• 한국해양공학회지
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• 제37권5호
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• pp.198-204
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• 2023

In response to the complexity and time demands of conventional methods for estimating the hydrodynamic coefficients, this study aims to revolutionize ship maneuvering analysis by utilizing automatic identification system (AIS) data and the Support Vector Regression (SVR) algorithm. The AIS data were collected and processed to remove outliers and impute missing values. The rate of turn (ROT), speed over ground (SOG), course over ground (COG) and heading (HDG) in AIS data were used to calculate the rudder angle and ship velocity components, which were then used as training data for a regression model. The accuracy and efficiency of the algorithm were validated by comparing SVR-based estimated hydrodynamic coefficients and the original hydrodynamic coefficients of the Mariner class vessel. The validated SVR algorithm was then applied to estimate the hydrodynamic coefficients for real ships using AIS data. The turning circle test wassimulated from calculated hydrodynamic coefficients and compared with the AIS data. The research results demonstrate the effectiveness of the SVR model in accurately estimating the hydrodynamic coefficients from the AIS data. In conclusion, this study proposes the viability of employing SVR model and AIS data for accurately estimating the hydrodynamic coefficients. It offers a practical approach to ship maneuvering prediction and control in the maritime industry.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.256-261
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• 2011

Labor productivity is a significant factor related to control time, cost, and quality. Many researchers have developed models to define method of measuring the relationship between productivity and various constraints such as the size of working area, maximum working hours, and the crew composition. Most of the previous research has focused on estimating productivity; however, this research concentrates on estimating labor productivity and developing time and cost data for repetitive concrete pouring activity. In Korea, "Standard Estimating" only contains the average productivity data of the construction industry, and it is difficult to predict the time and cost of any particular project; hence, there are some errors in estimating duration and cost for individual activity and project. To address these issues, this research collects data, measures productivity, and develops time and cost data using labor productivity based on field conditions from the collected data. A probabilistic approach is also proposed to develop data. A case study is performed to validate this process using actual data collected from construction sites and it is possible that the result will be used as the EVMS baseline of cost management and schedule management.

• 한국통신학회논문지
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• 제41권11호
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• pp.1549-1556
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• 2016

항공기의 이동속도의 증가로 인해 위치 측위의 중요성이 더욱 부각되고 있다. 이러한 요구는 GPS의 등장으로 충족되었으나 이는 트래픽 재밍 등 위성으로부터의 신호 수신이 어려운 경우에는 측위가 불가능하게 된다. 이러한 경우 통신용 링크가 측위에 부가적으로 사용된다면 상대적인 위치를 추정하여 위치를 추정할 수 있다. 통신용 링크를 이용한 측위는 추가적인 장치 없이 신호 처리만으로 위치를 추정할 수 있는데 대표적으로 ESPRIT이 존재하며 이는 수신 신호의 상관 행렬을 기반으로 한다. 이론적으로 상관 행렬의 추정에는 평균 연산이 필요하나 이는 실제 상황에서 많은 수의 샘플이 필요해 충분한 샘플이 주어지지 않은 경우 오류가 발생할 수 있다. 이에 적은 수의 샘플에서의 상관 행렬의 오류 행렬을 정의하고 추정하여 순시적으로 제거하는 알고리즘을 제시한다. 제안하는 알고리즘은 송신기가 밀집되어 있는 경우 기존의 알고리즘에 비해 우세한 성능을 보인다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권4호
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• pp.569-579
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• 2013

