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Queue Storage Design for Metered On-Ramps

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International Journal of Transportation Science and Technology 2013年第1期2卷 47-63页

作者： Zhongren Wang division of traffic operations California Department of Transportation1120 N StreetMS-36SacramentoCA 95814

Queue storage at a metered freeway on-ramp is an essential design element for metered on-ramps to prevent on-ramp queue from extending beyond *** this paper,various existing methodologies that are used to size the queue storage at metered on-ramps were first *** was found that queue storage sized using 7%of peak hour on-ramp demand is widely accepted in practice.A limited dataset collected in California helps provide some reality check for this *** is recommended that queue storage be recognized as an indispensable design element at metered on-ramps,and detailed sizing guidance be developed in the highway geometric design policy of the American Association of State Highway and Transportation Officials(AASHTO).

关键词： On-Ramp Design Queue Storage Design Ramp Metering

An Evaluation of Ramp Control Signal Head Placement Based on Motorist’s Cone of Visions

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International Journal of Transportation Science and Technology 2014年第3期3卷 265-276页

作者： Zhongren Wang Hiep Nguyen division of traffic operations California Department of Transportation1120 N StreetMS-36SacramentoCA 95814

Roadside mounted ramp control signals have one upper head,and one lower head in *** upper head is intended for use by the approaching motorists,while the lower one for use by the stopped *** have been received regarding the visibility of these signal *** evaluation presented in this paper is to mathematically analyze the visibility of these signal heads on a tangent roadway alignment based on satisfactory motorists’cones of *** design,signal placement,and driver characteristics are integrated into one analytic *** results indicated that the horizontal satisfactory cone of vision controls the placement *** meet the 20 degree satisfactory horizontal cone of vision as specified by the Manual on Uniform traffic Control Devices(MUTCD),a ramp control signal head has to be placed a minimum of 13.3 m downstream of the limit line.

关键词： mounted approaching specified

The Sight Distance Issues with Retrofitted Single-Lane HOV Facilities

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International Journal of Transportation Science and Technology 2013年第2期2卷 149-157页

作者： Zhongren Wang division of traffic operations California Department of Transportation 1120 N StreetMS-36SacramentoCA 95814

It is well-known that obstruction inside a highway horizontal curve will lead to impaired sight *** alignment design standards in terms of the minimum horizontal curve radius are specified to allow for adequate stopping sight distance at given design *** a singlelane HOV facility,inside curve obstruction may occur no matter when the facility curves to the left(per travel direction)or right.A unique situation that calls for special attention is that the adjacent mixed-flow lane traffic,once queued,may become sight *** indicated that such obstruction may govern the minimum curve radius design as long as the left shoulder is not less than 0.92 m,when the HOV lane is contiguous to the mixed-flow *** governance may necessitate design speed reduction,horizontal and cross-section design adjustment,or both.

关键词： HOV radius alignment

A Discussion on the Current MUTCD Standards on traffic Control Signals for Freeway Entrance Ramps

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International Journal of Transportation Science and Technology 2012年第1期1卷 73-82页

作者： Zhongren Wang Vinh Dang division of traffic operations California Department of Transportation1120 N StreetMS-36SacramentoCA 95814 NW Region Freeway operations Washington Department of Transportation

In Section 4I.02 of the newly published Manual on Uniform traffic Control Devices(MUTCD),standards were specified for the placement of signal heads for traffic control signals at freeway entrance ramps,or ramp *** simultaneous operations,*** ramp control signals are operated such that green signal indications are always displayed simultaneously to all of the lanes on the ramp,a minimum of two signal faces per ramp shall face entering *** staggered operations,*** ramp control signal are operated such that green signal indications are not always displayed simultaneously to all of the lanes on the ramp,one signal face shall be provided over the approximate center of each separately-controlled *** on a nation-wide survey,it was realized that the two standards did not fully reflect the state-of-the-practice with respect to ramp metering *** to the lack of significant conflicting movements at ramp meters,for any on-ramp lane,a minimum of one overhead mounted,or one upper and one lower roadside-mounted signal face is sufficient to control the metering *** minimum necessary number of signal faces changes according to the total number of lanes,how the signal faces are mounted(overhead or roadside mounting),and how the meters are operated(simultaneous or staggered).Suggestions are made to revise the two standards to better reflect the current nation-wide practices,and better consider the specific operational needs for ramp meters.

