• Korea-Australia Rheology Journal
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• v.19 no.2
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• pp.75-80
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• 2007

The slotted plate technique has previously been shown to be a successful method for directly measuring the static yield stress of suspensions. In this study, we further establish the usefulness of the slotted plate device as a rheometer especially at low shear rates, taking advantage of the extremely low speeds of the slotted plate technique. Newtonian fluids, a shear thinning fluid, and yield stress fluids were tested using the slotted plate device and the results were compared with those from a commercial rheometer using different standard flow geometries. The relationship between the stress on the plate and the viscosity for the slotted plate device obtained by dimensional analysis (drag) predicts a linear relationship between the force at the plate and the plate speed, consistent with the experimental data. The slotted plate device can measure viscosities at very low shear rates. The apparent viscosity - shear-rate data obtained from the slotted plate device are complementary to those obtained using a commercial rheometer. That is : the slotted plate can measure viscosity in the shear rate range $10^{-7}<\dot{\gamma}<10^{-3}\;s^{-1}$, while the commercial rheometer measures viscosity at shear rates higher than $10^{-3}\;s^{-1}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.397-398
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• 2008

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1289-1297
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• 2011

Objective of this study was to characterize $PM_{10}$ sources on subway tunnels and development of simple particulate matters measuring device based on wireless sensor network. A new wireless sensor module, PMX, has been designed and manufactured to measure $PM_{10}$ and$PM_{2.5}$ simultaneously. The measurements have been conducted at a specific subway station on the Seoul metro line. The accuracy of the device was verified and compared with commercial measuring device based on weighting method.

• Journal of Aerospace System Engineering
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• v.4 no.1
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• pp.32-37
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• 2010

Guided weapon is very excellent strategy system than conventional weapons. Recently, several devices and a technology developed much developing more, inertia measuring device is one example. Inertia measuring device is device that is used to improe more accuracy of guided weapon, this device is operated by sensors of inside. Sensors of inside are parts that is very sensitive about impact or shock, heat that interact when shoot, it is main purpose that verify durability of sensor by heat delivered from outside in this study.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.111-116
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• 2018

Recently, shape manufacturing method has been changed to a 3D printer. Since lamination type manufacturing method is the basis for forming a three-dimensional shape by repeated lamination, the horizontal accuracy of the lamination layer is very important. In the current paper, we have proposed a new leveling system to be installed in a large 3D printer. The light source was reflected from the water surface contained in the measuring device, and the inclination of the measuring device was measured from the light that entered into four regions of a quarter photodetector. The electrical signals generated differently according to the position of the beam spot incident on the quarter photodetector was acquired and compensated to be horizontal by using a motor mounted at the corner. Compared to a digital leveler, the newly developed leveling system gave errors of only 2 to 3%. This new device can be applied to various fields including the 3D printer in future.

• Journal of Distribution Science
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• v.10 no.11
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• pp.89-99
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• 2012

Purpose - Mobile devices, especially mobile terminals capable of telecommunication and wireless connectivity, are leading the advancements in consumer electronics. Digital convergence drives the functions of various devices, such as cellular phones, MP3 players, personal digital assistants, and gaming, into a single device. This trend would continue and applications such as digital audio and video streaming (including personalized content delivery mechanisms) would soon be on a handheld device. As customers want mobile convergence devices, manufacturers are driving new initiatives in the emerging mobile device market. Given the roles played by device design and service content in user satisfaction of a mobile convergence device, this study focuses on identifying and measuring the constructs for the process by which user satisfaction is achieved. This study synthesizes the expectation-disconfirmation paradigm with empirical theories in user satisfaction. Device and service levels are separated, and nine key constructs for user satisfaction of mobile convergence devices are proposed. Insight into this process could help web-based businesses to improve user satisfaction, thus enhancing the effectiveness of e-commerce for sellers and buyers. Research design, data, methodology - This study draws on three users of mobile convergence devices as examples. To test there search model and hypotheses, survey questionnaires were sent to 607 mobile device users. Mobile device users were initially identified from several members, and subjects were randomly drawn. Data from 577 survey responses were finally analyzed. The unit of measurement and analysis in this research study is at a personal level. Results - The measurements for the constructs were developed and tested in a two-phase study. In the first phase, the device and service dimensions were identified, and instruments for measuring them were developed and tested. In the second phase, using the salient dimensions of the device and service as the formulating first-order factors, instruments were developed and empirically tested to measure satisfaction of the device and service. In measuring satisfaction of mobile convergence devices, the critical tasks are to identify the key constructs of such user satisfaction and to develop validated instruments to measure them. Hence, the results of this study have immediate implications for businesses and for research in user satisfaction of mobile convergence devices. Conclusions - This study provides reliable instruments for operationalizing key constructs in the analysis of user satisfaction of mobile convergence devices within the expectation-disconfirmation paradigm. Hence, convergence device makers will be able to examine whether their websites meet their customers' expectations by examining the device aspect of the mobile convergence device customers, and the service aspect expectations and disconfirmation. Moreover, the introduction of expectation and disconfirmation constructs brings the marketing aspect of convergence devices into focus for such retailers, an aspect crucial to the effective design of websites for online businesses. In addition,this study provides the metrics required to initiate future studies on user satisfaction of mobile convergence devices.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.91-94
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• 2003

