87value/wos11967 huggingface dataset:
It is well known that optimizing network topology by switching on and off transmission lines improves the efficiency of power delivery in electrical networks. In fact, the USA Energy Policy Act of 2005 (Section 1223) states that the United States should encourage, as appropriate, the deployment of advanced transmission technologies including optimized transmission line configurations. As such, many authors have studied the problem of determining an optimal set of transmission lines to switch off to minimize the cost of meeting a given power demand under the direct current (DC) model of power flow. This problem is known in the literature as the Direct-Current Optimal Transmission Switching Problem (DC-OTS). Most research on DC-OTS has focused on heuristic algorithms for generating quality solutions or on the application of DC-OTS to crucial operational and strategic problems such as contingency correction, real-time dispatch, and transmission expansion. The mathematical theory of the DC-OTS problem is less well developed. In this work, we formally establish that DC-OTS is NP-Hard, even if the power network is a series-parallel graph with at most one load/demand pair. Inspired by Kirchoff's Voltage Law, we provide a cycle-based formulation for DC-OTS, and we use the new formulation to build a cycle-induced relaxation. We characterize the convex hull of the cycle-induced relaxation; this characterization provides strong valid inequalities that can be used in a cutting-plane approach to solve the DC-OTS. We give details of a practical implementation, and we show promising computational results on standard benchmark instances.
Intensive economic and shipping activities in Singapore Strait have caused Singapore coastal waters to be under high risk of water pollution. A nested three-dimensional unstructured-grid SUNTANS model is applied to Singapore coastal waters to simulate flow and pollutant transport. The small domain (similar to 50 m resolution) Singapore coastal model is nested within a large domain (similar to 200 m resolution) regional model. The nested model is able to predict water surface elevations and velocities with high R-2 values of 0.96 and 0.91, respectively. Model results delineate the characteristics of circulation pattern in Singapore coastal waters during the Northeast and Southwest monsoons. The pollutants are modeled as passive tracers, and are released at six key sailing locations Points 1-6 in Singapore coastal waters and are named as Passive Tracers 1-6, respectively. Our results show that the rate of dispersionis twice as large for the Northeast monsoon compared to the Southwest monsoon due to differences in large-scale monsoons and small-scale local winds. The volume averaged concentration (VAC) diminishes faster and the local flushing time is shorter during the Northeast monsoon than the Southwest monsoon. Dispersion coefficients K and the VAC decreasing rate are maximum for Tracers 2 and 3 with shortest local flushing time due to the strong surrounding currents and abrupt bathymetry changes near Senang and St. John Islands. Dispersion coefficients K and the VAC decreasing rate are minimum for Tracer 1 due to weak currents induced by the semi-enclosed coastline near Tuas. It is found that both the lateral dispersion coefficient K-y and the compound dispersion coefficient K obey a 4/3-law, which defines a linear correlation between dispersion coefficients and 4/3-power of selected length scale. (C) 2016 Elsevier Ltd. All rights reserved.
This paper describes the necessity of integrated computerization of manufacturing engineering process, the aims and requirements of modem integrated systems; also presents the integrated Computer Aided Manufacturing Engineering system SAT, its structure, main functions, data base and area of application.
Individuals are not merely passive vessels of whatever beliefs and opinions they have been exposed to; rather, they are attracted to belief systems that resonate with their own psychological needs and interests, including epistemic, existential, and relational needs to attain certainty, security, and social belongingness. Jost, Glaser, Kruglanski, and Sulloway (2003) demonstrated that needs to manage uncertainty and threat were associated with core values of political conservatism, namely respect for tradition and acceptance of inequality. Since 2003 there have been far more studies on the psychology of left-right ideology than in the preceding half century, and their empirical yield helps to address lingering questions and criticisms. We have identified 181 studies of epistemic motivation (involving 130,000 individual participants) and nearly 100 studies of existential motivation (involving 360,000 participants). These databases, which are much larger and more heterogeneous than those used in previous meta-analyses, confirm that significant ideological asymmetries exist with respect to dogmatism, cognitive/perceptual rigidity, personal needs for order/structure/closure, integrative complexity, tolerance of ambiguity/uncertainty, need for cognition, cognitive reflection, self-deception, and subjective perceptions of threat. Exposure to objectively threatening circumstances-such as terrorist attacks, governmental warnings, and shifts in racial demography-contribute to modest conservative shifts in public opinion. There are also ideological asymmetries in relational motivation, including the desire to share reality, perceptions of within-group consensus, collective self-efficacy, homogeneity of social networks, and the tendency to trust the government more when one's own political party is in power. Although some object to the very notion that there are meaningful psychological differences between leftists and rightists, the identification of elective affinities between cognitive-motivational processes and contents of specific belief systems is essential to the study of political psychology. Political psychologists may contribute to the development of a good society not by downplaying ideological differences or advocating Swiss-style neutrality when it comes to human values, but by investigating such phenomena critically, even-or perhaps especially-when there is pressure in society to view them uncritically.
