• Title/Summary/Keyword: Location of the opening

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Study of Flow Characteristics behind a Sunroof Wind Deflector for Wind Noise Reduction (바람소리 저감을 위한 선루프 디플렉터 주위의 유동에 관한 연구)

  • Lee, Dug-Young;Yoon, Jong-Hwan;Shin, Jae-Hyuk;Kim, Sang-Kon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.1
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    • pp.182-189
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    • 2009
  • The noise from the sunroof can be divided into the low frequency buffeting noise and the high frequency turbulence noise generated when a car runs at the high driving speed. The wind deflector suppresses the buffeting noise generation by accelerating the vortex shedding from the front edge of sunroof opening, and guides the flow direction so that air can pass smoothly over the sunroof opening. To reduce the buffeting noise and the high frequency noise, it is very important to locate a deflector in a proper position depending on the driving speed and the sunroof opening width. The deflector's sectional shape also plays an important role in efficiently reducing the buffeting and high frequency noise. In this paper, we determined the optimum deflector's sectional shape and examined the flow characteristics behind a sunroof deflector through CFD analysis with changing the deflector height, the driving speed and the sunroof opening width. It is found that the deflector needs to be located in the higher location to control the buffeting noise by shedding the higher frequency vortices to accelerating vortices from the sunroof front edge. The deflector may act as a new noise source at the high driving speed, then it is desirable to put the deflector at the proper height to reduce the flow fluctuations and the noise generation. We also made a road test to verify CFD analysis results in this study.

Numerical Study on the Effect of Heat Release Rate and Interior Opening on Fire Flow Velocity in the Case of Interior Fire in an Apartment Building (공동주택 화재 시 화재크기 및 실내 개구부 크기가 화재풍속에 미치는 영향에 관한 수치해석적 연구)

  • Seo, Chanwon;Shin, Weon Gyu
    • Fire Science and Engineering
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    • v.28 no.5
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    • pp.37-43
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    • 2014
  • In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operating when fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heat release rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator were carried out. In simulations, actual dimensions and configuration of an apartment building were considered and interior leakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantly influenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown that there is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral plane becomes closer to the ceiling.

THE PROSPECTS FOR THE LOCATION BASED SERVICES AND APPLICATION (LBS의 활용 분야 및 전망)

  • Shon, HoWoong;Kim, InHyun;Kim, YoungWoo
    • Journal of the Korean Geophysical Society
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    • v.7 no.2
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    • pp.135-149
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    • 2004
  • The present time is wanted quickness corretness position so as having more and more concern about present my position AS a doncing fan the intrenet marketed of fornation and recongnition about spatial generel is changed now is opening that present my position is where? to questing is answering through smaller (Mobile Device : Mobile Phone, PDA, GPS) then palm of the hand like this background, we know about that what is LBS?, service commercial of LBS SUCH embodiment practical use and possibilities of the future!!

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Changes in Layout Structure and Space in the Vicinity of Jongno in Hanseong-bu(漢城府) in the Early 20th Century (20세기 초 한성부 종로 주변 시전의 배치구조와 공간 변화)

  • Jeong, Su-In;Han, Dong-Soo
    • Journal of architectural history
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    • v.30 no.5
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    • pp.17-28
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    • 2021
  • The Sijeon (Licensed Markets) legally permitted by the government along the Jongno and the Namdaemunro Avenues played a central commercial role in Hanyang. However, after the opening of the port in the late Joseon era, the Licensed Markets suffered a blow and declined due to the introduction of a new product of civilization and the appearance of foreign merchants. Although the Licensed Markets, which have been maintained without major changes for a long time, have played a major role in the urban spatial structure, the exact location has not been still determined, and researches until now has remained limited for such that. In this study, based on the 1912 land survey records, the location of the Licensed Markets pre-and post- 1910 is identified, and the spatial change of the dismantling process is investigated.

Calculation Of Mobile Location Based On TOA/SS Measurements

  • Huang, Jiyan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.12
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    • pp.3166-3181
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    • 2012
  • Localization of mobile station (MS) has now gained considerable attention. Since the hybrid measurements can help to improve the positioning accuracy, several hybrid localization methods have been proposed in the literature. However, the high performance estimator with the closed-form solution and complete performance analysis for time-of-arrival/signal strength (TOA/SS) localization technique is still an opening issue. Two TOA/SS localization algorithms with the closed-form solutions are proposed for the cases with or without uncertainty in the positions of base stations. Furthermore, performance analysis for the TOA/SS localization technique is presented. Both the theoretical variances and Cramer-Rao lower bounds (CRLBs) are derived and the relationship between the cases with or without uncertainty is given. The paper also proves that the TOA/SS scheme has a lower CRLB than the TOA (or SS) scheme. Theoretical analysis and simulations show that the proposed method can reach its CRLB.

