• Journal of the Korean Magnetics Society
• /
• v.24 no.6
• /
• pp.179-185
• /
• 2014

The existing USB connection type of the clip-type pulsmeter equipped with a Hall sensor and a permanent magnet does not have any error or malfunction to measure the pulse wave. The property of the wireless networking system communicating the pulse wave data through the wireless LAN communication by combination USB with Ethernet and Ethernet to Wi-Fi converting system instead of existing USB connection method was investigated. There are exited that the patient needs to stay at close site of the desktop PC without USB connector and the wireless transfer and receiver networking system has pulse wave measurement SW to receive the pulse wave data. Thus it is expected that the study becomes helpful to measure and transfer the exact pulse wave of the patient in a comfortable pose at close range.

• Journal of Information Display
• /
• v.3 no.4
• /
• pp.19-22
• /
• 2002

In this paper, we introduce an efficient three-dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode-Ray Tube (CRT). A three-axis Hall probe mounted in a small cylindrical bar and three-stepping motors placed in a non-magnetic frame were utilized for the mapping. Prior to the mapping starts, the inner contour of DY was measured by a laser sensor to make a look-up table for inner shape of DY. Three-axis magnetic fields are then digitized by a three-dimensional Hall probe. The results of the mapping can be transformed into various output formats such as multi pole harmonics of magnetic fields. Field shape in one, two and three- dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and some analysis results.

• Journal of the Korean Magnetics Society
• /
• v.21 no.3
• /
• pp.104-107
• /
• 2011

We measured signals at the "Guan" region of a radially arterial pulse using the prototype of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure by using the cuffless clip type pulsimeter without an unpleasant oppressive feeling due to the use of pressurization.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.5
• /
• pp.60-70
• /
• 2001

This landscape design proposal was presented to a design competition for Gwangjin-gu Community Center and Assembly Hall. The site is located in 227-7 Jayang-dong, Gwangjin-gu, Seoul and is part a block designated as \`Kunkuk University Detailed Planning District\`. The judging criteria for landscape design set by the Gwangjin-gu could be articulated as follows: an identity of Gwangjin-gu, a relationship with surrounding environment, a locale as a community center of Gwangjin-gu, and an environment-friendly design. An identity of Gwangjin-gu was expressed by introducing lends and decks around the building which were transformed from the image of the old Gwangjin Ferry. The concept\` was strengthened by \`Nori-madang\` or Korean version of \`plaza\` which was designed by a motive of \`mungsuk\` or Korean old fashioned straw mat. An ambiguous relationship between the site and the surroundings was set by \`transparent exhibition frame\` which not only bleaks the massive Chungdam-daegyo, an elevated road, and frames it into small parts, but also attracts pedestrians toward the site-the \`park\`. Pedestrians from the adjacent\` Nengdong-ro Walkable Streets\` views the site through the many parts of frames. By introducing diverse resting and dynamic spaces for many kinds of cultural activities the site could function as a locale of the Gwangjin-gu community. The main paving system reflects the environment- friendly design. It was detailed by \`PC-block-deck-paving\` which was elevated from the ground so that rains could be absorbed.

• Journal of Magnetics
• /
• v.16 no.4
• /
• pp.449-452
• /
• 2011

A wrist wearable cuffless pulsimeter with a portable and small size apparatus using Hall effect is fabricated. The analysis of the pulse wave measured by the testing product of pulsimeter is done to measure the pulse rate and blood pressure. The blood pressure obtained by the puslimeter is compared with the practical values measured by electronic or mercury liquid blood pressure meters. The detail analysis of a pulse wave measured by a wrist wearable cuffless pulsimeter detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of blood pressure applying for oriental medical apparatus.

• Journal of the Korean Vacuum Society
• /
• v.19 no.2
• /
• pp.121-127
• /
• 2010

Neutral gas in a Hall-effect thruster in a small satellite is simulated using a molecular dynamics code. Investigated are neutral density, pressure, axial average velocity, and temperature for the variation of diffusive reflection ratio, initial gas temperature, and channel length. Expected through this research are improving of discharge simulation through the neutral simulation and understanding of real system.

