• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1359-1375
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• 2015

Energy efficiency is critical for Wireless Sensor Networks (WSNs) since sensor nodes usually have very limited energy supply from battery. Sleep scheduling and nodes cooperation are two of the most efficient methods to achieve energy conservation in WSNs. In this paper, we propose an adaptive energy optimization approach for target tracking applications, called Energy-Efficient Node Coordination (EENC), which is based on the grid structure. EENC provides an unambiguous calculation and analysis for optimal the nodes cooperation theoretically. In EENC, the sleep schedule of sensor nodes is locally synchronized and globally unsynchronized. Locally in each grid, the sleep schedule of all nodes is synchronized by the grid head, while globally the sleep schedule of each grid is independent and is determined by the proposed scheme. For dynamic sleep scheduling in tracking state we propose a multi-level coordination algorithm to find an optimal nodes cooperation of the network to maximize the energy conservation while preserving the tracking performance. Experimental results show that EENC can achieve energy saving of at least 38.2% compared to state-of-the-art approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2603-2605
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• 2005

This paper describes an experience on the equipment qualification of CRCS(control rod control system) that has been developed for nuclear power plants. A very high level criteria should be satisfied for the equipment to be used for nuclear power plants. We have developed a CRCS that is aimed to be applied to commercial plants. This system adopts a duplex system structure that is based on the state-of-the-art digital technology so that it has higher reliability than the existing systems. The CRCS has been tested at a licensed testing organization and finally qualified. In this paper, the procedures and some trial-and-errors we have been through in the qualification process are explained. It is expected that our experience will be a helpful tips to the industry that are developing various systems for safety-critical plants.

• 기본간호학회지
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• 제15권1호
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• pp.107-113
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• 2008

Purpose: The purpose of this study was to identify the degree and relationship between self-esteem, depression, and suicidal ideation of youths in the auxiliary police force. Method: This descriptive study was conducted using a structured questionnaire from February 1 to March 25, 2007. The participants were 180 youths from 19 to 25 years old (average 20.82 years old) who were auxiliary policemen. The data were analyzed using the SPSS Win 12.0 program. Results: Six of the auxiliary police (3.34%) reported critical scores in suicidal ideation. There was a significant difference in depression according to work area. Self-esteem showed a significant negative correlation with depression (r=-0.38, p<.001) and suicidal ideation (r=-0.39, p<.001). There was a positive correlation between depression and suicidal ideation(r=0.53, p<.001). Conclusion: The findings suggest that auxiliary policemen have higher levels of depression and suicidal ideation. Therefore, further study is needed to develop and examine nursing interventions the enhance self-esteem, so that depression and suicidal ideation can be minimized.

• 한국조리학회지
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• 제12권3호
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• pp.91-107
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• 2006

This thesis aims to consider theories of job information on foodstylist, conduct a survey among culinary arts science high school students who are in the most critical period of decision-making for the future career, and analyse the survey results on foodstylist by using SPSS10.0. The analysis shows that culinary high school students mainly get their job information on foodstylist through mass media. Thus, it can be deduced that use of mass media and the Internet can be the most effective to promote the awareness level of foodstylist. Culinary high schoolers' parents were positive about female students' being foodstylists, and those going to college showed more interest than job seekers about being foodstylists. In addition, the result of Bonferroni post-hoc test according to parents' monthly income showed that those with higher monthly income were positive about their children's being foodstylists. However, given that culinary high schoolers' overall satisfaction is low, provision of the information through a variety of information channels is necessary. It is expected that promotion of the information provision will serve a turning point in awareness.

• 세라미스트
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• 제23권1호
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• pp.54-88
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• 2020

Global effort has resulted in tremendous progress with energy harvesters that extract mechanical energy from ambient sources, convert it to electrical energy, and use it for systems such as wrist watches, mobile electronic devices, wireless sensor nodes, health monitoring, and biosensors. However, harvesting a single energy source only still pauses a great challenge in driving sustainable and maintenance-free monitoring and sensing devices. Over the last few years, research on high-performance mechanical energy harvesters at the micro and nanoscale has been directed toward the development of hybrid devices that either aim to harvest mechanical energy in addition to other types of energies simultaneously or to exploit multiple mechanisms to more effectively harvest mechanical energy. Herein, we appraise the rational designs for multiple energy harvesting, specifically state-of-the-art hybrid mechanical energy harvesters that employ multiple piezoelectric and triboelectric mechanisms to efficiently harvest mechanical energy. We identify the critical material parameters and device design criteria that lead to high-performance hybrid mechanical energy harvesters. Finally, we address the future perspectives and remaining challenges in the field.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.678-681
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• 2003

