• Journal of Energy Engineering
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• v.19 no.4
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• pp.251-257
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• 2010

Korea have a plan to enforce the Renewable Portfolio Standard(RPS) in 2012 for climate change action and effective use of energy but because of lack of renewable energy resources and limits of technology development, it will be hard to fullfill a target for RPS obligation in domestic power generation sector and woodchip biomass cofiring with coal combustion is the one of the alternative methods of the goal. Woodchip biomass cofiring with coal combustion is easy to approach technical design and has competitiveness of $CO_2$ & renewble energy certificate benefit and also has much lower generation cost than any other renewable energy resources. Because of that reason, woodchip biomass cofiring with coal combustion should be needed to fullfill the goal for RPS obligation in domestic power generation sector with midlong-term direction.

• Journal of Conservation Science
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• v.36 no.5
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• pp.326-332
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• 2020

The this study's objective was to conduct species identification and tree-ring dating for the wood elements of Daewoong-jeon(main temple), Hwagye-temple, Seoul, Korea. Most of the wood elements were made from Pinus spp.(hard pine). However, one large beam was constructed from Abies spp.. For the tree-ring dating, cores were taken from the elements using a drill, and ring-width plots of individual samples were produced with the TSAP software program. The tree-ring dating results showed that, the date of the outermost ring of most elements (20 elements), including beams and pillars, were from AD 1839 to 1870. Among them, five elements had bark, and felling dates were AD 1868 and 1869. These dates confirmed the historical records that Daewoongjeon was rebuilt in AD 1870 from the records of hidden materials(Bokjangmul) in Jongdori by the survey 2012.

• Journal of the Korean Society for Library and Information Science
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• v.28
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• pp.71-81
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• 1995

There are no exact copies or carvings of India's original Buddhist Scripts published in Korea that had been flowed into Japan except those of WanSanJungUiMongSanPuPo(환산정의몽산법어). YaWoonJaKyung (야운자경). KyeChoShimHakInMoon(계초심학인문) PalSimSooHangChang(발심수행장) and MongsanWhaSangPupoRackLock published by a mid-Chosun Dynasty Buddhist monk, YaWoon TaesunSa. Others are the translations by Chinese people. All printings were of woodblock except ChonjimyungYangsoo- RhockChapMoon(천지명양수육잡문) of Inkyng wood printing type. This shows perhaps that the Buddhists were so devout that they spared no effort in their prayers to head for the Paradise. Even the woodblock carver himself took his hard work for granted in his belief and engraved the blocks with all his heart taking his work as God-given task. Or. perhaps they to use wood-block printing as the demand for the Scripts soared. By the way. as the Koryo Dynasty took Buddhism as the state religion, it was natural that the Buddhist Scripts were published at TaeJangToKam (the publishing office) and were much encouraged. It is noteworthy. however, that not a few Buddhist Scripts had been published during the Chosun Dynasty despite its crack-down on Buddhism as the Confucianism was declared as the state principle. The Scripts were even published by such temples as MoonJooSa(문수사), MyoHeeAm(묘희암). SsangbongSa(쌍봉사). PyoHoonSa(표훈사), YooJupSa(유점사), YongJangSa(용장사). and AnShimSa(안심사). The fact that the Scripts were even published by KanKyungToKam(간경부감) leads us to reconsider the traditional way of thinking of the Chosun Dynasty as anti-Buddhist or flunkeyist. The historical fact that a record number of Buddhist publications had been transmitted to Japan - is it accidental? - This issue could well be another subject matter for further research. However, it should be noted that very few of above­mentioned Buddhist Scripts are found in present-day Korea.

• Journal of the Ergonomics Society of Korea
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• v.34 no.1
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• pp.1-10
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• 2015

Objective: The purpose of this paper is to evaluate old and newly designed ammunition boxes from an ergonomic point of view. Background: The ammunition boxes made of wood, which are currently used by the military, have some difficulties such as corrosion and damage of ammunition, environmental pollution, and stock management. Also, damages to the wooden ammunition boxes take place frequently, because soldiers carry them manually. Method: Sixteen participants volunteered to randomly perform lifting, carrying, and side-by-side moving tasks with 4 different old and new boxes, respectively for the ammunitions of 5.56mm, 60mm, 81mm, and 105mm in diameter. The old boxes are made of wood and are currently used in the military, while the new boxes are made of plastics. The joint moments of the elbow, shoulder, back, and knee were measured by using a motion analysis system and force platforms. In addition, an electromyographic system was used to measure the forces of hand and wrist muscles. Results: In most tasks, new boxes caused less joint moments at the elbow and shoulder than old boxes, because the new boxes were lighter and smaller than the old boxes. New boxes also derived less hand and wrist muscle forces due to the provision of fixed hard handles rather than string handles. Conclusion: The ergonomically designed new boxes could reduce the physical stresses of soldiers manually handling ammunitions and be helpful for storage and reuse. Application: This study shows an ergonomic application example for product development and evaluation.

