• Asian Oncology Nursing
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• v.9 no.1
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• pp.31-42
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• 2009

Purpose: The purpose of the study was to understand how patients experience everyday life in an isolation unit for hematopoietic stem cell transplantation (HSCT). Method: The data were collected from 25 patients with HSCT at the isolation unit from January to March in 2008 in one general hospital in Korea. The data were collected by participant observations and ethnographic interviews and were analyzed using ethnographic method. Results: Four themes regarding environmental area emerged: 'barrier pulling up the drawbridge', 'very strange world', 'small and restricted space tied by IV and other treatment lines', and 'loud noise in a silent space.' Three themes regarding patients emerged: 'facing fear and anxiety', 'continuation of loneliness and lethargy', and 'compromising with a very long, dull, and boring time'. These themes describe how patients with HSCT suffer from continuous physical and psychosocial problems in a confined space, while endeavoring to control these problems and to search for hope for a new life. Conclusion: The results of the study provide an in-depth understanding of the experience and culture of patients in an isolation unit for HSCT. They would be used in developing practical programs to decrease patient's culture shock including fear and anxiety at isolation unit for HSCT.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.103-108
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• 2012

Radiofrequency(RF) signal is a key medium to the most of the present wireless communication devices including RF identification devices(RFID) and smart sensors. However, the most critical barrier to overcome in RFID application is in the failure rate in detection. The most notable improvement in the detection was from the introduction of EPC Class1 Gen2 protocol, but the fundamental problems in the physical properties of the RF signal drew less attention. In this work, we focused on the physical properties of the RF signal in order to understand the failure rate by noting the existence of the ground planes and noise sources in the real environment. By using the mathematical computation software, Maple, we simulated the distribution of the electromagnetic field from a dipole antenna when ground planes exist. Calculations showed that the dark area can be formed by interference. We also constructed a test system to measure the failure rate in the detection of a RFID transponder. The test system was composed of a fixed RFID reader and an EPC Class1 Gen2 transponder which was attached to a scanner to sweep in the x-y plane. Labview software was used to control the x-y scanner and to acquire data. Tests in the laboratory environment showed that the dark area can be as much as 43 %. One who wants to use RFID and smart sensors should carefully consider the extent of the dark area.

• Smart Structures and Systems
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• v.24 no.6
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• pp.803-812
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• 2019

Triplex composite is an epoxy-bonded joint structure, which constitutes the secondary barrier in a liquefied natural gas (LNG) carrier. Defects in the triplex composite weaken its shear strength and may cause leakage of the LNG, thus compromising the structural integrity of the LNG carrier. This paper proposes an autonomous triplex composite inspection (ATCI) system for visualizing and classifying hidden defects in the triplex composite installed inside an LNG carrier. First, heat energy is generated on the surface of the triplex composite using halogen lamps, and the corresponding heat response is measured by an infrared (IR) camera. Next, the region of interest (ROI) is traced and noise components are removed to minimize false indications of defects. After a defect is identified, it is classified as internal void or uncured adhesive and its size and shape are quantified and visualized, respectively. The proposed ATCI system allows the fully automated and contactless detection, classification, and quantification of hidden defects inside the triplex composite. The effectiveness of the proposed ATCI system is validated using the data obtained from actual triplex composite installed in an LNG carrier membrane system.

• Journal of Auto-vehicle Safety Association
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• v.16 no.1
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• pp.12-20
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• 2024

Side impact with MDB (moving deformable barrier) is common in side crash test protocols around the globe, most of which are quite similar to that of US NCAP side impact protocol but IIHS side impact protocol is considered to be the most harsh one due to the MDB's weight and impact speed. In this study US NCAP side impact and IIHS side impact test conditions are compared with respect to delta-V (impulse of the test vehicle), roll speed, and yaw speed as well as survival space (the smallest distance between the front driver seat cushion center to B pillar after the test). Error factors (friction between tire and ground, tolerance of vertical and longitudinal position of the MDB with respect to the test vehicle), which are resident in the test protocol is studied with respect to the global vehicle behavior (delta-V, roll, yaw) as well as survival space.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.597-603
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• 2014

The aim of the present study is to compare sound performance depending on thickness, materials, and structure of polymer soundproof panels consisting of PC, PMMA, HDPE, and PP, respectively. As a result of comparing sound transmission loss (STL) of single layer panel made of four types of polymer, the better sound transmission loss was obtained in order of PC, PMMA, HDPE, and PP, which was obviously followed mass law. 8 mm of single panel showed 5~6 dB(A) greater STL than that of 4 mm panels and lower frequency for coincidence effect so that STL of 8 mm panels decreased around 4,000~5,000 Hz, indicating less STL of 4 mm panels than those of 8 mm. When it comes to structure, 4 mm panels with air layer appeared similar value of STL with 8 mm single panels under 300 Hz. In range of high frequency above 2,000 Hz, 4 mm panels with air layer performed better than 8 mm of single layer panel while resonance effects were observed at 500~630 Hz. It was found that these results could be practically utilized as fundamental data for noise barriers design considering the change to each condition.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.153-170
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• 2022

