Stop Characteristics Research Articles

A real-time signal control strategy for mitigating the impact of bus stops at urban signalized intersections

ABSTRACTBuses stopping at transit stops reduce the capacity of signalized intersections, which can lead to excessive delays for all users. In order to avoid such phenomena, signal control strategies can be utilized. This article presents a real-time signal control strategy to mitigate the impact of bus stop operations on traffic operations along an undersaturated approach. The objective of the proposed strategy is to ensure that any residual queues due to a bus stopping are fully dissipated as soon as possible by increasing the green time for the bus stop approach as soon as the bus departs. In addition, this strategy ensures that the cross-street approaches do not become oversaturated. Kinematic wave theory is utilized to track the formation and dissipation of queues and determine the green extension (or red truncation) for the subject approach. The benefits achieved from the proposed strategy are illustrated through simulation tests at a single intersection for a variety of bus stop and bus operation characteristics. Average delay and average queue length for the bus stop and cross-street approaches, as well as for the whole intersection, are used to assess the performance of the strategy. The tests performed indicate that the signal control strategy can achieve substantial reductions in delay for the bus stop approaches and the intersection as a whole without adversely affecting the cross street operations, when the demand at those cross streets is low.

Voice onset time of alveolar stop /t/ and realization of unaspirated affricates associated with Mandarin-speaking children with repaired cleft palate

PurposeTo examine perceptually the realization of unaspirated affricates and voice onset time (VOT) features of /t/ in Mandarin-speaking children with repaired cleft palate, and to explore the difficulties associated with unaspirated affricate production from the perspective of the VOT of /t/. MethodTwenty-three children with repaired cleft palate and 22 age-matched typical native Mandarin speakers were recruited. Speakers with cleft palate were allocated into two groups based on expert perceptual judgment of nasality: one group with perceived normal resonance (PNR) (n = 14, average age = 9.3 years), and another group with perceived hypernasal resonance (PHR) (n = 9, average age = 10.3 years). InterventionStimuli were collected through a series of picture naming tasks, targeting the production of initial consonants /t/ and three unaspirated Mandarin affricates /ts, tʂ, tɕ/. The productions of each affricate were evaluated by two experienced speech therapists. The VOT of /t/ was measured using PRAAT speech analysis software. ResultThe majority of unaspirated affricates were omitted and/or weakly realized by the group of PHR speakers, but not for the PNR group. A significantly smaller mean VOT value associated with /t/ was identified for the PHR group, as compared to the PNR group. A group difference for VOT value was not found between the PNR group and the typical control group. ConclusionThe voicing features of /t/ and omitted/weak realization of unaspirated affricates identified in the PHR group indicated that the deviant production of unaspirated affricates in the cleft palate group could be associated with the voicing characteristics of the alveolar stop /t/, and this merits further investigation.

Study of harmonic suppression using defected ground structure for OSRR antenna

In this study, a co-planar waveguide (CPW) fed open split ring resonator (OSRR) antenna with defected ground structure (DGS) is proposed to achieve harmonics suppression. The proposed antenna consists of OSRR structure and two modified F-shaped DGS (MFDGS), which is responsible for miniaturization and wide-band stop characteristics respectively. From the results of measured reflection coefficient, we observe that the proposed antenna structure is able to suppress higher frequencies between 3 GHz and 8 GHz. Particularly in the second frequency, suppression is attained up to 19 dB. Further analysis shows, the peak gain and radiation pattern of proposed structure is suppressed up to 20 and 30 dB respectively at second harmonic frequency. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1353–1358, 2016

Frequency and time domain analysis of a novel UWB antenna with dual band-notched characteristics