In this paper, we present a simple framework to measure BRDF(Bidirectional Reflectance Distribution Function) values of objects and to render them using the values more realistically. There are lots of BRDF measurement methods, but the methods have been separated from the effective rendering of the values. Therefore, we suggest the framework which includes the BRDF measurement methods of objects and the effective rendering methods of the measured BRDF data. Before measuring the BRDFs, we do light sources analysis, camera calibration and display device characterization. After measuring them, we apply them to the characterized display device for rendering effectively and realistically.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.653-660
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• 2015

This paper describes the design of the force measuring system for an industrial robot's deburring work. The force measuring system is composed of a three-axis force sensor, a measuring device, a housing and a cover. The three-axis force sensor can detect x-direction force, y-direction force and z-direction force at the same time. The measuring device is designed using DSP(Digital Signal Processor), and have a RS-232 and a RS-485 communication port for sending force data to PC or other controller. As a result of test, the repeatability error and the non-lineality error of the three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.95%. It is thought that the force measuring system can be used for an industrial robot's deburring work.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.5
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• pp.484-489
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• 2011

Some patients can't use their hands because of inherent and acquired paralysis of their fingers. Their fingers can recover with rehabilitative training, and the extent of rehabilitation can be judged by grasping a cylindrical-object with their fingers. At present, the cylindrical-object used in hospitals is only a cylinder which cannot measure grasping force of the fingers. Therefore, doctors must judge the extent of rehabilitation by watching patients' fingers as they grasp the cylinder. A cylindrical-type finger force measuring system which can measure the grasping force of patients' fingers should be developed. This paper looks at the development of a cylindrical-type finger force measuring system with two-axis force/moment sensor which can measure grasping force. The two-axis force/moment sensor was designed and fabricated, and the high-speed force measuring device was designed and manufactured by using DSP (digital signal processing). Also, cylindrical-type finger force measuring system was developed using the developed two-axis force/moment sensor and the high-speed force measuring device, and the grasping force tests of men were performed using the developed system. The tests confirm that the average finger forces of right and left hands for men were about 186N and 172N respectively.

• Biomedical Science Letters
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• v.14 no.3
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• pp.167-172
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• 2008

We compared the clinical efficacy of LED therapy using 880 nm and 630 nm LED to test collagen accumulations in subcutaneous tissue of mouse after LED irradiation by measuring the quantity of collagen. 880 nm and 630 nm LED was irradiated on the back of ICR mouse given at $10.8J/cm^2$ followed for 30 minutes everyday for 5 weeks. Histological observation was performed by Hematoxylin & Eosin staining and Masson's Trichrome collagen staining. We also used Sircol soluble collagen assay kit for measuring the amounts of collagen in the mouse skin tissue after 1, 3, and 5 weeks post LED irradiation, respectively. Collagen generation was found at subcutaneous tissue, and the quantity of collagen in 880 nm LED group had grown more than that of 630 nm LED group at 5 weeks follow-up later. About 75% more efficacies for collagen generation were found in the group of 5th week of 880nm LED irradiation. The efficacy of 880nm LED could be more useful than 630 nm LED for synthesizing collagens in mouse subcutaneous tissue as time followed.