• Korean Institute of Interior Design Journal
• /
• v.21 no.5
• /
• pp.46-56
• /
• 2012

Though Korea and China have a lot of things in common, these two countries have developed different housing style. However, after modernization, apartments have become major housing style in both Korea and China. So this research analyzed 240 apartment plans which was build in Seoul and Beijing in 2000s and 2010s to predict the future trends for apartments. The results are as follows: The opening direction of the front door will be outwards as the hallway space of small apartments in China become wider as the living standards is increasing. Because of the floor sitting lifestyle, Koreans end outdoor activities when take off their shoes at the entrance hall and continue for indoor activities, they separate entrance hall from livingroom. However, because Chinese have chair sitting lifestyle, entrance hall and livingroom is not divided. Korean apartment shows a trend which connects livingroom, diningroom and kitchen altogether; however, Chinese apartment shows a trend which separates kitchen from livingroom and diningroom. Bedrooms are showing a trend of distributed layout. Master bedroom are showing a trend which includes separate bathroom or attached room as the size of apartment increases and so on.

• Journal of the Korean Institute of Rural Architecture
• /
• v.20 no.4
• /
• pp.19-29
• /
• 2018

This study examines the 1960s' townscape through the small-scale restoration model in Seongan-dong and Jungang-dong, Cheongju, one of the historical cities in South Korea. In the 1960s, Jungang-dong actively was developed outside the north gate of Cheongju castle, and Cheongju's townscape was changed by the relocation of railway station and construction of city hall. In the streetscape, the new roads, the east-west Sajik-ro and north-south Sangdang-ro were opened instead of old railroads, and they clarified the typical grid road system with the existing Seongan-ro, which connected north and south gate of the old castle. In the buildingscape, city hall was built in front of the railway station outside the north gate of old castle, and had a great effect on the existing buildings and facilities. The public, educational, and commercial buildings had been replaced by reinforced concrete, and the cement brick & block public housing were distributed widely. But the existing dwelling areas, located in the inside of old castle and outside south gate, showed the low and dense townscape, sustaining the former streets and building types.

• Journal of Magnetics
• /
• v.20 no.3
• /
• pp.312-316
• /
• 2015

Unlike conventional Eddy Current Test (ECT), Pulsed Eddy Current (PEC) uses a multiple-frequency current pulse through the excitation coil. In the present study, the detection of subsurface cracks using a specially designed probe that allows the detection of a deeper crack with a relatively small current density has been attempted using the PEC technique. The tested sample is a piece of 304 stainless steel (SS304) with a thickness of 30mm. Small electrical discharge machining (EDM) notches were put in the test sample at different depths from the surface to simulate the subsurface cracks in a pipe. The designed PEC probe consists of an excitation coil and a Hall sensor and can detect a subsurface crack as narrow and shallow as 0.2 mm wide and 2 mm deep. The maximum distance between the probe and the defect is 28 mm. The peak amplitude of the detected pulse is used to evaluate the cracks under the sample surface. In time domain analysis, the greater the crack depth the greater the peak amplitude of the detected pulse. The experimental results indicated that the proposed system has the potential to detect the subsurface cracks in stainless steel plates.

• Carbon letters
• /
• v.13 no.1
• /
• pp.44-47
• /
• 2012

We analyzed the effect of etchants for metal catalysts in terms of the characteristics of resulting graphene films, such as sheet resistance, hall mobility, transmittance, and carrier concentration. We found the residue of $FeCl_3$ etchant degraded the sheet resistance and mobility of graphene films. The residue was identified as an iron oxide containing a small amount of Cl through elemental analysis using X-ray photoelectron spectroscopy. To remove this residue, we provide an alternative etching solution by introducing acidic etching solutions and their combinations ($HNO_3$, HCl, $FeCl_3$ + HCl, and $FeCl_3+HNO_3$). The combination of $FeCl_3$ and acidic solutions (HCl and $HNO_3$) resulted in more enhanced electrical properties than pure etchants, which is attributed to the elimination of left over etching residue, and a small amount of amorphous carbon debris after the etching process.