• Journal of Radiation Protection and Research
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• v.42 no.3
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• pp.141-145
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• 2017

Background: The concrete walls inside the vaults of cyclotron facilities are activated by neutrons emitted by the targets during radioisotope production. Reducing the amount of radioactive waste created in such facilities is very important in case they are decommissioned. Thus, we proposed a strategy of reducing the neutron activation of the concrete walls in cyclotrons during operation. Materials and Methods: A polyethylene plate and B-doped Al sheet (30 wt% of B and 2.5 mm in thickness) were placed in front of the wall in the cyclotron room of a radioisotope production facility for pharmaceutical use. The target was Xe gas, and a Cu block was utilized for proton dumping. The irradiation time, proton energy, and beam current were 8 hours, 30 MeV, and $125{\mu}A$, respectively. To determine a suitable thickness for the polyethylene plate set in front of the B-doped Al sheet, the neutron-reducing effects achieved by inserting such sheets at several depths within polyethylene plate stacks were evaluated. The neutron fluence was monitored using an activation detector and 20-g on de Au foil samples with and without 0.5-mm-thick Cd foil. Each Au foil sample was pasted onto the center of a polyethylene plate and B-doped Al sheet, and the absolute activity of one Au foil sample was measured as a standard using a Ge detector. The resulting relative activities were obtained by calculating the ratio of the photostimulated luminescence of each foil sample to that of the standard Au foil. Results and Discussion: When the combination of a 4-cm-thick polyethylene plate and B-doped Al sheet was employed, the thermal neutron rate was reduced by 78%. Conclusion: The combination of a 4-cm-thick polyethylene plate and B-doped Al sheet effectively reduced the neutron activation of the investigated concrete wall.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.69-76
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• 2017

This study evaluated the activation of the shielding wall and the components around the accelerator by using the medical linear accelerator. We performed simulations for energy values of 20 MV with the operating time ranging from day 1 to 30 years, and linear accelerator head and shielding wall concrete were also evaluated. The results showed that neutrons in large quantities were analyzed using high energy around thetarget point where photons were formed. Based on the activation analysis with these results, radioactivity increased with an increase in operation time and activated nuclides usually start saturating in10 years. Furthermore, the general types of nuclides formed owingto the activation were Co-60, W-181, 185, 187, Na-24, Ca-45, Mn-54, 56, and Fe-55, 59.

• Journal of the Korean Society for information Management
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• v.37 no.3
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• pp.157-175
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• 2020

This study aimed to understand why small libraries, which have been continuously extended by the increase of social interest in them and the enactment of 「Promotion of Small Library Act」, an independent law about small libraries, are poorly activated. To this end, it examined the actual status of small library operation, related policies, support and legislations. By summarizing the results, it proposed a policy direction and tasks for activating small libraries. The policy tasks for activating them consist of three main tasks such as 'the improvement of laws and institutions for establishing the base of policies and securing practical momentum', 'the reestablishment of roles by policy units and the reinforcement of cooperation systems' and 'the construction of stable operation support system for small libraries', and their 14 sub-tasks, under the vision of 'the activation of small libraries support local residents' happy life' and the core value of 'a comprehensive policy ground, the innovation of policy systems and sustainable management support'.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.97-140
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• 2006

The purpose of this study is to activate Korea's coastal passenger shipping by improvement of the deterrent factors on the basis of field data collected in order to help stimulate it and enhance its competitiveness. As the representative model of this study, the "P" car-ferry liner was chosen, whereby various deterrent factors were observed in the course of the SWOT analysis and through the questionnaires. The major deterrent factors in summary were inflexible government regulations for additional ship operation, disadvantages of taxes policy, port facility shortages, non-allowing of ship's night operation, complicated and inflexible ship's operation controls by the concerned authorities, unreasonable divisions of steaming areas, and existences of obstacles on the ship's running routes, etc. which considered all are important to activate the liners.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.713-729
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• 2011

