• Advances in aircraft and spacecraft science
• /
• v.5 no.4
• /
• pp.431-444
• /
• 2018

Numerical simulations have been conducted to study the unstart/restart characteristics of an over-under turbine-based combined-cycle propulsion system (TBCC) inlet during the inlet transition phase. A dual-solution area exists according to the Kantrowitz theory, in which the inlet states may be different even with the same input parameters. The entire transition process was divided into five stages and the unstart/restart hysteresis loop for each stage was also obtained. These loops construct a hysteresis surface which separates the operating space of the engine into three parts: in which a) inlet can maintain a started state; b) inlet keeps an unstarted state; c) inlet state depends on its initial state. During the transition, the operation of the engine follows a certain order with different backpressures and splitter angles, namely control route, which may result in disparate inlet states. Nine control routes with different backpressures and transition stages were designed to illuminate the route-dependent behavior of the inlet. The control routes operating towards the unstart boundary can make the inlet transit from a started state into an unstarted one. But operating backward the same route cannot make the inlet restart, additional effort should be made.

• Journal of Digital Contents Society
• /
• v.8 no.2
• /
• pp.129-139
• /
• 2007

The past interactive art was only attempted through interdisciplinary study of art and science. As it goes to the digital age, however, the artistic methods based on digital technology have been gradually increasing in combination with other media in various ways. This paper analyzes how spectators' individual selection of viewing-route increases the interaction between spectators and interactive art work by focusing on $\ulcorner$Meta 4Saisons$\lrcorner$. In the process of route selection, each spectator selects his/her own viewing-route almost different from the others', respectively. This individual viewing-route makes each spectator placed in a position of individual interaction, thus leading him/her to the experience of various feelings through the act of immersing in the interactive art interface.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.72-75
• /
• 2005

Uncertainty of objects in Moving Object Database is a coherent property. It has been discussed in a lot of researches on modelling and query processing. The previous studies assume that uncertain future time is determined through utilizing recent speed and direction of vehicles. This method is simple and useful for estimating the time of the near future location. However, it is not appropriate when we estimate the time of the far future location. Therefore, in this paper, we propose a concept of planned route. It is used to estimate uncertain future time, which has to be located at a given point. If the route of an object is planned beforehand its locations are uncertainly distributed near that route. By a simple projection operation, the probability that a location lies in the planned route is increased. Moreover, we identify the future time of an object based on the speed for passing the route, which is offered via a website.

• The Journal of the Korea Contents Association
• /
• v.16 no.9
• /
• pp.12-21
• /
• 2016

The emergency evacuation support system supports evacuation assistance when an urgent disaster occurs. We have implemented evacuation route search algorithm to assist people's escape when a disaster occurs such as fires or terrorism in the building. The algorithm will guide the escape route at the fastest emergency exit of each region at the emergency state. The algorithm calculates the escape route by applying the weighting factor of age groups and population density around the emergency exit and of other regions. So the system helps escape to bypass the crowded emergency exit and the disaster area, and reduces the congestion of emergency exit and overloading of evacuation route.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.04a
• /
• pp.144-148
• /
• 2001

A geophysical and geochemical study was performed to verify the depth of landfill as well as the horizontal/vertical distribution of leachate at the landfill site located in Gongju. The electrical resistivity, with dipole-dipole array and dipole spacing of 5m, was applied along the nine survey lines and electromagnetic induction survey was conducted along the perimeter traverse surrounding the landfill. Cations, anions and stable isotope ($\delta$D and $\delta$$^{18}$ O) analyses were performed on about 63 water and leachate samples collected in dry and rainy seasons at 31 sites. The result of electromagnetic induction survey make it possible to derive the potential route of leachate in the past or present. The imaging of processed resistivity field data show that the possible route of leachate doesn't exist except the survey line 7. The weak zone traversing the landfill, however, is revealed by the electrical resistivity imaging, which may be the potential route of leachate toward the deep ground. The geochemical data agree well with geophysical data for deducing possible route of leachate of the site.

