• Communications for Statistical Applications and Methods
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• v.23 no.6
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• pp.543-553
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• 2016

The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary variables for treatment allocation in crossover designs using Latin squares models. We evaluate the improvement of the efficiency in treatment comparisons using the proposed method. Our simulation study reveals that our proposed method provides a more powerful test compared to simple randomization with the same sample size. The proposed method is illustrated by conducting an experiment to compare two different concentrations of titanium dioxide nanofiber (TDNF) on rats for the purpose of comparing weight gain.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.474-477
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• 2000

Two experiments were conducted to study the use of urea-treated rice straw (UTRS) and whole sugar cane (WSC) crop as roughage sources for dairy cattle during the dry season. Experiment I, four rumen-fistulated dairy crossbred steers were assigned to receive roughage treatments according to a $4{\times}4$ Latin square design: $T_1=urea-treated$ (5%) rice straw, $T_2=UTRS$ and WSC at 75:25% DM, $T_3=UTRS$ and WSC at 25:75% DM, and $T_4=WSC$. Experiment II, three rumen fistulated, late lactating multiparous Holstein-Friesian crossbreds were randomly allotted to a $3{\times}3$ Latin square design to receive three types of roughages; $T_1=WSC$, $T_2=UTRS$, $T_3=WSC+UTRS$ at 50:50% DM. It was found that combination of UTRS and WSC at 75:25 ratio significantly increased DM intake while intake of WSC alone was lowest. Moreover, inclusion of UTRS into WSC enhanced digestibilites (Exp. I). In Exp. II, combination of UTRS with WSC at 50:50 ratio (DM) enhanced DM intake (kg/d) (p<0.05) and especially milk yield, milk fat and protein percentages. The findings suggest the combined use of WSC and UTRS improved the feeding values of these roughages for dairy cattle during the dry season.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.15-27
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• 1997

Randomized block design (RBD) with three replication is very frequently adopted in agricultural experiments of the Rural Development Administration of Korea. Even though it works well in field trials of traditional crops, it may not accomodate trial site conditions and/or experimental environment. In this research report, we deal with two such cases. The first case is for a crop experiment in green houses. In house conditions, RBD may not be appropriate since it cannot reflect two directions of the yield gradient. So, a Latin square design is suggested as an alternative. The second case is for local field experiments of the newly-inbred rice. RBD with three replications is used without doubt for decades, even though the site layout is not appropriately shaped for the design. In this case, we suggest the RBD in two blocks with multiple replicates for control varieties as an alternative. To improve the quality of statistical experimental designs in over one-thousand agricultural trials performed annually in the Rural Development Administration, we need to re-train agricultural researchers on the design and analysis of experiments and call for concerns of Korean statisticians.

• International Journal of Fluid Machinery and Systems
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• v.9 no.3
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• pp.229-236
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• 2016

Exergetic analysis was introduced in optimization of a rotating equilateral triangular internal cooling channel with staggered square ribs to maximize the net exergy gain. The objective function was defined as the net exergy gain considering the exergy gain by heat transfer and exergy losses by friction and heat transfer process. The flow field and heat transfer in the channel were analysed using three-dimensional Reynolds-averaged Navier-Stokes equations under the uniform temperature condition. Shear stress transport turbulence model has been selected as a turbulence closure through the turbulence model test. Computational results for the area-averaged Nusselt number were validated compared to the experimental data. Three design variables, i.e., the angle of rib, the rib pitch-to-hydraulic diameter ratio and the rib width-to-hydraulic diameter ratio, were selected for the optimization. The optimization was performed at Reynolds number, 20,000. Twenty-two design points were selected by Latin hypercube sampling, and the values of the objective function were evaluated by the RANS analysis at these points. Through optimization, the objective function value was improved by 22.6% compared to that of the reference geometry. Effects of the Reynolds number, rotation number, and buoyancy parameter on the heat transfer performance of the optimum design were also discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.980-989
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• 2005

