• 디지털산업정보학회논문지
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• 제15권1호
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• pp.77-86
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• 2019

Comparative analysis to secure safety of Blockchain Many investors have invested in virtual currency such as bit coins as a new investment due to increased popularity of virtual currency around the world. Also, virtual currency such as bit coin has a security technology and it has been relatively proved. popularity of virtual currency is rising as a new investment alternative because of this reason. This paper focused on the block chain's transparency and security of distributed ledger technology, which is relatively safe without third party's intervention. Many governments and companies around the world are developing and working on block chain technological development to introduce due to these reasons However, there are some suggestion that block chain has minor risks to its security. In this paper, it will examine security vulnerabilities from importance of security of Blockchain which relates to transactions of Bitcoin which stored by governments and companies around the world. This paper will propose measure which will improve safety and efficiency of Blockchain technology such as the existing Blockchain method, Blockchain proposal, traceability and awareness about hacking.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5234-5251
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• 2018

It is well-known that virtualization technology can bring many benefits not only to users but also to service providers. From the view of system security and resource utility, higher resource sharing degree and higher system reliability can be obtained by the introduction of virtualization technology in distributed cloud. The small size time-sharing multiplexing technology which is based on virtual machine in distributed cloud platform can enhance the resource utilization effectively by server consolidation. In this paper, the concept of memory block and user satisfaction is redefined combined with user requirements. According to the unbalanced memory resource states and user preference requirements in multi-virtual machine environments, a model of proper memory resource allocation is proposed combined with memory block and user satisfaction, and at the same time a memory optimization allocation algorithm is proposed which is based on virtual memory block, makespan and user satisfaction under the premise of an orderly physical nodes states also. In the algorithm, a memory optimal problem can be transformed into a resource workload balance problem. All the virtual machine tasks are simulated in Cloudsim platform. And the experimental results show that the problem of virtual machine memory resource allocation can be solved flexibly and efficiently.

• International Journal of Advanced Culture Technology
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• 제12권3호
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• pp.419-426
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• 2024

Due to the government's announcement of the 2025 policy mandating coding education, there is a growing need for effective coding learning methods in elementary education. However, there are few methods available that can easily help younger students understand coding. While text-based coding and visual block coding methods exist, they have limitations. To address these issues, we propose a block coding learning platform that combines virtual reality (VR) technology with gamification elements. The traditional two dimensional (2D) block coding methods have some limitations, so this platform aims to overcome these by providing an environment where learners can intuitively understand and experience coding in a three dimensional (3D) virtual space. The primary goal is to enhance immersive, learner-centered experiences and improve creative problem-solving skills and computational thinking. This study proposes an experimental approach to demonstrate the effectiveness of a learning platform that combines VR technology with block coding. Furthermore, we expect that the VR-based platform will significantly contribute to improving the quality of education and promoting self-directed learning among students.

• 한국의상디자인학회지
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• 제15권2호
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• pp.1-13
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• 2013

The study is to provide basic data on improving costume's fitting by developing physical integrated Basic Bodice Block's development for body types of adult women, which is based on setting up body-type information per truncus as fundamental of adult women's top product manufacture in being ready for Mass Customization era. Also, after review on the objectivity and accuracy of fitting information by real wear and virtual wear experiment on body types, not only 3D virtual clothing system was used as way of information provider of Clothing product, but also provided as basic data in order to use effectively on portion of clothing passion in responding to trend of Mass customization in advance. The consequence of the study is as followings. After analyzing significance differences per items on real and virtual wear evaluation, bowed type of type 1 had significance differences on waist measurement and hip circumference in back and side, which would be knowing as not integrated with costume, affecting form of human body according to virtual wear system bended on back region. Also, in side evaluation, every types except straight body type of type 3 appeared significant differences. In virtual wear evaluation, costume's expression with side body types were not similar to real wear until now except straight body types. It would be improvement things from 3D virtual wear system in advance.

• 한국게임학회 논문지
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• 제17권6호
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• pp.113-120
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• 2017

최근 가상현실 기술의 발전으로 가상의 3D 객체와 자연스러운 상호작용이 가능하도록 하는 사용자 친화적인 손 제스처 인터페이스에 대한 연구가 활발히 진행되고 있다. 그러나 대부분의 연구는 단순하고 적은 종류의 손 제스처만 지원되고 있는 실정이다. 본 논문은 가상환경에서 3D 객체와 보다 직관적인 방식의 손 제스처 인터페이스 방법을 제안한다. 손 제스처 인식을 위하여 먼저 전처리 과정을 거친 다양한 손 데이터를 이진 결정트리로 1차 분류를 한다. 분류된 데이터는 리샘플링을 한 다음 체인코드를 생성하고 이에 대한 히스토그램으로 특징 데이터를 구성한다. 이를 기반으로 학습된 MCSVM을 통해 2차 분류를 수행하여 제스처를 인식한다. 본 방법의 검증을 위하여 3D 블록을 손 제스처를 통하여 조작하는 'Virtual Block'이라는 게임을 구현하여 실험한 결과 16개의 제스처에 대해 99.2%의 인식률을 보였으며 기존의 인터페이스보다 직관적이고 사용자 친화적임을 알 수 있었다.

