• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권1호
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• pp.17-24
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• 2004

The purpose of this study was to evaluate the stability and efficacy of biologic membrane made of freeze-dried cartilage as a barrier to facilitate guided bone regeneration in experimental non-healing bone defects in the rat mandible. Nine adult Sprague-Dawley rats (400-500g) were used in experiment. 5.0mm in diameter were created on the mandibular angle area by means of slow-speed trephine drill. In microscopic examination, dynamic immature bone forming at 2 weeks and its calcification at 4 weeks were observed. The membrane made of lyophilized cartilage taken from human costal cartilage seems to be very effective for guided bone regeneration as a biologic membrane and the scaffold for attachment of cells or local drug delivery system of growth factor, which may meet the ideal requirement of a barrier membrane and graft materials.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권5호
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• pp.273-278
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• 2002

Even though the modulating signal frequency of the light is too high to detect directly, the signal can be extracted by frequency conversion at the same time as the detection by means of the non-linearity of the APD. An analysis is presented for super-high-speed optical demodulation by an APD with electronic mixing. A normalized gain is defined to evaluate the performance of the frequency conversion demodulation. The nonlinear effect of the internal capacitance was included in the small signal circuit analysis. We showed theoretically and experimentally that the normalized gain is dependent on the down converted difference frequency component. In the experiment, the down converted different frequency outputs became larger than the directly detected original signal for the applied local signal of 20㏈m.

• Structural Engineering and Mechanics
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• 제26권5호
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• pp.499-516
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• 2007

An experimental method denoted as Impulse Method is proposed as a cost-effective non-destructive technique for the on-site evaluation of concrete elastic modulus in existing structures: on the basis of Hertz's quasi-static theory of elastic impact and with the aid of a simple portable testing equipment, it makes it possible to collect series of local measurements of the elastic modulus in an easy way and in a very short time. A Hypothesis Testing procedure is developed in order to provide a statistical tool for processing the data collected by means of the Impulse Method and assessing the possible occurrence of significant variations in the elastic modulus without exceeding some prescribed error probabilities. It is based on a particular formulation of the renowned sequential probability ratio test and reveals to be optimal with respect to the error probabilities and the required number of observations, thus further improving the time-effectiveness of the Impulse Method. The results of an experimental investigation on different types of plain concrete prove the validity of the Impulse Method in estimating the unknown value of the elastic modulus and attest the effectiveness of the proposed Hypothesis Testing procedure in identifying significant variations in the elastic modulus.

• 한국산업정보학회논문지
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• 제27권2호
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• pp.61-69
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• 2022

다수 에이전트 시스템(Multi-agent system)은 에이전트 각자의 결정으로 최상의 조직화 된 결정을 달성하는 것을 목표로 하는 시스템으로 본 논문에서는 다수 에이전트-다수 작업의 할당 문제를 제시한다. 본 문제는 각 에이전트가 하나의 작업에 할당이 되어 수행하고, 작업 수행에 대한 작업 완료 확률(completion probability)이 있으며 모든 작업의 수행 확률을 최대화하는 할당을 결정한다. 비선형(non-linearity)의 목적함수와 조합 최적화(combinatorial optimization)로 표현되는 본 문제는 NP-hard로, 효과적이면서 효율적인 문제 해결 방법론 제시가 필요하다. 본 연구에서는 한계 이익(marginal gain)의 감소를 의미하는 하위모듈성(submodularity)을 활용한 근사 알고리즘(approximation algorithm)을 제안하고, 확장성(scalability)과 강건성(robustness) 측면에서 우수한 알고리즘임을 이론 및 실험적으로 제시한다.

