• Tunnel and Underground Space
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• v.34 no.1
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• pp.1-14
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• 2024

An image-reconstruction technology, involving the deployment of an unmanned mobility equipped with high-speed LiDAR (Light Detection And Ranging) has been proposed to reconstruct the shape of abandoned mine. Unmanned mobility operation is remarkably useful in abandoned mines fraught with operational difficulties including, but not limited to, obstacles, sludge, underwater and narrow tunnel with the diameter of 1.5 m or more. For cases of real abandoned mines, quadruped robots, quadcopter drones and underwater drones are respectively deployed on land, air, and water-filled sites. In addition to the advantage of scanning the abandoned mines with 2D solid-state lidar sensors, rotation of radiation at an inclination angle offers an increased efficiency for simultaneous reconstruction of mineshaft shapes and detecting obstacles. Sensor and robot posture were used for computing rotation matrices that helped compute geographical coordinates of the solid-state lidar data. Next, the quadruped robot scanned the actual site to reconstruct tunnel shape. Lastly, the optimal elements necessary to increase utility in actual fields were found and proposed.

• Progress in Superconductivity
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• v.14 no.2
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• pp.99-101
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• 2012

Fluorescent yield X-ray absorption fine structure (XAFS) spectroscopy is useful for analyzing local structure of specific elements in matrices. We developed an XAFS apparatus with a 100-pixel superconducting tunnel junction (STJ) detector array with a high sensitivity and a high resolution for light-element dopants in wide-gap semiconductors. An STJ detector has a pixel size of $100{\mu}m$ square, and an asymmetric layer structure of Nb(300 nm)-Al(70 nm)/AlOx/Al(70 nm)-Nb(50 nm). The 100-pixel STJ array has an effective area of $1mm^2$. The XAFS apparatus with the STJ array detector was installed in BL-11A of High Energy Accelerator Research Organization, Photon Factory (KEK PF). Fluorescent X-ray spectrum for boron nitride showed that the average energy resolution of the 100-pixels is 12 eV in full width half maximum for the N-K line, and The C-K and N-K lines are separated without peak tail overlap. We analyzed the N dopant atoms implanted into 4H-SiC substrates at a dose of 300 ppm in a 200 nm-thick surface layer. From a comparison between measured X-ray Absorption Near Edge Structure (XANES) spectra and ab initio FEFF calculations, it has been revealed that the N atoms substitute for the C site of the SiC lattice.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1067-1073
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• 2007

This paper presents development of an special metal hydride(SMH) actuator system using a peltier module. The newly developed simple SMH actuator, consisting of the plated hydrogen-absorbing alloy as a power source, Peltier elements as a heat source and a cylinder with metal bellows as a functioning part, has been developed. The SMH actuator is characterized by its small size, low weight, noiseless operation and a compliance similar to that of human body. A new SMH actuator that uses reversible reactions between the heat energy and mechanical energy of a hydrogen absorbing alloy. It is well known that hydrogen-absorbing alloys can reversibly absorb and desorb a large amount of hydrogen, more than about 1000 times of their own volume. To improve the thermal conductivity of the hydrogen-absorbing alloy, an electro-less copper plating has been carried out. For this purpose, the effects of the electro-less copper plating and the dynamic characteristics of the SMH actuator have been studied. The hydrogen equilibrium pressure increases and hydrogen is desorbed by heating the hydrogen-absorbing alloys, whereas by cooling the alloys, the hydrogen equilibrium pressure decreases and hydrogen is absorbed. The SMH actuator has the characteristic of being light and easy to use. Therefore, it is suitable for medical and rehabilitation applications.

