• Journal of the Korea Furniture Society
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• v.18 no.3
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• pp.177-187
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• 2007

Since the 1960s when paper began to use as a structural material in furniture, design, the way of using paper was dramatically changed. Before the 1960s, paper was used mostly in decorative purposes like paper $mach\acute{e}$. The development of consumer culture in the 1960s created a new trend for paper in design. Paper became a material for dresses and chairs. Also, the types of paper that adapted on furniture varies from cardboard, paper tubes, glassine paper, honeycomb, etc. The variation of the material results to make possible to create a new form. Moreover, paperboard was broadly used in current society in such area that mostly structural based as architecture. Paper gives great opportunity not only to consumers to buy furniture in inexpensive price also to manufacturers to produce furniture and to test market easily, Moreover, paper furniture is mostly fun. Therefore, the creation of paper furniture becomes diverse in terms of design concept. This study explored the characteristics of paper furniture responding to social backgrounds by decade. Relation between types of paper and the characteristics is one of main points in this research. This study covers furniture design from the 1960s to present and mostly focuses on seating furniture where paper used as structural material. Researching on patent records and contemporary periodicals gave me helpful information on details of design process and consumer culture.

• Applied Microscopy
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• v.45 no.3
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• pp.177-182
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• 2015

The boiler tubes of X20CrMoV12.1 used in fossil-fired power plants were obtained and analyzed for the effect of water treatment on the steam corrosion-induced oxide scale in an effort to better understand the oxide formation mechanism, as well as pertinent method of maintenance and lifetime extension. The specimens were analyzed using various microscopy and microanalysis techniques, with focuses on the effect of water treatment on the characters of scale. X-ray diffraction analysis showed that the scales of specimens were composed of hematite ($Fe_2O_3$), magnetite ($Fe_3O_4$), and chromite ($FeCr_2O_4$). Electron backscatter diffraction analysis showed that the oxides were present in the following order on the matrix: outer $Fe_2O_3$, intermediate $Fe_3O_4$, and inner $FeCr_2O_4$. After all volatile treatment or oxygenated treatment, a dense protective $Fe_2O_3$ layer was formed on the $Fe_3O_4$ layer of the specimen, retarding further progression of corrosion.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.161-167
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• 2003

The preparations of deodorizing fibers using $TiO_2$ have been investigated. The fibers were coated with $TiO_2$ for the purpose of deodorizing by dipping fibers into the $TiO_2$ sol solutions and calcined at $450^\circ{C}$, $500^\circ{C}$ and $750^\circ{C}$ for 1 h after coating. The surface structure of the coated fibers was studied with XRD on the different preparation conditions of calcination temperatures. The deodorizing function of the prepared fibers was studied by the determination of the decomposing capability for $NH_3,\;CH_3SH\;and\;CH_3CHO$. The deodorant activity(D.A.) of these deodoriBing fibers was measured by chromogenic gas detector tubes. The deodorizing effect of the prepared fibers were shown to be similar for the three model compounds; 5wt% $TiO_2$ sol solution calcined at $450^\circ{C}$ < 5 wt% $TiO_2$ sol solution calcined at $500^\circ{C}$< 5 wt% TiO$_2$ sol solution calcined at $750^\circ{C}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.100-106
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• 2006

NiTi alloy known as its shape memory effect also has superelastic characteristic, which makes it possible to be elastic under large deformation. Since the tensile strength of the alloy is very high and density is low compared to carbon steel, it can be applied to lightweight structural design. In order to design structures with shape memory alloy, finite element analysis is used and a constitutive algorithm based on Aurrichio's model is added to LS-DYNA as a user subroutine. Explicit time integration and shell element formulation are used to simulate thin-walled structures. The algorithm uses Drucker-Prager type loading condition to calculate martensite volume fraction during the transformation. The implemented algorithm is verified in uni-axial loading condition and martensite phase transformation can be detected well with the algorithm. In this study, as a energy absorbing structure, thin-walled tube is modeled with finite elements and the deformation behavior is studied. Simulation results has shown that the martensite transformation was generated in loading condition. After plastic deformation reached, the load decreases linearly without reverse martensite transformation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.158-166
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• 2002

