• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3150-3158
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• 1997

In the ATM networks, there are two method in traffic control as schemes to improve the quality of service; one is the reactive control after congestion and the other is the preventive control before congestion. The preventive control include the CAC(Connection Admission Control), the UPC(Usage Parameter Control), the NPC(Network Parameter Control) and the PC(Priority co ntrol). In this paper, we propose an efficient UPC algorithm that has a complex structure using the Jumping window algorithm within the Leaky Bucket algorithm. The proposed algorithm controls peak hit rate by the Leaky Bucket algorithm, then it does the traffic control to evaluate by the Jumping Window whether violates mean bit rate or not. As we assume On/Off traffic source model, our simulation results showed cell loss rate less than the pre-existential Leaky Bucket algorithm method, and it could decrease the demanded Bucket size.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.739-746
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• 2004

License mechanisms are the key elements in almost all DRM(digital rights management) systems. The license mechanisms are designed for the clear identification and enforcement of contents, principals, and usage rules in DRM systems. But current license mechanisms are lacking in the flexibility for the secure and efficient sharing of the contents among the members of a group such as a family or a part of an enterprise. This paper suggests a new license mechanism for efficient and secure sharing of contents in DRM systems among the members of a group. We named it member/group license mechanism. The mechanism extends the current license mechanisms by introducing new concepts such as group licenses, member licenses, and derivation relationships between licenses.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.575-578
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• 2004

Since a construction project is a series of works that utilizes resources to accomplish the project goal for a given time period, efficient resource management is a prerequisite for the success of the project. Two major areas of resource management are resource constrained scheduling focusing on the limited resource availability and resource leveling focusing on smoothing resource usage pattern on the fixed project completion time. It is not available, however, to apply both techniques to a project at the same time. This paper proposes a model to enhance the minimum moment algorithm of resource leveling, aiming to find an efficient usage of resources and an appropriate project completion time. A survey is performed to evaluate the major five factors using the AHP.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.138-145
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• 2010

Stereoscopic technology can be regarded as core basis technology which is commonly requested in field of next generation stereoscopic multi media information communication. Realization of stereoscopic image in order to express natural images that are close to reality is a part that human constantly put effort, it first began with visual recognition system, went through stereo picture by using binocular disparity and were conducted as video clip stereoscopic age. Life is changing, a new culture is formed, there were technological development which realized imagination as reality based on expansion of IT industry and core trend, and there is 3D stereoscopic image technology in the center. We will look at technology development tendency and development strategy of 3D stereoscopic image in this essay, and will suggest efficient usage plan of 3D stereoscopic image technology for continuous market expansion.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.13-22
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• 2011

The purpose of this study is to analyze Alva Aalto's libraries for understanding his efficient induction of natural light. To fulfill this purpose, Alvar Aalto's thought about library and natural light are examined through his working years and building types. The comparison of his libraries on usage of natural light shows different ways of natural light induction based on different locations and programs of libraries. Similarities and differences of Alvar Aalto's library architecture have strong relationship to the usage of natural light in libraries because Alvar Aalto himself regard reading as the core function of library and the efficient use of natural light is the main key of reading. In his natural light planning, regional characteristics including environmental factors and programmatic differences act as a basic standard for natural light plan. Especially, altitude of sun and its path, seasonal features affect the induction way of natural light. While conical skylights used at Viipuri library shows the characteristics of universality in Modernism architecture, later libraries presents not only various kinds of pan-shape plan but different ways of inducing natural light in according to appropriate function. From conical skylight to monitor with curved reflection wall make it possible shed diffused light to reading space and this affects to form Alvar Aalto's organic architecture. As a result, using natural light in Alvar Aalto's library architecture act as the core of forming library concepts and their development.