The influence of treated, extruded, partially expelled soybean meals as undegradable protein and bypass fat sources on lactation performance and ruminal fermentation of dairy cows was studied. Experiment 1: nine cows were used in a replicated 3${\times}$3 Latin square design with each period being 3 wk in duration. Cows were fed 440 g/kg forage and 560 g/kg grain diet with one of three extruded soybean meals fed at 110 g/kg of the diet. The 3 soybean meals were 1) twice-extruded soybean meal (ESM; as a control); 2) lignosulfonate-treated, twice-extruded soybean meal (LSM); and 3) calcium oxide plus lignosulfonate-treated, twice extruded soybean meal (CLSM). Experiment 2: 3 ruminally cannulated cows were used in a 3${\times}$3 Latin square to study the treatment influence on ruminal fermentation characteristics. Feeding treated soybean meal to cows in LSM and CLSM treatments did not improve feed intake, milk yield, or milk composition except that cows fed the LSM and CLSM treatments produced less milk protein compared with the ESM treatment. The proportion of $C_{18:2}$ was greater in milk fat of cows fed CLSM compared with that of cows fed the ESM or LSM treatments. Ruminal pH, ammonia, and total volatile fatty acids were not affected by treatment. An increased proportion of $C_{18:2}$ in milk fat suggests that there is a potential use of calcium salts of fatty acids in protecting the lipid portion of extruded soybean meal and further research is needed to explore this potential with full-fat extruded soybeans not with extruded and partially oil expelled soybeans.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.699-707
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• 2002

Diets with foliage of Flemingia (Flemingia macrophylla) or Jackfruit (Artocapus heterophyllus were fed to goats with the objective to study nitrogen (N) balance and effect of a daily supplementation of polyethylene glycol (PEG) on intake and digestion. In experiment 1, three male Alpine${\times}$Jamnapary goats with initial weights varying from 26.9 to 27.7 kg were used in a $3{\times}3$ Latin square design in the dry season. Three Alpine${\times}$Bachthao crosses, 15.3-16.7 kg, were used in the same design in the wet season. The three diets were based on chopped whole sugar cane complemented with the two green foliages, Jackfruit and Flemingia, or soybean meal (SBM). The level of dry matter (DM) offered was 4% of body weight (BW), 2.7% as foliage and 1.3% as chopped whole sugar cane. The amount of SBM offered was calculated to give the same amount of crude protein (CP) as the foliages. Each experimental period lasted 32 days (14 days for adaptation, 7 days for collection and 10 days for rest). Feed intake, apparent digestibility of DM, organic matter (OM), CP, neutral detergent fiber (NDF) and acid detergent fiber (ADF) and retained nitrogen (N) were measured by total faecal and urine collection. In experiment 2, four male goats (Alpine${\times}$Jamnapary) with initial weights from 17.1 to 23.1 kg were used in a $4{\times}4$ Latin square design. The four treatments were Jackfruit or Flemingia with or without addition of PEG, which was fed at a level of 5 g/goat and day by mixing with a small amount of rice bran. Each experimental period lasted 15 days (8 days for adaptation, 7 days for collection). Measurements were done as in experiment 1. The DM digestibility was highest (65.9-74.3%) for goats fed the SBM diet in both the dry and wet season. The DM digestibility of goats fed the Jackfruit and the Flemingia diets was similar in both the dry (58.6-59.2% respectively) and the wet season (53.9-56.1% respectively). The CP digestibility was highest (73.0-73.6%) for the SBM diet followed by the Jackfruit diet (47.0-38.5%) and was lowest (36.8-30.0%) for the Flemingia diet in both dry and wet seasons, respectively. The NDF digestibility was low for both the Jackfruit (36.4%) and Flemingia (38.0%) diets in the wet season. All diets resulted in a positive N balance. The N retention was highest (0.465-0.604 g/kg $W^{0.75}$) in the SBM diets and lowest (0.012-0.250 g/kg $W^{0.75}$) in the Flemingia diet. Addition of PEG had no effect on feed intake for any of the diets. PEG added in the Flemingia diet had a positive effect only on NDF digestibility, but the digestibility of the Jackfruit diet was significantly increased. Supplementation with PEG reduced digestibility and N retention of Flemingia, possibly because of the low tannin level, but increased digestibility and N retention for Jackfruit foliage.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.255-259
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• 1998