The purpose of this study is to suggest an activation plan for community centers. The community centers, categorized into 3 types by the number of visitors, were comparatively analyzed by their programs, operation, and visitors' opinion. 6 community centers in Heungduk-gu, Cheongju-city, their 6 operators, and their 220 visitors were the sample. This study surveyed community centers on the spot about their space characteristics and programs, interviewed operators, and asked questionnaires to visitors. The data of the 3 categorized centers were analyzed by frequency, average, and percentage. The following is the result: 1) The number of visitors was dependent on the type of residence and age of the residents. The activated community centers were found in residence type apartment blocks, and with an age group in its 40s. 2) The space satisfaction was dependent on the year of construction; it was higher with newer buildings and wider sizes. 3) All the centers were affirmative on the communication of the participants of programs. In conclusion, the activation plan of the community center has to comprise a renovation of old buildings, public promotion, and the development of programs taking into consideration the age group of the residents.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.87-95
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• 2012

This technical paper describes the analysis results of telemetry data for the initial activation of star trackers for an agile high accuracy low earth orbit satellite. The satellite was recently launched and is in the Launch and Early Operation Phases. It uses two SED36 star trackers manufactured by SODERN. The star tracker is separated by three parts, an optical head, an electronics box, and a baffle with maintaining optical head base plate temperature 20 degC in order to achieve the better performance in low frequency error. This paper presents the initial activation status, requirements and performance, anomaly occurrence, and noise equivalent angle performance analysis during the mission mode by processing the telemetry data.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.251-255
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• 2009

Foreign and domestic seawater desalination plant market investigation was performed to analyze the worldwide trend of seawater desalination plant market and to establish the activation plan for seawater desalination plant application. Water demand and seawater desalination related laws and regulations were investigated and analyzed for the activation plan. RO type and large scale plants are popular nowadays however there are only small plants in island region in Korea. There will be about $1 million\;m^3/day$ deficit in 2015 according to the water demand forecasting from Ministry of Environment and Ministry of Land, Transportation, and Maritime Affairs in Korea. Therefore, it is necessary to activate the domestic application of seawater desalination plant to secure stable water resources. To activate the domestic application of seawater desalination plant, first, we need to establish regulations, support system in the water service law for seawater desalination plant. Second, related Ministry should increase the support for the operation and management of seawater desalination plant and suggest the construction of seawater desalination plant for water resources security near seaside region.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.4
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• pp.115-137
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• 2022

This research aims to suggest the way of activation of book curation in secondary school libraries by analyzing examples of book curation and the recognition of the persons in charge of secondary school libraries. A documentary research and a survey is conducted. 192 school librarians are chosen for that survey in Incheon region secondary school. 4 teacher librarians of Incheon region secondary school and a professor of library and information science are interviewed. Also an investigation is executed by visiting school libraries. Augmentation of the persons in charge of secondary school libraries, coordinating and information sharing with educational teachers, establishment of manual for book curation operation, publishing examples of subject selection are suggested for the measure of activation of book curation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.16-21
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• 2008

This paper introduces a new type of Hopfield neural network using newly developed single-electron devices. In the electrical model of the Hopfield neural network, a single-electron synapse, used as a voltage(or current)-variable resistor, and two stages of single-electron inverters, used as a nonlinear activation function, are simulated with a single-electron circuit simulator using Monte-Carlo method to verily their operation.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.132-139
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• 2008

In an electric railway feeding system, transient over-voltage often appears due to the feeder's direct lightning and induced lightning, while switching over-voltage also frequently occurs during operation of electric feeding in substation facilities. Such over-voltage is several times larger than the regular power, and accordingly leads to the dieletric breakdown of eletric power products such as invasion transformers and circuit breakers. Arresters are installed to protect these machines, while arrester counters are installed to observe the arrester's activation. This thesis aims to explore the status of an arrester counter that is being activated several thousand times, determine whether the arrester has actually been activated in relation to the counter, and investigate the over-heatedness and risks of the arrester.