• 한국산학기술학회논문지
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• 제20권9호
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• pp.255-261
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• 2019

본 시험은 이유자돈 사료 내 동애등에(Hermetia illucens)의 사용 수준에 따른 성장, 영양소소화율 및 경제성을 평가하여 이유자돈 사료 내 동애등에의 적정 사용수준을 도출하기 위해 실시하였다. 본 시험을 위해 총 192 두의 이유자돈($Landrace{\times}Yorkshire{\times}Duroc$; $6.51{\pm}0.15kg$)을 공시하여 4 처리 6 반복, 반복당 8 두씩 완전임의 배치하였다. 시험 처리구는 옥수수-대두박 기초사료를 대조구로 하여 기초사료 내 동애등에를 각각 1, 2 및 3% 첨가하였다. Phase I, II 및 overall의 사양성적에서 유의적인 차이가 나타나지 않았으나, overall의 일당증체량에서 동애등에 첨가 수준에 따라 선형적으로 증가하는 것으로 나타났다(p < 0.05). 건물 소화율이 동애등에 첨가수준에 따라 유의적으로 증가하는 것으로 나타났으나, 다른 항목에서 유의적인 효과는 나타나지 않았다. 경제성 분석에서 overall의 총증체량이동애등에의 첨가수준이 증가함에 따라 증가하였으며(p < 0.05), 이를 제외한 모든 항목에서 유의적인 효과가 나타나지 않았다. 본 연구결과를 요약하면, 사료 내 동애등에의 첨가는 경제성의 영향 없이 이유자돈의 성장과 건물 영양소소화율 개선에 유의한 효과를 미치며, 이는 이유자돈 사료 내 3%까지 사용이 가능한 것을 시사한다.

• 설비공학논문집
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• 제13권7호
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• pp.579-587
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• 2001

This study investigates particle collection characteristics of a cylindrical electrostatic precipitator. Experimental work has been made for the submicron particles. The effects of polarity of discharge electrode wire, particle diameter, gas velocity, gas temperature, and specific corona power on the particle collection efficiency are investigated. The efficiency of negative corona is higher than that of positive corona. as the particle diameter increases, the efficiency is decreased when the diameter is in the range of 0.02-0.6 micron, but is increased for the nanometer particles with diameter smaller than 0.02 micron. The efficiency is increased with increase of specific corona power. As the gas temperature increases, overall collection efficiency is increased for a negative corona, but is deceased for a positive corona.

• 한국유기농업학회지
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• 제17권1호
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• pp.19-33
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• 2009

This paper evaluates the technical efficiency of organic farm management practices and studies its main determinants in Hongdongmyeon of Hongsung county, Chungnam province. The analysis is performed in two stages. First, the efficiency is measured via the nonparametric "Data Envelopment Analysis" (DEA) technique. The DEA models are constructed not only to assess the overall technical efficiency of organic fanning practices but also to evaluate the management efficiencies. In a second stage critical determinants of efficiency are determined using a Tobit model. In this analysis the focus is on technical and socio-economic variables. The analytical results show that technically efficient farms is about 13 percent and the mean technical efficiency is found to be 0.73 indicating that many farms are not operating at an efficient scale.

• 한국대기환경학회지
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• 제16권6호
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• pp.633-640
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• 2000

The effects of structure modification of the vortex finder on the collection efficiency and pressure drop have been investigated. The pressure drop in a cyclone having the two stage vortex finder is higher than that in a conventional cyclone and increases proportionally with the increase of square of gas inlet velocity in both cases. The pressure drop of both conventional cyclone of friction resistance at the boundary layer. The collection efficiency of fine dust has been enhanced by addition of vortex finder in a conventional cyclone and gas inlet velocity showing maximum dust removal efficiency increase to 17 m/s(1.7 times of saltation velocity). Optimum size of two stage vortex finder has been induced to 13 cm I.D$\times$2.6cm Length from the results of overall dust collection efficiency. Previous models were tested for the simulation of collection efficiency of cyclone having two stage vortex finder and the Dietz model predict the similar value with experimental results of the present study.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.729-740
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• 2020

The study examines the efficiency of private sector banks in India with the help of Window DEA (Data Envelopment Analysis) for a period from 2005 to 2017. With a window of three years, the period was divided into 11 windows. The study outcomes show that 59.9% of all private sector banks in India operate at more than 0.9 level of efficiency, and there are only three occasions when banks were operating at the efficiency value between 0.6 to 0.7. Further, the consistency in the efficiency scores of the banks has also been analyzed using an efficiency mapping matrix, and the mean efficiency score of the bank in each window is studied. The score of standard deviation was interpreted accordingly for these banks. Banks that are showing the highest efficiency scores also have a higher variance of efficiency scores. There was no bank identified in the matrix that promises high-efficiency ratings with low variability. The study concludes that the analysis of the efficiency mapping matrix indicates that, as a DMU escalates in the efficiency scores, the standard deviation reflecting the risk in overall efficiency scores also tends to rise. The findings complement the concept of higher risk to higher return or greater efficiency.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1340-1347
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• 2010

