• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.209-216
• /
• 2004

In A bridge which connects Mokpo North Harbor and Com Island is going to be constructed until 2009. For the bridges being built in the navigable water area, it is indispensible to carry out vessel traffic safety assessment from the viewpoint of shiphandlers, however, there exist no specific guidelines for the necessary conditions whim the bridge designers can rely on. In this paper, traffic safety assessment procedures for the layout of the bridge is briefly introduced, and the conditions whim should be taken into account at the initial design stage of the bridge is surveyed. For the safety assessment of the bridge design, ship navigation simulations, such as RTS(real time simulation} and FTS(fast time simulation), are carried out, the results of which are statistically analysed to estimate the probability of collision between the ship and the pier of the bridge.

• The Journal of the Korea Contents Association
• /
• v.12 no.7
• /
• pp.94-101
• /
• 2012

Design reflects the time and cultural trends and thus can have different symbolic significance and functions depending on the perspective. While this is evident, corporations still insist that designers achieve viewers' complete understanding and satisfaction in their designs. Also, they refuse to accept the designers' interpretation on the grounds that they are subjective and incomplete interpretations even when in fact they are of superior intellectual standard. This problem is also found among the designers dealing with the clients. Thus, as long as all they are willing to accept is the fallibility of each other, the clash between designers and users is inevitable. To solve these problems, we need to have more objective and logical framework for achieving collective understanding on the interpretation of designs and symbols from the very stage of their development. The graphic design is a tangible product that represents the cultural phenomenon and needs to be interpreted as visual symbols. This makes the graphic design a semiological subject. Thus, a semiological approach will enable more analytical interpretations of polysemy of visual symbols. In this light, this study seeks to apply a semiological approach to suggest criteria for interpreting graphic designs as symbols. The criteria will serve as a useful tool for rational evaluation as well as strategic design development.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.17 no.2
• /
• pp.179-185
• /
• 2011

A marine collision accident occurred at the Jin-do water way. A barge loaded with heavy equipment of Power Generation Plant was being towed at its side by two tugs "A" and "B" from Byeg-pa harbour to the designated position to be used for power generation plant near Jin-do bridge. The Power Generation Plant was 40-meters high loaded atop the barge. When the "tugs and tow" were approaching the Jin-do the bridge, the two towing tugs lost maneuvering control of the barge and it went off-course, hit first the waterway embankment and finally struck the lower part of bridge's span and post musing the barge to capsize and sunk its cargo into the sea. The bridge also suffered damages where the top of the Plant struck At the time of the accident, there was a strong tidal current at the waterway. This paper calculates the safe towing force of barges with heavy loads when traversing in a strong tidal current situation in narrow waterway.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.11
• /
• pp.73-82
• /
• 2011

As a demand of IP based packet service is increasing, transport network is evolving from circuit based transport technology using TDM to Ethernet based packet transport technology. In this paper we introduce packet transport network based on PBB-TE and MPLS-TP and propose a quality of service(QoS) management scheme to satisfy various user requirements in packet transport network. The proposed flow-based QoS management scheme guarantees that per-flow bandwidth control satisfies the predefined QoS requirement perfectly under bandwidth congestion condition by using perflow and per-PTL tunnel management. In order to evaluate the proposed scheme we defined flow and PTL tunnel per input frame and configured QoS parameters for each flow and PTL tunnel respectively. Simulation was done by using OPNET modeler 16.0 version.

• Journal of Navigation and Port Research
• /
• v.28 no.8
• /
• pp.735-743
• /
• 2004

A bridge which connects Mokpo North Harbor and Goha Island is going to be constructed until 2009. For the bridges being built in the navigable water area, it is indispensible to carry out vessel traffic safety assessment from the viewpoint of shiphandlers, however, there exist no specific guidelines for the necessary conditions which the bridge designers can rely on. In this paper, traffic safety assessment procedures for the layout of the bridge are briefly introduced, and the conditions which should be taken into account at the initial design stage of the bridge are surveyed For the safety assessment of the bridge design, ship navigation simulations, such as RTS( real time simulation) and FTS(fast time simulation), are carried out, the results of which are statistically analysed to estimate the probability of collision between the ship and the pier of the bridge.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.10
• /
• pp.1860-1866
• /
• 2016

