• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2095-2100
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• 2012

In this paper, we propose the channel sounding scheme which is made for ideal communication between some application as well as the short distance of high speed data transmission in MIMO-OFDM system for Wireless PAN. This method is able to perceive the duration of the impulse response through the delaying of power delay profile, modeled a power delay profile which has an attenuate characteristic, and obtained the coefficient of channel response by ML (maximum likelihood). Through the amplitudes, phases and delays associated with each multipath component which were acquired from this channel sounding scheme, we can describe the wave propagation characteristics of channels between the transmitter and receiver so that the receiver could enhance not only the reliability but also the ability of communication link. Multi agent system models can be used to analyze the path of the system within any time frame. Further, parameter values can be perturbed to examine how the path of the system changes in response to exogenous shocks.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.72-81
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• 2013

In this paper, we propose the architecture and user interaction mechanism to implement N-Screen services on Multi-Vision System (MVS) that are not supported in existing systems. N-Screen services enable users to control the MVS displays through any of their devices and share contents among MVS displays and user's active-devices with service continuation at any location. We provide N-Screen interactive services on MVS by introducing N-Screen interaction & session management server and agent. Furthermore, we present some examples of the protocols such as application launching, user interaction for service control and visualcasting to support N-Screen services. In addition, we explain the N-Screen service scenarios for providing split sessions on user's active-devices and launching metadata content on any of his devices at any location supported by these protocols. The simulation result demonstrates the feasibility and performance improvement of the proposed visualcasting mechanisms.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.577-588
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• 2017

There are many constraints, both economically and ethically that experimenting human evacuation behavior in situations such as fire. Therefore, the evacuation behavior is simulated based on the existing studies. In recent years, the foundation has been established as computer performance advances, models closer to reality can be studied. In this study, the evacuation time in the subway platform was analyzed from modeling human behavior and smoke propagation in a fire. The evacuation efficiency was also examined by dividing the shape of the subway station platform by the stair position and comparing the evacuation times for each platform. As a result, it was found that the side platform was longer than the island platform by 36.82% more time to evacuation. The shape of the stairs is most advantageous in terms of evacuation form side type platform was 210 seconds and island type platform was 186 seconds, when a fire occurs in the center of the platform. And most favorable in location of evacuation stairs were located at 2/5 point and 4/5 from depending on the step location.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.190-197
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• 2010

The ACR (Access Control Router) of WiBro processes location registration of the Correspondent Node and Home Agent as the Correspondent Node moves between ACRs. Therefore, the location update cost is low compared with MIPv6. However, all packets which are sent and received are sent through the ACR, so as the number of mobile nodes that are managed by the ACR increases, the cost of packet delivery also increases. Therefore, the communication state of the ACR domain remains smooth when the ACR which manages the mobile node in the ACR domain has good performance. However, network delays occur unless the ACR performs well, so the role of the ACR is important. In this paper, we analysis performance of the ACR for efficient realization of the WiBro standard. By using the Deny Probability and the Total Profit of ACR performance and apply it to the Random Walk Mobility model as the mobility model.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.68-78
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• 2006

In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

• Journal of the Korean Institute of Navigation
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• v.24 no.1
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• pp.1-12
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• 2000

The ships over the certain navigation area or her length are required to carry charts under the relevant laws. Charts are indispensible to the ships and fishing vessel, because their crew should know the water depth and location of obstacle in order to avoid danger in the navigation and fishing area. But it was found that many ships do not carry proper charts onboard according to the research marine accidents files of marine accident inquiry agency, and questionnaire survey. Consequently, many ships run aground on the coast and port. This study examined the present status of the coastal ship and the fishing vessels, and explained some problems in the aspect of the covering area, the place, the number of the selling agent and adjoining chart, as well as the geographical and traffic density, the crew on board the ship's characteristics, and so on. In this study we propose the way to solve the problem. firstly, the category of the fishing vessel which should carry the chart on bard under the related laws are required to be lowered to 10 gross tons. Besides a ship inspector should examine if the charts covering the area where to navigate even when the temporary inspection is done are carried on board property. Secondly, the inspection body or the controlling office of ship's entry and departure should check throughly whether the ships concerned carry the chart on board. Thirdly the fishing vessels should used the fishing charts, and the body concerned should train the offices about how to use chart, especiany the difference between Tokyo datum and WGS-84 datum. Fourthly the customized chart such as an atlas like a map, a calenda-type chart, a small chart, as a coated chart needs to be publish for the safety of small ship and fishing vessel. Fifthly, it is advisable to draw a recommended course in the route where the coastal navigate mainly and in the narrow channel, The adjoining area should be improved, as well as the qualify of the chart paper. Sixthly, publication of additional new chart in the southern part of East Sea, the eastern part of South Sea, the western part of South Sea and middle part of Yellow Sea near Incheon port should be thought over. Seventhly, the number of chart selling agent should be increased for the sake of purchaser in proportion to the number of port, and small correction of charts in selling agent must be carried out completely.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.195-200
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• 2011

