• Journal of Welding and Joining
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• v.33 no.1
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• pp.35-40
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• 2015

Recently, there have been the increase of ship size and the development of oil and gas in arctic region. These trends have led to the requirements such as high strength, good toughness at low temperature and good weldability for prevent of brittle fracture at service temperature. There has been the key issue of crack arrestability in large size structure such as container ship. In this report for the first time, crack arrest toughness of thick steel plate welds was evaluated by large scale ESSO test for estimate of brittle crack arrestability in thick steel plate. For large structures using thick steel plates, fracture toughness of welded joint is an important factor to obtain structural integrity. In general, there are two kinds of design concepts based on fracture toughness: crack initiation and crack arrest. So far, when steel structures such as buildings, bridges and ships were manufactured using thick steel plates (max. 80~100mm in thickness), they had to be designed in order to avoid crack initiation, especially in welded joint. However, crack arrest design has been considered as a second line of defense and applied to limited industries like pipelines and nuclear power plants. Although welded joint is the weakest part to brittle fracture, there are few results to investigate crack arrest toughness of welded joint. In this study, brittle crack arrest designs were developed for hatch side coaming of large container ships using arrest weld, hole, and insert technology.

• Fire Science and Engineering
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• v.24 no.4
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• pp.116-122
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• 2010

The fire protection system of nuclear power plants shall be designed, constructed and operated, through a defense-in depth criterion to suppress the leakage of radioactivity to the outside and to allow the safety shutdown function when a fire occurs. In order to achieve these purposes, most of countries abroad operating the nuclear power plants keep up the integrated regulations, however we have two guidelines, the fire protection service act and the nuclear energy act, as mandatory requirements to apply to the fire protection systems in nuclear power plants. It has shown that USA, Canada and Japan which have long experience in operating nuclear power plants have regulations integrated technically for fire protection system of nuclear power plants. It is proposed that the things once verified the risk analysis of the fire hazard by the nuclear law in the design for fire suppression system in plants should be authorized by the fire protection service act as an exception.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.444-449
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• 2017

The development of molecular markers is one of the most useful methods for molecular breeding and marker-based molecular associated selections. Even though there is less information on the reference genome, molecular markers are indispensable tools for determination of genetic variation and identification of species with high levels of accuracy and reproducibility. The demand for molecular approaches for marker-based breeding and genetic discriminations in Panax species has greatly increased in recent times and has been successfully applied for various purposes. However, owing to the existence of diverse molecular techniques and differences in their principles and applications, there should be careful consideration while selecting appropriate marker types. In this review, we outline the recent status of different molecular marker applications in ginseng research and industrial fields. In addition, we discuss the basic principles, requirements, and advantages and disadvantages of the most widely used molecular markers, including restriction fragment length polymorphism, random amplified polymorphic DNA, sequence tag sites, simple sequence repeats, and single nucleotide polymorphisms.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.561-570
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• 2014

Nuclear Power Plant Instrumentation and Control System(NPP I&C) which is used to operate safely is changing from analog technology to digital technology. Ever since NPP Centrifuge of Iran Bushehr was shut down by Stuxnet attack in 2010, the possibility of cyber attacks against the NPP has been increasing. However, the domestic and international regulatory guidelines that was published to strengthen the cyber security of the NPP I&C describes security requirements and method s to establish policies and procedures. These guidelines are not appropriate for the development of real applicable cyber security technology. Therefore, specialized cyber security technologies for the NPP I&C need to be developed to enhance the security of nuclear power plants. This paper proposes a cyber security technology development system which is exclusively for the development of nuclear technology. Furthermore, this method has been applied to the ESF-CCS developed by The KINCS R&D project.

• Korean Journal of Medicinal Crop Science
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• v.28 no.4
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• pp.254-259
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• 2020

Background: Centella asiatica is a well-known medicinal plant having a wound healing effect. In this study, the growth, asiaticoside content, and antioxidant components and activity were investigated in C. asiatica resources under different cultivation and irrigation conditions. Methods and Results: The cultivation and irrigation methods were divided as greenhouse and open field, and sprinkler and sub irrigation. respectively. Growth characteristics were measured in aerial parts of C. asiatica. Asiaticoside content was analyzed using high performance liquid chromatography. Total polyphenol, total flavonoid and 2,2-diphenyl-1picryl hydrazyl (DPPH) radical scavenging activity were analyzed for antioxidant activities. Growth was higher under greenhouse and sub irrigation than open field and sprinkler conditions. In the leaves, asiaticoside content was 53.45 mg/g (open field) and 34.38 mg/g (sub irrigation), total polyphenol was 41.14 mg/g (open field) and 25.73 mg/g (sub-irrigation), and total flavonoid was 27.26 mg/g (open field) and 23.72 mg/g (sub-irrigation). DPPH radical scavenging activity in the leaves was 85.97 mg·ascorbic acid equivalent (AAE)/g (open field) and 54.83 mg·AAE/g (sub irrigation). Conclusions: Asiaticoside and antioxidant components and activity were not accompanied with high yield, although high growth was observed under greenhouse conditions. Therefore, cultural requirements of C. asiatica should be sufficiently considered to suit each purpose.

