• KIEE International Transactions on Electrophysics and Applications
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• 제5C권3호
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• pp.102-110
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• 2005

Piezoelectric transformers(PT) are expected to be small, thin and highly efficient, and which are attractive as a transformer with high power density for step down voltage. For these reasons, we have attempted to develop a step-down PT for the miniaturized adaptor. We propose a PT, operating in thickness extensional vibration mode for step-down voltage. This PT consists of a multi-layered construction in the thickness direction. In order to develop the step-down PT of 10 W class and turn ratio of 0.1 with high efficiency and miniaturization, the piezoelectric ceramics and PT designs are estimated with a variety of characteristics. The basic composition of piezoelectric ceramics consists of ternary yPb(Zr$_{x}$Ti$_{1-x}$)O$_{3}$-(1-y)Pb(Mn$_{1/3}$Nb1$_{1/3}$Sb$_{1/3}$)O$_{3}$. In the piezoelectric characteristics evaluations, at y=0.95 and x=0.505, the electromechanical coupling factor(K$_{p}$) is 58$\%$, piezoelectric strain constant(d$_{33}$) is 270 pC/N, mechanical quality factor(Qr$_{m}$) is 1520, permittivity($\varepsilon$/ 0) is 1500, and Curie temperature is 350 $^{\circ}C$. At y = 0.90 and x = 0.500, kp is 56$\%$, d33 is 250 pC/N, Q$_{m}$ is 1820, $\varepsilon$$_{33}$$^{T}$/$\varepsilon$$_{0}$ is 1120, and Curie temperature is 290 $^{\circ}C$. It shows the excellent properties at morphotropic phase boundary regions. PZT-PMNS ceramic may be available for high power piezoelectric devices such as PTs. The design of step-down PTs for adaptor proposes a multi-layer structure to overcome some structural defects of conventional PTs. In order to design PTs and analyze their performances, the finite element analysis and equivalent circuit analysis method are applied. The maximum peak of gain G as a first mode for thickness extensional vibration occurs near 0.85 MHz at load resistance of 10 .The peak of second mode at 1.7 MHz is 0.12 and the efficiency is 92$\%$.

• 대한건축학회논문집:계획계
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• 제35권8호
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• pp.35-46
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• 2019

This study started from the interest about a theme repeated in a similar way among a group of architects in Japan. They argue that a building composed of random elements can lead to discoverable functions rather than fixed functions. Their work supports this to a certain extent, but at the same time raises the following two research questions. Can 'formal randomness' and 'functional discoverability' be completely identical? Does such a form sufficiently fulfill other functions of the building? In order to answer these two research questions, this study analyzes the relationship between form and function in the 'Children's Center for Psychiatric Rehabilitation' of Sou Fujimoto. The analysis proceeded in three steps. In the first step, I found that alcoves were the most important factor in functional discoverability by comparing scenarios with different conditions. At the same time, however, I could see that these alcoves were weakened in the process of functional adjustment. In the second step, I analyzed the final design and found Sou Fujimoto's response to the preceding problem. He thought that in-between alcoves created from formal randomness, were not enough and thus introduced a new method, cutting alcoves. This means that formal randomness alone does not fully guarantee both the functional discoverability and the fulfillment of the basic functions. In the third step, I searched for the significance of this problem through a brief comparison with other similar projects.

• Interdisciplinary Bio Central
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• 제4권4호
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• pp.14.1-14.6
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• 2012

Splice site prediction in DNA sequence is a basic search problem for finding exon/intron and intron/exon boundaries. Removing introns and then joining the exons together forms the mRNA sequence. These sequences are the input of the translation process. It is a necessary step in the central dogma of molecular biology. The main task of splice site prediction is to find out the exact GT and AG ended sequences. Then it identifies the true and false GT and AG ended sequences among those candidate sequences. In this paper, we survey research works on splice site prediction based on support vector machine (SVM). The basic difference between these research works is nucleotide encoding technique and SVM kernel selection. Some methods encode the DNA sequence in a sparse way whereas others encode in a probabilistic manner. The encoded sequences serve as input of SVM. The task of SVM is to classify them using its learning model. The accuracy of classification largely depends on the proper kernel selection for sequence data as well as a selection of kernel parameter. We observe each encoding technique and classify them according to their similarity. Then we discuss about kernel and their parameter selection. Our survey paper provides a basic understanding of encoding approaches and proper kernel selection of SVM for splice site prediction.

• 융합정보논문지
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• 제9권2호
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• pp.1-6
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• 2019

본 논문에서는 의료용 빅 데이터를 활용하여 비즈니스와 연계하여 새로운 서비스를 창출하기 위한 프레임 워크를 설계하였다. 단순한 데이터 분석 단계를 나타내는 것이 아니라 데이터의 활용 목적을 명확히 하고, 이에 대한 분석을 수행하여 그 속에서 가치를 추출하고 실제 사업이나 서비스를 운용할 때까지의 과정을 설계한다. 설계된 프레임워크는 기본 아키텍처, 사회 시스템 모델까지 커버할 수 있도록 하였다. 설계된 프레임 워크를 참조하여 사회 시스템에 적용될 수 있도록 디자인하였으며, 기본 데이터로는 의료용 빅 데이터를 중심으로 하였다. 의료용 기본 데이터를 적용한 프레임 워크 설계로 여러 의료용 사업 제휴 및 서비스 창출을 실현할 수 있을 것으로 기대하고 있다.