A steel-type breakwater that uses a submerged dual horizontal porous plate was originally proposed by Kweon et al. (2005), and its hydrodynamic characteristics and design methodology were investigated in a series of subsequent researches. In particular, Kweon et al. (2011) proposed a method of estimating the vertical uplift force that acts on the horizontal plate, applicable to the design of the pile uplift drag force. However, the difference between the method proposed by Kweon et al. (2011), and the wave force measured at a different time without a phase difference, have not yet been clearly analyzed. In this study, such difference according to the method of estimating the wave force was analyzed, by measuring the wave pressure acting on a breakwater model. The hydraulic model test was conducted in a two-dimensional wave flume of 60.0 m length, 1.5 m height and 1.0 m width. The steepness range of the selected waves is 0.01~0.03, with regular and random signals. 20 pressure gauges were used for the measurement. The analysis results showed that the wave force estimate in the method of Kweon et al. (2011) was smaller than the wave force calculated from the maximum pressure at individual points, under a random wave action. Meanwhile, the method of Goda (1974) that was applied to the horizontal plate produced a smaller wave force, than the method of Kweon et al. (2011). The method of Kweon (2011) was already verified in the real sea test of Kweon et al. (2012), where the safety factor of the pile uplift force was found to be greater than 2.0. Based on these results, it was concluded that the method of estimating the wave force by Kweon et al. (2011) can be satisfactorily used for estimating the uplift force of a pile.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.579-583
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• 2004

고속도로 신설 및 확장공사는 국가의 기반시설을 설치하기 위한 대규모 공공사업으로 정확한 산출근거에 의해 공사비용을 산정하여 적정 예산을 책정하여야 한다. 그러나 현재 고속도로 신설 침 확장공사의 구조물 해체 비용은 단지 구조물 설치 비용에 표준품셈에 명기된 일정 비율($10\~70\%$)을 곱하여 산정되고 있다. 해체 비용 산정에 이용되고 있는 표준품셈 상의 일정 비율은 과거 실적데이터를 기반으로 구축된 것이 아니라 해외 산정방식을 참고로 공사 관리자의 주관적 경험을 적용하여 도출된 것이다. 설치비에 일정비율을 곱하여 해체 비용을 산정하는 기존 방식은 프로젝트의 특성 및 건설현장의 주변 여건을 고려할 수 없으므로 노무량 및 장비 투임량의 변화를 고려할 수 없는 문제점을 가지고 있다. 따라서, 본 연구에서는 다양한 현장 조사 및 실측을 통한 해체 공사비 원가 분석을 수행하여 구조물 해체를 위한 적정원가 산정기준을 제시하고 기존 비율단가 적용방식의 적정성을 검토하고자 한다.

• 한국건설관리학회논문집
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• 제3권1호
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• pp.97-106
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• 2002

설계단계에서 VE를 적용하면 커다란 효과를 볼 수 있음에도 불구하고 국내에서는 설계단계의 VE가 활성화되지 못하고 있다. 특히 적절한 VB수행에 대한 적절한 용역대가 산정 기준의 부재는 설계VE의 적극적 활용을 가로막는 주요원인이 되고 있다. 본 논문에서는 설계YE와 유사한 용역업무의 대가산정 현황과 국내외 설계YE 용역대가 산정현황을 분석하여 현재 YE 용역대가 산정의 주요한 문제점을 도출하고 개선방향을 제시하였다. 다음으로 VE 용역대가 산정방안과 수행결과에 따른 인센티브 지급 방안을 제시하였다 마지막으로 면담을 통해 제안된 방안의 유효성을 검증하였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제29권1호
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• pp.21-34
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• 1990

This is a study on an instruction of estimation for error correction in the calculation with a computer or a calculator. The aim of this study is to survey a new aspect of calaulation teaching and the teaching strategy of estimation and finally to frame a new curriculum model of estimation instruction. This research required a year and the outcomes of the research can be listed as follows: 1. Social utilities of estimation were made clear, and a new trend of calculation teaching related to estimation instruction was shown. 2. The definition of estimation was given and actual examples of conducting an estimation among pupils in lower grades were given for them to have abundant experiences. 3. The ways of finding estimating values in fraction and decimal fraction were presented for the pupils to be able to conduct an estimation. 4. The following contents were given as a basic strategy for estimation. 1) Front-end strategy 2) Clustering strategy 3) Rounding strategy 4) Compatible numbers strategy 5) Special numbers strategy 5. In an instuction of estimation the meaning, method. and process of calculation and calculating algorithm were reviewed for the cultivation of children's creativity through promoting their basic skill, mathematical thinking and problem-solving ability. 6. The following contents were also covered as an estimation strategy for measurement 1) Calculating the sense of quantity on the size of unit. 2) Estimating the total quantity by frequent repetition of unit quantity. 3) Estimating the length and the volume by weighing. 4) Estimating unknown quantity based on the quatity already known. 5) Estimating the area by means of equivalent area transformation. 7. The ways of instructing mental computation were presented. 8. Reviews were made on the curricular and the textbook contents concerning estimation instructions both in Korea and Japan. and a new model of curriculum was devised with reference to estimation instruction data of the United States.

