• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.262-269
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• 2003

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Management (SCM). One of the key issues in the current SCM research area involved reducing both production and distribution costs. The purpose of this study is to determine the optimum quantity of production and transportation with minimum cost in the supply chain network. We have presented a mathematical model that deals with real world factors and constructs. Considering the complexity of solving such model, we have applied the genetic algorithm approach for solving this model computational experiments using a commercial genetic algorithm based optimizer. The results show that the real size problems we encountered can be solved In reasonable time

• Korean Journal of Plant Taxonomy
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• v.50 no.1
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• pp.1-7
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• 2020

Cynanchum L. in the subfamily Asclepiadoideae (Apocynaceae) includes four recognized species on the Korean peninsula, two of which are native to South Korea. However, the species ranges in South Korea are poorly defined. During a field survey, we discovered C. thesioides, previously unrecorded in South Korea, in Gimpo-si, Gyeonggi-do, and found an additional population of C. chinense, for which only one population has been reported in South Korea. The two taxa are considered rare species with extremely restricted distributions in South Korea, especially C. thesioides. We provide fundamental information, including descriptions, images of the habitats and morphological characters, and a taxonomic key for identification and assessments of the conservation status of Cynanchum species in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.57-57
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• 2022

A taxonomic revision of Deutzia in Korea was conducted based on critical observations of wild populations and herbarium specimens. Species delimitations were re-evaluated on the basis of morphological characters and distributions resulting in the recognition of five taxa. The texture of leaf, flower disk and capsules, the shape of leaf, inflorescence and capsules are useful diagnostic traits at the specific level. The five taxa are well distinguished from each other. Deutzia grandiflora var. baroniana can be distinguished by its distribution and calyx from Deutzia uniflora, which are morphologically similar. Deutzia paniculata Nakai, a rare and endemic plant, is characterized by having panicle in inflorescences. On the other hand, Deutzia glabrata Kom. is occasionally confused with Deutzia parviflora, but the most distinctive characters include the surface of leaves, the surface and size of capsules. Photographs and a key to five species of Deutzia were provided in addition to distribution.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.6
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• pp.615-630
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• 2016

Complex stress distributions often exist in ocean engineering structures. This stress influences structural vibrations. Finite Element Methods exhibit some shortcomings for solving non-uniform stress problems, such as an unclear physical interpretation, complicated operation, and large number of computations. Analytical methods research considers mainly uniform stress problems, and often, their methods cannot be applied in practical marine structures with non-uniform stress. In this paper, an analytical method is proposed to solve the vibration of plates with general stress distributions. Non-uniform stress is expressed as a special series, and the stress influence is inserted into a vibration equation that is solved through decoupling to obtain an analytical solution. This method has been verified using numerical examples and can be used in arbitrary stress distribution cases. This method requires fewer computations and it provides a clearer physical interpretation, so it has advantages in some qualitative research.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.5
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• pp.115-124
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• 2005

We propose a new binding update(BU) protocol between mobile node(CN) and correspondent node(CN) for the purpose of preventing redirect attacks and DoS attacks observed from the existing BU protocols and enhancing the efficiency of the BU protocol. Home agent plays a role of both authentication server validating BU message and session key distribution center for MN and CN. Also propose the stateless Diffie-Hellman key agreement based on cryptographically generated address (CGA). Suity of our proposed Protocol is analyzed and compared with other protocols. The proposed protocol is more efficient than previous schemes in terms of the number of message flows and computation overhead and is secure against both redirect and DoS attacks.

• Geomechanics and Engineering
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• v.12 no.6
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• pp.1003-1020
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• 2017

Estimation of groundwater inflow into underground opening is of critical importance for the design and construction of underground structures. Groundwater inflow into a pilot underground storage facility in China was estimated using analytical equations, numerical modeling and field measurement. The applicability of analytical and numerical methods was examined by comparing the estimated and measured results. Field geological investigation indicated that in local scale the high groundwater inflows are associated with the appearance of open joints, fractured zone or dykes induced by shear and/or tensile tectonic stresses. It was found that 8 groundwater inflow spots with high inflow rates account for about 82% of the total rate for the 9 caverns. On the prediction of the magnitude of groundwater inflow rate, it was found that could both (Finite Element Method) FEM and (Discrete Element Method) DEM perform better than analytical equations, due to the fact that in analytical equations simplified assumptions were adopted. However, on the prediction of the spatial distribution estimation of groundwater inflow, both analytical and numerical methods failed to predict at the present state. Nevertheless, numerical simulations would prevail over analytical methods to predict the distribution if more details in the simulations were taken into consideration.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.37-44
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• 2019

