• 드라이브 ㆍ 컨트롤
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• 제21권2호
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• pp.65-71
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• 2024

In this study, we suggested a key-point detection method for robot harvesting of oriental melon. Our suggested method could be used to detect the detachment part and major composition of oriental melon. We defined four points (harvesting point, calyx, center, bottom) based on tomato with characteristics similar to those of oriental melon. The evaluation of estimated key-points was conducted by pixel error and PDK (percentage of detected key-point) index. Results showed that the average pixel error was 18.26 ± 16.62 for the x coordinate and 17.74 ± 18.07 for the y coordinate. Considering the resolution of raw images, these pixel errors were not expected to have a serious impact. The PDK score was found to be 89.5% PDK@0.5 on average. It was possible to estimate oriental melon specific key-point. As a result of this research, we believe that the proposed method can contribute to the application of harvesting robot system.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1605-1614
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• 2013

This paper presents a probabilistic methodology for small signal stability analysis of power system with correlated wind sources. The approach considers not only the stochastic characteristics of wind speeds which are treated as random variables with Weibull distributions, while also the wind speed spatial correlations which are characterized by a correlation matrix. The approach based on the 2m+1 point estimate method and Cornish Fisher expansion, the orthogonal transformation technique is used to deal with the correlation of wind farms. A case study is carried out on IEEE New England system and the probabilistic indexes for eigenvalue analysis are computed from the statistical processing of the obtained results. The accuracy and efficiency of the proposed method are confirmed by comparing with the results of Monte Carlo simulation. The numerical results indicate that the proposed method can actually capture the probabilistic characteristics of mode properties of the power systems with correlated wind sources and the consideration of spatial correlation has influence on the probability of system small signal stability.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.447-450
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• 2004

국내 건설업계는 공기보다는 공사비에 초점을 맞추어 왔다. 그러나 근래에 들어 사회적 요구 변화로 인하여 공기에 대한 관심이 증대되고 있다. 적정한 공사기간은 다른 방면으로서의 비용절감과 관리의 효율성을 줄 수 있다. 특히 공동주택과 같은 경우 대부분의 공정이 타 기업과 유사하여 다른 기업의 장점을 쉽게 얻을 수 있으나 현재 대부분의 기업에서는 공기에 대한 연구가 부족한 형편이다. 본 연구는 공기가 타기업에 비해 짧은 기업을 대상으로 대공정 수준의 일반 공기 산정 기준을 검토하고 이에 따른 기업의 공기 우위요인을 연구하여 공기 산정을 위해 검토하여야 할 요소와 이를 통한 공기 단축에 영향을 줄 수 있는 요소를 제시하려 한다.

• 한국공작기계학회논문집
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• 제15권2호
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• pp.99-106
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• 2006

In this paper, the new method that estimates a sensing ability of smart sensor will be proposed. A study is estimation method that evaluates sensing ability about smart sensor respectively. According to acceleration(g) and displacement changing, we estimated sensing ability of smart sensor using SAI(Sensing Ability Index) method respectively. Smart sensors was made fer experiment. The types of smart sensor are two types(hard and soft smart sensor). Smart sensors developed for recognition of material. Experiment and analysis are executed for estimate the SAI method. In develop a smart sensor, the SAI method will be useful for finding optical design condition of smart sensor that can sense a material. And then dynamic characteristics of smart sensors(frequency changing, acceleration changing, critical point, etc.) are evaluated respectively through new method(SAI) that use the power spectrum density. Dynamic characteristic of sensor is evaluated with SAI method relatively. We can use the SAI for finding critical point of smart sensor, too.

• 한국산업보건학회지
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• 제9권2호
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• pp.79-89
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• 1999

A quantitative fit test, condensation nuclei counting (Portacount 8025, TSI), was performed concurrently with a banana oil (isoamyl acetate: IAA) qualitative fit test (MSA) to evaluate reliability on IAA QLFT and correlation between two methods. One brands of quarter mask (3M model 7500 medium) was prepared for QLFT with HEPA filter and gas & vapor removing media, i.e., combination cartridge. 110 subjects (65 male, 45 female) were fit tested QNFT and QLFT each three times. For a wearer combination having a FF<10, as determined by CNC QNFT, the point es timate (${\beta}$-error) of the probability of that combination not being rejected by the banana oil QLFT was found to be 0.0 with 95% confidence that this statistic is not expected to exceed 0.15. For a wearer combination having a FF<100, as determined by CNC QNFT, the point estimate of the probability of that combination not being rejected by the banana oil QLFT was found to be 0.07 with 95% confidence that this statistic is not expected to exceed 0.13. The uncertainty associated with each estimate, however, is large due to the small number of study subjects with inadequately fitting respirators.

