• Nuclear Engineering and Technology
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• 제55권2호
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• pp.717-724
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• 2023

An essential step in evaluating and comparing the performance of two passive radiation dosimeter types, thermosluminescent (TLD) and optically stimulated luminescence (OSL), used by workers in environments with ionizing radiation for individual radiological monitoring and control of external exposure at various times (cumulative dose for 1 month), is to compare the measured dose accuracy, energy response, and coefficient of variation. In fact this performance study consists in determining the accuracy of both R(10) and R(0.07) which are considered as the ratios of the measured dose (Hp(10) or Hp(0.07)) to the delivered dose (Hp(10) or Hp(0.07)) for each photon energy. The validity of the results of this test is based on the acceptance limits of the ICRP and the international standard IEC-62387. The relative energy response used is normalized to the ¹³⁷Cs 662 keV energy to find which energy response is closest to the ideal case, and the coefficient of variation that allows to determine the statistical fluctuation of the Hp(10) and Hp(0.07) doses. The results of the accuracy test for the OSL and TLD dosimeters are acceptable because they fall within the ICRP limits. For the energy response, the OSL performs better than the TLD for Hp(10) and Hp(0.07), and for the coefficient of variation, the OSL satisfies the requirements of ISO 62387 for both Hp(10) and Hp(0.07), while the TLD satisfies these requirements only for the measurement of Hp (0.07).

• 한국식품위생안전성학회지
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• 제36권1호
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• pp.9-16
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• 2021

2018년과 2019년에 서울에서 유통 중인 건고추 및 고춧가루에 대해 잔류 농약 안전성 검사를 실시하였다. 총 101건의 시료에 대해 71종 농약을 모니터링한 결과 잔류허용기준을 초과한 시료는 없었으나 잔류농약이 검출된 시료는 87건으로 86.1%의 검출률을 나타내었다. 건고추와 고춧가루 검출률은 각각 73.3%, 91.5% 이었다. 고춧가루의 잔류농약 검출률이 건고추에 비해 다소 높게 나타났다. 검출된 농약은 12종이었으며 모두 작물보호제 지침서에 따른 고추에 사용가능한 살균제 및 살충제이었다. 가장 다빈도로 검출된 농약은 pyraclostrobin이었으며 다음으로 flubendiamide, azoxystrobin, chlorantraniliprole 순이었다. 검출된 농약에 대한 위해성을 ADI(Acceptable daily intake)대비 식이섭취율로 산출하여 평가한 결과, %ADI는 모두 5.66E-05 - 3.34E-02%로 나타나 안전한 것으로 나타났다.

• 전력전자학회논문지
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• 제18권3호
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• pp.240-246
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• 2013

An Uninterruptible Power Supply(UPS) is a system designed to deliver energy during accidents that the AC mains is out of its acceptable limits, without interruption of power flow through the load. Battery Discharger is the device to supply high quality power to the Inverter, when accidents occur, such as Power Failure. The Battery Discharger should have a fast response characteristics. The LLC resonant converter for UPS battery discharger is proposed. The proposed Battery Discharger offers substantial improvements in efficiency, size and cost. The proposed Battery Discharger of UPS approach is a good solution for high power applications above KW. To verify the validity of proposed Battery Discharger, simulations and experiments are carried out.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.391-400
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• 2016

In satellite operations, stable maneuvering of a satellite's onboard antenna to prevent undesirable vibrations to the satellite body is required for high-quality high-resolution images. For this reason, the onboard antenna's angular rate is typically minimized while still satisfying the system requirement that limits the speed of the onboard antenna. In this study, a simple yet effective method, called the ground station searching method, is proposed to reduce the angular rate of a satellite's onboard antenna. The performance of the proposed method is tested using real flight data from the KOMPSAT-3 satellite. Approximately 83% of arbitrarily selected real flight scenarios from 66 test cases show reductions in the onboard antenna's azimuth angular rates. Additionally, reliable solutions were consistently obtained within a reasonably acceptable computation time while generating an onboard antenna tracking profile. The obtained results indicate that the proposed method can be used in real satellite operations and can reduce the operational loads on a ground operator. Although the current work only considers the KOMPSAT-3 satellite as a test case, the proposed method can be easily modified and applied to other satellites that have similar operational characteristics.

• Earthquakes and Structures
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• 제10권2호
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• pp.409-428
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• 2016

To realise the full benefits of a self-centering seismic resilient system, the designer must ensure that the entire structure does indeed re-center following an earthquake. The idealised flag-shaped hysteresis response that is often used to define the cyclic behaviour of self-centering concrete systems seldom exists and the residual drift of a building subjected to an earthquake is dependent on the realistic cyclic hysteresis response as well as the dynamic loading history. Current methods that are used to ensure that re-centering is achieved during the design of self-centering concrete systems are presented, and a series of cyclic analyses are used to demonstrate the flaws in these current procedures, even when idealised hysteresis models were used. Furthermore, results are presented for 350 time-history analyses that were performed to investigate the expected residual drift of an example self-centering concrete wall system during an earthquake. Based upon the results of these time-history analyses it was concluded that due to dynamic shake-down the residual drifts at the conclusion of the ground motion were significantly less than the maximum possible residual drifts that were observed from the cyclic hysteresis response, and were below acceptable residual drift performance limits established for seismic resilient structures. To estimate the effect of the dynamic shakedown, a residual drift ratio was defined that can be implemented during the design process to ensure that residual drift performance targets are achieved for self-centering concrete wall systems.

