• Journal of Korean Library and Information Science Society
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• v.44 no.1
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• pp.409-432
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• 2013

The purpose of this study is to examine 5 writing guidelines of reference collection development policy(RCDP) and to identify major elements of RCDP through the comparison and analysis of 24 RCDP in academic libraries in the U.S. As a result of this study, a total of 9 elements(5 core elements and 4 selective elements) were identified. Five core elements were (1) introduction, (2) scope, size, and level, (3) format, (4) types, and (5) management(i.e., selection, weeding, evaluation, and responsibilities) of reference collection. The results of this study would be helpful to those academic libraries which are planning to write RCDP in academic libraries in the near future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1200-1209
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• 2003

In this paper, a unified methodology based on the local stress concept to estimate residual strength of locally thinned pipes. An underlying idea of the proposed methodology is that the local stress in the minimum section for locally thinned pipe is related to the reference stress, popularly used in creep problems. Then the problem remains how to define the reference stress, that is the reference load. Extensive three-dimensional finite element (FE) analyses were performed to simulate full-scale pipe tests conducted for various shapes of wall thinned area under internal pressure and bending moment. Based on these FE results, the reference load is proposed, which is independent of materials. A natural outcome of this method is the maximum load capacity. By comparing with existing test results, it is shown that the reference stress is related to the fracture stress, which in turn can be posed as the fracture criterion of locally thinned pipes. The proposed method is powerful as it can be easily generalised to more complex problems, such as pipe bends and tee-joints.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.2
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• pp.79-85
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• 2015

Existing Differential GPS (DGPS) pseudorange correction (PRC) generation techniques based on a virtual reference station cannot effectively assign a weighting factor if the baseline distance between a user and a reference station is not long enough. In this study, a virtual reference station DGPS PRC generation technique was developed based on an enhanced inverse distance weighting method using an exponential function that can maximize a small baseline distance difference due to the dense arrangement of DGPS reference stations in South Korea, and its positioning performance was validated. For the performance verification, the performance of the model developed in this study (EIDW) was compared with those of typical inverse distance weighting (IDW), first- and second-order multiple linear regression analyses (Planar 1 and 2), the model of Abousalem (1996) (Ab_EXP), and the model of Kim (2013) (Kim_EXP). The model developed in the present study had a horizontal accuracy of 53 cm, and the positioning based on the second-order multiple linear regression analysis that showed the highest positioning accuracy among the existing models had a horizontal accuracy of 51 cm, indicating that they have similar levels of performance. Also, when positioning was performed using five reference stations, the horizontal accuracy of the developed model improved by 8 ~ 42% compared to those of the existing models. In particular, the bias was improved by up to 27 cm.

• Journal of Korean Library and Information Science Society
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• v.37 no.3
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• pp.75-101
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• 2006

This study is about the factors required to be considered in the aspects of policy and operation before introducing the real-time reference service and about the way to use the real-time reference service effectively, The real-time reference service should not be accepted and applied just based on the case of advanced nations without deciding how to apply and use through enough advanced investigation and example analysis. Working out in service policies, selecting appropriate programs. securing service manpower, devising privacy policies, groping the ways of cooperation between libraries, and operating the adequate evaluation system are the factors which should be considered in the policy aspect. Preparation of proper ways of application. operation time, and promotion are the factors which should be considered and reviewed in the operative aspect.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.123-128
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• 2001

The creep constants which are used to the reference stress equations of creep damage were obtained to type 316LN stainless steel, and their determining methods were described in detail. Typical Kachanov and Rabotnov(K-R) creep damage model was modified into the damage equations with reference stress concepts, and the modified equations were applied practically to type 316LN stainless steel. In order to determine the reference stress value, a series of high-temperature tensile tests and creep tests were accomplished at $550^{\circ}C$ and $600^{\circ}C$. By using the experimental creep data, the creep constants used in reference stress equations could be obtained to type 316LN stainless steel, and a creep curve on rupture strain was predicted. The reference stress concept on creep damage can be utilized easily as a design tool to predict creep life because the process, which is quantified by the measurement of voids or micro cracks during creep, is omitted.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.131-138
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• 2002

This paper provides the fully plastic J solutions for circumferential cracked pipes with inner, semi- elliptical surface cracks, subject to internal pressure and global bending. Solutions are given in the form of two different approaches, the GEF/EPRl approach and the reference stress approach. For the GE/EPRl approach, the plastic influence functions for fully plastic J are tabulated based on extensive 3-D FE calculations using the Ramberg-Osgood (R-O) materials, covering a wide range of pipe and crack geometries. The developed GEf/EPRl-type fully plastic J estimation equations are then re-formulated using the concept of the reference stress approach for wider applications. Based on the FE results, optimized reference load solutions for the definition of the reference stress are found for internal pressure and for global bending. Advantages of the reference stress based approach over the GE/EPRl-type approach are fully discussed. Validation of the proposed reference stress based J estimation equations will be given in Part II, based on 3-D elastic-plastic or elastic creep FE results using typical tensile properties of stainless steels and generalized creep- deformation behaviours.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.6
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• pp.358-365
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• 2021

Crabbing motion is a pure sway motion with only sway velocity. The ship's crabbing motion is essential for an ideal berthing/unberthing process. The unberthing situation proceeds in sequential order such as crabbing motion section, pivoting section, and outer port section. For the berthing situation, the sequence has a reverse order: the inner port section, pivoting section, and crabbing motion section. In this paper, the berthing/unberthing data of the reference ship, Pukyong National University research ship "NARA", was analyzed to develop a sway velocity reference model. Several constraints were defined to derive the crabbing motion section during berthing/unberthing. The sway velocity reference model for the auto-berthing/unberthing was developed using the estimated sway velocity. A reproduction simulation of the ship was performed to compare the designed reference model and the reference ship data.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.559-568
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• 2006

In this paper, we develop the noninformative priors for the linear mixed models when the parameter of interest is the ratio of variance components. We developed the first and second order matching priors. We reveal that the one-at-a-time reference prior satisfies the second order matching criterion. It turns out that the two group reference prior satisfies a first order matching criterion, but Jeffreys' prior is not first order matching prior. Some simulation study is performed.

• Journal of the Korean Statistical Society
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• v.35 no.3
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• pp.225-238
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• 2006

This paper considers noninformative priors for the scale parameter of exponential distribution when the data are collected in step stress accelerated life tests. We find the Jeffreys' and reference priors for this model and show that the reference prior satisfies first order matching criterion. Also, we show that there exists no second order matching prior in this problem. Some simulation results are given and we perform Bayesian analysis for proposed priors using some data.

• Communications for Statistical Applications and Methods
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• v.7 no.1
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• pp.165-178
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• 2000

Bayesian methods are considered for the multiple caputure-recapture data. Reference priors are developed for such model and sampling-based approach through Gibbs sampler is used for inference from posterior distributions. Furthermore approximate Bayes factors are obtained for model selection between trap and nontrap response models. Finally one methodology is implemented for a capture-recapture model in generated data and real data.