• 한국물환경학회지
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• 제36권1호
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• pp.29-35
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• 2020

To manage the non-point source pollution and restore the water circulation, many technologies including infiltration or reservoir systems were installed in the urban area. These facilities have many problems regarding maintenance as their operation period becomes lengthier. The purpose of this study was to estimate the optimal maintenance timing through a long-term load test on the infiltration trench as one of the low impact development techniques. An infiltration trench was installed in the demonstration test facility, and stormwater was manufactured by Manual on installation and operation of non-point pollution management facilities from the Ministry of Environment, Korea and entered into the infiltration trench. Particle size distribution (PSD), suspended solids (SS) removal efficiency, and infiltration rate change tests were performed on inflow and outflow water. In case of the PSD, the maximum particulate size in the outflow decreased from 64 ㎛ to 33 ㎛ as the operating duration elapsed. The SS removal efficiency improved from 97 % to 99 %. The infiltration rate changed from 0.113 L/sec to 0.015 L/sec during the operation duration. The maintenance timing was determined based on the stormwater runoff requirements with these changes in water quality and infiltration rate. The methodologies in this study could be used to estimate the timing of maintenance of other low impact development techniques.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.673-682
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• 2018

One of the most widely used methods to estimate core damage during a nuclear power plant accident is containment radiation measurement. The evolution of severe accidents is extremely complex, leading to uncertainty in the containment dose rate (CDR). Therefore, it is difficult to accurately determine core damage. This study proposes to conduct uncertainty analysis of CDR for core damage assessment. First, based on source term estimation, the Monte Carlo (MC) and point-kernel integration methods were used to estimate the probability density function of the CDR under different extents of core damage in accident scenarios with late containment failure. Second, the results were verified by comparing the results of both methods. The point-kernel integration method results were more dispersed than the MC results, and the MC method was used for both quantitative and qualitative analyses. Quantitative analysis indicated a linear relationship, rather than the expected proportional relationship, between the CDR and core damage fraction. The CDR distribution obeyed a logarithmic normal distribution in accidents with a small break in containment, but not in accidents with a large break in containment. A possible application of our analysis is a real-time core damage estimation program based on the CDR.

• 한국항공우주학회지
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• 제49권3호
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• pp.197-204
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• 2021

유도탄의 비행 시험 중 고장 또는 비정상적인 기동이 발생하는 경우 비행을 계속하지 않도록 의도적으로 자폭한다. 이때 파편이 발생하며 안전 지역을 벗어났는지 여부를 실시간으로 추정하는 것이 중요하다. 본 논문에서는 Fully-Connected Neural Network(FCNN)를 이용하여 실시간으로 파편의 예상 낙하 영역 및 낙하 시간을 추정하는 방법을 제안한다. 많은 양의 학습 데이터 생성을 위해 Unscented Transform(UT)를 적용하였으며 신뢰도 확보를 위해 Monte-Carlo(MC) 시뮬레이션과 비교하여 파라미터를 선정하였다. 또한 제안한 방법의 추정 결과를 MC와 비교하여 성능을 분석하였다.

• Smart Structures and Systems
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• 제32권2호
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• pp.123-133
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• 2023

This paper proposes a thermography-based coating thickness estimation method for steel structures using model-agnostic meta-learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured using an infrared (IR) camera. The measured heat responses are then analyzed using model-agnostic meta-learning to estimate the coating thickness, which is visualized throughout the inspection surface of the steel structure. Current coating thickness estimation methods rely on point measurement and their inspection area is limited to a single point, whereas the proposed method can inspect a larger area with higher accuracy. In contrast to previous ANN-based methods, which require a large amount of data for training and validation, the proposed method can estimate the coating thickness using only 10- pixel points for each material. In addition, the proposed model has broader applicability than previous methods, allowing it to be applied to various materials after meta-training. The performance of the proposed method was validated using laboratory-scale and field tests with different coating materials; the results demonstrated that the error of the proposed method was less than 5% when estimating coating thicknesses ranging from 40 to 500 ㎛.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권8호
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• pp.655-667
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• 2006

본 논문은 목표 및 시나리오 기반의 요구사항을 이용하여 기능점수 (function point)를 산정하는 방법을 제안한다. 기능점수는 소프트웨어의 규모를 계산하는 방법으로 널리 사용되고 있으며 비용계산의 기본자료가 된다. 기능접수를 산정하기 위해서는 요구사항 도출 및 분석이 선행되어야 하나 기존의 기능점수 방법론은 이를 다루지 않고 있다. 한편 시스템 개발의 초기단계에서 대부분의 요구사항은 자연어 형태로 수집된다. 목표와 시나리오 방법론은 자연어 형태의 요구사항을 사용하여 요구사항을 도출하고 분석하는 방법으로 널리 사용되고 있으며 추적성에 대한 장점을 가지고 있다. 그러므로 목표 및 시나리오 기반의 요구사항으로부터 기능점수를 산정 할 수 있다면 요구사항과 기능접수 간의 추적성 관리가 쉬워진다. 이에 본 논문에서는 목표와 시나리오 기반의 요구사항으로부터 기능점수를 산정하는 방안을 제안한다. 제안된 방안은 자연어 형태로 기술된 목표 및 시나리오로부터 기능접수 분석에 필요한 규칙을 제공한다. 제안된 방안은 Order Processing System 예제를 통해 적용 방안을 설명한다.