• 디지털콘텐츠학회 논문지
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• 제10권2호
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• pp.269-278
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• 2009

본 연구는 학교 현장에 보급되고 있는 디지털교과서를 활용한 학습에서 디지털교과서가 학습자들에게 어떠한 만족도를 갖고 활용되고 있는지를 유비쿼터스 학습특성의 관점에서 살펴보고, 학습자의 컴퓨터 자기효능감과 디지털교과서의 활용도가 어떠한 조절적 작용을 하고 있는지를 검증해 봄으로써 디지털교과서의 콘텐츠와 시스템 개발에 지침을 제공하고자 하였다. 연구방법은 SPSS win13.0 프로그램으로 실증분석을 위한 기술통계, Cronbach's $\alpha$ 계수 산출과 상관분석을 하였고, 가설검증을 위해서는 조절회귀분석(MMR)을 실시하였다. 연구가설의 검증을 통해 나타난 결과는 다음과 같다. 첫째, 유비쿼터스 학습특성은 디지털교과서 학습만족도에 직접적인 영향력을 가지는 것으로 나타났다. 둘째, 유비쿼터스 학습특성이 디지털교과서 학습만족도에 긍정적인 영향력을 줄 때 컴퓨터 자기효능감과 디지털교과서 활용도가 유비쿼터스 학습특성과 각각 상호작용을 하여 조절 효과를 가지는 것으로 밝혀졌다. 이러한 결과들은 통계적으로 유의미한 결과로서 나타났다.

• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.725-730
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• 2013

This paper proposed a novel method for an analysis feature of an Electroencephalogram (EEG) at all channels simultaneously. In a BCI (Brain-Computer Interface) system, EEGs are used to control a machine or computer. The EEG signals were weak to noise and had low spatial resolution because they were acquired by a non-invasive method involving, attaching electrodes along with scalp. This made it difficult to analyze the whole channel of EEG signals. And the previous method could not analyze multiple stimuli, the result being that the BCI system could not react to multiple orders. The method proposed in this paper made it possible analyze multiple-stimuli by grouping the channels. We searched the groups making the largest correlation coefficient summation of every member of the group with a BHS (Binary Harmony Search) algorithm. Then we assumed the EEG signal could be written in linear summation of groups using concentration parameters. In order to verify this assumption, we performed a simulation of three subjects, 60 times per person. From the simulation, we could obtain the groups of EEG signals. We also established the types of stimulus from the concentration coefficient. Consequently, we concluded that the signal could be divided into several groups. Furthermore, we could analyze the EEG in a new way with concentration coefficients from the EEG channel grouping.

• Journal of Power Electronics
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• 제18권2호
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• pp.627-639
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• 2018

The fact that the reliability of IGBTs has become a more and more significant aspect of power converters has resulted in an increase in the research on the open circuit (OC) fault location of IGBTs. When an OC fault occurs, a zero-current phenomena exists and frequently appears, which can be found in a lot of the existing literature. In fact, fault variables have a very high correlation with the zero-current interval. In some cases, zero-current interval actually decides the most significant fault feature. However, very few of the previous studies really explain or prove the zero-current phenomena of the fault current. In this paper, the zero-current phenomena is explained and verified through mathematical derivation, based on two-level and three-level NPC static var generators (SVGs). Mathematical models of single OC fault are deduced and it is concluded that a zero-current interval with a certain length follows the OC faults for both two-level and NPC three-level SVGs. Both inductive and capacitive reactive power situations are considered. The unbalanced load situation is discussed. In addition, simulation and experimental results are presented to verify the correctness of the theoretical analysis.

• Journal of the Korean Data and Information Science Society
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• 제22권5호
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• pp.921-929
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• 2011

정보화시대에 대학에서의 교양 컴퓨터교육과정은 컴퓨터에 대한 소양을 쌓고 정보화 사회에 능동적으로 대처할 수 있는 능력을 배양하여 생산성 향상은 물론 국가 간의 경쟁력에서 뒤지지 않게 하는데 목표를 두고 있다. 본 논문에서는 대학생을 대상으로 컴퓨터교육 만족도에 영향을 미치는 결정적인 변인의 발견 및 만족도를 분석한다. 전처리과정으로 자바 기반의 학습 도구인 속성 부분집합의 선택기반을 사용하여 최적의 변인을 선택한 후 통계적 학습이론에 기반을 둔 다중 최소제곱 서포트벡터 기계를 사용하고자 한다. 대학의 교양 컴퓨터교육 만족도 분석을 위하여 새로운 알고리즘을 제시하기 보다는 기존의 다중 서포트벡터기계와 다중 최소제곱 서포트벡터기계를 비교 분석한다. 본 논문의 연구결과는 컴퓨터교육 만족도 자료의 분석에서 다중 최소제곱 서포트벡터기계가 다중 서포트벡터기계와 같이 우수한 성과를 나타내는 것을 확인하였다.

