• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.147-158
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• 2005

Most of the statistical models that real data can be applicable are static in nature, and thus it is not possible to analyze the effect of variations in the real world over time. Usual specification of the models does not produce the length and the time path of the effect even if the effect of an exogenous variation continues for periods of time. In this study, deriving the dynamic inherence from the static structure of the linear model for better utilization, we attempt to apply actual data to compare and analyze the long-run effect of variations in the market variables between the related markets by formulating a simultaneous equation system. Accordingly, it is proved to be possible to obtain efficient analytical results and to derive various useful implications.

• Fire Science and Engineering
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• v.16 no.4
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• pp.20-27
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• 2002

This study in focused on proposing the improvement plans for refuge and fire-fighting facilities in large shopping malls that are radically spreading. The main subjects are as follows. - The refuge measure for large shopping malls - Problems of installing the refuge facilities in stores and the solutions - Problems of installing the incendiary facilities in stores and the solutions - Problems of installing the indoor fire plug in stores and the solutions As result of the study, it has turned out that escape stairs which are set up according to the standard of size in the process of design plan, have to be decided for their amount, position, specification, etc, in consideration of the number of residents. It is also required to tighten a standard of installing a sprinkler instead of lightening the fire-fighting section in stores, considering obstacles due to facilities installed and procurement of the escape path. In addition, it needs to lighten a standard of installing the indoor fire plug, which is voluntarily set up at the store section incase of installing a sprinkler to make a practical fire-fighting facility available.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.1-13
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• 2007

GPS/GIS and RFID technologies have been changing the paradigm af our society toward ubiquitous era. Especially, geographically distributed mobile agents with transporting objects need to be automatically recognizable and traceable under certain conditions. To do this, fundamental theories and technologies are required to specify and verify spatial and temporal behaviors of agents on geographical space. This paper presents a new formal method, called Calculus of Real-Time Distribution, Mobility, and Interaction (CaRDMI), for this purpose. For specification, CaRDMI defines a map, mobile agents with transporting objects. The movement of on agent is represented by a path on the map, consisting of a list of nodes and a list of edges with spatial and temporal constraints. Interactive constraints among agents are represented by synchronization modes on objects at nodes. These constraints are distinguishable features of CaRDMI from other methods. Especially, many-to-many timed synchronization constraints are noticeable. For verification, CaRDMI presents the spatial, temporal and interactive deduction rules and the spatial and temporal equivalence relations.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.355-368
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• 2001

Protocol conformance test is used to promote interoperability of protocol implementatons developed by venders. Non-interopcrability between protocol implementations may be caused by ambiguity and/or misintellJretation of the protocol specifications by vendors. Conventional method on protocol conformance test has been standardized by IS0;IEC JTCI with the purpose of whether a protocol implementation conforms to its specification. However, sometimes the conventional method gives wrong test results because the test is based on static test sequences. This problem is caused by the fact as some failed transitions of a protocol FSM included in test sequences have an effect on the test result of transitions to be tested. In this paper, a new approach called Dynamic Conformance Test Method (DCTM) is proposed to solve this problem. DCTM dynamically selects test sequence durng testing depending on an information showing an alternative path without failed tranistions. As a result, the fault coverage of the DCTM is better than that of the conventional test method. In order to demonstrate the fault coverage of DCTM compared to that of the conventional method. a testing tool is implemented and appied to the TCP protocol.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.97-103
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• 2020

Wireless sensor networks collect and analyze sensing data in a variety of environments without human intervention. The sensor network changes its lifetime depending on routing protocols initially installed. In addition, it is difficult to modify the routing path during operating the network because sensors must consume a lot of energy resource. It is important to measure the network performance through simulation before building the sensor network into the real field. This paper proposes a WSN model for a low-energy adaptive clustering hierarchy protocol using DEVS kernel models. The proposed model is implemented with the sub models (i.e. broadcast model and controlled model) of the kernel model. Experimental results indicate that the broadcast model based WSN model showed lower CPU resource usage and higher message delivery than the broadcast model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.91-103
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• 2009

A cryptographic module (CM) is an implementation of various cryptographic algorithms and functions by means of hardware or software, When a CM is validated or certified under the CM validation program(CMVP), a finite state model(FSM) of the CM should be developed and provided, However, guides or methods of modeling and analysis of a FSM is not well-known, because the guide is occasionally regarded as a proprietary know-how by developers as well as verifiers of the CM. In this paper, we propose a set of guides on modeling and analysis of a FSM, which is needed for validation of a CM under CMVP, and a transition test path generation algorithm, as well as implement a simple modeling tool (CM-Statecharter). A FSM of a CM is modeled by using the Statechart of UML 2.0, Statechart, overcoming weakness of a FSM, is a formal and easy specification model for finite state modeling of a CM.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.409-414
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• 2008

In mobile ad hoc networks, most of on demand routing protocols such as DSR and AODV do not deal with traffic load during the route discovery procedure. To solve the congestion and achieve load balancing, many protocols have been proposed. However, the existing load balancing schemes has only considered avoiding the congested route in the route discovery procedure or finding an alternative route path during a communication session. To mitigate this problem, we have proposed a new scheme which considers the packet bursting mechanism in congested nodes. The proposed packet bursting scheme, which is originally introduced in IEEE 802.11e QoS specification, is to transmit multiple packets right after channel acquisition. Thus, congested nodes can forward buffered packets promptly and minimize bottleneck situation. Each node begins to transmit packets in normal mode whenever its congested status is dissolved. We also propose two threshold values to define exact overloaded status adaptively; one is interface queue length and the other is buffer occupancy time. Through an experimental simulation study, we have compared and contrasted our protocol with normal on demand routing protocols and showed that the proposed scheme is more efficient and effective especially when network traffic is heavily loaded.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.210-220
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• 2005

This paper presents and analyzes laboratory test results of Equalization Digital On-Channel Repeater (EDOCR) using ATSC(Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The EDOCR laboratory test, which is done at CRC(Communications Research Centre) Canada, is classified to receiver test, transmitter test, and synchronization test between transmission and reception frequencies. The receiver part includes feedback signal, random noise, single echo, multi-path ensemble, and NTSC/DTV interference test. The transmitter part includes out-of channel emission, quality of transmitting signal, and phase noise test. By the field test results, the receiver part of the EDOCR eliminates average 5.5 dB of feedback or single echo signal in range of 0 to 11 ${\mu}s$ and has average 18.6 dB at TOV(Threshold of Visibility) under random noise environment. Also, the transmitter part of the EDOCR satisfies the specification of US FCC(Federal Communications Commission), and frequency difference between transmitter and receiver is zero.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.12
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• pp.726-734
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• 2004

This paper presents a facial animation method that enables the user to select a sequence of facial frames from the facial expression space, whose level of details the user can select hierarchically Our system creates the facial expression space from about 2400 captured facial frames. To represent the state of each expression, we use the distance matrix that represents the distance between pairs of feature points on the face. The shortest trajectories are found by dynamic programming. The space of facial expressions is multidimensional. To navigate this space, we visualize the space of expressions in 2D space by using the multidimensional scaling(MDS). But because there are too many facial expressions to select from, the user faces difficulty in navigating the space. So, we visualize the space hierarchically. To partition the space into a hierarchy of subspaces, we use fuzzy clustering. In the beginning, the system creates about 10 clusters from the space of 2400 facial expressions. Every tine the level increases, the system doubles the number of clusters. The cluster centers are displayed on 2D screen and are used as candidate key frames for key frame animation. The user selects new key frames along the navigation path of the previous level. At the maximum level, the user completes key frame specification. We let animators use the system to create example animations, and evaluate the system based on the results.