• KIPS Transactions on Computer and Communication Systems
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• v.10 no.10
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• pp.261-268
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• 2021

Cloud computing is a computing paradigm in which users can utilize computing resources in a pay-as-you-go manner. In a cloud system, resources can be dynamically scaled up and down to the user's on-demand so that the total cost of ownership can be reduced. The Modeling and Simulation (M&S) technology is a renowned simulation-based method to obtain engineering analysis and results through CAE software without actual experimental action. In general, M&S technology is utilized in Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD), Multibody dynamics (MBD), and optimization fields. The work procedure through M&S is divided into pre-processing, analysis, and post-processing steps. The pre/post-processing are GPU-intensive job that consists of 3D modeling jobs via CAE software, whereas analysis is CPU or GPU intensive. Because a general-purpose desktop needs plenty of time to analyze complicated 3D models, CAE software requires a high-end CPU and GPU-based workstation that can work fluently. In other words, for executing M&S, it is absolutely required to utilize high-performance computing resources. To mitigate the cost issue from equipping such tremendous computing resources, we propose HEMOS-Cloud service, an integrated cloud and cluster computing environment. The HEMOS-Cloud service provides CAE software and computing resources to users who want to experience M&S in business sectors or academics. In this paper, the economic ripple effect of HEMOS-Cloud service was analyzed by using industry-related analysis. The estimated results of using the experts-guided coefficients are the production inducement effect of KRW 7.4 billion, the value-added effect of KRW 4.1 billion, and the employment-inducing effect of 50 persons per KRW 1 billion.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.61-71
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• 2015

Purpose : 3D Printers are used to create three-dimensional models based on blueprints. Based on this characteristic, it is feasible to develop a bolus that can minimize the air gap between skin and bolus in radiotherapy. This study aims to compare and analyze air gap and target dose at the branded 1 cm bolus with the developed customized bolus using 3D printers. Materials and Methods : RANDO phantom with a protruded tumor was used to procure images using CT simulator. CT DICOM file was transferred into the STL file, equivalent to 3D printers. Using this, customized bolus molding box (maintaining the 1 cm width) was created by processing 3D printers, and paraffin was melted to develop the customized bolus. The air gap of customized bolus and the branded 1 cm bolus was checked, and the differences in air gap was used to compare $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$ and $V_{95%}$ in treatment plan through Eclipse. Results : Customized bolus production period took about 3 days. The total volume of air gap was average $3.9cm^3$ at the customized bolus. And it was average $29.6cm^3$ at the branded 1 cm bolus. The customized bolus developed by the 3D printer was more useful in minimizing the air gap than the branded 1 cm bolus. In the 6 MV photon, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 102.8%, 88.1%, 99.1%, 95.0%, 94.4% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 101.4%, 92.0%, 98.2%, 95.2%, 95.7%, respectively. In the proton, at the customized bolus, $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of GTV were 104.1%, 84.0%, 101.2%, 95.1%, 99.8% and the $D_{max}$, $D_{min}$, $D_{mean}$, $D_{95%}$, $V_{95%}$ of branded 1cm bolus were 104.8%, 87.9%, 101.5%, 94.9%, 99.9%, respectively. Thus, in treatment plan, there was no significant difference between the customized bolus and 1 cm bolus. However, the normal tissue nearby the GTV showed relatively lower radiation dose. Conclusion : The customized bolus developed by 3D printers was effective in minimizing the air gap, especially when it is used against the treatment area with irregular surface. However, the air gap between branded bolus and skin was not enough to cause a change in target dose. On the other hand, in the chest wall could confirm that dose decrease for small the air gap. Customized bolus production period took about 3 days and the development cost was quite expensive. Therefore, the commercialization of customized bolus developed by 3D printers requires low-cost 3D printer materials, adequate for the use of bolus.

• Journal of Korean Society of Forest Science
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• v.29 no.1
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• pp.1-19
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• 1976