Revocation and key evolving paradigms are central issues in cryptography, and in PKI in particular. A novel concern related to these areas was raised in the recent work of Sahai, Seyalioglu, and Waters (CRYPTO 2012) who noticed that revoking past keys should at times (e.g., the scenario of cloud storage) be accompanied by revocation of past ciphertexts (to prevent unread ciphertexts from being read by revoked users). They introduced revocable-storage attribute-based encryption (RS-ABE) as a good access control mechanism for cloud storage. RS-ABE protects against the revoked users not only the future data by supporting key-revocation but also the past data by supporting ciphertext-update, through which a ciphertext at time T can be updated to a new ciphertext at time T 1 using only the public key. Motivated by this pioneering work, we ask whether it is possible to have a modular approach, which includes a primitive for time managed ciphertext update as a primitive. We call encryption which supports this primitive a self-updatable encryption (SUE). We then suggest a modular cryptosystems design methodology based on three sub-components: a primary encryption scheme, a key-revocation mechanism, and a time-evolution mechanism which controls the ciphertext self-updating via an SUE method, coordinated with the revocation (when needed). Our goal in this is to allow the self-updating ciphertext component to take part in the design of new and improved cryptosystems and protocols in a flexible fashion. Specifically, we achieve the following results: We first introduce a new cryptographic primitive called self-updatable encryption (SUE), realizing a time-evolution mechanism. In SUE, a ciphertext and a private key are associated with time. A user can decrypt a ciphertext if its time is earlier than that of his private key. Additionally, anyone (e.g., a cloud server) can update the ciphertext to a ciphertext with a newer time. We also construct an SUE scheme and prove its full security under static assumptions. Following our modular approach, we present a new RS-ABE scheme with shorter ciphertexts than that of Sahai et al. and prove its security. The length efficiency is mainly due to our SUE scheme and the underlying modularity. We apply our approach to predicate encryption (PE) supporting attribute-hiding property, and obtain a revocable storage PE (RS-PE) scheme that is selectively-secure. We further demonstrate that SUE is of independent interest, by showing it can be used for timed-release encryption (and its applications), and for augmenting key-insulated encryption with forward-secure storage. (C) 2017 Elsevier B.V. All rights reserved.
Electric machines and their corresponding power electronic drives are key components of electric/hybrid electric vehicle (EV/HEV) powertrains. Thus, computationally-efficient models for electric machines and drives are essential for powertrain-level design, simulation, and optimization. In this paper, a finite-element-based method for quickly generating torque-speed curves and efficiency maps for electric machines and drives is presented. First, magneto-static finite element analysis (FEA) is conducted on a base machine design. This analysis produces normalized torque, flux linkage, current, and losses for the operating points of interest. These values are then adjusted based upon changing the size of the machine and the effective number of turns of the machine windings to quickly generate a variety of new machine designs and their corresponding efficiency maps. Results suggest that the proposed techniques can be useful for EV/HEV powertrain design and optimization.
For decades, person perception research has grappled with the distinction between the targets' actual characteristics (substance) and how positively or negatively those characteristics are viewed by perceivers (evaluation); however, lack of an overarching theoretical framework makes it difficult to establish connections between related lines of research. We review the relevant literature, and present and test an algebraic model that incorporates the major insights from that literature. The model posits that all person judgments reflect substance and evaluation to different extents. The evaluation component reflects an interaction between the item's evaluative tone and the perceiver's evaluative attitude regarding the target person. The model may function as an integrative framework that helps improve conceptual clarity and cumulative progress in person perception research. (C) 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Drastic urbanization has taken place in China during the last two decades. Recently, a considerable number of ghost cities have emerged due to the extensive and unreasonable urban expansion which far exceeds the practical demand. In order to investigate ghost cities, we proposed a feasible framework by utilizing multi-source remote sensing datasets, including nighttime light imagery, land cover type products and population grid. After eliminating blooming effect of nighttime imagery by a proposed modified optimal threshold method (MOTM) and extracting built-up area from land cover type products, we developed a ghost city index (GCI) to quantify and evaluate the intensity of ghost city phenomenon in Yangtze River Delta at county/district level. The GCI was established according to the intrinsic features of ghost cities, comprising three criteria: consistency of lit area and built-up area, illumination intensity and population density. Then, we explored the spatial pattern of ghost cities of different GCI categories and the ternary contour was applied to demonstrate the key factor among three criteria. Our finding implies that ghost cities are prominently spatial clustered. Meanwhile, counties and new development zones have higher risk of suffering from the phenomenon, while capital cities and municipal cities have an alleviative effect for ambient regions. Besides, regions with higher intensity of the phenomenon tend to have less balanced composition among three criteria. Our results show good consistency with previous reports and studies, providing a more objective and spatial explicit insight into the ghost city phenomenon. Our findings do not only prove the capability of monitoring ghost cities using remote sensing data, but would also be beneficial to urban planning and regional sustainable development.(C) 2017 Elsevier Ltd. All rights reserved.
