• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.482-484
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• 2019

Learning and analyzing 3D point clouds with deep networks is challenging due to the limited and irregularity of the data. In this paper, we present a data-driven point cloud augmentation technique. The key idea is to learn multilevel features per point and to reconstruct to a similar point set. Our network is applied to a projection loss function that encourages the predicted points to remain on the geometric shapes with a particular target. We conduct various experiments using ShapeNet part data to evaluate our method and demonstrate its possibility. Results show that our generated points have a similar shape and are located closer to the object.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.312-326
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• 2021

The prey-predator model is one of the most influential mathematical models in ecology and evolutionary biology. In this study, we considered a modified prey-predator model, which describes the rate of change for each species. The effects of modifications to the classical prey-predator model are investigated here. The conditions required for the existence of the first integral and the stability of the fixed points are studied. In particular, it is shown that the first integral exists only for a subset of the model parameters, and the phase portraits around the fixed points exhibit physically relevant phenomena over a wide range of the parameter space. The results show that adding coupling terms to the classical model widely expands the dynamics with great potential for applicability in real-world phenomena.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.210-224
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• 2019

Given a positive integer k as input, a spatial preference query finds the k best data objects based on the scores (e.g., qualities) of feature objects in their spatial neighborhoods. Several solutions have been proposed for spatial preference queries in Euclidean space. A few algorithms study spatial preference queries in undirected spatial networks where each edge is undirected and the distance between two points is the length of the shortest path connecting them. However, spatial preference queries have not been thoroughly investigated in directed spatial networks where each edge has a particular orientation that makes the distance between two points noncommutative. Therefore, in this study, we present a new method called ALPS+ for processing spatial preference queries in directed spatial networks. We conduct extensive experiments with different setups to demonstrate the superiority of ALPS+ over conventional solutions.

• Structural Engineering and Mechanics
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• 제70권6호
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• pp.711-722
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• 2019

Considering stress singularities at point support locations, buckling solutions for plates with arbitrary number of point supports are hard to obtain. Thus, new Hp-Cloud shape functions with Kronecker delta property (HPCK) were developed in the present paper to examine elastic buckling of point-supported thin plates in various shapes. Having the Kronecker delta property, this specific Hp-Cloud shape functions were constructed through selecting particular quantities for influence radii of nodal points as well as proposing appropriate enrichment functions. Since the given quantities for influence radii of nodal points could bring about poor quality of interpolation for plates with sharp corners, the radii were increased and the method of Lagrange multiplier was used for the purpose of applying boundary conditions. To demonstrate the capability of the new Hp-Cloud shape functions in the domain of analyzing plates in different geometry shapes, various test cases were correspondingly investigated and the obtained findings were compared with those available in the related literature. Such results concerning these new Hp-Cloud shape functions revealed a significant consistency with those reported by other researchers.

• 산업융합연구
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• 제2권1호
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• pp.47-72
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• 2004

The study has tried to address particular situations relating to HRM. In my paper I give suggestions based on the present state of Korean Corporations. They are from 2 view points. These view points include the level of vertical fitness as a basic task of strategic human resource management and the level of empowerment to the line managers. This study could be defined by examining the following question: What are the contingent factors and organizational policies that enable us to foresee levels of strategic integration and empowerment? We seem to require the wisdom of human resource management for establishing the foundation of presenting a standard.

• 응용통계연구
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• 제27권4호
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• pp.589-603
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• 2014

본 연구는 시간의 순서에 따라 순차적으로 발생한 신호 자료에 있어서, 변화점 검출을 위한 베이지안 방법을 개발하고자 한다. 특히, Reversible Jump MCMC를 이용하여, 차원이 정해지지 않은 모수 공간을 탐색할 수 있는 효율적인 베이지안 추론 모형을 개발한다. 신호가 각 구간에서 선형함수인 경우에 대한 모형과 이해가 용이한 모형을 제안하고, 추정을 위해 고유의 MCMC알고리즘을 개발하였다. 제안된 방법을 모의실험 자료에 적용함으로써 그 정확성 및 효율성을 검증하였고, 실제 자료에도 적용하여 보았다.

