• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.22-28
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• 2019

In this study, as part of the subway braking system, the structural analysis was performed with the fatigue analysis by comparing subway brake disc and wheel-type brake. When structural analysis was performed, it was possible to verify that the wheel-type brake were higher than the brake discs in case of total deformation. As the same loading conditions were given to the subway brake disc and wheel-type brake, wheel-type brakes was shown to have more deformation than brake disk but lower damage than the subway brake disc. Comparing with each fatigue loading condition, the maximum fatigue life for 'Sample history' is found to be about 60 times longer than for 'SAE bracket history'.

• Applied Microscopy
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• v.50
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• pp.19.1-19.9
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• 2020

Deformation twinning, one of the major deformation modes in a crystalline material, has typically been analyzed using generalized planar fault energy (GPFE) curves. Despite the significance of these curves in understanding the twin nucleation and its effect on the mechanical properties of crystals, their experimental validity is lacking. In this comparative study based on the first-principles calculation, molecular dynamics simulation, and quantitative in-situ tensile testing of Al nanowires inside a transmission electron microscopy system, we present both a theoretical and an experimental approach that enable the measurement of a part of the twin formation energy of the perfect Al crystal. The proposed experimental method is also regarded as an indirect but quantitative means for validating the GPFE theory.

• The Journal of the Petrological Society of Korea
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• v.7 no.3
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• pp.190-206
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• 1998

The microstructures and time-relationship between deformation and growth of metamorphic minerals(metamorphism) of the Paleozoic metasedimentary rocks(Joseon Supergroup and Pyeongan Group) in the Janggunbong area at the central-south part in the North Sobaegsan Massif, Korea, have been analyzed in this paper. The first phase metamorphism (low-pressure type metamorphism), recognized as the crystallization of stack-type chloritoid and biotite and augen-type old andalusite, occurred under non-deformational condition before D1 deformation related to the formation of an E-W trending isocline-synclinal fold(Janggunbong fold) and associated its axial plane S1 foliation, and produced regional mineralogical zoning of E-W trend in the Paleozoic rocks. The second phase metamorphism(medium-pressure type metamorphism), related to the growth of staurolite and garnet porphyroblasts with straight or curved internal foliations(Si), occurred under non-deformational condition after D1 deformation related to the formation of E-W trending thrusts modifying the Janggunbong fold and during D2 deformation related to the formation of E-W trending Yecheon shear zone. This metamorphism also produced regional mineralogical zoning of E-W trend. After D2 deformation occurred the intrusion of Jurassic Chunyang granite and associated its contact metamorphism which crystallized patchy-type young andalusite and prismatic- or fibrous-type sillimanite and coarse-grained garnet. This metamorphism occurred under non-deformational condition before D3 deformation related to the formation of S3 crenulation cleavage and during early phase of D3 deformation, and formed narrow mineralogical zoning of N-S trend near Chunyang granite.

• Korean Journal of Acupuncture
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• v.30 no.4
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• pp.252-263
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• 2013

Objectives : Skin color deformation by cupping has been widely used as a diagnostic parameter in Traditional Korean Medicine(TKM). Skin color deformation such as ecchymoses and purpura is induced by local vacuum in a suction cup. Since existing studies have relied on a visual diagnostic method, there is a need to use the quantitative measurement method. Methods : We conducted an analysis of cross-polarization photographic images to assess the changes in skin color deformation. The skin color variation was analyzed using $L^*a^*b^*$ space and the skin erythema index(E.I.). The meridian theory in TKM indicates that the condition of primary internal organs is closely related to the skin color deformation at special acupoints. Before conducting these studies, it is necessary to evaluate whether or not skin color deformation is influenced by muscle condition. Hence, we applied cupping at BL13, BL15, BL18, BL20 and BL23 at Bladder Meridian(BL) and measured blood lactate at every acupoint. Results : We confirmed the high system measurement accuracy, and observed the diverse skin color deformations. Moreover, we confirmed that the $L^*$, $a^*$ and E.I. had not changed after 40 minutes(p>0.05). The distribution of blood lactate levels at each part was observed differently. Blood lactate level and skin color deformation at each part was independent of each other. Conclusions : The negative pressure produced by the suction cup induces a reduction in the volumetric fraction of melanosomes and subsequent reduction in epidermal thickness. The relationship between variations of tissue and skin properties and skin color deformation degree must be investigated prior to considering the relationship between internal organ dysfunction and skin color deformation.

