• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.277-281
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• 2017

Lately rainfall characteristics that it rains a lot in a short space of time often occurs. Because of this meteorological phenomena, the flow rate and concentration of initial rainfall for runoff and combined sewer overflows are changed. In the case of this inlet fluctuation, the flotation method at high surface loading rate is suitable for water quality management. the flotation method is able to meet the removal rate requirements of water public zone in 5 to 10 min which is irelatively short period. For assessment and diagonision of flotation method, A/S ratio is applied until now. But unfortunately, this has some limits for evaluation standard for certification and assessment of technical diagnosis and operation. This is why there is different efficiency in the bubble distribution at the same A/S ratio. The velocity and time of floating is changed by the different bubble distributions. The floating time affects the plant volume because the time factor make size dicision. Therefore the charateristics of bubble distribution and floating time at the same A/S ratio is necessary to apply to evaluation standard for certification and assessment of technical diagnosis and operation. For generalization of the method in certification and assessment, the characteristics of bubble distribution was studied. Until recently, using the optical device and shooting live video, there are some analysis technology of the floating factors. But this kind of technology is influenced by the equipment. with this level of confidence about the results, it is difficult to apply to generalize. According this reasons, this study should be applied on experiment generalization of method about measurement of relation between bubble distribution and floating time.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.17-27
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• 2022

A certain level of stability margin airworthiness criteria should be met to secure robustness against uncertainties between the real plant and the model in a flight control system design. The U.S. Department of Defense (DoD) specification of MIL-F-9490D and airworthiness certification standard of MIL-HDBK-516B uses gain and phase margin criteria of flight control system. However, the same stability margin criteria is applied at all development phases without considering the design maturity of each development phase of the aircraft. Ultimately, a problem arises when the aircraft operation envelope is excessively restricted. This paper proposes the relation of handling qualities and stability margin, and presents re-established stability margin criteria as a development phases and verification methods. The results of the research study are considered to contribute to the verification of the stability margin criteria more flexibly and effectively by applying the method to not only the currently manned developing aircrafts but also the unmanned vehicle to be developed in the future.

• Journal of Climate Change Research
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• v.9 no.2
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• pp.197-207
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• 2018

The Korean government views coal-fired power plants as the key cause of the fine dust generation, and is developing an energy policy to replace and demolish old coal-fired power plants. According to the Eighth Power Supply Base Plan (2017-2031), the maximum power capacity in 2030 is expected to be 100.5GW, which is 17.9% higher than the current level (85.2GW). The plan aims to reduce the facility size and power generation ratio from nuclear and coal resources to even lower levels than today, and to rapidly expand power generation from new and renewable energy. Despite that, the proportion of coal power generation is still much higher than other resources, and it is expected that the reliance on goal will maintain for next several decades. Under such circumstances, the development, supply, and expansion of clean coal technology (CCT) that is eco-friendly and highly efficient, is crucial to minimize the emission of pollutants such as carbon dioxide and fine dust, as well as maximize the energy efficiency. The Korean government designated the Yong-Dong Thermoelectric Power Plant in Gangneung to develop clean coal power generation, and executed related projects for three years. The current study aims to suggest a plan to develop parts, technologies, testing, evaluation, certification, and commercialization efforts for coal-fired power generation, In addition, the study proposes a strategy to vitalize local economy and connect the development with creation of more jobs.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.187-196
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• 2022

