• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.304-307
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• 1998

High speed railway is under construction from Seoul to Pusan. A traveling train is large single phase load that consumes 14MW power in feeding system of high speed railroad. In this paper, measurement scheme and method of power system harmonics which are generated from those loads in railroad supply system are described. This measurement scheme will be used as a first step to pave a way to power quality management due to harmonic distortion by the highspeed rail way.

• Journal of Animal Environmental Science
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• v.5 no.3
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• pp.203-216
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• 1999

Recent public concern about air pollution caused by swine production facilities has forced to develop the methods to reduce and control the swine odors. Swine odors were affected the life of pig farm neighborhoods, swine productivity, pig health, diseases, and human right, safety, sanity as negatively. The first approaches of control of swine odors are the change or improve of the classical management systems, which are manure treatment method, manure storage facility, phase feeding, sex-divided feeding, feeder type, liquid-slurry feeding, environment control of swine building and dust control of indoor swine facility. The methods to control odor emission from manure have to include the diet modification as nutritional basis. In recent, research emphasis has focused on manipulating the swine diet to increase the nutrient utilization of the diet to reduce excretion products and reduction of odors. There are lots of feed additives and pit additives introduced as practical basis for reducing odor emissions. The ozone treatment method is candidate as the good system for reducing swine odor. But this system is still too expensive to practice in present.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.185-195
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• 2015

Glucoamylase is an important industrial enzyme. Glucoamylase production by industrial Aspergillus niger strain featured with two major problems: (i) empirical substrate feeding methods deteriorating the fermentation performance; and (ii) the high raw materials cost limiting the economics of the glucoamylase product with delegated specification. In this study, we first proposed a novel three-stage varied-rate substrate feeding strategy for efficient glucoamylase production in a 5 L bioreactor using the standard feeding medium, by comparing the changing patterns of the important physiological parameters such as DO, OUR, RQ, etc., when using different substrate feeding strategies. With this strategy, the glucoamylase activity and productivity reached higher levels of 11,000 U/ml and 84.6 U/ml/h, respectively. The performance enhancement in this case was beneficial from the following results: DO and OUR could be controlled at the higher levels (30%, 43.83 mmol/l/h), while RQ was maintained at a stable/lower level of 0.60 simultaneously throughout the fed-batch phase. Based on this three-stage varied-rate substrate feeding strategy, we further evaluated the economics of using alternative carbon sources, attempting to reduce the raw materials cost. The results revealed that cornstarch hydrolysate could be considered as the best carbon source to replace the standard and expensive feeding medium. In this case, the production cost of the glucoamylase with delegated specification (5,000 U/ml) could be saved by more than 61% while the product quality be ensured simultaneously. The proposed strategy showed application potential in improving the economics of industrial glucoamylase production.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.91-104
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• 2000

Many synthetic bone materials have been studied for their potential of regenerative effects in periodontal tissue. Safflower seeds have been traditionally used as a drug for the treatment of fracture and blood stasis in oriental medicines. The purpose of this study was to assess and compare the osseous responses in rat calvarial defects between bone substitutes such as calcium carbonate and bovine-derived hydroxyapatite and feeding of safflower seeds. The calvarial defects were made with 8 mm trephine bur in 24 Sprague-Dawley rats. Two graft materials were implanted in each experimental groups, whereas the control and safflower seed feeding groups were sutured without any other treatment. And then the rats of safflower seed feeding group were supplied with 3 g/day of safflower seeds. Each group was sacrificed at 4 weeks and 8 weeks. To study a histopathology related to bone healing and regeneration, Goldner's Masson Trichrome stain was done at each weeks. The tissue response was evaluated under light microscope. There were more osteoblastic activity, new bone formation, dense bony connective tissues in bovine-derived hydroxyapatite group compared to other groups at 8 weeks. The osseous defect area of safflower seed feeding group was filled with prominent fibrous tissues, where less inflammatory infiltration and new capillary proliferation. In the early phase of bone healing, safflower seed feeding reduces the inflammatory response and promotes the proliferation of connective tissue. These results suggest that natural bovine-derived HA and safflower seed feeding could enhance the regenerative potential in periodontal defects.

