• Journal of Institute of Control, Robotics and Systems
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• v.4 no.4
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• pp.420-426
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• 1998

It is the purpose of this paper to make a preliminary study on the use of repetitive control to improve velocity accuracy by eliminating repetitive disturbances caused by machining inaccuracies of the axis of rotation location. If the control system can be intelligent enough to compensate for such machining errors, then one may be able to improve the accuracy of the velocity control, or alternatively, one may maintain the same accuracy and relax the machining tolerances required. This could decrease cost significantly. Experiments are performed testing repetitive control methods on a constant speed rolling operation testbed. The experimental results show very substantial decreases in the tracking error of the system. Spectral data of the output motion are given to demonstrate the attenuation of the disturbance frequencies and harmonics, related to the bandwidth being used. It is seen that the simplest form of repetitive control which is very easily implemented, can produce striking improvement in control system performance in such belt drive rolling operations, and the learning can be accomplished in a short time.

• Animal Bioscience
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• v.37 no.7
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• pp.1303-1315
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• 2024

Objective: This study aimed to determine the effects of increasing energy and protein levels in diets by including protected fat (PF), glycerol (GL), and soybean meal (SBM) on growth performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions. Methods: Thirty-six steers (initial body weight, 724.9±58.3 kg; age, 25.5±0.4 month) were assigned into control (total digestible nutrient [TDN] 76%, crude protein [CP] 15%), PF (TDN 83.6%, CP 15%), PF+GL (TDN 83.6%, CP 15%) and PF+GL+SBM (TDN 83.6%, CP 16.5%) by randomized complete block design for a total of 16 weeks with division of 4-week periods. The average temperature-humidity index was 87.0 (1st period; severe), 82.8 (2nd; moderate), 71.4 (3rd; comfort), and 68.1 (4th; comfort). Results: The dry matter intake (DMI) showed no treatments differences during the whole experiment. However, DMI in 1st and 2nd period decreased by approximately 30% and 10% compared to 4th period, respectively. Higher average daily gain and feed conversion ratio were noted for treatments compared to control at both 1st and 2nd period (p<0.05). There were no treatment effects on rectal temperature (RT), cortisol, and behaviors during the entire experiment. However, both RT and cortisol in 0, 1st and 2nd period were higher than those of 3rd and 4th period (p<0.05). Carcass yield and grade remained unaffected by increasing TDN and CP levels. Behavioral changes in the hot season (1st period) included reduced lying (43%), increased standing (48%), decreased walking (62%), and decreased eating (38%) (p<0.05), with an increase in drinking by 54%. Rumination during standing was 53% higher, while rumination during lying was about 33% lower compared to the post-hot season (3rd period) (p<0.05). Conclusion: Dietary supplementation of protected fat in late-fattening Hanwoo steers under heat stress had a positive effect on preventing a reduction in performance.

• Journal of the Korea Institute of Building Construction
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• v.8 no.2
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• pp.107-112
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• 2008

According to Korean Architectural Standard Specification (KASS) , at the design stage of the specified concrete strength, strength correction with each temperature level should be considered to secure required strength at 28 days even in low temperature condition, In this paper, the period for the strength correction at the stage of mixture design of the concrete using ordinary Portland cement(OPC) specified in KASS was determined with each region of south Korea based on the meteorological data of KMA(Korea meteorological administration) by applying KASS-5 regulation. In case of 28 days of strength control age, the period for strength correction with 6MPa was calculated to $50{\sim}60$ days and, with 3 MPa. to around 80 days. The period for the strength correction was shown to be decreased with the rise of altitude. The period to consider the delay of the strength development due to low temperature including the period of cold weather concrete was nearly 7 months around 1 year. References for determining the strength correction factors with each region of south Korea was provided in this paper. Further investigation of strength correction of the concrete containing blended cement is to studied.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.139-146
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• 2011

This study investigated physical and physiological changes of normal young adults, who are cadets of the Air Force Academy, have kept long-term physical activities and healthy behavior. The physical and physiological indices were the blood and body composition. Data were collected at the first year period, and then 4th year period from same group of cadets. The amounts of blood components were not changed, but variation among cadets was significantly reduced in the 4th grade period. The red blood cells(RBCs) were significantly reduced and the concentration of hemoglobin(HGB) were significantly increased. The body weight was significantly decreased in the 1st grade period since the body fat was rapidly decreased after the basic military drill, and then it was recovered with building up of the skeletal muscle in the 4th grade period. Asymmetry of the arms was decreased with the increased physical activities and usage of various equipments. The muscular endurance were significantly enhanced in the 4th grade period. The long-term physical activities and healthy behaviors may keep the physical strength through enhanced blood stream and oxygen supply by reduction of the RBCs and increased HGB concentration, and fat and muscle control.

