• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.4-17
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• 2011

The Baekje's cotton fabrics were excavated from 'Neungsan-ri temple site in Buyeo' (September 1999-April 2000) and stored at Buyeo National Museum after conservation treatment. In this study, it carred out non-destructive, chemical and morphological analysis for fiber identification, also considered on influx, features and difference between the 'Baek-cheop-po(Three kingdom period's cotton fiber)' and 'Mok-myeon(imported by Munikjeom, late Korea dynasty)'. As a result, the fiber proved cellulose fiber through analytical researches like color reaction, FT-IR(chemical analysis). It was also confirmed lumens, typical dimensional structure(morphological analysis) as an features of cotton fiber. The fiber was the first evidence in ancient Korea's cotton. But it can not prove that whether weaving were made in Baekje's area. However there were documentation that people in Beakje make cloth to silk fabric from 'Mahan period'. We can suppose that they have had an old weaving techniques. This study has a great historical, academic values as the only evidence for the hypothesis of a weaving technique of the Baekje's cotton. Through comparison to each region's ancient cottons, we can investigate the species of Baekje's cotton and ancient Korea cotton's influx.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2672-2678
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• 2011

Carbody of rolling stock has been gradually changed as whole wood, steel frame with wood car body, whole steel car body with rivet and whole monocoque carbody with welding. And also mild steel has been used widely to material of structure, but usage of stainless and aluminium which have lightweight and high corrosion resistance is being increased lately. Structure is being commercialized to AED(All Extrusion Design),whole double skin with hollow excluded shape such as aluminium structure from SSD(Sheet Stringer Design), single skin consists of traditional frame and outside plat. Traditional aluminium carbody had many problems from reduced strength in welding combination section because car body is consist of small extruded material affected heat by welding. On this study, we proposed the plan to improve the body strength and quality with large-scale aluminium extruded material by minimizing welding concentration in combination section.

• Magazine of the Korea Concrete Institute
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• v.6 no.1
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• pp.89-100
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• 1994

The current test procedure for transfer length, which determine transfer length by measuring concrete strain, has an actual bond stress state in the prestressed pretensioned member : however, it is difficult to determine the bond properties of maximum bond stress and bond stiffness with this method. It is also difficult for design engineer to understand and select a correct safety criterion from the widely distributed results of such a ransfer test alone. An alternative testing procedure is provided here to determine the bond properties without measuring the concrete strain. In this test the bond stress is measured directly by creating a similar boundary condition within the transfer length in a real beam during the transfer of prestressing force. The prestressing force was released step by step by step from the unloading side. The release of force induces a swelling of the strand at the unloading side of concrete block, bonding force in the block, and a bond slip of the strand toward the other side of the block. Two center-hole load cells are used to record the end loads until the point of general bond slip(maximum bond stress). It is suggested that this test procedure be performed with the ordinary transfer test when determining the transfer length in a prestressed, pretensioned concrete beam.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.361-369
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• 2011

The effect of an increase in the temperature of inlet air on the performance of a membrane humidifier for a PEMFC (Polymer Electrolyte Membrane Fuel Cell) vehicle was investigated both experimentally and numerically. A shell-and-tube type gas-to-gas humidifier with Nafion membrane was tested. The experimental result showed that water transfer varies nonlinearly with the temperature elevation. Numerical analysis based on detailed modeling was also conducted in simplified geometry of a single tube to explain this nonlinear behavior. The simulation revealed that the local water flux varies nonlinearly and dramatically along the tube. The analysis was based on the inverse relationship between the increase in temperature and decrease in relative humidity, both of which seriously affect the water conductivity of the membrane.

• Tunnel and Underground Space
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• v.32 no.4
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• pp.243-253
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• 2022

In this study, the cutting efficiency of TBE (Tunnel Boring Extender) was evaluated by using rotary cutting tester. In the rotary cutting test, a specimen which has a drilled hollow hole at the center was made of rock-like material. The specimen was cut by UDC (undercutting disc cutter) with spiral cutting path to simulate the cutting process of TBE. The cutting forces and specific energy were evaluated under different cutting conditions. The results indicated that the cutter forces of UDC linearly increased with the vertical and radial penetration depths. Among the three directional cutter forces, the normal force is larger than other force components. While the specific energy decreased with the two penetration depths, in particular, it was presumed that the specific energy was minimized at a certain value of the ratio of radial to vertical penetration depth.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.273-278
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• 2019

