Influence of German “Dual Education System” on Vocational Education of China Design

YANQING,Koh KyeongWook 한국디자인학회 2011 디자인학연구 Vol.24 No.3

Design and Implementation of an Adaptive Sliding-Mode Observer for Sensorless Vector Controlled Induction Machine Drives

Yanqing Zhang,Zhonggang Yin,Jing Liu,Xiangqian Tong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

An adaptive sliding-mode observer for speed estimation in sensorless vector controlled induction machine drives is proposed in this paper to balance the dilemma between the requirement of fast reaching transient and the chattering phenomenon reduction on the sliding-mode surface. It is well known that the sliding-mode observer (SMO) suffers from the chattering phenomenon. However, the reduction of the chattering phenomenon will lead to a slow transient process. In order to balance this dilemma, an adaptive exponential reaching law is introduced into SMO by optimizing the reaching way to the sliding-mode surface. The adaptive exponential reaching law is based on the options of an exponential term that adapts to the variations of the sliding-mode surface and system states. Moreover, the proposed sliding-mode observer considering adaptive exponential reaching law, which is called adaptive sliding-mode observer (ASMO), is capable for reducing the chattering phenomenon and decreasing the reaching time simultaneously. The stability analysis for ASMO is achieved based on Lyapunov stability theory. Simulation and experimental results both demonstrate the correctness and the effectiveness of the proposed method.

USING CROWD SOURCING TO SOLVE THE FITTING PROBLEM IN ONLINE FASHION SALES

Yanqing Zhang,Oskar Juhlin 글로벌지식마케팅경영학회 2015 Global Fashion Management Conference Vol.2015 No.06