• Korean Journal of Logic
• /
• v.18 no.2
• /
• pp.265-289
• /
• 2015

The idea that an effect counterfactually depends on its cause is simple and intuitive. However, this simple idea runs into various difficulties. The active route account, in order to avoid the difficulties, analyzes causation in terms of counterfactual dependence under certain control. In her recent article, Seahwa Kim criticizes Sungsu Kim's earlier attempt to defend the active route account from its counterexamples. Her criticisms are convincing, and defenders of the active route account or counterfactual analysis of causation in general need another defense. In response, a two-step defense is proposed. First, the scope of the active route account is restricted to 'proximate' causal relation. Second, a control over factors that are in proximate causal relation is offered to figure out 'distant' causal relation. The result is that with proper control, an effect indeed counterfactually depends on its cause.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1741-1745
• /
• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we proposes and describes a developed program which required to change AutoCAD files to wiring diagrams, to generate them to data of tracks, to identify errors of those data, to construct the structure of necessary resource(s) for sub-systems of a train control system, and to provide simulations of data structure.

• Journal of Navigation and Port Research
• /
• v.42 no.5
• /
• pp.331-340
• /
• 2018

Shipping containers promote rapid development of the transport industry, and generate economic and social value. However, problems often occur due to imbalance in dynamics between exports and imports, container relocation, traffic congestion, and general shipping network designs. So, efficient and cost-effective cargo management has become crucial for the Jeju Island - Mokpo container route (JMCR) in South Korea. Dozens of recent studies reveal that collapsible or foldable containers, may become an innovative solution to problematic issues within the shipping industry. The major purpose of this study is to discuss conditions required for successful commercial application of foldable containers, based on a cost-benefit analysis precisely for the JMCR. Findings reveal usage of foldable containers can be cost-effective, if containers make a "FULL<->EMPTY" route. To the contrary, a "FULL<->FULL" route can drastically increase expenditure. However, economic analysis of actual figures for 2010-2015 indicate that benefits for Mokpo - Jeju direction are significant to cover losses on the Jeju - Mokpo line. Seasonal patterns and mixing percentages of foldable and standard containers on the route, may also produce cost-effective solutions. Sensitivity analysis reveals that benefits from using foldable containers, depend mostly on empty container shares in addition to various extra costs.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.9
• /
• pp.4271-4294
• /
• 2018

Communication cost is the most important factor in Wireless Sensor Networks (WSNs), as exchanging control keying messages consumes a large amount of energy from the constituent sensor nodes. Time-based Dynamic Keying and En-Route Filtering (TICK) can reduce the communication costs by utilizing local time values of the en-route nodes to generate one-time dynamic keys that are used to encrypt reports in a manner that further avoids the regular keying or re-keying of messages. Although TICK is more energy efficient, it employs no re-encryption operation strategy that cannot determine whether a healthy report might be considered as malicious if the clock drift between the source node and the forwarding node is too large. Secure SOurce-BAsed Loose Synchronization (SOBAS) employs a selective encryption en-route in which fixed nodes are selected to re-encrypt the data. Therefore, the selection of encryption nodes is non-adaptive, and the dynamic network conditions (i.e., The residual energy of en-route nodes, hop count, and false positive rate) are also not focused in SOBAS. We propose an energy efficient selection of re-encryption nodes based on fuzzy logic. Simulation results indicate that the proposed method achieves better energy conservation at the en-route nodes along the path when compared to TICK and SOBAS.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.3
• /
• pp.369-374
• /
• 2005

Currently, ECDIS and GPS plotters are much used as equipment providing operators with route information, but they do not have any function of automatic route creation and route explanation, so available for only experienced operators. Especially, the present situation is that no study is made of the automatic route creation and route explanation using ENC for ECDIS, substitution system of paper chart. ENC is the electronic navigation chart that is produced using S-52, 5-57 standard format required by IHO. In this paper, an Navigation Guiding System(NGS) is proposed to generate an optimal route where ENC and GPS data is fusioned including the wind direction and speed of an anemometer. The proposed system was testified by a simulation, and its effectiveness was verified.