Template-based modeling methodology of a virtual plant for virtual commissioning

Ko, Minsuk,Park, Sang C Sage Publications Ltd. 2014 Concurrent Engineering Vol.22 No.3

<P>This article presents a template-based modeling methodology for the effective construction of a virtual plant that can be used for the virtual commissioning of a programmable logic controller. For virtual commissioning, the corresponding virtual plant, consisting of virtual devices, is required to interact with the input and output symbols of a programmable logic controller. In other words, the behavior of a virtual device should be the same as that of the real device. Conventionally, discrete event systems specifications formalism has been used to represent the behavior of a virtual device. However, modeling using discrete event systems specifications formalism requires in-depth knowledge of simulation as well as significant amounts of time and effort. One of the key ideas of the proposed methodology is to provide a device template model representing the relations between the tasks of a device. The proposed template is very intuitive and can be used to generate a comprehensive behavior model of a virtual device. The proposed approach has been implemented and demonstrated for a robotic cell.</P>

Control Method of a Haptic Device with a Virtual Prismatic Joint

Kota Abe,Masamitsu Kurisu 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

We are developing a multi-purpose haptic device which can represent various operation manners by changing control methods. Usually, operation manners for one device that can be represented by configuration constraints such as joint placement are limited. To overcome this limitation and to represent more operation manners, a virtual axis is introduced to the device. The virtual axis is one of the virtual configuration, and is the joint axes of virtual prismatic joints and revolute joints. The virtual axis is different from an actual configuration of the device and realized by controlling multiple actual axes in conjunction. When an operator manipulates the device which is represented by the virtual axis, the operator feels as if the axis exists. This paper describes a control method of the haptic device with a virtual prismatic joint axis. The virtual prismatic joint axis is realized by two-stage control with linearization and servo compensation. Verification experiments are conducted to confirm the effectiveness of the control method, and show that the virtual prismatic joint axis is represented to the device.

가상 장치의 성능 향상을 위한 커널 레벨 장치 가상화 기술

김정한(Junghan Kim),이동우(Dongwoo Lee),민창우(Changwoo Min),엄영익(Young Ik Eom) 한국정보과학회 2013 정보과학회 컴퓨팅의 실제 논문지 Vol.19 No.2

가상화 기술은 하드웨어와 소프트웨어의 발전과 함께 다양한 분야에 적용되어 컴퓨팅 환경의 자원 활용성을 높이고 있다. 이와 같이 가상화 환경이 널리 사용됨에 따라서 프로세서/메모리/장치 가상화를 효과적으로 지원하기 위한 관련 연구가 진행되고 있다. 그중에서도 장치 가상화는 빈번한 입출력 워크로드를 갖는 대규모 가상 머신 환경을 지원하기 위한 핵심 기술로써 주목받고 있다. 이를 위해 기존의 연구에서 다양한 모델이 제안되었으나 장치 접근 요청에서 발생하는 모드 전환 비용에 대한 해결 방법을 제시하지 못하고 있다. 이에 본 논문에서는 폴링 기반의 커널 레벨 장치 가상화 기술을 제안하여 모드 전환 비용을 제거하였다. 또한, 이에 대한 프토토타입을 구현하여 높은 입출력 워크로드에서 본 폴링 기반장치 가상화 기술의 성능 개선을 확인하였다. Virtualization technologies have been applied in various area, and they improve the utilization of the computing resources. Accordingly, it is important to study on processor, memory, and device virtualization. Above all, the device virtualization has been attracting a core technology to support large scale virtual machines in complex I/O workloads. Even though various models for device virtualization have been proposed, there is no answer to handle mode transition cost. In this paper, we propose a I/O virtualization technology, which is the in-kernel device virtualization technology, to accelerate virtual devices in a virtual machine based on a polling scheme. And, we show experimental results on the complex storage and network workloads using our prototype implementation based on the polling scheme.

