• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.62-70
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• 2016

Increased bus traffic leads inefficiency at near-side bus stops in median exclusive bus lane because buses are waiting for a signal does not have a vehicle arrived. This study suggests a method for estimating a proper spacing between bus stops and signalized intersection to prevent the inefficiency. We modified the Poisson model for a proper spacing by using both dwell time and waiting time of signal instead of using dwell time only. The waiting time of signal changes by spacing and it was measured using micro simulation program. The iterative algorithm using the change of waiting time of signal was also suggested. By applying the proposed method, measure waiting time by simulation and iterative algorithm, the spacing of near-side bus stops, proper spacing is suggested according to flow rate level.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.8
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• pp.37-44
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• 1997

We implemented a code searcher which is used for the PN(pseudo noise) code acquisition in CDMA cellular mobile station. To reduce the reuired hardware and the code acquisition time, we used the double dwell structure which is an effective serial code acquisition metho. We designed a code acquisition has acquired within 1/2 PN chip range. The code searcher is implemented using 0.8 micron code searcher is successfully working in CDMA cellular mobile station and it satisfies the code acquisition time specified in IS-95 standard.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.122-131
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• 2014

This study aimed to conduct an eye-tracking experiment carried with facade images as a medium and to do research on 'the interest of the eyes' resulted from people's gazing phenomena. This study secured gazing data which appeared according to visual response and analyzed gazing phenomena to find the basic theory of 'the interest of the eyes' as a methodological role, which consumer interest and attention could be grafted when a plan and a design for space design was made. Data terms used in eye-tracking backgrounds and the movement of the eyes were investigated in literature review. Twenty (20) facade images were selected through a case study to get experimental stimuli for the related experiment. Thirty (30) subjects (men and women) suitable for the experiment were recruited to conduct an eye-tracking experiment. After the experiment, five (5) areas were set up in the facade image to identify the focus level of interest and attention. The level of interest and focus was connected to the interest of the eyes. The analysis to study the interest of the eyes was based on nine (9) items such as sequence, entry time, dwell time, hit ratio, revisits, revisitors, average fixation, first fixation and fixation count. Through gaze analysis, the following conclusion was drawn about the 'interest level of sight' for gaze frequency. The interest level can be interpreted to be higher for faster sequence, shorter entry time, longer all fixation(ms) for dwell time, faster all saccade(%), higher hit ratio, more revisits, more revisitors, longer average fixation, faster and longer first fixation, and more fixation count, and the person can be said to have felt interest faster and/or more.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.117-123
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• 2003

In a bi-fuel engine using gasoline and LPG fuel, with the current ignition timing for gasoline being used, the effective performance could not be taken in LPG fuel supply mode. The ignition timing in LPG fuel mode must be advanced much more than that of gasoline mode for the compensation of its lower flame speed, due to engine torque drop. This study aims to develop the control system for ignition spark timing conversion which is composed of hardwares and control algorithm for gasoline/LPG engine. We propose the control system which can advance the ignition spark timing in LPG fuel mode more than used in gasoline fuel mode. The advance of ignition timing is achieved by change of the ignition dwell time of coil igniter. The engine torque and F/E(Fuel-Economy) in LPG fuel mode are measured to evaluate the difference of engine performance between before and alter changing ignition spark timings. The engine torque and F/E are increased respectively, which proves the developed control system is effective so much for gasoline and LPG bi-fuel engine.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1133-1143
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• 2005

In this paper, we propose an enhanced two-step search scheme for rapid and reliable signal acquisition in UWB systems under multipath channels. The proposed TSS-LS (Two-Step Search scheme with the Linear search based Second step) achieves rapid acquisition performance comparable to the conventional TSS-BS (Two-Step Search scheme with the Bit reversal search based Second step) already proposed by the authors, based on the single-dwell search with two-step thresholds and search windows. However, unlike the TSS-BS which employs the bit reversal search in the second step, the proposed TSS-LS utilizes the linear search in the second step to improve the reliability of signal acquisition. Simulation results with multipath channel models by IEEE 802.15.3a show that the two-step search schemes for the UWB signal acquisition can achieve sig nificant reduction of the required mean acquisition time as compared to general search schemes. In addition, we observe that the proposed TSS-LS achieves quite good bit error rate performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.56-64
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• 2011

