• 제목/요약/키워드: Multi-start

검색결과 211건 처리시간 0.028초

유도된 이진난수 생성법을 이용한 uDEAS의 Multi-start 성능 개선 (Performance Improvement of Multi-Start in uDEAS Using Guided Random Bit Generation)

  • 김은숙;김만석;김종욱
    • 전기학회논문지
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    • 제58권4호
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    • pp.840-848
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    • 2009
  • This paper proposes a new multi-start scheme that generates guided random bits in selecting initial search points for global optimization with univariate dynamic encoding algorithm for searches (uDEAS). The proposed method counts the number of 1 in each bit position from all the previously generated initial search matrices and, based on this information, generates 0 in proportion with the probability of selecting 1. This rule is simple and effective for improving diversity of initial search points. The performance improvement of the proposed multi-start is validated through implementation in uDEAS and function optimization experiments.

위스타트(We Start) 언어중재 프로그램이 다문화가정 유아들의 수용.표현 언어에 미치는 영향 (The Effects of the We Start Language Intervention Program on the Improvement of Children's Receptive-Expressive Language Abilities in Multi-Cultural Families)

  • 방소영;황혜정
    • 대한가정학회지
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    • 제49권7호
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    • pp.51-66
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    • 2011
  • The purpose of this study was to review the current language level of children from multi-cultural background and whether the language level of these children would be increased after participating in the 'We Start Language Intervention Program'. The subjects were 30 36-75-month old children attending daycare centers in Ansan city, South Korea. The results showed that the receptive and expressive language levels of children from multi-cultural families were low compared to those of other children, and that their expressive language level was evaluated more negatively than their receptive language level. After participating in the 'We Start Language Intervention Program', language test scores, language age and language percentile rank were all increased. It was also found that the developmental language level of multi-cultural children increased, and that of the children that had a language delay or language disorder decreased.

Development and validation of a fast sub-channel code for LWR multi-physics analyses

  • Chaudri, Khurrum Saleem;Kim, Jaeha;Kim, Yonghee
    • Nuclear Engineering and Technology
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    • 제51권5호
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    • pp.1218-1230
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    • 2019
  • A sub-channel solver, named ${\underline{S}}teady$ and ${\underline{T}}ransient$ ${\underline{A}}nalyzer$ for ${\underline{R}}eactor$ ${\underline{T}}hermal$ hydraulics (START), has been developed using the homogenous model for two-phase conditions of light water reactors. The code is developed as a fast and accurate TH-solver for coupled and multi-physics calculations. START has been validated against the NUPEC PWR Sub-channel and Bundle Test (PSBT) database. Tests like single-channel quality and void-fraction for steady state, outlet fluid temperature for steady state, rod-bundle quality and void-fraction for both steady state and transient conditions have been analyzed and compared with experimental values. Results reveal a good accuracy of solution for both steady state and transient scenarios. Axially different values for turbulent mixing coefficient are used based on different grid-spacer types. This provides better results as compared to using a single value of turbulent mixing coefficient. Code-to-code evaluation of PSBT results by the START code compares well with other industrial codes. The START code has been parallelized with the OpenMP algorithm and its numerical performance is evaluated with a large whole PWR core. Scaling study of START shows a good parallel performance.

다시점 비디오 부호화를 위한 움직임 벡터들의 상관성을 이용한 움직임 추정 기법 (Motion Estimation Method Based on Correlations of Motion Vectors for Multi-view Video Coding)

  • 윤효순;김미영
    • 한국멀티미디어학회논문지
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    • 제21권10호
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    • pp.1131-1141
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    • 2018
  • Motion Estimation which is used to reduce the redundant data plays an important role in video compressions. However, it requires huge computational complexity of the encoder part. And therefore many fast motion estimation methods has been developed to reduce complexity. Multi-view video is obtained by using many cameras at different positions and its complexity increases in proportion to the number of cameras. In this paper, we proposed a fast motion estimation method for multi-view video. The proposed method predicts a search start point by using correlated candidate vectors of the current block. According to the motion size of the start search point, a search start pattern of the current block is decided adaptively. The proposed method proves to be about 2 ~ 5 times faster than existing methods while maintaining similar image quality and bitrates.

AHP에 기반을 둔 기술창업 요인 분석 시스템 (AHP-based Technology Start-ups Factors Analysis System)

  • 전향순;이상용
    • 디지털융복합연구
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    • 제13권4호
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    • pp.311-317
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    • 2015
  • 사회경험이 부족한 대학생들의 기술창업을 체계적이고 성공적으로 지원하기 위해서는 대학생에게 특화된 창업 영향요인을 분석하여 제공하는 것이 중요하다. 그러나 현재에는 통계 패키지에 의존하여 기술창업 요인 분석이 이루어짐으로써 지속적으로 변화하는 창업환경 분석이 곤란하다는 문제점이 발생하고 있다. 본 논문에서는 AHP를 이용하여 기술창업 의사결정에 관한 영향요인을 계층구조로 나타내고 전처리 후 판단행열에 입력, 표준화값 및 가중치 산정, 일관성 검증, 가중치 종합화를 통한 우선순위를 도출하여 분석할 수 있는 ATSA시스템을 제안하였다. ATSA 시스템은 창업자의 내외적 요인과 지속적으로 변화하는 다양한 창업환경 분석에 다기준 의사결정을 적용하여 정성적인 요인들을 정량적으로 분석함으로써, 기술창업을 위한 의사결정을 효율적으로 지원할 수 있음을 실험을 통해 확인하였다.

