• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2002.11a
• /
• pp.296-303
• /
• 2002

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types or effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs)

• Journal of the Institute of Convergence Signal Processing
• /
• v.20 no.2
• /
• pp.105-110
• /
• 2019

People sleep about one-third of their lives and their sleep time varies according to age. Adult usually sleep 8 hours a day. However, that dose not guarantee good sleep. The cause of this is due to sleep disorders like snoring and sleep apnea. In this paper, the smart pillow for detecting snoring among sleep disorders is investigated. This pillow consists of two microphones located on the left and right side of the pillow. For simple detecting, the snoring signal was converted into the pulse using a peak detection circuit. The decision of the snoring occurrence was by pulse duration. The accuracy of the snoring detection was about 97%. The research results show that the smart pillow can be use to detect the snoring during sleeping.

• Journal of Convergence for Information Technology
• /
• v.10 no.11
• /
• pp.195-201
• /
• 2020

There have been many developments and innovations in the educational environments in line with the rapidly evolving information age. E-Learning is a representative example of this rapid evolution. However, E-Learning is challenging to maintain students' concentration because of the low engagement level and limited interactions between instructors and students. Additionally, instructors have limitations in identifying learners' concentration. This paper proposes a system that can measure E-learning users' concentration levels by detecting the users' eyelid movement and the top of the head. The system recognizes the eyelid and the top of the head and measures the learners' concentration level. Detection of the eyelid and the top of the head triggers an event to assess the learners' concentration level based on the users' response. After this process, the system provides a normalized concentration score to the instructor. Experiments with experimental groups and control groups were conducted to verify and validate the system, and the concentration score showed more than 90% accuracy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.1002-1005
• /
• 2015

Mobile operating systems have been typically classified into Apple and Android. Samsung showed its own new mobile OS developing Tizen based on Linux kernel. Mobile operating system has developed a technology using low-power by itself because of the limitation of capacity of battery, a feature of mobile. Samsung Tizen OS has a low-power technology called Power Manager controling LCD states as users'inputs or time-out events occur. However, if users'input occurs frequently, energy consumption jumped before-and-after users'input because CPU clock is increased rapidly due to overhead increase for frequent LCD state changes. This paper proposes a mechanism to reduce the overhead for LCD state changes, when user's input is frequent, by adding a new state to the Power Manager the current Tizen OS is using. We have implemented the proposed mechanism at Tizen phone kernel layer in this paper and experimented the mechanism according to users' LCD touch inputs. The experiment shows that it is possible to decrease energy by reducing the CPU clock increase according to the frequent user's inputs.

• Journal of the Korean Institute of Gas
• /
• v.11 no.4
• /
• pp.64-72
• /
• 2007

Under the AE methods, the valid condition analysis and evaluation the leak etc, resulted by the AE signal pattern on the bottom plate of ground tank at full. In next more, the gradient of accumulation amplitude distribution analysis and comparison the energy, count, and duration time that noise of EMI signal were removed. EMI signal showed height-energy, count, and duration time, it also appeared great gradient of accumulation distribution. Then, with the pure remaining AE signals cluster analysis and location. It would possibly assume of damage with corrosion. Total cluster 20 and energy showed between the maximum 11,990 and 8,565 which is much lower than above figure and event number showed from 8 to 5. Even when it difficult to certify damage by open, as it is raised higher height-sensitivity and threshold by 60 dB. It would possibly presume of location source more accurately.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.4 s.36
• /
• pp.239-248
• /
• 2005

The reliability and efficiency of network must be considered in the large scale wireless sensor networks. Broadcast method must be used rather than unicast method to enhance the reliability of networks. In recently proposed GRAB (GRAdient Broadcast) can certainly enhance reliability of networks fy using broadcast but its efficiency regarding using energy of network is low due to using only one sink. Hence, the lifetime of networks is reduced. In the paper we propose the scheme of SMSGB (Selective Multi Sink Gradient Broadcast) which uses single sink of multi-sink networks. The broadcast based SMSGB can secure reliability of large scale wireless sensor networks. The SMSGB can also use the network's energy evenly via multi sink distribution. Our experiments show that using SMSGB was reliable as GRAB and it increased the network's lifetime by 18% than using GRAB.

• Journal of Intelligence and Information Systems
• /
• v.16 no.1
• /
• pp.45-56
• /
• 2010

Sensor Networks are composed of many sensor nodes, which are capable of sensing, computing, and communicating with each other, and one or more sink node(s). Sensor networks collect information of various objects' identification and surrounding environment. Due to the limited resources of sensor nodes, use of wireless channel, and the lack of infrastructure, sensor networks are vulnerable to security threats. Most research of sensor networks have focused on how to detect and counter one type of attack. However, in real sensor networks, it is impractical to predict the attack to occur. Additionally, it is possible for multiple attacks to occur in sensor networks. In this paper, we propose the Secure Routing Mechanism to Defend Multiple Attacks in Sensor Networks. The proposed mechanism improves and combines existing security mechanisms, and achieves higher detection rates for single and multiple attacks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.2
• /
• pp.585-588
• /
• 2005

The Presence Agent Server receives user's presence information via PUBLISH request message and let subscribers to know that information. IMPP client has a functions for PUA(presence user agent) as a base operational entity. In some circumstance, the client has both pua and pa logical entities. However presence agent server has take part only of PA. In this paper, we describes the design and implementation that contains modules based configurations and approaches for presence agent server. Also, we describe how we handle each events and database API instruction set.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.3
• /
• pp.606-619
• /
• 1998

In this paper, we have tfesigned and ihlplemented ACE(Application sharing Collaboration Engine) which is pessible an application sharing to collaborate among peoples who are geographically dispersed. The application sharing is a technology whereby two or more users collaborate to share the output of single application running on one computer system to the other users, and to provide input to the applications. We defined ASO(Applicatio!1 Sharing Object) object and its behavior to share applications in real time and ACE processes a sharing using ASO object among the distributed systems. ASO is classified into activateASO, updateASO, inputASO, and controlASO. The each ASO's behavior involves both events which occur at specific moments such as keystrokes and mouse clicks and more persistent status which can be observed at any time such as the image on the screen. The implemented ACE can be applied to the data conferencing, distance education, and project collaboration for engineer in distributed environments.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.24 no.2
• /
• pp.353-371
• /
• 2014

We already have seen many studies and articles about the methodology responding the security risks and threats. But we still have some controversial subjects to be settled. Now, we are living in the era that we should focus on how to use the security systems instead of how to make it. In this point of view, a company need to find out the answer for these questions, which security risks have to be handled in a corporate, which system is better for responding the security threats, and how we can build necessary security architecture in case of developing systems. In this article, we'd like to study on-site scenarios threatening the corporate assets, the limit on dealing with these threats, and how to consolidate the security events and information from enormous assets. Also, we'd like to search for the direction form the actual cases which have shown the desired effect from converging the assets and network informations.