• Title/Summary/Keyword: Choke Point

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Relations between Choke Point Types and Cover Pattern Properties in FPS Game Level Design (FPS게임 레벨디자인에서 Choke Point유형과 Cover Pattern속성의 관계)

  • Choi, GyuHyeok;Jin, HyungWoo;Kim, Mijin
    • Journal of Korea Game Society
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    • v.14 no.4
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    • pp.27-36
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    • 2014
  • Accurate information on players, namely player analytics is one of the key factors in a game development environment where a scientific approach to user-oriented game analysis is in the spotlight. This study is intended to examine effects of relations between choke point types and cover pattern properties on level difficulties in FPS games. As for FPS games, interaction between players' behaviors and game levels is higher compared to other genres and choke point types as well as cover pattern properties are key factors of level design. Choke point is the main crossroad that must to pass for achieving the goal and Cover Pattern is the type of object on the level except buildings. Two elements directly or indirectly affect the level of difficulty. This study analyzed 10 types of representative FPS gameplays to classify choke point types and assigned 4 types of cover pattern properties to organize 16 target levels for the experiment. In addition, this study collected and analyzed players' 800 behavior data (video clips) from 5 repetitive plays performed by 10 players. In conclusion, analytical results obtained from the empirical study will contribute to realizing systematic game level development by providing specific information for a game level design phase. The findings are also meaningful in that they suggest efficient and effective methods of utilizing the existing academic study results for industrial applications.

Air Influx Characteristics of Turbo Pumps (공기 유입시의 터보펌프 특성)

  • Kim, You-Taek;Nam, Cheong-Do;Kang, Ho-Keun;Lee, Young-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.43-48
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    • 2004
  • A screw-type centrifugal pump was manufactured to carry solids primarily and its impeller has a wide flow passage. However, the effect of flow passage shape on delay of the choke due to entrained air has not been clarified yet. Moreover, because its impeller has a particular shape, only few studies have tried to clarify the pump performance and details of internal flow pattern of that pump. For that reason, we carried out the pump performance experiment under air-water two-phase flow condition with different impeller tip clearances, pump rotational speeds and void fractions by using a small screw-type centrifugal pump designed to acquire basic data. In a general centrifugal pump, it was reported that loss of pump head from single-phase flow to the choke due to air entrainment new the best efficiency point was large. However, the loss near the best efficient point in a screw-type centrifugal pump became less than that in a general centrifugal pump.

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Characteristics of a Small Screw-type Centrifugal Pump Operating in Air-Water Two-Phase Flow (소형 스크류식 원심펌프의 기액 이상류 특성)

  • Kim, You-Taek;Tanaka, Kazuhiro;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.4 s.5
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    • pp.9-15
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    • 1999
  • A screw-type centrifugal pump was manufactured to carry primarily solids and its impeller had a wide flow passage. However, there was an effect on the flow passage shape on delay of the choke due to entrained air not being clarified yet. Moreover, because its impeller has a particular shape, only few studies have tried to clarify the pump performance and details of internal flow pattern of that pump. For this reason, we carried out the pump performance experiment under air-water two-phase flow condition with different impeller tip clearances, pump rotational speeds and void fractions by using a small screw-type centrifugal pump designed to acquire basic data. In a general centrifugal pump, it was reported that there was a loss of pump head from single-phase flow to the choke due to air entrainment near the best efficiency point being large. However, the loss near the best efficient point in a screw-type centrifugal pump became less than that in a general centrifugal pump.

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Investigation of Off-Design Performance of Vaned Diffusers in Centrifugal Compressors - Part I : A Channel-Wedge Diffuser - (원심압축기용 베인디퓨져의 탈설계점 성능연구 - 제1부 : 채널디퓨져 -)

  • Oh, JongSik;Hyun, YongIk
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.83-90
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    • 2001
  • Experimental and numerical investigations of the off·design performance of a simple channel-wedge diffuser in a small centrifugal compressor are presented. Surge and choke conditions as well as design point are considered using somewhat limited range of experimental data and also supplementary 3D CFD results. Some critical meanline design parameters' behavior is investigated numerically, to render the basis for improved modelings in the meanline performance prediction.

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Upgrade Development of a Centrifugal Compressor for Marine Engine Turbochargers (선박용 터보차져 원심압축기의 성능향상 개발)

  • Oh, Jong Sik;Oh, Koon Sup;Yoo, Kwang Taek
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.1 s.6
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    • pp.43-50
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    • 2000
  • Upgrade development of a high pressure ratio centrifugal compressor in marine engine turbochargers is presented. A new matched operating point at increased speed of rotation was determined through system cycle analysis using the exisitng test data of turbine performance. Under some severe restrictions for geometric parameters, the state-of-the-art methods of both aerodynamic design and CFD analysis were applied, in which only an impeller, a vaned diffusor and some part of casing wall were modified. Prototype hardware was fabricated and assembled for system performance tests. Excellent performance in pressure ratio and efficiency was obtained over whole speed region. Reduced surge and choke margin was, however, observed at design speed of rotation.

