• International journal of advanced smart convergence
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• 제5권4호
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• pp.26-31
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• 2016

In a cloud computing environment, a cryptographic service allows an information owner to encrypt the information and send it to a cloud server as well as to receive and decode encrypted data from the server which guarantees the confidentiality of shared information. However, if an attacker gains a coded data and has access to an encryption key via cloud server, then the server will be unable to prevent data leaks by a cloud service provider. In this paper, we proposed a key management server which does not allow an attacker to access to a coded key of the owners and prevents data leaks by a cloud service provider. A key management server provides a service where a server receives a coded public key of an information user from an owner and delivers a coded key to a user. Using a key management server proposed in this paper, we validated that the server can secure the confidentiality of an encryption key of data owners and efficiently distribute keys to data users.

• 한국정보통신학회논문지
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• 제10권2호
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• pp.315-320
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• 2006

분산 컴퓨터 네트워크는 단일 시스템의 동작 정지로 인한 전체 시스템에 미치는 영향을 적 게 함으로써 신뢰도를 높일 수 있고, 한 개의 대형 시스템을 활용하는 것 보다 저렴한 비용으로 보다 나은 성능을 얻을 수 있는 장점이 있다. 또한 시스템이 확장 및 재구성이 용이하다[1]. 그러나, 분산 컴퓨팅 환경에서 네트워크를 통한 데이터의 공유는 실생활이 되고 있는 반면 네트워크 환경에서 데이터의 무결성과 보안에 대한 위험성은 증가하고 있다[2],[3]. 따라서 본 논문에서는 운영적 요소와 기술적 요소에 대한 분석을 통해 이러한 요소들을 결합시키기 위한 네트워크 암호화 데이터베이스 보안시스템 모델을 제시한다. 제시한 모델에 운영적 요소와 기술적 요소를 체계적으로 결합시킨다면 분산 컴퓨팅 환경에서 허가받지 않은 사용자로부터 데이터를 안전하게 보호할 암호화 데이터베이스 보안 시스템을 구축할 수 있을 것이다.

• ETRI Journal
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• 제43권5호
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• pp.825-834
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• 2021

Based on its simplicity and user-friendly characteristics, OpenMP has become the standard model for programming on shared-memory architectures. Checkpointing-aided parallel execution (CAPE) is an approach that utilizes the discontinuous incremental checkpointing technique (DICKPT) to translate and execute OpenMP programs on distributed-memory architectures automatically. Currently, CAPE implements the OpenMP execution model by utilizing the DICKPT to distribute parallel jobs and their data to slave machines, and then collects the results after executing these distributed jobs. Although this model has been proven to be effective in terms of performance and compatibility with OpenMP on distributed-memory systems, it cannot fully exploit the capabilities of multicore processors. This paper presents a novel execution model for CAPE that utilizes two levels of parallelism. In the proposed model, we add another level of parallelism in the form of multithreaded processes on slave machines with the goal of better exploiting their multicore CPUs. Initial experimental results presented near the end of this paper demonstrate that this model provides significantly enhanced CAPE performance.

• 한국국방경영분석학회지
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• 제11권1호
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• pp.8-32
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• 1985

The objective of this study is to develop the Transportation Model of Linear Programming in which optimal transportation pattern by regions (origins and destinations) to minimize the total transportation costs can be obtained for handling government-held grains. As a result of computing the Transportation Model, the total transportation costs of transporting 1,058,507 metric tons from origins to destinations are 7,234 million won. So, the transporation cost is 6,834 won per ton in this model. But actual transportation cost in 1983 is 11,498 won per ton. Therefore when we distribute and transport the government-held grains from production factories to consumption warehouses, using this Transportation Model of Linear Programming is benefitable. Especially excluding the cost of computer, we could save more than two billion won of Government budget per year.

• 디지털콘텐츠학회 논문지
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• 제8권3호
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• pp.393-401
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• 2007

P2P systems have gained a lot of research interests and popularity over the years and have the capability to unleash and distribute awesome amounts of computing power, storage and bandwidths currently languishing - often underutilized - within corporate enterprises and every Internet connected home in the world. Since there is no central control over resources or devices and no before hand information about the resources or devices, device discovery remains a substantial problem in P2P environment. In this paper, we cover some of the current solutions to this problem and then propose our feed forward neural network (FFNN) based solution for device discovery in mobile P2P environment. We implements feed forward neural network (FFNN) trained with back propagation (BP) algorithm for device discovery and show, how large computation task can be distributed among such devices using agent technology. It also shows the possibility to use our architecture in home networking where devices have less storage capacity.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.382-387
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• 2005

There are many studies on arbitrarily divisible load scheduling problem in a distributed computing network consisting of processors interconnected through communication links. It is not efficient to arbitrarily distribute the load that comes into the system. In this paper, how to schedule in case that arbitrarily indivisible load comes into the system is studied. Also, the cases of the divisible load mixed with the indivisible load that come into network were dealt with optimal load distribution in parallel processing system by scheduling applied to linear programming.

