• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.19-25
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• 2016

Anti-icing is important in gas turbines because ice formation on compressor inlet components, especially inlet guide vane, can cause performance degradation and mechanical damages. In general, the compressor bleeding anti-icing system that supplies hot air extracted from the compressor discharge to the engine intake has been used. However, this scheme causes considerable performance drop of gas turbines. A new method is proposed in this study for the anti-icing in combined cycle power plants(CCPP). It is a heat exchange heating method, which utilizes heat sources from the heat recovery steam generator(HRSG). We selected several options for the heat sources such as steam, hot water and exhaust gas. Performance reductions of the CCPP by the various options as well as the usual compressor bleeding method were comparatively analyzed. The results show that the heat exchange heating system would cause a lower performance decrease than the compressor bleeding anti-icing system. Especially, the option of using low pressure hot water is expected to provide the lowest performance reduction.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.151-157
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• 2010

This paper proposes the Pyramid strategy which is based on the straddle sell. The Pyamid strategy has multi-entry features with starting date and delta parameters. And It is hedged against a loss by mutual trades and dynamic ripples. This paper analyzes the profit and MDD(maximum draw down) of the Pyramid strategy on system trading. The portfolio tool is used for the experiment which is one of the Multicharts' package. The Multicharts is a good trading system of recent years. For the experiment, three call options and three put options are used at october in 2009. Two parameters are used which are the starting date from first October to twentieth October in 2009 and delta from eight percent to fifty percent. As a result, the profit of composite option is about 3 million won. If the strategy starts before the beginning of option month, investors feel uncomfortable because of a large MDD. If a delta belows 20%, it shows high profit and the ratio of profit and MDD builds up a low value. However a low delta makes frequent trades and results in a loss unless increasing entry levels which mean more amount of investment. This work provides a safer trade system than native option trades. It is important how much levels of multi-entry are acceptable. And an amount of investment with appropriate levels of multi-entry is a subject of a future study.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1194-1197
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• 2009

Nowadays many Internet users have their own homepages and blogs on the Internet. Developers and designers offer a lot of options to users to increase their satisfaction. Do users prefer a lot of options? This study shows that users may prefer simple web-sites to complex web-sites. Moreover, users' attitudes can be affected by individual characteristics users have. This study focuses on one of the individual differences, computer anxiety. As a result, users who have high computer anxiety had more negative attitudes to web-sites than users having low computer anxiety had. This result emphasizes the importance of understanding users when designing interfaces.

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.2
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• pp.5-12
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• 2010

Unlike housing development project that can ensure profit by selling built units, a hotel development depends on long-term business operation to be profitable due to characteristics of service industry. The expected cash flow has substantial uncertainty depending on room occupancy rate and room charge. Thus, even after construction is complete, business risk tends to rise. It is necessary to ensure strategic response to uncertainty in future value of a hotel. The objective of the study is to explore strategic measures to deal with risk and uncertain future value in hotel development project by adopting abandonment option, which is a type of real options. The case in analysis had sevenyears of project period: Two years for construction, and five years for operation; a plan was made to sell the hotel after five years' of operation. For the research purpose, option value ofrecoverable investment amount was estimated, and value of abandonment option was KRW 124.921 billion. When abandonment option is applied, the project value was deemed to be KRW 120.592 billion. Generally, the amount of loss is enormous when a real estate project like a hotel development fails, and therefore, application of option is expected to be an effective measure to leverage uncertainty of a project.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.573-575
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• 1994

Resent research activities and technical trends for UPS(UNINTERRUPTIBLE POWER SUPPLY) are reviewed. There are increasing demands for UPS to get mote useful performance. This needs are high-efficiency, high-confidency, high-quality, low-cost. self-diagnosis. maintenance-free, and a wide variety of options. These can be satisfied with high-technology and optimal system coordination. In this paper. according to these demands. a newly developed UPS and a wide variety of options are introduced. Also. the data related are presented.

• Management Science and Financial Engineering
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• v.21 no.2
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• pp.13-23
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• 2015

This study addresses the question as to whether the option prices have useful predictive information on the direction of stock markets by investigating a forecasting power of volatility curvatures and skewness premiums implicit in S&P 500 index option prices traded in Chicago Board Options Exchange. We begin by estimating implied volatility functions and risk neutral price densities every minute based on non-parametric method and then calculate volatility curvature and skewness premium using them. The rationale is that high volatility curvature or high skewness premium often leads to strong bullish sentiment among market participants. We found that the rate of return on the signal following trading strategy was significantly higher than that on the intraday buy-and-hold strategy, which indicates that the S&P500 index option prices have a strong forecasting power on the direction of stock index market. Another major finding is that the information contents of S&P 500 index option prices disappear within one minute, and so one minute-delayed signal following trading strategy would not lead to any excess return compared to a simple buy-and-hold strategy.

• Journal of Korea Technology Innovation Society
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• v.9 no.1
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• pp.84-102
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• 2006

This paper compares four models to value a biotechnology R&D project; option tree model, dynamic discounted cash flow(DCF) model, and option thinking DCF model with general DCF model. Real Options, especially 6-folded option tree model yields boner estimate of value than values using other methods. According to sensitivity analysis, sales of final products, number of investigational new drug developments(INDs) and success rates of each stage are key factors for the value of biotechnology R&D investment.

• International Journal of Railway
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• v.5 no.3
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• pp.103-113
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• 2012

Infrastructure costs could be greatly reduced if the need for bridges and tunnels was reduced, or if the line could be shortened. Tilting trains might be a less costly alternative to building new tracks with large curve radii, because tilting trains can negotiate tighter curves without having to decrease their speeds. Tracks built for tilting trains would be cheaper, as they require fewer bridges and tunnels. This paper compares the construction costs of two different options for the new Dodam-Yeoncheong section on the Central line, which includes 148.65 km of new electrified double-track with a design speed of 250 km/h. The first option is to straighten the high-speed line. The second option is to build a line with small radii curves and run tilting trains on the line. In the first option, tunnels would account for about 51% of the new section. In comparison, the second option would have shorter curves and fewer tunnels and bridges which would reduce construction costs. Furthermore, alignment modifications could be made to several segments on the straight line, making the most of the existing roadbed. The analysis concluded that the line suited to tilting trains would be 95.7 million USD cheaper to build the straight route. That is a savings of 2.8% of the total project cost. However, this option would increase the total travel time of the route by 1.2 minutes, which means it is not necessarily the best choice.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.29-45
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• 1979

In this paper. nuclear characteristics of TRIGA Mark-III has been analyzed in detail for six different fuel options. Presently, 70 w/o enriched FLIP fuels are adopted for TRIGA core to improve fuel lifetime. However, such highly enriched fuels are not easily obtained due to nonproliferation treaty. This research examines the possible substitution for FLIP fuels with high density fuels without reducing the nuclear performance. This work will provide long-time plan for TRIGA operation.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.583-598
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• 2009

From the engineering standpoint, this study puts a special emphasis on application of adaptive management. To do this, we analyze the recent issue about water scarcity of the Gwangdong dam. Using the system dynamics model, we defined the system including water balance in the dam, dam manager's operation rules, regional water supply and local water distribution, and customer damage. It was expected that the model is useful to explain the real case, and also water scarcity of Gwangdong led to total damage of about 2.56 billion won, mainly to customers in the Taebaeck city. Two adaptive management options (i.e., optimal allocation of limited water resources, and early control of dam storage) were applied to the model in order to examine whether adaptive management is effective to mitigate the damage, it is concluded that the case study could largely reduce or entirely avoid the damage with adaptive engineering options.