진공관형 태양열집열기의 집열성능 및 집열특성 실험을 통하여 다음과 같은 결론을 얻을 수 있었다. 1) 집열성능 실험을 통하여 진공관형 태양열집열기의 순간집열효율이 60%로 높게 나타났다. 2) 진공관형 태양열집열기의 집열특성 실험에 의해 얻어진 결론은 다음과 같다. \circled1 경사각 0$^{\circ}$일 때 집열기에 조사된 광 강도는 630W/m$^2$이었으며, 5시간 24분의 광 조사 후 초기온도에 비해 물탱크내의 물 132$\ell$를 8.1$^{\circ}C$ 상승시켰다. \circled2 경사각 $10^{\circ}$일 때 광강도는 615W/m$^2$이었으며, 5시간 24분의 광 조사 후 초기온도에 비해 물탱크내의 물의 온도를 7.3$^{\circ}C$ 상승시켰다. \circled3 경사각 20$^{\circ}$일 때 광 강도는 605W/m$^2$이었으며, 5시간 24분의 광 조사 후 초기온도에 비해 물탱크의 물 132$\ell$을 6.6$^{\circ}C$ 상승시켰다. 집열기에 대한 솔라시뮬레이터의 경사각이 작을수록 광 강도가 커 물탱크내의 물 온도를 크게 상승시키는 것으로 나타났다.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.155-165
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• 1998

The resistance coefficient and heat transfer performance are studied for the turbulent water flow in a smooth coiled tube having variable curvature ratios and a corrugated-coiled tube having a ratio of coil to tube diameter of 22. Experiments are carried out for the fully developed turbulent flow of water in tube coils on the uniform wall temperature condition. This work is limited to tube coils of R/a between 22 and 60 and Reynolds numbers from 13000 to 53000. The tube having a ratio of coil to tube diameter of 27 among the 3 smooth tube coils shows the best heat transfer performance. A corrugated-coiled tube(R/a=60) shows more excellent performance than a smooth coiled tub (R/a=60) at a similar curvature ratio. The friction factor f is sensitive to changes in the velocity profile caused by a temperature gradient. Allowance was made for the pressure loss in the short inlet and outlet lengths and due to the presence of the thermocouple inlet and outlet as a result of separate experimental on a straight tube. It is to be expected that the allowance at the exit will be somewhat too low because of secondary flow effects carried over from the coil.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.108-112
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• 2010

Confocal Imaging System is an essential machine for a wide range of inspection wafer. For concurrent and fast acquiring the image data of four channels, the new image acquisition system used the protocol of camera-link standard with the full mode of configuration in interconnection with a frame grabber integrated in a computer, which is popularly used for many cameras, so the programming environment of image processing is optional such as Visual C++, Matlab. In addition, many conventional methods were coordinately used for contribution to build the high quality of images for precise processing analog signals of PhotoMutiplier Tubes(PMTs), accurate control of scanning device, sensitivity of PMTs, and laser source. The prototype of new image acquisition system, could meet the goal of development, it is used in LSCM for high content screening to investigation the processes of elements of living specimens at the same time by simultaneous grab image data on 4 PMTs channels.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.133-140
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• 2018

A nonlinear finite element analysis was conducted in order to examine the moment capacity and flexural behaviour of hollow prestressed concrete filled steel tube(HCFT) piles which compose hollow PHC piles inside thin wall steel tubes. The parameters investigated in this study were various contact conditions between concrete and steel tube, thickness of concrete tube and various PC strands. A simple method is proposed to determine the ultimate flexural strength based on plastic stress distribution method. In order to verify the proposed method, calculated moment capacity of various HCFT piles are compared with the experiment and numerical analysis results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.238-239
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• 2007

The important merit of Bi-2212/Ag wire is to apply cable as round wire state. Bi-2212 high Tc superconducting wires were fabricated in order to apply Rutherford cable near the future. Various Ag ratio from 0.22 to 0.42 of Ag tubes for PID (powder-In-Tube) process were used to investigate the workability and to prevent breakage of filaments during drawing. KERI and Nexans Korea manufactured Rutherford cabling machine by ourselves. Rutherford cables with 20 - 30 strands could be fabricated by this machine. The shape of Rutherford cables were satisfied. The critical current of Bi2212/Ag round wire with 847 filaments showed 400 A at 4.2K and self field.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.848-859
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• 2016

System failures in thermal power plants (TPPs) can lead to serious losses because the equipment is operated under very high pressure and temperature. Therefore, it is indispensable for alarm systems to inform field workers in advance of any abnormal operating conditions in the equipment. In this paper, we propose a clustering-based fault detection method for steam boiler tubes in TPPs. For data clustering, k-means algorithm is employed and the number of clusters are systematically determined by slope statistic. In the clustering-based method, it is assumed that normal data samples are close to the centers of clusters and those of abnormal are far from the centers. After partitioning training samples collected from normal target systems, fault scores (FSs) are assigned to unseen samples according to the distances between the samples and their closest cluster centroids. Alarm signals are generated if the FSs exceed predefined threshold values. The validity of exponentially weighted moving average to reduce false alarms is also investigated. To verify the performance, the proposed method is applied to failure cases due to boiler tube leakage. The experiment results show that the proposed method can detect the abnormal conditions of the target system successfully.