This study has been made to make an observation regarding present status of the coal mine props which is desperately needed for coal production, despite of great shortage of the timber resources in this country, and investigate the effects of diffusion process on the decay resistances of the mine props as applied preservatives of Malenit and chromated zinc chloride. The results are as follows. 1. Present status of the coal mine props Total demand of coal mine props in the year of 1975 was approximately 456 thousand cubic meters. The main species used for mine props are conifer (mainly Pinus densiflora) and hardwood (mainly Quercus). Portions between them are half and half. With non fixed specification, wide varieties of timber in size and form are used. And volume of wood used per ton-of coal production shows also wide range from 0.017 cubic meter to 0.03 cubic meter. 2. Decay resistance test a) The oven dry weight decreased between untreated specimen and treated specimen has not shown any significantly, although it has shown some differences in average values between them. It may be caused by the shorter length of the test. b) The strength of compression test between untreated specimen and treated specimen has also shown the same results as shown in case of weight decrease. Reasons assumed are the same. c) The amounts of the extractives in one percent of sodium hydroxide (NaOH) between untreated and treated specimen have shown the large value in case of untreated specimen than that of treated. 3. The economical benifit between untreated and treated wood when applied in field has seen better in long term base in case of treated wood, although the primary cost of treated wood add a little bit more cost than that of the untreated wood.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.511-520
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. To reduce the production cost, we should insure large cultivation area. The one of the best candidate places to expand the useful kenaf production was 'Saemangeum' reclaimed land. To confirm the possibility of kenaf growth in reclaimed land, we seeding and cultivated the kenaf in 'Saemangeum'. The germination percentage of kenaf on 5.0 dS/m soil salinity was 18%. It is less 66% than that of 4.0 dS/m soil salinity and at 6.0 dS/m, the germination percentage of kenaf was under 10%. The growth and development of kenaf in reclaimed land grew worse with increasing soil salinity. The stem diameter which the most important factor that decide the value and yield of product was upper 2.6 cm when soil salinity maintained under 4.0 dS/m, but if soil salinity marked over 4.0 dS/m, the stem diameter of kenaf was drop under 2.0 cm and it deteriorate the number of leaves per plant by 20~46%. The necrosis on older tip and marginal leaves were noted approximately first month after seeding which was correlated directly with the salinity levels of reclaimed soil. Reduction of total yield was coincide with increasing levels of EC. If soil salinity over 5.0 dS/m, the amount of decreased by soil salinity was 51% than that of non-reclaimed region. The allowable soil salinity level of which could be maintained within 20% reduction rate was 4.2 dS/m. Consequently kenaf can be grown successfully with moderately saline soil condition. However, salt levels in excess of 4.2 dS/m severely have restricted plant growth and development and will result in significant yield reduction.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.15-21
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• 2009

A 10-wk layer feeding trial was conducted to investigate the effects of high quality corn distiller's dried grains with solubles (DDGS) on performance, egg qualities, and yolk fatty acid composition. The economics of using DDGS in the Korean situation was also analyzed. A total of 216 Hy-line Brown layers, 23-wk of age, were employed in this trial consisting of three dietary treatments (0%, 10%, and 20% DDGS), and six replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not affect the feed intake, laying rate, egg weight, and feed conversion ratio (P>0.05). At 5th and 10th wk of the trial, the eggshell color, albumen height, and Haugh unit were not influenced by the DDGS supplementation. At 5th wk of the trial, the eggshell qualities, like eggshell weight, eggshell thickness, and eggshell strength, were not affected by the DDGS feeding; however, these eggshell qualities were decreased at 10th wk due to the 20% DDGS feeding (P<0.05). Yolk color of DDGS 20% increased compared to DDGS 0% at 5th and 10th wk of the trial (P<0.05). At 10th wk, yolk/egg ratio of DDGS 20% decreased compared to DDGS 0% (P<0.05). The yolk fat content was not changed due to DDGS feeding. The monounsaturated fatty acid content of yolk decreased linearly by feeding DDGS (P<0.05). The yolk polyunsaturated fatty acid content of DDGS 20% increased significantly compared to DDGS 0%. The DDGS feeding was not found to affect the degree of yolk fat unsaturation. The cost of feed (￦/kg feed) decreased as the level of DDGS increased. The production costs of egg (￦/kg egg) were cheap in the order of DDGS 10%, DDGS 20%, and DDGS 0%, indicating that DDGS is a viable alternative feed ingredient to corn and soybean meal. In conclusion, high quality DDGS ($L^*$ 61.72) could be used economically up to 20% level without any harmful effect on laying performance: however, the use of DDGS up to 10% is more economical than DDGS 20%.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.104-110
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• 2015