• Journal of Conservation Science
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• v.34 no.5
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• pp.359-368
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• 2018

The purpose of this study was to analyze the wood species of the stern plank and persimmon seed from Daebudo shipwreck No.2 excavated from Daebudo, Danwon-gu, Ansan-si, and Gyeonggi-do by wiggle-matching of radiocarbon measurements. Results of the analysis showed that all the wooden boards of the hull were made from Pinus Hard Pine Group. The other parts of hull and wooden pegs were made from Pinus Hard Pine Group, Castanea spp., Quercus spp. sect. Lepidobalanus, Alnus spp., and Zelkova serrata Makino. Excavated wide-tooth wooden comb and fine-tooth bamboo comb were made from Acer spp. and Bambusoideae. Excavated rope was made from Pueraria thunbergiana Benth. The stern plank, wooden support, and persimmon stone showed ${\pm}2{\sigma}$ radiocarbon date(95.4% confidence interval) of AD 1151-1224. This indicated that the Daebudo shipwreck No.2 occurred during the early or middle 12-13th century. Our radiocarbon dating results confirmed the date speculated by archeologists based on the ceramic style.

• Journal of the Korean Wood Science and Technology
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• v.46 no.5
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• pp.610-621
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• 2018

In conservation treatment lacquer has been used variously as a restoration material. However, dealing with Lacquer is very difficult as it dried in high humidity that can be harmful to the base materials. Also being natural varnish, dried lacquer layer is very different from the drying condition and the quality of the lacquer. These make difficult to predict the result of drying lacquer. In this study, using the humidity control machine, firstly, the main contents of the two different type of lacquer was experimented. And these lacquers was cured in various conditions. The duration time was checked until totally hardened. After that, obtained lacquer layers was analyzed to understand optical properties. Therefore, this study made a result about the relationship between characteristics of lacquer layer and the hardening condition. As a result, duration time of the Korean lacquer drying which has average 13.4% more urushiol than the Chinese lacquer is recorded a twice or triple decrease over it of the Chinese one. And, in all types of lacquer, the higher humidity makes the faster a pace of lacquer dried. In same lacquer, the shorter the duration time of drying lacquer is much darker and glossier. However, gloss deteriorated in saturated humidity. In humidity lower than RH 70%, lacquer is not hardened in 336 hours. When the layer totally cured through long period more than 30 days, the drying lacquer is appeared high brightness and almost transparent. Thus, in lower than RH 70%, it is hard to obtain durable layer.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.91-98
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• 2006

The purpose of this study is to investigate the opacity and printing strength of MG paper overlaid plywood. The printing strength of ink on MG paper can be evaluated effectively by a formula $E^{*2}=[(L^{*})^{2}+(a^{*})^{2}+(b^{*})^{2}]^{1/2}$ that we proposed. Higher E value indicates good printing strength of ink-on-paper. We also assess the real color of translucent printed MG paper with a formula CIE ${\bigtriangleup}E^{*}$ (color difference between a pile of same paper to be opaque and fancy paper laminated board). In addition, the color difference on paper surface caused by the color of wood-based board (bottom) can be evaluated by a formula of Pc. No. Generally, an acceptable appearance quality of fancy boards is ${\bigtriangleup}E^{*}$ <2.0 and small Pc.No. value. The experimental results showed that Japan-made MG papers -J1, J2 and J3 have better printing strength and gloss than that of Taiwan-made paper (T1). The reason for this was that Taiwan-made paper has poor printing strength and low gloss, which might be correlated to the fiber compositions in paper. Higher printing strength can be seen for short fiber containing handsheets when comparing to that of handsheets. Nonetheless, low-freeness sheets gives better printing strength than that of high-freeness sheets. High-opacity MG paper gives good opacifying effect to the fancy paper laminated wood-based boards. Comparing the surface color of 2 kinds of fancy paper laminated boards, paperboard T1 laminated with high-opacity fancy paper showed slight color difference. The same results can be seen for $??g/m^{2}$ handsheets. Higher-opacity Acacia and Eucalyptus bleached sulfate pulps (short fiber) gives higher opacifying effect on the plywood when comparing to Northan pine and Radiata pine sulfate pulps(long fiber). The former ones also showed small color differences when comparing the color differences between the color of fancy paper and laminated paper board. Additionally, the color of bottom plywood can't be shown through for the high-opacify surface paper adhered to. Besides, the PC No of the base paper laminated board is small as well. Apparently, we can add colorants to the binders for the manufscture of various handsheets ($30g/m^{2}$) with various pulp mix ratios to increase the opacity of paperboards to certain extents. When we using yellow and brown binders in paper laminated board, the color difference between Acacia and Eucalyptus handsheets overlaid boards decreasing to 2.0 (acceptable ${\bigtriangleup}E^{*}$ <2.0, hard to discern), but not much improvement for Northern and Radiata pines. Definitely, show-through defects can be discernible for lower opacity papers. In general, admirable printing strength of fancy paper by which glued to plywood can be made with high-opacity paper and colored binders techniques.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.52-59
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• 2015

