• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.8
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• pp.432-439
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• 2015

Current building procedures seek to minimize external air supplies to reduce the energy consumption of air conditioning, resulting in a high dependency on mechanical ventilation. We therefore studied an economizer-cycle system, whereby the introduction of external air saves energy. We analyzed different economizer-control methods, addressing mixed-air temperatures and outdoor-air fractions according to outdoor-air temperatures; also, we analyzed the energy consumption of the three economizer-cycle control types using detailed EnergyPlus simulation modeling. A differential enthalpy control method showed a lower energy consumption range from 5.8% to 6.2% than that of other methods during the simulated period. A differential dry-bulb control method showed a 12.7% lower energy consumption than the no-economizer method in the intermediate period, but also showed 7.1% more energy consumption during the summer period. When latent heat was not removed due to high summer humidity, we found a significant level of resultant energy consumption.

• Journal of Sensor Science and Technology
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• v.28 no.1
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• pp.64-70
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• 2019

Wireless sensors have been developed in numerous ways for enhancing the convenience of installation, management and maintenance of sensors. Energy harvesting wireless sensors, which can collect energy from the external environment for permanent usage without the need of recharging and exchanging batteries, have been developed and employed used in Internet of Things and at various industrial sites. Energy harvesting wireless sensors are significantly affected by the sensor lifespan to sudden variation in the external environment. Furthermore, reduction in the sensor operating timespan can greatly affect the characteristics of the devices connected through a network. In this paper, a system performance index is proposed that can comprehensively evaluate the lifespan of a solar cell wireless sensor, determine the characteristics of devices connected to the associated network, and recommend dynamic power distribution control for improving the system performance index. Improvement in the system performance index was verified by applying the proposed dynamic power distribution control to an air conditioner network system using a solar cell wireless sensor. Obtained results corroborate that the dynamic power distribution control can extend the lifespan of the incorporated wireless sensor and reduce the air conditioner's power consumption.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.95-102
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• 2024

In distributed computing, accessible encryption strategy over Auditable data is a hot research field. Be that as it may, most existing system on encoded look and auditable over outsourced cloud information and disregard customized seek goal. Distributed storage space get to manage is imperative for the security of given information, where information security is executed just for the encoded content. It is a smaller amount secure in light of the fact that the Intruder has been endeavored to separate the scrambled records or Information. To determine this issue we have actualize (CBC) figure piece fastening. It is tied in with adding XOR each plaintext piece to the figure content square that was already delivered. We propose a novel heterogeneous structure to evaluate the issue of single-point execution bottleneck and give a more proficient access control plot with a reviewing component. In the interim, in our plan, a CA (Central Authority) is acquainted with create mystery keys for authenticity confirmed clients. Not at all like other multi specialist get to control plots, each of the experts in our plan deals with the entire trait set independently. Keywords: Cloud storage, Access control, Auditing, CBC.

• The KSFM Journal of Fluid Machinery
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• v.6 no.4 s.21
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• pp.58-65
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• 2003

Stall inception means the phenomena of rotating stall initiation. The initiation mechanism of rotating stall, the existence of stall precursor, the behavior of stall precursor, stall warning scheme and control scheme are the main interests in stall inception research. Compared to the studies on rotating stall which has long history, the stall inception has been studied for about recent 20 years. After the first discovery of stall precursor in about 20 years ago, many studies were reported on stall inception phenomena. The inception pattern of 'mode' and 'spike' were found, and some of its characteristics are known. And now the stall inception has become one of the fascinating fields in turbomachinery. The development stall control scheme which apply the reliable stall warning scheme will play a great role in future compressor and aeroengine. This paper reviews the results and analysis methods on stall inception studies.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.839-844
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• 2009

