• 제목/요약/키워드: Structural Changes

검색결과 2,959건 처리시간 0.031초

Effect of Input Data Video Interval and Input Data Image Similarity on Learning Accuracy in 3D-CNN

  • Kim, Heeil;Chung, Yeongjee
    • International Journal of Internet, Broadcasting and Communication
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    • 제13권2호
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    • pp.208-217
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    • 2021
  • 3D-CNN is one of the deep learning techniques for learning time series data. However, these three-dimensional learning can generate many parameters, requiring high performance or having a significant impact on learning speed. We will use these 3D-CNNs to learn hand gesture and find the parameters that showed the highest accuracy, and then analyze how the accuracy of 3D-CNN varies through input data changes without any structural changes in 3D-CNN. First, choose the interval of the input data. This adjusts the ratio of the stop interval to the gesture interval. Secondly, the corresponding interframe mean value is obtained by measuring and normalizing the similarity of images through interclass 2D cross correlation analysis. This experiment demonstrates that changes in input data affect learning accuracy without structural changes in 3D-CNN. In this paper, we proposed two methods for changing input data. Experimental results show that input data can affect the accuracy of the model.

Evolution of China's Economy and Monetary Policy: An Empirical Evaluation Using a TVP-VAR Model

  • Kim, Seewon
    • East Asian Economic Review
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    • 제25권1호
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    • pp.73-97
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    • 2021
  • China has experienced many structural changes in the process of economic development over the past three decades. Using a time-varying parameter VAR model with stochastic volatility and mixture innovations, this study investigates whether such structural changes in, especially tools and operational aims of monetary policy, affect the monetary transmission mechanism. We find that impulse responses of output growth and inflation to monetary shocks have substantially increased and then reversed to decrease around 2005-2006. This time variation is mainly caused by changes in the monetary transmission mechanism, i.e., the manner in which main macroeconomic variables respond to policy shocks, rather than by changes in volatilities of exogenous shocks. The result implies that aggressive monetary policy to facilitate economic growth in the developing economies may be legitimized, unless it causes inflation seriously.

Improvement of the earthquake resistance of R/C beam-column joints under the influence of P-△ effect and axial force variations using inclined bars

  • Tsonos, Alexander G.
    • Structural Engineering and Mechanics
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    • 제18권4호
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    • pp.389-410
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    • 2004
  • In this study, theoretical and experimental results are presented which were obtained during an investigation of the influence of the $P-{\Delta}$ effect that was caused by the simultaneous changing of the axial load P of the column and the lateral displacement ${\Delta}$ in the external beam-column joints. The increase or decrease of ${\Delta}$ was simultaneous with the increase or decrease of the axial compression load P and caused an additional influence on the aseismic mechanical properties of the joint. A total of 12 reinforced concrete exterior beam-column subassemblies were examined. A new model, which predicts the beam-column joint ultimate shear strength, was used in order to predict the seismic behaviour of beam-column joints subjected to earthquake-type loading plus variable axial load and $P-{\Delta}$ effect. Test data and analytical research demonstrated that axial load changes and $P-{\Delta}$ effect during an earthquake cause significant deterioration in the earthquake-resistance of these structural elements. It was demonstrated that inclined bars in the joint region were effective for reducing the unfavourable impact of the $P-{\Delta}$ effect and axial load changes in these structural elements.

부재응력분포계수와 부재간 응력 상관성 (Response Force Distribution Factors of Members and Mutuality of Response Forces between Members)

  • 김치경;이시은;홍건호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.363-370
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    • 2004
  • This Paper presents the response force distribution factor(RDF) and its application to recalculation of member forces in case of partial changes of structures. Using RDF, the mutuality of response forces between members can be estimated. The reanalysis technique recalculates directly any displacement or member force under consideration in real time without a full reanalysis in spite of local changes in member stiffness or connectivity using RDF. It is expected that RDF and the reanalysis technique can be used to develop efficient analysis techniques for tall buildings.

