• BMB Reports
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• v.56 no.4
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• pp.252-257
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• 2023

The hypoxia-inducible factor-1α (HIF-1α) is a key regulator of hypoxic stress under physiological and pathological conditions. HIF-1α protein stability is tightly regulated by the ubiquitin-proteasome system (UPS) and autophagy in normoxia, hypoxia, and the tumor environment to mediate the hypoxic response. However, the mechanisms of how the UPS and autophagy interplay for HIF-1α proteostasis remain unclear. Here, we found a HIF-1α species propionylated at lysine (K) 709 by p300/CREB binding protein (CBP). HIF-1α stability and the choice of degradation pathway were affected by HIF-1α propionylation. K709-propionylation prevented HIF-1α from degradation through the UPS, while activated chaperon-mediated autophagy (CMA) induced the degradation of propionylated and nonpropionylated HIF-1α. CMA contributed to HIF-1α degradation in both normoxia and hypoxia. Furthermore, the pan-cancer analysis showed that CMA had a significant positive correlation with the hypoxic signatures, whereas SIRT1, responsible for K709-depropionylation correlated negatively with them. Altogether, our results revealed a novel mechanism of HIF-1α distribution into two different degradation pathways.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.3-21
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• 2010

By the significant structural change in 1999, a partial privatization has occurred in Korean fossil-fuel power generation sector. Under the current price scheme wholesale electricity price is dependent on output size, and hence, may not satisfy the assumption of price-taking producers. The purpose of our study is constructing the productivity change measurements of Korean power generation sector taking into account possibly imperfect competition and variable returns to scale. Our approach based on Harrison (1994) and Levinsohn (1993) derives the plant-level productivity measurements of the period between 2001 and 2007, as well as the measurements of mark-ups and returns to scale. It is shown that the mark-up size is dependent on the plants' fuel type and is decreasing over time. Allowing for imperfect competition and variable returns to scale adjusts the productivity measurements substantially.

• Korea Journal of Hospital Management
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• v.8 no.1
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• pp.1-23
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• 2003

General drug prices involve three stages: shipment stage, wholesaler stage and retail stage. Policies on drug price differ from country to country. Shipment stage prices are tightly regulated in countries like France and Netherlands. They are free in only a minority of advanced countries, even if these include some major players such as the US, Germany and, in a very limited sense, Japan. The situation in the UK is very complex with a semi-free system, where drug companies are free to set their own prices but cannot exceed a predetermined profit ceiling. Mark-up at both wholesaler and retail stages is formally admitted in most countries observed. Apart from the general drug prices, reimbursement price of insured drugs has been major policy concerns. Most countries reviewed in this study has exerted some control over reimbursement prices, but differ both in the way how and in the extent to which prices are admitted or fixed. Price fixing has been used in France and Japan. Some countries have transformed their system over time, particularly to move to reference pricing in the last decade. This mechanism has empowered the customer, and improved price competition on the market. Referring to the drug price policies in the advanced countries, this study makes some suggestions for the redirection of Korean price policy for reimbursement drug in health insurance as follows: to match appropriate policy tools to each policy goal; to maximize market mechanism through effective reimbursement price fixing which admits mark-ups in wholesaler and retail prices; to introduce reference pricing system in order to redirect patient's demand with a financial incentive to choose the best-priced drugs and to save the finance of health insurance; and to strengthen surveillance and monitoring mechanism in the drug market.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.63-70
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• 2007

The aims of this study are to draw the project risk factors by grasping the relation especially between the construction preparation cost calculation and the project risk factors in the project's bidding stage, and to draw the cost estimate based on the risk when the orderer or the constructer performs the project and the main factors in calculating the most suitable construction cost by clarifying the understanding degree of the influence between the risk factors and the construction cost. In addition, this study can give a help to the proper decision -making through the prediction of the construction preparation cost, and this study is expected to give the basic data in developing the assessment tool for the most suitable construction cost of the project.

• Applied Science and Convergence Technology
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• v.25 no.6
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• pp.108-115
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• 2016

Even if ion pumps are widely and mostly used in ultra-high vacuum (UHV) conditions, virtually every existing ion pump has its maximum pumping speed around 1E-6 mbar (1E-4 Pa). Discharge intensity in the ion pump Penning cell is defined as the current divided by pressure (I/P). This quantity reflects the rate of cathode bombardment by ions, which underlies all of the various pumping mechanisms that occur in ion pumps (chemisorption on sputtered material, ion burial, etc.), and therefore is an indication of pumping speed. A study has been performed to evaluate the influence of magnetic fields and cell dimensions on the ion pump discharge intensity and consequently on the pumping speed at different pressures. As a result, a combination of parameters has been developed in order to design and build an ion pump with the pumping speed peak shifted towards lower pressures. Experimental results with several different test set-ups are presented and a prototype of a new 200 l/s ion pump with the maximum pumping speed in the 1E-8 mbar (1E-6 Pa) is described. A model of the system has also been developed to provide a framework for understanding the experimental observations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.6 s.261
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• pp.635-643
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• 2007

As many engineers and technicians are involved in the design process of large scale and/or complex products, there are a lot of miss matches and interferences due to designers' faults and several kinds of CAD systems. Recently, CAD systems are applied to verify and check the assembly process. Digital Mock-Up(DMU) system, a tool to build a virtual mock-up in the design stage, has been used to prevent the interferences and miss matches during precision design processes. Using the virtual assembly tool, engineers are able to design precision and interference free parts without physical mock-ups. Instead of a single CAD source, several CAD systems are used to design a complex product. Several organizations are involved in the distributed design environment for heterogeneous multi-CAD assembly. XML and the lightweight CAD file are proposed for the multi-CAD assembly. XML data contains hierarchy of the heterogenenous multi-CAD assembly. STEP PDM schema and STEP ISO 10303-28 formations are applied to construct the XML data. The lightweight CAD file produced from various CAD files through ACIS kernel and InterOp not only contains mesn, B-Rep and topological data, but also is used to visualize CAD data and to verify dimensions. Developed system is executed on the desktop computers. It does not require commercial CAD systems to visualize 3D assembly data. Real-time interference and fitness checks, dimensional verification, and design and assembly verification are performed on the developed system. Assembly of heterogeneous models for a car is conducted to verify the effectiveness of the developed DMU system on the Internet.