Waterjet has been comprehensively used in urban areas owing to a suitable technique for cutting concrete and rock, and low noise and vibration. Recently, the abrasive waterjet technique has been adopted and applied by the Korea Atomic Energy Research Institute to demolish concrete plugging without disturbing and damaging In-situ Demonstration of Engineered Barrier System in the disposal research tunnel. In this study, the use of abrasive waterjet in the tunnel was evaluated for practical applicability and the existing cutting model was compared with the experimental results. As a variable for waterjet cutting, multi-cutting, water flow rate, abrasive flow rate, and standoff distance were selected for the diversity of analysis. As regarding the practical application, the waterjet facilitated path selection for cutting the concrete plugging and prevented additional disturbances in the periphery. The pump's noise at idling was 64.9 dB which is satisfied with the noise regulatory standard, but it exceeded the standard at ejection to air and target concrete because the experiment was performed in the tunnel space. The experimental result showed that the error between the predicted and measured cutting volume was 12~13% for the first cut and 16% for second cut. The standoff distance had a significant influence on the cutting depth and width, and the error tended to decrease with decrement of standoff distance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.1-6
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• 2013

This study has focused on transparency recovering of the polycarbonate by polishing its surface for recycling. The polycarbonate has many properties such as excellent mechanical strength, electrical insulating, superior heat resistance to other plastic material and especially good transparency. It has been used as barrier for the traffic noise at the roadside and the greenhouse for the palm house. But the polycarbonate has changed slightly as time goes by 10 years because of exposure to the strong sunlight and oxidization in the atmosphere, as result has lost its transparency. Magnetic assisted polishing has been utilized as an effective polishing method to recover the transparency of polycarbonate. The polycarbonate which has been used for 10 years was adopted as the sample. The first surface roughness of the sample was 1$1.23{\mu}mRa$, $7.5{\mu}mRz(DIN)$ respectively. In the experimental results, it showed that the surface roughness of the polished sample improved $0.013{\mu}mRa$, $0.08{\mu}mRz(DIN)$ from the first surface roughness respectively. The surface roughness get almost back again by magnetic assisted polishing. These results also showed that the magnetic assisted polishing was efficient machining method to reuse the polycarbonate material.

• Progress in Superconductivity
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• v.10 no.2
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• pp.99-102
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• 2009

We report our development of the fabrication process of sub-micron scale $Al-AlO_x-Al$ tunnel junction by using electron-beam lithography and double-angle shadow evaporation technique. We used double-layer resist to construct a suspended bridge structure, and double-angle electron-beam evaporation to form a sub-micron scale overlapped junction. We adopted an e-beam insensitive resist as a bottom sacrificing layer. Tunnel barrier was formed by oxidation of the bottom aluminum layer between the bottom and top electrode deposition, which was done in a separate load-lock chamber. The junction resistance is designed and controlled to be 50 $\Omega$ to match the impedance of the transmission line. The junctions will be used in the broadband shot noise thermometry experiment, which will serve as a link between the electrical unit and the thermodynamic unit.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.1
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• pp.22-29
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• 2006

We demonstrate highly manufacturable Multi-channel Field Effect Transistor (McFET) on bulk Si wafer. McFET shows excellent transistor characteristics, such as $5{\sim}6 times higher drive current than planar MOSFET, ideal subthreshold swing, low drain induced barrier lowering (DIBL) without pocket implantation and negligible body bias dependency, maintaining the same source/drain resistance as that of a planar transistor due to the unique feature of McFET. And suitable threshold voltage ($V_T$) for SRAM operation and high static noise margin (SNM) are achieved by using TiN metal gate electrode.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.455-461
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• 2006

In this study, we have described a method for the fabrication of a protein chip on silicon substrate using hydrophobic thin film and microfluidic channels, for the simultaneous detection of multiple targets in samples. The use of hydrophobic thin film provides for a physical, chemical, and biological barrier for protein patterning. The microfluidic channels create four protein patterned strips on the silicon surfaces with a high signal-to-noise ratio. The feasibility of the protein chips was determined in order to discriminate between each protein interaction in a mixture sample that included biotin, ovalbumin, hepatitis B antigen, and hepatitis C antigen. In the fabrication of the multiplexed assay system, the utilization of the hydrophobic thin film and the microfluidic networks constitutes a more convenient method for the development of biosensors or biochips. This technique may be applicable to the simultaneous evaluation of multiple protein-protein interactions.