• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.237-244
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• 2017

This study proposes a numerical model to explain the closely placed double modes in the vibration of a layered stone pagoda system. The friction surface between the stones is modelled as the Timoshenko finite element while each stone layer is modelled as a rigid body. It is assumed that the irregular asperity on the friction surface enables the stone to be excited. This results in the closely placed modes that are composed of natural modes and self-excited modes. To examine the validity of the proposed model, a set of modal testing and analysis for a layered stone pagoda mock-up model has been conducted and a set of closely placed double modes are extracted. Applying the extended sensitivity-based system identification technique, the various system parameters are identified so that the modal parameters of the proposed numerical model are the same with those of the experimental mock-up. For a horizontal impulse excitation, the simulated acceleration responses are compared with measurements.

• KIEAE Journal
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• v.7 no.5
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• pp.107-114
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• 2007

This study purposed to review the alternative criteria for preserving urban scenic view and establishing its management methods by selecting preliminary viewpoints to preserve the views of woomyeon mountain. The contents of this research consists of the representative urban scenic view by analyzing its viewpoints and landscape preference. For this study, seventeen preliminary viewpoints were selected, the ratio of visual structure was calculated by types of landscapes and an analysis was conducted on landscape preference through a questionnaire survey to draw results. Conclusively, various side studies through statistical method for characteristic analysis with preference elements about viewpoint and visual structure for urban landscape management. This research will contribute to management on objective point of view in environmentally friendly urban landscape planning.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2479-2481
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• 2001

오프라인에서만 가능했던 일들이 인터넷 속도의 향상으로 온라인을 통한 실시간 제어가 가능해지고 있다. TCP/IP를 기반으로 이루어지는 경우 대개 소켓을 이용한 PC기반에서 해석되어 지고 처리되어 진다. 본 논문에서는 PC기반의 원격제어 시스템을 임베디드화하여 온실시스템에 적용해 봄으로써 시스템의 안정성과 효율성에서 우수한 시스템을 구현하려고 한다. 이를 위하여 임베디드 시스템은 웹서버의 기능을 가진 HelloDevice 1300보드를 이용하였다. 실질적인 제어물의 제어를 위해서 제어기를 HelloDevice 1300보드와 시리얼을 통하여 통신하였다. 이와 같은 시스템을 구현하여 온실시스템의 자동화에 관한 실효성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.721-722
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• 2007

Currently, there has been a special practical program in Transmission for developing country(Southeast Asia, China and the Middle East) in KEPCO..And it will enhance the value of KEPCO by having highly competitive practical programs compare to other electric power company in developed countries. In this program, we focused on actual affairs to help engineers become experienced and all lecturers-experts in practical work-are giving the know-how of technique and skill..This program consists of 16 courses(Power system, Transmission construction and maintenance )which is designed for customers own needs. Therefore anyone can make the order of the course as they need. This program has contributed much to the growth of the company and helped to achieve a world-wide reputation. Also foreign aid project created a KEPCO image which will enjoy the nation's love and confidence. Through this course we can increase our international competeitivenessand and will have a chance to start a business that has a future in Northwest Africa.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.459-460
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• 2005

The global consumption of aspheric surfaces will expand rapidly on the Electronics and Optical Components, Information and Communications, Aerospace and Defense, and Medical optics markets etc. We must research on market, technology forecast and analysis of aspheric surfaces that is a principle step of ultra precision machine technology with a base one of optical elements. Especially, F-theta lens is one of the important parts in LSU(Laser scanning unit) because it affects on the optical performance of LSU dominantly. The core is most of important to produce plastic F-theta lens by plastic injection molding method, which is necessary to get the ultra-precision aspheric and non-axisymmetric machine processing technology.

• 순환기질환의공학회:학술대회논문집
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• 2003.11a
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• pp.32-32
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• 2003

• Parasites, Hosts and Diseases
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• v.38 no.3
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• pp.187-190
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• 2000

To determine association of grassland with parasitic diseases of livestock in Bangladesh, the 'Tracer' animals (two cow calves and two goats) were released for a month in a grassland used for communal grazing of livestock near school premise in Kanthal, Trishal, Mymensingh, Bangladesh. After slaughtering of the tracer animals, their gastrointestinal tract examination revealed six species of nematode and one cestode. The nematode species were Haemonchus contortus, Trichostrongylus axei, Mecistocirrus digitatus, Oesophagostomum spp., Trichuris spp. and Bunostomum sp. The cestode was one of the genus Moniezia. With this preliminary study, grasslands are thought to be one of the main sources of gastrointestinal parasitic diseases of livestock in Bangladesh.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.3
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• pp.308-315
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• 2010

This study introduces a new technique to estimate modal parameters of a vibrating string using motion pictures. The approach requires two motion pictures for a vibrating string captured simultaneously by typical potable digital cameras or camcorders. Applying the space intersection theory and the space resection theory in photogrammetry, the steroscopic images for the string are constructed from two flat plane pictures. Then the three dimensional displacement components of the string are extracted by a multiple template matching technique. Finally the modal parameters of the string are estimated from the resulting displacement time histories. The accuracy of the approach has been examined through a small-scale mock-up of a string.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.620-628
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• 2010

Using the responses of deck plate, a new bridge weigh-in-motion system has been introduced. The approach includes not only a systematic algorithm for the extraction of moment influence sequence but also a sensitivity-based system identification technique. The algorithm indentifies the influence sequence, the axle loads, and axle location of moving vehicles on a bridge, simultaneously. The accuracy and practicability of the algorithm have been examined experimentally for a folded deck plate on Yongjong Grand suspension bridge. It turns out that the two-dimensional effects of the behavior of deck plate should be considered for further accuracy improvement.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1229-1236
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• 2008

A set of modal parameters of a stay-cable have been extracted fi:on a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.