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Wireless power transfer (WPT) is a well-known technique for electric vehicle (EV) charging. In this context, the power transfer profile is the key factor especially for the dynamic wireless power transfer (DWPT), where the time of magnetically coupling between track and pickup coils is significantly less. In this regard, this paper has proposed a three-element compensation network (3ECN) capable to transfer nominal power in the large portion of coupling, in other words, nominal power transfer is possible in the considerably large interval of mutual inductance. The paper has also included 1ECN and 2ECN and moved to 3ECN with a proper description of every CN and step-wise consideration and evolvement based on supply voltage limit, power transfer limit, and supply current limit. Simulation has been carried out in the MATLAB simulation environment considering the fundamental theory.

Integrated multimodal cross-sectional or volumetric imaging techniques give us fruitful information to understand the behavior or status of target objects such as biological samples. Most of the reported systems for this purpose are either time consuming due to scanning or use additional reference beams such as in interferometry. Therefore, fast, simple, highly efficient, and powerful multimodal imaging systems that can perform cross-sectional imaging with simple algorithms are worth to be investigated. In this paper, a multimodal technique for cross-sectional quantitative phase and fluorescence imaging with computational microscopy is presented. We combine cross-sectional fluorescence and quantitative phase imaging by using the transport of intensity equation (TIE) and numerical wave propagation. The amplitude and phase of the fluorescence light wave with partially spatial coherence are obtained from three defocused intensity patterns. The proposed hybrid imaging system is simple, compact, and non-iterative. We present experimental results of microbeads and fluorescent proteinlabeled living cells of the moss Physcomitrella patensto demonstrate the performance of the proposed imaging system.

In this study, we developed a new system to co-culture human induced pluripotent stem cells (hiPSCs)-derived brain organoids and vasculature made of HUVECs in a microfluidic device. Our device can make perfusable vascular networks in a microchannel. We firstly optimized the type of media to co-culture hiPSCs-derived brain organoids and HUVECs. Then, the effect of vasculature on the differentiation of brain organoids was evaluated by our new culture system. We found that on-chip vasculature promoted neural differentiation and maturation as compared to the conventional mono-culture. This brain organoids-on-a-chip system would be a powerful tool for various stem cell-based organoids engineering and its application in developmental biology and human disease studies.

Context: This Research to Practice Full Paper presents a systematic review of methodologies that propose ways of reducing dropout rate in Virtual Learning Environments (VLE). This generates large amounts of data about courses and students, whose analysis requires the use of computational analytical tools. Most educational institutions claim that the greatest issue in virtual learning courses is high student dropout rates. Goal: Our study aims to identify solutions that use Machine Learning (ML) techniques to reduce these high dropout rates. Method: We conducted a systematic review to identify, filter and classify primary studies. Results: The initial search of academic databases resulted in 199 papers, of which 13 papers were included in the final analysis. The review reports the historical evolution of the publications, the Machine Learning techniques used, the characteristics of data used, as well as identifies solutions proposed to reduce dropout in distance learning. Conclusion: Our study provides an overview of the state of the art of solutions proposed to reduce dropout rates using ML techniques and may guide future studies and tool development.

Social coding platforms (SCPs) have realized spontaneous software evolution, where new source code and ideas are spontaneously proposed by altruistic developers. Although there are many projects operated by active communities performing spontaneous evolution, it is yet unclear that how such successful projects and communities have been formed and governed. In this paper, we propose a method that can investigate the history of every project in the SCP. Introducing the concept of project as a city, we consider every project in the SCP as a city, where a government and citizens develop a city through collaborative activities. We then identify essential attributes that characterize a state of a city. For each attribute, we develop metrics that quantity the state S(p, t) of a project p at time t. An experimental evaluation investigating GitHub projects of famous code editors shows that the proposed metrics well visualize the history of the projects from essential perspectives of a city.

In recent years, the tendency to use glass as a cover material of automotive displays is accelerating due to its high durability and attractive appearance. When used as an in-vehicle application, properties such as high reliability and anti-glare property are required in addition to the properties required for tablets and smartphones. By selecting a glass composition with high weather ability and easy chemical strengthening, it was possible to achieve both strength and reliability for the first time. By forming the anti-glare structure and the anti-reflection coating on the substrate surface, the visibility of the display image could be greatly improved. From these verifications it was possible to clarify design guidelines for automotive cover glasses.