IOMMU Para-Virtualization for Efficient and Secure DMA in Virtual Machines

( Hongwei Tang ),( Qiang Li ),( Shengzhong Feng ),( Xiaofang Zhao ),( Yan Jin ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.12

IOMMU is a hardware unit that is indispensable for DMA. Besides address translation and remapping, it also provides I/O virtual address space isolation among devices and memory access control on DMA transactions. However, currently commodity virtualization platforms lack of IOMMU virtualization, so that the virtual machines are vulnerable to DMA security threats. Previous works focus only on DMA security problem of directly assigned devices. Moreover, these solutions either introduce significant overhead or require modifications on the guest OS to optimize performance, and none can achieve high I/O efficiency and good compatibility with the guest OS simultaneously, which are both necessary for production environments. However, for simulated virtual devices the DMA security problem also exists, and previous works cannot solve this problem. The reason behind that is IOMMU circuits on the host do not work for this kind of devices as DMA operations of which are simulated by memory copy of CPU. Motivated by the above observations, we propose an IOMMU para-virtualization solution called PVIOMMU, which provides general functionalities especially DMA security guarantees for both directly assigned devices and simulated devices. The prototype of PVIOMMU is implemented in Qemu/KVM based on the virtio framework and can be dynamically loaded into guest kernel as a module, As a result, modifying and rebuilding guest kernel are not required. In addition, the device model of Qemu is revised to implement DMA access control by separating the device simulator from the address space of the guest virtual machine. Experimental evaluations on three kinds of network devices including Intel I210 (1Gbps), simulated E1000 (1Gbps) and IB ConnectX-3 (40Gbps) show that, PVIOMMU introduces little overhead on DMA transactions, and in general the network I/O performance is close to that in the native KVM implementation without IOMMU virtualization.

가상현실 웨어러블 기기의 구매 촉진을 위한 태도 자신감과 사용자 저항 태도

손봉진(Bong-Jin Sohn),박다슬(Da-Sul Park),최재원(Jaewon Choi) 한국지능정보시스템학회 2016 지능정보연구 Vol.22 No.3

Over the past decade, there has been a rapid diffusion of technological devices and a rising number of various devices, resulting in an escalation of virtual reality technology. Technological market has rapidly been changed from smartphone to wearable devices based on virtual reality. Virtual reality can make users feel real situation through sensing interaction, voice, motion capture and so on. Facebook.com, Google, Samsung, LG, Sony and so on have investigated developing platform of virtual reality. the pricing of virtual reality devices also had decreased into 30% from their launched period. Thus market infrastructure in virtual reality have rapidly been developed to crease marketplace. However, most consumers recognize that virtual reality is not ease to purchase or use. That could not lead consumers to positive attitude for devices and purchase the related devices in the early market. Through previous studies related to virtual reality, there are few studies focusing on why the devices for virtual reality stayed in early stage in adoption & diffusion context in the market. Almost previous studies considered the reasons of hard adoption for innovative products in the viewpoints of Typology of Innovation Resistance, MIR(Management of Innovation Resistant), UTAUT & UTAUT2. However, product-based antecedents also important to increase user intention to purchase and use products in the technological market. In this study, we focus on user acceptance and resistance for increasing purchase and usage promotions of wearable devices related to virtual reality based on headgear products like Galaxy Gear. Especially, we added a variables like attitude confidence as a dimension for user resistance. The research questions of this study are follows. First, how attitude confidence and innovativeness resistance affect user intention to use? Second, What factors related to content and brand contexts can affect user intention to use? This research collected data from the participants who have experiences using virtual rality headgears aged between 20s to 50s located in South Korea. In order to collect data, this study used a pilot test and through making face-to-face interviews on three specialists, face validity and content validity were evaluated for the questionnaire validity. Cleansing the data, we dropped some outliers and data of irrelevant papers. Totally, 156 responses were used for testing the suggested hypotheses. Through collecting data, demographics and the relationships among variables were analyzed through conducting structural equation modeling by PLS. The data showed that the sex of respondents who have experience using social commerce sites (male=86(55.1%), female=70(44.9%). The ages of respondents are mostly from 20s (74.4%) to 30s (16.7%). 126 respondents (80.8%) have used virtual reality devices. The results of our model estimation are as follows. With the exception of Hypothesis 1 and 7, which deals with the two relationships between brand awareness to attitude confidence, and quality of content to perceived enjoyment, all of our hypotheses were supported. In compliance with our hypotheses, perceived ease of use (H2) and use innovativeness (H3) were supported with its positively influence for the attitude confidence. This finding indicates that the more ease of use and innovativeness for devices increased, the more users’ attitude confidence increased. Perceived price (H4), enjoyment (H5), Quantity of contents (H6) significantly increase user resistance. However, perceived price positively affect user innovativeness resistance meanwhile perceived enjoyment and quantity of contents negatively affect user innovativeness resistance. In addition, aesthetic exterior (H6) was also positively associated with perceived price (p<0.01). Also projection quality (H8) can increase perceived enjoyment (p<0.05). Finally, attitude confidence (H10) increased user intention to use virtual reality devices. howe