In this paper, we propose an example of designing and constructing a roof-type solar power plant structure equipped with a Pseudo-BIPV (Building-Integrated Photovoltaic) shape suitable for use as a roof of a small warehouse with a sandwich-type panel structure. As the characteristics of the roof-type solar power generation facility to be installed in the small warehouse proposed in this study, the shape of the roof is not a general A type, but a right-angled triangle shape with the slope is designed to face south. We chose a structure in which an inverter for one power plant and a control facility are linked by grouping several roofs of buildings. In addition, the height of the roof structure is less than 20 cm from the floor, and it has a shape similar to that of the BIPV, so it is building-friendly because it is almost in close contact with the roof. At the same time, the roof creates a reflective light source due to the white color. By linking this roof with a double-sided solar panel, we designed it to obtain both the advantage of the roof-friendliness and the advantage of efficiency improvement for the electric power generation based on the double-sided panel. Compared to the existing solar power generation facilities using A-shaped cross-sectional modules, the power generation efficiency of roofs in this case is increased by more than 11%, which we can confirm, through the comparison analysis of monitoring data between power plants in the same area. Therefore, if the roof-type solar structure suitable for the small warehouse we have presented in this paper is used, the facilities of electric power generation is eco-friendly. Further it is easier to obtain facility certification compared to the BIPV, and improved capacity of the power generation can be secured at low material cost. It is believed that the roof-type solar power generation facility we proposed can be usefully used for warehouse or factory-based smart housing. Sensor devices for monitoring, CCTV monitoring, or safety and environment management, operating in connection with the solar power generation facilities, are linked with the Internet of Things (IoT) solution, so they can be monitored and controlled remotely.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.23-23
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• 2019

Cypripedium is an orchid genus of over 50 species widely distributed in the northern temperate zone, with a few taxa extending central America and the Himalayas and the southwesternmost tip of China in Asia. Of the known species approximately two thirds are found in China. In Korea, 4 species were reported to find with rare popularity ; C. macranthos, C. guttatum, C. japonicum, and C. calceolus. The seed has a firm brown fusiform testa with an opening at one end where the micropyle of the ovule was situated. Cypripedium has small, fusiform, wind-dispersed seeds that weigh about $1{\sim}2{\mu}g$ and range from 0.1 to 2 mm long and 0.07 to 0.4 mm across. The germination of Cypripedium was previously thought to be hard to cultivate in one's garden and impossible to propagate artificially, nowadays lab-propagated seedlings are readily available in EU or United States. We had already reported the successful micropropagation of lady's slipper orchids with green pod sowing methods. The collected Cypripedium species and hybrids were planted in Korea National Arboretum (KNA) on Oct. 2018. The 11 species including C. candidum and the 31 hybrids such as C. Ingrid were introduced from Germany with CITES certification. The lady's slipper orchids bloomed on May to June, and the flowers were pollinated in the same species or hybrids to get seeds for in vitro germination on 2~3 days after fully flowering. The green pods were collected after 49~70 days after pollination. The 6 species of Cypripedium seeds were easily germinated on the POM within 70 days after sowing, and the 12 hybrids PLBs were observed with small roots. We had established the scheme of lady's slipper orchids germination in 3 months with green pods, and get the possibility of seedling in 10 months of sowing in vitro.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.495-502
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• 2020

The 37 indicators for performance evaluation of public sewage management agencies are divided into four major categories (agency manpower management ability, wastewater treatment plant operation and management, sludge and water reuse, service quality) in the first stage, and the necessity and score acquisition for the detailed indicators by each major category in the second stages. Priority was investigated through the Analytic Hierarchy Process (AHP) analysis technique for ease and relevance of company efforts. Also, based on the results of this analysis, integrated type weighting and relative importance were analyzed. As a result of the analysis, the weight and relative importance of the first stage classification were in the order of wastewater treatment plant operation and maintenance, operation agency manpower management ability, sludge and water reuse, and service quality. As a result of analyzing the weights and priorities of the detailed performance indicators in the second stage, it was found that operator's career years, the percentage of certification holding rate in operators, compliance with the effluent water quality standards, training times for operators, and efforts to manage hazardous chemicals were important. Some of the indicators of operation agency performance evaluation may include indicators in which the performance of the company's efforts is underestimated or overestimated. In order to improve this, it is necessary to give weights in consideration of the necessity of the indicator, the relevance of the company's efforts, and the ease of obtaining scores.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.583-591
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• 2011

