• Title/Summary/Keyword: engine performance

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Snippet Extraction Method using Fuzzy Implication Operator and Relevance Feedback (연관 피드백과 퍼지 함의 연산자를 이용한 스니핏 추출 방법)

  • Park, Sun;Shim, Chun-Sik;Lee, Seong-Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.3
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    • pp.424-431
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    • 2012
  • In information retrieval, search engine provide the rank of web page and the summary of the web page information to user. Snippet is a summaries information of representing web pages. Visiting the web page by the user is affected by the snippet. User sometime visits the wrong page with respect to user intention when uses snippet. The snippet extraction method is difficult to accurate comprehending user intention. In order to solve above problem, this paper proposes a new snippet extraction method using fuzzy implication operator and relevance feedback. The proposed method uses relevance feedback to expand the use's query. The method uses the fuzzy implication operator between the expanded query and the web pages to extract snippet to be well reflected semantic user's intention. The experimental results demonstrate that the proposed method can achieve better snippet extraction performance than the other methods.

A study on the characteristics of electrochemical deburring in the governor shaft cross hole (거버너샤프트 교차구멍 내경의 전해디버링 특성에 관한 연구)

  • Choi, In-Hyu;Kim, Jeong-Du
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.12
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    • pp.1984-1991
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    • 1997
  • Recently burr technology is rising in the fields of the precision manufacturing and the high quality machining, deburring has treated as a difficult problem on going to the high efficiency, automation in the FMS. Removal of burr with various shapes, dimensions and properties couldn't be standardized and has depended on manual treatment. Especially, deburring for cross hole inside owing to passing through out perpendicular to a main hole is more difficult, the electrochemical method is proper as its solution at practical aspects. Burr elimination in the cross hole drilling of governor shaft used in the automobile engine so far has been worked by a manual post-processing by a skillful worker, which becomes a factor of productivity-down and cost-up so that improvement of machining process is needed. Therefore, for the high efficiency and automation of internal deburring in the cross hole, development of electrochemical deburring technology is needed. So, the new process in the burr treatment is supposed. In this study, characteristics of electrochemical deburring through experiments were identified and factors such as electrolytic gap and electorlytic fluid contributed to removal burr height were analyzed. Also, deburring efficiency and electrolytic performance for cross hole were examined according to electrolytic current and electrochemical deburring condition corresponding to acquired edge quality was found out.

A study on the optimization of manufacturing processes of double wall bellows for dual fuel engine I - Design optimization by buckling and stress analysis - (Dual Fuel 엔진용 이중관 벨로우즈 제작 공정의 최적화에 관한 연구 I - 좌굴해석 및 응력해석을 통한 설계 최적화 -)

  • Kim, Pyung-Su;Kim, Jong-Do
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.6
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    • pp.499-503
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    • 2016
  • Dual fuel engines are suitable for stricter regulations as they significantly decrease exhaust gas output. Hence, research and development of double wall bellows for dual fuel engines is important. In this study, optimum forming methods and welding conditions were derived to develop double wall bellows made of austenite stainless steel. The reliability of the prototypes was ensured by various performance evaluations. In this study, the buckling load and bellows stress were obtained by structural design, buckling, and stress analysis to design optimum bellows. As a result, the buckling load in the embossing shape of bellows increased by approximately 1.6 times, and no buckling and squirming occurred at 30.0 bar, which was twice that of the maximum design pressure.

An Effective Path Table Method Exploiting the Region Numbering Technique (영역 할당 기법을 이용한 효율적인 경로 테이블 기법)

  • Min Jun-Ki
    • The KIPS Transactions:PartD
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    • v.13D no.2 s.105
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    • pp.157-164
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    • 2006
  • Since XML is emerging as the de facto standard for exchanging and representation of data on the web, the amount of XML data has rapidly increased. Thus, the need for effective store and retrieval of U data has arisen. Since the existing techniques such as XRel which is an XML storage and management technique using RDBMS simply record the existing all label paths, diverse classes of label path expressions could not be efficiently supported. In this paper, we present a technique which supports storage and retrieval for XML data using RDBMS efficiently compared with the existing approaches. Since the proposed technique keeps the XML path index on the relational database and replace label paths with path identifiers, diverse XML queries can be evaluated compared with existing approaches. Also, the proposed technique does not require the modification of the relational database engine and consumes the disk space less. Our experimental result demonstrates the better query performance compared with existing techniques.