Friction stir spot welding between 5454 aluminum alloy sheets with the different thicknesses of 1.4 and 1.0 mm was performed. In the welding process, the tool for welding was rotated ranging from 500 to 2500, and plunged to the depth of 1.8 mm under a constant tool plunge speed of 100 mm/min. And then, the rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 sec. The pull-out speed of the rotating tool was 100 mm/min. The increase of tool rotation speed resulted in the change of the macrostructure of friction-stir-spot-welded zone, especially the geometry of welding interface. The results of the tensile shear test showed that the total displacement and toughness of the welds were increased with the increase of the tool rotation speed, although the maximum tensile shear load was decreased. However, the change in the dwell time at the plunge depth of the tool did not produce the remarkable variation in the macrostructure and mechanical properties of the welds. In all cases, the average hardness in friction-stir-spot-welded zone was higher than that of the base metal zone. By the friction stir spot welding technique, the welds with the excellent mechanical properties than the mechanically-clinched joints could be obtained.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1262-1264
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• 1995

The question-"How fast a electron tunnels a potential barrier?" looks like simple, but is controversy for more than 40 years. Because "tunneling" involves complicated internal processes and its definition is ambiguous. Recent experiments showed that the phase time is the best model of tunneling time among other times-for example, dwell time, Larmor clock time etc. In this paper, we simulated the tunneling time for Gaussian wave packet by program InterQuanta and compared with the phase time. In particular we focused on the effect of wave packet spreading in momentum space(or real space) which is not expressed by the phase time formula.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.5
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• pp.77-83
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• 2012

The importance of mobility management is becoming to be one of the upcomming issues to be addressed to provide the converged services and the convergence of the heterogeneous network environments. In this paper, the new user mobility management scheme which can be utilized to model the user's mobility behaviors for interworking with heterogeneous overlay convergent networks under the time-varying radio propagation environment has been proposed. Thus user mobility management scheme based on user mobility model is considered in order to optimize the dwell time of users in the overlay convergent networks. This Mobile IP user mobility management will be very useful to model the user mobility behaviors and can be used to estimate the signaling traffic and frequency spectrum demands for massive data transfer for the heterogeneous overlay convergent networks.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.64-75
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• 2014

This study has attempted to explore the audience's visual attention about the subtitles types of CATV entertainment program. To achieve this, this research has measured the dwell time and average fixation data through the eye-tracking test and analysed the reason of particular visual attention by in-depth interview. According to the eye-tracking research findings, four types of subtitles(character metaphor, character metonymy, event metaphor, event metonymy) were measured the highest dwell time and average fixation time. Also, according to in-depth interview, visual attention was clearly turned up that event metonymy constructs the conflicts between characters and overstates the trip place romantically. This results means that staffs of intensify the reality and visual pleasure through event metonymic subtitles.

• Journal of Korean Clinical Nursing Research
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• v.21 no.2
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• pp.188-195
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• 2015

Purpose: The purpose of this study was to evaluate the appropriateness of the replacement time intervals of 18 gauge peripheral intravenous catheters (PICs) by investigating the development of phlebitis. Methods: The subjects were 200 hospitalized patients over 18 yrs old aged who have 18 gauge PICs placed for surgery. After the insertion of PICs, the researcher monitored the insertion site daily for 96 hours for any signs of phlebitis. Results: Phlebitis developed in 25.7% of patients. Patients who developed phlebitis were significantly older and were receiving fluids with faster infusion rate. However, patients with and without phlebitis were not different by gender, insertion site, fluid osmolality, or pH of drugs administered. The incidence rate of phlebitis was higher than 10%(12.9%) starting 24~48 hours after the insertion of 18 gauge PICs. Conclusion: It is recommended to replace 18 gauge PICs within 24~48 hours after insertion. Close monitoring of the PICs insertion site for the signs of phlebitis is recommended.