• 한국통신학회논문지
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• 제38C권5호
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• pp.409-419
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• 2013

키넥트 카메라는 마이크로소프트사에서 2010년 11월에 출시한 xbox360의 움직임 감지 카메라로 깊이 영상과 색상 영상을 획득할 수 있다. 하지만 적외선 패턴을 이용한 깊이 영상의 획득 방법의 한계로 인해 객체의 경계 주변으로 홀(hole) 및 잡음이 생기고 영상으로 재생 시 경계 주변에서 흔들림(flickering) 현상이 발생한다. 본 논문에서는 이러한 흔들림 현상을 보정하여 화질이 좋은 가상 시점 영상을 실시간으로 생성하는 기법을 제안한다. 제안하는 기법에서는 먼저 결합형 양방향 필터를 이용하여 경계 주변의 홀을 채운다. 경계 주변의 흔들림 현상은 화소를 탐색하여 처리하는 기법을 적용하여 보정한다. 향상된 깊이 영상과 색상 영상에 3D 워핑(3D warping) 기법을 적용하여 가상 시점 영상을 획득한다. 획득된 영상에서 가려짐 영역(occlusion region)으로 인하여 생기는 홀은 블록기반의 기울기 탐색 기법과 블록의 신뢰도를 이용하여 채우게 된다. 실험을 통해 제안하는 시스템이 가상 시점 영상을 실시간으로 합성하는 것을 확인하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.211-214
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• 2006

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.99-106
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• 2017

With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

• 한국정보과학회논문지:시스템및이론
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• 제33권1_2호
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• pp.119-127
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• 2006

가상환경에서의 실시간 캐릭터 애니메이션은 컴퓨터 게임 및 가상현실 분야에서 중요한 문제이다. 최근에는 캐릭터 애니메이션의 사실성을 높이기 위해 대규모 동작 캡쳐 데이타를 활용하고 있다. 그러나 거대하고 복잡한 가상환경을 만들기 위해서는 현실 환경에서 동작을 캡쳐하고 이를 넓은 가상환경에 적용해야하는 어려움이 따른다. 본 논문에서는 애니메이션 캐릭터가 몇 가지 빌딩 블록(building block)들로 건설된 넓은 가상공간에서 자유롭게 활동하게 하는 새로운 방법을 제안한다. 빌딩 블록들은 반복적인 형태로 배열되어 더 큰 환경을 생성할 수 있다. 이러한 각각의 블록들을 모션 패치(motion patch)라고 부른다. 모션 패치는 해당 블록 내부에서 캐릭터가 수행할 수 있는 동작들에 대한 정보를 가지고 있다. 본 논문은 다수의 캐릭터가 방대하고 복잡한 가상환경 속에서 실시간으로 애니메이션되고 제어되는 예제들을 통해 이 논문에서 제시하는 방법이 다양한 목적에 유용하게 사용될 수 있음을 보인다.

• The Korean Journal of Pain
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• 제35권4호
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• pp.403-412
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• 2022

Background: Most pain management techniques for challenging procedures are still performed under the guidance of the C-arm fluoroscope although it is sometimes difficult for even experienced clinicians to understand the modified three-dimensional anatomy as a two-dimensional X-ray image. To overcome these difficulties, the development of a virtual simulator may be helpful. Therefore, in this study, the authors developed a virtual simulator and presented its clinical application cases. Methods: We developed a computer program to simulate the actual environment of the procedure. Computed tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data were used for the simulations. Virtual needle placement was simulated at the most appropriate position for a successful block. Using a virtual C-arm, the authors searched for the position of the C-arm at which the needle was visualized as a point. The positional relationships between the anatomy of the patient and the needle were identified. Results: For the simulations, the CT DICOM data of patients who visited the outpatient clinic was used. When the patients revisited the clinic, images similar to the simulated images were obtained by manipulating the C-arm. Transforaminal epidural injection, which was difficult to perform due to severe spinal deformity, and the challenging procedures of the superior hypogastric plexus block and Gasserian ganglion block, were successfully performed with the help of the simulation. Conclusions: We created a pre-procedural virtual simulation and demonstrated its successful application in patients who are expected to undergo challenging procedures.