• Nuclear Engineering and Technology
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• 제44권7호
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• pp.755-766
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• 2012

A Binary Decision Diagram (BDD) is a graph-based data structure that calculates an exact top event probability (TEP). It has been a very difficult task to develop an efficient BDD algorithm that can solve a large problem since its memory consumption is very high. Recently, in order to solve a large reliability problem within limited computational resources, Jung presented an efficient method to maintain a small BDD size by a BDD truncation during a BDD calculation. In this paper, it is first identified that Jung's BDD truncation algorithm can be improved for a more practical use. Then, a more efficient truncation algorithm is proposed in this paper, which can generate truncated BDD with smaller size and approximate TEP with smaller truncation error. Empirical results showed this new algorithm uses slightly less running time and slightly more storage usage than Jung's algorithm. It was also found, that designing a truncation algorithm with ideal features for every possible fault tree is very difficult, if not impossible. The so-called ideal features of this paper would be that with the decrease of truncation limits, the size of truncated BDD converges to the size of exact BDD, but should never be larger than exact BDD.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.229-239
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• 2022

Today's Internet of Things (IoT) has had a dramatic increase in the use of various daily aspects. As a consequence, many homes adopt IoT technology to move towards the smart home. So, the home can be called smart when it has a range of smart devices that are united into one network, such as cameras, sensors, etc. While IoT smart home devices bring numerous benefits to human life, there are many security concerns associated with these devices. These security concerns, such as user privacy, can result in an insecure application. In this research, we focused on analyzing the vulnerabilities of IoT smart home cameras. This will be done by designing a new model that follows the STRIDE approach to identify these threats in order to afford an efficient and secure IoT device. Then, apply a number of test cases on a smart home camera in order to verify the usage of the proposed model. Lastly, we present a scheme for mitigation techniques to prevent any vulnerabilities that might occur in IoT devices.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.7-12
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• 2023

Remote sensor systems are utilized in a few applications, including military, restorative, ecological and family unit. In every one of these applications, vitality use is the deciding component in the execution of wireless sensor systems. Thusly, strategies for information steering and exchanging to the base station are critical in light of the fact that the sensor hubs keep running on battery control and the vitality accessible for sensors is constrained. There are two explanations for the various leveled directing Low Energy Adaptive Clustering Hierarchy convention be in investigated. One, the sensor systems are thick and a considerable measure of excess is engaged with correspondence. Second, with a specific end goal to build the versatility of the sensor arrange remembering the security parts of correspondence. In this exploration paper usage of LEACH steering convention utilizing NS2 test system lastly upgraded vitality productive EE-LEACH directing convention guarantees that the chose cluster heads will be consistently conveyed over the system with a specific end goal to enhance the execution of the LEACH convention. EE-LEACH enhances vitality utilization by around 43%.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2021년도 제64차 하계학술대회논문집 29권2호
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• pp.225-228
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• 2021

본 연구는 스마트폰 중독과 관련된 다양한 분석을 위한 스마트폰 사용 앱과 관리자 웹을 개발하고자 한다. 연구방법으로 이전 연구에서 중요한 변수로 작용되었던 '화면 켠 횟수', '실사용시간-인지사용시간' 변수를 분석할 있도록 적용하여 스마트폰 사용시간, 사용량, 사용 앱, 화면 잠금을 해제한 횟수 등 다양한 데이터 수집이 가능한 앱을 개발한다. 관리자 웹은 수집된 데이터를 저장, 분석할 수 있는 공간으로 사용할 것이다. 앱에서 수집된 데이터는 서버에 전송한 후, 시각화 분석 기능을 제공하는 관리 프로그램으로 개발하여 스마트폰 중독 연구에 사용한다. 향후 데이터 수집과 사용 목적에 동의한 사용자를 모집하여 데이터를 수집하고 스마트폰 사용 패턴, 데이터마이닝, 중독 등과 관련된 다양한 분석을 할 것이다. 이를 통해 보다 정확하고 효과적인 스마트폰 중독 진단이 가능해질 것과 나아가 스마트폰 중독 치료방안 연구에 기여할 것으로 기대한다.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.75-80
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• 2023

Rare earth barium copper oxide (REBCO) materials have shown the possibility of high-temperature superconductor (HTS) magnetic resonance imaging (MRI) magnets due to their elevated transition temperature. While numerous MRI magnet designs have emerged, there is a growing emphasis on estimating the cost before manufacturing. In this paper, we propose two designs of REBCO whole-body MRI magnets: (1) 1.5 T and (2) 3.0 T, the standard center field choices for hospital use, and compare their costs based on conductor usage. The basis topology of the design method is based on discretized solenoids to enhance field homogeneity. Magnetic stress calculation is done to further prove the mechanical feasibility of their construction. Multi-width winding technique and outer notch structure are used to improve critical current characteristic. We apply consistent constraints for current margins, sizes, and field homogeneities to ensure an equal cost comparison. A graph is plotted to show the cost increase with magnetic flux growth. Additionally, we compare our designs to two additional MRI magnet designs from other publications with respect to the cost and magnetic flux, and present the linear relationship between them.