It is known that polymer concretes are 8~10 times more expensive than ordinary Portland cement concretes; therefore, in the production of polymer concrete products, it is very important to reduce the amount of polymer binders used because this occupies the most of the production cost of polymer concretes. In order to develop a technology for the reduction of polymer binders, smooth and spherical aggregates were prepared by the atomizing technology using the oxidation process steel slag (electric arc furnace slag, EAFS) and the reduction process steel slag (ladle furnace slag, LFS) generated by steel industries. A reduction in the amount of polymer binders used was expected because of an improvement in the workability of polymer concretes as a result of the ball-bearing effect and maximum filling effect in case the polymer concrete was prepared using the smooth and spherical atomized steel slag instead of the calcium carbonate (filler) and river sand (fine aggregate) that were generally used in polymer concretes. To investigate physical properties of the polymer concrete, specimens of the polymer concrete were prepared with various proportions of polymer binder and replacement ratios of the atomized reduction process steel slag. The results showed that the compressive strengths of the specimens increased gradually along with the higher replacement ratios of the atomized steel slag, but the flexural strength showed a different maximum strength depending on the addition ratio of polymer binders. In the hot water resistance test, the compressive strength, flexural strength, bulk density, and average pore diameter decreased; but the total pore volume and porosity increased. It was found that the polymer concrete developed in this study was able to have a 19% reduction in the amount of polymer binders compared with that of the conventional product because of the remarkable improvement in the workability of polymer concretes using the spherical atomized oxidation steel slag and atomized reduction steel slag instead of the calcium carbonate and river sand.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.525-537
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• 2016

This study was aimed to grow organic forage as a prime requirement for organic Hanwoo cattle production over a period of 3 years (2012~2015) in Gyeongbuk region, Korea through mixed cropping of winter fodder barley with legume and application of fermented cattle manure. The effect of barley-legume mixed cropping and application of different levels of fermented cattle manure was studied on forage productivity of whole-crop barley (WCB) and evaluation of feeding capacity of Korean native cattle (Hanwoo) per unit area. The collected data was analyzed using SAS 9.3 software. Barley-legume mixed cropping increased (P<0.05) yields of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) as compared to those of sole WCB as monoculture. Similarly, acid detergent fiber (ADF) contents and relative feed value (RFV) were also higher (P<0.05) in barley-legume mixed sowing forage compared with those of sole WCB as monoculture. In case of manure application, yields of DM, CP and TDN were also found (P<0.05) highest in 100~150 kg N/ha. However, varying cattle manure levels did not influence (P>0.05) CP and neutral detergent fiber (NDF) contents. In response to increasing nitrogen application level, ADF content increased (P<0.05) but TDN content and RFV decreased (P<0.05). The Barley-legume mixed sowing and increasing application levels of fermented cattle manure also significantly enhanced (P<0.05) feeding capacity of organic Hanwoo (head/ha) having 450 kg body weight with 400 g of daily gain. Findings of present study indicated that barley-legume biculture not only cut nitrogen application level of fermented cattle manure by over 50 kg per ha but also increased their feed value and productivity of forage as compared to WCB monoculture. This would be contribution to the diversity of forage resources as well as production of organic animal product by creating low cost and high quality organic forage.

• Analytical Science and Technology
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• v.8 no.1
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• pp.91-99
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• 1995

One of alternative conventional technologies used for treatment of livestock wastes is composting process, and recently some mechanical composting processes are being practiced. It is, however, recognized the composting process also has its own limitations such as longer time requirement, and difficulties to estimate the degree of decomposition, etc. The incomplete compost contains potentially harmful materials to crops and public health due to instabilized organic contents and pathogenic organisms. The purpose of this investigation is to develop an innovative system whereby anxious livestock wastes are thoroughly stabilized and disinfected. Thus the overall management scheme should meet the following requirements. 1. A system should be in a cost-effective and environmentally sound manner. 2. Sludges must be chemically stabilized and bacteriologically safe. 3. Odor-free by product should be applied to crop land. 4. Sludges are sources of fertilizer nutrients and/or soil amendments to enhance crop production. 5. And they can be used as potential pH adjusting agent of the acidified soils. Overall effectiveness of the developed system is experimentally tested to satisfy the preset criteria and requirements. Major experiments are divided into four categories: they are 1. chemical stability test, 2. optimal condition test of stabilization process, 3. bacteriological examination and disinfection tests, and 4. deodorization tests The stabilization process is consisted of the stabilizing reaction process and the drying process. Stabilized wastes is dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. The stabilization process is consisted of the stabilizing reaction process and drying process. Stabilized wastes are dried by both sun dryer and rotary dryer. It is shown that an additive dosage of about 300g/kg solid in wastes with a minimum of 5-minutes reaction would be necessary for effective stabilization reaction. In the stabilization reaction process, the pH of wastes is lowered from initial values of 12.3 to 8.6. High pH prevents odor production and kills pathogenic organisms. Organic matter contents in the stabilized wastes are about 50% and the sum of contents of fertilizer elements such as total nitrogen, $P_2O_5$ and $K_2O$ are about 5.3%. The livestock wastes that are stabilized chemically and hygienically can be used as a good soil conditioner and/or organic fertilizer.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.93-103
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• 1981

