• Bulletin of the Korean Chemical Society
• /
• v.34 no.3
• /
• pp.917-921
• /
• 2013

A simple, quick and reliable analytical method for the confirmation and quantification of propisochlor was developed. The propisochlor was extracted from water, soil and rice (stalks, rice and hull) matrices using acetonitrile, and cleaned up with primary secondary amine and determined by UPLC-MS/MS. The LODs of propisochlor ranged from 0.03 ${\mu}g/kg$ to 0.12 ${\mu}g/kg$, while the LOQs ranged from 0.1 ${\mu}g/kg$ to 0.4 ${\mu}g/kg$ in different matrixes. The mean recoveries of propisochlor at three levels (0.005, 0.01 and 0.05 mg/kg) were in the range of 73.7-94.9% with intra-day relative standard deviations (RSD) of 1.1-13.9% and inter-day $RSD_R$ of 3.3-12.7%. This method is suitable for routine analysis of propisochlor under field conditions. The half-lives of propisochlor in rice stalks, water and soil were 1.7, 1.5 and 2.3 days in Hunan, 5.7, 1.0 and 1.9 days in Anhui and 4.8, 1.0 and 3.1 days in Guangxi.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.5
• /
• pp.377-387
• /
• 2016

In recent, in case that the underpass is constructed by trenchless method, its stability increases by reinforcing steel pipe with re-bar and mortar after propulsion into the ground to form pipe-roof. Therefore, it can be predicted that the integrated pipe-roof decreases the stress acting on the underpass by sharing load. In this study, to analyze the effect of integrated pipe-roof and behavior of stress around underpass, experimental tests for the rectangular and arch cross section of the underpass are performed using soil chamber. As a result, stress and strain acting on the underpass decrease due to sharing load by integrated pipe-roof. This phenomenon is more pronounced by increasing the stiffness of pipe-roof. Furthermore it can be expected that cross-section of underpass can be economically designed.

• Journal of English Language & Literature
• /
• v.55 no.1
• /
• pp.107-128
• /
• 2009

Literature had been at center-stage in the traditional grammar-translation-focused English classrooms up to the mid-twentieth century. As the Audiolingual Method and the Communicative Language Teaching have gained popularity in the English classrooms, however, literature has receded into the background of English education. The main reasons for using literary texts in the English classrooms for communication-focused English instruction need to be examined. First of all, students can come in touch with the subtle and varied uses of language through literature-based teaching. They also feel close to certain characters in the literary work and share the emotional reponses with them. They get personally involved in the plot of the story. Universal human experience and cultural enrichment are two other merits which can be conferred on students by literary texts. Such linguistic and literary experiences can be significantly integrated into the literature-based instruction. More significantly, the four language skills (reading, writing, listening and speaking) can be combined with one another and integrated into a literature-focused curriculum for English education. The value of literary texts in the English classrooms can be clearly demonstrated by effective ways of using such texts as Charlotte's Web for integrated instruction. The full array of benefits that literature can bring to English instruction, however, has yet to be fully realized. These potentials need to be materialized into classroom practice.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.10
• /
• pp.120-129
• /
• 2002

An integrated structure and controller design approach for rotating cantilever beam is presented. An optimization method is developed for improving positioning performance considering the elastic deformations during high speed rotation and adopting the beam shape and the control gains as design variables. For this end, a dynamic model is setup by the finite element method according to the shape of the beam. The mass and stiffness of the beam are distributed in such a way that the closed-loop poles of the control system should be located leftmost in the complex s-plane. For optimization method, the simulated annealing method is employed which has higher probability to find the global minimum than the gradient-based down-hill methods. Sequential design and simultaneous design methods are proposed to obtain the optimal shape and controller. Simulations are performed with new designs by the two methods to verify the effectiveness of the approach and the results show that the settling time is improved for point-to-point position controls.