This paper presents a methodological approach for formulating the clutching sequence associated with an automatic transmission. Rank ordered clustering technique has been used to achieve the optimal clutching sequence which is compared with the present designs to show the reduction in the number of actuators thereby leading to a more compact gearbox design. The proposed transmission schematic or stick diagram aids in developing the gearbox layout design. Data with respect to actuation and gear shifting sequence has been retrieved from the available literature, including patent documents, and has been used in this proposed heuristics based methodology for modeling actuation sequence in a gearbox. The proposed modeling approach is simpler for designing gearbox and implementing it for automotive applications.

The software birthmark methods are proposed to find the stolen software from the huge number of suspects. The software birthmark methods are classified into two manners, static and dynamic manners. Different from the static birthmarks, dynamic birthmarks require inputs since they base on runtime behaviors. Also, the dynamic birthmark varies depending on the inputs, therefore, it is difficult to extract beforehand. Hence the extraction cost of the dynamic birthmarks is generally high than the static birthmarks. This paper focuses on unit test codes in a project in order to extract the dynamic birthmarks beforehand, and reduce the extraction cost. The experiments evaluated the credibility and resilience performance of the birthmarks. The performance evaluation showed good results, the similarities were greater than 0.8 between most recent two versions of the same products, and were under 0.355 among different projects. In the cost evaluation, the proposed method can reduce the extraction cost of dynamic birthmarks.

The obfuscation methods are often used to hide sensitive information in software. Especially, an identifier renaming method (IRM) is well used because it is easy to implement. IRM is one of the obfuscation methods, and to change the names of function, and variables into meaningless one. However, if we can restore the identifiers to the original names, IRM is invalidated. One of the serious problems about IRM is that the tolerance against de-obfuscation is not discussed. This paper tries to de-obfuscate IRMed programs. Thereby, this paper evaluates the tolerance and effectiveness of IRM. From the experimental evaluation, the proposed method can restore the 49.71 % of method names to the original verbs. Furthermore, focusing on the meanings of verbs, the proposed method recommends the verbs of similar meanings to the original verbs in 57.01 % of methods.

Vibrotactile stimulation to the gluteal or back regions through seats is a promising approach to deliver supplemental information to humans. Designing a method to achieve pleasant vibrotactile stimuli was addressed in this study, as such stimuli tend to result in unpleasant experiences for users. In particular, we investigated the properties of continual vibrotactile stimulation to the gluteal region through experiments and found that decreases in the duration of individual stimuli and vibratory frequency significantly increased the experienced pleasantness, whereas variations in the interval between consecutive stimuli exhibited no effect. Such principles are expected to generally hold in designing vibrotactile signals.

Previous research has clarified that applying two-dimensional stress to a welding target is effective for ultrasonic metal welding. Thus, we develop a new complex vibration source that can control separate vibrations and generate a planar vibration locus for ultrasonic metal welding. The structure of the vibration source is one in which a longitudinal transducer and a torsional transducer are connected to either end of the horn. We propose matching the wavelengths of the longitudinal and torsional vibrations by adjusting the resonance frequencies of the two transducers. By studying vibration sources with this structure, we clarify that the distributions of the vibrations propagating through the horn match, and that longitudinal and torsional vibrations can be controlled separately. Also, a planar locus is obtained by developing the vibration source.

Continuous voltage compensator was developed to improve power quality issues of distribution lines. It consists of series and shunt transformer connected through static power converters. In this paper, the compensation methods using series and shunt converters were investigated, and manufacturing of actual rating 6.6kV 3MVA prototype was reported.

A compressed sensing method using a cross sampling and self-calibrated off-resonance correction is proposed. Estimation of the magnetic field inhomogeneity based on image registration enables the off-resonance correction with no additional radio-frequency pulses or acquisitions. In addition to this advantage, a fast and straightforward calculation was achieved by using the first-order components of the magnetic field inhomogeneity. Imaging experiments using a phantom and a chemically fixed mouse demonstrated practical benefits in improving blurring and artifacts in magnetic resonance images in low field magnetic resonance imaging systems.

