• Journal of the Korea Computer Graphics Society
• /
• v.8 no.2
• /
• pp.31-38
• /
• 2002

This paper presents a method for real-time 3D Sumi-e rendering us ing normal graphics hardware. Sumi-e is one of the traditional oriental painting styles. Most research on Sumi-e paintings has focused on 2D or :2.5D Sumi-e brushwork simulation. On these systems. complicated user's hand drawing is required to generate the image of Sumi-e effects. and it can render the 2D or 2.5D Sumi-e images only. We present an automated rendering system for 3D image of Sumi-e painting. It uses 3D common object as an input data and does not need any additional input of user brushwork. Especially for the real-time rendering. hardware-accelerated algorithm for Sumi-e rendering is newly suggested in our system. It is designed with efficiency for customer level graphics hard ware. The results of this paper show that the features of traditional Sumi-e painting are successfully modeled and that 3D Sumi-e painting is rendered in real-time effectively.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.5
• /
• pp.477-481
• /
• 2008

Place recognition is necessary for a mobile user to be provided with place-dependent information. This paper proposes real-time video based place recognition system that identifies users' current place while moving in the building. As for the feature extraction of a scene, there have been existing methods based on global feature analysis that has drawback of sensitive-ness for the case of partial occlusion and noises. There have also been local feature based methods that usually attempted object recognition which seemed hard to be applied in real-time system because of high computational cost. On the other hand, researches using statistical methods such as HMM(hidden Markov models) or bayesian networks have been used to derive place recognition result from the feature data. The former is, however, not practical because it requires huge amounts of efforts to gather the training data while the latter usually depends on object recognition only. This paper proposes a combined approach of global and local feature analysis for feature extraction to complement both approaches' drawbacks. The proposed method is applied to a mobile information system and shows real-time performance with competitive recognition result.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37A no.12
• /
• pp.1106-1114
• /
• 2012

In order to provide high data rate and real time services under maritime environment, link-level performance of ship ad-hoc network (SANET) based on 3GPP LTE and IEEE 802.11p (WAVE) specifications are investigated and discussed in this paper. The measured maritime channel, whose delay spread is longer than the length of guard interval (GI) of both 3GPP LTE and IEEE 802.11p specifications, is adopted for the link-level simulations. For the purpose of eliminating inter-symbol interference (ISI) due to insufficient GI length, double antenna pattern (DAP) scheme and advanced time-domain decision-feedback equalizer (DFE) are proposed for LTE and WAVE systems, respectively. The proposed DFE removes the ISI in a same manner as the residual inter-symbol interference cancellation (RISIC) algorithm, but the inter-carrier interference (ICI) is reduced via cyclicity removal instead of cyclicity restoration used in the RISIC algorithm. Compared with existing schemes, our proposed DFE is a robust technique to overcome the severe ISI channel which has a comparatively large delay spread. Based on simulation results, not only comparisons between systems are discussed, but also some reformative suggestions are given.

• Journal of Korea Multimedia Society
• /
• v.18 no.6
• /
• pp.723-733
• /
• 2015

High availability is of utmost importance in real-time embedded systems. Temporary failures due to software or hardware faults should not result in a system crash. To achieve high availability, embedded systems typically use a combination of hardware and software techniques. A watchdog timer is a hardware component in embedded microprocessors that can be used to automatically reset the processor if software anomalies are detected. The embedded system relies on a single watchdog timer, however, can be permanently disabled if the timer is not properly configured, e.g. falling into an indefinite loop. STM32F4 provides two different types of watchdog timer in terms of timing accuracy and robustness. In this paper, we propose a hybrid approach, called long-tail watchdog timer, to utilize both timers to achieve self-reliance in embedded systems even though one of timers fails. Experimental results confirm that the proposed approach successfully handles various failure scenarios and present performance comparisons between single watchdog timer and hybrid approach in terms of configuration parameters of watchdog timers in STM32F4, counter value and window size.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.444-448
• /
• 2005

This paper presents a developing procedure of the CAN-based real-time simulator for car body control, aiming at replacing the actual W/H (Wiring Harness) and J/B(Junction Box) couple eventually. The CAN protocol, as one kind of field-bus communication, defines the lowest 2 layers of the ISO/OSI standard, namely, the physical layer(PL) and the data link layer(DLL), for which the CSMA/NBA protocol is generally adopted. For CPU, two PIC18Fxx8x's are used because of their built-in integration of CAN controller, large internal FLASH memory (48K or 64K), and their costs. To control J/B's and actuators, 2 controller boards are separately implemented, between which CAN lines communicate through CAN transceivers MCP255. A power motor for washing windshield, 1 door lock motor, and 6 blink lamps are chosen for actuators of the simulator for the first stage. For the software architecture, a polling method is used for the fast global response time despite its slow individual response time. To improve the individual response time and to escape from some eventual trapped-function loops, High/Low ports of the CPU are simply used, which increases the stability of the actuator modules. The experimental test shows generally satisfactory results in normal transmitting / receiving function and message trace function. This simulator based on CAN shows a promising usefulness of lighter, more reliable and intelligent distributed body control approach than the conventional W/H and J/B couple. Another advantage of this approach lies in the distributed control itself, which gives better performance in hard real-time computing than centralized one, and in the ability of integrating different modules through CAN.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.21 no.48
• /
• pp.299-310
• /
• 1998