This paper presents the dual band notch characteristics of Ultra wideband (UWB) monopole antenna. Proposed antenna (30 × 30 mm2) consists of arrow shaped patch and truncated ground plane. Operating range of the proposed antenna (voltage standing wave ratio < 2) is 2.2–11 GHz. In order to achieve dual band stop characteristics, λ/2 open ended angularly separated slit pair has been inserted on the radiator for world interoperability for microwave access (WIMAX) (3.3–3.9 GHz) band rejection performance and wireless local area network (WLAN) (5.1–5.9 GHz) band rejection has been realized by introducing a pair of angularly separated λ/2 conductor backed plane (CBP). Using proper adjustment of angular separation for both slit pair and CBP pair, enhanced band rejection can be achieved for the WIMAX and WLAN band, respectively. The performance of antenna has been investigated in terms of frequency domain and time domain to assess its suitability in UWB communication.

Measuring Bus Stops toward a Sustainable Urban Environment

This paper describes how a bus stop measuring system can be developed not only to achieve transit operation efficiency but also to collaborate proactively with urban planners and traffic engineers on transit–land use interface activities. The measuring system was developed by identifying transit performance variants at the bus stop level with the use of a dynamic composite weighting factor approach on a geographic information system platform. A tier structure framework was used to categorize the composite scores of bus stops into six groups. Specific transit improvement actions were then tailored on the basis of their bus stop characteristics. Two project application examples are presented in this paper. One is a bus stop thinning project for speed improvement, and the other is for prioritizing capital project improvements. As various active transportation programs emerge to encourage local jurisdictions to plan transit connectivity with other community gathering places, this bus stop measuring approach presents a con tinued process to monitor their performance. It is also used to strengthen integration with other street improvement activities, including pedestrian paths and bikeways, to create a safe and sustainable urban environment.

Coplanar waveguide fed 9‐point star shape monopole antennas for worldwide interoperability for microwave access and wireless local area network applications

In this Letter, a coplanar waveguide fed monopole antenna with a band stop characteristic is proposed for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) applications. The antenna has a small size of 30 × 45 mm2. The antenna consists of a 9-point star radiating patch. The band rejection characteristic is realised by introducing a pair of L-shaped slots in the ground plane. The prototype and proposed antennas have been constructed and experimentally studied. The measured return loss shows a reasonable agreement with the simulated one. Impedance and radiation characteristics of the antenna are studied. It is found that the results are suitable for 3.05–3.84 GHz WiMAX and 5.15–5.825 GHz WLAN applications. The antenna exhibits omni-directional radiation pattern and appreciable gain across the operating bands. It is suitable for portable wireless communication systems.

High-Voltage Three-Phase Asynchronous Motor Soft-Starter via Hyristor for Water Cooling System of Steel Mill

This article introduces a high-voltage three-phase asynchronous motor soft-starter via thyristor that is suitable for water cooling system of steel mill. It improves motor start and stop characteristics, effectively eliminates water-hammer" effect caused by traditional direct start and stop, and is making more and more important positive impacts in the water cooling system of steel mill.

DUAL-BAND FILTER FOR WIMAX AND WLAN WITH IMPROVED UPPER STOP BAND PERFORMANCE

In this paper, a novel and compact dual-band fllter with enhanced upper stop characteristics has been presented. Dual band pass fllter characteristics are achieved by introducing transmission zero (TZ) in pass band of band pass fllter (BPF). The wide band pass fllter (BPF) is implemented by combining low pass fllter characteristics (i.e., stepped impedance resonator) and high pass fllter characteristics (i.e., short stubs). Closed rectangular ring resonator (CRRR) and open loop rectangular ring (OLRR) combination is used to produce two transmission zeros (TZs). One TZ is placed on the pass band of BPF such that resultant fllter characteristic consists of two pass band. However, the second TZ is placed at edge of the pass band in BPF to improve skirt selectivity. The two pass bands are designed to cover two popular wireless bands namely WiMAX (center frequency f1 (3.5GHz) and WLAN (center frequency f2 (5.7GHz)) bands, i.e., 3.35{3.65GHz and 5.5{5.85GHz respectively. Equi-ripple low pass stepped impedance resonator (SIR) fllter response is responsible for improved and spurious free upper stop band (> 20GHz, i.e., > 6f1) and also provides sharp skirt attenuation at upper stop band. The proposed fllter is implemented on an RT/Duroid 5880 (r = 2:2) substrate with thickness of 0.785mm and surface area of 19 £ 12sq ¢ mm. Good agreement between simulated and measured results ensures that the proposed fllter is a suitable candidate for modern dual band communications.