Consumers struggle to find clothes that are fit. This is a problem that has been accentuated with the increasing online sales. It is the largest contribute to sales returns and make customer return about every third item they buy (Ratcliff, 2014). If consumers select to buy online, they can no longer try them out in a fitting room. Most of fast fashion brands have opened their online shops, and many designers’ brands have also started to sell their ready-to-wear lines online. While online shopping is seen as a significant new way to reach more consumers in fashion industry, the size problem becomes more visible and is waiting to be solved. It may decrease the fashion industry’s ambition to piggyback on recent advances in e-commerce. Previous studies on clothing consumption have already touched upon the topic of size and fitting. Consumer surveys in the clothing industry indicate that in general between 35% and 50% of female consumers in the USA were not satisfied with the fitting in their clothing already ahead of the surge in online stores (Desmarteau 2000; Goldsberry et al. 1996). Alexander et al. studied the shopping behaviour of young women in south-eastern USA and found that almost 64% of the respondents frequently changed ready-to-wear clothes to achieve the desired fit (Alexander et al. 2005). Ashdown and Loker pointed out the size problem in current clothing shopping experiences and proposed a conceptual framework called “mass-customized target market sizing”, which is a size system “based on and derived from measurement data exclusively from the people who represent an apparel firm’s target market” (Ashdown and Loker 2010, p147). In this paper we study how innovative mobile technology, social media and crowd sourcing can contribute to solving the size problem. We summarize the current digital approaches that deal with the fitting issues in online clothing shopping and present a new concept, called “Figuracy”, which attempts to find consumers new fitted clothing items through matching their own clothes with anonymous persons’ virtual wardrobe. We have built a mobile application to implement the idea and have done two initial feedback studies to see the consumers’ attitudes. This concept provides new perspectives and opportunities of tackling the fitting problem in online shopping. Ready-to-wear and fast fashion brands are selling their clothes all over the world, not just to one local community. This business model of constantly new collections, draws on standardizing size series that come only in a selected number of models. This adds to the continuous size problem where the interpretation of a particular size varies in-between brands, and even within different models from a single manufacturer. Firms in the ready-to-wear apparel industry in the world use different sizing systems, like general sizes as XS, S, M, L, or more specific standards as numbered sizes from UK, US, FR systems, which can make consumers confused. These sizing systems are usually based on the ideal body types of consumers from certain geographic regions (Nordic Council of Ministers, 2009), thus, a size standard from one region may not fit all types of body within this region. What’s worse, there has been vanity sizing in clothing industry in recent several decades, which actually makes the garments of the normal sizes bigger in physical size (Dooley, 2013). This adds to the difficulty of finding well-fitting apparels. Recently, a few companies have provided a number of solutions to the fitting problem. The solutions are based on fine-grained automatic body measurements; self-generated extended body or garment measurement and body matching. First, the approach to use technology for more automatic and detailed measurements has attracted many interests. For example, it has been to generate a visual presentation of the body by using three-dimensional scan technology. Then consumers do not need to type information manually. A UK-based company, called Bodymetrics, provides the services that use three-dimensional body scanner and “On-line Virtual Try-On” technology to help find the perfect pair of jeans. Second, there are a number of services that require users to manually type the measurements of their bodies or garments that they own and fit. It can be done by users input information of their body types by answering simple questions, such as weight, height, body type, or measurements of bust, waist and hip. Some systems like Mipso, SmartFit can add more personal preferences, such as colours, cuts and budgets. Then the system runs some algorithms to determine the users’ full set of body measurements. It can also be done such as Virtusize, Truefit and Clothes Horse by measuring a garment that the user knows it fits in detail (Perez, 2012). When the personal data is added to the service, it can then match individual’s body measurements with specific brands and sizes of garments. The service recommends fitted ready-to-wear clothing from various brands in online stores, like Fashion Metric and Virtusize. The data can be used to see how fitted the clothing item in an online website is on a virtual avatar built upon the input measurements of the users, like in Virtusize and Mipso. Third, it has been suggested to use self-described body descriptions and then match consumers’ new purchases as a way to recommend clothes that are fit. For instance, Fitbay attempts to personalize clothes suggestions based on the selection of other users with similar descriptions of size and body shape (Lomas, 2014). Through the help of anonymous persons in the community, one could find fitted clothing items. We investigate a fourth approach, called “Figuracy”, where people get suggestions on the garments that are fit by crowd sourcing their existing clothing items and then matching wardrobes among members in the community. It draws on utilizing the matching of consumer-generated data, i.e. crowd sourcing as Fitbay also does. But it uses a description of existing fitting garments in people’s wardrobes in terms of brands, models and size, rather than self-description of bodies. The idea depends on that a community of people are willing to share information of their favourite and fitting clothes from their own wardrobes. The system matches the clothes from one wardrobe with that of other members in order to recommend new fitting clothes to the user. In specific, if the system finds that a user shares a single clothing item with another person in the community, it will predict that the two of them have similar body types. Then it recommends other items from the second person’s wardrobe to the first user. Therefore, the system gains data from the fitting clothes in users’ wardrobe and matches the information with the items from someone else’ wardrobe. If the approach is successful, consumers would not need to input any personal body-data but only data on existing fitting clothes. The concept depends on the existence of a massive database of clothing items from individual wardrobes, i.e. a critical mass, which is also a big challenge to build. The Figuracy concept and implementation is at an early state and it has not yet the amount of content to start generating matching suggestions. Still, the concept is intriguing and the size problem is highly relevant. Thus we were interested in acquiring early users’ feedback. We have done two user studies of two variations of the concept, with a focus on one type of clothing item- the bra. Bras have high requirements on fitting (Chena et al. 2010) and it is considered specifically difficult to find garment of this type that is fit. Since the number of test persons was limited to around ten people each, the system did not generate any matching suggestions. The first test was done in November in 2013 on the app that was available in iPhone’s App-store. This version of the system reads the barcodes, which are usually attached to the price tag, to acquire a unique identifier for brand, model and size. We invited the participants to download the app and scan the barcodes of fitting bras when they try new bras in stores. We conducted phone interviews with six participants. The early feedback identified that users hesitated to add garments based on the barcodes. They did not feel comfortable with adding it in a fitting room in a shop, and they did not have any saved prize tags for the bras at home. Thus, although the barcode is theoretically and technically an easy and effective way of uploading garments, it proved to be inadequate in practice. Based on this feedback, we built a new version, which includes a manual and text-based tag function allowing users to add information about a garment, which do not require barcode reading. The second user feedback study was carried out in December in 2014. We recruited female students on the campuses of Stockholm University and Royal Institute of Technology in Stockholm, Sweden. In the end, nine participants tested the application and input data of their bras at home. After the try-out, we contacted the participants for either a phone interview or a face-to-face interview, each of which lasted between twenty and forty minutes. Each interview was recorded and transcribed. We used a method of qualitative content analysis to study the transcripts. “Qualitative”, as opposed to quantitative, indicates that the analysis goes beyond systematic data coding to identify interesting topics and allow us to contextualize the interpretation of the materials, given theoretical preconceptions (Mayring 2004). Through studying the transcripts, we find the following preliminary results. First, our participants all provided concrete examples of size problems they met in real life. Seven participants considered bras as one of the clothing items that are most difficult in this respect. Three participants stated that size should not be independent from other qualities, such as comfort and style. This implies that future design of similar systems may take into account not only sizes, but also other aspects of clothing. Second, in terms of the input function, all of them followed the instructions and managed to input information of their fitted bras from their wardrobes. Seven participants considered it easy to use while two of them thought it was a bit confusing when to add information. They got stuck at whether they should scan the barcode or just type, since the two functions were presented in one place. All of them used “type” to add items and thought the information on what they should input was acceptable. Four participants felt it complicated to take photos by themselves, so they downloaded pictures from the Internet. In addition, the participants tended to add the latest and favourite items from their wardrobes into the system. Thus these items could represent their personal tastes and styles, which will be useful to link fitting and styles in the future improvement of the application. This also points to a general problem. From an individual perspective, a single item would in the long run be enough to get matches from other people’s wardrobes, if they have added more than one item. If they also only add only a single item, the first person would not get any matches. The users must crowd source their wardrobe, and not for example their latest purchase. The user study shows that this concept might be restricted by users’ unwillingness to present data in such a way. Third, as to social interaction, eight participants at least “liked” one item from others’ wardrobe. Although none of the participants commented on other’s items, they all thought it was important to have some kind of social interactions. Four participants expected more interactions, such as reviews and discussions of certain clothing items, or following fashionable people. Most of the existing fitting systems, except Fitbay, lack the opportunities for social interaction, but Figuracy provides such a platform for users to share their interests and exchange their ideas. Two participants asked for increased opportunities to add the information on their own profile pages even though they were sharing images of their underwear. They asked for means similar to those available when building a blog space so that people in the community would get to know each other better. According to the participants, more social interactions could make them more engaged with the application. Social communities are good for those looking to learn, help and/or support like-minded individuals with common interests. Last but not the least, most of the participants were very interested in the “buy” function, which link the item to online shopping sites. But still three participants revealed their concerns and discussed the problems of it, such as how the system can guarantee the fitting of the item if they conduct a purchase through the system. In sum, the use of crowd sourcing and social interaction to fixing the size problem in online shopping gained great interests among participants. However, they also expressed their uncertainties towards how the system would work. They needed the system to make sure that it could provide fitting clothing items. They thought the biggest problem was that it was unclear what real help they could get from the application at this stage. Although the application failed to provide new recommendations based on matching, the user study allows us to see the feedback of the potential users so that we could improve the system, such as clearer interaction flows in adding items and more interesting interactions. Future research will continue the improvement of the system, start collaborations with online clothing stores and a third recruitment of users to test. On a general level, the study provides an example on how to investigate critical topics in online fashion through the so-called design research. Such research needs to be interdisciplinary and span technology and social science.

