• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.6
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• pp.1053-1058
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• 2010

A large modern wind farm should satisfy the requirements for a grid and accomplish the optimization of the wind farm system. The wind farm intertie protection system should consider a Fault Ride-Through (FRT) requirement for more reliable protection. The wind farm should keep connected to the grid in the case of a grid fault whilst it should be isolated for an intertie fault. This paper proposes a distance relaying algorithm suitable for wind farm intertie protection considering the FRT requirement. The proposed algorithm estimates the impedance based on a differential equation method because the frequency of the voltage and current deviates the nominal frequency. The algorithm extends the reach of Zone 1 up to 100 % of the length of the intertie to implement the FRT requirement. To discriminate an intertie fault from a grid fault, the algorithm uses a voltage blocking scheme because the magnitude of the voltage at the relaying point for an intertie fault becomes less than that for a grid fault. The performance of the algorithm is verified using a PSCAD/EMTDC simulator under various fault conditions. The algorithm can discriminate successfully the intertie fault from grid fault and thus helps to implement the FRT requirement of a wind farm.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.442_443
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• 2009

A large wind farm should satisfy the requirements for a grid and accomplish the optimization of the wind farm system. In that point of view, the wind farm intertie protection system, which must consider the Fault Ride-Through (FRT) requirement for more reliable protection, should be improved. This paper proposes a modified distance relay suitable for protection of a wind farm intertie considering a FRT requirement. The frequency change is used to discriminate the intertie fault from a outside zone fault. The performance of the proposed algorithm is verified using a PSCAD/EMTDC simulator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.10
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• pp.946-951
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• 2011

This paper presents the simulation results of GBAS availability and requirement (with respected to Vertical Protection Level) using simulated data at CAT I, CAT II/III DH point (Decision Height), which are generated using Jeju international GNSS reference position, aircraft horizontal velocity and reference/aircraft GNSS antenna performance index and so on. Two kinds of protection levels are presented, one is from a hypothesis (H0) and other is from a alternative hypothesis (H1). These protection levels are compared with AL (Alert Limit), and we analyse the GBAS availability and requirement for CAT I and CAT II/III at the airport.

• ETRI Journal
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• v.30 no.6
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• pp.874-876
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• 2008

Ethernet ring protection is a new technology introduced in ITU-T Recommendation G.8032, which utilizes the generic Ethernet MAC functions. We introduce an alternative enhanced protection switching scheme to suppress penalty in the switching transient, in which the Ethernet MAC filtering database (FDB) is actively and directly modified by information disseminated from the nodes adjacent to failure. The modified FDB at all nodes are guaranteed to be consistent to form a complete new ring network topology immediately. This scheme can reduce the capacity requirement of the G.8032 by several times. This proposed scheme can be also applied in IP protection rings.

• The Korean Society of Law and Medicine
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• v.14 no.1
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• pp.275-302
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• 2013

The Unites States has been plagued with soaring health care costs and an alarmingly large number of uninsured population. The Patient Protection and Affordable Care Act of 2010 ushered in the most sweeping health care reform in the United States since the introduction of Medicare and Medicaid in 1965 to address these issues. The law's requirement for individuals to purchase health insurance (the so-called "individual mandate"), however, not only caused a political stir but also prompted constitutional challenges. Some questioned whether the federal government, lacking general police power, could require its citizens to buy unwanted insurance based on its enumerated powers under the U.S. Constitution. This paper summarizes the decision of the U.S. Supreme Court on the constitutionality of individual mandate, and explores how the decision relates to Korea's own universal health care.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.200-215
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• 2002

There are some international standards and organization controling the quality characteristics of varieties and seeds such as UPOV, OECD, ISTA, AOSA. The National List system to check variety performance such as quality characteristics of plant varieties and seeds was established by each countries. The UPOV (International Union for the Protection of New varieties of Plant) regulates the requirement of plant variety protection that is distinctness (D), uniformity (U), stability (S) (here in after called DUS), Novelty and Denomination, and some quality characteristics are used to examine the requirement of plant variety protection by each crops. OECD (Organization for Economic Cooperation Development) seed scheme regulates the seed certification for seed trade between countries. ISTA (International Seed Testing Association) and AOSA(Association for Official Seed Analyst) regulates the seed analysis standard and methods. Most of the countries in Europe has the National List system, which check the value for cultivation and use(VCU), that is to say, variety performance such as yield, quality and stress to environment. All the seeds should be enlisted in the National List before sell the seed in their country. All the quality characteristics checked variety performance are for instance, amylose and amylopectin content in rice, molting quality, $\beta$-glucan, protein in barley, protein and sugar content in soybean, sugar and amylopectin content in corn etc. Conditions for the protection of new variety of plant are DUS. Quality characteristics may be the important characteristics and used to check DUS in crop by crop. It is very important to develop a new characteristics and establish standard method fur examine the VCU and DUS test for each crop.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1212-1216
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• 2014