• Journal of Information Processing Systems
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• 제10권2호
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• pp.240-255
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• 2014

Cloud computing has increasingly been drawing attention these days. Each big company in IT hurries to get a chunk of meat that promises to be a whopping market in the future. At the same time, information is always associated with security and risk problems. Nowadays, the handling of these risks is no longer just a technology problem, with a good deal of literature focusing on risk or security management and framework in the information system. In this paper, we find the specific business meaning of the BMIS model and try to apply and leverage this model to cloud risk. Through a previous study, we select and determine the causal risk factors in cloud service, which are also known as CSFs (Critical Success Factors) in information management. Subsequently, we distribute all selected CSFs into the BMIS model by mapping with ten principles in cloud risk. Finally, by using the leverage points, we try to leverage the model factors and aim to make a resource-optimized, dynamic, general risk control business model for cloud service providers.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 추계학술발표대회
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• pp.109-110
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• 2009

최근 IT산업의 화두인 클라우드 컴퓨팅에서, HDFS는 널리 사용되고 있는 분산 파일 시스템이다. HDFS는 분산된 데이터의 저장과 검색의 장점이 있는 반면, 대용량 파일처리를 목적으로 설계되었기 때문에 실시간 파일처리와 저용량 데이터 처리에 비효율적이다. 본 논문에서는 이러한 문제를 해결하기 위해 HDFS의 파일 처리 과정을 개선하여 저용량 파일 처리를 향상시키는 방법을 제안한다. 본 기법은 데이터 블록에 저용량 파일들을 병합함으로써 데이터 처리의 효율성을 높이는 결과를 보였다.

• Journal of information and communication convergence engineering
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• 제21권4호
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• pp.261-267
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• 2023

Public research, which requires large computational resources, utilizes the supercomputers of the National Supercomputing Center in the Republic of Korea. The average utilization rate of resources over the past three years reached 80%. Therefore, to ensure the operational stability of this national infrastructure, specialized centers have been established to distribute the computational demand concentrated in the national centers. It is necessary to predict the computational demand accurately to build an appropriate resource scale. Therefore, it is important to estimate the inflow and outflow of computational demand between the national and specialized centers to size the resources required to construct specialized centers. We conducted a logit model analysis using the probabilistic utility theory to derive the preferences of individual users for future supercomputer resources. This analysis shows that the computational demand share of specialized centers is 59.5%, which exceeds the resource utilization plan of existing specialized centers.

• 인터넷정보학회논문지
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• 제8권2호
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• pp.23-31
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• 2007

노력 (인력)과 일정이 추정된 경우, 인력을 일정 시간대별로 효율적으로 배분하기는 매우 어렵다. 지금까지 Putnam의 Rayleigh 분포모델이 널리 적용되고 있다 이 분포는 프로젝트 전반부에서 인력이 집중적으로 투입되는 형태를 표현하고 있다. 그러나 실제 수행된 프로젝트의 대부분이 중반부나 후반부시점에서 인력이 집중적으로 투입되는 현상을 나타내 Rayleigh 분포를 적용할 수 없다. 따라서 본 논문은 인력을 효율적으로 배분하기 위한 모델을 제안한다. 먼저, 소프트웨어 개발 분야에서 제시하고 있는 전형적인 형태와 실제 수행 프로젝트들의 인력 프로파일 형태를 고찰하였다. 다음으로, 효율적인 인력 배분을 위해 인력 프로파일에 대한 윤곽을 그려 모델을 유도하는 방법을 제안하였다. 제안된 모델은 기존의 Rayleigh와 Gamma 모델보다 좋은 성능을 나타내었다. 제안된 모델을 적용할 경우 소프트웨어 개발계획단계에서 개발기간에 대한 투입될 인력을 적절히 배분하여 프로젝트를 성공적으로 관리할 수 있을 것이다.