• International Area Studies Review
• /
• v.15 no.2
• /
• pp.247-273
• /
• 2011

This study analyzes the impacts on the M&A and greenfield of macroeconomic variables of home and host countries, after identifying current status and characteristics of the M&A and greenfield related to the entering way of Korean firms in China. Main empirical results are summarize as follows. First, as for foreign exchange variable, the decreased value of Korea won shows the negative correlations with both of the greenfield and M&A. Second, the real interest rate of Korea to measure the cost of capital is not significant statistically. Third, while the host country's stock market index, Shanghai Comprehensive Index, shows the expected negative correlations with the investment in the case of small & medium firm and light industry, it shows the positive correlations which is not consistent with general expectation in the case of large firm and heavy industry. Fourth, the openness of host country shows the positive correlations with both of the greenfield and M&A. Finally, in regard to the M&A, China's GDP to measure the market size of host country is not significant statistically while it shows the strong positive relationship with the greenfield investment.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.8
• /
• pp.634-641
• /
• 2019

The world's population reached 7.7 billion in 2019. Despite this trend, not all cities are growing. Most of the growing population is driven to large cities for convenience and jobs. This phenomenon has led to a decrease in the population of small and medium-sized cities, and in certain cities, a decrease in employment as well as recession have resulted. Korea is no exception. The nation's population is concentrated in the metropolitan cities. To solve these problems, researchers started to study how to deal with the contraction of a city, i.e., a shrinking city, rather than focusing on only the growth of a city. In this paper, demographically outstanding declined domestic cities were selected as shrinking cities and their characteristics were analyzed. The concept of smart shrinking cities was then defined for the selected cities, which were chosen as a good case in overseas countries to solve the shrinking city problem. Through this process, the strategic differences were compared between domestic and oversea cases. As a result, a modified strategy for the smart shrinking city concept, FSSC (flexible smart shrinking city), is proposed as an alternative strategy that can save resources and cost.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.2
• /
• pp.53-59
• /
• 2019

As solve the shortage problems of storage space for exhibition facilities, the South Korean government is establishing plans to expand storage space for exhibition facilities. From a medium- to long-term perspective, an energy-efficient storage space for exhibition facility is needed to implement efficient state budget execution and achieve national greenhouse gas reduction goals. In this regard, this study analyzed the energy consumption of storage space for exhibition facilities according to the use of absorption materials. To this end, a case study was conducted on 12 storage spaces for exhibition facilities in South Korea. Compared to the storage space using the absorption material, the storage space without using the absorption material showed an increase in HVAC system operation time by 47.50% during summer periods and 58.85% in non-summer periods. In particular, the analysis found that in the case of storage for 'H' exhibition facility, the energy cost was reduced by 2,721,700 won/year after remodeling work using the absorption material. It is expected that the findings of this study can help the government and the person in charge from construction companies to construct energy-efficient storage space room for exhibition facilities.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.13 no.6
• /
• pp.143-154
• /
• 2018

This study is intended to look into the effects of SCM(supply chain management) competency and process improvement on operational performance in small and venture companies. To achieve this, a survey was empirically carried out to 179 small and venture manufacturing companies. The findings showed that the SCM competency had a significant effect on the process improvement and operational performance in small and venture companies, adopting all hypotheses. And the process improvement had a significant mediating effect on the relationship between SCM competency and operational performance in small and venture companies, adopting hypothesis 4. As for the findings, strategic alliance, technology development, competency concentration as SCM competencies and starting preparation, detailed planning, implementation management as process improvements were factors that have positive effects on quality performance, cost reduction and profit increase as operational performances in small and venture companies. In other words, the better process and performance by the maximized SCM competencies require selective input strategies for strategic alliance, technology development and competency concentration in small and venture companies. And for its early application and settlement, the starting preparation and detailed planning of business process within small and venture companies need to be jointly put in action under clear company-wide goal management. Consequently, the expected performance can be maximized when strict management and implementation lead to these attributes.

• Journal of Wetlands Research
• /
• v.21 no.2
• /
• pp.181-190
• /
• 2019

Recently, Low impact development techniques, a form of nature-based solutions (NBS), were seen cost-efficient alternatives that can be utilized as alternatives for conventional stormwater management practices. This study evaluated the effectiveness of an infiltration trench (IT) and a small constructed wetland (SCW) in treating urban stormwater runoff. Long-term monitoring data were observed to assess the seasonal performance and cite the advantages and disadvantages of utilizing the facilities. Analyses revealed that the IT has reduced performance during the summer season due to higher runoff volumes that exceeded the facility's storage volume capacity and caused the facility to overflow. On the other hand, the pollutant removal efficiency of the SCW was impacted by the winter season as a result of dormant biological activities. Sediment data also indicated that fine and medium sand particles mostly constituted the trapped sediments in the pretreatment and media zones. Sediments in SCW exhibited a lower COD and TN load due to the phytoremediation and microbiological degradation capabilities of the system. This study presented brief comparison LID facilities equipped with pre-treatment zones. The identified factors that can potentially affect the performance of the systems were also beneficial in establishing metrics on the utilization of similar types of nature-based stormwater management practices.

