 모유 수유 장점과 수유의 방법에 대한 인식항목 20개에 대한 점수의 중앙값 12점을 기준으로 할 때 12점 이상인 사람의 모유 수유율은 41.5%였던 반면, 12점 미만인 경우 34.5%의 모유 수유율을 보여 인식이 높은 군이 낮은 군에 비해 1.35(95% 신뢰구간 0.70-2.62)배의 모유 수유율을 보였다(P>0.05). 5) 출산 장소가 산부인과 의원인 경우 종합병원 보다 모유 수유율이 3.97(95% 신뢰구간 11-14.23)배로 유의하게 높았다(P>0.05). 출산아 성별, 병원내 모유 수유, 모자동실 및 분만 형태에 따른 모유 수유율의 유의한 차이는 없었다. 결 론 : 모유 수유율 높이기 위해서 적극적인 산전 교육과 출산 후 병의원에서 모유 수유를 할 수 있도록 모자동실, 모유 수유 상담 및 교육이 적절하게 제공되어야 할 것이다. 또한 취업 수유모의 모유 수유를 위한 공간과 시설 및 휴가 문제 등이 사회 정책이나 국가 정책으로 제도화 되어야 할 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.952-955
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• 1996

It is difficult to determine the feeding rate of coagulant in water treatment process, due to nonlinearity, multivariables and slow response characteristics etc. To deal with this difficulty, the fusion of genetic algorithms and fuzzy inference system was used in determining of feeding rate of coagulant. The genetic algorithms are excellently robust in complex operation problems, since it uses randomized operators and searches for the best chromosome without auxiliary information from a population consists of codings of parameter set. To apply this algorithms, we made the look up table and membership function from the actual operation data of water treatment process. We determined optimum dosages of coagulant (PAC, LAS etc.) by the fuzzy operation, and compared it with the feeding rate of the actual operation data.

• 제어로봇시스템학회논문지
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• 제5권7호
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• pp.876-882
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• 1999

It is difficult to determine the feeding rate of coagulant in the water treatment process, due to nonlinearity, multivariables and slow response characteristics, etc. To deal with this difficulty, the genetic-fuzzy system was used in determining the feeding rate of the coagulant. The genetic algorithms are excellently robust in complex optimization problems. Since it uses randomized operators and searches for the best chromosome without auxiliary informations from a population consists of codings of parameter set. To apply this algorithms, we made the lookup table and membership function from the actual operation data of the water treatment process. We determined optimum dosages of coagulant(LAS) by the fuzzy operation, and compared it with the feeding rate of the actual operation data.

• Journal of Biosystems Engineering
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• 제26권3호
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• pp.271-278
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• 2001

Many workers in the garlic peeling factory are separating the sound peeled garlics from the unpeeled and defective ones in a manual way. In order to reduce the seasonal labor requirement and operating cost, the mechanized garlic sorting system such as the vision-based garlic sorter should be developed. This study was conducted as one of basic studies on developing quality evaluation technique for peeled garlics, especially to developed the system for acquiring the whole surface images of garlics with a CCD camera. The following results were obtained from this study. 1. The belt-type garlic rotation system was devised to apply for the vision-based garlic sorter and was tested to decide the criteria of design and optimum conveying speed. 2. To evaluate the performance of the developed garlic rotation system, feeding rate and rotating rate were measured under the conditions of four experimental factors such as the inclined angle of rotating belt, the inclined angle of feeding belt, the height of plate arrays on feeding belt and the conveying speed of belts. And the capacity of the system according to mixture ratios of peeled garlics and unpeeled garlics was analyzed as a feasibility test. 3. For the inclined angle of rotating belt 20°and height of plate array on feeding belt 22㎜, the maximum rotating rate for garlic samples including unpeeled ones was 81.1% at the conveying speed of 4.2 garlic/sec. And under these condition, the maximum feeding rate was 85% at the inclined angle of feeding belt 6.5°. 4. The capacity of the developed garlic rotation system was almost constant regardless of mixture ratio of peeled garlics and unpeeled garlics and its range was 2.95∼3.92 garlic/sec. At the conveying speed of 4.2 garlic/sec, the capacity of the garlic rotation system was calculated ad 58∼64 kg/hr. 5. To improve performance of the garlic rotation system, it is recommended to develop a device to slide garlics into feeding belt.

• 수산해양교육연구
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• 제26권4호
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• pp.789-796
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• 2014

This study was conducted to investigate the effects of feeding rate on growth performance, blood components and histology of growing olive flounder. The experiment was carried out to determine the optimum feeding rate of the fish (initial fish mean weight of $97{\pm}3.0$ g) at the optimum water temperature. Two replicated groups of fish were fed commercial diet at the feeding rates of 0, 1.0, 1.65 and 2.3% body weight (BW)/day and satiation. Feeding trial was conducted under a flow-through system with ten 1.2 metric ton aquaria receiving filtered seawater at $21{\pm}2^{\circ}C$ for three weeks. Weight gain and specific growth rate (SGR) for fish fed to satiation were significantly higher than those for the unfed fish and for fish fed at 1.0 and 1.65% BW/day. There were no significant differences in values of such parameters between fish fed at 1.65% and those fed at 2.3% BW/day and between fish fed at 2.3% and those fed to satiation. Weight gain and SGR for the unfed fish were significantly lower than those for fish in the other treatments. All the tissues (hepatopancreas, kidney and anterior intestine) were in good condition in fish fed the experimental diet at different feeding rates. This result indicates that the optimum feeding rates of olive flounder (97-160 g) was approximately 2.52% BW/day at the optimum water temperature.