Nutrition plays an important role in human metabolism and health. Metabolomics is a promising tool for clinical, genetic and nutritional studies. A key question is to what extent metabolomic profiles reflect nutritional patterns in an epidemiological setting. We assessed the relationship between metabolomic profiles and nutritional intake in women from a large cross-sectional community study. Food frequency questionnaires (FFQs) were applied to 1,003 women from the TwinsUK cohort with targeted metabolomic analyses of serum samples using the Biocrates Absolute-IDQ (TM) Kit p150 (163 metabolites). We analyzed seven nutritional parameters: coffee intake, garlic intake and nutritional scores derived from the FFQs summarizing fruit and vegetable intake, alcohol intake, meat intake, hypo-caloric dieting and a traditional English diet. We studied the correlation between metabolite levels and dietary intake patterns in the larger population and identified for each trait between 14 and 20 independent monozygotic twins pairs discordant for nutritional intake and replicated results in this set. Results from both analyses were then meta-analyzed. For the metabolites associated with nutritional patterns, we calculated heritability using structural equation modelling. 42 metabolite nutrient intake associations were statistically significant in the discovery samples (Bonferroni P < 4 x 10(-5)) and 11 metabolite nutrient intake associations remained significant after validation. We found the strongest associations for fruit and vegetables intake and a glycerophospholipid (Phosphatidylcholine diacyl C38:6, P = 1.39 x 10(-9)) and a sphingolipid (Sphingomyeline C26:1, P = 6.95 x 10(-13)). We also found significant associations for coffee (confirming a previous association with C10 reported in an independent study), garlic intake and hypo-caloric dieting. Using the twin study design we find that two thirds the metabolites associated with nutritional patterns have a significant genetic contribution, and the remaining third are solely environmentally determined. Our data confirm the value of metabolomic studies for nutritional epidemiologic research.
BACKGROUND CONTEXT: Sitting spinal alignment is increasingly recognized as a factor influencing strategy for deformity correction. Considering that most individuals sit for longer hours in a slumped rather than in an erect posture, greater understanding of the natural sitting posture is warranted. PURPOSE: This study aimed to investigate the differences in sagittal spinal alignment between two common sitting postures: a natural, patient-preferred posture; and an erect, investigator-controlled posture that is commonly used in alignment studies. DESIGN/SETTING: This is a randomized, prospective study of 28 young, healthy patients seen in a tertiary hospital over a 6-month period. PATIENT SAMPLE: Twenty-eight patients (24 men, 4 women), with a mean age of 24 years (range 19-38), were recruited for this study. All patients with first episode of lower back pain of less than 3 months' duration were included. The exclusion criteria consisted of previous spinal surgery, radicular symptoms, red flag symptoms, previous spinal trauma, obvious spinal deformity on forward bending test, significant personal or family history of malignancy, and current pregnancy. OUTCOME MEASURES: Radiographic measurements included sagittal vertical axis (SVA), lumbar lordosis (LL), thoracolumbar angle (TL), thoracic kyphosis (TK), and cervical lordosis (CL). Standard spinopelvic parameters (pelvic incidence, pelvic tilt [PT], and sacral slope) and sagittal apex and end vertebrae were also measured. METHODS: Basic patient demographics (age, gender, ethnicity) were recorded. Lateral sitting whole spine radiographs were obtained using a slot scanner in the imposed erect and the natural sitting posture. Statistical analyses of the radiographical parameters were performed comparing the two sitting postures using chi-squared tests for categorical variables and paired t tests for continuous variables. RESULTS: There was forward SVA shift between the two sitting postures by a mean of 2.9 cm (p<.001). There was a significant increase in CL by a mean of 11.62 degrees (p<.001), and TL kyphosis by a mean of 11.48 degrees (p<.001), as well as a loss of LL by a mean of 21.26 degrees (p<.001). The mean PT increased by 17.68 degrees (p<.001). The entire thoracic and lumbar spine has the tendency to form a single C-shaped curve with the apex moving to L1 (p=.002) vertebra in the majority of patients. CONCLUSIONS: In a natural sitting posture, the lumbar spine becomes kyphotic and contributes to a single C-shaped sagittal profile comprising the thoracic and the lumbar spine. This is associated with an increase in CL and PT, as well as a constant SVA. These findings lend insight into the body's natural way of energy conservation using the posterior ligamentous tension band while achieving sitting spinal sagittal balance. It also provides information on one of the possible causes of proximal junctional kyphosis or proximal junctional failure. (C) 2016 Elsevier Inc. All rights reserved.
