• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.361-364
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• 1997

Bayesian MAP-EM approaches have been quite useful or tomographic reconstruction in that they can stabilize the instability of well-known ML-EM approaches, and can incorporate a priori information on the underlying emission object. However, MAP reconstruction algorithms with expressive priors often suffer from the optimization problem when their objective unctions are nonquadratic. In our previous work [1], we showed that the use of deterministic annealing method greatly reduces computational burden or optimization and provides a good solution or nonquadratic objective unctions. Here, we further investigate the convergence of the deterministic annealing algorithm; our experimental results show that, while the solutions obtained by a simple quenching algorithm depend on the initial conditions, the estimates converged via deterministic annealing algorithm are consistent under various initial conditions.

• Design Convergence Study
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• v.15 no.4
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• pp.59-70
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• 2016

Due to the newly emerging market for telepresence robots and the research in the area, designers and developers lack guidelines for specifying the physical characteristics of telepresence robots. On the basis of the previous literature, we attempted to make a distinction between two robot height approaches for telepresence robot designs: floor- versus desk-based robot designs. This research investigated the effects of these robot height approaches on consumer acceptance. We predicted that there would be difference between floor-based robots and desk-based robots regarding consumers' evaluation of and intent to purchase social robots. A study using two types of robots was conducted with sixty university students. The results showed that participants perceived desk-based robots as more useful than floor-based robots. In addition, the participants evaluated desk-based robots more positively than floor-based robots. Purchase intention and willingness to pay also showed similar results as evaluation. The implications for the design of telepresence robots in terms of increasing acceptance of robots are discussed in detail.

• Journal of information and communication convergence engineering
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• v.8 no.3
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• pp.301-306
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• 2010

This project is to study and design a meteorological buoy. It mainly covers and compares two approaches to design a meteorological buoy where their functions are same. The comparison will be made between mechanical structure, type of sensors, and electronics system design and power consumption issues.

• Coupled systems mechanics
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• v.7 no.5
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• pp.583-610
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• 2018

This paper discusses the issues associated with modeling frictional contact between solid bodies undergoing large deformations. The most common model for friction on contact interfaces in solid mechanics is the Coulomb friction model, in which two distinct responses are possible: stick and slip. Handling the transition between these two phases computationally has been a source of algorithmic instability, lack of convergence and non-unique solutions, particularly in the presence of large deformations. Most computational models for frictional contact have used penalty or updated Lagrangian approaches to enforce frictional contact conditions. These two approaches, however, present some computational challenges due to conditioning issues in penalty-type implementations and the iterative nature of the updated Lagrangian formulation, which, particularly in large simulations, may lead to relatively slow convergence. Alternatively, a plasticity-inspired implementation of frictional contact has been shown to handle the stick-slip conditions in a local, algorithmically efficient manner that substantially reduces computational cost and successfully avoids the issues of instability and lack of convergence often reported with other methods (Laursen and Simo 1993). The formulation of this approach, however, has been limited to the small deformations realm, a fact that severely limited its application to contact problems where large deformations are expected. In this paper, we present an algorithmically consistent formulation of this method that preserves its key advantages, while extending its application to the realm of large-deformation contact problems. We show that the method produces results similar to the augmented Lagrangian formulation at a reduced computational cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.559-575
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• 2023

3D human pose estimation is widely applied in various fields, including action recognition, sports analysis, and human-computer interaction. 3D human pose estimation has achieved significant progress with the introduction of convolutional neural network (CNN). Recently, several researches have proposed the use of multiview approaches to avoid occlusions in single-view approaches. However, as the number of cameras increases, a 3D pose estimation system relying on a CNN may lack in computational resources. In addition, when a single host system uses multiple cameras, the data transition speed becomes inadequate owing to bandwidth limitations. To address this problem, we propose a distributed real-time 3D pose estimation framework based on asynchronous multiple cameras. The proposed framework comprises a central server and multiple edge devices. Each multiple-edge device estimates a 2D human pose from its view and sendsit to the central server. Subsequently, the central server synchronizes the received 2D human pose data based on the timestamps. Finally, the central server reconstructs a 3D human pose using geometrical triangulation. We demonstrate that the proposed framework increases the percentage of detected joints and successfully estimates 3D human poses in real-time.

