• Annals of Clinical Neurophysiology
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• 제25권1호
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• pp.32-37
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• 2023

Background: Type 2 diabetic mellitus (T2DM) is an emerging global pandemic which is associated with lots of co-morbidities and reported vascular dysfunctions. T2DM associated vascular dysfunctions leads to vasculopathy in the form of altered peripheral vascular dynamics. Cold stress test (CST) is a reliable sympathetic reactivity test used for assessing vascular dysfunctions. In this study we are trying to quantify vascular dysfunctions in T2DM patients non invasively by various parameters of photoplethysmography (PPG) of cold stress test. Methods: Case control study had done in referral health center AIIMS, Raipur. Parameters are recorded by finger-PPG before, during and after CST (1 min) in 2 groups, control (n = 20 healthy volunteers) and case (n = 20 diagnosed T2DM patients). Results: Due to cold stress, PPG parameter peak amplitude was significantly decreased in both healthy and T2DM groups (p <0.001 and p <0.001, respectively). However, recovery trend of amplitude was significantly slow in T2DM compared to healthy subjects. Another PPG parameter peak to peak interval was significantly higher in healthy group compared to T2DM patients. Conclusions: This study showed that T2DM patients has significant deranged pulse volume parameters like amplitude and peak to peak interval can be used to objectively quantify the vasculopathy in T2DM patients by using sympathetic reactivity to cold stress.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4601-4619
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• 2022

The classical Probabilistic Safety Analysis (PSA) does not include any time dependence explicitly. However, the success criteria (SC) could evolve during the cycle for some initiating events. In that sense, there is a type of sequence in which this time-dependency is quite important, the family of Anticipated Transient without Scram (ATWS) sequences in Pressurized Water Reactors. Therefore, a new risk-informed approach is proposed in this paper, which makes it possible to obtain the time-dependent SC evolution of the safety functions affected by the Moderator Temperature Coefficient (MTC) value. Then, the evolution of the ATWS conditional core damage probability (CCDP) could be obtained using a PSA model. To quantify the CCDP, the average values of the time-dependent failure probabilities must be computed. Finally, the comparison between the CCDP obtained through the application of the classical PSA approach and the new one makes it possible to quantify the impact of time-dependence on the SC of the headers that this new risk-informed ATWS approach can provide.

• 천문학회보
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• 제46권2호
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• pp.67.4-68
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• 2021

In studying the dynamical evolution of galaxy clusters, one intriguing approach is to compare the spatial distributions of various components, such as the dark matter, the member galaxies, the gas, and the intracluster light (ICL; the diffuse light from stars, which are not bound any individual cluster galaxy). If we find a visible component whose spatial distribution coincides with the dark matter distribution, then we could draw a dark matter map without requiring laborious weak lensing analysis. Furthermore, if the component traces the dark matter distribution better for more relaxed galaxy cluster, we could use the similarity as a dynamical stage estimator of the galaxy cluster. We present a novel new methodology to quantify the similarity of two or more 2-dimensional spatial distributions. We apply the method to a sample of galaxy clusters at different dynamical stages simulated within N-cluster Run, which is an N-body simulation using the galaxy replacement technique. Among the various components (stellar particles, galaxies, ICL), the velocity defined ICL+ brightest cluster galaxy (BCG) component traces the dark matter best. Between the sample galaxy clusters, the relaxed clusters show stronger similarity of the spatial distribution between the dark matter and ICL+BCG than the dynamically young clusters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.528-550
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• 2024

Warehousing demand prediction is an essential part of the supply chain, providing a fundamental basis for product manufacturing, replenishment, warehouse planning, etc. Existing forecasting methods cannot produce accurate forecasts since warehouse demand is affected by external factors such as holidays and seasons. Some aspects, such as consumer psychology and producer reputation, are challenging to quantify. The data can fluctuate widely or do not show obvious trend cycles. We introduce a new model for warehouse demand prediction called MAGRU, which stands for Multi-layer Attention with GRU. In the model, firstly, we perform the embedding operation on the input sequence to quantify the external influences; after that, we implement an encoder using GRU and the attention mechanism. The hidden state of GRU captures essential time series. In the decoder, we use attention again to select the key hidden states among all-time slices as the data to be fed into the GRU network. Experimental results show that this model has higher accuracy than RNN, LSTM, GRU, Prophet, XGboost, and DARNN. Using mean absolute error (MAE) and symmetric mean absolute percentage error(SMAPE) to evaluate the experimental results, MAGRU's MAE, RMSE, and SMAPE decreased by 7.65%, 10.03%, and 8.87% over GRU-LSTM, the current best model for solving this type of problem.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1330-1338
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• 2024

Information on isotopic composition and geometric structure is necessary for identifying a true warhead. Nevertheless, such classified information should be protected physically or electronically. With a novel Hash encryption algorithm, this paper presents a Monte Carlo-based design of a neutron activation analysis verification module. The verification module employs a thermal neutron source, a non-uniform mask (physically encrypting information about isotopic composition and geometric structure), a gamma detector array, and a Hash encryption algorithm (for electronic encryption). In the physical field, a non-uniform mask is designed to distort the characteristic gamma rays emitted by the inspected item. Furthermore, as part of the Hash algorithm, a key is introduced to encrypt the data and improve the system resolution through electronic design. In order to quantify the difference between items, Hamming distance is used, which allows data encryption and analysis simultaneously. Simulated inspections of simple objects are used to quantify system performance. It is demonstrated that the method retains superior resolution even with 1% noise level. And the performances of anti-statistical attack and anti-brute force cracking are evaluated and found to be very excellent. The verification method lays a solid foundation for nuclear disarmament verification in the upcoming era.

