• Animal Bioscience
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• 제35권10호
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• pp.1592-1605
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• 2022

Objective: The objective of this study was to select an effective in vitro digestion-fermentation model to estimate the effect of decreasing dietary crude protein (CP) on odor emission during pig production and to suggest potential prediction markers through in vitro and in vivo experiments. Methods: In the in vitro experiment, three diet formulations with different CP contents (170 g/kg, 150 g/kg, and 130 g/kg) but containing the same standardized ileal digestible essential amino acids (SID-EAA) were assessed. Each diet was evaluated by two different in vitro gastric-intestinal phase digestion methods (flask and dialysis), combined with fresh pig feces-ferment inoculation. Eighteen growing barrows (31.9±1.6 kg) were divided into three groups: control diet (180 g CP/kg, without SID-EAA adjustment), 170 g CP/kg diet, and 150 g CP/kg diet for 4 weeks. Results: The in vitro digestion results indicated that in vitro digestibility was affected by the gastric-intestinal phase digestion method and dietary CP level. According to the gas kinetic and digestibility results, the dialysis method showed greater distinguishability for dietary CP level adjustment. Nitrogen-related odor compounds (NH₃-N, indole, p-cresol, and skatole) were highly correlated with urease and protease activity. The feeding study indicated that both EAA-adjusted diets resulted in a lower odor emission especially in p-cresol and skatole. Both protease and urease activity in feces were also closely related to odor emissions from nitrogen metabolism compounds. Conclusion: Dialysis digestion in the gastric-intestinal phase followed by fresh fecal inoculation fermentation is suitable for in vitro diet evaluation. The enzyme activity in the fermentation and the fecal samples might provide a simple and effective estimation tool for nitrogen-related odor emission prediction in both in vitro and in vivo experiments.

• Animal Bioscience
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• 제37권6호
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• pp.1085-1095
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• 2024

Objective: The main objective of this study was to determine available energy and nutritional digestibility of extruded cereals and the effect of extrusion on the nutritional value of feed ingredients, aiming to provide scientific basis for efficient application of extrusion in the diets of growing pigs. Methods: In Exp. 1, 48 crossbred growing pigs (Duroc×Landrace×Yorkshire) with an initial body weight (BW) of 34.6±2.2 kg were selected and fed with eight diets (non-extrusion or extrusion) to determine the digestible energy (DE), metabolizable energy (ME), and nutrients digestibility. Eight diets included extruded grains (barley, wheat, sorghum, or broken rice), while four had unprocessed grains. In Exp. 2, 9 diets were formulated including 4 cereals with extrusion or non-extrusion and a N-free diet. In addition, 9 growing pigs (BW = 22.3±2.8 kg) were fitted with T-cannula in the distal ileum and arranged in a 9×6 Youden square design. Results: Results show that apparent total tract digestibility of gross energy, dry matter, organic meal, ether extract, neutral and acid detergent fiber was not affected by the extrusion process and there was no interaction between cereal type and extrusion treatment on DE, ME. However, the apparent total tract digestibility for crude protein (CP) increased markedly (p<0.05). The standardized ileal digestibility (SID) of all amino acids (AA) except for leucine remarkably increased by extrusion (p<0.05). There was an interaction on the SID of arginine, leucine, isoleucine, methionine, phenylalanine, cystine, and tyrosine in growing pigs between type of grain and extrusion treatment (p<0.05). Conclusion: Extrusion increased the ileal digestibility of CP and most AA in cereals, however, the DE and ME of cereals were not affected in growing pigs.

• Structural Engineering and Mechanics
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• 제67권4호
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• pp.369-383
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• 2018

In this work, a novel hyperbolic shear deformation theory is developed for free vibration analysis of the simply supported functionally graded plates in thermal environment and the FGM having temperature dependent material properties. This theory has only four unknowns, which is even less than the other shear deformation theories. The theory presented is variationally consistent, without the shear correction factor. The present one has a new displacement field which introduces undetermined integral variables. Equations of motion are obtained by utilizing the Hamilton's principles and solved via Navier's procedure. The convergence and the validation of the proposed theoretical model are performed to demonstrate the efficacy of the model.

• 디지털산업정보학회논문지
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• 제15권4호
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• pp.71-84
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• 2019

Various researchers conducted the research on two-factor authentication suitable for wireless sensor networks (WSNs) after Das first proposed two-factor authentication combining the smart card and password. After then, To improve the security of user authentication, elliptic curve cryptography(ECC)-based authentication protocols have been proposed. Jiang et al. proposed a privacy-aware two-factor authentication protocol based on ECC for WSM for resolving various problems of ECC-based authentication protocols. However, Jiang et al.'s protocol has the vulnerabilities on a lack of mutual authentication, a risk of SID modification and a lack of sensor anonymity, and user's ID exposed on sensor node Therefore, this paper proposed security enhanced privacy-aware two-factor authentication protocol for wireless sensor networks to solve the problem of Jiang et al.'s protocol, and security analysis was conducted for the proposed protocol.

• Structural Engineering and Mechanics
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• 제81권4호
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• pp.461-479
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• 2022

A finite element method analysis framework is introduced for the free vibration analyses of functionally graded porous beam structures by employing two variables trigonometric shear deformation theory. Both Young's modulus and material density of the FGP beam element are simultaneously considered as grading through the thickness of the beam. The finite element approach is developed using a nonlocal strain gradient theory. The governing equations derived here are solved introducing a 3-nodes beam element. A comprehensive parametric study is carried out, with a particular focus on the effects of various structural parameters such as the dispersion patterns of GPL reinforcements and porosity, thickness ratio, boundary conditions, nonlocal scale parameter and strain gradient parameters. The results indicate that porosity distribution and GPL pattern have significant effects on the response of the nanocomposite beams.

