Real Options Analysis of Oil and Gas Resource Development for Independent E&P Firms in the North America

박은천,박호정 한국경제학회 2014 The Korean Economic Review Vol.30 No.2

Since the beginning of the global oil crisis in the mid-2000s, oil and gas prices have been more volatile than other commodity prices. Accordingly, it is increasingly important for the independent E&P companies that are relatively vulnerable to market uncertainty to choose appropriate additional reserves of oil and gas. This paper provides a real options framework for analyzing the reserve replacement decisions of independent E&P companies, considering uncertain revenues and irreversible costs. The model considers the extraction cost per unit well associated with the remaining reserve level per well and instant production. Focusing on the North American E&P companies, threshold levels of oil and gas prices are identified for economic feasibility, above which it is optimal to undertake investment for reserve additions. The results indicate that the relative gains from gas E&P projects are steadily decreasing, primarily because of lowered gas prices triggered by recent gas development booms in the North America. The policy implications from this finding support a more conservative strategy and increased attempts in the field of gas development projects.

건축구조물의 풍하중 구현 및 풍특성 평가를 위한 가진시스템 설계

박은천,이성경,민경원,정란,강경수,이상현,Park, Eun-Churn,Lee, Sung-Kyung,Min, Kyung-Won,Chun, Lan,Kang, Kyung-Soo,Lee, Sang-Hyun 한국전산구조공학회 2007 한국전산구조공학회논문집 Vol.20 No.6

본 논문에서 건축구조물의 풍응답 구현을 위한 선형질량가진기(linear mass shaker, LMS)와 능동동조질량감쇠기(active tuned mass damper, ATMD)를 이용한 가진시스템을 제안한다. 가진시스템을 위한 가진기의 힘은 가진기에 의한 구조물의 목표응답의 전달함수를 사용하여 계산된다. 필터와 포락곡선함수는 예측하지 못한 모드응답에 의한 가진과 초기 과도응답을 제거함으로써 실제 바람에 의한 응답과 가진기에 의한 응답의 오차를 최소화하기 위하여 사용되었다. 수치예제로는 풍동실험을 통한 풍하중이 주어진 76층 벤치마크 구조물을 이용하여 수치해석을 수행하였으며, 그 결과는 특정층에 설치된 가진시스템은 풍하중이 전층에 가진되었을 때의 응답을 근사하게 구현할 수 있음을 보여준다. 제안된 방법에 의해 설계된 가진시스템은 실제 건축구조물의 풍응답 특성을 평가하는데, 그리고 풍하중을 받는 건물의 정확한 수치모델을 얻는데 효과적으로 사용될 수 있다. In this paper, excitation systems using linear mass shaker (LMS) and active tuned mass damper (ATMD) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

Design of an actuator for simulating wind-induced response of a building structure

박은천,이상현,민경원,정란,이성경,조승호,유은종,강경수 국제구조공학회 2008 Smart Structures and Systems, An International Jou Vol.4 No.1

In this paper, excitation systems using a linear mass shaker (LMS) and an active tuned mass damper (ATMD) are presented to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop functions are used to prevent the actuator from exciting unexpected modal responses and an initial transient response and thus, to minimize the error between the wind and actuator induced responses. The analyses results from a 76-story benchmark building problem for which the wind load obtained by a wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately reproduce the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

건축구조물의 풍하중 구현 및 풍특성 평가를 위한 가진 시스템 설계

박은천,이상현,이성경,민경원,정란,강경수 단국대 부설 리모델링연구소 2007 리모델링 연구소 논문집 Vol.5 No.2

In this paper, excitation systems using linear mass shaker (LMS) and active tuned mass damper (ATMD) are presented in order to simulate the wind induced responses of a building structure. The actuator force for the excitation systems is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between the wind and actuator induced responses is minimized by preventing the actuator from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the excitation system installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The excitation system designed by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.

M2M기반 지하공간 재난대응 EL 디스플레이 통합 보드 개발

박은천,박완순,박미연,나용현,이정훈 한국재난정보학회 2017 한국재난정보학회 학술대회 Vol.2017 No.11

사물 인터넷을 기반으로 지하철역사의 재난 전조를 조기에 발견하고 승객들에게 피난을 유도하는 지하 철 재난전조 감지 시스템 개발에 있어서 재난 발생시 상황대피 유도방법과 정확한 재난 위치 알림 및 대 피경로 안내는 재난 상황에 빠른 대피와 인명피해를 최소화 할수 있는 매우 적극적인 대안이 될 수 있다. 따라서 본 연구에서는 대피를 가장 효율적으로 유도할 수 있는 재난대응 EL Display 통합 보드를 개발하 였으며 이를 현장 실험을 통해 실제 활용성에 대한 검토를 실험하였다. 특히, EL패널을 재난 대피유도용으 로 활용한 사례가 없어 현장적용테스트를 거쳐 그 활용 가능성을 검증하였다.

