• Nuclear Engineering and Technology
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• 제39권1호
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• pp.1-8
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• 2007

Hydrogen and electricity are expected to dominate the world energy system in the long term. The world currently consumes about 50 million metric tons of hydrogen per year, with the bulk of it being consumed by the chemical and refining industries. The demand for hydrogen is expected to increase, especially if the U.S. and other countries shift their energy usage towards a hydrogen economy, with hydrogen consumed as an energy commodity by the transportation, residential and commercial sectors. However, there is strong motivation to not use fossil fuels in the future as a feedstock for hydrogen production, because the greenhouse gas carbon dioxide is a byproduct and fossil fuel prices are expected to increase significantly. An advanced reactor technology receiving considerable international interest for both electricity and hydrogen production, is the modular helium reactor (MHR), which is a passively safe concept that has evolved from earlier high-temperature gas-cooled reactor (HTGR) designs. For hydrogen production, this concept is referred to as the H2-MHR. Two different hydrogen production technologies are being investigated for the H2-MHR; an advanced sulfur-iodine (SI) thermochemical water splitting process and high-temperature electrolysis (HTE). This paper describes pre-conceptual design descriptions and economic evaluations of full-scale, nth-of-a-kind SI-Based and HTE-Based H2-MHR plants. Hydrogen production costs for both types of plants are estimated to be approximately $2 per kilogram.

• Korean Journal of Plant Resources
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• 제26권1호
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• pp.90-102
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• 2013

This study was carried out in order to catalogue the folk plants of 5 counties and cities of Chungcheongbuk-do Province from March to October, 2011. 429 pages of field notes relating to the folk plants were collected from approximately 92 local inhabitants and analyzed subsequently. The identified folk plants were of 173 taxa, composed of 150 species, 1 subspecies, 22 varieties and 129 genera under 56 families. Naturalized plants were included. The use by its usage was: 349 taxa; edible, 68 taxa; medicinal, 2 taxa; dye, 1 taxa; aroma, 4 taxa; spice, 1, taxa; ornamental, 3 taxa; oil, 1 taxa; starch, 18 taxa; others respectively, so the edible use is the highest. The most useful part was the leaf, followed by stem, and whole plant. The consistency comparison between the scientific name and the local name were the highest in the 50's and the lowest in 90's.

• Korean Journal of Plant Resources
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• 제25권1호
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• pp.48-62
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• 2012

This study was carried out to classify the folk plants in inland of northern region of Gangwon-do. According to the survey results from 35 places of 9 counties and cities from April to October, 2010, the folk plants in inland of northern region of Gangwon-do consisted of a total 261 taxa; 73 families, 185 genera, 225 species, 2 subspecies, 30 varieties, and 4 form. Among the investigated 261 taxa, 3 Korean endemic, 11 rare plants and 9 naturalized plants were also included. The use by usage of 261 taxa was: 378 times; Edible, 53 times; Medicinal, 8 times; Dye, 7 times; Ornamental, 6 times; Fuel, 5 times; Spice, 3 times; Aroma, 2 times; Nectar, 41 times; Others, respectively, so the edible use is the highest. The most useful part was the leaf, followed by whole plant and root. The consistency comparison between the scientific name and the local name were the highest in the 20's and the lowest in 80's.

• Korean Journal of Plant Resources
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• 제23권5호
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• pp.465-479
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• 2010

This study was carried out to classify the regional folk plants in the inland of Gyeongsangbuk-do. According to the survey results from 582 survey sheets of 126 residents at 85 places of 17 counties and cities from March to October, 2009, the folk plants in the inland of Gyeongsangbuk-do consisted of a total 254 taxa; 76 families, 207 genera, 225 species, 2 subspecies, 26 varieties, and 1 form. The use by its usage was: 216 taxa; edible, 82 taxa; medicinal, 30 taxa; dye, 3 taxa; aroma, 4 taxa; spice, 4 taxa; ornamental, 1 taxa; fiber, 2 taxa; oil, 1 taxa; starch, 5 taxa; fuel, 9 taxa; others, respectively, so the edible use is the highest. The most useful part was the leaf, followed by stem and root. The folk plants of 3 head families from Yeongyang and Cheongsong were 42 taxa. The consistency comparison between the scientific name and the local name were the highest in the 50's and the lowest in 80's.