비만 환자를 대상으로 한 가상대장 내시경 검사에서 Device 사용의 유용성 평가

최성민(Seong min Choi),김영남(Yeong nam Kim),김정훈(Jeong hoon Kim),김상현(Sang hyeong Kim) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.1

목 적 비만 환자에 대하여 CTC 검사를 시행할 경우 그렇지 않은 환자에 비하여 Prone position을 취하였을 때, 환자 본인의 하 복부 비만 부위로 인해 배가 눌려 S상 결장 부위의 장 팽창이 상대적으로 부족함을 보인다. 이러한 이유로 검사 시 환자의 hip joint 부위와 가슴 부위에 device를 사용하여 하복부에 직접적인 압박이 가해 지지 않도록 하여 device를 사용하지 않았을 때에 비하여 S상 결장 부위의 장 팽창의 용이함을 2D axial 영상과 재구성된 3D 이미지에서 대장 내 지름을 측정 비교하여 Device 사용의 유용성을 알아보고자 하였다. 대상 및 방법 2009년 12월 과 2010년 1월 서울 아산병원 입원 또는 외래를 통한 Virture colonoscophy 검사자 중 체중과 신장을 이용한 체질량 지수를 구하여 그 중 비만도가 높은 환자를 대상으로 검사 하였다. 총 195명의 환자를 검사 했으며 그 중 남자 15명, 여자 15명을 대상으로 하였다. prone position 검사 시 device를 사용하지 않았을 때와 device를 사용하였을 때 복부 전체를 두번 scan 하였다. scan 후 평가는 S상 결장의 확장 정도를 PACS 상에서 measure program을 사용하여 size를 측정하여 넓어진 정도를 비교하였다. 결 과 Device를 사용하지 않은 남자와 여자 15명 모두 대장의 직경이 평균 3.1 cm의 팽창을 보였으며, 동일 환자에 대하여 device를 사용 하면서 검사한 경우에는 남자 15명의 경우 평균 4.3 cm으로 측정, 사용하지 않았을 때 보다 평균 1.2 cm 더 넓어져 38%의 증가를 가져왔으며, 여자 15명의 경우 평균 4.2 cm으로 평균 1.1cm 더 넓어져 35%의 증가를 가져왔다. 결 론 S상 결장은 전체 대장암 중에서 그 차지하는 비중이 두 번째로 높은 호발 부위이다. 이러한 부위가 충분히 확장이 되지 않을 경우 1 cm 이하의 병변은 구별해 내기가 쉽지가 않다. 따라서 비만 환자의 경우 device를 환자의 hip joint와 가슴 부위에 사용하여 복부가 눌리지 않게 해줌으로서 상대적으로 체중으로 눌렸을 때에 비하여 S상 결장부위가 더 많이 확장시키는 결과를 보여 주기 때문에 device를 사용하는 것이 더 효율적이라 하겠다. Ⅰ. Purpose In a CTC examinations, Obesity patients especailly show less distension than thin patients adapting Prone position, because abdomen is pressed by a own redoubling obesity parts. so distension of sigmoid colon is relatively insufficient. For this reason, in CTC exam, we use the device both hip joint and thoracic portion not to push direct pressure. our purpose is to show usefulness of distension in sigmoid colon comparing CTC using device with CTC using not device. and we measure a diameter of colon and compare with 2D axial image and 3D. finally, we reveal utility of using device in CTC. Ⅱ. Materials and Methods target: inpatients and outpatients who are tried virtual colonoscopy from December, 2009 to January, 2010 in Asan Medical Center. measure: we calculate body mass index of total 195patients based on weight and height and select high level of 30patients(male: 15, Female: 15). method: twice scan in entire abdominal region using device versus not using device adapting prone position. evaluation: compare an expansion degree of sigmoid colon on PACS as we measured using measure program. Ⅲ. Results 15 men and women patients who don’t use device show the colon distension of average 3.1cm, but in same 15 men patients who use device show the colon distension of average 4.3 cm(increase +1.2 cm) and in same 15 women patients who utilize device show the colon distension of average 4.2 cm(increase +1.1 cm). Ⅳ. Conclusion Sigmoid colon is part to well occur colon cancer where is known for the second high portion. If distension doesn’t work enough in these part, region of less than 1cm can’t have distinguished it. Therefore, for obesity patients, to put device in hip joint and thoracic portion can help to prevent to push abdominal portion in prone position. as a result, device can help to distent sigmoid colon very efficiently.

