• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.41-48
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• 2011

In order to detect driver's state in a driver safety system, both overt and covert measures such as driving performance, visual attention, physiological arousal and traffic situation should be collected and interpreted in the driving context. In this paper, we suggest a vehicle monitoring system that provides multimodal information on a broad set of measures simultaneously collected from multiple domains including driver, vehicle and road environment using an elaborate timer equipped as a soft synchronization mechanism. Using a master timer that records key values from various modules with the same master time of short and precise interval, the monitoring system provides more accurate context awareness through synchronized data at any given time. This paper also discusses the data collected from nine young drivers performing a cognitive secondary task through this system while driving.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.40-49
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• 2015

PicoCast is a recently proposed short-range wireless communications technology that supports both low rate sensor/control data and high speed data such as voice and video traffic in the personal space, defined by the user-centric space of radius tens of meters, with one unified protocol. When the users are in the same area, personal spaces defined by each user may overlap. Since these PicoCast piconets may simultaneously operate, mutual interference is unavoidable. It is necessary to investigate the effect of mutual interference on data transmission and to conduct research on minimizing the interference among PicoCast devices. In this paper we analyze the effect of mutual interference between PicoCast piconets based on data throughput using OPNET network simulator. We have implemented the PicoCast protocol and measured the average throughput and packet loss rate.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.9 s.351
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• pp.88-98
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• 2006

VANET has several different characteristics from MANET such as high mobility of nodes and frequent change of node density and network topology. Due to these characteristics, the network topology based protocol, often used in MANET, can not be applied to VANET. In this paper, we propose an emergency warning message broadcast protocol using range based relay node selecting algorithm which determines the minimal waiting time spent by a given node before rebroadcasting the received warning message. Because the time is randomly calculated based on the distance between sender node and receiver node, a node chosen as a relay node is assured to have a minimal waiting time, even though it is not located at the border of radio transmission range. The proposed emergency warning message broadcast protocol has low network traffic because it does not need to exchange control messages for message broadcasting. In addition, it can reduce End-to-End delay under circumstances of low node density and short transmission range in VANET.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.43-50
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• 2011

The monitoring system for link travel speed using taxi probe is one of key sub-systems of ITS. Link travel speed collected by taxi probe has been widely employed for both monitoring the traffic states of urban road network and providing real-time travel time information. When sample size of taxi probe is small and link travel time is longer than a length of time interval to collect travel speed data, and in turn the missing state is inevitable. Under this missing state, link travel speed data is real-timely not collected. This missing state changes from single to multiple time intervals. Existing single interval prediction techniques can not generate multiple future states. For this reason, it is necessary to replace multiple missing states with the estimations generated by multi-interval prediction method. In this study, a multi-interval prediction method to generate the speed estimations of single and multiple future time step is introduced overcoming the shortcomings of short-term techniques. The model is developed based on Non-Parametric Regression (NPR), and outperformed single-interval prediction methods in terms of prediction accuracy in spite of multi-interval prediction scheme.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.126-129
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• 2007

In order to ruduce traffic-jam, it is requested to extend road. As a result, the construction of tunnels is inevitable considering our mountatinous topography. In tunnel construction work, major contamination materials occur from rock drilling, blasting rock, rock transporting, and short-creat. After rock blasting, a very high concentration of particles over $5000{\mu}g/m^3$ is maintained for 4 h when air is supplied by pans, by which the construction work has to be delayed at least 30 min. Although dry dust collectors are used, the effective operation time span is limited to 3 h. In this work, the behavior of particles in air and use of particle removal instruments are investigated. As a result, it was important to compare efficiencies of dry and hydro dust collectors.

