• Design & Manufacturing
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• 제11권2호
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• pp.46-50
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• 2017

EPS used in lost foam casting elastic modulus is extremely low. So it is necessary to derive machining conditions for effective cutting. Therefore this study were analyzed end-milling machining conditions to affecting the surface roughness of EPS foam. The machining conditions were set to depth, feed, and RPM at 3-level. And 18experimental conditions were derived using mixed orthogonal array. The most important condition for surface roughness is RPM. In addition, RPM machining condition range test that can realize surface roughness less than $10{\mu}m$ was performed. he range of RPM conditions is more than 15,000. However the range of RPM conditions is a condition that is difficult to use in actual field. In the future variance analysis and experiments are needed to derive the range of machining conditions available.

• 한국정밀공학회지
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• 제21권7호
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• pp.62-69
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• 2004

This paper presents an experimental study on the dimensional error in ball-end milling. In the 3D free-formed surface machining using ball-end milling, while machining conditions are varied due to the Z component of the feed and existing hemisphere part of the ball-end mill, the mechanics of ball-end milling are complicated. In the finishing, most of cutting is performed the ball part of the cutter and the machined surface are required the high quality. But the dimensional errors in the ball-end milling are inevitably caused by tool deflection, tool wear, thermal effect and machine tool errors and so on. Among these factors, the most significant one of dimensional error is usually known as tool deflection. Tool deflection is related to the instantaneous horizontal cutting force and varied the finishing cutting path. It lead to decrease cutting area, thus resulting cutting forces but the dimensional precision surface could not be obtained. So the machining experiments are conducted fur dimensional error investigation and these results may be used for decrease dimensional errors in practice.

• Animal Bioscience
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• 제37권1호
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• pp.105-115
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• 2024

Objective: A study was conducted to determine the chemical composition of barley and co-products from barley, corn, and wheat produced in South-East Asia or Australia, and to test the hypothesis that production area or production methods can impact the chemical composition of wheat co-products. Methods: Samples included seven barley grains, two malt barley rootlets, one corn gluten feed, one corn gluten meal, one corn bran, eight wheat brans, one wheat mill mix, and four wheat pollards. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid hydrolyzed ether extract, ash, minerals, starch, and insoluble dietary fiber and soluble dietary fiber. Malt barley rootlets and wheat co-products were also analyzed for sugars. Results: Chemical composition of barley, malt barley rootlets, and corn co-products were in general similar across countries. Wheat pollard had greater (p<0.05) concentrations of tryptophan, magnesium, and potassium compared with wheat bran, whereas wheat bran had greater (p<0.05) concentration of copper than wheat pollard. There were no differences in chemical composition between wheat bran produced in Australia and wheat bran produced in Thailand. Conclusion: Intact barley contains more starch, but fewer AA, than grain co-products. There were only few differences in the composition of wheat bran and wheat pollard, indicating that the two ingredients are similar, but with different names. However, corn gluten meal contains more protein and less fiber than corn bran.

• Journal of the Korean Wood Science and Technology
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• 제29권2호
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• pp.100-108
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• 2001

제재목으로부터 얻을 수 있는 부재(部材)(parts)의 수율을 미리 예측할 수 있다면 최고의 수율 보장이 가능한 방법으로 재단할 수 있으므로 목재산업의 생산성을 크게 향상시킬 수 있다. 특히, 옹이와 같은 결점들이 많이 포함되어 있는 국산 중소경재의 경우 수율 예측을 통한 재단최적화는 매우 필요한 공정이 아닐 수 없다. 본 연구에서는 국산 상수리나무와 소나무를 대상으로 제재목 database를 구축하여 다중 종절우선 공정 모형에 적용함으로써 국산재의 가공효율을 탐색하는 동시에 최고의 수율이 보장되는 재단 방법을 제시하고자 하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제8권6호
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• pp.635-639
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• 1995

Digestibility trial was performed with carps weighing 200 g/fish. Fecal collection was made over 7 days using a settling column. The water temperature was in the range of 27 to $30{^{\circ}C}$ during whole experimental period. Fishes were fed 5 diets (Control, $F_{24}S_{13}$, $F_{16}S_{27}$, $F_8S_{40}$ and $F_0S_{56}$) containing both 32%, 24%, 16%, 8% and 0% of fish meal (F) and 0%, 13%, 27%, 40% and 56% of roasted full-fat soybean (S), respectively. Water volume in each recirculated rearing tank was maintained at 130 l with flow rate of 10-12 l/min. Apparent digestibility coefficients (ADCs) of dry matter, protein, lipid, total carbohydrates and energy in diets showed a reduction (p < 0.05) with the increase of dietary full-fat soybean level, although there was no difference in the ADCs between Control and $F_{24}S_{13}$ (p > 0.05). The ADCs of ash, Ca and P in diets significantly increased with the increase of dietary full-fat soybean level, suggesting the high availability of phosphorus in monocalcium phosphate.

