• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.5
• /
• pp.300-310
• /
• 2007

The Session Initiation Protocol (SIP) is one of the major protocols used in call-setup over IP telephony. The SIP-signaled calls use many-sided states according to a request of user. In this paper, we suggest seven states and some events that help developers to design and implement new applications efficiently. And they enable an object-oriented design of the system. If you design the call-setup procedure only by the processing model suggested in RFC 3261 over commercial network, a fatal error may occur in the system because of heavy data traffic or unpredicted exception cases. However, according to the suggested seven states, if they are predefined events in the current system state, the standardized processing routine is executed. Otherwise, they can be processed by the exception routine in system. All event processing routines are designed and implemented using Finite State Machine (FSM).

• The Journal of the Acoustical Society of Korea
• /
• v.17 no.4E
• /
• pp.28-34
• /
• 1998

In most switching system, the processing unit is designed to work efficiently even at relatively high loads, but when the offered traffic exceeds a particular level, the rate of completed calls can fall drastically. A single call handled by the switching system consists of a sequence of events or messages that has to be processed by the control unit. The control unit is not only incapable of handling all of the offered calls, but also its call handling capability can drop as the offered load increases. The real time available for call processing is a critical resource that requires careful management. Therefore, the overloading of this resource must be detected by a subscriber in the from of a dial tone delay or an uncompleted call which is either blocked or mishandled. The subscriber may respond by either dialing prematurely or by re-attempting a call. This action can further escalate the processors load, which is spent for uncompleted calls. Unless a proper control is used, the switching system can finally break down. In this paper, we paper, we propose a fuzzy overload detection and control method for switching systems, which can by generating fuzzy rules via fuzzy aggregation networks. Simulation results involving a switching system is given.

• Journal of Internet Computing and Services
• /
• v.14 no.6
• /
• pp.125-139
• /
• 2013

Distribution of malicious applications developed by attackers is increasing along with general normal applications due to the openness of the Android-based open market. Mechanism that allows more accurate ways to distinguish normal apps and malicious apps for common mobile devices should be developed in order to reduce the damage caused by the rampant malicious applications. This paper analysed the normal event pattern from the most highly used game apps in the Android open market to analyse the event pattern from normal apps and malicious apps of mobile devices that are based on the Android platform, and analysed the malicious event pattern from the malicious apps and the disguising malicious apps in the form of a game app among 1260 malware samples distributed by Android MalGenome Project. As described, experiment that extracts normal app and malicious app events was performed using Strace, the Linux-based system call extraction tool, targeting normal apps and malicious apps on Android-based mobile devices. Relevance analysis for each event set was performed on collected events that occurred when normal apps and malicious apps were running. This paper successfully extracted event similarity through this process of analyzing the event occurrence characteristics, pattern and distribution on each set of normal apps and malicious apps, and lastly suggested a mechanism that determines whether any given app is malicious.

• International Commerce and Information Review
• /
• v.9 no.3
• /
• pp.305-320
• /
• 2007

With expanded use of B2B(between enterprises), B2G(between enterprises and government) and EDI(Electronic Data Interchange), and increased amount of available network information and information protection threat, as it was judged that security can not be perfectly assured only with security technology such as electronic signature/authorization and access control, Bayesian networks have been developed for protection of information. Therefore, this study speculates Bayesian networks system, centering on ERP(Enterprise Resource Planning). The Bayesian networks system is one of the methods to resolve uncertainty in electronic data interchange and is applied to overcome uncertainty of abnormal invasion detection in ERP. Bayesian networks are applied to construct profiling for system call and network data, and simulate against abnormal invasion detection. The host-based abnormal invasion detection system in electronic trade analyses system call, applies Bayesian probability values, and constructs normal behavior profile to detect abnormal behaviors. This study assumes before and after of delivery behavior of the electronic document through Bayesian probability value and expresses before and after of the delivery behavior or events based on Bayesian networks. Therefore, profiling process using Bayesian networks can be applied for abnormal invasion detection based on host and network. In respect to transmission and reception of electronic documents, we need further studies on standards that classify abnormal invasion of various patterns in ERP and evaluate them by Bayesian probability values, and on classification of B2B invasion pattern genealogy to effectively detect deformed abnormal invasion patterns.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.4
• /
• pp.47-56
• /
• 1996

For the implementation of callcontrol software, it will be shown how to divide problems into dimain and also presents methodologies to specify domains according to the object-orented analysis techniques. Domains is specified by the set of related objects as shown in call control examples. Events and conditons are able to be transformed into system invariant so that is possible to figure out the relationship between domains and those concludes that the software requirements specification can be established for the design and implementation. Relationships existing between domains can be formalized so as to verify software requirements.

