• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.426-430
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• 1994

To establish the proper size of seedling of A. gigas, different weight of seedlings were used for this study. Agronomic characters including plant height, number of leaf, leaf length, number of inflorescence, fresh weight and rate of bolting of the aerial parts, root length, root diameter, number of lateral root and root weight of the underground parts were determined and correlation coefficients among them were estimated. Growth of A. gigas showed the significant vigor for all the characters of the aerial parts along with increasing of seedling weight, but root weight in yield decreased in proportion to increasing of seedling weight due to lignification of the root tissue. When the smaller seedlings were transplanted, bolting rates decreased to about 16% as compared with the traditional size of seedlings. Correlation coefficients between aerial and root characters in A. gigas were negative, and the characters such as plant height, number of leaf, number of inflorescence and fresh weight per plant showed highly significant correlation with the rate of bolting which is one of the characters having great influence on yield.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.843-852
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• 2019

In the present study, we established a comprehensive dataset of dose coefficients (DCs) of the new meshtype ICRP reference computational phantoms (MRCPs) for idealized external exposures of photons and electrons with the Geant4 code. Subsequently, the DCs for the nine organs/tissues, calculated for their thin radiosensitive target regions, were compared with the values calculated by averaging the absorbed doses over the entire organ/tissue regions to observe the influence of the thin sensitive regions on dose calculations. The result showed that the influences for both photons and electrons were generally insignificant for the majority of organs/tissues, but very large for the skin and eye lens, especially for electrons. Furthermore, the large influence for the skin eventually affected the effective dose calculations for electrons. The DCs of the MRCPs also were compared with the current ICRP-116 values produced with the current ICRP-110 reference phantoms. The result showed that the DCs for the majority of organs/ tissues and effective dose were generally similar to the ICRP-116 values for photons, except for very low energies; however, for electrons, significant differences from the ICRP-116 values were found in the DCs, particularly for superficial organs/tissues and skeletal tissues, and also for effective dose.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.342-348
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• 1996

This paper describes the formulation for the vibration analysis of cylindrical shells with stiffeners by the transfer influence coefficient method. This method was developed on the base of the concept of the successive transmission of dynamic influence coefficients. The simple computational results from a personal computer demonstrate the validity of the present method, that is, the numerical high accuracy and the flexibility of programming, are compared with results of the transfer matrix method. It is also confirmed that the present algorithm could provide the solutions of high accuracy for system with a number of intermediate rigid supports. And all boundary conditions and the intermediate stiff supports such as intermediate rigid supports between shell and foundation can be treated only by adequately controlling the values of the spring constants.

• Communications for Statistical Applications and Methods
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• v.24 no.3
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• pp.317-324
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• 2017

An influence measure known as Cook's distance has been used for judging the influence of each observation on the least squares estimate of the parameter vector. The distance does not reflect the distributional property of the change in the least squares estimator of the regression coefficients due to case deletions: the distribution has a covariance matrix of rank one and thus it has a support set determined by a line in the multidimensional Euclidean space. As a result, the use of Cook's distance may fail to correctly provide information about influential observations, and we study some reasons for the failure. Three illustrative examples will be provided, in which the use of Cook's distance fails to give the right information about influential observations or it provides the right information about the most influential observation. We will seek some reasons for the wrong or right provision of information.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.128-135
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• 2006

Rational dynamic modeling and analysis method f3r complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by using the influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method, the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model could be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models, which demonstrated the practical applicability of the proposed method.

• Journal of KSNVE
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• v.4 no.4
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• pp.469-478
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• 1994

This paper desfcribes the formulation for the analysis of the free vibration of a circular cylindrical shell with elastic supports by the transfer influence coefficient method. This method was developed on the base of the concept of the successive transmission of dynamic influence coefficients. The analysis algorithm for circular cylindrical shell elastically restrained by springs, which plays an important role in many industrial fields, is discussed. The supporting springs have the axial, circumferential, radial and rotational spring constants uniformly distributed along the circumference of the shell. The simple computational results on a personal computer demonstrate the validity of the present method, that is, the numerical high accuracy, the high speed analysis method and the flexibility for programming, compared with results of the transfer matrixmethod and reference. We also confirmed that the present algorithm could obtain the solutions of high accuracy for system with a number of intermediate rigid supports. And we could easily treat the intermediate support and all boundary conditions by adequately varying the values of spring constants.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.447-458
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• 2009

