• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.562-565
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• 2017

In this letter, we consider a 7-step transmission procedure of a large number of machine nodes when they simultaneously request random access to transmit uplink data. We model the radio resource utilization of LTE systems, and analyze the overloaded resources. From the simulation results, we show that the resource of PDCCH becomes significantly overloaded as the number of machine nodes increases in a cell. To alleviate the overload of PDCCH, we allocate radio resource of PDSCH to PDCCH. The result shows that the resource utilization of PDCCH is improved.

• Journal of Platform Technology
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• v.10 no.4
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• pp.70-81
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• 2022

In this paper, we proposed a Virtual Machine Placement (VMP) method to provide live vertical scaling services for cloud resources. Since free space on the physical server must be secured in advance for vertical scaling, a "general-mixed-vertical" mode conversion algorithm based on the FirstFit placement strategy that variably adjusts the allocation ratio of virtual servers to physical servers for this purpose is presented. Simulations were performed using parameters such as vertical scaling ratio, virtualization ratio, and free resource ratio. When the vertical scaling ratio is 50%, considering free space, 150% of resources are required as a whole, but simulation results of the proposed algorithm show that only up to 125% of free space is required.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.37-42
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• 2003

Physical properties of paper can be explained in terms of the changes in fiber's morphological properties. As the paper machine speed increases, the basis weight decreases and the mixing ratio of inferior recycled fibers increases, paper break becomes important than ever before. One of the objectives of this study is to analyze paper's physical, mechanical and fracture mechanical properties depending on softwood(SW) and hardwood(HW) mixing ratios and recycling. Fibers were refined by Valley beater to 450 mL CSF. Handsheets of 30 g/$\textrm{m}^2$ were prepared at different mixing ratios. Fracture toughness was measured as the amount of energy applied to cracked sample before total failure. Fracture toughness showed different trend to other strength properties. At the mixing ratio of SW 80: HW 20, papers showed the maximum fracture toughness. At this mixing ratio, flexible softwood fibers were mostly broken and stiff hardwood fibers were mostly pulled out.

• Textile Coloration and Finishing
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• v.20 no.1
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• pp.28-35
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• 2008

Texturing is the process of including a characteristic of a natural fiber in a synthetic fiber. The most common method of it the false twist texturing. Nylon textured yarn is primarily manufactured by the disk type. The major process parameters or the disk type false twist machine ratio, disk/yarn, and heater temperature. This study therefore investigated the effects of false twist texturing, especially speed and draw ratio, on the physical properties of nylon textured yarn. The increase of speed was proportional to the increase of unwinding tension, which could reduce the production efficiency by elevating the tension affecting to fiber during the process. In addition, the increase of speed was inversely proportional to the increase of crimp rigidity of nylon textured yarn. Draw ratio was proportionally increased with the increase of tenacity and the reductions of fineness and elongation, showing the influence or draw ratio to the ultimate physical properties of textured yarn.

• Textile Coloration and Finishing
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• v.16 no.3
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• pp.39-46
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• 2004

This study surveys the physical properties of DTY composite yarns manufactured by pin, disk and belt texturing systems. For this purpose, 208d/36f POY PET and 40d/12f high shrinkable PET filaments are prepared for specimens. The composite yarns are manufactured with this texturized POY and high shrinkable PET filament using the pin, disk and belt type texturing machines. While the processing conditions of the pin and disk types texturing machines were fixed, those of a belt type texturing machine were varied with over feed to compare and analyze with the yarn physical properties of pin and disk type composite yarns.

• Journal of Magnetics
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• v.18 no.3
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• pp.339-341
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• 2013

The magnetic field standards, facilities and capabilities available at NPL for the calibration of magnetometers and gradiometers and the measurement of the magnetic properties of materials will be introduced. The details of the low magnetic field facility will be explained and the capabilities this facility enables for the characterisation and calibration of ultra-sensitive room temperature magnetic sensors will be presented. Building on core material capabilities that are compliant with the IEC 60404 series of written standards, the example of a standard permeameter that has been modified for the measurement of strips for real world conditions is discussed. This was incorporated into a stress machine to measure the DC properties of the soft magnetic materials used by the partners of a collaborative industry led R&D project at stress levels of up to 700 MPa. The results for three materials are presented and the changes in the properties with applied stress compared to establish which material exhibits favourable properties.

• International Journal of Computer Science & Network Security
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• v.21 no.2
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• pp.221-228
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• 2021

Recent improvements on the quality, fidelity and availability of biometric data have led to effective human physical activity detection (HPAD) in real time which adds significant value to applications such as human behavior identification, healthcare monitoring, and user authentication. Current approaches usually use machine-learning techniques for human physical activity recognition based on the data collected from wearable accelerometer sensor from a single wearable smart device on the user. However, collecting data from a single wearable smart device may not provide the complete user activity data as it is usually attached to only single part of the user's body. In addition, in case of the absence of the single sensor, then no data can be collected. Hence, in this paper, a continuous HPAD will be presented to effectively perform user activity detection with mobile service infrastructure using multiple wearable smart devices, namely smartphone and smartwatch placed in various locations on user's body for more accurate HPAD. A case study on a comprehensive dataset of classified human physical activities with our HAPD approach shows substantial improvement in HPAD accuracy.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.666-675
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• 1993

In order to prevent bodily injuries frequently suffered in using bush cutters, especially from spattered stones, we developed a unique new cutting system equipped with a fixed blade on top of the rotary blade, and checked into the mowing performance of the cutter. From experimental test of mowing efficiency and measuring test of physical stress (O$_2$ consumption and heartbeat rates) , the new cutting system with a fixed blade proved that it keeps good cutting performance with lower peripheral speed of the rotary blade(22m/sec), compared to that of ordinary cutting blade, yielding more safety in operation. Weight of the cutter head is, however, heavier than that of ordinary machine by about 70% which increased a physical stress on the operator with slightly faster heartbeat rates. In mowing along edge of concrete wall, the operator enjoyed using the cutter with no anxiety , owing to function of the fixed blade.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.87-90
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• 2008

The purpose of this experiment is to understand a possibility for the techniques of collecting the Korean Rhus lacquer by the traditional method(Hwachil) against the diminishing lacquer industry. Hwachil method, making use of fire to collect lacquer, is practiced at only some areas, but the lacquer is very efficacious for foods and oriental medicine. A comparative experiment between traditional method and new machine method by processing unit 5 kg of lacquer tree was made to improve Hwachil method technically. The results showed that the machine method produced more about 45% of lacquer than the traditional one. The traditional method, moreover, needed intense labour quality and high leveled techniques, which caused to bring physical sufferings. In comparison with the traditional method for the collecting time required, the machine one showed to take more than minutes per a unit. But the machine method was easy and convenient to handle the machine without special techniques.

• Journal of IKEEE
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• v.20 no.1
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• pp.94-102
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• 2016

This paper proposes a new prediction method to reduce times and labor of repetitive multi-physics simulation. To achieve exact results from the whole simulation processes, complex modeling and huge amounts of time are required. Current multi-physics analysis focuses on the simulation method itself and the simulation environment to reduce times and labor. However this paper proposes an alternative way to reduce simulation times and labor by exploiting machine learning algorithm trained with data set from simulation results. Through comparing each machine learning algorithm, Gaussian Process Regression showed the best performance with under 100 training data and how similar results can be achieved through machine-learning without a complex simulation process. Given trained machine learning algorithm, it's possible to predict the result after changing some features of the simulation model just in a few second. This new method will be helpful to effectively reduce simulation times and labor because it can predict the results before more simulation.