Evaluation of bus emissions generated near bus stops

The purpose of this research is to demonstrate a methodology for quantification of bus emissions generated near bus stops based on the real-world on-road emissions data collected by the Portable Emission Measurement System (PEMS). Data collection was carried out on an urban diesel bus throughout a bus line under normal operation condition on four work days. Stop influence zone is defined as the area in which the normal bus driving is interrupted by bus stops. The second-by-second data were screened out within the stop influence zone. And the bus running state near a stop was classified into three driving modes, deceleration, idling, and acceleration. Then emission characteristics were analyzed for each mode. Under the idling condition, the emission rates (g s−1) were not constant all the time. The NOX emission rate decreased in the first 4–6 s while the corresponding emission rates of CO2, CO, NOX, and HC increased in the last 4 s of idling. Besides, the influence of bus stop characteristics on emissions was investigated using statistical methods. Platform type, length and location of bus stops showed significant effects on the length of the stop influence zone. However, there were no significant effects on distance-based emission factors.

Bus stops and pedestrian–motor vehicle collisions in Lima, Peru: a matched case–control study

ObjectiveTo evaluate the relationship between bus stop characteristics and pedestrian–motor vehicle collisions.MethodsThis was a matched case–control study where the units of study were pedestrian crossings in Lima, Peru. We performed...

Compact thin ground plane UWB antenna with dual band stop characteristics

AbstractA compact coplanar waveguide (CPW)‐fed convex hexagonal‐shaped ultrawide band (UWB) antenna, with L‐shaped thin ground plane for lower frequency band stop function and tapered rectangular vertical slot in radiating patch for upper frequency band stop is presented. The proposed antenna of dimension 40 × 22 × 1.6 mm3 provides good impedance matching over dual operational UWB resonating at 5.4 and 9.6 GHz with fractional bandwidth 69.54 and 33.83%, respectively. The lower frequency stop band in the vicinity of 2.4 GHz and higher frequency stop band in the vicinity of 7 GHz has bandwidth of 3.17 and 1.8 GHz, respectively, to avoid the interference of PCS, GSM 800/1900, ISM, WLAN, and X‐band satellite uplink (7.25–7.75 GHz) and downlink (7.9–8.4 GHz) communication system. The E‐plane radiation pattern observed is bidirectional in nature due to CPW feed and that of the H‐plane pattern is omnidirectional. The resonating lower and higher UWB achieves the peak gain 2.16 and 6.5 dBi, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1045–1049, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27470

Prediction of impulsive vehicle tyre-suspension response to abusive drive-over-kerb manoeuvres

This article presents a minimal parameter vehicle simulation model to predict the vertical suspension loads expected during abusive driving manoeuvres, such as a kerb strike event. Impulsive suspension loads are applied to tyre and suspension elements under such conditions. In particular, the aim is to specifically study the reactions of jounce bumper–rebound stop and tyre characteristics. For this purpose, a vehicle in-plane pitch dynamics model with 7 degrees of freedom suffices. Non-linear and hysteretic characteristics of the bump-stop elements are included through a new parametric map concept, based on displacement and velocity-dependent hysteresis. Furthermore, a static tyre model is described, tailored to predict the radial stiffness against penetration of an edge with a flat-type rigid body geometry. The tyre model is derived on the basis of classical membrane theory and represented in terms of only a few input parameters. Model validation is supported through experiments at both component and system levels.

