• 항공우주시스템공학회지
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• 제15권1호
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• pp.95-101
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• 2021

현재 국내에서 구축·운영 중인 문형금속탐지장비는 제조사마다 탐지감도가 다소 상이하여 항공보안 등급에 따른 단계별 적용이 어려운 실정이다. 또한 국내 항공보안 감독기관이 승인한 점검용 시험물품(FAA 3-GUN Test)은 단일 시험물품으로 문형금속탐지장비의 항공보안 등급별 운영을 위한 복수 시편으로 구성된 시험물품이 부재한 상황이다. 본 논문에서는 국내 구축 및 운영 중인 문형금속탐지장비에 대해 상용 시험물품을 적용한 탐지감도 측정시험을 실시하였으며, 이를 바탕으로 문형금속탐지장비 탐지감도 기준을 마련하였다. 또한 항공분야 특성을 고려한 한국형 표준 시험물품(OTP) 개발 방안 제시를 통해, 국내 항공보안등급별 동일 감도를 유지 할 수 있는 제도적 방안을 제시하였다.

• 한국전기전자재료학회논문지
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• 제29권5호
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• pp.312-316
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• 2016

In this study, we fabricated $NO_x$ gas sensor by using multi-walled carbon nanotubes(MWCNT)/zinc oxide(ZnO) composite film. Carbon nanotubes (CNTs) have good electronic, chemical-stability, and sensitivity characteristics. And zinc oxide (ZnO) is a wide band gap and large exciton binding energy semiconductor. In particular, gas sensors require characteristics such as high speed, sensitivity, and selectivity. The fabricated gas sensor was used to detect $NO_x$ gas for different values of the $NO_x$ gas concentrations. The gas sensor that absorbed$NO_x$ gas molecules showed a increasing in resistance. The sensitivity of the gas sensor was increased by increasing the gas concentrations. Additionally, while changing the temperature inside the chamber for the MWCNT/ZnO composite film gas sensor, we obtained the sensitivity. And the comparison analysis to ZnO film gas sensor for detecting $NO_x$ gas. From the experiment result, we confirmed improvement of $NO_x$ gas detection characteristics using the MWCNT/ZnO composite film.

• 열처리공학회지
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• 제24권2호
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• pp.87-91
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• 2011

Single layer Sn doped $In_2O_3$ (ITO) films and ITO 50 nm / Au 10 nm / ITO 40 nm (IAI) multilayer films were prepared with electron beam assisted magnetron sputtering on glass substrates. The effects of the Au interlayer, post-deposition atmosphere annealing and intense electron irradiation on the methanol gas sensitivity were investigated at room temperature. As deposited ITO films did not show any diffraction peaks in the XRD pattern, while the IAI films showed the diffraction peak for $In_2O_3$ (400). In this study, the gas sensitivity of ITO and IAI films increased proportionally with the methanol vapor concentration and an intense electron beam irradiated IAI film shows the higher sensitivity than the others film. From the XRD pattern, it is supposed that increased crystallization promotes the gas sensitivity. This approach is promising in gaining improvement in the performance of IAI gas sensors used for the detection of methanol vapor at room temperature.

• 한국콘텐츠학회논문지
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• 제3권4호
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• pp.63-68
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• 2003

본 논문은 통신 네트워크 운용관련 민감도 측정에 관한 연구를 위해 네트워크 운용 적정비용 산출 및 효율화 방안을 제안하였다. 통신 네트워크 운용효율화를 위해 네트워크 운용 효율성 측정을 위한 모형을 개발하였다. 전반적/포괄적 관점에서 산출된 네트워크 운용의 적정비용에 대해 품질수준 개선을 위한 요소, 고객만족도 관련 요소 등과의 연계성을 중심으로 재평가하고 개선하는 것이 본 논문의 가장 핵심적인 연구이다. 이러한 과정은 네트워크 운용의 가장 큰 부분을 차지하는 것이 품질관련 활동이고 품질관련 활동은 결국 고객만족도로 나타나게 되는 것이기 때문에, 각 요소별 개별적인 변화가 상호간에 미치는 영향을 중심으로 상관관계를 정립하여 민감도 측정을 바탕으로 네트워크운용비용을 산출하는 것이 진정한 의미의 적정수준 분석이라 할 수 있다. 따라서, 본 논문에서는 네트워크 운용에 대한 체계적인 모형의 구축 및 효율성 측정을 위한 다양한 시나리오에 따른 민감도 측정을 위한 시스템을 개발하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제47권1호
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• pp.1-6
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• 2024

In Recent years, there has been a noticeable increase in the global incidence of breast cancer, with approximately 2.3 million cases of female breast cancer reported worldwide in 2020. Numerous studies are currently underway to enhance the accuracy of breast cancer diagnosis through the development of digital mammography detectors. This study aims to create Monte Carlo simulation-based mammographic anti-scatter grids and investigate their utility in evaluating the performance of digital mammography detector. Two types of mammographic anti-scatter grids, MAM-CP and Senographe 600T HF, were created using Monte Carlo simulation software (MCNPX 2.7.0), with grid ratios of 3.7 : 1 and 5 : 1, respectively. The grid physical characteristics (sensitivity, exposure factor, contrast improvement ratio) were calculated based on the KS C IEC60627 in the simulations using two X-ray qualities, RQA-M2 (28 kVp) and MW4 (35 kVp). As the X-ray tube voltage increased from 28 kVp to 35 kVp, sensitivity and exposure factor exhibited a decreasing trend, while contrast improvement ratio demonstrated an increasing trend. With an increase in grid ratio from 3.7 : 1 to 5 : 1, all physical characteristics showed an upward trend. Our results were consistent with a previous study that conducted measurements of physical properties using a real phantom. However, the pattern of change in the contrast improvement ratio with X-ray tube voltage differed from the previous study.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.759-767
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• 2009

