• English Language & Literature Teaching
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• v.18 no.2
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• pp.189-211
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• 2012

The purpose of the study was to explore ways to improve the test items on the Korean scholastic ability test. More specifically, the researchers investigated whether use of the target language in test items would make a difference in total scores, discriminatory power, and item difficulty. A total of 288 high school seniors participated in the study. The subjects were divided into the experimental group (N=145) and the control group (N=143). A 25-item test resembling the Korean scholastic ability test was administered to both groups. The experimental group was given items whose questions and alternatives were all presented in English, whereas the control group was given items whose questions and alternatives were presented in Korean only. Statistical analyses revealed that use of English vs. Korean in the questions and alternatives made a significant difference in total scores, item discrimination, and item difficulty level. The findings strongly suggest that use of English is one way to improve the quality of the Korean scholastic ability test by enhancing item discrimination and face validity. Considering that the test in question is a high-stakes exam in Korea, further research on how to improve the Korean scholastic ability test is urgently called for.

• Convergence Security Journal
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• v.17 no.4
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• pp.31-37
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• 2017

This study compares the main features of the Act of National Contract with the Act of Defense Aquisition Program, which is the only one in Korea for long-term contracts. When applying the progress payments system to the defense R&D project, We can prevent disputes between parties and create a stable development environment through smooth partnerships. Smaller, direct and indirect losses can be alleviated, such as the waste of administrative power required to deal with disputes due to the payment of delayed prizes and restrictions on business activities due to the difficulty of forecasting the results of companies. In large measure, we will be able to procure a high-quality weapon system in a timely manner to support the security of the nation as well as international competitiveness through the growth of our defense industry.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.473-479
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• 2005

A key issue toward mobile multimedia communications is to create technologies for broadband signal transmission that ran support high quality services. Such a broadband mobile communications system should be able to overcome severe distortion caused by time-varying multi-path fading channel, while providing high spectral efficiency and low power consumption. For these reasons, an adaptive suboptimum decision feedback equalize. (DFE) for the single-carrier short-burst transmissions system is considered as one of the feasible solutions. For the performance improvement of the system with the short-burst format including the short training sequence, in this paper, the multiple-training least mean square (MTLMS) based DFE scheme with soft decision feedback is proposed and its performance is investigated in mobile wireless channels throughout computer simulation.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.213-222
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• 2009

IEEE 802.15.3 HR-WPAN is designed to enable wireless connectivity of high-speed, low-power, low-cost multimedia-capable portable consumer electronic devices. For quality of service, the standard specifies the use of TDMA (Time Division Multiple Access). However, during low contention TDMA gives much lower channel utilization and higher delays than CSMA (Carrier Sensing Multiple Access) because in TDMA, a node can transmit only during its scheduled time slots whereas in CSMA, nodes can transmit at any time as long as there is no contention. By mixing CSMA and TDMA, Hybrid MAC becomes more robust to timing failures, time-varying channel conditions, slot assignment failures and topology changes than a stand-alone TDMA.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.8-14
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• 2008

For nondestructive inspection of electron beam (EB) welding part in automotive power transmission assembly, a pulse-echo ultrasonic testing apparatus in water immersion has been applied using the ultrasonic waves with a frequency of 10MHz. However various problems have appeared during the ultrasonic inspection, which led to some significant mistakes in automatic quality evaluation of the welding parts. Experimental study showed that the state of water couplant medium containing some amount of contaminants, rusts and anti-corrosion agents had considerable influences on the reduction of ultrasonic amplitudes during wave propagation. The amplitude reduction depending on the coupling medium state could bring about some mis-diagnoses for defects in the welding parts. The results proposed that for a reliable inspection of defects in welds the state of water medium should be kept in about 15 volume fractions (vol.%) of anti-corrosion agents and in minimized contaminants.