To study the effects of ${\alpha}$-galactosidase (${\alpha}$-Gal) supplementation on performance and energy metabolism, 216 Arbor Acres male broilers were placed in 36 cages of 6 birds each and allotted to 4 diets for 42 d, with 0-21 d as starter period and 22-42 d as grower period. The 4 diets were based on corn non-dehulled soybean meal in a $2{\times}2$ factorial arrangement, with 2 levels of ${\alpha}$-Gal (0 vs. 60 U/kg feed) and 2 levels of ME (normal metabolizable energy (NME) and low metabolizable energy (LME)). Bird performance was obtained at 21 and 42 d of age with samples of feces collected for nutrient digestibility from 19-21 d and 40-42 d. At 21 and 42 d, 1 bird from 6 cages of each treatment was killed to determine liver weight, intestinal pH and chyme viscosity. With the addition of ${\alpha}$-Gal the 42 d body weight (BW) and 0-42 d average daily gain (ADG) were significantly improved (p<0.05). Average daily feed intake (ADFI) of birds fed the LME diet was significantly increased compared to those fed the NME diet during starter (p<0.01) and grower (p<0.05) periods and overall (p<0.01). There was an interaction of ${\alpha}-Gal{\times}ME$ on 0-21 d ADFI (p<0.01). Supplementation of ${\alpha}$-Gal significantly improved (p<0.01) feed efficiency during the grower period and overall. Feed efficiency of birds fed the LME diet was significantly decreased (p<0.05) compared to those fed the NME diet during the starter period and overall. With the addition of ${\alpha}$-Gal apparent metabolizable energy (AME) was improved (p<0.01) by 2.1% and 1.8% during starter and grower periods, respectively. There was a main effect (p<0.05) of ${\alpha}$-Gal on the digestion of neutral detergent fiber (NDF) during the starter period and crude protein (CP), NDF and acid detergent fiber (ADF) during the grower period. With the addition of ${\alpha}$-Gal, the relative weight of liver was reduced (p<0.01) during the two phases. The duodenal and jejunal pH were significantly decreased (p<0.01) with the supplementation of ${\alpha}$at the two phases. ${\alpha}$-Gal addition reduced (p<0.01) chyme viscosity of the ileum during the starter and grower periods. Overall, ${\alpha}$-Gal showed a major effect on nutrient efficiency, improved ADG and feed efficiency, whereas LME decreased feed efficiency. The incorporation of ${\alpha}$-Gal into a LME diet could at least partially offset ME deficiency of non-dehulled soybean meal.

• Safety and Health at Work
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• 제8권3호
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• pp.296-305
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• 2017

Background: Surfactant-containing water sprays are commonly used in coal mines to collect dust. This study investigates the dust collection performance of different surfactant types for a range of coal dust particle sizes and charges. Methods: Bituminous coal dust aerosol was generated in a wind tunnel. The charge of the aerosol was either left unaltered, charge-neutralized with a neutralizer, or positively- or negatively-charged using a diffusion charger after the particles were neutralized. An anionic, cationic, or nonionic surfactant spray or a plain water spray was used to remove the particles from the air flow. Some particles were captured while passing through spray section, whereas remaining particles were charge-separated using an electrostatic classifier. Particle size and concentration of the charge-separated particles were measured using an aerodynamic particle sizer. Measurements were made with the spray on and off to calculate overall collection efficiencies (integrated across all charge levels) and efficiencies of particles with specific charge levels. Results: The diameter of the tested coal dust aerosol was $0.89{\mu}m{\pm}1.45$ [geometric $mean{\pm}geometric$ standard deviations (SD)]. Respirable particle mass was collected with $75.5{\pm}5.9%$ ($mean{\pm}SD$) efficiency overall. Collection efficiency was correlated with particle size. Surfactant type significantly impacted collection efficiency: charged particle collection by nonionic surfactant sprays was greater than or equal to collection by other sprays, especially for weakly-charged aerosols. Particle charge strength was significantly correlated with collection efficiency. Conclusion: Surfactant type affects charged particle spray collection efficiency. Nonionic surfactant sprays performed well in coal dust capture in many of the tested conditions.