• 농촌계획
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• 제16권4호
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• pp.117-129
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• 2010

This study is to make value estimating system to valuate prototype landscape of rural and to derive itemized importance to select priority preservable object The results of the study are summarized as follows, It is examined value estimating standard by analyzing prototype landscape related previous study, law and order. Also, It is derived conclusive prototype landscape value estimating system by doing attribute assessment of preserving objects while surveying the site and interviewing professionals, Value estimating system is classified into five items of physical value which are integration, harmony, diversity, symbolism and aesthetics, The historical-cultural value are divided into four categories which are religious value, originality, historicity and scarcity, The communal values are divided into three categories which are sociality, continuing and regional locality and also divided into three categories which are rarity, primitiveness and diversity as the ecological value, Relative priority of prototype landscape value estimating system result is derived as historical-cultural value as the superior position and physical value, communal value and ecological value as the priority order. In the subordinate, historical categories are derived to be the most valuable and originality, symbolism, integration, regional locality, continuing, harmony, aesthetics, religious value, primitiveness, diversity of physical values and diversity of ecological value in order of the priority assessment The results of the study have the meaning of practical use in prior selection and preservation plan of preserving prototype landscape as practical alternative plan for systematical preservation of damaging prototype landscape.

• 한국건설관리학회논문집
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• 제10권5호
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• pp.104-112
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• 2009

90년대 중반이후 도시하천을 중심으로 추진되던 자연형 하천 정비사업은 2008년 4월 하천법의 개정으로 인해 하천의 친환경적인 기능이 더욱 강조되어, 그 적용 분야는 지방하천까지 폭넓게 확대 되었다. 그러나 기존의 이 치수형 하천정비사업에 초점을 맞춘 하천의 개략공사비 산정모델은 자연형 하천공사에 실시되는 주요공종을 포함하고 있지 않아, 축제공, 호안공사가 전부인 소규모 하천정비공사를 제외하고는 그 적용성이 많이 떨어진다. 따라서 본 연구는 최근의 친환경적인 기능을 강조하는 하천정비공사의 패러다임 등 하천시설공사 관련 환경 및 정책 변화에 따라서 기획 및 설계 단계에서 적용될 수 있는 자연형 하천공사 개략공사비 산정모델을 개발하는 것을 목적으로 한다.

• 대한교통학회지
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• 제21권3호
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• pp.121-134
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• 2003

횡단보도의 안전성과 교통 소통을 동시에 고려하면서 횡단보도 보행자사고를 감소시키기 위한 방안으로 보행자사고 예측모형이 꾸준히 연구되어 왔으나, 기존의 예측모형에서는 횡단보도 보행자사고의 당사자에 해당하는 보행량이라는 변수를 제대로 반영하지 못하고 있는 실정이다. 실제로 보행량과 관련한 자료가 구축되어 있지 않고. 보행량 추정방법 역시 없는 실정이기 때문이다. 이러한 점에 착안하여 본 연구에서는 기준년도 신호교차로 주변의 토지이용특성과 횡단보도 보행량을 조사하여 횡단보도 보행유출입량 추정모형을 구축하였다. 다음으로, 추정된 횡단보도 보행유출입량을 중력모형의 마찰계수와 구역간 조정계수, 그리고 대각횡단 보행비율을 적용하여 횡단보도 보행경로별로 보행량을 분포시킴으로서 목표년도(보행자사고 발생 시점 또는 장래)의 횡단보도 보행량 추정방법을 제시하였다.