• Journal of information and communication convergence engineering
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• 제20권3호
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• pp.160-165
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• 2022

This paper proposes an efficient method of reconstructing interconnections when the terminals of each plane change in real-time situations where randomly divided planes are interconnected. To connect all terminals when the terminals of each plane are changed, we usually reconstruct the interconnections between all terminals. This ensures a minimum connection length, but it takes considerable time to reconstruct the interconnection for the entire terminal. This paper proposes a solution to obtain an optimal tree close to the minimum spanning tree (MST) in a short time. The construction of interconnections has been used in various design-related areas, from networks to architecture. One of these areas is an ad hoc network that only consists of mobile hosts and communicates with each other without a fixed wired network. Each host of an ad hoc network may appear or disappear frequently. Therefore, the heuristic proposed in this paper may expect various cost savings through faster interconnection reconstruction using the given information in situations where the connection target is changing.

• 한국생산제조학회지
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• 제22권3호
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• pp.402-407
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• 2013

In this paper, the image processing for flexible disk grinding and the effect of the grinding conditions on the flat zone length of a workpiece are investigated, with the purpose of automating the grinding process. To accomplish this, three issues should be carefully studied. The first is finding the relationship between the flat zone length and the grinding conditions such as the cutting speed and feeding speed. The second is developing a neural network algorithm to predict the flat zone. The third is developing an image processing algorithm to measure the flat zone length of a workpiece. Slope analysis is used to determine straight and curved sections during the image processing. For verification, the estimated length and the length from the image processing are compared with the length measured by a projector. There is a minimum difference of 1.7% between the predicted and measured values. The results of this paper will be useful in compiling a database for process automation.

• Imaging Science in Dentistry
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• 제50권2호
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• pp.105-115
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• 2020

Purpose: This study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters(H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean crosssectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance. Results: The mean airway volume differed significantly among the malocclusion classes(P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 ㎣) and class III (2826.6±2505.3 ㎣), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions. Conclusion: The position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.

• Tribology and Lubricants
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• 제34권3호
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• pp.107-114
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• 2018

This paper presents a computational model of a gas foil journal bearing with shim foils between the top foil and bumps, and predicts its static and dynamic performance. The analysis takes the previously developed simple elastic foundation model for the top foil-bump structure and advances it by adding foil models for the "shim foil" and "outer top foil." The outer top foil is installed between the (inner) top foil and bumps, and the shim foil is installed between the inner top foil and outer top foil. Both the inner and outer top foils have an arc length of $360^{\circ}$, but the arc length of the shim foil is shorter, which causes a ramp near its leading edge in the bearing clearance profile. The Reynolds equation for isothermal and isoviscous ideal gas solves the hydrodynamic pressure that develops within the bearing clearance with preloads due to the ramp. The centerline pressure and film thickness predictions show that the shim foil mitigates the peak pressure occurring at the loading direction, and broadens the positive pressure as well as minimum film thickness zones except for the shortest shim foil arc length of $180^{\circ}$. In general, the shim foil decreases the journal eccentricity, and increases the power loss, direct stiffness, and damping coefficients. As the shim foil arc length increases, the journal eccentricity decreases while the attitude angle, minimum film thickness, and direct stiffness/damping coefficients in the horizontal direction increase.

• Plant Resources
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• 제6권3호
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• pp.159-164
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• 2003

This study was conducted to investigate the relationship between yearly variations of climatic elements and yearly variations of productivity in malting barley. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1991 to 2000. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly varation of the amount of precipitation in December and January were large with coefficients of variation(c. v.) of 97.9, 51.3%, respectively, but the variation of the maximum temperature and minimum temperature in April were relative small. Yield, weight of 1,000 grains and culm length were greatly with c. v. of 37.3, 49.3 and 41.3%, respectively. spike length and number of spikes show more or less c. v. of 3.8, 24.7% respectively and number of grains per spike show still less variation with c. v. of 9.4%. Correlation coefficients between temperature of mean, maximum and minimum in February and seed yield and yield components were positively significant at level of 5.1%, respectively. Correlation coefficients between precipitation of April and seed yield were positively significant correlation at the level of 5.1 %, respectively, but the duration of sunshine in April and seed yield were negatively significant at the level of 5.1%, respectively. Correlation coefficients of those, yield components and yield, culm length, spike length, number of grains per spike, number of spikes per $m^2$, weight of 1,000 grains and seed yield were positively significant at the level of 5.1 % respectively.

