• Plant Journal
• /
• v.11 no.1
• /
• pp.39-49
• /
• 2015

The objective of this study is to improve the classification structure of commodity code for piping material management which is considered as the fundamental of commodity code and piping material management system. It enhances the efficiency of piping material management directly or indirectly affecting the engineering, procurement and construction in a petrochemical plant projects. To establish an improved code classification structure, this study identifies the problems of former code classification structure in details, as well as the characteristics of other domestic and global EPC company's code classification structures and presents the improved direction considering the recently mega-sized and specialized projects. Accordingly, to efficiently enhance piping material management, the improved code classification structures have been derived from defining suitable code classification structure for specific piping component, adding more standard attribute, expanding the number of code digits and classifying code hierarchy. The results of applying the improved classification structure of commodity code to on-going project have led to reduce the rate of rework from 4.98% to 2.48% for developing purchase description and also have saved working time for executing piping design by 3D modeling from 6 months by two persons to 4 months by a person which is decreased 67% consequently. In addition, the structures of pyramid code management have resulted to accumulation and analysis of the various piping data for other disciplines such as procurement and estimation team which require commodity code information through the company's material control system.

• Conservation Science in Museum
• /
• v.7
• /
• pp.53-62
• /
• 2006

The wooden armor frame and various lacquerware artifacts excavated from the low swamp remains in Imdang, Gyeongsan have very weak material and lacquer coating; in case they are exposed in the air, they are likely to be shrunken and deformed immediately. The wooden armor frame has large size and it might be dissolved during freeze-drying. The lacquer coating of lacquerware blocks the penetration of chemicals and it is very likely to swell or peel off during the treatment. Therefore, to prevent the dissolution during vacuum freeze-drying, the wooden armor frame was replaced with t-butanol and impregnated in t-butanol solution with PEG#3, 350 43%, and lacquerware was impregnated in PEG#3, 350 40% solution at room temperature and freeze-dried. According to the analysis of the lacquer fragment from the lacquerware, the lid and the mounted cup was pasted with the mixture of lacquer and black pigment (soot) on the base layer after the first coating and pasted two or three times more with natural lacquer; the red lacquered wooden cup was pasted with the mixture of lacquer and black pigment on the base layer and pasted once on the middle layer. The top lacquer (red) was pasted with the mixture of iron oxide(Fe₂O₃).

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.4
• /
• pp.330-339
• /
• 2009

The material properties of Cedar (Cryptomeria japonica) were evaluated according to heat treatment conditions. The special focus was made on the color control of cedar wood by heat treatment. The difference of color between sapwood and heartwood could be reduced by heat treatment at a temperature above $170^{\circ}C$. Long heating time was more effective in reducing the difference. The Equilibrium Moisture Content (EMC) of heat-treated wood was as low as 50 percent. The result obviously indicates that heat-treated wood is more dimensionally stable in the change of moisture condition than the control. The heat-treated wood was also effective in increasing the durability against wood rotting fungi. However, more study is required to develop heat treatment as an environmentally-friendly technology for wood preservation without chemical. The mechanical properties of heat-treated wood showed relatively higher performance than the control in general. Meanwhile the dramatic decrease in impact bending stress due to the loss of ductility may limit uses of heat-treated wood in certain cases. There were no significant changes in microscopic structure which may cause changes in mechanical properties. Further study on the chemical analysis of heat-treated wood is needed to scrutinize the causes of changes of material properties.

• Journal of Conservation Science
• /
• v.34 no.2
• /
• pp.119-128
• /
• 2018

This study revealed the material composition and characteristics of 19 glass fragments excavated from stone chamber No. 1 of Jeongchon Tomb in Naju through chemical composition analyses and observations. These characteristics were compared with the characteristics of the glass fragments excavated from No. 3 tomb of Bogam-ri in Naju. The purpose of this study was to identify the characteristics of the ancient glass of the Mahan-Baekje period. The glass fragments excavated from the Jeongchon Tombs can be classified into purplish blue, light-purplish blue, greenish blue, green, and mixture of purple blue and purple, based on their color. These beads were made using a drawn and casting technique. In addition, blue glass fragments were primarily excavated form No. 3 tomb of Bogam-ri. However, red glass fragments were not excavated from either of the tombs. According to chemical composition analyses, soda glass group and potash glass group were common in both the tombs. Additionally, alkali mixed glass group and lead barium glass group were excavated from Jeongchon Tombs and No. 3 tomb of Bogam-ri, respectively. The glass fragments excavated from No. 3 tomb of Bogam-ri have more color variations than those excavated from Jeongchon Tombs.