• Structural Engineering and Mechanics
• /
• v.36 no.5
• /
• pp.625-642
• /
• 2010

The Integrated Force Method (IFM) is a novel matrix formulation developed for analyzing the civil, mechanical and aerospace engineering structures. In this method all independent/internal forces are treated as unknown variables which are calculated by simultaneously imposing equations of equilibrium and compatibility conditions. This paper presents a new 12-node serendipity quadrilateral plate bending element MQP12 for the analysis of thin and thick plate problems using IFM. The Mindlin-Reissner plate theory has been employed in the formulation which accounts the effect of shear deformation. The performance of this new element with respect to accuracy and convergence is studied by analyzing many standard benchmark plate bending problems. The results of the new element MQP12 are compared with those of displacement-based 12-node plate bending elements available in the literature. The results are also compared with exact solutions. The new element MQP12 is free from shear locking and performs excellent for both thin and moderately thick plate bending situations.

• Architectural research
• /
• v.22 no.4
• /
• pp.105-112
• /
• 2020

The purpose of this study is to establish a method for assessing a building's risk against disaster, tentatively named the Korean integrated disaster evaluation simulator (K-IDES). Based on previous studies, FEMA's risk management series and FEMA IRVS are selected as case studies for developing a frame work of K-IDES, through the comparative analysis of domestic building design guides, codes, and special acts related to disasters, in order to develop a risk assessment methodology for quantitative results. The assessment method consists of a classification system and calculating risk, and a simulation applying the developed checklist in K-IDES to similar types of high-rise buildings will be conducted to validate its accuracy. The final goal is to systemize an integrated risk management in a high-rise building against disasters for the purpose of recognizing vulnerable areas from the beginning of the design process and reinforcing it from potential threats after construction.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.669-677
• /
• 2022

In this paper, different types of traditional project delivery methods in the construction industry were explored and a comparative analysis against Integrated Project Delivery (IPD) were performed. The advantages of IPD method for all parties, owner/engineer/architect/general contractor, were explored by reviewing the most recent literature. The literature suggests that IPD method should be the dominating project delivery method and diluting the conventional methods such as Design-Bid-Build due to more collaborative and mutually beneficial ways of doing construction; IPD is newer and a more comprehensive method to capture the intrinsic values of project collaboration. This paper presents a comparison of the commonly used methods of project delivery, Design-bid-build, CMAR, & Design-Build and addresses their advantages and disadvantages in differing project scopes and sizes. Several industry leaders with experience in the four types of project delivery addressed were surveyed. The survey results show an overwhelming desire for future projects to go toward IPD from the contractor/owner/RDP. The biggest obstacle facing a project from using IPD appears to be trust.

• Journal of Korean Society on Water Environment
• /
• v.39 no.3
• /
• pp.215-222
• /
• 2023

Zooplankton are primary consumers in the food web connecting primary producers and predators such as small fish, playing an important role in energy transfer in aquatic ecosystems. Therefore, it is essential to understand the zooplankton community structure in material cycle and energy flow in aquatic ecosystems. Zooplankton in large rivers with a low flow rate would distribute vertically as in lakes. In this study, we collected zooplankton by surface water filtration and vertical haul method with 64 ㎛-mesh plankton net at three stations (ND-1, ND-2, ND-3) in Nakdong River fortnightly from June 2018 to December 2019. Species composition and individual densities were analyzed. All three stations showed differences in relative abundance of zooplankton groups between surface water and vertical integrated water, with the largest difference shown in the deepest station, ND-2. In vertically integrated water at ND-2, the relative abundance of rotifera was low by a maximum of 25% and that of cladocera was high by a maximum of 22% compared to surface water samples. These results indicate that surface water filtration method is not enough to represent the community structure of zooplankton compared to the vertical haul method in large rivers.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.653-654
• /
• 2005

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.11
• /
• pp.1039-1044
• /
• 2000

In this paper, the error caused by the measurement delay in INS/GPS integrated systems with Kalman filtering is defined and analyzed through the analytical method and the simulation. It is proved that the error of measurement delay causes not only the position error but also the estimate error of the x-axis accelerometer bias when a vehicle turns. And the estimation method of the delay time and the compensation method using an extrapolation method are presented. The performance of the compensation method is shown by the analytic method and the simulation.