• The Journal of the Petrological Society of Korea
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• v.10 no.2
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• pp.106-120
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• 2001

The Busan area in the northeastern part of the Ogcheon metamorphic zone, Korea, consists mainly of Precambrian Busan and Bakdallyeong gneiss complexes, Ogcheon metamorphic rocks and Mesozoic granitoids. The Busan gneiss complex shows Heart-shaped distribution laying down eastward, and is surrounded by the Ogcheon metamorphic rocks in the central part of the Busan area. In this study structural examination on the main constituent rocks (Busan gneiss complex and Ogcheon metamorphic rocks) was conducted to clarify the geological structure of the Ogcheon metamorphic zone in the Busan area. It indicates that the geological structure was formed at least by three phases of deformation. (1) Dl deformation: the formative period of the structural units of WNW trend (Sanjeoteo, Busan-II, Busan-I, and Chungiu nappes) and the mylonitic foliations related to the compression of NNE-SSW direction, (2) D2 deformation: the differential E-W shortening and N-S extension period of the structural units of WNW trend related to the compression of E-W or WNW-ESE directions, (3) D3 deformation: the formative period of the kink or open folds of E-W trend related to the compression of N-S direction in the eastern and southern parts of Busan area where the structural units of N-S or NNE trends reoriented owing to the intense D2 deformation were developed. These three phases of deformation are closely connected with the distribution of the structural units and the Heart-shaped Busan gneiss complex laying down eastward, and in this paper a new geodynamic model to the Heart-shaped Busan gneiss complex is suggested: Dl deformation-the zonal distribution of WNW trend with a constant width, D2 deformation - the formation of convex wedges northeastward and southward, D3 deformation - the formation of concave wedge westward.

• Design & Manufacturing
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• v.12 no.1
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• pp.18-25
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• 2018

Both injection and injection molding dies have evolved into advanced technology. Product quality is also evolving day after day. Therefore, the conditions of the injection mold and the injection conditions are becoming important. In order to improve the quality of the product, the Hardware part of the mold has developed as an advanced technology, and the Software part has also developed with advanced technology. This study deals with the cooling part, which is part of the hardware. In addition to fluid cooling, which is commonly used in the industry, by using gas cooling identify the phenomena that appear on the surface of the product and the critical point strain of the product to find the optimal cooling. Electronic parts and automobile parts whose surface condition is important, the cooling process is important to such a degree that they are divided with good products and defective products according to the cooling process at the time of injection. By controlling this important cooling and reducing the injection time with additional cooling, the product quality can be increased to the highest production efficiency. In addition, high efficiency can be achieved without additional investment costs. This study was conducted to apply these various advantages in the field.

• The Journal of the Petrological Society of Korea
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• v.13 no.4
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• pp.179-190
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• 2004

Precambrian metamorphic rocks of Yeongyang-Uljin area, which is located in the eastern part of Sobaegsan Massif, Korea, are composed of Pyeonghae, Giseong, Wonnam Formations and Hada leuco granite gneisses. These show a zonal distribution of WNW-ESE trend, and are intruded by Mesozoic igneous rocks and are unconformably overlain by Mesozoic sedimentary rocks. This study clarifies the deformation history of Precambrian metamorphic rocks after the formation of gneissosity or schistosity on the basis of the geometric and kinematic features and the forming sequence of multi-deformed rock structures, and suggests that the geological structures of this area experienced at least four phases of deformation i.e. ductile shear deformation, one deformation before that, at least two deformations after that. (1) The first phase of deformation formed regional foliations and WNW-trending isoclinal folds with subhorizontal axes and steep axial planes dipping to the north. (2) The second phase of deformation occurred by dextral ductile shear deformation of top-to-the east movement, forming stretching lineations of E-W trend, S-C mylonitic structure foliations, and Z-shaped asymmetric folds. (3) The third phase deformation formed I-W trending open- or kink-type recumbent folds with subhorizontal axes and gently dipping axial planes. (4) The fourth phase deformation took place under compression of NNW-SSE direction, forming ENE-WSW trending symmetric open upright folds and asymmetric conjugate kink folds with subhorizontal axes, and conjugate faults thrusting to the both NNW and SSE with drag folds related to it. These four phases of deformation are closely connected with the orientation of regional foliation in the Yeongyang-Uljin area. 1st deformation produced regional foliation striking WNW and steeply dipping to the north, 2nd deformation locally change the strike of regional foliation into N-S direction, and 3rd and 4th deformations locally change dip-angle and dip-direction of regional foliation.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.1
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• pp.47-57
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• 1986

