• Conservation Science in Museum
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• v.17
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• pp.55-68
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• 2016

Conservation and research efforts are currently underway at the National Museum of Korea on a series of artifacts excavated from Tomb No. 9 at Seogam-ri nearly a century ago by an archaeology team from the institution's colonialera predecessor. Among these objects are a number of bronze and gilt bronze buttons. The present study explores the production techniques used in making such buttons. Both bronze and gilt bronze buttons are hemispherical in shape and are similar in external appearance. However, their shanks differ significantly in size and cross-sectional shape, some with a round cross-section while others are square. The buttons, first sorted into two groups by each type of shank, were further subdivided by size. Analysis of round shanks has found variations in design and location as well as in shank thickness. In addition, the location where round shanks attach to buttons are usually irregular in surface. Square shanks, on the other hand, are more uniform in design and location. The shanks are typically located on the backs of buttons and attach to a groove which ostensibly serves to mark the correct position. X-ray imaging has revealed that round shanks have thick borders made from metal rather than dirt or other material. The buttons themselves appear to been cast using lost-wax technique. The ways in which each shank attaches to its respective button varies based on its cross-sectional shape.

• Conservation Science in Museum
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• v.17
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• pp.85-100
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• 2016

The Bukji-ri Stone Pensive Bodhisattva of Bonghwa in the collection of Kyungpook National University Museum was transported to the National Museum of Korea for display in a special exhibition('Masterpieces of Early Buddhist Sculpture 100 BCE - 700 CE') and therefore underwent conservation ahead of the exhibition's start date. The stone sculpture had visibly encrusted surface dirt, granular disintegration and fissures upon arrival. Notably, a crack running obliquely across its lower half rendered the object unable to support its own weight without a pedestal, so one was created in order to maintain the sculpture in an upright position while on exhibition. The sculpture was further examined using a polarizing microscope and a stereoscopic microscope. SEM-EDS resulted in petrographic analysis of the stone's mineral composition and identification of its surface contaminants. Polarizing light microscopy confirmed biotite granite as the main mineral component of the object. Several urethane resins cast in round cross-sections were inserted into the newly made pedestal and stability tests were perform to measure the frictional force of the resins. An additional test was performed to compare urethane resin and epoxy resin, with results showing urethane to have a higher coefficient of friction. Utilizing a pedestal with urethane resin effectively ensured the stability of the Bukji-ri Stone Pensive Bodhisattva of Bonghwa during the aforementioned exhibition.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.46-48
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• 2002

본 연구는 신문지 고지의 점착성 이물질 중 Primary Stickies의 정 량에 관한 것으로 서, 실제 신문지료를 화상분석하여 실시간으로 매크로크기의 점착성 이물질올 측정할 때 효율적인 측정조건을 탐색하여 제지공정의 l 현장에서 일차 점착성 이물질을 정량 하는 새로운 측정기의 측정 기준을 제시하고자 하였다. 이물질이란 제지공정에 의도적으로 첨가되지 않은 불질의 총칭으로 dirt 및 각종 점착 성 이물질 즉, stickies를 들 수 있다. 이 가운데 스틱키{stickies}란 부드럽고, 점착성을 나타내는 이물질의 총청으로 주로 점착제와 확스에 의해 형성된다. 스틱키는 고지 재활 용의 효율성을 가장 크게 저해하는 이물질로 와이어, 펠트 및 기타 공정요소에 부착되 어 초지 시 지절을 발생시킴으로써 생산성을 저하시킬 뿐 아니라, 외관상 상품가치와 인쇄적성올 저하시키며, 최종 제품의 강도적 물성 및 가공적성에도 영향을 미친다. 특 히 국내에서는 원가절감을 위해 고지의 재활용율올 증대시키고자 전력을 다하고 있으 며 환경보호 및 용수 절감올 위해 공정수를 절감하고 궁극적으로는 무방류화를 목표로 하고 있어 토지 계 내의 점착성 이물질의 투입과 농축 현상이 심각하게 진행되고 있는 실정이다. 초지공정에서 발생하는 스틱키 즉 점착성 이물질은 미세한 스크린의 슬롯 폭인 0.15 - -0.3mm 이상의 크기를 가져 스크린에 의해 분리될 수 있는 매크로 스틱키{macro s stickies}와 이보다 작은 마이크로 스틱키(micro stickies)로 크게 분류된다. 즉 매크로 스틱키는 스크린에 의해 분리될 수 있으나 마이크로 스틱키는 스크린을 통하여 기계적 으로 분리할 수 없다는 문제점을 지니고 있다. 스틱키는 또 거동 특성에 따라 primary s stickies와 secondary stickies로 구분할 수 있다. primary stickies는 펄핑과정에서 점착 성 이물질이 파괴됨에 따라 나타나지만, secondary stickies는 지류 제지공정의 백수에 용해 되거나 분산된 상태인 1때1 이하의 콜로이 드로 폰재 한다. 이 러 한 secondary stickies 는 pH, 온도의 변화나 각종의 첨가제에 의해 웅집이나 홉착 등을 발생할 수 있는 잠재 적 문제점 등을 가지고 있다. 예를 들어 양성 고분자의 첨가는 펄프 섬유를 웅집시킬 뿐 아니라 지료에 함유된 secondary dtickies의 안정성을 저하시켜 응집, 침적시키는 작용을 한다. 따라서 분리가 어렵고, 제지공정에서 문제를 일으키기 쉬운 2차 스퇴키를 적절히 제어하기 위한 기술 개발은 용수절감 뿐 아니라, 초지공정의 침적물 절감을 통 한 공정개선에도 매우 중요한 요소기술이라 할 수 있다.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.60-66
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• 2009

