• 한국수자원학회논문집
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• 제54권spc1호
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• pp.1195-1204
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• 2021

최근 이상기후로 인한 국지성호우가 잦아져 하천변 사회기반시설을 포함한 인적·물적 피해가 급증하고 있다. 본 연구에서는 해당 시설들의 침수 피해를 예측·방지하고자 기계학습 중 시계열자료에 특화된 LSTM(Long Short- term Memory)기법을 활용하여 수위 예측 알고리즘을 개발하였다. 연구대상지는 잠수교로 연구기간은 총 6년(2015년~2020년)의 6, 7, 8월로 3시간 후의 잠수교 수위를 예측하였다. 입력자료(Input data)는 잠수교 수위(EL.m), 팔당댐 방류량(m³/s), 강화대교 조위(cm), 서울시 트윗의 개수로 기존 연구에 주로 사용된 정형자료뿐만 아니라 워드클라우드를 통해 구축된 비정형자료도 함께 사용하여 상호 보완형 자료를 구축하고, 비정형자료 활용 유무의 비교·분석을 통해 비정형자료의 역할도 제시하였다. 잠수교의 수위 예측 시 상호 보완형의 자료가 정형자료만을 사용한 경우에 비해 예측 정확도가 향상하였는 데, 이는 인명 피해를 감소시킬 수 있는 보수적인 예/경보가 가능함을 알 수 있었다. 본 연구에서는 하천변 사회기반시설의 이용자 안전 및 편의 제공에 상호 보완형 자료의 사용이 보다 효과적이라 판단하였다. 향후에는 비정형자료의 종류를 추가하거나 입력자료의 세밀한 전처리를 통하여 더욱 정확한 수위 예측을 기대해본다.

• Smart Structures and Systems
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• 제22권1호
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• pp.95-103
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• 2018

Active vibration control via inertial mass actuators has been shown as an effective tool to significantly reduce human-induced vertical vibrations, allowing structures to satisfy vibration serviceability limits. However, a lot of practical obstacles have to be solved before experimental implementations. This has motivated simple control techniques, such as direct velocity feedback control (DVFC), which is implemented in practice by integrating the signal of an accelerometer with a band-pass filter working as a lossy integrator. This work provides practical guidelines for the tuning of DVFC considering the damping performance, inertial mass actuator limitations, such as stroke and force saturation, as well as the stability margins of the closed-loop system. Experimental results on a full scale steel-concrete composite structure (behaves similar to a footbridge) with adjustable span are reported to illustrate the main conclusions of this work.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.224-226
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• 2015

Outwardly, the people in the shipping industry are aware that multicultural working environments and conditions could have a strong influence on the operation of ships. With a lack of cultural awareness and foreign language skill of crew members on ships, there are lots of misunderstandings and miscommunications among (cross-cultural) crews. More and more maritime accidents are caused by human error in the world's oceans. Nevertheless the research on cultural diversity and human interaction on ships is still in its infancy. Due to the rapid change of the demographic make-up of crews, not only teaching and training technical skills for the crews, but also education in nontechnical skills such as cultural awareness, cultural sensitivity, intercultural competence is urgently needed. This study will deal with intercultural issues on ships. It aims to emphasize the necessity of intercultural training in MET.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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• pp.231-234
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• 2005

The ecological theory of perception provides the human living, and meaning integrating norm to overcome the crisis caused by an eastern belief in human-centered wrong rationality formed at the past process of modernization. Prior to the overall consideration of ecological perception theory, looked into the concepts, contribution extent and its limitation of the existing perception theories for the environmental design. By experimentally applying inferred concepts of design to department bridge space and forming the space, certified the applicability of it to the green amenity space. The site Is located in Nowon- Gu Sangge- Dong. The design was processed on the basis of survey, plants growth environment and plants characters. It is expected that this design would serve the commercial space- consumer as a symbolic, environmentally friendly space design

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1543-1561
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• 2020

Taxonomy of human brain activity is a complicated rather challenging procedure. Due to its multifaceted aspects, including experiment design, stimuli selection and presentation of images other than feature extraction and selection techniques, foster its challenging nature. Although, researchers have focused various methods to create taxonomy of human brain activity, however use of multivariate pattern analysis (MVPA) for image recognition to catalog the human brain activities is scarce. Moreover, experiment design is a complex procedure and selection of image type, color and order is challenging too. Thus, this research bridge the gap by using MVPA to create taxonomy of human brain activity for different categories of images, both colored and gray scale. In this regard, experiment is conducted through EEG testing technique, with feature extraction, selection and classification approaches to collect data from prequalified criteria of 25 graduates of University Technology PETRONAS (UTP). These participants are shown both colored and gray scale images to record accuracy and reaction time. The results showed that colored images produces better end result in terms of accuracy and response time using wavelet transform, t-test and support vector machine. This research resulted that MVPA is a better approach for the analysis of EEG data as more useful information can be extracted from the brain using colored images. This research discusses a detail behavior of human brain based on the color and gray scale images for the specific and unique task. This research contributes to further improve the decoding of human brain with increased accuracy. Besides, such experiment settings can be implemented and contribute to other areas of medical, military, business, lie detection and many others.

