• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.114-120
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• 2012

There are lots of buildings which were built before the Legislation on building energy rating system. Remodeling of the buildings would be required for an improvement of the building energy rating system was enforced by the government. In the Passive Building Design, Elements which will be used for the remodeling are Insulation, Window, External venetian blind, Heat exchanger. The Purpose of this study is to indicate a Method for the improvement of Energy saving by an analysis of Construction Cost, Cost Evaluation, Energy performance Efficiency in applied design elements. In this study, the remodeling of existing public buildings to improve energy efficiency rating was applied to extract the elements of design-specific energy performance, efficiency, and the application of the designs that has been analyzed. The results were as follows: applying the design-specific cost-effective investment that represents the economy (investment efficiency/%) surveyed the average insulation(7.0%), triple glazed windows(10.1%), double glazed windows(12.1%), external shading(24.5%), and Heat(77.2%) were analyzed in order to be more efficient. Analysis of the basis of information on the existing public buildings to improve energy efficiency rating for the remodeling depending on driving conditions at a degree of individual difference. The main effect, however, depending on economic investment, design elements, heat exchangers, external awning, double glazed windows, triple glazed windows, insulation, is recommended as review of the order shall be determined.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.10-18
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• 2008

This paper presents the design and imelementation of an electronic ballast with a passive PFC structure from which acoustic resonance of the metal halide lamp was removed by introducing the frequency modulation(FM) method. The proposed ballast consists of an EMI filter, passive PFC circuit full-bridge inverter, LC resonance type igniter and a circuit for removing acoustic resonance. The FM method solved two problems associated with single frequency driving: variation of the acoustic resonance range according to lamp aging and the acoustic resonance range discrepancy caused by different materials sealed inside the arc tube and their pressures for arc tubes of identical sizes from different manufacturers. Performance of the prototype developed for this study of the electronic ballast for 1[kW] metal halide lamp was verified by evaluating its optical conversion efficiency, input PF, input current THD and power conversion efficiency.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.31-36
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• 2000

We developed embedded inductors in MCM-D substrate for RF applications. The increasing demand for high density packaging was the driving forces to the development of MCM-D technology. Most of these development efforts have been focused on high performance digital circuits. However, recently there is a great need fur mixed mode circuits with a combination of digital, analog and microwave devices. Mixed mode modules often have a large number of passive components that are connected to a small number of active devices. Integration of passive components into the high density MCM substrate becomes desirable to further reduce cost, size, and weight of electronic systems while improving their performance and reliability. The proposed MCM-D substrate was based on Cu/photosensitive BCB multilayer and Ti/Cu is used to form the interconnect layer. Seed metal was formed with 1000 $\AA$ Ti/3000 $\AA$ Cu by sputtering method and main metal was formed with 3 $\mu\textrm{m}$ Cu by electrical plating method. The multi-turn sprial inductors were designed in coplanar fashion. This paper describe the manufacturing process of integrated inductors in MCM-D substrate and the results of electrical performance test.

• Earthquakes and Structures
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• v.12 no.4
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• pp.425-436
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• 2017

Vibration control using a tuned mass damper (TMD) is an effective technique that has been verified using analytical methods and experiments. It has been applied in mechanical, automotive, and structural applications. However, the damping of a TMD cannot be adjusted in real time. An excessive mass damper stroke may be introduced when the mass damper is subjected to a seismic excitation whose frequency content is within its operation range. The semi-active tuned mass damper (SATMD) has been proposed to solve this problem. The parameters of an SATMD can be adjusted in real time based on the measured structural responses and an appropriate control law. In this study, a stiffness-controllable TMD, called a leverage-type stiffness-controllable mass damper (LSCMD), is proposed and fabricated to verify its feasibility. The LSCMD contains a simple leverage mechanism and its stiffness can be altered by adjusting the pivot position. To determine the pivot position of the LSCMD in real time, a discrete-time direct output-feedback active control law that considers delay time is implemented. Moreover, an identification test for the transfer function of the pivot driving and control systems is proposed. The identification results demonstrate the target displacement can be achieved by the pivot displacement in 0-2 Hz range and the control delay time is about 0.1 s. A shaking-table test has been conducted to verify the theory and feasibility of the LSCMD. The comparisons of experimental and theoretical results of the LSCMD system show good consistency. It is shown that dynamic behavior of the LSCMD can be simulated correctly by the theoretical model and that the stiffness can be properly adjusted by the pivot position. Comparisons of experimental results of the LSCMD and passive TMD show the LSCMD with less demand on the mass damper stroke than that for the passive TMD.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.153-170
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• 2020

