• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.125-132
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• 2010

Recently, construction companies have had difficulty in managing their business due to economic hardship domestically and abroad, decreased orders, and low profitability due to intensified competition. To address these issues, construction companies need to develop or introduce construction methods that improve productivity. The purpose of this study is to investigate a re-bar construction method that reduces the high expenses of transport by folding a pre-fabricated re-bar cage. It was concluded that the application of rebar pre-fabrication would be activated and the productivity of construction sites improved by adopting the folding rebar pre-fabrication method.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.137-143
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• 2021

As an electrochemical water electrolysis for green hydrogen production, both polymer electrolyte membrane (PEM) and alkaline electrolyte are being developed extensively in various countries. The PEM electrolyzer with high current density (above 2 A/cm²) has the advantage of being able to design a simple structure. Also, it is known that it has high response to electrical output fluctuations. However, the cost problem of major components is the most important issue that a PEM electrolyzer must overcome. Instantly, there are platinum group metal (PGM)-based electrocatalysts, fluorine-based polyfluoro sulfuric acid (PFSA) membrane, Ti felt (porous transport layer, PTL) and so on. Another challenging issue is productivity. A securing outstanding productivity brings price benefits of the electrolytic cells. From this point of view, we conducted basic studies on manufacturing electrode and membrane electrode assembly (MEA) for PEM electrolyzer production.

• Design & Manufacturing
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• v.18 no.2
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• pp.35-40
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• 2024

Injection molding is a process widely used across various industries for molding plastics, and it is the most commonly applied process in root industries utilizing molds. Among the different types of injection molding, insert injection molding, where busbars are used as inserts, is increasingly being applied in the electric vehicle industry. However, currently, the insert injection molding process is manually performed, with workers placing insert components by hand before injection molding. This results in issues related to productivity, safety, and quality. Additionally, there is a growing demand for automation of such production lines due to hazardous working conditions, economic difficulties in the manufacturing industry, and the decline in the labor force caused by an aging population. This study focuses on the application of an automated system for the insert injection molding process used in electric vehicles. The development of an automated system for the transport and insertion of insert components, as well as the inspection and stacking processes after injection, has resulted in over a 25% improvement in productivity and more than a 27% reduction in defect rates.

• Journal of Korean Port Research
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• v.2 no.1
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• pp.75-106
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• 1988

As port transport system consists of subsystems such as navigation system, cargo handling system, storage system, inland transport system, and Management and Information system, the productivity of this system is determined by the minimum level of subsystem. From the viewpoint of elaborating the efficiency of integrated system, it is valuable to determine the optimal level of harbour tug boat which is the most important factor of navigation system. This paper treats the optimal amount of harbour tug boat by simulation, and applied to Pusan port. In the course of simulation, an emperical formula is introduced for determining the Horse Power (HP) of tug boat by the ship's gross tonnage (G/T) refering to the cases of various ports of other countries, that is ; $Y=9.96X^{0.6}+569$. X : The gross tonnage of vessel (G/T). Y : The Horse Power (HP) of tug boat. The results of the simulation are summarized as follows ; 1) In 1987, three or four low-powered harbour tug boats, five mid-powered harbour tug boats and four high-powered harbour tug boats are necessary in the mean level. But, five or seven low-powered harbour tug boats, ten mid-powered harbour tug boats and eight high-powered harbour tug boats are necessary lest delay should occur at all. 2) In 1992, 1lee or four low-powered harbour tug boats, six mid-powered harbour tug boats and seven high-powered harbour tug boats are estimated and be necessary in the mean level.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.749-754
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• 2021

In order to solve problems such as a decrease in the agricultural population and an aging population, research on agricultural robots is being actively conducted for the purpose of automating various agricultural tasks. The harvesting process is the most labor-intensive process among farm work and this process consumes about 2-3 times more compared to other processes. Since the transport of agricultural crops requires the most labor costs and there is a risk of injury during the operation, automating the transport operation through an agricultural robot can improve safety and significantly improve productivity. Therefore, this paper proposes an agricultural robot that is optimized for farm worksites and capable of autonomous driving.

• The Journal of Economics, Marketing and Management
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• v.9 no.3
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• pp.11-21
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• 2021

Purpose: The purpose of this study is to understand the status quo of production efficiency in private industrial enterprises above designated scale in China's 31 provinces (including municipalities directly under the central government, autonomous regions) (hereinafter referred to as China's 31 provinces). Research design, data and methodology: Find out the factors affecting the development of production efficiency in private industrial enterprises, using DEA, Data Envelopment Analysis and Malmquist index analysis, build the evaluation model of production efficiency in private industrial enterprises, and analyze the data of China's 31 provinces private industrial enterprises in 2015-2019. Results: The research results show that the production efficiency of private industrial enterprises in China is improving on the whole. Although the total factor productivity has decreased slightly, the overall efficiency and pure technical efficiency have increased significantly. Conclusions: The conclusion of this study can provide reference for Chinese private industrial enterprises to improve production efficiency and make development plan. The limitation of this paper lies in the fact that the private industrial enterprises in inefficient provinces have not been given specific improvement plans.