• Archives of Reconstructive Microsurgery
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• v.9 no.1
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• pp.62-67
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• 2000

Recently, the incidence of pressure sore has been increased, due to increased number of patients with central nervous system injuries after traffic and industrial accidents or with long term loss of consciousness due to drug intoxication. The management of sacral pressure sore has been improved through the development of myocutaneous flap. However, sacrifice of the deep muscle cause some problems such as intraoperative bleeding, functional disabilities of donor site and further limitation of reconstruction for recurrent pressure sores in paraplegic patients. The development of perforator-based island skin flap introduce a new treatment modality for sacral pressure sores. We used perforator-based island skin flap in 15 cases with reasonable result from January 1998 to February 2000. This flap has a many advantages such as no significant sacrifice of the gluteus maximus muscle, wide rotation arc, reliable blood flow of the perforator, short elevation time for the flap, and no post-operative hindrance to walking in patients who are not paraplegic. There was no significant complication without significant sequelae and donor sites could be repaired primarily.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.73-81
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• 2011

The WBAN(Wireless Body Area Network) technology is a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. The The WBAN servides consists of both medical and non-medical applications. The medical application service uses the sensor that transfer the periodic traffic and have different data rates. It uses GTS method to guarantee QoS. In this paper, a new method is proposed, which are suitable design for MAC Protocol. Firstly, MAC frame structure and a primitive based on the WBAN are proposed. Secondly, we proposed the GTS algorithm improved the channel utilization based on the WFQ(Weighted Fair Queuing). The proposed scheduling method is improved channel utilization compared with i-Game(Round Robin scheduling method).

• Journal of the Korean Society of Clothing and Textiles
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• v.8 no.3
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• pp.31-42
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• 1984

This paper is a research on the origins and the developing process of $Dan-Ry\={o}ng$ centering on the change of its form. From the beginning of A. D era Central Asia had played the important role of a traffic route connecting China and its western adjacent world. Through this route $Dan-Ry\={o}ng$ was introduced into China (South-North Dynasty era). The form of $Dan-Ry\={o}ng$ in early period was Ban-Gum-Po (Open-collared costume that turn down the collar to the outside), and it could be worn close-collared or open-collared. From the fact that the people who wore $Dan-Ry\={o}ng$ in early period were mainly Iranian and that it was also worn by lower class like a waiting maid, it can be said that $Dan-Ry\={o}ng$ was not the costume of Han race. In early period the motif of the inside of collar was Persian style, and the people of central Asia was mostif Iranian. In short, $Dan-Ry\={o}ng$ was the costum of the people lived in the adjacent world west of China, particulary Iranians. The form of $Dan-Ry\={o}ng$ changed from Ho-Bok to Ban-Gum-Po owing to the differences in climate. In conclusion, $Dan-Ry\={o}ng$ originated in Ho-Bok ana was introduced into the world west of china by the movement of Horrse-riding Race. Then its form was changed owing to the factors like climate, natural and cultural features, and consepuently it was introduced into China by way of Centeral Asia. In China it was settled as $Dan-Ry\={o}ng$ through the ages of T'ang dynasty, Sung dynasty, Ming dynasty.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1297-1307
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• 2013

Several multi-hop applications developed for vehicular ad hoc networks use broadcast as a means to either discover nearby neighbors or disseminate useful traffic information to othet vehicles located within a certain geographical area. However, the conventional broadcast mechanism may lead to the so-called broadcast storm problem, a scenario in which there is a high level of contention and collision at the link layer due to an excessive number of broadcast packets. To solve broadcast storm problem, we propose an RPB-MACn-based LV-CAST that is a vehicular broadcast algorithm for disseminating safety-related emergency message. The proposed LV-CAST identifies the last node within transmission range by computing the distance extending on 1 hop from the sending node of an emergency message to the next node of receiving node of the emergency message, and the last node only re-broadcasts the emergency message. The performance of LV-CAST is evaluated through simulation and compared with other message dissemination algorithms.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.421-429
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• 2018

While IoT device sensing data or financial transaction data is transmitted in real time, huge data traffic is generated in processing it. This huge data can be effectively compressed or transmitted using universal code, which is a real-time lossless compressor. In this paper, we propose our BL-beta code, which is newly developed universal code for compressing stock trading data, which the maximum range of measured values is difficult to predict and is generated within a relatively constant range over a very short period of time. For compressing real-time stock trading data, Compared with the fixed length bit transmission, the compression efficiency is at least 49.5% higher than that of the fixed length bit transmission, and the compression transmission performance is 16.6% better than the Exponential Golomb code.