• 한국디지털정책학회:학술대회논문집
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• 2007.06a
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• pp.51-58
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• 2007

Considering innovation a key to raising living standards, the Ministry of Science and Technology has put in place various measures meeting the needs of the newly promoted Deputy Prime Minister of Science and Technology. Such measures include business process reengineering as streamlining the work process to achieve the improvement in quality and efficiency: building the integrated performance management system to promote performance-or tented environment; and running the 1ifelong learning system for better competitiveness of government officials. Further to the innovation efforts at work, the number of steps of the R&D budget execution is streamlined from eight to five and its payment period is considerably reduced to 15 days from 60 days. In addition, the digitalized R&D budget management systems such as e-Contract System, One-click Processing Monitoring System, and Information Service System through Short Message Service (SMS) will contribute to improving R&D performance. And these systems are efficiently integrated into a portal interface named "Yeon-gu-ma-ru." The Ministry of Science and Technology, spearheading nationwide innovation, will continue efforts to make viable achievements of innovation.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1669-1679
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• 2017

Background: Steam generator (SG) is one of the significant components in the nuclear steam supply system. A variety of SGs have been designed and used in nuclear reactor systems. Every SG has advantages and disadvantages. A brief account of some of the existing SG designs is presented in this study. A high surface to volume ratio of a SG is required in small modular reactors to occupy the least space. In this paper, performance improvement for SGs of integral small modular reactor is proposed. Aims/Methods: For this purpose, cross-grooved microfins have been incorporated on the inner surface of the helical tube to enhance heat transfer. The primary objective of this work is to investigate thermal-hydraulic behavior of the proposed improvements through modeling in RELAP5-3D. Results and Conclusions: The results are compared with helical-coiled SGs being used in IRIS (International Reactor Innovative and Secure). The results show that the tube length reduces up to 11.56% keeping thermal and hydraulic conditions fixed. In the case of fixed size, the steam outlet temperature increases from 590.1 K to 597.0 K and the capability of power transfer from primary to secondary also increases. However, these advantages are associated with some extra pressure drop, which has to be compensated.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.35-42
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• 2017

Process Hazard Analysis(PHA) have been performed for a risk management of process (petrochemical) industry for nearly 50 years. There are many PHA methods for application in the process industry, Hazop Study method has been recognized as a good method used typically in most of phase of process plant. And also there was inconvenient opinion that Hazop Study is too resource (man power, time etc.) consuming comparing its result performance (a quality of recommendations) for a good operating and existing plant. In this study, two types of PHA method - checklist and K-PSR - were performed respectively for a new para-xylene(PX)plant and 30 year old PX plant. Past history and experience of incident, operation, maintenance and so on are very important in PHA by those two methods. The higher effectiveness were realized in PHA by a checklist and K-PSR Method than prior Hazop study. And also some suggestions including PHA cycle determination, RBPS application, Follow-up plan of PHA result etc. were proposed about PHA improvement measures for a best risk management.

• Journal of IKEEE
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• v.19 no.4
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• pp.603-609
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• 2015

Thermal comfort is one of the fundamental aspects of indoor environmental quality and it is strongly related to occupant satisfaction and energy used in building. In this paper, we proposes smart comfort algorithm that save energy and provide a pleasant and comfortable environment for workers by the indoor comfort conditions(Predictive Mean Vote) detection and controlling the temperature and humidity, air flow. Simulation results, heating and cooling control of the thermal comfort control can be compared with the existing general air conditioners reduces the power of 0.5kW and indoor comfort can be maintained. Also, It showed a 49.2% improvement in the light by lighting control algorithm.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2241-2243
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• 2005

Although the boundary image sticking is one of major factors to determine display quality in AC PDP, a reliable measurement method has not reported so far. The boundary image sticking is recognized clearly by our eyes, but it is difficult to compare with adjacent cells by using a measurement method. However, the boundary image sticking can be analyzed by CCD DSLR camera method because this method can distinguish between the boundary cell and the adjacent cells. Moreover, we suggested new driving waveform for the reduction of the boundary image sticking.