This study was conducted to investigate into the effective drying method for three greens such as bang-a (Isodon japonicus), aster (Aster yomena) and lettuce greens (Ixeris dentata) Nakai. We have dried three greens using the different drying methods, have made methanol extracts and have also determined the physiological activities in $1,000mg{\cdot}L^{-1}$ extracts. Total phenolic compound contents were most increased by 65.1 and $60.2mg{\cdot}L^{-1}$ in the extracts of bang-a and aster which were frozen dried, however, that in lettuce greens were oven dried by $51.2mg{\cdot}L^{-1}$. Total flavonoid contents were extremely much more in bang-a extracts dried in the oven by $70.6mg{\cdot}L^{-1}$, however, aster and lettuce greens extracts frozen dried by 53.9 and $35.8mg{\cdot}L^{-1}$. DPPH radical scavenging activity in bang-a extracts were greatly increased by 78.8% when bang-a were frozen and dried, however, that in aster were not significant by $89.8{\sim}90.9%$. DPPH radical scavenging activities in lettuce greens extracts were became highest in the order f oven drying (91.9%), natural drying (91.0%) and freeze drying methods (90.9%). Nitrite radical scavenging activities in bang-a and aster extracts were most increased in the natural drying treatment by 73.3 and 78.2%, however, that in lettuce greens extracts were highest in freeze drying treatment by 75.1%.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.64-74
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• 2016

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.255-263
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• 1998

Dust-free garment prevents contamination which otherwise is caused by skin and clothes to protect from dust or dirt. Therefore, it requires high performance and should function as a working clothes. Clothes are a medium between human and thermal environmental system, and it is required to study human enviroment to ensure comfortableness of clothes and to satisfactorily go along with enviroment .This study investigates the physical and physiological features of dust-free garment used in the clean room at a semiconductor factory in oredr to scientifically clarify what the dust-free garmint is as well as to contribute to the design and development of high performance material and clothes. Three kinds of dust-free fabrics (DFG-I, DFG-II, DFG-III) which are being developed by a local company are used to manufacture dust-free garment. These dust-free garments are dressed and tested in such an enviroment as similar to semiconmemts with temperature at 23${\pm}$1$^{\circ}C$ and humidity at 50${\pm}$5%RH in order to investigate the thermo physiological and psychological features of human body. The results of this study are as follows. The results of this study are as follows. 1.The mean skin temperature was significantly different among the clothes, subjects and experimental time. Temperature tends to rise from the time of exercising load. Continuous motion coupled sealed clothes prevents heat transmittance, and temperature rises in the order of DFG-l, DFG-ll and DFG-lll as time course. 2.As for the skin temperature by local timperature is minimun on the head and torso and increares remarkably at the terminal part of human body. 3. As for the body mass loss was significantly higher in DFG-lll than DFG-l and DFG-ll. 4. Though there is no significant difference in the temperature within clothes among the kind of clothes temperature is 1$^{\circ}C$ higher in the back. Temperature within all the dust-free garments 29.7$^{\circ}C$ in the back and 31.3$^{\circ}C$ in the chest which belong to the comfort zone(31-33$^{\circ}C$). The relative humidity is 39.7%RH in the chest and 33.8%RH in the back which is slightly below the comfort zone(40-60%RH) 5. The thermal sensation belong to the comfort zone regardless of the kinds of clothes. The subjects feels a slight fatigue as times goes. As for the subjective sense of subjects the mean skin temperature as well as temperature and humidity within clothes show similar tendency. This means that they relate with each other.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1123-1129
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• 2015