The purpose of this study is to rationally determine the priority of seismic reinforcement of main(key) members of bridges. Cable Supported bridge was selected as the evaluation target and the reliability based on the probability distribution was used to evaluate the seismic fragility of the key members as a quantitative indicator. The safety factor, which is a random variable, is considered an artificial (fixed load and live load) load and a natural (earthquake, wind, temperature, etc.) load. The seismic load is applied as a possible earthquake during the lifetime of the bridge. From analyzing the fragility of each key member based on the seismic reliability, it can be concluded that the shoe (23.8%) was the most fragile, where the other members are ranked as place concrete (20.5%), pier (18.9%), foundation (17.3%) and cable (5.0%) respectively.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2573-2578
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• 2007

In order to investigate the vortex body frame interaction around the side mirror of a passenger car, velocity vector fields in the wake, pressure distributions and boundary layer flows over both the mirror surface and the mirror housing, have been measured by several experimental tools. It was resulted that only within an half downstream distance of the mirror span there appears the recirculation zone, and also found that vortex trail towards to the driver side window between A and B pillars, making the acoustic noise and vibration. Wake vortex rolls up after this recirculating zone and makes the trail of the vortex center towards the driver side window, which was also confirmed by measurements of wake velocity vectors in the vertical sections of the trail and visualization over the side mirror surfaces as well. It was also observed that total pressure distribution over the mirror surface has the minimum peak near the lower tip region which can be considered as the origin of the vortex center. It can be concluded that the geometrical modification of the lower tip and the upper root area of the mirror housing is the key to control the wake vortex.

• Journal of computational fluids engineering
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• v.19 no.3
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• pp.20-23
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• 2014

The flow pattern inside the inlet chamber of the tube side is one of the key parameters influencing on the performances of the shell-and-tube type of heat exchangers(STHE). In order to improve the flow distribution, the baffle shaped as the porous plate is installed in the inlet chambers. In the present study, numerical simulation has been performed to investigate the flow features of the tube side of the STHE in sense of the hydraulic performances. The flow fields have been analysed by the three-dimensional Navier-Stokes solvers with the proper turbulent models. Computational domain is ranged in the whole of the tube side of the STHE. The numerical results showed that the presence of the baffles improves the redistribution of the flow injecting to the tube bundels. The good agreements of the numerical results with the experimental results of PIV measurements have been shown for the validation of the numerical methods adopted in the present papers.

• Mass Spectrometry Letters
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• v.10 no.1
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• pp.11-17
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• 2019

Drosophila melanogaster (fruits fly) is a representative model system widely used in biological studies because its brain function and basic cellular processes are similar to human beings. The whole head of the fly is often used to obtain the key function in brain-related diseases like degenerative brain diseases; however the biomolecular distribution of the head may be slightly different from that of a brain. Herein, lipid profiles of the head and dissected brain samples of Drosophila were studied using electrospray ionization-mass spectrometry (ESI-MS). According to the sample types, the detection of phospholipid ions was suppressed by triacylglycerol (TAG), or the specific phospholipid signals that are absent in the mass spectrum were measured. The lipid distribution was found to be different in the wild-type and the microRNA-14 deficiency model ($miR-14{\Delta}^1$) with abnormal lipid metabolism. A few phospholipids were also profiled by comparison of the head and the brain in two fly model systems. The mass spectra showed that the phospholipid distributions in the $miR-14{\Delta}^1$ model and the wild-type were different, and principal component analysis revealed a correlation between some phospholipids (phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS)) in $miR-14{\Delta}^1$. The overall results suggested that brain-related lipids should be profiled using fly samples after dissection for more accurate analysis.