• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.146-156
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• 2007

In this paper, the TVC actuation test and analysis results for a flexible seal kick motor nozzle are presented. A real-sized test model of KSLV-I kick motor system is applied to water pressurizing TVC tests which investigate the property changes in TVC nozzle expansion and TVC actuation performance against chamber pressure changes. The equipments which are required for TVC actuation tests are briefly explained. The TVC actuation tests are firstly accomplished in static mode, which reveals TVC error characteristics including thrust misalignment, control accuracy, and TVC stroke increase, etc. The properties in frequency domain is given via dynamic tests. These results may play an important role in enhancing the TVC control performance of KSLV-I.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.187-192
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• 2006

The combustion performance tests of a 30 tonf-class full-scale combustion chamber performed with water as a coolant were described. The combustion chamber has chamber pressure of 53bara and propellant flow mass rate of 90kg/s. Since it was first firing test for 30tonf-class combustion chamber using channel cooling, water coolant mass flow .ate of 35kg/s and 18kg/s were performed which correspond to 110% of kerosene design volume flow rate and equivalent cooling performance of kerosene. The test results are described and the results showed that the water cooling performance of this combustion chamber is sufficient and the firing test is feasible using the kerosene as a coolant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.240-246
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• 2005

A series of combustion tests of a 30-tonf-class full scale liquid rocket thrust chamber under development has been carried out to verify its design. The test results revealed decent performance in the aspects of efficiency. The combustion stability is one of the most important parameters of liquid rocket engine in addition to the efficiency. Assessment tests of combustion stability must be accomplished to confirm the possibility of combustion instability due to spontaneous or external disturbances. The combustion stability rating tests of the full scale thrust chamber with temporary baffles made of stainless steel were carried out utilizing pulse guns to estimate combustion stability characteristics. The tests results show highly stable combustion stability characteristics. The outcome acquired from the present experimental study will be used to design an actively cooled baffle that can survive for the life time operation of the thrust chamber.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.161-174
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• 2017

최근 들어 기술벤처기업에 대한 투자가 증가하고, 이를 위한 기술신용평가의 역할이 증대하였다. 그러나 금융권에서 바라보는 기술신용평가의 경우, 해당 기업의 신용등급이나 기술(력) 등급평가에 초점을 두어, 대상기술의 사업화 및 수익성 관점을 체계적으로 반영하지 못하는 한계를 지닌다. 따라서, 벤처캐피털(VC)이나 엔젤투자자를 비롯한 금융권에서 대상기술의 수익성 정보를 참조하거나 기술벤처기업 설립시 기술지분을 참고하는 등, 기존 기술이전거래 협상참조용이나 담보 보증용에 널리 이용되던 기술가치평가의 활용범위가 급격히 확대되고 있다. 제조 서비스 분야의 일반 기술 뿐만이 아니라, 바이오 제약 의료 분야 기술에서도 미래 투입되어야 하는 사업화 소요기간 및 비용을 고려하여 기술가치를 산정해야 할 때가 있다. 기존의 현금흐름할인법(DCF법)이 연속된 투자에 대한 고려를 못하거나 기술적용 제품의 상용화 투입비용에 대한 확률적인 속성을 반영하지 못하는 등 한계점을 지니고 있다. 그러나 기술과 투자의 가치는 기회가치로 보고 자원배분을 위한 의사결정 정보를 감안해야 하므로, 실물옵션의 개념을 적용하는 것이 바람직하다고 여겨진다. 흔히 기업가치를 평가할 때 주가의 변동성(volatility) 개념을 도입하여 전일종가 대비 익일시가의 분산값을 활용하기도 한다. 이러한 개념을 기술가치평가에 적용하기 위해서는 '주가의 연속성(상대적 미세한 변화)' 및 '양(+)의 조건'을 고려해야 하는데, 실제 기술가치평가 상의 현금흐름은 사업초기년도 음(-)의 값이 나타나거나 2~3년 내외의 짧은 수익예상기간 하에서는 주가와 같은 변동성을 도출하는데 무리가 있다. 따라서 많은 문헌에서 연구된 바와 같이, 실물옵션 기반의 기술가치 산정을 위한 블랙-숄즈 모형에서 변동성과 기초자산가치, 그리고 사업화비용 간의 관계를 살펴볼 필요가 있다. 아울러 옵션가격결정모형(Option Pricing Model)에서 불확실성을 반영한 기초자산의 현재가치와 사업화비용의 현재가치분이 특정 임계조건 하에서 '옵션행사 포기(NAT; no action taken)' 영역으로 구분되는 지를 수학적으로 도출하고 관찰변수(입력값)에 따른 옵션가치 산출표를 개발하여 제시한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.125-130
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• 2007

Firing tests have been performed for a 30 tonf-class full-scale regeneratively cooled combustion chamber. It was the first model which has welded construction of the injection head and the combustion chamber. A number of firing tests have been performed to evaluate combustion efficiency, regenerative cooling performance and durability of the combustor. This paper describes the results of firing tests performed at the design and off-design conditions which correspond to the chamber pressure of 60 bar, 68 bar respectively and the O/F ratio of 2.5 and 2.8 respectively. The data at each test condition have provided successful results in terms of combustion performance, combustion stability and durability. The tests are considered to be quite meaningful in the sense that the technologies for kerosene regeneratively cooled combustion chamber are successfully proven.

