• The Korean Journal of Physiology and Pharmacology
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• v.18 no.6
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• pp.457-460
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• 2014

At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing, storage, learning, and memory under both physiological and pathological conditions. One widely accepted model of learning mechanism and information processing in the brain is Hebbian Plasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectively activity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid and synapse-specific processes. A number of recent studies have a strong focal point on the critical importance of another distinct form of synaptic plasticity, non-Hebbian plasticity. Non-Hebbian plasticity dynamically adjusts synaptic strength to maintain stability. This process may be very slow and occur cell-widely. By putting them all together, this mini review defines an important conceptual difference between Hebbian and non-Hebbian plasticity.

• English Language & Literature Teaching
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• v.17 no.1
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• pp.147-163
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• 2011

In recent years, the relationship of language maintenance to culture and identity has received increased attention in the language acquisition and education fields. Korean immigrants in the U.S. form one of the biggest Asian groups and their language and cultural maintenance has been a major issue for both parents and ESL teachers. The present research is designed to investigate the cultural and social identities as well as the psychological investment factors that contribute to heritage language maintenance. Three Korean immigrant families in a small Midwest university town in the U.S. were surveyed and later interviewed. Issues and strategies concerning their children's Korean education in the U.S., coupled with the competing goal for the children to learn English were documented through parent interviews and interviews with school-aged focal children. Strategies and stances that facilitate or hinder both heritage and target language maintenance goals are presented along with participants' major reasons for heritage language maintenance in their homes and via Saturday schools. This work will assist ESL teachers and sociolinguists in situating both Korean student and parent goals in the context of shifting cultural and linguistic identities in countries where they have immigrated.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.464-469
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• 2003

The traditional and still most widely used, test methods for concrete structures are destructive method, such as coring, drilling or otherwise removing part of the structure to permit visual inspection of the interior. While these methods are highly reliable, they are also time consuming and expensive, and the defects they leave behind often become focal point for deterioration. In this study, tomography by theoretical inversion method in case of elastic wave using impact-echo method among concrete non-destruction test method was made. Taken model experiments are theoretical inversion method and time domain and frequency domain test on pier test model at laboratory level. Also experiment concerning frequency domain on 3 kinds of tunnel model with I-dimension form was carried out.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.506-509
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• 2006

Purpose: The cutaneous squamous cell carcinoma is the second most common skin malignancy. It is noted that keratoacanthoma is difficult to differentiate from squamous cell carcinoma, clinically or historically. It is still a hypothetical question whether keratoacanthoma is a pseudomalignancy or a form of squamous cell carcinoma. Methods: We report the case of squamous cell carcinoma around left ala of nose in a 64-year-old female patient. Through an incisional biopsy, the mass was found to be keratoacanthoma in the pathologic report. An excisional biopsy was performed. Results: Pathologic report notified that it was found well-differentiated squamous cell carcinoma arising in keratoacanthoma with focal involvement of deep resection margin. Wide excision was made with 0.5-1.5 cm margin and immediate reconstruction was performed. Conclusion: The relationship between keratoacanthoma and squamous cell carcinoma has been debated in the treatment. It is still controversial whether to excise it or not. We concluded that kerathoacanthoma must be removed completely.

• Korean Journal of Radiology
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• v.2 no.3
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• pp.171-174
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• 2001

Shaken baby syndrome (SBS) is a form of child abuse that can cause significant head injuries, of which subdural hematoma (SDH) is the most common manifestation. We report the MRI findings of chronic SDH in three cases of SBS, involving two-, three- and eight-month-old babies. The SDH signal was mostly low on T1-weighted images and high on T2-weighted images, suggesting chronic SDH. In chronic SDH, a focal high signal on T1-weighted images was also noted, suggesting rebleeding. Contrast-enhanced MRI revealed diffuse dural enhancement.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.197-202
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• 2002

In this paper, we want to help understanding about telecentric as introducing the concept of the system and researching the optical properties after we choose the designed profile projection lens. An analyzed optical system is F-number=2.8 and the first lens is used negative lens. Accordingly, we can know this system is compacter, because the front focal position is to the inside of the system and aperture stop is designed to the inside of the optical system. The field is about $21^{\circ}$. Since the entrance pupil is located the front focal point, we can certify the exit pupil is -49404.1mm, located on the infinite toward the object space. Therefore, the optical system is the form of 'image space telecentricity'.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.515-519
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• 2011

