• Journal of electromagnetic engineering and science
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• 제18권1호
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• pp.7-12
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• 2018

This article proposes an ultrahigh frequency band radio frequency identification (RFID) tag antenna for drug runout management that can be used in hospitals. The RFID tag antenna is designed to function as a sensor that alerts drug runout when a drug inside a drip chamber is completely consumed but does not work when a drug remains inside a drop chamber. A previously proposed 915 MHz dipole antenna, is too large to be attached to the drip chamber of a feeding bag. Moreover, the length of the dipole (L) should be increased for conjugate matching with an RFID chip. Therefore, the dipole antenna is downsized so that it can be attached to the drip chamber through a fine meander line structure coupling with a corrugate meander line. A transparent cover is added to enhance the grip force between the designed antenna and the drip chamber and to enable detachment. The dimensions of the completed antenna structure attachable to a drip chamber are 32.59 mm (height) and 13.5 mm (width). The gain reduction due to the decreased antenna length is enhanced. The fabricated antenna shows an average omni-directional read range of 10.65 m on a horizontal plane and has the function of sensing the presence of a drug.

• Journal of Korean Port Research
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• 제10권1호
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• pp.25-36
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• 1996

Generally, it is pointed out that a nonlinear analysis is needed to estimate accurately the water surface fluctuation and dynamic responses of a floating structure in case of large wave reflection. In this study, a frequency-domain method is applied and newly developed to analyze the nonlinear characteristics of the air-chamber floating breakwater. The air-chamber floating breakwater in this study can control well the wave transformation, motions of the structure and its natural frequency by adjusting the air depth in the chamber. Experiments are carried out to verify the numerical results. It is appeared that the mean water level is setup in the anti-node and setdown in the node, while the nonlinearity in wave profile is larger in the node than in the anti-node. Because of vertical mooring system, the sway, especially the time-independent nonlinear component, plays predominant role in the motion. On the other hand, the time-dependent component, as well as the time-independent one to the tensile force of mooring line contributes greatly, and the time averaged value presents tensional force oriented to the onshore side due drift force.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제33권6호
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• pp.2343-2350
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• 2013

The wave height distributions in front of a vertically perforated wall structures for obliquely incident uni-directional irregular waves are mainly investigated by using 3D hydraulic experiments. The difference and similarity of wave propagation along the plain and perforated wall structures are investigated and particularly the effects of side walls in chamber and relative chamber width are analyzed. This study shows that the wave height distribution patterns for normalized wave heights in front of structure is significantly different between the plain and perforated wall structures, and the side wall in the chamber suppresses the growth of waves.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제31권10호
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• pp.1046-1052
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which was operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreased the thermal load and strain of the cooling channel structure. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Transactions of the Korean Society of Automotive Engineers
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• 제7권7호
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• pp.24-31
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• 1999

The MPI engine becomes increasingly popular because it meets two requirements of stringent pollutant emission and the lower fuel consumption. Even though supplies the same amount of fuel to each cylinder , it is hard to precisely control the air-duel ration due to the different amount of air flowing into each cylinder. The uniformity of air-fuel ration in each cylinder is considerably affected by the plenum chamber configuration . This study is focused on experimentally analyzing the flow characteristics within the plenum chamber In the present experiment , steady and valve dynamic state flow tests are performed and the flow field inside the plenum chamber is visualized and measured by utilizing a laser sheet visualization technique and a PTV method. These measured results indicate that the flow structure in the plenum chamber is highly influenced by the plenum chamber configurations, suction flow rates, crank speeds and so on.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.251-256
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• 2003

The detailed flow characteristics inside a compression chamber due to the orbiting motion of a scroll is studied numerically. The orbiting motion of a scroll is modelled at 7 orbiting angles. At each orbit angle, the central compression chamber is modelled. All computations are carried by using an in-house code. It is based on the SIMPLE algorithm. Computation results show that the flow structure inside the compression chamber is dependent on the orbit angle. The pressure variation inside the compression chamber also shows great dependence on the orbit angle. The pressure variation shows local maxima when the orbiting motion of a scroll directs toward the center of the compression chamber.

