• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.531-533
• /
• 1997

PI(proportional-integral) controller has been extensively used in the industrial field. But in practicle case, it is difficult to tune PI gains. Evolution Strategy(ES) is used as an effective search algorithm in optimization programs. In this paper we proposed a PI controller for Spot welder system using ES with varying search space. ES with varying search space which depends on fitness values at each generation is used to tune PI control parameters. Simulation results show the proposed algorithm has accurate and robust performance with effective search ability.

• Journal of the Korean Chemical Society
• /
• v.7 no.2
• /
• pp.115-121
• /
• 1963

Aliphatic hydrocarbon gases from rubber pyrolysis have been identified by gas chromatography with tetraethyleneglycol dimethylether column. Rubbers used in this work are polyisoprene, SBR, NBR, polybutadiene, buthyl rubber, polychloroprene and polyurethane rubber. The chromatogram is characteristic for each polymer. Author proposes a method of identification of synthetic rubbers by gas chromatograph of pyrolyzed gas. Sample is pyrolyzed at $450^{\circ}C$ under nitrogen or more effectively helium and gaseous portion, which eliminated liquid condensate, is passed to the column. The appearance of exclusively large peak of isoprene, isobutylene and carbon dioxide shows the presence of polyisoprene, polyisobutylene and polyurethane, respectively. Large peak of butadiene will appear in case of polybutadiene, SBR and NBR, but SBR can be identified through the styrene peak in gas chromatogram of liquid pyrolyzate and NBR can be identified by the evolution of hydrogen cyanide during pyrolysis. Polychloroprene is identified by the evolution of hydrogen chloride. This method could be applied to the identification of copolymer or polymer blend.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.641-644
• /
• 2017

Usage of LTE(Long Term Evolution) technology is expanded to industrial an emergency service field beyond commercial communications of mobile internet focused on smartphone. In this paper, transmission performance of LTE technology be supplied to various service area is analyzed on the level of application traffics. Performance is evaluated with compter simulation based NS(Network Simulator)-2, CBR(Constant Bit Rate), VBR(Variable Bit Rate File) traffic is used as simulation target. Results and methods of this paper can be used for research and developmemt of LTE based networks.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.29 no.1
• /
• pp.116-124
• /
• 2006

In this paper, we proposed the SCM logistics roadmap in other that the 'Northeast Asian Distribution Hub' policy of the government can be realized more effectively. First, we analysed the requirements of SCM roadmap by examining the situation of Northeast Asian Distribution Hub roadmap, and developed 3 key dimensions of SCM roadmap-national, industrial, and technological dimensions. Second, we suggested integrated SCM on the 4-stage evolution axis, and suggested 9 strategies for realizing the roadmap. Finally, we discussed a cyclical improvement system for the suggested SCM roadmap to keep pace with the change of technical and industrial environment. We expect that the suggested SCM roadmap would be refined by the reaction of logistics groups and various opinions of experts, and become the foundation of execution strategies.

• Applied Chemistry for Engineering
• /
• v.9 no.1
• /
• pp.52-57
• /
• 1998

The effects of additives such as zinc compounds in 4M KOH electrolyte of Al-air cell have been studied. Zinc compounds in electrolyte increased hydrogen evolution overpotential and TPC(tripotasium citrate)/CaO formed fine film on aluminum surface, and these additives decreased hydrogen evolution rate and corrosion rate of aluminum. These additives shifted the OCP in the positive direction on high purity aluminum(purity, 99.999%) and in the negative direction on Al No 1050(purity,99.5%). Addition of two or more additives resulted in the prevention or the reduction of corrosion rate and hydrogen evolution at OCP. As the overpotential on Al electrode increased, the hydrogen evolution rate decreased and the utilization of aluminum increased. At high current density$(>100mA/cm^2)$, TPC/CaO/ZnO additives increased the utilization of high purity aluminum up to that of aluminum alloys containing indium, gallium and thallium.