대규모 연약지반개량 설계는 압밀영향인자의 불확실성으로 대부분 신뢰성해석을 도입하여 설계를 수행하는 추세이다. 신뢰성해석은 이론습득의 어려움으로 인하여 실무 기술자들에게 범용되지 못하고 있다. Duncan(2000)이 제안한 간편하고 유용하게 사용할 수 있는 신뢰성해석 간편법과 전통적인 신뢰성해석법의 해석결과를 비교하여 간편법의 적용성을 평가하였다. 민감도분석에서는 동일한 경향을 보였으나, 파괴확률은 약 20~50%의 오차를 보이고 확률변수의 확률분포에 따른 적용성이 떨어지는 것으로 평가되었다. 신뢰성해석 간편법은 개략설계시 결정론적해석과 상호 보완적으로 적용한다면 최적설계가 이루어질 수 있을 것으로 사료된다.

• 한국멀티미디어학회논문지
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• 제22권3호
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• pp.349-356
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• 2019

When a prescription change occurs in the hospital depending on a patient's improvement status, pharmacists directly classify manually returned pills which are not taken by a patient. There are hundreds of kinds of pills to classify. Because it is manual, mistakes can occur and which can lead to medical accidents. In this study, we have compared YOLO, Faster R-CNN and RetinaNet to classify and detect pills. The data consisted of 10 classes and used 100 images per class. To evaluate the performance of each model, we used cross-validation. As a result, the YOLO Model had sensitivity of 91.05%, FPs/image of 0.0507. The Faster R-CNN's sensitivity was 99.6% and FPs/image was 0.0089. The RetinaNet showed sensitivity of 98.31% and FPs/image of 0.0119. Faster RCNN showed the best performance among these three models tested. Thus, the most appropriate model for classifying pills among the three models is the Faster R-CNN with the most accurate detection and classification results and a low FP/image.

• Journal of Electrochemical Science and Technology
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• 제2권2호
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• pp.124-129
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• 2011

A simple process of fabricating micropillar structure and its influence upon enhancing electrochemical biosensor response were studied in this work. Conducting polymer PEDOT was used as a base material in formulating a composite with PVA. Micro porous PC membrane filter was used as a template for the micropillar of the composite on ITO electrode. This structure could provide plenty of encapsulating space for enzyme species. After dosing enzyme solution into this space, Nafion film tent was cast over the pillar structure to complete the micropillar cavity structure. In this way, the encapsulation of enzyme could be accomplished without any chemical modification. The amount of enzyme species was easily controllable by varying the concentration of the dosing solution. The more amount of enzyme is stored in the sensor, the higher the electrochemical response is produced. One more reason for the sensitivity improvement comes from the large surface area of the micropillar structure. Application of 0.7 V produced the best current response under the condition of pH 7.4. This biosensor showed linear response to the glucose in 0.1~1 mM range with the average sensitivity of $14.06{\mu}A/mMcm^2$. Detection limit was 0.01 mM based on S/N = 3.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
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• pp.445-450
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• 1997

Self-Powered Neutron Detectors(SPNDs) are currently used to estimate the power generation distribution and fuel burn-up in several nuclear power reactors in Korea. In this paper, Monte Carlo simulation is accomplished to calculate the escape probability of beta particle as a function of their birth position fur the typical geometry of rhodium-based SPNDs. Also, a simple numerical method calculates the initial generation rate of beta particles and the change of generation rate due to rhodium burn-up. Using the simulation and the numerical method, the burn-up profile of rhodium density and the neutron sensitivity are calculated as a function of burn-up time in the reactor. The sensitivity of the SPNDs decreases non-linearly due to the high absorption cross-section and the non-uniform burn-up of rhodium in the emitter rod. In addition, for improvement of some properties of rhodium-based SPNDs which are currently used, this paper presents a new material. The method used here can be applied to the analysis of other types of SPNDs and will be useful in the optimum design of new SPNDs for long term usage.

• 대한감각통합치료학회지
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• 제2권1호
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• pp.33-42
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• 2004

Objective : To evaluate the sensory processing ability in relation to parenting stress and find the sensory modulation areas affecting the parenting stress in disabled children Methods : Parents of 124 children with disabilities between 3 to 7 years receiving occupational therapy in Seoul and Gyeonggi-do made out the questionnaire and in items of questionnaire, Short Sensory Profile and Parenting Stress Index of short form was included. Results : Among general information, parenting stress of parents had significant correlation with the degree of disability and correlation with the lower level 2 of Parenting Stress Index. The more sensory processing disability was increased, the more parenting stress was increased. Parenting stress showed the significant correlation with movement sensitivity area and under-responsiveness/behaivor area seeking specific stimulation among sensory processing areas and had significant correlation with tactile sensitivity and auditory filtering. Sensory processing areas which affect the most the Parenting Stress were movement sensitivity and under-responsiveness/behaivor area seeking the specific behavior among sensory control disabilities. Conclusion : The parenting stress of parents with the disabled children had the correlation with sensory processing ability. The difficulty of sensory processing increased the parenting stress. Hence, in order to improve children's sensory processing ability, the appropriately coping program should be developed and the appropriate intervention for improvement of sensory processing ability of children will be necessary.