KS F 2782 (for shotcrete accelerators) standard cross-section of tunnel construction or repair is a reinforcement used in the field of shotcrete accelerators as a criterion in assessing shotcrete performance. Thus, KS F 2782 by standard accelerator will determine the nature of the product of concrete accelerators that will be used to record variations in the product roles, through determination of the quality of the experimental method to identify only the quality of the many variables that exist. This evaluation standard has so far distinguished accelerator products in indoor experiments that do not meet quality standards but were mostly for an on-site accelerator mixed with the shotcrete after being quite satisfied with the level of quality in a certain number of products. This observation is derived from the results of an indoor experiment considered to verify whether the site is suitable for indoor experiments, and whether its actual location in the city is relevant to the accelerator quality, to find a way to test if it fits. This study centers on the material conditions of the shotcrete accelerator and a variety of experimental results, and used the Gilmore needle to compare the compressive strength and KS F 2782 specification of the accelerator as a means to ensure product quality conformity analysis and for further research experiments. In conclusion, a portion of KS F 2782 standard that fixes the problems that can be resolved from the ground up as a whole is not a review for the domestic reality. As an indoor experiment to ensure uniformity in the field when applied in a sufficient correlation, complement must be in place.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1319-1327
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• 2008

There has been a lot of research on the creation of emergency evacuation simulators for analyzing the evacuation behaviors. However, it is remarkable that there are very few research on the characteristic of the behavior pattern in crowing, especially the evacuation time delay caused by the collisions and falling-downs, etc. In addition, it is necessary to point out the lack of the research on specifying the location where the collisions and the falling-downs take places. This research aims at creating an emergency evacuation simulator which takes the characteristic of the behavior pattern in crowing - collisions, falling downs, etc - into account. We are also hoping that it will be possible to provide more accurate and useful data ffr emergency evacuation system design through using this simulator.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.43-45
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• 2006

Unlike RNA interference, whose usage is limited to eukaryotic cells, Peptide Nucleic Acid (PNA) technique is applicable to both eukaryotic and prokaryotic cells. PNA has been proven to be an effective agent for blocking gene expressions and has several advantages over other antisense techniques. Here we developed a parallel computing software that provides the ideal sequences to design PNA oligos to prevent any off-target effects. We applied a new approach in our location-finding algorithm that finds a target gene from the whole genome sequence. Message Passing Interface (MPI) was used to perform parallel computing in order to reduce the calculation time. The software will help biologists design more accurate and effective antisense PNA by minimizing the chance of off-target effects.

• Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.125-129
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• 2013

Vibrio ichthyoenteri is a facultatively anaerobic gram-negative bacterium with straight or slightly curved rod morphology. The bacterium is an etiological agent of bacterial enteritis of Olive flounder Paralichthys olivaceus. Only a handful of studies, using a limited number of isolates, have investigated the phenotypic and genetic characteristics of V. ichthyoenteri. We isolated 40 V. ichthyoenteri strains, identified based on the 16S rRNA gene sequence, from the diseased flounder larvae and investigated the API 20E and ZYM profiles. The isolates exhibited highly divergent phenotypic characteristics regardless of sampling time point and location, and fish age. Essential enzymes produced by V. ichthyoenteri seemed to be alkaline phosphatase, leucine arylamidase, and N-acetyl-${\beta}$-glucosaminidase. This study reveals a much greater enzymatic and biochemical phenotype diversity than has been evident to date. These results suggest that a given population of V. ichthyoenteri could be heterogeneous in terms of its phenotypic characteristics.