Transverse Tensile Deformation and Failure of Three-dimensional Five-directional Braided Carbon Fiber Composites

Wei Zhou,Zhi-yuan Wei,Guang-fei Wang,Kang-ning Han,Ran Liu,Lian-Hua Ma 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

Accurate characterisation of transverse tensile deformation and damage evolution is of importance for evaluatingthe failure behaviors of three-dimensional (3D) braided composites. In the present study, a finite element method (FEM) andseveral non-destructive testing methods including acoustic emission, digital image correlation, and infrared thermography aredeveloped to investigate the transverse tensile deformation and damage evolution of 3D five-directional braided composites. In the finite element approach, a matrix-impregnated fiber bundles (MIFB) model and a representative volume cell (RVC)model, which take into account the fiber bundles and matrix, are respectively established to predict the effective mechanicalproperties of fiber bundles and simulate the deformation and progressive damage of such composites. The damaged locationsand the failure modes including matrix crack, fiber debonding and shear fracture of fiber are predicted and verified byexperimental tests. The non-destructive tests show that the transverse tensile fracture process can be divided into four stageswhich correspond to acoustic emission signals severally. The combination of the FEM based numerical modeling andmultiple non-destructive characterisation methods can accurately monitor the deformation and damage behaviors of 3Dbraided composites under transverse tensile loads and thus provide a reference for structural health monitoring of compositesin practical application.

Effects of Government Regulations on Spam

Wei Ran,Xiaoming Hao 한국언론학회 2010 Asian Communication Research Vol.7 No.1

The advent of 3G networks provides marketing agencies and advertisers with expanded opportunities to explore the mobile phone as a viable advertising medium. However, because mobile advertising is already used indiscriminately, SMS ads are likened to spam on mobile phones. Using survey data collected from 407 mobile phone users in a well-regulated mobile advertising market, Singapore, this study examines consumer responses to mobile phone ads. The results show that even though respondents disliked mobile ads delivered to mobile phone screens, they may not inevitably avoid the ads. Perceived goal impediment, past negative experience and privacy concerns would cause them to avoid mobile phone advertising. Interestingly, perceived irritation was not a significant predictor of mobile ad avoidance in multivariate analyses, suggesting that in a well-regulated telecommunications market like Singapore, mobile phone ads do not necessarily reach a stage of excessiveness and cause massive consumer avoidance as seen in other Asian countries.

A Study on the Efficiency of Design Education in Colleges Based on Cognitive Neuroscience

Wei, Ran Ran(위란란),Lyu, Xin(류신),Cho, Taig Youn(조택연) 한국디자인문화학회 2021 한국디자인문화학회지 Vol.27 No.4

대학의 디자인 교육방식은 바우하우스 워크숍 시스템을 이어받아 경험주의를 강조한다. 하지만 감각과 경험에 의존한 디자인 방식은 이를 학생들에게 전달하는 과정에 어려움을 겪는다. 이로 인해 디자인 교육활동에서는 정보의 비대칭 현상이 빚어지고 있다. 이런 한계를 극복하기 위해 본 연구는 디자인 교육에 인지신경과학을 접목해, 균형 잡힌 디자인 교육 방법을 연구한다. 홍익대학교 공간디자인과 20명의 학생을 대상으로 시각 회상(시각 기억), 관찰 묘사(시각 기억), 구조인지(의미 기억) 세 가지 방법으로 망태버섯의 모양을 재현하였다. 이후 20명의 학생에게 그림을 평가하게 하였다. 각각 현실과 가장 가깝고 조형적인 아름다움, 인지하기 쉬운 방법, 그리고 어떤 방법이 디자인을 학습하는 데 가장 도움이 되는지 네 가지 측면에서 평가한다. 실험 결과 시각 기억만으로는 물체의 모양을 정확하게 재현할 수 없었다. 오히려 의미기억을 형성했을 때 그 물체의 모양을 효과적으로 모방하고 재현할 수 있다. 실제 응용하는 과정에서 긍정적인 역할을 한다. 따라서 조형 생성 규칙에 기초한 의미 기억 교육 방법이 교육을 받는 대상과 제공 대상 사이에서 정보의 대칭성을 형성할 수 있음을 발견하였다. 이를 통해 보다 효과적인 교육방식이 이루어질 수 있음을 제안한다. The method of design education in colleges inherits the Bauhaus workshop system and emphasizes empiricism. However, design methods that rely on feelings and experience are difficult to convey to students. Therefore, information asymmetry exists in teaching activities. In order to solve this limitation, this study tries to combine design education with cognitive neuroscience and studies a more balanced approach to design education. In this study, 20 students from the department of spatial Design of Hongik University were selected as experimenters to reconstruct the shape of phallus indusiatus using three methods: visual recall (visual memory), observation and imitation (visual memory), and structural cognition (semantic memory). After that, the 20 experimenters were asked to evaluate their works from four aspects: the closest to reality, the most aesthetic in modeling, the easiest to be recognized, and which method was most helpful for learning design. The experimental results show that visual memory can not accurately reproduce the shape of the object. On the contrary, the method of semantic memory can effectively imitate and reproduce the shape of objects and play a positive role in the process of application. Therefore, it is hypothesized that the rule-based semantic memory education method may be able to maintain the symmetrical transmission of information between the object receiving education and the object providing education. Furthermore, it become a more effective way of teaching.

