• Horticultural Science & Technology
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• v.16 no.2
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• pp.242-243
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• 1998

This research was conducted to find the most effective and economical artificial propagation method of Lycoris squamigera among chipping, half-chipping, twin-scaling, coring, scooping and notching, in order to investigate the number of bulblets obtained from one bulb and the number of bulbs treated by a man in a day for artificial propagation. We got 42.2 bulblets from one bulb by twin-scaling, 23.2 bulblets by half-chipping, 18.2 bulblets by chipping, 14.3 bulblets by notching, 1 bulblet by coring and also 1 bulblet by scooping. Although we got the most bulblets by twin-scaling, it took the most time to treat the bulbs for artificial propagation (200 bulbs per day) and the bulblets formed were very small. But 400 bulbs were treated in a day by chipping and the bulblets formed were comparatively large. In addition, machines could be used for chipping, so chipping was considered to be the most effective and economical artificial propagation method.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.43-54
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• 2009

The purpose of this study is to explore variables that affect users' perceived value of mobile advertising and actual response intention and to analyze causal relationships among variables. In order to verify the relational significance, we built new research model and hypotheses based on the Ducoffe's model(1996). And we found out four independent variables such as entertainment, information usefulness, convenience, economical efficiency, and advertising impact's value as a mediating variable. Especially, we classified into four multi-age groups to investigate properly moderating effects through SEM(path analysis) and difference test. Therefore, it is academical and practical worth that we developed our model to appropriate on mobile advertising's unique property and that we verified our hypotheses and variables focused on age group, whereas previous research did not. For this, we surveyed 345 samples for conducting structural equation modeling in empirical approach. The results of this study supported the statistical significance of all hypotheses except but convenience.

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.294-299
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• 2012

Rail transport has been considered an environmental-friendly transport mode compared with other transport modes such as ship, truck, and aircraft. However, air pollutions emitted by diesel locomotives have emerged as social issues. In addition, the railway industry may not be able to avoid a duty of alleviating greenhouse gases emission owing to the Korean government policies for green growth which is an economic paradigm that simultaneously pursues growth and environmental improvement. Moreover, rising oil prices has burdened a train operating company. The purpose of this paper is to develop a methodology of determining an economical speed of diesel freight locomotive from the viewpoint of the train operating company. In the methodology, we first define an operational cost function based on various cost factors and then suggest formula to calculate an economical speed of diesel freight locomotive. To estimate the influence of cost factors such as diesel price, carbon taxes, and time costs on the speed of diesel freight locomotive, sensitivity analysis was conducted.

• International Journal of Railway
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• v.7 no.3
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• pp.71-79
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• 2014

Subway systems have been a proved method of public transport and are widely used in major cities around the world. However, the time and cost it takes to construct such systems are very high, as it requires underground tunnels. Cities in various countries have implemented monorail systems as public railway transport as it can be more economical and quicker compared to subway systems in terms of construction. In addition, it provides more convenience towards the public as it is not affected to traffic, and also provides an aerial view of the city. However, the overall construction cost for monorail systems is still significantly high, and as a possible solution to further reduce the overall cost, implementation of ground-level stations and wireless power transfer technology has been proposed in this paper. A concept application layout of ground-level stations and wireless power transfer systems has been discussed, using the Daegu monorail Line 3 system as a simulation base. The expected cost for monorail systems implementing ground-level stations and/or wireless power transfer technology has been estimated based on literature survey, and was compared with the current construction cost of Daegu monorail system. Based on comparison, it has shown that implementation of ground-level stations are the most economical, and can be easily implemented for either starting or expanding the monorail line. Implementation of wireless power transfer technology is also economical, but is more feasible when starting a new monorail line as it requires components which will alter the configuration of the train and infrastructure.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.39-49
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• 2021

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force's de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.7
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• pp.3-12
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• 2018

The present remodeling makes almost no difference from rebuilding as all the building materials are removed remaining frame structure only. And, in case of vertical extension of building, higher construction cost and safety problem occur. The Ministry of Land, Transport and Maritime Affairs, therefore, recommends customized remodeling that can be made in light of the resident' needs such as parking lot, elevator, bathroom, and room for the alternative of remodeling of vertical extension of building. The purpose of this study is to present real data that can be referred to the constructor's decision making before starting the remodeling, by investigating and analyzing the weight and importance between evaluation factors for customized remodeling at the completed time of remodeling. Accordingly, the factors were divided into environmental factor, social factor, and economical factor, and the survey was performed for the residents living in remodeling houses. In addition, for the professionals, AHP (Analytic Hierarchy Process) has been carried out for the priority in the customized remodeling. For environmental factor, the level of importance made difference from that before remodeling, except parking level. For social factor, every item, including psychological satisfaction and community satisfaction, made difference. For economical factor, the recognition level of importance in rent made difference, except sale price of the factor for price satisfaction. In case of the factor for cost satisfaction, it was checked that construction cost and administration cost both could be considered important. As a result of AHP, the most importantly emphasized item was construction cost, and sale price, administration cost, residence structure, and parking lot were followed by priority in order. This study could contribute to reliably settle down customized remodeling by giving reasonable and substantial help from the analysis of the differences in the customized remodeling items before/after the remodeling.