• Korean Journal of Heritage: History & Science
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• 제55권1호
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• pp.223-242
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• 2022

The main purpose of this study is to find out the meaning of structural changes that appeared in the royal tombs of the Joseon Dynasty after the application of a compound lime-mortar(Sammulhoe三物灰: the mortar with lime, sand, ocher). In the early Joseon Dynasty, the royal tomb was constructed by following the system of the stone chamber tomb in the Goryeo Dynasty. However the system of the stone chamber tomb recorded in 『GukJo-OReYi(國朝五禮儀: The five category's formalities in the Joseon Dynasty)』 is very different from that in the Goryeo Dynasty. The biggest difference is that a compound lime-mortar was applied into the system of the stone chamber tomb in order to attempt structural reinforcement. This change reflects King Sejong's willingness to build a dense structure in which water does not permeate the stone chamber when Yeongneung(英陵) was built in 1446(the 28th year of King Sejong's reign). Yeongneung is a complex structure consisting of a stone chamber and compound lime-mortar wall. After constructing a stone chamber, the 1.2m(4尺) thick wall with a compound lime-mortar is additionally constructed outside the stone chamber structure. In 1468(the year of King Yejong's accession), according to the will of King Sejo, the stone chamber system was abolished and the Hyeongung(玄宮: the chamber enshrining a coffin of the deceased king or queen consort) was constructed only by the thick wall with a compound lime-mortar. This change become a primary cause for the royal tomb to be constructed as Hoekyukneung(灰隔陵: the royal tomb with chamber constructed only by the thick wall with compound lime-mortar) in the late Joseon Dynasty. The Hoekyukneung in the late Joseon Dynasty has been constructed with the method of structure and construction for the thick wall with a compound lime-mortar since the complex structure recorded in 『GukJo-OReYi(國朝五禮儀)』. The Hoekuykseoksilneung(灰隔石室陵: the complex structure consisting of a stone chamber and compound lime-mortar wall) is unique tomb style of Joseon Dynasty and become a motive of tomb system(Hoekuykneung) in the late Joseon Dynasty.

• Journal of Industrial Technology
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• 제33권A호
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• pp.9-14
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• 2013

Reliability plays a pivotal role in the development of medical instruments. A hyperbaric oxygen chamber, as a medical/health device, is known to help medical therapy for diversity of diseases through provision of high purity oxygen. The use of hyperbaric oxygen chamber is expected to increase in the future and study to examine reliability and safety is needed. We have performed reliability assessment for a newly developed hyperbaric oxygen chamber in this study. We first briefly discussed the system structure and mechanism. We then performed FMEA (Failure Mode and Effect Analysis) for the chamber. We drew major failure modes affecting the system performance and performed in depth analysis for measuring the expected effects.

• Journal of Ocean Engineering and Technology
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• 제22권1호
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• pp.22-29
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• 2008

A numerical investigation is made on the effects of the location and shape of the front wall of an OWC(Oscillating Water Column) chamber on the hydroelastic response of a VLFS. Most of the studies on the effects of an OWC chamber on the response of a VLFS have assumed the location of the OWC chamber to be at the front of the VLFS. In the present study, an OWC-chamber is introduced at an arbitrary position in relation to a VLFS to determine the influence of the location and shape of the OWC chamber on the hydroelastic response of the VLFS. A finite element method is adopted as a numerical scheme for the fluid domain. or the finite element method, combined with a mode superposition method, is applied in order to consider the change of mass and stiffness The OWC chamber in a piecewise constant manner. or the facilitated anefficient analysis of The hydroelastic response of the VLFS, as well as the easy modeling of different shape and material properties for the structure. Reduction of hydroelastic response of the VLFS is investigated for various locations and front wall shapes of the owe chamber.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제33권12호
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• pp.109-116
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• 2005

Elastic-plastic structural analysis for regenerative cooling chamber of liquid rocket thrust chamber is performed. Uniaxial tension test is also conducted for the copper alloy in order to get material data necessary for the structure analysis. The results of uniaxial tension test reveal that copper alloy become ductile after brazing process and flow stress becomes lower as temperature becomes higher. As a result of structural analysis using the material data, the deformation of cooling channel is more increased by thermal load than by internal pressure of cooling fluid. Therefore, the results of analysis show that structural stability and cooling performance of combustion thrust chamber which is designed to endure mechanical load and minimized a channel thickness are improved by decreased thermal load as possible.