• Title/Summary/Keyword: resistance change

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A Study on Combustion Characteristic of the Using Wood Flooring as Wall Material (목질바닥재의 벽재사용에 따른 연소특성에 관한 연구)

  • Yoo, Ji Chang;Choi, Chul;Yang, Sung Min;Lee, Chang Goo;Kang, Seog Goo
    • Journal of the Korea Furniture Society
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    • v.27 no.1
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    • pp.8-14
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    • 2016
  • Increasing concerns of environment need to make change furniture field to more environmentally friendly approach, such as reuse of by-products from wooden products. As it is, the methods of recycling wood for industrial purposes have the advantage of productivity and adaptability. However, the industrial way is required a certain production facility of processing wooden by-products and has possible hygienic problems due to contaminated sources. Many designers have developed their own methods for reuse of wood in unique and artistic ways. Even so, because of confined sources, it could be not enough supply. Therefore, I developed the design methodology utilizing wooden by-products from S Design Company to relieve former ways' problems. The design suggestion took materials from a safe and abundant source. The wooden leftover pieces were connected together with epoxy clay, so previous process traces of furniture are remained as a decorative factor. Moreover, the synthesized material was able to be processed by ordinary woodworking facilities without additional installations. In doing so, console table focused on a commercial purpose and dining table for an artistic objective were successfully fabricated as final suggestions. In consideration of the proposal using wooden furniture leftovers, diverse recycling designs should be investigated for future reference.

Climate Change and Its Impact on Agricultural Ecosystem (기후변화에 따른 농업생태계 변동과 대책)

  • Yun Seong Ho
    • Proceedings of the Korean Society of Crop Science Conference
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    • 1998.10a
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    • pp.313-335
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    • 1998
  • If the atmospheric concentrations of greenhouse gases double, the annual temperature increase in mean surface temperature relative to 1990 will be about 2.0 to $2.5^{\circ}C$ and the annual precipitation increase about $15{\%}$ by 2100 in Korea. When the temperature rises $2^{\circ}C$, the annual temperature will be $13^{\circ}C,\;15^{\circ}C,\;and\;16^{\circ}C$ in Western Central, Yeongnam Basin, and Southern Coastal respectively. Consequently the crop period could be prolonged $10{\~}29$ days. In the case of gradual global warming, annual crops could be adapted to the changed environment by breeding, and the perennial crops should be shifted to ether area. If global warming happens suddenly over the threshold of atmospheric greenhouse gases concentration, then we shall have disturbance of ecosystem. When $2^{\circ}C$ higher than present, the optimum flowering date of rice plant delayed about 10 days, so it may not possible to adopt the fate with present japonica rices, therefore, the recommended characteristics of rice varieties are longer basic vegetative period, more late maturing and higher ripening temperature. Barley and wheat crops could be shifted to northern coastal areas and apple production areas should be shifted to those areas under $13.5^{\circ}C$ in annual mean temperature at global warming. Ideotypes of crops under climate changes should have such ecological characteristics that are indispensable to accomplish the sustainable agriculture under increased $CO_{2}$ and temperature condition as the diversification of genetic resources from yield-oriented to biomass-oriented characteristics with the higher potentials of $CO_{2}$ absorption and Primary production. In addition, a heat-tolerance, a pest resistance, an environmental adaptability and a production stability should be also incorporated collectively into our integrated agroecosystem.

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Why Do Consumers Resist Innovative Wearable Devices? The Case of Smartwatches (사용자 선호기반 웨어러블 디바이스의 수용성 연구: 스마트워치를 중심으로)

  • Kim, Minseok;Kim, Wonjoon;Kim, Minki;Kang, Jae Won
    • The Journal of the Korea Contents Association
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    • v.17 no.9
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    • pp.523-535
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    • 2017
  • Despite consumers' increasing awareness and interests in innovative wearable devices, the sales growth has been stagnant. To analyze this phenomenon, we investigate consumer preferences for various innovative features embedded in wearable devices. Conducting conjoint analysis on smartwatches, we empirically show that the curse of innovation can occur when the consumer's expected utility from the smartwatch falls short of his/her psychological cost associated with behavior change from smartwatch usage. Therefore, our findings provide managerial implications on the R&D strategy for new technologies and more importantly on the marketing strategy easing consumers' resistance to highly innovative products.