With the recent development of AI and ICT, autonomous vehicles are becoming a reality, and sales of the vehicles equipped with partial autonomous driving technology are also rapidly expanding. In this situation, technology research on autonomous vehicles has been actively conducted, but research on exploring the perception of autonomous vehicles from the user's perspective is relatively insufficient. Therefore, this study categorizes autonomous vehicle users into four types - , , , and . Then, it examines the characteristics of each type. For this purpose, we applied Q-methodology, a qualitative research method, to observe self-referent subjectivity of 32 P-samples using a Q-sample which consists of 34 statements. The results of our study have significance in that they provide domestic and global automakers with strategic directions for technological development and market expansion of autonomous vehicles, and academically provide hypotheses for subsequent quantitative research.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.317-324
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• 2003

In this paper, we propose the ATM based Passive Optical Network (PON) using the optical CDMA scheme with optical switches and PN codes in time domain. We also propose the bipolar optical receiving correlator for PN codes. As optical CDMA is performed by driving directly an optical switch on-off switching with PN codes, the number of distinct code sequences can be increased and the flexibility in assigning PN codes can be improved. Finally we theoretically analyze the signal-to-interference -plus-noise ratio and the bit error probability of regenerated signal and compare the performance of proposed scheme compared with ATM based PON using conventional optical CDMA with optical delay lines.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.2030-2039
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• 2001

Recently, various inpipe inspection robots are developed and its effective values are increased in industrial use. However, it is so difficult to make a inpipe inspection robot system which has flexible mobility and accuracy of inspection in pipelines. Especially, it is very important to know the exact crack position. In this paper, we are to present a lately developed inpipe inspection robot system which can resolve the above Problems. The robot is configured as an articulated structure like a snake. Two active driving vehicles are located in front and rear of the inspection robot respectively and passive modules such as a nondestructive testing module and a control module are chained between the active vehicles. Special feature of the robot system is a ground interface, which is able to show informations of robot and pipelines. By using this, so called virtual map in this paper, user is able to know the pipelines'feature and crack position.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.121-129
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• 2000

The robotic automation in NonDestructive Testing(NDT) is a promising field of research and it helps to expand the applications of NDT enormously. Especially, in the case of pipelines which are widely used in various industrial facilities, it is required to secure adequate ways of inspection in the usual maintenance activitites. In this paper, we present a robot system for inpipe inspection of underground urban gas pipelines. The robot is configured as an articulated structure like a snake with a tether cable. Two active driving vehicles are located in front and rear of the system, respectively and passive modules such as a NonDestructive Testing module and a control module are chained between the active vehicles. The proposed system has outstanding mobility by employing a new steering mechanism called Double Active Universal Joint, which makes it possible to cope with complicated configurations of underground pipelines. Characteristic features of the system are described and the construction of the system is briefly outlined.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.89-93
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• 2001

In recent years Fiber optic hydrophone systems have been the focus of much attention in the sonar world. For sonar arrays, a fiber optic approach offers the major benefit of passive multiplexing of large numbers of hydrophones without underwater electronics. This paper describes recent development work covering array construction, opto-electronics development, hydrohpone design and sea trials. And the development of an interferometric mult-channel fiber optic hydrophone system which uses time division multiplexing capable of driving in excess of 32 channel is described. For this, a 12 channel time division multiplexing array has been constructed, and the performance of this system is demonstrated by sea trial.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.265-267
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• 2008

As generally recognized, the driving performance of a SRM at higher speed will be degraded due to the effects of back electromagnetic force (EMF). This phenomenon can be improved via voltage boosting. So in this paper an improved converter of enhancing the performance for four-phase switched reluctance motor (SRM) is proposed. By using one additional capacitor and switches, an extra controllable boosted voltage can be produced during the rise and fall periods of a motor phase current. Then this active boosted voltage can reduce the effect of EMF on the current, particularly at high speeds. The attractive features of the proposed converter are as follows: obtaining boosted voltage to improve performance of SRM with same numbers of switch and diode as asymmetric converter, having higher control flexibility and capability of boosting voltage compared with passive boosting converters, possessing lower cost and simple control in comparison with existing active boosting converters. The performances of the proposed circuit are verified by the simulation and experiment results.