• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.1
• /
• pp.26-32
• /
• 2010

SM45C steel rods using generally for machine components were selected and welded by butt-GMA welding method for this study. And then they were studied about characteristics of fatigue behavior and fracture surfaces by rotary bending test. Fatigue strength in weld zone present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. The region of infinite life by Haigh diagram present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. Fatigue cracks in unnotched specimens of base metal and weld zone introduce simultaneously from extensive out-side of circumferential cross-section and propagate to the other side indicating beach markings and dimples according to consolidation of fatigue cracks. Fatigue cracks in all of notched specimens introduce simultaneously in out-side of circumferential cross-section by high stresses and propagate to center of it indicating beach markings.

• International Journal of Fluid Machinery and Systems
• /
• v.3 no.2
• /
• pp.122-128
• /
• 2010

The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance; however, cavitation surge oscillation with low frequency occurs with blade cavity growing to each throat section of blade passage simultaneously. Then, one conceptual method of installing suction axi-asymmetrical plate has been proposed so as to keep every throat passage away from being unstable at once, and the effect on suppression of the oscillation were investigated. In the present study, cavitation behaviors in the inducer is observed with distributing multi-cameras circumferentially, recording simultaneously and reconstructing multi-photos on one plane field as moving a linear cascade. Observed results are utilized for discussion with other measuring results as casing wall pressure distribution. Then the suppression mechanism of oscillation by installing axi-asymmetrical inlet plate will be clarified in more details.

• Journal of Environmental Science International
• /
• v.6 no.6
• /
• pp.697-709
• /
• 1997

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 61 bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10, 680 mg/l, TBm : 6, 893 mg/l, $NH_4^+-N$ : 1, 609 mg/l, $PO_4^{3-}-P$ : 602 mg/l on average. The cycling time In SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and inoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT From the experimental results, the optimum cycling time for biological nutrient removal with nlght-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic), Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.571, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.2
• /
• pp.164-169
• /
• 2005

Tuberculosis is a systemic disease with a world-wide distribution, and its occurance in the oral cavity is well documented in the literature. Disease of oral cavity and jaw caused by Mycobacterium tuberculosis is very rare, so it is often difficult to diagnose tuberculosis in the oral cavity. When granulomatous and ulcerative lesion persists in the oral cavity for a long time, it may be considered a tuberculosis. When differential diagnosis is needed, the most reliable indicators of mycobacterial infection are careful clinical evaluation, skin test, acid-fast staining, biopsy and culture. We report a case of tuberculous osteomyelitis which simultaneously occurred on the maxilla and mandible in a 85 years old man that proved diagnosis difficult, but which responded very well to surgical treatment and chemotherapy.

• International Journal of Costume and Fashion
• /
• v.12 no.1
• /
• pp.49-63
• /
• 2012

The objectives of this study were to investigate appearance management behaviors and hairstyle preferences in accordance with personality types and self-image, and to examine the characteristics that influence simultaneously the appearance management behaviors. A survey was used for as for this research. The personality properties of introversion and extroversion were further divided, based on the aspects of emotions, thoughts, behaviors, and interpersonal psychological functions. The subjects were 383 girls in their first year of high school in Seoul. The extrovert type showed a higher level of management for clothing, hair and face than the introvert type. The emotional extrovert type and the interpersonal extrovert type showed the highest level of clothing management, the active extrovert type showed the highest level of face management, and the interpersonal introvert type showed a very low level of hail management. The high school girls who had a higher social and mature self-image showed a higher level of clothing, hair and face management. Introverted girls preferred a mid-length straight hairstyle more than extroverted girls. The higher the social and mature self-images girls had, the more they preferred a long wave hairstyle. The higher the cute image they had, the more they preferred wave hairstyle. The entire appearance management behavior was affected significantly by extroversion, mature image, and allowance, simultaneously.

