• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.227-234
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• 2011

Recently, a high strength concrete of more than 40 MPa has been increasingly used in practice. However, use of the high strength concrete may influence on design parameters, particularly stress distribution. This is very true since the current everyday practice employs equivalent rectangular stress distribution that is derived from normal strength concrete. Subsequently, the stress distribution seems to be reevaluated and then a new distribution with new parameters needs to be suggested for the high strength concrete. For this purpose, linear and multiple regression analyses have been carried out in term of using experimental data for the high strength concrete of 40 to 80 MPa available in literatures. Accordingly, new parameters associated with the stress distribution have been proposed and employed for the design of flexural and compressive members. Comparative design examples indicate that designs with new parameters reduce section dimensions compared to those with the current code parameters for concrete strengths of 40 to 70 MPa. In particular, for compressive members, design with new parameters exhibit conservative compressive force compared to those with the current code parameters.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.309-319
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• 2022

As a study on the mechanisms by which creativity is improved in an organization, this study tried to verify the serial multiple mediating effects of relational energy and creative process engagement in the effect of leader-member exchange(LMX) on creativity. To test the hypothesis, a survey was conducted on 200 workers in China, and 154 of them were analyzed. The analysis used model 6 of the PROCESS macro. As a result, first, LMX has positive effects on creativity. Second, relational energy mediated the relationship between LMX and creativity. Third, creative process engagement mediated the relationship between LMX and creativity. Forth, relational energy and creative process engagement continuously mediated the relationship between LMX and creativity. Based on these research results, the implications and limitations of this study were presented, and methods to improve creativity in the organization were discussed.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.269-276
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• 2022

This study was conducted with the purpose of verifying the effect of the working environment of elderly care workers on service quality and the mediating effect of emotional labor and recognition of filial piety. The subjects of the study were 460 elderly care workers. For the collected data, SPSS Process macro was used. As a result, First, it was found that all variables had a significant positive (+) relationship. Second, the parallel mediating effect of emotional labor and recognition of filial piety was confirmed. Third, the mediating effect of recognition of filial piety and the moderating effect of emotional labor were verified. Based on this study, it was found that filial piety awareness education and emotional labor management are necessary. A follow-up study with a more expanded concept should be conducted.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.1997-2004
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• 1994

A model analysis method has been developed in the paper. The method estimates the modal parameters of multiple input-output systems, assesses their quality, and seperates structural modes form computation ones. The modal parameter extraction algorithm is the least squares method with a finite difference model relating input and output time data. The quality of the estimated system model can be assessed in narrow frequency bands by comparing the measured and model predicted responses in time domain with the aid of digital filters. Structural modes can be effectively separated from computational ones using the convergence factor which represents the pole convergence rate. The modal analysis method has been applied to simulated and experimental vibration data to evaluate its utility and limitations.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.238-240
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• 2005

인터넷과 같은 개방된 공간에서 중요한 정보는 상당한 발전을 이룩한 암호화 기술에 의해 보호된다 그러나 컴퓨터의 급속한 발전은 암호화의 근간이 되는 키에 대하여 더욱 길고 안전한 키를 요구한다. 이는 기억해야할 또는 안전하게 소지해야할 정보가 더 많아짐을 의미한다. 이러한 상황에서 개인의 생체정보를 기반으로 하는 키의 이용은 일정 수준의 보안성을 만족하기위한 키의 길이가 증가됨을 억제하고, 외우거나 소지해야하는 불편함도 해소해준다. 그러나 기존의 생체인식 기반의 키 생성 기법 연구는 여러 종류의 생체인식을 동원한 특징점 및 매개변수 정보를 기반으로 하고 있어 실제 활용함에 제한이 있다. 따라서 본 논문에서는 적용할 단 하나의 생체인식으로 얼굴인식을 채택하였고, 이 얼굴인식의 다중 고유얼굴을 이용하여 특징점 및 매개변수 집합을 형성하고, 이 집합으로부터 더욱 안전하고 편리한 키를 생성하는 기법을 연구하였다.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.151-163
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• 2018

The objective of this study was to estimate LOADEST (LOAD Estimator) coefficients for simulating pollutant loads in ungauged watersheds. Regression models of LOADEST were used to simulate pollutant loads, and the multiple linear regression (MLR) was used for coefficients estimation on watershed characteristics. The fifth and third model of LOADEST were selected to simulate T-N (Total-Nitrogen) and T-P (Total-Phosphorous) loads, respectively. The results and statistics indicated that regression models based on LOADEST simulated pollutant loads reasonably and model coefficients were reliable. However, the results also indicated that LOADEST underestimated pollutant loads and had a bias. For this reason, simulated loads were corrected the bias by a quantile mapping method in this study. Corrected loads indicated that the bias correction was effective. Using multiple regression analysis, a coefficient estimation methods according to the watershed characteristic were developed. Coefficients which calculated by MLR were used in models. The simulated result and statistics indicated that MLR estimated the model coefficients reasonably. Regression models developed in this study would help simulate pollutant loads for ungauged watersheds and be a screen model for policy decision.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.213-213
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• 2017