In this paper, a real-time eye tracking method using fast face detection is proposed. Most of the current eye tracking systems have operational limitations due to sensors, complicated backgrounds, and uneven lighting condition. It also suffers from slow response time which is not proper for a real-time application. The tracking performance is low under complicated background and uneven lighting condition. The proposed algorithm detects face region from acquired image using elliptic Hough transform followed by eye detection within the detected face region using Haar-like features. In order to reduce the computation time in tracking eyes, the algorithm predicts next frame search region from the information obtained in the current frame. Experiments through simulation show good performance of the proposed method under various environments.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.199-200
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• 2011

Absorption of lightweight aggregate affects the properties of fresh and hardened concrete, so care must be taken. In this study, according to KS F 2533 absorption is measured to aggregate size, submerged time, holding time and practically ways to maintain a constant absorption was to seek. The findings for quality control of the lightweight aggregate concrete mixture is saturation of the surface-dry aggregate humidity 100% after 24 hours immersion in the environment has been stored for more than two days to absorb the state was able to define. Dry density at the surface of the lightweight aggregate and lightweight concrete mix design and placement is possible for it to apply.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.3
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• pp.256-262
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• 2007

In mass customization, the focus is variety and customization through flexibility and quick responsiveness. Mass customizers seek to provide personalized, custom-designed products at low prices to give customers exactly what they want and to provide sufficient variety in products and services. The idea of the product family is the most adequate approach to realize mass customization. An understanding of customer needs using functional decomposition becomes necessary to enhance the performance of the product family. This paper focuses on functional architecture modeling based on customer need regarding sub-functions for the product family. A quantitative functional model captures product functionality and customer need. Based on customer need ratings and sub-function, a product-function matrix was created. Additionally, a product-product matrix was generated to provide a similarity index among product families. A case study for implementing the functional architecture modeling was performed on the single use cameras.

• The Journal of Korean Academy of Sensory Integration
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• v.5 no.1
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• pp.51-63
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• 2007

The purpose of this study is to provide definition of proprioception, foundations and roles of neuroanatomy, and systemical review of proprioceptive activities in sensory integration intervention. Proprioception exists in muscle, ligaments, joints and skin and it plays important role in controling body movements and interacting with environment during child development. Proprioception interacting with tactile and vestibular systems contributes to the change of muscle tone, postural control, refinements of planning and praxis. Children who are deficit in proprioceptive processing would seek hypo-responsive proprioceptive input or avoid hyperactive one. Outcome of poor proprioceptive input would cause the problems of praxis and postural control. Because proprioception provides information about the position and movement of body and limb it is important for development of body scheme and motor planning. It also influences the arousal and emotional tone. Sensory integration intervention which provides rich proprioceptive activities will improve the level of arousal and enhance motor planning.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.81-87
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• 2000

As for M/G/1 queueing system, we use various control policies, with which we can optimize the system. Up to now the most widely adopted policies are N-Policy, T-Policy, D-Policy, and so on. The existing researches are largely concerned to find an optimal operation condition or to optimize the system under single policy in M/G/1 system. There are, however, few literatures dealing with multiple control policies at once to enhance the flexibility of the model. In this study, we consider M/G/1 system adopting N-Policy and T-Policy simultaneously. If one of two conditions is satisfied, then, the server starts the service. We call this Min(N,T)-Policy. We find the probability distribution of the number of customers and mean waiting time in steady state and derive a cost function. Next, we seek the $N^*$, optimal threshold under various N values. Finally, we reveal the characteristics of cost function.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.12
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• pp.1072-1080
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• 2013

In a the present day, many vision inspection techniques are used in productive industrial areas. In particular, in the semiconductor industry the vision inspection system for wafers is a very important system. Also, inspection techniques for semiconductor wafer production are required to ensure high precision and fast inspection. In order to achieve these objectives, parallel processing of the inspection algorithm is essentially needed. In this paper, we propose the GPU (Graphical Processing Unit)-based parallel processing algorithm for the fast inspection of semiconductor wafers. The proposed algorithm is implemented on GPU boards made by NVIDIA Company. The defect detection performance of the proposed algorithm implemented on the GPU is the same as if by a single CPU, but the execution time of the proposed method is about 210 times faster than the one with a single CPU.