• Progress in Medical Physics
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• v.25 no.4
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• pp.225-232
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• 2014

We evaluated the effect of scatter on a build-up region based on the measured percent depth dose (PDD) of high-energy photon beams that penetrated a handmade build-up modifier (BM) as a substitute of bolus. BM scatter factors ($S_{BM}$) were calculated based on the PDDs of photon beams that penetrated through the BM. The calculated $S_{BM}$ values were normalized to 1 at the square field side (SFS) of 30 mm without a BM. For the largest SFS (200 mm), the SBM values for a 6-MV beam were 1.331, 1.519, 1.598, 1.641, and 1.657 for the corresponding BM thickness values. For a 10-MV beam, the $S_{BM}$ values were 1.384, 1.662, 1.825, 1.913, and 2.001 for the corresponding BM thickness values. The BM yielded 76% of the bolus efficiency. We expect BM to become useful devices for deep-set patient body parts to which it is difficult to apply a bolus.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.4
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• pp.355-362
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• 2012

Remaining useful life(RUL) prediction of a system is important in the prognostics field since it is directly linked with safety and maintenance scheduling. In the physics-based prognostics, accurately estimated model parameters can predict the remaining useful life exactly. It, however, is not a simple task to estimate the model parameters because most real system have multivariate model parameters, also they are correlated each other. This paper presents representative methods to estimate model parameters in the physics-based prognostics and discusses the difference between three methods; the particle filter method(PF), the overall Bayesian method(OBM), and the sequential Bayesian method(SBM). The three methods are based on the same theoretical background, the Bayesian estimation technique, but the methods are distinguished from each other in the sampling methods or uncertainty analysis process. Therefore, a simple physical model as an easy task and the Paris model for crack growth problem are used to discuss the difference between the three methods, and the performance of each method evaluated by using established prognostics metrics is compared.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.85-94
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• 2002

For Exp, 1, eighty [(DurocYorkshire)Landrace) pigs(38.63$\pm$0.68kg average initial BW) were used to evaluate the effects microbial phytase supplementation on the growth performance and nutrient digestibility in growing pigs. There were ten pigs per pen and four pens per treatment. Treatments were 1) CON(com-SBM based diet), 2) Low-P(low-P diet+500 FTU/kg microbial phytase). For overall period, ADG, ADFI and gain/feed were significantly improved(P<0.05) by supplementation of Low-P diet. Also, pigs fed Low-P diet increased N, crude ash, Ca and P digestibilities compared to pigs fed CON diet(P<0.05). For Exp. 2, sox [(DurocYorkshire) Landrace) pigs(32.7kg average initial BW) were used to evaluate the effects microbial phytase supplementation on the nutrient excretion in growing pigs. Experimental treatments were as described for Exp. 1. pigs fed Low-P diet decreased N(8.70 vs 6.43g/d), crude ash(38.13 vs. 25.33 g/d), Ca(6.03 vs. 3.93g/d) and P(4.53 vs. 2.77g/d) excretion compared to pigs fed CON diet(P<0.05). In conclusion, microbial phytase supplementation in low P diets improved growth and nutrient digestibility.

• Journal of Animal Science and Technology
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• v.61 no.5
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• pp.294-303
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• 2019

This study was performed to evaluate the effects of dietary vitamin levels on physiological responses, blood profiles, and reproductive performance in gestating sows. A total of 52 F1 multiparous sows ($Yorkshire{\times}Landrace$) with an average body weight of $223.5{\pm}31.7kg$, an average parity of $6.4{\pm}2.7$, and an average backfat thickness of $18.5{\pm}4.9mm$ were divided into four treatment groups considering body weight, backfat thickness, and parity in a completely randomized design with 13 replicates. The treatments were 100% (V1), 300% (V3), 600% (V6) and 900% (V9) of the National Research Council (NRC) Nutrient Requirements of Swine. The gestation diet was formulated based on corn-soybean meal (SBM) and contained 3,265 kcal of metabolizable energy (ME)/kg and 12.00% crude protein. During the lactation period, all sows were fed the same commercial lactation diet. There was no significant difference in body weight of gestating sows. However backfat thickness tended to increase when higher levels of vitamins were provided to gestating sows (p < 0.10). When high levels of dietary vitamins were provided, the body weight change of lactating sows increased (p < 0.01). When sows were fed higher levels of vitamins, the feed intake of lactating sows tended to decrease (p = 0.06). There were no treatment differences in the number of total born, born alive, stillbirth piglets, or the body weight of piglets according to different dietary vitamin level. As dietary vitamin level increased, the serum concentration of $25(OH)D_3$ in sows at 90 days of gestation linearly increased (p < 0.01). Furthermore, the serum vitamin E level of gestating sows was linearly increased with increasing dietary vitamin level (p < 0.05). The current NRC vitamin requirements are sufficient for gestating sows and higher levels of vitamins in the gestation diet did not show any beneficial effects for gestating and lactating sows.

