• Journal of Life Science
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• v.14 no.2
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• pp.235-238
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• 2004

The possibility for developing multistage culture system to cultivate larvae by computer simulation with basic experiments was investigated. This culture system was composed of 3 stages. At the 1st stage, Chlorella sp. were cultivated and at 2nd stage Chlorella sp. were supplied to rotifer (Brachionus plicatilis), and rotifer were supplied to larvae at the 3rd stage. In this study, Chlorella sp. were cultivated by batch culture to search for the possibility of continuous feeding to rotifer at 2 nd stage. The maximum specific growth rate ($\mu$$_{max}$) of Chlorella sp. at the logarithmic phase was 0.56 [1/day]. Rotifer was cultivated by fed-batch culture at the feeding rate of Chlorella sp., $10^3$, $10^4$, $10^{5}$ and $10^{6}$ [cells/rotiferㆍh] to search for the relation between the feeding rate of Chlorella sp. and the growth rate of rotifer. As the results, the minimum feeding rate of Chlorella sp. was 2.8 ${\times}$ $10^4$ [cells/rotiferㆍday] in the multistage culture system, then the change of rotifer concentration at 2nd stage was simulated by computer. The required amount of rotifer for the growth of larvae was also increased as the growth of larvae. On the 9th day of the culture, the rotifer uptake rate of larvae was 250 [cells/rotiferㆍday]. Based on these basic experiments and results, It was suggested that the possibility of multistage culture system to cultivate larvae with continuous feeding of Chlorella sp. and rotifer.r.

• Journal of the Korean Home Economics Association
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• v.33 no.2
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• pp.151-157
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• 1995

This is a study on types of foodservice system, the menu, role of the Dietitian, management of the facilities and utensil through the survey conducted at 105 enterprises located in Seoul industrial foodservices which were evenly divided into three groups ; large size of feeding group, medium size of feeding group, small size of feeding group. The sresults are below, 1. Most institutional foodservice was enterprise under direct management. 2. Selective menu was set for the large size of feeding group than small size of feeding group. At budget making, personal management and purchansing management, the dietition role was not important in the large size of feeding group than in the small size of feeding group. 3. Equipped rate of facilities and utensil were greater volume for the large size of feeding group.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.333-335
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• 2001

In this paper, an algorithm for fault location in Auto Transformer(AT) Feeding Railway system is presented. If a fault occurs at the AT feeding circuits of electrical railway system, it is very important to find fault location and to remove it immediately for the purpose of ensuring safety for transportation. Because the characteristics of reactance-distance are not linear, only using one terminal signals to give fault distance is difficult. In this paper, first, using the KVL, 4 voltage equation are obtained. Secondly, eliminating voltage a distance equation which consists of currents at rail and line parameters including mutual effects.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.652-656
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• 2006

Constant load model is widely used for an electric train to perform the static analysis of AT (Auto Transformer) feeding systems. In this model, the train will be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However there must be some constraints imposed on the pantagraph voltage in actual operations. These constraints are established for the reason of protecting the feeding facilities from excessive rise of regenerative braking voltage or guaranteeing the minimum traction power of train. In normal operating situation, the pantagraph voltage of the train should be maintained within these limits. Keeping these facts in minds, we suggest new methods or analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do. The proposed methods are believed to contribute to the assessment of TCR-TSC for compensating reactive powers too.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.51-53
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• 2005

At the railway feeding system, a role of dead section is very important. Because, dead section is essential installation that AC feeding system meets DC feeding system or phase is changed between AC feeding systems. But, in dead section it is possible that an electric train meets interruption. In Korea, a study on the dead section isn't yet accomplished in depth. Accordingly. In this paper, when electric train is in dead-section power quality problem on electric train was dealt. Modeling and simulation using PSCAD/EMTDC was accomplished to analyze.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.883-887
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• 2016

The power supply system in Korean electrified railway has adopted AT feeding. If a fault occurs in some substation for any reason, the vicinity substation must feed electric power on the outage substation through catenary. So, the feeding distance grows twice of the normal state at extended feeding condition. If substation's feeding distance is longer than normal condition, the catenary impedance and train to supply electric power from the substation. Therefore, the severe voltage drop can occur and power supply shall be not allowed. This paper presents the model of compensator against voltage drop using multi-port network algorithm. Whole traction power supply system can be analyzed with this model. Computer simulation including this model is performed based on real train schedule and increased schedule in case studies.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.4
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• pp.174-179
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• 2002

