• Journal of the Korea Computer Graphics Society
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• v.21 no.4
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• pp.1-10
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• 2015

Recently, calligraphy has become popular because people focused on emotion. The strokes, dots, swoops, cracks and shading are the calligraphy factors for expressing various emotions such as joy, anger, sorrow, and delight. However, the emotion which is expressed by cracks and shading can be destroyed in the digital work when the calligraphy is used for a variety sizes of prints. Professionals work with high-resolution images which are obtained through the scanner, however normal users should work with low-resolution images taken with the smart phone for calligraphy image editing. We propose a raster image scaling method focused on calligraphy that maintains the emotion with cracks and shading, when normal users use the low-resolution calligraphy images in the digital work. The method recolors aliasing boundary of enlarged rasterized image. When recolored by our method, our method decreases aliasing by using the image gradient method, vivify calligraphy images, and maintains the emotion in cracks and shading by using the alpha value.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.129-138
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• 2011

Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.

• Journal of the Korean Geotechnical Society
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• v.27 no.8
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• pp.63-71
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• 2011

In case of applying BIM method to the civil engineering of irregularly shaped structure, BIM method is recognized to have relatively high construction productivity. In this paper, we developed quantity calculation algorithms applying BIM method to NATM tunnel construction method and implemented BIM based 3D-BIM Modeling Quantity Calculation. The results showed that BIM-based method has high reliabilty in structure work in which errors occurred only in the range between 0.00% and -1.45%. On the other hand, BIM method applied to earth work showed great error range of -19.78% to 35.30%. So the benefit and applicability of BIM method in civil engineering were confirmed. In addition, routine method for the quantity of earth work has negligible error as in the case of structure work. But, rock type's quantity calculation showed significant errors so that the reliability of 2D-based volume calculation is problematic. It may thus be concluded that 3D-BIM is more reliable than the routine method in estimating the quantity of earth work. Considering the reliability and merits in the stage of its design, construction and maintenance levels, the application of BIM to civil engineering works is recommended.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.457-468
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• 2011

Recently, the non-vibration mass excavation method is used on sewage pipes and road construction sites in Jeju. However, a construction cost estimation based on the unit quantity does not provide a proper unit price. In this study, a comparison of the productivity of the standard quantity-per-unit costing method and the one of the work crew combination method was made based on the site monitoring of the non-vibration mass excavation method that is used in construction sites near Jeju. For this, data of 35 sites were collected: a regression equation was derived from the 30 data, and verification was carried out through the remaining 5 data. The analysis concluded that a day's workload is $16.43m^3$. In addition, a combination of the equipment considering the site conditions and the amount of labor, which varies with the number of work crew was obtained in order to estimate the construction cost of the work crew combination method. The construction cost was calculated based on the one-day workload ($16.43m^3$) derived from the regression analysis. The cost then was analyzed and compared with the standard quantity-per-unit costing method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.4
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• pp.19-28
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• 1999

In order to control thermal deformation of the machine origin of machine tools a empirical model and a compensation system have been developed, Prior to empirical modeling the volumetric error considering shape errors and joint errors of slides is formulated through the homogeneous transformation matrix (HTM) and kinematic chain. Simulation results of the HTM method show that the thermal error of the machine origin is more critical than position-dependent errors. In order to make a stable and effective software error compensation system the GMDH (Group Method of Data Handling) models are constructed to estimate the thermal deformation of the machine origin by measuring deformation data and temperature data. A test bar and gap sensors are used to measure the deformation data. In order to compensate the estimated error the work origin shift method is developed by implementing a digital I/O interface board between a CNC controller and an IBM PC. The method shifts the work origin as much as the amounts which are calculated by the pre-established thermal error model. The experiment results for a vertical machining center show that the thermal deformation of the machine origin is reduced within $\pm$5$mu extrm{m}$.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.157-171
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• 1999

In this work, an automatic software verification method for Nuclear Power Plant (NPP) protection system is developed. This method utilizes Colored Petri Net (CPN) for system modeling and Prototype Verification System (PVS) for mathematical verification. In order to help flow-through from modeling by CPN to mathematical proof by PVS, an information extractor from CPN models has been developed in this work. In order to convert the extracted information to the PVS specification language, a translator also has been developed. ML that is a higher-order functional language programs the information extractor and translator. This combined method has been applied to a protection system function of Wolsong NPP SDS2(Steam Generator Low Level Trip). As a result of this application, we could prove completeness and consistency of the requirement logically. Through this work, in short, an axiom or lemma based-analysis method for CPN models is newly suggested in order to complement CPN analysis methods and a guideline for the use of formal methods is proposed in order to apply them to NPP Software Verification and Validation.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.81-88
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• 2007

The objective of this study was to investigate the validity of the digital ergonomic simulation (DES) method as a prospective alternative to the ergonomic analyses conducted by experts. The DES method utilizes commercial digital manufacturing software, and can compute the RULA scores continuously throughout the simulated work cycle. It was shown in a case study that the accuracy and objectivity of the DES method are superior to those obtained by experts. Also, it was demonstrated that the DES method has a distinct capability to simulate and validate a proposed work plan. Major limitations of the current DES method lie in the extensive time and efforts required for accurate digital simulation, which may be overcome through an automatic module for RULA data acquisition and a motion capture system.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1125-1134
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• 2017

In this paper, we present a new multilevel in space and energy diffusion (MSED) method for solving multigroup diffusion eigenvalue problems. The MSED method can be described as a PI scheme with three additional features: (1) a grey (one-group) diffusion equation used to efficiently converge the fission source and eigenvalue, (2) a space-dependent Wielandt shift technique used to reduce the number of PIs required, and (3) a multigrid-in-space linear solver for the linear solves required by each PI step. In MSED, the convergence of the solution of the multigroup diffusion eigenvalue problem is accelerated by performing work on lower-order equations with only one group and/or coarser spatial grids. Results from several Fourier analyses and a one-dimensional test code are provided to verify the efficiency of the MSED method and to justify the incorporation of the grey diffusion equation and the multigrid linear solver. These results highlight the potential efficiency of the MSED method as a solver for multidimensional multigroup diffusion eigenvalue problems, and they serve as a proof of principle for future work. Our ultimate goal is to implement the MSED method as an efficient solver for the two-dimensional/three-dimensional coarse mesh finite difference diffusion system in the Michigan parallel characteristics transport code. The work in this paper represents a necessary step towards that goal.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.4
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• pp.252-259
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• 2009

When various kinds of outputs are produced from a single energy system, the methodology which allocates the common cost to each output cost is very important because it is directly related with the profit and loss of producers and purchasers. In the cost allocation methodology of the heat and the electricity on a cogeneration, there are energy method, work method, proportional method, benefit distribution method, various exergetic methods, and so on. On the other hand, we have proposed a worth evaluation method which can be applied to any system. The definition of this methodology is that the unit cost of a product is proportion to the worth. Where, worth is a certain evaluating basis that can equalize the worth of products. In this study, we applied this methodology to a gas-turbine cogeneration which produces 119.2 GJ/h of electricity and 134.7 GJ/h of steam, and then we allocated 3,150 $/h of fuel cost to electricity cost and steam cost. Also, we compared with various cost allocation methods. As the result, we conclude that reversible work of various kinds of worth basis evaluates the worth of heat and electricity most reasonably.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.