• Journal of Forest and Environmental Science
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• 제33권3호
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• pp.239-242
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• 2017

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was $1.76km^{-2}$ (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in $1.4km^2$ of our study area. This estimate was not statistically different from the previous leopard cat population count ($2.33{\pm}0.58$) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

• 인터넷정보학회논문지
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• 제5권1호
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• pp.33-39
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• 2004

정보시스템 개발 프로젝트의 효율적이고 효과적인 관리를 위한 국내 실정에 맞는 CMM 기준 프로젝트관리와 정보시스템 감리 항목등과 분석도구가 요구되고 있다. 이 논문에서는 CMM을 기준하여 각 프로세스별 수행결과를 정량적으로 측정하여 해당 수치의 목표범위 내 관리가 가능하게하기 위해 gap 분석 및 평가를 반복해서 수행하여 품질관리, 생산관리, 원가관리, 지식의 통합관리를 가능하게 하여 정보화 기반의 지식 경영을 강화하고, 정보의 고급화, 차별화를 통해 고객 서비스를 강화하고, 프로세스 최적화를 통해 업무효율을 향상시키고 조직의 자발적 노력을 통해 조직 성숙도를 지속적으로 향상시키기 위한 조직 내 정보능력 측정에 있어 4단계 수준에 도달하기 위한 관리 및 감리 항목을 설정하고, 국내 5전문 업체에 적용 분석, 평가하는 모델을 제안하였다.

• KIEAE Journal
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• 제10권5호
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• pp.181-186
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• 2010

Research on construction waste unit was in progress in the 1995 when 'Proper Disposal and Recycling Measures for Construction Waste' was made by the Seoul Development Institute. Such an effort has been made in order to cope with the lack of natural resources in Korea and to utilize the reusable resources. Furthermore, these efforts have also increased due to the improved standing of Korea in the international community. A large number of residential buildings were built in the response to the government's policy by increasing the supply of houses between the 1970's and 1980's. In 2000, more reconstruction and redevelopment was done because of the aged buildings and change of use for those buildings. And the project has been actively promoted until now, which caused a sharp increase in the generation volume of construction waste. In Korea, 8 kinds of construction waste unit, including the standard construction manpower and materials estimation, are introduced. Currently, they provide standards to different building categories and waste properties while for construction sites different standards are applied. This study aims to measure the actual amount of construction waste after sample buildings are dismantled and analyzes the estimation of the waste quantity by using various standard units. Through comparison, this study will figure out the differences among the standard units in order to find out how to apply the standard units properly. Moreover, this research will provide practical measures to apply such units to construction sites.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권5호
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• pp.555-562
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• 2004

소프트웨어 회사들은 새로운 개발보다는 기존 프로젝트의 유지보수와 성능향상 프로젝트를 보다 많이 수행한다. 기존의 비용 추정 모델들은 유지보수 프로젝트들에 적용할 수 있지만, 유지보수 분야에 적용시키기 위해서는 변경이 필요하다. 본 논문은 개발 프로젝트와 유지보수 프로젝트의 기능점수 계산방법을 분류하고 ISBSG의 밴치마킹 자료를 회귀 분석한 결과를 토대로 유지보수 프로젝트의 비용을 측정할 수 있는 방법을 제안하였다. 먼저, ISBSG 자료를 소프트웨어 비용에 영향을 미치는 요소인 프로그램 추가, 변경과 삭제 3가지 요소의 8가지 중에서 실제 유지보수가 나타나는 4가지 그룹으로 분류하였다. 그리고, 그룹별로 통계적 모델과 RBF 망(Radial Basis Function Network)을 이용한 모델을 개발하여 각각의 성능을 분석 평가한 결과 RBF 망이 통계적 모델보다 좋은 성능을 보였다.

• Smart Structures and Systems
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• 제15권1호
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• pp.57-80
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• 2015

Extended Kalman Filter (EKF) has been widely used for structural identification and damage detection. However, conventional EKF approaches require that external excitations are measured. Also, in the conventional EKF, unknown structural parameters are included as an augmented vector in forming the extended state vector. Hence the sizes of extended state vector and state equation are quite large, which suffers from not only large computational effort but also convergence problem for the identification of a large number of unknown parameters. Moreover, such approaches are not suitable for intelligent structural damage detection due to the limited computational power and storage capacities of smart sensors. In this paper, a two-stage and two-step algorithm is proposed for the identification of structural damage as well as unknown external excitations. In stage-one, structural state vector and unknown structural parameters are recursively estimated in a two-step Kalman estimator approach. Then, the unknown external excitations are estimated sequentially by least-squares estimation in stage-two. Therefore, the number of unknown variables to be estimated in each step is reduced and the identification of structural system and unknown excitation are conducted sequentially, which simplify the identification problem and reduces computational efforts significantly. Both numerical simulation examples and lab experimental tests are used to validate the proposed algorithm for the identification of structural damage as well as unknown excitations for structural health monitoring.