Optimal location of overwork-allowed facilities subject to choice of various equipment modes

  • Kwon, Min-Kyu;Sung, Chang-Sup
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.332-335
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    • 2006
  • This paper considers a facility location problem, which is concerned with locating facilities on a supply chain network and installing the associated equipments at the facilities to meet a given set of demands. The objective function is to minimize the sum of setup cost (facility opening cost and equipment installation cost), operation cost, and distribution cost. For the equipments, various choices of equipment modes need to be determined. Moreover, in the problem, overwork is allowed each facility but at expensive operation cost. The proposed problem is characterized as being NP-hard problem, so that a heuristic algorithm is derived. In order to evaluate the performance of the proposed algorithm, computational experiments with various numerical instances are conducted.

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A Study on the Ventilation Effect by Establishment Location of Supply Opening and Exhaust Fan of Bathroom in Apartment House (공동주택 화장실의 급기구 및 배기팬 설치 위치에 따른 환기효과에 관한 연구)

  • 함진식
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.321-326
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    • 2002
  • To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

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Deviation Characteristics of Clamp-on Type Ultrasonic Flowmeter Installed in Downstream of Valves (밸브 하류에 설치된 건식 초음파유량계의 편차특성)

  • Lee, Dong-Keun;Cho, Yong
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.4
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    • pp.12-18
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    • 2012
  • This study was performed to found out the deviations for clamp-on type ultrasonic flowmeter installed in downstream of valves. It was selected three types of two-path flowmeter mainly used for K-water as test. Experiment carried out to confirmed characteristics of deviation depending on the sensor location, straight pipe length and maker for 1-path, 2-path and 4-path combined 2-path flowmeter. It was selected two kinds of valves with 100 % and 50 % opening, butterfly valves and gate valves, for flow disturbance factor. Finally, we suggested number of sensors by maker, straight pipe length and installed location of sensors satisfying the tolerance depending on the experiment results.

Characterization of the Anatomic Location of the Pituitary Stalk and Its Relationship to the Dorsum Sellae, Tuberculum Sellae and Chiasmatic Cistern

  • Gulsen, Salih;Dinc, Ahmet Hakan;Unal, Melih;Canturk, Nergis;Altinors, Nur
    • Journal of Korean Neurosurgical Society
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    • v.47 no.3
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    • pp.169-173
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    • 2010
  • Objective : The normal anatomic relationships characteristic of the pituitary stalk area were previously thought to involve only one location. The purpose of this study was to re-evaluate the anatomic location of the pituitary stalk and possible varying locations in relation to the tuberculum sellae and dorsum sellae using morphometric evaluation and anatomic dissection of human cadaveric specimens. The surgical implications of the variations are discussed. Methods : The calvaria were removed via routine autopsy dissections, and the brains were removed from the skull while preserving the pituitary stalk. The diaphragma sellae, tuberculum sellae, and the location of the pituitary stalk were examined in 60 human cadaveric heads obtained from fresh adult cadavers. Empty sellae were excluded. Results : The openings of the diaphragma sellae averaged $6.62{\pm}1.606mm$ (range, 3-9 mm). The distance between the tuberculum sellae and the posterior part of the pituitary stalk was 1 to 8 mm. The upper face of the diaphragma sellae appeared flat in 26 (43%), concave in 24 (40%), and convex in 6 cases (10%), with a prominent tuberculum sellae in 4 cases (7%). The location of the chiasm was normal in 47 cases (78%), with a prefixed chiasm in 3 cases (5%) and a postfixed chiasm (17%) in the 10 cases. Four cadaver specimens had prominent tuberculum sellae and other parameters were not evaluated. Conclusion : When opening the chiasmatic cistern, neurosurgeons should be aware about the relationship between the pituitary stalk and the surrounding structures to prevent inadvertent injury to the pituitary stalk.

Implementation of Location-Aware VOD Service supporting User Mobility in Ubiquitous Spaces (편재형 공간에서 사용자 이동성을 지원하는 위치 인식 VOD서비스의 구현)

  • Choi Tae Uk;Chung Ki Dong
    • Journal of KIISE:Information Networking
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    • v.32 no.1
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    • pp.80-88
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    • 2005
  • In ubiquitous spaces, a user wants to be provided with a VOD service while moving one space to another freely. Since the traditional VOD system is dependent on user location, the VOD server transmits video data to a single client during a session. If the user moves to another space, he/she should close the old session and make a new request for the same video. However, the location-aware VOD system supports user mobility by closing and opening the session automatically. That is, the VOD system automatically perceives the movement of a user and allows the server to change the data flow so that a client near the user can receive the video data. This paper proposes a location-aware VOD service architecture and a session handoff scheme to provide a mobile user with continuous video delivery and implements a location-aware VOD prototype system based on Jini and Java. In experiment, we show that the proposed handoff scheme has a smaller handoff delay than the other handoff scheme.