• Journal of architectural history
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• v.18 no.6
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• pp.7-22
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• 2009

This writing is to understand some trends and its meaning of Regionalism Architecture in Jeju Island since 1950's. This thesis began with an interest in the identity crisis implicit in the simultaneous striving for modernism and the so-called regional values in Jeju Island. Regionalism is a response in architectural terms to re-establish continuity in a given place between past and present forms, and also a unique result related to particular places, cultures and climates in region. This is one way of looking at the issues of regional identity. The study began by observing the general characteristics of contemporary ideas on Regionalism in Jeju architecture. This means that tracing the history of development of Regionalism architecture in research area is not the focus of this thesis. The thesis demonstrates that Regionalism architectures in Jeju shows some trends related to the local cultural elements (or ideas) such like traditional architectural forms, natural environment, local construction-materials, etc. In summation, in the perspective of Regionalism architecture,mostofbuildingsin Jeju bring out them only as vernacular architecture as it was once produced, by the simple combination and imitation without any creative interaction of the regional culture. I stress the point in this paper that, in over the last fifty years, there have been very narrowed attempts to design the regional values in the main, and also point out that there are problems in the manner in which local architects have gone about trying to define the regional themes. So, a grate depth is required to understand the phenomenon that Jeju area is with its various nuances of traditions, art, culture, climate and light and then to reinterpret it into the modern building type with all the high sense. In addition to that, some conclusions are reached on future directions and the significance of the study.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.347.1-347.1
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• 2016

Screen printing is commonly used to form the electrode for crystalline silicon solar cells. However, it has caused high resistance and low aspect ratio, resulting in decrease of conversion efficiency. Accordingly, Ni/Cu/Ag plating method could be applied for crystalline silicon solar cells to reduce contact resistance. For Ni/Cu/Ag plating, laser ablation process is required to remove anti-reflection layers prior to the plating process, but laser ablation results in surface damage and then decrease of open-circuit voltage and cell efficiency. Another issue with plating process is ghost plating. Ghost plating occurred in the non-metallized region, resulting from pin-hole in anti-reflection layer. In this paper, we investigated the effect of Ni/Cu/Ag plating on the electrical properties, compared to screen printing method. In addition, phosphoric acid layer was spin-coated prior to laser ablation to minimize emitter damage by the laser. Phosphorous elements in phosphoric acid generated selective emitter throughout emitter layer during laser process. Then, KOH treatment was applied to remove surface damage by laser. At this step, amorphous silicon formed by laser ablation was recrystallized during firing process and remaining of amorphous silicon was removed by KOH treatment. As a result, electrical properties as Jsc, FF and efficiency were improved, but Voc was lower than screen printed solar cells because Voc was decreased due to surface damage by laser process. Accordingly, we expect that efficiency of solar cells could be improved by optimization of the process to remove surface damage.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.8
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• pp.1227-1240
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• 2009

This study examines the actual conditions of toddler playwear preference survey for design and function. The study develops proper indoor and outdoor playwear for toddlers based on the analysis. A survey of 200 parents with toddlers between 2 and 6 years old and 120 teachers was conducted to find the conditions and needs for playwear along with the necessary design elements. Second, 6 designs including 3 designs for indoor playwear and 3 designs for outdoor playwear were made. These designs emphasized on soil contamination part, color, pattern, form, material, detail, and fasteners. Art play and cooking play are considered for indoor playwear and ways to decrease contamination on sleeve hem, elbow, chest, and knee were determined through the use of yellow, green, and blue colors. Applying a character and separate top with sleeves were determined. Light with breathable and waterproof fabric was determined. The correct amount of Velcro fasteners or buttons was determined for front fastening in addition a pocket was considered necessary as a detail part. The common design for both boys and girls along with a proper design for diverse play were determined. For outdoor playwear, water play, sand play, movement play, and ecology experience are considered and ways to decease contamination on hip, sleeve hem, and knee should be applied to the design as determined through the use of yellow, green, blue, and red colors. The demands for pattern, form, material, and details were similar to indoor playwear. Zipper and buttons for front fastening were determined. These final 6 playwear designs are presented using CAD WALK DESIGNWARE.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.130-136
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• 1998

