• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1723-1730
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• 2014

The use of strand wire in structure has been increased by the recent development of construction technologies. Until now, in spite of difficult problems in measuring strand stresses within PSC girders, indirect estimation with a load cell or accelerometer has been often used. In this paper, the electrical resistance strand meter for effective measurement of strand stresses is proposed with experiments considering material, location and thickness of sensor. The reliability and feasibility of the strand meter is enhanced through the experiment with 29.9m PSC girder.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.432-440
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• 2016

The consumption of pre-treated vegetables (including fresh-cut vegetables) that are washed, peeled, and trimmed has been significantly increased because of their easy use for cooking. Vegetable cutting machines have been widely utilized for producing fresh-cut vegetables or agricultural products of different sizes; however, the design standard is not established for specific types of agricultural products. Therefore, this study was conducted to determine mechanical properties (compressive and shear forces) of targeted agricultural products (radish, carrot, squash, cucumber, shiitake mushroom, and sweet potato) for developing a multipurpose vegetable cutting machine. According to ASAE standard (s368.3), compressive and shear forces of targeted agricultural products were measured by using a custom built UTM (universal testing machine). Shape type of samples and speed ranges (5 - 15 mm/min) of loading rate on bioyield and shear points varied depending on the targeted agricultural product. The range of averaged bioyield points of targeted agricultural products were between 7.89 and 146.98 N. On the other hand, their averaged shear points ranged from 22.50 to 53.47 N. Results clearly showed that the bioyield and shear points of targeted agricultural products were thoroughly affected by their components. As measuring compressive and shear forces of a variety of agricultural products, it will be feasible to calculate blade cutting force for designing multipurpose vegetable cutting machine.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1672-1677
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• 2004

Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modem air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras($1280pixel{\times}1024pixel$) were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.

• Journal of the Korean Society of Fashion and Beauty
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• v.2 no.3 s.3
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• pp.36-43
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• 2004

This is a research on the effect of formula containing of vitamin A and vitamin E(Frie of oil, Wlter Bouhon GmBH, Germany) on the strech mark. The participants of this study were 20 women at the age of early 20s through middle 20s, who had strech marks that had been over 1 year at the minimum and at less than 5 years at the maximum. Formula containing of vitamin A and vitamin E was applied with typical massage to strech marks for 4 months and twice per day. Improvement resulting from the application was evaluated through observation with the naked eye, questionnaire survey, and the equipment used was DermaScan C Ver3(Cortex Technology, Denmark). The experiment showed that parts cared with formula containing of vitamin A and vitamin E had less strech marks than those control site(treated with jojoba oil).In around 2 months since the use of the formula containing of vitamin A and vitamin E, the tensile of the skin increased and deep wrinkles on the chapped surface became unclear, and in around 4 months the tensile force again decreased and the resilience of the skin increased, and the ultrasonic image showed the decrease of echo pore-zone, which indicates the degree of tissue damage. According to the result of the questionnaire survey, strech marks of less than red strech marks of primary stage were improved more quickly than white strech marks and all participants appeared to experience improvement. The result shows that if this formula is used continuously over 4 months, it reduces strech marks and increase the resilience of the skin. It is considered necessary to continue objective measuring and research concerning strech marks.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.295-302
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• 2013

Purpose: The grindability of Ti-10%Zr-X%Cr(X=0,1,3) alloys in order to develop Ti alloys for dental applications with better machinability than unalloyed titanium has been evaluated. Methods: Experimental Ti-10%Zr-X%Cr(X=0,1,3) alloys were made in an argon-arc melting furnace. Slabs of experimental alloys were ground using a SiC abrasive wheel on an electric handpiece at one of the four rotational speeds of the wheel (12000, 18000, 25000 or 30000rpm) by applying a force(100gf). Grindability was evaluated by measuring the amount of metal volume removed per minute(grinding rate) and the volume ratio of metal removed compared to the wheel material lost, which was calculated from the diameter loss (grinding ratio). Experimental datas were compared the results with those of cp-Ti(commercially pure titanium) Results: It was observed that the grindability of Ti-10%Zr-X%Cr(X=0,1,3) alloys increased with an increase in the Cr concentration. More, they are higher than cp-Ti, particularly the Ti-10%Zr-3%Cr alloy exhibited the highest grindability at all rotational speeds except 12000rpm. There was significant difference in the grinding rate and grinding ratio between Ti-10%Zr-3%Cr alloy and cp-Ti at all rotational speeds(p<0.05). Conclusion: The Ti-10%Zr-3%Cr alloy exhibited better grindability at high rotational speeds, great potential for use as a dental machining alloy.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.203-210
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• 2017

