• Journal of radiological science and technology
• /
• v.41 no.1
• /
• pp.39-45
• /
• 2018

The purpose of this study is to evaluate the usefulness of a software-based quality assurance system based on Volumetric Modulated Arc Therapy treatment plan. Evaluate treatment plan through the D VH analysis, PTV mean dose ($D_{mean}$) and PTV 95% dose($D_{95}$) compare the MFX based on original treatment plan, Average error rate was $0.9{\pm}0.6%$, $1.0{\pm}0.8%$, respectively. Measuring point dose using phantom and ion chamber, the average error rate between the ionization chamber and MFX was $0.9{\pm}0.7%$, $1.1{\pm}0.7%$ (high dose region), $1.1{\pm}0.9%$, $1.2{\pm}0.7%$ (low dose region). The average gamma though of MFX and $Delta^{4PT}$ is $98.7{\pm}1.2%$, $98.4{\pm}.3%$, respectively. Through this study, A software based QA system that simplifies hardware based QA procedures that involve a lot of time and effort. It can be used as a simple and useful tool in clinical practice.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.1
• /
• pp.103-114
• /
• 2024

In a situation where drone-related crimes continue to rise, research in drone forensics becomes crucial for preventing and responding to incidents involving drones. Conducting forensic analysis on flight record files stored internally is essential for investigating illegal activities. However, analyzing flight record files generated through the exclusive DUML protocol requires a deep understanding of the protocol's structure and characteristics. Additionally, a forensic analysis tool capable of handling cryptographic payloads and analyzing various drone models is imperative. Therefore, this study presents the methods and characteristics of flight record files generated by drones. It also explains the structure of the flight record file and the features of the DUML packet. Ultimately, we conduct forensic analysis based on the presented structure of the DUML packet and propose an extension forensic analysis system that operates more universally than existing tools, performing expanded syntactic analysis.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.885-888
• /
• 2007

본 논문은 무선 센서노드에서 측정되는 데이터들에 대한 저장 및 검색을 효율적으로 하기 위한 플래시 메모리 공간 관리 기법을 제안한다. 플래시 메모리는 외부 충격에 강하고, 비휘발성이며 접근이 빠른 장점이 있지만, 덮어쓰기 및 쓰기 횟수가 제한되는 단점이 있다. 이러한 특성으로 플래시 메모리는 기존의 저장매체와는 다른 관리 방법이 요구되었고 지금까지의 센서노드에서는 플래시 메모리를 사용 하지 않았다. 본 논문에서는 센서노드안의 플래시 메모리에서 순차적으로 측정되는 데이터를 관리하기 위해 LFS(Log-Structured File System)방식을 제안한다. 그리고 순차적으로 정렬된 데이터에 효율적인 검색방법을 제시하고, 이를 ZigbeX Mote의 TinyOS안에서 NesC로 구현하였다.

• Journal of Digital Convergence
• /
• v.9 no.5
• /
• pp.225-233
• /
• 2011

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. Recently, the introduction of smart phones has led to a growth in social networking services and thus, the research and development of Internet telephony has been actively progressed and has the potential to become a replacement for the telephone service that is currently being used. In this paper we designed and implemented a recording system which records voice data of SIP-based Internet telephone's voice calls. It is developed on the linux system and has some features such as audio mixing of two in/out voice channels, live packet sniffing, and the ability to transfer mixed audio files to the log file server. These functions are implemented using various open source softwares. Afterwards, this VoIP recording system will be applied as a base technology to advanced services like a VoIP-based call center system.

• The KIPS Transactions:PartD
• /
• v.13D no.7 s.110
• /
• pp.1027-1038
• /
• 2006

There are many technical problems in the recommendation system based on very large database(VLDB). So, it is necessary to study the recommendation system' structure and the data-mining technique suitable for the large scale Internet shopping mail. Thus we design and implement the product recommendation system using k-means clustering algorithm and sequential pattern technique which can be used in large scale Internet shopping mall. This paper processes user information by batch processing, defines the various categories by hierarchical structure, and uses a sequential pattern mining technique for the search engine. For predictive modeling and experiment, we use the real data(user's interest and preference of given category) extracted from log file of the major Internet shopping mall in Korea during 30 days. And we define PRP(Predictive Recommend Precision), PRR(Predictive Recommend Recall), and PF1(Predictive Factor One-measure) for evaluation. In the result of experiments, the best recommendation time and the best learning time of our system are much as O(N) and the values of measures are very excellent.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.3
• /
• pp.499-510
• /
• 2023