The purpose of this study is to investigate fatigue phenomema of woven fabric. In order to obtain the basic data which is available for predicting the fabric fatigue phenomena, the change of mechanical properties of woven fabrics caused by the wearing and the changes of mechanical properties of woven fabrics which were subjected to repeated tensile-shearing deformation using fabric testing machine has been investigated and compared. The fatigue of woven fabrics was examined with the value of basic mechanical properties of specimens measured by the KES-F fabric testing system and their hand value and wearing ability. The results were as follows. 1) The fatigue phenomena of woven fabrics by the wearing for 800 hours are different on the position of the body: On the portion of hip, the change of surface property was the greatest, bending hysterisis was greatly increased, thickness weight, stiffness, fullness shearing hysterisis were more increased than original fabric and T.H.V. was decreased. On the portion of knee, decreasing of tensile resilience and increasing of bending, shearing hysterisis were observed greater than any other part, and increasing of stiffness, crispness was more than original fabric. On the bottom area, the changes of mechanical property was comparatively small, H.V. and T.H.V. showed near the value of the original fabric. 2) By drycleaning most of mechanical properties showed the tendency to recover the value of the original fabric, but bending hysterisis and thickess were increased, tensile and com-pression resilience were decreased more than original fabric in all parts. 3) The fatigue phenomena caused by fabric fatigue testing machine were as follows. The decreasing of hystersis in the repeated deformation such as bending, shearing was appeared at the $10^2$ deformation, but with the increasing cycle, the tendency was slightly regained. Handle value was also appeared the lowest value at the $10^2$ deformation.

• Journal of the Korean Geotechnical Society
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• v.31 no.10
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• pp.29-36
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• 2015

This paper deals with inspecting and monitoring cracks developed on a subway tunnel liner during the construction of temporary supports and excavation. The cracks have developed near a enlarged part of the tunnel. Several measurements, crack gauge, internal displacement measurement, 3-D laser scanner have been conducted to monitor the progress of cracks and effects of them on the tunnel. Local measurement, additional propagation of cracks and deformation of liner, have been conducted by crack gauge and internal displacement measurement. Global inspection has been conducted by 3-D laser scanner. From the scanned data, occurrence of global deformation of tunnel and rail has been evaluated. Because of limited sequence of construction at the ground, no apparent deformation of crack propagation has been measured. As presented in this paper, deformation of tunnel liner and effects of rail need to be investigated in view of local and global aspects.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.127-133
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• 2016

Purpose: Currently advanced in Dental CAD/CAM technology increase a use of Co-Cr sinter metal block at Dental CAD/CAM part traditionally it has been being used with metal casting method. There is an advantage that can leave out a step of investment and casting as well as reducing a working time to compare with conventional casting method in a dry milling. Methods: In this research, compare a deformation of before and after sinter result of Co-Cr sinter metal block. Design a specimen figure by 3D CAD software and transformed it to a STL file can be used at Dental CAD/CAM. With a transformed STL file, milled a Co-Cr sinter metal specimen by using a Dental CAD/CAM dry milling machine. It arrived at the following conclusions after measuring an outer form and thickness of a machined specimen and then after sinter measure it again in a way of before sinter measurement method. Results: It is confirmed that there is no error while a 3D design figure specimen is transformed to a Dental CAD data. It is observed that there is no error at Co-Cr sinter metal specimen which consider a length of single coping and bridge. Conclusion: It is observed that there is no deformation at a specimen of AS05 and AB05 are made of 0,5mm thickness. On the other hand, the out of range of deformation is observed at a specimen of AS10 and AB10 which are made of 1mm thickness.