• Korean Journal of Materials Research
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• v.11 no.7
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• pp.556-561
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• 2001

We prepared a new a SOS(silicon-on-silicide) wafer pair which is consisted of Si(100)/1000$\AA$-NiSi Si (100) layers. SOS can be employed in MEMS(micro- electronic-mechanical system) application due to low resistance of the NiSi layer. A thermally evaporated $1000\AA$-thick Ni/Si wafer and a clean Si wafer were pre-mated in the class 100 clean room, then annealed at $300~900^{\circ}C$ for 15hrs to induce silicidation reaction. SOS wafer pairs were investigated by a IR camera to measure bonded area and probed by a SEM(scanning electron microscope) and TEM(transmission electron microscope) to observe cross-sectional view of Si/NiSi. IR camera observation showed that the annealed SOS wafer pairs have over 52% bonded area in all temperature region except silicidation phase transition temperature. By probing cross-sectional view with SEM of magnification of 30,000, we found that $1000\AA$-thick uniform NiSi layer was formed at the center area of bonded wafers without void defects. However we observed debonded area at the edge area of wafers. Through TEM observation, we found that $10-20\AA$ thick amourphous layer formed between Si surface and NiSix near the counter part of SOS. This layer may be an oxide layer and lead to degradation of bonding. At the edge area of wafers, that amorphous layer was formed even to thickness of $1500\AA$ during annealing. Therefore, to increase bonding area of Si NiSi ∥ Si wafer pairs, we may lessen the amorphous layers.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.569-576
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• 2003

An experiment was conducted to investigate the effect of microbial phytase (Natuphos$^{\circledR}$) supplementation, individually and in combination with carbohydrase enzyme complex (composed of enzymes targeted to SBM dietary components such as $\alpha$-galactosides and galactomannans; ENDO-POWER$^{\circledR}$) to corn-soy basis diet with low nutrient levels on growth performance and nutrient digestibility of growing pigs. A total of 48 crossbred weaned pigs (Landrace${\times}$Yorkshire${\times}$Duroc), 29.1$\pm$0.14 kg of initial body weight, were randomly allotted to four dietary treatments, based on weight and age, according to a Randomized Complete Block Design. There were three pens per treatment and 4 pigs per pen. The dietary treatments were 1) CON (control diet with 3,380 kcal/kg of metabolizable energy, 18.96% of crude protein, 1.10% of lysine, 0.75% of calcium and 0.35% of available phosphorus), 2) LP+NTPS (CON diet with 0.15% unit lower available P levels+0.1% phytase (500 FTU/kg; Natuphos$^{\circledR}$)), 3) LEL+ENP (CON diet with 3.0% unit lower ME and lysine levels + 0.1% carbohydrase enzyme complex (ENDO-POWER$^{\circledR}$), and 4) LPEL+ENZ (CON diet with 0.15% unit lower available P levels and 3.0% unit lower ME and lysine levels+0.1% ENDO-POWER$^{\circledR}$ and 0.1% Natuphos$^{\circledR}$ (500 FTU/kg). There was no significant difference (p〉0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) among dietary treatments during the whole experimental period (0 to 4 weeks). Apparent digestibility of gross energy was greater in LP+NTPS and LPEL+ENZ groups than in the LEL+ENP (p<0.05). Apparent digestibility of phosphorus was greater in LP+NTPS than in LEL+ENP (p<0.05). Dry matter excretion was lowest in LPEL+ENZ and phosphorus excretion was lowest in LP+NTPS (p<0.05). Overall, pigs fed on LPEL+ENZ group tended to have better nutrient digestibility (dry matter, gross energy, crude protein and phosphorus) than pigs fed on control group. All dietary enzyme treatment groups showed lower feed cost/body weight gain of pigs than control group. In conclusion, the results from the present study suggest that the simultaneous inclusion of phytase and carbohydrase enzyme complex to diets is advantageous with respect to reducing nutrient excretion of growing pigs and may contribute to increased economic return when added to corn-soy based growing pig diets.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.251-264
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• 2003

This study was conducted to make on-site survey on the output pattern and utilization situation of 19 by-products selected, to evaluate their nutritional characteristics, to find out a reliable index with which digestion of by-products can be predicted on the basis of chemical compositions analyzed and to diagnose the risk of using book values in the absence of the actual values analyzed for diet formulation. Production and utilization situations of by-products were quite various. Nutritionally, fruit processing by-products such as apple pomace (AP), pear pomace (PP), grape pomace (GP), and persimmon peel (PSP), and bakery by-products (BB) were classified as energy feeds. Soybean curd meal (SCM), animal by- products such as blood (BD), feather meal (FM) and poultry by-products (PB), and activated milk processing sludge (AMS) were classified as protein feeds. Soy hulls (SH), spent mushroom compost (SMC), barley malt hulls (BMH), waste paper (WP) and broiler litter (BL) were classified as roughage. Rumen contents (RC) and restaurant food waste (FW) were nutritionally analogous to complete diets for cattle and swine, respectively. Compared to soybean meal (SBM), BD and FM contained high (P<0.05) levels of amino acids and barley malt sprouts (BMS), AMS and FW contained low (P<0.05) levels of amino acids. Enzymatic (pepsin) digestibilities of proteinaceous feeds ranged between 99 and 66%. In vitro DM digestibility was high (P<0.05) in the order of FW, BB, AP, SH, PP, PSP, BMH, BMS, SCM, GP, RC, PB, BL, WP, SMC, AMS, FM and BD. In vitro DM digestibility had the highest correlation (r=0.68) with nonfibrous carbohydrate among chemical components. Differences between analyzed values of chemical components and book values were considerable. Caution is required in using book values when large amount of by-products are used in diets.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.211-218
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• 2003