On-line Identification Methods of Parameters for Permanent Magnet Synchronous Motors Based on Cascade MRAS

Yanqing Zhang,Zhonggang Yin,Xiangdong Sun,Yanru Zhong 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Motor parameters should be on-line estimated to realize precise control of PMSM in sensorless vector control system. In this paper, an on-line identification method for PMSM parameters based on cascade MRAS is proposed by analyzing the conventional MRAS. By means of Popov’s hyper-stability theory, the model of motor parameters identification is built in synchronous d-q coordinates, and PMSM stator voltage, stator current and their errors are used to obtain the adaptive laws of motor parameters, and it is realizable to estimate rotor speed, stator resistance and rotor flux at the same time. The simulation results demonstrate the correctness and effectiveness of the proposed method.

On the fashionalization of digital devices: a study of the representation of mobile phones in fashion magazines

Yanqing Zhang,Oskar Juhlin 한국의류학회 2020 Fashion and Textiles Vol.7 No.1

We asked when and how mobile phones are represented in Vogue (US) and L’Officiel (FR) between 1993 and 2017, and in what sense their presence in such magazines can be understood as making them into fashion items. The question is warranted since these magazines act as critical gatekeepers to fashion, at the same time as it has been argued that the latter is spreading its influence from clothes to other objects. We study the occurrence, changing styles and visual aesthetics of phones through a quantitative and a qualitative analysis. The former shows mobile phones did appear in the magazines, indicating that the important gatekeepers allow these devices to enter the fashion world. The qualitative analysis reveals that the aesthetic representation of mobile phones both conforms to and diverges from how garments are aestheticized in these magazines. The overall picture is one of a fluctuating and heterogeneous relation, with intermittent and temporary interactions between fashion gatekeeping and the digital devices. When carefully studying the interest in displaying the digital objects in these magazines we see a rather limited influence and not a trend.