• 한국컴퓨터정보학회논문지
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• 제17권9호
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• pp.9-16
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• 2012

본 논문에서는 유한요소법에서 희소행렬의 효율적인 저장을 위한 2차원 가변길이 벡터 저장구조를 제안한다. 제안한 저장구조는 유한요소 전체 방정식의 거대희소행렬 $N{\times}N$ 대신, 전체 행의 개수 N의 상삼각행렬에서 0이 아닌 실제 필요한 값들만 2차원 가변길이 벡터를 이용하여 저장하는 방법이다. 이 방법을 이용하면, 해석대상의 2차원 격자구조에서는 각 절점당 최소 1개에서 최대 5개까지의 저장 공간이 필요하게 되고, 3차원 격자구조에서는 각 절점당 최소 1개에서 최대 14개까지의 저장 공간이 필요하게 된다. 인덱스를 포함해도 2배 이상을 넘지 않는다. 본 논문의 실험 결과에 의해, 제안한 저장구조는 총 절점 개수가 많아질수록 기존의 최대칼럼 높이를 저장하는 스카이 라인 저장구조보다 메모리 공간을 효과적으로 줄일 수 있는 구조임을 알 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제17권1호
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• pp.161-169
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• 2012

일반적으로 유클리드 최소신장트리는 2차원 평면상에 존재하는 입력노드들이 최소 비용으로 연결된 것이다. 그러나 생성된 유클리드 최소신장트리는 3차원의 현실세계에 적용할 경우 그 연결비용은 최소비용이 아닐 수 있다. 본 논문에서는 3차원 공간상에 존재하는 입력노드를 최단 길이로 연결하는 3차원 유클리드 최소신장트리를 제안한다. 100%의 공간비율의 3차원 공간상에 존재하는 30,000개의 입력 노드에 대한 실험에서, 본 논문에서 제안된 방법에 생성된 트리는, Prim의 2차원 최소신장트리 알고리즘에 의해 생성된 유클리드 최소신장트리에 비해, 2차원 평면에서만 고려했을 때 251.2%의 연결 비용의 증가를 보이지만 이것은 3차원 실세계에서는 의미가 없다. 본 논문에서 제안된 방법에 의해 생성된 트리는 3차원 공간에서는 90.0%의 비용의 절감율을 보인다. 이는 제안된 방법이 3차원적 연결에 관한 많은 현실적인 문제에 잘 적용될 수 있음을 나타낸다.

• 대한수학회보
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• 제38권4호
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• pp.797-801
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• 2001

The purpose of this paper is to give an upper bound for A[n,4], the maximum number of codewords in a binary code of word length n with minimum distance 4 between codewords. We have improved upper bound for A[12k+11,4]. In this correspondence we prove $A[23,4]\leq173716$.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.287-300
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• 2005

In this paper, we analyze Pseudo-Noise (PN) sequences generated by a maximum-length 90/150 Null Boundary Cellular Automata and we give the relationship among minimum offsets.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권1호
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• pp.23-32
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• 2007

The nature of genetic variation and diversity among the 65 multivoltine silkworm genotypes was evaluated for 16 post cocoon characters. The components of genetic variation revealed higher PCV (60.487%) and GCV (44.56%) for evenness (variation 1) followed by cohesion (PCV=55.38%, GCV=40.36%) and non-broken filament length (PCV=32.05%, GCV=31.28%). The higher heritability ($h^2$ in broad sense) was observed for boil-off loss (95.6%) followed by non-broken filament length (95.22%). The both genotypic and phenotypic correlation indicated significant positive correlation of filament length with non-broken filament length, silk recovery, raw silk, neatness, and low neatness; and negative correlation with denier, renditta and silk waste. The principal component analysis (PCA) revealed 75.381 % of total variance from the five principal components extracted. On the basis of Mahalonobis' $D^2$ values (Ward's minimum variance), the sixty-five multivoltine silkworm genotypes were classified in to 9 clusters with substantial inter and intra cluster distances. Number of genotypes included in different clusters varied from 3 to 17. The results indicated that the optimum distance obtained in cluster VII (15.059) along with higher cluster mean values especially for filament length, non broken filament length, renditta, silk recovery, silk waste, and raw silk emphasized the utilization of these genotypes in the conventional silkworm breeding programme for improvement of multivoltine silk fibre quality. The possibility of exploiting genetic variation in post cocoon traits for efficient breeding programme is discussed.