• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.169-170
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• 2017

Recently in the construction industry there has been an increasing use of increasing replacement of cement with blast furnace slag cement(BS), an industrial by-product, to reduce environment load and production costs, and other increasing uses of BS cement. However in the case of BS being delivered in RMC factories, only score reports submitted when the are delivered are relied upon and ways to test the quality of fineness is inadequate. Therefore this study gave many changes to various cements and BS fineness to test the variations of BS as a cement, then used the correlation between this and the density value in the Hydrometer method to test the possibility for rapid appraisal of quality fineness of BS cement. Results showed that if the one fifth graph of the density and fineness correlation were to be used, a rapid appraisal of BS cement fineness quality would be possible.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.59-68
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• 2015

PURPOSES : This study suggests the application of glow line marking technology for reducing traffic accidents at nighttime. METHODS : In this study, using a statistical analysis, we analyzed the characteristics of traffic accidents occurring at nighttime. Next, the strength, weakness, opportunity, and threat (SWOT) factors were derived based on a current-status analysis of glow line marking technology and road environments. An SO strategy, ST strategy, WO strategy, and WT strategy were established in accordance with the four SWOT factors. RESULTS : This study suggests that the following strategies should be promoted to apply glow line marking technology to a road environment: 1) an activation strategy for the technological development of glow line markings for a new paradigm in reducing traffic accidents, 2) a benefit enhancement strategy applying glow line marking technology in places where nighttime traffic accidents frequently occur, 3) a strategy for the expansion of glow line marking by replacing streetlights, and 4) a strategy for enhancing road applications through the development of various line marking methods in consideration of both performance and costs. CONCLUSIONS : The application of glow line markings in a road environment can contribute to a reduction of traffic accidents at nighttime, and aid energy savings from the replacement of streetlights.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.171-178
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• 2013

In a polymer membrane fuel cell stack, the bipolar plate is a key element because it accounts for over 50% of total costs of the stack. In order to lower the cost of bipolar plates, 316L stainless steels coated with nitrides such as TiN and CrN by physical vapor deposition were investigated as alternative materials for the replacement of traditional brittle graphite bipolar-plates. For this purpose, interfacial contact resistances were measured and electrochemical corrosion tests were conducted. The results showed that although both TiN and CrN coatings decreased the interfacial contact resistances to less than $10m{\Omega}{\cdot}cm^2$, they did not significantly improve the corrosion resistance in simulated polymer electrolyte membrane fuel cell environments. A CrN coating on 316L stainless steel showed better corrosion resistance than a TiN coating did, indicating the possibility of using modified CrN coated metallic bipolar plates to replace graphite bipolar plates.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42
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• pp.85-91
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• 2000

Dwindling supplies and increasing costs of conventional highway materials used in road construction as well as concerns over shrinking landfill spaces prompt researchers to investigate the use of waste products, such as fly ash, as substitute materials in highway construction. The highway industry is capable of utilizing waste materials in large quantities if their effect on pavement performance proves to be technically, economically and environmentally satisfactory. This research examines the effects of fly ash when used as partial replacement of aggregate in asphaltic concrete mixtures. And measuring the effect of fly ash on bulk specific gravity, air void, indirect tensile strength (ITS) under dry and wet conditioning as well as the tensile strength ratio (TSR) of asphaltic concrete mixture. The results indicated that asphaltic concrete mixtures containing 2% and 5% fly ash produced about the same TSR value as control mixture. And all of the mixtures met the minimum ITS and TSR requirements established by the South Carolina Department of Transportation (SC DOT) for Type 1A surface courses. At this point and with this limited study, these asphaltic concrete mixtures is recommended in several applications such as parking lot, secondary roads and driveways.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.60-67
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• 2014

Wind power is one of the fastest growing renewable energy sources. The blades length and tower height of wind turbine have been growing steadily in the last 10 years in order to increase the output amount of wind power energy. The amount of wind turbine energy is increased by increasing the capacity of wind turbine, but the costs of preventive, corrective and replacement maintenance are also increased accordingly. Recently, Condition Monitoring System that can repair the fault diagnose and repair of wind turbine in the real-time. However, these system have a problem that cannot predict and diagnose of the fault. In this paper, wind turbine predict methodology is proposed by using the SVM method. In the case study, correlation analysis between wind turbine fault and external environmental factors is performed by using the SVM method.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.212-226
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• 2002

North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

• Biomedical Science Letters
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• v.28 no.1
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• pp.1-8
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• 2022