A pair of two-way valves typically is used in automotive washing machines, where the water flow direction is frequently reversed and highly pressurized clean water is sprayed to remove the oil and dirt remaining on machined engine and transmission blocks. Although this valve system has been widely used because of its competitive price, its application is sometimes restricted by surging effects, such as pressure ripples occurring in rapid changes in water flow caused by inaccurate valve control. As an alternative, one three-way reversing valve can replace the valve system because it provides rapid and accurate changes to the water flow direction without any precise control device. However, a cavitation effect occurs because of the complicated bottom plug shape of the valve. In this study, the cavitation index and percent of cavitation (POC) were introduced to numerically evaluate fluid flows via computational fluid dynamics (CFD) analysis. To reduce the cavitation effect generated by the bottom plug, the optimal shape design was carried out through a parametric study, in which a simple computer-aided engineering (CAE) model was applied to avoid time-consuming CFD analysis and difficulties in achieving convergence. The optimal shape design process using full factorial design of experiments (DOEs) and an artificial neural network meta-model yielded the optimal waist and tail length of the bottom plug with a POC value of less than 30%, which meets the requirement of no cavitation occurrence. The optimal waist length, tail length and POC value were found to 6.42 mm, 6.96 mm and 27%, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.361-366
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• 2012

This paper presents speed control of an electric motorcycle using a fuzzy controller. The electric motorcycle required to meet not only fast throttle response but also stability, when it is on a cruise. However, a 1.5KW (50cc) electric motorcycles selling in the current market are difficult to cruise under the following conditions which are occupant's weight, load weight, wind resistance and road conditions (dirt roads, asphalt road). Because of these reasons, the rapid speed changing occurs in uphill and downhill road. To solve these problems, The input value for Improved fuzzy controller use the speed error and error variance. The output value for improved fuzzy controller uses Q-axis of the motor controlled variable. The D-axis of the motor output for improved fuzzy control uses D-axis controlled variable in proportional to Q-axis controlled variable. Improved fuzzy controller drives the electric motorcycle equipped with IPMSM. The control subject used in this paper is a 1.5KW electric motorcycle equipped with improved fuzzy controller that was used to control the motor speed. To control IPMSM Type of motor torque, D, Q-axis current controller was used. The Fuzzy controller using the proposed algorithm is demonstrated by experimental hardware simulator.

• Journal of Korean Society of Rural Planning
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• v.26 no.2
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• pp.107-116
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• 2020

Up to date, the majority research on the major landscape elements in organic farming has been mainly focused on the practice of seeking efficiency. The problem is that this type of study contributes to polluting the agricultural environment and damaging the ecological circulation system. As an alternative, there is a growing body of research on organic farming, but it is not widely applied that research on how to manage the landscape considering the scenic characteristics of farming villages practicing organic farming. Therefore, this study was carried out in the conservative aspects of rural landscapes in order to effectively manage the landscape of organic agriculture and, intended to be used to maintain and preserve natural and ecologically harmonious landscapes by deriving management methods suitable for landscape elements targeting the major landscape elements of the organic farming complex. To carry out, this study performed the experts survey which is composed of 13 major landscape elements, including rice paddies and fields, monoculture and diverse crops, dirt roads, windbreak trees, accent planting, dum-bung(small pond), natural small river, natural waterways, plastic film houses, one-storied houses, and pavilion. As a result, Farm land was formed in a square shape, concentrated in an independent space, planted companion plants around the crop, and covered with plants to manage the borders. As for the surrounding environment, it was analyzed that the aspart road system circulating through the village, the evergreen broad-leaved windbreak forest around the cultivated land, and the accent plant located at the entrance of the village were suitable. The hydrological environment consists of Round small pond made of stone in an open space, natural rivers around the village, and natural channels around the farmland, and The Major facilities are suitable for greenhouses that are shielded by plants in independent regions, and wooden duck houses located inside the cultivation area are suitable and The settlement facilities were analyzed to be suitable for single-story brick houses located in independent residential areas, pavilion located with greenery in the center of the village, and educational spaces shielded with wood from arable land. If supplementary evaluation criteria suitable for the management of organic farming landscape are additionally supplemented based on the results derived from this study, It is expected to enhance the landscape value of ecologically superior organic farming.

• Journal of Conservation Science
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• v.34 no.6
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• pp.525-538
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• 2018

Myazedi Quadrilingual Stone Inscription of Myanmar, inscribed to the World Heritage List in 2015, is a rare historical artifact which has an exact date of inscription. It is a written record that displays the history, religion, and culture of Myanmar. Since the surface of the Stone Inscription has been rubbed with ink many times during the process of making printed copies for interpretation and academic research, it has developed a serious stain problem. Therefore, scientific analysis of the stain and research on the treatment for its removal have been conducted. In particular, an experiment was conducted on stain removal using laser cleaning and chemical treatment. The stains are mostly ink dirt, which accumulated from previous ink-rubbing processes. In order to conduct the experiment under similar conditions, a sample with similar stain has been reproduced, and a set of different conditions for treatment was applied to the sample to determine an effective solution. Laser cleaning was found to be effective in removing stains from most samples. However, chemical treatment showed different results. The physical friction method using ethanol provided the best result. In conclusion, laser cleaning is an effective universally-applicable technique but chemical treatment with laser cleaning can be considered an alternative method in certain situations.