• 기술사
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• 제21권2호
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• pp.51-57
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• 1988

The writer has worked out his original philosophy both scientific and religious, which he calls "Knownism" The new thought states; the word "known" in "knownism" means "already well-informed in the providence" about the essence of the things, and the true state of the reality, hence the knownism, as the existence of God is set forth as a premise. The knownism is a philosophy unified reasonably the science and the faith into one, for the humans can perceive and realize the essence and the true state, and authorize the truth transcending the experience by the scientific method. The new thought of the knownism is a bridge-building between the natural science and the religious faith. The idea explains that the life is the process to pursue the essence of the things and the god, and the truth is immanent in the original nature of things and in God′s sphere. This thought is a philorophy of possibility to solve the paradigms-to-be such as thinking, faith experience, and supernatural power, so that it presents a vision in the human life as a profitable religious science philosophy. The knownism is much different from agnosticism, skepticism, empiricism, and agnosticism. The grace of God may be detected differently from the supernatural power. The new dark clouds overspread abruptly the summer sky are not new ones but originally derived frosm worn-out water drops. Thus those are called the old clouds. The Korean word "known"(노운) of which pronunciation is same with the English "known" means the old clouds, hence also the name, Knownism. The root of the new clouds is detectable from the preserved old clouds. The old clouds symbolized in the paper indicate the essence and the principles of the things and the fittest, or the key for the solution of the problem in the epistemology, believing that everything has its own, proper nature, the writer sums up his theory by insisting that the humans have to find out the "old clouds" or the "known" in knownism to live eternally either in this world or in other dimensions, though the human beings are transformed into the other phases of life. The writer proclaims through the ideas for the United Nations to fortify the Confederate System of World Nations in order to ensure the world peace and the future of the humans.

• 한국산학기술학회논문지
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• 제13권7호
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• pp.3244-3251
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• 2012

대형 해양구조물의 건설과 운영에서 중요한 항목 중의 하나가 재해위험도를 분석하고 평가하는 것이다. 이에 본 연구에서는 수중터널의 건설과 운영 시에 발생할 수 있는 재해 위험요소를 도출하고 퍼지 AHP(Analytic Hierarchy Process) 방법으로 이러한 위험요소의 수준을 파악하고자 하였다. 재해 위험도로는 자연재해 위험도와 인적재해 위험도로 구분하고 이러한 위험도 항목들이 수중터널에 미치는 영향을 전문가 설문을 통하여 조사하였다. 조사된 전문가 설문결과 데이터를 퍼지 AHP 기법으로 분석하여 재해위험도를 각 위험요소별로 정량화하였다. 또한, 수중 터널과 교량, 해저터널, 침매터널의 재해위험도 수준을 분석하여 수중터널이 가지고 있는 고유의 재해위험도 수준을 평가하였다. 재해위험도에서는 쯔나미와 지진이 가장 위험도 인식수준이 높았고, 인적재해 위험도는 화재와 폭발의 위험도 인식이 높은 수준이었다. 또한, 수중터널은 침매터널에 비해서는 1.4배, 교량에 비해서는 3.2배 위험도 인식수준이 높은 것으로 조사되었다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 춘계학술대회
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• pp.107-109
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• 2012

본 연구는 STCW 2010에 기초를 두고 실습선 실습을 마친 해기사와 실습생을 대상으로 BRM 프로그램개선에 관한 설문조사를 실시하고 그 결과에 따른 BRM 교육방법 개선안을 찾는데 목적을 둔다. 설문조사 결과에 따라 BRM 교육프로그램의 항목별 평가, 즉 BRM 교육의 이론, 학습, 시간, 시뮬레이션에 대한 시간, 교육의 횟수, 교육자료 등에 대한 현황과 최종적으로 효과적인 BRM 프로그램 개선안을 제공한다.

• 전기학회논문지
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• 제56권5호
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• pp.938-943
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• 2007

In this paper, we show that, in case of piezoelectric micropower generator, just replacing Schottky diodes in the bridge rectifier with ultra-low reverse leakage current diodes improves the mechanical-to-electrical energy conversion efficiency by more than 100%. Experimental and PSPICE simulation results show that, due to the ultra-low leakage current, the charging speed of the circuit employing PAD1 is higher than that of the circuit employing Schottky diodes and the saturation voltage of the circuit employing PAD1 is also higher. This study suggests that , when the internal impedance of source is very large (a few tens of $M{\Omega}$) such that maximum charging current is a few microamperes or less, in order to realize literally the energy scavenging system, ultra-low reverse leakage current diodes should be used for efficient energy conversion. Since low-level vibration is ubiquitous in the environment ranging from human movement to large infrastructures and the mechanical-to-electrical energy conversion efficiency is much more critical for use of these vibrations, we believe that the improvement in the efficiency using ultra-low leakage diodes, as found in this work, will widen greatly the application of piezoelectric micropower generator.

• Steel and Composite Structures
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• 제14권4호
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• pp.367-377
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• 2013

Damage in structures often leads to failure. Thus it is very important to monitor structures for the occurrence of damage. When damage happens in a structure the consequence is a change in its modal parameters such as natural frequencies and mode shapes. Artificial Neural Networks (ANNs) are inspired by human biological neurons and have been applied for damage identification with varied success. Natural frequencies of a structure have a strong effect on damage and are applied as effective input parameters used to train the ANN in this study. The applicability of ANNs as a powerful tool for predicting the severity of damage in a model steel girder bridge is examined in this study. The data required for the ANNs which are in the form of natural frequencies were obtained from numerical modal analysis. By incorporating the training data, ANNs are capable of producing outputs in terms of damage severity using the first five natural frequencies. It has been demonstrated that an ANN trained only with natural frequency data can determine the severity of damage with a 6.8% error. The results shows that ANNs trained with numerically obtained samples have a strong potential for structural damage identification.