Helicopter-related collision accidents with structures mostly occur at landing, especially in a limited visibility environment, which necessitates some secondary equipment like a radar that can generate stationary clutter image. In this paper, we propose an algorithm that makes an image of stationary ground clutter in two dimensional range and azimuth angle domain. We present a mathematical model for the received signals from each clutter patch in the iso range ring and analyze their clutter and Doppler characteristics, assuming that a helicopter-borne radar has a rotational antenna. We propose a filter structure, which suppresses side lobe signal components while extracting a main lobe signal component, and suggest a solution for a problem stemmed from the filtering process. Finally, by conducting a simulation we show the performance of the suggested imaging algorithm on a two dimensional virtual scenario of the topographic clutter.

• The KIPS Transactions:PartC
• /
• v.16C no.1
• /
• pp.133-142
• /
• 2009

This paper proposes an analytical performance model of IEEE 802.15.4 in the presence of hidden nodes. Conventional 802.15.4 mathematical models assume ideal situations where every node can detect the transmission signal of every other nodes different from the realistic environments. Since nodes can be randomly located in real environments so that some nodes' presence is hidden from other ones, this assumption leads to wrong performance evaluation of 802.15.4. For solving this problem, we develop an extended performance model which combines the traditional 802.15.4 performance model with one for accounting the presence of hidden nodes. The extended model predicts the rapid performance degradation of 802.15.4 due to the small number of hidden nodes. The performance, for example, degrades by 62% at maximum when 5% of the total nodes are hidden. These predictions are confirmed to be equal to those of ns-2 simulations by less than 6% difference.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.2
• /
• pp.165-171
• /
• 2013

WAVE(Wireless Access in Vehicular Environments) is a representative V2V communication protocol and its standards of MAC and PHY parts except for security were published. In order to control traffic flow and ensure driver's safety using V2V communication, various projects are conducting. In particular, safety application has been researched. Therefore, in this paper, we designed the safety application algorithm, which informs a driver of the dangerous status when driver tries to turn left in an intersection and we also implemented the algorithm. Proposed algorithm configures a model for a host vehicle and a vehicle coming in opposite lane and in case that there is collision hazard it provides warning message to driver by using HMI. In order to evaluate the proposed algorithm's performance, we configured the test bed using test vehicles and we tested the algorithm on proving ground with the composed test scenarios. As test results, our system showed excellent performance. If the infrastructures for V2I communications are constructed, we will optimize our system more precisely and stably.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.12 no.1 s.24
• /
• pp.61-66
• /
• 2006

It have been known that the probability of occidental happening in towing-barge is higher than that of other merchant vessels. Bemuse the towing-barge is restricted in thier manoeuvring ability due to its towingline. A report from ministry maritime affairs and fisheries said that the rate of collision occident for towing-barge is 40% high than other transport system in sea A number of researches have been carried out to improve the safety policy in the towing-barge sea transportation system by the gorvenment. This study examined the safety status in domestic towing-barge sea transportation system The registration status, safety operational policy and past occidental data were also examined A survey research of experts relating to towing-barge operation also was carried out to fine the detailed of safety status. This study would be applicable to set up safety policy for towing-barge marine transportation system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.7
• /
• pp.752-760
• /
• 2010

This paper investigates the performance of EPCglobal Generation-2(Gen-2) radio frequency identification(RFID) protocol under reader-to-reader interfering environments. We establish a modified discrete-time Markov chain(DTMC) model for the Gen-2 and accordingly obtain quantitative results of query success rate(QSR) and tag identification speed (TIS). Extensive simulations validate our theoretical analysis and demonstrate that the number of tags over 100 has little impact on the performance. TIS linearly decreases by 10 tags/sec/reader as the number of interfering readers increases. Our model for Gen-2 protocol is also useful to study the performance of other RFID protocols.