Dynamic time warping is a popular technique for comparing time series, providing both a distance measure that is insensitive to local compression and stretches and the warping which optimally deforms one of the two input series onto the other. A variety of algorithms and constraints have been discussed in the literature. The dtw package provides an unification of them; it allows R users to compute time series alignments mixing freely a variety of continuity constraints, restriction windows, endpoints, local distance definitions, and so on. The package also provides functions for visualizing alignments and constraints using several classic diagram types.

/pdf/computing-and-visualizing-dynamic-time-warping-alignments-in-44vddeq1il.pdf

Computing and Visualizing Dynamic Time Warping Alignments in R: The dtw Package

The dermis is primarily composed of the extracellular matrix (ECM) and fibroblasts. During the aging process, the dermis undergoes significant changes. Collagen, which is a major component of ECM, becomes fragmented and coarsely distributed, and its total amount decreases. This is mainly due to increased activity of matrix metalloproteinases, and impaired transforming growth factor-β signaling induced by reactive oxygen species generated during aging. The reduction in the amount of collagen hinders the mechanical interaction between fibroblasts and the ECM, and consequently leads to the deterioration of fibroblast function and further decrease in the amount of dermal collagen. Other ECM components, including elastic fibers, glycosaminglycans (GAGs), and proteoglycans (PGs), also change during aging, ultimately leading to a reduction in the amount of functional components. Elastic fibers decrease in intrinsically aged skin, but accumulate abnormally in photoaged skin. The changes in the levels of GAGs and PGs are highly diverse, and previous studies have reported conflicting results. A reduction in the levels of functional dermal components results in the emergence of clinical aging features, such as wrinkles and reduced elasticity. Various antiaging approaches, including topicals, energy-based procedures, and dermal fillers, can restore the molecular features of dermal aging with clinical efficacy. This review summarizes the current understanding of skin aging at the molecular level, and associated treatments, to put some of the new antiaging technology that has emerged in this rapidly expanding field into molecular context.

https://www.mdpi.com/1422-0067/20/9/2126/pdf

Molecular Mechanisms of Dermal Aging and Antiaging Approaches.

Matching incomplete time series with dynamic time warping: an algorithm and an application to post-stroke rehabilitation

https://www.cct.lsu.edu/~huanxu4/papers/WangAMC08.pdf

Classification of plant leaf images with complicated background

Microfocused ultrasound (MFU) has been recently developed to meet the ever-growing public demand for achieving significant, noninvasive skin lifting and tightening. MFU can be focused on subcutaneous tissue where the temperature briefly reaches greater than 60°C, producing small (<1 mm3) thermal coagulation points to a depth of up to 5 mm within the mid-to-deep reticular layer of the dermis and subdermis. The intervening papillary dermal and epidermal layers of skin remain unaffected. The application of heat at these discrete thermal coagulation points causes collagen fibers in the facial planes such as the superficial musculoaponeurotic system and platysma, as well as the deep reticular dermis, to become denatured, contracting and stimulating de novo collagen. A commercially available device combines MFU with high-resolution ultrasound imaging (MFU-V), which enables visualization of tissue planes to a depth of 8 mm and allows the user to see where the MFU energy will be applied (Ultherapy®; Ulthera Inc., Mesa, AZ, USA). Using different transducers, MFU-V treatment can be customized to meet the unique physical characteristics of each patient by adjusting energy and focal depth of the emitted ultrasound. By targeting the facial superficial musculoaponeurotic system, noninvasive tightening and lifting of sagging facial and neck skin and improvements in the appearance of wrinkles can be achieved. MFU-V can also improve lines and wrinkles of the decollete. Treatment protocols for the use of MFU-V continue to be refined, and its use in combination with other rejuvenation techniques has been demonstrated. Brief discomfort that often occurs during treatment can be minimized with oral nonsteroidal anti-inflammatory drugs. Other treatment-related adverse events include transient erythema, edema, and occasional bruising. MFU-V is best suited for patients with mild-to-moderate skin and soft tissue laxity. For older patients with severe skin laxity and marked platysmal banding, surgical treatment should be considered.