• Journal of Forest and Environmental Science
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• 제39권3호
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• pp.155-166
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• 2023

Consumption and selling of Non Timber Forest Products (NTFPs) are important means to meet nutritional requirements and improve the socio-economic conditions of the rural population. The purpose of this study was to document the status and utilization pattern and assess the economic value of NTFPs sold in the markets of the Itanagar Capital Region (ICR) of Arunachal Pradesh. Five major markets with 182 vendors were surveyed, and a total of 94 plant-based products under 63 species belonging to 32 families were found to be sold in the markets. Species like Acmella oleracea, Clerodendrum glandulosum, Dioscorea alata, Houttuynia cordata, Phoebe goalparensis, Piper pedicellatum, Zanthoxylum rhetsa, etc. are found to be highly preferred and have a higher demand in the local markets. The edible products of species like Piper pedicellatum and Phoebe goalparensis though highly consumed in the study area, are used only within the region, and the national and international demands of the species are nil. The animal-base products are not included in the study.

• Toxicological Research
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• 제19권2호
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• pp.133-139
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• 2003

Allergic contact dermatitis may be caused by a wide variety of chemicals. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for assessing the contact sensitization potential of chemical. However, there is a need to develop a nonradioisotopic endpoint for the LLNA, because of the radioisotopic method's requiring the use of special facilities. In this study, we investigated the development of a nonradioisotopic endpoint for LLNA using ELISA (enzyme-linked immunosorbent assay). Female Balb/c mice were treated by the topical application on the dorsum of both ears with four different strong sensitizers, 2,4-dinitrochlorobenzene (DNCB), oxazolone (OXZ), toluene diisocyanate (TDI), and trimellitic anhydride (TMA), and a strong irritant, sodium lauryl sulfate (SLS), once daily for three consecutive days. The proliferation of cells in the auricular Iymph node was analyzed by means of the labelling index (Ll) of bromodeoxyuridine (BrdU) incorporation into cells. The weights of the Iymph nodes in the mice treated with allergens, DNCB, OXZ, TDl and TMA were increased compared to the vehicle control. The stimulation index (Sl) of mice treated with DNCB, OXZ, TDl, and TMA was over three-fold increase compared to the vehicle control. However, the S1 of mice exposed to SLS was not significantly increased compared to the vehicle control, while the lymph node weight of SLS was significantly increased. These results suggest that the LLNA modified endpoint using ELISA based on BrdU incorporation could provide a useful method of screening for irritants and allergens.

• 한국방사선학회논문지
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• 제17권5호
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• pp.663-670
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• 2023

본 연구에서는 기존의 노이즈 제거 알고리즘을 적용한 영역 확장 기반의 분할 방법과 U-Net을 이용한 분할 방법의 성능을 정량적 평가인자를 이용하여 비교평가 하고자 하였다. 먼저, 전산화단층검사 영상에 median filter, median modified Wiener filter, fast non-local means algorithm을 모델링하여 적용한 뒤 영역 확장 기반의 분할을 수행하였다. 그리고 U-Net 기반의 분할 모델로 훈련을 진행하여 분할을 수행하였다. 그 후, 노이즈 제거 알고리즘을 사용한 경우와 U-Net을 사용한 경우의 분할 성능을 비교 평가하기 위해 평균 제곱근 편차 (root mean square error, RMSE), 최대 신호 대 잡음비 (peak signal to noise ratio, PSNR), universal quality image index (UQI), 그리고 dice similarity coefficient (DSC)를 측정하였다. 실험 결과, U-Net을 이용하여 분할을 수행했을 때 분할 성능이 가장 향상되었다. RMSE, PSNR, UQI, 그리고 DSC 값은 각각 약 0.063, 72.11, 0.864, 그리고 0.982로 noisy한 영상에 비해 각각 1.97배, 1.09배, 5.30배, 그리고 1.99배 개선된 것을 확인할 수 있었다. 결론적으로, 전산화단층검사영상에서 U-Net이 노이즈 제거 알고리즘에 비해 분할 성능 향상에 효과적임을 입증하였다.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.105-112
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• 2022

