• Title/Summary/Keyword: stopping criteria

Search Result 44, Processing Time 0.023 seconds

Overall studies on the IMO manoeuvrability standard and problems arising in application of the criteria of it to various kinds of vessels

  • Lee Chun-Ki;Yoon Jeom-Dong
    • Proceedings of KOSOMES biannual meeting
    • /
    • 2005.11a
    • /
    • pp.27-33
    • /
    • 2005
  • The IMO manoeuvrability standard was established for preventing sea accidents such as collisions and strandings due to the lack of manoeuvrability. The standard of ship manoeuvrability enforced by resolution MSC.137(76) has been applied to vessels of 100m or more in length and all chemical tankers and gas carriers regardless of the length, which were constructed on or after 1 July 1994. The IMO manoeuvrability standard is able to be divided into three kinds as followings; (1) Turning capability standard: Estimated values in design stage are to be certified by turning cir치e test q the actual vessel (2) Course keeping quality standard: Estimated values in design stage are to be certified by 10 deg. and 20 deg. zig-zag tests of the actual vessel. (3) Shortest stopping distance standard: Estimated value in design stage is to be certified by the shortest stopping distance tested by the actual vessel. In this paper, the authors verified the criteria of IMO manoeuvrability standard comparing them with the values resulted from sea trial tests of various kinds q actual vessels and examined separately the validity of all criteria of the standard.

  • PDF

Complexity of Distributed Source Coding using LDPCA Codes (LDPCA 부호를 이용한 실용적 분산 소스 부호화의 복호복잡도)

  • Jang, Min;Kang, Jin-Whan;Kim, Sang-Hyo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.4C
    • /
    • pp.329-336
    • /
    • 2010
  • Distributed source coding (DSC) system moves computational burden from encoder to decoder, so it takes higher decoding complexity. This paper explores the problem of reducing the decoding complexity of practical Slepian-Wolf coding using low-density parity check accumulate (LDPCA) codes. It is shown that the convergence of mean magnitude (CMM) stopping criteria for LDPC codes help reduce the 85% of decoding complexity under the 2% of compression rate loss, and marginal initial rate request reduces complexity below complexity minimum bound. Moreover, inter-rate stopping criterion, modified for rate-adaptable characteristic, is proposed for LDPCA codes, and it makes decoder perform less iterative decoding than normal stopping criterion does when channel characteristic is unknown.

Modified Simulated Annealing Algorithms for Optimal Seismic Design of Braced Frame Struvtures (2차원 가새골조의 최적내진설계를 위한 MSA 알고리즘)

  • Lee, Sang Kwan;Seong, Chang Won;Park, Hyo Seon
    • Journal of Korean Society of Steel Construction
    • /
    • v.12 no.6
    • /
    • pp.629-638
    • /
    • 2000
  • With the positive features of simulated annealing algorithms such as simplicity of the algorithm and the possibility of finding global optimum solution, SA algorithm has been widely applied to structural optimization problems. However, the algorithms are far from practical applications in structural design or optimization of building structures due to requirement of a large number of iterations and dependency on cooling schedule and stopping criteria. In this paper, with the modification of annealing process and stopping criteria, a MSA algorithm is presented in the form of two phase annealing process for optimal seismic design of braced structures. The performance of the proposed algorithm has been illustrated in detail.

  • PDF

A Study on Improving Reliability of Benefit Estimation Based on User Equilibrium Traffic Assignment Results (이용자 균형 통행배정 결과를 이용한 편익추정의 안정성 제고방안 연구)

  • Kim, Jae-Yeong;Son, Ui-Yeong
    • Journal of Korean Society of Transportation
    • /
    • v.25 no.6
    • /
    • pp.19-31
    • /
    • 2007
  • When estimating the benefits from an investment project in the transportation sector, errors caused by many factors may exist. This study focuses on user equilibrium traffic assignment methods and stopping criteria. According to previous studies, when using a user equilibrium assignment model, the benefits of travel time savings can be effected by the relative gap value. As the stopping criteria decreases, the time needed for traffic assignment increases, so that lowering the criteria cannot be the best solution. Therefore, an effort is necessary to reduce this change rate and thus improve reliability. This paper considers three methods: reducing the links subject to benefit calculation, extracting sub-area O/D tables and networks, and applying the mean value of successive traffic assignment results. The results of the analysis show that the method using the mean value of five results is more proper than the other methods. Using the sub-area analysis method, if the study area is small the benefits of a project might be over- or under-estimated. This paper used a nationwide O/D table and network at peak time as a case study. The resulting patterns can differ according to basic data to be used in analysis. So further analysis using the data from metropolitan areas are needed.

A Study on Driver Behavior and Dilemma Zone during Yellow Interval at Signalized Intersections (신호교차로 황색현시에서의 운전자 형태 및 딜레마 구간 연구방안)

  • 이승환;이성호;박주남
    • Journal of Korean Society of Transportation
    • /
    • v.21 no.4
    • /
    • pp.7-16
    • /
    • 2003
  • Objective of this research is to analyze drivers' behaviors at signalized intersection during yellow interval. For this, deceleration rate of stopping, PRT(Perception-Response Time), and the relationship between dilemma zone and deceleration rate of stopping were surveyed at two signalized intersections located at urban area(Songtan and Suwon) and local area(Yongin) As a result, the deceleration rate of stopping at signalized intersections and a range of dilemma zone were estimated. It was found that the deceleration rate of stopping and PRT were 1.6m/sec$^2$ and 1.27sec, respectively. These values are bigger than ITE's values which have been used in our country. Accordingly, it is considered that these values should be used as a new design criteria for the traffic signal control.

