• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.751-755
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• 2005

We propose a sound source localization method using the Head-Related-Transfer-Function (HRTF) to be implemented in a robot platform. In conventional localization methods, the location of a sound source is estimated from the time delays of wave fronts arriving in each microphone standing in an array formation in free-field. In case of a human head this corresponds to Interaural-Time-Delay (ITD) which is simply the time delay of incoming sound waves between the two ears. Although ITD is an excellent sound cue in stimulating a lateral perception on the horizontal plane, confusion is often raised when tracking the sound location from ITD alone because each sound source and its mirror image about the interaural axis share the same ITD. On the other hand, HRTFs associated with a dummy head microphone system or a robot platform with several microphones contain not only the information regarding proper time delays but also phase and magnitude distortions due to diffraction and scattering by the shading object such as the head and body of the platform. As a result, a set of HRTFs for any given platform provides a substantial amount of information as to the whereabouts of the source once proper analysis can be performed. In this study, we introduce new phase and magnitude criteria to be satisfied by a set of output signals from the microphones in order to find the sound source location in accordance with the HRTF database empirically obtained in an anechoic chamber with the given platform. The suggested method is verified through an experiment in a household environment and compared against the conventional method in performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.3
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• pp.247-255
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• 2012

Numerical calculations are carried out for the natural convection in a square enclosure with two hot cylinders induced by temperature difference between a cold outer rectangular cylinder and two hot circular cylinders. A two-dimensional solution for unsteady natural convection is obtained, using the immersed boundary method (IBM) to model two inner circular cylinders based on finite volume method, for different Rayleigh numbers varying over the range of $10^3$ to $10^5$. The study goes further to investigate the effect of the location of two cylinders on the heat transfer and fluid flow. The location of inner circular cylinders is changed vertically along the center-line of square enclosure. The changes of heat transfer quantities have been presented.

• Archives of Craniofacial Surgery
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• v.25 no.1
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• pp.1-10
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• 2024

The facial nerve stimulates the muscles of facial expression and the parasympathetic nerves of the face. Consequently, facial nerve paralysis can lead to facial asymmetry, deformation, and functional impairment. Facial nerve palsy is most commonly idiopathic, as with Bell palsy, but it can also result from a tumor or trauma. In this article, we discuss traumatic facial nerve injury. To identify the cause of the injury, it is important to first determine its location. The location and extent of the damage inform the treatment method, with options including primary repair, nerve graft, cross-face nerve graft, nerve crossover, and muscle transfer. Intracranial proximal facial nerve injuries present a challenge to surgical approaches due to the complexity of the temporal bone. Surgical intervention in these cases requires a collaborative approach between neurosurgery and otolaryngology, and nerve repair or grafting is difficult. This article describes the treatment of peripheral facial nerve injury. Primary repair generally offers the best prognosis. If primary repair is not feasible within 6 months of injury, nerve grafting should be attempted, and if more than 12 months have elapsed, functional muscle transfer should be performed. If the affected nerve cannot be utilized at that time, the contralateral facial nerve, ipsilateral masseter nerve, or hypoglossal nerve can serve as the donor nerve. Other accompanying symptoms, such as lagophthalmos or midface ptosis, must also be considered for the successful treatment of facial nerve injury.

• Journal of the Korean Society of Combustion
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• v.18 no.1
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• pp.1-6
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• 2013

Authors' previous works on thermoacoustic(TA) model development showed good results in predicting combustion instability characteristics in a gas turbine combustor. However, they also suggested there were some limitations in growth rate estimation, which might be related with over-simplification of flame structure. As a first trial for improving the model accuracy, the current paper introduces the modified TA model considering the actual flame location in the combustor. The combustor is divided into the unburned and the burned area before and after the flame location, and then acoustic equations are re-organized. The modified TA model results show a better accuracy in predicting the growth rate of instabilities comparing with the previous results. However, obtained results still overestimate the conditions where the combustor goes unstable. Further researches considering heat release distribution through flames are required.

