• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.3
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• pp.45-59
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• 2011

OFDMA systems have been expected to be widely used to provide multimedia services over wireless channels. To evaluate performance of the OFDMA system, power should be considered as system resource as well as subcarriers. This study propose a queueing traffic model incorporating two kinds of resources (power and subcarriers), and an extended model giving a priority to handoff calls over new calls. Some extensive experiments are conducted to illustrate the usefulness of the proposed traffic model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.707-715
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• 2003

In this paper, we propose a new MAC(Medium Access Control) protocol using Movable-boundary, which tries to guarantee Qos for multimedia traffic in the slotted CDMA system. In this scheme, the traffic scheduler assigns channel resource according to the packet priority per service class and adapts the Movable-boundary concept in which the minimum resource is assigned to each traffic class; the remaining resource if it is available can be assigned dynamically according to the temporal demand of other traffic classes. For performance analysis, we performed computer simulations to obtain throughput and packet loss rate and compared the results with Fixed-boundary system. We observed that the error rate of voice traffic could be maintained below a prescribed value while bursty traffic such as video source shares the same channel. In comparison with Fixed-boundary scheme, our protocol exhibits better throughput and packet loss rate performance.

• Animal Bioscience
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• v.34 no.12
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• pp.1987-1994
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• 2021

Objective: The present study aimed to evaluate the effects of varying standardized ileal digestible lysine:threonine (SID Lys:Thr) ratio in the diet on the performance and meat quality of finishing pigs. Methods: In total 192 crossbred pigs ([Landrace×Yorkshire]×Duroc, 17 weeks old), with an initial body weight (BW) of 70.6±3.9 kg were used in an 8-wk trial. Pigs were randomly allotted to one of six dietary treatments based on their initial BW and sex (8 replications; 4 pigs per pen, 2 barrows and 2 gilts). The pigs in the 6 treatments were fed diets having different SID Lys:Thr ratios such as 1:0.65, 1:0.66, 1:0.67, 1:0.68, 1:0.69, and 1:0.70. Results: A linear increment (p<0.05) in average daily gain (ADG) and trends in reduction in feed conversion ratio (FCR) were observed during day 29 to 56 of the experiment and the apparent total tract digestibility (ATTD) of dry matter tended to increase linearly (p = 0.094) at the end of the experiment (day 56) with the increase in the dietary SID Lys:Thr ratios. The backfat thickness and lean percentage increased (linear effect, p<0.05) on day 28. In addition, at day 56, a linear (p<0.05) increment in lean percentage was observed. Significant quadratic responses (p = 0.02) for pH and drip loss at day 7 (p = 0.02), a linear increase (p<0.05) in cooking loss and drip loss at day 7, and a trend in quadratic response (p = 0.07) in the lightness of meat color (L^*) were observed, whereas other meat quality indices were unaffected by varying the SID Lys:Thr ratios. Conclusion: The SID Lys:Thr ratio for maximum ADG, minimum FCR and enhanced digestibility was found to be 0.70. However, for carcass trait and meat quality, the SID Lys:Thr ratio of 0.65 was enough.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.173-180
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• 2010

This study was conducted to investigate the effects of dietary supplementation of mulberry leaves and dandelion extracts on performance, proximate composition, heating loss, drip loss, and blood characteristics of chickens. One hundred sixty broiler chicks were fed diets for five weeks containing 1% mulberry leaves extracts (T1), 2% mulberry leaves extracts (T2), 1% dandelion extracts (T3), and 2% dandelion extracts (T4). At the end of five week feeding experiment, broiler were slaughtered, and stored at $4^{\circ}C$. T2 resulted in much better weight gain and feed conversion than other treatment groups. As storage time increased, all treatment groups resulted in increased heating loss and drip loss (P<0.05) but no significant difference were observed among the treatment groups. In blood composition, GOT (glutamic oxaloacetate transaminase), GPT (glutamic pyrubic transaminase), total cholesterol, and triglyceride were significantly decreased by the supplementation of mulberry leaves and dandelion extracts compared to the control (P<0.05). Especially, T4 was significantly (P<0.05) more effective in improving blood composition compared to other treatment groups. However, no significant difference (P>0.05) were found in LDL-cholesterol among all treatment groups. In conclusion, these data indicate that compared to other treatments, supplementation of 2% dandelion extracts (T4) were most effective in decreasing total cholesterol and triglyceride and increasing HDL-cholesterol.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.349-354
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• 2008

This study was conducted to evaluate the effects of a high protein diet containing barley on the growth performance and carcass characteristics of finishing pigs. A total of fifty six [(Landrace${\times}$Yorkshire${\times}$Duroc)] pigs (85.08 kg in average initial body weight) were used for a 6-week study. Dietary treatments included 1) Basal diet (CON) and 2) High protein diet with barley 5% (HB5). During the entire test periods, there were no significant differences in Average daily gain (ADG), Average daily feed intake (ADFI) and gain/feed ratio between treatments (p>0.05). The b value of M. logissimus dorsi muscle color was significantly increased in CON fed pigs compared to pigs fed the HB5 diet (p<0.05). The water holding capacity (WHC) was higher in HB5 than CON fed pigs (p<0.05). Also, drip loss was significantly decreased in HB5 compared to CON fed pigs (p<0.05). Backfat thickness, live weight, cold carcass weight, dressing, and carcass grade were not significantly affected by either treatment (p>0.05). In conclusion, the results of this study indicate that a high protein diet with 5% barley affects meat color, WHC and drip loss in finishing pigs.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.1-10
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• 2008