'EVE-SoundTM' Toolkit for Interactive Sound in Virtual Environment (가상환경의 인터랙티브 사운드를 위한 'EVE-SoundTM' 툴킷)

  • Nam, Yang-Hee;Sung, Suk-Jeong
    • The KIPS Transactions:PartB
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    • v.14B no.4
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    • pp.273-280
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    • 2007
  • This paper presents a new 3D sound toolkit called $EVE-Sound^{TM}$ that consists of pre-processing tool for environment simplification preserving sound effect and 3D sound API for real-time rendering. It is designed so that it can allow users to interact with complex 3D virtual environments by audio-visual modalities. $EVE-Sound^{TM}$ toolkit would serve two different types of users: high-level programmers who need an easy-to-use sound API for developing realistic 3D audio-visually rendered applications, and the researchers in 3D sound field who need to experiment with or develop new algorithms while not wanting to re-write all the required code from scratch. An interactive virtual environment application is created with the sound engine constructed using $EVE-Sound^{TM}$ toolkit, and it shows the real-time audio-visual rendering performance and the applicability of proposed $EVE-Sound^{TM}$ for building interactive applications with complex 3D environments.

Cross-layer Design of Packet Scheduling for Real-Time Multimedia Streaming (실시간 멀티미디어 스트리밍을 위한 계층 통합 패킷 스케줄링 기법)

  • Hong, Sung-Woo;Won, You-Jip
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11B
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    • pp.1151-1168
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    • 2009
  • Improving packet loss does not necessarily coincide with the improvement in user perceivable QoS because each frame carries different degree of importance. We propose Significance-aware packet scheduling (SAPS) to maximize user perceivable QoS. SAPS carries out two fundamental issues of packet scheduling: "What to transmit" and "When to transmit?" To adapt to the available bandwidth, it is necessarily to transmit the subset of the data packets if the entire set of packets can not be transmitted. "Packet Significance" quantifies the importance of the frame by elaborately incorporating frames' dependency. Greedy approach is used in selecting packets and transmission schedule is determined based on the Packet Significance. The proposed scheme is tested using publicly available MPEG-4 video clips. Decoding engine is embedded in the simulation software and user perceivable QoS is exposeed in termstermiSNR. Throughout the simulation based experiment, the performance of the proposed scheme is compared two other schemes: Size-based packet scheduling and Bit-rate based best effort packet scheduling. SAPS successfully incorporates the semantics of a packet and improves user perceivable QoS significantly. It successfully provides unequal protection to more important packets.

Study on Performance Improvement of a Head-Feeding Rice Combine for Foxtail Millet Harvesting

  • Jun, Hyeon Jong;Choi, Il Su;Kang, Tae Gyoung;Choi, Yong;Choi, Duck Kyu;Lee, Choung Keun
    • Journal of Biosystems Engineering
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    • v.40 no.1
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    • pp.10-18
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    • 2015
  • Purpose: The study was conducted to investigate the proper working conditions like the mesh size of the concave and the chaffer angle of the oscillating sieve, and the fan speed of the head-feeding rice combine for foxtail millet harvesting. Methods: The study aimed to determine the harvesting conditions for the rice combine harvester at a 0.5 m/s working speed and at $40^{\circ}$ and $55^{\circ}$ sieve chaffer angles. The harvesting loss of the foxtail millet based on the speed of the fan and the oscillating speed of the sieve was measured at three levels of fan speed and oscillating sieve speed. Results: The threshing rates of different foxtail millet varieties were 64.1~83.5% at a mesh size of 7 mm of the concave. In experimental foxtail millet harvesting, the optimal operating condition of the rice combine harvester included a $40^{\circ}$ sieve chaffer angle and a 4.8 Hz oscillating sieve (cleaning shoe) frequency. The grain loss was found to be lower at a $40^{\circ}$ than at a $55^{\circ}$ sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged between 0.2~0.5% at a 7 mm mesh concave, $40^{\circ}$ chaffer angle, 4.8 Hz sieve frequency, and a 20 m/s fan speed at an engine speed of 2,000 revolutions per minute (RPM). Conclusions: Findings showed that foxtail millet could be harvested using the combine harvester.