• The Journal of Asian Finance, Economics and Business
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• v.4 no.1
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• pp.25-38
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• 2017

This study investigates the causal relationship between stock prices and exchange rates for six Middle Eastern countries, namely, Egypt, Iran, Jordan, Kuwait, Oman, and Saudi Arabia before and during (after) the 2007 global financial crisis for the period between January 2004 and September 2015. The sample is divided into two sub-periods, that is, the period from January 1, 2004 to September 30, 2007 and the period from October 1, 2007 to September 30, 2015, to represent the pre-crisis period and the post-crisis period, respectively. Using Vector Autoregressive (VAR) model in a multivariate framework (including two control variables, inflation rates and oil prices) the results suggest that in the case of Jordan, Kuwait and Saudi Arabia, there exists bidirectional causalities after the crisis period but not the before. The opposite status is available for the case of Iran. In the case of Oman, there is bidirectional causality between the variables of interest in both periods. The results also reveal that the relationship between stock prices and exchange rates has become stronger after the 2007 global financial crisis. Overall, the results of this study indicate that fluctuations in foreign exchange markets can significantly affect stock markets in the Middle East.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.94-100
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• 2002

The effects of periodic fuel supply on the nonpremixed flame stability and soot formation were experimentally studied. A solenoid valve was used to control the period of fuel supply. The laser induced incandescence technique was used to visualize cool: volume fraction profile. The flame base shape was changed significantly by the fuel supply period and partially by the fuel flowrates. The portion of bluish flame near the flame base became larger as the period increased. When the period was long, two flames coexisted within one period. It seemed that the characteristic of flame stability were repeated with 4.68m change of fuel supply line length. The soot mass measurements and soot volume fraction measurements revealed that the maximum suppression of soot by the perioic fuel supply was approximately 75% , which occurred when the occurred when the fuel supply period was relatively long.

• Journal of Aquaculture
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• v.10 no.2
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• pp.189-197
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• 1997

A series of short (8 hours) and long term (96 hours) exposure studies was conducted on a laboratory scale to evaluation (1) the threshold concentrations of petroleum hydrocarbon in seawater which can lead to tainting problems in yellow tail (Seriola quinqueradiata) and (2) the time to recover (depuration period) once the tainting has occurred. The water-soluble fraction (WSF) of crude oil was prepared by stirring the oil with cold seawater. The main component of the WSF were low-boiling aromatics, although these were only al small proportion of the starting oil. From the sencory evaluation it was concluded that the threshold hydrocarbon levels in seawater which will impart a taint in yellow tail fillets within a 8-hour exposure period (short exposure period) are in the range of 0.4 to 1.0 ppm and within a 96-hour exposure period (long exposure period) are in the range of 0.2 to 0.5 ppm. Depuration trials were carried out with WSF from crude oil. The fish were exposed for 48 hours to concentration of 2.5 ppm hydrocarbons. After 48-hour exposure period, the fish were allowed to depurate in fresh, uncontaminated seawater. Depuration time for these fish was 10 days. The taste panelists were able to detect the contaminated fillets very easily while the depurated fish could not be distiguished from the control.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.897-906
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• 2006

This study was conducted to determine effects of different supplementation periods (2, 3 and 4 months) of spent composts of Se-enriched mushrooms (Se-SMC) on plasma glutathione peroxidase (GSH-Px) activity and selenium deposition of finishing Hanwoo steers for the optimal supplementing period determination in order to produce Se-fortified Hanwoo beef. In the present study, 30 Hanwoo steers were allotted to treatments in six groups of five steers per pen. Treatments were separated into control and Se-SMC for each supplementation period. Dietary selenium contents were 0.1 and 0.9 ppm for control and Se-SMC treatments, respectively. At the end of each supplementation period, steers by periods were slaughtered to collect hind leg and liver samples for their selenium analyses. Blood samples were taken to analyze whole blood Se concentration and plasma GSH-Px activity at the last day of each supplementation period. Dry matter intakes were unaffected by Se-SMC and supplementation periods. In addition, average daily gain was not different between control and Se-SMC treatments and among supplementation periods. There was no difference for total body weight gain between control and Se-SMC treatments within each supplementation period. The supplementation of Se-SMC significantly (P<0.001) increased whole blood Se concentration, but whole blood selenium concentration was not affected by the supplementation period. Furthermore, plasma GSH-Px activity showed similar trend as shown in the pattern of whole blood Se concentration, but no difference by supplementation periods was observed. Selenium contents in hind legs significantly (P<0.05) increased with increasing supplementation periods, and also they were significantly (P<0.001) higher for Se-SMC supplementation groups in comparison to controls. However, there was no difference for selenium contents of hind legs between three and four months supplementation. Selenium contents in livers tended to slightly increase with increasing supplementation periods with no significant difference, but they were significantly (P<0.01) higher for Se-SMC supplementation groups compared with controls within the same period. The results indicated that the optimal Se-SMC supplementation period for the selenium deposition in Hanwoo steers might be around two or three months when we considered selenium contents in hind legs and livers.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.77-88
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• 2005