Parametric Study on Seismic Performance of Internally Confined Hollow CFT Column (내부 구속 중공 CFT 교각의 내진성능에 대한 매개변수 연구)

  • Yeom, Eung-Jun;Kim, Hyun-Jong;Han, Taek-Hee;Kang, Young-Jong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.1
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    • pp.15-21
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    • 2008
  • The internally confined hollow-concrete filled tube (ICH-CFT) column has two tubes on the both sides (hollow part and outer part) of the concrete. The inner tube and the outer tube perform great seismic abilities, ductility and absorption of energy due to the steel tubes and the hollow part. So, the study of this column type for the practical use is needed. In this study, the qualitative analysis about seismic capacities depending on parameters is performed for the practical design of the ICH-CFT column. The parameters are diameter of column, hollow ratio and thickness of tubes with the same resistance of the moment. Also, the economical evaluation of ductility and comparison with CFT column make this study to be of practical use. Especially, a change of seismic performance depends on the hollow ratio and the thickness of the outer tube, and the economical hollow ratios according to the thickness of the outer tube in the ICH-CFT column are suggested.

Research on the public education goal of design (디자인 대중교육의 지향점에 관한 연구)

  • Cho, kyu-myung
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.743-748
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    • 2008
  • Design is objective and universal human aesthetic activity. Design originally began with the purpose 'to make public's life abundant and increase their quality of living." However, design education has bee developed to foster human resource to maximize production of company in the name of 'important production method for company.' Therefore, common people has been had many opportunities to learn about design. General people could not be satisfied their demand to learn about design due to narrow opportunities. Public has had resistance feeling for design that it has been exclusively occupied by certain designers. Therefore, it is urgent to expand the object of design education and change the contents which have been focused on fostering design professionals. This research examined about the goal of public design education (self-expression, enjoying quality of life, culture, and wisdom of living) as a way to increase our life quality by recognizing the need of public design education based on various social phenomena which strongly shows people's desire to pursue aesthetic life.

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Properties of AlTiN Films Deposited by Cathodic Arc Deposition (음극 아크 증착으로 제조된 AlTiN 박막의 특성)

  • Yang, Ji-Hoon;Kim, Sung-Hwan;Song, Min-A;Jung, Jae-Hun;Jeong, Jae-In
    • Journal of the Korean institute of surface engineering
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    • v.49 no.3
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    • pp.307-315
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    • 2016
  • The properties of AlTiN films by a cathodic arc deposition process have been studied. Oblique angle deposition has been applied to deposit AlTiN films. AlTiN films have been deposited on stainless steel (SUS304) and cemented carbide (WC) at a substrate temperature of $500^{\circ}C$. AlTiN films were analyzed by scanning electron microscopy, glow-discharge light spectroscopy, micro-vickers hardness, and nanoindenter. When applying a current of 50 A to the cathodic arc source, it showed that the density of macroparticle of AlTiN films was 5 lower than other deposition conditions. With the increase of the bias voltage applied to the substrate up to -150 V, the density of macroparticle was decreased. The change of the $N_2$ flow rate during coating process made no influence on the film properties. For the multi-layered films, the film prepared at oblique angle of $60^{\circ}$ showed the highest hardness of 28 GPa and $H^3/E^2$ index of 0.18. AlTiN films have been shown a good oxidation resistance up to $800^{\circ}C$.

Failure Probability Assessment of Natural Gas Pipeline under Combined Stresses (복합하중에 의한 천연가스 배관의 파손확률 평가)

  • Baek, Jong-Hyun;Chang, Yun-Chan;Kim, Ik-Jung;Kim, Cheol-Man;Kim, Young-Pyo
    • Journal of the Korean Institute of Gas
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    • v.24 no.4
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    • pp.10-17
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    • 2020
  • The structural reliability assessment can be used to improve the reliability in the asset integrity management of the pipeline by using a geometric variation, mechanical characteristics, load change and operating condition as evaluation factors. When evaluating structural reliability, the failure probability of the natural gas pipe is evaluated by the relationship of the resistance of the pipe material to external loads. The failure probability of the natural gas pipe due to the combined stresses such as the internal pressure, thermal stress and bending stress was evaluated by using COMREL program. When evaluating the failure probability of the natural gas pipe, a buried depth of 1.5 to 30 m, a wheel load of 2.5 to 20 ton, a temperature difference of 45℃, an operating pressure of 6.86MPa, and a soil density of 1.8 kN/㎥ were used. The failure probabilities of the natural gas pipe were evaluated by the Von-Mises stress criterion as the maximum allowable stress criterion under the combined stresses.