Actually mixed assembly line is mixed with open and close type workstation. This workstation is called hybridworkstation. The propose of this paper is to determine the sequencing of model that minimize line length for actual(hybridworkstation) mixed model assembly line. we developed three mathematical formulation of the problem to minimize the overall length of a line with hybrid station. Mathematical formulation classified model by operato schedule. Mixed model assembly line is combination program and NP-hard program. Thus computation time is often a critical factor in choosing a method of determining the sequence. This study suggests a tabu search technique which can provide a near optimal solution in real time and use the hill climbing heuristic method for selecting initial solution. Modified tabu search method is compared with MIP(Mixed Integer Program). Numerical results are reported to demonstrate the efficiency of the method.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.5
• /
• pp.191-198
• /
• 2013

It is required to transmit data through shorter path between sensor and base node for real time intrusion detection in wireless sensor networks (WSN) with a mobile base node. Because minimum Wiener index spanning tree (MWST) based routing approach guarantees lower average hop count than that of minimum spanning tree (MST) based routing method in WSN, it is known that MWST based routing is appropriate for real time intrusion detection. However, the minimum Wiener index spanning tree problem which aims to find a spanning tree which has the minimum Wiener index from a given weighted graph was proved to be a NP-hard. And owing to its high dependency on certain nodes, minimum Wiener index tree based routing method has a shorter network lifetime than that of minimum spanning tree based routing method. In this paper, we propose a multi-objective ant colony optimization algorithm to tackle these problems, so that it can be used to detect intrusion in real time in wireless sensor networks with a mobile base node. And we compare the results of our proposed method with MST based routing and MWST based routing in respect to average hop count, network energy consumption and network lifetime by simulation.

• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.11
• /
• pp.1333-1343
• /
• 1999

경성 실시간 시스템의 태스크들은 논리적으로 올바른 결과를 산출해야 하지만 또한 각자의 시간 제한 조건을 만족하여야 한다. 간격제한 스케줄링은 시간 제한 조건이 시간 간격 제한으로 주어지는 실시간 태스크들을 스케줄하기 위하여 도입되었다. 간격제한 스케줄링에서의 각 태스크들은 시간 간격 제한 조건을 갖는데, 이것은 태스크의 두 연속적인 수행의 종료시간에 대해 제한을 가한다. 다시 말해, 간격제한 스케줄링에서의 각 태스크 수행은 그 태스크의 직전 수행 완료 시간으로부터 발생하는 데드라인을 갖는다. 간격제한 태스크 스케줄링에 관한 많은 연구는 단순화 방법에 기초하고 있다. 그러나, 우리는 이 논문에서 단순화 방법을 사용하지 않고, 정적 우선순위 및 정적 분리 제한 정책을 채용한 새로운 간격제한 태스크 스케줄링 방법을 제안한다. 제안된 정적 할당 방법은 스케줄링 분석 및 구현을 매우 간단히 할 수 있으며, 또한 스케줄러의 실행시간 오버헤드를 줄일 수 있다.Abstract Tasks in hard real-time systems must not only be logically correct but also meet their timing constraints. The distance-constrained scheduling has been introduced to schedule real-time tasks whose timing constraints are characterized by temporal distance constraints. Each task in the distance-constrained scheduling has a temporal distance constraint which imposes restriction on the finishing times of two consecutive executions of the task. Thus, each execution of a task in the distance-constrained scheduling has a deadline relative to the finishing time of the previous execution of the task.Much work on the distance-constrained task scheduling has been based on the reduction technique. In this paper, we propose a new scheme for the distance-constrained task scheduling which does not use the reduction technique but adopts static priority and static separation constraint assignment policy. We show that our static assignment approach can simplify the scheduling analysis and its implementation, and can also reduce the run-time overhead of the scheduler.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.41 no.3
• /
• pp.11-16
• /
• 2004

Recently, collaborative works are increased more and more over the distributed heterogeneous computing environments. The availability of high-speed wide-area networks has also enabled collaborative multimedia applications such as video conferencing, distributed interactive simulation and collaborative visualization. Distributed high performance computing and collaborative multimedia applications, it is extremely important to efficiently perform group communication over a heterogeneous network. Typical group communication patterns are broadcast and Multicast. Heuristic algorithms such as FEF, ECEF, look-ahead make up the message transmission tree for the broadcast and multicast over the distributed heterogeneous systems. But, there are some shortcomings because these select the optimal solution at each step, it may not be reached to the global optimum In this paper, we propose a new heuristic algerian that constructs tree for efficiently collective communication over the previous heterogeneous communication model which has heterogenity in both node and network. The previous heuristic algorithms my result in a locally optimal solution, so we present more reasonable and available criterion for choosing edge. Through the performance evaluation over the various communication cost, improved heuristic algorithm we proposed have less completion time than previous algorithms have, especially less time complexity than look-ahead approach.

• The Journal of Korea Robotics Society
• /
• v.12 no.3
• /
• pp.313-321
• /
• 2017

One of the most frequently performed tasks in human-robot interaction (HRI), intelligent vehicles, and security systems is face related applications such as face recognition, facial expression recognition, driver state monitoring, and gaze estimation. In these applications, accurate head pose estimation is an important issue. However, conventional methods have been lacking in accuracy, robustness or processing speed in practical use. In this paper, we propose a novel method for estimating head pose with a monocular camera. The proposed algorithm is based on a deep neural network for multi-task learning using a small grayscale image. This network jointly detects multi-view faces and estimates head pose in hard environmental conditions such as illumination change and large pose change. The proposed framework quantitatively and qualitatively outperforms the state-of-the-art method with an average head pose mean error of less than $4.5^{\circ}$ in real-time.