IOMMU Para-Virtualization for Efficient and Secure DMA in Virtual Machines

Tang, Hongwei,Li, Qiang,Feng, Shengzhong,Zhao, Xiaofang,Jin, Yan Korean Society for Internet Information 2016 KSII Transactions on Internet and Information Syst Vol.10 No.12

IOMMU is a hardware unit that is indispensable for DMA. Besides address translation and remapping, it also provides I/O virtual address space isolation among devices and memory access control on DMA transactions. However, currently commodity virtualization platforms lack of IOMMU virtualization, so that the virtual machines are vulnerable to DMA security threats. Previous works focus only on DMA security problem of directly assigned devices. Moreover, these solutions either introduce significant overhead or require modifications on the guest OS to optimize performance, and none can achieve high I/O efficiency and good compatibility with the guest OS simultaneously, which are both necessary for production environments. However, for simulated virtual devices the DMA security problem also exists, and previous works cannot solve this problem. The reason behind that is IOMMU circuits on the host do not work for this kind of devices as DMA operations of which are simulated by memory copy of CPU. Motivated by the above observations, we propose an IOMMU para-virtualization solution called PVIOMMU, which provides general functionalities especially DMA security guarantees for both directly assigned devices and simulated devices. The prototype of PVIOMMU is implemented in Qemu/KVM based on the virtio framework and can be dynamically loaded into guest kernel as a module, As a result, modifying and rebuilding guest kernel are not required. In addition, the device model of Qemu is revised to implement DMA access control by separating the device simulator from the address space of the guest virtual machine. Experimental evaluations on three kinds of network devices including Intel I210 (1Gbps), simulated E1000 (1Gbps) and IB ConnectX-3 (40Gbps) show that, PVIOMMU introduces little overhead on DMA transactions, and in general the network I/O performance is close to that in the native KVM implementation without IOMMU virtualization.

Survey on the virtual commissioning of manufacturing systems

Lee, Chi G.,Park, Sang C. Society for Computational Design and Engineering 2014 Journal of computational design and engineering Vol.1 No.3

This paper reviews and identifies issues in the application of virtual commissioning technology for automated manufacturing systems. While the real commissioning of a manufacturing system involves a real plant system and a real controller, the virtual commissioning deals with a virtual plant model and a real controller. The expected benefits of virtual commissioning are the reduction of debugging and correction efforts during the subsequent real commissioning stage. However, it requires a virtual plant model and hence still requires significant amount time and efforts. Two main issues are identified, the physical model construction of a virtual device, and the logical model construction of a virtual device. This paper reviews the current literature related to the two issues and proposes future research directions to achieve the full utilization of virtual commissioning technology.