Research on the Influence of the Order Formed in Nature on the Architectural Modeling

Wei, Ran Ran(위란란),Cho, Taig Youn(조택연) 한국디자인문화학회 2021 한국디자인문화학회지 Vol.27 No.2

의식적이든 그렇지 않든, 건축 조형은 자연의 조형을 모방하고 있다. 즉 자연에서 생성되는 조형 질서를 건축 조형으로 변용해 활용된다. 자연 조형의 질서는 항상 건축가에게 영감을 주어 왔다(Alexander, 2002; Joye, 2007; Kellert, 2005; Ostwald, 2001). 본 연구는 신경 미학과 진화 미학의 두 지식 환경에서, 건축적 조형 가치를 학제적으로 고찰하고자 하였다. 신경 미학과 진화 미학을 바탕으로, 자연 조형과 건축 조형이 공유하는 질서 관계를 연구할 수 있다. 이를 바탕으로 건축조형에서 느끼는 아름다움에 질서가 미치는 영향을 알 수 있다. 본 연구는 건축 조형이 가진 형상 질서에 초점을 맞추고 있다. 따라서 색채와 재료가 조형에 미치는 영향은 본 연구에서 제외한다. 먼저 신경 미학적인 접근을 통하여, 두뇌에서 형상이 인지되고 미의식이 발생하는 신경 메커니즘을 분석한다. Ventral Pathway는 조형의 색상이나 모양 그리고 질서를 인식하는 두뇌의 중요한 시각 경로이다. 이 시각 경로는 강한 대비와 대칭성의 질서를 가진 특징 벡터 군(Feature Vector Group)에 대해 민감하게 반응한다(Ramachandran & Hirstein, 1999). 게슈탈트 시각 심리학에서 그룹 원칙은 이런 형상의 전체성과 일치한다. 같거나 비슷한 요소의 집합은 규칙적인 배열을 통해 하나의 전체로 쉽게 인지된다. 진화 미학은 특정 형상에 대한 선호를 형성한 두뇌의 구조를 잘 설명한다. 이 분야의 연구에 따르면 질서가 있고(연관적으로) 복잡한 (재미있는) 조형을 선호한다. 위와 같은 이유로 정확한 기하학적 대칭보다 자연의 형상이 보여주는 조금 불완전한 질서를 선호한다. 본 연구는 건축 조형이 가진 형상 질서에 초점을 맞추고 있다. 따라서 색채와 재료가 조형에 미치는 영향은 본 연구의 범위에서 제외한다. 본 연구는 자연을 흉내 낸 질서가 건축 조형에 미치는 영향은 세 가지 측면에서 분석된다. 첫째. 질서를 가진 건축 조형이 눈에 잘 띄어 인식될 가능성이 더 크다. 둘째, 질서는 건축 조형에 대한 미적 공감을 유발할 수 있다. 복잡계 과학은 자연에 나타나는 질서를 프랙털, 피보나치, 보로노이 등의 몇 가지 미적 원리로 구조화했다. 건축 조형에서 이러한 구조를 인지하면 자연스럽게 미적 호감을 느끼게 된다. 셋째. 이런 질서의 인식은 건축 조형 생산에 도움을 준다. 두뇌는 조형을 느끼는 것과 조형을 생산하는 지능이 서로 분리되어 있다. 또한 조형 가치를 느끼는 지능은 자동화되어 형성되는 반면, 조형을 생산하는 지능은 그렇지 못하다. 이런 신경 구조로 디자이너는 조형을 인지하는 능력에 비해, 다소 뒤지는 조형 생산 능력을 가진다. 이런 한계를 극복하는 방법이 자연의 질서를 해석하고 이를 건축 조형에 활용하는 것이다. 자연에서 나타난 질서를 건축 조형으로 해석해 이를 적용하는 디자인 방법이다. 자연 조형에 호감을 느끼는 두뇌의 미의식 구조를 건축 조형에 적용해, 더 호감을 느끼게 하는 건축을 디자인할 수 있음을 의미한다. 자연의 질서를 적용한 건축 조형에서 더 즐거운 조형을 경험할 수 있다. 자연 조형이 가진 질서는 건축 조형을 탐구하는 데 중요한 영감을 제공한다. 자연의 조형질서가 건축 조형에 어떤 영향을 미치고 있는지를 탐구하는 것이 본 연구의 목적이다. Architectural modeling often imitate shapes in nature consciously or unconsciously. That is, the order of shapes generated from nature can be applied to architectural modeling. The order of natural shapes is often a source of inspiration for architects. This paper adopts interdisciplinary research methods and combines theoretical knowledge of neuroaesthetics and evolutionary aesthetics. The orderly relationship shared by natural and architectural shapes can be studied based on neuroaesthetics and evolutionary aesthetics. The influence of order on the aesthetics of architectural modeling can also be studied based on this. This research focused on the shape order of architectural modeling, and the influence of colors and materials on architectural modeling was not included in this study. Firstly, through neuroaesthetics, the study