• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.5
• /
• pp.935-943
• /
• 1988

The forming limit diagram is assessed as a means of estimating the forming characteristics of sheet metal and is usually determined experimentally. The strain rates used in the determination are likely to be low. However, often in practice, the strain rates are much higher, so if forming limit diagram is determined at low rates, it may not be appropriate. This paper reconsiders the forming limit diagram for mild steel and aluminum sheet up to variation in strain rate from 10$^{-2}$ sec to 20/sec where its forming has been carried out under oil pressure using a hydraulic bulge test with circular and elliptical dies. To obtain higher strain rate, an impact bulge test had been employed with the same die sets as those used for a hydraulic bulge test. The results obtained are as follows: (1) As the strain rate increases, the fracture pressure increases and the polar height at fracture decreases. (2) Experiment has shown that, in the positive quadrant of the forming limit diagram, the diagram is lowered with increasing strain rate and the effect of strain rate changes according to strain paths and materials..

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.19 no.1
• /
• pp.51-56
• /
• 1983

In the stability problem of the U-grooved plate, it has a circular hole, the site of the hole determines some different deformation mode when it was loaded. To determine the optimal position of the circular hole-center which not to get large distortion of the hole itself, in this paper, we studied the distributions of stresses in the neck area between hole and U-groove and the distortion mode of the deformed hole by B.E.M(Boundary Element Method) and compared with experimental results in four cases. For a distributed load, according to the center of the hole moves closer to the U-groove center (c.-c. line), the shape of the circular hole was transformed to the elliptical one(it's major axis perpendicular to the c.-c. line). In this problem, the results by Boundary Element Method was well accorded with Experiments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.5
• /
• pp.766-769
• /
• 2000

This study was attempted to investigate granular properties of acorn flours which were prepared by soaked nut and sediment. X-ray diffraction pattern of acorn flour was B type and was not affected by soaking treatment. The principal indices of the pattern were at diffraction angles ($2{\theta}$) of $14.5^{\circ},\;17.2^{\circ},\;19.7^{\circ},\;22.2^{\circ}\;and\;24.5^{\circ}$. The shape of acorn flour was elliptical and some rounded triangular by scanning electron microscope (SEM). The granule size of acorn flours varies from $4\;{\mu}{\textrm}{m}$ to approximately $20\;{\mu}{\textrm}{m}$. although morphology of the acorn flour was not affected, the non-starchy substances of surface was slightly changed by soaking.

• Archives of Craniofacial Surgery
• /
• v.14 no.1
• /
• pp.16-23
• /
• 2013

Background: Even though degrees of deformation of microform cleft lip are not high, it has to be corrected with various procedures upon conditions and areas since it has various expressions. Many studies have focused on the classifications and procedures, but there are only a few studies on how much these procedures are performed in the actual field. This study aims to analyze the utilization of various procedures upon major correction points. Methods: A total of 52 patients who had been corrected by one surgeon from 1995 to 2011 were enrolled as subjects. Based on the medical records, it was checked whether the incision was made or not along with the correction procedures for alar base and philtral column, Cupid's bow, and vermillion free margin. Results: In case of an incision, full incision (42 times) was conducted most frequently. For alar base and philtral column, muscle re-approximation (25 times) was performed most frequently. However, recently, it was shown that excision on only the affected area and correction with dermis were more likely to be used. For Cupid's bow and vermilion free margin, elliptical excision on the only affected area followed by re-approximation was performed most frequently for 46 times (Cupid's bow) and 44 times (vermilion free margin), respectively. Conclusion: For the correction of microform cleft lip, less invasive procedures are preferred. However, in the actual field, if needed, aggressive procedures consisting of incisions have been conducted to correction. These trends are somewhat changed to utilization of a simple procedure, such as excision on the modified area, followed by a re-approximation rather than complicated procedures using the muscle.

• Korean Journal of Microbiology
• /
• v.53 no.4
• /
• pp.235-241
• /
• 2017

The purpose of this study was to investigate the enhanced physiological activities of two Pichia strains, yeasts isolated from grapes pericarp. Based on phylogenetic analysis using 18S rRNA sequencing, two isolates were identified as Pichia manshurica GU-3 and Pichia terricola GU-4, respectively. The scanning electron microscopic analysis showed that the two isolates grown on YPD medium were of typical elliptical shape with buds and bud scars on cell surface. Physiological activities of the single and mixed Pichia cultures were monitored and compared. In mixed cultures after 72 h of incubation, the maximum activities of tyrosinase inhibition, ACE inhibition, and antioxidant were 81.7%, 45.9%, and 42.7%, respectively. Superoxide dismutase-like activity was approximately 30% in the mixed cultures. These studies demonstrate that Pichia species cultured in the form of mixture can enhance the physiological activities and has potential for the development of new bioactive products.