• Korean Journal of Plant Resources
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• 제18권3호
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• pp.462-469
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• 2005

Effects of proton beam irradiation on seed germination and growth pattern of tobacco (Nicotiana tabacum L. cv. BY-4; N. plumbaginifolia) and rice (Oryasativa L.) plants were estimated to develop the efficient conditions of irradiation. Seed germination rate was decreased by increasing the proton beam the current and the beam irradiation time in both tobacco and rice seeds. The beam irradiation conditions showing $50\%$ germination were over 60 sec at 10 nA, approximately 5 sec at 100 nA and at 500 nA beam current in tobacco seeds. And the conditions of $50\%$ germination were 60 sec at 10 nA, and 100 nA and 30 sec at 500nA in rice (cv. Dongjin 1) seeds. The growth of irradiated plants was decreased, but significant difference in morphological changes was not observed by the proton beam treatment. The proton beam is able to use as a mutagen, but some of the factors including beam size and beam detector-system must be established for efficient usage of the beam.

• Journal of Welding and Joining
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• 제26권2호
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• pp.43-49
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• 2008

Fatigue cracks due to thermal stratification or corrosion in pipelines of nuclear power plants can cause serious problems on reactor cooling system. Therefore, the development of an integrated technology including fabrication of standard specimens and their practical usage is needed to enhance the reliability of nondestructive testing. The test material was austenitic STS 304, which is used as pipelines in the Reactor Coolant System of a nuclear power plants. The best condition for fabrication of thermal fatigue cracks at the notch plate was selected using the thermal stress analysis of ANSYS. The specimen was installed from the tensile tester and underwent continuos tension loads of 51,000N. Then, after the specimen was heated to $450^{\circ}C$ for 1 minute using HF induction heater, it was cooled to $20^{\circ}C$ in 1 minute using a mixture of dry ice and water. The initial crack was generated at 17,000 cycles, 560 hours later (1cycle/2min.) and the depth of the thermal fatigue crack reached about 40% of the thickness of the specimen at 22,000 cycles. As a results of optical microscope and SEM analysis, it is confirmed that fabricated thermal fatigue cracks have the same characteristics as real fatigue cracks in nuclear power plants. The crack shape and size were identified.

• The Journal of the Korea institute of electronic communication sciences
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• 제11권1호
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• pp.1-8
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• 2016

The Nuclear Power Plants(: NPP) are being protected as national infrastructure, and instrumentation and control(: I&C) systems are one of the principle facilities of the NPP, which perform the protection, control, and monitoring function. The I&C systems are being evolved into digitalization based on computer and network technology from analog system. In addition, the I&C systems are mostly employ the specialized logic controllers which are dedicated for the NPP, but the usage of generalized IT resources are steadily increased. The cyber security issues for the NPP are being emerged due to cyber incidents by Stuxnet and various accidents in the NPP. In this paper, hybrid access control model is proposed which are applicable to I&C system by analyzing the access control requirements specified in regulatory guides. The safety of in-service and under construction of NPP are effectively increased by applying proposed hybrid model.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.989-995
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• 2017

