• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2301-2309
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• 2018

In a field-oriented vector-controlled permanent magnet synchronous motor (PMSM) control system, the d-axis current control loop can offer a free degree of freedom which can be used to improve control performances. However, in the industry the desired d-axis current command is usually set as zero without using the free degree of freedom. This paper proposes a method to use the degree of freedom for control performance improvement. It is assumed that both the inner loop proportional-integral (PI) current controller and the q-axis outer loop PI speed controller are tuned by the well-known tuning rules. This paper gives an optimal d-axis reference current command generator such that some useful performance indexes are minimized and/or a tradeoff between conflicting performance criteria is made. This paper uses a differential evolution algorithm to autotune the parameter values of the optimal d-axis reference current command generator. This paper implements the proposed control system in real time on a Texas Instruments TMS320F28335 floating-point DSP. This paper also gives experimental results showing the practicality and feasibility of the proposed control system, along with simulation results.

• Industrial Engineering and Management Systems
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• v.13 no.4
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• pp.432-441
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• 2014

As the business model is receiving considerable attention these days, the ability to collect business model related information has become essential requirement for a company. The annual report is one of the most important external documents which contain crucial information about the company's business model. By investigating business descriptions and their future strategies within the annual report, we can easily analyze a company's business model. However, given the sheer volume of the data, which is usually over a hundred pages, it is not practical to depend only on manual extraction. The purpose of this study is to complement the manual extraction process by using text mining techniques. In this study, the text mining technique is applied in business model concept extraction and business model evolution analysis. By concept, we mean the overview of a company's business model within a specific year, and, by evolution, we mean temporal changes in the business model concept over time. The efficiency and effectiveness of our methodology is illustrated by a case example of three companies in the US video rental industry.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5972-5989
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• 2019

With the onset of the big data age, data is growing exponentially, and the issue of how to optimize large-scale data processing is especially significant. Large-scale global optimization (LSGO) is a research topic with great interest in academia and industry. Spark is a popular cloud computing framework that can cluster large-scale data, and it can effectively support the functions of iterative calculation through resilient distributed datasets (RDD). In this paper, we propose a hybrid mechanism of particle swarm optimization (PSO) and differential evolution (DE) algorithms based on Spark (SparkPSODE). The SparkPSODE algorithm is a parallel algorithm, in which the RDD and island models are employed. The island model is used to divide the global population into several subpopulations, which are applied to reduce the computational time by corresponding to RDD's partitions. To preserve population diversity and avoid premature convergence, the evolutionary strategy of DE is integrated into SparkPSODE. Finally, SparkPSODE is conducted on a set of benchmark problems on LSGO and show that, in comparison with several algorithms, the proposed SparkPSODE algorithm obtains better optimization performance through experimental results.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.577-584
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• 2020

Construction automation and robotics have been widely adopted in the construction industry as a promising solution to such issues like a shortage of skilled labor and the difficulties workers face in harsh working environments. The analysis of the knowledge structure and its evolution from the existing articles helps identify essential knowledge elements and possible future research directions. This study attempts to (1) construct keyword networks from the papers published in the International Symposium on Automation and Robotics in Construction (ISARC), (2) investigate how keywords and keyword communities are associated with each other, and (3) examine the changes in the crucial keywords over time. Through cluster analysis, 79 keywords were categorized into four groups (BIM, Building construction, Sensing, and GPS as representative keywords) with similar structural positions. Research trends show that research themes related to Infrastructure, Construction equipment, and 3D have consistently received a large amount of attention, regardless of geographical region. Research on as-built status model utilization through BIM and Laser scanning and improving Energy performance is taking place more frequently. In contrast, research studies related to problem-solving based on Neural networks are not as common as previously. This study provides useful insights into the construction automation field, at both the macro and micro levels.

• International Journal of Advanced Culture Technology
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• v.12 no.3
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• pp.370-379
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• 2024