Simulated Annealing Algorithm for Optimum Design of Space Truss Structures (입체 트러스구조물의 최적설계를 위한 SA기법)

  • 정제원;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1999.04a
    • /
    • pp.102-109
    • /
    • 1999
  • Two phase simulated annealing algorithm is presented as a structural optimization technique and applied to minimum weight design of space trusses subjected to stress and displacement constraints under multiple loading conditions. Univariate searching algorithm is adopted for automatic selection of initial values of design variables for SA algorithm. The proper values of cooling factors and reasonable stopping criteria for optimum design of space truss structures are proposed to enhance the performance of optimization process. Optimum weights and design solutions are presented for two well-blown example structures and compared with those reported in the literature.

  • PDF

Measurement Technology of Chamber Impedance for RF Matching (RF 정합 특성 개선을 위한 챔버의 임피던스 측정법)

  • 설용태;이의용;박성진
    • Journal of the Semiconductor & Display Technology
    • /
    • v.2 no.4
    • /
    • pp.13-17
    • /
    • 2003
  • An adaptor is designed for chamber impedance measurement of plasma process. Copper rod, fixed board and compensation circuit are the major components of the adaptor. An adaptor can be to measure chamber impedance on time unless stopping a process and Data to measure can do the database. We can use it to a criteria data for a failure diagnosis. So developed adaptor could be used for diagnosis the plasma process chamber in semiconductor industry.

  • PDF

Area Identification for Road Design (도로 설계 지역 구분)

  • Kim, Yong Seok
    • International Journal of Highway Engineering
    • /
    • v.16 no.6
    • /
    • pp.181-189
    • /
    • 2014
  • PURPOSES : Ambiguous decision on whether rural or urban area for road design can increase the construction cost and restrict the land use of surrounding area. However, administrative classification on rural and urban area is not directly related to road design because of this classification is not based on the engineering viewpoint, so method which can explain the road design context is required. METHODS : Method which enables to identify the area for road design is suggested based on the deceleration expected to be experienced by drivers who use the road section concerned. Deceleration rate corresponding to the area such as rural or urban suggested in Road Design Guideline is used as the criteria to identify the area by comparing this value with the estimated deceleration rate at the road section concerned. Speed profile method is utilized to derive the deceleration rate, and speed estimation way for reflecting both road geometry and intersection is suggested using stopping sight distance concept. RESULTS : The procedure of the method application is suggested, and the design example utilizing the method is provided. CONCLUSIONS : The method is expected to be used to identify the area for road design with engineering viewpoint, and design consistency among the roads with similar driving environment can be made.

A Study on Establishment of Essential Performance Evaluation Criteria for C-arm Computed Tomography (C-arm CT의 필수 성능평가 기준 마련을 위한 연구)

  • Kim, Eun-Hye;Park, Hye-Min;Kim, Jung-Min
    • Journal of radiological science and technology
    • /
    • v.45 no.2
    • /
    • pp.127-134
    • /
    • 2022
  • In order to overcome the image quality limitations of the conventional C-arm, a flat panel detector (FPD) is used to enhance spatial resolution, detective quantum efficiency, frame rate, and dynamic range. Three-dimensional (3D) visualized information can be obtained from C-arm computed tomography (CT) equipped with an FPD, which can reduce patient discomfort and provide various medical information to health care providers by conducting procedures in the interventional procedure room without moving the patient to the CT scan room. Unlike a conventional C-arm device, a C-arm CT requires different basic safety and essential performance evaluation criteria; therefore, in this study, basic safety and essential performance evaluation criteria to protect patients, medical staff, and radiologists were derived based on International Electrotechnical Commission (IEC) standards, the Ministry of Food and Drug Safety (MFDS) standards in Korea, and the rules on the installation and operation of special medical equipment in Korea. As a result of the study, six basic safety evaluation criteria related to electrical and mechanical radiation safety (leakage current, collision protection, emergency stopping device, overheating, recovery management, and ingress of water or particulate matter into medical electrical (ME) equipment and ME systems: footswitches) and 14 essential performance evaluation criteria (accuracy of tube voltage, accuracy of tube current, accuracy of loading time, accuracy of current time product, reproducibility of radiation output, linearity and consistency in radiography, half layer value in X-ray equipment, focal size and collimator, relationship between X-ray field and image reception area, consistency of light irradiation versus X-ray irradiation, performance of the mechanical device, focal spot to skin distance accuracy, image quality evaluation, and technical characteristic of cone-beam computed tomography) were selected for a total of 20 criteria.

Study on New Classification Indication about Work of Art through Multi-variate Data Analysis;On Focused Specialist (다변량분석에 의한 예술작품 분류 시도 연구;전문가를 중심으로)

  • Suh, Myung-Ae;Ree, Sang-Bok
    • Proceedings of the Korean Society for Quality Management Conference
    • /
    • 2006.11a
    • /
    • pp.251-259
    • /
    • 2006
  • Evaluation of the work of art with intention of the artist different is not a possibility of free oneself from the limit which estimates an evaluation at value of appreciator. We tried new interpreting about the work of art in this paper. The work of art respects the intention of the artist to make it and interprets intention until now. After critics distinguish by a period, an area that they set to philosophical thought which is the time and interpreted. We set to each one subjectivity and interpreted between artist to make the work of art and appreciator. But in this paper, we tied various criteria which appreciates the work of art. We tried so that we presented the intimacy each other newly. Otherwise we tied with the subjectivity of the individual and are the try to be an objectification low through statistical technique. We looked into the culture and art in the introduction and explain the discussion about the work of art interpreting which the main subject. We set the category 6 area, and explain an each criteria explanation and assessment method. We tried to propose new interpreting as the intimacy to be multivariate data analysis result of the assessment analysis. Stopping from the thing which sees the work of art knows, it will be able to give meaning thing from this research prerequisite.

  • PDF