A Novel Nonlinear Network Coding Signature Scheme Determined by the SIS problem

Yanqing Yao,Zhoujun Li,Hua Guo 보안공학연구지원센터 2012 International Journal of Security and Its Applicat Vol.6 No.2

Antioxidant and hepatoprotective activity of kaempferol 3-O-b-D- (2,6-di-O-a-L-rhamnopyranosyl)galactopyronoside against carbon tetrachloride-induced liver injury in mice

Yanqing Zang,Dongjie Zhang,Changqing Yu,Chenghao Jin,Kiharu Igarashi 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.4

This study aims to investigate the antioxidant and hepatoprotective effects of kaempferol 3-O-b-D- (2,6- di-O-a-L-rhamnopyranosyl)galactopyronoside (KG) isolated from unripe soybean leaves. Carbon tetrachloride (CCl4)-induced hepatotoxic ddY mice were used in the study. The mice were divided into three groups, namely the control group, the CCl4 group (CCl4, CCl4 injected), and the KG group (KG, CCl4 injected with KG administration). Hepatic injury markers of serum and liver were analyzed. The results show that serum ALT, AST activities, hepatic glutathione, superoxide dismutase, catalase, and glutathione peroxidase activities were normalized in mice pretreated with KG. Furthermore, the liver thiobarbituric acid reactive substances levels were found to be improved by pretreatment with KG, indicating that KG is available to alleviate liver injury, this may be due to its antioxidant properties. This study suggests that unripe soy leaves could be used as functional food materials.

Statics variation analysis due to spatially moving of a full ocean depth autonomous underwater vehicle

Yanqing Jiang,Ye Li,Yumin Su,Jian Cao,Yueming Li,Youkang Wang,Yeyi Sun 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

Changes in gravity and buoyancy of a Full Ocean Depth Autonomous Underwater Vehicle (FOD-AUV) during its descending and ascending process must be considered very carefully compared with a Human Occupied Vehicle (HOV) or a Remotely Pperated Vehicle (ROV) whose activities rely on human decision. We firstly designed a two-step weight dropping pattern to achieve a high descending and ascending efficiency and a gravity-buoyancy balance at designed depth. The static equations showed that gravity acceleration, seawater density and displacement are three key aspects affecting the balance. Secondly, we try our best to analysis the gravity and buoyancy changing according to the previous known scientific information, such as anomaly of gravity acceleration, changing of seawater states. Finally, we drew conclusion that gravity changes little (no more than 0.1kgf, it is impossible to give a accurate value). A density-depth relationship at the Challenger Deep was acquired and the displacement changing of the FOD-AUV was calculated preciously.

ANALYSIS AND OPTIMIZATION OF AN EXPANDING ENERGY ABSORBER WITH VARIABLE THICKNESS DISTRIBUTION TUBE UNDER AXIAL DYNAMIC LOADING

Yanqing Wang,Shiming Wang,Lin Hou,Yong Peng 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.6

An expanding energy absorber with variable thickness distribution tube is proposed and studied in this work. At first, a uniform thickness tube structure finite element (FE) model was developed and then verified by the results of an impact test. The parametric study found that outer obliquity angle β and inner obliquity angle γ have positive influence on initial peak force (Fp). While as axial distribution ratio l less than 0.1, the l has significant positive effect on Fp. The non-monotonicity of specific energy absorption (SEA) with design parameters of β and γ was found. Increasing the parameter l could obviously improve the SEA. To obtain the optimal design, an integrated optimization methodology was applied. The Pareto fronts show that there is a lot of room for improvement of original design. The optimal compromising solution increased the SEA by 12.60 % with Fp decreased by 14.24 kN comparing with that of original design. At last, the optimization result were verified. The study stated that the proposed variable thickness distribution tube of expanding energy absorber is conducive to improving the crashworthiness of rail vehicles.

A Novel Speed Estimation Method of Induction Motors Using Real-Time Adaptive Extended Kalman Filter

Yanqing Zhang,Zhonggang Yin,Guoyin Li,Jing Liu,Xiangqian Tong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

To improve the performance of sensorless induction motor (IM) drives, a novel speed estimation method based on the real-time adaptive extended Kalman filter (RAEKF) is proposed in this paper. In this algorithm, the fuzzy factor is introduced to tune the measurement covariance matrix online by the degree of mismatch between the actual innovation and the theoretical. Simultaneously, the fuzzy factor can be continuously self-tuned tuned by the fuzzy logic reasoning system based on Takagi–Sugeno (T-S) model. Therefore, the proposed method improves the model adaptability to the actual systems and the environmental variations, and reduces the speed estimation error. Furthermore, a simple exponential function based on the fuzzy theory is used to reduce the computational burden, and the real-time performance of the system is improved. The correctness and the effectiveness of the proposed method are verified by the simulation and experimental results.