• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1263-1269
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• 2004

The objective of this study was to characterize immunoliposomes carrying plasmid DNA with optimal encapsulation efficiency and antibody density. Plasmid DNA was encapsulated by the freezing/thawing method into liposomes composed of POPC (1-palmitoyl-2-oleoyl-sn-glycerol- 3-phosphocholine), DDAB (didodecyl dimethyl ammonium bromide), DSPE-PEG 2000 (distearoyl phosphatidyl ethanolamine polyethylene glycol 2000) and DSPE-PEG 2000-maleimide. The liposomes carrying plasmid DNA were extruded through two stacked polycarbonate filters, of different pore size, to control the liposome size. Then, rat IgG molecules were conjugated to the liposomes. The immunoliposomes containing plasmid DNA were separated from the free plasmid DNA and unconjugated IgG by Sepharose CL-4B column chromatography. The DNA amount encapsulated was affected by DDAB (cationic lipid) concentration, the initial amount of plasmid DNA between 10 ${\mu}g$ and 200 ${\mu}g$, the total lipid amount and plasmid DNA size, but not significantly by liposome size. By varying the ratio of DSPE-PEG 2000-maleimide to IgG, the number of IgG molecules per liposome was changed significantly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.10 s.241
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• pp.1353-1360
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• 2005

Injection-molded products serve a wide range of applications in our modem lives and their significance is ever increasing. However, difficulty of communication among related companies under the present system results in increase of lead time and decrease of production efficiency. The objective of this paper is the development of a web-based draft verification system in mold design processes. Although several commercial CAD systems offer draft verification functions, those systems are very expensive and inadequate to perform collaborative works. For collaborative work under the distributed environment, the proposed system uses native file transforming of CAD data into optimal format by using the ACIS kernel and InterOp. Functions of draft verification modules are constructed over the ActiveX control using the visual C++ and OpenGL. Therefore, collaborators related to the development of a new product are able to verify the draft and undercut over the Internet without commercial CAD systems. The system helps to reduce production cost, errors and lead-time to the market. Performance of the system is confirmed through various case studies.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1209-1215
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• 2017

Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, $108^{\circ}C$ of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

• ETRI Journal
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• v.27 no.6
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• pp.733-746
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• 2005

In the context of multi-protocol label switching (MPLS) traffic engineering, this paper proposes a scalable constraintbased shortest path first (CSPF) routing algorithm with multiple QoS metrics. This algorithm, called the multiple constraint-based shortest path first (M_CSPF) algorithm, provides an optimal route for setting up a label switched path (LSP) that meets bandwidth and end-to-end delay constraints. In order to maximize the LSP accommodation probability, we propose a link weight computation algorithm to assign the link weight while taking into account the future traffic load and link interference and adopting the concept of a critical link from the minimum interference routing algorithm. In addition, we propose a bounded order assignment algorithm (BOAA) that assigns the appropriate order to the node and link, taking into account the delay constraint and hop count. In particular, BOAA is designed to achieve fast LSP route computation by pruning any portion of the network topology that exceeds the end-to-end delay constraint in the process of traversing the network topology. To clarify the M_CSPF and the existing CSPF routing algorithms, this paper evaluates them from the perspectives of network resource utilization efficiency, end-to-end quality, LSP rejection probability, and LSP route computation performance under various network topologies and conditions.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.3
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• pp.206-212
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• 2009

This paper presents an optimized integrated task planning and control approach for manipulating a nonholonomic robot by mobile manipulators. Then, we derive a kinematics model and a mobility of the mobile manipulator(M2) platform considering it as the combined system of the manipulator and the mobile robot. to improve task execution efficiency utilizing the redundancy, optimal trajectory of the mobile manipulator(M2) platform are maintained while it is moving to a new task point. A cost function for optimality can be defined as a combination of the square errors of the desired and actual configurations of the mobile robot and of the task robot. In the combination of the two square errors, a newly defined mobility of a mobile robot is utilized as a weighting index. With the aid of the gradient method, the cost function is minimized, so the path trajectory that the M2 platform generates is optimized. The simulation results of the 2 ink planar nonholonomic M2 platform are given to show the effectiveness of the proposed algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.530-533
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• 2006