In conventional optical data storage numerical aperture (NA) cannot be over 1 because of diffraction limit. To overcome this limitation. solid immersion lens(SIL) have produced a great interest in near-field optical data storage. In conventional optical recording method, the dual lens system using object lens and SIL had been studied generally. But the conventional SIL system has some critical problems that must be solved. The problems are heat, contamination. alignment of optical components and so on. To solve these problems. this work proposes enhanced SIL which has several advantages for mechanical and optical issues. This new SIL system named elliptic SIL(ESIL) can use evanescent energy in near-field more effectively. In addition. because of applying the inside recording unlike previous surface recording, ESIL can clear up the problems. The design and analysis of ESIL art executed by using CODE V. Also, in this paper we composed actual data recording system and achieved recording experiment by applying ESIL to magneto-optical recording. In conclusion. we analyze the improvement of aerial density and the reasonability of application to real data storage system.

• 한국멀티미디어학회논문지
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• 제18권12호
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• pp.1432-1438
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• 2015

We present a methodology to detect moving shadows in video sequences, which is considered as a challenging and critical problem in the most visual surveillance systems since 1980s. While most previous moving shadow detection methods used hand-crafted features such as chromaticity, physical properties, geometry, or combination thereof, our method can automatically learn features to classify whether image segments are shadow or foreground by using a deep learning architecture. Furthermore, applying Markov Random Field enables our system to refine our shadow detection results to improve its performance. Our algorithm is applied to five different challenging datasets of moving shadow detection, and its performance is comparable to that of state-of-the-art approaches.

• 복식
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• 제33권
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• pp.157-173
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• 1997

The Mannerism which was born on Italy in 16th century was the critical trend of art influencing the political economical and psychological trends and was the first mo-dality which respected the individual sense of artist. The cultural situation of that time es-pecially the alienation of men is similar to the pluralism of value the coexistency of conflict the acceptance of heterogeneity and uncer-tainty I modern century. This paper analysed the pattern of change in the trend of Mannerism in modern costume by comparing current trend from the past focus-ing th fact that the over-all situation in this century is similar to that of Mannerism in 16th century. In this paper the author suggests the Defor-mation Ambiguity and Irreglarity as the character of manneristic trend which has re-solved the sense of alienation of men by paradoxic expression. The results of comparing the characteristic of mannerism to the modern costume is followd; 1. The Deformation in modern costume is grossly subdivided to the transfrmation of morphology the transformation of scale and the breakdown of equilibrium 2. The ambiguity in the modern costume can be subdivided to the eclecticistic expression and the ambiguity of spatial concept(between inner and outer garments). 3. The illogiclities in modern costume are the technique of illusion structural illogicality and the collage technique.

• 공학교육연구
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• 제23권1호
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• pp.3-9
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• 2020

The purpose of the study was to develop the Arduino based STEAM instruction materials for creative engineering design class. PDIE model was used in this study. We developed a STEAM lesson plan and a STEAM lesson worksheet for a total of six sessions through the steps of preparation, development, implementation and evaluation. The validity of the instruction materials was evaluated by the 10 experts using a survey. The instruction materials were applied to the class (52 students attended) of the creative engineering designs unit in technology and home economics subject. The class satisfaction and the creative solving-problem ability were examined after the calss. The class satafacition was high as the average of 10 item was 4.57 (out of 5). The paired t-test was conducted to compare the means of the creative solving-problem ability. It was observed that 'understanding and mastery of knowledge, thought, function and skills in a specific domain', 'divergent thinking', 'critical and logical thinking' and ' motivational factors' were significantly increased after the class. The instruction materials develped in this study were successfully designed to enhance the creative solving-problem ability by designing creative tasks and to intrique the interest by adding visual and auditory stimuli with the Arduino.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5243-5263
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• 2017

Data center networks provide critical bandwidth for the continuous growth of cloud computing, multimedia storage, data analysis and other businesses. The problem of low link bandwidth utilization in data center network is gradually addressed in more hot fields. However, the current scheduling strategies applied in data center network do not adapt to the real-time dynamic change of the traffic in the network. Thus, they fail to distribute resources due to the lack of intelligent management. In this paper, we present an improved adaptive traffic scheduling strategy utilizing the simulated annealing genetic algorithm (SAGA). Inspired by the idea of software defined network, when a flow arrives, our strategy changes the bandwidth demand dynamically to filter out the flow. Then, SAGA distributes the path for the flow by considering the scheduling of the different pods as well as the same pod. It is implemented through software defined network technology. Simulation results show that the bisection bandwidth of our strategy is higher than state-of-the-art mechanisms.