• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.408-411
• /
• 1995

Microstructure and magnetic properties of $Fe-Nd_{13.5}-Co_{15}-B_{6-8}Ga_{0-1}-Zr_{0.2-1}$ alloys during HDDR process were studied. $ZrB_{2}$ phase was detected and identified by X-Ray diffraction. Influence of Ga, Zr and Ga+Zr additions on phase relations at different stages of HDDR process was studied by X-ray diffraction and magnetic measurements.

• Bulletin of the Korean Mathematical Society
• /
• v.56 no.2
• /
• pp.383-390
• /
• 2019

We consider special curves (rectifying-type curves) in the simplest Myller configuration and study their properties, in order to compare these properties in both cases, Myller and Euclidean settings.

• Journal of Radiation Protection and Research
• /
• v.20 no.1
• /
• pp.8-15
• /
• 1995

An estimate of a change in radioactivity's circumstances around the nuclear power plant is validated with the results of the radioactivity measurements are compared. In this study, to further enhance the reliability of the results obtained from the environmental radioactivity measurements and analysis around the nuclear power plants that have been carried out up to the present. In the korea standard, there is the technical analysis guide for general stable chemical element's, but there is not the technical analysis guide for the radionuclei. therefore the environmental sample collection, the pretreatment of the sample and radionuclide analysis in the sample, the result's of the environmental radioactivity measurements by each organization, etc. are different. It is not sufficient for the database to forecasting a change in radioactivity's circumstances. A comparative study of collection and pretreatment techniques for the soil sample, the results by comparison, the method of minimizing the relative error are proposed. At one side of sample collection, there are going to considered that the surroundings of sample collection like the lay of the land, the provision of the selection standard for the area and pathway of radionuclide adhesion, the coherence of sample collection, etc.. at another side of pretreatment of the sample and measurement in the case of soil sample, how to do homogeneously the soil particle size and the standard tools, i.e. kinds of meshes, must to be selected.

• Smart Structures and Systems
• /
• v.7 no.2
• /
• pp.83-102
• /
• 2011

As a testbed for various structural health monitoring (SHM) technologies, a super-tall structure - the 610 m-tall Guangzhou Television and Sightseeing Tower (GTST) in southern China - is currently under construction. This study aims to explore state-of-the-art wireless sensing technologies for monitoring the ambient vibration of such a super-tall structure during construction. The very nature of wireless sensing frees the system from the need for extensive cabling and renders the system suitable for use on construction sites where conditions continuously change. On the other hand, unique technical hurdles exist when deploying wireless sensors in real-life structural monitoring applications. For example, the low-frequency and low-amplitude ambient vibration of the GTST poses significant challenges to sensor signal conditioning and digitization. Reliable wireless transmission over long distances is another technical challenge when utilized in such a super-tall structure. In this study, wireless sensing measurements are conducted at multiple heights of the GTST tower. Data transmission between a wireless sensing device installed at the upper levels of the tower and a base station located at the ground level (a distance that exceeds 443 m) is implemented. To verify the quality of the wireless measurements, the wireless data is compared with data collected by a conventional cable-based monitoring system. This preliminary study demonstrates that wireless sensing technologies have the capability of monitoring the low-amplitude and low-frequency ambient vibration of a super-tall and slender structure like the GTST.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2000.06a
• /
• pp.1-10
• /
• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control sub-process through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are-white water consistency control which is the most effective way to control retention - charge demand measurement and control which takes care of concentration of the anionic material entering to PM -ash measurements and controls which are deeply related to retention and paper quality This paper presents and concentrates to two of these key controls ; retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloida material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately , and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation , and results of our unique wet end analyzers (retention and charge ) which are at the level of automation solutions as a part of paper machine quality control Especially our newest member of the platform , on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.5
• /
• pp.44-53
• /
• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs, the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control subprocesses through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are - white water consistency control which is the most effective way to control retention. - charge demand measurement and control which takes care of concentration of the anionic material entering to PM. - ash measurements and controls which are deeply related to retention and paper quality. This paper presents and concentrates to two of these key controls: retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloidal material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately, and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation, and results of our unique wet end analyzers (retention and charge) which are at the level of automation solutions as a part of paper machine quality control. Especially our newest member of the platform, on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Geomechanics and Engineering
• /
• v.13 no.6
• /
• pp.893-906
• /
• 2017