关键词： Ramp Meter Signal Head Placement Standard operations

A Comparison of Floating Car *** Detector Estimated Freeway Travel Time Delay

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International Journal of Transportation Science and Technology 2012年第2期1卷 147-169页

作者： Zhongren Wang Senior Transportation Engineer Division of Traffic OperationsCalifornia Department of Transportation1120 N StreetMS-36SacramentoCA 95814

Floating car-and loop detector-based methods are two different types of methods frequently used to collect travel time delay information across a freeway ***,it is necessary to use them jointly to achieve the necessary freeway network coverage,due to the high labor costs for the floating car-based method and the indispensability of sufficient network instrumentation for the loop detector-based *** example,both floating car-and loop detector-based methods were once used in the Highway Congestion Monitoring Program in the California Department of *** is therefore necessary to evaluate whether these two types of methods estimate similarly in terms of total travel time *** this end,corresponding delay information estimated using both types of methods from 37 freeway segments in the Greater Sacramento Area were collected and *** was found that these two types of methods do not estimate similarly in terms of total segment travel time *** mean absolute relative difference(MARD)can be as high as 78%,especially when delay is defined using a lower reference speed,such as 56 km/***,in terms of total segment travel time,the loop detector and the modified floating car method estimated *** MARD is 19%.It was also found that the estimation from the different methods did correlate fairly well,which provides a means of conversion when different methods are used to monitor the total delay across a freeway *** a spin-off,it was also found that a 1.5 km spacing of loop detectors is sufficient to achieve the 19%MARD as compared with the modified floating car method in terms of total travel time estimation.

关键词： Freeway Travel Time Delay Floating Car Loop Detector Comparison spacing

FALSE FAILURE RETURNS： OPTIMAL PRICING AND RETURN POLICIES IN A DUAL-CHANNEL SUPPLY CHAIN

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Journal of Systems Science and Systems Engineering 2018年第3期27卷 292-321页

作者： Guojun Ji Shangqing Han Kim HuaTan School of Management Xiamen University 361005 Fujian China operations Management & Information Systems division Nottingham University Business School

This paper aim is to examine the optimal pricing and return policies for false failure returns in a dual-channel supply chain. Four prevailing return policies in which a manufacturer both operates an E-shop and sells its product through a brick-and-mortar retailer are analyzed, i.e. （I） the manufacturer handlings E-shop＇s returns, while the retailer addresses brick-and-mortar store＇s returns （NR）; （II） the retailer tackles the whole （both E-shop＇s and brick-and-mortar store＇s） returns （ORR）; （III） the manufacturer tackles the whole returns （ORM）; and （IV） the manufacturer and the retailer are jointly responsible for the whole returns （RRM）. Firstly, the optimal pricing and return policies comparing these four scenarios under uniform-pricing strategy are presented. Our conclusions show that the ORR is an optimal return policy. Compared with the NR, consumers will get a lower product pricing under the ORR and a higher product pricing under the ORM. With regard to the RRM, the product pricing is depended on consumer preference, return-rates of the E-shop and the brick-and-mortar store. Then, the optimal pricing and return policies are analyzed under differential-pricing strategy by conducting two-stage sequential games between the manufacturer and the retailer. The findings show that if consumers in the market prefer to purchase via the E-shop, the ORR is an optimal return policy. Otherwise, the NR is the optimal return policy. Compared with the NR, the ORR retailer＇s product pricing will rely on the retailer＇s and the manufacturer＇s return-costs; the RRM retailer＇s product pricing will depend on the return-costs of the retailer and the manufacturer, the return-rates of the E-shop and the brick-and-mortar store and so on. Finally, the influences of the manufacturer and the retailer establishing a Buy-back contract are discussed. Our results illustrated that the Buy-back contract doesn＇t affect optimal pricing and return policies under both the uniform and the differen

关键词： Dual-channel optimal return policy optimal pricing false failure returns game theory

Patient Feedback for Acupuncture Practice Improvement:A Survey from Mayo Clinic

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Chinese Journal of Integrative Medicine 2017年第11期23卷 816-821页

作者： Barbara S Thomley Saswati Mahapatra Brent A Bauer Molly J Mallory LI Guang-xi Alexander Do Tony Y Chon division of operations Mayo Clinic HospitalAZ(85054)United States Integrative Medicine and Health Division of General Internal MedicineMayo ClinicMN(55902)United States

Objective： To understand patient satisfaction with acupuncture appointment duration for the first and subsequent appointments in the plan of care, time spent with the acupuncture provider, willingness to pay for longer duration appointments, and lack of insurance coverage. Methods： Patients who were referred for an acupuncture consult to the Center for Integrative Medicine at Mayo Clinic were asked to participate in the survey in August 2014. Patients were given paper survey at time of appointment check-in and entered into Research Electronic Data Capture Survey database tool to reveal patient-reported outcomes. Results： In total, 104 of 329 patients receiving acupuncture treatment responded to the survey with a 32% response rate. Insight and recommended changes to the duration of the initial and subsequent appointments were obtained. Most patients reported that time spent with the provider（76 cases, 74%） and appointment length（74 cases, 68%） were ＂just right＂. Seventy cases（70%） of respondents indicated that they wanted longer treatment. Patients reported return appointments with duration of 30 min was not enough. Fifty-three patients（62%） were willing to pay for additional costs not covered by insurance. Conclusions： We used patient feedback to assess the acupuncture practice in a complementary and integrative medicine program. Most patients referred for the acupuncture consult appeared to be satisfied with the current level of practice. These findings were used to establish a quality improvement plan that may be implemented to improve patient satisfaction with the acupuncture practice.