• 한국의류학회지
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• 제41권4호
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• pp.709-721
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• 2017

This study researches the application methods of Wearable Technology (WT) realizing the convergence of Design and Electronics that could broaden the fashion expression boundaries to correspond to current convergence trends. For this, students in the Department of Fashion design and the Department of Electronics conducted an oriented convergence-design-workshop. The initial step of the workshop, included a lecture on WT including existing cases and brainstorming. As a result, two types of concepts; 'Light' using the lighting technology and 'Complex' using transforming and lighting technologies together were generated. Designers created garments that did not externally expose digital devices and engineers then configured basic systems with the minimum size of the devices applying. At the development stage, designers constructed internal structures of garments which do not influence the comfort situation and activities of those wearing the garments. Engineers then adjusted and finished the fashion prototypes' whole WT systems drawing on designers' guidelines. As the result of this study's workshop, the fashion prototypes were extracted by collaboration according to WT concepts; therefore, there could be the promising potential to broaden fashion expression boundaries through the application of WT.

• 한국실내디자인학회논문집
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• 제25권5호
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• pp.16-30
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• 2016

There is an increasing interest in and efforts for safe residential environment from crimes nationwide. Many cities are making efforts to create safe residential environment by enacting ordinances and guidances on safe design for preventing crimes and implementing demonstration projects. In line with the trends of the times toward 'improvement of living conditions' through urban regeneration, the importance of the Crime Prevention Through Environmental Design(CPTED) has recently emerged in the field of residential housing regeneration. Indeed, the CPTED is included as essential factor in the recent deteriorated residential area regeneration related projects. In this respect, the purpose of this study is to provide the basic data on the methodology of CPTED to be applied to the regeneration of deteriorated residential area in the future. To this end, this study selected three representative CPTED projects in Busan - 'Deokpo-dong Hope and Stepping Stone Village,' 'Chilsan-dong CPTED Happiness Village' and 'Sujeong-dong Crime Prevention and Safe Village' as objects of this study and then investigated and analyzed project contents, application of CPTED strategy, subjects who are implementing projects, and the time when they implement projects as the framework of my analysis. The findings from this study are as follows: First, the projects that were largely based on hardware should be improved by including software in the future. Second, the current Step 2 should expand into Step 3 Maintenance in applying CPTED strategy. Third, it is necessary to encourage exchange and cooperation between unit projects and subjects who are operating related projects.

• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1306-1311
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• 2004

We suggest a new type of swing motion control system for a crane system in which a small auxiliary mass is installed on the spreader. The actuator reacting against the auxiliary mass applies inertial control forces to the spreader of the container crane to reduce the swing motion in the desired manner. In this paper, as the basic and first step, we apply the $H_{\infty}$ control approach to anti-sway control system design problem. And, it will be shown that the proposed control strategy is useful and it can be easily applicable to the real world. So, in this study, we investigate usefulness of the proposed anti-sway system and evaluate system performance through simulation and experimental studies.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1350-1354
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• 2007

As the importance of low power design is emphasized, power consumption became one of the standards that represent the performance of the system. The purpose of this study is to decide design variable that minimize power consumption for the oxygen concentrator in two bed-one compressor 8 step PSA process that has above 90% purity at 3lpm by using given constants and selected parameters. Setting selected parameters as cycle time and equalization time, optimization for PSA process in the oxygen concentrator is progressed. For this, we need to know the features and basic principals of PSA process and to deduce objective function of performance analysis. Validations for objective function and lots of experiments are needed too. By using the characteristic curve of the compressor and the pressure curve of the process for 1 cycle, objective function was set. After theoretical 2 dimensional optimized paths was obtained. And then, by experiment, theoretical optimized path was verified.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.276-279
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• 2007

This study aims to present the application of pv system for apartment buildings. Regarding to the domestic housing politics to improve residing environment and effective use of country land, apartment buildings have been constructed since early of 1790's. Now apartment is taking over 50% out of entire housing in Korea. PV System of apartment buildings has been developed periodically and recently gable roof or canopy is popular which pv installation is more favorable. For balcony part with double skin facade sassy window, it has a preferable condition to install on the wall depending on the window direction. In case of superhigh floor apartment buildings where facade is mostly double skin facade of curtain wall system, pv module can replace the traditional curtain wall and will reduce architectural materials and obtain various out look design thereof. So, the purpose of this research is a basic study for clean energy source and present to applicability of pv systems for apartment buildings in preliminary design step.

• Journal of Advanced Marine Engineering and Technology
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• 제16권4호
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• pp.50-59
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• 1992

The paper presents a digital speed control approach of induction motor systems by using a digital servo control method and a well-known second order differential equation as model. The basic concept of using the modeling equation stated in the above is induced from the control theory stand point such that we can describe usually the motor system connected by inverter, generator and load etc, just as a mechanical system to be controlled. The concept does not demand us the complicated vector-based modeling equation adopted in the traditional methods for the speed control of induction motor. Futhermore, the proposed speed control system can be treated as a single input and single output system. The effectiveness of the servo control system obtained by the above-mentioned design concept is illustrated by the experimental results in the presence of both step reference changes and load variations. It is observed from the experimental results that the steady state-error of the experimental set up becomes zero after some regulation time and the induction motor system is robust in spite of reference signal changes and load variations.