In this paper, we explore the historical development and revolutionary impact of music in mass media across various forms, including radio, television, film, and digital platforms. The evolution of music in mass media reflects significant technological and cultural shifts over the past century. From the early days of radio to the advent of digital streaming, music has played a crucial role in shaping the types of mass media. Early radio broadcasts in the 1920s relied on live performances and recordings to captivate audiences, establishing music as a central element of media content. The rise of television in the 1950s brought new opportunities for music integration, with theme songs, variety shows, and music videos becoming staples of TV programming. The film industry further revolutionized the use of music, with iconic scores enhancing cinematic storytelling and emotional depth. The digital revolution of the late 20th century introduced new formats and services, expanding access to music and transforming consumption patterns. Recently, streaming platforms and social media allow for personalized music experiences and direct artist-fan interactions. Through an analysis of technological advancements, this study highlights the integral role of music in enhancing narrative, evoking emotions, and creating cultural identities. We present our understanding of this evolution to provide insights into future trends and potential innovations in the integration of music with mass media, including the use of artificial intelligence and virtual reality to create immersive auditory experiences.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.2
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• pp.101-113
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• 2011

As information and communication technology advances driving the rapid evolution of e-commerce and e-business becomes on effective marketing means for both business and institutions, the industry deals with these changes and has a profound, positive impact on production and operations management. But the construction industry falls behind compared with other industries in productivity, informationalization, automatization and globalization. Especially even though the informationalization is inevitable in any developing society, a number of construction industries can hardly cope with it properly. As the construction industry gets informationalized and advanced, the introduction of PMIS (Project Management Information System) is making progress actively for the effective construction project control and productivity improvement in construction. With the government officials' political promotion and the rising desire for construction informationalization of enterprises, many are attempting to develop integrated systems or to replace a previous system with a more advanced alternative. Construction Industry, however, has the peculiar properties that the period for the completion of construction is limited and on top of that, most of its data processing systems are seen as being an early stage in the design of management information systems. As a result, there are extremely few applications in the construction industry. In this paper, we propose the PMIS system based on new model 4CM that improves on previous models.

• Fashion & Textile Research Journal
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• v.23 no.4
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• pp.439-447
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• 2021

The purpose of this study is to examine the evolution of precious metal and gem stores, and to derive the characteristics of this period from the government, industry, and consumers. Correspondingly, the contents of daily newspaper articles during this period were analyzed using Naver's news library search engine. The historical development process is as follows. Before the Korean War, precious metal jewelers operated in Jongno, Namdaemun, and Chungmuro, dealing with gold, silver, and platinum. Large stores not only sold jewelry and watches, but also functioned as craftsmen and watch repairers. After the war, a shopping district for precious metals and jewelry was formed around Midopa Department Store. By 1963, the number of jewelry stores in Seoul increased to about 130 and to about 280 by 1966. The characteristics of the government, industry, and consumers are as follows. The government continued to implement a policy to regulate the precious metal and jewelry industry. Despite challenges, the industry exhibited the potential for foreign currency acquisition and growth through domestic amethyst. Consumers could access information regarding precious metal jewelry in daily newspapers. In the late 1960s, various types of jewelry were distributed in line with an increase in income levels.

• Journal of Engineering Education Research
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• v.20 no.4
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• pp.3-11
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• 2017

In this study, more than 2,500 cases using TRIZ methodology for 10 years from 2006 to 2016 in S company were analyzed to identify which TRIZ tools have been used for solving field problems. In the previous studies, some attempts were made to analyze the utilization of TRIZ tools, but all of them were based on very limited surveys or cases. The results of this study show that 40 inventive principles were most used, followed by separation principles, standard solutions, trimming, modeling using little people, patterns of evolution, ARIZ and Effects. In addition, detailed analysis were performed for widely used tools such as 40 inventive principles, separation principles, standard solutions, etc. The analysis would be a useful guide for the study and application of TRIZ tools in industry.

• Journal of Korea Technology Innovation Society
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• v.2 no.2
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• pp.275-289
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• 1999

This study aims at investigating the stylized facts of the complex system products innovation in Korea. It reviewed the preceeding studies on the innovation patterns of complex system products and selected the issues to be examined in investigating Korean case. In addition, the stylized facts of innovation patterns of Korean complex system products were suggested. The peculiar characteristics of Korean cases are as follows: Korea has succeeded in integrating foreign technologies and components into commercial complex system products and in substituting the foreign system products in the domestic market. However, it faces a great difficulty in upgrading the products to the next generation. It lacks capabilities which facilitate the evolution of system products competing in the world market.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1135-1136
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• 2008

Error correcting codes (ECC) are widely used in all types of memory in industry, including caches and embedded memory. The focus in this paper is on studying of power consumption in memory ECCs circuitry that provides single error correcting and double error detecting (SEC-DED) designed by various evolution strategies. The methods are applied to two commonly used SEC-DED codes: Hamming and odd column weight Hsiao codes. Finally, we conduct some simulations to show the performance of the various methods.