• Journal of information and communication convergence engineering
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• 제21권4호
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• pp.268-280
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• 2023

Several companies have migrated their existing monolithic web applications to microservice architectures. Consequently, research on the identification of microservices from monolithic web applications has been conducted. Meanwhile, the use-case model plays a crucial role in outlining the system's functionalities at a high level of abstraction, and studies have been conducted to identify microservices by utilizing this model. However, previous studies on microservice identification utilizing use-cases did not consider the components executed in the presentation layer. Unlike existing approaches, this paper proposes a technique that considers all three layers of web applications (presentation, business logic, and data access layers). Initially, the components used in the three layers of a web application are extracted by executing all the scenarios that constitute its use-cases. Thereafter, the usage rate of each component is determined for each use-case and the component is allocated to the use-case with the highest rate. Then, each use-case is realized as a microservice. To verify the proposed approach, microservice identification is performed using open-source web applications.

• International Journal of Computer Science & Network Security
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• 제24권6호
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• pp.161-170
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• 2024

With the technological advances, the humans have made so much progress in the ease of living and now incorporating the use of sight, motion, sound, speech etc. for various application and software controls. In this paper, we have explored the project in which gestures plays a very significant role in the project. The topic of gesture control which has been researched a lot and is just getting evolved every day. We see the usage of computer vision in this project. The main objective that we achieved in this project is controlling the computer settings with hand gestures using computer vision. In this project we are creating a module which acts a volume controlling program in which we use hand gestures to control the computer system volume. We have included the use of OpenCV. This module is used in the implementation of hand gestures in computer controls. The module in execution uses the web camera of the computer to record the images or videos and then processes them to find the needed information and then based on the input, performs the action on the volume settings if that computer. The program has the functionality of increasing and decreasing the volume of the computer. The setup needed for the program execution is a web camera to record the input images and videos which will be given by the user. The program will perform gesture recognition with the help of OpenCV and python and its libraries and them it will recognize or identify the specified human gestures and use them to perform or carry out the changes in the device setting. The objective is to adjust the volume of a computer device without the need for physical interaction using a mouse or keyboard. OpenCV, a widely utilized tool for image processing and computer vision applications in this domain, enjoys extensive popularity. The OpenCV community consists of over 47,000 individuals, and as of a survey conducted in 2020, the estimated number of downloads exceeds 18 million.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
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• pp.865-867
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• 2005

자바 프로그램은 클래스의 집합으로 이루어지며 클래스는 필드와 메소드로 구성된다. 필드는 힙 메모리에 저장되므로 필드의 사용 형태는 힙 메모리의 사용 형태에 직접적인 영향을 미친다. 즉 자바 힙 메모리의 사용을 분석하기 위해서는 필드의 사용 형태를 분석해야 한다는 것이다. 본 논문에서는 전형적 자바 프로그램에서 필드가 어떻게 사용되어지는지를 정성적으로 분석하고 실험을 통해 확인하였다. 본 연구의 결과는 자바가상기계의 힙 메모리 구조 개발에 도움을 줄 것이며, 나아가 효율적인 자바가상기계의 개발을 가능하게 할 것으로 기대된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.147-150
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• 1998

To determine the satellite orbital positions under consideration of interference caused by inter-satellite systems is one of the most important issues in terms of optimal usage of satellite network resources. In this paper, we present the orbital positioning method for a new satellite to minimize inter-satellite system interference effect in the fixed satellite communication using a new method. Through the computer simulation, it is clear that the proposed method is suitable to determine the satellite orbital positions.

• 인터넷정보학회논문지
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• 제17권4호
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• pp.1-9
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• 2016

Algorithms implementing distributed shared memory (DSM) were developed for ensuring consistency. The performance of DSM algorithms is dependent on system and usage parameters. However, ensuring these algorithms to tolerate faults is a problem that needs to be researched. In this study, we proposed fault-tolerant scheme for DSM system and analyzed reliability and fault-tolerant overhead. Using our analysis, we can choose a proper algorithm for DSM on error prone environment.