• Journal of Microbiology
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• 제43권5호
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• pp.424-429
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• 2005

In previous studies, it has been reported that both S. enteritidis, the most common serotype, and S. enteritidis Phage Type 4 (SEPT 4) isolates were identified as the most prevalent PT in domestic poultry and also in humans in Korea until 2002. The aim of this study was to analyze the genetic diversity and epidemiological properties of both PT isolates, and also to trace the source of SEPT 4 isolates from domestic poultry and humans by Pulsed-field gel electrophoresis (PFGE). In order to understand the molecular epidemiologic properties of SEPT 4 isolates, which have very similar phenotypic properties to our preliminary investigations (serotyping, phage typing, large plasmids and antibiograms), PFGE analysis with XbaI enzyme was performed on the representative SEPT 4 isolates. Thirty-six SEPT 4 isolates were analyzed and differentiated with 10 pulsed-field profiles (PFP) expressing very high discriminative ability (SID: 0.921). In PFP, SEPT 4 isolates from human patients showed a perfect genetic match with those from broiler chickens and meats. Therefore, this study was able to successfully trace the major source of SEPT 4 isolates and also to determine the usefulness of the PFGE method for genetic analysis of epidemic strains.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.1016-1025
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• 2009

Two experiments were conducted to determine energy and nutrient digestibility in four sources of distillers dried grains with solubles (DDGS) produced from corn and fed to growing pigs. The objective was to test the hypothesis that energy and nutrient digestibility in DDGS does not vary if samples are procured from ethanol plants that use similar production technologies and use corn that is grown within a narrow geographical area. The four sources of DDGS that were used were procured from ethanol plants that were less than 10 yr old and located within 250 km of each other. In Exp. 1, five growing barrows (initial BW = 71.4 kg) that were fitted with a T-canula in the distal ileum were allotted to a 5${\times}$5 Latin square design and used to measure apparent (AID) and standardized (SID) ileal digestibility of AA in the four sources of DDGS. Results of this experiment showed that the SID of CP and all AA except Cys and Pro were greater (p<0.05) in two of the DDGS sources than in the other two sources. Exp. 2 was conducted to measure the concentration of DE and ME and the apparent total tract digestibility (ATTD) of energy, N, P, ether extract, NDF, and ADF in corn and in the same four sources of DDGS as used in Exp. 1. Five pigs (initial BW = 29.7 kg) that were placed in metabolism cages and allotted to a 5${\times}$5 Latin square design were used. Results of Exp. 2 showed that the average DE and ME in DDGS were 4,072 and 3,750 kcal/kg DM, respectively, which was less (p<0.01) than the DE and ME in corn (4,181 and 4,103 kcal/kg DM, respectively). The average ATTD for P in DDGS was 56.1%, which was greater (p<0.01) than the ATTD for P in corn (31.9%). The ATTD for ADF in DDGS was also greater (p<0.05) than in corn, but the ATTD for ether extract and NDF were greater (p<0.05) in corn than in DDGS. It is concluded that energy and nutrient digestibility vary among sources of DDGS even when the DDGS is procured from ethanol plants that use corn grown within a narrow geographical region. Thus, factors other than corn growing region are responsible for the variability of energy and nutrient digestibility in DDGS.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.343-347
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• 2004

As a first demonstration of proven stability for a-Si, over 7000h of stability data for a high drive current a-Si AMOLED pixel driver circuit was presented at SID 2004. Also demonstrated was an AMOLED display operating at 6V using the IGNIS 4-T pixel driver circuit [1] and based on a top-emission reverse OLED architecture. In this paper, an update to that information is presented with test data that is representative of lifetime in excess of 25,000 hours taking into account pertinent acceleration factors, extracted from high current drive and high temperature stressing conditions. Lifetimes will continue to increase, given the high and ever-increasing OLED efficiency.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 추계학술대회 논문요약집
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• pp.16-16
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• 2003

In this study, for a safety assessment of wheelchair occupant in side impact, we used a dynamic sled impact test results. The test was carried out total 6 times and impact speed was 13g$\pm$0.43/28km/h$\pm$0.95, By using EURO SID-1 dummy, head performance criteria(HPC), abdominal peak force, etc. were measured. We evaluated wheelchair occupant safety by motion criteria(MC) which was measured by head, trunk and side deformation change of wheelchair and Head & Neck injury criteria(HNI) measured by using head and neck deformation angle and time relation. When we assumed that the maximum injury value in side impact was 100%, the results of motion criteria(MC) of wheelchair occupant were max 80.3, mim 32.3 and average 60.3%, Head & Neck injury criteria(HNI) value were max 118.4, min 14.5 and average 59.7%.

• 소성∙가공
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• 제7권4호
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• pp.354-363
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• 1998

In order to analyze the stretch forming characteristics of tailored blanks, laser welded blanks of different thickness and strength combinations were prepared and stretching tests were done. The stretching formability of laser welded blanks was reduced as increasing the deformation restraining force ($strength{\times}thickness$) ratio between two welded sheets. Weld line movement was attributed to strain concentration at weaker sheets and resulted in fracture at weaker sid, so that fracture could be predicted by the forming limit of the weak sheet. In the case of a welded blank with the similar deformation restraining force rations between two welded sheets, crack occurred at weld and its forming limit was about 15% less than the base sheet. The effects of lubrication and weld line position on stretch-ing formability were also investigated by experiments. Lower friction did not always give better formability for tailored blanks. Stretching formability was observed to be improved as increasing the area of weak sheet.