저수지 유입량은 효율적 저수지 운영을 위해 중요한 요소로, 이는 하류 하천 등과 복합적으로 연계되기에 통합적 수자원 관리를 위해서 정확한 추정이 중요하다. 국내의 일부 저수지에서는 상류에서 유입되는 유량을 측정하고 있으나, 모든 저수지에 대해 측정하기에는 현실적 한계가 있다. 한편, 한국농어촌공사에서는 유효저수량 10만톤 이상 저수지에 대해 수위 계측기를 설치하여 수위자료를 관측하고 있으며, 이는 수위-내용적 곡선을 통해 저수량으로 변환이 가능하다. 저수량 자료가 확보되면 물수지식 기반으로 간접적으로 유입량의 추정이 가능하나, 수위가 상승하는 구간에 대해서만 적용이 가능하기에 연속적인 자료의 확보에 한계가 있다. 이 경우 불연속 유량자료를 대상으로 수문모형의 매개변수를 최적화하여 장기간 연속자료로 변환하는 것이 한 방안이 될 수 있다. 본 연구에서는 저수지 수위 기반으로 추정된 간헐적 유입량 자료를 기반으로 수문모형의 매개 변수를 최적화하여 장기유량으로 변환하고자 한다. 수문 모형과 매개변수 최적화 기법은 각각 Tank 모형과 SCE (Shuffled Complex Evolution) 기법을 이용하였다. 매개변수 최적화를 위한 목적함수는 고유량 저유량 총량 분산 관련 지표에 가중치를 부여한 다중 목적함수로 설정하였으며, 이를 통해 도출된 다양한 매개변수 후보군 중 고유량 저유량 총량 유황곡선의 유사정도가 전반적으로 일치하는 매개변수 군을 선택하였다. 본 연구 결과는 미계측 저수지 유입량을 추정할 수 있음으로써 저수지의 효율적인 물관리와 용수관리 의사결정에 활용할 수 있을 것으로 사료된다.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.204-226
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• 2023

One of the most important types of Customer Empowerment Strategy (CES) is select empowerment, where firms allow customers to vote on a product to be marketed. However, there is limited research on the advantages and disadvantages of select empowerment. In particular, there are few studies on the composition of a voting system. This study analyzes customer participation behavior, such as willingness to vote and strategic voting (i.e., voting for candidates not based on utility orders), under the different voting systems: 1) the number of votes per customer (single or multiple), and 2) the number of final choices (single or multiple). Uncertainty is proposed as a mediator that links the voting system difference and customer participation. Two research hypotheses are tested using multiple linear regression analysis and a natural effects model based on data from two online experiments. As a result, the multiple voting system (i.e., multiple winners are selected by customer votes) shows a direct positive effect on willingness to vote and strategic voting behavior. In addition, the result shows that uncertainty insignificantly mediates the relationship between the voting system and customer participation. Academic and managerial contributions are discussed with several future research directions.

• Information and Communications Magazine
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• v.28 no.10
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• pp.50-59
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• 2011

본 논문에서는 신호 정보의 뿌리를 더듬어 분석했다. 통신신호 처리 분야의 선구자(pioneer)인 푸리에(Jean Baptiste Joseph Fourier, 1768~1830)가 1822년 발표한 푸리에 행렬은 하나의 매개변수(parameter)로 고정된 값을 갖지만, 멀티미디어에 대한 요구가 급증한 오늘날의 상황에 맞추어 2N-1의 매개변수를 갖는 수정된 푸리에 행렬을 제안, 중계 망(Relay Network)으로 어떻게 적용하는지와 융합 DFT와 DCT-II를 보이고, 직교 푸리에 다중 분할(Orthogonal Fourier Division Multiplexing, OFDM) 의 변천과 표준화에 대해 간략히 논한다.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.686-701
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• 2020

The purpose of this study is to find out how employee's gratitude disposition affects Organizational Citizenship Behavior(OCB) and empirically validating multiple mediation effect of perceived organizational support(POS) and job satisfaction. For this study, an online survey has been conducted on office workers to analyze 380 sets of answers, reviewed reliability and validity through CFA and used SPSS 25.0, AMOS 25.0, Macro Process 3.0, a bootstrap method to test hypothesis. As a result, it is verified that an employee's gratitude disposition positively affects OCB, POS and job satisfaction and that there exists a multiple mediation effect of POS and job satisfaction. In this study, it is validated that an employee's gratitude disposition has a positive influence on OCB and an employee's gratitude disposition, an individual trait, is a related antecedent variable of POS. The result of this study is meaningful that it suggests boosting gratitude disposition, a positive psychological factor, in an organization can positively affect employees' job attitude and organization effectiveness.