The Implementation of Multi-Port UTOPIA Level2 Controller for Interworking ATM Interface Module and MPLS Interface Module (MPLS모듈과 ATM모듈과의 Cell Mode 인터페이스를 위한 Multi-Port지원 UTOPIA-L2 Controller구현)

  • 김광옥;최병철;박완기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.11C
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    • pp.1164-1170
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    • 2002
  • In the ACE2000 MPLS system, MPLS Interface Module(MIM) is composed of an ATM Interface Module and a HFMA performing a packet forwarding. In the MIM, the HFMA RSAR receive cells from the Physical layer and reassemble the cells. And the IP Lookup controller perform a packet forwarding after packet classification. Forwarded packet is segmented into cells in the HFMA TSAR and transfer to the ALMA for the transmission to an ATM cell switch. When the MIM make use of an ATM Interface Module, it directly connect the ALMA with a PHY layer using the UTOPIA Level2 interface. Then, an ALMA performs Master Mode. Also, the HFMA TSAR performs the Master Mode in the MIM. Therefore, the UTOPIA-L2 Controller of the Slave Mode require for interfacing between an ALMA and a HFHA TSAR. In this paper, we implement the architecture and cell control mechanism for the UTOPIA-L2 Controller supporting Multi-ports.

Study on Friction Characteristic of Sintered Friction Component for Synchronizer-Ring of Diesel Vehicle (디젤차량 싱크로나이저링을 위한 소결마찰재 개발 및 접합특성 평가)

  • Song, Joon Hyuk;Kim, Eun Sung;Kim, Kyung-Jae;Oh, Je-Ha;Yang, Sung Mo;Kang, Shin Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.3
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    • pp.373-378
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    • 2013
  • The speed change performance of transmissions has become a serious issue because of the increase in the inertia moment that has accompanied increases in engine output and transmission size. Therefore, it is necessary to develop better wear resistant friction materials. In this study, an appropriate sintered friction component for the synchronizer ring of a diesel manual transmission was developed, and its bonding characteristics were analyzed. That is, a process for bonding an Fe-based base material and Cu-based sintered friction material was developed. BSE and EDX analyses of this bonding layer were conducted, along with a shear strength test, to determine the bonding characteristics.

The present and future of SWRO-PRO hybrid desalination technology development (SWRO-PRO 복합해수담수화 기술의 현재와 미래)

  • Chung, Kyungmi;Yeo, In-Ho;Lee, Wonil;Oh, Young Khee;Park, Tae Shin;Park, Yong-gyun
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.4
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    • pp.401-408
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    • 2016
  • Desalination is getting more attention as an alternative to solve a global water shortage problem in the future. Especially, a desalination technology is being expected as a new growth engine of Korea's overseas plant business besides one of the solutions of domestic water shortage problem. In the past, a thermal evaporation technology was a predominant method in desalination market, but more than 75% of the current market is hold by a membrane-based reverse osmosis technology because of its lower energy consumption rate for desalination. In the future, it is expected to have more energy efficient desalination process. Accordingly, various processes are being developed to further enhance the desalination energy efficiency. One of the promising technologies is a desalination process combined with Pressure Retarded Osmosis (PRO) process. The PRO technology is able to generate energy by using osmotic pressure of seawater or desalination brine. And the other benefits are that it has no emission of $CO_2$ and the limited impact of external environmental factors. However, it is not commercialized yet because a high-performance PRO membrane and module, and a PRO system optimization technology is not sufficiently developed. In this paper, the recent research direction and progress of the SWRO-PRO hybrid desalination was discussed regarding a PRO membrane and module, an energy recovery system, pre-treatment and system optimization technologies, and so on.