• Nuclear Engineering and Technology
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• v.23 no.1
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• pp.20-29
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• 1991

The system analysis for Korean nuclear power reactor option is made on the basis of reliability, cost minimization, finite uranium resource availability and nuclear engineering manpower supply constraints. The reference reactor scenarios are developed considering the future electricity demand, nuclear share, current nuclear power plant standardization program and manufacturing capacity. The levelized power generation cost, uranium requirement and nuclear engineering professionals demand are estimated for each reference reactor scenarios and nuclear fuel cycle options from the year 1990 up to the year 2030. Based on the outcomes of the analysis, uranium resource utilization, reliability and nuclear engineering manpower requirements are sensitive to the nuclear reactor strategy and associated fuel cycle whereas the system cost is not. APWR, CANDU longrightarrow FBR strategy is to be the best option for Korea. However, APWR, CANDU longrightarrow Passive Safe Reactor(PSR）longrightarrowFBR strategy should be also considered as a contingency for growing national concerns on nuclear safety and public acceptance deterioration in the future. FBR development and establishment of related fuel cycle should be started as soon as possible considering the uranium shortage anticipated between 2007 and 2032. It should be noted that the increasing use of nuclear energy to minimize the greenhouse effects in the early 21st century would accelerate the uranium resource depletion. The study also concludes that the current level of nuclear engineering professionals employment is not sufficient until 2010 for the establishment of nuclear infrastructure.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.788-793
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• 2011

To evaluate fertilizer value of animal cadavers for agricultural recycling, fertilizer components of animal cadavers by pig and poultry were investigated using rendering and alkali (KOH) treatment methods. Total nitrogen concentrations in meat waste by pig and poultry using rendering treatment method were 7.80% and 9.30%, respectively. Total nitrogen concentration in meat waste of pig by KOH treatment method was lower than that by rendering treatment method. Organic matter concentrations in meat waste of pig and poultry ranged 87.8~97.4%. Total phosphorus concentrations in bone waste of pig using rendering and KOH treatment methods ranged 5.59~11.18%. Animal cadavers contains nitrogen, phosphorus, potassium and other nutrients essential to plant growth. The results of this study suggest that animal cadavers can supply some of the nutrient requirements of crops and is a valuable fertilizer as well.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1037-1040
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• 2019

For the past 50 years, graphite has been widely used as a moderator, reflector and fuel matrix in different kinds of gas-cooled reactors. Resulting in approximately 250,000 metric tons of irradiated graphite waste. One of the most significant long-lived radioisotope from graphite reactors is carbon-14 ($^{14}C$) with a half-life of 5730 years, this makes it a huge concern for deep geologic disposal of nuclear graphite (NG). Considering the lifecycle of NG a number of waste management options have been developed, mainly focused on the achievement the radiological requirements for disposal. The existing approaches for recycling depend on the cost to be economically viable. In this new study, an affordable process to remove $^{14}C$ has been proposed using samples taken from the Nuclear Power Plant in Latina (Italy) which have been used to investigate the capability of organic and inorganic solvents in removing $^{14}C$ from exfoliated nuclear graphite, with the aim to design a practicable approach to obtain graphite for recycling or/and safety disposed as L& LLW.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.2
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• pp.65-80
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• 2019

With the advent of the ICT-based 4th industrial revolution, the convergence of the manufacturing industry and ICT seems to be the new breakthrough for achieving the company's competitiveness and play a role on the key element for accelerating the revival of the manufacturing industry. When the smart factory is implemented, each plant can analyze the quantity of data collected, build the data-driven operation systems which can make decisions, and ultimately discover the correlation among many events in the manufacturing sites. As the customers' needs become diversified more and more, it is required for the company to change its operating method from large quantity batch production systems to customizable and flexible manufacturing systems. For performing this requirements, it is essential for the company to adopt the smart factory. Based on technology acceptance model (TAM), this study investigates the factors influencing continuous use intention and switching intention of the smart factory. To do so, a questionnaire survey is conducted both online and offline. 122 samples are used for the study analysis. The results of this study will provide many implications with many researchers and practitioners relevant smart factories.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.6
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• pp.497-504
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• 2018

Platform Support Vessels operated in the Arctic Ocean support diverse operations of offshore plant in the sea, and the PSV is also needed to support works to exploit the oil and gas in the Arctic Ocean. Both of the ice breaking and the open sea performance have been considered together to secure the enhanced operational performance at the harsh environment in the Arctic Ocean and the open sea as well. In this study, One of the design requirements of a PSV is to guarantee continuous icebreaking performance with 3 knots at 1 m thickness of level ice, where the design draft is 7.5m and the engine power is 13 MW. Three hull forms were designed, and the ice resistance based on empirical formulas was estimated to select the initial hull form having an outstanding performance. The full scale performance of the designed hull forms was predicted by the ice model test conducted in the ice model basin of Korea Research Institute of Ships & Ocean Engineering(KRISO). The analysed results show that the selected hull form satisfies the above design requirement.