/pdf/noninvasive-skin-tightening-focus-on-new-ultrasound-1t3x3yrx3c.pdf

Noninvasive skin tightening: focus on new ultrasound techniques

BACKGROUND Skin laxity is a common complaint of patients who request skin rejuvenation. Radiofrequency and infrared light are widely used for nonablative treatment of skin laxity. Intense focused ultrasound (IFUS) has been investigated as a tool for the treatment of solid benign and malignant tumors for many decades but is only now beginning to emerge as a potential noninvasive alternative to conventional nonablative therapy. OBJECTIVES To evaluate the efficacy of IFUS for the treatment of face and neck laxity. METHODS Twelve female volunteers were enrolled in the study, and 10 were ultimately evaluated. The device under investigation was an IFUS. Areas treated included the face and neck. For treatment, the 4-MHz, 4.5-mm probe was used first, followed by the 7-MHz, 3.0-mm probe. Two blinded, experienced clinicians evaluated paired pretreatment and post-treatment (day 90) photographs. Patient self-assessments were also obtained. RESULTS On the first primary outcome measure, two blinded clinicians felt that 8 of 10 subjects (80%) showed clinical improvement 90 days after treatment. Nine of 10 subjects (90%) reported subjective improvement.

Multiple Pass Ultrasound Tightening of Skin Laxity of the Lower Face and Neck

In this paper, we propose an efficient leaf image retrieval scheme based on its shape feature. To represent leaf shape, we first derive a distance curve from each leaf using distances between its center and the points along the contour. Next, for the storage and matching purpose, we extract a set of Fourier Coefficients (FCs) from the curve. Typically, a set of FCs fails to restore the original curve completely. In order to reduce the difference between original and restored curves, we divide whole curve into several partitions such that each partition has a small difference with the original curve. For image matching, we propose a Partial Dynamic Time Warping (PDTW) algorithm. We also propose a categorization scheme using the number of unit curves for filtering purpose. In the experiment, we show that our proposed scheme improved both efficiency and accuracy of leaf image retrieval.

A Leaf Image Retrieval Scheme Based on Partial Dynamic Time Warping and Two-Level Filtering

This demonstration presents a content-based leaf image retrieval system that supports wired/wireless access. For example, if we want to know about a plant that we encounter in a mountain or field, we might look it up in an illustrated book. But, it will take a long time to search due to the lack of appropriate indexing or search clues and huge amounts of similar plants. In order to solve this problem, we developed a content-based leaf image retrieval system called mCLOVER that supports both wired and wireless access and includes a set of novel features for easy querying and efficient retrieval.

mCLOVER: mobile content-based leaf image retrieval system

Hierarchical querying scheme of human motions for smart home environment

The convergence of information and medical technologies has resulted in the emergence and active development of the ubiquitous healthcare (U-Healthcare) industry. The U-healthcare industry provides telepathology and anytime-anywhere wellness services. The main purpose of these wellness services is to provide health information to improve the quality of life. Human skin is an organ that can be easily examined without expensive devices. In addition, there has recently been rapidly increasing interest in skin care products, resulting in a concomitant increase in their consumption. In this paper, we propose a new scheme for a self-diagnostic application that can estimate the actual age of the skin on the basis of the features on a skin image. In accordance with dermatologists' suggestions, we examined the length, width, depth, and other cell features of skin wrinkles to evaluate skin age. Using our highly developed image processing method, we could glean detailed information from the surface of the skin. Our scheme uses the extracted information as features to train a support vector machine (SVM) and evaluates the age of a subject's skin. Evaluation of our proposed scheme showed that it was more than 90% accurate in the analysis of the skin age of three different parts of the body: the face, neck, and hands. Therefore, we believe our model can be used as a standard or as a scale to measure the degree of damage or the aging process of the skin. This scheme is implemented into our Self-Diagnostic Total Skin Care system, and the information obtained from this system can be utilized in various areas of medicine.

Yoon-Sik Tak

Papers

Multiple Pass Ultrasound Tightening of Skin Laxity of the Lower Face and Neck

A Leaf Image Retrieval Scheme Based on Partial Dynamic Time Warping and Two-Level Filtering

mCLOVER: mobile content-based leaf image retrieval system

Hierarchical querying scheme of human motions for smart home environment

Skin feature extraction and processing model for statistical skin age estimation