• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.1-9
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• 2014

Recently, with the enlargement of cloud computing, virtual desktop infrastructure(VDI) can be an alternative of the existing personal computer based information environment. For the case of partially introduced VDI coexisting with personal computer environment, we suggest a virtual folder based approach to control the overall digital contents within an organization with a case of implementation. Although a centralizing device was used for storage and sharing of organization's digital contents, it was not easy to accomplish centralizing digital contents completely. It is tried to prevent users from utilizing their own storage in their personal computers or virtual machines and to use virtual folder which transfer and store digital contents to and in EDMS. The virtual folder system of this paper looks like a real folder in a personal computer, but it is another virtual device for outer storage devices including EDMS. It can be an alternative and reference of digital contents control for future applications of cloud computing.

• Information and Communications Magazine
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• v.28 no.10
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• pp.30-37
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• 2011

본고에서는 클라우드 데스크탑 서비스의 개요와 이 서비스를 구현하기 위해 필요한 가상 데스크탑 인프라스트럭쳐(VDI : Virtual Desktop Infrastructure) 기술의 동향을 살펴보고, 유사점과 차이점을 분석한다.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1473-1473
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• 2003

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.239-242
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• 2016

In this paper, we proposed the dual curved lens of concave type. HDPE (High Density Polyethylene) used to fabricate the dual curved lens. The dual curved lens consisted of two concave structures. Role of two concave structures is to beam uniform and expansion. A small concave structure has the greater curvature than big concave structure. The dual curved lens will apply to millimeter imaging system. We measured the dual curved lens performance using 250 GHz VDI source. And we simulated the dual curved lens using ZEMAX. Fabricated lens have a good performance for beam uniform and expansion.

• Journal of Computing Science and Engineering
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• v.5 no.4
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• pp.331-337
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• 2011

Recently, Virtual Desktop Infrastructure (VDI) has been widely adopted to ensure secure protection of enterprise data and provide users with a centrally managed execution environment. However, user experiences may be restricted due to the limited functionalities of thin clients in VDI. If thick client devices like laptops are used, then data leakage may be possible due to malicious software installed in thick client mobile devices. In this paper, we present Data Firewall, a security framework to manage and protect security-sensitive data in thick client mobile devices. Data Firewall consists of three components: Virtual Machine (VM) image management, client VM integrity attestation, and key management for Protected Storage. There are two types of execution VMs managed by Data Firewall: Normal VM and Secure VM. In Normal VM, a user can execute any applications installed in the laptop in the same manner as before. A user can access security-sensitive data only in the Secure VM, for which the integrity should be checked prior to access being granted. All the security-sensitive data are stored in the space called Protected Storage for which the access keys are managed by Data Firewall. Key management and exchange between client and server are handled via Trusted Platform Module (TPM) in the framework. We have analyzed the security characteristics and built a prototype to show the performance overhead of the proposed framework.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.155-164
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• 2014

Recently interest on production of biogas from biomass resources has increased because of climate change in worldwide. In this study, anaerobic digestion efficiency of 17 different types of agricultural waste was evaluated using biochemical methane production potential estimated from the International biochemical methane potential standard method (Germany VDI4630). As a result, theoretical biochemical methane potential ($B_{th}$) of agricultural waste biomass ranged from 0.266 to $0.488Nm^3kg^{-1}$-Volatile Solid $(VS)_{added}$. Ultimate biochemical methane potential ($B_u$) of agricultural waste biomass ranged between 0.176 and $0.417Nm^3kg^{-1}-VS_{added}$. The agricultural waste biomass anaerobic biodegradability with $B_u/B_{th}$ and VDI4630 determined by VS contents was 36.0~95.9% and 30.8~91.1%, respectively. Ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.126-127
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• 2014

현재 방송에서는 제공되지 않은 해상도, 촬영 시점 등에 대한 사용자 요구에 따라 방송 서비스를 선택적으로 제공받고자 하는 요구가 생겨나고 있다. 기존 서비스들은 촬영 시점에 따라 정지 영상을 보여주는 정도의 연구가 진행되어 왔다. 본 논문에서는 그 한계점을 극복하고자 가상실세계에서 스트리밍을 제공할 수 있는 방법에 대해 연구하였으며, 실시간 멀티뷰 중계 서비스를 구현하고자 한다. 이를 통해 시청자는 다양한 각도에서 자신이 원하는 화면을 선택적으로 서비스 받을 수 있으며, 미래형 서비스를 위한 원천기술 확보에 도움이 될 것이다. 특히 스포츠 분야에 적용할 때 사용자가 즐길 수 있는 콘텐츠의 질적 향상을 가져올 것으로 기대된다.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.433-442
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• 2014

In this paper, we introduce the client side cache of distributed file system for enhancing read performance by eliminating the network latency and decreasing the back-end storage burden. This performance enhancement can expand the fields of distributed file system to not only cloud storage service but also high performance storage service. This paper shows that the distributed file system with client side SSD cache can satisfy the requirements of VDI(Virtual Desktop Infrastructure) storage. The experimental results show that full-clone is more than 2 times faster and boot time is more than 3 times faster than NFS.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.37-44
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• 2020

Due to the recent COVID 19 pandemic, public institutions are increasingly working from home. Working in public institutions is rapidly changing into a smart work environment where time and space constraints disappear. However, many public institutions currently lack a security model for an efficient smart work environment due to the physical network separation system that separates the Internet network and the business network. Therefore, in this paper, we describe the current limitations for implementing smart work in a physical network separation environment of public institutions, and propose a security model necessary for a work environment to supplement them. As a related study, explain SSL VPN and explain smart work business model through security model research of SDP (Software Defined Perimeter), RDP (Remote Desktop Protocol), and VDI (Virtual Desktop Infrastructure) to overcome the security limitations of SSL VPN. As a result, we intend to propose a security model for a smart work environment suitable for public institutions while complying with the physical network separation security guide.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.55-65
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• 2021

This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 11 waste biomasses from agricultural fields were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the Double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the biomasses applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 10 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of biomass decompositions. The easily degradable factors (k₁) were raged between 0.097~0.152 day^-1 from vegetable crops and persistent degradable factor (k₂) were 0.002~0.024 day^-1. Among these results, greater organic matter decomposition rates from VDI4630 had greater k₁ values (0.152, 0.144day^-1) and smaller k₁ values (0.002, 0.005day^-1) from cucumbers and paprika. In a meanwhile, radishes and tangerine rinds which had low decomposition rates showed 0.097 and 0.094 day^-1 of k₁ values and decomposition rates seems to affect k₁ values.