For the Exp. 1, a total of sixty pigs (10.57$\pm$0.30kg average initial body weight) were used in a 15-d growth assay to determine the effect of dietary $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase on growth performance and nutrient digestibility. Dietary treatments included 1) CON (corn-dried whey-SBM based diet), 2) EC0.1 (CON diet+0.1% enzyme complex of $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase). Through the entire experimental period, gain/feed of pigs fed EC0.1 diet was higher (0.43 vs 0.52) than that of pigs fed CON diet (P<0.05). Pigs fed EC0.1 diet showed significant (P<0.05) improvement in dry matter (74.82% vs 82.41%) and nitrogen (70.59% vs 77.88%) digestibilities compared to pigs fed CON diet. For the Exp. 2, a total of thirty six pigs (22.30$\pm$0.45kg average initial body weight) were used in a 30-d growth assay to determine the effects of dietary $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase in low energy diet on growth performance and nutrient digestibility. Dietary treatments included 1) AME (adequate ME diet), 2) AME+EC0.1 (AME diet+0.1% enzyme complex) and LME+EC0.1 (low ME diet + 0.1% enzyme complex). Through the entire experimental period, average daily feed intake of pigs fed enzyme complex supplemented diets was higher than that of pigs fed CON diet (P<0.05). Also, pigs fed AME+EC0.1 diet showed significant (P<0.05) increase in ADFI (1,401g vs 1,733g) compared to pigs fed CON diet. Pigs fed enzyme complex supplemented diet showed significant (P<0.05) improvement in dry matter and nitrogen digestibilities compared to pigs fed CON diet. In conclusion, the results obtained from these feeding trials suggest that the supplementation of $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase was an effective means for improving growth performance and dry matter and nitrogen digestibilities in nursery and growing pigs.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.120-129
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• 2003

The anodic alumina is synthesized using 0.3M oxalic acid and the barrier layers of the anodic alumina are removed using the 20wt% $H_2SO_4$ solution. The structure of the anodic alumina is analyzed by XRD and SEM. It is observed by SEM that the size of anodic alumina pore is about 60nm. And the uniformity of the anodic alumina surface under the 20wt% $H_2SO_4$ solution is poorer than the unifomity of the the normal anodic alumina surface. The anodic alumina and the carbon are used cathode and anode in$Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions. In this study, the constant D.C. electrical current is flowed in each solution for 24hours. It is found that the voltages so far as 4.6, 3.4 and 5.1V at $Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions increase with increasing the flowing current time and after the voltage does not change which values are 4.2, 2.7 and 2.4V, respectively. The amount of metal ions in solutions decrease with increasing the flowing current time until the flowing current time is 18hours and the metals are formed at the surface of anodic alumina. After the metal ions are removed using the anodic alumina, and $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are removed again using flow cell with retriculate vitreous carbon(RVC) working electrode. The concentration of $Cd^{2+}$, and $Co^{2+}$ions decrease until the flowing time of the solutions is 20minutes and the concentration of $Pb^{2+}$ ion decreases until that time is 30minutes. In this case, the removal effects of $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are 34.78, 28.79 and 86.38%, respectively. And it is possible that both $Cd^{2+}$ and $Co^{2+}$ions are adsorbed in pore of RVC at the same time and the removal effects of $Cd^{2+}$ and $Co^{2+}$ions are 32.30 and 31.37%.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.367-371
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• 2001

In this paper, theS $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) films among ferroelectric materials having a low dielectric constant for metal-ferroelectric-semiconductor field effect transistor(MFS-FET) were discussed. The STNO thin films were deposited on p-type Si(100) at room temperature by co-sputtering with S $r_2$N $b_2$ $O_{7(SNO)}$ ceramic target and T $a_2$ $O_{5}$ ceramic target. The composition of STNO thin films was varied by adjusting the power ratios of SNO target and T $a_2$ $O_{5}$ target. The STNO films were annealed at 8$50^{\circ}C$, 90$0^{\circ}C$ and 9$50^{\circ}C$ temperature in oxygen ambient for 1 hour. The value of x has significantly influenced the structure and electrical properties of the STNO films. In the case of x= 0.4, the crystallinity of the STNO films annealed at 9$50^{\circ}C$ was observed well and the memory windows of the Pt/STNO/Si structure were 0.5-8.3 V at applied voltage of 3-9 V and leakage current density was 7.9$\times$10$_{08}$A/$\textrm{cm}^2$ at applied voltage of -5V.of -5V.V.V.