The development and spread of IT-technologies has raised interest in teaching programming pupils. The article deals with problems related to programming and ways to overcome them. The importance of programming skills is emphasized, as this process promotes the formation of algorithmic thinking of pupils. The authors determined the level of pupils' interest to programing learning depending on the age. The analysis has showed that the natural interest of younger pupils in programming is decreasing over the years and in the most productive period of its study is minimized. It is revealed that senior school pupils are characterized by low level of interest in the study of programming; lack of motivation; the presence of psychological blocks on their own abilities in the context of programming; law level of computer science understanding. To overcome these problems, we conducted the second stage of the experiment, which was based on a change in the approach to programing learning, which involved pupils of non-specialized classes of senior school (experimental group). During the study of programming, special attention was paid to the motivational and psychological component, as well as the use of game technologies and teamwork of pupils. The results of the pedagogical experiment on studying the effectiveness of teaching programming for pupils of nonspecialized classes are presented. Improvement of the results provided the use of social and cognitive motives; application of verbal and non-verbal, external and internal means; communicative attacks; stimulation and psychological setting; game techniques, independent work and reflection, teamwork. The positive effect of the implemented methods is shown by the results verified by the methods of mathematical statistics in the experimental and control groups of pupils.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.378-385
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• 2021

본 연구는 도시계획·설계 전공생들에게 도시 문제 해결을 위한 물리적 환경에 대한 대안제시능력과 함께 날이 갈수록 중요해지고 있는 비물리적 대안을 제시하는 능력을 함양할 수 있도록 관련 비교과과정을 개발하고 그 효과를 분석하는데 그 목적이 있다. 이를 위해 관련 전공 대학생 총 30명을 대상으로 약 1년 동안 전공 교육 과정과 연계하여 지역 내 유휴공간을 활용한 리빙랩 프로젝트의 비교과과정을 운영한 뒤, 전공만족도, 전공 관련 직업 취직 의사, 학업성취도 등을 분석하였다. 분석을 위해서는 솔로몬 4집단 설계를 활용하여 수업에 참여한 학생들과 참여하지 않은 학생들의 차이를 제시하고자 하였다. 분석 결과 리빙랩 프로젝트의 비교과과정에 참여한 학생들의 전공만족도와 전공 관련 직업취직 의사가 유의한 수준에서 높게 나타났다. 본 연구 결과는 리빙랩 프로젝트라는 수단을 활용하여 도시계획·설계 전공학생들이 지역 주민, 상인과 호흡하며 지역 문제 해결을 위한 물리적·비물리적 대안을 제시하는 능력을 함양하는 과정이 학생들의 전공에 대한 애착과 자긍심에 긍정적인 영향을 미친다는 점에서 그 시사점이 크다고 할 수 있다.

• 한국산학기술학회논문지
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• 제21권3호
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• pp.253-268
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• 2020

성장관리방안의 주요 정책수단이 성장관리지역 내에서 개발 입지에 어떠한 영향력을 미치는지를 확인하고자 세종시의 수립 사례를 대상으로 이항로짓모형을 이용하여 분석하였다. 2012년부터 2017년까지 세종시의 필지기반 자료를 사용하여 자연환경요인, 인문환경요인, 제도적 요인, 성장관리방안 정책수단요인을 독립변수로, 필지별 개발여부를 종속변수로 하는 이항로짓모형을 구축하였다. 분석 결과, 성장관리지역 내에서 인센티브와 물리적 규제는 영향력이 없는 것으로 나타났으며 시간적 규제는 연접필지 개발을 억제하는 영향력을 발휘하는 것으로 나타났다. 성장관리방안 시행 이전과 이후를 비교하여 분석한 결과, 성장관리방안 시행 이후에 시간적 규제의 영향력이 강화된 것으로 나타났다. 본 연구를 통한 정책적 시사점은 다음과 같다. 첫째, 성장관리방안의 용적률 인센티브는 효과가 미미한 바 지역적 특성이나 용도별 특성에 맞게 적용할 수 있도록 인센티브를 다양화할 필요가 있다. 둘째, 세종시 성장관리방안에서 적용하고 있는 시간적 규제는 간접적으로 개발시기를 조절하고 기허가지 내 기반시설 확보를 앞당기는 효과가 있으므로 규모·입지 규제 위주로 이루어진 현 성장관리방안을 보완하는 정책수단으로서 활용될 수 있을 것으로 기대된다.