• Journal of Animal Science and Technology
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• v.56 no.7
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• pp.24.1-24.6
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• 2014

The present study investigated the effects of varying durations of nursery diets differing in percentages of milk products on growth performance of pigs during the nursery phase (NP) and subsequent grow-finish phase (GFP) to find the feasibility of reducing the use of nursery diets containing costly milk products. A total of 204 21-d-old weanling female and castrated male pigs were subjected to one of three nursery phase feeding programs differing in durations on the NP 1 and 2 and GFP diets containing 20%, 7%, and 0% lacrosse and 35%, 8%, and 0% dried whey, respectively, in 6 pens (experimental units) for 33 d: HIGH (NP 1, 2 and 3 diets for 7, 14, and 12 d), MEDIUM (NP 2 and 3 for 14 and 19 d), and LOW (NP 2 and 3 and GFP 1 for 7, 14, and 12 d). Subsequently, 84 randomly selected pigs [14 pigs (replicates)/pen] were fed the GFP 1, 2 and 3 diets during d 54-96, 96-135, and 135-182 of age, respectively. The final body weight (BW) and average daily gain (ADG) of nursery pigs did not differ among the HIGH, MEDIUM, and LOW groups (14.8, 13.3, and 13.7 kg in BW and 273, 225, and 237 g in ADG, respectively). The average daily feed intake during the nursery phase was greater (p < 0.01) in the HIGH group than in the MEDIUM and LOW groups, whereas the gain:feed ratio did not differ across the treatments. The BW on d 182 and ADG during d 54-182 were greater in the HIGH and MEDIUM groups vs. the LOW group (110.0, 107.6, and 99.6 kg in BW, respectively; p < 0.01). The backfat thickness and carcass grade at slaughter on d 183 did not differ across the treatments. In conclusion, the MEDIUM program may be inferior to the commonly used HIGH program in supporting nursery pig growth. Nevertheless, the former appears to be more efficient than the latter in production cost per market pig whereas the LOW program is thought to be inefficient because of its negative effect on post-nursery pig growth.

• Journal of Welding and Joining
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• v.11 no.2
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• pp.74-85
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• 1993

Effect of Si metal powders addition with the plasma transferred arc(PTA) overlaying process on characteristics of the alloyed layer in aluminum alloy(A5083) has been investigated. The overlaying conditions were 175-250A in plasma arc current, 500mm/min in travel speed, the 5-20g/min in powder feeding rate. Main results obtained are summarized as follows. 1)Sufficient size of molten pool on surface of base metal was required for forming an alloyed layer; in a fixed travel, the formation of alloyed layer with clear and beautiful surface depend upon the plasma arc current and powder feeding rate; the greater plasma arc current and the smaller powder feeding rate were, the better bead was formed. Optimum alloyed conditions by which an excellent alloyed bead obtained was 225A in plasma arc current. PTA process made it possible to form an alloyed layer with up to 67wt% Si. 2)Microstructure in the alloyed layer was in accord with prediction from the Al-Si phase diagram 3)The hardness of the alloyed layer increased in proportion to Si content. 4)As volume fraction of primary Si increased, the specific wearness of the alloyed layer was significantly improved. However, no further improvement was found when the volume fraction was greater than about 30%. 5)Utilizing the PTA process, a crack free alloyed layer with maximum hardness of about Hv 310 could be obtained.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.353-359
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• 1988