Pooling designs are fundamental tools in many applications such as biotechnology and network security. Many famous pooling designs have been constructed from mathematical structures by containing relations. Recently, pooling designs constructed by intersecting relation have been proposed by Guo and Wang (2011). Constructing by intersecting relation provides much better error-tolerance capabilities. We study the error-tolerance capabilities of pooling designs constructed by intersecting relation from combinatorial structures proposed by D'yachkov et al. (2007) and Lv et al. (2014). (C) 2015 Elsevier B.V. All rights reserved.
Drug delivery systems (DDS) are based on the concept of providing the optimal amount of a drug to a specific area requiring treatment. Liposomes are lipid-based nanoparticles capable of encapsulating any drug into both their membrane and aqueous phases. They have the potential to be targeted when their surfaces are modified with functional molecules such as antibodies and peptides. Thus, liposomes have strong potential as drug carriers if designed for active targeting. Our research group has recently developed a new concept for liposome targeting called reverse targeting DDS (RT-DDS). RT-DDS differs from conventional active targeting in that the surface of the liposomes is modified with an antigenic molecule that is specifically recognized by antigen-specific immune cells. This review describes in detail the differences between these two DDS targeting concepts and proposes the application of RT-DDS to the treatment of allergies based on research using ovalbumin as a model allergy antigen.
This paper presents the results of a brushless permanent magnet (PM) starter-generator design, which caters for low-cost manufacture and a highly constrained mechanical space envelope. The starter-generator design addresses the low-cost requirement through the use of aluminium winding conductors and ferrite PM. This presents several challenges which include, but are not limited to, the selection of an appropriate machine topology to realise a high specific output with the lower performance materials, minimizing the power losses associated with the higher resistivity of aluminium, and the enhancement of thermal performance. The problem is further exacerbated by the demanding space envelope, operating requirements, and the necessity of design for manufacture. The selection of an appropriate machine topology is paramount in the present application as the limited mechanical space-envelope results in a pancake like geometry in which the aspect ratio of the stator outer diameter to the machine active length is high. To provide a solution satisfying all these challenging design requirements, an approach combining the theoretical electromagnetic and thermal analyses together with tests on machine subassemblies has been employed here. Such a method allows for a more informed design process, where the manufacture and assembly nuances affecting the starter-generator's performance are identified and accounted for prior to prototyping of the complete machine assembly. This paper discusses the employed design methodology in detail. A number of machine designs with alternative winding constructions have been considered providing an insight into challenges and limitations for the cost- effective winding construction utilizing aluminium conductors. The results from analysis of the starter generator suggest that the proposed machine design is capable of achieving the design requirements for both continuous and transient operating modes.
Temporary anaesthesia or analgosedation used for awake craniotomies carry substantial risks like hemodynamic instabilities, airway obstruction, hypoventilation, nausea and vomiting, agitation, and interference with test performances. We tested the actual need for sedatives and opioids in 50 patients undergoing awake craniotomy for brain tumour resection in eloquent or motoric brain areas when cranial nerve blocks, permanent presence of a contact person, and therapeutic communication are provided. Therapeutic communication was based on the assumption that patients in such an extreme medical situation enter a natural trance-like state with elevated suggestibility. The anaesthesiologist acted as a continuous guide, using a strong rapport, nonverbal communication, hypnotic suggestions, such as dissociation to a safe place, and the reframing of disturbing noises, while simultaneously avoiding negative suggestions. Analgesics or sedatives were at hand according to the principle as much as necessary, but not more than needed. No sedation was necessary for any of the patients besides for the treatment of seizures. Only two-thirds of the patients requested remifentanil, with a mean dosage of 96 mu g before the end of tumour resection and a total of 156 mu g. Hemodynamic reactions indicative of stress were mainly seen during nerve blockades and neurological testing. Postoperative vigilance tests showed equal or higher scores than preoperative tests. The main challenges for patients undergoing awake craniotomies include anxiety and fears, terrifying noises and surroundings, immobility, loss of control, and the feeling of helplessness and being left alone. In such situations, psychological support might be more helpful than the pharmacological approach. With adequate therapeutic communication, patients do not require any sedation and no or only low-dose opioid treatment during awake craniotomies, leaving patients fully awake and competent during the entire surgical procedure without stress. This approach can be termed awake-awake-awake-technique.