• Parasites, Hosts and Diseases
• /
• v.57 no.5
• /
• pp.521-524
• /
• 2019

We are going to describe the female soboliphymid nematodes, which were recovered from the stomach of a Asian badger, Meles leucurus (Mammalia: Mustelidae), in Geochang-gun, Gyeongsangnam-do, Korea. In February 1998, we found 2 peculiar nematodes with a cup-like organ in the anterior end from the stomach of badger. Recovered worms were fixed with 10% formalin, cleared in glycerin-alcohol solution and observed under a light microscope with a micrometer. They were 34.46 (33.43-35.50) mm long by 2.13 mm at maximum width. Cephalic sucker cup-like, 3.34 (3.13-3.55) mm wide, 2.40 (2.25-2.55) mm long, with the oral aperture and meridionally striated on the buccal capsule. Oral aperture 2.38 mm in diameter. Circumoral membrane 0.41 (0.38-0.45) mm wide. Esophagus muscular, 4.81 (4.50-5.00) mm long by 0.80 (0.78-0.83) mm at maximum width. Vulva situated at 3.13 mm ventro-anterior level from the esophago-intestinal junction. Vagina anteriad, 3.38 mm long, making a canal from the uterus to the vulva opening. Uterus single, large. Tail 0.35 (0.33-0.38) mm long. Intrauterine eggs long elliptical, 0.058-0.065 (0.062) mm long and 0.030-0.033 (0.031) mm wide. Based on the some morphological characters and host-specificity, our specimens are nearly identical with S. baturini. Therefore, the present report describes S. baturini for the first time in Korea.

• Korean Journal of Logic
• /
• v.22 no.1
• /
• pp.151-182
• /
• 2019

According to the realization criterion that distinguishes deductive argument from inductive argument, the realized necessity relation between the premises and the conclusion defines deductive argument. In this case, 'invalid deductive argument' is an oxymoron. According to the intention criterion, the intended necessity relation between the premises and the conclusion defines deductive argument. In this case, 'invalid deductive argument' is not an oxymoron. In this paper, we will argue for the intention criterion. The realization criterion cannot classify an elliptical argument without referring to the intention represented in the argument. It cannot distinguish an argument from a set of propositions that is not an argument either. On the other hand, the problem that an intention may not be recognized in an argument can be resolved by referring to the principle of charity. Moreover, by distinguishing the expressions showing the conviction or the attitude to the argument from the intention of the argument, we conclude that the intention criterion successfully distinguishes deductive argument from inductive argument.

• Korean Journal of Optics and Photonics
• /
• v.30 no.5
• /
• pp.197-203
• /
• 2019

In this paper, we studied a reflector design that can improve the illuminance uniformity when using a xenon flash lamp in the photonic sintering process. To achieve complete sintering of substrates in the irradiated area, the light efficiency and illuminance uniformity were set to target performance. Existing elliptical reflectors or parabolic reflectors make it easy to satisfy the target light efficiency, but have difficulty satisfying the illuminance uniformity. In this paper, a twin-concave feature has been added to the center of the parabolic reflector to satisfy the illuminance uniformity. It was confirmed that the illuminance uniformity of the parabolic reflector with a twin-concave feature was improved, compared to that of the traditional reflector.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.24 no.65
• /
• pp.51-63
• /
• 2001

The present experiment investigated the possibility of evaluating of the human sensibility contingent on the speed and modes of driving using the responses from the autonomic nervous system, subjective assessments, Simulator Sickness (55) in dynamic simulator. The three conditions of the speed of driving were 40 $\pm$ 10 km/h, 100$\pm$10 km/h, 160 $\pm$ 10 km/h, and the participant was instructed to drive the car for three minutes on the elliptical track. It is programed in such a way that the modes of driving can be changed smoothly using road DB in Dynamic Simulator, and for signifying the change of the condition the road signs were used. The instruction was given to the participant to drive the car on the fixed speed of 20 km/h for 30 seconds, then to drive the car on sudden-start mode of driving from the 20 km/h to 160 km/h within 10 seconds. For the sudden-stop mode of driving, it was instructed that stop the car from the speed of 160km/h to 20km/h within 10 seconds when the subject see the road sign, then drive the car at the fixed speed of 20 km/h for 30 seconds. The results of the subjcetive assessment showed that the level of pleasantness and the tension was increased, and physiological response showed that the level of activity of the autonomic responses were also increased as the speed of the car increased. Also, for results on the driving modes showed that the level of pleasantness was highest for the sudden-stop, next highest was sudden-start, and the lowest was 20 km/h fixed speed condition for the subjective assessment, and tile order of the level of activation of the autonomic nervous system showed the same results as above. From the results of the present study it was concluded that the presentation and evaluation of the stimulus for the human sensitivity is possible in dynamic simulator.

• Journal of the Korean Solar Energy Society
• /
• v.35 no.3
• /
• pp.65-71
• /
• 2015

A solar thermal simulator is suitable for indoor experiments of solar receivers and reactors when solar insolation and weather conditions are not favorable. Moreover, due to the easy control of electric power input, the solar thermal simulator allows the adjustment of power input incident on solar receivers and reactors and thus the implementation of accurate experiments. We manufactured a solar simulator, which is comprised of three sets of a xenon lamp and an elliptical reflector. In order to serve as a test facility, optical characterization of the solar simulator via radiation heat flux measurement is a critical prerequisite. We applied the flux mapping method to measuring the heat flux distribution of the three lamps. We presented the measurement results in terms of the heat flux distribution, the peak heat flux, the power distribution, the maximum power, and the efficiency for electric power conversion into radiation power. Characterization results show that our solar simulator provides the peak heat flux of $3,019kW/m^2$, the maximum power of 16.9 kW, and the conversion efficiency of 45%, additionally with a 10% operation margin for output increase.