In order to high-performance data Processing, effective resource selection is needed since grid resources are composed of heterogeneous networks and OS systems in the grid environment. In this paper. we classify grid resources with data properties and user requirements for resource selection using a decision tree method. Our resource selection method can provide suitable resource selection methodology using classification with a decision tree to grid users. This paper evaluates our grid system performance with throughput. utilization, job loss, and average of turn-around time and shows experiment results of our resource selection model in comparison with those of existing resource selection models such as Condor-G and Nimrod-G. These experiment results showed that our resource selection model provides a vision of efficient grid resource selection methodology.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.5
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• pp.763-772
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• 2018

Objective: Swine manure in Korea is separated into solid and liquid phases which are composted separately and then applied on land. The nutrient accumulation in soil has been a big issue in Korea but the basic investigation about nutrient input on arable land has not been achieved in detail. Within the nutrient production from livestock at the national level, most values are calculated by multiplication of the number of animals with the excreta unit per animal. However, the actual amount of nutrients from swine manure may be totally different with the nutrients applied to soil since livestock breeding systems are not the same with each country. Methods: This study investigated 15 farms producing solid compost and 14 farms producing liquid compost. Composting for solid phase used the Turning+Aeration (TA) or Turning (T) only methods, while liquid phase aeration composting was achieved by continuous (CA), intermittent (IA), or no aeration (NA). Three scenarios were constructed for investigating solid compost: i) farm investigation, ii) reference study, and iii) theoretical P changes (${\Delta}P=0$), whereas an experiment for water evaporation was conducted for analyzing liquid compost. Results: In farm investigation, weight loss rates of 62% and 63% were obtained for TA and T, respectively, while evaporation rates for liquid compost were 8.75, 7.27, and $5.14L/m^2{\cdot}d$ for CA, IA, and NA, respectively. Farm investigation provided with the combined nutrient load (solid+liquid) of VS, N, and P of 117.6, 7.2, and $2.7kg/head{\cdot}yr$. Nutrient load calculated from farm investigation is about two times higher than the calculated with reference documents. Conclusion: The nutrient loading coefficients from one swine (solid+liquid) were (volatile solids, 0.79; nitrogen, 0.53; phosphorus, 0.71) with nutrient loss of 21%, 47%, and 29%, respectively. The nutrient count from livestock manure using the excretion unit has probably been overestimated without consideration of the nutrient loss.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.271-278
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• 2018

In this study, the conventional cylinder-shaped lower bar on the canvas was modified and its performance was tested to improve the opening force of the stow net on anchor. The improved new lower bar used in the test is consisted of 13 flat bars with a length of 1.8 m, a width of 0.075 m and a thickness of 4 mm, and a pipe with a length of 2.0 m and a diameter of 50 mm. A stow net with the improved lower bar and a stow net with an existing lower bar were installed underwater and their trajectories for 21 hours were examined. To confirm their trajectories, GPS loggers were attached to the buoys on the left and right canvases and the buoy of the hauling rope. As a result of the test, the rotation of the gear with the improved bar was smoother than that with the existing bar. As a result of comparing the changes in the interval of the buoys attached to the canvas after the low and high tide, the buoy spacing of the gear with the improved bar is wider than that of the conventional gear; moreover, the larger the interval, the smoother the rotation of the fishing gear was. Therefore, it is considered that using the improved lower bar can enhance the performance of the stow net.

• Journal of the Korea Society of Computer and Information
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• v.13 no.3
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• pp.169-177
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• 2008

Grid resources are composed of various communication networks and operation systems. When a grid system searches and selects grid resources, which meet requirements of a grid user, existing grid resource selection systems are limited due to their storage methods for resource information. In order to select grid resources suitable for requirements of a grid user and characteristics of data, this paper constructs an ontology for grid resources and proposes an ontology-based grid resource selection system. This system provides an inference engine based on rules defined by SWRL to create a resource list. Experimental results comparing the proposed system with existing grid resource selection systems, such as the Condor-G and the Nimrod-G, verify the effectiveness of the ontology-based grid resource selection system with improved job throughput and resource utilization and reduced job loss and job processing time.

• Journal of the Korea Society of Computer and Information
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• v.15 no.8
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• pp.79-87
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• 2010

It is widely accepted that the coverage with high user densities in mobile multimedia environments can only be achieved with small cell such as micro- and pico-cell. If handover events occur during the transmission of multimedia, the efficient resource reservation and handover methods are necessary in order to maintain the same QoS of transmitted multimedia traffic because the QoS may be defected by some delay and information loss. In this paper, we propose a resource allocation method in the next generation mobile communication systems, in which the resource allocation process has a tight relation with call admission, call load, and packet scheduling. The simulation results show that our proposed method provides a excellent performance.