• ETRI Journal
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• v.33 no.2
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• pp.267-274
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• 2011

This paper proposes an efficient masking method for the block cipher SEED that is standardized in Korea. The nonlinear parts of SEED consist of two S-boxes and modular additions. However, the masked version of these nonlinear parts requires excessive RAM usage and a large number of operations. Protecting SEED by the general masking method requires 512 bytes of RAM corresponding to masked S-boxes and a large number of operations corresponding to the masked addition. This paper proposes a new-style masked S-box which can reduce the amount of operations of the masking addition process as well as the RAM usage. The proposed masked SEED, equipped with the new-style masked S-box, reduces the RAM requirements to 288 bytes, and it also reduces the processing time by 38% compared with the masked SEED using the general masked S-box. The proposed method also applies to other block ciphers with the same nonlinear operations.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.6
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• pp.507-513
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• 2004

In this paper, we consider the methodology of efficient resource usage, specially web clustering system. We develope an algorithm that distributes the load on the web cluster system to use the system resources, such as system memory equally. The response time is chosen as a performance measure on the various clustering models. And based on the concurrent user to the web cluster system, the response time is also examined as the number of users increases. Simulation experience with this algorithm shows that the response time seems to have a good results compare to those with the other algorithm. And, also the effectiveness of clustered system becomes better as long as the number of concurrent user increases. The usage of developed algorithm is more useful when the system consists of many different sub-systems, a heterogeneous clustering system.

• Journal of Climate Change Research
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• v.9 no.3
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• pp.253-261
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• 2018

As user-involved energy saving activities have become important in recent years, many forms of energy feedback experiments have been conducted. We conducted a study to determine if energy feedback activities affect energy saving for students living in dormitories at a university in Seoul. In particular, smart plugs were used for efficient research and quantitative performance measurements, and the extent of the impact of competition and rewards on participant energy saving behavior was further analyzed. The main findings of this study are as follows. First, the power usage of groups using smart plugs was lower than that of those without them. Second, energy feedback delivered to smart plug users did not have a significant impact on reduction of electric power consumption. Third, competition and compensation strategies had additional effects in reducing power usage for smart plug users. As a result, methods to deliver energy feedback more effectively as ICT technologies develop and efficient energy activities using IoT technologies can be expected to spread widely in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5357-5381
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• 2018

Cloud computing offers a wide range of on-demand resources over the internet. Utility-based resource allocation in cloud data centers significantly increases the number of cloud users. Heavy usage of cloud data center encounters many problems such as sacrificing system performance, increasing operational cost and high-energy consumption. Therefore, the result of the system damages the environment extremely due to heavy carbon (CO2) emission. However, dynamic allocation of energy-efficient resources in cloud data centers overcomes these problems. In this paper, we have proposed Energy and Service Level Agreement (SLA) Aware Resource Allocation Heuristic Algorithms. These algorithms are essential for reducing power consumption and SLA violation without diminishing the performance and Quality-of-Service (QoS) in cloud data centers. Our proposed model is organized as follows: a) SLA violation detection model is used to prevent Virtual Machines (VMs) from overloaded and underloaded host usage; b) for reducing power consumption of VMs, we have introduced Enhanced minPower and maxUtilization (EMPMU) VM migration policy; and c) efficient utilization of cloud resources and VM placement are achieved using SLA-aware Modified Best Fit Decreasing (MBFD) algorithm. We have validated our test results using CloudSim toolkit 3.0.3. Finally, experimental results have shown better resource utilization, reduced energy consumption and SLA violation in heterogeneous dynamic cloud environment.

• The Journal of the Acoustical Society of Korea
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• v.38 no.1
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• pp.9-22
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• 2019

In this paper, we propose a method that can be applied to the efficient implementation of multi-channel active noise controller. Since the normalized MFxLMS (Modified Filtered-x Least Mean Square) algorithm for the multi-channel active noise control requires a large amount of computation, the difficulty has lied in implementing the algorithm using a low-cost MCU (Microcontoller Unit). We implement the multi-channel active noise controller efficiently by optimizing the software based on the features of the MCU. By maximizing the usage of single-cycle MAC (Multiply- Accumulate) operations and minimizing move operations of the delay memory, we can achieve more than 3 times the performance in the aspect of computational optimization, and by parellel processing using the auxillary processor included in the MCU, we can also obtain more than 4 times the performance. In addition, the usage of additional parts can be minimized by maximizing the usage of the peripherals embedded in the MCU.