'Formosa' plums were picked at three maturity stages according to skin redness, treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP at $10^{\circ}C$ for 24 h and then stored for 21 days at $10^{\circ}C$. Ethylene production, respiration rate, firmness, color, TSS, TA, and ethanol concentration were determined. Total phenolic content, total flavonoid content, and antioxidant capacity were determined periodically by separating the flesh from the peel. Ethylene production and respiration rate were strongly inhibited in all stages of the 1-MCP-treated fruit, while ethylene production dramatically increased in all stages of non-treated fruit until 11 days after harvest, after which it decreased until the end of the experiment. The respiration rate of the stored fruit increased for 11 days in stages 1 and 2 and for 7 days in stage 3 and decreased after. 1-MCP-treated fruit in all stages showed delay in fruit quality changes such as firmness, TA, skin color, and ethanol concentration, but non-treated fruit did not. Total phenolic contents, total flavonoid contents and antioxidant capacity of 'Formosa' plums were not affected by 1-MCP treatment or maturity stage. However, those values were higher in the peel than in the flesh.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.968-973
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• 2007

The systems such as the railway control system, satellite control system and nuclear power plant control system are the safety critical systems because the failure of them could lead to risk significant events. These softwares of digital systems must follow the life cycle process from the beginning of software development to guarantee their safety and reliability. The NRC(Nuclear Regulatory Commission) Reg Guide of nuclear fields, the RTCA/DO-178B standard which is used to acquire the certification for software in industrial aero field in European Union and United State, the DEF STAN 00-55 standard for the safety of electronic weapon in England, the IEC 601-1-4 for medical equipment and the IEC 62279 for railway system recommended the development life cycle. This paper introduces the development process and compares each other. Also it indicates applicable development criteria for the software of systems related to railway fields and describes the detailed procedure of development criteria. We describe the procedure to make the software development criteria in nuclear filed. For the software development related to railways, the process from plan phase to maintenance phase must be satisfied. The safety and reliability is guaranteed through these standards.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.153-158
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• 2019

It is estimated that about 2,515 persons have been injured by conveyor for the past five years(2013 ~ 2017). Conveyors used in various industrial sites for transporting iron ore, coal, courier goods, etc., have various incidents such as a worker putting on or pulling a part of the body or work clothes on the driving part during maintenance. It is necessary for preventing similar accidents to conduct various researches. In order to propose the basis for revising laws and standards for the safety standards of the full cord switch to prevent conveyor accidents, this study compares Korea's Industrial Safety and Health Law (KISHL) with those of IEC, EN, Canada, and Australia. In addition, surveys of conveyor use plant and full cord switch domestic and foreign manufacturers was conducted. In this study, domestic and overseas related laws and technical standards compare and analyze to prevent conveyor accidents. In addition, we propose extension of safety certification for full code switch, establishment of safety inspection standard, and improvement of working method regulation through actual working condition investigation. It can be used as a basis for revising the occupational safety and health regulation and related notices, and thus contributing to enhancing the safe atmosphere of the conveyor business and improving the safety consciousness of the concerned persons.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.305-312
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• 2017

To evaluate the reliability of fly ash quality supplied to ready-mixed concrete plant using mass cylinder and hydrometer, in this research, the correlationship between the fly ash properties provided from certification and density measurement with suspension was evaluated. As a result, the reliability of the certification, except fineness and loss on ignition, all properties had a discord. Additionally, in the case of density, fineness, and L.O.I, the relation with the density measured using hydrometer showed high correlation, especially fineness was strongly related with the density measured using hydrometer. Furthermore, according to the comparative analysis with previous research, the fly ash used in this research was similar measurement with raw powder without any refining process, it is considered that the constant error of blaine test or using raw ash sample as a fly ash. In current standard regarding fly ash, the fineness range of class 2 can be changed from $3,000-4,500cm^2/g$ to $3,500-4,500cm^2/g$ for improved quality of fly ash in fineness aspect.