• 로봇학회논문지
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• 제3권4호
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• pp.308-314
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• 2008

Recently, simultaneous localization and mapping (SLAM) approaches employing Rao-Blackwellized particle filter (RBPF) have shown good results. However, no research is conducted to analyze the result representation of SLAM using RBPF (RBPF-SLAM) when particle diversity is preserved. After finishing the particle filtering, the results such as a map and a path are stored in the separate particles. Thus, we propose several result representations and provide the analysis of the representations. For the analysis, estimation errors and their variances, and consistency of RBPF-SLAM are dealt in this study. According to the simulation results, combining data of each particle provides the better result with high probability than using just data of a particle such as the highest weighted particle representation.

• 전기학회논문지
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• 제56권12호
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• pp.2084-2090
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• 2007

The DGA (Dissolved Gases Analysis) technique has been widely using for fault diagnosis of the power transformers. Some electric power utility company establishes the criteria of DGA to improve reliability, because of difference of operation environment and design of power transformer. In this paper, we introduce intelligent diagnosis system for DGA result of KEPCO (Korea Electric Power Cooperation). This system can classify patterns type of gases ratio that frequently occurs in recent result of gases analysis using Fuzzy Inference. The classification of Patterns let us know that major causes of gases generation based on type of patterns. Finally, Neural Network based on patterns diagnose transformer. NN was trained using result data of DGA of actually faulted transformers recently. Result of intelligent diagnosis system is right well in comparison with actual inner inspection of transformers.

• 한국군사과학기술학회지
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• 제8권4호
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• pp.5-13
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• 2005

The impact of a long-rod penetrator into oblique plates with combined obliquity and yaw is investigated. The study was done using a newly developed three dimensional dynamic and impact analysis code, which uses the explicit finite element method. Through the comparison of simulation result with experimental result and other code's result, the adaptability and accuracy of the developed code is evaluated under the complex situation in which yaw angle and oblique angle exist simultaneously. As a result of comparison, it has found that deformed shape, residual length and velocity, rotational velocity of long-rod show good agreement with experimental data. Through this study, the applicability and accuracy of the code as a metallic armour system design tool is verified.

• 한국조리학회지
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• 제13권4호
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• pp.31-44
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• 2007

The verified results of this study on the selected study assignments are as follows: Brand awareness of the western-style family restaurants in both study assignment One and Two is examined by showing and comparing the restaurants ranked from first to third. The ranking is based on the survey response rate only. And the familiarity of family restaurants' logos is investigated by statistical techniques such as T-test Anova, Duncan's Multiple Range Test, etc. Firstly, the analytical result of study assignment One shows that the brand awareness of the family restaurants can vary depending on how often customers use the restaurants. Secondly, the analytical result of study assignment Two shows that the familiarity and the preference of the restaurants ranked from first to third are identical each other depending on customers' sex, marital status, and income. Besides, the result shows that the brand awareness shows different rankings depending on customers' age, educational background, and occupation. Thirdly, the analytical result of study assignment Three indicates that the familiarity is different depending on customers' age, educational background, occupation, and annual income.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.30-37
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• 2022

Because fine dust (PM10) has a close effect on the environment, fine dust generated in the climate and living environment has a bad effect on the human body. In this study, the LSTM model was applied to predict and analyze the effect of fine dust on Gwangju Metropolitan City in Korea. This paper uses prediction values of input variables selected through correlation analysis to confirm fine dust prediction performance. In this paper, data from the Gwangju Metropolitan City area were collected to measure fine dust. The collection period is one year's worth of data was used from january to December of 2021, and the test data was conducted using three-month data from January to March of 2022. As a result of this study, in the as a result of predicting fine dust (PH10) and ultrafine dust (PH2.5) using the LSTM model, the RMSE was 4.61 and the test result value was as low as 4.37. This reason is judged to be the result of the contents of the one-year sample.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.136-142
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• 2004

Effects of Nb(Niobium) contents and solution annealing on the strength and fatigue lift of 18%Ni maraging steel commonly using in aircraft, space field, nuclear energy, and vehicle etc. were investigated. Also the fatigue life stress intensity factor were compared experiment result and FEA(finite element analysis) result. The more Nb content, the higher or the lower fatigue lift on base metal specimens or solution annealed specimens showing that the fatigue life was almost the same. The maximum stresses of X, Y, and Z axis direction showed about 2.12${\times}$10$^2$MPa, 4.40${\times}$10$^2$MPa and 1.32${\times}$10$^2$MPa respectively. The Y direction stress showed the highest because of the same direction as the loading direction. The fatigue lives showed about 7% lower FEA result than experiment result showing almost invariable error every analyzed cycle. Stress intensity factor of the FEA result was lower about 3.5∼10% than that of the experiment result showing that the longer fatigue crack length, the higher error. It considered that the cause for the difference was the modeled crack tip having always the same shape and condition regardless of the crack growth.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권5호
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• pp.309-317
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• 2004

