• Hip & pelvis
• /
• v.34 no.1
• /
• pp.56-61
• /
• 2022

Purpose: Histopathologic analysis of femoral head specimens following total hip arthroplasty (THA) is a routine practice that represents a significant use of health care resources. However, it occasionally results in discovery of undiagnosed hematopoietic malignancy and other discrepant diagnoses such as avascular necrosis. The purpose of this study was to determine the rate of discordant and discrepant diagnoses discovered from routine histopathological evaluation of femoral heads following THA and perform a cost analysis of this practice. Materials and Methods: A review of patients undergoing primary THA between 2004-2017 was conducted. A comparison of the surgeon's preoperative and postoperative diagnosis, and the histopathologic diagnosis was performed. In cases where the clinical and histopathology differed, a review determined whether this resulted in a change in clinical management. Medicare reimbursement and previously published cost data corrected for inflation were utilized for cost calculations. Results: A review of 2,134 procedures was performed. The pathologic diagnosis matched the postoperative diagnosis in 96.0% of cases. Eighty-three cases (4.0%) had a discrepant diagnosis where treatment was not substantially altered. There was one case of discordant diagnosis where lymphoma was diagnosed and subsequently treated. The cost per discrepant diagnosis was $141,880 and per discordant diagnosis was $1,669 when using 100% Medicare reimbursement and Current Procedural Terminology (CPT) code combination 88304+88311. Conclusion: Histopathologic analysis of femoral head specimens in THAs showed an association with high costs given the rarity of discordant diagnoses. Routine use of the practice should be at the discretion of individual hospitals with consideration for cost and utility thresholds.

• Korean Journal of Microbiology
• /
• v.37 no.1
• /
• pp.92-99
• /
• 2001

High-cell-density cultivation of Ralstonia eutopha KHB 8862 by fed-batch fermentation in a 200 l pilot plant was carried out for the mass production of poly(3-hydroxybutyrate) (PHB). After 80 h of cultivation, the dry cell weight (DCW), PHB concentration, and PHB yield from fructose syrup reached 168 g/l, 74%DCW, and 0.27 (w/w), respectively, resulting in a productivity of 1.6 g of PHB/L/h. Based on these results, the PHB production cost from bacterial fermentation was analyzed and economic evaluation was performed. In the case of new investment being implemented or not, the production cost of PHB was US$ 3.15/kg and US$ 2.41/kg, respectively. PHB productivity and PHB yield on a carbon substrate were both important factors to be optimized. The increase of PHB yield on a carbon sources significantly decreased the PHB production cost but the increase in productivity had a relatively slight effect on the decrease in PHB production cost because the cost of carbon sources (37%) for PHB was larger in proportion to total cost than the depreciation cost (17%). These results suggest that the increased PHB yield from carbon sources and the development of new cheaper substrates would be more effective in decreasing PHB production cost than the increase in productivity. It was demonstrated that PHB is not in competition with consumable plastics such as PET in present market. Therefore, it is essential to lower production cost to be used as a bulk product and desirable to develop new application fields for PHB such as biomedical and cosmeceuticals.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2001.05a
• /
• pp.94.2-94
• /
• 2001

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.16 no.1
• /
• pp.3324-3333
• /
• 1974

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.10a
• /
• pp.317.2-317
• /
• 1999

• Journal of Korean Association for Spatial Structures
• /
• v.19 no.2
• /
• pp.4-7
• /
• 2019

• Journal of Electrical Engineering and Technology
• /
• v.12 no.1
• /
• pp.335-345
• /
• 2017

Recently, location systems using RFID technology have been studied in indoor environments. However, the existing techniques require high computational cost to compute the location of a moving object because they compare the location proximity of all reference tags and objects. In this paper, we propose an RFID based location positioning scheme using event filtering, which reduces the computation cost of calculating the locations of moving objects while maintaining the accuracy of location estimation. In addition, we propose an incremental location update policy to reduce the location update cost for moving objects. We also compare the proposed scheme with one of the localization schemes, LANDMARC using a performance evaluation. As a result, the proposed scheme outperforms LANDMARC in terms of the computational cost of location estimation. The proposed scheme also reduces the cost of location update by using the RFID-based update policy.

• 한국경영정보학회:학술대회논문집
• /
• 2008.06a
• /
• pp.428-433
• /
• 2008

The online advertising industry's business model undertakes the change from CPM (cost-per-mille)-based to CPC (cost-per-click)-based. However, due to the problem of 'Click Fraud', CPA (cost-per-action) has been regarded as a new step. For CPA, publishers need to get information after a user clicks an advertisement. Therefore, in CPA, the key is to get Conversion Action Data (CAD). This paper introduces two existing mechanisms for getting CAD, compare their characteristics, and analyze their limitations. Then the two new mechanisms are introduced and their requirements and feasibility are analyzed. Lastly, we compare the existing two and the new two mechanisms, and point out each mechanism's business possibility, value and Application Area. This paper will help publishers choose the most appropriate mechanism on the basis of their situation.

• Journal of Mechanical Science and Technology
• /
• v.16 no.10
• /
• pp.1287-1295
• /
• 2002

In this work, the fuel economy of a parallel hybrid electric vehicle is investigated. A vehicle control algorithm which yields operating points where operational cost of HEV is minimal is suggested. The operational cost of HEV is decided considering both the cost of fossil fuel consumed by an engine and the cost of electricity consumed by an electric motor. A procedure for obtaining the operating points of minimal fuel consumption is introduced. Simulations are carried out for 3 variations of HEV and the results are compared to the fuel economy of a conventional vehicle in order to investigate the effect of hybridization. Simulation results show that HEV with the vehicle control algorithm suggested in this work has a fuel economy 45% better than the conventional vehicle if braking energy is recuperated fully by regeneration and idling of the engine is eliminated. The vehicle modification is also investigated to obtain the target fuel economy set in PNGV program.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.5
• /
• pp.905-912
• /
• 2011

In this paper, the method on calculating benefits of combined heat and power is introduced for standard evaluation in electrical power system. This paper calculates benefits about new national viewpoint and viewpoint of independent power producers and assesses benefits of combined heat and power in Korea and In Seoul national capital area. Benefit costs are composed of avoid cost of centralized generation, line upgrading adjustment, loss adjustment and electrical power trade cost per year in earlier study, in addition trade cost of $CO_2$, construction cost of combined heat and power for accurate calculation. Benefit of combined heat and power is calculated by simulation results of real electrical power system.