235 research outputs found
Network Saturation: Key Indicator for Profitability and Sensitivity Analyses of PRT and GRT Systems
No full textPersonal Rapid Transit (PRT) and Group Rapid Transit (GRT) are classes of fully automated public transport systems, where passengers can travel in small vehicles on an interconnected, grade-separated network of guideways, non-stop, from origin to destination. PRT and GRT are considered sustainable as they are low-emission and able to attract car drivers. The parameterized cost modeling framework developed in this paper has the advantage that profitability of different PRT/GRT systems can be rapidly verified in a transparent way and in function of a variety of relevant system parameters. This framework may contribute to a more transparent, rapid, and low-cost evaluation of PRT/GRT schemes for planning and decision-making purposes. The main innovation is the introduction of the “peak hour network saturation” S: the number of vehicles in circulation during peak hour divided by the maximum number of vehicles running at line speed with minimum time headways. It is an index that aggregates the main uncertainties in the planning process, namely the demand level relative to the supply level. Furthermore, a maximum S can be estimated for a PRT/GRT project, even without a detailed demand estimation. The profit per trip is analytically derived based on S and a series of more certain parameters, such as fares, capital and maintenance costs, daily demand curve, empty vehicle share, and physical properties of the system. To demonstrate the ability of the framework to analyze profitability in function of various parameters, we apply the methods to a single vehicle PRT, a platooned PRT, and a mixed PRT/GRT. The results show that PRT services with trip length proportional fares could be profitable already for S>0.25. The PRT capacity, profitability, and robustness to tripled infrastructure costs can be increased by vehicle platooning or GRT service during peak hours
TAMBUS: A novel authentication method through covert channels for securing industrial networks
No full textNowadays, many companies still use old and insecure protocols in Industrial Control Systems (ICSs). An example of such protocols is Modbus, one of the most employed industrial protocols. Also, companies are moving to Modbus/TCP when there are TCP devices involved in the facility. While remaining insecure, this migration also disrupts the assumption of air-gapped industrial networks, opening more attack surface to previously isolated systems. Due to legacy and efficiency constraint, the replacement of Modbus/TCP with secure protocols is not possible, generating big security issues. In this paper, we present TAMBUS (Transmitter Authentication and packet integrity in Modbus/TCP). This method is the first that at the same time: is not implemented in a secure by obscurity design and keeps the Modbus/TCP protocol compatible with legacy devices. TAMBUS allows detecting attacks with high statistical confidence, by leveraging two covert channels as a mean of providing security: 1) Storage-based, that hides authentication messages into the Modbus/TCP protocol fields; 2) Timing-based, that considers the inter-arrival time of packets. We demonstrate the feasibility and effectiveness of our method through a prototype implementation and testing in an industrial testbed environment. Our experiments confirm that TAMBUS introduces only a small overhead, negligible in most application, and it preserves the regular functioning of industrial systems. In particular, considering the storage-based covert channel, TAMBUS introduces an error into transmitted values of only 1.19×10−5%, without traffic overhead. On the other hand, TAMBUS can transmit correct security information through the timing-based covert channel with an accuracy of more than 99.99%
DOUBLE-ELECTRON EXCITATION AT THE Si K-EDGE OF AMORPHOUS SILICON
No full textIn this paper we report the experimental evidence of a double-electron excitation involving two deep core states in the X-ray absorption coefficient of a solid amorphous system. For the first time a fine structure (EXAFS) in a double-electron excitation cross section has been identified. Such feature has unambiguously allowed us to assign the dominant excitation channel to a (1s,2p) → (3p,ϵp) shake-up transition
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We Can’t Compare Apples to Oranges: Establishing Validity Between Drastically Different Emotional Intelligence Tests
No full textAutism and alexithymia are two disorders characterized by deficiencies in interpersonal and emotional processing. For example, both of these disorders are associated with deficits in the ability to identify and judge the emotions of others. For diagnosis, patients are typically assessed for such deficiencies using published tests of emotion perception (e.g., the DANVA-2, the MSCEIT, the PONS) that require one to assess the emotion being displayed by a target person in a photograph or brief film clip. These tests are well known and used often, but it is rare for researchers or clinicians to ever give more than one of them to an individual. Although all three look like they are assessing the same skill, a systematic study of their agreement to show convergent validity has yet to be undertaken. The purpose of this study is to cross validate three measures of emotion perception ability. High correlations between these tests will increase the confidence researchers and clinicians will have in their validity to assess one’s skill in emotion perception and validate current diagnostic procedures for detecting disorders of interpersonal and emotional processing (e.g., autism or alexithymia).