An Immunostimulating polysaccharide was produced from the suspension culture of Angelica gigas H4, plant cells. In order to enhance the polysaccharide production by the A. gigas cell culture, medium composition and physical conditions were optimized. Schenk and Hildebrandt (SH) medium was selected as an optimal basal medium for the growth of A. gigas. The maximum cell and polysaccharide concentration obtained in SH medium were 15.8 g DCW/l and 0.85 g polysaccharide/l, respectively, at $25^{\circ}C$ under dark condition. For the enhanced polysaccharide production, a polysaccharide production medium (PPM) was established by modifying Gamborg B5 medium with optimized carbon sources, growth regulators, organic and inorganic elements. Optimal initial pH and temperature were 6.0-6.6 and $20^{\circ}C$, respectively, and the dark condition was better than the light condition. The maximum polysaccharide concentration of 1.5 g/l could be obtained through the optimization of the medium composition and physical conditions.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.21-28
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• 2009

Most of domestic shipyards are located at coastal regions which are affected by typhoons nearly every year. For effectiveness of shipbuilding, shipyards contain many facilities which are light-weighted and affected dominantly by wind. In the present paper, we analyze various wind fields over a shipyard including surrounding topology and structures to evaluate the structural safety of the facilities posed in the strong wind. Extreme wind speed for a study region was estimated by typhoon Monte Carlo simulation and then used for inlet wind speed for CFD analysis for wind load on the facilities. Considering geometrical wind effects, we assess the surface pressure of the elements as the pressure factor, the ratio of surface pressure to dynamic pressure. The results show that the simulated wind speed is greater than the design wind speed for the some facilities because of the shipyard's geometry. It also shows that surrounding topography in coastal area is needed to be considered and adjustment for design wind speed at wind load standard application is necessary for mooring ship and industry facilities.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.551-555
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• 2005

This paper presents the temperature-pressure characteristics of SMH actuator using a peltier module. The simple SMH actuator, consisting of the plated hydrogen-absorbing alloy as a power source, Peltier elements as a heat source and a cylinder with metal bellows a functioning part has been developed. The SMH actuator is characterized by its small size, low weight, noiseless operation and a compliance similar to that of the human body. A new special metal hydride(SMH) actuator that uses the reversible reaction between the heat energy and mechanical energy of a hydrogen absorbing ally. It is well known that hydrogen-absorbing alloys can reversibly absorb and desorb a large amount of hydrogen, more than about 1000 times as their own volume. To improve the thermal conductivity of the hydrogen-absorbing alloy, an electro-less copper plating has been carried out. The effects of the electro-less copper plating and the dynamic characteristics of the SMH actuator have been studied. The hydrogen equilibrium pressure increases and hydrogen is desorbed by heating the hydrogen-absorbing alloys, whereas by cooling the alloys, the hydrogen equilibrium pressure decreases and hydrogen is absorbed. Therefor, the SMH actuator has the characteristic of being light and easy to use and so is suitable for use in medical and rehabilitation applications.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.2
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• pp.103-110
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• 1979

The contents of Sodium, Magnesium, Iron, nickel , Copper, Maganese and Zinc in Korean tobacco leaves Produced in 1978, were investigated. The contents of each mineral element in tobacco leaves of various varieties were as follows ; Mg was 5370$\mu{g}/g-7640\mu{g}/g$, Burley> Flue -cured >Native. Mn was 210$\mu{g}/g-1290\mu{g}/g$, Burley>Flue -cured>Native. Fe was 330$\mu{g}/g-590\mu{g}/g$, Burley>Flue -cured>Native. Zn was 500$\mu{g}/g$ -100, Native > Burley>Flue-cured. Na, Ni and Cu showed no difference between the types. The contents of Ha, Mg, Mn, Ni and Cu were reduced in the order of Heavy 5, 3, 1 and increased in the order of Light 1, 3, 5 grades. The correlation coefficient (r) between Mg and grade in Hicks, SC 72 and HC 2326 were 0.770-0.981, and significance level was 0.1 % .