• 한국정밀공학회지
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• 제30권4호
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• pp.397-402
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• 2013

In this study, we carried out the each lines of section, using GC (green silicon carbide) whetstone, the SCM415 material which separated by after and before heat treatments process, in 3+2 axis machining centers for integrated grinding after cutting end mill works, the spindle speed 8000 rpm and feed rate 150 mm/min. For the analysis of the centerline average roughness (Ra), we measured by 10 steps stages. Using Finite element analysis, we found the result of the load analysis effect of the assembly parts, when applied the 11 kg's load on both side of the ATC (Automatic tool change) arm. The result is as follows. For the centerline average roughness (Ra) in the non-heat treatment work pieces, are appeared the most favorable in the tenth section are $0.510{\mu}m$, that were shown in the near the straight line section which is the smallest deformation of curve. In addition, the bad surface roughness appears on the path is to long by changing angle, the more inclined depth of cut, because the chip discharging is not smoothly.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.224-230
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• 2001

This study was conducted to evaluate the extruding effects of corn and wheat on growth performance and fecal digestibility of amino acids in early-weaned pigs. Ground corn and wheat by a hammer mill (3 mm screen in diameter) were extruded at $130{\pm}2^{\circ}C$ with a moist-type extruder ($Matador^{(R)}$). Treatments were: 1) 3 mm ground corn, 2) extruded corn, 3) 3 mm ground wheat, and 4) extruded wheat. A total of 160 pigs (14 d of age and $4.3{\pm}0.74kg$ BW) were allotted with the dietary treatments for a 21-d feeding trial. All diets were mash and contained 30% corn or wheat products. For a digestibility trial, 16 pigs (14-d old and $4.2{\pm}0.32kg$ BW) were employed in individual metabolic crates. There were no differences (p>0.15) in growth performance between corn-fed and wheat-fed groups. Feeding pigs diets containing extruded corn or wheat did not affect ADG (p>0.15) and ADFI (p>0.15), but it improved feed/gain (p<0.01). Also, feeding pigs diets containing extruded corn or wheat had lower true fecal digestibilities of arginine, histidine, isoleucine, lysine and valine (p<.007) in the pigs. In conclusion, our results suggest that extruding corn and wheat had no benefit on the growth of early-weaned pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.545-551
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• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.

• 한국식품과학회지
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• 제8권4호
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• pp.212-218
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• 1976

생선(生鮮)으로 부터 생선(生鮮) 냄새를 효과적(效果的)으로 제거(除去)하기 위한 기초작업(基礎作業)으로서 ethanol과 물을 추출용매(抽出溶媒)로 사용(使用)하여 꽁치로 부터 생선(生鮮) 냄새의 주성분(主成分)인 trimethylamine과 변패(變敗)의 원인(原因)이 되며 직접간접(直接間接)으로 불쾌취(不快臭)를 조성(造成)하는 지방(脂肪)을 제거(除去)할 목적(目的)으로 실험(實驗)하였던 바 다음과 같은 결과(結果)를 얻었다. 1. 꽁치중(中)의 trimethylamine은 추출시(抽出時)의 ethanol의 최종농도(最終濃度)가 $40{\sim}55%$ 수준이었을 때 가장 추출(抽出)이 잘되었다. 2. 꽁치를 boiling absolute ethanol로서 연속추출(連續抽出)을 행(行)할 때 추출(抽出)은 서로 다른 두 단계로 진행(進行)되었다. a) 추출(抽出)의 첫 단계에선 생선(生鮮)의 탈수(脫水)와 동시(同時)에 trimethylamine이 주(主)로 추출(抽出)되었으며 b) 생선(生鮮)이 탈수(脫水)된 그다음 단계에서 지방(脂肪)이 효율적(?率的)으로 추출(抽出)되었다.

• Journal of Biosystems Engineering
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• 제10권2호
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• pp.55-62
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• 1985

박(朴)(1982, 1983, 1984 및 1985)이 개발(開發)한 배합사료공장(配合飼料工場)의 투자비용(投資費用) 및 운전비용(運轉費用)의 수학적모형(數學的模型)을 이용(利用)하여, 배합사료공장(配合飼料工場)의 적정(適正) 시스템의 설계(設計)를 예(例)를 들어 소개하였다. 적정(適正)시스템의 설계(設計)를 위(爲)하여 비선형(非線型) 프로그램의 "Single Objective Programming Problem(단일목적함수(單一目的函數))"와 "'Multiple Objective Decision Making Method(다목적함수(多目的函數))"의 2가지 방법(方法)을 적용(適用)하였다. Single Objective Programming Problem에서는 "Generalized Reduced Gradient(GRG) Method"를 이용(利用)하였고, Multiple Objective Decision Making Method(MODM)에서는 "Interactive Nonlinear Goal Program(INGP)"를 이용(利用)하였으며 그 결과(結果)는 다음의 몇가지로 요약(要約)할 수 있다. 1. 박(朴)이 개발(閒發)한 수학적(數學的) 모형(模型)들은 2 가지 방법(方法) 모두 사료공장(飼料工場)의 최적화(最適化) 설계(設計)에 효과적으로 이용(利用)할 수가 있었다. 2. MODM방법(方法)에 의(依)하여 얻어진 최적(最適)시스템은 Single Objective Program Problem에서 구(求)한 결과(結果)보다 균형(均衡)이 있는 시스템이었으며 장래(將來)의 사료원료(飼料原料), 사료구매시장(飼料購買市場), 기타 다른 조건(條件)들의 변화)에 대(對)해서 보다 탄력(彈力)이 있는 시스템으로 나타났다. 3. 엄밀한 의미(意味)에서 절대적(絶對的)인 최적사료공장(最適飼料工場)이란 있을 수 없으며, 주위의 조건(條件), 원료가격(原料價格), 사료가격(飼料價格), 공장주(工場主)의 취향 및 설계조건등(設計條件等)에 따라 최적(最適) 시스템은 각각(各各) 다르게 나타난다.