• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.7-12
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• 2003

In recent years, many attempts have been made to predict the behavior of bonds, currencies, stock or other economic markets. Most previous experiments used the neural network models for the stock market forecasting. The KOSPI 200 (Korea Composite Stock Price Index 200) is modeled by using different neural networks and fuzzy logic. In this paper, the neural network, the dynamic polynomial neural network (DPNN) and the fuzzy logic employed for the prediction of the KOSPI 200. The prediction results are compared by the root mean squared error (RMSE) and scatter plot, respectively. The results show that the performance of the fuzzy system is little bit worse than that of the DPNN but better than that of the neural network. We can develop the desired fuzzy system by optimization methods.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1019-1026
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• 2008

The goal of this paper is to analysis the trend of stream quality about the upstream, middle stream and high areas of Nakdong River measurement points from January 1998 to December 2006. and to suggest some policy alternatives in Nakdong river. It used the three different monthly time series data such as BOD (biochemical oxygen demand), TN (Total Nitrogen) and TP(Total Phosphorus), of the three of Nakdong River measurement points. BOD, TN and TP data are analyzed with the LOWESS(Locally Weighted Scatter plot Smoother) nonparametric method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2030-2032
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• 2001

In recent years, many attempts have been made to predict the behavior of bonds, currencies, stock, or other economic markets. Most previous experiments used multilayer perceptrons(MLP) for stock market forecasting. The Kospi 200 Index is modeled using different neural networks and fuzzy system predictions. In this paper, a multilayer perceptron architecture, a dynamic polynomial neural network(DPNN) and a fuzzy system are used to predict the Kospi 200 index. The results of prediction is compared with the root mean squared error(RMSE) and the scatter plot. Results show that both networks can be trained to predict the index. And the fuzzy system is performing slightly better than DPNN and MLP.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.249-249
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• 2017

본 연구에서는 낙동강 본류의 진동과 적포교, 남강의 거룡강, 대산, 정암 수위표의 관측된 2015년부터 2016년 2년간 수위자료를 이용하여, Self-Organizing Maps(SOM)과 LOcally WEighted Scatter plot Smoother(Lowess) 기법으로 패턴과 추세를 분석하였다. SOM 분석 결과, 낙동강 본 류의 진동과 적포교, 남강의 거룡강, 대산은 동일한 패턴과 추세를 나타냈다. 수위의 범위도, SOM 분석에서 진동 최소 EL. 4.41m, 최대 EL. 5.01m 범위, 적포교 최소 EL. 4.56m, 최대 EL. 5.38m 범위, 거룡강 최소 EL. 4.53m, 최대 EL. 5.18m 범위, 대산 최소 EL. 4.57m, 최대 EL. 5.35m 범위로 큰 차이가 발생하지 않았다. 거룡강과 대산 수위 관측지점은 낙동강 본류의 배수위 영향을 받는 것을 알 수 있었으며, 두 지점의 수위 관측 목적에 따라 상류로 지점 변경이 필요 할 수도 있을 것으로 판단된다.

• 대한치과의사협회지
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• 제22권7호통권182호
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• pp.607-620
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• 1984

Mandibular Kinesiograph (MKG-5R)으로부터 얻어지는 자료의 유효성에 관한 연구를 위하여 비철, 비자석성의 기구를 이용해서 3cm×4cm×5cm의 4차원적 입체공간내에서 수행하였다. Kinesiograph로 부터의 직접 얻어지는 자료(관찰치)와 실제 움직인 거리(실제치)간의 관계를 먼저 보기위해 Scatter plot과 Correlation이 연구됐다. 그러나 최종의 목표는 어떤 형태의 공식을 만들어 이것으로 Kinesiograph관찰치를 이용, 실제치를 알도록 하는 것이었으므로 관찰치의 통계학적 회귀분석이 수행되었다. 통계분석의 결과는 Kinesiograph 관찰치와 실제치 간의 강한 상관관계를 보였다. 그러나 높은 상관계수가 반드시 얻어진 선형모형의 완벽한 예측성을 의미하는 것은 아니다. 이 연구로부터 얻어진 선형모형이 실제치를 모두 완벽하게 예측할수는 없었다. 그 이유로서는 종속변수(실제치)의 불연속성과 관찰치(비종속변수) 상호간의 독랩성 때문이다. 결론적으로 Kinesiograph가 어떤 형태로든 적절한 방법에 의해 수정이 있지 않으면 그 계통자체내에 내재하는 비선형적 특성 때문에 그 이용이 하악운동의 제한된 범위내에만 적용될 수 있다.