• Journal of Navigation and Port Research
• /
• v.43 no.1
• /
• pp.42-48
• /
• 2019

The significance of PNT information in the fourth industrial revolution is viewed differently in relation to the past. Autonomous vehicles, autonomous vessels, smart grids, and national infrastructure require sustainable and reliable services in addition to their high precision service. Satellite navigation system, which is the most representative system for providing PNT information, receive signals from satellites outside the earth so signal reception power is low and signal structures for civilian use are open to the public. Therefore, it is vulnerable to intentional and unintentional interference or hacking. Satellite navigation systems, which can easily acquire high performance of PNT information at low cost, require alternatives due to its vulnerability to the hacking. This paper proposed R-Mode (Ranging Mode) technology that utilizes currently operated navigation and communication infrastructure in terms of Signals of OPportunity (SoOP). For this, the Nationwide Differential Global Navigation Satellite System (NDGNSS), which currently gives a service of Medium Frequency (MF) navigation signal broadcasting, was used to validate the feasibility of a backup infrastructure in domestic maritime areas through simulation analysis.

• Journal of Internet of Things and Convergence
• /
• v.8 no.6
• /
• pp.55-63
• /
• 2022

In recent years, with the rapid development of large and medium-sized urban rail transit in China, the total operating mileage of high-speed railway and the total number of EMUs(Electric Multiple Units) are rising. The system complexity of high-speed EMU is constantly increasing, which puts forward higher requirements for the safety of equipment and the efficiency of maintenance.At present, the maintenance mode of high-speed EMU in China still adopts the post maintenance method based on planned maintenance and fault maintenance, which leads to insufficient or excessive maintenance, reduces the efficiency of equipment fault handling, and increases the maintenance cost. Based on the intelligent operation and maintenance technology of PHM(prognostics and health management). This thesis builds an integrated PHM platform of "vehicle system-communication system-ground system" by integrating multi-source heterogeneous data of different scenarios of high-speed EMU, and combines the equipment fault mechanism with artificial intelligence algorithms to build a fault prediction model for traction motors of high-speed EMU.Reliable fault prediction and accurate maintenance shall be carried out in advance to ensure safe and efficient operation of high-speed EMU.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.571-580
• /
• 2020

In this study, an experimental study on storage media for thermal energy storage system was conducted. For thermal energy storage medium, concrete has excellent thermal and mechanical properties and also has various advantages due to its low cost. In addition, the ultra-high strength concrete reinforced by steel fibers exhibits excellent durability against exposure to high temperatures due to its high toughness and high strength characteristics. Moreover, the high thermal conductivity of steel fibers has an advantageous effect on heat storage and heat dissipation. Therefore, to investigate the temperature distribution characteristics of ultra-high-strength concrete, concrete blocks were fabricated and a heating test was performed by applying high-temperature thermal cycles. The heat transfer pipe was buried in the center of the concrete block for heat transfer by heat fluid flow. In order to explore the temperature distribution characteristics according to different shapes of the heat transfer pipe, a round pipe and a longitudinal fin pipe were used. The temperature distribution at the differnent thermal cycles were analyzed, and the thermal energy and the cumulated thermal energy over time were calculated and analyzed for comparison based on test results.

• Journal of Life Science
• /
• v.32 no.5
• /
• pp.411-419
• /
• 2022

Carotenoids are red, orange, and yellow fat-soluble pigments that exist in nature, and are known as physiologically active substances with various functions, such as provitamin A, antioxidant, anti-inflammatory, and anticancer. Because of their physiological activity and color availability, carotenoids are widely used in the food, cosmetics, and aquaculture industries. Currently, most carotenoids used industrially use chemical synthesis because of their low production cost, but natural carotenoids are in the spotlight because of their safety and physiologically active effects. However, the production of carotenoids in plants and animals is limited for economic reasons. Carotenoids produced by bacteria have a good advantage in replacing carotenoids produced by chemical synthesis. Since carotenoids produced from bacteria have limited industrial applications due to low productivity, studies are continuously being conducted to increase the production of carotenoids by bacteria. Studies conducted to increase carotenoid production from bacteria include the activity of enzymes in the bacterial carotenoid biosynthesis pathway, the development of mutant strains using physical and chemical mutagens, increasing carotenoid productivity in strain construction through genetic engineering, carotenoid accumulation through stress induction, fermentation medium composition, culture conditions, co-culture with other strains, etc. The aim of this article was to review studies conducted to increase the productivity of carotenoids from bacteria.

• Journal of Life Science
• /
• v.33 no.8
• /
• pp.680-691
• /
• 2023

Peak oil, climate change, and microplastics caused by the production and usage of petroleum-based plastics have threatened the sustainability of our daily life, and this has emerged as a recent global issue. To solve this global issue, the production and usage of biodegradable eco-friendly bioplastics such as polyhydroxyalkanoates (PHAs) has been suggested as an alternative. Therefore, in this review, the present status of global PHA manufacturers, the advantages of the production of PHAs using marine-origin microorganisms (with their productivity potential) and further required research and development strategies for cost-competitive production of PHAs using marine-based microorganisms were investigated. In this review, PHAs produced from marine microorganisms were found to have similar physical properties to petroleum-based plastics but with several advantages that can reduce the costs of PHA production. Those advantages include, seawater used in the medium preparation step, and osmotic-based cell lysis technology used in the separation and purification steps. However, the PHA productivities from marine microorganisms showed somewhat lower efficiencies than those from the commercial strains isolated from terrestrial environments. In order to solve the problem, further research strategies using synthetic microbiology-based technology, the development of long-term continuous culture technology, and solutions to improve PHA efficiency are required to meet future market demands for alternative bioplastics.