초기 슬로우 스타트 단계에서 SCTP의 평균 전송 시간 (Mean Transfer Time for SCTP in Initial Slow Start Phase)

  • 김주현;이용진
    • 대한공업교육학회지
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    • 제32권2호
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    • pp.199-216
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    • 2007
  • SCTP(stream control transmission protocol)는 데이터 전송을 위한 전송 계층 프로토콜로서, 많은 부분에서 TCP(transmission control protocol) 방식을 따른다. 하지만 멀티 호밍(multi-homing)과 멀티 스트리밍(multi-streaming)의 특징을 가짐으로 성능의 차이를 갖는다. 이 논문에서는 SCTP 혼잡제어 중에서 초기 슬로우 스타트 단계에 초점을 맞추어 데이터 전송을 분석하고, 대역폭, 지연시간 및 데이터 크기에 따른 SCTP와 TCP 평균 전송 시간을 측정하고 비교하였다. 아울러 SCTP와 TCP의 평균 전송시간에 영향을 미치는 요인인 초기 윈도우 크기를 데이터 크기에 따라 측정하였다. 실험을 위한 서버와 클라이언트 프로그램은 SCTP socket API를 이용하여 C 언어로 작성되었고, 전송 시간은 이더리얼 프로그램을 사용하여 측정되었다. 서버와 클라이언트 사이의 데이터 전송 방법은 라운드 로빈(round robin) 방법을 사용하였다. 실험 결과, SCTP는 초기 슬로우 스타트 단계에서 TCP 보다 평균 전송 시간에 있어 약 15% 정도 향상된 성능을 보였으며, 그 이유는 SCTP 초기 윈도우 크기가 TCP 보다 크기 때문으로 확인되었다.

Personalized Web Service Recommendation Method Based on Hybrid Social Network and Multi-Objective Immune Optimization

  • Cao, Huashan
    • Journal of Information Processing Systems
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    • 제17권2호
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    • pp.426-439
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    • 2021
  • To alleviate the cold-start problem and data sparsity in web service recommendation and meet the personalized needs of users, this paper proposes a personalized web service recommendation method based on a hybrid social network and multi-objective immune optimization. The network adds the element of the service provider, which can provide more real information and help alleviate the cold-start problem. Then, according to the proposed service recommendation framework, multi-objective immune optimization is used to fuse multiple attributes and provide personalized web services for users without adjusting any weight coefficients. Experiments were conducted on real data sets, and the results show that the proposed method has high accuracy and a low recall rate, which is helpful to improving personalized recommendation.

변속시의 멀티 스팬 연속 공정 시스템의 장력제어 (Longitudinal Tension Control at Start and Stop in a Multi-span Continuous Process System)

  • 신기현;권순오
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.584-589
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    • 1994
  • A time-varying nonlinear mathematical model was derived to consider the effect of change in roll radius on tension varation during winding and unwinding. A variable-gain PID controller was designed for tension control at start and stop in a multi-span continuous process system. The controller gains are updated at every control loop as roll radii continuously change. Computer simulation was carried out by using the mathematical model and the controller developed for a typical operating condition including acceleration and deceleration. When the variable-gain PID controller was used, the tension control performance was improved compared with that of existing control method during start-up and stop.

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간호창업에 대한 리터러시 고찰 (Review of Nursing Start-Up Literacy)

  • 임지영;김주행;김슬기
    • 가정간호학회지
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    • 제25권2호
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    • pp.127-138
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    • 2018
  • Purpose: This study aimed to provide an overview of the present status of start-up literacy. Methods: The study selected literature from KoreaMed, RISS (Research Information Sharing Service), KISS (Korean studies Information Service System), KISTI (Korea Institute of Science and Technology Information), Ovid-MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase, and Cochrane Library DB. Start-up curricula were collected from the homepage of nursing schools in Korea and the USA. Their contents were searched using Massive Open Online Course (MOOC) platforms; KOCW, K-MOOC, and Coursera. Results: Fifteen articles were selected through a systematic literature review. The main themes of nursing start-up were "driver," "barrier," "required competency," and "importance of education." The courses contained business planning, finance, marketing, leadership, and entrepreneurship. The main contents of MOOCs were similar. Conclusion: The results indicate the necessity to develop multi-scope nursing start-up education programs. Nursing start-up models integrated with appropriate business knowledge and skills in health care settings are needed. This study can be used as a guideline to design start-up education programs in nursing.

이중사출 성형을 위한 저온 경화 액상실리콘고무 (LSR)의 경화 거동 분석 (Analysis of cure behavior of low temperature curing liquid silicone rubber (LSR) for multi-material injection molding)

  • 유형민
    • Design & Manufacturing
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    • 제17권1호
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    • pp.1-5
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    • 2023
  • In multi-material injection molding, since two or more materials with different process conditions are used, it is essential to maximize process efficiency by operating the cooling or heating system to a minimum. In this study, Liquid silicone rubber (LSR) that can be cured at a low temperature suitable for the multi-material injection molding was selected and the cure behavior according to the process conditions was analyzed through differential scanning calorimetry (DSC). Dynamic measurement results of DSC with different heating rate were obtained, and through this, the total heat of reaction when the LSR was completely cured was calculated. Isothermal measurement results of DSC were derived for 60 minutes at each temperature from 80 ℃ to 110 ℃ at 10 ℃ intervals, and the final degree of cure at each temperature was calculated based on the total heat of reaction identified from the Dynamic DSC measurement results. As the result, it was found that when the temperature is lowered, the curing start time and the time required for the curing reaction increase, but at a temperature of 90 ℃ or higher, LSR can secure a degree of cure of 80% or more. However, at 80 ℃., it was found that not only had a relatively low degree of curing of about 60%, but also significantly increased the curing start time. In addition, in the case of 110 ℃, the parameters were derived from experimental result using the Kamal kinetic model.

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