analyzed the neural mechanism of shape recognition and aesthetic awareness in the brain. The ventral pathway is a major visual pathway for the brain to recognize colors, shapes and orders. The visual pathway is sensitive to the feature vector group with strong contrast and symmetrical order (Ramachandran & Hirstein, 1999). In Gestalt psychology, the principle of groups is consistent with the integrity of the shape. A collection of identical and similar elements is easily perceived as a whole through the orderly arrangement. Evolutionary aesthetics explains the construct of brains that has a specific preference for specific shapes. According to research in the field, people prefer shapes that are both ordered (coherent)and complicated (amusing). This is the reason why people prefer natural shapes with relatively imperfect order than precise geometric symmetry. The research scope of this paper pay attention to the shape order of architectural modeling, and the influence of colors and materials on architectural modeling is not included in this research. The influence of imitating the order of nature on the formation of architectural modeling was analyzed from three aspects. Firstly, orderly architectural modeling is more likely to stand out and be perceived. Secondly, an order may trigger people’s aesthetic resonance with architectural modeling. Complicated science structures make the order appears in nature structured, such as Fractal, Fibonacci sequence, Voronoi diagram, and other aesthetic principles. When people perceive shapes with this structure in architectural forms, they naturally become attached to them. Thirdly, the perception of this order contributes to the formation of architectural modeling. The brain’s ability to perceive shape and produce shape are separated. The ability to perceive the value of shapes is formed automatically, while the ability to produce shape is not. Because of this neural structure, the ability to produce shapes is a bit inferior compared to the ability to perceive them. The method to overcome these limitations is to interpret the natural order and apply it to architectural modeling. It means that by applying the aesthetic structure of the brain that feels favorable to natural shapes to architectural modeling, we can design an architecture that makes us feel more favorable. More pleasant modeling can be experienced in architectural modeling that employs natural order. The order of natural shapes provides an important inspiration for exploring architectural modeling. How the order of natural shapes will affect architectural modeling is the purpose of this paper.