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전기화재에 의한 전선의 현미경 조직변화에 관한 물성적 해석의 연구 (A Microscopic Study on Structural Changes in Electric Conductors Due to Electric Fire)

  • 우형주
    • 전기의세계
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    • 제20권5호
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    • pp.9-14
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    • 1971
  • This paper aims to study structural changes in electric conductors which are heated during electric fire by means of microscope. The results are applicable to the pursuit of the causes of electric fire and to the establishment of criteria for the indentification of electric fire. This work is an extension of the previous study by the author, particularly with emphasis on quantitative analysis.

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Experimental and numerical study of Persian brick masonry barrel vaults under probable structural hazards

  • Saeid Sinaei;Esmaeel Izadi Zaman Abadi;Seyed Jalil Hoseini
    • Structural Engineering and Mechanics
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    • 제87권4호
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    • pp.317-332
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    • 2023
  • Understanding and analysing the behaviour and response of historical structures in the face of climate changes and environmental conditions is of utmost significance for their preservation. There are several structural hazards associated with climate and hydrology changes in the region, including the settlement of piers, the rotation of piers, and temperature changes. The present study investigates the experimental and numerical structural behaviour of skewed and non-skewed Persian brick masonry barrel vaults under various conditions. The external loading conditions included pier rotation in five modes, settlement, and temperature variations in four states. Initially, the experiments extracted the mechanical properties of the scaled materials. Then, three semi-circular brick barrel vaults were tested with gravitational loads. The outcomes were used to develop and validate the finite element model. Following the development of the finite element model, numerical and parametric studies were conducted on the effect of the aforementioned structural hazards on the response of brick masonry barrel vaults with various Persian geometries (semi-circular, drop pointed, and four-centred), angles of skew (0, 15, 30, and 45 degrees), and dimensional ratios. According to the findings, the fragility of masonry materials makes historical structures susceptible to failure under different loading. A brick barrel vault fails in the presence of minor rotation and settlement of the piers. The four-centred geometric shape has the lowest performance among the seven Persian geometries; therefore, its health monitoring and retrofitting should be prioritised. In Isfahan, Iran, temperature variations, particularly during the warm seasons, cause critical conditions in such structures.

Evaluation of Physicochemical Changes in Hard-Boiled Eggs Stored at Different Temperatures

  • Gamaralalage Schithra Rukshan Eregama;Shine Htet Aung;Herath Mudiyanselage Jagath Chaminda Pitawala;Mahabbat Ali;Seong-Yun Lee;Ji-Young Park;Edirisinghe Dewage Nalaka Sandun Abeyrathne;Ki-Chang Nam
    • 한국축산식품학회지
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    • 제44권1호
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    • pp.74-86
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    • 2024
  • Eggs that have been hard-boiled are frequently used as ready-to-eat food. Refrigerated and frozen storage of hard-boiled eggs causes issues, such as customer rejection owing to textural changes. The objective of this research is to ascertain how storage temperature affects hard-boiled eggs' alteration in texture over time. Medium-sized brown shell eggs were acquired from a local market, boiled at 100℃ for 15 min, and then stored at room temperature (25℃), refrigeration (4℃), and freezing (-18℃) conditions for 0, 12, 24, and 48 h. Fourier transform infrared spectroscopy (FTIR), texture profile, visual observation using a gemological microscope, free amino acid content, and color were measured. Freezing had a substantial impact on the eggs' hardness, gumminess, chewiness, and cohesiveness (p<0.05). The FTIR spectrums confirmed the textural changes in bonds of amide A (3,271 cm-1), amide I (1,626.2 cm-1), amide II (1,539.0 cm-1), C=O stretch of COO- (1,397 cm-1), asymmetric PO2- stretch (1,240 cm-1). Microscopic images confirmed structural changes in eggs stored at -18℃. The free amino acid content was lower in fresh and frozen eggs than in the rest (p<0.05). However, there was no discernible variation in the egg white's color when eggs were kept at 4℃ (p>0.05). Salmonella spp. was found exclusively in eggs kept at room temperature. In conclusion, hard-boiled eggs did not exhibit structural or chemical changes when stored at 4℃ for up to 48 h compared to freezing and room temperature conditions.