• Applied Chemistry for Engineering
• /
• v.34 no.6
• /
• pp.567-575
• /
• 2023

Water electrolysis is undergoing active research as one of the promising technologies for producing effective green hydrogen. Using seawater directly as a raw material for a water electrolysis system can solve the problem of the limitations of existing freshwater raw materials, as seawater accounts for approximately 97% of the water on Earth. At the same time, abundant by-product materials can be obtained, representative examples of which are Cl₂, ClO^-, Br₂, and Mg(OH)₂ produced during electrolysis, depending on their composition and pH environment. In order to develop a successful seawater electrolysis system and oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts, it is necessary to understand the causes and consequences of reactions that occur in the seawater environment. Therefore, in this paper, we will investigate the reaction mechanism and characteristics of the seawater electrolysis system as well as the research and development trends of electrochemical catalysts used in anode and cathode electrodes.

• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.4
• /
• pp.24-34
• /
• 2008

The study aims to anticipate evolution direction of mobile content business in the future, and derive successful strategies at the same time with multiple and composite analysis of evolution process and environmental change of mobile business. In conclusion, Firstly, it should strengthen customer approach performance, secondly, approaches with sensitively, and needs opened business model. Fourthly, it needs planning and production of contents which reflects the need of customers, and fifthly, it requires development of mobile platform leading contents group and multiplication of CP business model. In the aspect of industrial policy, sustainable and future-oriented policy should be arranged rather than short-term and simple police, for the continual development of mobile content industry. To establish healthy and active mobile contents industry, the government and regulatory institutes are more preferable to devote to the role of circumstance builder rather than the leader of mobile content market. In other words, they are recommended to focus on establishing basic regulation and order for smooth operation of the market and its management.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.115-128
• /
• 2019

Small and Medium-sized Enterprises (SMEs) are being faced with rapid changes in their business environments due to evolution of technologies and innovation in societal eco-systems. Particularly, dynamic interactions between such environments and enterprise activities have become significant, so technology planning, which is a process of identifying appropriate directions regarding product and technology development, has received much attention to cope with such dynamics proactively. However, SMEs typically have limits in performing independent, strategical and systematical technology planning activities due to the lack of human, material and financial resources. This paper proposes the development of a product roadmapping method so that SMEs carry out efficient technology planning activities with interconnections of external business environments. The present work provides product roadmap templates that directly accommodate the influence of business environments on the product's system and its associated super/sub-systems with the use of external environment analysis techniques including TRIZ methodology, PEST and 5Forces analysis. These templates are useful to efficiently forecast the directions of product's development and evolution, which arise from changes in external environments. Consequently, the present work enables SMEs to flexibly cope with the era of the next R&D generation, which pursues value creation through mutual interconnection between business environments and technology development.

• Asian Journal of Innovation and Policy
• /
• v.10 no.3
• /
• pp.380-403
• /
• 2021

Recently, smart factories have gained significant importance since the development of the fourth industrial revolution and the rise of global industrial competition. Therefore, the industries' survival to meet the global market trends requires accurate technological planning. Although, different works are available to investigate forecasting technologies and their influence on the smart factory. However, little significant work is available yet on the analysis of technological trends concerning the smart factory, which is the core focus herein. This work was performed to analyze the technological trends of the smart factory, followed by a detailed investigation of recent research hotspots/frontiers in the field. A well-known topic modeling technique, namely Latent Dirichlet Allocation (LDA), was employed for this study described above. The technological trends were further strengthened with the in-depth analysis of a smart factory-based case study. The findings produced the technological trends which possess significant potential in determining the technological strategies. Moreover, the results of this work may be helpful for researchers and enterprises in forecasting and planning future technological evolution.

• Industrial Engineering and Management Systems
• /
• v.10 no.1
• /
• pp.7-14
• /
• 2011

In solving the Job Shop Scheduling Problem, the best solution rarely is completely random; it follows one or more rules (heuristics). The Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Simulated Annealing, and Tabu search, which belong to the Evolutionary Computations Algorithms (ECs), are not efficient enough in solving this problem as they neglect all conventional heuristics and hence they need to be hybridized with different heuristics. In this paper a new algorithm titled "Shaking Optimization Algorithm" is proposed that follows the common methodology of the Evolutionary Computations while utilizing different heuristics during the evolution process of the solution. The results show that the proposed algorithm outperforms the GA, PSO, SA, and TS algorithms, while being a good competitor to some other hybridized techniques in solving a selected number of benchmark Job Shop Scheduling problems.