Active Disturbance Rejection Control for Nanopositioning Systems with Piezoelectric Actuators

Wei Wei,Ran Zhang,Jing Wang,Guang-Bo Hao 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

Nanopositioning proposes a high demand for its control system. However, hysteresis, a common nonlinear phenomenon existing in piezoelectric actuator, decreases precision of nanopositioning. In this paper, active disturbance rejection control (ADRC) is designed to estimate and cancel the influence of hysteresis, and integral time absolute error (ITAE) optimal index is chosen to determine the parameters of ADRC. Simulations are performed on the basis of mathematic model of nanopositioning system, and numerical results show that ADRC is effective in the control of nanopositioning.

The research of sleep staging based on single-lead electrocardiogram and deep neural network

Ran Wei,Xinghua Zhang,Jinhai Wang,Xin Dang 대한의용생체공학회 2018 Biomedical Engineering Letters (BMEL) Vol.8 No.1

The polysomnogram (PSG) analysis is consideredthe golden standard for sleep staging under the clinicalenvironment. The electroencephalogram (EEG) signal isthe most important signal for classification of sleep stages. However, in-vivo signal recording and analysis of EEGsignal presents us with a few technical challenges. Electrocardiogramsignals on the other hand, are easier torecord, and can provide an attractive alternative for homesleep monitoring. In this paper we describe a method basedon deep neural network (DNN), which can be used for theclassification of the sleep stages into Wake (W), rapid-eyemovement(REM) and non-rapid-eye-movement (NREM)sleep stage. We apply the sleep stage stacked autoencoderto constitute a 4-layer DNN model. In order to test theaccuracy of our method, eighteen PSGs from the MIT-BIHPolysomnographic Database were used. A total of 11 featureswere extracted from each electrocardiogram recordingThe experimental design employs cross-validationacross subjects, ensuring the independence of the trainingand the test data. We obtained an accuracy of 77% and aCohen’s kappa coefficient of about 0.56 for the classificationof Wake, REM and NREM.

Automatic blood pressure measurement device using oscillometric method and Korotkoff sounds

Wei, Ran,Lim, Young Chul,Im, Jae Joong The Institute of Internet 2012 Journal of Advanced Smart Convergence Vol.1 No.2

The oscillometric method and Korotkoff sound method are the most common ways to measure the blood pressure. A new automatic blood pressure measurement device, which uses both oscillometric method and Korotkoff method, was developed. A pressure sensor was used to obtain cuff pressure and oscillation signal, and a microphone was used to detect Korotkoff sounds. Forty-five measurements from fifteen subjects were used for analysis. Correlation coefficients between the traditional auscultatory method and Korotkoff sound method were 0.9820 and 0.9721 for the systolic and diastolic blood pressure values, respectively. Standard deviations of differences for the systolic and diastolic blood pressure values were 1.3019 and 1.4495, respectively. Correspondingly, correlation coefficients between the traditional auscultatory method and oscillometric method using newly developed algorithm were 0.9651 and 0.9136 for the systolic and diastolic blood pressure values, with the standard deviations of 1.42 and 1.73, respectively. The results showed that the newly developed algorithm for oscillometirc method provide accurate blood pressure values, moreover, Korotkoff sound method using microphone provides even higher accuracy. Therefore, a new automatic device which utilizes both oscillometric method and Korotkoff sound method would provide the accurate and reliable blood pressure values.

Effect of freezing on electrical properties and quality of thawed chicken breast meat

Ran Wei,Peng Wang,Minyi Han,Tianhao Chen,Xinglian Xu,Guanghong Zhou 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.4

Objective: The objective of this research was to study the electrical properties and quality of frozen-thawed chicken breast meat and to investigate the relationship between these parameters at different times of frozen storage. Methods: Thawed samples of chicken breast muscles were evaluated after being kept in frozen storage at –18°C for different periods of time (1, 2, 3, 4, 5, 6, 7, and 8 months). Results: The results showed that water-holding capacity (WHC) and protein solubility decreased while thiobarbituric acid-reactive substances content increased with increasing storage time. The impedance module of samples decreased during 8-month frozen storage. Pearson correlation coefficients showed that the impedance change ratio (Q value) was significantly (p<0.05) related to pH, color, WHC, lipid oxidation and protein solubility, indicating a good relationship between the electrical properties and qualities of frozen-thawed chicken breast meat. Conclusion: Impedance measurement has a potential to assess the quality of frozen chicken meat combining with quality indices.

The Convergent Mobile Phone as a Bridging Medium for Mobile Communications : Exploring the Making of a Critical Mass of Mobile TV

Ran Wei,Huang Jinhua 한국방송학회 2007 한국방송학회 세미나 및 보고서 Vol.- No.-

This study assesses the notion of the mobile phone as the third screen and to explore the important role of critical mass in using the mobile phone as TV. Results of a survey of mobile phone users in China show that the adoption of mobile TV is low. Among the 856 respondents, only 12 (1.4%) users had viewed it. Among the 844 non-users of mobile TV, their interest in viewing mobile TV was examined. Results show that it is low. Among the 844 respondents, only 167 (18.6%) found it desirable. This small number of interested users is most likely to become early adopters. Their interest in mobile TV was found to be related to social locators such as age, gender, and income, mobility, use of broadcasting media, and technology cluster.

Anti-inflammatory Effects of Ethyl Acetate Fraction from Ecklonia stolonifera on LPS-Stimulated RAW 264.7 Cells

Ran Wei,Min-Sup Lee,Min-Woo Choi,Wi-Gyeong Gwon,Jae-Il Kim,Hyeung-Rak Kim 한국식품영양과학회 2012 한국식품영양과학회 학술대회발표집 Vol.2012 No.10