Cemento-osseous dysplasia occurs in the tooth bearing areas of the jaws and is probably the most common fibro-osseous manifestation. They are usually classified into three main groups according to their extent and radiographic appearance: periapical (surrounds the periapical region of teeth and are bilateral), focal (single lesion) and florid (scleroticsymmetrical masses) cemental-osseous dysplasias. Florid cemento-osseous dysplasia clearly appears to be a form of bone and cemental dysplasia that is limited to the jaws. Patients do not have laboratory or radiologic evidence of bone disease in other parts of the skeleton. For asymptomatic patients, the best management consists of regular recall examinations with prophylaxis and the reinforcement of good home hygiene care to control periodontal disease and prevent tooth loss. The treatment of symptomatic patients is more difficult. At this stage, there is an inflammatory component caused by the disease and the process is basically a chronic osteomyelitis involving dysplastic bone and cementum. Antibiotics might be suggested, but are not always effective. Two cases of florid cemento-osseous dysplasia diagnosed in two Korean females are reported with a review of the relevant literature.

• Korean journal of communication and information
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• v.46
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• pp.148-176
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• 2009

The purpose of this study is to analyze recognition cases on media education for disabled people, discovering tasks to improve media competence of disabled people and to find adequate supporting program. Semi-open type focus group interview is conducted with participation from media education teachers having teaching experience over disabled people. Main goal for this interview is to locate the aim, causes of disability, education methodology and revitalizing method for the media education for disabled people. Specifically, semi open type focus interview is selected to form questionnaires while catalyzing free discussion between participants. The intention of selecting quantitative research by FGI is to derive various recognition and experiences of participants by free discussions and opinion sharing. In addition, both teachers and learners are selected to find differentiated and common views towards the theme, realistically analyzing recognition experience from various angles.

• Korean Journal of Remote Sensing
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• v.13 no.2
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• pp.85-98
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• 1997

A geometric model of pushbroom-type linear CCD camera images is proposed in this paper. At present, this type of cameras are used for obtaining almost all kinds of high-resolution optical images from satellites. The proposed geometric model includes not only a forward transformation which is much more efficient. An inverse transformation function cannot be derived analytically in a closed form because the focal point of an image varies with time. In this paper, therefore, an iterative algorithm in which a focal point os converged to a given pixel position is proposed. Although the proposed model can be applied to any pushbroom-type linear CCD camera images, the geometric model of the high-resolution multi-spectral camera on-board KITSAT-3 is used in this paper as an example. The flight model of KITSAT-3 is in development currently and it is due to be launched late 1998.

• Geophysics and Geophysical Exploration
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• v.14 no.4
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• pp.274-281
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• 2011

We analysed ground motions form Mw 4.3 earthquake around Backryoung Island for the seismic source focal mechanism and horizontal response spectrum. Focal mechanism of the Backryoung Islands area was compared to existing principal stress orientation of the Korean Peninsula and horizontal response spectrum was also compared to those of the US NRC Regulatory Guide (1.60) and the Korean National Building Code. The ground motions of 3 stations, including vertical, radial, and tangential components for each station, were used for grid search method of moment tensor seismic source. The principal stress orientation from this study, ENE-WSW, is consistent fairly well with that of the Korean Peninsula. The horizontal response spectrum using 30 observed ground motions analysed and then were compared to both the seismic design response spectra (Reg Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). Response spectrum of 30 horizontal ground motions were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that the horizontal response spectrum revealed higher values for frequency bands above 3 Hz than Reg. Guide (1.60). The results were also compared to the Korean Standard Response Spectrum for the 3 different soil types and showed that the vertical response spectra revealed higher values for the frequency bands below 0.8 second than the Korean Standard Response Spectrum (SD soil condition). However, through the qualitative improvements and quantitative enhancement of the observed ground motions, the conservation of horizontal seismic design response spectrum should be considered more significantly for the higher frequency bands.