In this paper, the modified simulation algorithms of the Auto Transformer (AT) feeding electric train system were proposed. To obtain terminal voltage of train by using equivalent circuit or the AT feeding system, the iterative method is proposed for which determine the train voltages. The train voltages are iteratively calculated from the system voltage drop and line impedance. In the carte study, the proposed method is verified from actual operation data of the Kwa-Chon line. Also it is verified that the proposed method can be extent to the multi-train simulation tool. The terminal voltage of the multi-train can be calculated by using superposition principle and it is easily applied to the proposed method. Therefore, the proposed method can be a solution for the complexity of the circuit analysis in the existing methods.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.416-421
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• 2002

The purpose of t his paper is to database each factors from experimental results and develop the servo-controlled feeding system on these database. At first, spring back and bending farce are analyzed by basic theory of bending processing. In database, through practical experiment by the expert various types of bending angel and thickness of plate are tested and classified with SB34P and Aluminum. For the development of servo-controlled feeding system, automatic feeding system is designed and manufactured with ball screw and LM guide and performance of the developed feeding system is tested under condition of standard machine tool examination. Also, Mechanical consideration of mainframe in press brake, development of controller based on NC, program for servo-control are studied. Finally, based on experimental data, the system is operated and compared with theoretical data

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.734-740
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• 2023

The effect of feeding frequency on growth performance, body nutrient composition, and hematological parameters of juvenile chum salmon Oncorhynchus keta was investigated. The juveniles (10.9±0.3 g) were fed commercial feed for 30 days with feeding frequencies of 1, 2, 3, 4, or 5 meal (s)/day (n=2 tanks per treatment) in a recirculating aquaculture system (RAS). Fish were fed to satiation at each of the feeding frequencies. At the end of the feeding trial, final body weight, weight gain, and specific growth rate of fish fed 2 meals/day were significantly higher than those of fish fed 1 meal/day(P<0.05); however, no difference was detected among the other feeding frequencies. Daily feed intake significantly increased with increasing feeding frequency, whereas feed and protein utilization efficiencies continuously decreased with increase in the feeding frequency. Among the treatments, fish fed 1 meal/day showed the lowest value in whole-body lipid content and total protein concentration in plasma. Taken together, the optimal feeding frequency for growth performance and feed utilization efficiency in chum salmon juveniles reared in the RAS was determined to be 2 meals/day.

• Journal of Animal Science and Technology
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• v.58 no.10
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• pp.36.1-36.5
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• 2016

Background: Liquid feeding system has been introduced to domestic swine farms, but negative cognition about liquid feeding system has been remained for feed waste decay related with poor management and microbial contamination. For these reasons, this study was conducted to evaluate the effects of feeding method in lactating sows. Methods: A total of 30 mixed-parity (average 4.13) lactating sows (Yorkshire ${\times}$ Landrace) with an initial BW of $218.8{\pm}19.5kg$ was used in a 3 week trial. Sows were allotted to 1 of 2 treatments in a completely randomized design by their body weight, backfat thickness, parity and alive litter weight. One of treatments was dry feeding and the other was liquid feeding (water to feed ratio, 1:1). Experimental diets contained 3265 kcal ME/kg, 12.6 % CP, 5.76 % EE, 1.09 % total lysine, 0.25 % total methionine, as fed basis. Results: Dry feeding treatment had high body weight loss rather than liquid feeding treatment (P = 0.04). Dry feeding treatment had tendency to increase litter weight at 21d of lactation (P = 0.06) and litter weight gain (P = 0.04) during lactation period (0-3 week). Sows fed dry feeding method made milk containing high content of casein and total solid rather than sows fed liquid feeding method (P = 0.04). In addition, dry feeding treatment had tendency to higher content of milk fat, protein and solid not fat on 21d of lactation (P = 0.07). Sows fed dry feeding type also showed higher milk energy content in milk of 21d lactation (P = 0.05). Furthermore, liquid feeding treatment showed high occurrence in feed waste during lactation period (P <0.01). Conclusion: Dry feeding method was more suitable feeding method to lactating sows under high temperature environment like lactating barn.