• Journal of the Korean Society of Costume
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• v.65 no.2
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• pp.33-47
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• 2015

The purpose of this study is to understand the ideas of characteristic of convergence design related to slow fashion design. Convergence design in digital stage can be defined as a social phenomenon which different function of product move toward one direction for greater efficiency. Slow fashion is based on the Slow Movement. (This is a movement with similar principles to the Slow Food Movement, as it promotes an alternative mass production, such as fast fashion.) The aims of this research are to study slow fashion that has appeared in the fashion industry through various approaches for convergence designs, and to find the possibility of use for slow fashion. The research method consisted of carrying out case studies and analyzing literatures and proceeding cases. The characteristics of convergence designs are classified into technical convergence, emotion-oriented convergence and complex convergence. Technical convergence has an effect on slow fashion as a multi-functional design. Second, emotion-oriented convergence affects social-cultural design. Slow fashion related to a complex convergence design reveals emotion-oriented deign. Slow fashion is related to convergence design is to expect contribute to provide a good source for the future fashion industry and fashion market.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.2
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• pp.45-56
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• 2013

The precise identification of vehicle positions, known as the vehicle localization problem, is an important requirement for building intelligent vehicle ad-hoc networks (VANETs). To solve this problem, two categories of solutions are proposed: stand-alone and data fusion approaches. Compared to stand-alone approaches, which use single information including the global positioning system (GPS) and sensor-based navigation systems with differential corrections, data fusion approaches analyze the position information of several vehicles from GPS and sensor-based navigation systems, etc. Therefore, data fusion approaches show high accuracy. With the position information on a set of vehicles in the preprocessing stage, data fusion approaches is used to estimate the precise vehicular location in the local map building stage. This paper proposes an efficient local map building scheme, which increases the accuracy of the estimated vehicle positions via V2V communications. Even under the low ratio of vehicles with communication modules on the road, the proposed local map building scheme showed high accuracy when estimating the vehicle positions. From the experimental results based on the parameters of the practical vehicular environments, the accuracy of the proposed localization system approached the single lane-level.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.213-218
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• 2016

Korea faces new social needs of community-based service for senior citizen as aging is getting fasten. Targeting elderly people who are beneficiaries of long-term care insurance and caring service, this paper aims to explore decent and proper services for senior citizens in terms of rehabilitation, health improvement and quality of life. Especially this research approaches from the perspective of service providers, including service facilities and care-service givers. Using FGI methods with care-providers and in-depth interviews with community social workers as well as nurses, convergence approaches are explored. As a result, welfare field and nursing practices are clearly divided in the community, so that the convergence education and team work tool would be developed in the near future.

• Structural Engineering and Mechanics
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• v.37 no.5
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• pp.543-560
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• 2011

In structural engineering there are randomness inherently exist on determination of the loads, strength, geometry, and so on, and the manufacturing of the structural members, workmanship etc. Thus, objective and constraint functions of the optimization problem are functions that depend on those randomly natured components. The constraints being the function of the random variables are evaluated by using reliability index or performance measure approaches in the optimization process. In this study, the minimum weight of a space truss is obtained under the uncertainties on the load, material and cross-section areas with harmony search using reliability index and performance measure approaches. Consequently, optimization algorithm produces the same result when both the approaches converge. Performance measure approach, however, is more efficient compare to reliability index approach in terms of the convergence rate and iterations needed.

• Journal of Korea Multimedia Society
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• v.22 no.11
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• pp.1259-1268
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• 2019

Recently, Communication media have been developed for the underwater communication in underwater environments where the underwater communication failures occur frequently. Although the underwater communication by one medium is not stable due to the influence of the underwater environment, the use of various communication media can complement each other and so this makes the underwater communication more stable. For this reason, this paper proposes approaches to the design and implementation of integrated MAC for complementing individual unstable underwater communications. In addition this paper presents the comparison and analysis on each of the proposed approaches so to be able to provide guidelines to designers and implementers of integrated MAC.