• 한국구조물진단유지관리공학회 논문집
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• 제10권1호
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• pp.115-122
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• 2006

현재 콘크리트 구조물의 보수에서 품질의 검사 기준이 없는 상태에서, 단순한 경험에 의한 보수는 문제점을 가지고 있다. 이 문제점을 개선하기 위하여 이 논문은 균열폭과 주입량, 균열폭과 주입시간, 균열폭과 주입압력, 균열폭과 주입압력과 주입시간, 구조물 규모와 주입량, 구조물 별 균열 위치와 주입량, 균열폭 및 구조물 두께와 주입시간과의 관계를 분석하였다. 분석한 결과에서 얻은 자료는 콘크리트 구조물의 보수에 대한 체계적인 품질관리에 도움이 될 것이라 생각한다.

• 한국수자원학회논문집
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• 제49권3호
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• pp.187-196
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• 2016

증발산량과 강수량을 변수로 하는 SPEI (Standardized Precipitation Evapotranspiration Index)는 보편적으로 기상학적 가뭄심도를 정량화하는데 이용되고 있다. 또한 RDI (Reconnaissance Drought Index)는 가뭄의 피해를 받고 있는 지역에 활용도가 높은 가뭄지수이지만 이를 이용한 국내 적용사례는 부족한 실정이다. 따라서 본 연구에서는 Thornthwatie, Hargreaves, Blaney-Criddle 증발산량 산정 방법을 이용하여 증발산량과 강수량을 변수로 하는 SPEI와 RDI를 비교하였다. 1992년부터 2015년까지 한강 유역에 대한 가뭄 정량화 및 특징 비교를 위해 기상청 관할 16개 지점의 기상자료를 이용하였다. 연구결과, 한강유역의 경우 최근 들어 급격히 극한 가뭄이 발생하고 있는 지점들이 증가하였다. 두 가뭄지수 사이에 상관정도는 비교적 높았으나 가뭄의 심도 및 극한가뭄의 발생 연도 사이에는 일부 차이를 보였다. 따라서 가뭄 심도와 발생 시기의 정량화를 위해 RDI 또한 활용이 필요함을 확인하였다.

• 대한교통학회지
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• 제19권1호
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• pp.17-28
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• 2001

본 연구의 목적은 기업과 소비자간 전자상거래에서 물류운송체계의 물류비용을 상품운송 유형에 따라 분석하는 것이다. 먼저 물류운송체계를 3가지 유형 즉, 공급업체에서 소비자에게 직송하는 방법(유형 I), 자가물류업체를 통해 각 권역에 운송센타를 두어 운송하는 방법(유형 II), 3자 물류업체에게 운송에 관한 모든 일체를 위임하는 방법(유형 III)으로 분류하고 각 유형의 물류비 항목을 운송비, 보관비, 물류정보비로 구성하였다. 전자상거래에서의 물류는 다품종 소량 다빈도 특성을 가지고 있고, 주문특성 및 상황에 따라 소요물류비용이 변한다. 그러므로 본 연구에서는 대상권역의 주문에 대한 1일 주문건수 운송거리, 운송량, 그리고 1일 배정화물트럭대수에 따라 변하는 물류비용함수를 도출하였고, 가상네트웍을 구성하여 시뮬레이션 함으로서 각 운송유형의 주문특성에 따른 물류비용의 변화를 분석하였다. 하지만, 본 연구는 공급업체의 물류인프라와 운송서비스 시간에 대한 고려를 하지 않았기 때문에 현실에 적용하기에 한계가 있다. 만일 이에 대한 연구가 보충된다면 전자상거래에서 일정 단위기간 동안 상품운송에 소요되는 물류비를 좀더 정확히 추정하여 전자상거래에서의 효율적인 화물운송방안을 제시할 수 있을 것이다. 본 연구의 결과로 전자상거래에서의 1일 주문발생 빈도와 공급상품의 중량. 그리고 운송거리에 따라 변하는 물류비용을 추정할 수 있다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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• pp.63-68
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• 1991

The frequency window method has been extended to include strong coupling and multiple connections between the primary structure and the secondary structures. The rational polynomial expansion of the eigenvalue problem and the analytical methods for its solution are novel and distinguish this work from other eigenvalue analysis methods. The key results are the identification of parameters which quantify the resonance and coupling characteristics; the derivation of analytical dosed-form expressions describing the fundamental modal properties of the frequency windows; and the development of an iterative procedure which yields accurate convergent results for strongly-coupled primary-secondary structures.

• 천문학논총
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• 제10권1호
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• pp.31-55
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• 1995

We have developed a new device, Plate-to-CCD Convertor (PCC), to conveniently digitize photographic plates in a relatively short time without losing any plate information (Oh et al. 1995). Using this device we have performed surface photometry of 12 early type galaxies. We determined relative orientations and scales to analyze PCC images. We also determined an ellipticity, position angle of the major axis, and $a_4$ of each galaxy to quantify the distribution of surface brightness. We checked the performance and limitation of this device by comparing the PCC images with those digitized by the ST microdensitometer and those obtained with CCD observations.