• International Journal of Precision Engineering and Manufacturing
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• 제7권2호
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• pp.60-65
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• 2006

A vibrational model of powder transfer equipment based on the lumped parameter method was developed, in which the operating motion consists of surging, bouncing, and pitching. After decoupling the equation of motion, the vibrational excitation source of the pitching motion was removed. So the designers are able to plan the optimum design to adjust the motion trajectory of the powder transfer equipment. That is, a procedure to adjust the motion trajectory of powder transfer equipment by changing design specifications such as the installation position, the direction of the motor, the driving speed, the mass unbalance, the stiffness coefficient, and the installation position of the support spring, is presented in this paper. The powder transfer equipment manufactured according to the results of this study did not suffer fatigue destruction, since the maximum stress on the basket structure was sufficiently small.

• 항공우주기술
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• 제6권2호
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• pp.188-196
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• 2007

복합재 케이스는 KSLV-I 킥모터 시스템 요구 조건을 만족하도록 설계하였다. 비행모델 제작에 앞서 신뢰성을 확보하기 위해 구조시험과 연소시험을 수행하였다. 구조시험으로는 수압시험, 진공시험, 비 파괴검사를 수행하여 연소시험 전에 케이스의 구조적 건전성을 확인하였으며 지상연소시험을 통해 열적 구조적 특성을 고찰하였다.

• 치과방사선
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• 제6권1호
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• pp.23-25
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• 1976

The patient, 19 years old male, visited with complaints of trismus and consults for construction of denture. 4 years ago, he received /sup 60/Coteletherapy of left laryngeal area for treatment of throat tumor. Clinical apperance showed rampant dental caries, multiple root rests, xerostomia, disturbance of mandibular growth and asymmetry of face. Roentgenographic examination disclosed deep cervical caries, destruction of alveolar crest, punched out bone destruction of mandible and maxilla.

• 한국임상수의학회지
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• 제15권2호
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• pp.410-416
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• 1998

These experiments were designed to evaluate the possibility of brain-stem auditory evoked responses(BAER) as a diagnostic tool for deafness in dogs. The BAER was recorded from three different groups of dogs; the normal dogs,'dog with otitis externa and dogs with unilateral destruction of cochlear. BAER of the normal dogs was consisted of distinct five peaks(I, II, III-IV, V). Furthermore, the clear shapes of waveform were observed at 85 dB. The latency of BAER was increased with reducing the intensity of sound-stimulus. The highest threshold of BAER was measured at 2 KHz with 10-30 dB. Dog with otitis externs demonstrated unclear shapes of BAER compared to the that of normal dogs. In the dogs with unilateral destruction of cochlear, the flat and indistinct waveform of BAER was recorded from the cochlear destroyed ear while that of BAER from normal side of ears did not show any differences from the normal BAER. These results indicate that the BAER can be clinically used in order to diagnose the deafness in dogs.

• 환경위생공학
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• 제13권3호
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• pp.133-140
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• 1998

The food wastes from a refectory and an eating house were heated in domestic microwave oven(700W) equipped with a fan and the drying rates and destruction of microorganisms were investigated. The drying rate was decreased with the size of food waste and the food wastes in polypropylene basket were dried faster than that on glass dish. The rate was increased with lower initial moisture content. Death rate of microorganisms was also decreased with the size of food waste. Ninety eight percent of reduction in viable cell numbers for the 400g of food waste could be achieved in 240sec of microwave irradiation. The growth of microorganisms in food wastes after microwave irradiated was observed at $32^{\circ}C$ and 95% relative humidity after 7days and the cell numbers in microwave irradiated food wastes were found to be 1/2 ~ 1/20 of the numbers in untreated wastes in accordance with the mass and the length of exposed time to microwave. To minimize the moisture and microorganisms in food wastes, the use of microwave oven are recommended.