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Effects of Entrained Air on the Characteristics of a Small Screw-type Centrifugal Pump (공기 흡입이 소형 스크류식 원심펌프의 특성에 미치는 영향)

  • Kim, You-Taek;Tanaka, Kazuhiro;Lee, Young-Ho;Matsumoto, Yoichiro
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.3 s.4
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    • pp.37-44
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    • 1999
  • In a screw-type centrifugal pump, the pump head deteriorates from single-phase flow to the choke due to an increased air entrainment at a wide tip clearance compared to that of a narrow tip clearance. Moreover, at a narrow tip clearance, the pump head became partially higher in a two-phase flow than that of a single-phase flow near the best efficiency point in low void fraction region. Therefore, we observed the internal flow pattern by using a stroboscope and we measured the mean size of bubbles from the images obtained with a high speed camera. Then, we investigated the influences of the mean size of bubbles, tip clearances and flow patterns on pump performance.

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Pressure Distributions of a Screw-type Centrifugal Pump Operating in Air-Water Two-Phase Flow (기액 이상류시의 스크류식 원심펌프의 압력분포)

  • Kim, You-Taek;Choi, Min-Seon;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.4 no.3 s.12
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    • pp.39-45
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    • 2001
  • It is reported recently that the pump head deterioration near the best efficiency point, from single-phase flow to the choke due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. Moreover, at a narrow tip clearance, the pump head became partially higher in two-phase flow than that in single-phase flow. However, the internal pressure fluctuations on this pump due to air entrainment have not been studied yet. For that reason, we have examined the influences of void fraction, flow coefficient and impeller tip clearance on pressure fluctuations in the casing. The void fraction became larger, the influence of tip clearance on pressure distribution became less.

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Upgrade Development of a Centrifugal Compressor for Marine Engine Turbochargers (선박용 터보차져 원심압축기의 성능향상 개발)

  • Oh, JongSik;Oh, KoonSup;Yoo, KwangTaek
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.33-40
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    • 1999
  • Upgrade development of a high pressure ratio centrifugal compressor in marine engine turbochargers is presented. A new matched operating point at increased speed of rotation was determined through system cycle analysis using the exisitng test data of turbine performance. Under some severe restrictions for geometric parameters, the state-of-the-art methods of both aerodynamic design and CFD analysis were applied, in which only an impeller, a vaned diffuser and some part of casing wall were modified. Prototype hardware was fabricated and assembled for system performance tests. Excellent performance in pressure ratio and efficiency was obtained over whole speed region. Reduced surge and choke margin was, however, observed at design speed of rotation.

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A Study on Game Dynamics of Battle Royale Genre (배틀로얄 장르의 게임 다이나믹 고찰 -<배틀그라운드>를 중심으로-)

  • Ahn, Jin-kyoung
    • Journal of Korea Game Society
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    • v.17 no.5
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    • pp.27-38
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    • 2017
  • The purpose of this study is to analyze the game dynamics of 'Battle Royale' genre and how these dynamics create dramatic tension, focused on . Battle Royale games maintain the dramatic tension through the intersection of uncertainty and inevitability. Uncertainty is reinforced by randomness of the game world and hidden information of player statement. Inevitability is emerged from the level design with choke point, and restriction of playable field over time. From this mechanism, Battle Royale genre establishes the gameness which derives player's meaningful choice and maintains player's tension until the end of the game.

GNSS Antenna PCO/PCV and Position Changes due to the Switch IGS08/igs08.atx to IGS14/igs14.atx

  • Choi, Byung-Kyu;Sohn, Dong-Hyo;Yoon, Ha-Su;Lee, Sang Jeong
    • Journal of Positioning, Navigation, and Timing
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    • v.11 no.2
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    • pp.83-89
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    • 2022
  • For precise GNSS applications, the antenna phase center correction (PCC) is absolutely required. The PCC magnitude can reach the centimeter level with the antenna structure. In the present study, we first investigate the phase center offset (PCO) and phase center variation (PCO) of three different antenna models in two different reference frames, IGS08/igs08.atx and IGS14/igs14.atx. Clear L1 and L2 PCO differences were found between IGS08 and IGS14. In addition, the PCV showed characteristics that is dependent upon the signal direction (azimuth and elevation angle). The remarkable thing is that the changes of a Dorne Margolin choke-ring antenna model (AOAD/MT DOME) was very small in two reference frames. In order to analyze changes in positions according to different reference systems, GNSS data obtained from DAEJ, SUWN, and TSKB stations were processed by the precise point positioning (PPP) method. We suggest that an antenna PCO/PCV can affect the precise GNSS positioning on the order of several millimeters in two different reference frames.