Distributed Control System (DCS) communication networks, which use Fast Ethernet with redundant networks for the transmission of information, have been installed in digitalized nuclear power plants. Normally, failover tests are performed to verify the reliability of redundant networks during design and manufacturing phases; however, systematic integrity tests of DCS networks cannot be fully performed during these phases because all relevant equipment is not installed completely during these two phases. In additions, practical verification tests are insufficient, and there is a need to test the actual failover function of DCS redundant networks in the target environment. The purpose of this study is to verify that the failover functions works correctly in certain abnormal conditions during installation and commissioning phase and identify the influence of network failover on the entire DCS. To quantify the effects of network failover in the DCS, the packets (Protocol Data Units) must be collected and resource usage of the system has to be monitored and analyzed. This study introduces the use of a new methodology for verification of DCS network failover during the installation and commissioning phases. This study is expected to provide insight into verification methodology and the failover effects from DCS redundant networks. It also provides test results of network performance from DCS network failover in digitalized domestic nuclear power plants (NPPs).

• Journal of Korean Society of Forest Science
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• 제107권4호
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• pp.456-477
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• 2018

We analyzed the data on medicinal plants and related traditional knowledge in Korea and China using data analysis method. There are 108 families 214 genera 542 species, and 202 families 660 genera 1,261 species were found in Korea and China respectively. Total of 86 families (79.6%) and 130 genera (60.7%) were in common both countries. More than one information were recorded in many species, however, there was only one information from some species (32.7% of genera in Korea, and 58.8% of genera in China). The most frequent appeared plant family was Compositae (Asteraceae) in both countries (8.4% in Korea and 10.7% in China) and followed by Rosecease and Leguminocae (Fabaceae). Plant parts were classified 11 parts and roots were mostly used in Korea and whole plants in China. Usages were described in different terms of ailments or symptoms. There are 120 usage in Korea and 230 in China. Plant uses for the ailment or symptoms are pain, digestive system disorder, cold and etc. in Korea. In China, plants were mostly used for clear heat, digestive system disorder, cough and etc. Relation between the plant and ailment(symptom) of the top 10 plants in Korea and China was different although from same plant family. We also analyzed the relations between plant species and part used, and plants parts and ailment(symptom). With the data analysis method, we were able to collect the medicinal plant resources data and found the differences in plant resources, usage, and plant part for use. The result provide important information of the plant resources and related traditional knowledge of Korea for use of plant resources in industry and facilitate to plan a strategy to cope with Nagoya Protocol in the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• 제11권1호
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• pp.23-32
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• 2008

In order to discern the development of technology in creating, properly managing, and characterizing the types used in facade greening, this article examines the instances of facade greening of Bulgaria, Greece and Turkey which is not only located in the latitude similar to South Korea's but also influenced by the both continental and oceanic climate. The study was carried out for 11 months from October 2002 to September 2003. The total 242 places were researched and they were 83 sites in Athens, 77 sites in Istanbul, and 82 sites in Sofia. Varieties, usage, configuration, foundation and characteristics of plants were studied. The goals of greening, and building's surface roughness and thickness, direction of the wall were also researched. The result of survey are as follows; 17 families and 33 species of climbing plants were found in Athens, Istanbul, and Sofia. Thickness of facade greening in the three cities is 46cm in Athens, 39cm in Istanbul, and 53cm in Sofia. The possible facade greening size per a climbing plant, Parthenocissus tricupidata takes up the largest portion of the wall in the three cities similarly followed by Vitis vinifera and Wistaria spp. By its diversity it can be assumed that these plants are most practical for large scale of facade greening and full covering. Evergreen climbing plants such as Hedera helix and Ficus niponica are useful plants for relatively large scale of facade greening area. In the facade greening types, the climbing type is the most dominant in the three cities and most of the climbing type was planted on the natural foundation but the hanging and combination types were planted on an artificial foundation located on the balcony or on the roof of the building. In the directions of the walls for facade greening, the west direction are most popular which is for the improvement of sun shading in summer season. In Sofia the apartments were most applied with facade greening but In Istanbul and Athens the residential buildings and the public buildings were adapted with facade greening actively as well as residential building. The purpose of lowering summer heat took up the highest portion followed by the purpose of ornamentation and maintaining privacy in all surveyed cities.