Cross-cut disks from small diameter oak logs were thermally modified and developed to make accessories such as a brooch. However it is known that domestic oaks are refractory and it is hard to dry their cross-cut disks without any drying defects. The cross-cut disks of Quercus variabilis (7 mm long in the longitudinal direction) were forced to dry in air at two different air velocities in summer and fall season, and their drying yields were investigated. Under the same condition, the average final moisture contents (MCs) of the specimens dried in the fall were lower than those dried in the summer. The average final MCs of the small diameter specimens dried at higher air velocity were slightly lower than those at lower air velocity while those of the large diameter specimen were not influenced by the air velocity. The number of the large diameter specimens with cross checkings was higher than that of the small diameter specimen. This discrepancy between two different diameters was twice in the fall, while it was more than four times in the summer. The large diameter specimens dried at low air velocity in Summer were cross-checked most, which was attributed to repeated water condensation and evaporation due to high humidity and low air velocity.

• Journal of architectural history
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• v.24 no.5
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• pp.33-40
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• 2015

The present study is aimed to reconsider the time of installation and the purpose of the square footstone located at the center of the wooden pagoda in Hwangnyongsa Temple, based on related precedent studies. Precedent studies are divided into two streams of assertions: one is that the square footstone was to support the major pillars at the time of building and the other is that it was installed to store Buddhist reliquaries inside the central foundation stone after the wood pagoda burnt down in the Invasion of Mongol. Summarizing the grounds with which the precedent studies support their assertions, they are the relation with Gaseopbul Yeonjwaseok, the emerging time of the square footstone, repairing work at the level of reconstruction, additional enshrinement of general Buddhist reliquaries and so on. The present study reviewed the key grounds suggested in the previous studies regarding the square footstone. First, it was determined that the square footstone has nothing to do with Gaseopbul Yeonjwaseok, after looking into the timings of appearance, condition and shape in literatures. Rather, it was assumed that Gaseopbul Yeonjwaseok resembles a stone column. Next, the square footstone is assumed to be installed after the 4th year of King Kwangjong's rule because the wood pagoda was lost in fire in the 4th year of Kwangjong's rule and it had been left alone for 68 years until the repair work finished in the 13th year of King Hyunjong. It is assumed that repair works at the level of reconstruction had been twice in total, say, once during King Kyungmun and Hyunjong, respectively. Next, looking into the establishment of the general Buddhist reliquaries and the repair work during King Kyungmun, it was not common then to enshrine additional Buddhist reliquaries when repair work progressed and so there was not an additional enshrinement of Buddhist reliquaries after King Kyungmun. However, it is hard to decide that there was no repair work at the level of reconstruction at that time. Last, we can find a similar case to the square footstone of the wood pagoda in Hwangnyongsa Temple in the copper pagoda in Japanese Yaksasa Temple. In conclusion, it is assumed that the wooden pagoda in Hwangnyongsa Temple was lost to the fire in the 4th year of King Kwangjong's rule and thus the square footstone had been used as Jinho stone to protect Buddhist reliquaries and used as a propping stone for the major pillars after King Hyungjong.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.120-125
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• 2014

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.