ChatOps is an industry practice of conversation-driven development using instant messaging to automate common development or monitoring tasks. It makes team members communicate with each other efficiently to work, learn and create together. We expect ChatOps to have intelligent agents, which can perform predictive operations based on users' activities, in the near future. To enable such intelligent agents, we worked on building prediction models of users' next actions. We collected action histories and their objectives and then applied sequential pattern mining to predict next actions. The result shows that some rules that meet some conditions could apply in 99% rate. Even if data do not meet the conditions, excluding rules in unnecessary actions improved the quality of the rules. Then, we analyzed generality of rules. To relate different actions as the same action based on an interpretation, the quality of the rules was improved.

The software birthmarks were proposed for detecting the software theft, which is suspected a copy. The birthmark system extracts native characteristics of a program. Then, the system computes the similarity between two birthmarks. This paper proposes the reduction method of the comparison time for the birthmark system. The conventional birthmark systems did not care the comparison time. Therefore, the enormous amount of programs could not compare practically for requiring quite a huge comparison time. To solve the problem, we tackled to reduce the comparison time with the search engine. So that we introduce the pre-comparison phase into conventional birthmark procedures to narrow the defendant programs. We implemented the proposed method with Apache Solr search engine and evaluated the method. The result was shown that the method for UC birthmark dramatically reduces the comparison time 81.35%, and narrows the target programs 74.81%. On the other hand, the results were not good in the default threshold e = 0.75 (high false negative rates CFN = 67.01%, and low accuracies Ma = 34.18%). However, the results were improved CFN = 21.17% and Ma = 78.56% in average by lowering e = 0.25.

This article presents an in-depth description of Stanford University's Biodesign, the post-graduate program established in 2001 with a mission to train a new generation of leaders in biomedical innovation. We examined the Biodeslgn's multidisciplinary curriculum In which the competitively selected fellows undergo an Intensive 10.5-month training to identify clinical needs, find innovative solutions and plan business strategies for implementation. The strength of the Stanford Biodesign program lies in its unique selection of the applicants where the committee looks for the following “innovation personalities” (Brinton, et. al, 2013) and put them together as a team: (1) the buider (i.e. engineer), (2) the researcher (i.e. scientist), (3) the organizer (i.e. business expert), and (4) the clinician (i.e. medical doctor). The team members collaborate and learn from each other's expertise as they go through the intensive training. The multidisciplinary nature of Biodesign program enables the participants to acquire critical biomedical thinking, entrepreneurial resource, team-building skills and networking opportunities.

Multi-modal 3D imaging based on digital holography is reviewed. In the developed system, 3D phase and 2D fluorescence distributions can be measured simultaneously. This characteristic can be used for measurement of live cell activity. We present the preliminary experimental results. One is the observation of microbeads embedded by fluorescence molecules. Second is the observation of plant cell.

Fluorescent imaging and phase contrast imaging are two major techniques for live cell studies. One can obtain those two types of images by switching illumination and filter sets, and this process usually consumes unnecessary time. In order to image dynamical cell behaviors, we have presented a multi- modal digital holographic microscopic method to obtain both quantitative phase images and fluorescent images at the same time. We used Physcomitrella patens the moss to test the proposed system. Two-dimensional images of chloroplasts and quantitative phase information were obtained simultaneously under continuous exposure of laser light. We observed shrinkage in cell size and concentration in the chloroplasts distribution.

Recently, to prevent cracking, the various protection methods have been proposed. One of the protection methods is the obfuscation method. Obfuscation method changes the program into hard to understand for hiding secret information in the program. On the other hand, de-obfuscation is an interesting research topic for protecting the software. Since, though vulnerable protection methods are dangerous, measuring the robustness of the method was not discussed. In this paper, we tackle to identify the applied obfuscation methods towards de-obfuscation. To perform de-obfuscation requires a suitable method for each obfuscation method. For this, we obfuscated programs by two practical tools and three algorithms from one academic tool. Then, we analyzed the programs and extracted characteristics from them based on opcodes. By using the proposed method, we could identify the applied obfuscation method.