The effect of different particle sizes of scoria inclusion in weanling-growing-finishing diets on growth performance and carcass quality was investigated in this study. Treatments were the control (basal diet), and 3 scoria treatments with different partical sizes (500, 1,000, 1,700 ${\mu}m$, respectively) in which $3\%$ of basal diet was replaced by scoria. This study was carried out for 143 days using 84 pigs. Each treatment has 3 replicates (4 gilts and 3 barrows per pen). 1. During nursery period, all scoria treatment levels showed poor Average daily gain (ADG) and feed efficiency compared to the control. During growing period, The ADG and feed efficiency of pigs fed the $1,000\;{\mu}m$ swine treatment tended to improve. For the whole growth period (d 0-143), $1,000\;{\mu}m$ scoria treatment showed significantly higher (P<0.05) ADG and feed efficiency than the $1,700\;{\mu}m$ scoria treatment. 2. Carcass weight was higher in all of scoria treatment levels Either the control (P<0.05), while backfat thickness was unaffected among treatments. Carcass Grade A or B grade appearance was more evident in all of scoria treatments compared to the control. 3. Hunter L value was numerically higher in the control while there was no significant differences among the control, $1,000\;{\mu}m$ scoria and $1,700\;{\mu}m$. Hunter a value was highest (P<0.05) in $1,000\;{\mu}m$ scoria, while Hunter b values were not influenced by the scoria treatment levels. 4. The different scoria treatment levels reduced N and P excretion. For growing period, $1,000\;{\mu}m$ scoria was most efficient in reducing N excretion, while during the finishing period, $1,700\;{\mu}m$ scoria was the best. The P excretion was affected by scoria particle size during growing-finishing periods rather than weanling period. The above findings indicated that the inclusion of different scoria partical sizes in nursery diet resulted to adverse effects on growth performance in contrast to the growing finishing diets wherein the growth performance and carcass quality were not affected. Finally, scoria regardless of particle size proved to be effective in reducing N and P excretion and can be considered an environment friendly mineral source for growing-finishing hog diets.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.237-244
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• 2004

This study was conducted to investigate the effects of dietary Animunin Powder$^{?}$ on the egg quality characteristics, blood components and nutrient digestibility in laying hens. A total of two hundred seventy laying hens were randomly allocated into three treaments with fifteen replications for eight weeks. Dietary treaments included 1) Control (CON), 2) Control + $0.1\%$ Animunin Powder$^{?}$ (AM1), 3) Control + $0.2\%$ Animunin Powder$^{?}$ (AM2). During the period of 0~4weeks, the birds fed the AM1 diet had an improved egg production compared to the birds fed the CON (P<0.05). During the period of 4~8weeks the birds fed AM1 diet showed a statistically improved egg production compared to the CON (P<0.05). However, no significant differences were founded in the egg weight. During the period of $4\~8$ weeks the hens fed the AM2 diet had improved egg yolk color compared to the hens fed CON and AM1 diets (P<0.05). In the Haugh unit for the period of $0~4$$weeks, the AM2 treatment showed significantly improved results compared to the CON (P<0.05). Average egg shell breaking showed no significant differences through the experiment period, but in the period of $4\~8$weeks the AM2 treatment tended to be improved compared to the CON and AM1 treatment (P<0.05). There was no significant differences in egg shell thickness. In the serum cholesterol, the AM1 and AM2 treatments were significantly lower than the CON (P<0.05). The concentration of RBC and WBC in the AM treatments tended to increase but there were no significant differences. For the differences of lymphocytes between the end and initiation of the experiment, the hens fed the AM1 treatment were significantly different compared to the hens fed the CON and AM2 treatment (P<0.05). During the period of the experiment, the hens fed the AM1 diet were tended to show higher DM digestibility than the hens fed the CON and AM2 diet, but it was not statistically different. In conclusion, dieatry fed of Animunin Powder$^{?}$ could improve egg production, egg yolk color, and haugh unit.