• Journal of the Korea Convergence Society
• /
• v.8 no.4
• /
• pp.25-36
• /
• 2017

As smartphone users have increased in recent years, various applications have been developed and used especially for Android-based mobile devices. However, malicious applications developed by attackers for malicious purposes are also distributed through 3rd party open markets, and damage such as leakage of personal information or financial information of users in mobile terminals is continuously increasing. Therefore, to prevent this, a method is needed to distinguish malicious apps from normal apps for Android-based mobile terminal users. In this paper, we analyze the existing researches that detect malicious apps by extracting the system call events that occur when the app is executed. Based on this, we propose a technique to identify malicious apps by analyzing the sequence similarity of kernel layer events occurring in the process of running an app on commercial Android mobile devices.

• Journal of KIISE:Computer Systems and Theory
• /
• v.28 no.9
• /
• pp.469-478
• /
• 2001

It is difficult to test a distributed system because of the task of controlling concurrent events,. Existing works do not propose the test sequence generation algorithm in a formal way and the amount of message is large due to synchronization. In this paper, we propose a formal test sequence generation algorithm using logical clock to control concurrent events. It can solve the control-observation problem and makes the test results reproducible. It also provides a generic solution such that the algorithm can be used for any possible communication paradigm. In distributed test, the number of channels among the testers increases non-linearly with the number of distributed objects. We propose a new remote test architecture for solving this problem. SDL Tool is used to verify the correctness of the proposed algorithm and it is applied to the message exchange for the establishment of Q.2971 point-to-multipoint call/connection as a case study.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.807-814
• /
• 2004

Land seismic reflection survey has been increasingly demanded in various civil engineering works because of its own ability to delineate layers, water table, to detect cavities or fracture zones, to estimate seismic velocities of each layer. However, our shallow subsurface structures are very complex. The relatively thin layer(mostly soil) to the wavelength directly followed by a basic rock with high impedance used to generate complicated surface waves, kind of channel waves with high amplitude that is dominate in entire seismograms and hence the useful reflection events will be almost hopelessly immersed in the undesired surface waves. Thus, it would seem that the use of traditional seismic survey could not be likely to provide in itself a satisfactory information about our exploration targets. This paper hence introduces an efficient measuring strategy illustrating a properly controlled arrangement of the vertical single force sources commonly used, yielding a very sharply elongated form of P-energy with a minimum of S radiation energy, what we call, P-beam source. Abundant experiments of physical modeling showed that in that way the surface waves could be enormously reduced and the reflection events would be additive and thus reinforced. Examples of field data are also illustrated. The contribution of P-beam source will be great in civil engineering area as well as in general geological exploration area.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.8 no.2
• /
• pp.79-85
• /
• 2013

This paper proposes a system that utilizes USN(Ubiquitous Sensor Network), Bluetooth and smart phone to improve the function of senior houses. In typical approach, a system in a senior house either directly accesses the status of elderly people by its sensor or is alerted by elderly people who trigger an emergency bell, derive a decision and take an appropriate action. In addition, it is possible for a designated social worker to check the status of senior patients through monitoring system connected by UTP(Unshielded Uwisted Pair) cables, but the responsible person has to be present to monitor patients' status. However, the new system, suggested in this paper, embed Bluetooth function in a blood pressure gauge, thus the smart phone receives patients' health information such as blood pressure through Bluebooth, if any abnormal event occurs. Consequently, the smart phone sends SMS(Short Message Service) to a responsible social worker or a designated hospital. When this program in the paper becomes a reality, an unmanned system that is able to determine suitable actions for certain events will be established, even if a social worker were absence.

• Journal of Biomedical Engineering Research
• /
• v.15 no.3
• /
• pp.317-324
• /
• 1994

This paper proposed a new method in the implementation of ISDN (integrated services digital network) LAPD (link access procedure on the D-channel) and LAPB (link access procedure on the B-channel) protocols. The proposed method in this paper implement ISDW LAPD protocol through multi-tasking operating system and adopt a kernel part that is changed operating system to target board. The features of implemented system are (1) the para.llel processing of the events generated at each layer, as follows (2) the supporting necessary timers for the implementation of ISDW LAPD protocol from the kernel part by using software, (3) the recommanded SAP (Service Access Point) from CCITT was composed by using port function in the operating system. With the proposed method, the protocols of ISDH layerl, layer2 and layer3 (call control) were implemented by using the kernel part and related tests were carried out by connecting the ISDH terminal simulator to ISDN S-interface system using the ISDN LAPD protocol The results showed that ISDW S-interface terminals could be discriminated by TEI (Terminal Equipment Identifier) assignment in layer 2 (LAPD) and the message transmission of layer 3 was verified by establishing the multi-frame transmission and then through the path established by the LAPD protocol, a user data was tranfered and received on B-channel with LAPB protocol Thererfore, as new efficient ISDN S-interface environment was implemented in the thesis, it was verified that the implemented system can be utilized by connecting ISDW in the future to transfer a medical image data.