It is well-known that nowadays heat resisting and anti-corrosive materials have been widely used as the components materials of gas turbines, nuclear power plants and engines etc. In the fields of machine production industry. And materials for engine components, like as the exhaust valve of internal combustion engine, have been required to operate under the high temperature range of $700^{\circ}C$-$800^{\circ}C$ and high pressured gas with repeated mechanical load for the high performance of engines. For these components, friction welding for bonding of dissimilar steels can be applied for in order to obtain process shortening, production cost reduction and excellent bonding quality. And age hardening recently has been noticed to the heat resisting materials for further strengthening of high temperature strength, especially high temperature fatigue strength. However, it is difficult to find out any report concerning the effects of age hardening for strengthening high temperature fatigue strength to the Friction welded heat resisting and anti-corrosive materials. In this study the experiment was carried out as the high temperature rotary bending fatigue testing under the condition of $700^{\circ}C$ high temperature to the friction welded domestic heat resisting steels, SUH3-SUS303, which were 10hr., 100hr. aging heat treated at $700^{\circ}C$ after solution treatment 1hr. at $1, 060^{\circ}C$ for the purpose of observing the effects of the high temperature fatigue strength and fatigue fracture behaviors as well as with various mechanical properties of welded joints. The results obtained are summarized as follows: 1) Through mechanical tests and micro-structural examinations, the determined optimum welding conditions, rotating speed 2420 rpm, heating pressure 8kg/mm super(2), upsetting pressure 22kg/mm super(2), the amount of total upset 7mm (heating time 3 sec and upsetting time 2 sec) were satisfied. 2) The solution treated material SUH 3, SUS 303, have the highest inclination gradient on S-N curve due to the high temperature fatigue testing for long time at $700^{\circ}C$. 3) The optimum aging time of friction welded SUH3-SUS 303, has been recognized near the 10hr. at $700^{\circ}C$ after the solution treatment of 1hr. at $1, 060^{\circ}C$. 4) The high temperature fatigue limits of aging treated materials were compared with those of raw material according to the extender of aging time, on 10hr. aging, fatigue limits were increased by SUH 3 75.4%, SUS 303 28.5%, friction welded joints SUH 3-SUS 303 44.2% and 100hr. aging the rates were 64.9%, 30.4% and 36.6% respectively. 5) The fatigue fractures occurred at the side of the base matal SUS303 of the friction welded joints SUH 3-SUS 303 and it is difficult to find out fractures at the friction welding interfaces. 6) The cracking mode of SUS 303, SUH 3-303 is intergranular in any case, but SUH 3 is fractured by transgranular cracking.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.40-47
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• 2023

There are many different types of cultivation in tomatoes for year-round production. One of them, semi-forcing cultivation is characterized by growing seedlings in winter season. If grafted seedlings are used in winter season that energy cost can be reduced, because they have tolerance to cold stress. This study was conducted to analyze the rootstock performance by measuring the growth, yield, and leaf-macronutrient content of cherry tomatoes grown in semi-forcing hydroponics. Three domestic rootstocks 'HSF4', '21LM', '21A701', and a control cultivar 'B-blocking' were grafted onto jujube-shaped cherry tomato (Lycopersicon esculentum L.) commercial cultivar 'Nonari'. The total yield per plant with grafted cherry tomato '21A701' was 3,387g, which was 11%, 22% and 24% higher than the yield with 'B-blocking', non-grafted one and 'HSF4'. The stem diameter of '21A701' was thick with 8.26mm, whereas non-grafted one was thin with 7.23mm at 160 days after transplanting. The flowering position of '21LM' was 34% and 47% higher than the flowering position of 'B-blocking' and non-grafted one at 153 days after transplanting. The NO₃-N concentration in petiole sap of '21LM' was the highest with 1,746mg·L^-1 and non-grafted one and 'HSF4' were the lowest with 1,252mg·L^-1 and 1,245mg·L^-1 at 167 days after transplanting. The results indicated that rootstock/scion combinations in cherry tomatoes can affect the plant growth, yield, and the concentration of different NO₃-N in leaves at the late growth stage. Both '21A701' and '21LM' have vigorous root system, which influence the growth and yield increased.