• Advances in concrete construction
• /
• v.10 no.6
• /
• pp.527-536
• /
• 2020

In this study, a process is proposed to calculate analytical correction values for the vertical shortening of all columns on all floors in a high-rise building that minimizes the error between the structural analysis predictions and values measured during construction. The weight ratio and the most probable value were accordingly considered based on the properties of the shortening value analyzed at several points in each construction stage and the distance between these measured points and unmeasured points at which the shortening was predicted. The effective range and shortening value normalization were considered using the column grouping concept. These tools were applied to calculate the error ratio between the predicted and measured values on a floor where a measured point exists, and then determine the estimated error ratio and estimated error value for the unmeasured point using this error ratio. At points on a floor where no measured point exists, the estimated error ratio and the estimated error value were calculated by applying the most probable value considering the weight ratio for the nearest floor where measured points exist. In this manner, the error values and estimated error values can be determined at all points in a structure. Then, the analytical correction value, defined as this error or estimated error value, was applied by adding it to the predicted value. Finally, the adequacy of the proposed correction method was verified against measurements by applying the analytical corrections to all unmeasured points based on the points where the measurement exists.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.6
• /
• pp.11-18
• /
• 2014

Vulnerable areas by non-point source pollution and prioritizing control areas were researched using hydrological and geomorphological data, non-point source loads, and water quality data. Using overlay analysis, vulnerable areas were graded with various scenarios. Vulnerable areas were selected near the metro city with impermeable landuse because non-point source loads and water quality data had influence on overlay analysis to rank vulnerable area. Analysis scenarios and weighted values can be changed under regional characteristics and given conditions.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.1
• /
• pp.325-330
• /
• 2015

With approval from the Asia Pacific Metrology Program Working Group on Materials Metrology (APMP WGMM), an international comparison for sheet resistance standards for silicon wafers was firstly conducted among Korea Research Institute of Standards and Science (KRISS) in Korea, CMS/ITRI in Taiwan, and NIM in China, which are national metrology institutes (NMIs), from August 2011 to January 2012. The sheet resistance values of the standards are $10{\Omega}$, $100{\Omega}$, and $1000{\Omega}$; the measurement was conducted in sequence at KRISS, CMS/ITRI, NIM, and KRISS again using the four-point probe method with single and dual configuration techniques. The reference value for the measurement results of the three NMIs was obtained through averaging the values of the three results for each sheet resistance range. The differences between the reference value and the measured values is within 0.22% for $10{\Omega}$, 0.17% for $100{\Omega}$, and 0.12% for $1000{\Omega}$. Therefore, the international consistency for conducting sheet resistance measurements is confirmed within 0.22% through the APMP WGMM approved comparison.

• Journal of the Korean Institute of Gas
• /
• v.20 no.6
• /
• pp.31-36
• /
• 2016

The flash point is one of the most important indicators of the flammability of liquid solutions. The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. In this study the flash points of ternary liquid solutions, n-nonane+n-decane+n-dodecane system, were measured using Seta flash closed cup tester. The measured values were compared with the calculated values using Raoult's law and empirical equation. The calculated data by empirical equation described the measured values more effectively than those calculated by Raoult's law.

• Journal of Korean Critical Care Nursing
• /
• v.12 no.2
• /
• pp.26-38
• /
• 2019

Purpose : The aims of this study were to identify the incidence of pressure ulcers and to compare the predictive validities of pressure ulcer risk assessment scales among trauma patients. Methods : This was a prospective observational study. A total of 155 patients admitted to a trauma intensive care unit in a university hospital were enrolled. The predictive validity of the Braden, Cubbin & Jackson, and Waterlow scales were assessed based on the sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC). Results : Of the patients, 14 (9.0%) subsequently developed pressure ulcers. The sensitivity, specificity, positive predictive values, and negative predictive values were 78.6%, 75.9%, 24.4%, and 97.3%, respectively, for the Braden scale (cut-off point of 12); 85.7%, 68.8%, 21.4%, and 98.0%, respectively, for the Cubbin & Jackson scale (cut-off point of 26); and 71.4%, 87.2%, 35.7%, and 96.9%, respectively, for the Waterlow scale (cut-off point of 18). The AUCs were 0.88 (Waterlow), 0.86 (Braden), and 0.85 (Cubbin & Jackson). Conclusion : The findings indicate that the predictive validity values of the Waterlow, Braden, and Cubbin & Jackson scales were similarly high. However, further studies need to also consider clinical usefulness of the scales.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.1
• /
• pp.222-233
• /
• 1995

For effective module generation, a detailed router which can handle complicated routing regions on multimple layers of interconnection under various constraints is necessary. In this paper, a new improved maze routing technique is described, which can find the shortest path for each net without allowing stacked vias. In this method, two cost values are stored at each grid point. The cost values represent the routing costs from the terminal of the net being routed to the grid point. One cost value shows the cost of the shortest path without making a via at the grid point and the other cost value shows that with making a via at the grid point. This is the first systematic maze routing technique which can find the shortest path without via-stacking.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.4
• /
• pp.1644-1654
• /
• 2018

Eigenvalue distributions for a periodic metal-insulator-metal waveguide, classified into the point spectrum and the discretized continuous spectrum (DCS), are investigated as functions of frequencies, gap widths, and periods. Muller's method is suggested for solving exact eigenvalues, and we propose the scheme for finding proper initial values in the Muller's method by considering only ${\Re}e({\varepsilon}_r)$ in the dispersion equation. We then find that anti-crossing behavior, repulsive effect between the point spectrum and the DCS, becomes stronger when the real parts of the roots in the point spectrum have smaller values. Finally, we examine the transmittances of a single subwavelength slit for real metals using the mode matching technique. The transmittances in real metals similarly follow those of the perfect electric conductor (PEC) at low frequencies, while the patterns at higher frequencies begin to differ from the PEC.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.4
• /
• pp.475-480
• /
• 2004

Function approximation is one of the most important and active research fields in design optimization. Accurate function approximations can reduce the repetitive computational effort fur system analysis. So this study presents an enhanced two-point diagonal quadratic approximation method. The proposed method is based on the Two-point Diagonal Quadratic Approximation method. But unlike TDQA, the suggested method has two quadratic terms, the diagonal term and the correction term. Therefore this method overcomes the disadvantage of TDQA when the derivatives of two design points are same signed values. And in the proposed method, both the approximate function and derivative values at two design points are equal to the exact counterparts whether the signs of derivatives at two design points are the same or not. Several numerical examples are presented to show the merits of the proposed method compared to the other forms used in the literature.

• Honam Mathematical Journal
• /
• v.35 no.4
• /
• pp.757-764
• /
• 2013

In this paper, we give sufficient conditions for a map with nonconvex values to have a continuous selection and the selection extension property in LC-metric spaces under the one-point extension property. And we apply it to weakly lower semicontinuous maps and generalize previous results. We also get a continuous selection theorem for almost lower semicontinuous maps with closed sub-admissible values in $\mathbb{R}$-trees.

• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.1
• /
• pp.54-63
• /
• 1992

Force distribution of incomplete meshing teeth for the OHC drive timing belt system is investigated analytically. Finite difference equations of the belt tension are derived based on the force equilibrium and the deformation of the belt tooth. From the numerical results, it is found that of the force distribution prior to the boundary point shows higher values compared with those of the complete meshing state and the force distribution after the boundary point shows lower values. Also, the magnitude of the incomplete meshing region increases as the rotational speed increases and the tight side belt tension decreases.