• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.433-440
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• 2014

In this study, a method for the low-carbon active distribution system (ADS) planning is proposed. It takes into account the impacts of both network capacity and demand correlation to the renewable energy accommodation, and incorporates demand response (DR) as an available resource in the ADS planning. The problem is formulated as a mixed integer nonlinear programming model, whereby the optimal allocation of renewable energy sources and the design of DR contract (i.e. payment incentives and default penalties) are determined simultaneously, in order to achieve the minimization of total cost and $CO_2$ emissions subjected to the system constraints. The uncertainties that involved are also considered by using the scenario synthesis method with the improved Taguchi's orthogonal array testing for reducing information redundancy. A novel cuckoo search (CS) is applied for the planning optimization. The case study results confirm the effectiveness and superiority of the proposed method.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.71-80
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• 2019

The purpose of this study is to analyze the effects of brand evidence on brand value, brand trust, brand attitude and word of mouth intention. To achieve the purpose of the study, a research model and hypothesis were established based on previous studies, and survey was conducted on 222 passengers who had used the airline. As a result of the analysis, sub-factors of airline brand evidence had a positive impact on brand value. Except for employee services, perceived prices, core services, brand names, and brand logo had a positive impact on brand value. Brand value had a significant positive effect on brand trust and brand attitude. It was also found that brand trust had a significant influence on brand attitude. This study examined the extended range by adding the brand logo as a sub-factor of brand evidence, and it is considered necessary to study including brand emotion in next study.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.203-212
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• 2019

The purpose of this study was to identify the effects of stress factors of student pilots on mental health, and to reduce the safe and efficient misconduct education and psychological disharmony by identifying the psychological buffering role of stress coping style and social support. In order to achieve the research purpose, a research model and hypothesis were presented based on previous studies, and regression analysis and mediation effect verification were conducted through a questionnaire survey of 202 student pilots. As a result of the analysis, factors such as flight stress, values stress, professor stress, and friend relationship stress have been shown to affect emotional conditions or psychological well-being. Also we found that the parameters of disengagement coping, family/friend support and organization Support had a mediating effect on the factors between student pilot stress and psychological health. Therefore, student pilots need to manage problems and negative emotions that may cause from flight training, value distractions, professor and friendships' relationship and it is suggested that organization support for training and safety related to emotional support and delinquency of family and friends.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.435-435
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• 2016

기후변화에 따라 강우 패턴이 변화하며, 집중호우 발생 빈도의 증가가 예상된다. 이로 인해 저수지 상류에서 유실된 토사는 저수지로 유입하여 정수 처리비용 증가, 1차생산성 감소, 어류폐사, 하천경관 악화 등 다양한 문제를 유발한다. 따라서 위와 같은 탁수 피해 저감을 위해 과학적인 모니터링과 예측, 저수지 운영과 관리기술 개발 등의 대응이 요구된다. 본 연구에서는 극한 탁수사상 발생시 대응 기술의 일환으로 저수지 탁수예측 모델의 신뢰도 향상을 위해, 기존 탁수예측 모형인 CE-QUAL-W2(이하 W2)의 탁수 예측 알고리즘을 개선하고 소양강댐 저수지에 적용하여 그 성능을 평가하였다. 최근 W2모델 3.72 버전까지 출시되었으나, 모델은 단순 침강속도만 고려하여 저수지 밀도 특성을 반영하지 못하고, TSS 모의시 독립침강을 가정하여 응집 침강 및 장기탁수 예측에 취약한 한계점을 가지고 있다. 따라서, 과거 연구내용을 바탕으로 수온에 따른 점성계수 변화(Stoke's), 다중 부유 입자별 침강속도 고려 기능을 추가하였으며, 새롭게 점착성유사의 응집 침강을 고려할 수 있는 기능을 추가하여 모델을 개선하였다. 모델에 점착성 유사 모의 전략은 입자 크기 $63{\mu}m$를 기준으로 비점착성유사(NCS)와 점착성유사(CS)로 구분하고, 비점착성유사는 독립침강, 점착성 유사는 응집침강을 가정하였다. 응집 후 중간 입경의 추정은 Gailani et al(1991)의 식을 사용하였으며, 침강속도 계산 공식은 Hwang and Mehta(1989)식을 적용하였다. 수정된 모델은 소양강댐 운영이후 최대 탁수사상이 발생했던 2006년을 대상으로 기존 탁수해석 결과와 수정된 모델의 모의결과를 실측값과 비교 분석 하였다. Stoke's 식 적용시 기존의 모의결과 대비 AME 평균 23%, RMSE 평균 18%가 개선되는 것으로 나타났으며, Hwang and Metha식 적용시에 SS 모의값이 전반적으로 과소평가되는 것으로 나타났다. 또한, 실측 방류 탁수 농도와 모의값을 비교하여 평가 하였으며, 모의기간인 Julian Day 173~365(192일) 동안 모의 결과의 총 TSS 부하량은 실측값의 약 80%수준을 보였으며, TSS 방류 부하기준 Stoke's 식 적용시 기존 모의대비 오차가 1.3% 개선되는 것으로 나타났다.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.522-533
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• 2019