• BMB Reports
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• 제31권5호
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• pp.459-467
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• 1998

A new set of functional group interaction energy descriptors relevant to the ACE (Angiotensin-Converting Enzyme) inhibitory peptide, QSAR (Quantitative Structure Activity Relationships), is presented. The functional group interaction energies approximate the charged interactions and distances between functional groups in molecules. The effective energies of the computationally derived geometries are useful parameters for deriving 3D-QSAR models, especially in the absence of experimentally known active site conformation. ACE is a regulatory zinc protease in the renin-angiotensin system. Therapeutic inhibition of this enzyme has proven to be a very effective treatment for the management of hypertension. The non bond interaction energy values among functional groups of six-feature of ACE inhibitory peptides were used as descriptor terms and analyzed for multivariate correlation with ACE inhibition activity. The functional group interaction energy descriptors used in the regression analysis were obtained by a series of inhibitor structures derived from molecular mechanics and semi-empirical calculations. The descriptors calculated using electrostatic and steric fields from the precisely defined functional group were sufficient to explain the biological activity of inhibitor. Application of the descriptors to the inhibition of ACE indicates that the derived QSAR has good predicting ability and provides insight into the mechanism of enzyme inhibition. The method, functional group interaction energy analysis, is expected to be applicable to predict enzyme inhibitory activity of the rationally designed inhibitors.

• 한국조경학회지
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• 제30권5호
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• pp.31-38
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• 2002

This study attempts to grasp the correlation between the image of bridges and bridge landscapes with their surroundings during day and nighttime viewing, and to understand the psychological influence of nighttime lighting through quantitative analysis. In addition, it presents a design to construct bridges in order to increase viewers enjoyment of bridge landscapes lit at night. To attain this objective and contrive generalization of the results, this paper selects 8 of 9 bridges with lightings in Seoul and excludes bridges constructed by 2004. The criteria for selection of the viewpoints is that each must be within easy reach of bridges, and must allow viewers to recognize surrounding landscape details both in daylight and at night. As well, the pictures of bridges are taken in the terraced land by the riverside. The study selects 16 pictures, judged to be of similar quality and angle, to establish the conditions of luminosity, color, definition and angle. The results are as follows. First, viewers preferences of night landscapes are higher than day landscapes due to the effect of lighting. By day, viewers preferred bridges with various structures such as cable-stayed bridges and arch bridges more than simple bridges like girder bridges. Viewers also indicated preferences for lightings which feature a unique color and which are harmonized with their surroundings. Second, components representing the images of bridge landscape are classified into three types, 'beauty', 'system' and 'agreeableness'. Third, the factors affecting preference are the shape of bridge by day and lighting at night. Esthetic appeal is the most important factor in visual preference so each bridges own esthetic appeal and surroundings must be considered. Thus, a complete plan must be created which considers safety, beauty and the local surroundings. In addition, when the lighting of a bridge is selected, the design of the bridge landscape must consider various lighting schemes to harmonize the upper and lower parts of the structure. At this point, the study reveals the basic elements of bridge planning in order to increase appreciation of the bridge landscape.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.1942-1951
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• 2017

Campylobacter jejuni and Campylobacter coli are important foodborne pathogenic bacteria, particularly in poultry meat. In this study, the presence of extracellular DNase activity was investigated for biofilm-deficient Campylobacter strains versus biofilm-forming Campylobacter strains isolated from chickens, to understand the relationship between extracellular DNase activity and biofilm formation. A biofilm-forming reference strain, C. jejuni NCTC11168, was co-incubated with biofilm non-forming strains isolated from raw chickens or their supernatants. The biofilm non-forming strains or supernatants significantly prohibited the biofilm formation of C. jejuni NCTC11168. In addition, the strains degraded pre-formed biofilms of C. jejuni NCTC11168. Degradation of C. jejuni NCTC11168 biofilm was confirmed after treatment with the supernatant of the biofilm non-forming strain 2-1 by confocal laser scanning microscopy. Quantitative analysis of the biofilm matrix revealed reduction of extracellular DNA (16%) and proteins (8.7%) after treatment. Whereas the biofilm-forming strains C. jejuni Y23-5 and C. coli 34-3 isolated from raw chickens and the C. jejuni NCTC11168 reference strain showed no extracellular DNase activity against their own genomic DNA, most biofilm non-forming strains tested, including C. jejuni 2-1, C. coli 34-1, and C. jejuni 63-1, exhibited obvious extracellular DNase activities against their own or 11168 genomic DNA, except for one biofilm non-former, C. jejuni 22-1. Our results suggest that extracellular DNase activity is a common feature suppressing biofilm formation among biofilm non-forming C. jejuni or C. coli strains of chicken origin.