Sixteen Friesian Cows were allocated equally into 4 groups in a $4{\times}4$ Latin square design to evaluate the effects of utilizing bean by-products on the feed intake and milk production. Cows were fed on 4.5% of their body weight fresh alfalfa; the remainder of their requirements were covered by one of 4 experimental concentrate treatments: 1) commercial concentrate (CC), 2) 70% CC + 30% bean hulls (BH), 3) 70% CC + 30% Polished bean (PB) and 4) 70% CC+ 15% BH + 15% PB. Results showed that the inclusion of bean hulls at 30% improved (p<0.05) milk yield, 4% fat corrected milk yield, feed conversion ratio and fat percent of the milk over the other treatments. Feeding cows on a commercial concentrate plus 30% BH or 30% PB or 15% from each of BH and PB decreased the cost of feed per kg milk by 13.6, 2.5 and 1.3 %, respectively, lower than those fed on the commercial concentrate.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.117-122
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• 1996

The purpose of this study was to investigate the effect of colors of feed-trough on the eating behaviour of pullets. A total of 64 12wks old pullets were assigned to a $4{\times}4$ Latin square design with 4 treatments(control, blue, yellow, red colored feed-troughs). The results of the study are summarized as follows: 1. Average daily gain and eed intake of the pullets were significantly(P<0.05) decreased with red color feed-troughs. 2. Feed conversion ratio appeared to be improved in the yellow color group compared to the others. 3. Total time spent for eating were not significantly different, among treatments.

• Journal of Powder Materials
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• v.13 no.6 s.59
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• pp.450-454
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• 2006

Wear of steel plate was measured during unlubricated sliding against TiC composites. These composites consist of round TiC grains and steel matrix. TiC grain itself exhibits low surface roughness and round shape, which does not bring its counterpart into severe damage from friction. In our work a classical experimental design was applied to find out a dominant factor in counterpart wear. The analysis of the data showed that only the applied load has a significant effect on the counterpart wear. Wear rate of counterpart increased non-linearly with applied load. Amount of wear was discrepant from expectation of being in proportion to the load by analogy with friction force. Our experimental result from treating matrix variously revealed bimodal wear behavior between the composites and counterpart where a mode seems to result from the special lubricant characteristic of TiC grains, and the other is caused by metal-to-metal contact. The two wear mechanisms were discussed.

• Journal of Pharmaceutical Investigation
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• v.17 no.3
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• pp.127-133
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• 1987

Dissolution characteristics and urinary excreted amount of commercially available three brands of sulfisoxazole tablets were investigated in order to elucidate the in vitro-in vivo correlations and relative bioavailability in humans. All the tablets tested met the K.P. IV and the USP XXI specifications for tablet weight variation, content uniformity, disintegration and dissolution. The disintegration and dissolution rate constants of sulfisoxazole tablets in pH 2.0 HCl-KCl buffer were reduced more significantly (p<0.05) than those in diluted HCl $(1{\rightarrow}12.5)$ and pH 6.5 phosphate buffer. It seemed to be attributed to the pH dependent solubility of sulfisoxazole. We could see that the relative bioavailability of brand B to sulfisoxazole powder was about 90% and that its value was higher than those of other two brands from the urinary excretion data obtained from eight healthy male volunteers by means of Latin square cross over design. No useful correlation was observed between the in vitro and in vivo studies in this experiment.