关键词： care survey health integrative medicine acupuncture practice

Eight-week ledipasvir/sofosbuvir in non-cirrhotic, treatment-na?ve hepatitis C genotype-1 patients with hepatitis C virus-RNA < 6 million: Single center, real world effectiveness and safety

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World Journal of Gastroenterology 2017年第26期23卷 4759-4766页

作者： Nyan L Latt Beshoy T Yanny Derenik Gharibian Rita Gevorkyan Amandeep K Sahota division of Gastroenterology and Hepatology Mayo Clinic College of Medicine division of Gastro-enterology and Hepatology Kaiser Permanente Los Angeles Medical Center Pharmacy operations Office Kaiser Permanente Los Angeles Medical Center Department of Clinical operations Kaiser Permanente Southern California

AIM To evaluate sustained viral response(SVR) of 8-wk ledipasvir/sofosbuvir therapy among non-cirrhotic, genotype-1 hepatitis C virus(HCV) patients with RNA < 6 million IU/m *** We performed a retrospective cohort study to examine SVR rates, predictors of treatment failure and safety analysis of 8-wk ledipasvir/sofosbuvir(LDV/SOF) therapy among non-cirrhotic, genotype 1 HCV patients with viral load < 6 million IU/m L. Primary outcome was an achievement of SVR at 12 wk after treatment. Secondary outcomes were identifying predictors of treatment failure and adverse events during *** Total 736 patients: 55% males, 51% Caucasians and 65% were genotype 1a. Non-cirrhotic state of 53% was determined by clinical judgment(imaging, AST, platelet count) and 47% had documented liver fibrosis testing(biopsy, vibration-controlled transient elastography, serum biomarkers). Overall SVR12 was 96%. No difference in SVR12 was seen between patients whose non-cirrhotic state was determined by clinical judgment and patients who had fibrosis testing. Age groups, gender, ethnicity and genotype 1 subtype did not predict SVR. Non-cirrhotic state determined by clinical judgment based on simple, non-invasive tests were not associated with lower SVR [OR = 1.02, 95%CI: 0.48-2.17, P = 0.962]. The AUROC for hepatitis C RNA viral load was 0.734(P < 0.001, 95%CI: 0.66-0.82). HCV RNA 2.2 million IU/m L was identified as the cutoff value with sensitivity 73% and specificity 64%. HCV RNA < 2.2 million IU/m L was associated with significantly higher SVR 98% with OR = 0.22(95%CI: 0.1-0.49, P < 0.001) compared to SVR 92% in HCV RNA ≥ 2.2 million IU/m L. No death or morbidities were *** Our outcomes validate safety and effectiveness of 8-wk LDV/SOF therapy in non-cirrhotic, untreated HCV genotype 1 patients with HCV RNA < 6 million IU/m L.

关键词： Hepatitis C Sustained viral response Ledipasvir Cirrhosis Sofosbuvir

A STUDY ON DECISION-MAKING OF FOOD SUPPLY CHAIN BASED ON BIG DATA

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Journal of Systems Science and Systems Engineering 2017年第2期26卷 183-198页

作者： Guojun Ji Limei Hu Kim Hua Tan Collaborative Innovation Center for Peaceful Development of Corss-Strait Relations School of Management Xiamen University Xiamen Fujian361005 China operations Management & Information Systems division Nottingham University Business School

As more and more companies have captured and analyzed huge volumes of data to improve the performance of supply chain, this paper develops a big data harvest model that uses big data as inputs to make more informed production decisions in the food supply chain. By introducing a method of Bayesian network, this paper integrates sample data and finds a cause-and-effect between data to predict market demand. Then the deduction graph model that translates products demand into processes and divides processes into tasks and assets is presented, and an example of how big data in the food supply chain can be combined with Bayesian network and deduction graph model to guide production decision. Our conclusions indicate that the analytical framework has vast potential for supporting support decision making by extracting value t^om big data.

关键词： Big data Bayesian network deduction graph model food supply chain