Total joint arthroplasty is a successful joint replacement treatment that improves joint function and overall quality of life and provides pain relief. However, the prevalence of periprosthetic joint infection (PJI) has become prevalent with the rise in the incidence of arthroplasty surgery. PJI occurs rarely following arthroplasty however presents with serious complications, including high morbidity. The identification of causative microorganisms is essential for the treatment of PJI. Managing PJI requires complex treatment strategies, including long-term antibacterial treatment, and significant medical costs can be incurred. The American Academy of Orthopedic Surgeons, the Centers for Disease Control and Prevention, and Surgical Care Improvement Project guidelines recommend that prophylactic antibiotics such as first-generation cephalosporins be infused completely 1 hour before surgical incision. However, these preventative antibiotics are very limited, therefore risk factors must be identified to diagnosis and treat patients effectively. Moreover, determining antimicrobial susceptibility during artificial joint surgery and choosing the most appropriate treatment strategy following an accurate diagnosis of microbial infections are essential. In the present review, we describe the management, including the etiology, diagnosis, and classification of PJI, and approaches to its diagnosis using the available novel molecular diagnostic methods.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.837-847
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• 2007

The study focused on the evaluation of maintenance management strategies used in public hospital buildings in Lagos state. It also assessed the labour composition for maintenance operations. In achieving these objectives, opinions of maintenance officers of ten (10) different hospitals in different local government areas of the state were sampled through well structured questionnaires. The data collected were analyzed using descriptive and inferential statistics. From the analysis, the study revealed that majority of those public hospitals do not have specific budget for maintenance programmes, maintenance policies, maintenance log book and maintenance manual to guide the operatives. About 98% of them do not understand the type of maintenance strategy being used for their maintenance operations. 78% of the maintenance work are only executed when there is a breakdown or in response to user's request. For labour composition, the cleaning of interior and exterior of the building, inspection of building elements, repairs and replacements of building elements are mainly carried out by in-house staff, while the repair and replacement of equipment is by outsourcing. The study also revealed that using in- house staff, reduces costs and provides a higher security while outsourcing provides more flexibility in staffing reduces equipment expenditures and provide better access to special skills. The study recommended proactive measures to provide necessary training and support for maintenance staff and users of these facilities and a means of securing sufficient funds for maintenance programmes.

• Resources Recycling
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• v.33 no.2
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• pp.16-23
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• 2024

The electrolysis for extracting magnesium from seawater or brine primarily involves recovery of magnesium via precipitation as the form of magnesium hydroxide. The technology is classified into cation-exchange membranes (CEM), anion-exchange (AEM) membranes, electrodialysis, and membraneless methods. Recent research has focused on enhancing the efficiency and selectivity of magnesium recovery from seawater or brine containing magnesium, with expectations of effective magnesium recovery even with normal seawater. In a future, the optimization of the selective and efficient recovery of magnesium and various valuable substances through long-term operation of scaled-up systems is crucial with enhancing economic and environmental viability. It is essential to realistically estimate operational costs considering the membrane's lifespan and replacement cycle. Also, detailed and practical process models should be developed based on monitoring data on various factors.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.235-244
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• 2007

Potentials of AR CDM project in North Korea are assessed and feasible land area for AR CDM project is estimated. According to our estimation, There could be 515,000 hectares of forest lands deforested before 1990 in North Korea and 8,854 hectares at the regional level of Gae-sung City, which are eligible for AR CDM project, based on researches of satellite image analyses conducted from 1980's to 1990's. A baseline scenario assumed 44.73 tones of carbon stored in soil per hectare with no vegetation above ground remained during the project period following the default value of IPCC's Good Practice Guidance for LULUCF considering soil structure, climate and land use of the project area. The scenario also assumes that black rocust (Robinia pseudoacacia) is planted and the CDM project is implemented for 20 years. The costs for producing greenhouse gases CER (certified emission reduction) credits include costs of tree planting and forest management, and costs of project negotiation and transactions for issuing the credits. It is estimated that 376 tones of carbon dioxide per hectare can be accumulated and 503 temporary CER credits per hectare and 265 long-term CER credits per hectare could be produced during the project period. It is estimated to cost US$ 4.04 and US$ 7.67 to provide one unit of temporary credit and long-term credit, respectively. These values can be regarded as the cost of conferring emission commitment of a country or a private entity. However, it is not clear which option is better economically because the replacement periods are different in these two cases.