Automatic large scale soil model generation is very critical stage for earthquake hazard simulation of urban areas. Manual model development may cause some data losses and may not be effective when there are too many data from different soil observations in a wide area. Geographic information systems (GIS) for storing and analyzing spatial data help scientists to generate better models automatically. Although the original soil observations were limited to soil profile data, the recent developments in mapping technology, interpolation methods, and remote sensing have provided advanced soil model developments. Together with advanced computational technology, it is possible to handle much larger volumes of data. The scientists may solve difficult problems of describing the spatial variation of soil. In this study, an algorithm is proposed for automatic three dimensional soil and velocity model development of southern part of the European side of Istanbul next to Sea of Marmara based on GIS data. In the proposed algorithm, firstly bedrock surface is generated from integration of geological and geophysical measurements. Then, layer surface contacts are integrated with data gathered in vertical borings, and interpolations are interpreted on sections between the borings automatically. Three dimensional underground geology model is prepared using boring data, geologic cross sections and formation base contours drawn in the light of these data. During the preparation of the model, classification studies are made based on formation models. Then, 3D velocity models are developed by using geophysical measurements such as refraction-microtremor, array microtremor and PS logging. The soil and velocity models are integrated and final soil model is obtained. All stages of this algorithm are carried out automatically in the selected urban area. The system directly reads the GIS soil data in the selected part of urban area and 3D soil model is automatically developed for large scale earthquake hazard simulation studies.

• Journal of radiological science and technology
• /
• v.42 no.4
• /
• pp.259-263
• /
• 2019

This study was purpose to compare image quality of Indirect digital radiography (IDR) system by using the International electro-technical commission standard(IEC 62220-1) which were applied to IEC in medical imaging. To evaluation the analysis of Modulation transfer function(MTF) measurements edge device each angle by using edge method. In this study, Aero (Konica, Japan) which is Indirect flat panel detector(FPD) was used, the size of image receptor matrix $1994{\times}2430$ which performed 12bit processing and pixel pitch is $175{\mu}m$. In IEC standard method were applied to each angle were compared. The results of shown as LSF at $2.0^{\circ}$ and $3.0^{\circ}$ angeles. Shape is constant and shows smooth shape. The amount of data seemed reasonable and 2.19 cycles/mm and 2.01 cycles/mm at a spatial frequency of $2.0^{\circ}$ and $3.0^{\circ}$ at an MTF value of 0.1. At an MTF value of 0.5, the spatial frequencies were $2.0^{\circ}$ and 1.11 cycles/mm and 0.93 cycles/mm at an angle of $3.0^{\circ}$. This study were to evaluate MTF by setting the each $2{\sim}3^{\circ}$ each angle and to suggest the quantitative methods of measuring by using IEC.

• The Research Journal of the Costume Culture
• /
• v.16 no.3
• /
• pp.502-517
• /
• 2008

The purpose of the study lies in the measurements of breast shapes and upper body types for the women in their 40's, with the use of 3D measurement system, and in the presentation of brassiere patterns fit for their body types. As for the study method, 3D human body types were analyzed with RapidForm 2006, and the upper-body types and breast shapes were statistically classified through technical statistics analysis, cluster analysis, t-test, variance analysis, and cross analysis. The wearing tests went through the comparison of the brassieres of three makers in the market and the experiment brassieres(first and second) and then the evaluations were made by the subjects, the outer appearance assessment by experts, and 3D measurements. The findings of the study indicated that the evaluation of experiment brassieres was excellent in every item, and he significant difference was found out particularly in the items of pressure, rear center, front center, breast underneath, adequate level by wing, and adequate level by armhole. According to the results of 3D evaluation, experiment brassieres had a highest point in fitness with no physical pressure at the wing part and no overall deviation at the cup art. The pattern comparison showed the differences in the parts of total cup angle, cup circumference length, lower cup height, wing length, and wing angle.

• The Research Journal of the Costume Culture
• /
• v.16 no.3
• /
• pp.488-501
• /
• 2008

The purpose of this study presents bra pattern using the 3D measurements of the upper body subject to women in their 30's. Brassieres available in the market are mostly designed for straight body shape and many women seem to have experienced bearing discomfort in a great extent as they grow older. Brassieres should be designed to cover diverse body types and the accurate measurement of body type and breast shape is needed to accomplish that. As for the study method, 3D human body types were analyzed with RapidForm 2006, and the upper-body types and breast shapes were statistically classified through technical statistics analysis, cluster analysis, t-test, variance analysis, and cross analysis. The wearing tests went through the comparison of the brassieres of three makers in the market and the experiment brassieres(first and second) and then the evaluations were made by the subjects, the outer appearance assessment by experts, and 3D measurements. The results of this study showed that the evaluation of experiment brassieres was excellent in every item, and the significant difference was found out particularly in the items of pressure, rear center, front center, breast underneath, adequate level by wing, and adequate level by armhole. According to the results of 3D evaluation, experiment brassieres had a highest point in fitness with no physical pressure at the wing part and no overall deviation at the cup part.