• Journal of Communications and Networks
• /
• 제12권3호
• /
• pp.240-245
• /
• 2010

Jacket matrices, motivated by the complex Hadamard matrix, have played important roles in signal processing, communications, image compression, cryptography, etc. In this paper, we suggest a novel approach to design a simple class of space-time block codes (STBCs) to reduce its peak-to-average power ratio. The proposed code provides coding gain due to the characteristics of the complex Hadamard matrix, which is a special case of Jacket matrices. Also, it can achieve full rate and full diversity with the simple decoding. Simulations show the good performance of the proposed codes in terms of symbol error rate. For generality, a kind of quasi-orthogonal STBC may be similarly designed with the improved performance.

• 센서학회지
• /
• 제30권5호
• /
• pp.286-289
• /
• 2021

Image classification is one of the fundamental applications of computer vision. It enables a system to identify an object in an image. Recently, image classification applications have broadened their scope from computer applications to edge devices. The convolutional neural network (CNN) is the main class of deep learning neural networks that are widely used in computer tasks, and it delivers high accuracy. However, CNN algorithms use a large number of parameters and incur high computational costs, which hinder their implementation in edge hardware devices. To address this issue, this paper proposes a lightweight image classifier that provides good accuracy while using fewer parameters. The proposed image classifier diverts the input into three paths and utilizes different scales of receptive fields to extract more feature maps while using fewer parameters at the time of training. This results in the development of a model of small size. This model is tested on the CIFAR-10 dataset and achieves an accuracy of 90% using .26M parameters. This is better than the state-of-the-art models, and it can be implemented on edge devices.

• Journal of Information Processing Systems
• /
• 제17권1호
• /
• pp.124-135
• /
• 2021

Object detection is a fundamental yet challenging task in computer vision that plays an important role in object recognition, tracking, scene analysis and understanding. This paper aims to propose a multiproperty fusion algorithm for moving object detection. First, we build a scale-invariant feature transform (SIFT) vector field and analyze vectors in the SIFT vector field to divide vectors in the SIFT vector field into different classes. Second, the distance of each class is calculated by dispersion analysis. Next, the target and contour can be extracted, and then we segment the different images, reversal process and carry on morphological processing, the moving objects can be detected. The experimental results have good stability, accuracy and efficiency.

• 대한화학회지
• /
• 제58권3호
• /
• pp.313-323
• /
• 2014

이 연구의 목적은 예비 화학교사의 PCK를 신장시키기 위하여 교육실습과 연계된 대학 강좌를 개발하는 것이다. 연구자는 교육실습 연계 대학 강좌의 실러버스와 교수학습 자료를 개발하고, 교육실습을 나갈 화학교육과 예비교사를 대상으로 '화학수업의 실제'란 강좌를 개설하여 개발한 교육과정을 적용하였다. 연구 참여자를 대상으로 반구조화된 면담을 실시한 결과, 예비교사들은 이 수업이 이론과 실제를 연계 지어줌으로써 좋은 과학수업에 대한 안목을 형성할 수 있게 하였으며 실습에 대한 실제적 준비를 할 수 있었고, 반성적 성찰을 가능하게 하여 결과적으로 교수 능력을 신장시킬 수 있었다고 언급하였다. 이 연구를 통해 실습과 연계된 대학 교과목의 실습 전후 교육으로 교육실습 경험을 재구성함으로써 예비교사의 수업 전문성을 신장시킬 수 있음을 확인할 수 있었다.

• Journal of Forest and Environmental Science
• /
• 제36권1호
• /
• pp.37-46
• /
• 2020

Vegetation carbon sequestration and regeneration are the two major parameters of forest research. In this study, we analyzed the vegetation carbon stock and regeneration of community-managed pine plantation of Kathmandu, central Nepal. Vegetation data were collected from 40 circular plots of 10 m radius (for the tree) and 1m radius (for seedling) applying a stratified random sampling and nested quadrat method. The carbon stock was estimated by Chave allometric model and estimated carbon stock was converted into CO₂ equivalents. Density-diameter (d-d) curve was also prepared to check the regeneration status and stability of the plantation. A d-d curve indicates the good regeneration status of the forest with a stable population in each size class. Diversity of trees was very low, only two tree species Pinus roxburghii and Eucalyptus citriodora occurred in the sample plots. Pine was the dominant tree in terms of density, basal area, biomass, carbon stock and CO₂ stock than the eucalyptus. The basal area, carbon stock and CO₂ stock of forest was 33±1.0 ㎡ ha^-1, 108±5.0 Mg ha^-1 and 394±18 Mg ha^-1, respectively. Seedling and tree density of the plantation was 4,965 ha^-1 and 339 ha^-1 respectively. The forest carbon stock showed a positive relationship with biomass, tree diameter, height and basal area but no relationship with tree density. Canopy cover and tree diameter have a negative effect on seedling density and regeneration. In conclusion, the community forest has a stable population in each size class, sequestering a significant amount of carbon and CO₂ emitted from densely populated Kathmandu metro city as the forest biomass hence have a potentiality to mitigate the global climate change.