Recently, a basic access method about IEEE 802.11 MAC layer protocol using IEEE 802.11 wireless LANs is the DCF thatis based on the CSMA/CA. But, cause of IEEE 802.11 MAC layer uses original backoff algorithm (exponential backoff method), when collision occurred, the size of contention windows increases the double size. Also, a time of packet transmission delay increases and efficiency is decreased by original backoff scheme. In this paper, we have analyzed TCP packet transmission time of IEEE 802.11 MAC DCF protocol for wireless LANs a proposed enhanced backoff algorithm. It is considered the transmission time of transmission control protocol (TCP) packet on the orthogonal frequency division multiplexing (OFDM) in additive white gaussian noise (AWGN) and Rician fading channel. From the results, a proposed enhanced backoff algorithm produces a better performance improvement than an original backoff in wireless LAN environment. Also, in OFDM/quadrature phase shift keying channel (QPSK), we can achieve that the transmission time in wireless channel decreases as the TCP packet size increases and based on the data collected, we can infer the correlation between packet size and the transmission time, allowing for an inference of the optimal packet size in the TCP layer.

• Journal of Drive and Control
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• v.11 no.2
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• pp.22-29
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• 2014

This paper presents simulation-based analysis of energy flow of a wheel loader. The objective of this study is to analyze the energy flow of a wheel loader during driving and working. Because the wheel loader powertrain consists of a mechanical and hydraulic powertrain, the generated power from the engine is divided into 2 powertrains. Further, a virtual prediction of energy flow in the powertrains is a key factor in terms of optimal design. Accordingly, the simulation model that is able to predict the virtual energy flow is developed and analyzed in this study. The proposed wheel loader simulation model has been constructed in the Matlab/Simulink environment. It is expected that the developed simulation model will analyze the energy flow and efficiency in the design stage.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.51-59
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• 2019

Flow forming is an eco-friendly and high-efficiency plastic deformation process with fewer chips during a process which is specifically used to manufacture seamless tubular products like tire wheels, rocket motor cases etc. On the development of mortar barrel using Inconel718 tube, some flow formed products had dimensional errors on their thickness. In this study, our purpose is to optimize the process conditions with the smallest dimensional error. In order to find an optimum process condition, 2D axisymmetric FEM simulation analyses with Taguchi method were conducted. Geometric variables (attack angle, flatting angle, roller nose radius) and operating parameters (depth of forming, feed rate) are considered as control factors. Forward flow forming with single roller was first analyzed to determine the effective factors using AFDEX software and attack angle of the roller was identified as the most influential factor. Also, the nose radius of the rollers was confirmed as a significant factor in multi-rollers flow forming system. The effect of rollers offset values are also studied and finally, we proposed optimal conditions to improve the accuracy of flow forming process with Inconel718 tube for mortar barrel manufacturing.

• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.137-146
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• 2002

The benefit of TPL(Third-party Logistics) is reduction of transportation time, accuracy, improved expertise knowledge and access to logistics information system, improved operational efficiency, improved customer service, ability to focus in core business and greater flexibility. On the contrary, the defect of TPL is loss of control, unreliable promise of the enterprise (provider),inability to respond to logistics system requirement, lack of understanding of the user business goals . This thesis aims to suggest the optimal strategic to improve the logistics system and to satisfy the customer needs and also aims to suggest the TPL method to strengthen the TPL companies. And strategic plan Total (enterprise-TPL-customer) Logistics Information System(TLSI) of TPL operation. focused on transportation service and mechanism to use GPS model.

• Journal of Drive and Control
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• v.16 no.1
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• pp.1-6
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• 2019

The use of micro bubbles in industrial fields has been increasing in the recent years., particularly micro-bubble sterilization and water purification effects. Various methods have been developed for the generation of micro-bubbles. Depending on the method of generating bubbles, the micro-bubbles can be roughly classified into saturation molding, cavitation and rotation flow types. The objective of this study was to use ventilated tube type as a method of generating micro-bubbles in order to purify large amount of water quality such as lakes and reservoirs. This method shows a difference in efficiency in which micro-bubbles are generated depending on the contact ratio of gas to liquid. The study also investigated the optimal gas liquid contact ratio by applying various orifice methods and investigated the optimum condition of micro-bubble generation by gas Based on this, a technology to develop a micro-bubble generator with a venturi type nozzle shape that has a high water purification effect was developed.