This study had 189 undergraduate psychology students take the PONS, DANVA-2, and MSCEIT. The PONS features video clips of various facial, body and voice expressions, where participants identify the emotional context. The DANVA-2 features face and body pictures, as well as voice clips, where participants identify what emotion is expressed. The MSCEIT features face and environmental pictures for emotional quantification by participants.
As expected, all three tests of emotion processing skill correlated significantly with each other, thus providing evidence of their general validity. However, an unexpected result was observed as subscales that were most comparable in content (e.g., “reading faces for emotion”) did not show the strongest level of agreement with each other. Specifically, none of three tests subscale for perceiving emotional expressions in faces correlated significantly despite being the subtest that looked the most familiar across tests. This implies each test may be assessing different aspects of emotion processing that have not been recognized by researchers or even the test creators. Until the convergent validity for the subscales of these three tests can be established, the DANVA-2, MSCEIT, and PONS should not be considered interchangeable. They may be diagnosing aspects of emotional intelligence relevant to disorders such as autism or alexithymia, but they are not assessing the same exact thing
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We Can’t Compare Apples to Oranges: Establishing Validity Between Drastically Different Emotional Intelligence Tests
No full textAutism and Alexithymia are two disorders characterized by deficiencies in interpersonal and emotional processing. For example, both of these disorders are associated with deficits in the ability to identify and judge the emotions of others. For diagnosis, patients are typically assessed for such deficiencies using published tests of emotion perception (e.g., the DANVA-2, the MSCEIT, the PONS) that require one to assess the emotion being displayed by a target person in a photograph or brief film clip. These tests are well known and used often, but it is rare for researchers or clinicians to ever give more than one of them to an individual. Although all three look like they are assessing the same skill, a systematic study of their agreement to show convergent validity has yet to be undertaken. The purpose of this study is to cross validate three measures of emotion perception ability. High correlations between these tests will increase the confidence researchers and clinicians will have in their validity to assess one’s skill in emotion perception and validate current diagnostic procedures for detecting disorders of interpersonal and emotional processing (e.g., autism or alexithymia).
This study had 189 undergraduate psychology students take the PONS, DANVA-2, and MSCEIT. The PONS features video clips of various facial, body and voice expressions, where participants identify the emotional context. The DANVA-2 features face and body pictures, as well as voice clips, where participants identify what emotion is expressed. The MSCEIT features face and environmental pictures for emotional quantification by participants.
As expected, all three tests of emotion processing skill correlated significantly with each other, thus providing evidence of their general validity. However, an unexpected result was observed as subscales that were most comparable in content (e.g., “reading faces for emotion”) did not show the strongest level of agreement with each other. Specifically, none of three tests subscale for perceiving emotional expressions in faces correlated significantly despite being the subtest that looked the most familiar across tests. This implies each test may be assessing different aspects of emotion processing that have not been recognized by researchers or even the test creators. Until the convergent validity for the subscales of these three tests can be established, the DANVA-2, MSCEIT, and PONS should not be considered interchangeable. They may be diagnosing aspects of emotional intelligence relevant to disorders such as Autism or Alexithymia, but they are not assessing the same exact thing
A test bed for in-laboratory calibration of optical-based speedometers
No full textNon-contact optical-based speedometers are widely used for many kinds of applications, ranging from vehicle driving dynamics tests to train speed measurements. The accuracy of these measuring instruments is maintained if they are periodically checked and calibrated according to the ISO 17025 standard. Nowadays, they are calibrated on tracks, mounting them on a vehicle, and comparing the speed measured by the device under calibration with that provided by a reference instrument. Even if this approach is valid, it is expensive, especially if very high speeds must be tested. Furthermore, the safety of the driver and technicians involved in the calibration process represents a non-negligible cost. Trying to overcome these limits, this paper proposes a novel test-bed for in-laboratory calibration of the optical-based speedometers even at very high speeds. The experimental results, reported in this paper, confirm the goodness of this proposal
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