The multi-layer insulating curtains used in the experiment was produced in six combinations using non-woven fabric containing aerogel and compared and analyzed by measuring heat flux and heat perfusion rates due to weight, thickness and temperature changes. Using silica aerogel, which have recently been noted as new material insulation, this study tries to produce a new combination of multi-layer insulating curtains that can complement the shortcomings of the multi-layer insulating curtains currently in use and maintain and improve its warmth, and analyze the thermal properties. The heat flux means the amount of heat passing per unit time per unit area, and the higher the value, the more heat passing through the multi-layer insulating curtain, and it can be judged that the heat retention is low. The weight and thickness of multi-layer insulation curtains were found to be highly correlated with thermal insulation. In particular, insulation curtains combined with aerogel meltblown non-woven fabric had relatively higher thermal insulation than insulation curtains with the same number of insulation materials. However, the aerogel meltblown non-woven fabric is weak in light resistance and durability, and there is a problem that the production process and aerogel are scattering. In order to solve this problems, the combination of expanded aerogel non-woven fabric and hollow fiber non-woven fabric, which are relatively simple manufacturing processes and excellent warmth, are suitable for use in real farms.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1273-1284
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• 2000

In this study, ultrafiltration was performed to remove humic acid from aqueous solution. Since the effects of system variables on the ultrafiltration were tangled with non-linearly. Response Surface Methodology(RSM) was used to know optimum conditions of ultrafiltration process, relations among system variables, and the effects of system variables such as pressure difference across the membrane, concentration of humic acid, and feed flow rates. As concentrations of humic acid were 10ppm, 40ppm, and 70ppm in feed stream, permeation fluxes were 2.56, 2.27, and $2.10({\times}10^{-2}cc/cm^2{\cdot}min)$ respectively ; in other words, permeation fluxes of 10ppm, 40ppm and 70ppm feed concentration decreased by 17.7%, 26.7% and 32.2% of pure water permeation flux respectively. Concentration of humic acid in permeate side were 0.5ppm, 1.2 ppm, and 2.1ppm respectively. When pressure difference(${\Delta}P$) increased from 1atm to 2atm and 3atm, permeation fluxes of 40ppm feed concentration increased by 66% and 152% of permeation rate at 1atm respectively. However, concentrations of humic acid in permeate side increased from 0.5ppm to 1.5ppm and 3.5ppm. RSM showed that the optimum condition of system variables is 38.5~40ppm of humic acid concentration in feed stream, 30~30.7cc/min of feed flow rate, and 2atm of pressure difference.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.317-327
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• 2013

Air pollution and artificial heat of urban areas have caused the urban heat island in which asphalt pavements absorb solar heat during the daytime and release the heat at night. Hence, in order to improve the environment of urban areas, it is necessary to examine cooling pavements that can reduce heat on road pavements in urban areas. The application of temperature insulation paints on road pavements require to reduce black brightness for visibility, to increase the reflection rate of infrared light and minimize the reflection rate of visible light. In the study, one part of Acrylic-emulsion was used as a main binder, and the changes in black brightness and the changes of addition ratio (0%, 15%, 30%) of hollow ceramics, as well as kinds of paints (carbon black pigment, mixed mineral pigment) were selected as the main experimental factors. The performance of temperature reduction of cooling pavements was analyzed through the reflection rate of spectrum, the reflection rate of solar heat, and the lamp test. Abrasion resistance, UV accelerated weather resistance, and sliding resistance were tested in real situations. In addition, the performance of heat reduction of testing pavements covered with high-reflection paints was analyzed by using an infrared camera. As the test results, when using mixed mineral paints and hollow ceramic of 30%, the reflection rate of spectrum was 43% in the area of near-infrared ray and 17% in the area of visible light at black brightness of $L^*$=42.89 and the reflection rate of solar heat was 27.5%. Total color difference was ${\Delta}E$=0.27 in the test of UV Accelerated Weather Resistance, indicating almost no changes in color. BPN was more than 53 when scattering #2 and #4 silica sand of more than $0.12kg/m^2$. In Taber's abrasion resistance test, abrasion loss was up to 86.4mg at 500 rotations. The performance of heat reduction was evaluated using an infrared camera at the test section applying high-reflection paints to asphalt pavements, in which the results showed that the temperature was reduced by $12.7^{\circ}C$ on CI-30-40 cooling pavements ($L^*$=38.76) and by $14.2^{\circ}C$ on CI-30-60 cooling pavements ($L^*$=57.12).

• Journal of Korean Medical classics
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• v.19 no.4
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• pp.182-192
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• 2006

