• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.5
• /
• pp.753-760
• /
• 2023

KakaoTalk has the highest market share among domestic messengers. As such, KakaoTalk's conversation content is an important evidence in digital forensics, and the conversation is stored in the form of an encrypted database on a user's device. In addition, macOS has the characteristic that it is difficult to access because the disk encryption function is basically activated. The decryption method of the KakaoTalk database for Windows has been studied, but the decryption method has not been studied for KakaoTalk for macOS. In this paper, research the decryption method of the KakaoTalk database for macOS and a way to Brute-Force plan using the characteristics of KakaoTalk's UserID and compare it with KakaoTalk for Windows to examine the commonalities and differences. The results of this paper are expected to be used to analyze users' actions and events when investigating crimes using macOS.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.4
• /
• pp.33-43
• /
• 2023

The impact of prolonged rainfall, such as during the monsoon season or intense concentrated rainfall over a short period, can lead to mountainous disasters such as landslides and debris flows. These events, such as landslides and debris flows, cause both human and material damage, prompting the implementation of various measures and research to prevent them. In the context of researching debris flow disasters, numerical models for debris flows provide a relatively simple way to analyze the risk in a study area. However, since empirical equations are applied in these models, yielding different results and variations in input variables across models, the validation of numerical models becomes essential. In this study, a numerical model for debris flows was employed to compare and analyze the mitigation effects of facilities such as check dams and water channel work, aiming to reduce the damage caused by debris flows.

• Journal of Environmental Health Sciences
• /
• v.42 no.6
• /
• pp.465-477
• /
• 2016

Objectives: This review examined the scientific evidence regarding the impact of climate change on food safety. Methods: The impact of climate change on food safety was assessed based on a survey of related publications reported in the past 20 years. The terms used for literature selection reflect three aspects: climate change; food; and food safety. Results: Climate change is expected to affect the key elements of food production - water and climate. These impact on food safety through many different pathways. Directly, food shortages according to the population grovoth result in a food security/food supply problem, These relationships are commonly understood. The indirect impacts include an increase in food-borne diseases and pathogens, increased mycotoxin production, and increased risk of pesticide residues in foods due to greater use of pesticides in response to warming and increased precipitation and the accompanying diseases in certain crops. Field studies and statistical and scenario analyses were performed to provide evidence. However, quantification of these relationships is still lacking. Conclusion: Adaptation measures at the local and community levels are essential since the pressures from weather and climate events may differ according to region and sector. It is recommended that we go beyond empirical observations of the association between climate change and food safety and develop more scientific explanations. We also need to explore alternative materials for bioenergy demands in order to improve sustainability.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.2
• /
• pp.27-33
• /
• 2009

The emergences of GeoSensor and researches about GIS have promoted many researches of u-GIS. The disaster application coupled in the u-GIS can apply to monitor accident area and to prevent spread of accident. The application needs the u-GIS DSMS technique to acquire, to process GeoSensor data and to integrate them with GIS data. The u-GIS DSMS must process big and large-volume data stream such as spatial data and multimedia data. Due to the feature of the data stream, in u-GIS DSMS, query processing can be delayed. Moreover, as increasing the input rate of data in the area generating events, the network traffic is increased. To solve this problem, in this paper we describe TRIGGER ACTION clause in CQ on the u-GIS DSMS environment and proposes data source management. Data source weight table controls GES information and incoming data rate. It controls incoming data rate as increasing weight at GES of disaster area. Consequently, it can contribute query processing rate and accuracy

• Nuclear Engineering and Technology
• /
• v.52 no.7
• /
• pp.1436-1442
• /
• 2020

Nuclear infrastructure systems play an important role in national security. The functions and missions of nuclear infrastructure systems are vital to government, businesses, society and citizen's lives. It is crucial to design nuclear infrastructure for scalability, reliability and robustness. To do this, we can use machine learning, which is a state of the art technology used in various fields ranging from voice recognition, Internet of Things (IoT) device management and autonomous vehicles. In this paper, we propose to design and develop a machine learning algorithm to perform predictive maintenance of nuclear infrastructure. Support vector machine and logistic regression algorithms will be used to perform the prediction. These machine learning techniques have been used to explore and compare rare events that could occur in nuclear infrastructure. As per our literature review, support vector machines provide better performance metrics. In this paper, we have performed parameter optimization for both algorithms mentioned. Existing research has been done in conditions with a great volume of data, but this paper presents a novel approach to correlate nuclear infrastructure data samples where the density of probability is very low. This paper also identifies the respective motivations and distinguishes between benefits and drawbacks of the selected machine learning algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.3
• /
• pp.1533-1556
• /
• 2017