This paper suggested the vibration characteristic improvement by variation mode of ring type ultrasonic motor. Design for the piezoelectric ceramic and elastic body of stator were calculated by the finite element method(FEM) that consider the resonance frequency, vibration mode and coupling efficiency etc. Through the result of vibration analysis from 6 order mode to 8 mode, the 7 order mode was gained very an excellent results that it was the coupling efficient, minimum power loss and bending vibration value. Here over 7 order mode, this paper was acquired that an output current for input voltage was very a large increased results. The result of vibration calculation, from thickness 0.5[mm] to 2[mm], knew the fact that the vibration displacement at 0.5[mm] is an high value too. From such result, this paper was manufactured the ultrasonic motor of outer diameter 5O[mm] , inter 22[mm] having the about 43.86[KHz] resonance frequency. We have gated that a simulation result is 42.2[KHz] and an experiment result is 43.86[KHzl The propriety of this paper was established though comparison. investigation of simulation and experiment result.

• 한국컴퓨터산업학회논문지
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• 제3권7호
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• pp.881-890
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• 2002

본 논문에서는 에이전트 기술을 이용하여, 사용자 기호 분석을 통해 사용자 기호에 가까운 결과를 제공하는 검색시스템을 제안하고 구현한다. 일반 검색 시스템의 불필요하고 중복된 검색내용을 지양하면서 보다 양질의 정보를 사용자에게 제공하기 위하여 본 시스템은 검색시 사용자의 정보를 입력받고, 입력된 정보에서 검색키와 카테고리를 생성한다. 그리고 에이전트 기반의 검색엔진을 통해 상용 검색엔진의 검색결과와 사용자 기호 정보를 비교하여 사용자 기호에 근접하는 결과만을 제공한다. 동시에 검색결과는 카테고리별로 데이터베이스화하여 또 다른 검색의 결과에 추가로 제공되도록 한다. 시스템 구현결과 사용자에게 제공되는 검색결과는 일반 검색 시스템의 중복 검색이 제거됐으며, 사용자 기호에 가까운 내용들로 검색이 이루어졌다.

• 한국안전학회지
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• 제20권4호
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• pp.1-8
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• 2005

Effects of Nb(Niobium) contents and solution annealing on the strength and fatigue life of 18%Ni maraging steel commonly using in aircraft, space field, nuclear energy, and vehicle etc. were investigated. Also the fatigue life stress intensity factor were compared experiment result and FEA(finite element analysis) result. The more Nb content, the higher or the lower fatigue life on base metal specimens or solution annealed specimens showing that the fatigue lift was almost the same. The maximum stresses of X, Y, and Z axis direction showed about $2.12{\times}10^2MPa,\;4.40{\times}10^2MPa\;and\;1.32{\times}10^2MPa$ respectively. The Y direction stress showed the highest because of the same direction as the loading direction. The fatigue lives showed about 7% lower FEA result than experiment result showing almost invariable error every analyzed cycle. Stress intensity factor of the FEA result was lower about $3.5{\sim}10%$ than that of the experiment result showing that the longer fatigue crack length the higher error. It considered that the cause for the difference was the modeled crack tip having always the same shape and condition regardless of the crack growth.

• Clinics in Shoulder and Elbow
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• 제16권1호
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• pp.63-72
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• 2013

임상 의학의 연구에 사용되는 대표적 다변량 분석 방법은 다중 회귀 분석 방법인데, 이는 인과 관계를 토대로 여러 개의 변수에 의한 한꺼번에의 영향력을 분석하기 위한 방법이다. 다중 회귀 분석은 기본적으로 회귀 분석의 기본 가정을 만족해야 함은 물론, 여러 개의 독립 변수들이 포함되기 때문에 변수들을 모형에 포함시키는 방법 및 다중 공선성 문제에 대한 고려가 필요하다. 다중 회귀 분석 모형의 설명력은 결정 계수 $R^2$으로 표현되어 1에 가까울수록 설명력이 크며, 각 독립 변수들의 결과에의 영향력은 회귀 계수인 ${\beta}$값으로 표현된다. 다중 회귀 분석은 종속 변수의 형태에 따라 다중 선형 회귀 분석, 다중 로지스틱 회귀 분석, 콕스 회귀 분석으로 나눌 수 있다. 종속 변수가 연속 변수인 경우 다중 선형 회귀 분석, 범주형 변수인 경우 다중 로지스틱 회귀 분석, 시간의 영향을 고려한 상태 변수인 경우는 콕스 회귀 분석을 시행해야 하며, 각각 결과에의 영향력은 회귀 계수 ${\beta}$, 교차비, 위험비로 평가한다. 이러한 다변량 분석에 대한 이해는 연구를 계획하고 결과를 분석하고자 하는 임상 의사에게 있어 보다 효율적인 연구를 위해 필수적인 소양이라고 할 수 있다.