Recently, an intelligent and advanced cyber attack attacks a computer network of a public institution using a file containing malicious code or leaks information, and the damage is increasing. Even in public institutions with various information protection systems, known attacks can be detected, but unknown dynamic and encryption attacks can be detected when existing signature-based or static analysis-based malware and ransomware file detection methods are used. vulnerable to The detection method proposed in this study extracts the detection result data of the system that can detect malicious code and ransomware among the information protection systems actually used by public institutions, derives various attributes by combining them, and uses a machine learning classification algorithm. Results are derived through experiments on how the derived properties are classified and which properties have a significant effect on the classification result and accuracy improvement. In the experimental results of this paper, although it is different for each algorithm when a specific attribute is included or not, the learning with a specific attribute shows an increase in accuracy, and later detects malicious code and ransomware files and abnormal behavior in the information protection system. It is expected that it can be used for property selection when creating algorithms.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.29-37
• /
• 2007

In this paper, we propose a new real-time ground motion monitoring system using MMA data which can be gathered more earlier than generic seismic data transmission method. Proposed system receives maximum, minimum and average data based on 20sps which is sent from station on every second continuously. And it calculates a PGA as a quantity of ground motion then visualizes that data to monitor the ground motion around whole country. To verify PGA data from MMA data, we checked Mu-dan-jang earthquake data of China on 2002/6/29. The proposed system was inspected by using log file of Oh-dae-san earthquake data on 2007/1/20. As results of experiment, the proposed system is proven to detect the event(earthquake) faster then existing method and to produce a useful quantitative information.

• Journal of KIISE:Software and Applications
• /
• v.31 no.5
• /
• pp.586-594
• /
• 2004

Because web documents become creation and disappearance rapidly, users require the recommend system that offers users to browse the web document conveniently and correctly. One largely untapped source of knowledge about large data collections is contained in the cumulative experiences of individuals finding useful information in the collection. Recommendation systems attempt to extract such useful information by capturing and mining one or more measures of the usefulness of the data. The existing Information Filtering system has the shortcoming that it must have user's profile. And Collaborative Filtering system has the shortcoming that users have to rate each web document first and in high-quantity, low-quality environments, users may cover only a tiny percentage of documents available. And dynamic recommendation system using the user browsing pattern also provides users with unrelated web documents. This paper classifies these web documents using the similarity between the web documents under the web document type and extracts the user browsing sequential pattern DB using the users' session information based on the web server log file. When user approaches the web document, the proposed Dynamic recommendation system recommends Top N-associated web documents set that has high similarity between current web document and other web documents and recommends set that has sequential specificity using the extracted informations and users' session information.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.11
• /
• pp.221-232
• /
• 2009

To purpose of the study was to analyze faculty utility of Web-Based course support system in Universities. Data were collected from log file in server computer, 5,023 faculties and 12,733 courses offered at spring semester of 2009 in the Metropolitan area S, K, D universities were analyzed. Specifically, frequency and percentile of faculties and courses using course management system were analyzed. In addition, the frequencies and percentiles of courses using sub-functions of course management system were analyzed and X2 test used to examine the difference of frequencies of faculties and courses using course system at using announcement, providing instructional material, public bulletin board and free board. Results were as follows. The 62.28% of faculties and 50.3% of courses have used Web-Based course support system. The results of Subfunction utility analysis showed the highest use as 80.4%. in providing instructional material. However, the use of announcement functions and online discussion was more or less low. Results imply that most of faculties and course are using course management system as supplementary system of off-line instruction.

• Journal of Internet Computing and Services
• /
• v.6 no.2
• /
• pp.69-84
• /
• 2005

As the Internet users are increasing rapidly, a cluster web server system is attracted by many researchers and Internet service providers. The cluster web server has been developed to efficiently support a larger number of users as well as to provide high scalable and available system. In order to provide the high performance in the cluster web server, efficient load distribution is important, and recently many content-aware request distribution techniques have been proposed. In this paper, we propose a new content-aware load balancing technique that can evenly distribute the workload to each node in the cluster web server. The proposed technique is based on the hash histogram transformation, in which each URL entry of the web log file is hashed, and the access frequency and file size are accumulated as a histogram. Each user request is assigned into a node by mapping of (hashed value-server node) in the histogram transformation. In the proposed technique, the histogram is updated periodically and then the even distribution of user requests can be maintained continuously. In addition to the load balancing, our technique can exploit the cache effect to improve the performance. The simulation results show that the performance of our technique is quite better than that of the traditional round-robin method and we can improve the performance more than $10\%$ compared with the existing workload-aware load balancing(WARD) method.