• The Journal of the Korea Contents Association
• /
• v.18 no.1
• /
• pp.359-369
• /
• 2018

When expressing Christ visually in the medieval Christian painting, the most important issue was how to express the divinity as Son of God and the humanity as attribute of human in a balanced manner. The purpose of the study is to examine both formative and symbolic characters of divinity and humanity on the Christ's body and clothes in the Medieval paintings, Transfiguration of Christ. In the paintings, Christ's body is definite evidence to show both his divinity and humanity. In connection with the body, the clothes reveal Christ's humanity and divinity as well. Through this research, the study found that the divinity and humanity on the Christ's clothes in the Transfiguration of Christ were as follows: Blue, gold, purple, white and bleaching effect are the emblem of divinity, and red and color contrast effect with a high chroma stand for humanity of Christ. In addition, unstructured wrinkles of clothes reveal Christ's divinity, on the other hand, structured drapery shows his humanity through emphasizing volume of the body. Finally, divinity of Christ is shown on the gold clavus and red clavus intensify his humanity. Medieval Christian paintings are products planned out to express Christ's dual nature. There is a significance that the paintings represent the profession of painter's faith and the dogma of the era. Furthermore, they suggest the importance of the image to deliver the abstract concepts by visualizing.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.8
• /
• pp.592-597
• /
• 2013

It is widely known that the sound insulation of soundproof panel is highly correlated to two factors, surface density of material and the frequency of noise. Accordingly, the character of traffic noise released in actual situation is important requisite for determining thickness to determine surface density and material of soundproof panel. This present study selected polymer panel with advantage of light weight and workability and evaluates according to frequency of traffic noise. Polypropylene (PP) and high-density polyethylene (HDPE) were selected as subjects based on economic valuation and efficiency. The sound transmission loss of selected polymer panels were compared with the currently used panels such as polycarbonate (PC) and polymethyl methacrylate (PMMA) depending on thickness and materials. As a result, PC showed the highest sound transmission loss followed by PMMA, HDPE, and PP in range of mass law. In terms of acoustic performance on thickness, the transmission loss increased with thickness of soundproof panel meanwhile coincidence dip was observed in lower frequency where had reduced transmission loss. Therefore, it is suggested that after determining target frequency, the kind of materials and thickness of soundproof panel need to be designed so that traffic noise can be more efficiently reduced.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.6
• /
• pp.91-100
• /
• 2012

Wireless monitoring system for the structural health evaluation has a limit to the reliability of measured response. The objective of this study is to evaluate an effective measurement range of the wireless monitoring system on the analyzed data. For the wireless monitoring system, Bluetooth and Wi-Fi are applied to datalogger-receiver and receiver-personal computer, respectively. For the model of the monopile structure response, a laboratory-scale monopile is manufactured with Mono Cast Nylon and a lateral loading is applied by hammer impacting. Strain gauges attached on the model monopile are connected with the datalogger. The distances of datalogger-receiver and receiver-personal computer are changed for the evaluation of the measurement range. Experimental results show that the receiving rates of the response remain almost constant within limited distance, while the receiving rates dramatically decrease out of effective range. In addition, the receiving rates affect on the measured natural frequencies of the model monopile. This study suggests that the effective range evaluation of the wireless monitoring system may be used for the determination of a monitoring distance to the monopile installed in the offshore wind farm.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.3
• /
• pp.243-254
• /
• 2014

It is essential to predict the coil temperature under over load and over speed conditions for reliability in high speed low torque surface mounted PM synchronous motors(SPM). In the present study, the losses and coil temperature are measured under rated condition and calculated under over speed and over load conditions in the three different motors with 35PN440, 25PN250 and 15HTH1000. The heat transfer modeling has been performed based on acquired losses and temperature. The difference of coil temperature between heat transfer modeling and experiment is less than 6.4% under no load, over speed and over load conditions. Subsequently, the coil temperature of the motor with 15HTH1000 is 84.4% of the coil temperature of the motor with 35PN440 when speed is 0.9 and load is 3.0. The output of motor with 15HTH1000 is 85.2% greater than the output of the motor with 35PN440 when the dimensionless coil temperature is 1.0.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.11
• /
• pp.1721-1725
• /
• 2010

This paper reports the fabrication of geometry-controlled carbon microneedles by a backside exposure method and pyrolysis. The SU-8 microneedles are a polymer precursor in a carbonization process, which geometries such as base diameter, spacing, and aspect ratio can be controlled in a photolithography step. Using this fabrication method, highly reproducible carbon microneedles, which have high aspect ratios of more than 10 and very sharp nanotips, can be realized. The quartz surface with carbon microneedles becomes very hydrophilic and its wettability is adjusted by carrying out the silane treatment. In the carbon microneedle array ($3\;{\mu}m{\times}3\;{\mu}m$), the contact angle is extremly enhanced (${\sim}180^{\circ}$); this will be advantageous in developing low-drag microfluidics and labs-on-a-chip as well as in other bio-applications.

• Journal of the Korean Society for Railway
• /
• v.14 no.4
• /
• pp.313-319
• /
• 2011

In a modern society, various type of transportation modes are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day in Seoul. Due to the increased interests on the indoor air quality (IAQ) of underground facilities, public concerns on IAQ of subway system are increasing also. Platform screen door (PSD) recently installed at the whole stations of Seoul subway and tunnel washing-out appeared to be effective in reducing particulate matters in the platform and tunnel. However there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin due to the problem of maintenance cost. Therefore, the object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. In this paper, we focused on the development of particle removing system utilizing a roll-filter for increasing operating time of air filter. The prototype of system was designed and manufactured based on the numerical prediction results. For rollfilter device, 5 candidate filter materials were tested in point of particle collection efficiency and pressure drop. It was found that the electrically charged filter material showed the highest performance among them.