• 산업경영시스템학회지
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• 제21권48호
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• pp.37-52
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• 1998

In many distribution systems important cost reductions and/or service improvements may be achieved by adopting an efficient inventory policy and proper selection of facilities. These efficiency improvements and service enhancements clearly require an integrated approach towards various logistical planning functions. The areas of inventory control and transportation planning need to be closely coordinated. The purpose of this paper is to construct an integrated model that can minimize the total cost of the transportation and inventory systems between multiple origin and destination points, where in origin point i has the supply of commodities and in destination point j requires the commodities. In this case, demands of the destination points are assumed random variables which have a known probability distribution. Using the lot-size reorder-point policy and the safety stock level that minimize total cost we find optimal distribution centers which transport the commodities to the destination points and suggest an optimal inventory policy to the selected distribution center. We also show if a demand greater than one unit will occur at a particular time, we describe the approximate optional replenishment policy from computational results of this lot-size reorder-point policy. This model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and a computer program with UNIX C language. In the usefulness review, we show the meaning and validity of the proposed model and exhibit the results of a comparison between our approach and the traditional approach, respectively.

• Parasites, Hosts and Diseases
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• 제45권3호
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• pp.239-243
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• 2007

Many allergists are currently focusing on the development of new diagnostic tools, and are attempting to improve both the sensitivity and specificity. A multiple allergen simultaneous test-chemiluminescent assay (MAST-CLA) is one of the most popular diagnostic tools used in the Republic of Korea. However, there remains controversy among allergists with regard to the cut-off point for a positive result. The present study was conducted in order to determine the validity of MAST-CLA as compared with that of the skin prick test, with particular emphasis on arthropod allergens, on the basis of percentage agreement rates and k-values, and also to suggest the optimal positive cutoff points using receiver operating characteristic (ROC) curves. The study was conducted with 97 subjects (54 men, 43 women). Optimal individual cut-off points were calculated as follows; class II for Dermatophagoides farinae, class I for Dermatophagoides pteronyssinus, and trace for a cockroach mix. These findings suggest that attempting to apply optimal individual cut-off points will be a good way of improving diagnostic tests, particularly MAST-CLA.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.192-198
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• 2016

The distributions of (or constraints for) amplitude and phase around C-points, including Lemon, Mon-Star and Star, are studied. A Cartesian coordinate system with origin at the C-point is established. Four curves, where the azimuthal angles of polarization ellipses are 0°, 45°, 90°, and 135° respectively, are used to determine the distributions. Discussions of these constraints illustrate why Mon-Star is rarer than Lemon or Star in experiments. The transformation relationships between these three polarization singularities (PSs) are also discussed. We construct suitable functions for amplitude and phase according to their constraints, and simulate several PSs of particular shapes. With the development of modulation techniques for amplitude and phase, it is clear that this work is helpful for generating arbitrarily shaped C-points in experiments.

• 동의생리병리학회지
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• 제30권6호
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• pp.402-411
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• 2016

The concept of the meridian system is originated from an empirical, systematic references in the clinical setting, which does not always require anatomical features. As the principles of systems biology are mainly associated with regulating the body's internal environment to maintain a stable condition, they are closely similar to the theory of the meridian system. In this review, I describe the origin of the concept of the meridian system, current status of research on the meridian system and acupuncture points, and the future directions of the research. To unravel the entity of the meridian system, we have to start from understanding its origin and clinical significance. The meridian system, as a theoretical model of the indications of acupuncture points, can help to understand the interconnections that underlie the pathologies of particular diseases or symptoms. Based on the establishment of clinical data platform for acupuncture research, we can extract novel medical information from the clinical data and generate analytical models that are useful for medical knowledge discovery on acupuncture points in the future.