• 산업진흥연구
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• 제9권2호
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• pp.13-22
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• 2024

본 연구 목적은 주요 항공사별 여객의 동향과 변동률을 도출하고 방향성과 동조화현상을 파악하는데 있다. 통계청 국가통계포럼에서 항공사별 자료를 수집하고 2011년 1월부터 2023년 11월까지 총 155개 월간자료를 활용하였다. 국내 대형항공사인 대한항공과 아시아나항공, 저비용항공사인 제주항공, 진에어, 티웨이 그리고 외국항공사를 대상으로 변동률을 산출하였다. 분석결과, 상관관계분석은 한국 총 여객에 대해 아시아나, 대한항공, 제주항공, 티웨이, 진에어, 외항사 순으로 높게 나타났다. 상승률은 티웨이, 진에어, 제주항공, 외항사, 아시아나, 대한항공 순으로 높게 나타났다. Scatter 분석에서 한국 총 여객에 대해 아시아나와 대한항공이 매우 강한 동조화현상을 보여주었고, 제주항공, 티웨이, 진에어, 외항사은 일정 수준 유사한 방향성을 보여주었다. Box-Box Plot 분석에서, 각 항공사는 코로나 19 발생으로 일시적인 급등락현상이 다수 발생하였던 것으로 보였다. 저비용항공사의 출현으로 승객 입장에서는 선택의 폭이 넓어지면서 서비스에 대한 기대감이 커질 것이고 그럴수록 항공사 간 경쟁이 높아질 것으로 보여 기업 발전을 위해 이를 만족시킬 수 있는 환경개선이 뒤따라야 할 것이다.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.409-422
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• 2016

A parametric study based on an unsteady mathematical model of a pyrotechnically actuated device was performed for design optimization. The model simulates time histories for the chamber pressure, temperature, mass transfer and pin motion. It is validated through a comparison with experimentally measured pressure and pin displacement. Parametric analyses were conducted to observe the detailed effects of the design parameters using a validated performance analysis code. The detailed effects of the design variables on the performance were evaluated using the one-at-a-time (OAT) method, while the scatter plot method was used to evaluate relative sensitivity. Finally, the design optimization was conducted by employing a genetic algorithm (GA). Six major design parameters for the GA were chosen based on the results of the sensitivity analysis. A fitness function was suggested, which included the following targets: minimum explosive mass for the uniform ignition (small deviation), light casing weight, short operational time, allowable pyrotechnic shock force and finally the designated pin kinetic energy. The propellant mass and cross-sectional area were the first and the second most sensitive parameters, which significantly affected the pin's kinetic energy. Even though the peak chamber pressure decreased, the pin kinetic energy maintained its designated value because the widened pin cross-sectional area induced enough force at low pressure.

• 한국병원경영학회지
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• 제17권3호
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• pp.83-98
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• 2012

The purpose of this study is to investigate IPA(Importance Performance Analysis) of the hospital choice factor between internal and external customers at S general hospital. This study was used 5 types of choice factors such as physical, interpersonal, accessibility, connection, and image. This study was used Importance Performance Analysis which can be applied to identify the strengths and weaknesses attributes from hospital customers' viewpoint. The sample was selected 116 patients and 97 internal employees for S hospital in Seoul. Data were collected with self-reported questionnaires from April 1 to 29 in 2012 and analyzed by paired t-test, scatter plot graph. The result of the study was that the perceptional gaps between internal and external consumers were existed in physical, connection and image factors, except interpersonal, accessibility. The "Keep up the good work" quadrant was interpersonal factor, and the "Low Priority" quadrant was accessibility. The findings of this study will be applied to make hospital strategic decision making and to improve marketing service quality in administrative department of hospital.

• 한국해양공학회지
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• 제34권3호
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• pp.167-179
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• 2020

Recently, the increasing importance of artificial intelligence (AI) technology has led to its increased use in various fields in the shipbuilding and marine industries. For example, typical scenarios for AI include production management, analyses of ships on a voyage, and motion prediction. Therefore, this study was conducted to predict a response amplitude operator (RAO) through AI technology. It used a neural network based on one of the types of AI methods. The data used in the neural network consisted of the properties of the vessel and RAO values, based on simulating the in-house code. The learning model consisted of an input layer, hidden layer, and output layer. The input layer comprised eight neurons, the hidden layer comprised the variables, and the output layer comprised 20 neurons. The RAO predicted with the neural network and an RAO created with the in-house code were compared. The accuracy was assessed and reviewed based on the root mean square error (RMSE), standard deviation (SD), random number change, correlation coefficient, and scatter plot. Finally, the optimal model was selected, and the conclusion was drawn. The ultimate goals of this study were to reduce the difficulty in the modeling work required to obtain the RAO, to reduce the difficulty in using commercial tools, and to enable an assessment of the stability of medium/small vessels in waves.

• Interdisciplinary Bio Central
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• 제4권4호
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• pp.11.1-11.8
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• 2012

Genes that are indispensable for survival are referred to as essential gene. Due to the momentous significance of these genes for cellular activity they can be selected potentially as drug targets. Here in this study, an essential gene for Streptococcus suis was predicted using coherent statistical analysis and powerful genome comparison computational method. At first the whole genome protein scatter plot was generated and subsequently, on the basis of statistical significance, a reference genome was chosen. The parameters set forth for selecting the reference genome was that the genome of the query (Streptococcus suis) and subject must fall in the same genus and yet they must vary to a good degree. Streptococcus pneumoniae was found to be suitable as the reference genome. A whole genome comparison was performed for the reference (Streptococcus pneumoniae) and the query genome (Streptococcus suis) and 14 conserved proteins from them were subjected to a screen for potential essential gene property. Among those 14 only one essential gene was found to be with impressive similarity score between reference and query. The essential gene encodes for a type of 'Clp protease'. Clp proteases play major roles in degrading misfolded proteins. Results found here should help formulating a drug against Strptococcus suis which is responsible for mild to severe clinical conditions in human. However, like many other computational studies, the study has to be validated furthermore through in vitro assays for concrete proof.