This study aims to find out the best anode location for buried pipelines. Numerical simulation program known as CATPRO (Elsyca, Belgium) were used for confirming the best location of anodes and the effects of impressed current cathodic protection system. Applied conditions for numerical simulation were similar to on-site environmental conditions for optimal application of cathodic protection system. Used criterion of cathodic protection was NACE SP 0169, which describes that minimum requirement for cathodic protection is -850mV vs. CSE. Various layouts for anodes' installation were applied, which were distance between anodes, anode installation location, and applied current. The areas where cathodic protection potential was lower than -850mV vs. CSE was limited up to 50m from anode installation locations. It was founded numerical analysis obtain cost-effective and efficient cathodic protection methods before design and application the impressed cathodic protection system to on-site environment.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.592-596
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• 2004

Corrosion is never avoided in the use of materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP(Impressed Current Cathodic protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. The anode of ICCP system is controlled by an external DC source with converter. The function of anode is to conduct the protective current into seawater. The proposed algorithm includes the harmonic suppression control strategy and the optimum protection strategy and has tried to test the requirement current density for protection, the influence of voltage, the protection potential. This paper was studied the variation of potential and current density with environment factors, time and velocity, and the experimental results will be explained.

• Journal of Korean society of Dental Hygiene
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• v.5 no.1
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• pp.1-13
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• 2005

The study aimed to estimate the importance of job tasks, job training requirement and work satisfaction felt by dental hygienists to help dental hygienists work efficiently and effectively. A total of 142 dental hygienists working in dental hospitals located in J participated in the study. A SPSS 10.10 for Windows was used for statistical analysis. The statistical significance was defined as ${\alpha}$=.05. The results of the study are summarized as follows: 1. The mean score for the importance of job tasks was 4.09. The respondents considered dental clinic management and assistance to dentists the most important among their job descriptions showing the mean score of 4.44. The need for job training was 4.15 in average. The respondents wanted to have training on how to make a dental health insurance claim to receive payment other than any training with the mean score of 4.42. The work satisfaction of the respondents was 3.65 in average. The respondents were most satisfied with their work in dental assistance. 2. By the category of job tasks, the levels of importance of job tasks, job training requirement and work satisfaction were higher in plague removal with an ultrasonic scaler related to clinical oral prophylaxis, pit and fissure sealants related to preventive dental treatment and instruction in the correct usage of toothbrush related to public dental health education 3. In dealing with dental radiation machines, the radiation protection was considered the most important. While the training for periapical radiography was most needed, the respondents were satisfied with working in the same area. The levels of job importance, training requirement and work satisfaction were high in preventive dental care in the community performed in relation to the public dental health care. 4. In the dental health insurance claim category, the levels of importance of job task, training requirement and work satisfaction were higher in insurance claiming. The levels of job importance and training requirement were high in dental clinic management and assistance to dentists performed for preventive dental treatment. The work satisfaction was higher in maintaining medical chart records. The levels of job importance, training requirement and work satisfaction were higher in dental assistance in relation to dental protection. 5. There was significant relationship between the level of importance and work experience. Those with a longer period of work experience had higher levels of job importance in dental health insurance claim, dental clinic management and assistance to dentists and the overall task(pE0.05). 6. A significant relationship was observed between the need for job training in dental cleaning and preventive dental treatment and work experience. Those with more than 8 years of work experience demonstrated that job training is most needed(pE0.05). 7. The work satisfaction level was higher in the group with more than 8 years of work experience, compared with those in other work experience periods(pE0.05). 8. A positive correlation was seen between the level of importance and the need for job training among three variables.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.220-223
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• 2007

Acoustic test of the payload fairing of Korea satellite launch vehicle was conducted to verify the performance of acoustic protection system installed inside the payload fairing. This paper briefly introduces the acoustic test procedures and its results. Overall 148 dB acoustic loads were exerted on the payload fairing structures which mated with the upper stage structure of the launch vehicle. In order to verify the increase of insertion loss by the acoustic protection system, two kinds of test were performed. One is conducted with acoustic protection system and the other without acoustic protection system. Internal acoustic loads as well as external ones were measured and the measured insertion losses were compared with the requirement. The results showed that the acoustic protection system increases the insertion loss by more than 6 dB above 125 Hz. They also indicated that some design modification of Helmholtz resonator array is required to increase the insertion loss at a cavity resonant frequency.