The concept of trust in vehicular ad hoc networks (VANETs) is usually utilized to assess the trustworthiness of the received data as well as that of the sending entities. The quality of safety applications in VANETs largely depends on the trustworthiness of exchanged data. In this paper, we propose a self-organized distributed trust computing framework (DTCF) for VANETs to compute the trustworthiness of each vehicle, in order to filter out malicious nodes and recognize fully trusted nodes. The proposed framework is solely based on the investigation of the direct experience among vehicles without using any recommendation system. A tier-based dissemination technique for data messages is used to filter out non authentic messages and corresponding events before even going farther away from the source of the event. Extensive simulations are conducted using Omnet++/Sumo in order to investigate the efficiency of our framework and the consistency of the computed trust metrics in both urban and highway environments. Despite the high dynamics in such networks, our proposed DTCF is capable of detecting more than 85% of fully trusted vehicles, and filtering out virtually all malicious entities. The resulting average delay to detect malicious vehicles and fraudulent data is showed to be less than 1 second, and the computed trust metrics are shown to be highly consistent throughout the network.

• Journal of the Korean Home Economics Association
• /
• v.39 no.2
• /
• pp.1-13
• /
• 2001

The purpose of this study is to examine the effects of poor female-headed families' family life events on their well-being under economic crisis in Korea and to investigate how they overcome their alienation. Specific research questions were as follows : (1) How are poor female earner's life satisfaction level and alienation level after economic crisis\ulcorner (2) How are poor female earner's demands for social security\ulcorner For this empirical analysis, the data was collected from 359 poor female-earners whose first child was of school age in the Seoul metropolitan area from the 14th Feb. to the 18th Mar. 2000. The questionnaire for the survey dealt with demographic information, alienation, life satisfaction and family life event. The major findings of the research project were as fellows: First, poor female-earners'alienation level was not higher than the average level. However among sub areas of alienation, powerlessness was higher than the average level. Second, poor female-easer made a strong claim for social welfare. Especially, they desired so much to be granted the national economic assistance.

• Korean Management Science Review
• /
• v.33 no.2
• /
• pp.29-47
• /
• 2016

Trust is formed from the day-to-day and persistent interaction relationship. The trust demands more and more at the age of uncertainty. Human beings are using media interaction. The area of communication with media is extended to virtual space. The purpose of this study is to qualitatively explain trust building process in virtual team by media using. In the pursuit of this purpose, we executed in-depth interview with the person who have experience communicating by media with a man of a complete stranger. They experienced the trust building process. Interview data were analyzed by a Structured Coding Techniques. The derived seven categories were reconstructed in consideration of the cause-and-effect relationship and the flow of events. We have discovered a new trust model that was the result from communication by a media using. The model presented is very useful to Individuals who need a new trust building relationship with stranger or virtual team member.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.283-284
• /
• 2015

Smartphone, tablet PC, notebook, such as the Internet banking and electronic commerce using a mobile device, as well as process and to their work. While going to high availability and convenience of mobile devices castle, SNS, letters, using an email Smishing financial fraud and leakage of personal information such as crime has occurred many. Smishing smartphone accidents increased sharply from 2013, MERS infection cases, landmine provocative events, such as the delivery of Thanksgiving has occurred cleverly using social engineering techniques. In this paper, i analyze the trends in Smishing hacking attacks on mobile devices since 2014. With regard to social issues, it analyzes the process of hacking attacks Smishing leading to financial fraud to mobile users.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.8 no.6
• /
• pp.439-444
• /
• 2015

The Social infrastructure systems such as communication, transportation, power and water supply systems are now facing various types of threats including component failures, security attacks and natural disasters, etc. Whenever such undesirable events occur, it is crucial to recover the system as quickly as possible because the downtime of social infrastructure causes catastrophic consequences in the society. Especially when there is a network link-failure, we need an automatic link-recovery method. This means that customers are aware of network failures that can be recovered before you say that service. In this paper, we analysis the relation between Auto-recovery performance and cost.