Energy loss at manholes, often exceeding friction loss of pipes under surcharged flow, is considered as one of the major causes of inundation in urban areas. Therefore, it is necessary to analyze head loss at manholes, especially in case of surcharged flow. Hydraulic experiments were conducted with three cases. Case A is to test whether the shapes of the manholes influence head loss coefficients. Case B and C were proposed to further reduce head losses by improving the manhole hydraulic efficiency. In case B, the joining part of the pipe at both shapes of manholes is shifted from central part to side part. The test in case C is to check the average head loss coefficient by installing the side benching in square manhole, based on shifted joining part model. The average head loss coefficient for circular and square manhole on case A was 1.6. This did not show much difference of the head loss coefficients in spite of the discharge variation in this case. However, case B and C show large difference between head loss coefficients due to the strong oscillation of water surface and the horizontal swirl motion. The circular and square manholes in case B reduced the head loss by 30% and 6% than ones in case A, respectively. The average head loss coefficient for circular manhole in case B was 1.1. Case C reduced average loss coefficients of the square manhole in case A from 1.6 to 1.1. Accordingly, the circular manhole in case B and the square manhole in case C showed the effective way to reduce the head loss. These head loss coefficients could be available to apply to the urban sewer system with surcharged flow.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2390-2398
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• 2002

For integrity analysis of nuclear reactor pressure vessel, including the Pressurized thermal shock analysis, the fast and accurate calculation of the stress intensity factor at the crack tip is needed. For this, a simple approximation scheme is developed and the resulting stress intensity factors for axial semi-elliptical cracks in cylindrical vessel under various loading conditions are compared with those of the finite element method and other approximation methods, such as Raju-Newman's equation and ASME Sec. Xl approach. For these, three-dimensional finite-element analyses are performed to obtain the stress intensity factors for various surface cracks with t/R = 0.1. The approximation methods, incorporated in VINTIN (Vessel INTegrity analysis-INner flaws), utilizes the influence coefficients to calculate the stress intensity factor at the crack tip. This method has been compared with other solution methods including 3-D finite clement analysis for internal pressure, cooldown, and pressurized thermal shock loading conditions. The approximation solutions are within $\pm$2.5% of the those of FEA using symmetric model of one-forth of a vessel under pressure loading, and 1-3% higher under pressurized thermal shock condition. The analysis results confirm that the VINTIN method provides sufficiently accurate stress intensity factor values for axial semi-elliptical flaws on the surface of the reactor pressure vessel.

• Wind and Structures
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• v.20 no.3
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• pp.449-468
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• 2015

Current wind-resistance designs of large-scale indirect dry cooling towers (IDCTs) exclude an important factor: the influence of the ventilation rate for radiator shutter on wind loads on the outer surfaces of the tower shell. More seemingly overlooked aspects are the effects of various ventilation rates on the wind pressure distribution on the tower surfaces of two IDCTs, and the feature of the flow field around them. In order to investigate the effects of the radiator shutter ventilation rates on the aerodynamic interference between IDCTs, this paper established the numerical wind tunnel model based on the Computational Fluid Dynamic (CFD) technology, and analyzed the influences of various radiator shutter ventilation rates on the aerodynamic loads acting upon a single and two extra-large IDCTs during building, installation, and operation stages. Through the comparison with the results of physical wind tunnel test and different design codes, the results indicated that: the influence of the ventilation rate on the flow field and shape coefficients on the outer surface of a single IDCT is weak, and the curve of mean shape coefficients is close to the reference curve provided by the current design code. In a two-tower combination, the ventilation rate significantly affects the downwind surface of the front tower and the upwind surface of the back tower, and the larger positive pressure shifts down along the upwind surface of the back tower as the ventilation rate increases. The ventilation rate significantly influences the drag force coefficient of the back tower in a two-tower combination, the drag force coefficient increases with the ventilation rate and reaches the maximum in a building status of full ventilation, and the maximum drag coefficient is 11% greater than that with complete closure.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.1
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• pp.56-63
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• 2009

Nowdays, Most of Internet Contents delivered as a compressed file. It gives many advantages like deduction of communication bandwidth and transmission time etc. In case of JPEG Compression, Quantization is the most important procedure which accomplish the compression. In general signal processing, Quantization is the process which converts continuous analog signal to discrete digital signal. As you known already, Quantization over JPEG compression is to reduce magnitude of pixel value in spatial domain or coefficient in frequency domain. A lot of Data Hiding algorithms also developed to applicable for those compressed files. In this paper, we are going to unveil the influence of quantization table which used in the process of JPEG compression. Even thought most of algorithm modify frequency coefficients with considering image quality, they are ignoring the influence of quantization factor corresponding with the modified frequency coefficient. If existing algorithm adapt this result, they can easily evaluate their performances.