대공간 건축물 골조물량 최적화를 위한 파라메트릭 설계 프로세스 (Parametric Design Process for Structural Quantity Optimization of Spatial Building Structures)

  • 최현철;이시은;김치경
    • 한국전산구조공학회논문집
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    • 제30권2호
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    • pp.103-110
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    • 2017
  • 본 논문에서는 StrAuto를 이용하여 구조물의 형상 변경을 통한 대안을 생성하고, 이에 대한 최적화를 수행하는 과정을 상세하게 다루었다. 비정형 대공간 전시장 구조물을 대상으로 전체 형상을 파라메트릭하게 디자인하고, 가장 폭이 넓은 경간의 구조 형상을 변경하면서 물량 변화를 관측하여 최적안을 도출하였다. 기존 연구들에서는 형상 변경의 제약 때문에 대부분 단면과 물성을 통한 최적화를 수행하는데 그쳤으나, 본 연구에서는 형상 변경이 가능한 부분을 찾아내어 StrAuto의 가장 핵심적인 능력인 형상 변경을 통한 최적화를 수행했다는 점에서 중요한 의미를 지닌다. 형상 변경으로 충분한 여유를 확보하고 단면 최적화로 물량을 줄이는 프로세스를 통해, 대공간 구조물의 일부만을 대상으로 하면서도 전체 물량의 11.7%를 줄일 수 있었다.

Investigation on structural symmetry of CsCoCl3·2H2O crystals by magic-angle spinning 1H and static 133Cs nuclear magnetic resonance

  • Park, Sang Hyeon;Jang, Du Chang;Jeon, Hara;Gyeong, Oh Yi;Lim, Ae Ran
    • 한국자기공명학회논문지
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    • 제26권1호
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    • pp.10-16
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    • 2022
  • The phase transition temperatures of CsCoCl3·2H2O crystals are investigated via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Three endothermic peaks at temperatures of 370 K (=TC1), 390 K (=TC2), and 416 K (=TC3) were observed for phase transitions from CsCoCl3·2H2O to CsCoCl3·1.5H2O, to CsCoCl3·H2O, and then to CsCoCl3·0.5H2O, respectively. In addition, the spin-lattice relaxation time T in the rotating frame and T1 in the laboratory frame as well as changes in chemical shifts for 1H and 133Cs near TC1 were found to be temperature dependent. Our analyses results indicated that the changes of chemical shifts, T, and T1 are associated with structural phase transitions near temperature TC1. The changes of chemical shifts, T, and T1 near TC1 were associated with structural phase transitions, owing to the changes in the symmetry of the structure formed of H2O and Cs+ ions. Consequently, the structural symmetry in CsCoCl3·2H2O crystals based on temperature is discussed by the environments of their H and Cs nuclei.

한국 제조업 내 수출산업의 변화와 산업별 총요소생산성 변화 분석 (Structural Changes of Exporting Industries and their Changes of Total Factor Productivity in Korean Manufacturing)

  • 김태기
    • 무역학회지
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    • 제41권5호
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    • pp.353-371
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    • 2016
  • 본 연구는 1980-2013년 기간 동안 한국 제조업 내 수출산업과 수입산업의 구조변화와 총요소 생산성의 변화를 분석하고 있다. 분석결과는 제조업 내 13개 산업 중 절반 이상의 산업이 수출입의 방향이 바뀌는 등 전반적으로 산업구조의 변화가 상당히 큰 폭으로 진행되어 왔음을 보여준다. 또 수입산업보다 수출산업에서 수출만이 아니라 생산도 크게 증가하였다. 이는 수출산업이 한국경제의 성장을 주도해 왔음을 보여준다. 또 어느 산업에서나 노동투입보다는 자본투입 증가율이 더 높은데, 이는 그간 생산방법이 보다 자본집약적인 형태로 변해 왔음을 말해준다. 마지막으로 총요소생산성 증가율도 수입산업보다는 수출산업에서 훨씬 더 높다. 패널회귀분석 결과도 수출산업에서 총요소생산성이 더 높음을 말해준다.

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