Software birthmarks have been proposed as a method for enabling the detection of programs that may have been stolen by measuring the similarity between the two programs. A birthmark is created from each program by extracting its native characteristics. The birthmarks of the programs can then be compared. However, because the extracted birthmarks contain a large amount of information, a large amount of time is needed when using them to compare large programs. This paper describes our work to reduce this comparison time. Achieving faster comparisons will enable the evaluation of large programs and simplify the use of birthmarks. Specifically, our method creates hashes from conventional birthmark information using fuzzy hashing, and then measures the similarity of the programs using the obtained hash values. Using the proposed method, we achieved a major speed increase over the conventional birthmark method with distinction rates of over 90%. On the other hand, because preservation performance decreased substantially, the similarity threshold value needed to be lowered when using the proposed method.

To enhance the quality of software, many software development support tools and software development methodologies have been proposed. However, not all proposed tools and methodologies are widely used in software development. We assume that the evaluation of tools and methodologies by developers is different from the evaluation by researchers, and that this is one of the reasons why the tools and methodologies are not widely used. We analyzed the decision criteria of software developers as applied to the tools and methodologies, to clarify whether the difference exists or not. In behavioral economics, there are theories which assume people have biases, and they do not always act reasonably. In the experiment, we made a questionnaire based on behavioral economics, and collected answers from open source software developers. The results suggest that developers do not always act to maximize expected profit because of the certainty effect and ambiguity aversion. Therefore, we should reconsider the evaluation criteria of tools such as the f-measure or AUC, which mainly focus on the expected profit., SANER 2016 : 2016 IEEE 23rd International Conference on Software Analysis, Evolution, and Reengineering, 14-18 March 2016, Suita, Japan

A planar floating-gate NAND technology has previously realized a 0.87Gb/mm2 memory density using 3b/cell [1] and achieved a minimum feature size for 16nm [2]. However, the development of planar NAND flash is expected to reach the scaling limit in a few technology generations. To break though this limit, a significant shift to 3D NAND flash has begun and several types of 3D memory cell structures have been proposed and discussed [3–5]. Recently a 3D V-NAND technology achieved 1.86Gb/mm2 using charge-trap cells and 3b/cell [6]. This paper presents a 3b/cell NAND flash memory utilizing a 3D floating gate (FG) technology that achieves 4.29Gb/mm2.

In this paper, we propose new isolated AC-DC converters which have only one conversion stage; in addition it can operate zero voltage switching in all switching devices. Moreover, we propose control strategy for these converters, and also confirmed it by experimentation or simulation using 100W prototype.

In software development, multiple developers compose a team, and perform a development process. To succeed the development, understanding developers' characteristics are needed. However, there is no way to measure the characteristics of the developer by quantitative analysis. Therefore, a project manager often assigns team members based on his/her own sense, considering experience year of them. This paper proposes a measurement framework for developers' characteristics using quantitative historical data. The proposed framework is useful for measuring developers' characteristics and building a team based on quantitative analysis. We collected historical data from a PBL project for graduate students, and applied our framework to the collected data. As a result, our framework measured developers' characteristics suitability in our subjective view.

This paper proposes an obfuscation method against illegal analysis. The proposed method tries to build a fake call flow graph from debugging tools. The call flow graph represents relations among methods, and helps understanding of a program. The fake call flow graph leads misunderstanding of the program. We focus on a hook mechanism of the method call for changing a callee. We conduct two experiments to evaluate the proposed method. First experiment simulates attacks by existing tools: Soot, jad, Procyon, and Krakatau. The Procyon only succeeded decompilation, the others crashed. Second experiment evaluates understandability of the obfuscated program by the hand. Only one subject in the nine subjects answered the correct value. The experiments shows the proposed method has good tolerance against existing tools, and high difficulty of understanding even if the target program is tiny and simple program.

This paper proposes a new type of Modular Multilevel Converter (MMC) applying a three winding transformer. In general, MMC requires a buffer reactor in each arm, which increases number of components and converter footprint. The proposed MMC with three winding transformer does not require the buffer reactors. We describe mathematical properties of the proposed MMC. We also confirmed it operated as same as typical MMC (with reactor topology) by experimentation using a prototype 10kVA converters.