光ファイバケーブル(<メカライフ特集>起のものづくり)

Provided is an optical fiber cable which is configured by having a sheath that houses a core assembly of optical fibers, wherein a prescribed water stop characteristic can be achieved while satisfying a sufficient mechanical characteristic. The optical fiber cable is provided with: a core assembly (1) comprising a plurality of optical fibers (11) and water stop threads (12); a tape body (2) that covers the core assembly (1); and a cylindrical sheath (5) that covers the core assembly (1) and the tape body (2). The tape body (2) is permeable, so that when water enters inside the tape body (2) the water stop threads (12) dissolve and the dissolved water stop material flows inside the sheath (5).

Transient response model of standing wave piezoelectric linear ultrasonic motor

A transient response model for describing the starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor was presented. Based on the contact dynamic model, the kinetic equation of the motor was derived. The starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor according to different loads, contact stiffness and inertia mass were described and analyzed, respectively. To validate the transient response model, a standing wave piezoelectric linear ultrasonic motor based on in-plane modes was used to carry out the simulation and experimental study. The corresponding results showed that the simulation of the motor performances based on the proposed model agreed well with the experimental results. This model will helpful to improve the stepping characteristics and the control flexibility of the standing wave piezoelectric linear ultrasonic motor.

PIN 다이오드를 이용한 대역 통과 여파 특성을 갖는 리미터 설계 및 실험

본 논문에서는 레이다 시스템의 수신단의 도파관 리미터와 대역 통과 여파기를 하나의 소자로 구현하는 방법을 제시하고자 한다. 먼저 대역 통과 여파 특성을 갖는 아이리스 구조를 제안하고 PIN 다이오드를 연결하여 도파관에 입사되는 전력의 크기에 따른 PIN 다이오드 바이어스 동작 특성에 따라서 각각 여파기와 리미터로 동작하는 구조를 설계하였다. 제작된 구조는 낮은 전력의 마이크로파가 입사하는 경우, 10 GHz에서 -0.7 dB의 삽입 손실을 갖는 통과 대역을 형성하는 여파기로, 높은 전력의 마이크로파가 입사하는 경우 대략 25 dB의 분리도를 갖는 리미터로 동작한다. In this paper, the method of design of the waveguide band-pass filter and limiter in radar system is proposed. First, we design a self-resonant iris, which can behave as a band-pass filter by mounting the PIN diode on the iris. When low power microwave is incident on the proposed element, the element behaves as a band-pass filter. Under a high power microwave condition, however, the element behaves as a limiter having wide band stop characteristics. The fabricated element has a pass band with -0.7 dB insertion loss at 10 GHz under the low power condition and isolation about 25 dB under the high power condition.

FDTD ANALYSIS OF THE DISPERSION CHARACTERISTICS OF THE METAL PBG STRUCTURES

Two dimensional metallic photonic band gap (PBG) structures, which have higher power handling capability, have been analyzed for their dispersion characteristics. The analysis has been performed using flnite difierence time domain (FDTD) method based on the regular orthogonal Yee's cell. A simplifled unit cell of triangular lattice PBG structure has been considered for the TE and TM modes of propagation. The EM fleld equations in the standard central-difierence form have been taken in FDTD method. Bloch's periodic boundary conditions have been used by translating the boundary conditions along the direction of periodicity. For the source excitation, a wideband Gaussian pulse has been used to excite the possible modes in the computational domain. Fourier transform of the probed temporal flelds has been calculated which provides the frequency spectrum for a set of wave vectors. The determination of eigenfrequencies from the peaks location in the frequency spectrum has been described. This yields the dispersion diagram which describes the stop and pass bands characteristics. Efiort has been made to describe the estimation of defect bands introduced in the PBG structures. Further, the present orthogonal FDTD results obtained have been compared with those obtained by a more involved non-orthogonal FDTD method. The universal global band gap diagrams for the considered metal PBG structure have been obtained by varying the ratio of rod radius to lattice constant for both polarizations and are found identical with those obtained by other reported methods. Convergence of the analysis has been studied to establish the reliability of the method. Usefulness of these plots in designing the devices using 2-D metal PBG structure has also been illustrated.

