• Nuclear industry
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• v.33 no.3
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• pp.92-99
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• 2013

영국은 천층 처분에 부적합한 일부 저준위 방사성폐기물을 포함하여 지층 처분의 대상인 중준위 및 고준위 방사성폐기물의 효율적인 저장 관리를 위한 지침을 3년간의 방대한 노력 끝에 성공적으로 개발하여 그 결과를 최근 공개했다.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.11-19
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• 2013

This study analyzed relative efficiencies of fourteen airports in Korea with radial and non-radial approaches such as DEA(Data Envelopment Analysis) and SBM(Slack Based Measure) from 2004 to 2011. To suggest an improvement scheme for these airports, we analyzed slack airports and compared then with respective reference airports. To measure efficiency, we used the length of runway, the number of employees, and the size of terminal as input factors, and the number of passengers, the amount of cargo, and the number of flights as output factors. The analysis results showed that efficiencies of most airports had been decreasing and that the gap between efficient airports and inefficient airports was widening. Additionally, most airports had much slacks in its terminal size. It meant that they had been operated with a size not proportionate to their demands and that it is a major cause of inefficiency.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.93-101
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• 2014

Underwater radiated noise is the key in acoustic stealth performance of modern naval ships. The underwater radiated noise predicted by the hull vibration with radiation efficiency cannot always give the information of radiation pattern which is essential to analyze of detection probability by enemy and to improve the operational performance of the naval ship. The radiation pattern of underwater radiated noise is able to be obtained with radiation efficiency and radiation directional coefficient. In this paper, a new method to extract the radiation efficiency and radiation directional coefficient is suggested and proved with the simulation and experiment by using cylindrical shell of 70 cm diameter in air.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.738-743
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• 2013

Underwater radiated noise is the key in acoustic stealth performance of modern naval ships. The underwater radiated noise predicted by the hull vibration with radiation efficiency cannot give the information of radiation pattern which is essential to the analysis of detection possibility by enemy and to improve the operational performance of the naval ship. The radiation pattern of underwater radiated noise is able to be obtained with radiation efficiency and radiation direction coefficient. In this paper, a new method to extraction the radiation efficiency and radiation direction coefficient is suggested and proved with the simulation and experiment by using cylindrical shell of 70cm diameter in air.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.8-14
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• 2008

In this paper, the effects of ground size on the characteristics such as input resistance, fractional bandwidth, and radiation efficiency of epsilon negative (ENG) zeroth order resonance (ZOR) antennas were investigated theoratically. Two types of ENG ZOR antennas were studied: mushroom ENG ZOR antenna with via and via-free defected ground structure (DGS) ENG ZOR antenna. It was confirmed that the ground size had more effects on the characteristics of a Via-free ZOR antenna than those of mushroom ZOR antenna with via. The via-free antenna could radiate properly with the required size of ground plane since the size of ground plane should exceed some critical value for DGS to suitably operate. As a height of substrate of mushroom ZOR antenna with via increased, the fractional bandwidth and radiation efficiency were improved. On the other hand, as a height of via-free ZOR antenna increased, the fractional bandwidth and radiation efficiency were degraded. Finally, a via-free ZOR antenna had an advantage of compactness even though its fractional bandwidth is narrow and its radiation efficiency is poor, compared with thoses of mushroom ZOR antenna with via.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.114-114
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• 2008

자동차 보수도료 경화는 주로 열풍방식을 사용하고 있지만 적외선 가열방식을 사용하면 품질이 향상 되고 에너지 절약 등의 이점이 있다. 따라서 자동차 보수도료의 경화용으로 사용할 적외선 방사체를 개발하였다. 자동차 보수도료의 적외선 흡수 스펙트럼과 적외선 방사체 방사 스펙트럼이 일치해야 도료의 경화효율이 우수해짐을 알 수 있었고 열풍방식과 비교하여 경화된 도막의 품질 및 경화시간에 대한 실험데이터를 분석하였다.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.240-246
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• 2009

Quality control test in this field of study were carried out in 3 categories, radionuclidic purity, chemical purity and radiochemical purity. Also, indication efficiency was tested every 3 hours changed after binding the radiopharmaceutical to see how long the medicine is available for usage after indicating. The result showed that currently used radiopharmaceutical have good radionuclidic purity and chemical purity. However, radiochemical purity indication showed small differences depending on indication method and indication period. Radiopharmaceutical are indicated by treatment providers, so they need to pay more attention to the indication process and quality control to provide more efficient treatment.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.1-6
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• 2023

Sound radiated from a structure in vibration is an important physical characteristic to evaluate vibro-acoustic problem. Although sound radiation power can be typically obtained by intensity measurement, long measuring time and strict measuring condition remain difficult. As an alternative method, simulation-based estimation can be taken into account and its accuracy is known to be acceptable. However, difficulty still lies in that specialized softwares may be necessary to obtain sound radiation power and radiation efficiency. In this context, this study suggests two methods using an ordinary FE method to calculate sound radiation power. They are well-known reciprocity technique and p-p method, which are basically test methods. It is shown that either method can practically estimate sound radiation in the frame of conventional Finite Element Method (FEM). The methods and their corresponding limit are discussed with some results.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.3
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• pp.153-160
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• 2009

Vertical electrokintic-flushing remediation equipment was developed for the remediation of a radioactive soil near nuclear facilities. An optimum reagent was selected to decontaminate the radioactive soil near nuclear facilities with the developed vertical electrokintic-flushing remediation equipment, and the optimum remediation conditions were established to obtain a higher remediation efficiency. Namely, acetic acid was selected as an optimum reagent due to its higher remediation efficiency. When the electrokinetic remediation and the electrokinetic-flushing remediation results were compared, the removal efficiency of 4.6% and the soil waste solution volume of 1.5 times were increased in the electrokinetic remediation. When the potential gradient within an electrokinetic soil cell was increased by two times (4.0 V/cm), the removal efficiencies of $Co^{2+}$ and $Cs^+$ were increased by about 4.3%($Co^{2+}$ : 98.9%, $Cs^+$ : 96.7%). Also, when the reagent concentration was increased from 0.01M to 0.05M, the removal efficiency of $Co^{2+}$ was increased but that of $Cs^+$ was decreased. Therefore, the optimum remediation conditions were that the acetic concentration was $0.01M{\sim}0.05M$, the potential gredient was 4 V/cm, the injection of reagent 2.4ml/g, and the remediation period was 20days.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.96-100
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• 2003

Filtering system is installed at post irradiation examination facility(PIEF) to maintain optimized operating condition of the facility by keeping different negative pressure condition depending on contamination level in the PIEF due to its treatment of radioactive materials. Inspection on each system, filter leak test and other related test are periodically performed as the performance test for increasing operational efficiency and safety.