• Earthquakes and Structures
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• 제23권4호
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• pp.385-401
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• 2022

Uncertainty quantification is the most important challenge in seismic fragility assessment of structures. The precision increment of the quantification method leads to reliable results but at the same time increases the computational costs and the latter will be so undesirable in cases such as reliability-based design optimization which includes numerous probabilistic seismic analyses. Accordingly, the authors' effort has been put on the development and validation of an approach that has reduced computational cost in seismic fragility assessment. In this regard, it is necessary to apply the appropriate methods for consideration of two categories of uncertainties consisting of uncertainties related to the ground motions and structural characteristics, separately. Also, cable-stayed bridges have been specifically selected because as a result of their complexity and the according time-consuming seismic analyses, reducing the computations corresponding to their fragility analyses is worthy of studying. To achieve this, the fragility assessment of three case studies is performed based on existing and proposed approaches, and a comparative study on the efficiency in the estimation of seismic responses. For this purpose, statistical validation is conducted on the seismic demand and fragility resulting from the mentioned approaches, and through a comprehensive interpretation, sufficient arguments for the acceptable errors of the proposed approach are presented. Finally, this study concludes that the combination of the Capacity Spectrum Method (CSM) and Uniform Design Sampling (UDS) in advanced proposed forms can provide adequate accuracy in seismic fragility estimation at a significantly reduced computational cost.

• 한국물환경학회지
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• 제26권5호
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• pp.802-809
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• 2010

An automatic calibration tool of Hydrological Simulation Program-Fortran (HSPF), Parameter Estimation (PEST) program, was applied at the Imha lake watershed to get optimal hydrological parameters of HSPF. Calibration of HSPF parameters was performed during 2004 ~ 2008 by PEST and validation was carried out to examine the model's ability by using another data set of 1999 ~ 2003. The calibrated HSPF parameters had tendencies to minimize water loss to soil layer by infiltration and deep percolation and to atmosphere by evapotranspiration and maximize runoff rate. The results of calibration indicated that the PEST program could calibrate the hydrological parameters of HSPF with showing 0.83 and 0.97 Nash-Sutcliffe coefficient (NS) for daily and monthly stream flow and -3% of relative error for yearly stream flow. The validation results also represented high model efficiency with showing 0.88 and 0.95, -10% relative error for daily, monthly, and yearly stream flow. These statistical values of daily, monthly, and yearly stream flow for calibration and validation show a 'very good' agreement between observed and simulated values. Overall, the PEST program was useful for automatic calibration of HSPF, and reduced numerous time and effort for model calibration, and improved model setup.

• 한국지역지리학회지
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• 제12권5호
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• pp.595-613
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• 2006

개발이익은 토지소유자의 노력과 투자를 동반하지 않은 토지가치의 증가를 일반적으로 지칭하며, 개발이익 환수는 이러한 유형의 토지가치 증가는 공유하여야 한다는 사고를 전제하고 있다. 이러한 개발이익의 발생메커니즘, 향유 주체 및 환수의 경제적 효과를 둘러싸고 많은 논쟁이 전개되었다. 정책대상으로서 개발이익은 토지가치세와 같은 조세형평성의 강화, 도시하부구조 건설재원조달, 토지이용 및 공간계획 관리 목적으로 활용하고 있다. 그러나 개발이익에 대한 이러한 이론적 정책적 논의의 발전을 위해서는 개발이익 발생규모와 특성을 구체적으로 규명하는 작업이 필요하다. 본 연구에서는 택지개발촉진법 도입 이후 주도적으로 택지개발사업을 수행하고 있는 한국토지공사와 대한주택공사의 1995년 이후 전체 204개 개발사업지구를 대상으로 화폐의 시간적 가치를 고려한 할인현금흐름분석법으로 개발이익을 추계하고 그 특성을 밝힌다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1466-1483
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• 2008

This paper discusses the development of an up-to-date computerized CPT (Cone Penetration Test) based soil engineering classification system to provide geotechnical engineers with a handy tool for their daily design activities. Five CPT soil engineering classification systems are incorporated in this effort. They include the probabilistic region estimation and fuzzy classification methods, both developed by Zhang and Tumay, the Schmertmann, the Douglas and Olsen, and the Robertson et al. methods. In the probabilistic region estimation method, a conformal transformation is used to determine the soil classification index, U, from CPT cone tip resistance and friction ratio. A statistical correlation is established between U and the compositional soil type given by the Unified Soil Classification System (USCS). The soil classification index, U, provides a soil profile over depth with the probability of belonging to different soil types, which more realistically and continuously reflects the in-situ soil characterization, which includes the spatial variation of soil types. The CPT fuzzy classification on the other hand emphasizes the certainty of soil behavior. The advantage of combining these two classification methods is realized through implementing them into visual basic software with three other CPT soil classification methods for friendly use by geotechnical engineers. Three sites in Louisiana were selected for this study. For each site, CPT tests and the corresponding soil boring results were correlated. The soil classification results obtained using the probabilistic region estimation and fuzzy classification methods are cross-correlated with conventional soil classification from borings logs and three other established CPT soil classification methods.

• 대한기계학회논문집B
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• 제36권9호
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• pp.915-921
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• 2012

이 연구에서는 실린더 압력과 모터링 압력의 차이인 차이 압력(difference pressure)을 이용하여 IMEP를 추정하는 방법을 제안하고, 추정된 IMEP를 $IMEP_{diff}$로 정의하였다. $IMEP_{diff}$는 차이 압력이 연소 시작 시점에서 연소 종료 시점까지만 존재하는 압력이라는 사실에 기반하여 이론적인 IMEP 계산식의 연산 구간을 최적화한 것으로 IMEP와 비교 시 $R^2$ 0.9955의 높은 선형관계를 보였다. 또한 이론적인 IMEP 계산 방법과 비교하여 21 %의 실린더 압력 데이터 및 31 %의 계산량만으로 IMEP 획득이 가능하여 실시간 제어에 용이하다. $IMEP_{diff}$ 추정 및 제어 성능은 엔진 실험을 통하여 검증하였으며, $IMEP_{diff}$ 제어를 통하여 실린더 간 토크 편차 감소를 확인하였다.