• 한국항공운항학회지
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• 제24권2호
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• pp.25-30
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• 2016

Obstacle defines all fixed and mobile objects, or parts thereof, that are located on an area intended for the surface movement of aircraft or extend above a defined surface intended to protect aircraft in flight or stand outside those defined surfaces and that have been assessed as being a hazard to air navigation. The airspace around airports are maintained free from obstacles so as to permit the intended aeroplane operations at the airports to be conducted safely and to prevent the airports from becoming unusable by the growth of obstacles around the airports. This is achieved by establishing a series of obstacle limitation surfaces or airspace imaginary surfaces that define the limits to which objects may project into the airspace. This is a case study that shows an application of obstacle limitation criteria, which must be maintained free from an critical obstacle, for specific conditions of two airports. For the purpose of the application, aeronautical studies/flight safety influence assessments were used to identify possible solutions and select a solution that is acceptable without degrading aviation safety.

• Biomolecules & Therapeutics
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• 제11권2호
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• pp.145-150
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• 2003

The bioequivalence of two tablet formulations of 12.72mg domperidone maleate (Sinil "$Perinal^{\circledR}$" tablets vs. Janssen Korea "Motilium-$M^{\circledR}$" tablets) was assessed in healthy Korean volunteers after oral administration in a randomized crossover study. Blood samples were collected at spccified time intervals, and plasma concentration was measured as the amount of domperidone base using a validated HPLC method. The pharmacokinetic parameters of $AUC_{0{\rightarrow}48},\; C_{max},\;T_{max}$ and $t_{1/2}$ were determined from plasma concentration-time profile of two formulations. Any significant statistical differences were not observed between these two formulations. On the evaluation of bioequivalence according to Korea Food and Drug Administration Guideline, 90％ confidence limits after logmithmic transformation fell within the acceptable range (log 0.8∼log 1.25). Based on these data, it can be concluded that two domperidone maleate tablets showed comparable pharmacokinetic profiles, which means that the Sinil "$Perinal^{\circledR}$" tablet is bioequivalent to the Janssen Korea ""Motilium-M$^{\circledR}$".

• 전력전자학회논문지
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• 제21권3호
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• pp.231-237
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• 2016

Recently, the interest in DC systems to achieve more efficient connection with renewable energy sources, energy storage systems, and DC loads has been growing extensively. DC systems are more advantageous than AC systems because of their low conversion losses. However, the DC-link voltage is variable during operation because of different random effects. This study focuses on DC voltage stabilization applied in stand-alone DC microgrids by means of voltage ranges, power management, and coordination scheme. The quality and stability of the entire system are improved by keeping the voltage within acceptable limits. In terms of optimized control, the maximum power should be tracked from renewable resources during different operating modes of the system. The ESS and VSDG cover the power shortage after all available renewable energy is consumed. Keeping the state of charge of the ESS within the allowed bands is the key role of the control system. Load shedding or power generation curtailment should automatically occur if the maximum tolerable voltage variation is exceeded. PSIM-based simulation results are presented to evaluate the performance of the proposed control measures.

• 한국안광학회지
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• 제10권3호
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• pp.221-228
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• 2005

현재 국내에서 유통되고 있는 국내외 렌즈제품들을 대상으로 굴절력과 중심부 두께의 측정을 통해 제품간의 차이를 분석하였다. 국내 제품들은 해외제품에 버금갈 정도로 제작되었지만 허용기준에 맞지 않는 경우가 있었으며, 또 통일 제품들에서도 차이를 줄일 필요가 있다. 국내제품들이 해외 제품들에 비해 더 경쟁력을 가지기 위해서는 전문인력의 육성, 엄격한 품질검사, 공정관리, 규격의 표준화가 필요하다.

• 한국식생활문화학회지
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• 제27권4호
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• pp.383-390
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• 2012

This study was conducted to investigate the physicochemical and sensory changes of 6 kinds of commercial Makgeolli (A, B, C, D, E, and F) during storage at $4{\pm}1^{\circ}C$ for 30 days. The initial pH was 3.50~4.23, but it increased to 3.65~4.37 by the end of the storage period (p<0.05) There were no significant differences in titratable acidity between the beginning and end of the storage period. The reducing sugar content of A and B increased, whereas C, D, E, and F decreased with increasing storage time. A decrease in lightness (L values) was observed in all samples with increasing storage time (p<0.05). The alcohol content increased from beginning values of 5.90~6.10% to ending values of 6.30~7.35% at the end of storage, of which sample B exhibited the highest value. A sensory evaluation test revealed that the overall acceptability of samples A, B, D, and E were still within acceptable limits, but samples C and F showed undesirable changes during 30 days of storage at $4^{\circ}C$.