Implementation of Domain Separation-based Security Platform for Smart Device

김정녀 한국디지털정책학회 2016 디지털융복합연구 Vol.14 No.12

Recently, important information related with smart work such as office and video conference are handled in smart device quite a lot compare with before. Also, execution environment of smart devices is getting developed as open software environment. It brought convenience to download and use any kind of application software. By that, security side of smart devices became vulnerable. This paper will discuss characteristics of smart device security technology based on virtualization that is a mobile device platform with isolated secure execution area based on TEE (Trusted Execution Environment). Also, this paper will suggest an implementation method about safe smart device security platform based on domain separation for application software which can be executed in smart devices. The domain separation based smart device security platform technology in this paper blocks unauthorized access and leakage of sensitive information in device. Also it will be the solution can block transmission and execution of malicious code in various area including variety of IoT devices in internet rather than just smart devices

가상현실(Virtual Reality) 디바이스 이용의도와 구매의도에 영향을 미치는 요인 연구: 확장된 통합기술수용모델(UTAUT2)을 중심으로

최원석,강다영,최세정 한국정보사회학회 2017 정보사회와 미디어 Vol.18 No.3

This study proposed and empirically tested an acceptance model for the VR device in the consumer context by combining the Unified Theory of Acceptance and Use of Technology (UTAUT2) model and the VR-specific variables. Specifically, variables derived from UTAUT2 – performance expectancy, effort expectancy, social influence, facilitating conditions and price value – were hypothesized to influence usage intention of the VR device. Perceived risk, content quality and innovativeness were identified as the factors related to the use of VR devices and postulated as the antecedents of usage intention of the VR device. Usage intention then was presumed to influence purchase intention of the VR device. Results found that performance expectancy, social influence, perceived risk and innovativeness significantly influenced usage intention, which eventually led to purchase intention of the VR device. In addition, a further analysis found that effort expectancy, facilitating conditions, and price value have significant effects on purchase intention of the VR device. Lastly, a significant moderating effect of the VR experience (experience versus inexperience group) was identified. For the experience group, among the verified hypotheses, the effect of performance expectancy on usage intention and that of price value on purchase intention were not shown to be significant. On the other hand, in terms of the inexperience group, innovativeness was not shown to significantly influence usage intention. Effort expectancy was not a significant predictor of purchase intention for both groups. Managerial and industrial implications and suggestions for future research were provided. 가상현실(Virtual Reality)이 새로운 혁신 기술로 주목을 받고 있다. 가상현실과 같은새로운 기술이나 매체가 출현하고 확산이 시작되는 도입 초기 단계에서는 소비자들의 수용과 채택 과정을 관찰하고 예측하는 연구가 필수적이다. 본 연구에서는 확장된 통합기술수용모델(UTAUT2)을 바탕으로 대중화 시작 단계에 있는 가상현실 기기에 대한 소비자의 이용의도와 구매의도에 영향을 미치는 요인들을 분석하였다. 연구 결과, 성과기대와 사회적 영향, 인지된 위험, 혁신성향 등의 4가지 변인이 가상현실 기기 이용의도에유의미한 영향을 미치는 것으로 확인되었다. 노력기대와 촉진조건, 가격 효용성 변인은가상현실 기기 이용의도에 대한 유의미한 영향력이 확인되지 않았지만, 구매의도 형성에직접적인 영향을 주는 요인들로 확인되었다. 콘텐츠 품질 요인의 가상현실 기기 이용의도와 구매의도에 대한 영향력은 모두 유의미하지 않게 나타났다. 추가적으로 가상현실이용 경험의 조절효과가 유의미하게 확인되었다. 가상현실 이용 경험이 있는 그룹은 혁신성향이 이용의도에 유의미한 영향을 미치는 반면, 비경험 그룹은 성과기대가 이용의도에 영향을 주는 것으로 나타났다. 사회적 영향과 인지된 위험은 두 그룹 모두에서 영향력이 유의미했다. 구매의도에는 두 그룹 모두 촉진조건과 이용의도의 영향력이 확인되었고, 비경험 그룹에서는 가격 효용성이 구매의도에 영향을 미치는 것으로 나타났다.