통과대복의육십사괘차서도(通過對伏義六十四卦次序圖), 방도(方圖), 원도적연구(圓圖的硏究), 이급장개빈대육십사괘방원도중소천발적의역학내용적연구(以及張介賓對六十四卦方圓圖中所闡發的醫易學內容的硏究), 득출여하결론(得出如下結論): 1. 육십사괘적생성원리중(六十四卦的生成原理中), 존재소강절적일분위이법설화번사전적일정팔회설(存在邵康節的一分爲二法設和繁辭傳的一貞八悔說), 이사지횡향배열적도(而使之橫向排列的圖), 칭위복의육십사괘차서원(대횡도)(稱爲伏義六十四卦次序圓(大橫圖)). 종차원(從此圓), 가청초지효육십사괘적생성근원(可淸楚知曉六十四卦的生成根源). 2. 복의육십사괘원도(伏義六十四卦圓圖), 파대횡도분위료양부분(把大橫圖分爲了兩部分), 즉전삼십이괘종좌상방향하진행료배치(卽前三十二卦從左上方向下進行了配置), 이후삼십이괘종우상방향하원형진행료배치(而後三十二卦從右上方向下圓形進行了配置). 차원이자오묘유위중심청초지현시출료양시(자)(此圓以子午卯酉爲中心淸楚地顯示出了陽始(子)), 양진(묘)(陽辰(卯)), 양극(오)(陽極(午)). 음시(오)(陰始(午)), 음진(유)(陰辰(酉)), 음극(자)등적상(陰極(子)等的象), 체현료천도순환적도리(體現了天道循環的道理). 3. 복의육십사괘방원(伏義六十四卦方圓), 야유래어대횡도(也由來於大橫圖), 역체현료지도원리급선천법상적자연지묘(亦體現了地道原理及先天法象的自然之妙). 4. 복의육십사괘방위원시근거천지지리(伏義六十四卦方位圓是根據天地之理), 재복의육십사괘원도내배치료복의육십사괘방원(在伏義六十四卦圓圖內配置了伏義六十四卦方圓). 저시유주자수차배치적(這是由朱子首次配置的). 원도이원형진행료배치(圓圖以圓形進行了配置), 중공상태체현료천지순환적질서(中空狀態體現了天之循環的秩序), 이방도이방형진행료배치(而方圖以方形進行了配置), 중간충실체현료지지존재적상태(中間充實體現了地之存在的狀態), 기작용균시어중심부(基作用均始於中心部). 방원도중포함착일개월적변화(方圓圖中包含着一個月的變化), 일년적운행(一年的運行), 129,600년지우주일년적변화(年之宇宙一年的變化), 천지적종시(天地的終始), 인물적생사(人物的生死), 고금세변적원리등(古今世變的原理等). 5. 장개빈확립료용역학원리해석의학적의역학(張介貧確立了用易學原理解釋醫學的醫易學), 파육십사괘방원여인체진행결합작료천발(把六十四卦方圓與人體進行結合作了闡發). 기일(基一), 기인위육십사괘원도적중심시태극(基認爲六十四卦圓圖的中心是太極), 차부상당어인체지심, 이건남곤북화리동감서(而乾南坤北和離東坎西), 분별대응어상수하복화좌우이목(分別對應於上首下腹和左右耳目). 기이(基二), 원도이사등분적사상(圓圖以四等分的四象), 파인생분위료사분(把人生分爲了四分), 병분별진행료배속(幷分別進行了配屬). 저설명료파육십사괘여 "소문·상고천진론" 중이팔수위변적장부원리(這設明了把六十四卦與『素問·上古天眞論』中以八수爲變的丈夫原理), 소진행적배속관계(所進行的配屬關係). 기삼(基三), 기인위재원도중(基認爲在圓圖中), 여동양시생적복괘(천근)여음시생적구괘(월굴), 相互交替進行循環一樣, 인적생장쇠로적도리화일일중오매적도리시일양적(人的生長衰老的道理和一日中寤寐的道理是一樣的). 기사(基四), 기재원도중(基在圓圖中), 이천양재남화천부족서북(以天陽在南和天不足西北), 래설명료건재남화곤재북적도리(來說明了乾在南和坤在北的道理), 병재방토중이지강재북화지불만동남(幷在方土中以地剛在北和地不滿東南), 래설명료건재서북화건재동남적도리, 이육십사괘적원리여의학밀접결합, 대지진행료설명(對之進行了說明).

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.282-291
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• 2010

As compared with existing center-boring timber, skin timber which be hollowed out of its considerable inner parts has some merits as like short drying time, less developed checks during drying, a advantage of lower MC (8~%), more easy injection of chemicals, a possibility of using as a lighter structural heavy timber including Hanok and heavy timber construction, a possibility for the various living necessaries and furniture materials. However, development of hybrid skin timber is required for using as a value-added materials and giving a confidence for the structural safety of skin timber to general user. Thus, improved pine skin timber (IPST) and improved larch skin timber (ILST) were manufactured using the lighter steel plate possible. And compressive capacity of improved skin timber was analyzed. From the results of this study, the following conclusions have been made: 1. Both of IPST and ILST can give a uniformity of material capacity compared with non-treated skin timber. 2. Both IPST and ILST, there was not statistical significancy among the thickness of steel plate. Therefore, it concluded that it was not necessary to use thicker steel plate. 3. There was also not statistical significancy between IPSR and ILST, so it need not to be selective about the species of improved skin timber. 4. IPST showed various failure types, but most failure types of ILST is a splitting type.