In this paper, we propose a electrical/mechanical method to effectively diagnose the local deterioration of a 10m long power shielded twist pair cable defined by the American Wire Gauge (AWG) 14 specification using electrical/mechanical methods. The rapid deterioration of the cable proceeded by using the heating furnace, which is based on the Arrhenius equations proceeds from 0 to 35 years with the deteriorated equivalent model. In this paper, we introduce a method to diagnose the characteristics of locally deteriorated cable by using $S_{21}$ phase and frequency change rate measured by vector network analyzer which is the electrical diagnostic method. The measured $S_{21}$ phase and rate of change of frequency show a constant correlation with the number of years of locally deteriorated cable, thus it can be useful for diagnosing deteriorated cables. The change of modulus due to deterioration was measured by a modulus measuring device, which is defined by the ratio of deformation from the force externally applied to the cable, and the rate of modulus change also shows a constant correlation with the number of years of locally deteriorated cable. Finally, By combining the advantages of electrical/mechanical diagnostic methods, we can efficiently diagnose the local deterioration in the power shielded cable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.450-450
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• 2006

Organic light-emitting diodes (OLED) as pixels for flat panel displays are being actively pursued because of their relatively simple structure, high brightness, and self-emitting nature [1, 2]. The top-emitting diode structure is preferred because of their geometrical advantage allowing high pixel resolution [3]. To enhance the performance of TOLEDs, it is important to deposit transparent top cathode films, such as transparent conducting oxides (TCOs), which have high transparency as well as low resistance. In this work, we report on investigation of the characteristics of an indium tin oxide (ITO) cathode electrode, which was deposited on organic films by using a radio-frequency magnetron sputtering method, for use in top-emitting organic light emitting diodes (TOLED). The cathode electrode composed of a very thin layer of Mg-Ag and an overlaying ITO film. The Mg-Ag reduces the contact resistivity and plasma damage to the underlying organic layer during the ITO sputtering process. Transfer length method (TLM) patterns were defined by the standard shadow mask for measuring specific contact resistances. The spacing between the TLM pads varied from 30 to $75\;{\mu}m$. The electrical properties of ITO as a function of the deposition and annealing conditions were investigated. The surface roughness as a function of the plasma conditions was determined by Atomic Force Microscopes (AFM).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.4
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• pp.1263-1274
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• 1996

In this paper, as elastic-plastic fracture toughness test under mixed mode loading was proposed using a single edge-cracked specimen subjected to bending moment(M), shearing force(F), and twisting moment(T). The J-integral of a crack in the specimen is expressed in the form J=$J_I$+ $J_II$$J_III$, where $J_I$, $J_II$ and $J_III$ are the components of mode I, mode II and mode III deformation, respectively. $J_I$, $J_II$ and $J_III$ can be estimated from M-$\theta$ ($\theta$;crack opening angle), F-U(U; crack shear displacement) and T-$\alpha$ ($\alpha$;crack twisting angle). In order to obtain the the M<-TEX>$\theta$, F-U and T-$\alpha$ diagram inreal time, a new deformaiton gage for mixed mode loading was proposed using the optical position sensing device(PSD). The elastic-plastic fracture toughness test was carried out with an aluminum alloy. The loading apparatus was designed and manufactured for this experiment. For the loading condition of the crack initatio in the mixed mode, the MMT -3(mode I+ mode II+ mode III) has the lowest values out of the all specimens. This implies that MMT-3 is possible of the crackinitation at lower load, if the specimen acts on together with the torque under the same loading condition. An elastic-plastic fracture toughness test using the PSD brings a successful experimentation in measuring the crack deformation(mode I+ mode II+ mode III).

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.903-907
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• 2006

Frozen stability of proteins recovered from white croaker and jack mackerel have been tested by measuring oxidation of residual lipid, browning, total plate count, and texture of gel during storage at $-20^{\circ}C$. The oxidation of residual lipid in recovered protein from Jack mackerel increased up to 60 days, and then decreased. Both browning values significantly was increased after 90 days. Total plate count was $1.2{\times}10^4\;CPU/g$ for proteins recovered from white croaker and $3.2{\times}10^4\;CPU/g$ for proteins recovered from jack mackerel in 60 days. The breaking force, deformation, and whiteness of gel formed from proteins recovered from white croaker did not change up th 120 days significantly, while proteins recovered from jack mackerel did not form heat-induced gel in 120 day. Frozen storage of the recovered protein was limited to 90 days for white croaker and to 60 days for jack mackerel considering the gelling ability and textural properties.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.1
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• pp.11-23
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• 2015

In this study, the new segment assembling method using cable tensible force was developed to improve the problem of bolt assembling method of shield tunnel. In the field test construction, cable assembling method reduced the assembling time of segment in comparison with bolt assembling method because of guide role of segment shear-key. In the result of measuring the necessary time for segment assembling process, it took 420sec to assemble one segment in bolt method and 400sec to assemble one segment in cable method, but in case of using the cable automatic feeder, it could reduce the necessary time as 60sec in comparison with bolt assembling method. The cable automatic system modeling using BIM, that connected shield TBM also will be utilized in the area of design TBM, excavation plan, method process understanding, construction management and so on.