• 한국항만경제학회지
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• 제24권4호
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• pp.47-70
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• 2008

본 연구의 목적은 확률적 생산변경함수를 이용하여 총요소생산성 성장을 도출하고 그 내부요소를 기술효율성 변화, 기술진보, 규모효율변화, 배분적 효율변화로 구분하여 생산성 성장의 요인을 파악해 보고자 함이다. 1990-2003년간 항만물류산업의 총요소생산성 증가율은 연간 0.019 (1.9%)로서 전산업의 증가율 0.010보다 높다. 그 내부의 주된 기여요인은 기술진보이고 기술효율성변화는 감소하였다. 총요소생산성의 주된 기여요인으로는 항만산업은 배분효율성, 해운산업은 기술진보, 수송장비산업은 규모효율변화를 들 수 있다. 총요소생산성 변화는 1990년대 후반이후에 감소하는 추이를 보였다. 항만물류산업은 전산업에 비하여 매우 낮은 수준의 기술효율성수준을 보여주고 있고 산출탄력성 관점에서는 1990-2003년간 자본의 탄력성(0.391)이 노동의 탄력성(0.227)보다 높지만 규모에 대한 보수는 0.618로서 최적규모에 상당히 벗어나 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권3호
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• pp.383-387
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• 1994

Six heifers each of $F_1$, $F_2$, $F_3$, $F_4$ H. Friesian $\times$ Sahjwal halfbreds and pure Sahiwal with overall average initial age and live weight of $315.6{\pm}134.8 days$ and $143.8{\pm}48.5kg$, respectively were used for this study. The under trial animals were fed according to N.R.C. (1978). The overall average age at maturity, first conception and first calving was $563.8{\pm}116.8$, $675.8{\pm}135.6$ and $956.8{\pm}149.8days$ with live weights as $302.2{\pm}58.6$, $342.6{\pm}41.5$ and $433.9{\pm}38.1kg$, respectively. The overall 305 days and total milk yield for 1st lactation was $2,729.0{\pm}669.3$ and $2,992.7{\pm}377.5litre$ while the FCM (at 4%) was $2,934.2{\pm}410.8litre$. The lactation length was $336.6{\pm}69.6days$. The fat and solids not fat contents were $4.5{\pm}0.2$ and $8.2{\pm}0.3percent$, respectively. The milk production in Sahiwal cows was significantly lower than crossbred cows. The services per conception were $2.5{\pm}1.3$. The overall per head per day consumption of DM, TCP and ME was $10.9{\pm}1.2kg$, $1,399{\pm}199gm$ and $22.6{\pm}2.4 M.Cal.$, respectively. The overall milk producing efficiency for the production of one litre of FCM was $1.12{\pm}0.15kg$ of DM, $142.2{\pm}17.76gm$ of TCP and $2.31{\pm}0.27M.Cal.$ of energy while the feeding cost was Rs. $1.46{\pm}0.22$ per litre of FCM produced. The feeding cost per litre FCM was significantly higher in Sahiwal and $F_2$ than in other genetic groups.

• 한국항만경제학회지
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• 제31권4호
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• pp.39-52
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• 2015

본 논문에서는 3개의 투입요소(수심, 총면적, 크레인 수)와, 1개의 산출요소(컨테이너화물처리량)[다른 경우에는 2개의 산출물(TEU와 BDC 총점수)], 그리고 3개년(2009년, 2010년, 2013년)자료를 이용하여 한 중 일 주요항만을 포함한 아시아 13개국의 항만들을 대상으로 하여, 교차효율성 측정, 웹 접근성 평가(KWAH 4), 웹 사이트 평가(BDC, 캐나다 비즈니스 개발은행)결과를 이용하여 각각의 항만들의 순위를 결정한 후에, 상관관계관계분석을 통해서 교차효율성, 웹접근성, 웹 사이트 평가결과의 순위 간에 유의미한 상관관계가 존재하는지를 파악하였다. 실증분석의 핵심적인 결과는 다음과 같다. 첫째, 웹 접근성 및 BDC웹 사이트 평가순위와 교차효율성 모형에 의한 효율성 순위사이의 상관관계분석에서 선형적 연관성은 낮은 것으로 나타났다. 둘째, BDC의 종합점수를 교차효율성 측정의 산출요소로 간주하여 새롭게 측정한 효율성 순위와 웹 사이트 평가와 웹 접근성에 의한 평가순위 사이의 상관분석에서도 낮은 수준의 단조적 증가를 보여 유의미한 상관관계는 보이지 않았다. 본 연구가 갖는 정책적인 시사점은 국내항만의 정책입안자나 경영관리자들은 웹 접근성 지침준수 및 웹 사이트 품질평가 결과를 참고로 하여 웹 사이트를 사용자 편의 중심으로 세심하게 개편해야만 한다.