• 한국산학기술학회논문지
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• 제11권12호
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• pp.5042-5048
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• 2010

유비쿼터스 환경에서 다양한 센서로부터 생성되는 데이터 스트림에 대해 사용자가 요구하는 위치 기반 서비스를 효과적으로 지원하기 위해 연산자 네트워크와 공유 등을 통한 연속 질의 처리 기법이 활용되고 있다. 위치 정보 기반의 연속 질의 처리는 특정 영역을 중심으로 유사 질의가 집중적으로 발생할 수 있으므로, 본 논문에서는 유사한 조건을 갖는 공간 연산을 공유하기 위해 그리드 영역 분할을 이용한 공간 연산 공유 기법을 제안한다. 제안기법은 공간 연산을 직접 공유하지 않고 그리드 셀 별로 이동객체를 공유하기 때문에 유사한 조건을 갖는 공간 연산의 공유가 가능하여 공간 연산의 실행 빈도수를 크게 감소시켜 질의 처리 속도의 향상과 함께 메모리 이용률을 향상시킨다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1362-1369
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• 2007

Seoul Metro continuously converted the standard rail into continuous welded rail since the later part of 1990's, and currently, most of the sectors of the Seoul Metro are continuous welded rails. As the continuous welded rail is inhibited by the contraction and expansion force of the rail as well as rail-bed, this force is stored as the internal stress of the rail with the exception of portion of the both ends of the continuous welded rail. If the contraction and expansion of the rail is restricted, the internal stress, that is, the force in the direction of the axis, is proportional to the cross-sectional area of the rail. Therefore, with regards to the temperature changes, the internal stress changes in accordance with the type of rail, bolting apparatus, railroad tie and rail-bed. As such, the rail temperature becomes important data in securing the gap at the adjoining section of the rail in the standard rail section, and to determine the setting temperature for the continuous welded rail. In addition, it becomes basic data for maintenance of the track. Accordingly, this thesis introduces cases of installation of rail temperature detector in order to prevent and manage track defectiveness due to increase in rail temperature, and to utilize as basic data at the time of various construction and maintenance. Furthermore, this thesis aims to assist maintenance of track through systematic temperature management in the future by looking into means of its utilization.

• 산업경영시스템학회지
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• 제39권1호
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• pp.123-129
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• 2016

In the manufacturing industry fields, thousands of quality characteristics are measured in a day because the systems of process have been automated through the development of computer and improvement of techniques. Also, the process has been monitored in database in real time. Particularly, the data in the design step of the process have contributed to the product that customers have required through getting useful information from the data and reflecting them to the design of product. In this study, first, characteristics and variables affecting to them in the data of the design step of the process were analyzed by decision tree to find out the relation between explanatory and target variables. Second, the tolerance of continuous variables influencing on the target variable primarily was shown by the application of algorithm of decision tree, C4.5. Finally, the target variable, loss, was calculated by a loss function of Taguchi and analyzed. In this paper, the general method that the value of continuous explanatory variables has been used intactly not to be transformed to the discrete value and new method that the value of continuous explanatory variables was divided into 3 categories were compared. As a result, first, the tolerance obtained from the new method was more effective in decreasing the target variable, loss, than general method. In addition, the tolerance levels for the continuous explanatory variables to be chosen of the major variables were calculated. In further research, a systematic method using decision tree of data mining needs to be developed in order to categorize continuous variables under various scenarios of loss function.

• 품질경영학회지
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• 제47권2호
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• pp.237-254
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• 2019

Purpose: The purpose of this study is to analyze correlation of perceived cosmetics brand apps attributes and use intentions, mediating role of customer satisfaction, and relationship between customer satisfaction and continuous usage intention. Then provide basic data for development management strategy of beauty industry and enhancement of competitiveness corresponding to smart era. Methods: The questionnaires were surveyed by an online company(EMBRAIN). After data collection, frequency analysis was performed on the general attributes of questionnaire survey using SPSS 22.0, and data conclusions were derived by verifying reliability and validity of data and hypotheses. Results: First, perceived cosmetic brand app attributes have a positive effect on customer satisfaction, Second, perceived cosmetic brand app attributes have a positive effect on continuous usage intention. Third, customer satisfaction was found to have a mediating role in the effect of perceived cosmetic brand app attributes on continuous usage intention. Fourth, involvement proved to control the relationship between perceived cosmetic brand app attributes perceived interactivity and customer satisfaction. Finally, Involvement has proven to control the relationship between cosmetic brand app attributes perceived interactivity and continuous usage intention. Conclusion: Consumers buying products from cosmetics brand apps will be more likely to use cosmetics brand apps if they feel comfortable with calculation process, search, booking confirmation and payment methods.

• 한국콘텐츠학회논문지
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• 제9권1호
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• pp.147-158
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• 2009

최근 스트림데이터 환경의 데이터 모델은 데이터의 양이 아주 크고 연속적이며 무한하다. 이에 반해 제한된 용량의 디스크나 메모리 등을 이용해서 질의 처리나 데이터 분석을 처리한다. 이러한 환경에서 트랜잭션 데이터베이스에 대한 전통적인 빈발패턴탐사는 불가능하다고 할 수 있다. 왜냐하면, 연속적으로 들어오는 스트림 데이터에 대해 어떤 항목집합이 빈발항목인지 아닌지에 대한 정보를 계속적으로 유지 관리하기가 어렵기 때문이다. 본 논문에서는 연속적으로 들어오는 스트림 데이터에 회귀모델을 적용하여 빈발 항목들을 예측할 수 있는 방법을 제안한다. 스트림 데이터로부터 회귀모델을 생성함으로써 불확실한 항목들에 대한 예측 모델로 사용할 수 있다. 다양한 실험을 통하여 제안하는 방법이 스트림 데이터 환경의 데이터에 효율적으로 사용될 수 있음을 보인다.