• Journal of Navigation and Port Research
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• v.42 no.1
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• pp.47-56
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• 2018

In this study, the focus is on the issue of whether a container terminal is facing the limitation of its productivity for serving mega-vessels with numerous containers. In order to enhance the terminal operations, a new conceptual design of the container handling system have been proposed. This research focuses on the rail-based container transport system and its operations. This system consists of rail-based shuttle cranes and rail-based transporters called flatcars. The deadlock problem for managing automated transporters in container terminals has been an important issue for a long measurement of time. Therefore, this study defines the deadlock situation and proposes its avoidance rules at the rail-based container transport system, which is required to handle numerous container throughput operations. The deadlock in the rail-based container transport system is classified into two parts: deadlock between cranes and flatcars; deadlock between flatcars. We developed the simulation model for use with characterizing and analyzing the rail-based container transport system. By running the simulation, we derived possible deadlock situations, and propose the several deadlock avoidance algorithms to provide results for these identified situations. In the simulation experiments, the performances of the deadlock avoidance algorithms are compared according to the frequency of deadlocks as noted in the simulations.

• Journal of Information Management
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• v.42 no.2
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• pp.151-165
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• 2011

Patent information as the innovative index for activity of industry, science and technology reflects the inventive outcome of the nation, region, technology, or company etc.. and is able to be used as a tool evaluating the R&D product and technology diffusion. In this study, the index for analysing the productivity, innovation, and activity of the technology is provided to evaluate the technology in fields of the pharmaceutic, transport, biotechnology, textile, construction, machine parts, information media, and electric/telecommunication, which are becoming the national core technology. As a result of analysis, the technology activity in fields of the construction, pharmaceutic, and biotechnology shows a growing trend which reflect the interest in the quality and the extension of the life, but vice versa in fields of the textile, and information media. The innovation index in fields of the construction, pharmaceutic, and biotechnology index more than average, but vice versa in fields of the information media and electric/telecommunication. In case of technology productivity, more than 2 patentees are included in one patented technology. It has been determined that the technology productivity is decreased because of an increasing number of researcher participating the technology development, which is the recent trend of technology advancement.

• Journal of Korean Port Research
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• v.11 no.1
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• pp.85-99
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• 1997

The improvements of berth productivity is closely related to berth/port systems and its relationship extends to the overall pattern of port development/logistics, transport and trade. Since ports in general and berths in specific function as a bridge transferring seaborne cargoes from seaside to landside and vice versa, berth productivity improvements should be considered in terms of the total system in which the cargoes are transported from origin to destination via berths/ports. In that respect, the objective of this study is to improve berth productivity which is a vital factor in the strategic planning in port development and operation and logistics. According to a literature survey on the subject, the contents of the studies have been limited to either a macro-perspective or a micro-perspective which is only a partial solution to the problem. Hence, this limitation requires an integrated approach to find and ultimate solution, which should be considered not separately, but as a whole. The contents and scope of this study cover the improvements of berth productivity in conjunction with strategic planning in port development. efficient operation and logistics from two different viewpoints, macro- and micro-perspective. After that, a combination of these two perspectives is applied to the integrated approach due to lacking a comprehensive perspective from either macro-approach or micro-approach. In reality, a port itself is a complex and dynamic organization. Therefore, a comprehensive insight needs an integrated approach for the long-term national economic development. In this approach, the utmost importance is how to find the bottlenecks and to solve the problems effectively from the beginning stage in port development. In conclusion, derived from the macro- and micro-perspective. the attempt to establish an integrated approach is the merit of this study, which is required as a comprehensive measure since none of the two can be a solution independently. In terms of reinforcing this study, it needs further empirical research due to the restriction of the theoretical method of this paper. Consequently, the reinforced research will be able to enhance the integrated approach on the basis of the conceptual perspective.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.41-44
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• 2000

Fermentation characteristics of recombinant Saccharomyces cerevisiae containing the xylose reductase gene from Pichia stipitis were analyzed in an attempt to convert xylose to xylitol, a natural five-carbon sugar alcohol used as a sweetener. Xylitol was produced with a maximum yield of 0.95 (g xylitol/g xylose consumed) in the presence of glucose that is used as a cosubstrate for cofactor regeneration. However addition of glucose caused inhibition of xylose transport and accumulation of ethanol. Such problems were solved by adopting glucose-limlted fed-batch fermentation. This process done with S, cerevisiae EHl3.15:pY2XR at$30\;^{\circ}C$ resulted in 105.2g/L xylitol concentration with maximum productivity of 1.69 g $L^{-1}$ $hr^{-1}$.