In this paper, the design and implementation of a multi-processor based die bonder machine for the semiconductor will be described. This is a final research results carried out for two years from June, 1986 to July, 1988. The mechanical system consists of three subsystems such as bonding head module, wafer feeding module, and lead frame feeding module. The overall control system consists of the following three subsystems each of which employs a 16 bit microprocessor MC 68000 : (i) supervisory control system, (ii) visual recognition / inspection system and (iii) the display system. Specifically, the supervisory control system supervises the whole sequence of die bonder machine, performs a self-diagnostics while it controls the bonding head module according to the prespecified bonding cycle. The vision system recognizes the die to inspect the die quality and deviation / orientation of a die with respect to a reference position, while it controls the wafer feeding module. Finally, the display system performs a character display, image display ans various error messages to communicate with operator. Lead frame feeding module is controlled by this subsystem. It is reported that the proposed control system were applied to an engineering sample and tested in real-time, and the results are sucessful as an engineering sample phase.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.504-510
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• 2016

In general, a fault locator is installed in Sub-Station of AT(Auto-transformer) feeding system to estimate the fault location and to protect the Korean AT feeding system. Since the line impedance characteristic is different to normal 3-phase transmission line, we need particular modification factors, which can be calculated using fault location recording data, to estimate the accurate fault location. Up to recently, forcible ground test has been used to calculate the modification factors of the fault locator. However, large amount of current is occurred when the forcible ground test is performed, and this current affects to adjacent equipments. Therefore, we proposed a novel calculation method of modification factors, arbitrary trip test, using boosting current of the operating electric train. Through several field test, we confirmed that modification factors for fault locator can be easily calculated by using proposed method. Moreover, we verified the accuracy and stability of the proposed calculation method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.5
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• pp.355-365
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• 2017

In this paper, we propose the design of a dual-band GPS antenna using in-direct feeding pads. The antenna consists of an upper patch for the GPS L1 band, a lower patch for the GPS L2 band, and two pads on the middle layer for feeding the two radiating patches. A hybrid chip coupler with a phase difference of $90^{\circ}$ is employed at the two feeding ports for achieving a broad circular polarization (CP) bandwidth. The proposed antenna shows bore-sight gains of 3.0 dBic(L1) and 5.1 dBic(L2), and axial ratios of 3.3 dB(L1) and 0.3 dB(L2) by measurement. The active element patterns of the fabricated array with 7 elements show bore-sight gains of -0.4 dBic (L1) and -2.4 dBic(L2), respectively. It proves that the proposed antenna structure is suitable for use in GPS array applications.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1394-1399
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• 2001

Influence of pre-weaning nutrition on post-weaning gain was assesses under intensive feeding in Malpura lambs. Thirty six Malpura (15 days old) lambs divided in to 3 equal groups were maintained on high (G1), medium (G2) and low (G3) energy and protein containing creep mixture with free suckling and ad libitum roughage (pala leaves: Ziziphus nummularia) up to 90 days of age. The lambs during post-weaning phase were fed on a 40:60 roughage and concentrate based composite diet to assess their post-weaning growth response. Total dry matter intake in pre-weaning phase was higher (p<0.01) in G3 than G2 and G1 while feed conversion efficiency was better in G1 than G2 and G3. The birth weight, 15 days body weight and weaning weight were however similar in the three groups. The finishing body weight, total body weight gain and average daily gain during post-weaning phase were higher (p<0.01) in G3 than in G1 and G2. The lambs in G3 consumed more (p<0.01) dry matter during post-weaning phase along with better feed conversion efficiency than other two groups. However, the DCP intake/kg body weight gain was higher in G1 than G2 and G3. Digestibility of DM, OM, CP, NDF, ADF and energy were similar among the three groups during post-weaning phase. Percent nitrogen retention as nitrogen intake was higher (p<0.01) in G3 (71.1%) than G1 (67.7%) and G2 (69.7%) during the post-weaning phase of study. The G1, G2 and G3 lambs in post-weaning phase consumed 8.1, 7.7 and 8.1 g DCP and 246.8, 227.2 and 246.1 kcal $DE/kg\;W^{0.75}/d$ and had 84.4, 80.0 and 111.1 g average daily gain, respectively. It is concluded that the lambs fed on low energy and protein containing creep mixture in pre-weaning phase showed improvement in growth during post-weaning phase under optimum feeding regime.