Crystal Structure and Electrochemical Properties of LiMn2-yMyO4 Cathode Material by Complex Substitution of Mg and Zn (Mg와 Zn의 복합치환에 따른 LiMn2-yMyO4 정극 활물질의 결정 구조 및 전기화학적 특성)

  • 정인성;정해덕;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.4
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    • pp.361-366
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    • 2002
  • Spinel $LiMn_{2-y}M_yO_4$ and $LiMn_{2-y}M_yO_4$ (M=Mg, Zn) powders were synthesized by solid-state method at $800^{\circ}C$ for 37h. Crystal structure and electrochemical properties were analyzed by X-ray diffraction, charge-discharge test, cyclic voltammetry and ac impedance to $LiMn_{2-y}M_yO_4$. All cathode material showed spinel structure in X-ray diffraction. Ununiform distortion which calculated by (111) face and (222) face was almost constant in spite of the change of the kind and the substituting ratio of the metal cation in $LiMn_{2-y}M_yO_4$ (M=Mg, Zn). $LiMn_{1.9}Mg_{0.05}Zn_{0.05}O_4/Li$ cell substituted $Mg^{+2}$ and $Zn^{+2}$ showed excellent discharge capacities than other cells, which it presented about 120mAh/g at the 1st cycle and about 73mAh/g at the 250th cycle, respectively. AC impedance of $LiMn_{2-y}M_yO_4/Li$ cells showed the similar resistance of about 65~110$\Omega$ before cycling.

Photoelectric Conversion Efficiency of DSSC According to Plasma Surface Treatment of Conductive Substrate (전도성 기판의 플라즈마 처리에 따른 염료감응형 태양전지 광전변환 효율 특성 변화)

  • Ki, Hyun-Chul;Kim, Seon-Hoon;Kim, Doo-Gun;Kim, Tae-Un;Hong, Kyung-Jin;So, Soon-Yeol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.11
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    • pp.902-905
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    • 2012
  • This study is explore the photoelectric conversion change of dye-sensitized solar cells with surface treatment of the conductive substrate. gases of FTO surface treatment were $N_2$, and $O_2$. Treatment conditions of surface were gas flux from 25 sccm to 50 sccm and RF power were from 25 W to 50 W. Treatment time and pressure were fixed 5 min and 100 mtoor. The best sheet resistance and surface roughness were obtained by $O_2$ 50 sccm and 50 W and that result were 7.643 ${\Omega}/cm^2$ and 17.113 nm, respectively. The best efficiency result was obtained by $O_2$ 50 sccm and 50 W and that result of Voc, Jsc, FF and efficiency were 7.03 V, 14.88 $mA/cm^2$, 63.75% and 6.67%, respectively.

Optimum Condition of Micro Fuse Fusing as a Function Changed Thickness of Thermosetting Ink Epoxy (열경화성 잉크 에폭시의 두께 변화에 따른 마이크로 퓨즈 용단의 최적 조건)

  • Kim, Do-Kyeong;Hwang, Neung-Hwan;Kil, Tae-Hong;Lee, Soo-Hwa;Seo, Dae-Man;Kim, Min-Ho;Kim, Jong-Sick
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.10
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    • pp.623-629
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    • 2014
  • For the semiconductor device safety from over current in the digital electronic circuit system must be surely designed that it's surface mount type micro fuse device. In this paper, We has analysed to the fusing character of micro fuse as a function changed thickness of thermosetting ink epoxy. To the change of thermosetting ink epoxy thickness with in production lot, in the electrically character (fusing test in the 2 multiple over current and 10 multiple over current, surface temperature test in the 1.25 multiple over current) of micro fuse has been tested. According to the electrically character result, changed thickness of thermosetting ink epoxy in designed micro fuse withheld direct effect in both end resistance changes. Also, because high thermal energy in the micro fuse test of over current was occurred to effect such as thermal runaway and explosion. Therefore, screen printing process in the design of micro fuse using thermosetting ink epoxy is very important for production quality improvement.