• Journal of Agricultural Extension & Community Development
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• v.19 no.4
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• pp.799-831
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• 2012

This study was accomplished to support farmers who want to introduce Automatic Milking System. The methods of analysis is considered on it as investment analysis that NPV, ROV and FROV. As a classical investment analysis technique, NPV showed 142 thousand won on the every senarioes. On the other hands, The Real Option Analysis showed 153,826, 154,937 and 152,858 on the normal, optimistic and pessimistic senarioes respectively. it is considered as a investment analysis technique for strategic decision-making. But, it may have problem to evaluate present value of expected cash flows and expected costs by a single number. To solve those problems, this paper tried to evaluate Fuzzy Real Option Model which were jointed with a real option model and Fuzzy set model. The result of analysis showed, on respective senarioes, 153,515 to 161,489, 154,612 to 162,970, and 152,573 to 159,835 on the interval estimation. Thereby It is a more realistic in many cases.

• Fire Science and Engineering
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• v.25 no.3
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• pp.51-56
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• 2011

The full-scale experiments are carried out to investigate the fire suppression characteristics of water-based fire fighting systems in a road tunnel. Applied systems are the low-pressure water spray system at 3.5 bar and the high-pressure water mist system at 60 bar. The water flow rate of the high-pressure system is one sixth only of the water spray system. A passenger car and a heptane fuel pan with area of $1.4m^2$ are used as fire sources. A blower system is installed at the tunnel exit to realize the longitudinal ventilation conditions (0.9~3.8 m/s) in the tunnel. Temperatures from the fire source to the down-stream direction are measured by K-type thermocouple trees. The experimental results show that the cooling effect of the high pressure water mist system in the test conditions were equivalent to that of the low pressure water spray system for B-class fire.

• Korean Journal of Construction Engineering and Management
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• v.17 no.1
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• pp.76-82
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• 2016

Decision-making in construction projects often include options features. Such embedded options are difficult to value properly and many decision makers do not have experience in option analysis. The purpose of this paper is to demonstrate how real option analysis can be used to value capital expenditures on construction materials. We propose a real option framework to evaluate decision-making processes involving the purchase of construction materials. A case study was conducted by evaluating the purchase decision-making of solar cells, a good with high price volatility. Using real option analysis two strategies to improve the financial feasibility of installing a solar panel system were derived. The first strategy involves using a price cap that gives the project manager the right, but not obligation, to buy the modules for a predefined price during the next year. The second strategy is to defer the purchase of the solar cells until future price information becomes clearer. Both of the strategies in the case study were valued using the binominal model. This study will help to improve the financial feasibility of purchasing construction materials with high price volatility by including the value of managerial flexibility.

• Journal of Korea Technology Innovation Society
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• v.14 no.3
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• pp.578-598
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• 2011

This study estimates the value of photovoltaic core material technology, which is getting attention as a clean energy source. The estimation is based on the real option pricing model (ROPM). This study has two main contributions. The first is in the methodology. The process of modeling volatility, which is the most complicated stage in ROPM, is greatly simplified by using the stock price as a covariate representing the volatility of the real option's basic asset. The second contribution is the application of technology. In this study, the economic value of poly-silicon, a core material in the photovoltaic industry and recently surging in demand, is evaluated as a manufacturing technology. In a case study of a company in the photovoltaic industry, the stochastic process of a basic asset follows geometric Brownian motion (GBM), and the option value of firm A's poly-silicon manufacturing technology is estimated at 3.4 trillion won.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.229-242
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• 2012

Although many companies acknowledge the necessity of investment of information security, it is difficult to grasp a tangible effect and to calculate a scale of damage from the security incident. Consequently, companies are under the reality that it is not easy to make an investment decision for information security and to calculate the investment scale. For the investment decision making, although there are several traditional techniques of investment analysis, the investment of information security, comparing to other tangible assets, has limitations in using traditional techniques due to the highly uncertain investment effects. In this study, the traditional technique of investment analysis will be described, and the application method of analytic technique for Real Option, which is developed from the evaluation technique of highly uncertain financial futures and options, will be suggested.