• Journal of Society of Preventive Korean Medicine
• /
• v.2 no.1
• /
• pp.175-192
• /
• 1998

A study on the antitoxic effects of Semen Mungo extracts against Cadmium Chloride Toxicity in Rats This study was performed to find out the effect of Semen mungo against Cadmium toxicity. The experimental rats were divided into 5 groups such as control group, Cadmium alone treatment group, three simultaneous treatment groups of semen mungo and cadmium. Rats were given pellets administration with three dosage of semen mungo glabrae such as 4mg/kg body weight for four weeks. The results were summarized as follows on: ' 1. The simultaneously administration of semen mungo and cadmium significantly more decreased cadmium concentration in liver and kidney tissues compared to the administration of cadmium alone.(p<0.05) 2. The simultaneously administration of semen mungo and cadmium significantly more decreased metallothionein concentration in liver and kidney tissues compared to administration of cadmium alone(p<0.05) 3. When liver and kidney tissues were observed with optical microscope obvious changes were visible in those tissues.1

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.8
• /
• pp.683-688
• /
• 2014

This paper presents a high-performance flexible tactile sensor based on inorganic silicon flexible electronics. We created 100 nm-thick semiconducting silicon ribbons equally distributed with 1 mm spacing and $8{\times}8$ arrays to sense the pressure distribution with high-sensitivity and repeatability. The organic silicon rubber substrate was used as a spring material to achieve both of mechanical flexibility and robustness. A thin copper layer was deposited and patterned on top of the pressure sensing layer to create a flexible temperature sensing layer. The fabricated tactile sensor was tested through a series of experiments. The results showed that the tactile sensor is capable of measuring pressure and temperature simultaneously and independently with high precision.

• Near Infrared Analysis
• /
• v.1 no.1
• /
• pp.1-7
• /
• 2000

A convenient algorithm for optimizing wavelength selection in multiple linear regression (MLR) has been developed. MOP (MLP Optimization Program) has been developed to test all possible MLR calibration models in a given spectral range and finally find an optimal MLR model with external validation capability. MOP generates all calibration models from all possible combinations of wavelength, and simultaneously calculates SEC (Standard Error of Calibration) and SEV (Standard Error of Validation) by predicting samples in a validation data set. Finally, with determined SEC and SEV, it calculates another parameter called SAD (Sum of SEC, SEV, and Absolute Difference between SEC and SEV: sum(SEC+SEV+Abs(SEC-SEV)). SAD is an useful parameter to find an optimal calibration model without over-fitting by simultaneously evaluating SEC, SEV, and difference of error between calibration and validation. The calibration model corresponding to the smallest SAD value is chosen as an optimum because the errors in both calibration and validation are minimal as well as similar in scale. To evaluate the capability of MOP, the determination of benzene content in unleaded gasoline has been examined. MOP successfully found the optimal calibration model and showed the better calibration and independent prediction performance compared to conventional MLR calibration.

• Fire Science and Engineering
• /
• v.25 no.1
• /
• pp.13-18
• /
• 2011

In the disaster prevention design, it is important point to secure escape way at event of fire which makes people away from the fire more quickly and safely. Development of construction techniques leads to build many skyscrapers, and skyscrapers contains various dangers and increase levels of disaster. At basic design stage for skyscrapers, evacuation scenario is considered that occupants are escape using escape stairs and emergency elevators simultaneously at fire, but there is no evacuation program to simulate using escape stairs and emergency elevators at the same time. In this study, evacuation simulation is performed using method of VR which is based on Virtools of 3DVIA Co., and Simulex of IES Co. for safety and effectiveness where occupants are escape using escape stairs and emergency elevators simultaneously at the fire.

• Journal of the Korean Applied Science and Technology
• /
• v.3 no.2
• /
• pp.29-34
• /
• 1986

The sulfuric acid sulfonation of 2-aminonaphthalene was preformed at $30^{\circ}C{\sim}200^{\circ}C$ for $1{\sim}15$ hours, using $4{\sim}10$ parts of 90% sulfuric acid${\sim}$20% oleum. This reaction was influenced by many factory such as reaction temperature, reaction time, strength of sulfuric acid and amount of sulfuric acid and among these factors, the effect of the reaction temperature was considerable. The main products of this reaction were Dahl's acid (2-aminonaphthalene-5-sulfonic acid, Broenner's-acid (2-aminonaphthalene-6-sulfonic acid), amnio-F-acid(2-aminonapthalene-7-sulfonic acid), and Baden acid (2-aminonaphthalene-7-sulfonic acid) and another isomers such as Tobia's acid (2-aminonaphthalene-1-sulfonic acid) and 2-aminonaphthalene-4-sulfonic acid were not formed. Of these isomeric acids, those containing the sulfonic acid group in an ${\alpha}-position$, namely, Dahl's acid and Baden acid, are simultaneously formed by sulfonation at low-temperature ($30{\sim}100^{\circ}C$), whilst those containing the sulfonic acid group in a ${\beta}$-position, namely, Broenner's acid and amino-F-acid, are formed simultaneously by sulfonation at high temperatures($150^{\circ}{\sim}200^{\circ}$).