• International Journal of Precision Engineering and Manufacturing
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• v.4 no.3
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• pp.55-61
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• 2003

The form accuracy of parts has become an important parameter. Therefore, not only dimensional tolerance but also geometric tolerances are used in the design stage to satisfy the required quality and functions of parts. But the information on the machining conditions, which can satisfy the assigned geometric tolerance in do sign, is insufficient. The objectives of this research are to study the effects of the grinding parameters such as traverse speed, work speed, depth of cut, and dwell time on the after-ground workpiece shape, and to find out the major parameters among them The results are as follows; The effects of work speed and depth of cut on the workpiece shape are negligible compared with the effect of traverse speed. These is an optimal dwell time depending on the traverse speed. The optimal dwell time is decreasing as the traverse speed is increasing.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.471-472
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• 2007

At this paper, we use non reversible hierarchical scheme and fixed channel assignment scheme at the hierarchical cellular system with macrocell and microcell for the call process strategy Using this strategy, we analyze the system performance in accordance with the various dwell time at each cell. In this simulation result, the more the dwell time is small at microcell, the more the blocking probability and the handover failure probability is low.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.61-68
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• 1998

The form accuracy of parts has become an important parameter. Therefore, dimensional tolerance and geometric tolerance are used in the design stage to satisfy required quality and functions of parts. But the informations on the machining conditions, which can satisfy the assigned geometric tolerance in design, are insufficient. The objectives of this research are to study the effects of the grinding parameters such as traverse speed, work speed, depth of cut, and dwell time on the after-ground workpiece shape, and to find out the major parameters among them. The results are as follows, The effects of work speed and depth of cut on workpiece shape are negligible compared with the effect of traverse speed. There is an optimal dwell time depending on the traverse speed. The optimal dwell time is decreasing as the traverse speed is increased.

• Journal of electromagnetic engineering and science
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• v.19 no.2
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• pp.107-114
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• 2019

Alert-confirm detection is a highly efficient method to improve phased array radar search performance. It comprises sequential detection in two steps: alert detection, in which a target is detected at a low detection threshold, and confirm detection, which is triggered by alert detection with a longer dwell time to minimize false alarms. This paper provides a design method for applying the alert-confirm detection to multifunctional radars. We find optimum dwell times and false alarm probabilities for each alert detection and confirm detection under the dual constraints of total false alarm probability and maximum allowable dwell time per position. These optimum values are expressed as a function of the mean new target appearance rate. The proposed alert-confirm detection increases the maximum detection range even with a shorter frame time than that of uniform scanning.

• International Journal of Railway
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• v.9 no.1
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• pp.1-9
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• 2016

In order to achieve a comprehensive utilization of railway networks, it is necessary to accurately assess the timetable indicators that effect the train operation. This paper describes the parameter calibration for two timetable indicators: scheduled running time and scheduled dwell time. For the scheduled running time, an existing model is employed and the single timetable parameter (percentage of minimum running time) in that model is optimized. For the scheduled dwell time, two intrinsic characteristics: the significance of stations and the average headway at each station are proposed firstly to form a new model, and the corresponding timetable parameters (the weight of the significance and the weight of the average headway) are calibrated subsequently. The Floyd Algorithm is used to obtain the connectivity among stations, which represents the significance of the stations. A case study is conducted in a light rail transportation system with 17 underground stations. The results of this research show that the optimal value of the scheduled running time parameter can be automatically determined, and the proposed model for the scheduled dwell time works well with a high coefficient of determination and low relative root mean square error through the leave-one-out validation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.41-48
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• 2011

This paper proposes an efficient code acquisition scheme for direct-sequence spread spectrum (DSSS) based real-time locating systems (RTLS). The proposed scheme employs multiple bit integration to significantly decrease false alarms when no packet signal is transmitted and increase the detection probability when the RTLS tags are excited. The performance of the proposed code acquisition scheme is analyzed and numerically evaluated, and compared with those of single-dwell and traditional double-dwell code acquisition schemes. The simulation results show that the proposed multiple-bit integration scheme outperforms single-dwell and double-dwell schemes.

• ETRI Journal
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• v.29 no.1
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• pp.1-7
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• 2007

In this paper, we analyze the performance of double-dwell hybrid initial acquisition in a direct sequence ultra-wideband (DS-UWB) system via detection, miss, false alarm probabilities, and mean acquisition time. In the analysis, we consider the effect of the acquisition sequence as well as the deployment scenario of the abundant multipath components over small coverage of the piconet in the DS-UWB system. Based on the simulation, we obtain various performance measures for the mean acquisition time by varying parameters such as the total number of hypotheses to be searched, subgroup size, and dwell time. We thereupon suggest the optimum parameter set for the initial acquisition in the DS-UWB system.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.189-192
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• 2000

In this paper, we consider a code acquisition of W-CDMA signals over multipath Rayleigh fading channel when double-dwell serial search code acquisition is used for initial synchronization. We derive the detection and false alarm probability, and mean acquisition time mathematically by taking into account of multiple H$\_$l/ cells and double-dwell serial search. It is noteworthy that the more the number of the post-detection integration, the shorter the mean acquisition time in low SNR.

• Progress in Medical Physics
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• v.15 no.3
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• pp.156-160
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• 2004

An essential quality assurance (QA) procedure in high dose rate (HDR) remote after-loading brachytherapy is that of the verification of the Ir-192 HDR source positioning accuracy. A number of methods using mechanical rulers or autoradiograph and video cameras have been reported to check the positional error of the Ir-192 source. In this study, the feasibility of a CMOS (Complementary Metal Oxide Semiconductor) PC camera, with a fluorescent screen, was investigated. The agreement between the planned and measured dwell position was better than 1 mm and dwell times better than 0.4 sec. Our results indicate that the CMOS PC camera system could be used as a QA tool for the on-line determination of the source position and dwell time.

• Industrial Engineering and Management Systems
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• v.6 no.2
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• pp.125-135
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• 2007

An automated guided vehicle (AGV) system is a group of collaborating unmanned vehicles which is commonly used for transporting materials within manufacturing, warehousing, or distribution systems. The performance of an AGV system depends on the dispatching rules used to assign vehicles to pickup requests, the vehicle routing protocols, and the home location of idle vehicles, which are called dwell points. In manufacturing and distribution environments which emphasize just-in-time principles, performance measures for material handling are based on response times for pickup requests and equipment utilization. In an AGV system, the response time for a pickup request is the time that it takes for the vehicle to travel from its dwell point to the pickup station. In this article, an exact dynamic programming algorithm for selecting dwell points in a tandem-loop multiple-vehicle AGV system is presented. The objective of the model is to minimize the maximum response time for all pickup requests in a given shift. The recursive algorithm considers time restrictions on the availability of vehicles during the shift.