The Discretion to Search

Understanding police decision making has been a priority for policing scholars since the middle part of the 20th century. Recent emphasis has focused on examining the decision to search drivers and vehicles during pedestrian and traffic stops. The current study contributes to this body of literature by testing a series of hypotheses based on Skolnick’s notion of “symbolic assailants” and Smith and Alpert’s social conditioning model. Using data gathered from a large, Midwestern municipal jurisdiction over an 8-month period during 2005 and 2006, we estimate a series of hierarchical models to assess the relationship between discretionary searches and driver, vehicle, stop, and officer characteristics. Results indicate that specific driver groups including young, Black males are more likely to be searched for discretionary reasons. This relationship is further conditioned by officer assignment. Policy implications and suggestions for future research are also discussed.

Explaining Leniency

Scholars have devoted significant attention to measuring the degree to which a driver’s personal characteristics affect police decisions to stop and sanction motorists. Following the pattern of research on gender and enforcement practices more broadly, traffic stop studies show that female drivers are less likely to receive formal sanctions such as a citation following routine traffic stops. Despite the consistency of these findings across places and times, we know little about the conditions under which female traffic violators are granted leniency. This article extends research on the effect of driver and stop characteristics on gender disparities in traffic enforcement decisions by examining 149,888 stops from across 37 communities in Rhode Island with different local needs and variation in police organizational culture and structure. The findings confirm that although women are less likely to be cited than men, community-level variation in police agency culture and structure, particularly the proportion of female officers in an agency, moderates the effect of driver sex on stop outcomes.

전동기 일체형 편로드 유압액추에이터의 기동 및 정지특성해석

전동기 일체형 유압액추에이터(EHA)는 전기모터와 직결되어 구동되는 유압펌프를 이용하여 유압 피스톤의 변위나 속도를 제어할 수 있도록 모듈화된 유압기기로 효율이 높고 독립된 동력원을 갖는 장점으로 인하여 항공기의 전자구동시스템에 적용되어 왔다. 최근에는 다양한 형태의 유압시스템이 적용되고 있는 건설중장비 분야에서 엔진과 전기모터를 결합한 하이브리드 기술이 개발됨에 따라 EHA의 활용범위가 확대될 것으로 예상된다. 본 연구에서는 편로드 유압실린더를 갖는 EHA가 적용된 유압시스템을 대상으로 펌프작동에 따른 유압실린더의 기동 및 정지특성을 고찰하기 위하여 EHA 내부 유압회로의 기능을 파악하고 동특성 모델을 유도하였으며 파일럿작동 체크밸브의 크래킹압력을 분석하여 개방 및 폐쇄특성을 예측하였으며 시뮬레이션을 통하여 분석된 결과를 검증하였다.

Characteristics of stop releases in American English spontaneous speech

This study examines the factors affecting the production of stop releases in American English spontaneous speech. Previous research has shown that releases are conditioned by phonetic and social factors. However, previous studies either rely exclusively on read speech, or for sociolinguistic studies, focus on phrase-final stops. In this study, spontaneous speech is collected from two sources: interviews from the non-profit StoryCorps project and from sentences spontaneously generated in a picture description task. Stop releases were examined before obstruents and nasals in word-medial position (e.g. ru gb y), word-final, phrase-medial position (e.g. They cra ck n uts), and pre-pausally (e.g. I look u p ). Phonetic factors taken into account include identity of the stop, directionality of place of articulation in the consonant cluster (front-to-back vs. back-to-front) and manner of C2. For the StoryCorps data, race of the speaker was also found to be an important predictor. Results showed that approximately a quarter of the stops followed by a consonant were released, but release was strongly affected by the place of the stop and the manner of the following consonant. Release of pre-pausal stops differed between black and white speakers; the latter had double the amount of final release. Other realizations of the stops, such as deletion, lenition, and glottalization are also analyzed.