대형 MR감쇠기가 설치된 건축구조물의 실시간 하이브리드 실험 및 준능동 알고리즘 적용

박은천,이성경,이헌재,문석준,정형조,민경원,Park, Eun-Churn,Lee, Sung-Kyung,Lee, Heon-Jae,Moon, Suk-Jun,Jung, Hyung-Jo,Min, Kyung-Won 한국전산구조공학회 2008 한국전산구조공학회논문집 Vol.21 No.5

실시간 하이브리드 실험법(real-time hybrid testing method)은 구조물의 수치해석부와 실험부 부분구조를 운동방정식으로 통합하여 실시 간으로 동시에 계산과 실험을 수행하는 방법이다 본 연구는 실시간 하이브리드 실험법을 사용하여 수동 및 준능동 MR감쇠기가 설치된 건축구조물의 내진성능을 정량적으로 평가한다. 건물 모델은 실물 크기 5층 건물을 강제진동실험 결과를 통해 식별한 수치모델로 사용하였고, MR감쇠기는 실험적 부분구조르 UTM에 설치되었다. 본 연구에서 수행되는 실시간 하이브리드 실험은 사인파 및 지진파 가진을 통하여 얻은 결과와 전류에 따른 MR감쇠기의 제어력을 이용하여 얻은 Bouc-Wen모델을 사용하여 얻은 해석모델과 일치함으로 그 유효성을 입증하였다. 또한 예비연구로써 구조물의 응답을 최적으로 제어하기 위한 clipped-optimal 제어알고리즘과 modulated homogeneous friction 준능동 제어알고리즘을 MR감쇠기에 적용하였다. 각 전류별 Bouc-Wen모델을 곡선맞춤하여 각각의 Bouc-Wen모델 파라미터를 식별하였으며 그 결과를 준능동 제어알고리즘 수치해석에 적용하였다. 또한 실시간 하이브리드 실험법을 이용한 준능동 제어 실험결과와 해석결과를 비교하여 준능동 제어알고리즘의 성능을 평가함에 있어 실시간 하이브리드 실험이 합리적임을 보여준다. The real-time hybrid testing method(RT-HYTEM) is a structural testing technique in which the numerical integration of the equation of motion for a numerical substructure and the physical testing for an experimental substructure are performed simultaneously in real-time. This study presents the quantitative evaluation of the seismic performance of a building structure installed with an passive and semi-active MR damper by using RT-HYTEM. The building model that was identified from the force-vibration testing results of a real-scaled 5-story building is used as the numerical substructure, and an MR damper corresponding to an experimental substructure is physically tested by using the universal testing machine(UTM). The RT-HYTEM implemented in this study is validated because the real-time hybrid testing results obtained by application of sinusoidal and earthquake excitations and the corresponding analytical results obtained by using the Bouc-Wen model as the control force of the MR damper respect to input currents were in good agreement. Also for preliminary study, some semi-active control algorithms were applied to the MR damper in order to control the structural responses optimally. Comparing between the test results of semi-active control using RT-HYTEM and numerical analysis results show that the RT-HYTEM is more resonable than numerical analysis to evaluate the performance of semi-active control algorithms.

ATMD를 이용한 건축 구조물의 풍응답 구현을 위한 가진시스템

박은천(Eun Churn Park),이상현(Sang-Hyun Lee),민경원(Kyung-Won Min),강경수(Kyung-Soo Kang) 한국소음진동공학회 2007 한국소음진동공학회 학술대회논문집 Vol.2007 No.11

고속열차의 주행 동적성능 평가시스템 개발

박은천(Eunchurn Park),강형구(Hyung-Goo Kang),최준성(Jun-Sung Choi),김은성(Eunsung Kim),김만철(Man-Cheol Kim) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.10

In this paper with the background features on which measuring the transverse left-right and up -down vibration of wheel bogie and body by wireless measurement system performance evaluation systems which can assess the running behavior of high speed trains based on UIC code 518-OR and evaluate the ride comfort of them based on ISO code 2631 and UIC code 513 were developed. The characteristics of dynamic vibration are generally analyzed by an acceleration of a car body of high speed train and the acceleration can be applied to evaluation of running safety. In this paper also matching system of distance from tachometer and vibration from accelerometer was programmed in development software and the SD card embedded system which prevent to loss of data in wireless measurement was mounted on this system. Finally the software perform to analysis with filtering and statistical post-process in the unit sections and zones and focus on developing the capability monitoring in the main control center. For the verification of this system the running behavior and safety factor were analyzed based on field measured data of the Cheonjun-gunnum-sun turn out point in the new KTX railway.

풍하중 구현 및 내풍특성 평가를 위한 선형질량 가진시스템 설계

박은천(Park Eun Churn),이상현(Lee Sang-Hyun),민경원(Min Kyung-Won),강경수(Kang Kyung-Soo) 한국소음진동공학회 2007 한국소음진동공학회 학술대회논문집 Vol.2007 No.11

고속열차 진동가속도 측정 시스템 개발과 측정 가속도 분석에 관한 연구

박은천(Eunchun Park),이용환(Yong-Hwan Lee) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.6