• 한국게임학회 논문지
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• 제18권6호
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• pp.39-48
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• 2018

최근에 신체적, 심리적 힐링(healing) 기능이 있는 게임들이 출시되고 있다. 힐링 게임은 사용자에게 힐링의 요소를 제공하는 장점이 있는 반면에, 힐링 콘텐츠의 속성 상 콘텐츠가 비교적 단순하여 강한 자극 보다는 심리적 안정을 주는 특성이 강하다. 지속적인 자극과 게임의 몰입성 측면이 다소 약하여 힐링 게임의 경우 인기가 지속적이지 못한 경향이 있다. 이에 본 논문에서는 국내외 힐링 게임을 모바일, 콘솔, PC 등 플랫폼 종류별로 분류하여 조사하고 Nicole Lazzro가 제안한 '4가지 재미요소(Hard Fun, Easy Fun, Serious Fun, People Fun)'를 기준으로 힐링 게임들의 특성을 분석한다. 이 분석을 통해 기존의 힐링 게임들이 '4가지 재미요소'를 얼마나 포함하고 있는지 분석하고, 재미요소와 힐링 게임의 인기 간의 상관관계를 파악한다.

• 보존과학회지
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• 제38권1호
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• pp.45-54
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• 2022

This study examined the production technique of bracket murals in Daeungjeon Hall, Gaeamsa Temple by conducting a analysis of their wall structure, material characteristics, and painting layers. Wall was a single-branch structure with support layer, middle layer, finishing layer, and painting layer. The support layer, middle layer and finishing layer, were produced by mixing sand (quartz, feldspars etc.), and loess. The ratio of above medium sand to below fine sand was approximately 0.7 : 9.3 in the support layer, 4 : 6 in the middle layer and 6 : 4 in the finishing layer, which had a more percentage of above medium sand than the support layer. The analysis of the painting layer showed that natural soil pigment was used to establish a relatively ground layer of up to 50 ㎛, and pigments such as Lead sulfate, atacamite and mercury sulfide were painted on top of the layer. This study's results confirmed that the bracket mural paintings in Gaeamsa Temple are within the category of the production style of murals during the Joseon period. However, the points that the middle layer was formed several times, the significant difference in particle size distribution between the wall, and the absence of chopped straw in the support layer are a feature of bracket mural paintings in Gaeamsa Temple. These properties of murals as material and structure may be viewed for correlation with the degree of damage to wall structure of mural painting and would serve as an important reference to diagnosis the conservation conditions of murals or prepare conservation treatments.

• 대한원격탐사학회지
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• 제40권1호
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• pp.93-101
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• 2024

Accurate field crop classification is essential for various agricultural applications, yet existing methods face challenges due to diverse crop types and complex field conditions. This study aimed to address these issues by combining support vector machine (SVM) models with multi-seasonal unmanned aerial vehicle (UAV) images, texture information extracted from Gray Level Co-occurrence Matrix (GLCM), and RGB spectral data. Twelve high-resolution UAV image captures spanned March-October 2021, while field surveys on three dates provided ground truth data. We focused on data from August (-A), September (-S), and October (-O) images and trained four support vector classifier (SVC) models (SVC-A, SVC-S, SVC-O, SVC-AS) using visual bands and eight GLCM features. Farm maps provided by the Ministry of Agriculture, Food and Rural Affairs proved efficient for open-field crop identification and served as a reference for accuracy comparison. Our analysis showcased the significant impact of hyperparameter tuning (C and gamma) on SVM model performance, requiring careful optimization for each scenario. Importantly, we identified models exhibiting distinct high-accuracy zones, with SVC-O trained on October data achieving the highest overall and individual crop classification accuracy. This success likely stems from its ability to capture distinct texture information from mature crops.Incorporating GLCM features proved highly effective for all models,significantly boosting classification accuracy.Among these features, homogeneity, entropy, and correlation consistently demonstrated the most impactful contribution. However, balancing accuracy with computational efficiency and feature selection remains crucial for practical application. Performance analysis revealed that SVC-O achieved exceptional results in overall and individual crop classification, while soybeans and rice were consistently classified well by all models. Challenges were encountered with cabbage due to its early growth stage and low field cover density. The study demonstrates the potential of utilizing farm maps and GLCM features in conjunction with SVM models for accurate field crop classification. Careful parameter tuning and model selection based on specific scenarios are key for optimizing performance in real-world applications.