The compressive sensing model for range-Doppler estimation can be expressed as an under-determined linear system y = Ax. To find the solution of the linear system with the compressive sensing method, matrix A should be sufficiently incoherent and x to be sparse. In this paper, we propose a transmission waveform design method that maintains the bandwidth required by the sonar system while lowering the mutual coherence of the matrix A so that the matrix A is incoherent. The proposed method combines two methods of optimizing the sensing matrix with the alternating projection and suppressing unwanted frequency bands using the DFT (Discrete Fourier Transform) matrix. We compare range-Doppler estimation performance of existing waveform LFM(Linear Frequency Modulated) and designed waveform using the matched filter and the compressive sensing method. Simulation shows that the designed transmission waveform has better detection performance than the existing waveform LFM.

• Journal of Convergence for Information Technology
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• v.8 no.4
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• pp.135-143
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• 2018

The purpose of this study was to examine the effect of early adolescents' depression on suicidal ideation and the mediating effects of self-esteem and life satisfaction in the process. For this purpose, the path analysis model for depression, self-esteem, life satisfaction, and suicidal ideation were used to examine the 225 early adolescent students of grades between 4 and 6 attending elementary school. The main results are as follows. First, the self-esteem of early adolescents was partially mediated between depression and suicidal ideation. Second, the satisfaction of life of early adolescents was partially mediated between depression and suicidal ideation. In other words, in order to lower the suicidal ideation of early adolescents, various programs are need to be developed to improve self-esteem and life satisfaction, as well as apply them to practice.

• Journal of Convergence for Information Technology
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• v.8 no.4
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• pp.115-120
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• 2018

This paper describes the design and trial development of a system that supports continuous hazard mapping by local residents in their daily life. We performed an interview survey to design our system in a model traditional town in Saga Prefecture, Japan. The results show that despite continued efforts, many practical problems remain and residents feel unsafe. Considering these results, we designed and developed a unique information and communication technology-based support system that contributes to community-based disaster prevention and reduction. The continuous resident participation and posting design are the core concept for our community-based approach. Our system continues to support making a hazard map by integrating the community-based hazard information. Local residents register information (disaster types, risk level, photographs, comments, positional information) about locations that could be dangerous in a disaster. In addition, our system enables information sharing through a Web server. We expect that this information sharing will allow local hazard information for each district to be used.

• Journal of Convergence for Information Technology
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• v.9 no.12
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• pp.39-46
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• 2019

The competition for standardization in the enterprise environment starts with the data tier of the back-end and the standard enterprise middle tier is being stabilized by standardization as it is accepted as the Spring Framework. In addition, with the advent of new devices in an increasingly rapid cycle, securing compatibility with web and mobile services has become an important competitive advantage for web service companies. However, companies are unable to secure competent technical personnel appropriate for the rapidly changing environment of the information generation, and the curriculum of educational universities does not reflect the demand of new competency-oriented curriculum. Therefore, in this study, in order to acquire competency-oriented skills required for such an enterprise system platform environment and to develop a curriculum, the system using Spring Data JPA in the Spring Framework environment was implemented through documenting for each analysis and design step. It aims to provide a reference model for the full stack competency-based curriculum and capstone design curriculum that can be applied immediately in the enterprise environment.

• Journal of Convergence for Information Technology
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• v.9 no.12
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• pp.88-97
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• 2019

This study was conducted to identify factors affecting patient safety management (PSM) of nursing student's who have experienced clinical practice. The study subjects were 232 nursing students in five universities in five cities. Data were collected between June 17 and July 30, 2019 using by completing structured self report questionnaires. Data were analyzed using T-test, ANOV A, Pearson's correlation coefficient, and multiple regression using SPSS/WIN 22.0. In correlation ana lysis, significant positive correlations were found between PSM practice, PSM importance awareness (r= .42, p<.001), PSM knowledge(r= .29, p<.001), and PSM attitude(r= .35, p<.001). In multiple regressi on analysis, PSM importance awareness(β=.19, p<.001) was factor predicting PSM practice of nursing students, which explained 36.2% of the variance in the model. Thus, we emphasize that continuing PSM education at the university is required to improve PSM competency.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.38-43
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• 2021

As the number of augmented reality games using augmented reality technology increases, the demands of users are also increasing. Game technologies used in augmented reality games are mainly games using MARKER, MARKERLESS, GPS, etc. Games using this technology can augment the background and other objects. To solve this problem, we want to help develop augmented reality games by analyzing objects in the background, which is an important element of augmented reality. To analyze the background in the augmented reality game, the background object was analyzed by applying a deep learning model using TensorFlow Lite in the UNITY engine. Using this result, we obtained the result that augmented objects can be placed in the game according to the types of objects analyzed in the background. By utilizing this research, it will be possible to develop advanced augmented reality games by augmenting objects that fit the background.