• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.664-666
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• 1987

In this study, the computation of optimum operating conditions for catalytic oxidation of sulfur dioxide to sulfur trioxide in CONVERTER which determines the yield ultimately in sulfuric acid plant is performed on an IBM/XT computer. The process simulator of rigorous converter model including mass & energy balance equations and supporting equations is linked to optimizer, which produces the desired results successfully.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.276-277
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• 2001

현재 컴퓨터 그래픽 분야에서 활동하는 전문 디자이너들은 WYSIWYG(What You See Is What You Get)을 지향하는 다양한 소프트웨어를 사용하고 있다. 그러나 이러한 소프트웨어들의 대부분은 디스플레이의 ${\gamma}$를 고려하여 색을 보정하도록 되어 있으므로, 시스템의 옵셋이 0이고 증폭률이 1이 되어 색 특성이 오로지 ${\gamma}$에 의존하는 최적상태로 조절된 디스플레이에 대해서만 정확한 보정이 이루어질 수 있다. (중략)

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.5
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• pp.88-93
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• 2003

Buckling behavior of stiffened laminated composite cylindrical panel was studied using linear and nonlinear deformation theory. Various buckling load factors are obtained for stiffened laminated composite cylindrical panels with rectangular type longitudinal stiffeners and various longitudinal length to radius ratio, which made from Carbon/Epoxy USN150 prepreg and are simply-supported on four edges under uniaxial compression. Buckling behavior design analyses are carried out by the nonlinear search optimizer, ADS.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1750-1752
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• 2005

This paper presents a variable speed wind generation system where fuzzy logic controllers is used as efficiency optimizer. The fuzzy logic controller increments the machine flux by on-line search to improve the generator efficiency in case of light load. The speed of the induction generator is controlled according to the variation of the wind speed in order to produce the maximum output power The generator reference speed is adjusted according to the optimum tip-speed ratio. The complete control system has been developed by simulation study.

• Journal of Advanced Information Technology and Convergence
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• v.8 no.2
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• pp.119-127
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• 2018

Training a very large deep neural network can be painfully slow and prone to overfitting. Many researches have done for overcoming the problem. In this paper, a combination of early stopping and ADAM based deep neural network was presented. This form of deep network is useful for handling the big data because it automatically stop the training before overfitting occurs. Also generalization ability is better than pure deep neural network model.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.6
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• pp.27-36
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• 1995

This paper covers algorithms to determine a machine assignment strategy to locations on a single straight track by minimizing the total backtrack distance. Three different algorithms ar presented: an efficient heuristic procedure, the branch-and-bound algorithm, and the nerual network approach. Simulation results show that the proposed algorithms have potential power to design an on-line optimizer.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.841-850
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• 1999

Many commercial database systems maintain histograms to summarize the contents of relations, permit efficient estimation of query result sizes, and access plan costs. In spatial database systems, most query predicates consist of topological relationship between spatial objects, and ti is ver important to estimate the selectivity of those predicates for spatial query optimizer. In this paper, we propose a selectivity estimation scheme for spatial topological predicates based on the multi-dimensional histogram and the transformation scheme. Proposed scheme applies two partition strategies on transformed object space to generate spatial histogram, and estimates the selectivity of topological predicates based on the topological characteristic of transformed space. Proposed scheme provides a way for estimating the selectivity without too much memory space usage and additional I/Os in spatial query optimizer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6A
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• pp.369-378
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• 2012

In this study, direct-search based optimization methods are applied for blade shape optimization of wind turbines and the optimization performances of several methods including conventional genetic algorithm, micro genetic algorithm and pattern search method are compared to propose a more efficient method. For this purpose, the currently available version of HARP_Opt (Horizontal Axis Rotor Performance Optimizer) code is enhanced to rationally evaluate the annual energy production value according to control strategies and to optimize the blade shape using pattern search method as well as genetic algorithm. The enhanced HARP_Opt code is applied to obtain the optimal turbine blade shape for 1MW class wind turbines. The results from pattern search method are compared with the results from conventional genetic algorithm and also micro genetic algorithm and it is found that the pattern search method has a better performance in achieving higher annual energy production and consistent optimal shapes and the micro genetic algorithm is better for reducing the calculation time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.817-838
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• 2014

Test environment on the company that handles a large amount of data such as telecommunications companies and financial institutions, may not always be the same as the production environment, which is caused by conversion of important columns about information and limitation of storage capacity due to the construction cost. Therefore, SQL performance degradation that occurs when the test and production environments are not the same, which is an important cause of connecting to the unexpected failures of online transactions, and it generates financial loss of business, customer complaints, a decrease in reliability. In studies related SQL performance, it has so far been conducted mainly studies of tuning associated with DBMS Optimizer, and it has not been addressed issues of this sector. Therefore, in this paper, I verify the validity about presentation of the advanced SQL Performance-based IT application change management process, in order to prevent failures of the online transactions associated with poor performance of SQL generated by differences in test and production environments.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.235-247
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• 2021

Today, the cloud computing has become a major demand of many organizations. The major reason behind this expansion is due to its cloud's sharing infrastructure with higher computing efficiency, lower cost and higher fle3xibility. But, still the security is being a hurdle that blocks the success of the cloud computing platform. Therefore, a novel Multi-tenant Decentralized Information Flow Control (MT-DIFC) model is introduced in this research work. The proposed system will encapsulate four types of entities: (1) The central authority (CA), (2) The encryption proxy (EP), (3) Cloud server CS and (4) Multi-tenant Cloud virtual machines. Our contribution resides within the encryption proxy (EP). Initially, the trust level of all the users within each of the cloud is computed using the proposed two-stage trust computational model, wherein the user is categorized bas primary and secondary users. The primary and secondary users vary based on the application and data owner's preference. Based on the computed trust level, the access privilege is provided to the cloud users. In EP, the cipher text information flow security strategy is implemented using the blowfish encryption model. For the data encryption as well as decryption, the key generation is the crucial as well as the challenging part. In this research work, a new optimal key generation is carried out within the blowfish encryption Algorithm. In the blowfish encryption Algorithm, both the data encryption as well as decryption is accomplishment using the newly proposed optimal key. The proposed optimal key has been selected using a new Self Improved Cat and Mouse Based Optimizer (SI-CMBO), which has been an advanced version of the standard Cat and Mouse Based Optimizer. The proposed model is validated in terms of encryption time, decryption time, KPA attacks as well.