• 대한수학회보
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• 제61권3호
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• pp.837-848
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• 2024

It is shown in [1] that the Cauchy problem for the Fornberg-Whitham equation is well-posed in C¹(ℝ) and the data-to-solution map is Hölder continuous from C^α to C([0, T]; C^α) with α ∈ [0, 1). In this short paper, we further show that the data-to-solution map of the Fornberg-Whitham equation is not uniformly continuous on the initial data in C¹(ℝ).

• 대한간호학회지
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• 제30권1호
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• pp.160-170
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• 2000

The purpose of this study was to develop an explanatory model to predict factors related to continuous participation in the Pap smear screening among Korean women. A hypothetical model was constructed on the basis of Health Belief Model and extensive review of literature on the Pap smear screening. Exogeneous variables included in this model were knowledge, perceived sensitivity, perceived severity, negative and positive emotional responses and professional support from physicians and nurses. Endogeneous variables were threat to cervical cancer, perceived benefit of the Pap smear screening, perceived barrier, and the final outcome variable was continuous participation in the Pap smear screening. The hypothetical model was tested with an empirical study. The data was collected from 623 married women whose age range was 24 - 83 using a self-reported survey questionnaire which was developed by the researcher. It's Cronbach's alpha score ranged from .6478 to .9118. Data was collected at different locations in Seoul; a university hospital, a local health center, and apartment complexes. Data analysis was done using SPSS 7.5 WIN Program for descriptive statistics and LISREL 8.12a WIN Program for covariance structural analysis. In conclusion, threat, perceived benefit, perceived barrier, positive emotion and professional support had a significant direct effect on continuous participation in the Pap smear screening among Korean women. The results of this study also showed that perceived barrier had the most significant direct effect on continuous participation in the Pap smear screening while negative emotional response had the most significant direct effect on perceived barrier. It can be suggested that decreasing perceived barrier by reducing negative emotional responses may be the most effective strategies for increasing continuous participation in the Pap smear screening among married Korean women.

• 한국산학기술학회논문지
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• 제12권5호
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• pp.2383-2389
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• 2011

유비쿼터스 응용은 실시간으로 입력되는 데이터 스트림과 저장된 공간 데이터를 동시에 처리하는 이중적인 공간 연속 질의 처리 기술이 요구된다. 이러한 공간 연속 질의 처리에서는 대용량 공간 데이터에 대한 디스크 접근 비용을 최소화가 요구되나 기존 공간색인 기법은 논리적 인접성을 공간 데이터의 물리적인 인접성을 보장할 수 없으므로 공간 데이터 탐색에 있어 비용이 증가한다. 또한 데이터 인접성 보장을 위한 공간 순서화 기법의 경우에도 빈번하게 접근되는 질의 공간 영역에 대한 클러스터링을 고려하지 않고 있다. 본 논문에서는 이중적인 공간 연속질의 처리에서 공간 데이터의 효율적인 접근을 위한 영역 기반 저장 구조를 제안한다. 제안 기법에서는 영역을 기반으로 데이터를 인접하게 저장하고 사용자 질의를 영역 기반으로 그룹 처리함으로써 질의 처리 비용을 감소시킬 수 있다.

• 한국물환경학회지
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• 제25권1호
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• pp.125-135
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• 2009

Reliable long-term flows by SWAT-K model were applied to the relationship between stream flow and pollutant load derived from 8-day measured data of Ministry of Environment (MOE) in order to obtain continuous loadograph and evaluate accuracy in water quality modeling for the Chungju dam watershed. The measured flow were compared with flow duration curve from the model, and it showed that measured values corresponded to the almost full range of stream flow conditions except at Odae A. And there was significant relationship ($R^2=0.60{\sim}0.97$) between measured flow and water quality load at all unit-watersheds. Applying this relationship to simulated flows, continuous loadograph was obtained and compared with modeled pollutant loads. Although there were some differences during some dry and flood seasons, those were not significant and overall trend showed a good agreement. From the results, we would be able to derive a continuous loadograph based on measured data at total maximum daily loads (TMDLs) unit-watersheds on a national scale, in which stream flow and water quality have been measured at 8-day intervals since 2004, and this could be helpful to utilize distributed water quality models with difficulty in calibrating and validating parameters from lack of measured data at present.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권6호
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• pp.1056-1063
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• 2015

Waves can be expressed in terms of a spectrum; that is, the energy density distribution of a representative wave can be determined using statistical analysis. The JONSWAP, PM and BM spectra have been widely used for the specific target wave data set during storms. In this case, the extracted wave data are usually discontinuous and independent and cover a very short period of the total data-recording period. Previous studies on the continuous wave spectrum have focused on wave deformation in shallow water conditions and cannot be generalized for deep water conditions. In this study, the Generalized Extreme Value (GEV) function is proposed as a more-optimal function for the fitting of the continuous wave spectral shape based on long-term monitored point wave data in deep waters. The GEV function was found to be able to accurately reproduce the wave spectral shape, except for discontinuous waves of greater than 4 m in height.