• Earthquakes and Structures
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• v.22 no.6
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• pp.561-570
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• 2022

It is of great importance to be able to evaluate different structural systems not only based on their seismic performance but also considering their lifetime service costs. Many structural systems exist that can meet the engineering requirements for different performance levels; therefore, these systems shall be selected based on their economic costs over time. In this paper, two structural systems, including special steel moment-resisting and the ordinary concentric braced frames, are considered, which are designed to meet the three performance levels: Immediate Occupancy (IO), Life Safety (LS), Collapse Prevention (CP). The seismic behavior of these two systems is studied under three strong ground motions (i.e., Tabas, Bam, Kajour earthquake records) using the Perform3D package, and the incurred damages to the studied systems are examined at two hazard levels. Economic analyses were performed to determine the most economical structural system to meet the specified performance level requirements, considering the initial cost and costs associated with damages of an earthquake that occurred during their lifetime. In essence, the economic lifetime study results show that the special moment-resisting frames at IO and LS performance levels are at least 20% more economical than braced frames. The result of the study for these building systems with different heights designed for different performance levels also shows it is more economical from the perspective of long-term ownership of the property to design for higher performance levels even though the initial construction cost is higher.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.69-72
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• 2022

This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.195-212
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• 1994

For the purpose to increase productivities of livestock the present investigations were undertaken in order to clarify the clinical and suclinical status of Korean native cattle, dairy cattle(holstein) and Korean native goat. Blood, feces and urine samples were collected from 247 Korean native cattle(222 adult and 25 calf), 224 dairy cattle(211 adult and 13 calf) and 142 Korean native goat rearing at Chonbuk area and analyzed for clinical, serum chemical, hematological and urinary findings. In addition, we were examined the infection rate of theileriosis, internal parasite and ring worm. The mean value for each component was calculated by statistical analysis using Excel computer program. From these investigations the following results were obtained. The mean values for RBC, PCV and etc in 433 adult cow(Korean native cattle and dairy cattle) were similar with other reports. But the mean values for MCHC of all species were lower than normal. Adult Korean native cattle and adult dairy cattle which showed hematologically normal levels were only 9.01% and 9.48%, respectively. Abnormally high values for PCV, RBC and Hb were recorded in 7.66% of adult Korean native cattle, 20% of korean native calf, 15.38% of dairy calf and 13.36% of Korean native goat. Adult Korean native cattle and adult dairy cattle which showed hematologically anemia were 4.95% and 19.43% respectively, but Korean native calf and dairy calf showed normal. Adult Korean native cattle, adult dairy cattle, Korean native calf and dairy calf which showed normal serum protein level 84.0%, 90.8%, 50% and 44.4%, respectively. In present investigations, 50% of Korean native calf and 55.6% of dairy calf were decreased serum protein values under range. These abnormally decreased serum protein values mean the shortage of antibody, and these have a possibility to occurs to pneumonia and diarrhea. From these results, the economical loss caused by pneumonia was calculated as 124,038,833 won in the KNC and 742,703,430 won in the dairy calf rearing in Chonbuk area. Calculated economical loss caused by enteritis was 56,658,690 won in Korean native cattle, 476,775,799 won in dairy calf, and the total loss amount of 533,434,488 won in Chonbuk area. Abnormally high values$(21.7{\pm}4.0mg/dl)$ for serum calcium were recorded 49.6% in dairy cattle. The mean values for serum total cholesterol were $170.8{\pm}99.8mg/dl$ in Korean native cattle, $196.0{\pm}40.6mg/dl$ in Korean native calf, $202.9{\pm}86.0mg/dl$ in adult dairy cattle and $289.4{\pm}97.5mg/dl$ in dairy calf. The infection rate of internal parsite were as follows; adult Korean native cattle: 21.2%, Korean native calf: 8.0%, adult dairy cattle: 67.8% and Korean native goat: 81.5%. The estimated economical loss caused by internal parasites infection were 1,120,855,837 won in Korean native calf, 4,994,959,405 won in adult Korean native cattle, 3,334,751,066 won in adult holstein, and the total loss amount to 9,450,566,308 won. The infection rate of theileriosis were 1.4% in Korean native cattle and 6.6% in dairy cattle. The presumed economical loss by T. sergenti infection were 154,408,482 won in Korean native cattle and 171,577,237 won in dairy cattle rearing at Chonbuk area. The infection rate of ringworm were 0.5% in Korean native cattle, 0.9% adult dairy cattle and 7.7% in dairy calf. The presumed economical loss by dermatomycophyte were 12,061,532 won in Korean native cattle, 16,895,403 won in dairy cattle, and the total estimated loss amount to 28,955,935 won a year in Chonbuk area.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.507-520
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• 2016

This research was performed to evaluate incineration facilities with different scale and type using performance index. Incineration facilities of 28 units, which occupying about 15% of 184 units in nationwide, were selected for questionnaire survey. The facilities were classified in scale with large(${\geq}100t/d$), middle(50~<100 t/d), small(<50 t/d) ones, and in type with stoker, pyrolysis, fluidized bed. Performance index was composed of technological, economical, and environmental items, which have 6, 10, and 30 kinds of questions, respectively. As a result of scale evaluation, large scale facility has higher score than small one in all technological, economical, and environmental items. In overall evaluation of the facilities with different type, stoker incinerator has higher score of 65.3 than 59.0 of fludized bed and 58.3 of pyrolysis. It was shown that there was significant difference in economical evaluation field, in all technological, economical, and environmental items.