• Coupled systems mechanics
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• 제7권2호
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• pp.111-139
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• 2018

A successful methodology for modelling controlled destruction and progressive collapse of 2D reinforced concrete frames is presented in this paper. The strategy is subdivided into several aspects including the failure mechanism creation, and dynamic motion in failure represented with multibody system (MBS) simulation that are used to jointly capture controlled demolition. First phase employs linear elasto-plastic analysis with isotropic hardening along with softening plastic hinge concept to investigate the complete failure of structure, leading to creation of final failure mechanism that behaves like MBS. Second phase deals with simulation and control of the progressive collapse of the structure up to total demolition, using the nonlinear dynamic analysis, with conserving/decaying energy scheme which is performed on MBS. The contact between structure and ground is also considered in simulation of collapse process. The efficiency of the proposed methodology is proved with several numerical examples including six story reinforced concrete frame structures.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.817-824
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• 2002

Granular activated carbon(GAC) is highly effective in removing organic compounds which are resistant to biological disintegration in wastewater treatment. However, GAC has reached its full adsorptive capacity, GAC needs to be regenerated before it can be used for a further adsorption cycle. Countercurrent oxidative reaction (COR) technique has been developed and evaluated for the regeneration of spent GAC. Various parameters such as flame temperature, the loss of carbon, destruction and removal efficiency (DRE) of organic compounds, surface area, surface structure, adsorptive capacity, etc. were examined to determine the performance of COR. The results of these tests showed that adosorptive capacity of regenerated GAC was completely recovered, the loss of carbon was controllable, flame temperature was high enough to insure complete destruction and removal $(\geq99.9999%)$ of specific organics of interest, polychlorinated biphenyls (PCBs), that are thermally stable, and on formation of toxic byproducts such as polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) were detected during the regeneration process. The COR technique is environmentally benign, easy to use and less copital intensive than other available regeneration technologies.

• STI Policy Review
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• 제4권1호
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• pp.1-13
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• 2013

The Schumpeterian process of "creative destruction", associated with the emergence and diffusion of new radical, so-called "general purpose" technologies, has throughout history impacted wealth and income, jobs creation, jobs displacement, and the emergence and submergence of new hotspots of innovation. Emerging countries have benefited most from such a renewing of those societies' dynamics, leading them to higher levels of economic development and welfare. Doing so they have shown a remarkable capacity in moving upstream in the value chain, from outsourcing of manufacturing activities to autonomous process technology development, product development, design, and applied research. At the same time however, such Schumpeterian processes have now and then turned into exactly opposite processes of "destructive creation." Such processes seem to have become common among what could be called "submerging" economies: innovation only benefitting a few at the expense of many with as a result an opposite pattern of a long term reduction in overall welfare, productivity, and employment growth.

• 한국대기환경학회지
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• 제22권3호
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• pp.361-371
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• 2006

This study examines ozone episodes occurred during the intensive sampling periods (Jun. 1-30, 2004) in the air of Seoul metropolitan area. During that period, there were 8 events (or days) in which 1 hr averaged ozone concentrations were greater than 100 ppbv. The photochemical analysis of ozone chemistry (i.e., budget and formation and destruction strengths of ozone) was carried out using a photochemical box model. Peaks in diurnal ozone variations during ozone episode periods occurred were concurrent with the sudden change of the slope of $NO_{2}/NO$ ratio, suggesting significant correlation with photochemical reactivity. In addition, the ozone peaks were concurrent with high concentrations of ozone precursors, peroxy radicals of $HO_{2},\;CH_{3}O_{2},\;and\;RO_{2}$. High ozone levels during the ozone episodes are likely to be affected by ozone destruction rate.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.75-76
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• 2015

This study has examined the impact resistance and blast resistance characteristics of HPFRCC as a research on impact resistance and blast resistance characteristics using high volume mortar and high velocity projectile for evaluating the protection performance of actual buildings as small quantity experiment of laboratory conditions is performed although there was an instance of performing research on mortar that has reinforced fiber followed by the rise of problems on the damage of human life and buildings created due to explosion and shock. As a result, the destruction loss area and depth have decreased in case of the surface compared to the rear side. As tensile strength and tenacity have increased with the increased fiber replacing ratio, a tendency of destruction loss area and depth getting decreased was shown as the impact resistance has increased.