Mid-sized manufacturing companies, which account for 0.7%(5,480 companies), 13.8%(1.169 million persons) of total employment, and 15.7% of total sales, have recently experienced a lot of difficulties in management activities due to the impact of COVID-19, the U.S.-China trade war, and the collapse of global supply chains. To overcome this, revitalization of quality management activities to strengthen corporate competitiveness is emerging as an urgent task. In order for these quality management activities to achieve their intended purpose, the positive leadership of corporate managers is very important above all else. There have been many studies related to positive leadership, but most have focused on charismatic leadership and transformational leadership centered on large companies or small and medium-sized enterprises. Therefore, this study aims to present ways to strengthen the leadership of managers by empirically analyzing how the positive leadership of managers of mid-sized manufacturing companies, which was relatively under-researched, affects quality management activities and Business performance(Balanced Score Card; BSC).

We attempted to provide an overview of the laws and current state of the 3D printing industry in South Korea and around the world, using the annual industry surveys and the Wohler report. Additionally, we reviewed articles relating to the potential exposure to hazards associated with 3D printing using metal materials. In South Korea, there were 406 3D printing-related businesses, employing 2,365 workers, and the market size was estimated at 455.9 billion won in 2021. Globally, the average growth rate of the 3D printing industry market over the past 10 years was 27.4%, and the market size was estimated at $11.8 billion in 2019. The United States had the highest cumulative installation ratio of industrial 3D printers, followed by China, Japan, Germany, and South Korea. A total of 6,168 patents related to 3D printing were registered in the US between 2010 and 2019. Harmful factors during metal 3D printing was mainly evaluated in the powder bed fusion and direct energy deposition printing types, and there is a case of material extrusion type with metal additive filaments. The number, mass, size distribution, and chemical composition of particles were mainly evaluated. Particle concentration increases during the opening of the chamber or post-processing. However, operating the 3D printer in a ventilated chamber can reduce particle concentration to the background level. In order to have a safe and healthy environment for 3D printing, it is necessary to accumulate and apply knowledge through various studies.

We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average Cr6+ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.

The aim of this study is to calculate process emission of GHGs(greenhouse gases) in nonferrous-metal industry, such as Zn, Pb, Cu and Ni. In addition, variation and emission of GHGs generated from these company were defined. And then, GHGs algorithm and calculation formular which were considered as production process in each part of nonferrous-metal industry were developed to develop calculation program of GHGs emission. These algorithm and calculation formular would present fundamental direction about other nonferrous-metal industry in the future.