• Journal of the military operations research society of Korea
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• v.35 no.2
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• pp.1-14
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• 2009

During wartime, the Air Force have to plan where, and how much, and what need to be distributed to surrounding local area from a chosen central bases. Each base, which has surplus more than needed amount of a certain material collected from near area of the base, is expected to distribute such surplus to other bases in shortage of it. By sending such surplus to other bases in shortage of the material, every base may get sufficient amount of all kinds of materials needed for each base during wartime. Because number of items of materials needed in each military bases during wartime are usually quite large and the frequencies of delivery from a place to other place are also pretty large if each item is delivered from a surplus place to other places in shortage, the Head Quarter of Air Force or the Logistics Command will face to difficulty to decide a reasonable delivery plan between bases for efficient and fast allocation of all materials needed to all bases during wartime. Therefore, this study suggests a solving algorithm with an established TC (transfer center: collecting and distributing center for all materials) to solve such a distribution and transportation problem.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.84-93
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• 2011

In order to provide the real time and proper information to the pedestrian who is using the transport connection and transfer center through data collecting and processing process, the design of the test-bed (Gimpo airport)'s communication construction and the technology of the pedestrian location tracking has been researched. The design of the communication construction should make sure that it can provide believable data to the user of the transfer center. At the same time, the location tracking should also be considered, so that the require of the communication efficiency and the location tracking efficiency can be met together. In order to make the efficient location tracking technology, the problems related to the commercial technology based real time location identification will be resolved and the new approach method was proposed and be applied and analysed to the test-bed. The wireless access points can be located in the most real-world situation which has added the characteristics of the real building to the electronic map, and through the analysis of theirs location, they can be set as the mainly necessary points for the communication construction design and the location tracking and the method to locate that points has been proposed. How to set, how to apply it to the test-bed and the examination result will be introduced in this paper.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.179-186
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• 2014

This study attempted to identify the characteristics of transfer trips between subways and buses in Daegu city and to analyze various impact factors that influence the number of transfer trips using a multiple regression analysis. Based on the results, this study aims to propose some policy implications to improve the operation efficiency of a transit center. As a result, it is found that the number of transfer trips is inversely proportional to transfer time, while directly proportional to the number of connected bus routes, subway's spatial location, and bus route connection index. Specifically, it is found that the number of transfer trips are mostly affected by bus route connection index.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.27-42
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• 2019

It is not easy to evacuate when people face with emergency situation in deep underground space because space perception and synthetic judgement are readily lowered. In stead of evacuating safely outside within the given time, evacuation safety zone is required to be designed and installed. In this study, PATS (Pedestrian movement based Assessment Toolkit for Simulation) is applied to build a comprehensive and analytic framework for seeking the optimal (or proper) numbers and locations of evacuation safety zone. With two scenarios of emergency situation at intermodal transfer center with the 6 floor in underground, the problematic location on the evacuation path has been identified and the proper locations has been presented.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.323-327
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• 1991

An experiment was conducted to determine the local heat transfer from a supersonic hot jet impinging at 45.deg. to a plate surface. A semi-analytic method was used to determine the Nusselt number from experimental data. The results indicates that the location of the peak heat transfer is displaced from the geometric center of the axisymmetric jet and that the radial variation of the local heat transfer is steeper than that in the subsonic impinging jet. In the stagnation region, the heat transfer from the supersonic impinging jet is about 10 times larger than that from the subsonic one, while the heat transer away from the stagnation region is of the same magnitude as that of the in compressible turbulent radial wall jet.

• Journal of Power System Engineering
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• v.11 no.2
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• pp.20-25
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• 2007

The performance of air-to-air heat exchanger has been investigated with rotating porous plates newly developed in this study. With an equal interval of 18 mm, the rotating porous plates are installed inside the heat exchanger where the hot and cold airs enter at opposite ends. When flowing in opposite directions by the separating plate installed in the center of the rotating porous plates, the airs give and receive the heat each other. Dry bulb temperature is set by adjusting heat supply at heater. In order to measure the temperature distribution of the hot air side inside heat exchanger, the thermocouples are inserted between the plates. The first location of thermocouple is 10mm downstream from the inlet of heat exchanger, and succeeding ten locations are aligned at an equal interval of 18mm. From the experiment of air-to-air heat exchanger with the rotating porous plates, the heat transfer rate increased as both air flow rate and RPM of the rotating porous plate increased. It was found that the overall heat transfer coefficient increased with the increase in RPM of porous plate at the conditions of the same air flow rate.