• Molecules and Cells
• /
• 제28권5호
• /
• pp.447-453
• /
• 2009

The quorum sensing (QS) inhibitors that antagonize TraR, a receptor protein for N-3-oxo-octanoyl-L-homoserine lactones (3-oxo-C8-HSL), a QS signal of Agrobacterium tumefaciens were developed. The structural analogues of 3-oxo-C8-HSL were designed by in silico molecular modeling using SYBYL packages, and synthesized by the solid phase organic synthesis (SPOS) method, where the carboxamide bond of 3-oxo-C8-HSL was replaced with a nicotinamide or a sulfonamide bond to make derivatives of N-nicotinyl-L-homoserine lactones or N-sulfonyl-L-homoserine lactones. The in vivo inhibitory activities of these compounds against QS signaling were assayed using reporter systems and compared with the estimated binding energies from the modeling study. This comparison showed fairly good correlation, suggesting that the in silico interpretation of ligand-receptor structures can be a valuable tool for the pre-design of better competitive inhibitors. In addition, these inhibitors also showed anti-biofilm activities against Pseudomonas aeruginosa.

• 한국지구과학회지
• /
• 제27권3호
• /
• pp.251-259
• /
• 2006

본 연구의 목적은 지구계 교육을 통하여 과학을 공부하는 10학년의 학생들에게 도움이 되고자 하는 것이다. 지구계 교육은 과학 교과 간 구분을 완화하고 조화로운 교수-학습을 이루어감으로써 올바른 자연관과 인간관 육성에 기여할 것이다. 본 연구에서는 지구계 교육 프로그램 중 '화산 폭발과 기후 변화(Volcanic Eruptions and Global Climate Change)'라는 주제를 선정하고 이를 7차 교육 과정의 '과학' 교과에 적합하도록 수정, 보완하여 그 적용가능성을 점검해 보았다. 그 결과 과학에 대한 인식(p=0.003), 과학에 대한 흥미(p<0.001), 과학적 태도(p<0.001) 등의 과학에 대한 태도의 변화에 있어서 실험 집단이 통제 집단에 비해 거의 모든 영역에서 긍정적 변화를 보였다. 학업 성취도면에서는 지구계 교육 프로그램을 적용한 실험 집단이 전통적 수업을 진행한 통제 집단보다 높은 학업 성취도를 보였다(p=0.038). 실험 집단의 학생들은 적극적이고 진지한 태도로 수업에 임했으며 자기 주도적으로 학습하였다. 이러한 결과를 토대로 과학 교과에 지구계 교육 프로그램의 적용은 학생들의 과학적 흥미와 호기심 고양 및 과학적 소질과 올바른 자연관 신장에 좋은 영향을 줄 것으로 기대할 수 있다.

• Journal of Microbiology and Biotechnology
• /
• 제21권5호
• /
• pp.470-476
• /
• 2011

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at $30^{\circ}C$ and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at $30^{\circ}C$ for 20 min, and no inhibitory effect of $Ca^{+2}$ ions on amylase production was observed.

• 한국초등과학교육학회지:초등과학교육
• /
• 제38권1호
• /
• pp.116-129
• /
• 2019

This study investigated elementary students' spatial thinking and visualization when they learned the shape of volcanoes. For this purpose we used GeoMapApp to design instruction program and assessment items. In the instruction, students were asked to connect the floor plan view of Jeju island with the cross-sectional view of the same figure producted by GeoMapApp. Then they were asked to classify four sets of pictures of volcanoes based on the similarities of figures, that is, dome-shaped and shield volcanoes. In the assessment students solved three questions which examined how they connected the plan view and cross-sectional profile of Kilauea, draw cross-sectional profile of Mt. Fuji, and distinguished a shield volcano and dome-shaped one. Students' discourse data during the class were analyzed according to the amount to showing their spatial thinking and visualization. The instruction program using GeoMapApp assisted students to facilitate their spatial thinking for understanding of volcanoes. The outcomes of assessment showed even elementary students had good spatial thinking and visualization. Therefore, we argued spatial thinking and visualization for geoscientific understanding need to be included in the national science curriculum for elementary students.

• Journal of the Korean Wood Science and Technology
• /
• 제47권5호
• /
• pp.617-632
• /
• 2019

This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian's method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.